defence infrastructure organisation thanckes oil fuel

+

Defence Infrastructure Organisation

Thanckes Oil Fuel Depot Loading Facility and Tank Farm Fire Fighting Upgrade

Environmental Statement

Volume 2: Main Text

Hyder Consulting (UK) Limited

2212959

5th Floor The Pithay All Saints Street Bristol BS1 2NL United Kingdom

Tel: +44 (0)117 372 1200

Fax: +44 (0)117 37

www.hyderconsulting.com

Defence Infrastructure Organisation

Thanckes Oil Fuel Depot Loading Facility and Tank Farm Fire Fighting Upgrade

Environmental Statement

Volume 2: Main Text

Author

Various. Compiled Sarah

Hart

Checker David Hourd

Approver James Prescott

Report No 5402-UA004737-UE31R-02

Date 13 April 2015

This report has been prepared for Defence Infrastructure

Organisation in accordance with the terms and conditions of

appointment for PSP Support dated 11th July 2002.

.

Page i

CONTENTS

Volume 1: Non-Technical Summary

Volume 2: Main Text

1 INTRODUCTION .............................................................................. 1

1.1 Background ...................................................................................... 1

1.2 Site Location ..................................................................................... 1

1.3 Legal Basis Environmental Statement ................................................ 2

1.4 Structure of Environmental Statement ................................................ 4

1.5 Inspection of the Environmental Statement ........................................ 4

2 THE PROJECT ................................................................................. 5

2.1 Project Context ................................................................................. 5

2.2 Need For The Project ........................................................................ 6

2.3 Site Operations and Maintenance ...................................................... 7

2.4 Project Description ............................................................................ 8

2.5 Design Considerations .................................................................... 11

2.6 Indicative Construction Method ........................................................ 12

2.7 Project Programme ......................................................................... 20

2.8 Alternatives Considered .................................................................. 21

3 ENVIRONMENTAL IMPACT ASSESSMENT METHODOLOGY ...... 26

3.1 Introduction ..................................................................................... 26

3.2 Legislation and Guidance ................................................................ 26

3.3 Scoping of Environmental Topics ..................................................... 26

3.4 Environmental Impact Assessment General Methodology ................. 29

3.5 Consultation .................................................................................... 30

3.6 Assessing Cumulative Effects .......................................................... 34

3.7 Other Relevant Consents, Licences and Assessments ..................... 36

4 PLANNING POLICY CONTEXT ...................................................... 39

5 WATER, CONTAMINATION AND SEDIMENT QUALITY ................ 40

5.1 Introduction ..................................................................................... 40

5.2 Regulatory and Policy Framework ................................................... 40

5.3 Methodology ................................................................................... 42

5.4 Description of the Baseline Conditions ............................................. 50

5.5 Design and Mitigation ...................................................................... 61

5.6 Assessment of Effects ..................................................................... 68

Page ii

5.7 Cumulative Effects .......................................................................... 69

5.8 Summary ........................................................................................ 70

6 ECOLOGY ...................................................................................... 73

6.1 Introduction ..................................................................................... 73

6.2 Regulatory and Policy Framework ................................................... 73

6.3 Methodology ................................................................................... 80

6.4 Description of the Baseline Conditions ............................................. 87

6.5 Selection of Ecological Receptors .................................................. 111

6.6 Design and Mitigation .................................................................... 116

6.7 Assessment of Effects ................................................................... 130

6.8 Cumulative Effects ........................................................................ 143

6.9 Enhancement measures ................................................................ 144

6.10 Summary ...................................................................................... 144

7 ARCHAELOGY AND CULTURAL HERITAGE ............................... 150

7.1 Introduction ................................................................................... 150

7.2 Regulatory and Policy Framework ................................................. 150

7.3 Methodology ................................................................................. 152

7.4 Description of the Baseline Conditions ........................................... 163



7.7 Summary ...................................................................................... 169

8 NOISE AND VIBRATION .............................................................. 171

8.1 Introduction ................................................................................... 171


8.3 Methodology ................................................................................. 172





8.8 Summary ...................................................................................... 188

9 LANDSCAPE AND VISUAL IMPACT ASSESSMENT .................... 190

9.1 Introduction ................................................................................... 190


9.3 Methodology ................................................................................. 191





9.8 Summary ...................................................................................... 200

10 Conclusion .................................................................................... 202

GLOSSARY AND ABBREVIATIONS....................................................... 205

REFERENCES ....................................................................................... 212

Page i

Volume 3: Drawings

1-1 Site Location

1-2 Aerial View of Site Location

1-3 Application Boundary

1-4 Designated Sites within 2.5km study area

2-1a Existing structures sheet 1 of 2 - plans and section

2-1b Existing structures sheet 2 of 2 - overall layout

2-2 General Arrangement drawing 1

2-3 General Arrangement drawing 2

2-4 Setting out details plan

2-5 Berthing pocket

2-6 Jetty Head plan

2-7 Berth pocket relocation

2-8 Navigation Plan

2-9 Proposed tank drenching system

2-10 Fire fighting System Proposed Fire Main Pipe Plan

3-1 Cumulative Effects

5-1 Surface Water Features

5-2 Sediment Sample locations – June 2013 and 1984 borehole locations

5-3 Proposed Jetty borehole location plan

6-1 Phase 1 Habitat Survey

6-2 Designated sites within 5km study area

7-1 Recorded heritage assets

7-2 Location of boreholes taken within and in the vicinity of the site. Data available for numbered

boreholes.

7-3 Extract from the 1643 Hollar Seige Map, position approximate

7-4 Extract from a chart dating to 1774

7-5 Extract from 1798 chart of Plymouth Sound

7-6 Extract from 1840 Tithe Map of Anthony

7-7 Extract from 1887 Chart

7-8 Impacts associated with the proposed Development.

7-9 Historic Photographs showing vessels moored in the vicinity of the Site

8-1 Baseline Noise Monitoring Locations

9-1 Zone of theoretical visibility and designated sites within 2.5km study area

9-2 Viewpoints 1 and 2 - Sheet 1 of 4




9-6 Photomontage A (Viewpoint 2)

9-7 Photomontage B (Viewpoint 4)

Volume 4: Appendices

1-A Marine Conservation Zone Designation Features

1-B Screening/Scoping Request Letter

1-C Scoping Report

1-D Screening Opinion from Cornwall Council

1-E Scoping Opinion from Cornwall Council

1-F Screening & Scoping Opinion from Marine Management Organisation

Page ii

2-A Piling Restriction

3-A Hydrodynamic Technical Paper

3-B Update letter to consultees

3-C Assessment Study Consultations

3-D EIA Consultation Log

3-E MMO Marine Licencing Guidance

3-F Minutes of External Stakeholder EIA Scoping/HRA Screening Consultation Workshop

3-G Assessment of Effects workshop minutes

3-H Underwater Noise / Impact on Fish Meeting Minutes

3-I

3-J

Public Exhibition Feedback Form

Parish Council Update

5-A Water Framework Directive Assessment

5-B Soil Mechanics 1984 Borehole Logs

5-C Public Register Information

5-D Historical Maps

5-E Plymouth Sound Chemical Information

5-F Site Sediment Analysis Data 2013

5-G Information on Action Levels and Canadian Effect Levels

5-H

6-A

Waste Classification

Bird Count Data

6-B Target Notes

6-C Tamar Report

6-D HRA Screening

6-E

6F

6G

Conservation objectives for Plymouth Sound and Estuaries European Marine Site

Migratory fish species present in the Tamar Estuary

Confirmation of Natural England’s Opinion on European Smelt

7-A Gazetteer

7-B Detailed Baseline Information

8-A Baseline Noise Survey

8-B Construction Noise Assessment

List of Tables

2-1 Existing and Proposed Development Areas

2-2 Moat Uses and Capacities

2-3 Separator Function and Operation

2-4 Key planning and project milestones

2-5 Environmental and sustainability considerations

3-1 Determining significance

5-1 Regulatory References

5-2 Criteria for Determining the Value (Sensitivity) of the Hydrological Resource

5-3 Criteria for the Assessment of Overall Effect

5-4 Classification of Potential Consequence (Severity)

5-5 Classification of Probability (Only applies if there is a possibility of a pollutant linkage being

present)

5-6 Classification of Risk

5-7 Risk Classification Descriptions

5-8 Consultation Responses

5-9 Summary of Historical Potential Sources of Contamination

5-10 Summary of Recent Potential Sources of Contamination

5-11 Summary of Contamination Risk Assessment

5-12 Water, Contamination and Sediment Quality - Impact Summary Table

Page iii

6-1 Ecology Regulatory and Policy Framework

6-2 Assessment of significance

6-3 Consultation responses

6-4 BTO WeBS data compared with October 2009 survey results

6-5 Results of Marine and Intertidal Surveys

6-6 Migratory fish species present in the Tamar Estuary

6-7 Selection of Key Ecological Receptors

6-8 Current and anticipated habitat loss

6-9 Cumulative unmitigated noise impacts of piling the jetty approach, the jetty head and the

mooring dolphins

6-10 Cumulative unmitigated noise impacts during demolition

6-11 Ecology Impact Summary Table

7-1 Determining the Importance / Sensitivity of Resource

7-2 Assessment of the Magnitude of Change

7-3 Determination of the Significance of Effect

7-4 Qualitative Description of the Significance of Effect


7-6 Archaeology and Cultural Heritage Impact Summary Table

8-1 Regulatory and Policy Framework

8-2 Recommended indoor ambient noise levels BS 8233: 2014

8-3 Example of Threshold of Significant Effect at Dwellings (Table E1 in BS5228)

8-4 Criteria for the rating of noise impacts during construction

8-5 Determining the Importance / Sensitivity of Resource

8-6 Significance of Noise Impact


8-8 Noise monitoring location and sensitive receptor locations

8-9 Summary of Baseline Noise Survey Data

8-10 Significance of Predicted Weekday Daytime Construction Noise Impacts

8-11 Significance of Predicted Dredging Noise Impacts

8-12 Significance of Predicted Weekend Daytime Construction Noise Impacts

8-13 Calculated Noise Limit for Operational Plant to be Installed on Site

8-14 Noise Impact Summary Table

9-1 Landscape and Visual Regulatory and Policy Framework

9-2 Definitions of Landscape Sensitivity

9-3 Definitions of Visual Sensitivity

9-4 Assigning Magnitude of Landscape Impact

9-5 Assigning Magnitude of Visual Impact

9-6 Significance Matrix

9-7 Landscape and Visual Impact Summary Table

List of Figures

2-1 Aerial view of the Yonderberry Jetty

2-2 Contractor’s Compound

2-3 Contractor’s Working Area: Jetty Head

6-1 Distribution of avocet within the Tamar Estuaries Complex SPA at low tide 2002/03

6-2 Tamar Estuary (South) Sector 10

6-3 Tamar Complex

6-4 Distribution of little egret at low tide, winter 2002/3

6-5

6-6

Results of inter-tidal survey

Results of subtidal survey

1 INTRODUCTION

1.1 Background

Defence Infrastructure Organisation (DIO) has appointed Hyder Consulting Ltd (herein referred to

as ‘Hyder’) to submit planning and marine consent applications for the replacement of a jetty in the

Hamoaze1 and the upgrade of associated fire-fighting infrastructure at Thanckes Oil Fuel Depot

(OFD). The existing jetty, named Yonderberry Jetty, will be demolished upon completion of the new

structures and there will also be relocation of the existing berth pocket. The proposed site location

is shown on Drawing 1-1.

This Environmental Statement (ES) reports the findings of the Environmental Impact Assessment

(EIA) for the project and it applies to both the Planning Application and the Marine Licence

Application. The ES describes the project, the baseline environment and the significant and non-

significant environmental effects after mitigation. The purpose of the ES is to ensure that the likely

effects of the Development on the environment are fully understood and taken into account before

any decision by the consenting authorities (Cornwall Council (CC), and the Marine Management

Organisation (MMO)) is taken.

Due to the nature of this planning application the ES should be read in conjunction with the

following supporting documents:

• Planning Statement

• Design and Access Statement

• Statement of Community Involvement

1.2 Site Location

The Thanckes OFD lies on the west bank of the Hamoaze opposite the north yard of Her Majesty's

Naval Base (HMNB), Devonport. The Hamoaze forms part of the Tamar Estuary which forms the

border between Devon and Cornwall (Drawing 1-1). An aerial view of the proposed site location

can be found on Drawing 1-2 and the indicative boundary for the project can be found on Drawing

1-3. The site is located on a headland with a maximum elevation of 35 metres above ordnance

datum (mAOD) at the site entrance and minimum elevation of approximately 2m AOD at the

perimeter of the site above the estuary foreshore. The estuary system is a large marine inlet

comprising the estuaries of the rivers Tamar, Lynher and Tavy which collectively drain an extensive

part of Devon and Cornwall. The River Tamar and its tributaries provide the main input of fresh

water into the estuary complex, and form a ria (drowned river valley) with Plymouth lying on the

eastern shore.

The high quality of the natural environment is reflected by the large number of national and

international designations protecting the area (Drawing 1-4). The Plymouth Sound and Estuaries

are designated a Special Area of Conservation (SAC) under the European Habitats Directive

(92/43/EEC) (Ref 1-1) and parts are also designated as Special Protection Areas (SPA) under the

Birds Directive (79/409/EEC) (Ref 1-2). The two designated areas collectively form a European

Marine Site. The Yonderberry Jetty lies partially within the SAC. The mudflats adjacent to the

shore, within the site, are within an Area of Great Scientific Value.

1 The Hamoaze is an estuarine stretch of the River Tamar between the River Lynher and Plymouth Sound.

There are also two Marine Conservation Zones (MCZ) within the vicinity of the project

(Drawing 1-4); Tamar Estuary Sites to the north and Whitsand and Looe Bay to the south

(shown on Drawing 1-4). These MCZs were designated under the Marine and Coastal

Access Act 2009 (Ref 1-3) as part of the first tranche of designations in November 2013.

Further information on the features of the relevant MCZs can be found in Appendix -1A.

The project is also located within the wider landscape context is the Tamar Valley Area of

Outstanding Natural Beauty (AONB).

There are a large number of maritime and port facilities within the estuarine complex. The

Tamar Estuaries Consultative Forum (TECF) has been established to improve management

and to implement the Plymouth Sound and Estuaries Marine Site Management Plan. The

work of the TECF is currently guided by the Tamar Estuaries Management Plan 2013 to

2018 (Ref 1-4).

1.3 Legal Basis Environmental Statement

EIA is a procedure for ensuring that the likely environmental effects of a new development

are properly understood by the public and relevant competent authorities, before a decision

is made to grant planning and marine consent.

The Project has been considered under the Town and Country Planning Act 1990 (as

amended) (Ref 1-5), the Town and Country Planning (Environmental Impact Assessment)

Regulations 2011 (Ref 1-6), Marine and Coastal Act, 2009 (Ref 1-3) and the Marine Works

(Environmental Impact Assessment) Regulations 2007 (as amended) (Ref 1-7) which

implement EC Directive 2011/92/EU (as amended) (Ref 1-8).

The project is considered to be a ‘Schedule 2’ development under the Town and Country

Planning (EIA) Regulations 2011 and an Annex II project under the Marine Works (EIA)

Regulations 2007. A formal EIA is required due to the projects scale and nature and the

site’s proximity to sensitive areas (there are a number of sites designated for their ecological

importance in close proximity to the Project site, as outlined in section 1.2).

A formal screening request was issued to the consenting authorities (CC and MMO) on 17

December 2012 (Appendix 1-B), this was accompanied by a scoping report (Appendix 1-C).

A screening opinion was received from CC (Appendix 1-D) on 19 February 2013 and a

subsequent scoping opinion (Appendix 1-E) was received on 1 March 2013 (letter dated 13

February 2013). CC confirms that an EIA is required for the proposed development. CC

have made their decision with regard to the criteria set out within Schedule 2 (10 (m) Coastal

work to combat erosion and maritime works capable of altering the coast through the

construction, for example, of dykes, moles, jetties and other sea defence works, excluding

the maintenance and reconstruction of such works); with appropriate consideration to

Schedule 3 of the Town and County Planning (Environmental Impact Assessment)

Regulations 2011, in particular paragraph 3 (i), and the Governments Guidance contained

within Circular 02/99 – Environmental Impact Assessment.

A screening and scoping opinion was received from the MMO (Appendix 1-F) on 27 March

2013. The MMO determined that a statutory EIA under the Marine Works (Environmental

Impact Assessment) Regulations 2007 (as amended) was required for this proposal under

Annex II ‐ 10 (k): Coastal work to combat erosion and maritime works capable of altering the

coast through the construction, for example, of dykes, moles, jetties and other sea defence

works, excluding the maintenance and reconstruction of such works.

The iterative nature of the design process has resulted in a revision to the jetty location, inclusion of

the tank farm fire-fighting upgrade and other design amendments. Full details of the design and

alternatives are covered in Chapter 2 and details of consultation are covered in Chapter 3.

Based on further consultation with regard to the design revision, as detailed in Chapter 3 the

scoping opinions received from both the MMO and CC are still valid.

The scoping opinions identified that the development could potentially have significant

environmental effects on the following topic areas:

� Water Quality, Sediment Quality, Geology & Contamination

� Marine & Terrestrial Ecology

� Archaeology & Cultural Heritage

� Noise & Vibration

� Landscape & Visual

The EIA has been prepared on this basis. Further details of the screening and scoping are

discussed in Chapter 3.

In addition to observing the formal requirements of the EIA Directives (Ref 1-8) and the EIA

Regulations (Ref 1-6 & 1-7), further formal guidance has informed the assessment. Examples

include; the National Planning Policy Framework 2012 (NPPF) (Ref 1-9); and the Institute of

Environmental Management and Assessment’s (IEMA) Guidelines for Environmental Impact

Assessment 2004 (Ref 1-10).

Information that should be included within an ES in accordance with Schedule 3 of the Marine

Works (EIA) Regulations 2007 and Schedule 4 of Town and Country Planning (Environmental

Impact Assessment) Regulations 2011, is as follows:

• a description of the development

• an outline of the main alternatives studied by the developer and an indication of the main

reasons for the choice, taking into account the environmental effects

• a description of the aspects of the environment likely to be significantly affected by the

development including, in particular, population, fauna, flora, soil, water, air, climatic factors

and material assets including the architectural and archaeological heritage, landscape and

the inter-relationship between the above

• a description of the likely significant effects of the development on the environment, which

should cover the direct effects and any indirect, secondary, cumulative, short, medium and

long-term, permanent and temporary, positive and negative effects of the development

• a description of the measures envisaged to prevent, reduce and where possible offset any

significant adverse effects on the environment.

• a non-technical summary

1.4 Structure of Environmental Statement

The ES is structured as follows:

• Volume 1 - The Non-Technical Summary (NTS) summarises the principle sections of

the ES in non-technical language to make it readily understandable by members of

the public.

• Volume 2 – the ES main text (this volume): explains the purpose of the proposal

(Chapter 1); describes the project and summarises alternatives considered (Chapter

2); explains the overall approach to the EIA and alternatives (Chapter 3); and, within

Chapter 4, refers to planning policy context. It presents the mitigation measures and

draws together the significant environmental effects after mitigation for each

environmental topic in Chapter 5 to 9.

• Volume 3 – contains the ES drawings referred to in Volume 1 ES main text.

• Volume 4 – contains the ES appendices referred to in Volume 1 ES main text.

1.5 Inspection of the Environmental Statement

A copy of the ES has been submitted to CC and the MMO to accompany the planning and

marine consent applications respectively. The ES will be available to the public for inspection

for the duration of the consultation period (3 weeks for the CC and 6 weeks for MMO) at the

following location.

Cornwall Council Offices

Planning and Regeneration

Cornwall Council

3-5 Barn Lane

Bodmin, PL31 1LZ

The documents will also be available to view through Cornwall Council online planning

register (http://www.cornwall.gov.uk/environment-and-planning/planning/online-planning-

register/), in addition to the MMO’s Marine Case Management System

(https://marinelicensing.marinemanagement.org.uk/mmo/fox/live/MMO_PUBLIC_REGISTER

#South_Western).

All interested parties are invited to comment in writing on the ES and the dates for

consultation will be publicised through the CC and MMO websites. Comments should be

sent to CC at the following address:

FAO

Michelle Billing

Cornwall Council Offices

Planning and Regeneration

Cornwall Council

3-5 Barn Lane

Bodmin, PL31 1LZ

Comments for the MMO should be emailed to [email protected].

2 THE PROJECT

2.1 Project Context

Thanckes OFD was built in the 1920’s and occupies a 39ha peninsula site on the banks of the

River Tamar directly opposite the north yard of HMNB Devonport. Thanckes OFD comprises

Yonderberry fuelling jetty and storage tanks that are used to store diesel, aviation fuel, hazardous

oily waste (known as sullage) and firefighting water, together with an extensive network of

pipelines, pumps, filtration equipment and containment moats.

From 1st April 2013 Thanckes OFD came under the management and control of The Oil &

Pipelines Agency (OPA), who have a service agreement to manage the asset on behalf of the

Ministry of Defence (MOD). The OPA are the safety duty holder for the site, operating under the

Control of Major Accident Hazard regulations 1999 (COMAH) (Ref 2-1). Thanckes OFD has a total

storage capacity for class 3 fuels that exceeds the upper tier COMAH threshold of 25,000 tonnes of

named substances under amendments to the COMAH regulations in 2002.

The COMAH Regulations are regulated by the Competent Authority (Health & Safety Executive

(HSE) and the Environment Agency (EA)). As a crown property the buildings also fall under the

regulatory authority of the Crown Premises Fire Inspection Group (CPFIG). CPFIG is a regulatory

body and following discussions have deferred all matters relating to the fire safety for this project to

the HSE.

Yonderberry Jetty is the depot’s primary issue and receipt facility. It is capable of berthing tankers

of up to 50,000 displacement tonnes, plus the numerous marine services craft used to transfer fuel

and sullage to and from warships berthed in HMNB Devonport. The role of Yonderberry Jetty is

fundamental to the operation of Thanckes and to the support the depot provides to Navy Command

and other approved customers at Devonport.

The existing Yonderberry Jetty was constructed in the 1950’s. The existing structures are shown in

Drawing 2-1 and figure 2.1 below shows an aerial view of the Yonderberry Jetty. The jetty is 290m

long in total, comprising a 230m long approach and 60m long jetty head. The approach jetty is

constructed of reinforced concrete piles supporting reinforced concrete transverse beams and deck

slabs. A pipe rack housing fuel and hazardous oily waste (known as sullage) pipelines runs in

parallel alongside a 2.6m wide walkway. The jetty head is constructed of a 1m deep concrete deck

slab supported by 20 vertical steel box piles.

Figure 2-1 Aerial view of the Yonderberry Jetty

2.2 Need For The Project

The provision of fuels and waste disposal services is a fundamental requirement of the Royal

Navy and other customers operating within the HMNB Devonport. Without access to the

storage facilities available within Thanckes OFD effective bulk fuelling and hazardous oily

waste operations at Devonport could not take place. There is no alternative fuelling or

sullage waste facility within the Port of Plymouth area capable of handling the volumes of

product required.

In 1998, it was discovered that the steel piles supporting Yonderberry Jetty were suffering

from accelerated low water corrosion. A major refurbishment was undertaken the following

year in order to expand the jetty structure’s operational life for a further 10 years. During

2006/07 contractors undertaking further pile repairs had to abandon work after it was

discovered that the piles were in far poorer condition than previously indicated. Since that

time Yonderberry Jetty has continued to operate under strict berthing restrictions, as agreed

with the Competent Authority (HSE & EA) and the Queens Harbour Master (QHM). These

restrictions have a negative impact on operational efficiency of the jetty which is not

sustainable.

Also due to problems encountered with the existing jetty fire-fighting system at the Thanckes

OFD, the equipment is not adequate to meet the current fire-fighting requirements on

Yonderberry Jetty and in the tank farm.

Therefore, it is recognised that for jetty and tank farm operations to continue long term,

significant investment is required.

The resulting project objectives are:

a) To provide a loading facility suitable for ship to shore receipt and delivery of fuels, waste

products and fresh water at Thanckes OFD

b) To provide a site-wide fire-fighting capability for Thanckes OFD that meets current

requirements

c) To provide facilities with a minimum service life of 40 years that meet all current

legislation and user requirements

d) To comply with Ministry of Defence (MOD) policy and best practice

2.3 Site Operations and Maintenance

2.3.1 Oil Fuel Depot Operations

Thanckes OFD and Yondberry Jetty is operational 07:30 – 16:00 Monday to Saturday with the

notable exception of service to/from replenishment tankers, which are alongside for approximately

72 hours, approximately once a month.

Vessels that use the jetty to unload and load fuel are commercial product tankers, Royal Fleet

Auxiliary (RFA) vessels and occasionally, although not routinely, Royal Navy warships. Currently

fuel products are imported to Thanckes OFD by commercial ‘Handysize’ (approx. 35,000 tonne

displacement) product tankers which vary in colour.

Fuel products are transferred to and from vessels of Royal Navy fleet and other customers within

Devonport Dockyard by a fleet of lighter barges (black in colour) powered by tugs (yellow and black

colour), from the pontoon at the rear of the jetty head. In addition vessels of the RFA fleet, which

are grey in colour, berth at the jetty to load and unload fuel from the OFD.

The total annual occupancy for vessels alongside is approximately 30% and 60% for the main jetty

and pontoon jetty respectively. There are also approximately 360 Heavy Goods Vehicles (HGVs)

visiting the site per annum (Monday to Friday only), which access the site via the Main Gate at

Pengelly Lane.

The operation of the tank farm, use of the loading facility (in terms of the hours of operation and

frequency of use) and types of vessel that berth at the jetty are not expected to change as a result

of the project.

2.3.2 Maintenance Dredging

A berth pocket is maintained adjacent to the front face of Yonderberry Jetty by a regime of routine

maintenance dredging, undertaken as part of the maintenance dredging for the whole of HMNB

Devonport.

Where maintenance dredging is carried out in a Natura 2000 site, the UK Government has

requested that a “baseline document” is prepared to assess the activities in accordance with Article

6(3) of the European Commission (EC) Habitats Directive (92/43/EEC) (Ref 2-4). The baseline

document draws on readily available information to describe current and historic patterns of

dredging, in relation to the conservation objectives of adjacent European Marine Sites.

The baseline document prepared for the MOD at HMNB Devonport naval base (Ref 2-5), contains

information relevant to the integrity of the Plymouth Sound and Estuaries European Marine Site,

which comprises the Plymouth Sound and Estuaries SAC, the Tamar Estuaries Complex SPA and

eight associated Site of Special Scientific Interest (SSSIs).

The ‘Baseline Document’ completed in 2011 states that the actual maintenance dredging quantities

for the wider HMNB Devonport naval base over the past six years have averaged 72,500 tonnes

per annum with a maximum in any one year of 147,904 tonnes (2004 “catch-up” at start of new

term contract).

2.4 Project Description

In July 2010 an Assessment Study was completed by Hyder Consulting (Ref 2-6), to assess

options to ensure effective means of facilitating the issue and receipt of fuelling products to

and from Thanckes OFD for the next 40 years. In addition works required to provide

legislatively compliant fire-fighting arrangements covering the OFD tank farm and supporting

infrastructure were identified. A number of options were assessed; the recommendation of

the study was to proceed with Option 9 – to build a new jetty, demolish the existing (then

redundant) jetty structure and to upgrade the fire fighting system.

The project would allow current operational restrictions (size of vessel, approach speed &

operational wind conditions), placed by the QHM, to be revoked. The replacement jetty will

be designed to accommodate vessels of up to 50,000 tonne displacement and 235m length

and provide a minimum maintained dredge depth of 11.6m. This ensures current and

currently projected operational requirements of the MOD for Yonderberry Jetty can be

fulfilled upon completion of the project.

The new facility will be delivered by a Contractor who will be appointed to undertake the

detailed design, construction and commissioning of the new jetty and then demolition of the

existing jetty.

Concept designs of the new facility have been developed and are shown in Drawings 2-2 to

2-6.

2.4.1 New Jetty Structure and Berth Pocket

The proposed new loading facility will comprise of the following elements:

• New jetty head directly adjacent and to the north of the existing jetty head. The new

jetty head will comprise piles supporting a new jetty deck, with new fenders to eastern

face, new ladders, guard rails and lifesaving equipment. The jetty head will support

new fuelling manifold and loading arms, craneage and vessel access brows. A pontoon

will be provided at the rear (west side) of the new jetty head to facilitate the transfer of

fuels to lighter barges and the import of sullage. Six new mooring dolphins will be

constructed with walkways between each and connecting to the jetty head. A pontoon

will be provided alongside one mooring dolphin to enable the safe transfer of ship’s

crew to liberty vessels for transfer to HMNB Devonport.

• New jetty approach structure to the north of the existing jetty connecting the new jetty

head to the shore at Thanckes OFD, comprising of piles supporting a pipe rack and

walkway. It involves installation of new pipelines for fuels, fire-fighting, sullage, site

drainage and potable water. The pipelines on the new jetty will be connected to the

existing fuel pipelines, sullage pipeline, potable water supply, fire main, power supply,

telecoms and other services located on the land close to the jetty root. The jetty

approach structure will also support new personnel welfare facilities (located directly

adjacent to the jetty head) and new pumps to supply water to the fire-fighting system on

the jetty and for the tank farm fire-fighting system.

• Capital dredging will be required to:

a) Provide a berth pocket adjacent to the front (east) face of the new jetty head. The

proposed berth pocket (300m long by 45m wide) will be maintained at a minimum

maintained depth (MMD) of -11.6m Chart Datum (CD) with an approved dredge depth

(ADD) of -12.2mCD. The estimated volume of sediment arising’s from the dredging of

the berth pocket is estimated to be approximately 19,000m3 (subject to final design

calculations).

b) Provide a navigation channel to the fuel pontoon berth at the rear (west side) of the

jetty head. The navigation channel will be 40m wide with a MMD of-5.0mCD and ADD

of -5.6mCD. The estimated volume of sediment arisings from the dredging of the

approach channel is estimated to be approximately 18,000m3 (subject to final design

calculations).

The overall facility footprint area will remain largely unchanged, except for the addition of a dredged

approach channel to the rear of the jetty covering an area of 1.36ha, as indicated in Table 2-1 and

shown on Drawing 1-3.

The new berth pocket is the same plan area (1.35ha) and depth as the existing berth pocket.

There will be an overlap between the existing and new berth pockets of 0.92ha and, therefore, of

the total new dredge pocket area (1.65ha, including the new side slopes) capital dredging is

required over only 0.73ha. The remaining redundant area of the existing berth pocket will no

longer be maintained. Drawing 2-7 shows the extent of the proposed relocated berth pocket and

capital dredging required.

The new jetty will be 0.12ha larger than the existing Yonderberry Jetty to provide a larger working

deck area to improve the safety of operations on the jetty.

Table 2-1 Existing and Proposed Development Areas

Jetty Structure

(ha)

Berth Pocket (ha)

Approach Channel (ha)

Total Area

(ha)

Existing 0.20 1.35 - 1.55

Proposed 0.32 1.65*1 1.36*2 3.33

*1 includes 0.30ha of new side slopes (capital dredge only)

*2 includes 0.40ha of new side slopes (capital dredge only)

When the berth and navigation channel are being utilised an exclusion zone is required around the

fuelling operation for the purposes of safety and security. The extent of the exclusion zone is

indicated on Drawing 2-8.

2.4.2 Decommissioning of Existing Jetty

Firstly, all existing pipework, pumps and sumps will be drained and flushed. Then all pipelines,

plant and equipment will be removed from the jetty. The existing jetty and mooring dolphins will be

demolished and the piles will be cut off 300mm below the existing seabed, using floating plant and

divers. It has been assumed that concrete piles would be “snipped" at the base with hydraulic

shear cutters. Steel piles would be removed by either mechanical cutting or water jet cutting.

The existing bow and stern moorings and anchors will be removed.

The onshore pipelines and filterbed that are made redundant at the jetty root will be removed.

The existing berth pocket will no longer be dredged allowing it to return to its natural state thereby

resulting in no significant net change in overall maintenance dredge volume. Drawing 2-7 shows

the extent of the proposed relocated berth pocket.

2.4.3 Fire Fighting Upgrade

Currently there are nine concrete lined moats throughout the site that are designed to

capture any major spillage from the AVCAT, diesel and sullage tanks and contain it on site.

The moat capacities and the tanks served by each moat are listed in the table below.

Table 2-2: Moat Uses and Capacities

Moat String Tanks Covered Capacity (m3)

E & F Nil - Moats not maintained 10000

G, H, I & J T13, T14, T15, T16, T18 58000

K, L & M T-25, T-26, T-27, T-28 49600

The site also currently contains several Oil Water Separators (OWSs) that act as

interceptors to prevent oil from being discharged from site to the Hamoaze. All OWSs are

fitted with oil in water detectors and alarms.

The separators are of a simple under and over type which retain oil in the chamber. Apart

from OWS J and M, these separators are normally open as described in Table 2-3, below

and can be manually closed on the detection of oil by the OWS alarm system.

Table 2-3: Separator Function and Operation

Separator Serving Opening Status

Wilcove Storm water Permanent

N Semi-buried tanks Permanent

Primrose Legacy separator Permanent

J Moats G, H, I and J During working hours

M Moats K, L, M During working hours

Jetty car park Roadway storm water Permanent

AVCAT * AVCAT Loading Bay Permanent

*Note that this separator will become redundant on completion of the new AVCAT road loading bay

There are also six foam stores [film-forming fluoroprotein (FFFP)] currently distributed

around the site, with a total minimum stock of 18000 litres, for use by the emergency

services.

New fire-fighting facilities will be provided on the new jetty. Fire-fighting water for the jetty

and tank farm will be supplied by new submersible pumps suspended in the river from the

new jetty. Screens will cover the inlets to prevent fish and debris entering the pumps and

firemain. A new fire main with hydrants will be installed along the length of the jetty approach

structure.

At the jetty head there will be a sprinkler system to provide a protected escape route. Two

remotely controllable elevated fire monitors will be provided on the jetty head for fighting a

fire from a safe position. The monitors will be individually controllable and able to discharge a

spray or jet of water or non-aspirated foam.

Sufficient foam concentrate will be stored in a bunded bulk tank close to the jetty root and

pumped out to the foam proportionators as required. The fire monitors and foam will be

controlled from a kiosk at the jetty root where the operators will also be able to use the

Closed Circuit Television (CCTV) system to see the jetty head.

Foam concentrate will only be used in conjunction with the sea-water system on the jetty itself.

Foam will not be used within the system for the tank farm but may be used as supplied together

with portable foam monitors available on site. It is proposed that the foam will be a 6% FFFP, in

compliance with current MOD health and safety standards. FFFP is already approved for use within

the existing tank-farm and is a foam which is bio-degradable and contains natural proteins. Protein

foams flow and spread slower than synthetic foams, but provide a foam blanket that is more heat-

resistant and more durable. An annual plan of exercises to be held is established by the Depot

Manager.

A major site exercise is carried out at least every 3 years (in line with COMAH Regulations). The

Fire Services visit approximately every six months. Foam will only be used to tackle fires and will

not be used during physical exercises.

Within the tank farm the existing firemain will be replaced with a new firemain pipeline loop around

the existing tanks, with fire hydrants at regular spacing. The new firemain will be installed above

ground (typically less than one metre above ground level), supported by pipe supports and thrust

blocks, along its route.

It is a project requirement that new tank drenching sprinklers will be installed on all live fuel storage

tanks on the site (total of 8 tanks currently) and connected to the firemain. Due to the restrictions

on working on live fuel tanks, the drenching systems will be supported by a free-standing steel

frame over each tank. Drawing 2-9 shows a possible design for the tank drenching support frame.

2.5 Design Considerations

2.5.1 Flood Risk

The design of the jetty is to comply with current legislation and guidance with respect to flood risk

(NPPF (Ref 2-7). In order ensure that the risk to life (of personnel working on the jetty) and risk of

pollution from flooding oil sumps and trays, the jetty deck shall be higher than the predicted water

levels in the Hamoaze in 60years time (allowing for predicted sea-level rise).

The current predicted 1:1 and 1:200 year still water levels for Plymouth (Devonport) are +6.16mCD

and +6.68mCD respectively (Ref 2-8). Allowing for future sea-level rise over the lifetime of the

structure (60yrs) in accordance with current EA guidance (Ref 2-9), surge tides, waves and

freeboard, the minimum level of the landside facilities, jetty head and mooring dolphins deck shall

be no lower than +8.74mCD.

This is determined based on the following figures:

• 1:200 year Still Water Level: +6.68mCD

• 60 years of sea level rise to 2077 (increase of 1.045m)

• 1:100 year Wave (1.03m giving a rise of 0.515m)

• 500mm freeboard

2.5.2 Lighting & Noise

Adequate lighting would be provided to ensure that all ship/shore interface activities can be safely

conducted during periods of darkness. Lighting levels will meet national and international standards

as a minimum, including the requirements of the International Safety Guide for Oil Tankers and

Terminals (ISGOTT) and to ensure the security of the facility. The lighting levels are not expected

to change significantly from the existing Yonderberry Jetty operation.

The operation of the tank farm and use of the loading facility are not expected to change as

a result of the project. Therefore the noise generated by operations in the tank farm and on

the loading facility is not expected to change significantly from the existing.

2.5.3 Design Life & Maintenance

The new jetty will have a design life of 60 years, with regular maintenance throughout that

period. It is assumed at the end of its serviceable life the jetty will be dismantled in a similar

manner to that described in Section 2.6.7. Provision will be made in its design to enable

safe demolition of the structure at end of life.

Maintenance dredging will be required to maintain water depths in the berth pocket and safe

navigation in the approach channel to the rear of the jetty head. Due to an improved

alignment of the jetty head with the river flow, sediment accumulation in the new berth

pocket is expected to be similar or less than that currently experienced. The approach

channel to the rear of the jetty head does not currently require maintenance dredging. The

new approach channel may require infrequent maintenance dredging, but due to the

alignment of the channel with the river flow, frequency and quantity of dredging is expected

to be low.

Overall, it is anticipated that the future maintenance dredging quantities and frequencies will

be similar to the existing regime. The total area that will require maintenance dredging is

2.35ha which is approximately a 1% increase in overall maintenance dredge area under the

current HMNB Devonport maintenance dredge regime.

2.6 Indicative Construction Method

The construction method will be developed by the appointed Contractor to suit his design,

site constraints, contract programme and available plant and resources. Due to the nature of

the works, specialist construction plant is required, the availability of which will dictate the

design and construction method.

In order to inform EIA and consenting an indicative construction method and programme has

been prepared.

A construction waste management plan (CWMP) and construction traffic management plan

(CTMP) will be prepared.

2.6.1 Site Investigations

Immediately following award of contract, the Contractor may select to undertake further site

investigations to inform the detailed design. The site investigations may include intrusive

investigations (e.g. boreholes and trial pits) on land and within the Hamoaze. Marine

boreholes would be undertaken from a jack-up barge (marine plant).

2.6.2 Site Compounds and Access

Initially the construction of the new jetty will be undertaken from marine plant. A commercial

wharf will be used for receipt and transfer of materials and plant to working barges for

transport to the construction site. All materials for the construction of the approach jetty, jetty

head and mooring dolphins (e.g. piles, pre-cast concrete deck sections, warren trusses and

walkways) will be transported to the site from the commercial wharf. Some larger materials

and pre-fabricated elements are likely to be delivered to the wharf by ship, others may be

delivered by road.

The location of the commercial wharf has not been selected, however it is likely to be within Port of

Plymouth (e.g. Cattewater), where there is a choice of commercial wharfs and yards.

A mixture of jack-up barges and floating barges are likely to be used at the site as a platform for

construction of the jetty (piling, walkways, dolphin and jetty deck construction). Welfare and office

facilities will be provided on the working platform, as well as at the wharf. The Contractor’s staff will

be transferred on shift rotations to the working platform from the commercial wharf or another

convenient landing stage.

A site compound will be established within Thanckes OFD for use by the Contractor and the

Client’s Representative with administration and welfare facilities and materials storage.

It will be situated on an area of land between Tank 6 & the Tank row 15 – 18 (see Fig 2-2). This

compound will be used to store materials for construction of the new firefighting system in the tank

farm. In addition a working area will need to be established for materials storage and construction

of all land based elements of the new loading facility, including pipework and buildings in the jetty

root area and for installation of infrastructure on the jetty deck. This will be located in the existing

crew car park area, adjacent to the new Yonderberry Jetty root (see Fig 2-3).

Access to the compound will be from an existing surfaced access track through the Thanckes OFD

tank farm, via the main entry security gate on Pengelly Road (approximately 80m from the A374

trunk road).

Only once the jetty head and approach jetty structures are complete, will there be physical

connection between the marine construction works and the land-based construction at Thanckes

OFD. Whilst installing infrastructure on the jetty (e.g. pipelines and manifolds, fire-fighting systems,

the jetty welfare building, mooring equipment and fenders) it is anticipated that the majority of

materials and prefabricated elements will be delivered by barge and lifted on to the jetty head.

Other smaller deliveries may be made by road through the Thanckes OFD site.

During the demolition of the existing jetty, initial removal of plant and equipment is likely to be

exported by barge to a commercial wharf or broken down for transport by road through the

Thanckes OFD site. The demolition of the jetty and mooring dolphin structures will be undertaken

from marine plant and exported by barge to a commercial wharf for disposal or recycling.

2.6.3 Phasing of Construction Works

The fuelling operations on the existing jetty are intended to continue until the new jetty is

constructed and commissioned. However the close proximity of the new and existing jetty

structures will require the construction works to be phased to enable continuity of service. This will

entail parts of the existing structure being demolished prior to construction of parts of the new

structure, which will result in a reduced capability of the facility during some periods of the

construction programme.

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2.6.4 Plant and equipment

It is expected that the construction and demolition works will require the following plant:

• Jack-up barges with attendant workboats

• Floating self-powered and dumb barges with tugs

• Piling rigs mounted on jack-up barges

• Land-based piling rigs

• Floating and land-based cranes

• Concrete mix and batch plant

• Pipeline assembly line

• Trailer Suction Hopper Dredger (TSHD) / Cutter Suction / Backhoe

• General land-based plant including excavators, dumpers, cranes, cutting and drilling

equipment and temporary diesel generators.

The final choice of equipment and plant will reside with the contractor appointed to construct the

works.

2.6.5 Construction Activities

The following construction activities are anticipated:

Jetty Approach Structure

i. Procure and prepare tubular steel piles with protective coatings at the commercial wharf.

ii. Mobilise and position the piling rig on a jack-up barge.

iii. Drive piles into seabed from the jack-up barge.

iv. Bore out seabed material, side-cast arisings and drive piles until socketed into competent material.

v. Fabricate pile caps, crossbeams and warren trusses.

vi. Lift and fix in place pre-cast concrete or steel pile caps and crossbeams.

vii. Lift and install coated steel ‘Warren’ truss units to span between pile cross-beams.

viii. Lift and install platforms for fire-fighting pumps and welfare & office facilities

ix. Lift and install pre-fabricated welfare & office facilities and septic tank.

x. Install cathodic protection system.

Throughout the construction period piles and pre-fabricated structural elements will be

transported from the commercial wharf to site by barge, as required.


Jetty Head



iii. Drive jetty head piles into seabed from the jack-up barge.

iv. Bore out seabed material, side cast arisings and drive piles until socketed into competent material.

v. Lift and fix in place pre-cast concrete or steel pile caps and crossbeams.

vi. Cast in-situ reinforced concrete deck and ducting.

vii. Cast in fixings for equipment to be placed on the deck.

viii. Fix new guardrails to the deck.

ix. Drive piles for the refuelling mooring pontoon guide piles, vessel impact barrier and fendering.


xi. Fix 1no. linkspan (refuelling pontoon), new fenders, quick release hooks and mooring bollards to new jetty head.

xii. Install new crew access pontoon and brow.

Jetty Infrastructure

i. Procure and deliver pipeline lengths to Thanckes OFD site compound.

ii. Fix pipe rack to the approach deck. Install all pipes and cables onto the rack. Weld pipe lengths at the jetty root and pull the welded pipeline along the approach jetty length.

iii. Install the new manifold (including bund), valves, platforms, controls, sampling points, and pipe work.

iv. Lift and fix new fire monitors, towers and hydrants, telescopic crane, marine loading arms, hose rack and ship access tower with staircase, working area lighting, approach speed lasers & indicators, navigation lighting, CCTV and spares/equipment store.

v. Install all cabling and commission equipment.

Mooring Dolphins



iii. Drive mooring dolphin piles into seabed from the jack-up barge.

iv. Drive piles for the 1no. crew access mooring pontoon guide piles.

v. Bore out seabed material, side cast arisings and drive piles until socketed into competent material.

vi. Fix pile cap temporary works and cast in-situ concrete pile caps.

vii. Drive walkway support piles.

viii. Lift and install pre-fabricated walkways between dolphins.

ix. Fix 1no. linkspan (crew access pontoon), guardrails, rubbing strips, lighting and rigger shelters to the deck


xi. Fix quick release hook to each mooring dolphin

xii. Install all cabling and commission equipment.


Berth Pocket & Northern Approach Channel

i. Capital dredge the new berth pocket (extension of the existing berth pocket) and northern approach channel using a TSHD or barge mounted backacter (for dense materials).

ii. Transport and dispose of dredgings at Rame Head licensed disposal site by hopper dredger or split-bottom barge.

iii. Level the dredged seabed with a plough / bed leveller.

Tank Farm Fire Fighting System

ii. Excavate and dispose material off-site for the new foundations for pipe support plinths, road crossings culverts and tank drenching frame foundations.

iii. Construct pipe support plinths along new fire main route.

iv. Construct culverts at locations where the firemain crosses site roads and access tracks.

v. Install new firemain throughout the tank farm site

vi. Install diesel pump at Emergency Water Supply tank (Tank 7)

vii. Install new pump control building, new standby generator, new electrical feeder pillar, new foam storage and proportioner building and new firefighting control kiosk in Jetty Root area

viii. Install new tank drenching sprinklers and support frames over 8 live fuel storage tanks on the site

2.6.6 Piling Method

The anticipated piling methodology will be as follows:

i. Initially press the casing through the soft sediments until firm ground is encountered.

ii. Drill inside the casing and oscillate and tap the casing through the firm ground/weathered slate until hard ground is encountered. This may require limited hammering, however; the majority will be achieved by oscillating the casing in.

iii. Either drill through hard ground to form a pile bore into which steel reinforcing is placed and concreted or drill out and drive the casing as above to the required depth in the hard bedrock. This may require some hammering, however; the majority of the depth will be achieved through drilling and oscillating the steel casing into the bedrock.

iv. All sediment/soil/rock within the casing will be drilled out.

v. The arisings from the drilling are likely to be relatively fine grained.

vi. All pile arisings will be deposited around sub-tidal piles only.

As a result, piles will be within a casing, either down into strong rock, or down to weathered rock

with a column drilled below into strong rock to provide a rock socket.

2.6.7 Demolition Method

The anticipated method of demolition of the existing facility will be as follows:

i. Empty and flush all fuel and sullage pipelines.

ii. Remove all equipment, buildings, tanks, pipework, etc. from the jetty head to barges for transport to commercial wharf for disposal/re-cycling.

iii. Remove all pipelines, cables, ducting and pipe supports from the approach jetty to barges for transport to commercial wharf for disposal/re-cycling.


iv. Demolish and dispose/re-cycle the redundant buildings and pipework on the land at the jetty root.

v. Demolish the existing jetty head, approach structure and mooring dolphins by cutting and breaking out the concrete deck and beam elements, using floating plant.

vi. Piles to be cut-off 300mm below final seabed level, using floating plant and remotely operated vehicles (ROVs) or divers.

vii. Dispose of all materials by appropriate recycle or disposal method.

Measures are to be put in place to contain all demolition material and prevent waste materials

falling onto the seabed or polluting the watercourse.


2.7 Project Programme

Key planning and indicative project milestones for the project (assuming necessary consents

are obtained) are set out in Table 2-4:

Table 2-4: Key planning and project milestones

Milestone Assured programme

Undertake EIA December 2012 – November 2014

Submit planning & marine licence (construction)

applications. The EIA will be contained within the

ES will accompany the submission.

May 2015

Local Planning Authority (LPA) statutory

consultation period

28 days

MMO statutory consultation period 42 days

Obtain all statutory consents September 2015

Construction contract award Autumn 2016

Design and planning period Autumn 2016 – Spring 2017

Construction period 2017–2019

Handover of new jetty 2019

Demolition of existing jetty complete 2019

Assuming that all necessary consents are obtained and the design and construction contract is

awarded by Autumn 2016, it is anticipated that construction mobilisation will commence in early

2017 and works would commence in Spring 2017.

Consultation has been undertaken with Statutory Consultees with regard to seasonal

restrictions of piling activities. These restrictions are detailed below as per Natural England

email dated 2nd May 2014 (Appendix 2A):

• Non-percussive piling (i.e. vibro-piling, pile case oscillation and auguring/drilling) would

be possible at any time of year, provided that monitoring of noise levels is undertaken

for the first four piling events and comparing these to the predicted levels (see

Subacoustech paper in Appendix 2A), before carrying out these activities during the 1

April – 31 August key sensitive period.

• Percussive piling is to be restricted to the months of September to March, inclusive, to

minimise the impact on fish migration in the Tamar River. This constraint will mean that

multiple piling rigs may be required to work concurrently to enable the construction of

the new jetty head, approach jetty and mooring dolphins within the project programme.

Due to the proximity of the works to residential areas (Torpoint and Wilcove), it is anticipated

that construction works will generally be undertaken during normal working hours (Monday –

Friday between the hours of 0800 to 1800 and Saturdays 0800 to 1300). It may be necessary

to undertake some works, including dredging activities and movement of barges/plant, outside

these times due to tidal constraints.

Construction and commissioning is programmed to be complete by early 2019. The demolition

works will be phased with the construction works, to enable the tank farm to continue to operate


throughout the construction and demolition periods. Demolition works will be complete by

Autumn 2019.

2.8 Alternatives Considered

This section summarises the main alternatives considered during the development of the

scheme and reasons why alternative proposals have been discounted. This considers the

evolution of the proposal from the Assessment Study to Concept Design stage, including the

recently revised location of the proposed jetty structure.

2.8.1 Assessment Study

An Assessment Study was commissioned by Defence Estates in 2009, which evaluated a

number of options to provide a fuel loading facility and fire fighting upgrade at Thanckes OFD.

To ensure that all potential options were considered at the commencement of the assessment

study, a Brainstorming Workshop was held at HMNB Devonport on 4 September 2009. This

workshop derived 26 potential ideas for provision of a loading facility and fire main upgrade at

Thanckes OFD. Those ideas that clearly did not satisfy the requirements of the User

Requirement Document (URD) were discounted.

Further work was then undertaken to assess in detail the remaining options and reported in the

Initial Options Appraisal Report dated 15 January 2010 (Ref 2-10). The Options Appraisal

Report identified 14 options that were further evaluated before the Decision Conference held on

24 November 2009. The Decision Conference identified the 6 options that were subsequently

assessed during the Assessment Study. The 6 options considered were:

� Option 4 - Refurbish Approach and Jetty

� Option 6 – Refurbish Approach and new build Jetty Head north of Existing

� Option 7 – Build new approach and refurbish Jetty Head

� Option 8 – Refurbish Approach and Jetty Head and provide new floating platform

� Option 9 – New-build Approach and New-build Jetty Head

� Option 14 – Build new Approach and floating Jetty Head

An initial Environmental Appraisal and sustainability appraisal (SA) was undertaken for all

options as part of the Assessment Study. The findings of these appraisals are summarised

below in Table 2-5 as environmental and sustainability considerations for each option. These

considerations informed the principal conclusions from the Assessment Study (Section 2.8.2).

Table 2-5 Environmental and sustainability considerations

Option Environmental Considerations Sustainability

Considerations

Option 4 -

Refurbish Approach

and Jetty Head

Option 4 causes less environment impact during

construction than some of the other new build

options, as the option makes use of large

elements of the existing footprint. No dredging is

required for this option. The option is not

expected to give rise to need for material

mitigations or difficulties with permitting, but

further EIA fieldwork is likely to be necessary.

Option 4 has only limited

negative sustainability

impacts due to limited short-

term construction period.

Option 6 – Option 6 involves less environment impact Option 6 has only limited


Refurbish Approach

and new build Jetty

Head north of

Existing

during construction than some of the other new

build options as the option makes use of the

existing approach footprint. Dredging is required

for this option as there is a need to extend the

dredged box northwards, although this is

mitigated because a similar area at the southern

end of the dredged box would be released from

any need to dredge in the future. The Option is

not expected to give rise to need for material

mitigations or difficulties with permitting, but a




term construction period,

although any dredging works

to the north of the existing

dredge box will require careful

consideration.

Option 7 – Build

new approach and

refurbish Jetty

Head

Option 7 involves greater environmental impact


refurbishment options, as the option requires a

new approach. However dredging is not required

for this option. The option is not expected to give

rise to need for material mitigations or difficulties

with permitting, but a further EIA fieldwork is

likely to be necessary.

Option 7 has only limited negative sustainability impacts due to limited short-term construction period.

Option 8 –

Refurbish Approach

and Jetty Head and

provide new

floating platform

Option 8 involves less environment impact


build options, as the option makes use of the

existing Head footprint. A small amount of

dredging is required as the dredge box protrudes

further into the river than at present. The option

is not expected to give rise to need for material

mitigations or difficulties with permitting, but a






Option 9 – New-

build Approach and

New-build Jetty

Head

Option 9 involves more environment impact

during construction than some of the other

refurbishment options, as the option requires a

permanent new build Jetty in a new location.

Capital dredging is required for this option as the

works would require the creation of a new

dredge box. Maintenance dredging would also

be required.

Option 14 – Build

new Approach and

floating Jetty Head

Option 14 involves a moderate environment

impact during construction as dredging of a new

dredge box is required. This however will be

offset by the abandonment of the dredge box to

the south. The option is not expected to give rise

to need for material mitigations or difficulties with

permitting, but a further EIA fieldwork is likely to

be necessary.






2.8.2 Principal Conclusions Of The Assessment Study

The detailed findings of the study are given in the respective sections of this report. Principal

conclusions from the study were as follows:

• The “Do Nothing” is not viable given continuing deterioration of the jetty and the threat of its

closure on safety grounds. Closure of the facility would severely inhibit Navy Command

and other customers operating within the HMNB Devonport.

• A loading facility compliant with the URD can be provided by each of the appraised options

(Options 4, 6, 7, 8, 9 & 14) at Thanckes OFD.

• Options involving re-use of existing jetty piles (Options 4, 6, 7 & 8) provide the least

environmental impact but carry the highest risk in terms of future capacity of the facility.

Besides the impacts of estimated cost and programme risk identified for these options, it is

likely that a contractor would not accept the design liability associated with the existing piles

in which case the MOD would retain this significant risk. Post-project loading facility outages

are likely for further pile maintenance. Retention of this risk would blur responsibilities

should defects occur after completion and acceptance of the works.

• Fire-fighting facilities in compliance with the URD can be provided to both the tank farm and

loading facility via solutions that are essentially the same across all appraised options. Salt

water fire-fighting systems are considered to offer the best value for money solution given

the physical constraints at the site and for compatibility with existing Aquatrine Contract

arrangements.

• All appraised options are located within a European designated SAC and require statutory

marine consents. Subject to formal confirmation from the Local Planning Authority during

the future Develop Preferred Option stage of the project, all options shall require a statutory

Environmental Impact Assessment.

• Option 9 provides the optimum URD compliant option that provides the most cost effective

and operationally effective solution, taking into account through life cost.

Option 9 – ‘New build jetty approach and head’ was recommended as the preferred option.

2.8.3 Location Of Option 9

The Assessment Study (Section 2.8.1) was completed in July 2010, at the time it was concluded

that Option 9 provided the optimum URD compliant option. During the Assessment Study there

was no evidence to identify contamination of the riverbed sediments and therefore it was

assumed that all dredged material could be disposed at the offshore licensed disposal site at

Rame Head. However, subsequent chemical analysis of the sediments within the northern end

of the proposed dredge area identified that some sediments contain substances that are

elevated above Centre for Environment Fisheries and Aquaculture Science (Cefas) Action Level

2 whereby disposal at sea is not permitted.

