15. material assets15-1 - assets.gov.ie

Enterprise Energy Ireland Ltd Corrib Offshore EIS

RSK/H/P/P8069/03/04/01rev01 15-1

15. MATERIAL ASSETS ................................................................................................15-1

15.1 Introduction.....................................................................................................15-1

15.2 Solid Waste ......................................................................................................15-1

15.2.1 Introduction...................................................................................15-1

15.2.2 Study Methodology......................................................................15-1

15.2.3 Receiving Environment ................................................................15-1

15.2.4 Characteristics of the Proposed Development .........................15-3

15.2.5 Potential Impacts of the Proposed Development .....................15-3

15.2.6 Do-Nothing Scenario....................................................................15-7

15.2.7 Mitigation Measures .....................................................................15-7

15.2.8 Predicted Impacts of the Proposed Development ...................15-8

15.2.9 Monitoring ...................................................................................15-10

15.2.10 Reinstatement and Residual Effects .........................................15-10

15.3 Traffic Impact Assessment..........................................................................15-10

15.3.1 Introduction.................................................................................15-10

15.3.2 Study Methodology....................................................................15-11

15.3.3 Receiving Environment ..............................................................15-11

15.3.4 Characteristics of the Proposed Development .......................15-13

15.3.5 Potential Impact of the Proposed Development.....................15-14

15.3.6 Do-Nothing Scenario..................................................................15-16

15.3.7 Mitigation Measures ...................................................................15-17

15.3.8 Predicted Impact of the Proposed Development...................15-19

15.3.9 Monitoring ...................................................................................15-20

15.3.10 Reinstatement and Residual Effects .........................................15-20

Figure 15.1: Important shipping ports around the coast of Ireland showing total cargo handled (millions of

tonnes per year) in 1995 (Boelens et al., 1999) ............................................................................. 15-12 Figure 15.2: Study Area Road Network................................................................................................ 15-13 Figure 15.3: Recommended Routes to Construction Sites.................................................................... 15-19

Table 15.1: European Waste Legislation ................................................................................................ 15-2 Table 15.2: Estimated cuttings for containment and shipping to shore from three future Corrib wells... 15-4 Table 15.3: Solid Waste Production from Three Wells upon Drilling and Completion ......................... 15-5


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15. MATERIAL ASSETS

15.1 Introduction

Material assets are those resources available to the local community. In this section the impact of the proposed offshore and landfall development on the local road network and waste treatment facilities are addressed. There will be no significant consumption of natural resources such as iron ore, stone, timber or potable water by this project. This aspect of material assets is not considered further.

15.2 Solid Waste

15.2.1 Introduction

This section considers the various solid waste materials and substances that will be generated during the installation, operation and decommissioning of the offshore development. Treatment and disposal of liquid effluents/wastes are discussed in Section 9.

15.2.2 Study Methodology

The assessment of waste generation from the proposed Corrib offshore development has been conducted as a desktop study.

Waste has been categorised as general (controlled) waste, or special waste, in line with the Waste Management Act 1996.

15.2.3 Receiving Environment

The following legislation concerns waste management for the project.

15.2.3.1 European Union Legislation

Table 15.1 provides a list of the European waste legislation relevant to the offshore section of the Corrib development.

Corrib Offshore EIS Enterprise Energy Ireland Ltd

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Table 15.1: European waste legislation Directive Name Summary

75/442/EEC amended by 90/656/EEC 91/156/EEC 91/692/EEC

Council Directive on Waste

Requires that any establishment which carries out disposal operations, or possible recovery operations, will require a permit from the competent authority. Permits must cover types and quantities of waste, technical requirements, security precautions, disposal site and treatment method.

94/62/EC European Parliament and Council Directive on packaging and packaging waste

Regulation introduces the concept of “producer responsibility” for packaging waste. Member states are required to take measures to achieve the recovery of between 50% and 65% of packaging waste and the recycling of between 25% and 45% of such waste.

91/689/EEC Council Directive on hazardous waste

Requires that any establishment which carries out disposal operations, or possible recovery operations, of hazardous waste will require a permit from the competent authority. Permits must cover types and quantities of waste, technical requirements, security precautions, disposal site and treatment method.

75/439/EC Council Directive on the disposal of waste oils

Requires that any establishment undertaking “disposing” of waste oils (such as lubricating oils and used oils but not oil refinery wastes) must obtain a permit from the competent authority. Member states shall take the necessary measures to ensure that waste oils are collected and disposed of without causing any avoidable damage to man and the environment.

84/631/EEC amended by 86/279/EEC

Council directive on the supervision and control within the European Community of the transfrontier shipment of hazardous waste

Requires that any holder of any toxic and dangerous waste who intends to move it across a frontier is required to notify the competent authority of the member states concerned and where applicable, any third state, by means of a consignment note. Conditions are laid down covering packaging, labelling and instructions in the event of danger and an accident.

93/259/EEC

Council regulation on the supervision and control of shipments of waste within, into and out of the European Community

Establishes a system of supervision and control of all movements of waste. It provides for a common, compulsory notification system and for a standard consignment note for shipments of waste.

15.2.3.2 Irish Legislation

The most relevant piece of legislation currently in force is the Waste Management Act 1996.


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This act provides for:

• a comprehensive and modern regulatory framework for the application of higher environmental standards, particularly in relation to waste disposal, in response to EU and national waste management requirements;

• the assignment of functions to public authorities in relation to waste management, e.g. the Minister, the EPA and local authorities; and

• measures - mainly regulatory powers-designed to improve national performance in relation to the prevention, minimisation and recovery/recycling of wastes.

Other relevant regulations include:

• Waste Management (Licensing) Regulations, 2000;

• Waste Management (Permits) Regulations, 1998;

• Waste Management (Miscellaneous Provisions) Regulations, 1998;

• Waste Management (Hazardous Waste) Regulations, 1998;

• Dumping at Sea Act, 1996;

• Foreshore Acts 1933-1998

• European Communities (Transfrontier Shipments of Waste) Regulations, 1994; and

• MARPOL 73/78, Annex V.

15.2.4 Characteristics of the Proposed Development

The proposed offshore development includes the following operations:

• the drilling of three additional development wells;

• the completion of eight wells as producers;

• the construction of subsea facilities;

• the construction of a 20” gas pipeline and 6” umbilical from the Corrib Field to the Terminal and the construction of an 8” water discharge pipe in Broadhaven Bay from the Terminal;

• the construction of the landfall and crossings of Sruwaddacon Bay; and

• operation of the above facilities.

Solid waste generation associated with these activities is discussed below.

15.2.5 Potential Impacts of the Proposed Development

15.2.5.1 Drilling and Installation

The largest stream of waste solids from drilling comprises ‘wet cuttings’.

The drilling of wells necessarily involves the generation of rock cuttings. The cuttings are flushed from the well using a drilling fluid, and the ‘wet


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cuttings’ that are separated retain a coating of drilling fluid. The drilling process and generation of cuttings are described in Sections 2 and 3.

Cuttings from Sections I and II of the well are discharged to the seabed directly from the top of the well, the effects of this discharge are discussed in Section 9.

The cuttings from Sections III and IV will be coated with low toxicity oil-based mud (LTOBM). These cuttings are containerised and transported to shore. They are therefore considered a waste material. The estimated volumes of cuttings from well sections III and IV for the three future wells to be drilled in the Corrib Field are provided in Table 15.2. The discharges on a per well basis can be found in Appendix 9.2. Data on cuttings generation and discharge for previous Corrib wells are provided in Appendix 2.1.

Table 15