At present there is no restriction on the disposal at sea from the existing Yonderberry Jetty

dredge box which has been in place during the last 10 years of maintenance dredging.

Sampling and testing are required as part of the regulatory consent process for maintenance

dredging.

A workshop was undertaken on 11th March 2014 which brought together specialists to

investigate the options for dealing with the contaminated sediments and alternative jetty


locations to mitigate or avoid the associated issues. Four alternative locations for Option 9 were

identified:

• Location 1 – Build new Approach and Jetty Head on the footprint proposed at

Assessment Study stage (including contaminated sediment treatment and

disposal)

• Location 2 – Build new Approach and Jetty Head on existing jetty footprint

• Location 3 – Build new Approach and Jetty Head in front of existing jetty head

• Location 4 – Build new Approach and Jetty Head 170m south of Location 1

A Position Paper presents the findings of a high-level options appraisal to assess potential

solutions for dealing with contaminated sediment which has been discovered in the Tamar and

which will affect delivery of this project. The paper presents the advantages and disadvantages

of each option.

Locations 1 & 4 offer unhindered business continuity throughout the construction period.

However, Locations 2 & 3 requires the operator to make provision for alternative fuelling

arrangements for all or part of the construction period.

Location 1 carries a number of significant project risks connected with the capital dredging,

treatment and disposal of contaminated sediment (e.g. Waste Permits, Discharge Licence) that

are significantly greater than those of Locations 2 - 4 and which have not yet been quantitatively

assessed. Future maintenance dredging risks may be mitigated by over dredging a Buffer Zone.

Location 4 was the recommended option as it has the lowest estimated capital cost, low delivery

risks and enables business continuity throughout the construction period. Drawing 2-10 shows

Location 4 has subsequently been formally endorsed by DIO. This ES is therefore based on

Option 9 Location 4.

2.8.4 Alternative Disposal Site Options

There is a requirement to dredge and dispose of approximately 37,000m3 of material from the

seabed for this project. The Assessment Study identified the licensed offshore disposal site at

Rame Head to provide the most sustainable disposal option for uncontaminated dredged

material.

Since the Assessment Study, alternative disposal options have been assessed. The disposal

for the dredge arising’s was discussed with Statutory Consultees at the EIA Assessment of

Effects meeting on 24th September 2014. At that time no other projects or schemes were

identified which could provide an alternative use for dredge arising’s.

Subsequently investigations identified alternative disposal options as discussed below:

• Ernesettle Trots

Dispose of dredged material in the previously maintained dredge box at Ernesettle Trot

moorings, which were abandoned in 2005. However further investigation has found that

material has subsequently accreted at this location, providing insufficient capacity for

receipt of additional material from the Thanckes project.

• RAFT Project Site

Dispose of dredged material in the area previously dredged for the RAFT Project in

2001. However further investigation has found that the hydrodynamics at this site have

maintained levels at this location since the dredging was undertaken. It is observed,

therefore, that the “energy state” in this area is high and any material placed in this

location is likely to be unstable. The sea bed shear stresses are such that any material


deposited in this area is likely to be released into suspension in the water column,

increasing turbidity and distributing the material, for all but the heaviest grading sizes,

elsewhere in the estuary.

• High Water Bird Roost Improvements

Improvement of existing high water roosts and creation of new roosts from the proposed

dredged material have been considered. A potential site has been identified at Sango

Island in St John’s Lake, south of Torpoint. A high level review of the material type,

material quantity, placement method and programme of the works indicate that the work

would be difficult to undertake in shallow water and are likely to cause significant

disruption and environmental impact to the heavily designated (SSSI and SAC) site.

Therefore this option is unlikely to achieve consent.

• Onshore Disposal

Waste management companies who operate waste treatment and disposal facilities in

the local area have been consulted. There are three locations identified within Devon

and Cornwall where dredge arisings may be accepted and used for restoration

purposes. However, the sediment dredged straight from the river would have to be

sufficiently de-watered and dried before it could be transported and before it would be

acceptable to be received by these sites. No suitable site has been identified for

landing and dewatering the dredged material in its “wet” state. If a site can be found it

would require a considerable logistical and economical challenge and it is considered

that the environmental impact of the treatment and transport process would outweigh

the benefit of avoiding disposal at sea.

The investigation of the alternative disposal options has found that none of the alternative

options are feasible.

Since the volume of capital dredging and disposal is relatively small in the context of the volume

of maintenance dredgings disposed at the licensed offshore disposal site at Rame Head, the

investigation has concluded that disposal at the Rame Head licensed disposal site is the most

sustainable option for the Thanckes OFD project. The ES has been progressed on this basis.


3 ENVIRONMENTAL IMPACT ASSESSMENT METHODOLOGY

3.1 Introduction

The ES presents the assessment of the significant environmental effects likely to result from the

construction, operation and decommissioning of the Development. This chapter sets out the

various stages of the EIA and the approach used to assess impacts.

3.2 Legislation and Guidance

Each chapter contains a summary of the relevant regional, national and international legislation

and policies. In addition, each topic includes details of relevant technical guidance which has

been followed.

3.3 Scoping of Environmental Topics

3.3.1 Screening and Scoping

In accordance with Regulation 5 and 13 of the Town and Country Planning (Environmental

Impact Assessment) Regulations 2011 a request for screening and scoping opinion was

submitted to CC on 17th November 2012 (Appendix 1-B).

In accordance with Regulation11 and 13 of the Marine Works (Environmental Impact

Assessment) Regulations 2007, as amended 2011; a request for screening and scoping opinion

was submitted to MMO on 17th November 2012 (Appendix 1-B).

A scoping report (Appendix 1-C) accompanied the request. This identified that the Development

could potentially have significant environmental effects on the following topic areas:

• Water Quality, Sediment Quality, Geology & Contamination

• Ecology – Marine

• Ecology – Terrestrial

• Archaeology & Culture Heritage

• Noise & Vibration

The following areas were scoped out of the scoping report; the scoping opinion on these points

is covered in 3.3.3.

Flood Risk & Hydrology

No significant increase in flood risk is predicted to arise as a result of the construction,

operational and demolition phases of the project. Flood Risk & Hydrology were scoped out of

the EIA, although a separate Flood Risk Assessment (FRA) was proposed to accompany the

planning application.


Traffic & Transport (including Navigation)

Some disruption to existing fuelling operations but effects would only be temporary. An increase

in construction traffic comprising heavy vehicles and site visits by road by contractors and

supervisory staff would be temporary during the construction phase. No impact on navigation

channels predicted during construction, operation or decommissioning. A transport assessment

may be required for the planning application.

Air Quality

No significant or measurable increase in air pollution is predicted to arise as a result of the

construction, operational and decommissioning phase.

Human Environment

Due to the location of the project, there are unlikely to be significant effects on Public Rights of

Way (PRoW) during the construction and demolition phase. As the proposed jetty will replace

the existing jetty no significant effects are anticipated during the operational phase.

Landscape and Visual

No adverse impacts on Lynher and Tiddy River Valleys Landscape Character Area (LCA) and

Tamar Valley AONB for the construction, operational and decommissioning phase. The new

position of the jetty is likely to lead to minor beneficial impacts on views for properties located on

Albion Road in Torpoint. For some properties in and around the coastline settlement of Wilcove

impacts are likely to be minor adverse.

Overall, the landscape around the site is considered to have a low sensitivity to the type of

change proposed during construction and as such any impacts arising from it would most likely

not be significant.

A full assessment of landscape and visual was not considered necessary given the existing

context of the site and presence of the existing jetty. Therefore an assessment of impact on

views from properties within Wilcove may be necessary to support the planning application.

Hydrodynamics

As the new jetty does not interrupt the flow to any greater degree than the existing jetty it is

considered unnecessary in this instance to undertake hydrodynamic modelling of river flows.

Therefore, for the reason stated above it is not proposed to consider hydrodynamics further in

the EIA for the project.

3.3.2 Scoping opinions

Scoping opinions were received from CC (Appendix 1-E) and the MMO (Appendix 1-F) by

Hyder on 1 March 2013 and 27 March 2013 respectively. As a result of which clarification were

required for the following.

Hydrodynamics

MMO requested a more detailed justification for the scope out of hydrodynamics be included

within this ES. A Technical Note on hydrodynamics in the vicinity of the proposed new jetty has

been prepared and is included within Appendix 3A. This note also addresses the addition of the

navigation channel.


Flood Risk Assessment

CC agreed that a FRA was not required as part of the EIA, but that one would be required to

support the planning application.

Traffic & Transport

CC Agreed that traffic and transport does not need to be included within the EIA, however a full

Transport Assessment should be included with any formal submission which should include

details of deliveries and works machinery and transportation of waste etc.

During The Thanckes OFD assessment of effects workshop 24th September 2013, the inclusion

of a formal Transport Assessment was discussed and deemed as not to be required. It was

proposed that the Contractor provides a Construction Travel Plan/Traffic Management Plan

prior to the start of construction. This approach has been confirmed as acceptable by CC 16th

October 2014 as the transport during operation would remain the same.

Landscape and Visual

CC confirmed that a landscape assessment should be included within this ES considering the

visual impact upon the landscape /nearest properties and nearby historic parks and gardens.

Air Quality

CC agreed that air quality does not need to be included within the EIA and that a reference

should be made within the formal application. CC confirmed on 4th November 2014 that an air

quality assessment is not required to support the planning application and that an

acknowledgement of this is contained within the Planning Statement.

3.3.3 Revision to location of Jetty and inclusion of tank farm firefighting upgrade

Due to the iterative nature of the design process there has been a revision to the location of the

Jetty and the inclusion of the tank farm fire fighting update, since receipt of the MMO and CC

scoping opinions. The project description is provided Section 2.4, with Section 2.9.3 covering in

detail the reasons for the location change. As a result of these design changes the statutory

consultees were provided with an update letter and supporting drawings on 29th October 2014,

these are included within Appendix 3B).

3.3.4 Scope of this Environmental Statement

In accordance with above, the responses received and subsequent discussions with consultees,

the scope of this EIA includes:

� Water Quality, Sediment Quality, Geology & Contamination

� Marine & Terrestrial Ecology

� Archaeology & Cultural Heritage

� Noise & Vibration

� Landscape & Visual


3.4 Environmental Impact Assessment General Methodology

In accordance with relevant guidelines, the EIA has incorporated the following elements:

The Baseline: Baseline environmental conditions, including those that are predicted to exist

immediately prior to construction and operation of the development as well as those currently

existing, have been identified through a number of means. They were determined through

consultation, the use of existing data or through undertaking additional surveys, studies and

modelling. Each environmental discipline has identified key resources and receptors that have

been taken into account during the assessment process.

Spatial Scope: The area over which impacts could potentially occur is wider than the area of

land directly taken by the proposals. It is inappropriate to define a single study area for the

assessment, since the spatial scope varies depending on the topic under consideration. Spatial

scope is described within each chapter.

Temporal Scope: In considering the environmental effects of the development, it is necessary

to identify impacts that may occur during construction, operation and decommissioning of the

existing and proposed jetty

Construction extends from the commencement of site works to the date immediately prior to

opening of the development.

Operation extends from immediately after opening of the first phase of the development for the

remainder of its life.

Iterative Assessment and Mitigation Design: Impacts associated with the construction,

operational and decommissioning stages of the proposed development have been identified

during the course of the EIA process as the design has evolved. The approach to mitigation has

been based on the mitigation hierarchy of avoidance, reduction and compensation. These are

described in each assessment chapter as relevant, and represent the basis of the assessments

of residual impacts in this ES.

Assessing Impacts: Impacts associated with the construction and operational stages of the

Development have been identified. These have been considered in terms of their nature, the

physical extent of their influence and the magnitude of their effects. In considering the nature

and significance of the impacts, the effects were assessed on the basis of whether they would

be:

• Direct or indirect

• Temporary, short, medium or long term

• Reversible or irreversible

• Beneficial or adverse

• Cumulative

Qualitative and quantitative techniques have been used to assess these impacts, as

appropriate. The EIA identifies those elements of the development that have been introduced

to mitigate potential adverse effects and assesses the significance of the impacts that remain

after mitigation measures have been put in place (the “residual impacts”).


Determining Significance: Determining whether or not an effect is significant, is an important

step in the formal EIA process, and is necessary in order to satisfy statutory reporting

requirements. In general, the significance of an impact reflects the importance or value of the

affected resource or receptor, its sensitivity to change, and the magnitude of the predicted

impact. The criteria for determining significance varies from topic to topic but the general

principle that has been followed is that higher magnitude impacts on important resources would

be regarded as significant. Lower magnitude impacts on less important resources would not

generally be regarded as significant.

The principles of the assessment matrix shown in Table 3-1 have been followed to determine

impact significance for this EIA. Topic specific assessment will be based on Table 3-1, but may

differ depending on specific methodologies used.

Table 3-1 Determining significance

Importance/sensitivity of resource or receptor

Magnitude of

potential

impact

Very High High Medium Low Negligible

Major Very Large Large or Very

Large

Moderate or

Large

Slight or

Moderate

Slight

Moderate Large or Very

Large

Moderate or

Large

Moderate Slight Neutral or

Slight

Minor Moderate or

Large

Slight or

Moderate

Slight Neutral or

Slight

Neutral or

Slight

Negligible Slight Slight Neutral or

Slight

Neutral or

Slight

Neutral

No Change Neutral Neutral Neutral Neutral Neutral

The importance/sensitivity of resource or receptor has been determined through the baseline

studies, and each discipline sets out their criteria for this.

The terms “impact” and “effect” are used interchangeably throughout this ES.

3.5 Consultation

Extensive consultation was undertaken as part of the previous assessment study (Section

2.8.1), a summary of which is available in Appendix 3-C along with copies of responses

received from primary advisors and consultees.

Statutory and key non-statutory consultees have been involved during project development and

this has continued throughout the EIA process (both as a part of the scoping process and during

ES preparation). A full log of consultations undertaken as part of the EIA process is included in

Appendix 3-D.

Consultations with regard to the project have been carried out in accordance with MMO Marine

Licencing Guidance, as shown in Appendix 3-E, The Town and Country Planning (Development

Management Procedure) (England) (Amendment) Order 2013 (ref 3-1) and CC's Statement of

Community Involvement (ref 3-2). The following have been consulted during the EIA process:


Cornwall Council

Marine Management Organisation

Queens Harbour Master

The Duchy of Cornwall

Plymouth Council

Tamar Esturies Consultive Forum

Natural England

Environment Agency

Centre for Environment Fisheries and

Aquaculture (Cefas)

Cornwall Wildlife Trust (CWT)

British Trust for Ornithology (BTO)

Environmental Records Centre for

Cornwall and the Isles of Scilly

Cornwall Bird Watching &

Preservation Society

Oil and Pipeline Agency

The Crown Estate

Maritime and Coastguard Agency

(MCA)

Cornwall Council Historic

Environment Service

3.5.1 Statutory body and stakeholder consultation

Prior to the submission of the scoping report to the consenting authorities, consultations were

held with a number of statutory consultees. An external stakeholder consultation workshop was

held on 15th November 2012 at Thanckes OFD, where the draft scoping report (issued on 6th

November 2012) was discussed. The following consultees were present at the workshop:

• Cornwall Council

• Marine Management Organisation

• Queens Harbour Master Plymouth

• Plymouth City Council

• Natural England

• Environment Agency

• Tamar Estuaries Consultative Forum

The workshop gave the consultees an overview of the project and the proposed approach to the

EIA. Minutes of the workshop are provided in Appendix 3-F.

Furthermore an assessment of effects workshop took place on 24th September 2013, the

minutes of which are available in Appendix 3-G. This workshop covered discussions with regard

to the draft ES chapters.

In addition consultation has been undertaken with regard to underwater noise and fish

migration. Two consultation meetings took place on 14th November 2013 and 8th January 2014,

meeting minutes are contained within Appendix 3H. Ongoing discussions in relation to this issue

have resulted in the advice in respect of piling methods and restrictions due to key migratory

periods of all the fish species found in the Tamar. This advice is included in section 2.7.

Topic specific stakeholder and statutory consultation is covered within each technical chapter,

along with data requests.


3.5.2 Scoping consultation

Upon submission of the scoping report to the consenting authorities, formal consultation was

held, in accordance with the Town and Country Planning (EIA) Regulations (Ref 3-3) and the

Marine Works EIA Regulations (Ref 3-4), by both CC and the MMO.

As part of their consultation the MMO consulted with the following organisations, a copy of these

are contained within Appendix 3D

• Cefas

• Natural England

• Environment Agency

• English Heritage

• The Crown Estate

• Maritime and Coast Guard Agency

• Duchy of Cornwall

• Plymouth City Council

• Cornwall Council

• Queens Harbour Master

3.5.3 Update letter

Consultation responses received from the statutory consultees state that the scoping opinions

are still valid. Copies of the responses are provided in Appendix 3D.

3.5.4 Public and community consultation

A public exhibition was held on Wednesday 23rd October 2013 at Torpoint Town Hall between

3pm and 7pm. A preview for the councillors took place the previous night (Tuesday 22nd

October 2013) between 7pm and 8.45pm. During the public exhibition the councillors and public

were given the opportunity to complete a feedback form (Appendix 3I).

Proposed development at Thanckes OFD exhibition website was created

https://www.gov.uk/government/publications/proposed-development-at-thanckes-oil-fuel-depot-

exhibition. The information on the website included a replication of what was displayed at the

public exhibition at Torpoint Town Hall on Wednesday 23rd October 2013, and what has

subsequently been displayed in local facilities following the exhibition.The website went live on

24th October with a two week deadline for receipt of all representations.

Parish Council meetings for Torpoint and Antony Parish Council were attended on 28th October

and 7th November 2014 respectively. An update on the Thanckes project was provided. A copy

of the presentation is provided in Appendix 3J. Issues identified at the previous consultation

event were discussed within the presentation and it was demonstrated how these have been

addressed.

A Statement of Community Involvement accompanies the planning application, including a full

summary of responses received from the public exhibition. This is to satisfy the statutory

requirements as adopted in CC's Statement of Community Involvement.

3.6 Assessing Cumulative Effects

Cumulative impacts result from the incremental impacts of the project when added to other past,

present and reasonably foreseeable future actions. The impacts from a single development may


not be significant on their own but when combined with other impacts and other developments,

these effects become significant.

Cumulative effects will be considered by describing and assessing the following:

• Interaction of impacts from the project with those from other plans or activities, including

the various phases of the project

• Interaction of different impacts of the project, which affect the same resource or receptor.

Cumulative impacts have been considered in each topic chapter as necessary.

Other Proposed Developments

At present there are three reasonably foreseeable developments within the vicinity of the

proposed development that will be considered for cumulative impacts, as advised by statutory

consultees and DIO. A brief description of each development is given below. Locations of these

developments are shown on Drawing 3-1.

MOD Forward Operating Base at Kinterbury Point

The project proposal is the creation of a Forward Operating Base (FOB) at Kinterbury Point,

within HMNB Devonport, for the Fleet Helicopter Support Unit (FHSU) which transfers naval

staff to vessels.

Up to December 2011 the FHSU operations Main Operating Base (MOB) was at Plymouth City

Airport with the Helicopter Landing Site at Weston Mill Lake (WML) within HMNB Devonport

serving as a pick-up and drop-off point. In December 2012, following closure of Plymouth City

Airport and cessation of flights at the WML HLS due to flight safety concerns, the FHSU Main

Operating Base was relocated to Newquay Airport and the existing HLS at HMS Raleigh was

adapted to act as a temporary FOB. A project was initiated under DIO to study possible options

for providing a long-term solution for the FHSU. The maximum total number of flights in any one

month would be 100, with the average being 60 (a “flight” is one take-off and one landing). The

recommended option is to retain a MOB at Newquay Airport; construct a new permanent day

and night capable FOB at Kinterbury Point taking approximately 70% of the FHSU aircraft

movements; with the remaining 30% at a secondary FOB at HMS Raleigh.

As mitigation for the higher number of flights from the interim solution and longer-term proposals

for HMS Raleigh, the MOD has committed to planting and maintenance of an improved partial

screen along the foreshore at Trevol Range, to reduce cumulative disturbance to birds feeding

on St John’s Lake (including non-SPA species)

MOD Refurbishment and Operation of Trevol Jetty

The MOD are currently consulting with regulators over the refurbishment and operation of

Trevol Jetty at HMS Raleigh. This project will be subject to Marine License and Planning

permission including in-combination assessment. There are possible very localised and very

short term effects of construction on intertidal and subtidal habitats. Discussions with Natural

England (NE) on the 9th December 2013 suggest that they are of the opinion that there will be

limited disturbance to overwintering birds caused by the training operations associated with the

use of this jetty (approximately two operations a week) however NE have raised concerns that

in combination with the temporary interim increase in helicopter activities at HMS Raleigh there

will be disturbance to the bird assemblage in St Johns Lake. The MOD does not consider that

operational use of the jetty is likely to cause significant disturbance to Avocet or Little Egret

feeding or roosting in St John’s Lake due to the distance from the significant roosting areas and

the low usage of this jetty by personnel. However, MOD has committed to plant screening along


the shoreline in the vicinity of Trevol Jetty as a mitigation measure to reduce the overall

potential cumulative disturbance to the bird assemblage feeding in St Johns Lake.

South West Devon Waste Partnership Combined Heat and Power Plant

The South West Devon Waste Partnership has contracted MVV Environment Ltd to construct a

Combined Heat and Power Plant at Weston Mill Lake. Construction started in 2012 and will

likely coincide with construction of the proposed FOB at Kinterbury Point.

MOD’s Devonport Landing Craft Co-location

The scoping report identified the MOD’s Devonport Landing Craft Co-location Project (DLCCP)

at Weston Mill Lake as a cumulative development. This project has now been completed and is

operational. Ongoing military training activity within the Tamar Estuaries Complex was assessed

as part of the DLCCP EIA and Habitat Regulations Assessment (HRA) which concluded that

“the extent of the training areas will not change during operation of the DLCCP, and areas

within the Tamar estuary are already being used for training purposes by the two squadrons, so

the frequency of use is unlikely to increase greatly. Areas for landing craft and hovercraft

training have been identified avoiding some areas throughout the year, and other areas at

certain sensitive times of the year.

3.7 Other Relevant Consents, Licences and Assessments

The project requires a number of consents and licences for both the construction and

operational phases. It also requires assessment in relation to the Water Framework Directive

(WFD) and HRA. Details are provided below:

• Planning Consent under Town & County Planning Act 1990 (Ref 3-5)

• Marine Licence (for the construction of the permanent marine structures and disposal of

capital dredge material) under the Marine and Coastal Access Act 2009 (MCAA) (Ref 3-

6)

• Environmental Permit under Council Directive (2008/1/EC) Integrated Pollution

Prevention & Control (Ref 3-7) as implemented through Environmental Permitting

(England and Wales) Regulations 2010 (Ref 3-8)

• Water Framework Directive (WFD) Scoping under Council Directive (2000/60/EC)

Water Framework Directive (Ref 3-9) transposed into UK law through The Water

Environment (Water Framework Directive) (England and Wales) Regulations 2003 (Ref

3-10)

• Habitat Regulations Assessment (HRA) under Council Directive (92/43/EEC) Habitats

Directive (Ref 3-11) transposed into UK law through the Conservation of Habitats and

Species Regulations 2010 (Ref 3-12)

The abstraction of water for use in a firemain does not require a licence under Section 32(2)(a)

& (b) Water Resources Act 1991 (Ref 3-13) as it is viewed as being for ‘fire-fighting purposes’

(within the meaning of the [1947 c. 41.] Fire Services Act 1947 (Ref 3-14)).

OFD Thanckes is currently a COMAH top-tier site regulated by the HSE and the EA. The

controlling document is the Safety Report prepared by the operators (OPA). The current Safety

Report details Safety Critical Elements and their inspection regime.


HSE/EA will require review of documentation used to control the project:

• Strategic Brief (prior to tender).

• Pre-Construction Safety Report (PCSR) (during detailed design).

• Pre-Operation Safety Report (POSR) (during construction).

• Proposed revision to the Safety Report a full 6 months before the new facility is

commissioned. Also OPA will be required to provide the EA with an environmental

impact assessment 6 months prior to commissioning, coupled to the proposed Safety

Report.

The Enforcing Authority for 2005 Regulatory Fire Reform Order [RR9FS)O 2005] for the site is

the Crown Premises Inspection Group (CPIG) but this remains to be confirmed by CPIG.

3.7.1 Habitat Regulations Assessment (HRA)

This project requires statutory approvals from a number of public bodies which are Competent

Authorities under the Habitats Regulations. At the EIA scoping workshop in Sept 2013 it was

proposed and agreed that the MMO would act as the Lead Competent Authority for the HRA,

and that the ES would include information to inform their assessment and decision.

Under Article 6 of the Habitats Directive (92/43/EEC) (Ref 3-11), an assessment is required

where a plan or project may give rise to significant effects upon a Natura 2000 site (also known

as ‘European Sites’). Natura 2000 is a network of areas designed to conserve natural habitats

and species that are rare, endangered, vulnerable or endemic within the European Community.

This includes SACs designated under the Habitats Directive for their habitats and/or species of

European importance and SPAs classified under Directive 2009/147/EC on the Conservation of

Wild Birds for rare, vulnerable and regularly occurring migratory bird species and internationally

important wetlands (Ref 3-15).

Therefore, due to the proximity of Thanckes OFD to Plymouth Sounds and Estuaries SAC

(Project site is within SAC boundary) and Tamar Estuaries Complex SPA (within 500m of

Project site); an HRA has been undertaken, in accordance with the above. The locations of the

designated sites are shown on Drawing 1-4.Chapter 6 of this ES covers the HRA.

3.7.2 Water Framework Directive Assessment

The Water Framework Directive (2000/60/EC) (Ref 3-9) came into law through the Water

Environment (Water Framework Directive) (England and Wales) Regulations 2003 (Ref 3-10).

The WFD was put in place to:

• Enhance the status, and prevent further deterioration of aquatic ecosystems and

associated wetlands which depend on the aquatic ecosystems;

• Promote the sustainable use of water;

• Reduce pollution of water, especially by ‘priority’ and ‘priority hazardous’ substances;

and,

• Ensure progressive reduction of groundwater pollution.

It set targets for all waterbodies in Europe that are classified under the WFD, requiring that they

reach at least good ecological status (or potential) by 2015. This date has now been extended

to 2027 on a large number of waterbodies. Around 20% of waterbodies in England and Wales

are currently meeting the objective.


In England, WFD actions are managed through the River Basin Management Plan (RBMP)

process. For the proposed development, the relevant RBMP is the South West RBMP. The first

plan was initially published by Environment Agency in 2009 and is currently being updated.

The WFD has important implications for planning development works. It will only allow

proposals on a waterbody if they do not cause deterioration in waterbody status (and they

should ideally improve the status of the waterbodies).

If a proposed development would result in an adverse effect to a waterbody that could cause

deterioration in its WFD status or could prevent actions which are required to raise the WFD

status of the waterbody, then the proposed development must be assessed and justified with

mitigation proposed, as specified in Article 4.7 of the WFD. A WFD assessment for the project

has been included in Chapter 5.


4 PLANNING POLICY CONTEXT

A detailed consideration of relevant planning policy specific to each environmental topic is

contained in each topic chapter of the ES.

Details of the planning policy framework and a discussion of how the Development has been

designed in accordance with this framework are included in the accompanying Planning

Statement. The Planning Statement has been prepared to support the planning application but

does not form part of the ES.


5 WATER, CONTAMINATION AND SEDIMENT QUALITY

5.1 Introduction

This chapter addresses the potential impact on the environment, due to the proposed works by

the presence of contaminated sediment or water. This chapter provides information on and

assessment of;

• the baseline conditions, in relation to the sediment and the estuarine water, including

laboratory analysis of sediment samples taken from the proposed jetty location,

• the mechanisms by which the proposed construction activities could mobilise

contaminants in the sediment and thereby impact water quality,

• the potential for the construction work to impact water and sediment quality through the

addition of contaminants,

• the suitability of disposal at sea or on land of dredging and pile sediment/soil arisings;

• what further investigation work and mitigation measures could be carried out to mitigate

the identified risks.

5.2 Regulatory and Policy Framework

This impact assessment has been undertaken in accordance with current international and

national legislation relating to protection of the surface water environment in the context of the

proposed development. A summary of the relevant legislation and policies, the requirements of

these policies and the proposed development response has been provided in Table 5-1 below.

Table 5-8 Regulatory References

Policy/Legislation Summary of Requirements Development Response

Water Resources Act

(1991/2003)

Not to allow controlled waters to be

significantly polluted.

It is a criminal offence to:

-knowingly permit any poisonous,

noxious or polluting matter or any

solid waste matter to enter any

controlled waters

- cause or knowingly permit any

trade effluent or sewage effluent to

be discharged into any controlled

waters without a consent, or outside

of the conditions of a consent.

Location of the jetty will include

consideration of pile lengths required,

which will be minimised and therefore

minimise soil arisings

Site investigation carried out to

establish potential for contamination to

occur

Principal Contractor to be informed of

hazards and risks and required to

produce and comply with mitigation

measures in method statements

Part 2A of the

Environmental

Protection Act (1990)

To protect controlled waters from

pollution by hazardous substances

in, on or under the land

Carry out a desk study to identify

potential sources of contamination

which could have led to the

contamination of sediments in the river.

This will inform the site investigation

and any mitigation measures



considered necessary where a risk is

identified.

National Planning

Policy Framework

(March 2012)

The document streamlines national

planning policy into a consolidated

set of priorities, with the core theme

being the delivery of sustainable

development and economic growth.

The Planning Practice Guidance

relating to land affected by

contamination refers to the

methodologies outlined in Part 2A of

the Environmental Protection Act

Carry out a desk study to identify

potential sources of contamination

which could have led to the

contamination of sediments in the river.

This will inform the site investigation

and any mitigation measures

considered necessary where a risk is

identified.

Consideration of waste reuse and

disposal options

Contaminated Land

Report (CLR) 11 ‘The

model procedures for

the Management of

Land Contamination’

To investigate and assess potential

risk to sensitive receptors (including

controlled waters, and flora and

fauna) from contaminated soil or

water

As above

The Water Framework

Directive (2000/60/EC)

Driver for water quality monitoring

which is required to establish a

framework for the protection of

inland surface waters, transitional

waters, coastal waters and

groundwater.

A WFD Screening Assessment has

been completed and is included in

Appendix 5-A

Marine and Coastal

Access Act 2009

Part 5 of this Act enables the

designation of MCZs. These are a

type of Marine Protected Area,

which protect a range of nationally

important marine wildlife, habitats,

geology and geomorphology. MCZs

exist alongside European marine

Sites, SSSIs and Ramsar sites to

form an ecologically coherent

network of marine protected areas.

The Tamar Estuary MCZ is located in

two separate areas including the upper

reaches of the Tamar and Lynher

estuaries. The development is

approximately 2km away from this

MCZ, at its closest point within the

Lynher estuary.

These potential receptors have been

considered in the assessment and

mitigation measures designed

accordingly.

Conservation of

Habitats and Species

Regulations 2010 (as

amended)’

The Regulations provide for the

protection of both Special Protection

Areas (SPAs) and Special Areas for

Conservation (SACs) as part of the

Natura 2000 network of protected

areas across Europe.

.

The Regulations also provide

protection for European Protected

Species (EPS) from the deliberate

capture, killing or disturbance. It is

also an absolute offence to destroy

or damage the resting site or

breeding site of an EPS.

Covered in detail within Chapter 6


5.3 Methodology

5.3.1 Introduction

This assessment has been undertaken with due regard to the Water Resources Act. The

assessment has been carried out based on the principles outlined in MMO guidance and

contaminated land guidance documents issued by the Department of the Environment Food

and Rural Affairs (DEFRA) and the EA.

The Guidance requires a risk-based approach with the potential environmental risk assessed

qualitatively using the ‘source-pathway-receptor’ pollutant linkage concept contained in Part IIA

of the Environment Protection Act (1990) and CLR 11 ‘The Model procedures for the

Management of Land Contamination’ (Ref. 5-1). For example, if the sediment is not

contaminated then there is not a ‘source’ of contamination at the site and therefore there would

not be considered to be a risk. Similarly, if the contamination in the sediment is not leachable

then there is not a ‘pathway’ and it is unlikely that water quality would be impacted through

dissolution.

A full Water Framework Directive Assessment is presented in Appendix 5-A.

This assessment is intended to meet requirements under the planning regime, and therefore is

focused on potential contaminated land risks associated with the proposed construction works

and the ongoing use of the site.

Maintenance and construction workers are not considered in this assessment as they would be

protected through other regulation, e.g. Health and Safety at Work Act and Construction Design

and Management Regulations 2007. Protection of construction workers and the environment

during and following construction must be addressed as part of the development of method

statements and risk assessments prior to any work being carried out on the site. However, the

information provided in this report should be reviewed by the Principal Contractor to inform his

risk assessment, in accordance with Construction Design and Management (CDM) Regulations.

5.3.2 The Study Area

The area covered by this study is defined by the proposed footprint of the jetty and the vessel

approach area, the northern part of which is to be dredged. The majority of the vessel approach

area, which will be reduced to a river bed maximum design dredge level of 12.6m below CD,

falls within the area currently used for vessel approach to the existing jetty. Therefore only an

area of approximately 0.73ha needs to be dredged, which will produce a volume of dredge

arising’s for disposal of approximately 19,000m3.

In addition, some dredging will need to be carried out to enable access to the western side of

the jetty. This will bring the river bed levels down to approximately 5.6m below CD over an area

of 1.36ha and will produce approximately 18,000m3 of arising’s.

In addition, consideration has been given to the area over which an impact could occur, which

due to the tidal nature of the river at this location, includes reaches of the river both up and

downstream of the development site.

Public Register information and historical maps have been obtained for a radius of

approximately 1km from the jetty footprint. Information has been obtained relating to potential

sources of contamination and land quality at the Thanckes OFD site. Some basic information on

the activities carried out at Devonport Dockyard has been obtained from the internet and the

Client.


5.3.3 Establishing Baseline Conditions

The baseline conditions have been established based on the following sources of information;

• Historical maps

• Public register information

• Land quality and site activity information for Thanckes OFD and Devonport Dockyard

• Surface water quality data for the River Tamar / Hamoaze

• Sediment laboratory analysis – total and leachable concentrations

Site Investigation

The following site investigations have been carried out at or near to the site, and the information

has been used in this report;

• Baseline Document for Maintenance Dredging in Plymouth Sound and Estuaries

European Marine Site (Black and Veatch) - 2011 (Ref. 5-12)

• Dredged sediment analysis for the existing Yonderberry Jetty (Cefas) – 2004 and 2006

(data tables provided by the Client)

• Soil Mechanics 1984 – five boreholes drilled in a line from the foreshore at OFD

Thanckes out towards the river channel, approximately between 40-100m north of the

proposed jetty approach. Boreholes BH-G and BH-H were located in the

northern/western approach channel.

• Hyder Consulting June and August 2013 – site investigation which included geophysics

surveys and drilling fifteen boreholes. The investigation was centred around the

previously proposed location of the jetty and jetty approach, to the north of the current

revised location. The investigation provides a good indication of the geology of the site

and includes some geophysics coverage and borehole locations which are on the

currently proposed jetty site. Of particular relevance are;

o DBH03 and DBH04 which are in the area of the eastern jetty approach

which will require dredging,

o MBH02, MBH03, MBH07, MBH08, and MBH11 are in or near (within

~15m) the area of the northern/western jetty approach,

o MBH03, MBH10 and MBH07 which are near to the proposed northern

dolphins, and

o MBH08 which is at the proposed location of the jetty head.

Chemical analysis of sediment/soil samples taken from these boreholes was carried out, as

discussed below.


5.3.4 Assessing Effects

Overall Effect

In Section 5.6 the overall potential effects of the development have been assessed. The

significance of impacts has been determined using the approach described in Chapter 3 of this

ES, combined with current UK best practice approach as discussed below. Activities

anticipated during the construction and operational phases have been identified and their

potential effects discussed, and proposed mitigation measures identified.

The assessment of impacts on the water quality of surface waters within and near the study

area has been made using three stages. Firstly a judgement is made as to the value of potential

receptors within the water environment through the baseline study, and then a magnitude is

assigned to each of the potential impacts identified. The assessment of the potential magnitude

of impact, the ‘risk term’ is derived from the contaminated sediment risk assessment, which

uses the criteria outlined in Tables 5-4, 5-5, 5-6 and 5-7 and is discussed below.

The overall significance of impacts, taking into consideration the mitigation measures outlined in

Section 5.5, is then determined using the matrix presented in Table 5-3

Any potential effect assessed as being of moderate and negative significance or greater, would

be considered significant and would require further consideration and action where

possible/practicable.

The determination of value (sensitivity) of the surface water receptors has been applied using

the criteria summarised in Table 5-2.

Table 5-2 Criteria for Determining the Value (Sensitivity) of the Hydrological Resource

Sensitivity Criteria Typical Examples

Very High Attribute has a

high quality and

rarity on a

regional or

national scale

Surface

water:

EU designated salmonid/cyprinid fishery

Watercourse achieving Water Framework Directive (WFD) Class ‘High’

Site protected under EU or UK habitat legislation (Special Area of

Conservation, Special Protection Area, Site of Special Scientific Interest,

Ramsar site)

High Attribute has a

high quality and

rarity on a local

scale

Surface

water:

Watercourse achieving WFD Class ‘Good’

Major cyprinid fishery

Species protected under EU or UK habitat legislation

Medium Attribute has a

medium quality

and rarity on a

local scale

Surface

water:

Watercourse achieving WFD Class ‘Moderate’

Water feature that supports an abstraction for agricultural or industrial

use of between 50 and 499m3/day

Low Attribute has a

low quality and

rarity on a local

scale

Surface

water:

Watercourse that is not a fishery, achieving WFD Class ‘Poor’.

Supports an abstraction for agricultural or industrial use of < 50m3/day


Table 5-39 Criteria for the Assessment of Overall Effect

Risk Term – See

Table 5-7

Importance/Sensitivity of Resource or Receptor

Very High High Medium Low Negligible

Very High Risk Very Large Large or Very

Large

Moderate or

Large

Slight or

Moderate

Slight

High Risk Large or Very

Large

Moderate or

Large


Slight

Moderate Risk Moderate or

Large

Slight or

Moderate

Slight Neutral or

Slight

Neutral or

Slight

Low Risk Slight Slight Neutral or

Slight

Neutral or

Slight

Neutral

Very Low Risk Neutral Neutral Neutral Neutral Neutral

Contaminated Sediment/Soil Risk Assessment

In Section 5.4 the baseline conditions are described. This information has been used to develop

a conceptual model of the site on which a risk assessment has been based. This risk

assessment relates solely to the potential presence of contaminated sediments and their

potential to impact water quality.

UK guidance for the assessment of the risk posed by the presence of contamination indicates

that a risk does not exist unless a source of contamination is present, a sensitive receptor is

present, and there is a pathway which could link them, i.e. source-pathway-receptor pollutant

linkage. Therefore, in order to assess the potential effect of the development on the

environment a Conceptual Site Model (CSM) has been developed by ascertaining the presence

of a contamination source, identifying potential sensitive receptors, and identifying potential

exposure pathways.

Based on this CSM a risk assessment has been undertaken which examines the likelihood of

exposure occurring and the potential severity of the impact. The risk assessment is primarily

qualitative, based on the criteria outlined below, but all available quantitative data has been

used to inform the qualitative assessment.

The criteria used in the risk assessment in relation to the potential effect of the proposed

development through contaminated sediment and soil are based on information presented in

the following:

• CIRIA C552 (2001) Contaminated Land Risk Assessment: A guide to good practice;

• NHBC / EA/ CIEH (2008) R&D Publication 66: (Volume 1) Guidance for the Safe

Development of Housing on Land Affected by Contamination; and,

• DEFRA (2012) Environmental Protection Act 1990: Part 2A. Contaminated Land Statutory

Guidance.

The designation of risk is based upon the consideration of both:

• the severity of the potential consequence - this takes into account both the potential

severity of the hazard and the sensitivity of the receptor


• the magnitude of probability (i.e. likelihood) - this takes into account both the presence of

the hazard and receptor and the integrity of the pathway

Severity (consequence) can be defined as the adverse effects (or harm) arising from a defined

hazard, which impairs the quality of human health or the environment in the short or longer

term. Definitions of different categories of severity are detailed in Table 5-4 below. In this

section, only impact to the primary receptors controlled waters and human health are

considered. The potential impact to ecological receptors is discussed in Section 6.

Probability can be defined as the chance of a particular event occurring in a given period of

time. Definitions of different categories of probability are detailed in Table 5-5 below.

A contaminant linkage must first be established before tests for probability and consequence

are applied. If there is no contaminant linkage then there is no potential risk. Any pollutant

linkage assessed as posing a risk of moderate or above would require further consideration.

The risk term determined is then used in the assessment of the overall effect according to the

matrix outlined in Table 5-3.

Table 5-4 Classification of Potential Consequence (Severity)

Classification Human Health Controlled Water

Severe Short term (acute) risk to human health.

Concentrations present likely to result in

“significant harm” as defined by Part 2A.

Substantial pollution of sensitive water

resources.

Medium Chronic damage to human health.

Concentrations present that could result in

significant harm.

Pollution of sensitive water resources or

small scale pollution of sensitive water

resources

Mild Slight short term health effects to humans.

Exposure to human

health unlikely to lead to significant harm.

Pollution to non-sensitive water resources

Minor Non-permanent health effects to human health

(easily prevented by means such as personal

protective clothing.)

Insubstantial pollution to non-sensitive

water resources


Table 5-5 Classification of Probability (Only applies if there is a possibility of a pollutant linkage being

present)

High likelihood There is a pollution linkage and an event that either appears very likely in the short term and almost

inevitable over the long term or there is evidence at the receptor of harm or pollution.

Likely There is a pollution linkage and all the elements are present and in the right place, which means

that it is probable that an even will occur. Circumstances are such that an event is not inevitable,

but possible in the short term and likely over the long term.

Low Likelihood There is a pollution linkage and circumstances are possible under which an even could occur.

However it is by no means certain that even over a longer period such an event would take place

and is less likely in the shorter term.

Unlikely There is a pollution linkage but circumstances are such that it is improbable that an event would

occur even in the very long term.

Once the severity and probability have been classified for a pollutant linkage they can be compared to

produce a risk category from very high risk to very low risk as shown in the matrix below.

Table 5-6 Classification of Risk

Probability

Consequence

Severe Moderate/Low Moderate High Very High

Medium Low Moderate/Low Moderate High

Mild Very Low Low Moderate/Low Moderate

Minor Very Low Very Low Low Moderate/Low

Table 5-7 Risk Classification Descriptions

Risk Term Description

Very High Risk There is a high probability that significant harm could arise to a designated receptor from an

identified hazard at the site without appropriate remedial action or there is evidence that

significant harm to a designated receptor is already occurring.

High Risk Harm is likely to arise to a designated receptor from an identified hazard at the site without

appropriate remedial action. Remediation works may be necessary in the short-term and are

likely over the longer term.

Moderate Risk It is possible that harm could arise to a designated receptor from an identified hazard.

However it is either relatively unlikely that any such harm would be severe or if any harm

were to occur it is more likely that such harm would be relatively mild. Some remediation

work may be required in the longer term.

Low Risk It is possible that harm could arise to a designated receptor from an identified hazard, but it is

likely, at worst, that this harm if realised would normally be mild. Any subsequent

remediation works are likely to be relatively limited.

Very Low Risk It is a low possibility that harm could arise to a receptor, but it is likely at worst, that this harm

if realised would normally be mild or minor.


5.3.5 Consultation

We have consulted the MMO prior to carrying out this study. With respect to this chapter, they

have consulted the EA and Cefas, and have indicated that the following issues must be

considered by this chapter:

Table 5-8 Consultation Responses

Consultee Summary response Measures taken to address this

response

MMO Sampling and analysis is to be undertaken by Cefas as

part of the Marine Licence application.

Given the information available to date OSPAR

guidelines suggest sampling at 3 locations within the

proposed area to be dredged. Samples should be taken

at surface and every 1m for every meter to be dredged.

The applicant should follow the guidance on the MMO

website

(http://www.marinemanagement.org.uk/licensing/how/sa

mple_analysis.htm) to ascertain analytical requirements.

Sampling was carried out by Fugro in the

course of the site investigation, and

samples submitted to the Cefas

laboratory in accordance with their

guidance. None of the samples analysed

were subject to ‘non-conformity’.

Alternative waste disposal options must be considered Consultation was carried out with local

community groups (Local Authorities,

Tamar Group) to try to identify any local

projects for which the waste arisings may

be of use – none was identified.

Consultation with local waste treatment

and disposal contractors indicated that

significant large scale near site (on the

near shore) temporary works would be

required in order to make the arisings

acceptable to them.

The water quality section needs to include the other

water quality issues from general construction, including

use of machinery near water courses and risk of

sediment run off from land construction site. The project

will require the preparation of a Construction

Environment Management Plan prior to commencement

of works.

Addressed in Section 5.5.1

Consideration is required of the potential impacts on

water quality and designated sites from contamination

within the sediment. If levels of contamination are

significant and potential impacts are identified suitable

methods and mitigation measures must be incorporated

for all stages of the project.

Addressed through intrusive investigation

and risk assessment outlined in this

Chapter

If an Environment Agency water discharge activity

permit is required the EIA will need to address the

requirements needed of the permit.

No particular requirement needed over

and above the standard permit conditions

assessed necessary by the EA.

EA No comment in relation to this chapter


In addition, the following requests were put to Cefas by Hyder through MMO. Their responses

are provided below.

Request to Cefas Cefas Response

Are you content that sufficient sampling and

analysis has been carried out to characterise

the dredge areas?

Based on the sediment/soil chemical analysis

results, do you concur that dredge arisings

are suitable for disposal at sea?

‘In summary, the results show that material from the sample

locations highlighted in yellow on the attached map are not

acceptable for disposal to sea, therefore two exclusion zones have

been delineated on the attached map (shown as red lines) and I

recommend material from these areas is not permitted to be

disposed of at sea. Sediments from the exclusion zones would

need to be disposed of on land or alternatively used. The material

from the remaining areas, shown on the attached map, have

acceptable levels of contaminants and therefore this material can

be disposed to sea.’ (Email 20/1/14). Hyder note - Plan provided

by Cefas shows exclusion zone around MBH08 at 3m. This is the

only exclusion zone relevant to the proposed development area.

Dredging in this area will be above this depth (and other samples

indicate that the sediment is no impacted at these depths) and

therefore this exclusion zone only applies to piling.

‘Extension of the existing jetty dredge box north with associated

capital dredge of 16,000m3. This area has recently been

characterised (sampling stations DBH03 and DBH04) and

therefore does not require further sampling.’ (Email 26/3/14)

With respect to the western dredge area - ‘I am content that the

samples are representative of the dredge area and that the

material from this location (surface to 2.5m depth) is suitable for

disposal to sea.’ (Email 30/9/14)

With respect to localised areas where the dredge depth will extend

to upto 2.8m - ‘Cefas recommend that a 0.5m buffer is required

when dredging material close to contaminated material. However,

this is recognising errors on the actual depth of the sample and the

dredge, therefore I would recommend that mitigation i.e. closed

buckets could be employed in this area to minimise any re-

suspension of contaminated sediment.’ (Email 28/10/14)

We are considering changing the location of

the proposed jetty. Are you content that the

information from the site investigation is

sufficient to characterise the pile arisings?

‘I am content that this area has been characterised sufficiently for

contamination purposes and given the small volume of material

(250m3) associated with the jetty structure and dolphins, no further

sampling and sample analysis is required.’ (Email 5/8/14)

5.3.6 Limitations and Assumptions

The approach adopted by Hyder for the investigation and assessment of contamination at the

site is based on an evaluation of the methodologies currently available, to decide which are

most applicable to the site conditions and proposed end-use. No responsibility can be accepted

for future changes in legislation or guidance that may affect the approach used or the findings of

this report.

This report has been compiled using information from a number of sources, which Hyder

believes to be trustworthy. However, Hyder is unable to guarantee the accuracy of information

provided by others. This report is based on information available at the time of writing.


Consequently, there is potential for further information to become available which may affect the

conclusions drawn in this report, for which Hyder cannot be held responsible.

It should be noted that, due to the nature of a ground investigation, the ground conditions

between exploratory holes might vary from those identified. The coverage and scope of the

investigation was designed based on the information available at the time and current best

practice and is considered suitable to provide a good representation of the site. Since

undertaking the marine surveys, the development proposals have changed. However, the area

surveyed effectively covered the revised Development footprint and is considered suitable to

represent the proposed development.

5.4 Description of the Baseline Conditions

5.4.1 Environmental Setting

Geology

The British Geological Survey (BGS) geological map for the area (Ref. 5-3) indicates that the

site is underlain by Upper Devonian Slates.

Previous site investigation information (Soil Mechanics 1984 – Ref. 5-4) has been provided by

the Client, which includes logs for five boreholes drilled in a line perpendicular to the shore and

parallel to the existing jetty. This information is included in Appendix 5-B. The information gives

an indication of the depth of the sediment and soft soils above the bedrock level at that time, as

well as the nature of the soft and hard superficial strata in a progression from the foreshore out

towards the centre of the river to the proposed extent of the new jetty. The logs indicate that the

superficial soils are between 0.5m thick near to the foreshore, generally approximately 3.5m –

4.5m thick along the length of the jetty and up to 12m thick at the furthest extent of the proposed

jetty.

During a site investigation carried out by Hyder in August 2013, in which fifteen boreholes were

drilled, it was found that there is a steep rock escarpment semi parallel with the proposed line of

the jetty head.

The thickness of the river sediment deposits in the shallow boreholes drilled in the area to be

dredged was generally found to be greater than 3m. The thickness was proved in one borehole

(MBH08) approximately 8m from the outer edge of the proposed jetty head location as being

approximately 5.0m below the sediment level (bsl). However, a further borehole (MBH10) to the

north and along strike of the proposed jetty location proved a thicknesses of sediment down to

20.8mbsl indicating that there is a steep scarp slope leading to variable depths across a short

distance.

The top of the slate was encountered at depths of between 7.45mbsl and 20.4mbsl to the north

and west of the proposed jetty head location indicating that there may be a fault zone to the

north of the study site. Borehole BHG of the 1984 Soil Mechanics investigation indicated the

depth to slate as 4.3mbsl. The thickness of sediment deposits to the north of the proposed jetty

approach in MBH01 is approximately 5.2mbsl.

The sediment/superficial deposits are described in both investigations as comprising very soft or

soft organic slightly sandy (fine) silty clay or clayey silt with occasional shells. This is underlain

by weathered slates at the depths indicated above, the description of this bedrock strata

indicating that the competency of the rock generally increases with depth and with an

associated reduction in weathering.


The slates beneath the site are classified by the EA as a Secondary Aquifer but any

groundwater in the vicinity will have been impacted by saline water and public register

information (Appendix 5-C) indicates that there are no groundwater abstractions within 1km of

the site. Water abstraction licences listed are from the River Tamar.

Hydrology and Sensitive Receptors

Surface water features local to the site are illustrated in Drawing 5-1. The site lies within the

Hamoaze reach of the estuary of the River Tamar, which represents a sensitive receptor with

regard to surface water quality. Due to the flow dynamics of the estuary water quality both

upstream and downstream of the construction site has the potential to be affected. As

discussed in Chapter 6 Ecology, the proposed development site is located within the Plymouth

Sound and Estuaries SAC, designated for estuarine habitats and migratory fish species. In

addition it is approximately 1.5km away from the Tamar Estuaries Complex SPA, designated for

internationally important populations of wintering and on-passage birds. There are also two

MCZs within the vicinity of the project (Drawing 1-4); Tamar Estuary Sites to the north and

Whitsand and Looe Bay to the south. These MCZs were designated under the Marine and

Coastal Access Act 2009 (w-3). Of particular note to this study is the importance of the estuary

to migratory fish which are sensitive to changes in water quality.

On this basis the River Tamar is assessed as being of very high sensitivity.

There are no other surface water receptors within the study area, with the closest surface water

body being located approximately 100m to the south of Yonderberry Point. This is a creek that

drains an area of mudflat known as the Thanckes Lake.

5.4.2 Potential Sources of Contamination

Surrounding Historical and Recent Land Use

The following potential primary sources of contamination have been identified and are

discussed below:

• Thanckes OFD

• Naval Dockyard Activities

• Historical industrial activities including – mining, boat/ship building and maintenance,

fishing, agriculture

• Recent industrial activities – including discharge of waste water, pollution incidents,

current industrial activities

Thanckes Oil Fuel Depot (OFD)

The following information has been obtained from an Environmental Risk Assessment carried

out for Thanckes OFD by the MOD Environmental Science Group in May 2008 (Ref 5-6), and a

draft desk study Land Quality Assessment (LQA) report produced by SKM Enviros in 2013 (Ref.

5-6). These reports were produced to identify potential environmental hazards, and to assist in

the environmental management of the site. We have used the relevant information to identify

potential contaminants used and stored on the Thanckes OFD site which may have impacted

the sediment and soils in the area of interest.

The following is a list of the most likely potential contaminants which could be present due to

activities on the Thanckes OFD site.


These include:

• Petroleum hydrocarbons and mineral oils – diesel, aviation fuel, fuel oil, contaminated

waste water from ships (sullage)

• Polychlorinated biphenyls (PCB) – in conducting oils formerly used in electrical

equipment

• Polycyclic aromatic hydrocarbons (PAH) - various industrial processes associated with

partial combustion.

Other hazardous substances stored in significant quantities at Thanckes OFD include the

following:

• Fire fighting foam / Film Forming Fluoro Protein (FFFP)

• Gas oil marker concentrate

• Antifreeze

The 2013 LQA report produced by SKM Enviros concluded that the potential risk to surface

water from the storage of these other hazardous substances is ‘low’. This assessment has

been reached as these substances are stored in lesser quantities in drums and Intermediate

Bulk Containers (IBCs). Materials are generally stored in buildings with concrete floors although

not all have secondary containment. There are no recorded incidences of hazardous

substances being discharged to ground.

Dockyard Activities

We have referred to the Department of the Environment Industry Profile for Dockyards and

Dockland (Ref. 5-7) to provide general information on the type of contaminants which may be

associated with dockyard activities. We have also referred to a report produced by Babcock

Marine on the environmental monitoring of radioactivity around Devonport Dockyard (Ref. 5-8).

Identified potential contaminants from Devonport Dockyard include:

• Metals, including tin compounds – from paint and anti-foul, in fuel, spillage of cargo

(including metal ores and coal/coke), timber treatment, metal working

• Petroleum hydrocarbons and mineral oil – storage and use of fuel, lubricating oils,

hydraulic oils, paint, tar

• Pesticide – timber treatment and storage

• PCBs – formerly used in conducting oils within electricity substations and transformers

• PAHs including phenols – rope and sail making (treatment with tar), industrial

processing including partial combustion

• Radionucleides – used to power submarines. Including tritium, cobalt-60, carbon-14.

Historical Activities

Study of historical maps indicates that there have been the following potentially contaminative

activities which have the potential to have impacted the site, either because they are


downstream and near, or upstream of the area of interest. Consideration has also been given to

the tidal nature of the river at this location.

The historical maps are reproduced in Appendix 5-D.

Table 5-9 Summary of Historical Potential Sources of Contamination

Activity Date Approximate Distance

and Location

Potential / Likely Contaminants

Smith’s Shop 1867 875m ESE, downstream Metals, hydrocarbons

Gas and coke works 1867 875m ESE, downstream Metals, hydrocarbons, sulphur

compounds, cyanide compounds,

phenols, alkali, acid

Dock yard 1867 675m ESE, downstream Metals, hydrocarbons

Quarries 1867 1km NE, upstream Metals, hydrocarbons

Keyham chemical works 1867 1.5km NE, upstream Metals, hydrocarbons, solvents,

other

Sawmill 1888 1.1km NE, upstream Metals, hydrocarbons

Chemical works 1888 1.1km S, downstream Metals, hydrocarbons, solvents,

other

Gas works (Torpoint) 1888 1km S, downstream Metals, hydrocarbons, sulphur

compounds, phenols, cyanide

compounds, alkali, acid

Dock yard expansion 1907 500m E, upstream Metals, hydrocarbons, solvents,

radionuclides

Thanckes OFD constructed

(Ref. 5-6)

1920 100m W, upstream Metals, hydrocarbons

In addition to the sources identified on the historical maps, it is known that the land and water

around the site have, for many centuries, been used for farming, fishing and mining. The most

likely potential contaminants associated with these activities include metals, hydrocarbons,

pesticides, ammonia, and phosphate.

Recent Activities

Study of public register information indicates that there have been the following potentially

contaminative activities which have the potential to have impacted the site, either because they

are downstream and near, or upstream of the area of interest. Consideration has also been

given to the tidal nature of the river at this location.

The public register information is reproduced in Appendix 5-C.


Table 5-10 Summary of Recent Potential Sources of Contamination

Activity Details Approximate Distance and

Location

Discharge Consent

(current)

From Thanckes OFD for trade

effluent into the Tamar Estuary /

Hamoaze

Discharge point marked on the

existing jetty

~20m S, downstream

Discharge Consent

(current)


effluent / site drainage into the

Tamar Estuary / Hamoaze

Discharge point marked at root of

existing jetty

~30m S, downstream

Discharge Consents

(discontinued)


effluent / site drainage into the

Tamar Estuary / Hamoaze.

Surrendered 2010

Discharge points marked on

northern shore of OFD Thanckes.

~560-800m NW, upstream

Discharge Consents

(current and discontinued)

From Devonport Dockyard for trade

effluent, site drainage and sewage

into the Tamar Estuary / Hamoaze

Discharge points marked

throughout dockyard area.

~525-1000m E, up and downstream

Discharge Consents

(current and discontinued)

Held by South West Water for

treated sewage and trade effluent

and surface water

~530-1000m NW, SW, E, up and

downstream

Integrated Pollution

Prevention Control (IPPC)

permit

For Thanckes OFD for disposal of

waste oil >10 tonnes/day

Immediately west of site

Pollution incidents to

controlled waters

8 incidents recorded. 7 minor

incidents, 1 significant incident (at

Devonport Dockyard, ‘other

chemicals’, 1993). Oil, sewage,

other chemicals, algae. 1993-1995

listed

~525-910m, up and downstream

Landfill Former site at Torpoint. Multiple

waste types allowed. Closed prior to

1993.

~525m SW

Drain from landfill ~180m SW,

downstream

Waste management facility Thanckes OFD. Processing of

waste oil.

~150m W, upstream

The discharges from Thanckes OFD have the potential to have included fuel. The discharges

from Devonport Dockyard have the potential to have included those chemicals outlined above,

including fuel and radionuclides.

There are other discharge consents within 1km of the site, held by private individuals for

domestic sewage disposal. These are considered unlikely to have had a significant impact on

the site conditions.

The Contemporary Trade Directory indicates that there are numerous small businesses which

carry out potentially contaminative activities (e.g. garages, printers etc.). Any pollution of the

ground from these features is unlikely to have been sufficiently gross to have significantly


impacted the River Tamar, and therefore the area of interest. This assumption is supported by

the pollution incident records.

Potential Secondary Sources / Likely Contaminants

Contaminants which are considered most likely to be present in the sediments in significant

concentrations are listed below:

• Petroleum hydrocarbons and mineral oils

• PCBs

• PAHs

• Phenols

• Metals, including tin compounds

OSPAR guidance (Ref. 5-9), used by MMO and Cefas to regulate the protection of the marine

environment, indicates that PAH, PCB, and metals are of particular concern with respect to the

marine environment. Various research documents (Refs. 5-2, 5-10, 5-11) indicate that metals

including tin compounds, PAH and PCB are of particular concern in the Tamar estuary and

Plymouth Sound area. Several of these substances (PAH, metals) are also defined as WFD

Priority Substances, which are deemed harmful to the water environment.

Radionuclides could be present but it is unlikely that these would be at significant levels as they

are closely monitored and regulated through the discharge permitting process.

5.4.3 Surface Water Quality

The Hamoaze forms part of the Plymouth Sound Water Body, which is monitored for chemical

and ecological quality under the requirements of the WFD. This water body is designated as

heavily modified, due to substantial changes to its physical character resulting from physical

alterations caused by human use. As a result it has an objective status of ‘Good’ ecological

potential and currently achieves this status.

However Plymouth Sound does not meet the acceptable standards for chemistry and is classed

as failing the requirements of the WFD for chemical water quality. This failure is based on

threshold exceedance of Tributyltin compounds, which are defined by the Directive as a Priority

Hazardous substance. Further details are included in the WFD Assessment provided in

Appendix 5-A, which has screened the proposed development against WFD objectives.

Results from National Monitoring Programme surveys conducted between 1992 and 1995

revealed no evidence that Environmental Quality Standards (EQS) for Cadmium (Cd), Copper

(Cu), Nickel (Ni), Lead (Pb), and Zinc (Zn) were exceeded. The EQS for Tributyltin (TBT) was

often exceeded. Little TBT was found to enter the estuarine system from freshwater inputs i.e.

the Rivers Tamar, Tavy and Lynher which were all found to have annual concentrations of TBT

below the limit of detection, indicating that the EQS exceedance is attributable to sources within

the estuary.

The Tamar Estuaries Management Plan 2013 to 2018 identifies marine litter as a problem that

impacts on the water environment, and other sources of pollution reported as agricultural runoff

and point source discharges. The Tamar Estuaries Consultative Forum list disturbance of

contaminated sediments due to dredging as a potential challenge to achieving good estuarine

water quality.


There are no designated Bathing Waters or Shellfish Waters within the study area, defined as a

1km radius around the proposed new jetty as illustrated in Drawing 5.1, although the

development lies within 3km of the Designated Shellfish Waters of the Lynher and the Classified

Bivalve Mollusc Harvesting Area in the Tamar.

5.4.4 Sediment Quality

The existing sediment quality has been ascertained through the following information sources:

• Baseline Document for Maintenance Dredging in Plymouth Sound and Estuaries

European Marine Site (Black and Veatch) - 2011 (Ref. 5-2)

• Dredged sediment analysis for the existing Yonderberry Jetty (Cefas) – 2004 and 2006

(data tables provided by the Client)

• Sediment analysis of samples from on site and to the north of the site (Hyder) – June

and August 2013.

• This investigation work included the drilling of boreholes and the taking of near surface

‘grab’ sediment samples from twenty four locations on and to the north of the site, and

the analysis of up to thirty nine sediment samples for total concentrations of

determinands and eight for leachable concentrations.

The boreholes located within the site area include DBH03 and DBH04 which are in the

area of the eastern jetty approach which will require dredging, MBH03, MBH10 and

MBH07 which are near to the proposed northern dolphins, and MBH08 at the location of

the jetty head. MBH02, MBH03, MBH07, MBH08, and MBH11 are in or near the area of

the northern/western jetty approach.

The locations on or very close to the area of interest from which samples were analysed

include MBH02, MBH03, MBH08, DBH03, and DBH04, and tritium in a grab sample

taken from Sample Site 8. A total of nineteen samples were analysed from these

locations.

• The samples were variously analysed for metals including tin compounds and

hexavalent chromium, total petroleum hydrocarbons (TPH), mineral oil, semi volatile

organic compounds including PAH and phenols, PCB, pH and organic matter. Two

samples (combined) were analysed for tritium.

• The leachability testing was carried out using a matrix based on the likely salinity of the

estuary in order to represent (as closely as possible) the conditions on the site. The one

sample tested from the site in June 2013 was leached using a matrix which had a pH of

6.4 which is probably too low to be representative of the estuary but would indicate the

worst case for leachability of metals which will leach more easily in acidic conditions.

The two samples tested from on site in the August 2013 investigation were leached with

a matrix at a pH of 8.5 which is more representative of the likely estuarine conditions.

The leachate samples were analysed for the same determinands as above, plus one

combined sample for tritium.

• These determinands are considered to be the most likely to be present and are also

those which are of the greatest concern to the UK marine environment. In discussion

with the Cefas laboratory with respect to determinands which require investigation to

support a dredging licence application, they indicated that radionuclides would not

normally be analysed as this is regulated under the discharge permitting system. The


tritium analysis carried out was to test our assumption that this is unlikely to be present

at significant levels.

The data from the first two information sources listed above, summarising the results of

sediment chemical analysis in the River Tamar and Plymouth Sound, are included in Appendix

5-E. (Note: some of the highlighting in the tables is incorrect). The chemical analysis data

produced by sediment sampling at the site in June and August 2013 is included in Appendix 5-

F.

Drawings showing the locations of the sediment sampling are included as Drawing 5.2, showing

the locations of the June ‘grab’ samples, and Drawing 5.3 showing the proposed jetty borehole

location plan. The locations of the samples taken were targeted at the anticipated location and

configuration of the proposed jetty at that time. This has changed but the results are still

applicable to assessment of the dredge arisings from the jetty approach, and to the arisings

from the piles.

In order to provide an indication of the significance of the total concentrations found in the

sediment samples, the data has been compared to OSPAR/MMO Action Levels (AL) (Refs. 5-9

and 5-12). In the absence of a UK Action Level, Canadian guidance values have been used

(Ref. 5-13), namely threshold effect levels (TELs) and probable effect levels (PELs). The

leachate sample analysis results have been compared to European EQS for saltwater. The UK

Action Levels and Canadian Effect Levels are provided in Appendix 5-G, but a brief explanation

is given below.

• Below Cefas Action Level One (AL1): In general, contaminant levels in dredged material

below Action Level 1 are of no concern and are unlikely to influence the licensing decision.

• Between Cefas Action Levels One (AL1) and Two (AL2): Dredged material with

contaminant levels between AL1 and AL2 requires further consideration and testing before

a decision will be made (e.g. other factors would be considered, such as the sensitivity of

the disposal site, leachability analysis etc).

• Above Cefas Action Level Two (AL2): Dredged material with contaminant levels above

AL2 is considered unsuitable for sea disposal. This most often applies only to a part of a

proposed dredging area and so that area can be excluded from disposal at sea and

disposed of by other routes, e.g. landfill.

• Below the Canadian TEL; the minimal effect range within which adverse effects rarely

occur.

• Between the Canadian TEL and PEL; the possible effect range within which adverse

effects occasionally occur.

• Above the Canadian PEL; the probable effect range within which adverse effects

frequently occur.

The general background information for the River Tamar and Plymouth Sound indicates that;

• In summary, elevated concentrations of metals including tin compounds, PAH and PCB

are found widespread throughout the area.

• The 2011 data indicates average concentrations greater than AL2 were found in the

dockyard for arsenic, cadmium, mercury, zinc and PCB. In the River Tamar and at

Carbeile Mill average concentrations were found to be above AL1, but not AL2, for

arsenic, cadmium, chromium, mercury, lead, zinc, tin compounds and PCB. When


compared to Canadian Effect Levels, several PAH compounds were found to be above

the higher ‘probable effect levels’.

• In 2004, samples taken at Yonderberry Jetty were tested for PCB and tin compounds.

Neither showed concentrations greater than AL2, and the individual PCB compounds

were no greater than the AL1 for total PCB.

• In 2006, concentrations in samples taken from Yonderberry Jetty were above AL1 for

arsenic, mercury, copper, nickel, lead, and zinc. They were not elevated i.e. below AL1,

for tin compounds. When compared to Canadian Effect Levels, several PAH

compounds were found to be above the higher ‘probable effect levels’.

The data from the analysis of sediment samples taken from the site area (in June and August

2013) shows;

Leachable Concentrations

• Neither of the two samples (MBH08 0.6m and 5.0m) analysed from the site area

showed elevated concentrations of the determinands tested when compared to EQS for

“other surface waters” (including the marine and estuarine environment).

• The leachate analysis showed no detectable concentrations for the majority of

hydrocarbon determinands, including PCB and PAH compounds. Concentrations

greater than the laboratory detection limits were found for mineral oils in MBH08 5m

(28ug/l). There is no EQS for hydrocarbons of this type, but these are not considered to

be of significantly high concentrations and are likely to be associated with natural

organic matter accumulated at the interface between the river deposits and the top of

the slate encountered at this depth in the borehole.

• Two samples (combined from grab samples taken from Sites 8 and 10) analysed for

tritium showed no detectable concentration.

Total Concentrations in Sediment

The following provides a summary of the analysis results when compared to the guideline

criteria for disposal of sediment at sea. It should be noted that the samples were analysed at

two different laboratories using different techniques and therefore there is potential for different

readings to be obtained due to this factor rather than a reflection of the actual soil conditions. In

this section we have reviewed all of the data together in order to provide a general impression of

the conditions on the site.

• In the sixteen samples analysed from the site area for metals, several of the metal

determinands show total concentrations greater than the AL1, but not greater than the

AL2. These include arsenic (6 samples), cadmium (9 samples), total chromium (1

samples), copper (7 samples), lead (7 samples), nickel (15 samples), tributyltin (1

sample) and zinc (6 samples).

• One of the sixteen samples analysed for arsenic showed concentrations greater than

AL2. This was taken from MBH08 3.0m. A sample taken from MBH02 3.0-3.8m showed

a concentration above the AL2 in one test (140mg/kg), but a duplicate test showed a

concentration much below the AL2 of 9.9mg/kg. All other metals were below the AL2.

• One sample (MBH08 3.0m) showed a concentration for the sum of 25 PCB congeners

of 0.5mg/kg, greater than the AL2 of 0.2mg/kg. Six of the seventeen samples analysed

showed concentrations greater than the AL1 but less than the AL2. PCB strongly sorbs


to cohesive sediments and therefore is not easily mobilised into water. This isolated

marginally elevated concentration is therefore not considered to be indicative of a

significant hazard. This is reinforced by the lack of PCB found in the leachate samples.

• Four of the fifteen samples analysed for PAH compounds showed concentrations

greater than the PELs for ten of the sixteen compounds tested. This is not considered to

be indicative of widespread significant contamination with potential to impact water

quality, and this conclusion is supported by the lack of PAH compounds found in the

leachate samples.

• Seven samples were tested for TPH and ten for Total Hydrocarbon Content (THC). The

TPH analysis showed detectable concentrations only in the carbon range C16-40 in

three of the five samples, and the THC analysis showed notable concentrations (greater

than 10mg/kg) in six of the samples analysed. The maximum detectable TPH

concentration was 89mg/kg (MBH08 3.5m) and the maximum b concentration was

1,750mg/kg (MBH08 3.0m)

There is no UK or Canadian guidance value for TPH in the marine environment, and

therefore it is difficult to assess the significance of these concentrations. However, in

general terms these concentrations are low when compared to criteria for land based

assessment, and it is of note that the leachability testing showed no leachable

concentrations.

Summary

The concentrations found on the site in the sediment analysis, are consistent with the

concentrations found elsewhere in vicinity of the site.

Evidence of metals, PCB and PAH compounds were found as total concentrations in the

sediment samples across the site, the majority at concentrations below the upper guideline

limits.

The only exceedances of the upper limits were for arsenic and PCB 25 found in the sample

taken from MBH08 3.0m, and from one of two samples analysed from MBH02 3.0-

3.8m. MBH08 is located at the proposed jetty head and therefore this is of relevance to arisings

from pile drilling in this area. The dredge depth for the northern/western channel is shallower

than 3m and therefore it is concluded that the sediment mass which will be dredged has not

been impacted.

The samples did not show any elevated concentrations in the leachate analysis indicating that

they are not readily leachable into the estuarine waters.

5.4.5 Conceptual Site Model and Risk Assessment

During Construction Phase

Sources

Contaminated Sediment

The potential source of impact addressed here is the release of contaminants from the sediment

beneath the site. The construction works will inevitably lead to disturbance of the near surface

sediments, and the drilling of piles will bring deeper sediment and soil to the surface where it will

be deposited.


Analysis carried out to date indicates that the sediment has some elevated concentrations of

metals, PAH and PCB compounds, above lower action/effect levels but generally below upper

action/effect levels, but that there is a very low potential for these contaminants to be leached

into the water.

It is of note that the leachability analysis was completed using a saline matrix at a pH

representative of marine conditions, and the sediment sample was agitated in the leachate

matrix.

The concentrations found in the sediment samples on the site are consistent with those found

elsewhere in the estuary near to the site, and the site works activities proposed are similar to

those carried out nearby.

During the construction works, disturbance of the sediment at any one location will be of short

duration so that any locally elevated concentrations not identified will have limited temporal

impact.

Receptors

The primary receptor of consideration in this assessment is surface water quality in the River

Tamar, and whether it could be significantly changed by the proposed development. This

receptor is assessed as being of very high sensitivity due to its SAC designated status

associated with water based sensitive habitats and the nearby SPA associated with protected

birds which rely on the water environment habitats.

Secondary potential receptors are the ecological systems of the estuary, and people coming

into contact with water. The critical receptors are:

• The flora and fauna in the surrounding ecologically protected area (absorption, uptake).

In particular, protected fish species, marine mammals and protected flora. The risk to

ecological systems is discussed in Chapter 6.

• People coming into contact with the water (ingestion, dermal contact, inhalation of water

vapour).

Pathways

The pathway for potential impact on the quality of surface water due to contaminants in the

sediment/soil is through;

• dissolution of contaminants out of sediment/soil,

• suspension of contaminated or non-contaminated particulates, and

• subsequent migration up or downstream of the site (through convection) due to wave,

wind and tidal action.

It is important to note that the baseline sediment and water quality data shows that:

• there are already elevated concentrations of metals and hydrocarbon concentrations

in the water so that any small dissolution of contaminant during the construction works

is unlikely to have a significant impact.

• The presence of contaminants in the sediment means that there is a theoretical

potential for disturbance of the sediment to lead to their release into the water.


Leachability testing indicates that this is unlikely to occur as dissolved phase

contamination, but particulate transport cannot be ruled out.

Table 5-11summarises the assessment of the risk posed by the potential source-pathway-

receptor pollution linkage identified above. The mitigation measures which will be included at

each stage of the proposed construction are discussed in Section 5.5.

Table 5-11 Summary of Contamination Risk Assessment

Potential

Source

Potential

Receptor

Consequence Probability

(without mitigation)

Risk

Contaminated

Sediment

Metals,

hydrocarbons

Surface water

quality

Medium – the

surface water is

important for

ecological

receptors and is

assessed as

being of very

high sensitivity

Low likelihood – some elevated

concentrations have been found

but these are consistent with

levels in the surrounding area and

the proposed activity will be short

lived and is similar to that carried

out nearby.

Moderate/Low –

mitigation measures

should be considered

and are discussed below

Human Health Mild Low likelihood – the river is used

for water sports so that exposure

could occur but concentrations are

unlikely to be very high

Low – mitigation

measures to protect

surface water will also

reduce any residual risk

to human health

During Operational Phase

The proposed location and design of the jetty will not increase the potential risk to the

environment over and above that posed by the existing jetty. The potentially contaminating

activities carried out on the proposed jetty will be the same as for the existing i.e. receiving and

delivering fuel and the possible rare use of fire fighting foam. The risk will inherently be reduced

by the new and improved infrastructure.

5.5 Design and Mitigation

The following section outlines the identified activities which may lead to an effect during the

construction and operational phases, and the design and mitigation measures which are

anticipated at this stage. Construction may have implications for the physico-chemical quality of

waters downstream of the construction works, with potential for impacts on riverine habitats and

species, as detailed in Chapter 6 Ecology.

5.5.1 During Construction Phase

Prior to construction a Construction Environmental Management Plan (CEMP) will be prepared

that will incorporate environmental mitigation measures and procedures including Pollution

Prevention and Management Plans and Method Statements to include surface water protection.

The CEMP will take cognisance of the Water Resources Act (OPSI, 1991), EA guidance

(including Pollution Prevention Guidelines) and CIRIA guidance (CIRIA 2005 & 2001) (Refs 5-

14, 15, 16 and 17).

Disturbance of Sediment and Piling Activities

Construction activities have the potential to temporarily add significant sediment loads local to

the particular activity due to the disturbance of river bed materials/existing deposits of sediment


and silt. During the construction work there will be some activities which require contact with the

river bed and/or may cause considerable disturbance of the water, both of which may

encourage near surface sediment to become suspended in the water column. This may have an

impact either through mobilising contaminants, or through increasing turbidity and thereby

resettlement on the river bed impacting benthic flora and fauna. Due to the size of the river and

the river flow rates it is considered unlikely that this effect would be widespread.

The installation of piles for the proposed mooring dolphins, along the jetty approach and at the

jetty head has the potential to disturb sediments, and will lead to the production of arisings.

During the construction works measures will be taken to minimise disturbance of the sediment,

and to contain the migration of sediment. These will include:

• Taking additional precautionary measures while working in any locations identified as

having elevated concentrations of contaminants and where there is potential for

sensitive receptors at that location to be impacted(this is discussed further in the

ecology assessment in Chapter 6). Mitigation measures will depend on the activity

being carried out and the machinery being used. The elevated concentrations of arsenic

and PCB 25 (that is those greater than AL2) were only identified in borehole MBH08 so

that particular mitigation measures will be focussed on this location.

• Minimise as far as possible the extent of work requiring contact with the river bed.

• Ensuring the contractor uses methods which will minimise sediment disturbance,

sediment migration and arisings. This includes ensuring that best practice and available

plant are used in the design and execution of the works. This will include standard

measures such suction dredging plant, and flush containment and collection during

piling.

Use and Storage of Contaminating Substances

During the construction period it is anticipated that there will be bulk storage and use of

contaminative substances on the site, both on the land and on the river. These are likely to

include fuel, lubricating oils, antifreeze and hydraulic oils for machinery. Also, the use of

construction materials such as cements and concrete and generated construction wastes (solid

waste and wastewater). Risks of pollution are associated, for example, with the emptying and

flushing of existing fuel and sullage pipelines during demolition of the existing jetty, operation of

two land based site compounds, accidental spills/leaks, and inappropriate storage or disposal of

these materials.

Measures will be taken to ensure that contaminating substances are properly contained, during

storage and use, both in the marine operations and the land operations. These include:

• Pollution Prevention Guidelines 5 (PPG5) published by the Environment Agency, 2007,

for Working In or Near a Watercourse will be followed as a minimum standard. This

includes recommendations for fuel containment and the use of less hazardous types of

machinery oil.

• All bulk storage of fuel, oils and other contaminating substances will include secondary

containment. Emergency spill/leak containment kits will be available throughout the

construction site where contaminative substances are being used or transported. An

emergency spill response procedure will be put in place and conveyed to all site staff.

• Best practice procedures will be used to contain potentially contaminating substances

during the demolition of the existing jetty structures and construction of new jetty

structures.


• Refuelling, repair and maintenance of land based construction plant will be carried out

within a designated bunded area to avoid pollution from spillages and leaks.

• Measures will also be put in place to contain all demolition and construction wastes, to

prevent waste falling onto the estuary bed or into the water column.

Sediment Run-off from the Land

Where land-based construction activities are undertaken, activities such as stripping of

vegetation, stockpiling of soils and disturbance of soils in combination with flows of surface

water runoff across the works areas have the potential to generate runoff that is high in silt and

particulates.

During construction, best practice will be used to ensure that excess sediment/soil run off from

the land construction site does not occur. Controlling measures will include:

• Carry out site investigation in the locations affected by the proposed development,

including chemical analysis of soil samples. Where significantly elevated concentrations

(assessed based on current UK guidance and regulation) of determinands are identified

additional remediation measures will be taken. Depending on the volume of soil

impacted, this could include removal and off-site disposal of the impacted soils, or local

containment.

• A Drainage Management Plan will be produced to ensure that surface water runoff from

construction compounds is appropriately managed and treated prior to entering into any

waterbody.

• Containment of soil stockpiles.

• Hardstanding and roads will be cleaned frequently where soil is being deposited from

vehicles.

• Cleaning of vehicles and equipment will be carried out in an area with drainage

containment.

Waste Soil/Sediment

The proposed development requires the dredging of up to 2.5m of sediment from the area in

front of the northern dolphins on the east side of the jetty. At the time of writing this report the

volume of sediment arisings from the dredging is estimated to be approximately 18,000m3

(subject to confirmation at detailed design stage). Sediment samples were taken from two

locations within the proposed dredge area (DBH03 and DBH04), at metre intervals through the

proposed dredge depth at each location, as advised by Cefas, in order to characterise the

dredge materials. Sediment samples were taken and stored in accordance with Cefas guidance

and were submitted to Cefas for analysis.

In addition, approximately 18,000m3 (subject to confirmation at detailed design stage) of

sediment will be dredged from the western side of the jetty up to a depth of 2.5m. The ten

samples analysed from MBH02, MBH03 and MBH08 are considered to be most representative

of the dredge arisings from this area.

The drilling of the piles which will support the structure is likely to be carried out using a method

which requires the removal of sediment and soils. Representative samples were analysed from

varying depths throughout the different strata from 1m to 9m (refer to the results in Appendix 5-

F). It is considered that the likelihood of there being significant levels of contaminants with

potential to be mobilised below a depth of 10m is low, not least because the vast majority of the


piles are anticipated to be in the rock below this depth. Arisings from the bedrock are likely to

comprise silty sandy gravel. The proportion of the piles in the river deposits (sediment) and in

the rock is estimated to be 52% and 48% respectively.

European and UK legislation and guidance on waste management requires that a waste

producer must take measures to reduce and reuse waste, and that disposal is only a last resort.

Consultation with MMO has indicated that disposal of sediment at sea should be avoided where

possible and consideration should be given to reuse or disposal elsewhere.

In the course of this study we have consulted with the relevant Local Authorities, statutory

bodies, the Tamar Estuaries Consultative Forum, and with the MOD agencies to identify any

development projects proposed in the local area which may benefit from the sediment/soil

arising from the jetty construction. To date, no suitable scheme has been identified but this

process will continue later in the construction period.

We have also consulted with waste management companies who operate waste treatment and

disposal facilities in the local area. There are two or three locations within Devon and Cornwall

where dredge arisings can be accepted and used for restoration purposes. However, the

dredged sediment straight from the river would have to be sufficiently dried before it could be

transported and before it would be acceptable to be received by these sites. This would require

a considerable logistical and economical challenge and it is considered that the environmental

impact of the treatment and transport process would outweigh the benefit of avoiding disposal at

sea.

The following provides discussion of the different options for managing the soil/sediment

arisings based on the information available at present.

Disposal at Sea

The results of chemical analysis of sediment samples carried out by Hyder in June and August

2013 have been reviewed with reference to criteria defined by MMO and Cefas in order to

ascertain whether disposal at sea is likely to be considered appropriate.

This review has found that only the sample taken from MBH08 3.0m shows concentrations

greater than the upper criteria, and that the samples taken from the area to be dredged at the

northern end of the jetty approach pocket do not show elevated concentrations.

Through our review of the analysis results, and consultation with Cefas it has been concluded

that the arisings from the piles near to MBH08 are not suitable for disposal at sea and is not

suitable for side casting/depositing in the site area. Therefore pile arisings from within the

exclusion zone will be collected and disposed of differently, as discussed below.

For the remainder of the pile arisings (estimated as approximately 250m3), based on the

chemical analysis data reviewed from ground investigation work, the relatively small total

volume, and using the mitigation measures outlined above, it is concluded that these arisings

will be deposited immediately around each pile location. This is common practice, has been

used on other projects in the Tamar Estuary, and is generally not considered an issue with

respect to water quality, but it may have site specific ecological implications. Where additional

sediment loading is an ecological concern (e.g. due to smothering of benthic flora and fauna),

pile arisings will be collected rather than deposited. This is discussed in more detail in Chapter

6.

Analysis of samples from around the area to be dredged to the west of the jetty head indicates

elevated concentrations of arsenic in MBH02 3.0-3.8m and MBH08 3.0m, and PCB25 at MBH08

3.0m. None of the samples analysed at depths above 2.5m showed elevated concentrations


and therefore it is concluded that the dredge sediment arisings from this area are suitable for

disposal at sea. We have consulted with Cefas as to our conclusions with respect to the arisings

from the western/northern channel and they have confirmed that they are in agreement.

However, they have indicated that where the dredge depth exceeds 2.5m the method of

dredging must be chosen which will minimise the potential for over dredge and remobilisation of

contaminated sediments identified at 3.0m. At present, it is proposed to use a suction dredger to

dredge both the berth pocket and northern rear approach channel. This avoids re-suspension

of the sediment directly when dredging but it is usual to allow the hopper to discharge overflow

back into the water to maximise the amount of solids in the hopper. However, this practice

creates a re-suspension of the solids and therefore in the area where the dredge depth in the

northern approach is greater than 2.5m, we will impose a “no discharge overflow” requirement

on the dredging contractor.

Our review and consultation with Cefas has indicated that all other dredge and pile arisings

would be suitable for disposal at sea.

Land Disposal or Treatment

The results of the sample analysis (carried out by Hyder in June and August 2013) have been

used to characterise the sediment in terms of waste for disposal to landfill. This assessment

indicates that some of the sediment, at MBH02 1.0m, MBH03 (1.0m) and MBH08 (3.0m) may

be characterised as hazardous, due to the concentrations of hydrocarbons. However, it may be

that further characterisation indicates that this classification can be amended, or that the

particular permit conditions for a landfill site allow acceptance of soil with these characteristics.

The hazard assessment output sheets (from Hazwaste online) are included in Appendix 5-H.

In addition to the information obtained to date, the Principal Contractor who carries out the

construction would be responsible, under UK waste management legislation, for properly

characterising any waste and ensuring that it is reduced (through characterisation or treatment),

reused or disposed of in a suitable manner. One sample (MBH03 2.5-3.0m) was analysed for

the Waste Acceptance Criteria (WAC) determinands and this information will be of use to the

Principal Contractor in initially identifying a suitable disposal site should the need arise.

Reuse

The results of the sediment analysis carried out to date have been reviewed with regard to

possible reuse options, in particular on land. In order to provide an indication of whether the

sediment may be suitable for reuse on residential or commercial property on land, the results

have been compared to UK generic assessment criteria (GAC) for the protection of human

health (Refs 5-18 and 5-19). The review of the leachability analysis results discussed in Section

5.4.4 concludes that the sediment is unlikely to pose a significant risk to controlled waters,

although this risk will have to be assessed based on the proposed reuse location.

The concentrations of arsenic, benzo(a)pyrene and PCBs in several sediment samples are

greater than the criteria for residential use with gardens, and in some cases residential use

without gardens. Further analysis and assessment would need to be carried out to determine

whether the sediment could be re-used for this purpose, based on the proposed use on the

receiving site. It is possible that further standard totals and bioaccessibility (the proportion of the

total concentration which would be absorbed by a human body) testing may show that the

concentrations are less harmful than it would appear. The concentrations of arsenic found are

not unusual in the slate geology of the southwest as natural concentrations are often high due

to the mineralisation associated with metamorphosing processes.


None of the soil/sediment concentrations exceed the GAC for commercial or industrial use sites.

The soil arisings are therefore likely to be suitable for reuse on this type of site as soft

landscaping or fill, again subject to site specific risk assessment.

Notwithstanding the above it should be noted that the arisings will have a high silt and saline

content and therefore may not be suitable as an engineering soil or as a growing medium.

Discharge Consent Conditions

There are no particular considerations with respect to water quality required when setting

conditions for a discharge consent for activities during the construction phase at this site.

5.5.2 Decommissioning of Existing Jetty

Following construction of the new jetty the existing jetty will be demolished. There is potential for

hazardous substances or waste materials to enter the watercourse. The following measures will

be taken to minimise the potential for pollution of surface water and environmental impact from

these activities;

• Empty and flush all fuel and sullage pipelines and any associated equipment.

• Remove all equipment, buildings, tanks, pipework, etc. from the jetty head to barges for

transport to commercial wharf for disposal/re-cycling.

• Remove all pipelines, cables, ducting and pipe supports from the approach jetty to

barges for transport to commercial wharf for disposal/re-cycling.

• Demolish and dispose/re-cycle the redundant buildings and pipework on the land at the

jetty root.

• Demolish the existing jetty head, approach structure and mooring dolphins by cutting

and breaking out the concrete deck and beam elements, using floating plant.

• Piles to be cut off at or below existing seabed, using floating plant and ROVs or divers.

This will minimise the amount of sediment disturbance during these activities.

• Dispose of all materials by appropriate recycle or disposal method.

• Measures will be put in place to contain all hazardous substances, demolition material

and prevent waste materials falling onto the seabed or polluting the watercourse. There

will be response procedures in place to ensure that any materials entering the

watercourse are contained and recovered quickly to limit the impact caused.

• Specific mitigation and waste management measures will be developed by the

contractor carrying out the decommissioning work. The contractor will be required to

comply with current UK guidance and best practice.

5.5.3 During Operational Phase

The proposed structure includes the storage and delivery of very large quantities of fuel, and the

intake of fuel contaminated water from ships (as for the existing jetty).

The operation of the proposed fuel delivery jetty will include best practice and standard safety

measures designed to minimise the potential for a pollution event. These will include:

• Secondary containment on the jetty head – see below

• Real time pipeline/hose contents monitoring – see below

• Intercepted drainage and bunding at foot of jetty and around filter beds – see below.


• Emergency isolation valves (dual manual/automated)

• Run-off water collection and disposal – see below.

• Pressure monitoring and thermal relief (to guard against overheating of pipework).

• Leak detection – see below.

• Accumulators to regulate pressure in the pipelines.

• Procedure for controlling the delivery of fuel, including communication between the fuel

storage point and the jetty head.

• Emergency procedures for containing leaks and spills.

• Suitable equipment for containing leaks and spills, both on land and in the river.

Run-off Water Collection and Disposal

Rainwater that collects in the moats and other areas on site subject to potential fuel

contamination is currently connected to an oil interceptor located below and adjacent to the

crew car park near the existing jetty root. The interceptor is connected to a surface water

discharge pipe that discharges to the river approximately halfway along the current jetty.

This project will collect any additional surface water and divert it through the above or new oil

interceptor prior to discharge along the jetty approach span at or near the -2.5mbCD

bathymetric contour.

There will be no run-off water collection to the mooring dolphins, jetty head and jetty approach

span apart from the water that collects in the sumps situated below all joints and valves. Water

that collects in these sumps will be extracted and discharged into the sullage pipe frequently as

part of routine site management.

Drip Trays

Pipeline routing shall take into account the possibility of leakage from flanged connections and

the need to prevent consequential pollution of the river, by the introduction of drip trays at these

locations. Surface water and contaminants collected in the drip trays will be pumped into the

sullage pipeline. All pipework on the approach jetty structure will be welded to prevent leakage

and therefore does not require drip trays.

Landside Bunding

A bund shall be provided to the jetty side of the filtration station which shall be capable of

containing a fuel spill from a pipe which has ruptured between the point at which the pipe exits

the containment moat system and the bund itself. The bund will be capable of containing the

volume of fuel/sullage likely to be discharged (based on the volume of pipework below the

nearest cut off valve) with a 10% margin. All surface water that is collected within the bund shall

be passed into an oil interceptor prior to discharge

Fuel Monitoring System

Fuel monitoring has two functions:

a) A means of controlling and quantifying the issue and receipt of product; and

b) A means by which the size of any possible fuel leakage can be reduced since product

loss can be detected and appropriate actions undertaken to isolate the leak.


The monitoring system shall be fully Supervisory Control and Data Acquisition (SCADA)

compliant with monitoring capable from both the Jetty Head Control Office and the OPA offices

near Thanckes OFD Main Gate.

Monitoring is to be undertaken via instrumentation on valves in the Jetty Head Manifold Area

and on all valves located between the manifold area and the point of connection to the existing

pipelines.

5.5.4 Decommissioning of Proposed Jetty (end of life)

The jetty has a design life of 60 years, assuming regular maintenance is undertaken. It is

assumed that, at the end of its serviceable life the jetty will be dismantled in a similar manner to

that described in Section 5.5.2.

5.6 Assessment of Effects

The following section provides an overall assessment of the risk posed by the proposed

activities, based on the hazards identified and assuming implementation of the mitigation

measures outlined above. Please refer to Tables 5-2, 5-3 and 5-7 for clarification of the

assessment terms.

5.6.1 During Construction Phase

Marine Based Activities

Assuming that the mitigation measures described in Section 5.5 are in place, it is considered

that the potential for water quality effects on the Tamar Estuary associated with marine based

construction activities is restricted to the possibility of localised isolated sediment contamination,

contained spills, and local sediment disturbance on a short term basis. The mitigation

procedures in place will limit these to minor incidents and allow rapid remediation, with no

significant impact to the wider area. The conceptual model and contaminated land risk

assessment discussed in Section 5.4 concluded that the River Tamar is considered to be of

‘very high’ sensitivity, and that the potential risk posed to this receptor prior to mitigation

measures being taken is moderate to low. This would be reduced through the implementation of

the mitigation measures to low (refer to Table 5-7). The potential secondary impact on the

ecology associated with the river is discussed in more detail in Section 6.

If the arisings from the dredging can be reused on another development near to the Site, then

this may provide some environmentally beneficial effect.

As the Tamar Estuary is classified as a receptor of Very High sensitivity and the potential

magnitude of construction phase effects is judged as Low, the overall effect is classified as

having Temporary Slight Significance, in accordance with the matrix presented in Table 5-3.

Land Based Activities

Assuming that the mitigation measures described in Section 5.5 are in place, it is considered

that the potential for water quality effects on the Tamar Estuary associated with land based

construction activities is restricted to the possibility of localised, contained spills and/or silt

releases during the construction phase. The mitigation procedures in place will limit these to

minor incidents and allow rapid clean up, with no significant impact to the wider area.


As the Tamar Estuary is classified as a receptor of Very High importance and the magnitude of

construction phase effects is judged as Negligible, the overall effect is classified as having

Temporary Slight Significance, in accordance with the matrix presented in Table 5-3.

5.6.2 During Decommissioning Phase (existing jetty)

The contractor that carries out the demolition work will be obliged to design and work to a

method which will minimise the potential to pollute the watercourse, and which will include

responsive measures which will enable any accident to be contained. In addition, all demolition

materials will be recycled as far as possible, or suitably disposed of.

With these measures, the overall effect of the demolition of the existing jetty is a positive one

since it will remove any potential for impact through leaks of hazardous substances from

weathered infrastructure, and collapse into the watercourse.

As the Tamar Estuary is classified as a receptor of Very High importance and the potential

magnitude of decommissioning phase effects is judged as Moderate Positive, the overall effect

is classified as having Permanent Positive Moderate/Large Significance, in accordance with

the matrix presented in Table 5-3.

5.6.3 During Operational Phase

During the operational phase there is limited potential for effects on the surface water

environment. Once construction is complete on-site, land based activity will be considerably

reduced with a corresponding reduction in the potential for the generation of silt-laden or

contaminated runoff. The potential for water quality impacts is therefore limited to maintenance

activities and pollution risk associated with the transport of fuel along the jetty and possible, rare

use of fire fighting foam.

The scheme as a whole provides a beneficial environmental effect as the new and improved

infrastructure will significantly reduce the potential for pollution incidents to occur.

As the Tamar Estuary is classified as a receptor of Very High importance and the magnitude of

operation phase effects is judged as Moderate Positive, the overall effect is classified as

having Permanent Positive Moderate/Large Significance, in accordance with the matrix

presented in Table 5-3.

5.6.4 Decommissioning of Proposed Jetty (end of life)

The jetty has a design life of 60 years, assuming regular maintenance is undertaken. It is

assumed that, at the end of its serviceable life the jetty will be dismantled in a similar manner to

that described in Section 5.5.2. The effect is therefore expected to be similar to that outlined for

decommissioning of the existing jetty, as described in Section 5.6.2.

5.7 Cumulative Effects

In Section 3.6 of this report, three proposed developments have been identified located within

2.5km of the site. These projects are located close to the banks of the Tamar Estuary and

therefore there is potential for them to impact surface water quality if a pollution incident were to

occur.

It is not known whether these projects include construction or dredging in the estuary. If so, and

if these activities occurred at the same time as dredging operations at the Site, then there could

be a cumulative impact on the water quality.


The potential impact could be mitigated by co-ordination, through MMO, of dredging

programmes.

5.8 Summary

This chapter is focussed on the potential for impact on surface water quality from contaminated

sediment/soil due to the proposed construction and operational activities. Assessment of

subsequent impact on ecological receptors is discussed in Chapter 6.

Information reviewed in order to establish the baseline conditions indicates that;

• historical and current potentially contaminative activities have been identified which

could have impacted the water quality and the chemistry of the sediment and soils

beneath the site,

• the water quality in the Tamar Estuary and Plymouth Sound is generally good but is

impacted by elevated concentrations of tributyltin compounds. The chemistry and

sediment load of the surface water is important because the estuary supports protected

ecological systems,

• the chemistry of the sediments on the Site are consistent with conditions elsewhere in

the Tamar Estuary.

Evidence of metals, PCB and PAH compounds were found as total concentrations in

the sediment samples on the site, at concentrations sometimes above the lower limit

criteria but below the upper limits. At one location arsenic and PCB were found at

concentrations greater than the upper limits.

Neither of the two samples tested for leachability showed elevated concentrations of

determinands compared to EQS. One sample showed notable but not significant

concentrations of mineral oil which is likely to be partially representative of natural

organic material.

The activities associated with the construction and ongoing operation of the proposed

development, and the demolition of the existing jetty, with potential to cause impact to water

quality are similar to those already carried out in the estuary.

Table 5-12 summarises the possible impacts from the proposed activities, the proposed

mitigation measures, and an assessment of the residual significance of each activity whether

positive or negative.


Table 5-12 Water, Contamination and Sediment Quality - Impact Summary Table

Impact Description Temporary /

Permanent

Proposed Mitigation Measures Significance Rating

Construction Phase

Disturbance of sediment –

mobilisation of contaminants

through dissolution, and/or

additional sediment load

Temporary Take additional precautionary

measures while working in any

locations identified as having

elevated concentrations of

contaminants

Minimise as far as possible the

extent of work requiring contact

with the river bed.

Ensure the contractor uses

methods which will minimise

sediment disturbance, sediment

migration and arisings.

Slight negative

Deposition of sediment/soil arisings

on the river bed (in terms of water

quality)

Temporary Where there will be an ecological

effect then soil arisings will be

captured and disposed of off-site

Minimise pile soil arisings volume

Slight negative

Storage, transport and use of

contaminative substances on land

and over water – spill or leak to the

watercourse

Temporary Containment of hazardous

substances

Operational procedures including

monitoring and control

Emergency procedures and

equipment

Slight negative

Run off of silt laden or

contaminated surface water from

the land

Temporary Containment and removal of

soils


control of soil arisings

Slight negative

Decommission Phase (existing and proposed jetty)

Hazardous substances or foreign

materials entering the watercourse

Temporary Removal of hazardous

substances from the area before

proceeding with the work

Removal of all infrastructure to a

suitable transfer station

Suitable reuse/recycling and

disposal of materials

Responsive procedures and

equipment to contain/recover any

materials which enter the

watercourse

Slight negative

Removal of worn infrastructure Permanent Removal, reuse/recycle of the

old infrastructure which will

reduce the potential for a

pollution incident to occur

Large positive

Operational Phase


Storage, transport and use of

contaminative substances on land

and over water – spill or leak to the

watercourse

Improved infrastructure will reduce

the risk of pollution events and

therefore have a positive effect

Permanent Containment of hazardous

substances


monitoring and control

Emergency procedures and

equipment

Moderate positive

Review of chemical analysis data indicates that waste sediment/soil arising from the site;

• should be suitable for disposal at sea, only with the exception of pile arisings from near

to MBH08 located towards the northern end of the jetty head,

• may be characterised as hazardous for disposal on land. This has been identified at

MBH03 and MBH08, and

• would be chemically suitable for reuse in a commercial or industrial setting, but may not

be suitable for residential use. This is subject to further analysis and risk assessment

depending on the intended reuse setting. Other properties of the waste may render it

unsuitable e.g. engineering properties, saline content.

If these materials can be reused then there may be a positive environmental effect.

In conclusion – none of the potential effects identified are assessed as posing more than a slight negative

effect following the implementation of the mitigation measures, and in some cases will have a positive effect

in reducing the potential risk to the environment.


6 ECOLOGY

6.1 Introduction

This chapter assesses the likely significant effects of the Thanckes OFD Loading Facility and

Fire Fighting Upgrade in terms of terrestrial and marine ecology. The chapter details the impact

assessment methodology that has been adopted and provides a current ecological baseline

against which the predicted impacts of the proposed scheme are assessed. Mitigation

measures are proposed, which will prevent the proposed Development from having a significant

negative effect on the ecological receptors identified.

This chapter is supported by the information presented in Appendices 6A-F which present the

results of the field surveys carried out to date and the HRA that has been undertaken.

This impact assessment has been undertaken in accordance with the guidance set out in the

Institute of Ecology and Environmental Management’s (IEEM) Guidelines for Ecological Impact

Assessment (2006) (‘the IEEM Guidelines’) (Ref 6-1), in order to provide CC and the MMO with

“clear and concise information about the likely significant ecological effects associated with the

project” (IEEM, 2006).

The terrestrial ecology surveys and desk study that underpin the ecological impact assessment

were undertaken by Hyder Consulting in November 2012 and the marine ecology surveys were

undertaken by Tamar Consulting in June and July 2013.


This impact assessment has been undertaken in accordance with current international and

national legislation, and national, regional and local plans and policies relating to nature

conservation in the context of the proposed Development. A summary of the relevant legislation

and policies, the requirements of these policies and the proposed Development response has

been provided in Table 6-1 below.

Table 6-1 Ecology Regulatory and Policy Framework


Conservation of

Habitats and

Species Regulations

2010 (as amended)’

The Regulations provide for the

protection of both Special

Protection Areas (SPAs) and

Special Areas for Conservation

(SACs) as part of the Natura

2000 network of protected areas

across Europe.

.

The Regulations also provide

protection for European

Protected Species (EPS) from

the deliberate capture, killing or

disturbance. It is also an

absolute offence to destroy or

damage the resting site or

breeding site of an EPS.

Species which are relevant to this

application include the following:

• Atlantic salmon (Salmo salar) – Feature

of Dartmoor SAC.

• Allis shad (Alosa alosa) – Feature of

Plymouth Sound and Estuaries SAC.

• Twaite shad (Alosa falax) – present in

the Plymouth Sound and Estuaries SAC

but not at significant population levels.

• Sea lamprey (Petromyzon marinus) -

present in the Plymouth Sound and

Estuaries SAC but not at significant

population levels.

• Harbour porpoise (Phocoena phocoena)

– listed under Annex II of the Habitats

Directive, EPS.

• Bottlenose dolphin (Tursiops truncates)



- listed under Annex II of the Habitats

Directive, EPS.

• Risso’s dolphin (Grampus griseus –

EPS.

• Common dolphin (Delphinus delphis) –

EPS.

• Grey seal (Halichoerus grypus) - listed

under Annex II of the Habitats Directive.

• Otter (Lutra lutra) – feature of Dartmoor

SAC, EPS.

• Overwintering avocet (Recurvirostra

avosetta) – feature of Tamar Estuaries

Complex SPA.

• On-passage and overwintering little

egret (Egretta garzetta) – feature of

Tamar Estuaries Complex SPA.

Habitats which are relevant to this

application include the following:

• Estuaries – primary reason for selection

of Plymouth Sound and Estuaries SAC.

• Intertidal mudflats – listed under Annex I

of the Habitats Directive.

A description of SACs and SPAs potentially

affected by the proposed Development is

included in Section 6.4. Potential ecological

impacts are discussed in Sections 6.6 and

6.7, and the information to support a

Habitats Regulations Assessment (HRA) is

summarised in Annex F.

The Wildlife and

Countryside Act

(1981) (as amended)

This Act is the

principle mechanism

for the legislative

protection of wildlife

in England.

The Act provides for the

designation of Sites of Special

Scientific Interest (SSSI), which

are selected as the best national

examples of habitat types, sites

with notable species and sites of

geological importance.

Schedules 1-4 of the Act deal

with the protection of wild birds.

Schedule 5 of the Act details

protection of other animal

species. Full protection is given

under Section 9 of the Act to

certain animals listed on

Schedule 5, including otters and

all species of bats. Partial

protection under Section 9 is

given to certain other species,

including all common species of

reptile. Badgers are listed on

Schedule 6 of the Act which

Eight SSSIs are located within 5km of the

proposed Development. A description of

SSSIs potentially affected by the proposed

Development is included in Section 6.4.

Potential ecological impacts are discussed in

Sections 6.6 and 6.7.

No terrestrial species protected by the Act

have been recorded within the terrestrial

areas of the Site, although habitats were

identified that were suitable to support such

species. These include common species of

reptiles and bats. It is considered likely that

otters use the intertidal habitats around the

Site.

Marine species listed on Schedule 5

recorded within the study area are as

follows:

• Harbour porpoise

• Bottlenose dolphin

• Risso’s dolphin



outlaws certain methods of taking

or killing animals, where

necessary. Schedule 8 of the

Wildlife and Countryside Act

details protection for plants and

fungi.

Schedule 9 identifies non-native

species that should not be

introduced into, or spread in, the

wild.

• Common dolphin

• Allis and twaite shad

These marine species are also listed in the

Conservation of Habitats and Species

Regulations 2010 (as amended) and/or are

listed as a feature of the Plymouth Sound

and Estuaries SAC. A description of the

baseline conditions with regard to marine

mammals and migratory fish are included in

Section 6.4. Potential ecological impacts are

discussed in Sections 6.6 and 6.7.

Marine and Coastal

Access Act 2009

Part 5 of this Act enables the

designation of Marine

Conservation Zones (MCZs).

These are a type of Marine

Protected Area, which protect a

range of nationally important

marine wildlife, habitats, geology

and geomorphology. MCZs exist

alongside European marine

Sites, SSSIs and Ramsar sites to

form an ecologically coherent

network of marine protected

areas.

Two MCZs are considered within this

assessment; the Tamar Estuary MCZ and

the Whitsand and Looe Bay MCZ. The

Tamar Estuary MCZ supports migratory

European smelt (Osmerus eperlanus), which

breed within the Tamar Estuary and the

native oyster (Ostrea edulis). Native oysters

are also listed on the OPSAR List of

Threatened and/or Declining Species and

Habitats. Blue mussel (Mytilus edulis) beds

and European eel (Anguilla anguilla) are

also present.

Further detail is included in Section 6.4

which describes the baseline, and Sections

6.6 and 6.7 which describe the potential

ecological impacts of the proposed

Development.

National Parks and

Access to the

Countryside Act

1949

Local Nature

Reserves (LNRs) are

designated by Local

Authorities under

Section 21 of this act

as amended by

Schedule 11 of the

Natural Environment

and Rural

Communities

(NERC) Act 2006.

LNRs are places with a wildlife or

geological interest of local value

that are capable of being

managed with the conservation

of nature and/or the maintenance

of public access as priority

concerns.

Woodland Wood Valley LNR and Budshead

Wood LNR are located approximately 4.5

and 4.9km to the north-east of the Site

respectively, within the city of Plymouth.

NERC Act (2006) The NERC Act places a duty

upon public bodies to consider

conservation of biodiversity within

all of their actions. Sections 40

and 41 of this Act superseded

Section 74 of the Countryside

Rights of Way (CRoW) Act.

Section 41 lists flora, fauna and

Section 41 habitats and species recorded

within the study area include:

• Intertidal mudflats

• Seagrass beds

• Sublittoral sediments

• Allis shad



habitats considered by the

Secretary of State to be of

Principal Importance for

conserving biodiversity in

England.

• Twaite shad

• Atlantic salmon

• Sea trout (Salmo trutta)

• European smelt

• European eel

• Common dolphin

• Risso’s dolphin



• Otter

A description of the baseline conditions with

regard to these protected species and

habitats are included in Section 6.4.



1992 OSPAR

Convention for the

Protection of the

Marine Environment

of the North-East

Atlantic

OSPAR is the mechanism by

which fifteen Governments,

including the UK, of the western

coasts and catchments of

Europe, together with the

European Community, cooperate

to protect the marine

environment of the North-East

Atlantic. It begun in 1972 with the

Oslo Convention against

dumping. It was broadened to

cover land-based sources and

the offshore industry by the Paris

Convention of 1974. These two

conventions were unified, up-

dated and extended by the 1992

OSPAR Convention. An annex

on biodiversity and ecosystems

was adopted in 1998 to cover

non-polluting human activities

that can adversely affect the sea.

Habitats and species found in the vicinity of

the proposed Development and included on

the OSPAR List of Threatened and/or

Declining Species and Habitats are as

follows:

• Atlantic salmon

• European eel


• Intertidal seagrass beds

• Native oyster

• Thornback ray (Raja clavata)


A description of the baseline conditions with

regard to these protected/notable species

and habitats are included in Section 6.4.



The Convention on

the Conservation of

European Wildlife

and Natural Habitats

(the Bern

Convention, 1979)

This Convention was adopted in

Bern, Switzerland in 1979, and

came into force in the UK in

1982. The principal aims of the

Convention are to ensure

conservation and protection of all

wild plant and animal species

and their natural habitats (listed

in Appendices I and II of the

Convention), to increase

cooperation between contracting

parties, and to afford special

protection to the most vulnerable

or threatened species (including

Species that have been recorded in the

vicinity of the proposed Development and

are listed on the Bern Convention are as

follows:

• Atlantic salmon


• Sea and river lamprey



All of these species are also listed in the


Regulations 2010 (as amended) . A



migratory species). description of the baseline conditions with

regard to these protected/notable species is

included in Section 4. Potential ecological

impacts are discussed in Sections 6.6 and

6.7.

Convention on the

Conservation of

Migratory Species of

Wild Animals (Bonn

Convention or CMS,

1979)

This Convention was adopted in

Bonn, Germany in 1979 and

came into force in the UK in1985.

Contracting Parties work together

to conserve migratory species

and their habitats by providing

strict protection for endangered

migratory species (listed in

Appendix 1 of the Convention),

concluding multilateral

agreements for the conservation

and management of migratory

species which require or would

benefit from international

cooperation (listed in Appendix 2

of the Convention), and by

undertaking co-operative

research activities.

Species that have been recorded in the

vicinity of the proposed Development and

listed on the Bonn Convention are as

follows:



These species are also listed on the


Regulations 2010 (as amended) . A

description of the baseline conditions with

regard to marine mammals is included in

Section 4. Potential ecological impacts are

discussed in Sections 6.6 and 6.7.

National Planning

Policy Framework

(March 2012)

The document streamlines

national planning policy into a

consolidated set of priorities, with

the core theme being the delivery

of sustainable development and

economic growth. Paragraph 118

sets out how local planning

authorities should aim to

conserve and enhance

biodiversity when considering

planning applications.

Opportunities for the conservation and

enhancement of areas for biodiversity within

the proposed Development are considered

within the assessment.

UK Marine Policy

Statement (MPS)

(March 2011)

The MPS is the

national framework

for taking decisions

affecting the marine

environment

Paragraph 2.3.2.1 states that

authorisation decisions that affect

the UK marine area must be

made in accordance with the

relevant marine policy

documents. In the case of the

South West Region, where the

Marine Plan is currently absent,

‘decisions must be made in

accordance with the MPS’.

In considering marine ecology

and biodiversity, Paragraph

2.6.1.3 of the MPS identifies that

development should aim to avoid

harm to marine ecology,

biodiversity and geological

conservation interests including

Measures to avoid or mitigate any

potentially adverse impacts as a result of the

proposed Development are included within

the assessment.



through location, mitigation and

consideration of reasonable

alternatives. Where significant

harm cannot be avoided,

appropriate compensatory

measures should be sought.

Biodiversity 2020: A

Strategy for

England’s Wildlife

and Ecosystem

Services

Its aim is to halt the loss of

biodiversity, support healthy well-

functioning ecosystems and

establish coherent ecological

networks. It takes a landscape

scale approach to conservation

on both the land and at sea. It

identifies the need to establish

Local Nature Partnerships to

deliver the Strategy through

community involvement. It

supports the establishment of

Nature Improvement Areas,

measures to increase the number

of SSSI in favourable

conservation status and the

creation of a network of Marine

Protection Areas. It also

identifies that improvement and

protection of the natural

environment are part of the

planning system and identifies

that biodiversity offsetting will be

piloted to deliver planning policy

more effectively. It promotes

flood and erosion management to

conserve the natural environment

and improve biodiversity.

Measures to avoid or mitigate any potentially

adverse impacts as a result of the proposed

Development are included within the

assessment.

Caradon Local Plan

First Alteration

(August 2007)

Until a Local Plan for

Cornwall Council is

prepared, extant

planning policies

within each District of

the former County

Council will continue

to form the basis of

planning decisions.

The policies of most relevance to

this chapter are:

CL1: Nature Conservation,

where development that affects

sites of nature conservation

importance will not be permitted

without adequate mitigation or

the importance of the

development overrides the

significance of the site;

CL12: Sites of Special

Scientific Interest

(SSSI)/National Nature

Reserves (NNR), where

development that affects

SSSIs/NNRs will not be permitted

without adequate mitigation or

See also response to the Conservation of

Habitats and Species Regulations 2010 (as

amended).The Wildlife and Countryside Act

and the NERC Act (all above), with respect

to statutory designated sites and protected

species.

Four non-statutory designated sites of

County importance to nature conservation

known as County Wildlife Sites (CWS) are

found within 5km of the Site. These are:

• Lower Lynher Estuary;

• St John’s Lake;

• Tincombe Reserve;

• Clarrick and Pigshill Woods.

The potential effects on the Lower Lynher

Estuary and St John’s Lake are considered

in the context of the effects on the SAC and



the importance of the

development overrides the

significance of the site. European

designated sites will be given the

same protection as SSSIs.

CL13: Cornwall Nature

Conservation Sites and Nature

Reserves, where Development

proposals which would adversely

affect, directly or indirectly, locally

designated Nature Conservation

Sites, or the integrity or continuity

of other landscape features of

major importance to wild fauna or

flora will only be permitted where:

i) The reason for the

development clearly

outweighs the decrease

in nature conservation

value;

ii) Any damage to the

nature conservation

interest is minimised;

iii) Mitigating measures can

be provided to protect

remaining nature

conservation and secure

habitat creation or

enhancement elsewhere

within the site or local

area.

The policy applies to Areas of

Great Scientific Value (AGSVs),

Cornwall Nature Conservation

Sites (CNCS), Regionally

Important Geological Sites

(RIGS), Local Nature Reserves

(LNRs) as identified on the

proposals map.

CL15: The Coast, ‘In order to

maintain the nature conservation

value of the shoreline and

adjoining coastal water,

development which would cause

physical damage, disturbance or

pollution will not be granted

planning permission.’

CL16: Protected Species,

where development that would

have an adverse effect on

protected wildlife species will not

SPA.



be permitted without mitigation.

Cornwall Biodiversity

Action Plan (BAP)

Volume 4: Priority

Projects, Cornwall

Biodiversity Initiative,

2011

The Cornwall Biodiversity

Initiative (CBI) produced the

latest volume of Cornwall’s Local

Biodiversity Action Plan in 2011.

This volume focuses on

landscape scale projects to

achieve habitat targets and

benefit a wider range of species

than previous species specific

recovery projects. In addition,

the CBI has published a new

Cornish BAP list which contains

43 habitats and 360 species.

Cornish Local Biodiversity Action Plan

(LBAP) habitats and species recorded within

the study area include intertidal mudflats,

seagrass beds, estuarine rocky habitats,

subtidal sands and gravels, otter, allis shad,

twaite shad, Atlantic salmon, sea trout,

garden tiger moth, mouse moth.

Where impacts have been identified on

species listed on the LBAP, mitigation has

been proposed including timing of works and

control of pollution.

6.3 Methodology

6.3.1 Introduction

The methodology used to carry out the impact assessment is based upon the IEEM Guidelines

for Ecological Impact Assessment. In accordance with the IEEM Guidelines, a detailed

assessment has been carried out which attempts to collate all of the existing baseline

information through a desk-based study and field surveys, and confidently predict all of the

significant effects of the proposed Development on ‘Key Ecological Receptors’, with mitigation.

Where significant adverse effects are predicted, the assessment presents detailed measures to

mitigate these effects such that the residual effects of the proposed Development would not be

significant.

In addition, measures have been developed to address the legislative and policy requirements

associated with those protected species and valuable habitats for which significant effects are

not expected, but which nevertheless warrant mitigation. Measures to enhance biodiversity in

the area affected by the proposed Development and those which help to deliver Action Plan and

local policy targets are also recommended. Although these have not been developed in

response to significant effects, they do nevertheless contribute to the overall balance of effects

on nature conservation for the proposed Development. This approach is considered to

represent best practice.


The study area included the existing Thanckes OFD and habitats immediately adjacent

(including intertidal and subtidal habitats) in order to investigate direct impacts on species and

habitats. The study area was extended to investigate particular species and groups of

conservation concern where appropriate, including the whole of the Plymouth Sound and

Estuaries SAC, the Tamar Estuaries Complex SPA. Dartmoor SAC and the Tamar Estuary MCZ

to investigate the potential impacts of habitat loss and the effects on overwintering and

migratory birds and migratory fish. The study area also includes Whitsand and Looe Bay MCZ

to assess the potential impacts associated with the disposal of dredged material at Rame Head

disposal site.


A desk-based assessment also collated ecological records for the Site itself and for the

surrounding area up to a distance of 1km from the boundary of the Site. A distance of up to

10km was searched for European designated sites and 5km for bat species information.

The assessment area or Zone of Influence (ZoI) for ecology therefore extends to cover the

Plymouth Sound and Estuaries SAC, the Tamar Estuaries Complex SPA and the Dartmoor SAC

in addition to the terrestrial habitats of the existing Thanckes OFD and the intertidal mudflats in

the immediate vicinity of the Site, which are not subject to any statutory designation.


Desk Study

Ecological information relating to the study area (as defined above) was obtained from the

Environmental Records Centre for Cornwall and the Isles of Scilly (ERCCISS) and bat records

were requested from within a 5km search area. In addition, the Multi-Agency Geographical

Information for the Countryside (MAGIC) website was reviewed for designated sites within a

5km search area, and for European sites within a 10km search area. The National Biodiversity

Network (NBN) website (http://www.nbn.org.uk/), the Data Archive for Seabed Species and

Habitats (DASSH) website (http://www.dassh.ac.uk/) and the Marine Life Information Network

(MARLIN) website (http://www.marlin.ac.uk/) were all used to search for records of protected

species.

Detailed results of the desk-based assessment are included in Section 6.4.

The BTO provided Wetland Bird Survey (WeBS) core count (high tide) data for the count sector

that included the Site (Tamar Estuary South) in addition to the Tamar Complex as a whole. This

information consisted of tabulated five year synopses for the count sites, providing a range of

average and peak counts for individual species observed. No recent low tide count data was

available.

The Cornwall Bird Watching Preservation Society (CBWPS) was also contacted to obtain

records within 500m of the Site. The only records that were available were BTO WeBs counts

up to 2008 approximately 1km from the Site, however; more recent WeBs data had already

been obtained from the BTO, therefore, this assessment uses the BTO data.

Terrestrial Field Surveys

An initial extended Phase 1 Habitat Survey was undertaken on the 26th and 27th October 2009

of the jetty and the route of the existing fire main to identify any habitats or species which could

constitute potential constraints to the proposed Development.

A further extended Phase 1 habitat survey was carried out on 8th November 2012 of the whole

Thanckes OFD, which involved identifying and mapping the dominant habitat types following

standard Phase 1 habitat survey (Ref 6-2). Dominant plant species were noted, as were any

uncommon species or species indicative of particular habitat types. Botanical names follow

Stace, 1997 (Ref 6-3).

The Phase 1 habitat survey was extended to involve a critical assessment of the value of the

habitats present for their use by protected species or species of conservation concern, as

outlined below:

• The value of the Site for invertebrates was assessed and any habitats or features of

particular value were identified.


• The value of the Site for reptiles and amphibians was assessed and any habitats or features

of particular value for these species groups were identified. Great crested newts are

considered to be absent in this part of Cornwall, thus these amphibians have not been

included in this assessment.

• The value of the Site for breeding birds was assessed.

• An external inspection of all buildings, trees and other structures on Site was carried out to

assess their suitability for occupancy by roosting and/or hibernating bats. Potential roost

features were observed from the ground and scrutinised for their suitability to be used by

bats, alongside searching for any evidence of use, such as staining, feeding remains or

droppings. The likely value of the various habitat features for foraging and commuting bats

was also critically assessed.

• The Site was assessed for its potential to support dormice.

• The Site was investigated for its use by badgers by searching for the characteristic signs of

badger activity including setts, latrines, paths, footprints, hairs and feeding signs.

Ornithology Surveys

Low- and high-tide wintering bird surveys were undertaken during the October 2009 site visit. A

low-tide count was carried out as far as possible on the 26th October 2009 between 14:30 and

16:30 hours. Due to poor weather conditions and low light levels, it was not possible to

continue the low-tide count until the time of low water. Three count locations were used: the

platform on the jetty looking back towards Wilcove to the north and Thanckes Lake to the south

of the jetty, and two locations checking the extremities of the bays to the north and the south of

the jetty that could not be observed from the jetty itself.

Low-tide counts were made from the existing jetty at approximately 15 minute intervals, with

half-hourly counts carried out at Wilcove and Thanckes Lake. In addition, a high-tide count was

carried out on 27th October 2009 between 09:15 and 11:45 using the same count locations and

intervals as for the low-tide count.

The results of the surveys are presented in Appendix 6-A. The results from the vantage points

were verified and combined so that results are presented for two areas; Wilcove to the north,

and Thanckes Lake to the south of the existing jetty. Also in Appendix 6-A is data obtained

from the BTO with respect to core counts from the relevant count sector and the whole Tamar

Estuary (for the five year period 2006/07-2010/11), and low tide counts from 2002/03.

Marine Ecology Surveys

A sublittoral marine survey was conducted on the 18th June 2013 in dry, clear weather by three

surveyors on a chartered vessel collected from the Saltash Jetty at 09:30.

Drop-down video surveys were conducted using an underwater video camera on a frame with

an umbilical cable back to the survey vessel in order to view images in real time. Video footage

was also recorded along transects across the proposed and current dredge sites to allow a

comparison between ‘before’ and ‘after’ states. Footage was also taken along Global

Positioning System (GPS) referenced transects throughout the estuary for later analysis.

GPS referenced grab samples were collected using a Van Veen grab sampler (0.45m2). The

samples were taken to ground truth the video footage and confirm the sediment composition

and species present. The number of samples taken was determined by the homogeneity of the

sediment within the Site and the recommendation that single samples covering a wider area of

interest is preferred over replicate sampling from smaller areas (Ref 6-4). All samples were

retrieved from the seabed using a winch and were sieved through a fine mesh (0.5mm) sieve to

dissipate fine sediment.


Upon completion of fieldwork the video footage was analysed and the sieved grab samples

identified to species level, where possible in order to identify marine biological habitats

(biotopes) and ground-truth the video footage.

An intertidal survey was also undertaken on 12th July 2013 in dry, clear weather with access to

the jetty and foreshore on foot. The biotopes were mapped at the Site and across the foreshore

either side of the proposed Development. Quadrat searches and core samples were conducted

where possible to confirm biotope descriptions in accordance with the best practice

methodology outlined below.

The marine surveys were conducted according to best practice as set out in the Marine Nature

Conservation Review (MNCR) Rationale and Methods (Ref 6-5), the Marine Monitoring

Handbook (Ref 6-6) and the Guidelines for the Conduct of Benthic Studies at Marine Aggregate

Extraction Sites (Ref 6-4) as requested by CEFAS and the MMO. Classification of biotopes was

conducted according to the Joint Nature Conservation Committee (JNCC) classifications of

National Marine Habitat Classification for Britain and Ireland (Ref 6-7).


The significance of impacts is determined using the approach described in Chapter 3 of this ES.

In accordance with the Town and Country Planning (Environmental Impact Assessment)

Regulations 2011 (referred to as the ‘EIA Regulations 2011’), and the guidance set out in the

IEEM Guidelines, it is considered inappropriate to attempt to investigate in detail all potential

ecological issues in relation to the proposed Development. It is therefore necessary, under the

Regulations, to focus on those activities that could potentially generate significant ecological

effects on ‘Key Ecological Receptors’ thus our assessment has focussed on where there is the

potential for significant effects to arise.

In order to determine the likelihood of a significant ecological effect, it is first necessary to

identify whether a receptor is sufficiently valuable for a significant effect upon it to be material in

decision-making. To achieve this, where possible, animal species and their populations have

been valued on the basis of a combination of their rarity, status and distribution, using

contextual information where it exists. Habitats and plant communities are evaluated against

existing selection criteria, wherever possible (such as those developed to aid the designation of

SSSIs or non-statutory designated sites). Only those receptors that it was considered could

experience significant effects (i.e. impacts that could adversely affect the integrity of the habitat

or the favourable conservation status of a species’ local population), and which were identified

as being of sufficient value to be material to decision-making (i.e. of ‘District’ level importance or

above), have been classified as being ‘Key Ecological Receptors’ and have been considered in

the detailed assessment.

The habitats and features within the ZoI are known as the ‘ecological receptors’. The nature

conservation importance/value of each of the ecological ‘receptors’ considers the protected

species and species of conservation concern that they may support, to avoid pseudo-

replication. For example, the importance for species associated with the intertidal mudflats

(over-wintering birds) has been taken into account as part of categorising the overall

importance/value of that feature.

The following geographic frame of reference has been used to determine the value of ecological

receptors: International; National; Regional; County; District/Borough; and Parish/

Neighbourhood.

Those sites, habitats and/or species classified at ‘District/Borough’ level and above are

considered to be sufficiently valuable for a significant effect upon them to be material in decision

making. Where habitats and species within the Site do not constitute ‘Key Ecological Receptors’


based upon their nature conservation value, and have not formed part of the detailed

assessment, they still warrant consideration during the design and mitigation of the proposed

development on the basis of their legal protection, their implications for environmental (and

related) policies and plans, or other issues such as animal welfare issues. Therefore,

consideration has separately been given to these ‘Other Ecological Receptors Requiring

Mitigation’.

The results of the ecological valuation process are presented in Section 6.4 Baseline

Conditions; this summarises the results of the desk study and field surveys, and identifies which

of the resources are ‘Key Ecological Receptors’, which are ‘Other ecological receptors’ requiring

mitigation, and those which have been scoped out of the assessment altogether. It is important

to note that the selection of ‘Key Ecological Receptors’ has therefore been informed by an

assessment not only of nature conservation value but also of the likely impacts upon them, the

methodology for which is described below.

Impact Characterisation

Once the ecological receptors within the ZoI have been identified and valued, it is then

necessary to investigate potential impacts on those receptors in order to understand how they

might be affected by the proposed Development.

The impact assessment has been based on an understanding of the likely activities associated

with the proposed Development, the biophysical changes that could be predicted as a result of

these activities, and the area over which such effects might be experienced by different

receptors. These impacts have been considered for the construction, operational and

decommissioning phases of the proposed Development. They have been characterised and

described in Section 6.6 and possible mitigation measures identified.

Integration of impact characteristics

An informed integration of each of these impact characteristics is necessary in order to underpin

the determination of impact significance set out below.

Assessing significance

The significance of an impact has been determined on the basis of an analysis of the factors

that characterise the impact. An assessment is provided of the confidence of this assessment

in line with the information provided in Table 6.2 below. The nature conservation value of

significantly affected receptors has then been used to guide further mitigation and related

measures and help interpret the significance of residual impacts.

Table 6-2 Assessment of significance

Definition

Significant negative impacts on a feature of international value, inhibiting the delivery of

conservation objective(s) for a European site or the restoration to favourable status of a feature of

European importance

Significant negative impact on a feature of national value, inhibiting the delivery of conservation

objective(s) for SSSI (or equivalent) or the habitats and species of Principal Importance for the

conservation of biodiversity in England, as listed under Section 41 of the NERC Act (2006)

Significant negative impact on a feature of county value, inhibiting the delivery of conservation

objective(s) for sites of county importance; or county Development Plan Policy (or equivalent), or

county Biodiversity Action Plan objective(s)


Definition

Significant negative impact on a feature of district/borough value, inhibiting the delivery of

Local Development Plan Policy (or equivalent) or local UK Biodiversity Action Plan objective(s)

No significant impact

Significant positive impact on a feature of district/borough value, promoting the delivery of

Local Development Plan Policy (or equivalent) or the habitats and species of Principal Importance

for the conservation of biodiversity in England, as listed under Section 41 of the NERC Act (2006)

Significant positive impact on a feature of county value, promoting the delivery of conservation

objective(s) for sites of county importance; or county Development Plan Policy (or equivalent), or

county Biodiversity Action Plan objective(s)

Significant positive impact on a feature of national value, promoting the delivery of conservation

objective(s) for SSSI (or equivalent) or UK Biodiversity Action Plan objective(s)

Significant positive impacts on a feature of international value, promoting the delivery of

conservation objective(s) for a European site or the restoration to favourable status of a feature of

European importance

6.3.5 Consultation

Following submission of a Scoping Report and HRA Screening to CC in December 2012,

responses have been received from the MMO, NE, the EA and CC with respect to the scope of

the ecological assessment and the HRA Screening. The main points raised are identified in the

table below, with a response provided.

Table 6-3 Consultation responses

Consultee Summary response Measures taken to address this response

MMO Need for further benthic surveys

Benthic surveys undertaken. Detailed results contained within Appendix 6-C

Impacts on marine ecology receptors from the release of contaminated sediments and smothering from increased suspended sediments

Detailed assessment of potential impacts on key ecological receptors

Assessment of habitats and species listed on OSPAR List of Threatened and Declining Species and Habitats


MMO confirmed that there was no need for a separate MCZ assessment report in a conversation on 25th September 2014

No separate MCZ assessment has been produced. Potential impacts on MCZs are considered within this Ecology chapter

NE Potential impacts on migratory fish through underwater vibration

Detailed assessment of potential impacts on migratory fish as a key ecological receptor, including commissioning a report by Subacoustech Environmental into the underwater noise impact during construction on migratory fish species. This report was reviewed by NE and Cefas and, following this review, it has been agreed that percussive piling will restricted to the months of September to March (i.e. no percussive piling between 1st April and 31st August), outside the main migratory fish period, to avoid


disturbance to the EPS allis shad and Atlantic salmon. There are no timing restrictions with regard to vibro-piling, pile case oscillation and augering/drilling, subject to monitoring of initial operations outside of the key sensitive window of April to August to ensure that noise levels are within the levels predicted. Cefas are in agreement with this response.

Loss and damage to SAC, SPA and SSSI features


Insufficient information provided to undertake a Test of Likely Significant Effect

HRA Screening Report provided in Appendix 6-D

EA Map and survey habitats under the development footprint

Intertidal and subtidal surveys undertaken. Detailed results contained within Appendix 6-C

Benthic surveys required Benthic surveys undertaken. Detailed results contained within Appendix 6-C

Piling and dredging must be carried out between December and March

See response above regarding piling. it is recommended that Dredging will take place between and March.

Proposals to protect, restore and enhance nature conservation

The overall purpose of the proposed Development is to upgrade and modernise an ageing oil fuel depot/refuelling jetty and pipeline/fire-fighting system to make it safer, substantially reducing the risk of accidents, including pollution incidents.

Mitigation measures aim to protect the key ecological receptors. It is anticipated that areas of seabed affected will be allowed to re-colonise naturally, but this will be encouraged by removing crabbing tiles from the intertidal area within the DIOs control, and reducing the amount of crabbing and bait digging in the area by installing new signage to discourage these activities.


The terrestrial survey results used to inform the baseline conditions were from 2012. However,

no significant ecological constraints were identified at this time and it is considered that the

habitats are stable and unlikely to change. Nevertheless, it is anticipated that pre-construction

surveys will be undertaken to confirm the continued absence of protected species within the foot

print of the Development.

The marine survey results used to inform the baseline conditions were from 2013. The marine

habitats are relatively stable and are unlikely to have changed in the interim period.

Since undertaking the marine surveys, the proposals have changed. However, the area

surveyed effectively covered the revised Development footprint.

The low-tide wintering bird count carried out on the 26th October 2009 was curtailed due to poor

weather conditions and low light levels. However, it is considered that sufficient information was

collected in order to inform the baseline conditions.



The baseline conditions have been established through a desk-based assessment and field

surveys as described previously. The results are presented below, with a Phase 1 map of the

Site (Drawing 6-1) and accompanying Target Notes provided in Appendix 6-B. A map

illustrating the designated sites in the vicinity of the Site is presented in Drawing 6-2. The

detailed results of the marine surveys are presented in Appendix 6-C.

6.4.1 Site Description

The terrestrial part of the Site occupies the slopes of a promontory jutting out into the Tamar

Estuary and comprises a series of level terraces on which fifteen fuel storage tanks were

situated, along with an extensive network of pipelines, pumps, filtration equipment and

containment moats. Surrounding the fuel storage tanks are large areas of short mown amenity

grassland with a fringe of semi-natural broadleaved woodland along the shore line.

The existing Yonderberry Jetty lies on the Hamoaze (the estuarine stretch of the River Tamar

between the River Lynher and Plymouth Sound). The jetty approach is 254m x 5.8m and the

jetty head is 61m x 9m. The jetty comprises a bridge structure on piles connecting the jetty

head to the OFD and holding a pipe rack and walkway. The jetty head is also supported by piles

and there is an existing berth pocket alongside the jetty head, which is maintained by a

maintenance dredging regime. The walkway and jetty piles traverse through the intertidal habitat

extending to the subtidal habitats of Tamar Estuary. There are also three mooring dolphins, two

to the south of the jetty and one to the north, all situated in subtidal habitat.

6.4.2 Statutory Designated Sites

Plymouth Sound and Estuaries SAC

The subtidal habitats within the Site fall within the Plymouth Sound and Estuaries SAC. The

SAC is a large (6402ha) marine inlet comprising the estuaries of the rivers Tamar, Lynher and

Tavy. The River Tamar and its tributaries provide the main input of fresh water into the estuary

complex, and form a ria (drowned river valley) with Plymouth lying on the eastern shore. The

broader lower reaches of the rivers form extensive tidal mudflats bordered by saltmarsh

communities. The mudflats contain extensive and varied infaunal communities rich in bivalves

and other invertebrates, and provide feeding grounds for waterbirds in numbers of European

importance. Saltmarshes provide important feeding and roosting areas for large numbers of

wintering and passage waterbirds.

Annex I habitats that are a primary reason for selection of the SAC are as follows:

• sandbanks which are slightly covered by sea water all the time;

• estuaries;

• large shallow inlets and bays;

• reefs; and

• Atlantic salt meadows (Glauco-Puccinellietalia maritimae).

The Annex I habitats present as a qualifying feature, but not a primary reason for selection of

the SAC are: mudflats and sandflats not covered by seawater at low tide.


The conservation objectives for the estuaries feature of Plymouth Sound and Estuaries SAC are

as follows:

Subject to natural change, maintain the estuaries in favourable condition, in particular:

• Intertidal mud communities;

• Subtidal mud communities;

• Intertidal mixed muddy sediment communities;

• Subtidal mixed muddy sediment communities;

• Estuarine bedrock, boulder and cobble communities;

• Subtidal sandbank communities;

• Saltmarsh communities;

• Reedbed communities.

As such, the habitats that would be affected are considered to come under this primary reason

for SAC selection.

The Annex II species that is a primary reason for selection of the SAC is: Shore Dock (Rumex

rupestris). However, this species occurs on rocky shore habitats above the mean high water

mark and has not been found during surveys of the Site. This species is not considered further

in this assessment.

The Annex II species present as a qualifying feature, but not a primary reason for site selection

is allis shad.

Also listed on the SAC Natura 2000 data form (Ref 6-8) as being present (but not at qualifying

population levels) are the following Annex II species:

• sea lamprey

• river lamprey

• twaite shad

• bottlenose dolphin

• harbour porpoise

• otter

• grey seal

The effects on the migratory fish and marine mammals listed above will be considered in detail

under the ‘migratory fish’ and ‘marine mammals’ key receptors respectively. Otters are known to

be present along the Tamar Estuary but the Site is not considered to be of particular value to

otters given the lack of desk study records and the sub-optimal nature of the habitat within the

Site. Nevertheless, otters are likely to commute up and down the estuary and any effects on

them will be considered on account of their legal protection.


Given the considerable distance between Rame Head disposal site and this SAC, no impacts as

a result of sediment disposal at sea are envisaged. This is supported by a letter from NE dated

17th January 2014 (Ref 105344, MLA/2013/00432) in relation to the current maintenance

dredging licence which states: NE can confirm that the Rame Head marine disposal site is not

located within or in close proximity to any SAC, SPA or Ramsar.

Due to the nature conservation value of this site and the species it supports, the Plymouth

Sound and Estuaries SAC is considered to be of International importance.

More information regarding the potential impacts on this European site can be found in

Appendix 6-D the HRA Screening Report.

Tamar Estuaries Complex SPA

The Tamar Estuaries Complex SPA is 1955 ha in size, located approximately 1.4km south of

the Site. This SPA qualifies under Article 4.1 of the Directive (79/409/EEC) by supporting

populations of European importance of the following species listed on Annex I of the Directive:

• little egret (Egretta garzetta) on passage, and

• avocet (Recurvirostra avosetta) during the winter

As a result of the SPA Review process undertaken in 2001, over-wintering little egret (42

individuals at least 8.4% of the British population) was added to the published information for

the site. Although not yet legally classified, Natural England’s website

(www.naturalengland.org.uk) states that these sites are ‘…as a matter of Government policy

treated in the same way as classified features.’ The value of the Site for over-wintering little

egret will therefore be considered in the assessment (see paragraphs below).

Avocet

Core count (high-tide) data provided by BTO (from 2006/7-10/11) revealed that no avocet have

been recorded from the Tamar Estuary (South) Sector 10 (within which the Site is located) for at

least five years. The most recent low tide count dot distribution map provided by BTO (Figure 6-

1) indicates that avocet are not found within 3km of the Site, as they winter on the upper

reaches of the Tamar-Tavy Estuary. In addition, of the three underlying SSSI designations,

wintering avocet are only a feature of the Tamar-Tavy Estuary SSSI (located approximately

3.2km to the north of the Site) and are not a feature of either the Lynher Estuary SSSI or St

John’s Lake SSSI, both of which are closer to the proposed Development. It is considered

therefore that there will be no adverse impact on this species as a result of the Development,

and it will not be considered further in this assessment.


Figure 6-1: Distribution of avocet within the Tamar Estuaries Complex SPA at low tide

2002/03

Little egret

Table 6-4 (extracted from information provided in Appendix 6-A) provides a comparison of bird

survey results with BTO count data.

Table 6-4 BTO WeBS data compared with October 2009 survey results

BTO WeBS data Wilcove (north of jetty) Thanckes Lake (south of jetty)

Species High-tide count data from the Tamar Estuary Complex: 5 year (2006/7-10/11) autumn mean peak

High-tide Low-tide High-tide Low-tide

Little egret 103 2 3 0 2

Table 6-4 illustrates that, from the bird survey undertaken in October 2009 (during the autumn

passage period), the area to the north of the jetty (Wilcove) recorded a maximum of two little

egrets at high tide, 1.94% of the five year autumn mean peak high-tide count data for the Tamar

estuary as a whole (2006/7-10/11). For Thanckes Lake to the south of the jetty no little egrets

were recorded at high tide.

With respect to low tide counts, three little egrets were recorded at Wilcove and two were

observed at Thanckes Lake. There is no comparable data available from the BTO, however; as

low tide counts undertaken by the BTO are undertaken from November to February (winter

period).

Although the habitats around the existing jetty are not part of a designated SPA, they are clearly

functionally linked to the SPA habitats and support on-passage little egrets which are an SPA

feature.

Thanckes jetty


No surveys were undertaken during the wintering period, therefore BTO core count and low tide

data has been used to assess the importance of the intertidal habitats within and adjacent to the

Site for little egret.

Figures 6-2 and 6-3 below (taken from BTO website www.bto.org) illustrate the areas covered

by the BTO WeBS in the Tamar Estuary. For the five year period (2006/7-10/11) a mean peak

of five little egret were recorded in the Tamar Estuary (South) Sector 10 (illustrated in Figure 6-

2). This sector covers an area of approximately 390 ha and extends north from the Site to the

Tamar Bridge (approximately 3km away) and south to Torpoint ferry crossing, a distance of

approximately 940m. The Tamar Complex as a whole covers an area greater than the SPA

(which is 6402.03ha) and recorded a mean peak of 73 little egrets over the same time period.

Figure 6-2 Tamar Estuary (South) Sector 10

Thanckes jetty


Figure 6-3 Tamar Complex

The BTO data, indicates that fewer little egrets are recorded over winter than during passage.

The October 2009 bird survey was undertaken during the peak passage period and a maximum

of two little egrets were observed in the vicinity of the Site. It is therefore considered that the

Site is unlikely to support significant numbers of overwintering little egret. This conclusion is

supported by Figure 6-4 which illustrates the distribution of little egret at low tide during the

winter of 2002/3. It can be seen that no little egret were observed to the north of the jetty, and

only a small number to the south of the jetty on Thanckes Lake.

Figure 6-4 Distribution of little egret at low tide, winter 2002/3

Thanckes jetty

Thanckes jetty


Notwithstanding these data, the potential impacts on any little egret that may be using the

habitats in the vicinity of the Site (which are functionally linked to nearby SPA habitats) will be

considered further in Section 6.6.

Given the considerable distance of the Rame Head disposal site from this SPA, no impacts as a

result of sediment deposition here are envisaged. This is supported by a letter from NE dated




Due to the nature conservation value of this site and the species it supports, the Tamar

Estuaries Complex SPA is considered to be of International importance.


Appendix 6-D the HRA Screening Report.

Plymouth Sound and Estuaries European Marine Site

The conservation objectives for a European site are intended to represent the aims of the

Habitats and Birds Directives in relation to that site. The marine components of the Plymouth

Sound and Estuaries SAC and the Tamar Complex SPA qualify as European Marine Sites,

however; for simplicity, NE have provided the conservation objectives for both the SAC and

SPA components as a single European marine site: the Plymouth Sound and Estuaries

European Marine Site. The conservation objectives are summarised within Appendix 6-E. The

conservation objectives for the marine site focus on the area, range, structure and function of

habitats, to ensure that they are in a stable and suitable condition to support the species and

features for which the site is designated. Specific conservation objectives are also included for

the birds listed as qualifying features relating to habitat condition in recognition that bird

populations may change as a reflection of national or international trends or events.

The European Marine Site is considered vulnerable to a range of human activities, including

physical loss and damage, disturbance, and toxic and non-toxic contamination.

Dartmoor SAC

The Site is located approximately 10km to the south-east and downstream of Dartmoor SAC.

This SAC comprises areas of blanket bog, heathland and woodland. However, its qualifying

features include Atlantic salmon, which reach Dartmoor SAC via the Plymouth Sound and

Estuaries SAC.

Annex I habitats that are a primary reason for selection of the SAC are as follows:

• northern Atlantic wet heaths with Cross-leaved Heath;

• European dry heaths;

• blanket bogs;

• old sessile oak woods.

None of these Annex I habitats occur in the vicinity of the Site and there are no impact pathways

linking the Site to the habitats. Consequently no impacts on the habitats are predicted and they

will not be considered further in this assessment.

The Annex II species that is a primary reason for selection of the SAC is southern damselfly.

However, this species is found at a single valley mire at 280m altitude and is therefore not found


anywhere close to the Site. It is considered that the proposed Development would not affect the

habitats that support this species and therefore it is not considered further in this assessment.

The Annex II species present as a qualifying feature, but not a primary reason for site selection

are Atlantic salmon and otter. It is feasible that otters associated with this SAC may come down

as far as the Tamar. Otters are known to be present along the Tamar Estuary and are listed as

being present within Plymouth Sound SAC but not in significant numbers. The Site is not

considered to be of particular value to otters given the lack of desk study records, the sub-

optimal habitat within the Site and the large home ranges of otters. Nevertheless, otters are

likely to commute up and down the estuary and any effects on them will be considered on

account of their legal protection.

Given the considerable distance of the Rame Head disposal site from this SAC, no impacts as a

result of sediment deposition here are envisaged. This is supported by a letter from NE dated




The only SAC feature that will be considered in this assessment is Atlantic salmon, specifically

the effects on salmon migrating past the proposed Development. The effects on Atlantic

salmon will be considered in detail in this assessment under the ‘migratory fish’ key receptor.

Dartmoor SAC is considered to be of International importance.


Appendix 6-D the HRA Screening Report and Section 6.6 of this assessment.

Lynher Estuary SSSI

Lynher Estuary SSSI, located approximately 2km to the west of the Site is also part of the

Plymouth Sound and Estuaries SAC and the Tamar Estuaries Complex SPA (the Plymouth

Sound and Estuaries European Marine Site). It is designated for its saltmarsh and mudflat

communities, which provide important feeding and roosting grounds for large populations of

wintering wildfowl and waders including wigeon (Anas penelope), teal (Anas crecca), curlew

(Numenius arquata) and dunlin (Calidris alpina). The ancient woodlands of Sheviock and

Wacker are also included in the site. Due to the lack of impact pathways and distance from the

Site, the saltmarsh and woodland will not be considered further in this assessment.

Due to its nature conservation value and the species it supports, the Lynher Estuary SSSI is

considered to be of National importance. Impacts on the mudflat habitats the site supports are

considered in the context of the European Marine Site. Bird species associated with this SSSI

are considered along with birds associated with the Tamar Estuaries Complex SPA and the St

John’s Lake SSSI (see below) as a single key ecological receptor.

St John’s Lake SSSI

St John’s Lake SSSI, located approximately 1.4km to the south of the Site is part of the

Plymouth Sound and Estuaries SAC and the Tamar Estuaries Complex SPA. It is designated

for its extensive intertidal mudflat communities, which provide important feeding and roosting

grounds for large populations of wintering wildfowl and waders, including nationally important

populations of wigeon and black-tailed godwit (Limosa limosa).

Due to its nature conservation value and the species it supports, St John’s Lake SSSI is

considered to be of National importance. Impacts on the mudflat habitats the SSSI supports are


considered in the context of the European Marine Site. Bird species associated with this SSSI

are considered along with birds associated with the Tamar Estuaries Complex SPA and the

Lynher Estuary SSSI (see above) as a single key ecological receptor.

Tamar-Tavy Estuary SSSI

Tamar-Tavy SSSI, located approximately 3.2km to the north of the Site at its closest point, is

part of the Plymouth Sound and Estuaries SAC and the Tamar Estuaries Complex SPA. It is

designated for its nationally important wintering population of avocet and estuarine habitats,

including intertidal mudflats and saltmarsh. Several areas of semi-natural woodland also form

part of the site and the freshwater section of the estuary supports Triangular Club-rush and

kingfisher.

Due to its nature conservation value the Tamar-Tavy Estuary SSSI is considered to be of

National importance. The distance upstream from the Site means that there is little opportunity

for an impact pathway between the SSSI and the proposed Development, therefore no impacts

are predicted on the Tamar-Tavy Estuary SSSI and it will not be considered further in the impact

assessment.

Plymouth Sound Shores and Cliffs SSSI

A section of Plymouth Sound Shores and Cliffs SSSI is 4.9km to the south of the Site, with the

majority of this SSSI approximately 5.4km to the south-east of the Site. This SSSI encompasses

ecological zones from the open coast and sheltered bay parts of Plymouth Sound, and includes

shore communities with a south-western influence. The SSSI forms part of the Plymouth Sound

and Estuaries SAC and is considered to be of National importance. However, due to the

distance from the Site and lack of impact pathways to the woodland and freshwater sections of

the SSSI, the species associated with these features will not be considered further. In addition,

the distance from the Site means that any potential impacts from increased sediment discharge

as a result of works will not be significant so far downstream, therefore the Plymouth Sound

Shores and Cliffs SSSI will not be considered further in this impact assessment.

Mount Wise SSSI

Mount Wise SSSI is located approximately 2.5km south-east of the Site, and is designated for

its geological interest. Given the absence of impact pathways linking this SSSI to the Site, and

its nature as a geological SSSI it is considered unlikely that the Development would have direct

or indirect effects on this site of National importance. Mount Wise SSSI will not be considered

further within the impact assessment.

Western King SSSI

Western King SSSI is located approximately 3.5km to the south-east of the Site, and is

designated for its geological interest and area of amenity grassland and scrub which support

colonies of the nationally rare plant Field Eryngo (Eryngium campestre). Given the distance

from the Site and the lack of impact pathways linking to this SSSI, it is considered unlikely that

the Development would have direct or indirect effects on this site of National importance.

Western King SSSI will not be considered further within the impact assessment.

Richmond Walk SSSI

Richmond Walk SSSI is located approximately 3.3km south-east of the Site, and is designated

for its geological interest. Given the absence of impact pathways linking this SSSI to the Site,

and its nature as a geological SSSI it is considered unlikely that the Development would have


direct or indirect effects on this site of National importance. Richmond Walk SSSI will not be

considered further within the impact assessment.

Kingsand to Sandway Point SSSI

Kingsand to Sandway Point SSSI is located approximately 4.9km south of the Site, and is

designated for its geological interest. Given the absence of impact pathways linking this SSSI

to the Site, and its nature as a geological SSSI it is considered unlikely that the Development

would have direct or indirect effects on this site of National importance. Kingsand to Sandway

Point SSSI will not be considered further within the impact assessment.

Tamar Estuary Marine Conservation Zones (MCZ)

The Tamar Estuary MCZ is located in two separate areas including the upper reaches of the

Tamar and Lynher estuaries, and is part of the Plymouth Sound and Estuaries SAC, the Tamar

Estuaries Complex SPA, the Lynher Estuary SSSI and the Tamar-Tavy Estuary SSSI. The

proposed Development is approximately 2km away from this MCZ, at its closest point within the

Lynher estuary. The Tamar Estuary MCZ supports intertidal biogenic reefs and intertidal coarse

sediment, as well as migratory European smelt, which breed within the Tamar Estuary, and

European eel. It is also designated due to the presence of the native oyster and blue mussel

beds. Due to its nature conservation value and the species it supports, the Tamar Estuary MCZ

is considered to be of National importance.

It is unlikely that the proposed Development will have a significant effect on intertidal biogenic

reefs, intertidal coarse sediment, oysters or blue mussel beds within the MCZ given that the

control of sediment release from dredging will avoid the effects of fine sediment re-deposition

and associated pollution over such a distance. (See Table 6.5 for further information regarding

marine habitats within the study area.)

The only features that will be considered in this assessment are European smelt and European

eel, specifically the effects on these species migrating past the proposed Development. The

conservation objective for European eel is ‘maintain’ and for European smelt is ‘recover’. The

effects on European smelt and European eel will be considered in detail in this assessment

under the ‘migratory fish’ key receptor.

Rame Head and Whitsand Bay SSSI

The site extends for approximately 8km along the south Cornwall coast, located approximately

1.5km north of the Rame Head disposal site. The coastal cliff habitats are of particular

importance for the occurrence of the largest colony of the nationally rare Shore Dock. In

addition, the site also supports significant populations of other rare plant species including the

nationally rare Slender Bird’s-foot-trefoil (Lotus angustissimus) and Early Meadow-grass (Poa

infirma). Whitsand Bay is also of special interest for its geology and coastal geomorphology.

Given the lack of impact pathways between SSSI, which is designated on account of its

terrestrial features, and Rame Head disposal site, it is considered unlikely that the Development

would have direct or indirect effects on this site of National importance. Rame Head and

Whitsand Bay SSSI will not be considered further within the impact assessment.

Whitsand and Looe Bay MCZ

The Whitsand and Looe Bay MCZ is an inshore site located off the south coast of Cornwall

approximately 5.2km from the proposed Development across land, but approximately 10km

from the proposed Development by sea, around Rame Head. The site supports intertidal sand


and coarse sediment habitats, subtidal sand and coarse sediment habitats, as well as intertidal

rocky habitats at Hannafore and on Looe Island which support a high diversity of seaweeds and

invertebrates. The ocean quahog (Arctica islandica), a long-lived bivalve which is known to live

for over 400 years has been recorded within sediment habitats in the site. Within the shallower

part of the site the seagrass beds are likely to provide a nursery ground for ecologically and

commercially important species such as cuttlefish (Sepia officinalis). Further out to sea there are

shipwrecks and small areas of subtidal rocky reef that support pink sea-fans (Eunicella

verrucosa) and rare sea-fan anemones (Amphianthus dohrnii). Stalked jellyfish (Haliclystus

auricular) are also present within the site. Due to its nature conservation value and the species it

supports, the Whitsand and Looe Bay MCZ is considered to be of National importance.

A potential impact pathway exists between the Site and this MCZ via the Tamar River and the

sea around Rame Head. However, given the considerable distance of this impact pathway and

the control of dredging operations, no impacts are envisaged on this MCZ as a result of the

proposed Development. This MCZ will not be considered further in this assessment.

Woodland Wood Valley LNR

Woodland Wood Valley LNR is located approximately 4.9km to the north-east of the Site. It is a

valuable landscape and biodiversity resource for the surrounding urban area and includes a

variety of habitats including woodland, hedgerows, meadows and a stream. The LNR has no

links with the Site and it is considered that the proposed Development would have no direct or

indirect impacts on this site of County importance. Woodland Wood Valley LNR will not be

considered further in this assessment.

Budshead Wood LNR

Budshead Wood LNR is situated approximately 4.5km to the north-east of the Site, surrounded

by urban development. It is ancient woodland adjacent to a tidal creek that runs into the Tamar.

It is considered that the distance from the Site is sufficient that no impact pathway can connect

the Site to the tidal creek that is adjacent to the LNR, a site of County importance. As a result,

Budshead Wood LNR will not be considered further in this assessment.

6.4.3 Non-statutory designated sites

The mudflats adjacent to the shore, within the site, are within an AGSV (See Planning Policy

CL13 within the Caradon Local Plan First Alteration (August 2007) in Table 6-1). These

represent a broader approach to nature conservation than the protection of specific sites and

act as provide a buffer around the most important and sensitive nature conservation sites,

providing links between protected sites, facilitating the movement of wildlife. This site of County

importance considered under the ‘seagrass beds’ ecological receptor.

Four CWS are found within 5km of the Site. These are as follows:

• Lower Lynher Estuary;

• St John’s Lake;

• Tincombe Reserve;

• Clarrick and Pigshill Woods.

The Lower Lynher Estuary CWS and St John’s Lake CWS are in excess of 2km from the Site.

They are designated on account of the saltmarsh habitat they support. Given the distances

involved, it is considered unlikely that the Development would have any direct or indirect effects


the saltmarsh habitat within these sites of County importance, and they are not considered

further in this assessment.

Tincombe Reserve CWS is a small woodland approximately 3km to the north-west of the Site

close to the centre of Saltash. Given the distance from the Site and the lack of impact pathways

linking to this CWS, it is considered unlikely that the Development would have direct or indirect

effects on this site of County importance. Tincombe Reserve CWS will not be considered

further within the impact assessment.

Clarrick and Pigshill Woods CWS are situated approximately 3.5km to the south of the Site.

Given the distance from the Site and the lack of impact pathways linking this CWS to the Site, it

is considered unlikely that the Development would have direct or indirect effects on Clarrick and

Pigshill Woods CWS. Therefore, Clarrick and Pigshill Woods CWS will not be considered further

within the impact assessment.

Churchdown Farm Community Nature Reserve

The Cornwall Wildlife Trust manages this farm as a Community Nature Reserve for the benefit

of wildlife. The reserve is approximately 2.7km north of the Site, and given the absence of

impact pathways linking the reserve with the proposed Development, it is considered unlikely

that the Development would have direct or indirect effects on this Community Nature Reserve of

Parish/Neighbourhood value. Churchdown Farm will not be considered further within the

impact assessment.

6.4.4 Terrestrial plants and habitats

The Site occupies the slopes of a promontory jutting out into the Tamar Estuary and comprises

a series of level terraces on which the fuel tanks are situated. Drawing 6-1 illustrates the results

of the Phase 1 habitat survey and Appendix 6-B contains the accompanying Target Notes,

which provide further descriptions of features of interest.

The desk study revealed a number of species listed on Section 41 of the NERC Act and the

Local BAP as being recorded in the 1km study area, including Thorow-wax (Bupleurum

rotundifolium), Caraway (Carum carvi) and Stinking Goosefoot (Chenopodium vulvaria).

However, these records are historical (the most recent, Thorow-wax, dating from 1966) and not

in the immediate vicinity of the Site. In addition, the habitats that the Site supports are not

considered suitable for these species. The most recent record of a Section 41 species was for

Bastard Balm (Melittis melissophyllum), dated from 2001, and is considered likely to be a re-

discovery of a population last recorded at Anthony House (approximately 1km to the east of the

Site) in 1880. Again, it is considered unlikely that this species, which is associated with scrub

habitats on calcareous soils, would be present on Site.

In general, the records of vascular and non-vascular plants provided by the record centre are

considered unlikely to occur on the Site due to the modified nature of habitats present and the

limited extent of semi-natural habitats.

Surrounding the fuel tanks were extensive areas of short mown amenity grassland supporting

fine grasses such as Red Fescue (Festuca rubra) and occasional forb species including

Creeping Buttercup (Ranunculus repens), Selfheal (Prunella vulgaris) and the non-native Pirri-

pirri-bur (Acaena novae-zelandiae).

On the slopes between the terraces and fringing the shoreline along the northern and southern

boundaries of the Site were strips of broadleaved woodland, considered to be semi-natural in

origin. The woodland supported a number of species indicative of this type of habitat, including

Ash (Fraxinus excelsior), Hazel (Corylus avellana), Sweet Chestnut (Castanea sativa) and


Sycamore (Acer pseudoplatanus). A band of woodland comprising Evergreen Oak (Quercus

ilex), Ash, Hazel and Sycamore was situated north of the northern line of tanks. Ground flora

species included Hart's-tongue (Phyllitis scolopendrium), Bramble (Rubus fruticosus) and Male-

fern (Dryopteris filix-mas). There was also a line of mature Monterey Pines (Pinus radiate)

between the woodland and the tanks.

Areas of Butterfly-bush (Buddleja davidii) and Bramble (Rubus futicosus agg.) scrub were

present, principally along the top of the concrete emergency fuel containment tanks. These

areas of scrub were relatively low (1m high) and were clearly subject to regular periods of

cutting and other management activities. In addition, there was a large area of Butterfly-bush

scrub located west of the easternmost group of tanks, part of which had been cleared creating

an area of bare ground.

Large, steep-sided, concrete tanks used for emergency containment of fuel were present,

several of which contained standing open water up to 1m deep. These tanks supported virtually

no aquatic or emergent vegetation, with the exception of a few isolated stands of Bulrush

(Typha latifolia) in one of the containment tanks. A large area of shallow water (5cm deep) was

present at the time of the survey where a fuel tank had been removed. This supported no

aquatic or emergent vegetation. In addition to the tanks above, there was also a small concrete

water tank (4m x 4m) close to the main administrative buildings, containing water approximately

1m deep with a dense growth of Canadian Waterweed (Elodea Canadensis).

The majority of the terrestrial habitats across the Site (amenity grassland, scrub, tall ruderal

grassland) are considered to be of negligible conservation value. The small areas of semi-

natural woodland are considered to be of importance at a Parish/Neighbourhood level.

6.4.5 Invasive plants

Canadian Waterweed is listed on Schedule 9 of the Wildlife and Countryside Act 1981 (as

amended) and as such it is an offense to cause this plant to spread in the wild. Although the

non-native Pirri-pirri-bur is not listed on Schedule 9 of the Wildlife and Countryside Act it was

present across large areas of the Site and is clearly invasive in this location. Measures will be

put in place to ensure that these invasive weeds are not spread during construction.

6.4.6 Terrestrial Invertebrates

The desk study revealed that a number of moth species considered to be of Principal

Importance for biodiversity (listed on Section 41 of the NERC Act 2006) have been recorded in

the locality. These include the garden tiger moth (Arctia caja), the dusky thorn moth (Ennomos

fuscantaria), mouse moth (Amphipyra tragopoginis) and knotgrass moth (Acronicta rumicis).

The potential exists for several of these species to be found on the Site. However, given the

limited diversity of habitats and species found on site and the localised nature of the semi-

natural habitats, the Site is considered to be of negligible importance for invertebrates.

6.4.7 Amphibians

The desk study returned one record for common toad, listed on Section 41 of the NERC Act

2006, within the 1km study area. The standing open water present on site is considered to be

sub-optimal habitat for amphibians due to the lack of marginal and aquatic vegetation and the

steep sides of the tanks, which would make access by amphibians difficult. The Site is

considered to be of negligible value to amphibian species.


6.4.8 Reptiles

The mosaic of scrub, amenity grassland, woodland and steep concrete tanks are considered to

offer suitable foraging habitat and basking opportunities for reptiles, in particular common lizard

(listed on Section 41 of the NERC Act 2006). The desk study returned one historical record of

common lizard, dating from 1985. It is considered unlikely that the Site supports a large

population of common lizards, and therefore the Site is considered to be, at most, of

Parish/Neighbourhood importance for reptiles.

6.4.9 Breeding birds

The mudflat and shoreline habitats within the Site are of limited value to nesting and breeding

birds, since they are largely covered by water at high tide. The woodland and scrub areas are

considered likely to support a range of breeding bird species characteristic of woodland habitat.

Fifteen species of common woodland birds including blackbird (Turdus merula), robin (Erithacus

rubecula), blue tit (Cyanistes caeruleus) and great tit (Parus major), were incidentally observed

during the field survey, which provides an indication of the potential breeding bird assemblage.

In addition, site staff provided anecdotal evidence that the broadleaved woodland fringing the

shore supported a small heronry with 6-8 breeding pairs. The broadleaved woodland will not be

affected by the proposed Development. Due to the regular cutting of the amenity grassland it is

considered that ground nesting birds are unlikely to be present. The desk study returned

hundreds of bird records, however; very few were of relevance to the terrestrial habitats the Site

supports. The Site is considered to be of, at most, Parish/Neighbourhood importance for

breeding birds.

6.4.10 Otters

Otters are listed as being present within the Plymouth Sound and Estuaries SAC but not in

significant numbers. The desk study returned no records of otters within the 1km search area. It

is considered likely that otters commute up and down the estuary in the vicinity of the proposed

Development, however; given the large home range of otters (up to 20km) and the fact that the

Site itself is considered to provide sub-optimal habitat to support otter holts, the Site is

considered to be of Parish/Neighbourhood importance for otters. Nevertheless, otters are

legally protected and therefore mitigation measures will be provided.

6.4.11 Bats

The desk study revealed several records of lesser horseshoe (Rhinolophus hipposideros) and

greater horseshoe bat (Rhinolophus ferrumequinum), the most recent dating from 2005,

approximately 1km from the Site. The larger, more mature trees within the strips of woodland,

in particular the line of Monterey Pines may support bark crevices and cracks suitable for

roosting bats. However, no obvious features were noted. All the buildings present on Site were

well maintained and appeared to offer few opportunities for roosting bats to access the

structures. An occasional open window was noted, however; the interior of the building

appeared well lit with no obvious roof void. A tunnel was identified close to the northern

boundary of the Site that could potentially be accessed by roosting bats. However, this tunnel is

some distance from the proposed Development and therefore should bats use this feature it is

considered unlikely that they would be affected by the works.

The mosaic of grassland, scrub and woodland habitats was considered to offer foraging

opportunities for bat species. The Site is considered to be, at most, of Parish/Neighbourhood

importance for bats.


6.4.12 Dormice

The woodland areas on site support Hazel shrubs and Traveller's-joy (Clematis vitalba), both

species utilised by foraging dormice. In addition, there was good connectivity between the

canopy and shrub layers and therefore it may be considered potentially suitable to support

dormice. However, the desk study returned no records of dormice and a review of aerial

photographs indicates that the Site is relatively isolated and poorly connected to other areas of

woodland and hedgerows in the wider landscape. It is also considered that the extent of

woodland habitat available on site is not sufficient to support a viable population of dormice. It

is, therefore, considered unlikely that dormice are present on site and they will not be

considered further in the assessment.

6.4.13 Badgers

No evidence to suggest that badgers were present on the Site was identified. The Site security

fence is dug into the ground which would also make access by badgers more difficult. For these

reasons it is considered that badgers are not present within the Site boundary and they will not

be considered further in the assessment.

6.4.14 Marine Habitats

The desk study revealed areas of intertidal mudflats and seagrass beds within the study area

which are habitats of Principal Importance listed on Section 41 of the NERC Act 2006 and

Cornwall BAP Priority habitats.

Video examination and species identification from grab samples identified a number of marine

habitats (biotopes) as detailed in Figure 6.5 and Figure 6.6 and listed in Table 6-5. The results

of the marine survey are presented in Appendix 6-C together with the value of ecological

receptors and the justification for this valuation.


Figure 6-5 Results of inter-tidal survey


Figure 6-6 Results of subtidal survey (Note that this figure has been included to illustrate

the results of the subtidal survey only, and the proposed jetty and dredging locations

shown have since been revised)

Hyd

er

Consultin

g (

UK

) L

imited-2

212

95

9

Pag

e 1

04

Tab

le 6

-5 R

esu

lts o

f M

ari

ne a

nd

In

tert

idal S

urv

eys

Bio

top

e N

am

e a

nd

C

od

e

Bio

top

e/S

pecie

s

Descri

pti

on

E

co

log

ical R

ecep

tor

Co

rresp

on

din

g

Desig

nati

on

s

Eco

log

ical V

alu

e

Eco

log

ical V

alu

e a

nd

Sco

pin

g D

ecis

ion

Sub-litto

ral m

ud in

vary

ing s

alin

ities

(estu

aries)

SS

.SM

u.S

MuV

S

Shallo

w s

ublit

tora

l m

uds,

ext

endin

g fro

m the e

xtre

me

low

er

shore

into

the s

ubtidal

in v

ariable

salin

ity

(estu

arine)

conditio

ns

Benth

ic

Subtidal M

ud (

variable

salin

ity)

SA

C h

abitat

Section 4

1 N

ER

C A

ct

2006

Dis

tric

t/B

oro

ugh

The h

isto

rical dre

dgin

g r

egim

e a

nd h

igh u

se

of th

e e

stu

ary

heavily

impact

s th

e s

ublit

tora

l sedim

ents

leavi

ng the S

ite im

poveri

shed a

nd

no s

ignific

ant num

bers

of im

port

ant speci

es

were

identified. N

evert

hele

ss, th

e im

pacts

on the s

ubtidal m

ud w

ill b

e c

onsid

ere

d in the

conte

xt o

f th

e I

nte

rnati

on

ally im

port

ant

SA

C.

Sub-litto

ral m

ixed

sedim

ent in

vary

ing

salin

ity

(estu

aries)

SS

.SM

x.S

MxV

S

Shallo

w s

ublit

tora

l m

ixed

sedim

ents

in e

stu

arine

conditi

ons,

often w

ith

surf

ace s

hells

or

sto

nes,

enablin

g the d

evelo

pm

ent

of

div

ers

e e

pifaunal

com

munitie

s a

s w

ell

as

infa

unal co

mm

unitie

s.

Benth

ic

Subtidal M

ud (

variable

salin

ity)

SA

C h

abitat

Section 4

1 N

ER

C A

ct

2006

Dis

tric

t/B

oro

ugh

As for

SS

.SM

u.S

MuV

S

Cre

pid

ula

forn

icata

and

Medio

mastu

s fr

agili

s in

variable

salin

ity

infr

alli

ttora

l m

ixed

sedim

ent

SS

.SM

x.S

MxV

S.C

reM

ed

Vari

able

salin

ity

mix

ed

sedim

ent chara

cte

rised b

y th

e s

lipper

limpet (C

repid

ula

fo

rnic

ata

) and the

poly

chaete

s (

Medio

mastu

s fr

agili

s)

and (

Aphelo

chaeta

m

arion

i).

Benth

ic

Subtidal M

ixed

Sedim

ent

(variable

salin

ity)

SA

C h

abitat

Section 4

1 N

ER

C A

ct

2006

Dis

tric

t/B

oro

ugh

As for

SS

.SM

u.S

MuV

S

Yello

w a

nd g

rey lic

hens

on s

upra

litto

ral ro

ck

LR

.FLR

.Lic

.YG

Vert

ical to

gently s

lopin

g

bedro

ck a

nd s

table

bould

ers

in

the s

upra

litto

ral (o

r spla

sh

zone)

of th

e m

ajo

rity

of

rocky

shore

s a

re t

ypic

ally

chara

cterised b

y a

div

ers

e

com

munity o

f yello

w a

nd

gre

y lic

hens

such a

s X

anth

oria p

arietin

a,

Calo

pla

ca m

arina,

Lecanora

atr

a a

nd R

am

alin

a s

pp..

Spla

sh Z

one E

stuarine

Rocky h

abitat

Section 4

1 N

ER

C A

ct

2006

LB

AP

Priority

Habitat

Parish/N

eig

hbourh

ood

The s

mall

are

a o

f ro

cky

habitat th

at

support

ed this

bio

tope w

as

deem

ed t

o b

e o

f only

Pari

sh

/Neig

hb

ou

rho

od

import

ance

due t

o it

s li

mited e

xtent

and its

com

posi

tion

com

prisin

g c

om

mon lic

hen s

pecie

s. In

additio

n, it

is c

onsi

dere

d h

ighly

unlik

ely

that

both

terr

estr

ial and m

arine c

onstr

uct

ion

work

s w

ill a

ffect th

is b

ioto

pe.

Verr

ucaria m

aura

on

Upper

litto

ral f

ringe b

edro

ck,

S

pla

sh Z

one E

stuarine

Section 4

1 N

ER

C A

ct

Parish/N

eig

hbourh

ood

As for

LR

.FLR

.Lic

.YG

Hyd

er

Consultin

g (

UK

) L

imited-2

212

95

9

Pag

e 1

05

Bio

top

e N

am

e a

nd

C

od

e

Bio

top

e/S

pecie

s

Descri

pti

on

E

co

log

ical R

ecep

tor

Co

rresp

on

din

g

Desig

nati

on

s

Eco

log

ical V

alu

e

Eco

log

ical V

alu

e a

nd

Sco

pin

g D

ecis

ion

very

exp

osed t

o v

ery

sheltere

d u

pper

litto

ral

frin

ge r

ock

LR

.FLR

.Lic

.Ver.

Ver

bould

ers

and s

table

cobble

s

on v

ery

exp

osed t

o v

ery

sheltere

d s

hore

s w

hic

h

have a

bla

nket covering o

f th

e b

lack

lichen V

err

ucaria

maura

. T

his

zone is

norm

ally

found b

elo

w the

yello

w/g

rey lic

hen z

one a

nd

there

is

not

alw

ays

a c

lear

transiti

on b

etw

een t

he t

wo.

rocky

habitat

2006

LB

AP

Priority

Habitat

Pelv

etia c

analic

ula

ta o

n

sheltere

d,

variable

salin

ity

litto

ral fr

inge r

ock

LR

.LLR

.FV

S.P

eIV

S

Low

er

litto

ral f

ringe b

edro

ck

or

stable

bould

ers

and

mix

ed s

ubst

rata

on v

ery

sheltere

d t

o e

xtre

mely

sheltere

d v

ariable

salin

ity

shore

s c

hara

cte

rised b

y a

dense c

over

of th

e w

rack

Pelv

etia c

anlic

ula

ta,

whic

h

oft

en o

verg

row

s a c

rust of

bla

ck

lichens V

err

uca

ria

maura

.

Inte

rtid

al

Estu

ari

ne r

ocky

habitat

Section 4

1 N

ER

C A

ct

2006

LB

AP

Priority

Habitat

Parish/N

eig

hbourh

ood

As for

LR

.FLR

.Lic

.YG

Fucus s

piralis

on

sheltere

d v

ariable

salin

ity

upper

eulit

tora

l ro

ck

LR

.LLR

.FV

S.F

spiV

S

Sheltere

d t

o e

xtre

mely

sheltere

d u

pper

eulit

tora

l bedro

ck o

r m

ixed s

ubstr

ata

(b

ould

ers

, la

rge c

obble

s o

r shells

on m

ud)

in v

ariable

salin

ity

conditi

ons

chara

cterised b

y a

band o

f th

e s

pir

al w

rack

Fucus

spira

lis.

Inte

rtid

al

Estu

ari

ne r

ocky

habitat

Section 4

1 N

ER

C A

ct

2006

LB

AP

Priority

Habitat

Parish/N

eig

hbourh

ood

As for

LR

.FLR

.Lic

.YG

Ascophyllu

m n

odosum

and F

ucus

vesic

ulu

s o

n

variable

salin

ity m

id

eulit

tora

l ro

ck

LR

.LLR

.FV

S.A

ScV

S

Very

sheltere

d to e

xtre

mely

sheltere

d m

id e

ulit

tora

l bedro

ck, bould

ers

or

cobble

s s

ubje

ct to

variable

salin

ity

chara

cterised b

y a

n

impoverished c

om

munity

dom

inate

d b

y the w

racks

Ascophyllu

m n

odosum

and

Fucus v

esic

ulo

sus.

Inte

rtid

al

Estu

ari

ne r

ocky

habitat

Section 4

1 N

ER

C A

ct

2006

LB

AP

Priority

Habitat

Parish/N

eig

hbourh

ood

This

habitat w

ithin

the inte

rtid

al re

gio

n w

as

impoverished b

ut connecte

d t

o s

imila

r habitat alo

ng the s

hore

line a

nd s

o w

as

giv

en

a v

alu

e o

f P

ari

sh

/Neig

hb

ou

rho

od

im

port

ance. T

his

recepto

r is

there

fore

not

consid

ere

d v

alu

able

enough f

or

any

sig

nific

ant im

pacts

to a

rise.

Hyd

er

Consultin

g (

UK

) L

imited-2

212

95

9

Pag

e 1

06

Bio

top

e N

am

e a

nd

C

od

e

Bio

top

e/S

pecie

s

Descri

pti

on

E

co

log

ical R

ecep

tor

Co

rresp

on

din

g

Desig

nati

on

s

Eco

log

ical V

alu

e

Eco

log

ical V

alu

e a

nd

Sco

pin

g D

ecis

ion

Ephem

era

l gre

en a

nd

red s

eaw

eeds o

n

variable

salin

ity a

nd/o

r dis

turb

ed e

ulit

tora

l m

ixed

substr

ata

LR

.FLR

.Eph.E

phX

Eulit

tora

l mix

ed s

ubst

rata

(p

ebble

s a

nd c

obble

s

overl

ying s

and o

r m

ud)

that

are

subje

ct to

variations

in

salin

ity

and/o

r si

ltation,

chara

cterised b

y d

ense

bla

nkets

of

ephem

era

l gre

en a

nd r

ed s

eaw

eeds.

T

he m

ain

specie

s p

resent

are

Ente

rom

orp

ha

inte

stin

alis

, U

lva lactu

ca

and P

orp

hra

spp..

Inte

rtid

al

Mix

ed S

edim

ent

Section 4

1 N

ER

C A

ct

2006

Sheltere

d M

uddy

Gra

vels

.

Parish/N

eig

hbourh

ood

This

habitat w

ithin

the inte

rtid

al re

gio

n w

as

giv

en a

valu

e o

f P

ari

sh

/Neig

hb

ou

rho

od

im

port

ance a

s it pro

vides s

om

e d

ivers

ity

am

ong a

fucoid

dom

inate

d a

rea. A

n

ext

rem

ely

sm

all

are

a o

f th

is b

ioto

pe w

ill b

e

dir

ectly

under

the footp

rint of th

e

develo

pm

ent (<

40m

2)

but th

e r

ecepto

r is

not

consid

ere

d v

alu

able

enough f

or

any

sig

nific

ant im

pacts

to a

rise.

Seagra

ss b

eds o

n li

ttora

l sedim

ents

LS

.LM

p.L

Sgr

Mid

and u

pper

shore

wave-

sheltere

d m

uddy fin

e s

and

or

sandy

mud w

ith n

arr

ow

-le

afe

d e

el gra

ss

Zost

era

noltii

at

an a

bundance o

f fr

equent

or

above.

Inte

rtid

al seagra

ss

beds

(mudflats

)

As S

eagra

ss

Beds:

OS

PA

R L

ist of

Thre

ate

ned a

nd/o

r D

eclin

ing S

peci

es a

nd

Habitats

Section 4

1 N

ER

C A

ct

Corn

wall

BA

P P

riority

H

abitat

As M

udflats

:

SA

C/H

abitats

Directive

Annex

I H

abitat

Section 4

1 N

ER

C A

ct

Corn

wall

BA

P P

riority

H

abitat

County

S

eagra

ss B

eds a

re lis

ted a

s a h

abitat of

pri

ncip

al i

mport

ance o

n S

ection 4

1 o

f th

e

NE

RC

Act and the C

orn

wall

BA

P a

nd h

as

als

o b

een lis

ted b

y O

SP

AR

. T

he s

eagra

ss

beds a

dja

cent to

the s

hore

, w

ithin

the s

ite,

are

desig

nate

d a

s a

n A

GS

V. A

t th

e

pro

posed D

evelo

pm

ent si

te the s

eagra

ss

was found t

o b

e locally

abundant, b

ut

was

not a s

wath

e o

f pla

nts

. H

ow

ever,

the

seagra

ss a

t th

e S

ite w

as lin

ked t

o furt

her

seagra

ss h

abitat

either

sid

e o

f Y

onderb

err

y P

oin

t th

at

appeare

d t

o b

e o

f good q

ualit

y.

Inte

rtid

al m

udflats

are

lis

ted a

s a

habitat of

pri

ncip

al i

mport

ance o

n S

ection 4

1 o

f th

e

NE

RC

Act and the C

orn

wall

BA

P.

The

mudflats

adja

cent to

the s

hore

, w

ithin

the

site,

are

desig

nate

d a

s a

n A

GS

V. W

hils

t th

is

habitat is

outs

ide o

f th

e S

AC

boundary

, ‘m

udflats

and s

andflats

not covere

d b

y seaw

ate

r at lo

w tid

e’ i

s a

qualif

yin

g featu

re o

f th

e a

dja

cent

Ply

mouth

Sound a

nd E

stuaries

SA

C.

Although t

he m

udflat does n

ot show

exc

eptional div

ers

ity,

pro

bably

due t

o t

he

natu

re o

f th

e land u

se s

urr

oundin

g the S

ite, it

is f

unctionally

lin

ked to the S

AC

habitats

and

main

tain

s c

onnectivity

betw

een t

he m

udflats

acro

ss the w

ider

are

a.

Hyd

er

Consultin

g (

UK

) L

imited-2

212

95

9

Pag

e 1

07

Bio

top

e N

am

e a

nd

C

od

e

Bio

top

e/S

pecie

s

Descri

pti

on

E

co

log

ical R

ecep

tor

Co

rresp

on

din

g

Desig

nati

on

s

Eco

log

ical V

alu

e

Eco

log

ical V

alu

e a

nd

Sco

pin

g D

ecis

ion

Giv

en t

he a

bundance o

f seagra

ss

and the

low

div

ers

ity o

f th

e m

udflats

, th

is b

ioto

pe is

giv

en a

valu

e o

f C

ou

nty

im

port

ance. T

he

bio

tope w

ill b

e u

nder

the footp

rint

of th

e

develo

pm

ent in

additi

on t

o p

oss

ibly

bein

g

aff

ecte

d b

y s

edim

ent depositio

n.

Ste

rnaspis

scuta

ta

This

specie

s is

a s

tout

burr

ow

ing p

oly

chaete

worm

, w

hitis

h-g

rey in c

olo

ur,

with a

le

ath

ery

text

ure

.

Ste

rnaspis

scuta

ta

inhabits s

andy

and

muddy

substr

ata

, w

here

it

burr

ow

s head-

dow

n, exp

osin

g the

gill

s on its

poste

rior

end.

P

arish/N

eib

ourh

ood

This

indiv

idual w

as

found in g

rab s

am

ple

num

ber

3 n

ear

the p

ositi

on o

f th

e n

ew

jett

y.

Although it has

no d

esig

nation, it

is a

rare

specie

s o

nly

record

ed a

long t

he s

outh

D

evon c

oast

, fr

om

Ply

mouth

Sound to

Ottert

on P

oin

t, a

nd in D

ors

et at P

ort

land

Harb

our.

As

only

one indiv

idual w

as

found, it

is n

ot consid

ere

d v

alu

able

enough f

or

any

sig

nific

ant im

pacts

to a

rise. T

he e

ffects

on it

s habitat w

ill b

e a

ssessed in the c

onte

xt o

f th

e

SA

C.

Native o

yst

er

N

ative o

yst

er

is a

biv

alv

e

mollu

sc that has

an o

val or

pear-

shaped s

hell

with a

ro

ugh, scaly

surf

ace. T

he

two h

alv

es (

valv

es)

of th

e

shell

are

diffe

rent

shapes.

Ost

rea e

dulis

is

associ

ate

d w

ith h

ighly

pro

duct

ive e

stu

arine

and s

hallo

w c

oast

al

wate

r habitats

on firm

bottom

s o

f m

ud, ro

cks,

m

uddy

sand, m

uddy

gra

vel w

ith s

hells

and

hard

silt

.

OS

PA

R L

ist of

Thre

ate

ned a

nd/o

r D

eclin

ing S

peci

es a

nd

Habitats

Section 4

1 N

ER

C A

ct

2006

Corn

wall

BA

P p

riority

specie

s

Neglig

ible

O

nly

one liv

e o

yst

er

was found in g

rab

sam

ple

num

ber

6. O

yste

rs a

re u

sually

clu

stere

d in g

roups

asso

ciate

d w

ith h

ighly

pro

duct

ive e

stu

arine a

nd s

hallo

w c

oast

al

wate

r habitats

. T

hey c

an b

e found o

n firm

m

ud, ro

ck,

muddy

sand, m

uddy

gra

vel w

ith

shells

and h

ard

silt

. O

ne o

f th

e m

ost

suitable

sett

lem

ent subst

rate

s is

natu

ral oyst

er

shell.

H

ence t

hey a

re u

sually

found w

ith o

ther

oyste

rs. It is

lik

ely

that th

is indiv

idual

deta

ched f

rom

the o

yst

er

beds u

pstr

eam

and

is u

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part

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a s

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up,

thus

it w

ill n

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onsi

dere

d f

urt

her

in the

impact

assessm

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ay

A s

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ay w

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typic

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hape a

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egre

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olo

ur

is v

ariable

, usually

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ith

num

ero

us

small

dark

spots

Thorn

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ay

frequents

a w

ide

variety

of gro

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from

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gle

and g

ravel. It

is less fre

quently

record

ed o

n c

oars

er

sedim

ent ty

pes. T

hey

OS

PA

R L

ist of

Thre

ate

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nd/o

r D

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eig

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ood

Only

one indiv

idual w

as

seen o

n v

ideo

transect

num

ber

4. A

s only

one indiv

idual

was found, it is

not consi

dere

d v

alu

able

enough f

or

any s

ignifi

cant im

pact

s to

arise.

This

is a

hig

hly

mobile

specie

s a

nd there

fore

im

pact

s a

re c

onsid

ere

d u

nlik

ely

.

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er

Consultin

g (

UK

) L

imited-2

212

95

9

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e 1

08

Bio

top

e N

am

e a

nd

C

od

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top

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pecie

s

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on

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co

log

ical R

ecep

tor

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rresp

on

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g

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on

s

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log

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alu

e

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log

ical V

alu

e a

nd

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pin

g D

ecis

ion

and y

ello

wis

h p

atc

hes.

Dors

ally

the b

ody

is c

overe

d

with c

oars

e p

rickle

s, w

hic

h

are

pre

sent

from

hatc

hin

g.

In a

dditi

on, la

rge,

back

ward

poin

ting thorn

s (c

alle

d

buckle

rs)

are

sca

ttere

d o

ver

the d

ors

al surf

ace,

each o

f w

hic

h h

as

a t

hic

k button-lik

e

base.

are

als

o found o

n

patc

hes o

f sedim

ent

am

ong r

ocky

outc

rops

and b

ould

ers

. It m

ay

be f

ound t

o a

depth

of

300m

but m

ost

com

mon b

etw

een 1

0 –

60m

. A

lthough m

ain

ly

a n

on-m

igra

tory

specie

s, th

e fis

h o

ften

moves c

lose inshore

during the s

pring.


6.4.15 Migratory Fish

Migratory fish including Atlantic salmon, allis shad, twaite shad, sea trout, European smelt and

European eel are known to pass through the estuary (see Table 6-6 below, from information

provided by the EA). Atlantic salmon are a qualifying feature of Dartmoor SAC, and allis shad

are a qualifying feature of the Plymouth Sound and Estuaries SAC. The presence of European

smelt and European eel are a reason the Tamar Estuary MCZ is designated, and European eel

are classified as ‘critically endangered’ on the IUCN Red Data List (Ref 6-9). All of these fish

species are listed on Section 41 of the NERC Act 2006 as species of Principal Importance.

Table 6-6 Migratory fish species present in the Tamar Estuary

Species Designation Migratory Period

Allis shad Qualifying feature of Plymouth Sound and Estuaries SAC.

April – July (peak May/June)

Atlantic salmon Qualifying feature of Dartmoor SAC.

April – December (peak June/July/August/September/October)

Sea trout Section 41 of the NERC Act 2006 species of Principal Importance

March – December (peak May/June/July)

Salmon & Sea trout smolts

Section 41 of the NERC Act 2006 species of Principal Importance

April – June

Sea trout kelts Section 41 of the NERC Act 2006 species of Principal Importance

November – December (downstream migration)

European smelt

Reason for designation of Tamar Estuary MCZ

February – April

Eels (juvenile) ‘Critically endangered’ on the IUCN Red Data List

March – May (Sea to freshwater)

Eels (adult) ‘Critically endangered’ on the IUCN Red Data List

Autumn months (downstream migration)

River and sea lamprey

Listed as being present in the Plymouth Sound and Estuaries SAC but not at significant population levels

April - July

Twaite shad Listed as being present in the Plymouth Sound and Estuaries SAC but not at significant population levels

April – July (peak May/June)

The only known spawning site for allis shad within the UK is located in the upper Tamar estuary

and the lowest freshwater areas of the Tamar, with the main spawning site considered to be


below Gunnislake Weir (Appendix 6-F). Allis shad enter the Tamar mostly within the May to

June period.

During May Atlantic salmon and sea trout smolt are moving down the estuary to the open sea.

At the same time, adult Atlantic salmon and sea trout are beginning to move up the estuary to

freshwater spawning sites.

The main spawning site for European smelt in the Tamar is considered to be below Gunnislake

Weir. Smelt accumulate in the lower estuary from October onwards before ascending to spawn

between February and April.

Table 6-6 illustrates the importance of the Tamar Estuary for a wide range of migratory fish

species, particularly between the months of April to August. The study area is therefore

considered to be of International importance for migratory fish.

6.4.16 Other Fish Species

The Plymouth Sound and Estuaries Complex SAC is part of a year-round designated nursery

area for bass. The desk study revealed that the proposed Development is also located within

broader scale spawning areas for lemon sole, sole and sprat; and nursery areas for monkfish,

lemon sole, mackerel, spurdog and Whiting.

Of these, mackerel, whiting, monkfish and sole are all listed on Section 41 of the NERC Act

2006 as species of Principal Importance.

The study area is therefore considered to be of Regional importance for other fish species.

6.4.17 Shellfish

The Site lies within 3km of the Designated Shellfish Waters of the Lynher_E and the Classified

Bivalve Mollusc Harvesting Area in the Tamar. The bivalves specifically mentioned include the

Hard-shell clam, mussels, common cockle, razor shells and the great scallop. Commercial

fishing of bivalves in these grounds is currently prohibited.

None of the above species were found in significant numbers during the subtidal surveys. The

grounds are considered to be far enough away from the Site that any potential impacts from the

release of sediment as a result of the works will no longer be significant due to the naturally silty

nature of the estuary and the large dilution factor. The impacts on shellfish will therefore not be

considered further in this assessment.

6.4.18 Marine Mammals

The desk study revealed two records of stranded common dolphin dating from 2005 and 2007;

two records dating from 2007 of a group of four Risso’s dolphin in St John’s Lake; two records

(both from 2004) of harbour porpoise and two records of bottlenose dolphin, both from 1999

between Seaton and Murraytown. In addition, four records of grey seal were returned from

between 1966 and 2006. The results of the recent Cornwall Wildlife Trust Seaquest Netsafe

project, which aimed to gather information on the distribution of cetaceans around the Cornwall

coast, recorded only one common dolphin in three years, off Portwrinkle, at least 15km away

around the coast (Ref 6-10).


All the above species are afforded protection under the Conservation of Habitats and Species

Regulations 2010 (as amended), the Wildlife and Countryside Act 1981 (as amended), the Bern

and Bonn Convention. With the exception of grey seal, all are also listed on Section 41 of the

NERC Act (2006)

Although sightings are infrequent, the study area is considered to be of District/Borough

importance for marine mammals.

6.5 Selection of Ecological Receptors

Table 6-7 Selection of Key Ecological Receptors

Ecological Receptor Associated

species/habitats

Nature

Conservation

Value

Potentially significant

effect

Key Ecological Receptors

Subtidal mudflats

associated with

Plymouth Sound and

Estuaries SAC

Varied infaunal

communities,

particularly bivalves and

other invertebrates.

International.

However, the subtidal

mud and mixed

sediments surveyed

during the marine

survey were

impoverished and no

significant numbers of

important species

were identified. The

habitats within the

SAC surveyed during

the marine survey

were considered to

be of District/Borough

value.

Direct loss of SAC habitat

(subtidal mud and mixed

sediments) during

construction (piling and

dredging) and through

capital and maintenance

dredging.

Piling, capital dredging

and maintenance dredging

operations causing an

increase in suspended

sediment and sediment

deposition leading to

smothering of habitats.

Bird species associated

with the Tamar

Estuaries Complex SPA

Bird species associated

with the Lynher Estuary

SSSI, St John’s Lake

SSSI

The bird species for

which the Tamar

Estuaries Complex

has been designated

an SPA are included

within this receptor

(little egret). In

addition there are a

number of other

wader and wildfowl

species mentioned

within the SSSI

citations. These have

also been included

within this receptor.

International for

SPA qualifying bird

species

National importance

for SSSI habitats and

wintering wader and

wildfowl species

Disturbance to wintering

species throughout

construction works (in

particular piling works).

Capital and maintenance

dredging operations have

the potential to indirectly

affect intertidal habitats

e.g. by an increase in

suspended sediment and

sediment deposition

causing smothering of

habitats and a loss of

feeding resource.



species/habitats

Nature

Conservation

Value


effect

Intertidal mudflats and

subtidal sediments.

Habitats and associated

species within Whitsand

and Looe Bay MCZ

Intertidal sand and

coarse sediments,

subtidal sand and

coarse sediments, rocky

habitats, seagrass beds.

Ocean quahog, pink

sea-fan, sea-fan

anemone, stalked

jellyfish.

National Deposition of dredged

material at Rame Head

disposal site has the

potential to cause an



deposition leading to


Seagrass beds Wintering and on-

passage birds, intertidal

mudflats

County Direct loss of habitat under

piling.

Shading of habitat beneath

new jetty.

Capital and maintenance

dredging operations have

the potential to affect

seagrass beds by an



deposition causing


Migratory fish:

Atlantic salmon,

qualifying feature of

Dartmoor SAC

Allis shad, qualifying

feature of Plymouth

Sound and Estuaries

SAC

European smelt, reason

for designation of Tamar

Estuary MCZ

Sea trout, Section 41 of

the NERC Act 2006

European eel, reason

for designation of Tamar

Estuary MCZ,

‘critically endangered’

on the IUCN Red Data

List

Twaite shad, river

Subtidal habitats International Disturbance/risk of

mortality of migratory fish

during construction (piling

and dredging operations)

and operation

(maintenance dredging).



species/habitats

Nature

Conservation

Value


effect

lamprey and sea

lamprey, present in

Plymouth Sound and

Estuaries SAC but not

at significant population

levels

Other fish species:

bass, lemon sole, sole,

sprat, monkfish,

mackerel, spurdog,

whiting

Subtidal habitats Regional Disturbance/risk of

mortality of fish during

construction (piling and

dredging operations) and

operation (maintenance

dredging).

Marine mammals,

including bottlenose

dolphin, harbour

porpoise and grey seal,

which are present within

the Plymouth Sound

and Estuaries SAC but

not at qualifying

population levels.

Subtidal habitats District/Borough Disturbance due to piling

and dredging works

(construction phase) and

from maintenance

dredging.


species/habitats

Nature

Conservation

Value

Effect requiring

mitigation

Other ecological receptors requiring mitigation on the basis of legislation

Otter Intertidal mudflats Parish/

Neighbourhood

Disturbance to any

commuting otters during

construction.

Breeding birds Trees, scrub and

woodland

Parish/

Neighbourhood

Damage or destruction of

a nest while it is in use or

being built.

Invasive plant species Canadian waterweed Negligible Potential to spread plant

during construction.


species/habitats

Nature

Conservation

Value

Reason receptor

scoped out

Ecological receptors not considered further

Habitats associated with Sandbanks covered by International No direct or indirect effects


Plymouth Sound and

Estuaries SAC

including habitats

associated with Lynher

Estuary SSSI, and St

John’s Lake SSSI

sea water, estuaries,

shallow inlets and bays,

reefs, Atlantic salt

meadows, mudflats and

sandflats not covered by

seawater at low tide.

predicted on these

habitats.

Tamar Estuaries

Complex SPA

Avocet International No direct or indirect effects

predicted on avocet.

Dartmoor SAC (Atlantic

salmon considered

under migratory fish,

otters considered on

basis of legal protection)

Northern Atlantic wet

heaths with Cross-

leaved heath, European

Dry heaths, blanket

bogs and sessile oak

woods. Southern

damselfly

International No direct or indirect effects

predicted on these

habitats and species.

Tamar-Tavy SSSI Wintering and on-

passage birds, intertidal

mudflats

National No direct or indirect effects

predicted.

Plymouth Sound Shores

and Cliffs SSSI

Geological interest National No direct or indirect effects

predicted.

Mount Wise SSSI Geological interest National No direct or indirect effects

predicted.

Western King SSSI Geological interest National No direct or indirect effects

predicted.

Richmond Walk SSSI Geological interest National No direct or indirect effects

predicted.

Kingsand to Sandway

Point SSSI

Geological interest National No direct or indirect effects

predicted.

Tamar Estuary MCZ

European smelt and

European eel part of the

migratory fish receptor

Intertidal biogenic reefs,

intertidal coarse

sediment, native oyster

and blue mussel

National No direct or indirect effects

predicted.

Woodland Wood Valley

LNR

Woodland, hedgerows,

meadow, stream

District/Borough No direct or indirect effects

predicted.

Budshead Wood LNR Woodland, tidal creek District/Borough No direct or indirect effects

predicted.

Tincombe Reserve

CWS

Woodland County No direct or indirect effects

predicted.

Lower Lynher Estuary

CWS

Saltmarsh habitat County No direct or indirect effects

predicted.


St John’s Lake CWS Saltmarsh habitat County No direct or indirect effects

predicted.

Clarrick and Pigshill

Woods CWS

Woodland County No direct or indirect effects

predicted.

Churchdown Farm

Community Nature

Reserve

Meadows Parish/

Neighbourhood

No direct or indirect effects

predicted.

Terrestrial plants and

habitats

Broadleaved woodland,

Scrub, amenity

grassland, ruderal

grassland, common

species of reptile,

amphibians and

invertebrates

Parish/Neighbourhoo

d for broadleaved

woodland, negligible

for remaining habitats

Receptor not sufficiently

valuable for impacts to

arise. The area of scrub

and ruderal grassland

habitat to be directly

affected by the proposed

Development is negligible.

Terrestrial invertebrates Scrub, woodland,

amenity grassland

Negligible Receptor not sufficiently


arise. The area of

terrestrial habitat to be

directly affected by the

proposed Development is

negligible.

Amphibians Standing water in the

storage tanks, scrub,

woodland, amenity

grassland

Negligible Receptor not sufficiently


arise.

Reptiles Scrub, woodland,

concrete tanks and

areas of bare ground

Parish/

Neighbourhood



arise. The site compounds

will be situated on areas of

hardstanding and amenity

grassland, with only a

small amount of scrub

clearance required.

Bats Woodland, scrub,

amenity grassland,

ruderal grassland

Parish/

Neighbourhood



arise. The area of

terrestrial habitat to be



negligible.

Dormice Woodland, scrub Negligible No direct or indirect effects

predicted as considered to

be absent from the Site.

Badgers Woodland, scrub,

amenity grassland

Negligible No direct or indirect effects

predicted as considered to

be absent from the Site.


Intertidal mixed

sediment

Seaweed

Parish/

Neighbourhood



arise. The area of intertidal

mixed sediment to be



negligible.

Intertidal estuarine rocky

habitat

Intertidal Seagrass

beds, intertidal mixed

sediment

Parish/

Neighbourhood

Receptor not considered

valuable enough for

significant impacts to

arise.

Splash zone estuarine

rocky habitat

Intertidal mudflats Parish/

Neighbourhood

Receptor not considered

valuable enough for

significant impacts to

arise. No direct or indirect

impacts predicted.

Shellfish including

native oyster

Subtidal habitats Negligible Only one individual native

oyster was recorded on

Site, the habitat on Site is

unsuitable to support large

numbers of shellfish.



arise.

Thornback ray Subtidal habitats Parish/

Neighbourhood

Only one individual of this

highly mobile species was

recorded. Receptor not

sufficiently valuable for

impacts to arise.

Sternaspis scutata Subtidal habitats Parish/

Neighbourhood

Only one individual of this

rare species was

recorded. Receptor not

sufficiently valuable for

impacts to arise.


A number of ‘Key Ecological Receptors’ have been identified. This section identifies the likely

impacts upon these Key Ecological Receptors and details the mitigation measures proposed.

Mitigation for impacts on ‘other ecological receptors’ are also included in order to comply with

current wildlife legislation and take into account policy drivers and best practice guidelines.


6.6.1 Construction

Subtidal mudflats associated with Plymouth Sound and Estuaries SAC

Loss of habitat

The construction of a new jetty, dolphin moorings and the extension of the dredge pocket will

result in the permanent loss of subtidal estuarine habitats.

The footprint of the works has been limited as far as possible, with the proposed berth pocket

the same size (1.35ha) as the existing berth pocket. There is an overlap of 0.92ha between the

existing and the new, resulting in 0.43ha of currently un-dredged habitat to be removed. An

additional 0.3ha would also be lost during the capital dredge where the proposed berth pocket

sides would slope. In relation to the proposed berth pocket, this results in a total of 0.73ha of

currently un-dredged habitat to be removed, and a total dredge area of 1.65ha (= 0.92ha +

0.43ha + 0.3ha) .

Some dredging will also need to be carried out to enable access to the western side of the jetty

over an area of 1.36ha (the Northern Approach channel).

The overall permanent loss of habitat as a result of dredging will be 3.01ha (= 1.35ha + 0.3ha +

1.36ha)).

The detailed design for the Development has not yet been undertaken, but it is anticipated that

the area beneath the piles associated with the new jetty, dolphin moorings and pontoon will be

approximately 0.018ha, which represents a worst case scenario.

Current construction methodology includes proposals to side-cast arisings from pilings adjacent

to the new subtidal piles only (to reduce impacts on intertidal habitats, particularly seagrass

beds, where the piles fall outside of the contaminated area at the proposed jetty head. The

approximate volume of arisings to be side-cast is 250m3.

Habitat diversity may be limited through increased shading as a result of the presence of the

jetty (particularly in shallower waters). However, the removal of the existing jetty structure

should ensure the restoration of SAC habitats beneath. The existing jetty covers an area of

approximately 0.2ha and the new jetty will cover an area of 0.32ha, so only an additional 0.12ha

(=0.32-0.2) would be shaded when compared to the current situation. Whilst shading may

reduce habitat diversity, it is not considered to result in permanent habitat loss.

Physical damage to habitats as a result of increased siltation and release of contaminants from contaminated sediment

Construction activities, in particular piling and dredging, have the potential to temporarily add

significant sediment loads to the estuary. The proposed Development requires the dredging of

sediment up to a depth of 2.5m below bed level from the area in front of the jetty head to enable

access to the jetty. The estimated volume of sediment arisings from this capital dredging is

approximately 37,000m3 (19,000m3 from the area in front of the northern mooring dolphins on

the east side of the jetty and 18,000m3 from the western side of the jetty).


The drilling of the piles which will support the jetty will require the removal of sediment. The

current estimated volume of arisings is approximately 3,450m3, of which 250m3 will be side-cast

immediately around the subtidal pile locations only. The remaining material is contaminated

and will be collected and disposed of, or treated, on land.

Analysis carried out to date indicates that the sediment has some elevated concentrations of

metals, PAH and PCB compounds above the lower action/effect levels but generally below

upper action/effect levels. However, one of the sediment samples taken from the proposed jetty

head showed levels of arsenic and PCB 25 that exceeded the upper limits. Sediment arisings

from this location are not suitable for disposal at sea and will be collected and disposed of, or

treated, on land. It will be the contractors responsibility to characterise all waste and ensure that

it is reduced, reused or disposed of in a suitable manner.

There is therefore potential for:

• Dissolution of contaminants out of sediment/soil;

• Suspension of contaminated or non-contaminated particulates, and;

• Subsequent migration up or downstream of the Site due to wave, wind and tidal action.

During the construction works measures will be taken to minimise disturbance of sediment and

contain migration of sediment. These will include:

• Taking additional precautionary measures while working in any locations identified as

having elevated concentrations of contaminants. Elevated levels of contaminants were only

identified at a single location.

• Minimise as far as possible the extent of work requiring contact with the river bed.

• Ensuring the contractor uses methods which minimise sediment disturbance, migration and

arisings. This includes ensuring that the best practice and plant are used in the design and

execution of the works. This may include standard measures such suction dredging plant,

and flush containment and collection during piling.

The mitigation measures outlined above will limit disturbance and migration of sediment and

subsequent sediment re-deposition.

Pollution from construction

During construction of the new jetty and demolition of the existing jetty, there is the potential for

hazardous substances or waste materials to enter the watercourse. To limit the risk of pollution

entering the estuarine environment, measures will be taken to ensure that contaminating

substances are properly contained, during storage and use, both in the marine operations and

the land operations. These include:

• PPG5 published by the EA, 2007, for Working In or Near a Watercourse will be followed

as a minimum standard. This includes recommendations for fuel containment and the

use of less hazardous types of machinery oil.

• All bulk storage of fuel, oils and other contaminating substances will include secondary

containment. Emergency spill/leak containment kits will be available throughout the

construction site where contaminative substances are being used or transported. An

emergency spill response procedure will be put in place and conveyed to all site staff.


• Best practice procedures will be used to contain potentially contaminating substances

during the demolition of the existing jetty structures and construction of new jetty

structures.

• Refuelling, repair and maintenance of land based construction plant will be carried out

within a designated bunded area to avoid pollution from spillages and leaks.

• Measures will also be put in place to contain all demolition and construction wastes, to

prevent waste falling onto the estuary bed or into the water column.

The following measures will be taken to minimise the potential for pollution during the

demolition of the existing jetty:

• Empty and flush all fuel and sullage pipelines and any associated equipment.

• Remove all equipment, buildings, tanks, pipework, etc. from the jetty head to barges for

transport to a commercial wharf for disposal/re-cycling.

• Remove all pipelines, cables, ducting and pipe supports from the approach jetty to

barges for transport to a commercial wharf for disposal/re-cycling.

• Demolish and dispose/re-cycle the redundant buildings and pipework on the land at the

jetty root.

• Demolish the existing jetty head, approach structure and mooring dolphins by cutting

and breaking out the concrete deck and beam elements, using floating plant.

• Piles to be cut off at or below existing seabed, using floating plant and ROVs or divers.

This will minimise the amount of sediment disturbance during these activities.

• Dispose of all materials by appropriate recycle or disposal method.

• Measures will be put in place to contain all hazardous substances, demolition material

and prevent waste materials falling onto the seabed or polluting the watercourse. There

will be response procedures in place to ensure that any materials entering the

watercourse are contained and recovered quickly to limit the impact caused.

• Specific mitigation and waste management measures will be developed by the

contractor carrying out the decommissioning work. The contractor will be required to

comply with current UK guidance and best practice.

During construction, best practice will be used to ensure that excess sediment/soil run off from

the land construction site does not occur. Controlling measures will include:

• Carry out site investigation in the locations affected by the proposed Development,

including chemical analysis of soil samples. Where significantly elevated concentrations

(assessed based on current UK guidance and regulation) of determinands are identified

additional remediation measures will be taken. Depending on the volume of soil

impacted, this could include removal and off-site disposal of the impacted soils, or local

containment.

• A Drainage Management Plan will be produced to ensure that surface water runoff from

construction compounds is appropriately managed and treated prior to entering into any

waterbody.

• Containment of soil stockpiles.


• Hardstanding and roads will be cleaned frequently where soil is being deposited from

vehicles.

• Cleaning of vehicles and equipment will be carried out in an area with drainage

containment.

The above mitigation measures are contained within a CEMP which has already been prepared.

Assuming the mitigation measures described above, and in more detail in Chapter 5, are in

place, it is considered that the potential for water quality effects on the Tamar Estuary

associated with land based and marine based construction activities is restricted to the

possibility of localised isolated sediment contamination, contained spills, and local sediment

disturbance on a short term basis. The mitigation procedures in place will limit these to minor

incidents and allow rapid remediation with no significant impact to the wider area.

Bird species associated with Tamar Estuaries Complex SPA, Lynher Estuary SSSI, St John’s Lake SSSI

Disturbance to SPA features by piling

Given the low numbers of little egret recorded in the count sector, the amount of available

habitat nearby (in particular St John’s Lake, which provides foraging habitat for significant

numbers of waders and wildfowl and is designated as both an SSSI and an SPA), no specific

mitigation is proposed.

Disturbance to SSSI features by piling

St John’s Lake SSSI is approximately 1.4km to the south of the Site at its closest point beyond

Torpoint. There is no direct line of sight between the two areas. Although no surveys were

carried out during the winter, from BTO core count data for 2006/7-10/11, Tamar Estuaries

(South) Sector 10 supported low numbers of wigeon (51) and no black-tailed godwit. These

species are the SSSI interest features as defined by the condition assessment compiled in

August 2013 (Ref 6-11). The number of wigeon recorded in the entire count sector is 1% of the

number the SSSI was notified for.

The Lynher Estuary is located approximately 2km to the west of the Site beyond Wilcove. There

is no direct line of site between the two areas. Of the bird features listed on the citation,

including shelduck, oystercatcher, mallard and curlew, from BTO core count data for 2006/7-

10/11, the entire Tamar Estuaries (South) Sector 10 supported limited numbers of these

species.

It is considered that the numbers of waders and wildfowl to be found in the habitats adjacent to

the jetty are likely to be particularly low given the sub-optimal nature of the foraging habitat in

this area and that the area is subject to a degree of disturbance (from boat traffic and when re-

fuelling is in operation). Both SSSIs are of a sufficient distance from the Site that any birds using

the SSSI habitats will not be disturbed by piling works. No specific mitigation is therefore

proposed.

Disturbance from other construction activities


The demolition of the existing jetty and land-based infrastructure is planned for between

February 2018 and August 2018, just within the on-passage period and wintering period.

August to October is the peak on-passage period for little egret. By the time the on-passage

little egret arrive the majority of the demolition will be completed. The mudflats around the jetty

have already been assessed as not being a key foraging or roosting resource for little egret,

therefore should any little egret be disturbed when using those habitats, it is considered that

there is sufficient habitat nearby which the birds can move to. No specific mitigation is therefore

proposed.

The numbers of over-wintering waders and wildfowl in the vicinity of the Site is likely to be low

given the sub-optimal nature of the foraging habitat in this area and that the area is subject to a

degree of disturbance (from boat traffic and when re-fuelling is in operation). Both SSSIs are of

a sufficient distance from the Site that any birds using the SSSI habitats will not be disturbed by

piling works. No specific mitigation is therefore proposed.

Loss and damage to foraging habitats as a result of increased siltation and pollution

The proposed Development requires the dredging of sediment up to a depth of 2.5m below bed

level from the area in front of the jetty head. The estimated volume of sediment arisings from

the capital dredging is approximately 37,000m3.The drilling of the piles which will support the

structure will require the removal of sediment. The current estimated volume of arisings is

approximately 3,450m3, of which 250m3 will be side-cast immediately around the subtidal pile

locations only. The remaining sediment from the drilling of the piles is contaminated and will be

collected and disposed of or treated on land.

The potential exists for increased sediment loads to be released from construction works

affecting intertidal mudflats in the vicinity of the works. Dredging may also disturb sediment

containing toxic materials such as TBT, heavy metals and hydrocarbons, causing the

contaminated sediment to be re-deposited elsewhere or to leach into the water environment and

affect water quality. Potential also exists for pollution during construction, for example from

fuel/diesel spillages.

It has already been demonstrated that the intertidal mudflats close to the existing jetty are not

considered to be a key foraging resource for birds. However, although the intertidal mudflats in

this location are not included within any designated site they are clearly functionally linked to

nearby SPA and SSSI habitats.

During the construction works measures will be taken to minimise disturbance of the sediment,

to contain the migration of sediment and to minimise the risk of a pollution incident (as detailed

above for the Plymouth Sound and Estuaries SAC). In addition, side-casting will only be

undertaken within the subtidal zone to limit the potential impacts on intertidal mudflats.


Physical damage to habitats and species as a result of increased siltation

Disposal of approximately 37,000m3 of sediment from the capital dredging has the potential for

increased sediment loads to temporarily affect the habitats and species within the MCZ. As per


the existing maintenance dredge licence (licence number L/2014/0063/1), the conditions of the

licence for the capital dredge works are anticipated to state:

• No disposal is to take place at the disposal site from four hours before high water at

Devonport until the time of high water at Devonport.

• The licence holder must ensure material is disposed of to the south-west corner of the

Rame Head disposal site.

These measures will minimise the potential for movement of suspended sediment in a northerly

direction, towards the MCZ.

Seagrass beds

Loss and damage of habitat by piling and dredging

Construction of the jetty will result in the permanent loss of seagrass beds on the intertidal zone

through the installation of piles. The removal of the existing jetty structure should ensure the

restoration of seagrass habitats in this now unshaded area. The existing jetty covers an area of

0.2ha and the new jetty will cover an area of 0.33ha, so only an additional 0.13ha (=0.33 - 0.2)

would be beneath the new jetty structure when compared to the current situation. The

restoration of seagrass beds elsewhere in the intertidal zone will be encouraged by removing

crabbing tiles from the area within the DIOs control, which will increase the area of substrate

available for colonisation. In addition, it is understood that intertidal bait digging and crabbing,

currently causes disturbance to the seagrass beds. This activity will be discouraged through the

installation of new signage.

Dredging operations have the potential to affect seagrass beds by an increase in suspended

sediment and sediment deposition causing smothering of habitats. A small amount (250m3) of

uncontaminated sediment arising from piling operations will be side-cast immediately around the

subtidal pile locations only, as far as possible from the intertidal zone to reduce the risk of

sediment re-deposition on the intertidal area. Mitigation proposals outlined for the Plymouth

Sound and Estuaries SAC aim to minimise sediment deposition and dispersal during dredging

and are applicable to this key ecological receptor.

In addition, the risk of a pollution incident, particularly oil/fuel spillages during construction could

damage seagrass beds. The measures outlined for the Plymouth Sound and Estuaries SAC to

reduce the risk of a pollution incident occurring are considered suitable mitigation for this key

ecological receptor.

Migratory fish (Atlantic salmon, allis shad, European smelt, sea trout, European eel, twaite shad, river lamprey, sea lamprey)

Disturbance/mortality to migratory fish

Piling works associated with the construction of the new jetty head and the new mooring

dolphins could act as an acoustic barrier to fish migration if carried out during the core migratory

period. In addition, impact sound from any piling undertaken during the migratory period could

adversely affect the health of fish or adult eels if they are exposed to it for a sufficiently long time

and intensity. In addition, underwater noise and light from the demolition of the existing jetty

could disturb migratory fish.


The core sensitive period for migratory fish, particularly allis shad and Atlantic salmon, but also

sea trout, European eel and sea lamprey, is between 1st April and 31st August. The greatest

level of underwater noise generated by the proposed Development are likely to be during

percussive piling.

Subacoustech Environmental Ltd undertook an assessment of the potential impact of

underwater noise from activities associated with the proposed Development, with respect to

locally sensitive fish species. The assessment considered three main noise sources: percussive

piling, pile case oscillation and augering/drilling (Ref 6-12). It has not been possible to agree an

appropriate noise threshold for percussive piling given the uncertainty in the current evidence

base. As such, percussive piling will not be carried out during the core sensitive period of 1st

April until 31st August.

Vibro-piling, pile case oscillation and auguring/drilling typically generate significantly lower noise

levels in comparison with percussive piling, and NE and Cefas are in agreement that these

construction methods can be carried out at any time of year. However, in order to validate the

Subacoustech predictions and to provide additional reassurance regarding the noise levels

associated with these activities at this specific site, in-situ monitoring of the noise levels

generated by each of the different vibro-piling, pile case oscillation and auguring/drilling

activities at the beginning of the work, and outside the core sensitive period of 1st April to 31st

August, will be undertaken. This will involve monitoring the noise levels produced by these

activities for the first four piling events and comparing these to the predicted levels, before

carrying out these activities during the 1st April to 31st August period.

Demolition of the existing jetty is currently programmed for February to August 2018. This

includes the removal of the existing piles. Piles will be cut off 300mm below seabed level to

prevent leaving an obstruction on the seabed. Sediment surrounding the pile will first be moved

to allow access to the pile. Concrete piles will be ‘snipped’ at the base using hydraulic shear

cutters. For steel piles mechanical cutting or water jet cutting may be used.

The timing of these works are within the sensitive period for migratory fish. However, the noise

and vibrations from pile removal is expected to be lower than that experienced when installing

piles, and all equipment will operate from floating plant during daylight hours, reducing potential

impacts on migratory fish. Significant adverse impacts are therefore not anticipated.

Measures will be put in place to contain all demolition material and prevent waste materials

falling into the estuary.


The piling and dredging works are planned to take place outside of the fish migratory period. As

outlined earlier, mitigation measures are to be put in place to minimise sediment remobilisation

and movement and to reduce the risk of any pollution incident. The effects of any sediment

movement are likely to be localised both spatially and temporally, therefore by the time fish

migration is underway, localised effects will no longer be significant.

During the removal of piles, localised sediment disturbance is expected as it needs to be

removed to allow access to the pile. Some sediment may also be disturbed through the pile

removal process. However, this is expected to be extremely localised and of such a short

duration that no specific mitigation is proposed.


Other fish species (bass, lemon sole, sole, sprat, monkfish, mackerel, spurdog, whiting)

Disturbance/mortality to resident fish species

It is considered that the high levels of noise and vibration that already exist in the Estuary mean

that the limited period of percussive piling from September to March will not cause any

significant long term effects on resident fish species. From the results of the marine surveys it is

also considered that the subtidal habitats in the vicinity of the jetty provide sub-optimal foraging

habitat to species such as bass (due to the history of dredging) and that there is sufficient

alternative foraging habitat in the estuary that it is unlikely large shoals of young bass are found

around the jetty. In addition, fish are mobile species that can move quickly away from any

significant disturbance. Fish fry do not possess swim bladders and will be relatively resistant to

noise effects arising from the piling operation. No effects on this fish life stage are therefore

predicted and therefore no specific mitigation is proposed.

Loss and damage to spawning habitat for resident species

The timing of percussive piling and dredging throughout the winter means that any adverse

effects through sediment dispersal will no longer be significant by the time of the main spawning

season for lemon sole (April-September), sole (March to May, peaking in April) and sprat (May

to August) (Ref 6-13).

The mitigation measures outlined above for the Plymouth Sound and Estuaries SAC to minimise

sediment disturbance and re-deposition and reduce the likelihood of a pollution event are also

considered relevant for this key ecological receptor.


The mitigation measures outlined above for the Plymouth Sound and Estuaries SAC to minimise

sediment disturbance and re-deposition and to reduce the risk of pollution entering the estuary

are considered applicable to this key ecological receptor.

Marine mammals (bottlenose dolphin, harbour porpoise and grey seal)

Disturbance from piling and dredging

No mitigation is proposed given that marine mammals occur so infrequently in the Tamar.

Other ecological receptors requiring mitigation

Otter

Otter are known to commute through the estuary and the construction works have the potential

to disturb any otters moving past the works. However, construction will be limited to a 12 hour

day, with ten hours of activity and no evening/night time working. Access to the foreshore for

otters will be maintained at all times. Any construction lighting will be directional, focussing only

on the area of work, to maintain dark areas of water that the otter can utilise. It is anticipated


that disturbance to otters will be minimal due to the low numbers considered likely to use the

Site.

Breeding birds

It is proposed that a site compound and working area will be established within the Thanckes

OFD. This will involve clearance of small amounts of scrub. Access to the site compound and

working area will be on existing surfaced access tracks (see Figures 2-2 and 2-3 in Chapter 2 of

the ES). The habitat of most value to breeding birds on Site, broadleaved woodland, is to be

unaffected. To limit any impacts on breeding birds which may be using the scrub, vegetation

clearance will be completed outside of the bird breeding season (end of February to end of

August). If this is unavoidable, clearance will be carried out under close supervision by an

experienced ecologist. In the event that an active nest is identified, it will be left undisturbed with

a suitable buffer until the young have fledged.

Invasive plant species

Measures will be put in place as part of the CEMP to ensure that Canadian Waterweed and

Pirri-pirri-bur are not spread during construction.

6.6.2 Operation


Physical damage to habitats as a result of increased siltation

The existing berth pocket is dredged as and when necessary to maintain the minimum depth. It

has been dredged along with other areas under a general 3 year Food and Environment

Protection Act (FEPA) licence which allows for the removal of up to 367,000 tonnes over a three

year period. The berth was last dredged in 2005 and 4,036m3 was recorded as being removed.

This gives an average silt accumulation of 300mm depth over 7 years. The proposed berth

pocket is the same dimension as the existing berth pocket, it is therefore expected that a similar

routine of maintenance dredging will continue.

During the maintenance dredging, measures will be taken to minimise disturbance of the

sediment, and to contain the migration of sediment. These include:

Encourage the contractor to use methods which minimise sediment disturbance and migration.

This includes ensuring that the best practice and plant are used in the design and execution of

the works – e.g. appropriate choice of plant such as:

• using Trailer Suction Hopper Dredger (TSHD), Cutter Suction or Backhoe

• Adherence to dredging licence conditions.

• Disposal of the dredgings at a licenced disposal site, Rame Head.


Physical damage to habitats as a result of pollution or toxic contamination

Maintenance dredging has the potential to re-mobilise contaminated sediment and re-deposit it

on SAC habitats or the contaminants could leach out of the sediment into the water column,

affecting water quality. The Site will be used for storage and delivery of very large quantities of

fuel, and the intake of fuel contaminated water from ships (as is the case for the existing jetty).

There is therefore also the potential risk from spilt fuel (diesel and AVCAT), polluted surface

water run-off in the event of a pollution incident and fire-fighting foam to enter the Estuary.

As noted in Section 2.4.3, there are currently nine concrete lined moats throughout the site that

are designed to capture any major spillage from the AVCAT, diesel and sullage tanks and

contain it on site. The site also currently contains several OWSs that act as interceptors to

prevent oil from being discharged from site to the Hamoaze. All OWSs are fitted with oil in

water detectors and alarms.

If any leaks do occur then they will probably be associated with the joints required for valves

and manifolds. All other pipework will be continuously welded and checked for thinning on a

regular basis either by intelligent “PIGs” or external Non-Destructive Testing (NDT). The new

jetty head will place all valves and manifolds above a containment tank which will be regularly

drained by suction pump into the sullage line. The same containment will also be necessary for

the fuel filters located on land at the jetty root.

In addition to the above, a french drain is proposed to contain any leakage from the pipes as

they emerge from the protection of the moat arrangement. This drain will be located downhill

and, coupled with a new gully will pass any surface water contamination into a new 55,000litre

oil water separator with a pumped connection into the current jetty car park OWS. Discharge

from these OWSs will be along the jetty approach span as is currently permitted.

The Thanckes site currently maintains an emergency response spillage trailer which sits on hard standing to the east of the site main entrance. The trailer contains items such as:

• Absorbent pads

• Absorbent booms

• Strainers

• Disposable bags

There is also a major spillage kit on site, which is located in the foam store to the east of the main site entrance. The major spillage kit contains items such as:

• Sandbags

• Drain blockers

• Spill dry granules

There are also smaller spill kits in the following locations:

• Jetty head

• Jetty filter bed

• AVCAT loading bay

• Diesel loading bay

• Sullage loading bay transfer pump

• Diesel pump area

Chapter 5 assesses the potential for dredging to add significant sediment loads to the estuary

and the risk of pollution incidents during operation as small provided the mitigation detailed


within that chapter is adhered too. In addition to the mitigation outlined above, these measures

include:

• Secondary containment on the jetty head.

• Real time pipeline/hose contents monitoring.

• Intercepted drainage and bunding at foot of jetty and around filter beds.

• Emergency isolation valves (dual manual/automated).

• Run off water collection and disposal.

• Pressure monitoring and thermal relief.

• Accumulators to regulate pressure in the pipelines.

• Procedure for controlling the delivery of fuel, including communication between the fuel

storage point and the jetty head.

The current dredging licence includes the following condition, which will prevent marine pollution

incidents. It is anticipated that this condition will also be included in any new maintenance

dredging licence, and will be adhered to:

• The licence holder must install bunding and/or storage facilities to contain and prevent

the release of fuel, oils and chemicals associated with plant, refuelling and construction

equipment, into the marine environment. i.e. secondary containment should be used

with a capacity of not less than 110% of the containers storage capacity.

The proposed Development will upgrade and modernise the existing infrastructure, substantially

reducing the environmental risks during operation.

Chapter 5 also assessed the risk of toxic contamination leaching into the water column as low

due to the low leachability of the sediment.


Disturbance to birds by maintenance dredging

Maintenance dredging takes place for a short period of time (a matter of weeks) over the winter.

The most recent maintenance dredge was in 2005. The distance of over 300m from the closest

intertidal habitats that could be used by birds to the dredge location, combined with the fact that

the estuary is already subject to a degree of disturbance from boat traffic and during re-fuelling

operations at the jetty, means that the potential impacts of disturbance as a result of

maintenance dredging are considered to be low. In addition, it has been established that the

intertidal areas closest to the jetty are not optimum foraging habitat, and it is therefore

considered unlikely that significant aggregations of any birds will be using this habitat over

winter. No specific mitigation is therefore proposed.

Disturbance to birds by re-fuelling operations

The replacement of the jetty will not result in an increase in re-fuelling operations. The usage is

expected to remain the same as at present. The numbers of birds associated with the habitats

adjacent to the jetty are already low, and birds present in that area will either be habituated to


disturbance by re-fuelling operations, or will be able to move to areas close by which are less

disturbed. No specific mitigation is therefore proposed.

Physical damage to habitats as a result of increased siltation, pollution or toxic contamination from maintenance dredging

Implementation of the mitigation outlined above for the Plymouth Sound and Estuaries SAC

should reduce the potential for any damage to habitats used by over-wintering birds for foraging

or roosting.



A similar routine of maintenance dredging as is currently carried out will continue post-

construction and it anticipated that the conditions of the current maintenance dredging licence

will be included on any new licences. These include:

• No disposal is to take place at the disposal site from four hours before high water at

Devonport until the time of high water at Devonport.

• The licence holder must ensure material is disposed of to the south-west corner of the

Rame Head disposal site.

These measures will minimise the potential for movement of suspended sediment in a northerly

direction, towards the MCZ.

Seagrass beds

Loss and damage of habitat by maintenance dredging

Maintenance dredging operations have the potential to affect Seagrass beds by an increase in

suspended sediment and sediment deposition causing smothering of habitats. Mitigation

proposals outlined above for the Plymouth Sound and Estuaries SAC which aim to minimise

sediment deposition and dispersal during dredging and are applicable to this key ecological

receptor.

Loss and damage of habitat by pollution

The risk of a pollution incident, particularly oil/fuel spillages or the use of firefighting foam during

operation could damage seagrass beds. Maintenance dredging has the potential to re-mobilise

contaminated sediment and re-deposit it on seagrass beds or the sediments could leach out of

the sediment into the water column affecting the water quality. The measures outlined above for

the Plymouth Sound and Estuaries SAC to reduce the risk of a pollution incident or toxic

contamination occurring are considered suitable mitigation for this key ecological receptor.

Furthermore, the new, upgraded facility will reduce the potential for an incident to occur.



Disturbance to migratory fish by maintenance dredging

Noise from maintenance dredging could present a physical barrier to movement of fish up and

down the estuary if carried out during the migratory period. The current maintenance dredging

regime only carries out dredging during the winter period (December to March) to avoid

disturbance to migratory fish and, where possible, in-channel dredging is avoided during

February and March to avoid impacts on European smelt. It is anticipated that this will continue

and therefore no further mitigation is required.

Loss and damage to foraging habitats as a result of increased siltation and pollution from maintenance dredging

The maintenance dredging is undertaken outside of the fish migratory period. As outlined

earlier, mitigation measures are to be put in place to minimise sediment remobilisation and

movement and to reduce the risk of any pollution incident. Furthermore, the new, upgraded

facility will reduce the potential for an incident to occur. The effects of any sediment movement

and pollution during operation are likely to be localised both spatially and temporally, therefore

by the time fish migration is underway, localised effects will no longer be significant. No specific

mitigation is therefore required.


Disturbance to resident fish species by maintenance dredging

It is considered that the high levels of noise and vibration that already exist in the Estuary mean

that the short periods of maintenance dredging over intermittent winters will not cause any

significant long term effects on resident fish species. In addition, the fish are mobile species

which means that they can move quickly away from any disturbance. It is therefore considered

that no further mitigation is required.

Damage to spawning habitat for resident species as a result of maintenance dredging, pollution and toxic contamination

The timing of maintenance dredging throughout the winter means that any adverse effects

through sediment dispersal will no longer be significant by the time of the main spawning

season for lemon sole (April-September), sole (March to May, peaking in April) and sprat (May

to August).

The mitigation measures outlined above for the Plymouth Sound and Estuaries SAC to

minimise sediment disturbance and re-deposition are considered relevant for this key ecological

receptor.

In addition, the mitigation measures outlined to reduce the risk of a pollution incident entering

the estuarine environment are also considered applicable to this key ecological receptor.

Furthermore, the new, upgraded facility will reduce the potential for an incident to occur.



Disturbance from maintenance dredging

The intermittent and short length of time over which maintenance dredging takes place,

combined with the infrequent sightings of marine mammals means that it is considered highly

unlikely that any cetaceans or seals will be present in the Estuary during dredging operations.

However, should any marine mammals be present, they will easily be able to move away from

any significant disturbance. No specific mitigation to reduce potential impacts on marine

mammals is therefore proposed.

Otters

The distance of the dredging from the shore, combined with the intermittent and short length of

time which maintenance dredging takes place, means that is it considered highly unlikely that

any otters commuting past the jetty will be adversely affected by the dredging.

Operational lighting will be as existing, areas of dark foreshore will be maintained enabling

access by otters at all times. No specific mitigation to reduce potential impacts on otters is

therefore proposed.


6.7.1 Construction


Loss of habitat

The construction of a new jetty, dolphin moorings and the extension of the dredge pocket will

result in the permanent loss of subtidal estuarine habitats. It is anticipated that the area beneath

the piles will be approximately 0.018ha, this habitat loss will be balanced by the habitat that

would be restored when the existing piles, which cover an area of 0.009ha, would be removed.

Consequently, there would be a net loss of 0.009ha as a result of piling.

The proposed berth pocket is the same size as the existing berth pocket (1.35ha) and there is

an overlap of 0.92ha between the existing and the new, resulting in 0.43ha of currently un-

dredged habitat to be removed. An additional 0.3ha would also be lost during the capital dredge

where the proposed berth pocket sides would slope. In relation to the proposed berth pocket,

this results in a net loss of 0.73ha, and a total dredge area of 1.65ha (= 0.92ha + 0.43ha +

0.3ha).

Some dredging will also need to be carried out to enable access to the western side of the jetty

over an area of 1.36ha (the Northern Approach channel).

Habitat diversity may also be limited through increased shading as a result of the presence of

the jetty (particularly in shallower waters). However, the removal of the existing jetty structure


should ensure the restoration of SAC habitats within the now unshaded area. The existing jetty

covers an area of approximately 0.2ha and the new jetty will cover an area of 0.32ha, so only an

additional 0.12ha would be shaded by the proposed jetty. However, given that seagrass was

recorded in the intertidal area (outside of the SAC) beneath the existing jetty it is not considered

that the shading would lead to habitat loss.

The net permanent loss of habitat as a result of dredging and piling will therefore be 2.399ha.

This is shown in Table 6-8.

Table 6-8 Current and anticipated habitat loss

Aspect Temporary Damage Net Permanent Loss

Jetty area of piles (approx) 0.018ha 0.009ha (0.018ha – 0.009ha, the area of the existing piles to be

removed)

Berth Pocket dredging 1.65ha (1.35ha for berth pocket + 0.3ha where berth pocket sides

slope)

0.73ha

Western navigation channel dredging

(the Northern Approach Channel)

1.36ha 1.36ha

Total Area 3.028ha 2.099ha

The total marine and estuarine habitat feature of Plymouth Sound and Estuaries SAC is

5762.07ha, and 2.099ha represents 0.04% of the total available marine and estuarine habitat

within the SAC. Although the habitats to be lost are within the SAC, the habitats were

impoverished and no significant numbers of important species were identified.

Current construction methodology includes proposals to side-cast arisings from pilings adjacent

to the new subtidal piles only (to reduce impacts on intertidal habitats, particularly seagrass

beds, where the piles fall outside of the contaminated area at the proposed jetty head. The

approximate volume of arisings to be side-cast is 250m3. Information in Appendix 6-C (Results

of the marine surveys) indicates that the sublittoral sediments in the area of the jetty are

impoverished due to the historical and current heavy industrial use of the estuary and the

dredging regime. It is considered that the placing of this small volume of arisings close to the

new piles in subtidal habitats is unlikely to result in permanent habitat loss due to the naturally

turbid nature of the estuary and that any impact will be localised and temporary. Side casting

will also retain sediment within the estuary and thereby not reduce the sediment budget.

The minimal loss of impoverished habitat is classified as having No significant effect on this

feature of International importance.

Physical damage to habitats as a result of increased siltation, release of contaminants from contaminated sediment and pollution

Construction activities, in particular piling and dredging, have the potential to temporarily add

sediment loads to the estuary.


However, the estuary is naturally a turbid and silty environment. A study to assess the impacts

of dredging on the Tamar Estuary (Ref 6-14) stated that maintenance dredging in the lower

Tamar accounts for the annual removal of between 5,000 and 200,000 tonnes of dry sediment

per year. Each day, a semi-diurnal tide of average range mobilises approximately 5000m3 of

sediment in the upper Tamar Estuary. In addition, on a seasonal cycle, changes in river flow

cause bed sediment with an estimated volume of 164,000m3 to migrate up the estuary in

summer (low river flow) and down again in winter (high river flow). A fairly recent (2011) study

into the dredging regime of Plymouth Estuary (Ref 6-15) described the Tamar as a macro-tidal

estuary which is subject to climatic and tidal variations that influence sediment transport. These

variations can be on a daily to seasonal temporal scale. The study found that during the winter,

mobile sediment was more abundant in the lower reaches of the Estuary, with silt content

increasing to around 80% at the mouth of the Estuary, and in the summer, sediment

accumulates at the head of the Estuary. This was attributed to changes in flow conditions

resulting in much of the accumulated sediment at the head of the estuary being flushed to re-

charge mid-estuary.

The potential exists for pollution, in particular fuel/diesel spillages to be released from

construction works affecting water quality and nearby SAC habitats. Other potential sources of

pollution include fuels and oils from construction equipment, materials such as cements and

concrete, construction waste (solid waste and wastewater) and debris from the demolition of the

existing jetty. Dredging may also remobilise sediment containing toxic materials such as TBT,

heavy metals and hydrocarbons, causing it either to be re-deposited elsewhere or to leach into

the water environment.

Chapter 5 Water, Contamination and Sediment Quality addresses the possible effects of the

proposed Development on the water environment through the release of contaminants into the

water (through dissolution or suspension) and concluded the following:

• Elevated concentrations of metals and hydrocarbons already present in the sediments

mean that any small release of contaminant during the construction works is unlikely to

have a significant impact.

• During the construction works, disturbance of the sediment at any one location will be

localised and of short duration so that any locally elevated concentrations not identified will

have a limited impact.

• Leachability testing indicated that the release of contaminants in the sediment into the

water is unlikely to occur.

As such, the risk of damage caused by the release of contaminated sediment is considered to

be low.

Providing the mitigation measures outlined in Section 6.6.1 are implemented, it is considered

that the risk of large volumes of sediment, contaminated sediment or pollution entering the

estuary is reduced. The estuary is naturally a turbid and silty environment, therefore should any

impacts arise from increased sediment loads and pollution, they will be localised and temporary.

Physical damage to SAC habitats as a result of increased siltation and pollution are classified as

having No significant effect on this feature of International importance.



Disturbance to SPA features by piling

An assessment of baseline conditions has indicated that the areas of intertidal habitat closest to

the existing jetty (near Wilcove to the north and Thanckes Lake to the south) support small

numbers of on-passage little egret (an SPA qualifying feature) (a maximum of three birds were

observed during surveys) and may support low numbers of little egret over-winter. The SPA is

located approximately 1.5km to the south and 2km to the west of the Site. NE in its detailed

advice setting out how it has identified the conservation objectives for the SPA (Ref 6-16),

include an objective relating to disturbance in roosting/feeding areas, the target being ‘no

significant reduction in numbers (of little egret) or displacement of birds from an established

baseline, subject to natural change’.

Disturbance (which may be visual, noise or vibration) can result in a variety of responses, but

birds typically take flight expending unnecessary energy before resuming activity in the same

area or relocating to adjacent areas. The overall effect on a bird population is dependent on a

range of factors including: the frequency of disturbance, habituation and toleration to

disturbance, availability of other suitable habitat and the number of birds (if adjacent areas are

at their carrying capacity).

It is predicted that the greatest potential for disturbance to over-wintering birds will be from noise

generated from the percussive piling, particularly as piling is planned to be carried out between

September and March. Chapter 8 Noise includes a baseline noise assessment that confirms

background noise levels at five receptor sites (between 480m and 780m from the existing jetty)

are between 33.2 and 40.8dBLAeq T during the night and 45 and 53.6dBLAeq T during the day

indicating generally low levels of noise. Modelling has been undertaken of construction noise

(including piling) and the cumulative impacts of unmitigated noise of piling the jetty approach,

the jetty head and the mooring dolphins simultaneously has been assessed as being 84.1dBLAeq

at 50m from source, dropping to 68.5dBLAeq at 300m from the source (see Table 6-9).

Table 6-9 Cumulative unmitigated noise impacts of piling the jetty approach, the jetty

head and the mooring dolphins

Distance from jetty (m)

50 100 150 200 300

LAeq dB(A) 84.1 78.1 74.6 72.1 68.5

A study on the responses of wading birds and wildfowl by the University of Hull (Ref 6-17)

showed that construction noise levels should be restricted to below 70dB as these birds will

habituate to regular noise below this level. Where possible sudden irregular noise above 50dB

should also be avoided as this causes disturbance to birds.

Although BTO core count data cannot provide an indication of the spatial distribution of the birds

within a count sector, the peak numbers of little egret recorded (5) for the Tamar Estuary

(South) Sector 10 are considered to be small when taking into account the entire count sector

(which covers an area of approximately 390ha and extends north from the Site to the Tamar

Bridge (approximately 3km away) and south to Torpoint ferry crossing, a distance of


approximately 940m). In addition, the area of foraging/roosting habitat likely to be affected by

unmitigated noise impacts (approximately 300m to the north and 300m to the south of the

existing jetty) is also extremely small when compared to the count sector as a whole and indeed

the Tamar Estuaries Complex SPA. The fact that the intertidal mudflats around Thanckes jetty

are not designated also indicates that the foraging habitat is sub-optimal (reflected by the results

of the marine surveys which indicated an impoverished benthic flora). This reduces further the

possibility that significant aggregations of little egret will occur in close proximity to the proposed

Development. As the intertidal habitats within 300m of the proposed Development are unlikely

to support significant numbers of little egret, no specific mitigation is proposed to avoid

disturbance to overwintering little egret.

The Site is considered to be subject to a certain degree of disturbance from boat traffic and

during re-fuelling operations. There is sufficient habitat close by and throughout the estuary to

ensure that should any little egret be disturbed by piling works, they can easily move away and

should suffer no long term damage or behavioural changes. The piling works are temporary and

any effects are reversible, i.e. once complete, little egret may return to the habitats around the

jetty.

Disturbance to SPA features (specifically over-wintering little egret) by piling are classified as

having No significant effect on this feature of International importance.

Disturbance to SSSI features by piling

No specific mitigation measures are proposed to address any potential impacts on waders or

wildfowl that may use the habitats adjacent to the jetty, which are functionally linked to the

nearby SPA habitats, as it is considered that the habitats adjacent to the jetty are unlikely to

support significant numbers of birds due to habitat quality and the amount of disturbance the

area is subject to. There is sufficient habitat close by and throughout the estuary to ensure that

should any birds be disturbed by piling works, they can easily move away and should suffer no

long term damage or behavioural changes. The piling works are temporary and any effects are

reversible, i.e. once complete, birds may return to the habitats around the jetty.

St John’s Lake SSSI and Lynher Estuary SSSI are both of a sufficient distance away that any

birds using the SSSI habitats will not be disturbed by piling works.

Disturbance to SSSI features by piling is classified as having No significant effect on this

feature of National importance.

Disturbance from other construction activities

The demolition of the existing jetty and land-based infrastructure is planned for between

February 2018 and August 2018, just within the on-passage period and wintering period. The

activities likely to be occurring during February (wintering) and August (on-passage) may

include the cutting off of piles at the seabed, or below, using hydraulic shearing cutters for

concrete piles and either mechanical cutters or water jet cutting for steel piles. All the

machinery will be operated from marine plant. Noise modelling as set out in Table 6-10 below

has indicated that the cumulative noise impact of all the plant used for demolition (including

hydraulic breakers, dumpers and plate compactors) is above 70dBLAeq T until 200m from the

source of the noise.


Table 6-10 Cumulative unmitigated noise impacts during demolition

Distance from jetty (m)

50 100 150 200 300

LAeq dB(A) 81.5 75.5 72 69.5 65.9

However, is anticipated that the noise from this activity will be significantly less than the

cumulative impacts table illustrated above.

August to October is the peak on-passage period for little egret. By the time the on-passage

little egret arrive the majority of the demolition will be completed.

The mudflats around the jetty have already been assessed as not being a key foraging or

roosting resource for little egret and other species associated with the SSSIs due to habitat

quality and the degree of disturbance the area is already subject to. The construction activities

are temporary and any effects are reversible, i.e. once complete, birds may return to the

habitats around the jetty. No specific mitigation is therefore proposed.

Disturbance to birds from other construction activities is classified as having No significant

effect on this feature of International importance.



that the risk of large volumes of contaminated sediment or pollution entering the estuary is

reduced. The estuary is naturally a turbid and silty environment, therefore should any impacts

arise from increased sediment loads and pollution, they will be localised and temporary.

Loss and damage to foraging habitats as a result of increased siltation and pollution are

classified as having No significant effect on this feature of International importance.



The capital dredging will result in 37,000m3 (13066 tonnes) of sediment being deposited at

Rame Head. This is a relatively small volume when compared to the current maintenance

dredge licence for HMNB Devonport (to which the site is linked), which allows for the deposition

of 367,000 tonnes of sediment at Rame Head over a three year period. Cefas have undertaken

studies in relation to the impact of disposal of dredged material at Rame Head, and published a

report of findings in 2005 (Ref 6-18). These studies determined that whilst there may be some

minor local and temporary increases in turbidity resulting from disposal operations, evidence

from the monitoring surveys indicates that any environmental effects of deposited dredged

material are largely confined to the immediate vicinity of the licence disposal site. Sediment

transport modelling undertaken by Cefas, and described in their report (Ref 6-18), predicted the

location of the deposition of disposed material settling out following the release of individual

hopper loads. The results indicated that the sediment accumulation onto the seabed direct from


the disposal operation tends to occur in a band parallel to the shore, with only very limited

transport in an inshore direction.

The results of the Cefas monitoring, together with the mitigation measures outlined in 6.6.1

above, have resulted in a conclusion of No significant effect on this feature of National

importance.

Seagrass beds

Loss and damage of habitat by piling and dredging

Construction of the jetty will result in the permanent loss of seagrass beds on the intertidal zone

through the installation of piles. The results of the intertidal surveys indicated that seagrass was

locally abundant under the footprint of the proposed Development, but the plant growth was

sparse. It is considered that the seagrass beds are unlikely to be completely shaded by the

presence of the new jetty, as seagrass beds were present beneath the existing jetty. The

removal of the existing jetty structure should ensure the restoration of seagrass habitats in the

area that would no longer be shaded by the jetty. The existing jetty covers an area of 0.2ha and

the new jetty will cover an area of 0.33ha, so only an additional 0.13ha would be beneath the

proposed jetty. This is not considered to be significant given the sub-optimal quality of the

habitat and the availability of good quality habitat in the wider area. Notwithstanding this,

restoration of seagrass will be encouraged by removing crabbing tiles from the intertidal area

within the DIOs control and reducing bait digging and crabbing by installing new signage to

discourage these activities.





Measures to ensure that a small amount of uncontaminated arisings from piling on intertidal

habitat and 10m into the subtidal zone are removed to subtidal areas (around other piles) as far

as is possible from the intertidal zone will also reduce the risk of sediment re-deposition on the

intertidal area.

Loss and damage to Seagrass habitats as a result of increased siltation and pollution are

classified as having No significant effect on this feature of County importance.


Disturbance/mortality to migratory fish

Piling works associated with the construction of the new jetty head and the new mooring

dolphins could act as an acoustic barrier to fish migration if carried out during the core migratory

period. In addition, impact sound from any piling undertaken during the migratory period could

adversely affect the health of fish or adult eels if they are exposed to it for a sufficiently long time

and intensity. Underwater noise and light from the demolition of the existing jetty could disturb

migratory fish.


Noise affects fish species in different ways. Species with swim bladders (e.g. shad and

salmonids) are comparatively more vulnerable to underwater noise than those without (Ref 6-

19). Fish typically exhibit an initial startle response when initially exposed to a sound source

and may temporarily avoid adverse areas. Close to a strong sound source, however; fish may

suffer physiological damage and may be killed if in very close proximity.

Percussive piling works associated with the construction of the new jetty head and the new

mooring dolphins are to be undertaken outside of the main migratory fish period for allis shad,

Atlantic salmon, sea trout, European eel and sea lamprey (i.e. will take place between

September to March).

European smelt accumulate in the lower estuary from October onwards, before ascending to

spawn in the River Tamar between February and April. The February and March migratory

months of the European smelt coincide with the window available for percussive piling.

However, no percussive piling will take place during April, and it is considered by NE (email

dated 14th February 2014, see Appendix 6-G) that the time available is sufficient to allow smelt

to move pass the proposed Development to their spawning grounds.

Vibro-piling, pile case oscillation and auguring/drilling typically generate significantly lower noise

levels in comparison with percussive piling, and NE and Cefas are in agreement that these

construction methods can be carried out at any time of year, subject to monitoring of initial

operations outside of the core sensitive period of 1st April to 31st August to confirm noise levels

are within the range predicted.

Noise and vibrations from demolishing the existing jetty are expected to be lower than piling,

and significant adverse impacts are not anticipated.

Furthermore, no night time working will be carried out.

Disturbance/mortality to migratory fish through pile demolition is classified as having a No

significant effect on this feature of International importance.





arise from increased sediment loads and pollution, they will be localised and temporary and will

have dispersed by the time the migratory fish season begins.

During pile removal some localised sediment disturbance is expected as it needs to be removed

to allow access to the pile. However, this is expected to be extremely localised and of such a

short duration that no specific mitigation is proposed.





Disturbance/mortality to resident fish species

It is highly likely that fish that are resident in the Tamar Estuary are already subject to a high

degree of noise and vibration from commercial, naval shipping and recreational vessels, in

addition to routine maintenance dredging. Therefore local populations of fish are likely to be

habituated to underwater noise and vibration.

Flatfish (i.e. sole and lemon sole), sharks (i.e. spurdog) and some pelagic species such as

mackerel and sprat do not possess swim bladders and are therefore comparatively less

susceptible than those species which do, i.e. bass and whiting. The entire estuary is a

designated bass nursery all year round, although the majority of bass larvae arrive in the

estuary between June and August and are found as young fish in large shoals in shallow waters

of tidal pools, saltmarshes and marinas before moving to slightly deeper water nearby for the

winter. Young bass normally stay close inshore for approximately four years before moving into

wider coastal areas for a year as ‘school bass’ before coming fully mature.

No specific mitigation is proposed as it is considered that the high levels of noise and vibration

that already exist in the Estuary mean that the relatively short period of piling over winter from

December to March will not cause any significant long term effects on those resident fish

species with swim bladders (bass and whiting). In addition, the fish are mobile species which

means that they can move quickly away from any significant disturbance.

Disturbance/mortality to resident fish as a result of piling is classified as having No significant

effect on these features of Regional importance.

Loss and damage to spawning habitat for resident species

The timing of piling and dredging throughout the winter avoids the spawning season for lemon

sole, sole and sprat. Providing the mitigation measures outlined in Section 6.6.1 are

implemented, it is considered that the risk of large volumes of contaminated sediment or

pollution entering the estuary is reduced. The estuary is naturally a turbid and silty environment,

therefore should any impacts arise from increased sediment loads and pollution, they will be

localised and temporary and will have dispersed by the time the spawning season begins.

Given that the Site occupies 0.06% of the total estuarine habitat available in the Tamar Estuary,

the direct loss of breeding and spawning habitat through construction of the jetty, or by capital

dredging, will be negligible. It is also considered that the habitats under the existing jetty and

within the existing dredge pocket are unlikely to support spawning habitat for resident species

due to their disturbed and turbid nature.

Loss and damage to spawning habitat for resident fish as a result of construction is classified as

having No significant effect on these features of Regional importance.


The re-distribution of sediment beyond the immediate piling and dredge pocket may smother

feeding areas, although a high degree of tolerance will be expected given the naturally turbid

conditions within estuaries. Any smothering effects would also be temporary as subsequent

tidal movements will re-mobilise any settled fine sediment.




reduced. Any smothering effects would also be temporary as subsequent tidal movements will

re-mobilise any settled fine sediment. No long term damage to any fish foraging habitat is

anticipated as a result of the proposed Development.

Loss and damage to foraging habitat for resident fish as a result of construction is classified as



Disturbance from piling and dredging

Cetaceans (dolphins and porpoises) are susceptible to underwater noise, particularly pile-

driving, as it can affect their ability to echo-locate through masking their vocalisations causing

behavioural modifications such as temporary displacement from the area where the pile-driving

is taking place (Ref 6-20).

However, percussive piling will only take place between April and August, with the lower impact

vibro-piling technique taking place throughout the year. Should any cetacean enter the Estuary

when the piling is taking place, it will be able to move away from any noise, although the

likelihood of cetaceans being present is considered to be low as records in the vicinity of the

proposed Development are rare.

There are no known hauling out sites for grey seals in the vicinity of the development and

should any grey seal find itself in the vicinity of the proposed Development it will be able to

move away. The likelihood of grey seals being present is considered to be low as records in the

vicinity of the proposed Development are rare.

No specific mitigation is proposed to reduce any potential impacts on marine mammals

(dolphins, porpoises and grey seals) as they are considered to occur so infrequently in the

Tamar that it is extremely unlikely any will be found during piling over the winter months (as

most sightings are during the summer months).

Disturbance from piling and dredging is classified as having No significant effect on these

features of District/Borough importance.

6.7.2 Operation



The existing berth pocket is dredged intermittently (last dredged in 2005) to maintain the

minimum depth. The potential exists for increased sediment loads to be released from

maintenance dredging works affecting water quality and nearby SAC habitats.





arise from increased sediment loads and pollution, will be localised and temporary.

Physical damage to SAC habitats as a result of increased siltation is classified as having No

significant effect on this feature of International importance.

Physical damage to habitats as a result of pollution or toxic contamination

Maintenance dredging has the potential to re-mobilise contaminated sediment and re-deposit it

on SAC habitats or the contaminants could leach out of the sediment into the water column,

affecting water quality. There is also the potential risk from spilt fuel (diesel and AVCAT),

polluted surface water run-off in the event of a pollution incident and fire-fighting foam to enter

the Estuary.

Provided the mitigation measures outlined in Chapter 5 and Section 6.6.2 are adhered to, it is

predicted that there will be no long term adverse impact on SAC habitats as a result of pollution

or toxic contamination. Furthermore, the new, upgraded facility will reduce the potential for a

pollution incident to occur. This impact is classified as having No significant effect on this



Disturbance to birds by maintenance dredging

No specific mitigation is proposed due to the short period of time that maintenance dredging

takes over winter. The most recent maintenance dredge was in 2005. In addition, it has been

established that the intertidal areas closest to the jetty are not optimum foraging habitat for

wildfowl and waders, so it is considered unlikely that significant aggregations of any birds will be

using this habitat over winter.

Disturbance to birds as a result of maintenance dredging is classified as having No significant

effect on these features of International and National importance.

Disturbance to birds by re-fuelling operations

No specific mitigation is proposed as an increase in re-fuelling operations is not expected once

the new jetty is operational. The numbers of birds associated with the habitats adjacent to the

jetty are already low, and birds present in that area will either be habituated to disturbance by

re-fuelling operations, or will be able to move to areas close by which are less disturbed.

Disturbance to birds as a result of re-fuelling operations is classified as having No significant

effect on these features of International and National importance.

Physical damage to habitats as a result of increased siltation, pollution or toxic contamination from maintenance dredging




reduced. Furthermore, the new, upgraded facility will reduce the potential for a pollution incident

to occur. The estuary is naturally a turbid and silty environment, therefore should any impacts






A similar routine of maintenance dredging as is currently carried out will continue post-

construction. The last dredge event was in 2005, when 4036m3 (1425 tonnes) was dredged,

and it is anticipated that any future licences will include conditions to minimise the potential for

movement of suspended sediment in a northerly direction, towards the MCZ, as is currently the

case. Cefas have undertaken studies in relation to the impact of disposal of dredged material at

Rame Head, and published a report of findings in 2005 (Ref 6-18). These studies determined

that whilst there may be some minor local and temporary increases in turbidity resulting from

disposal operations, evidence from the monitoring surveys indicates that any environmental

effects of deposited dredged material are largely confined to the immediate vicinity of the

licence disposal site. Sediment transport modelling undertaken by Cefas, and described in the

above mentioned report, predicted the location of the deposition of disposed material settling

out following the release of individual hopper loads. The results indicated that the sediment

accumulation onto the seabed direct from the disposal operation tends to occur in a band

parallel to the shore, with only very limited transport in an inshore direction.

These findings, together with the mitigation measures outlined in 6.6.1 above, have resulted in a

conclusion of No significant effect on this feature of National importance.

Seagrass beds

Loss and damage of habitat by maintenance dredging





Loss and damage to Seagrass habitats as a result of maintenance dredging are classified as

having No significant effect on this feature of County importance.

Loss and damage of habitat by pollution

The risk of a pollution incident, particularly oil/fuel spillages or the use of fire fighting foam during

operation could damage Seagrass beds. Providing the mitigation measures outlined in Section

6.6.2 are implemented, the risk of a pollution incident occurring are considered to be reduced to

an acceptable level. Furthermore, the new, upgraded facility will reduce the potential for a

pollution incident to occur.

Loss and damage to Seagrass habitats as a result of pollution are classified as having No

significant effect on this feature of County importance.



Disturbance to migratory fish by maintenance dredging

The current maintenance dredging regime is only undertaken during the winter period to avoid

disturbance to migratory fish. It is anticipated that this will continue and therefore no further

mitigation is required.

It is considered that mitigation through avoidance means that disturbance/mortality to migratory

fish as a result of maintenance dredging is classified as having No significant effect on this


Loss and damage to foraging habitats as a result of increased siltation and pollution from maintenance dredging




to occur. The estuary is naturally a turbid and silty environment, therefore should any impacts

arise from increased sediment loads and pollution, they will be localised and temporary and will

have dispersed by the time the migratory fish season begins.




Disturbance to resident fish species by maintenance dredging

No specific mitigation is proposed as it is considered that the high levels of noise and vibration

that already exist in the Estuary mean that the short period of maintenance dredging in

occasional winters will not cause any significant long term effects on those resident fish species

with swim bladders (bass and whiting). In addition, fish are mobile species which means that

they can move quickly away from any significant disturbance.

Disturbance/mortality to resident fish as a result of maintenance dredging classified as having

No significant effect on these features of Regional importance.

Damage to spawning habitat for resident species as a result of maintenance dredging, pollution and toxic contamination




to occur. Any smothering effects would also be temporary as subsequent tidal movements will

re-mobilise any settled fine sediment. No long term damage to any fish foraging habitat is

anticipated as a result of maintenance dredging or any pollution incident.


Loss and damage to foraging habitat for resident fish as a result of construction is classified as



Disturbance from maintenance dredging

No specific mitigation is proposed to reduce any potential impacts on marine mammals

(dolphins, porpoises and grey seals) as they are considered to occur so infrequently in the

Tamar that it is extremely unlikely any will be encountered during maintenance dredging over

the winter (as most sightings are during the summer months).

Disturbance from piling and dredging is classified as having No significant effect on these

features of District/Borough importance.


There are three developments which will be considered for cumulative impacts. These are:

• MOD Forward Operating Base at Kinterbury Point;

• MOD Refurbishment and Operation of Trevol Jetty;

• South West Devon Waster Partnership Combined Heat and Power Plant.

Refer to chapter 3.8 for details of these developments.

The Kinterbury Point project involves the creation of a FOB at Kinterbury Point, within HMNB

Devonport, for the FHSU which transfers naval staff to vessels. The HRA for the Kinterbury

Point (Ref 6-21) project assessed the significance of effects of the proposals on the Plymouth

Sound and Estuaries SAC and the Tamar Estuaries Complex SPA. Potential hazards identified

include the risk of pollution from aircraft maintenance and refuelling, risk of crash and risk of

disturbance to overwintering avocet and overwintering and on passage little egret. However,

implementation of robust pollution prevention and control measures would result in a low

likelihood of a pollution incident, and neither little egret nor avocet were recorded feeding or

roosting in the vicinity of Kinterbury Point, As such, the HRA concluded that no likely significant

negative effects would occur as a result of the proposals. The Kinterbury Point project is unlikely

to affect any of the Key Ecological Receptors identified in relation to Thanckes, and as such

there will be no cumulative adverse effects on ecology as a result of the proposed

developments. The Trevol Jetty project involves the refurbishment and operation of Trevol Jetty

at HMS Raleigh. NE are concerned that in combination with the temporary interim increase in

helicopter activities at HMS Raleigh there will be disturbance to the bird assemblage in St

John’s Lake. The MOD does not consider that operational use of the jetty is likely to cause

significant disturbance to avocet or little egret feeding or roosting in St John’s Lake due to the

distance from the significant roosting areas and the low usage of this jetty by personnel.

However, the MOD has committed to plant screening along the shoreline in the vicinity of Trevol

Jetty as a mitigation measure to reduce disturbance to the bird assemblage feeding in St John’s

Lake. As the Site is not considered to be particularly important for birds associated with the

surrounding designated sites, and as it is further from St John’s Lake than Trevol Jetty, it is


unlikely that there will be cumulative adverse effects on ecology as a result of the proposed

developments.

It is anticipated that the Combined Heat and Power Plant proposed at Weston Mill Lake would

be a land-based project and as such cumulative adverse effects on marine ecological receptors

as a result of the proposed developments are considered unlikely, assuming the implementation

of standard pollution prevention measures. Given that the Site is not considered to be

particularly important for birds associated with the surrounding designated sites, it is unlikely

that there will be cumulative adverse effects on birds as a result of the proposed developments.

The Weston Mill Lake site is across the estuary from the Site it is therefore not envisaged that

the Power Plant would have any effect on the terrestrial habitats or species associated with the

Site.

6.9 Enhancement measures

Although not required address significant effects on key ecological receptors, DIO are

committed to their duties under the NERC Act (2006) which places a duty on public bodies to

consider conservation of biodiversity within all of their actions. As such, the following

enhancement measures are proposed:

• A programme of eradication will be implemented to remove Canadian Waterweed and

Pirri-pirri-bur from the Site. This will enhance the biodiversity value of the site and will

prevent invasive species from spreading into adjacent habitats.

• Consideration will be given to reusing the arisings from the dredging. This will be

subject to further analysis of the material. It has been suggested that the material could

be used to enhance the high tide roost at Sango Island in St John’s Lake which is

currently submerged by the highest tides, or creating a new additional high tide roost

here. However, this would be need to be subject to further assessments, as there would

be implications for the Plymouth Sound and Estuaries European Marine Site.

6.10 Summary

The ecology chapter has assessed the likely significant effects of the Thanckes OFD Loading

Facility and Fire Fighting Upgrade in terms of terrestrial and marine ecology, in accordance with

the guidance set out in the IEEM Guidelines for Ecological Impact Assessment (2006) (Ref 6-1).

Following a desk study, an extended Phase 1 habitat survey, ornithology surveys and a marine

survey, as well as a consultation exercise, the baseline conditions and key ecological receptors

were established.

The subtidal habitats within the Site are located within the Plymouth Sound and Estuaries SAC,

and the subtidal mudflats associated with this designated site have been identified as a key

ecological receptor. The proposed Development will result in the permanent loss of SAC habitat,

as well as a reduction in habitat diversity as a result of shading by the new jetty. However, the

area of habitat loss is minimal, and the marine survey identified the habitats as impoverished. In

addition, the removal of the existing jetty structure should ensure the restoration of SAC habitats

within the area that would no longer be shaded, and habitat restoration will be encouraged by

removing crabbing tiles and discouraging crabbing and bait digging in the intertidal area within

the DIOs control.


The Tamar Estuaries Complex SPA and St John’s Lake SSSI are located approximately 1.4km

south of the Site, and the Lynher Estuary SSSI is located approximately 2km to the west of the

Site. The habitats within and adjacent to the proposed Development are not considered to

support significant numbers of birds associated with these designated sites. There is sufficient

habitat close by and throughout the estuary to ensure that, should any birds be disturbed during

construction (particularly as a result of piling works), they can easily move away and should

suffer no long term damage or behavioural changes. The piling works are temporary and any

effects are reversible, i.e. once complete, birds may return to the habitats around the jetty.

The proposed disposal site for dredged material is Rame Head, located approximately 1.5km

south of the Whitsand and Looe Bay MCZ. It is predicted that a similar routine of maintenance

dredging as is currently carried out will continue post-construction. Any future licences are

expected to include conditions to minimise the potential for movement of suspended sediment in

a northerly direction, towards the MCZ, as is currently the case. Studies undertaken by Cefas

have demonstrated that the current dredging regime does not have a detrimental effect on the

Whitsand and Looe Bay MCZ.

A number of migratory fish species pass the Site, including Atlantic salmon which is a qualifying

feature of Dartmoor SAC, alis shad which is a qualifying feature of Plymouth Sound and

Estuaries SAC, and European smelt and European eel which are reasons for designation of

Tamar Estuary MCZ. Key migratory periods for these species have been taken into

consideration in programming the works, and percussive piling will take place outside of the

main migratory fish period (i.e. not between April and August). Vibro-piling, pile case oscillation

and auguring/drilling will be carried out at any time of year, subject to monitoring of noise levels.

The Plymouth Sound and Estuaries Complex SAC is part of a year-round designated nursery

area for bass, and the Tamar Estuary is also a spawning area for lemon sole, sole and sprat,

and a nursery area for monkfish, lemon sole, mackerel, spurdog and whiting. Given the high

levels of noise and vibration that already exist in the Estuary, the relatively short period of piling

will not cause any significant long term effects on these fish species.

Marine mammals are considered to occur so infrequently in the Tamar that no impacts on

marine mammals are envisaged as a result of the proposals.

Increased siltation, release of contaminants from contaminated sediment and pollution during

construction and operation has the potential to affect habitats within the Plymouth Sound and

Estuaries SAC, seagrass beds and foraging habitats used by fish and birds associated with the

SPA and SSSI’s. Mitigation measures have been proposed which would minimise disturbance

of sediment, contain migration of sediment and reduce the risk of a pollution incident. It should

be noted that the new, upgraded facility will reduce the potential for a pollution incident to occur.

No significant effects on any ecological receptors are anticipated as a result of the

Development.


Table 6-11 Ecology Impact Summary Table

Impact description Temporary/Permanent Significance rating

Construction

Plymouth Sound and Estuaries

SAC – Loss of habitat

Permanent No significant effect on feature of

International importance

Plymouth Sound and Estuaries

SAC – physical damage to

habitats as a result of

increased siltation, release of

contaminants from

contaminated sediment and

pollution

Temporary No significant effect on feature of


Bird species associated with

the Tamar Estuaries Complex

SPA, Lynher Estuary SSSI, St

John’s Lake SSSI –

disturbance to SPA features

by piling







Disturbance to SSSI features

by piling


National importance





disturbance from other

construction activities






John’s Lake SSSI – loss and

damage to foraging habitats as

a result of increased siltation

and pollution

Loss – permanent

Damage - temporary

No significant effect on feature of



– physical damage to habitats

and species as a result of

increased siltation


National importance

Seagrass beds – Loss and

damage of habitat by piling

and dredging

Loss – permanent

Damage - temporary


County importance

Migratory fish – (Atlantic Disturbance – temporary No significant effect on feature of


salmon, allis shad, European

smelt, sea trout, European eel,

twaite shad, river lamprey, sea

lamprey) disturbance/mortality

to migratory fish

Mortality - permanent International importance

Migratory fish – (Atlantic

salmon, allis shad, European

smelt, sea trout, European eel,

twaite shad, river lamprey, sea

lamprey) loss and damage to

foraging habitats as a result of

increased siltation and

pollution

Loss – permanent

Damage - temporary



Other fish species (bass,

lemon sole, sole, sprat,

monkfish, mackerel, spurdog,

whiting) –

disturbance/mortality to

resident fish species

Disturbance – temporary

Mortality - permanent


Regional importance




whiting) – loss and damage to



pollution

Loss – permanent

Damage - temporary


Regional importance

Marine mammals (bottlenose

dolphin, harbour porpoise and

grey seal) – disturbance from

piling and dredging


District/Borough importance

Operation

Subtidal mudflats associated

with Plymouth Sound and

Estuaries SAC – physical

damage to habitats as a result

of increased siltation

Temporary No significant effects on feature of


Subtidal mudflats associated

with Plymouth Sound and

Estuaries SAC – physical


of pollution or toxic

contamination




Tamar Estuaries Complex



disturbance to birds by

Temporary No significant effect on features of

International and National

importance


maintenance dredging





disturbance to birds by re-

fuelling operations

Temporary No significant effect on features of

International and National

importance




John’s Lake SSSI – physical


of increased siltation, pollution

or toxic contamination from


Temporary No significant effect on this feature

of International importance


– physical damage to habitats

and species as a result of

increased siltation


National importance.

Seagrass beds – loss and

damage of habitat by


Loss – permanent

Damage - temporary

No significant effect on this feature

of County importance

Seagrass beds – loss and

damage of habitat by pollution

Loss – permanent

Damage - temporary


of County importance

Migratory fish (Atlantic salmon,

allis shad, European smelt,

sea trout, European eel, twaite

shad, river lamprey, sea

lamprey) – disturbance to

migratory fish by maintenance

dredging



Migratory fish (Atlantic salmon,

allis shad, European smelt,

sea trout, European eel, twaite

shad, river lamprey, sea

lamprey) – loss and damage to



pollution from maintenance

dredging

Loss – permanent

Damage - temporary






whiting) – disturbance to

resident fish species by



of Regional importance





whiting) – damage to

spawning habitat for resident

species as a result of

maintenance dredging,

pollution and toxic

contamination


of Regional importance

Marine mammals (bottlenose

dolphin, harbour porpoise and

grey seal) – disturbance from


Temporary No significant effect on these

features of District/Borough

importance


7 ARCHAELOGY AND CULTURAL HERITAGE

7.1 Introduction

This chapter to the ES considers the likely significant effects of the Development upon

archaeology and cultural heritage. It describes the assessment methodology; the current

baseline conditions within the site and its environs; the significant environmental effects

anticipated during the construction, operation and decommissioning phases of the

Development; the mitigation measures required to prevent, reduce or offset any significant

adverse effects; and the likely residual effects after mitigation.


This assessment has been undertaken in accordance with current international and national

legislation, and national, regional and local plans and policies relating to archaeology and

cultural heritage. A summary of the relevant legislation and policies, the requirements of these

policies and the proposed Development response has been provided below.

National legislation, policy and guidance that are relevant to the Development include UK

statute, UK planning policy and guidance produced by UK governmental and non-governmental

organisations. In addition some maritime legislation, which is not specific to cultural heritage,

has an effect upon submerged archaeology. The list of legislation and policy is as follows:

• Ancient Monuments and Archaeological Areas Act (1979);

• Protection of Wrecks Act (1973);

• National Heritage Act 1983 (amended 2002);

• Protection of Military Remains Act (1986);

• Merchant Shipping Act (1995);

• Town and Country Planning Act (1990);

• Planning (Listed Buildings and Conservation Areas) Act (1990);

• National Heritage Act 1983 (amended 2002);

• National Planning Policy Framework (2012);

• PPS5 Practice Guide (2010);

• Marine and Coastal Access Act (2009)

• UK Marine Policy Statement (2011)

• English Heritage publication 2008: ‘Conservation Principles: policies and guidance for

the sustainable management of the historic environment’;

• English Heritage guidance 2011: ‘The Setting of Heritage Assets: English Heritage

Guidance’;

• Joint Nautical Archaeology Policy Committee Code for Practice for Seabed Developers.

• Cornwall Local Plan (March 2013)

7.2.1 National Planning Policy Framework (NPPF)

In the NPPF (CLG 2012), a ‘heritage asset’ is defined as a building, monument, site, place, area

or landscape positively identified as having a degree of significance meriting consideration in

planning decisions. Heritage assets are a valued component of the historic environment and

include both designated heritage assets and non-designated heritage assets. Designated


heritage assets include World Heritage Sites, Scheduled Monuments, Listed buildings,

Registered Parks and Gardens, Registered Battlefields, and Conservation Areas. Non-

designated heritage assets include those identified by the local planning authority during the

process of decision-making or through the plan-making process (including local listing). The

significance of a heritage asset is defined as the value of a heritage asset to this and future

generations because of its heritage interest (see section 7.3.4 below). Policies relate to both the

treatment of the assets themselves and their settings, both of which are a material consideration

in development management decision making.

The NPPF states that “The purpose of the planning system is to contribute to the achievement

of sustainable development” and that there are “three dimensions to sustainable development:

economic, social and environmental”. The role the environment will play is described as

“contributing to protecting and enhancing our natural, built and historic environment”.

Local planning authorities can request that the applicant should describe “the significance of

any heritage assets affected, including any contribution made by their setting”. The level of

detail required in the assessment should be “proportionate to the assets’ importance and no

more than is sufficient to understand the potential impact of the proposal on their significance”.

“Where a site on which development is proposed includes or has the potential to include

heritage assets with archaeological interest, local planning authorities should require developers

to submit an appropriate desk-based assessment and, where necessary, a field evaluation.”

Local planning authorities should take this assessment into account when considering the

impact of a proposed development, “to avoid or minimise conflict between the heritage asset’s

conservation and any aspect of the proposal”. A key policy within the NPPF is that “when

considering the impact of a proposed development on the significance of a designated heritage

asset, great weight should be given to the asset’s conservation. The more important the asset,

the greater the weight should be.”

“Significance can be harmed or lost through alteration or destruction of the heritage asset or

development within its setting. As heritage assets are irreplaceable, any harm or loss should

require clear and convincing justification. Substantial harm to or loss of a grade II listed building,

park or garden should be exceptional. Substantial harm to or loss of designated heritage assets

of the highest significance, notably scheduled monuments, protected wreck sites, battlefields,

grade I and II* listed buildings, grade I and II* registered parks and gardens, and World Heritage

Sites, should be wholly exceptional.”

However, where a proposed development will lead to “less than substantial harm to the

significance of a designated heritage asset”, this harm should be weighed against the public

benefits of the proposal. With regard to non-designated heritage assets specific policy is

provided in that a balanced judgement will be required having due regard to the scale of any

harm or loss and the significance of the heritage asset affected.

7.2.2 Maritime Legislation, Planning Policy and Guidance

Maritime archaeological sites in the UK are not protected unless specific action has been taken

to protect them. There are two different acts under which wrecks may be protected: the

Protection of Wrecks Act 1973 (PWA 1973), and the Protection of Military Remains Act 1986

(PMRA 1986). Designation of underwater archaeology (including wrecks and submerged

prehistoric sites) is also possible under a third act, the Ancient Monuments and Archaeological

Areas Act 1979 (AMAA 1979). In addition, there are UK-wide provisions applying generally to


people who find or take possession of wreck – including wreck of archaeological interest –

under the Merchant Shipping Act 1995 (MSA 1995).

The PMRA 1986 and the MSA 1995 are administered UK-wide by the MOD and the MCA

respectively. Section Two of the PWA 1973, which deals with dangerous wrecks, is also

administered UK-wide by the MCA.

The UK Marine Policy statement has been prepared and adopted for the purposes of section 44

of the Marine and Coastal Access Act (2009). This Policy Statement provides a framework for

the preparation of marine plans and decisions affecting the marine environment. The Policy

Statement aims to ‘ensure marine resources are used in a sustainable way’. Provision for

heritage is made, to ‘ensure a sustainable marine environment which promotes healthy,

functioning marine ecosystems and protects marine habitats, species and our heritage assets’.

7.2.3 Local Planning Policy

Local planning policy is set out within the Cornwall Local Plan. The Cornwall Local Plan has

been subject to two rounds of consultation since 2011, and currently the pre-submission version

of the document produced in March 2013 forms the local planning policy. Within this document

Policy 24 is of relevance to the proposed development site.

Policy 24- Historic Environment:

“Development proposals will need to sustain Cornwall’s local distinctiveness and character and

protect and enhance Cornwall’s historic environment and assets according to their international,

national and local significance through the following measures:

Protect, conserve and enhance the historic environment of designated heritage assets and their

settings, including historic landscapes, settlements, Conservation Areas, marine environments,

archaeological sites, parks and gardens and historic buildings.

Protect, enhance and promote the outstanding universal value of the world Heritage Site and its

setting; supporting the adopted management plan.

Development and management proposals should be informed by proportionate historic

environment assessments and evaluations. Where the balance of a decision in favour of

development results in the loss of a heritage asset, the Council will seek appropriate and

proportionate mitigation by using planning conditions, management agreements and

obligations.”

7.3 Methodology

7.3.1 Introduction

The content of this chapter has been guided by the Institute for Archaeologists guidance 2012:

Standard and Guidance for historic environment desk-based assessment (Ref 7-1). Additional

relevant documents include: The National Planning Practice Guidance on Environmental Impact

Assessment issued by Department of Communities and Local Government (DCLG), which

provides guidance on the Town and Country Planning (EIA) Regulations 2011; and

‘Environmental Impact Assessment: a Guide to Procedures’ issued by the former Department of


the Environment, Transport and the Regions (DETR) and the National Assembly for Wales (Ref

7-2)); and ‘The Design Manual for Roads and Bridges, Volume 11, Section 3, Part 2: Cultural

Heritage’ (Highways Agency document 208/07), henceforth referred to as Highways Agency

(HA) 208/07 (Ref 7-3).

Consultation with Phil Copleston, Historic Environment Planning Advice Officer, indicated that

the LPA would have no concerns relating to the historic environment in relation to the proposed

Development.


This assessment focuses on the nature and extent of the heritage resource identified within the

site and within a study area comprising a minimum 1km buffer around the redline site area. This

study area was defined using best practice. The study area was defined in order to better

contextualise the identified heritage resource by enabling examination of its wider landscape

setting. The baseline data is discussed in Appendix 7-B and a gazetteer of all known and

potential heritage assets is provided in Appendix 7-A. All heritage assets have been attributed a

unique reference number and their locations are recorded on Drawing 7-1. Both non-designated

and designated heritage assets within the study area were assessed in order to discuss the

archaeological potential of the proposed development site. A 1km study area for considering the

impacts upon settings of designated heritage assets was considered appropriate as the

proposed Development would constitute the replacement of an existing feature of the same

scale, form and massing, and would be located only a small distance to the north of the current

jetty.


The baseline survey involved the compilation of readily available archaeological and historical

information from documentary, cartographic and photographic sources. The major repositories

of information consulted were as follows:

UNESCO

Sites on the UNESCO list of World Heritage Sites and the Tentative List of Sites for World

Heritage status (January 2012) were assessed and included within the Baseline assessment

where relevant.

English Heritage

Listed Buildings, Scheduled Monuments, Registered of Parks and Gardens of Historic Interest

and Registered of Battlefields recorded by English Heritage were searched, and sites within the

study area were included within the Baseline assessment.

English Heritage Archives (EHA)

Aerial photographs (1940s onwards) and records of archaeological monuments and events

were searched and included within the Baseline assessment where relevant.

UK Hydrographic Office (UKHO)

Records of wrecks and obstructions and historic charts were searched and used to inform the

Baseline assessment

Cornwall Historic Environment Record (HER)


Known archaeological sites, find-spots and previous archaeological works and published and

unpublished documentary sources held by the Cornwall HER were searched and used within

the Baseline assessment.

Plymouth Historic Environment Record (HER)

Known archaeological sites, find-spots and previous archaeological works and published and

unpublished documentary sources held by the Plymouth HER were searched and used within

the Baseline assessment.

Cornwall Records Office

Historic maps, charts, documents and publications were used to inform the Baseline.

Plymouth Records Office (PRO)

Historic maps, charts, documents and publications were used to inform the Baseline.

Plymouth Central Library

Published documentary sources held by Plymouth library were used to inform the Baseline

The Cornish Local Studies Library

Historic maps, charts and published documentary sources were used to inform the Baseline.

Online sources

Online sources, including the National Heritage List website (NHL), Archaeological Data Service

(ADS), the BGS Geology of Britain Viewer and Local Plan information from the Cornwall Council

website were used within the Baseline assessment.

Marine Geophysical Data

Sidescan sonar, Magnetometer, seismic and bathymetric data collected by Aspect Land and

Hydrographic Surveys Ltd (November 2014) was analysed by Cotswold Archaeology as part of

this assessment.

Where they were mappable, records were included within the assessment GIS, listed in the

gazetteer and illustrated in Drawing 7-1. Other data was used qualitatively to inform the

assessment.

Chronology

The dating of archaeological remains relies on three distinct chronologies, these are as follows:

Absolute (or calendar) dates which are suffixed with BC (before Christ) and are generically

known as ‘big BC’. Such dates are part of our present day calendar (i.e. a date of 3,523 BC

occurred 5,537 years ago);

Calibrated radiocarbon dates which are either related to our modern calendar as BC dates or

presented as BP (before present) dates. BP dates are calculated in years before 1950, and take

into account the increased radioactivity background count following the proliferation of nuclear

testing after this date. Therefore, a calibrated date of 4,500 BP indicates a point in time 4,564

years before today (i.e. 2,550 BC).


Uncalibrated radiocarbon dates which are suffixed with bc (generally known as little bc) and are

the original radiocarbon determinations based on the half-life of C14 without compensating for

changes in the background count.

Archaeological convention dictates that dates that relate to the Lower, Middle and Upper

Palaeolithic periods are referred to in terms of years BP, whilst the Mesolithic and later periods

are usually quoted in years BC. These conventions are adhered to in this report.


Defining the importance/sensitivity of resource

The NPPF uses the term ‘significance’ to refer to what it describes as ‘the value of a heritage

asset to this and future generations because of its heritage interest’, i.e. the importance of an

asset. In order to avoid confusion with normal EIA terminology the term importance has been

used within this chapter.

The assessment of importance has been primarily guided by the policies and guidance

contained in ‘Conservation Principles’ (Ref 7-4). The importance of a heritage asset (termed

‘place’ within Conservation Principles) is defined with reference to four areas of value:

• Evidential value, derived from “the potential of a place to yield evidence about past

human activity” (Ref 7-4 p.28) and primarily associated with physical remains or historic

fabric;

• Historical value, derived from “the ways in which past people, events and aspects of life

can be connected through a place to the present” (Ref 7-4 p.28). This can derive from

particular aspects of past ways of life, or association with notable families, persons,

events or movements;

• Aesthetic value, derived from sensory and intellectual stimulation and including design

value, i.e. “aesthetic qualities generated by the conscious design of a building, structure

or landscape as a whole” (Ref 7-4p.30). It may include its physical form, and how it lies

within its setting. It may be the result of design, or an unplanned outcome of a process

of events; and

• Communal value, derived from “the meanings of a place for the people who relate to it”.

Communal value derives from the meanings that a historic asset has for the people who

relate to it, or for whom it figures in their collective experience or memory. It may be

commemorative or symbolic, such as meaning for identity or collective memory (Ref 7-4

p.31).

These four values have been discussed, where appropriate, within this assessment and inform

Table 7-1 below, which has also been guided by Tables 7-2, 7-3 and 7-4 below. Further relevant

guidance on informing judgement of heritage value includes the aims and objectives set out in

the South West Archaeological Research Framework, the research for which published online

(Ref 7-5). Additionally Tables 5.1, 6.1 and 7.1 of Annexes 5, 6 and 7 respectively of Highways

Agency (HA) 208/07 give further guidance on assessing heritage values. NPPF also identifies

designated heritage assets of ‘the highest significance’ namely: Scheduled Monuments;

Protected Wreck Sites; Registered Battlefields; Grade I and II* Listed buildings; Grade I and II*

Registered Parks and Gardens; and World Heritage Sites. Criteria for assessing heritage asset

value are set out in Table 7-1 below.


Table 7-1 Determining the Importance / Sensitivity of Resource

Importance/

sensitivity

of resource

or receptor

Description

High

World Heritage Sites and heritage assets of acknowledged international importance, or that can contribute significantly to acknowledged international research objectives. Historic landscapes of international sensitivity (designated or not) and extremely well preserved historic landscapes with exceptional coherence, time depth, or other critical factor(s) Scheduled Monuments and undesignated assets of Schedulable quality and importance, according to the non-statutory criteria for scheduling monuments utilised by the Secretary of State Heritage assets displaying considerable evidential, historic, aesthetic or communal value as identified by Conservation Principles Heritage assets or groups of assets that can contribute substantially to acknowledged national research objectives Historic landscapes exhibiting considerable coherence, time depth or other critical factors and displaying considerable evidential, historic, aesthetic and communal value as identified by Conservation Principles. The landscape may or may not be associated with Scheduled Monuments Grade I and II* Listed buildings or other Listed buildings that can be shown to have exceptional qualities in their fabric or associations not adequately reflected in their Listing grade, or undesignated structures of clear national importance. Conservation Areas containing very important buildings

Medium

Heritage assets that are not Scheduled and that do not meet the criteria for Scheduled Monuments according to the non-statutory criteria for scheduling ancient monuments utilised by the Secretary of State Heritage assets displaying evidential, historic, aesthetic or communal value as identified by Conservation Principles Heritage assets, or groups of assets or landscapes, that contribute to regional research objectives, particularly those identified in the research framework for the south-west Historic landscapes exhibiting reasonable coherence, time depth or other critical factors (including degree of preservation) and displaying evidential, historic, aesthetic and communal value as identified by Conservation Principles. Grade II Listed buildings or historic buildings. Conservation Areas containing important buildings which contribute significantly to their historic character, or historic townscapes with important historic integrity

Low

Heritage assets displaying limited evidential, historic, aesthetic or communal value as identified by Conservation Principles Heritage assets, or groups of assets, that contribute to a limited degree to regional research objectives, particularly those identified in the research framework for the south-west Historic landscapes exhibiting limited coherence, time depth or other critical factors and


Importance/

sensitivity

of resource

or receptor

Description

displaying evidential, historic, aesthetic and communal value as identified by Conservation Principles. Historic landscapes whose sensitivity is limited by poor preservation and/or poor survival of contextual associations.

Negligible

Heritage assets with very little or no surviving archaeological interest, and little or no evidential, historic, aesthetic or communal value as identified by Conservation Principles Heritage assets or groups of assets that cannot appreciably contribute to acknowledged regional research objectives Historic landscapes exhibiting little or no coherence, time depth or other critical factors and displaying evidential, historic, aesthetic and communal value as identified by Conservation Principles Buildings of no architectural or historical note and buildings of an intrusive character

Uncertain The importance of the resource has not been ascertained. Archaeological resources the importance of which cannot be ascertained. Buildings with some hidden (i.e. inaccessible) potential for historical significance.

The magnitude of development change upon heritage assets

The classification of the magnitude of change on heritage assets is rigorous and based on

consistent criteria. This takes account of such factors as the physical scale and type of

disturbance anticipated to affect them and whether features or evidence would be lost that are

fundamental to their historic character and integrity. Changes may be adverse or beneficial.

Depending on the nature of the change and the duration of development, effects can be

temporary and/or reversible or permanent and irreversible. The magnitude of the change is

assessed using the criteria in Table 7-2 below. This is based on Tables 5.3, 6.3 and 7.3 of

Annexes 5, 6 and 7 respectively of Highways Agency (HA) 208/07, (Ref 7-3).

The descriptions of change describe the ways in which an asset or elements of its setting may

be modified or removed by the proposed development, and will include the consideration of

such issues as which and how many elements of an asset are affected; whether the change

physically modifies the asset or whether it comprises changes in visual aspects, noise or access

that would alter its setting; and whether the change in the significance of an asset will be

adverse or beneficial.


Table 7-2 Assessment of the Magnitude of Change

Magnitude

of Change Description of Change

High

Change to most or all key archaeological or historic building elements, such that the asset is totally altered

Total changes to setting of archaeological or historic building assets

Change to most or all key historic landscape elements, parcels or components; extreme visual effects; gross change of noise or change to sound quality; fundamental changes to use or access; resulting in total change to the character of a historic landscape area.

Medium

Changes to many key archaeological or historic building elements, such that the asset is noticeably modified

Changes to setting of archaeological or historic building assets, such that it is noticeably modified

Changes to many key historic landscape elements, parcels or components; visual change to many key aspects of the historic landscape; noticeable differences in noise or sound quality; considerable changes to use or access; resulting in moderate changes to the character of a historic landscape area.

Low

Changes to key archaeological or historic building elements, such that the asset is slightly modified

Changes to setting of archaeological or historic building assets, such that it is slightly altered and noticeably changed

Change to few key historic landscape elements, parcels or components; slight visual changes to few key aspects of historic landscape; limited changes to noise levels or sound quality; slight changes to use or access; resulting in limited changes to the character of a historic landscape area.

Negligible

Very minor changes to archaeological or historic building elements or setting

Very minor changes to key historic landscape elements, parcels or components; virtually unchanged visual effects; very slight changes in noise levels or sound quality; very slight changes to use or access; resulting in very small change to the character of a historic landscape area.

No Change

No change to archaeological elements or historic building fabric and setting

No change to elements, parcels or components; no visual or audible changes; no changes arising from amenity or community factors

The significance of the effect of development

Following the evaluation of the importance of the cultural heritage resource and the magnitude

of the change, the significance of the effect after mitigation is assessed using the matrix shown

in Table 7-3 below, based on Table 5.1 of Highways Agency (HA) 208/07, (Ref 7-3). Where two

alternatives are given in the table, professional judgement is used to decide which best reflects

the significance of the effect of the impact identified. The significance of effect may be adverse

or beneficial.

Where the importance of the heritage asset is uncertain the Significance of Effect is unknown.

The identification of an Unknown significance of effect relates to situations where, based on the

historic development and background potential of the site area, there is some limited potential


for archaeological remains to be present within the site, although detailed surveys of the site in

line with industry standards have not provided any direct evidence of such remains. The range

of evidence assessed to understand potential within this chapter is in line with industry

standards and a proportionate level of assessment has been undertaken to minimize the risks of

significant effects going undetected. Thus the remaining potential is considered to be limited,

and the risks of encountering such remains minimised through thorough assessment. However

where the value of any such potential remains is uncertain, the Significance of Effect is

unknown.

Table 7-3 Determination of the Significance of Effect

Importance/Sensitivity of Receptor

High Medium Low Negligible Uncertain

Magnitude

of Change

High Major Major Slight to

Moderate

Neutral/ not

significant

Unknown

Medium Major Moderate Slight to

Moderate

Neutral/ not

significant

Unknown

Low Slight to

Moderate Slight

Slight to

Neutral

Neutral/ not

significant

Unknown

Negligibl

e

Neutral/

not

significant

Neutral/ not

significant

Neutral/ not

significant

Neutral/ not

significant

Unknown

The significance of the judged effect is then discussed, in line with Table 7-4 below, which

summarises the ‘qualitative’ effect with reference to key planning policy. Key principles that are

considered are whether the change comprises substantial harm or total loss, and whether the

asset is of such a value/importance that such a change would be exceptional, or indeed wholly

exceptional.


Table 7-4 Qualitative Description of the Significance of Effect

Significance of Effects

Significance Criteria

Major Adverse

Substantial harm or total loss of the value of a designated heritage asset (or

asset worthy of designation) such that Development should not be consented

unless substantial public benefit is delivered by the Development.

Moderate Adverse

Less than substantial harm or total loss of the value of a designated heritage

asset (or asset worthy of designation) such that the harm should be weighed

against the public benefit delivered by the Development to determine consent.

Harm to a non-designated heritage asset, of a greater degree than that

perceived of as Slight Adverse, which should be taken into account in

determining an application.

Slight Adverse

Harm to a non-designated heritage asset that can be adequately compensated

through the implementation of a programme of industry standard mitigation

measures.

Less than substantial harm to the value of a designated heritage asset, of a

lesser degree than that perceived as Moderate Adverse, but which should still

be weighed against the public benefit delivered by the Development to

determine consent.

Neutral/ Not

Significant Effect that is nil, imperceptible and not significant.

Slight Beneficial Development will deliver a positive contribution and / or better reveal the value

of a non-designated heritage asset.

Moderate

Beneficial

Development will deliver a positive contribution and / or better reveal the value

of a designated heritage asset (or asset worthy of designation) such that an

application should be treated favourably.

Major Beneficial

Development will deliver a positive contribution and / or better reveal the value

of a heritage asset of recognised international value such that an application

should be treated very favourably.


7.3.5 Consultation

This section provides information of the consultations undertaken to inform the assessment of

cultural heritage and archaeology. Advice and information provided by the consultees shaped

both the assessment methodology and the scope of the assessment.

In March 2013 the MMO provided a Screening and Scoping Opinion, which included advice

regarding the site in relation to archaeology and cultural heritage. This Opinion stated that: The

project will not impact upon any designated heritage assets, therefore English Heritage will not

play an active role in advising on the heritage impacts. This will be the responsibility of Cornwall

Council Historic Environment Service, who should be consulted on these works.

In February 2013 CC provided a Screening Opinion. No consultation response had, at that

stage, been received from the Historic Environment section and thus general advice was given,

as follows:

The ES should include a comprehensive desk based and walk over survey by an appropriately-

qualified archaeological contractor. This will be required of the widest affected development

area and include the transport links. Such assessment should include:-

(i) An assessment of impacts on any archaeological and historical assets and their

settings, and proposed mitigation and recording proposals where appropriate (a

“Written Scheme of Investigation”). Archaeological assessments should be undertaken

to the appropriate standards of the Institute for Archaeologists;

(ii) Consideration of any impacts on any nearby Listed Buildings, together with non-

designated archaeological sites, landscapes and any monuments in the vicinity which

are detailed in the Cornwall And Scilly Historic Environment Record and any nearby

Conservation Areas;

(iii) Photomontages should include views with receptors as well as the proposed

development accurately scaled in the same view;

(iv) Detailed consideration of impacts associated with groundworks, particularly (but not

exclusively) those resulting from the provision of, piling, access tracks;

(v) Assessment should make clear the impacts, both direct and indirect, on the significance

of heritage assets that may be affected by this development. These findings should be

presented in a Heritage Statement, summarising and quantifying all work undertaken in

the assessment. The Statement should also consider cumulative impacts on specific

heritage assets, as well as on their settings.

The Cornwall Council Historic Environment Service holds detailed information about designated

and undesignated archaeology and should be consulted during the pre-application stages.

In June 2013 Cornwall Historic Environment Record and Plymouth Historic Environment Record

was consulted in order to obtain data relating to archaeological sites, monuments, events and

finds within the site and study area. This data was provided by the HER. Information on any

wider studies, in particular considering the prehistoric remains of the Hamoaze or Tamar, was

also sought. Advice given by the Historic Environment Records led to consultation with

Plymouth University regarding research in the Hamoaze.


In June 2013 Plymouth University was consulted in order to discuss research carried out in the

Hamoaze area. This consultation resulted in the acknowledgement by Plymouth University of a

study carried out within the vicinity of the study area. Correspondence indicated that walkover

surveys of the foreshore in this area had been conducted by the University, and had recorded

remains, the majority of which are indicated to have been debris although a hulk and potential

archaeological site were also recorded away from the site, within Thanckes Lake.

In June 2013 the English Heritage Archives were consulted in order to obtain data relating to

archaeological sites, monuments and events within the site and study area. Additionally aerial

photographs covering the site were also consulted at this time.

In September 2013 the Historic Environment Planning Advice Officer at CC was consulted

about the proposals. The Council had no concerns relating to the historic environment over the

proposed Development.



MMO The project will not impact upon any designated heritage assets, therefore English Heritage will not play an active role in advising on the heritage impacts. This will be the responsibility of Cornwall Council Historic Environment Service, who should be consulted on these works

Consulted with Cornwall Council Historic Environment Service

Cornwall Council Historic Environment Service

No response to scoping opinion. Response received from Phil Copleston, Historic Environment Planning Advice Officer at Cornwall Council, who had no concerns relating to the historic environment over the proposed Development

None required


Information from investigations and archaeological remains recorded within the study area and

wider vicinity of the site has been interpreted taking into account the surrounding landscape,

environment, topography and geology, and has been used to inform the potential of the

proposed Development site. This has been done under the assumption that recorded remains

are in general representative of the nature and character of further potential remains surviving

within adjacent areas.



7.4.1 Introduction

This section provides an overview of the local geological, pedological, topographical and

palaeo-environmental conditions, and an overview of the historical and archaeological

background of the Study Area and its environs. All archaeological sites discussed in the text are

illustrated in Drawing 7-1. Photomontages have been produced for the development and these

are discussed in Chapter 9.

7.4.2 Designated Heritage Assets

No World Heritage Sites or sites included on the Tentative List of Future Nominations for World

Heritage Sites (January 2012) are situated within the site or the wider study area.

The baseline survey identified a total of thirty-four Listed buildings, comprising one Grade I

Listed building, three Grade II* Listed buildings, and twenty-eight Grade II Listed buildings within

the study area, and one Grade II* Registered Park and Garden (Anthony Park). The Listed

buildings occur primarily in clusters, with 23 of the total associated with Devonport Dockyard, a

further seven are situated within Torpoint, with the remaining three occurring separately and

comprising the Grade II Listed Pato Point, Pato House and Building 124 (Mixing House). None

of these designated heritage assets lie within, or adjacent to the site.

Within the wider area there are also a number of sites protected under the AMAA 1979

(scheduled monuments), those identified within the scoping document comprise three

scheduled monuments at Devonport South Yard, all associated with the early construction of

the dockyard. A further three scheduled monuments are located at Devonport North Yard,

relating to the Bullpoint gunpowder magazines and camber. Additionally a scheduled monument

is also located at Torpoint, comprising a ballast pond.

There are no wrecks within the site of the study area that are protected under the PWA 1973 or

the PMRA 1986.

7.4.3 Summary of Non-designated Heritage Assets

The range of sites within the study area includes medieval settlements and a small number of

wrecks, however most are post-medieval and modern features and relate primarily to the

development of Devonport Dockyard and the settlement of Torpoint. All identified non-

designated heritage assets are listed in the gazetteer in Appendix 7-A, and their locations are

depicted on Drawing 7-1.

Appendix 7-B discusses the identified heritage resource by period, setting identified sites within

their wider historical background.

The known and potential cultural heritage resource within the site and study area is discussed in

relation to two distinct types of archaeology: Prehistoric archaeology relating to the potential

inhabitation of land that is now submerged during periods of lower sea level; and maritime and

coastal archaeology relating to seafaring and the use of the inter-tidal area for a wide range of

activities.


The prehistoric archaeology is discussed with reference to what is known about sea level

change during the last one million years - the approximate period for which human activity is

known for the British Isles. This has been done in order to establish when the study area was

dry land, and therefore available for exploitation by humans. Thereafter the geology and palaeo-

environment of the area has been assessed in order to determine whether deposits relating to

those periods when the area was dry land may potentially survive. This is followed by a

discussion of the archaeological evidence for those periods where there is potential for the

survival of deposits. This discussion runs from the Lower Palaeolithic period up to the end of the

Iron Age, at which time sea level rose to a point close to its current position.

The assessment of baseline data within Appendix 7-B identified very low potential for remains of

Palaeolithic, Mesolithic, Neolithic, Bronze Age and Iron Age to be present as submerged

remains within the site. There is also considered to be very low potential for terrestrial remains

of Roman or early medieval archaeology to be present within or adjacent to the site. A low

potential for medieval and post-medieval remains on Yonderberry Peninsula has been

identified. Yonderberry peninsula appears to have undergone large scale disturbance and

remodelling associated with the construction of the oil depot, and as such any earlier

archaeological remains within the terrestrial area are likely to have been removed.

Maritime archaeology within the area is discussed in relation to known wrecks and the potential

for further wrecks. The inter-tidal zone has been separated out from the main maritime section

due to the potential for non-shipwreck related archaeology.

Geophysical surveys conducted within the site recorded a series of features within this area,

which included a small boat associated with a very small anchor, moorings, and debris. The

UKHO record other wreck remains within the study area. The potential for further wrecks to be

found within the site is considered to be low, although the area off Yonderberry point has been

as a mooring from at least the 19th century (Drawing 7-9) and historic maps indicate moorings

in the area from the post-medieval period.

7.4.4 Determining the Importance / Sensitivity of Resource

The only records that relate to identifiable sites, finds or objects within or close to the footprint of

the development are all geophysical anomalies. Where the features can be identified to type,

i.e. anchors, mooring blocks, cables and a small wreck, there is no confirmed date, and

therefore they are of Uncertain level of importance. However, the nature of the anomalies, and

their location on the surface of the river bed in the area close to the current jetty strongly

supports a modern date, therefore the likely level of importance can be amended to Negligible.

Those anomalies identified as debris are of unknown type, and thus are of uncertain

importance. However, their general nature and location within an area used for vessel mooring

over a long period of time, suggests that they are likely to be associated with that activity and

thus their level of importance is likely to be low.

In addition to the known sites and anomalies there is a general low level of potential for the

presence of currently unknown wrecks and wreck related material, and a very low potential for

the presence of submerged Prehistoric archaeology within the area of the site. The importance

of any sites that may be associated with this potential is currently Uncertain. However, in order

to remove uncertainty the precautionary principle has been used.


The potential for remains of submerged prehistory is considered to be very low, and no

evidence for such remains has been recorded by borehole surveys across the site. Restricted

areas of peat may potentially survive as discreet horizons in between borehole locations,

however this is again considered unlikely as the absence of any peat deposits within boreholes

indicates that the general area of the site is unlikely to have been conducive for peat formation

or survival. However, if discreet areas of submerged prehistoric landscapes were identified

within the site, they may have the potential to provide palaeoenvironmental or archaeological

data pertaining to the prehistoric period. The remains may have the potential to contribute to

Research Aim 23 in the South-West Archaeological Research Framework: Improve our

understanding of past climate and sea level changes together with their effects on the peoples

relationships with landscapes and the sea (Ref 7-5). Given their restricted potential areas, these

remains are unlikely to exceed medium heritage value.

As regards wrecks, the potential for remains of this nature of any period to be present within the

site is considered to be very low, and no timbers were recorded by boreholes taken within the

site. However silts and sands recorded by boreholes may provide a good preservation

environment for remains of wreckage. Thus, while the potential for such remains is very low, if

any remains of wrecks were to survive within the site they may be well preserved, could date

from the prehistoric period onward, and may encompass remains relating to important events

which are known to have taken place within the area, such as Civil War battles. Thus these

remains could potentially be of high heritage value.


Construction

Anticipated construction activities with the potential to physically affect any archaeological

remains within the Site comprise:

• The insertion of two dredged boxes

• The insertion of piles associated with the construction of the jetty and mooring dolphins

• The removal of the current jetty and associated mooring dolphins

• Vessel anchoring and use of jack-up barges during the construction and use of the jetty

• Indirect Impacts

The impact areas are shown on drawing 7-8.

Dredging - As described in Chapter 2,a new berth pockets will be constructed through

dredging. The berth pocket, to be situated on the channel side of the new jetty head, would

have a minimum maintained depth of -11.6mCD, and an approved dredge depth of -12.2mCD,

to enable safe mooring of ships at the jetty at all states of the tide. The new berth pocket will be

300m long by 45m wide.

Additionally an area will also be dredged to the rear (western) side of the new jetty head. This

would be to provide a navigational channel to the fuel pontoon, as described in Chapter 2. The

navigational channel would be 40m wide, with a minimum maintained depth of -5.0m CD and an

approved dredge depth of -5.6m CD.

Capital dredging will be required to create the new berth pocket and navigational channel. It is

anticipated that this dredging will be undertaken by TSHD or cutter suction dredger. The


maximum design dredge depth is -12.6mCD and -5.6m CD for the areas respectively. A new

Marine Licence will be required for the capital dredging proposed to accommodate the

construction of the new berth pocket and navigational channel. The estimated volume of

sediment arising from the dredging is estimated to be approximately 37,000m3 (subject to final

design calculations). Drawing 2-7 shows the extent of the proposed relocated berth pocket.

Impacts associated with this element of the construction would be restricted to the initial

dredging activities, with maintenance dredging posing no threat to potential archaeological

remains as it would remove only fill of the dredged box.

Material to be dredged is understood to be predominantly silt. Piles to be inserted as part of the

proposed development would be associated with the construction of the approach jetty, jetty

head, mooring pontoon, vessel protection barrier and mooring dolphins. It is likely that the

approach jetty will be constructed on piles in the order of 900mm and that the jetty head will be

constructed on tubular piles of 900mm to 1200mm diameter. The mooring pontoon and vessel

protection barrier will involve smaller piles (likely to be 600mm diameter). Note that all

dimensions quoted are approximate and may be subject to change at detailed design stage.

Construction plans indicate that the piles would extend through all deposits into the bedrock, as

such any archaeological remains situated within the footprint of the piles would be impacted.

However, the insertion of piles would not result in the complete removal of archaeological

deposits, but rather would result in localised areas of impact associated with the footprint of the

pile with a surrounding impact zone, which would be dependent on the piling technique used.

Removal of the current jetty and mooring dolphins to the south of the proposed

development is likely to cause limited disturbance of the seabed. However, any disturbance is

likely to be in areas which have already been impacted by insertion of the piles during the

construction of the current jetty.

Vessel anchoring and the use of jack-up barges during the construction of the jetty is likely

to cause some limited disturbance to the seabed in the areas around the proposed jetty. This

impact will be limited to the surface and top c.0.5m of the modern seabed sediments.

Impacts of construction have the potential to affect heritage assets through alterations to their

setting. However, as the proposed development would constitute the replacement of an existing

feature of the same scale, form and massing, and would be located only a small distance to the

north of the current jetty, impacts affecting the setting of heritage assets are not anticipated.

A site compound will be established within the current Thanckes OFD for use by the Contractor

and the Client’s Representative administration and welfare facilities, on an area of land between

Tank 6 & the Tank row 15 – 18. In addition a working area will be established for materials

storage and construction of all land based elements and for installation of infrastructure on the

jetty deck. This will be located in the existing crew car park area, adjacent to the new

Yonderberry Jetty root. These elements of the Development are not expected to be associated

with below ground impacts, and will be located in the area where extensive previous impacts,

associated with the construction of the depot have occurred. It is anticipated that the jetty

services will be connected to the pre-existing services in use with the current jetty, with no new

impacts.

Operation

Anticipated operational activities with the potential to physically affect any archaeological

remains within the Site relates to anchoring of vessels around the jetty.


Anchoring associated with vessels during the use of the jetty is likely to cause some limited

disturbance to the seabed in the areas around the proposed jetty, and may cause disturbance

to any archaeological remains however this disturbance is likely to be localised and restricted to

the top 0.5m of the modern seabed sediments.

Decommissioning of the jetty and its removal

Decommissioning and removal of the proposed jetty and associated features is likely to be

associated with limited disturbance of the seabed during removal of piles. However, any

disturbance is likely to be in areas which have already been impacted upon by the original

construction phase.


7.6.1 Magnitude of Development Change

Within the dredged boxes the magnitude of development change will be High for any

archaeology that survives within the sediments to be removed. The impact will also be high for

any archaeology within the footprint of the piling, though this will be restricted to a small

percentage of any site, and thus the magnitude of development change will be Low-Medium.

Where the impact will arise from vessel anchoring and the use of jack-up barges the impact will

be restricted to a small footprint and with a low level of damage, thus the magnitude of

development change will be Negligible-Low.

During decommissioning impacts are likely to be similar to those described for construction, and

related to impacts associated with anchoring of vessels and jack-up legs for barges. The

Magnitude of Development Change in these areas is Negligible-Low.

7.6.2 Assessment of Significance of Effect

Construction

Heritage assets within or close to the site comprise those identified by the geophysical survey.

These remains lie principally within the area of impact associated with the anchoring of vessels

during the construction of the jetty.

The level of Importance/Sensitivity attached to these sites varies from Negligible to Low, with

some degree of Uncertainty in some cases. The Magnitude of Development Change in areas

which would undergo impacts associated with anchoring vessels is Negligible-Low. Therefore

the Significance of the effect of the development upon the known archaeology is at worst Slight

in these areas.

Within the area proposed for dredging associated with the new navigational channel there are

four geophysical anomalies (Drawing 7.1: 63, 65, 66, 68). These anomalies have been

interpreted as a cable, two possible cables and a mooring. All are likely to be modern in date,

and have a negligible heritage value.

Three anomalies are recorded within the proposed dredge box for the new berth pocket, with

one of these lying on the edge of the dredge box adjacent to an area of proposed piling. The

latter comprises a piece of debris (Drawing 7.1, 54) with a further piece of debris located within


the area of the proposed dredge box (Drawing 7.1, 73). Additionally a side scan anomaly

interpreted as a small wooden vessel (a rowing boat/tender measuring 2.7m x 1m x 0.5m.) lying

next to a very small anchor, (Drawing 7.1, 53) and a magnetic anomaly thought to be associated

with the charted mooring buoy or it’s tackle (Drawing 7.1, 67) also lie within the dredge box. The

magnitude of change within the proposed dredge boxes would be high. For those remains of

negligible value, principally within the area of the proposed dredge box for the navigational

channel, a high magnitude of change upon the remains, of negligible value, would result in an

effect which is neutral or not significant.

As the pieces of debris (Drawing 7.1, 54, 73) lie within the dredge box and adjacent to an area

of proposed piling, both of which can reach up to a High Magnitude of change, the assessment

is based upon the maximum magnitude of change for these areas; high. An impact of High

Magnitude upon the debris of low value would result in a Slight to Moderate Significance of

effect. In instances where the significance of effect has two possible ratings professional

judgement must be used to determine between these. On balance, taking into account the

location of the debris on the surface of the river bed and its position adjacent to the current pier,

this would suggest that the remains are unlikely to be of archaeological interest. Thus its

removal would not be anticipated to constitute more than a Slight Significance of effect.

The likely remains of the small vessel and mooring buoy are considered to be of Negligible

Importance/ Sensitivity. Lying within the dredge box they would likely undergo impacts

anticipated to represent a High Magnitude of change, which would result in a Significance of

effect of Neutral/ Not significant.

There is low potential for as yet unrecorded shipwreck archaeology or submerged prehistoric

remains to be present within the site, the value of which is Uncertain. However, although the

potential is low, the precautionary principle has been used. Remains of submerged prehistory

would not be anticipated to exceed medium heritage value, while remains of wrecks within the

site could potentially be of high heritage value. The likelihood of either remains occurring is

considered to be very low. Such potential remains could incur impact of up to a high

magnitude of change, if encountered within the areas of proposed dredging. This would result

in, at most, a Major Significance of Effect. Although this significance of effect has been

identified in relation to remains which have a very low potential of occurring within the proposed

development site, mitigation would be necessary and is outlined below.

The proposed Development would constitute the replacement of an existing feature of the same

scale, form and massing, and would be located only a small distance to the north of the current

jetty, therefore no impacts on designated heritage assets through changes to their settings is

anticipated.

Operation

As for construction, the majority of heritage assets of assessable importance within or close to

the site lie within the area of impact associated with the anchoring of vessels during use of the

jetty. The level of Importance/Sensitivity attached to these sites varies from Negligible to Low,

with some degree of Uncertainty in some cases. The Magnitude of Development Change in

these areas is Negligible-Low. Therefore the Significance of the effect of the development upon

the known archaeology is at worst Slight.


Decommissioning

Decommissioning activities are unlikely to result in significant additional disturbance to the sea

bed (as the jetty is likely to be removed by cutting the supporting structures off just below bed

level. Impacts are therefore likely to be similar to those described for construction above

(related to impacts associated with anchoring of vessels and jack-up legs for barges). The

Magnitude of Development Change in these areas is Negligible-Low. Therefore the Significance

of the effect of the development upon the known archaeology is at worst Slight.

7.6.3 Cumulative Effects

Other Proposed Developments

Geophysical anomalies within the site footprint would not be anticipated to undergo any

cumulative impacts associated with the construction of other proposed developments as

described in chapter 3.6. As no other impacts to heritage assets within the site or study area

have been identified, no cumulative effects on archaeology and cultural heritage are anticipated.

7.6.4 Additional Mitigation

The significance of effect for the known archaeology is slight, therefore no mitigation is

considered to be warranted.

Action would be required at the construction phase in order to mitigate impacts upon potential

archaeological remains within the site. An archaeological watching brief, involving

archaeological attendance during dredging, would constitute an appropriate mitigation strategy

for dealing with the potentially Major Significance of Effect identified with regard to low

potential archaeological remains within the site area using the precautionary principle. During

the initial stages of the dredging programme an assessment would be made, on the basis of the

nature and inclusions within the material dredged, as to whether the continued presence of an

archaeologist would be required on site, or whether dredger staff could continue to monitor

operations. It would be necessary to report any finds made during the monitoring process using

an appropriate finds reporting protocol. The reporting protocol will be implemented by the

dredging contractor with archaeological support if necessary in the form of ad hoc advice

regarding any significant finds recovered. This will satisfy the requirements of the Merchant

Shipping Act 1995 as well as archaeological objectives. This would render the significance of

effect slight.

7.7 Summary

No designated heritage assets lie within the proposed development site. The only non-

designated heritage assets are geophysical anomalies, most of which are modern in date or

undated debris.

There is a very low potential for the presence of submerged prehistoric archaeology, and for the

presence of currently unknown pre-medieval watercraft. In addition there is a low potential for

remains of wreckage relating to vessels moored or sunk within the site during the post-medieval

and modern periods. Any such remains are not likely to be substantial or complete and their

importance is uncertain. An archaeological watching brief would be an appropriate mitigation

strategy to address potential archaeological remains within the site.


As the proposed Development would constitute the replacement of an existing feature of the

same scale, form and massing, and would be located only a small distance to the north of the

current jetty, no impacts on designated heritage assets, through changes to their settings, is

anticipated.

No cumulative impacts upon archaeology or cultural heritage are anticipated in association with

the proposed Development.

Table 7-6 Archaeology and Cultural Heritage Impact Summary Table

Impact description Temporary/Perm

anent

Proposed

Mitigation

Measures

Significa

nce

rating

Significant

Effect

Impact of vessel

anchoring during

construction and

operation

Permanent None Slight

Impacts of dredging

upon small vessel

Permanent None Neutral

Impacts of dredging

upon mooring buoy


Impacts of dredging

upon debris

Permanent None Slight

Impacts of dredging

upon cables and

possible cables


Impact of dredging

upon potential

archaeology

Permanent Archaeological

watching brief and

finds reporting

protocol during

dredging

operations

High/

Medium

Slight,

following

mitigation

Impact of piling upon

potential archaeology

Permanent None Unknown

Impact of vessel

anchoring upon

potential archaeology

Permanent None Unknown


8 NOISE AND VIBRATION

8.1 Introduction

The purpose of the noise and vibration assessment is to identify and assess the noise and

vibration impacts associated with the Development. Noise and vibration impacts will be

considered during the construction and operation of the Development and associated plant.


This impact assessment has been undertaken in accordance with current national legislation,

and national and relevant policies and guidance relating to noise and vibration in the context of

the proposed Development. A summary of the relevant legislation and policies, the

requirements of these policies and the proposed Development response has been provided in

Table 8-1 below.

Table 8-10 Regulatory and Policy Framework


Noise Policy Statement

for England

(NPSE)

The Noise Policy Statement for

England (published on 15 March

2010) sets out the long term

vision of Government noise

policy, which is to promote good

health and a good quality of life

through the management of

noise within the context of

Government policy on

sustainable development.

None. NPSE provides an overarching

policy framework that has been

embraced in assessing noise impacts.

National Planning Policy Framework. (July 2012)

National Planning Policy

Framework (NPPF) formally

published on 27 March 2012.

None. NPPF provides an overarching policy framework that has been embraced in assessing noise impacts.

Environment Protection

Act 1990

Once the development is

completed, noise and vibration

arising can be considered in

terms of statutory nuisance. Part

3 of the Environmental

Protection Act 1990, as

amended by the Noise and

Statutory Nuisance Act 1993

(Ref 8-1), contains the main

legislation on statutory nuisance

and enables local authorities

and individuals to take action to

secure the abatement of a

statutory nuisance.

None, for reference indicating the

importance of good acoustic design. The

assessment has considered BS4142

when assessing operational noise

impacts.

Control of Pollution Act The Control of Pollution Act Will be relevant should the authorities



1974 1974 Section 61 sets out

procedures for those

undertaking works to obtain

‘Prior Consent’ for construction

works within agreed noise limits.

advise that a Section 61 Consent

Application is required.

The Noise Insulation

Regulations 1975 (as

amended 1988)

Regulation 5 provides relevant

authorities with discretionary

powers to provide noise

insulation at dwellings to reduce

the impact of construction noise

No relevance at this stage of the

assessment.

BS5228:1 2009

+A1:2014 Code of

practice for noise and

vibration control on

construction and open

sites. Noise

BS 5228 gives

recommendations for basic

methods of noise control relating

to construction and open sites

where work activities/operations

generate significant noise levels,

including industry-specific

guidance.

Assessment carried out in accordance

with BS5228

BS 6472-1:2008: Guide

to Evaluation of Human

Exposure to Vibration in

Buildings

BS 6472 provides guidance on

predicting human response to

vibration in buildings. Frequency

weighting curves for human

beings exposed to whole-body

vibration are included, together

with advice on measurement

methods to be employed.

None. Distance separation between

construction works and receptor

locations means that vibration impacts

are unlikely.

BS8223: 2014: Sound

insulation and noise

reduction for buildings –.

Code of practice

BS8223 gives recommendations

for the control of noise in and

around buildings, and suggests

appropriate criteria and limits for

different situations. These

criteria and limits are primarily

intended to guide the design of

new or refurbished buildings

undergoing a change of use

Internal noise levels for living rooms and

bedrooms set out in BS8233 have been

considered.

8.3 Methodology

8.3.1 Introduction

This impact assessment has been undertaken in accordance with the following and guidance

relating to noise and vibration.

� Environmental Protection Act 1990 (Ref 8-2)


� The National Planning Policy Framework (NPPF) (Ref 8-3)

� BS 4142:1997 ‘Method for rating of industrial noise affecting mixed residential and

industrial areas’ (Ref 8-4)

� BS 8233: 2014 ‘Noise insulation and noise reduction for buildings – Code of practice’ (Ref

8-5)

� BS5228:1 2009 +A1 2014 Code of practice for noise and vibration control on construction

and open sites. Part 1 - Noise (Ref 8-6)


The Thanckes OFD lies on the west bank of the Hamoaze opposite the north yard of the HMNB,

Devonport. The Hamoaze forms part of the Tamar Estuary which lies on the border between

Devon and Cornwall.

The noise assessment has considered the closest residential receptor locations to the proposed

works. Noise sensitive receptors such as residential receptors that have a clear line of site to

the proposed refuelling jetty have been identified. Receptors within approximately 800m of the

jetty and construction area have been considered.


A full noise survey was undertaken at representative residential receptor locations near the Site.

Noise monitoring locations and the duration of monitoring was agreed with John Butterwick,

Environmental Protection Officer for CC.

It was agreed that noise measurements will be taken to reflect noise levels on a typical

weekday. The LAeq,T; LA90; LA10; LAmin and LAmax were measured at all locations. The

measurement locations for the whole site are indicated in Drawing 8-1.

An attended noise survey has been conducted at four locations, namely NM1, NM2, NM4 and

NM5. The measurements were carried out for 2 hours during the day and 1 hour for night time

period.

At NM3 unattended measurements were undertaken for a 24 hour period. Surveys were carried

out between 25 and 27 June 2013.


The significance of impacts is then determined using the approach described in Chapter 3 of

this ES.

Operational Plant Noise Impacts

British Standard BS 4142:1997 is used to determine the impacts of noise upon residential units.

The guidance provided within BS 4142 provides a method whereby the likelihood of complaints

due to noise from industrial sources can be assessed.

The standard advises that the existing background noise levels outside noise sensitive premises

are compared with the rating noise levels from any nearby industrial activities. The rating noise


level should include corrections for any acoustic character to the noise that makes it more

readily discernible to a listener (e.g. whines, crashes, bangs etc.).

The background noise level (LA90) is the noise level that is exceeded for 90% of the monitoring

period at the assessment location. For BS 4142 it is usual to measure the background noise

level at the nearest noise sensitive receptor to the industrial noise source.

The specific noise level is the LAeq produced by the noise source under investigation, measured

as close as possible to the source, over a given reference time interval.

The rating noise level is the specific noise level plus any adjustments for the acoustic

characteristics of the noise as specified in clause 8.2 of BS4142.

An adjustment of +5dB is applied when the specific noise has a discrete distinguishable tone or

distinct impulsive characteristic.

The greater the difference between rating level and background noise level, the greater the

likelihood of complaints.

� A difference of around +10 dB or more indicates that complaints are likely.

� A difference of around + 5 dB is of marginal significance.

If the rating level is more than 10 dB below the measured background noise level then this is a

positive indication that complaints are unlikely.

It is also recommended that BS4142 is considered in conjunction with other methods of

assessment, such as BS8233.

BS8233 sets out noise level targets for spaces within buildings. BS8233 also includes

information on sound insulation within buildings and sound insulation properties of building

materials and forms of construction.

The criteria in BS 8233 relevant to residential units are presented in Table 8-2.

Table 8-11 Recommended indoor ambient noise levels BS 8233: 2014

Activity Location 07:00 to 23:00 23:00 to 07:00

Resting Living room 35dB LAeq,(16hour) -

Dining Dining room

/area

40dB LAeq,(16hour) -

Sleeping

(Daytime resting)

Bedroom 35dB LAeq,(16hour) 30dB LAeq,(8hour)

Construction Noise Impacts

Construction noise impacts have been assessed in accordance with BS 5228: 2009. BS 5228-1:

2009 +A1:2014 gives recommendations for basic methods of noise control relating to

construction and open sites. It applies to work activities and operations that generate significant


noise levels. It also includes industry-specific guidance. BS 5228-2: 2009 deals with vibration

control on construction and open sites. BS5228 also provides guidance concerning methods of

predicting and measuring noise and assessing its impact on those exposed to it.

The noise levels were predicted with distance from source by using the measured. LAeq 1hr using

the following formula as described in BS5228:

Kh = 20 * log10 (R/10)

Where:

� Kh = the correction for propagation across hard ground

� R = the distance to the receptor location

� 10 = the distance in m at which the SPL from the plant has been measured.

There are no legislative criteria for limiting noise levels from construction sites. Traditionally , it

was stipulated that noise levels outside the nearest window of the occupied room closest to the

site boundary between 07.00 and 19.00, should not exceed 70 dB(A) in rural, suburban and

urban areas away from main road traffic and industrial noise; and 75 dB(A) in urban areas near

main roads in heavy industrial areas.

BS 5228-1, Annex E, sets out criteria for significance based upon noise change. The ABC

method describes a threshold of significant effect at dwellings when the total noise level,

rounded to the nearest decibel, exceeds a listed category value. If the total noise level

(construction plus ambient pre-construction) exceeds the appropriate category value, then a

significant effect is deemed to occur.

The criteria to consider for the ABC Method are set out in Table 8-3.

Table 8-12 Example of Threshold of Significant Effect at Dwellings (Table E1 in BS5228)

Assessment category and threshold value period

(LAeq)

Threshold value, in decibels (dB)

Category A (A)

Category B (B)

Category C (C)

Night-time (23.00−07.00) 45 50 55

Evenings and weekends (D) 55 60 65

Daytime (07.00−19.00) and Saturdays (07.00−13.00) 65 70 75

NOTE 1: A significant effect has been deemed to occur if the total LAeq noise level, including

construction, exceeds the threshold level for the Category appropriate to the ambient noise level.

NOTE 2 If the ambient noise level exceeds the threshold values given in the table (i.e. the ambient

noise level is higher than the above values), then a significant effect is deemed to occur if the total LAeq

noise level for the period increases by more than 3 dB due to construction activity.

NOTE 3 Applied to residential receptors only.

(A) Category A: threshold values to use when ambient noise levels (when rounded to the nearest 5 dB)

are less than these values


(B) Category B: threshold values to use when ambient noise levels (when rounded to the nearest 5 dB)

are the same as category A values

(C) Category C: threshold values to use when ambient noise levels (when rounded to the nearest 5 dB)

are higher than category A values

(D) 19.00–23.00 weekdays, 13.00–23.00 Saturdays and 07.00–23.00 Sundays.

The significance criteria used in the assessment are based on the significance criteria set out in

BS5228 and on the significance criteria set out in Chapter 3 Section 7 Noise impacts have been

assessed at residential receptor location and therefore in accordance with Table 8-5, would

have high sensitivity.

Based on the above criteria and the relatively quiet nature of the area, the following criteria are

proposed for assessing construction noise impacts (Table 8-4).

Table 8-13 Criteria for the rating of noise impacts during construction

Magnitude of Impact Noise Level dB LAeq

Major

Daytime noise levels at houses in excess of 70 dB LAeq (12 hour)

Saturday (afternoon), Sunday and weekday evening noise levels at houses

in excess of 65 dB LAeq (1 hour)

Night-time noise levels at houses in excess of 60 dB LAeq (1 hour)

Moderate

Daytime noise levels at houses in the range between 65 to 70 dB LAeq (12

hour)




Minor

Daytime noise levels at houses in the range between 55 to 65 dB LAeq (12

hour)





Defining the importance/sensitivity of resource

The importance or sensitivity of each resource is assessed using the criteria provided in Table

8-5.

Table 8-14 Determining the Importance / Sensitivity of Resource

Importance/sensitivity of

resource or receptor

Criteria

Very High Ambient noise level is intrinsic for community noise levels, health and

amenities, e.g. rural dwellings, hospitals, cultural heritage sites, existing

ambient level is low.

High Dwellings and other sensitive receptors located in urban areas

Medium Offices and Cultural Heritage sites located in urban areas

Low Commercial establishments such as large shopping complexes

Negligible Factories and industrial process sites

Source: Based on Technical Advice Note: Assessment of Noise (Scottish Government)

The significance of noise impacts, considering the magnitude of impact and sensitivity of

receptor, is indicated below (Table 8.6). The significance is based on the magnitude of impact

(Table 8-4) and the sensitivity of resource (Table 8-5).

Table 8-15 Significance of Noise Impact

Importance/sensitivity of resource or receptor

Magnitude of

impact Very High High Medium Low Negligible

Major Very Large Large or Very

Large

Moderate or

Large

Slight or

Moderate

Slight

Moderate Large or Very

Large

Moderate or

Large


Slight

Minor Moderate or

Large

Slight or

Moderate

Slight Neutral or

Slight

Neutral or

Slight

Negligible Slight Slight Neutral or

Slight

Neutral or

Slight

Neutral

No Change Neutral Neutral Neutral Neutral Neutral

Noise impacts between 70dB(A) and 75 dB(A) would be deemed ‘Large’, while noise impacts

above 75 dB(A) would be deemed ‘Very Large’.


8.3.5 Consultation

Noise monitoring locations and the duration of monitoring was agreed with John Butterwick,

Environmental Protection Officer for Cornwall Council. Consultation was carried out by

telephone and by e-mail, with final confirmation of noise monitoring locations received by e-mail

on 24 June 2013.



Cornwall Council Environmental Health Officer

Discussed existing noise climate in area of Development and existing noise sources

Noise surveys carried out at agreed locations (locations listed in Table 8-8)

Reviewed possible noise-sensitive areas

Agreed noise monitoring locations and

The noise monitoring locations were selected to represent the closest noise sensitive receptor

locations. The distance between noise monitoring location and site boundary indicated in table

8-8 represents the distance to the closest point at which dredging and piling has been indicated.

The agreed noise monitoring locations are as follows:

Table 8-8 Noise monitoring location and sensitive receptor locations

Receptors

Distance from

Site Boundary

(m)

NM1 Behind 47 Thanckes Drive 740

NM2 Behind 2 Albion Road 490

NM3

Yonderberry Cottages (near Wilcove

Inn) 876

NM4 12 Cove Meadow 860

NM5 2 Pato Point 510

8.3.6 Limitations

The assessment considers construction noise impacts based on information available at this

time. Construction method and plant to be used may change and this may alter predicted noise

levels.



A full noise survey was undertaken at representative residential receptor locations near the Site

between 25 and 27 June 2013. Noise monitoring locations and the duration of monitoring was

agreed with John Butterwick, Environmental Protection Officer for CC.

It was agreed that noise measurements will be taken to reflect noise levels on a typical

weekday. The LAeq,T; LA90; LA10; LAmin and LAmax were measured at all locations. The

measurement locations for the whole site are indicated in Drawing 8-1.

An attended noise survey has been conducted at four locations, namely NM1, NM2, NM4 and

NM5. The noise monitoring locations represent the closest residential receptor locations. The

measurements were carried out for 2 hours during the day and 1 hour for night time period. At

NM3 unattended measurements were undertaken for a 24 hour period.

All measurements were taken using Type 1 sound level analysers complying with BS EN

61672-1 & 2 (2013). The survey was carried out using the following sound level analysers:

Cirrus CR: 831 B Serial Number C19935FF

Rion NL 32 Serial Number 00451268

Various statistical acoustic parameters were recorded at each monitoring location, these

included; LAeq, LAMAX, LAMIN, LA1, LA10, LA50, LA90 and LA99. The full set of noise survey data is

included in Appendix 8-A. The noise survey data is summarised in Table 8-9.

Table 8-9 Summary of Baseline Noise Survey Data

Location Period LAeq,T

LA90

LAmax LAmin Average Minimum Maximum

NM1 Day 43.3 39.4 35.7 42.0 66.3 38.4

Night 36.6 31.5 26.9 34.5 63.7 26.0

NM2 Day 53.6 38.4 35.1 41.0 85.5 33.9

Night 35.5 34.3 33.6 35.3 57.7 32.5

NM3 Day 45.0 35.0 23.9 43.6 77.6 21.6

Night 40.8 35.4 23.5 40.6 70.7 22.2

NM4 Day 47.2 42.8 40.0 45.4 66.3 38.4

Night 36.6 35.1 33.2 37.6 50.7 31.7

NM5 Day 46.9 41.1 39.3 44.5 69.3 34.8

Night 33.2 29.8 24.4 33.2 50.6 22.8

NM1 is located at the back of the houses on Thanckes Drive and is screened from road traffic.

The monitoring location faces onto the harbour and harbour activities are audible at this

location. Daytime and night-time noise levels are generally low at this location.


Monitoring location NM2 is on a cul-de-sac leading off Albion Road in Torpoint. This location

experiences some noise from traffic movements on Albion Road. Activities at the harbour are

also audible at this location. The noise data recorded at this location indicate that at night noise

levels are much lower than daytime due to low levels of road .traffic on Albion Road.

Measurement location NM3 is located behind Yonderberry Cottages, next to the Wilcove Inn.

Occasional local traffic movements generate noise at this location. At time traffic noise from the

A74 is also audible at this location.

Measurement location NM4 is located at 12 Cove Meadow. Local use of yachts and other craft

as well as harbour activities are sometimes audible at this location.

Measurement location NM5 is located at 2 Pato Point. Harbour activities are audible at this

location.

Noise levels recorded at NM3, NM4 and NM5 are low, particularly at night. Night-time noise

generated from the operation of any plant on site or from any night-time construction activities

will be noticeable.

The measured ambient noise levels indicate that Category A in Table 8-3 would be applicable to

residential receptors locations, indicating that the suggested construction noise limits in Table 8-

4 are appropriate to these locations.


Prior to construction a CEMP will be prepared that will incorporate environmental mitigation

measures and procedures.

8.5.1 Construction

Reduction in construction and deconstruction (jetty removal) noise impacts is possible through

the adoption of Best Practicable Means (BPM), as outlined in Section 72 of the Control of

Pollution Act (1974) (Ref 8-7).

The mitigation measures to be implemented would be selected to suit the specific

circumstances at each construction area, considering the nature of the works, the plant to be

used and the distance and position of the receptor locations in relation to the works. Fixed plant

would for example be easier to screen, while screening would not be practical for mobile plant.

Screening of plant such as piling rigs placed on barges may also not be practicable.

The effectiveness of the screening would depend on the properties of the screening material,

the location of the acoustic screen in relation to the source, the height of the acoustic screen

and the height of the receptor in relation to the noise source. As a rule of thumb, when there is

no clear line of sight between noise source and receptor, a 10dB reduction in noise level can be

expected.

� Recommendations and good practice as shown in British Standard (BS) 5228: 2009 +A1:

2014 would be adopted. The typical mitigation measures would include:


� Careful selection of plant, construction methods and programming. Only plant

conforming with relevant national or international standards, directives and

recommendations on noise and vibration emissions would be used;

� Static and semi-static plant/equipment would be fitted with suitable enclosures where

practicable;

� Personnel would be instructed on BPM to reduce noise and vibration as part of their

induction training and as required prior to specific work activities;

� When plant is not being used, it would be shut down and not left to idle;

� Local residents would be consulted in advance of the works commencing;

� Localised mobile screening would be used where reasonably practicable to reduce the

noise levels. Use of screening on barges and dredgers may prove impractical.

More specific mitigation can be recommended once a detailed construction method statement

and inventory of plant is available. Similar mitigation measures would be applied during

decommissioning as it is expected similar plant will be used.

8.5.2 Operation

Detailed design information and noise levels for plant to be installed at the loading facility has

yet to be finalised, however it is expected that the jetty will operate in the same way as the

existing Yonderberry jetty, with similar plant and noise sources. Modern replacement

equipment is likely to be quieter in operation. At detailed design stage the exact location of

various items of plant and the plant type will be decided and more accurate noise predictions

will be possible.

In the absence of detailed design information, the assessment has considered current

background noise levels at receptor locations and suggested noise limits for plant that will need

to be met at detailed design stage.

Based on predictions in Section 8.6.2, a limit of 80dB for the combined noise from all plant on

site has been recommended. This would be in line with the Lower Exposure Limit in the Control

of Noise at Work Regulations. This would indicate a noise rating level (LAr,Tr) of 35dB at the

closest receptor locations at Pato Point and Albion Yard respectively .

Noise from plant to be installed on site can be reduced through enclosing plant where possible.

It is proposed that the fire pumps on the jetty are submersible pumps, which will mitigate noise

generation.

Pumps will be correctly installed and maintained to ensure proper running and avoid generating

unnecessary noise.

Low noise equipment has been considered in the initial design of the site.



8.6.1 Construction

Construction noise impacts have been assessed using the construction detail available at this

stage. Assumptions have been made regarding the plant to be used during construction based

on our experience from similar developments.

The noise emissions from assumed plant have been predicted using the sound pressure levels

as described in BS 5228: Part 1. The sound pressure levels (Lp) in BS 5228 have been

presented as a LAeq at a distance of 10 m (Table 8-B1 in Appendix 8-B). It has been assumed

that plant would be operating for long periods of time (“percentage on-time”) so as to present a

possible worst case.

It is proposed that a hybrid piling rig may be used, combining a steel tube hammer rig with a

rotary bored piling rig. Details of the exact rig to be used are not available at this stage. It has

been indicated that the pile casings will be pressed through the sediments until firm ground is

encountered. The use of vibrating hammer may also be required. When hard bedrock is

encountered there may be a need to use limited hammer piling, but the majority of the depth will

be achieved through drilling and oscillating the steel casing into the bedrock.

The hammer piling is likely to produce higher noise levels than the rotary bored or vibro-piling.

The exact extent or duration of hammer piling is however not known at this stage. A worst case

has therefore been presented in this assessment by considering noise levels for a hammer

piling rig. Piling works will be confined to daytime hours.

Typical combined impacts associated with the key construction activities are indicated in Table

8-B2 in Appendix 8-B. The predictions are based on typical plant required for each construction

activity, and assume that all the plant would run simultaneously, which is most unlikely.

Works on the new jetty head, the approach jetty and mooring dolphins may be undertaken

concurrently. The combined noise levels for these activities present the highest noise impact.

The highest predicted weekday daytime construction noise impact has been compared against

the magnitude of impact criteria set out in Table 8-4 and the significance criteria in Table 8-5.

The results are presented below (Table 8-10).


Table 8-10 Significance of Predicted Weekday Daytime Construction Noise Impacts

Sensitive Receptor Highest

Predicted Noise (LAeq,T) dB

Magnitude of Impact Significance of

Impact

NM1 Behind 47 Thanckes Drive 55.6 Minor Adverse

Slight or

Moderate

Adverse

NM2 Behind 2 Albion Road 59.2 Minor Adverse

Slight or

Moderate

Adverse

NM3 Yonderberry Cottages (near

Wilcove Inn) 54.2 Minor Adverse

Slight or

Moderate

Adverse

NM4 12 Cove Meadow 54.3 Minor Adverse

Slight or

Moderate

Adverse

NM5 2 Pato Point 58.9 Minor Adverse

Slight or

Moderate

Adverse

Daytime construction noise impacts are generally in the range of 50dB to below 65dB and are

therefore considered to be Minor Adverse. The receptor sensitivity is considered to be High

and the significance of the daytime construction noise impact is considered to be Slight or

Moderate.

Construction works, particularly piling works, are planned to take place during normal work

hours. Where there is any particular need to work outside normal hours (0800-1800 on a

weekday and 0800 – 1300 on a Saturday), prior agreement will be obtained from the local

Environmental Health Officer (EHO). The need for any works outside of normal hours will be

established once a contractor has been appointed and the work methods have been defined.

Dredging works will be required and it is expected that dredging will take place over a 24 hour

period for one to two weeks. The noisier dredging works, using a backackter dredger, will be

carried out during the day. At night a quieter trailer suction hopper dredger will be used.

Dredging operations are commonly carried out as part of normal harbour operations.

Noise from dredging would depend on proximity of dredging to receptor locations. Taking the

separation distance from the Site boundary to receptor locations, the typical noise impacts from

dredging are shown in Table 8-11. The magnitude of impact has been assessed against night-

time significance criteria.


Table 8-11 Significance of Predicted Dredging Noise Impacts

Sensitive Receptor

Highest Predicted

Noise (LAeq,T) dB

Magnitude of Impact

Significance of Impact

NM1 Behind 47 Thanckes Drive 42.4 Minor Adverse Moderate

Adverse

NM2 Behind 2 Albion Road 46.0 Moderate Adverse Moderate

Adverse



Moderate

Adverse

NM4 12 Cove Meadow 41.1 Minor Adverse Moderate

Adverse

NM5 2 Pato Point 45.6 Moderate Adverse Moderate

Adverse

Table 8-11 indicates that there is a potential for noise from dredging works to be slightly above

the night-time significance limit of 45 dB(A) at times, but generally impacts will be below 45

dB(A) and will be over a period of one to two weeks.

There may also be a need to move plant during high tide and barges may be required to

operate outside of normal daytime hours. The use of barges would however not be out of

character with normal operational activities in the harbour.

Construction works on Saturday afternoon and Sundays would be considered more disturbing to

local residents and the associated receptors. The need for and extent of works over a weekend

will only be confirmed once a contractor has been appointed. Assuming that the same works as

carried out on a weekday are carried out on a weekend, the impacts have been presented in

Table 8-12. Weekend construction noise impact has been compared against the magnitude of

impact criteria set out in Table 8-4 and the significance criteria in Table 8-5.


Table 8-12 Significance of Predicted Weekend Daytime Construction Noise Impacts

Sensitive Receptor

Highest Predicted

Noise (LAeq,T) dB

Magnitude of Impact

Significance of Impact

NM1 Behind 47 Thanckes Drive 55.6 Minor Adverse Moderate

Adverse

NM2 Behind 2 Albion Road 59.2 Minor Adverse Moderate

Adverse



Moderate

Adverse

NM4 12 Cove Meadow 54.3 Minor Adverse Moderate

Adverse

NM5 2 Pato Point 58.9 Minor Adverse Moderate

Adverse

Construction works on a Saturday afternoon (after 1300) and works on a Sunday are likely to be

below 60dB(A) and would be considered Moderate Adverse.

It is possible that crew living on board ships berthed alongside at Devonport may be affected by

noise and vibration associated with night time construction activity. However it would be very

difficult to assess this impact and there are also a number of factors that are unknown (including

mooring locations, dates when vessels will be present and durations, etc.).

More detailed construction noise predictions would be possible once a detailed method

statement and full inventory of plant is available. This could be carried out for example through

a Section 61 Consent Application in terms of the Control of Pollution Act (1974). Section 61 is a

voluntary process and would require agreement with the Local Council.

Given the distance to receptor locations, it is unlikely that vibration impacts will be experienced

at any sensitive receptor locations.

Peer reviewed literature indicates that vibration from construction activities such as use of piling

rigs is unlikely to impact on receptors more than 50-100m from source. Vibration impacts from

construction have therefore not been considered.

8.6.2 Operation

In the absence of detailed design information, the assessment has considered current

background noise levels at receptor locations and suggested noise limits for plant that will need

to be met at detailed design stage.

Operation of the tank farm and use of the loading facility (in terms of the hours of operation and

frequency of use) are not expected to change as a result of the project. The jetty is operational

07:30 – 16:00 Monday to Saturday with the notable exception of service to/from replenishment

tankers which are alongside for approximately 72hours, once a month, Total annual occupancy


for vessels alongside is approximately 30% and 60% for the main jetty and pontoon jetty

respectively.

Plant to be installed on site would be designed to ensure that noise from operational plant is not

disturbing to local residents.

In accordance with BS4142, a +5dB penalty to account for any tonal characteristic of the plant

noise has been considered in calculating the plant noise limit. BS4142 indicates that if the

rating level is more than 10 dB below the measured background noise level then this is a

positive indication that complaints are unlikely.

With service to/ from replenishment tankers indicated to take place at night, plant noise limits

would need to be set against measured background night-time noise levels. Table 8-8 indicates

that background (LA90) noise levels are very low at night, with LA90 levels below 30dB(A)

measured at NM1, NM3 and NM5.

Pato Point (NM5) and Albion Yard represent the closest points to operational plant. Pato Point

also presents low background noise levels (24.4 dB). This would indicate that, in accordance

with BS4142, the noise rating level for plant noise would need to be below 24.4 dB.

It is however stated in BS4142 that this method is not suitable for assessing the noise measured

inside buildings or when the background and rating noise levels are both very low. It is

indicated in BS4142 that for the purposes of this standard, background noise levels below about

30dB and rating levels below about 35 dB are considered to be very low.

Considering the limitations in BS4142, the criteria for ‘Good’ internal noise levels in bedrooms

and living rooms in BS8233 have been considered. BS8233 indicates an internal noise level of

30dB in an unoccupied living room or bedroom. Taking a 10dB reduction for an open window,

this would equate to an external noise level of 40dB at the façade of the building.

The Lower Exposure Limit in the Control of Noise at Work Regulations 2005 (the Noise

Regulations) of 80dB has been assumed. Calculating attenuation of noise with distance from

source, a combined noise limit for plant to be installed on site has been calculated.

Table 8-13 Calculated Noise Limit for Operational Plant to be Installed on Site

Receptors Distance Jetty (m)

Plant Noise Limit dB(A)

Tonal Penalty

(BS 4142)

Predicted Noise Rating Impact (LAr,Tr)

NM1 Behind 47 Thanckes Drive 740 80 5 22.6

NM2 Behind 2 Albion Road 490 80 5 26.2


Wilcove Inn) 876 80 5 21.1

NM4 12 Cove Meadow 860 80 5 21.3

NM5 2 Pato Point 510 80 5 25.8


Given the low background noise levels and the likelihood that plant noise will be noticeable at

night, it is recommended that an external noise level of 35dB (LAr,Tr) be achieved. This would be

in line with the limit for the noise rating level rating level for BS4142 to be considered a valid

method of assessment.

If plant noise levels on site comply with the Lower Exposure Limit of 80 dB(A) as stipulated in

the Control of Noise at Work Regulations, a noise rating level of 26.2dB(A) is predicted at Albion

Yard and 25.8 dB(A) at Pato Point.

Operations at the new jetty facility are expected to generate noise levels similar to those

currently generated on site. The most significant noise is probably the normal operating noise of

a ship, which will be similar to the other ships berthed at the current jetty.

Operational noise impacts will however alter with activities being located slightly closer to

Wilcove and further from Torpoint.

8.6.3 Decommissioning

There are no details of decommissioning works and the plant to be used. Plant to be used for

decommissioning works and methods to be used may have changed greatly by the time

decommissioning is carried out.

For the purposes of this assessment it has been assumed that plant to be used for

decommissioning will be similar to the plant to be used for removal of the existing jetty structure

and that noise impacts will be similar,


Refer back to chapter 3.6 for cumulative effects and a description of the developments

considered.

At present there are three reasonably foreseeable developments within the vicinity of the

proposed development that have been considered for cumulative impacts, as advised by

statutory consultees and DIO:

� MOD Forward Operating Base at Kinterbury Point

� MOD Refurbishment and Operation of Trevol Jetty

� South West Devon Waste Partnership Combined Heat and Power Plant

� The South West Devon Waste Partnership Combined Heat and Power Plant presents the

closest development at approximately 1200m from the proposed jetty location. Construction

and demolition noise impacts are predicted to be below 55dB at 500m. Given the separation

distance from the Combined Heat and Power Plant, cumulative construction noise impacts are

unlikely.

� The separation distance to the MOD Forward Operating Base at Kinterbury (over 2000m) and

the MOD Refurbishment and Operation of Trevol Jetty (1600m) and the fact that there is no

direct line of sight between these sites and the Thanckes jetty mean that there will not be

cumulative noise impacts.


8.8 Summary

Weekday daytime construction noise impacts are predicted to be Slight or Moderate Adverse

at Receptor locations. Particularly noisy activities such as piling will be confined to daytime

hours.

Daytime works on weekends (Saturday after 1300 and Sundays) are indicated to result in

Moderate Adverse. The assessment of weekend construction noise has however assumed

that similar activities will take place over a weekend as carried out on a typical weekday. The

extent and nature of weekend working will only be established once a contractor has been

appointed. Any works carried out outside of normal work hours would need to be agreed with

the local EHO.

At night there will be a need to carry out dredging over a period of one to two weeks. Dredging

is commonly carried out in the harbour and would not be totally out of character. The dredging

noise impacts will be of short duration and are predicted to be Moderate Adverse.

There will also be a need to move construction plant at high tide using barges. This may at

times require barges to operate at night. The movement of barges will however not be out of

character with normal harbour operations.

Further reduction in construction noise impacts is possible through the adoption of BPM, as

outlined in Section 72 of the Control of Pollution Act (1974). The mitigation measures to be

implemented would be selected to suit the specific circumstances at each construction area,

considering the nature of the works, the plant to be used and the distance and position of the

receptor locations in relation to the works.

Dredging and piling works will involve the use of jack-up barges and floating plant, which allows

little scope for use of acoustic barriers.

The effectiveness of any screening would also depend on the properties of the screening

material, the location of the acoustic screen in relation to the source, the height of the acoustic

screen and the height of the receptor in relation to the noise source. As a rule of thumb, when

there is no clear line of sight between noise source and receptor, a 10dB reduction in noise

level can be expected.

At detailed design stage it has been indicated that plant to be installed on site should meet a

cumulative site noise limit of 80dB, which is the Lower Exposure Limit in the Control of Noise at

Work Regulations. This would ensure a noise rating level (LAr,Tr) of below 30dB is met at the

closest receptor locations at Pato Point and Albion Yard.

Selection of low-noise operational plant, the correct installation of this plant and the use of

acoustic enclosures where necessary and possible will ensure that the required plant noise limit

is met.


Table 8-14 Noise Impact Summary Table

Impact description Temporary/Permanent Significance rating

Jetty Removal and

Construction Noise Impacts

Temporary Daytime construction noise

impacts are Slight or Moderate

Adverse

Night-time construction noise

impacts are Moderate Adverse

Operational Noise Impacts Permanent Negligible impact if appropriate

measures are considered during

detailed design.

Decommissioning Temporary Daytime construction noise


Night-time construction noise



9 LANDSCAPE AND VISUAL IMPACT ASSESSMENT

9.1 Introduction

This report considers the landscape and visual implications of the Development; a description of

the Development is provided in Chapter 2. Landscape is defined in the European Landscape

Convention as ‘...an area, as perceived by people, whose character is the result of the action

and interaction of natural and/or human factors’ (Ref 9-1). Visual or visual amenity

considerations relate specifically to the views of a landscape afforded to people. These

separate but related issues form the basis for landscape and visual impact assessment (LVIA).


This impact assessment has been undertaken in accordance with current national legislation,

and national, regional and local plans and policies relating to landscape and visual

considerations in the context of the Development. A summary of the relevant legislation and

policies, the requirements of these policies and the Development response has been provided

in the table below.

Table 9-17 Landscape and Visual Regulatory and Policy Framework


National Planning Policy

Framework (Ref 9-2)

Requires landscape to be taken

into account in the planning

process through protection and

enhancement of landscapes.

Confirms National Parks and

Areas of Outstanding Natural

Beauty (AONB) have the highest

status of protection in relation to

landscape and scenic beauty

(under the National Parks and

Access to the Countryside Act,

1949, and Countryside and

Rights of Way Act, 2000,

respectively).

The Development does not fall within a

protected landscape; however the Tamar

Valley AONB is situated approximately

1km north west of the Development at its

nearest point. The setting of the AONB

has therefore been taken into account in

this assessment, along with wider

landscape character and visual amenity

considerations. There are not anticipated

to be significant impacts on landscape

character or the setting of the AONB as a

result of the Development.

Caradon Local Plan First

Alteration (August 2007)

: Policy CL7 -

Development Near Areas

of Outstanding Natural

Beauty or Heritage Coast

(Ref 9-3)

Requires character and

appreciation of AONBs to be

taken into account in respect of

development near these

designated areas. Development

which will be unduly prominent

from view points within such

areas or will adversely affect the

view towards such areas from

The Tamar Valley AONB is situated

approximately 1km north west of the

Development at its nearest point. Views

from and to the AONB have been taken

into account in this assessment. There

are not anticipated to be significant

impacts on these views as a result of the

Development.



roads, footpaths, bridleways and

other public places will not be

acceptable.

9.3 Methodology

9.3.1 Introduction

The assessment process has been carried out based on ‘Guidelines for Landscape and Visual

Impact Assessment: Third Edition’ (Ref 9-4).


The overarching Study Area extends to a 2.5 km radius from the site (refer to Drawing 9-1).

Beyond this distance the Development would not be readily perceptible within the landscape.

To refine the assessment, a Zone of Theoretical Visibility (ZTV) has been generated within the

Study Area, which represents the theoretical area from which any part of Development may be

seen (refer to Drawing 9-1). ZTVs are based on bare ground data, with any ridgelines, plateaux

and valleys reflected in the extent of predicted visibility. ZTVs do not take into account local

conditions such as subtle variations in landform, built Development or vegetation cover, which

significantly reduce the extent of actual visibility.

The ZTV was modelled using a Digital Terrain Model (DTM), taking into account the curvature of

the earth and assuming a viewer height of approximately two metres above ground level. DTM

data was derived from Ordnance Survey (OS) Raster 50 data (elevation data on a fifty metre

grid). ZTV output was overlaid on OS mapping, with an overview reproduced at 1:25,000 scale.

Designations which are relevant to matters of landscape and visual amenity and the proposed

Development have also been identified (refer to Drawing 9-1).


Baseline conditions are defined by landscape character and respective sensitivity, together with

visual amenity (as represented by views) and the sensitivity of visual receptors (or potential

viewers), in accordance with the criteria set out below.

Table 9-2 Definitions of Landscape Sensitivity

Level of

Sensitivity

Definition of Sensitivity Examples

High Value: Typically of high importance and rarity, national scale, and limited

potential for substitution (e.g. National Parks or Areas of Outstanding

Natural Beauty).

*Susceptibility to change: Landscape unlikely to tolerate the change

proposed.


Level of

Sensitivity


Medium Value: Typically of moderate importance and rarity, regional scale, and

limited potential for substitution (e.g. Registered Historic Parks and

Gardens, Conservation Areas).

*Susceptibility to change: Landscape has the potential to tolerate the

change proposed.

Low Value: Typically of low importance and rarity, local scale, such as

undesignated or degraded landscapes.

*Susceptibility to change: Landscape likely to tolerate the change proposed.

*The judgement concerning susceptibility to change is made by considering the

nature/characteristics of the development and receiving landscape, following evaluation of

receptor value and prior to the assessment of effects.

Table 9-3 Definitions of Visual Sensitivity

Level of

Sensitivity


High Value: Typically nationally recognised/important (e.g. from landscape of

national importance);

Susceptibility to change: Views from residential properties; where

appreciation of affected views may be the principal activity.

Medium Value: Typically regionally/locally recognised/important (e.g. from landscape

of regional/local importance);

Susceptibility to change: Views from public rights of way, cycle trails, public

open space; where attention may be focused on an affected view.

Low Value: Typically views not recognised/of importance;

Susceptibility to change: Views from roads and railways which are transient

due to travelling through the landscape; places of work or commercial

properties; where attention is unlikely to be focussed on affected views.

Relevant desk-based information has been obtained from Natural England, Cornwall Council,

and Ordnance Survey. Field survey work was undertaken during summer 2013. At this time of

year, deciduous trees and shrubs are predominantly with leaves such that there is less visibility

within the landscape than in winter months (when there is not deciduous leaf cover). Viewpoints

have been selected to represent the range of visual receptors, that is those who would have a

view of the Development, and views affected, against which visual sensitivity was assessed.

Viewpoint photographs were taken in accordance with Landscape Institute guidance (Ref 9-5)

using a digital single lens reflex (SLR) camera, with lens selected to provide the digital

equivalent of 50 mm focal length for a 35 mm film format SLR camera. Photographs were then

stitched together to generate a panorama spanning up to approximately ninety degrees in the


direction of the Development (the extent of view that would be experienced by the viewer at the

selected viewpoint, when facing in that direction).


The significance of impacts is determined using the approach described in Chapter 3 of this ES.

The criteria and threshold matrices used to assess the magnitude of impact and significance of

landscape and visual effects are set out below. Impacts are assessed at the

construction/decommissioning phases and during the operational phase.

Table 9-4 Assigning Magnitude of Landscape Impact

Level of

Magnitude

Definition of Magnitude

High Total loss of or major alteration to key landscape characteristics such that

landscape character will be fundamentally changed.

Medium Partial loss of or alteration to key landscape characteristics such that landscape

character will be partially changed.

Low Minor loss of or alteration to key landscape characteristics such that landscape

character will be similar to the baseline conditions.

Negligible Very minor loss or alteration to key landscape characteristics such that change in

landscape character will be barely distinguishable from the baseline conditions,

approximating to the “no change” situation.

Table 9-5 Assigning Magnitude of Visual Impact

Level of

Magnitude

Definition of Magnitude

High Major change in existing view.

Medium Partial change in existing view.

Low Minor change in existing view such that view largely unchanged.

Negligible Very inconspicuous change in existing view, approximating to the ‘no change’

situation.

A combined assessment of sensitivity and magnitude is undertaken to determine how significant

an effect is, as set out in Table 9-6 below.


Table 9-6 Significance Matrix

MA

GN

ITU

DE

High Moderate Moderate / Major Major

Medium Minor / Moderate Moderate Moderate / Major

Low Minor Minor / Negligible Moderate

Negligible Negligible Negligible Negligible

Low Medium High

SENSITIVITY

Effects may be positive or negative. Only those effects that are recorded as major negative are

considered to be significant in respect of the decision making process (as shaded on Table 9-6).

Photomontages were produced in accordance with LI guidance (Ref 9-5). A photomontage is a

computer rendered image of the Development superimposed onto an existing photograph,

representing the likely appearance of the Development.

9.3.5 Consultation

An EIA Scoping Opinion, requesting a landscape and visual impact assessment for the

Development, was prepared by Cornwall Council on 13th February 2013. Michelle Billing, Senior

Development Officer at Cornwall Council was further consulted regarding the assessment on

13th August 2013. Viewpoints were requested from the Scheduled Monument to the north of the

Development (Barne Barton) and to the South of the Development, on the Devon side of the

river (Plymouth). These locations are not publically accessible, however, Viewpoints 5 and 7

have been included as the nearby representative viewpoints.


9.4.1 Landscape

Natural England (previously the Countryside Agency) has produced a landscape character

assessment of England entitled ‘Countryside Character’ (Ref 9-6). The site lies at the edges of

National Character Area 152, the ‘Cornish Killas’ and Area 151, South Devon. More locally, the

site lies within CA25 ‘Lynher and Tiddy River Valleys’ Landscape Character Area identified in

the Cornwall and Isles of Scilly Landscape Character Study (Ref 9-7), which describes this area

as having the following key characteristics:

• Estuarine landscape of winding inlets, extensive intertidal zones, with intertidal

Mudflats, large areas of Coastal Saltmarsh and a Saline Lagoon; very well used by

water sport enthusiasts.

• Tidal river valleys with Coastal Saltmarsh and wetlands, grading to mixed farming;

many hedgerow trees and tree lines along watercourse.

• Parkland at Mt Edgcumbe, Antony and Port Eliot.


• Small steep - sided upper river valleys inland with mix of farmland and woodland, with

mature trees on network of Cornish hedges adding to wooded feel.

• Farmland is a mix of pasture, arable, fruit and flower growing, with estate land with deer

park and much beech.

• Maze of narrow enclosed winding lanes throughout, with many trees on boundaries.

• Visual prominence of Torpoint and major conurbations in neighbouring LCAs: Plymouth

and Saltash.

The site falls within the Hamoaze estuarine landscape at the edge of Thanckes Oil Fuel Depot,

which is largely defined by utilitarian military buildings and oil storage infrastructure. The wider

landscape comprises the wooded coves and headlands at the edge of the Tamar Valley AONB,

to the north-west, Torpoint, to the south, and the major conurbation of Plymouth to the north and

west. The area of Plymouth nearest to the site comprises Devonport Docks, which provide an

immediate backdrop of substantial infrastructure.

Landscape Sensitivity

Whilst parts of the local landscape fall within the Tamar Valley AONB, the immediate site

context is largely defined by a mix of infrastructure and urban settlement at the edges of the

Hamoaze estuary, outside of the AONB, such that development of the type proposed could be

integrated with the local landscape without resulting in significant disruption to local landscape

character. Overall, taking into account the fact that the immediate landscape is not designated

together with scope to accommodate development of the type proposed, this landscape is

considered to have a medium sensitivity.

9.4.2 Visual Amenity

The ZTV relating to the Development, which does not take account of land cover, is illustrated

on Drawing 9-1. This extends northwards to Saltash, eastwards to Plymouth, southwards into

the Hamoaze estuary, and westwards to Antony Park. Extensive vegetation and built form in the

local landscape significantly reduce the extent of actual visibility. In particular, views from the

Antony Park Registered Park and Garden are obstructed by vegetation. Views from Plymouth

are largely obstructed by the dockyard infrastructure at the edge of the Hamoaze, however

there will be occasional views across/through the infrastructure to the Development. Taking

account of this, visual receptors include properties, public rights of way, and transport corridors

in Wilcove, Wearde Quay (within the Tamar Valley AONB), Torpoint and Plymouth, as

represented by Viewpoints 1 to 8. These viewpoints form the basis for visual assessment below.

Viewpoint photographs are provided within Drawings 9-2 to 9-5.

Viewpoint 1: View from Public Footpath at Pato Point, Looking South East

This view represents users of the Public Footpath, together with the private road and nearby

residential properties. Taking these receptors into account, visual sensitivity is considered to be

high. The foreground comprises the immediate shoreline and Cangapool bay, across which lie

a wooded headland, the site and Thanckes Oil Fuel Depot Jetty. The wider backdrop comprises

dockyard infrastructure at Devonport and the Plymouth urban area beyond.


Viewpoint 2: View from Wilcove Waterfront, Looking South East

This view represents users of the waterfront and adjacent residential properties at this location.

Taking into account these receptors, visual sensitivity is considered to be high. The foreground

comprises Wilcove waterfront and Cangapool bay, across which lie a wooded headland, the site

and Thanckes Oil Fuel Depot Jetty. The wider backdrop comprises dockyard infrastructure at

Devonport and the Plymouth urban area beyond.

Viewpoint 3: View from Minor Road at Wilcove Village Hall, Looking South East

This view represents users of the minor road, together with the Village Hall and nearby

residential properties. Taking these receptors into account, visual sensitivity is considered to be

high. The foreground is formed by agricultural fields, properties and tree cover, which partly

restrict views across Cangapool bay to the site, Thanckes Oil Fuel Depot Jetty and a wooded

headland where the Oil Fuel Depot storage tanks are visible above the treeline. The wider

backdrop, views to which are also partially restricted, comprises dockyard infrastructure at

Devonport and the Plymouth urban area beyond.

Viewpoint 4: View from Minor Road between Wilcove and Coombe Park, Looking South East

This view represents users of the minor road and residential properties at the edge of the

AONB. Taking into account these receptors visual sensitivity is considered to be high. This

elevated view is from a fieldgate, with foreground comprising agricultural fields, which slope

down to the edge of Wilcove and that adjoin the Oil Fuel Depot, where a fuel tank is visible. The

outer reaches of Cangapool bay, including the site, are visible in the middle ground with a

backdrop of dockyard infrastructure at Devonport and the Plymouth urban area beyond.

Viewpoint 5: View from Wearde Quay, looking South East

This view represents users of the minor road, quay, residential properties, and the setting of

nearby Scheduled Monument, all within the Tamar Valley AONB. This viewpoint is also a similar

distance and in a similar direction from the Development as the Scheduled Monument at Barne

Barton (which is not publically accessible) and is therefore also broadly representative of this

location. Taking these considerations into account, visual sensitivity is considered to be high.

The view is largely defined by views across the Hamoaze/Lynher River with a distant backdrop

of wooded headlands, including the location of the site, and dockyard infrastructure at

Devonport.

Viewpoint 6: View from Public Footpath at Torpoint, Looking North East

This view represents users of the Public Footpath and nearby residential properties. Taking this

into account, visual sensitivity is considered to be high. Views from the Public Footpath are

largely obscured by existing vegetation. Glimpsed views are available across Thanckes Lake to

Thanckes Oil Fuel Depot Jetty and fuel tanks, and the urban area of Plymouth beyond. From

residential properties, which back onto Thanckes Lake to the south and on higher ground there

are clearer views toward the site than from the Public Footpath, however there is no public

access to these properties.


Viewpoint 7: View from Torpoint Ferry, Looking North West

This view represents users of the Torpoint Ferry, which carries pedestrian and vehicular traffic.

This viewpoint is also a similar distance and in a similar direction from the Development as the

nearby Scheduled Monuments (which are not publically accessible) and residential properties in

Plymouth and is therefore also broadly representative of these locations; it should be noted,

however, that dockyard infrastructure at the edge of the estuary heavily restricts views from

these areas of Plymouth. Taking these considerations into account, visual sensitivity is

considered to be high. The view is largely defined by views over the Hamoaze estuary to

Thanckes Oil Fuel Depot Jetty and fuel tanks, framed by Torpoint and the dockyards at

Devonport. The conurbation of Saltash forms a very distant backdrop.

Viewpoint 8: View from Blackhouse Park, Plymouth, Looking North West

This view represents users of the Public Park and visitors to this setting of the Scheduled

Monument. Taking this into account, visual sensitivity is considered to be high. The elevated

viewpoint allows views over the immediate Plymouth urban area, dockyards and more distant

backdrop formed by the Hamoaze estuary, in which the site lies, beyond.


9.5.1 Construction and Demolition

Construction and demolition best practice would be employed to limit landscape and visual

disruption; measures will include locating the site compound within the existing Thanckes Oil

Fuel Depot and minimising temporary land use outside of the depot.

9.5.2 Operation

The Development has been sited and designed so that the proposals form similar landscape

elements to existing infrastructure, particularly in terms of built form, limiting landscape and

visual disruption.


9.6.1 Construction Phase Effects

Construction phase activity would introduce temporary elements within the landscape. Activities

located within the existing, land based Oil Fuel Depot would generally only be perceived within

the context of the existing infrastructure and as a result wider landscape character and quality

would remain intact. Activities within the Hamoaze would be more widely visible however,

considering the nature of construction/demolition activities, particularly their very transient

characteristics, the magnitude of landscape and visual impacts is considered to be low

negative, and, taking into account some high sensitivities described in Section 9.4, the overall

significance of landscape and visual effects during construction is considered to be moderate

negative.


9.6.2 Operational Phase Effects

Landscape

The site does not fall within any designated landscapes. The Development would result in minor

alteration to landscape characteristics, through construction of Thanckes Oil Fuel Depot Jetty in

a location very close to the current jetty and of similar built form. The current jetty would

subsequently be demolished. Lightweight gantries would be constructed atop of several of the

existing fuel storage tanks. Although the gantries would increase the height of the tanks, their

metal lattice construction would be similar to the tank’s existing walkways. As a result there

would be only minor change to baseline landscape character and the magnitude of landscape

impact is therefore considered to be low negative. Taking into account medium landscape

sensitivity, the overall significance of landscape effect is considered to be minor negative.

Visual Amenity

Viewpoint locations are shown on Drawing 9-1. Photographs and photomontages are provided

within Drawings 9-2 to 9-7.

Viewpoint 1: View from Public Footpath at Pato Point, Looking South East

The foreground would continue to comprise the immediate shoreline and Cangapool bay. The

Development would lie across the bay and fall closer than the current jetty, but would continue

to sit against a wider backdrop of dockyard infrastructure at Devonport and the wider urban area

beyond. As a result the magnitude of visual impact is considered to be low negative. Taking

into account high visual sensitivity, the overall significance of visual effect is considered to be

moderate negative.

Viewpoint 2: View from Wilcove Waterfront, Looking South East

The foreground would continue to comprise Wilcove waterfront and Cangapool bay. The

Development would lie across the bay and fall closer than the current jetty, but would continue

to sit against a wider backdrop of dockyard infrastructure at Devonport and the wider urban area

beyond. On the headland, lightweight lattice gantries added atop existing storage tanks would

be visible. These structures would be visually permeable. As a result the magnitude of visual

impact is considered to be low negative. Taking into account high visual sensitivity, the overall

significance of visual effect is considered to be moderate negative.

Viewpoint 3: View from Minor Road at Wilcove Village Hall, Looking South East

The foreground would continue to comprise agricultural fields, properties and vegetation. The

Development would lie across the bay and fall closer than the current jetty, but would be

partially obstructed by intervening vegetation and continue to sit against a wider backdrop of

dockyard infrastructure at Devonport and the wider urban area beyond. Lightweight lattice

gantries added atop existing storage tanks would increase the visibility of these features on the

headland. However, the additional structures would be visually permeable and within the

context of existing infrastructure. As a result the magnitude of visual impact is considered to be

low negative. Taking into account high visual sensitivity, the overall significance of visual effect

is considered to be moderate negative.


Viewpoint 4: View from Minor Road between Wilcove and Coombe Park, Looking South East

The Development would be visible at the outer reaches of Cangapool bay, introduced to the

middle ground. The Development would be largely screened by vegetation, with a backdrop of

dockyard infrastructure at Devonport and the Plymouth urban area beyond. As a result the

magnitude of visual impact is considered to be low negative. Taking into account high visual

sensitivity, the overall significance of visual effect is considered to be moderate negative.

Viewpoint 5: View from Wearde Quay, looking South East

The Development would be largely screened from view at this location by the headland at Pato

Point, with the jetty head and associated moored vessels visible at approximately 2km distant

and resulting in a very inconspicuous change in the existing view. As a result, the magnitude of

visual impact is considered to be negligible negative. Taking into account high visual

sensitivity, the overall significance of visual effect is considered to be negligible negative.

Viewpoint 6: View from Public Footpath at Torpoint, Looking North East

The Development would be a greater distance away from this viewpoint than the existing jetty

however it would be larger in width and mass. Lightweight lattice gantries added atop existing

storage tanks would increase the height of these features on the headland. However, the

additional structures would be visually permeable and within the context of existing

infrastructure. As a result, the magnitude of visual impact is considered to be negligible

negative. Taking into account high visual sensitivity, the overall significance of visual effect is

considered to be negligible negative.

Viewpoint 7: View from Torpoint Ferry, Looking North West

The Development would be a greater distance away from this viewpoint than the existing jetty

however it would be larger in width and mass. Lightweight lattice gantries added atop existing

storage tanks would increase the height of these features on the headland. However, the

additional structures would be visually permeable and within the context of existing

infrastructure. As a result, the magnitude of visual impact is considered to be negligible

negative. Taking into account high visual sensitivity, the overall significance of visual effect is

considered to be negligible negative.

Viewpoint 8: View from Blackhouse Park, Plymouth, Looking North West

This elevated viewpoint allows views over the immediate Plymouth urban area, dockyards and

more distant backdrop formed by the Hamoaze estuary, in which the site lies, beyond. The

Development would form a distant, inconspicuous element in the view. As a result, the

magnitude of visual impact is considered to be negligible negative. Taking into account high

visual sensitivity, the overall significance of visual effect is considered to be negligible

negative.

Overall significance of visual effect, taking into account the range of views and visual receptors

affected, is considered to be minor negative.


9.6.3 Decommissioning Phase Effects

Decommissioning phase activity would introduce temporary elements within the landscape.

Activities located within the existing, land based Oil Fuel Depot would generally only be

perceived within the context of the existing infrastructure and as a result wider landscape

character and quality would remain intact. Activities within the Hamoaze would be more widely

visible however, considering the nature of construction/demolition activities, particularly their

very transient characteristics, the magnitude of landscape and visual impacts is considered to

be low negative, and, taking into account some high sensitivities described in Section 9.4, the

overall significance of landscape and visual effects during decommissioning is considered to be

moderate negative.


There are three reasonably foreseeable developments within the vicinity of the proposed

development, identified for consideration of cumulative impacts, as advised by statutory

consultees and the Defence Infrastructure Organisation.

The three proposed developments, identified in Drawing 3-1 are as follows:

• MOD Forward Operating Base at Kinterbury Point

• MOD Refurbishment and Operation of Trevol Jetty

• South West Devon Waste Partnership Combined Heat and Power Plant

The proposed development at Kinterbury Point and refurbishment of Trevol Jetty are located to

the south of Torpoint, approximately 1-1.5km distant from the proposed development. The local

topography and built form means it would be unlikely that they would be visible from any of the

viewpoints identified. From the Hamoaze estuary and adjacent land to the south, it is likely that

these two sites and the proposed Thanckes Jetty will be visible in combination. However, given

that all of the proposals would be seen within the distance and against a backdrop of existing

settlement and marine infrastructure, it is considered that the cumulative impacts of the

combined sites would not be significant.

The South West Devon Waste Partnership Combined Heat and Power Plant may be visible in

conjunction with the proposed development, principally from the south (viewpoints 6,7 and 8).

However given its distance at approximately 1.5km from the proposed development and its

setting within existing marine infrastructure and the Plymouth urban area, which already define

the backdrop within these views, it is considered that the cumulative impacts would not be

significant.

9.8 Summary

The landscape and visual implications of the proposed Development have been considered

through comprehensive landscape and visual impact assessment, in accordance with best

practice guidance. The site falls within the Hamoaze estuarine landscape and is not subject to

landscape designations. The wider landscape is made up of the Tamar Valley Area of


Outstanding Natural Beauty, Torpoint and the Plymouth conurbation (including Devonport

Docks). Visual receptors, or those who would have a view of the Development, include

properties, public rights of way, and transport corridors in Wilcove, Wearde Quay (within the

Tamar Valley AONB), Torpoint and Plymouth.

The Development would result in minor alteration to landscape characteristics, through

construction of Thanckes Oil Fuel Depot Jetty in a location very close to the current jetty and of

similar built form. The current jetty would subsequently be demolished. Lightweight gantries

constructed atop of several of the existing fuel storage tanks would increase the height of the

tanks, but their metal lattice construction would be similar to the tank’s existing walkways. In the

majority of available views, the Development would be seen against a backdrop of infrastructure

formed by Devonport Docks, such that visual amenity would not substantially change. As a

result there would not be significant impacts on landscape character and visual amenity.

Table 9-6 Landscape and Visual Impact Summary Table

Impact description Temporary/

permanent

Proposed

mitigation

measures

Significance

rating

Significant

effect

Construction Phase

Impact – Landscape &

Visual Amenity

Temporary landscape

and visual disruption.

Temporary Moderate negative Not significant

Operational Phase

Landscape

Overall, landscape

character, composition

and quality would

remain largely

unchanged.

Permanent Minor negative Not significant

Decommissioning

Phase Impact –

Landscape & Visual

Amenity

Temporary landscape

and visual disruption.

Temporary Moderate negative Not significant

Visual Amenity

In the majority of

available views the

Development would

result in discernible

change however this

change would generally

not be uncharacteristic

of views, and visual

quality would remain

largely intact.

Permanent Minor negative Not significant


10 Conclusion

In conclusion there are no temporary or permanent significant effects identified for all topics

following the implementation of the mitigation measures. In some cases there will be a positive

effect in reducing the potential risk to the environment.

Water Contamination and Sediment Quality

The activities associated with the construction and on-going operation of the proposed

Development and the demolition of the existing jetty, with potential to cause impact to water

quality are similar to those already carried out in the estuary.

During the construction phase Temporary Slight Negative impacts are anticipated for both the

land and marine based activities, with the use of mitigation measures that are identified within

Section 5.5.

The operational scheme as a whole provides a beneficial environmental effect as the new and

improved infrastructure will significantly reduce the potential for pollution incidents to occur.

During the operation impacts are classified as of Permanent Positive Moderate/Large impact.

The decommissioning of both the existing jetty and the proposed jetty are considered as having

Temporary Slight Negative impact related to the removal of hazardous substances and foreign

materials from entering the watercourse will be minimised through mitigation measures.

As a result there would not be significant effects on Water Contamination and Sediment Quality

Ecology

No significant effects on any ecological receptors are anticipated during construction and

decommissioning of the existing jetty. Although the subtidal habitats within the Site are located

within the Plymouth Sound and Estuaries SAC, given the relatively small footprint of the works

and the impoverished nature of the habitats present, no significant effects are predicted. The

site is located close to the Tamar Estuaries Complex SPA and St John’s Lake SSSI, but the

habitats in the vicinity of the Site are not of particular importance to birds associated with these

designated sites. Pollution prevention measures that would be put in place will ensure no

significant impacts on any of the surrounding designated sites, valuable habitats or species as a

result of increased siltation and pollution during construction. Construction has been timed to

avoid impacts on migratory fish, a feature of International importance.

No significant effects on any ecological receptors are anticipated during operation. Mitigation

measures have been proposed which would minimise disturbance of sediment, contain

migration of sediment and reduce the risk of a pollution incident. Furthermore, the new,

upgraded facility will reduce the potential for a pollution incident to occur.

Archaeology and Cultural Heritage

The significance of the effect of construction upon the known archaeology is considered to be

Permanent Slight. No mitigation is considered to be warranted and would therefore overall

impact is not predicted to be significant.


The operational and decommissioning activities of both the existing and proposed jetty are

considered as Permanent Slight Impact upon known archaeology. Therefore the overall effect

is not predicted to be significant.

There is low potential for as yet unrecorded shipwreck archaeology or submerged prehistoric

remains to be present within the site, the value of which is Uncertain. However, although the

potential is low, the precautionary principle has been used. Remains of submerged prehistory

would not be anticipated to exceed medium heritage value, while remains of wrecks within the

site could potentially be of high heritage value. The likelihood of either remains occurring is

considered to be very low. Such potential remains could incur impact of up to a high

magnitude of change, if encountered within the areas of proposed dredging. This would result

in, at most, a Major Significance of Effect. Although this significance of effect has been

identified in relation to remains which have a very low potential of occurring within the proposed

development site, an Archaeological Watching Brief would be necessary. The residual effect will

be slight and that; therefore the overall impact is not predicted to be significant.

As a result there would not be significant effects on archaeology and cultural heritage.

Noise and Vibration

The daytime construction noise impacts of are considered to be Slight or Moderate Adverse,

with night time impacts anticipated to be Moderate Adverse. Both of these impacts will be

Temporary. Given the distance to receptor locations it is unlikely that vibration impacts will be

experienced at any sensitive location. Predicted construction noise levels for both daytime and

night-time are predicted to be below threshold values set out in BS5228 and would therefore not

be considered significant.

Operations at the new jetty facility are expected to generate noise levels similar to those

currently generated on site. The most significant noise is probably the normal operating noise of

a ship, which will be similar to the other ships berthed at the current jetty. Permanent

operational noise impacts will be negligible if appropriate mitigation measures are considered

during detailed design.

Decommissioning noise impacts would result in a Temporary Moderate Adverse impact during

the daytime and Temporary Moderate Adverse impacts during the night time.

Decommissioning noise impacts are predicted to be below threshold values set out in BS5228

and would therefore not be considered significant.

As a result there would not be significant effects on noise and vibration.

Landscape and Visual Impact Assessment

The Development would result in minor alteration to landscape characteristics, through

construction of Thanckes Oil Fuel Depot Jetty in a location very close to the current jetty and of

similar built form. This would be a Temporary Moderate Negative impact and would therefore

not be considered significant.

The current jetty would subsequently be demolished resulting in Temporary landscape and

visual disruption. This would be a Temporary Minor Negative impact and would therefore not

be considered significant.


During the operational phase the majority of available views the Development would result in

discernible change however this change would generally not be uncharacteristic of views, and

visual quality would remain largely intact. This would be a Permanent Minor Negative impact

and would therefore not be considered significant.

As a result there would not be significant effects on landscape character and visual amenity.

Cumulative Effects

Cumulative effects associated with Thanckes OFD Development have been considered. These

are the combined effects of Thanckes OFD with other developments within the vicinity of the

site, the combined effects of Thanckes OFD with MOD Forward Operating Base at Kinterbury

Point, MOD Refurbishment and Operation of Trevol Jetty and South West Devon Waste

Partnership Combined Heat and Power Plant, and the combined effects of different

environmental aspects of Thanckes OFD development on a particular receptor.

A cumulative impact assessment has been undertaken within the environmental statement for

the areas above. No likely cumulative effects are anticipated during the construction and

operational phase of these other developments.


GLOSSARY AND ABBREVIATIONS

Acoustic barrier Solid walls or partitions, solid fences, earth mounds, buildings,

etc. used to reduce noise, without eliminating it.

ADD Approved Dredge Depth

ADS Archaeological Data Service

AGSV Area of Great Scientific Value

AL Action Levels

Ambient sound The totally encompassing sound in a given situation at a given

time, usually composed of sound from all sources near and far.

AMAA Ancient Monuments and Archaeological Areas Act 1979

AONB Area of Outstanding Natural Beauty

Background Noise Background noise is the term used to describe the noise

measured in the absence of the noise under investigation. It is

described as the average of the minimum noise levels measured

on a sound level meter and is measured statistically as the A-

weighted noise level exceeded for ninety percent of a sample

period. This is represented as the L90 noise level (see below).

BAP Biodiversity Action Plan

BC Before Christ

Best Practicable Means

(BPM) (COPA 1974)

"Practicable" means reasonably practicable having regard among

other things to local conditions and circumstances, to the current

state of technical knowledge and to the financial implications.

The means to be employed include the design, installation, maintenance and manner and periods of operation of plant and machinery, and the design, construction and maintenance of buildings and acoustic structures.

BGS British Geological Survey

BP Before present

BPM Best Practicable Means

BS British Standard

bsl Below sediment level. This was the reference point used when

drilling the boreholes, based on the level at which sediment was

first encountered.

BTO British Trust for Ornithology

Capital Dredging Material arising from the excavation of the seabed, generally for construction or navigation purposes, in an area or down to a level (relative to Ordnance Datum) not previously dredged during the preceding 10 years

Cefas Centre for Environment Fisheries and Aquaculture Science


CBI Cornwall Biodiversity Initiative

CBWPS Cornwall Bird Watching Preservation Society

CC Cornwall Council

CD Chart Datum

CDM Construction and Design Management

CEMP Construction Environmental Managment Plan

CLR Contaminated Land Report

COMAH Control of Major Accidents and Hazards Regulations

CPIG Crown Premises Inspection Group

CCTV Closed Circuit Television

CROW Countryside Rights of Way Act (2000)

CSM Conceptual Site Model

CWS County Wildlife Site

CWT Cornwall Wildlife Trust

DASSH Data Archive for Seabed Species and Habitats

DCLG Department of Communities and Local Government

Decibel [dB] The level of noise is measured objectively using a Sound Level

Meter. This instrument has been specifically developed to mimic

the operation of the human ear. The human ear responds to

minute pressure variations in the air. These pressure variations

can be likened to the ripples on the surface of water but of course

cannot be seen. The pressure variations in the air cause the

eardrum to vibrate and this is heard as sound in the brain. The

stronger the pressure variations, the louder the sounds are heard.

The range of pressure variations associated with everyday living

may span over a range of a million to one. On the top range may

be the sound of a jet engine and on the bottom of the range may

be the sound of a pin dropping.

Instead of expressing pressure in units ranging from a million to

one, it is found convenient to condense this range to a scale 0 to

120 and give it the units of decibels.

The following are examples of the decibel readings of every day


sounds;

Four engine jet aircraft at 100m 120 dB

Riveting of steel plate at 10m 105 dB

Pneumatic drill at 10m 90 dB

Circular wood saw at 10m 80 dB

Heavy road traffic at 10m 75 dB

Telephone bell at 10m 65 dB

Male speech, average at 10m 50 dB

Whisper at 10m 25 dB

Threshold of hearing, 1000 Hz 0 dB

dB(A): A-weighted decibels

The ear is not as effective in hearing low frequency sounds as it is

hearing high frequency sounds. That is, low frequency sounds of

the same dB level are not perceived to be as loud as high

frequency sounds. The sound level meter replicates the human

response of the ear by using an electronic filter which is called the

"A" filter. A sound level measured with this filter switched on is

denoted as dB(A). Practically all noise is measured using the A

filter. The sound pressure level in dB(A) gives a close indication

of the subjective loudness of the noise.

Defra Department of the Environment Food and Rural Affairs

DETR Department of the Environment, Transport and the Regions

DIO Defence Infrastructure Organisations (‘the client’)

DLCCP Devonport Landing Craft Co-location Project

DTM Digital Terrain Model

EA Environment Agency

EC European Commission

EHA English Heritage Archives

EHO Environmental Health Officer

EIA Environmental Impact Assessment

EPS European Protected Species


EQS Environmental Quality Standards

ERCCISS Environmental Records Centre for Cornwall and the Isles of Scilly

ES Environmental Statement

FEPA Food and Environment Protection Act

FFFP Film-Forming Fluoroprotein

FHSU Fleet Helicopter Support Unit

FOB Forward Operating Base

FRA Flood Risk Assessment

GAC Generic Assessment Criteria

GPS Global Positioning System

HA Highways Agency

HER Historic Environment Record

HGV Heavy Goods Vehicles

HLS Helicopter Landing Site

HMNB Her Majesty’s Naval Base

HRA Habitat Regulations Assessment

HSE Health & Safety Executive

IBCs Intermediate Bulk Containers

IEEM Institute of Ecology and Environmental Management’s

IEMA Institute of Environmental Management and Assessment

IPG Integrated Projects Guide

ISGOTT International Safety Guide for Oil Tankers and Terminals

JNCC Joint Nature Conservation Committee

LBAP Local Biodiversity Action Plan

LAmax The maximum RMS A-weighted sound pressure level occurring

within a specified time period.

LCA Landscape Character Area

Loudness A rise of 10 dB in sound level corresponds approximately to a

doubling of subjective loudness. That is, a sound of 85 dB is twice

as loud as a sound of 75 dB which is twice as loud as a sound of

65 dB and so on. That is, the sound of 85 dB is 400 times the


loudness of a sound of 65 dB.

LNR Local Nature Reserve

LPA Local Planning Authority

LQA Land Quality Assessment

LVIA Landscape and Visual Impact Assessment

mAOD metres above ordnance datum

MARLIN Marine Life Information Network

MAGIC

MCAA

Multi-Agency Geographical Information for the Countryside

Marine and Coastal Access Act 2009

MCA Maritime and Coastguard Agency

MCZ Marine Conservation Zone

MMO Marine Management Organisation

MNCR Marine Nature Conservation Review

MOB Main Operating Base

MOD Ministry of Defence

MPS UK Marine Policy Statement

MSA Merchant Shipping Act 1995

NBN National Biodiversity Network

NDT Non-Destructive Testing

NE Natural England

NERC Natural Environment and Rural Communities Act 2006

NHL National Heritage List

NNR National Nature Reserve

Noise Sound which a listener does not wish to hear.

NPPF National Planning Policy Framework 2012

NPSE Noise Policy Statement for England

NTS Non-Technical Summary

OD Ordnance Datum

OFD Oil Fuel Depot


OIC Office In Charge

OPA Oil & Pipelines Agency

OS Ordnance Survey

OWS Oil Water Separator

PAH Polycyclic aromatic hydrocarbons

PCB Polychlorinated biphenyls

PCSR Pre-Construction Safety Report

PEL Probable Effect Levels

PMRA Protection of Military Remains Act 1986

POSR Pre-Operation Safety Report

PPG5 Pollution Prevention Guidelines 5

PPS Planning Policy Statement

PRO Plymouth records Office

PRoW Public Rights of Way

PWA Protection of Wrecks Act 1973

QHM Queen’s Harbour Master

Rating Level (LAr,Tr) The noise level of an industrial noise source which includes an

adjustment for the character of the noise. Used in BS 4142

RBMP River Basin Management Plan

RFA Royal Fleet Auxiliary

ROV Remote Operated Vehicles

Rw The weighted sound reduction index is a laboratory measurement

of the sound insulating properties of a building material or building

element.

SA Sustainability Appraisal

SAC Special Area of Conservation

SCADA Supervisory Control and Data Acquisition

SLR single lens reflex


Sound A fluctuation of air pressure which is propagated as a wave

through air.

Sound Level Meter An instrument consisting of a microphone, amplifier and indicating

device, having a declared performance and designed to measure

sound pressure levels.

Sound Pressure Level The fluctuations in air pressure, from the steady atmospheric

pressure, created by sound, when measured on the decibel scale.

SPA Special Protection Area

SSSI Site of Special Scientific Interest

Sullage Sullage is an oily water waste product which is removed from

ships and stored on site at the tank farm prior to removal for

processing by a licenced contractor.

TBT Tributyltin

TECF Tamar Estuaries Consultative Forum

TEL threshold effect levels

THC Total Hydrocarbon Content

TPH Total petroleum hydrocarbons

TSHD Trailing Suction Hopper Dredger

UKHO UK Hydrographic Office

URD User Requirements Document

WAC Waste Acceptance Criteria

WeBS Wetland Bird Survey

WFD Water Framework Directive

WML Weston Mill Lake

ZoI Zone of Influence

ZTV Zone of Theoretical Visibility


REFERENCES

Chapter One

1-1 The Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild

Fauna and Fora

1-2 The EC Directive on the Conservation of Wild Birds (791409/EEC)

1-3 Marine and Coastal Access Act 2009

1-4 Tamar Estuaries Management Plan 2013 to 2018 (Tamar Estuaries Consultative Forum,

2012)

1-5 Town and Country Planning Act 1990 (as amended)

1-6 Department for Communities and Local Government, 2011. Town and Country Planning

(Environmental Impact Assessment) Regulations 2011

1-7 Marine Works (Environmental Impact Assessment) Regulations 2007 (as amended)

1-8 EC Directive 2011/92/EU

1-9 Department for Communities and Local Government, March 2012, National Planning Policy

Framework

1-10 Institute of Environmental Management and Assessment, 2004. Guidelines for

Environmental Impact Assessment

Chapter Two

2-1 Control of Major Accidents and Hazards Regulations 1999

2-2 Existing Westminster Dredging Marine Licence

2-3 Westminster Dredging Marine Licence Application on public register


Fauna and Fora

2-5 Natura 2000 baseline document prepared for the MOD at Devonport Naval Base (2011)

2-6 Hyder Consulting Ltd (2010) Assessment Study

2-7 Department for Communities and Local Government, March 2012, National Planning Policy

Framework


2-8 Department for Communities and Local Government,2009, Planning Policy Statement 25

Development and Flood Risk Practice Guide

2-9 McMillan. A, Batstone. C, Worth. D, Tawn. J, Horsburgh. K, Lawless. M (2011). Coastal

flood boundary conditions for UK mainland and islands. Bristol: Environment Agency

2-10 Initial Options Appraisal Report dated 15 January 2010

Chapter Three

3-1

3-2

3-3

The Town and Country Planning (Development Management Procedure) (England)

(Amendment) Order 2013

Cornwall Council, Statement of Community Involvement, December 2011, available:

http://www.cornwall.gov.uk/media/3635991/SCI-as-Amended-220612.pdf

Town and Country Planning EIA Regulations

3-4

3.5

3.6

Marine Works EIA Regulations

Town and Country Planning Act 1990 (as amended)

Marine and Coastal Access Act 2009

3-7 Council Directive (2008/1/EC) Integrated Pollution Prevention & Control

3-8 Environmental Permitting (England and Wales) Regulations 2010

3-9 Council Directive (2000/60/EC) Water Framework Directive

3-10 The Water Environment (Water Framework Directive) (England and Wales) Regulations

2003


Fauna and Fora

3-12 Conservation of Habitats and Species Regulations 2010. Her Majesty’s Stationary Office

3-13 Water Resources Act 1991

3-14 Fire Services Act 1947

3-15 Directive 2009/147/EC on the Conservation of Wild Birds for rare, vulnerable and regularly

occurring migratory bird species and internationally important wetlands

Chapter Four

None


Chapter Five

5-1

5-2

Contaminated Land Report 11. Model Procedures for the Management of Land

Contamination. Defra/Environment Agency. September 2004.

Baseline Document for Maintenance Dredging in Plymouth Sound and Estuaries European

Marine Site. Black and Veatch for DIO. August 2010 Revised March 2011

5-3

5-4

1:50,000 series geology map (Drift Edition) Sheet 348 Plymouth. British Geological Survey.

Soil Mechanics Logs Boreholes BHF, BHG, BHH, BHJ, BHK. 2004

5-5 Site Investigation Report in Support of Waste Management Licence Surrender.

Environmental Science Group (ESG) for Defence Equipment and Support (DE&S) May

2008. ESG/08/011

5-6 OFD Thanckes, Torpoint Land Quality Assessment. SKM Enviros for Defence Infrastructure

Organisation. DIO Project Number: Z9L1285Y09 Commission DE31/7115-1. Draft v2 April

2013

5-7 Industry Profile for Dockyards and Dockland. Department of the Environment. 1995

5-8 Environmental Monitoring for Radioactivity Around Devonport Royal Dockyard. Annual

Report 2011. Babcock.

5-9

5.10

5-11

Technical Annex 1 of OSPAR Guidelines for the Management of Dredged Material

(Reference number: 2009/4) OSPAR Commission

A desk study to assess the impact of dredging activity on the Tamar Estuary. PML

Applications Ltd. January 2004

Tamar Estuaries Management Plan 2013 to 2018 (Tamar Estuaries Consultative Forum,

2012)

5-12 Marine Management Organisation (MMO) website accessed September 2013

http://www.marinemanagement.org.uk/licensing/how/sample_analysis.htm

5-13

5-14

5-15

5-16

5.17

Canadian Council of Ministers of the Environment (CCME) Canadian Environmental Quality

Guidelines. http://ceqg-rcqe.ccme.ca/ Website accessed 06/09/13

Construction Industry Research & Information Association (CIRIA) C650 – Environmental

Good Practice on Site, 2nd Ed. CIRIA. 2005

CIRIA C532 – Control of Water Pollution from Construction Sites (CIRIA, 2001)

Design Manual for Roads and Bridges (DMRB) - Volume 11, Section 3, Part 10 Road

Drainage and the Water Environment: HD 45/09. (Highways Agency, 2009)

Environment Agency, Pollution Prevention Guidelines No’s 1, 2, 3, 5, 6, 8 and 18

(Environment Agency, various publication dates)

5-18 Environment Agency. Soil Guideline Values and Toxicology Reports (2008)

5-19 Land Quality Management (LQM)/ Chartered Institute Environmental Health (CIEH)

Generic Assessment Criteria for Human Health Risk Assessment. 2nd Edition. Land Quality


Press 2009.

Chapter Six

6-1 Institute of Ecology and Environmental Management’s (IEEM) Guidelines for Ecological

Impact Assessment (2006) (‘the IEEM Guidelines’)

6-2 Handbook for Phase 1 habitat survey: a technique for environmental audit, Joint Nature

Conservation Committee, 2010

6-3 New Flora of the British Isles (2nd edition) Stace, C, 1997

6-4 Guidelines for the Conduct of Benthic Studies at Marine Aggregate Extraction Sites (2nd

Edition). Marine Aggregate Levy Sustainability Fund. Pp. 80. Ware, S. J. and Kenny, A. J.,

2011.

6-5 Marine Nature Conservation Review: rational and methods. Peterborough, Joint Nature

Conservation Committee. Pp. 167. Hiscock, K., ed. 1996

6-6 Marine Monitoring Handbook. Joint Nature Conservation Committee.

http://jncc.defra.gov.uk/page-2430. Accessed June 2013. Davies, J. et al., 2001

6-7 The Marine Habitat Classification for Britain and Ireland Version 04.05, Connor, D. W. et al,

2004, JNCC, Peterborough. ISBN 1 861 07561 8 (internet version).

www.jncc.gov.uk/MarineHabitatClassification. Accessed June 2013

6-8 Plymouth Sound and Estuaries SAC Natura 2000 data form, JNCC, 27/07/11

6-9 IUCN Red List of Threatened Species, accessed via http://www.iucnredlist.org/search

6-10 Cornwall Wildlife Trust Seaquest Netsafe Project - Final Report 2012, Cornwall Wildlife

Trust, 2012

6-11 St John’s Lake SSSI Condition of SSSI Units accessed online at

www.sssi.naturalengland.org.uk, August 2013.

6-12 Thanckes Oil Fuel Depot, Devonport – Underwater Noise Impact during New Jetty

Construction, Subacoustech Environmental, March 2014 (Report no E455R0305)

6-13 North Sea Fish and Fisheries, CEFAS, August 2001.

6-14 A desk study to assess the impact of dredging activity on the Tamar Estuary, PML

Applications Ltd, 2004

6-15 Baseline Document for Maintenance Dredging in Plymouth Sound and Estuaries European

Marine Site, Defence Estates, August 2010, revised March 2011

6-16 European Site Conservation Objectives for Tamar Estuaries Complex Special Protection

Area Site Code: UK9010141, Natural England, undated.

6-17 Construction and Waterfowl: Defining Sensitivity, Response, Impacts and Guidance. Report

to Humber INCA. Cutts, N; Phelps, A; Burdon, D. Institute of Estuarine and Coastal

Studies, University of Hull. 2008.

6-18 Environmental impacts resulting from disposal of dredged material at the Rame Head

disposal site, S.W. England: An analysis of existing data and implications for environmental

management. Cefas Contract BA004. Cefas (2005).

6-19 Wave and Tidal Consenting Position Paper Series: Impacts on Fish and Shellfish Ecology,

Natural Environment Research Council, October 2013.


6-20 Likely sensitivity of bottlenose dolphins to pile-driving noise, J.A. David MCIWEM, Water

and Environment Journal 2006.

6-21 Kinterbury Point (HMNB Devonport) FHSU Forward Operating Base MOD Decision Form

2223 (Stuart Otway, MOD, 2014).

Chapter Seven

7-1 Institute for Archaeologists (IFA) 2012 Standard and Guidance for historic environment

desk-based assessment

7-2 DETR, Environmental Impact Assessment: A Guide to Procedures, 2000

7-3 Department for Transport, Design Manual for Roads and Bridges (DMRB), Volume 11. Highways

Agency document 208/07, 1993

7-4 English Heritage, Conservation Principles: policies and guidance for the sustainable management of

the historic environment, 2008

7-5 Somerset County Council, South West Archaeological Research Framework, 2008.

Chapter Eight

8-1 Noise and Statutory Nuisance Act (1993). The Stationary Office

8-2 Environment Protection Act (1990) The Stationary Office

8-3 National Planning Policy Framework (2012), Department for Communities and Local

Government, March 2012.

8-4 BS 4142:1997 ‘Method for rating of industrial noise affecting mixed residential and industrial

areas’ BSI

8-5 BS 8233 Sound Insulation and Noise Reduction for Buildings – Code of Practice (2014) BSI

8-6 BS 5228:2009 ‘Noise and vibration control on construction and open sites’ – Part 1: Noise

BSI

8-7 Control of Pollution Act (1974). The Stationary Office

Chapter Nine

9-1 European Landscape Convention, 2000, Council of Europe.

9-2 National Planning Policy Framework, 2012, Department for Communities and Local

Government.

9-3 Caradon District Local Plan, 2007, Caradon District Council.

9-4 Guidelines for Landscape and Visual Impact Assessment: Third Edition, 2013, Landscape

Institute and Institute of Environmental Management and Assessment.

9-5 Photography and Photomontage in Landscape and Visual Impact Assessment, 1999,

Landscape Institute.

9-6 Countryside Character, 1999 (as amended), Countryside Agency/Natural England.

9-7 Cornwall and Isles of Scilly Landscape Character Study, 2008, Cornwall Council.

defence infrastructure organisation thanckes oil fuel

Documents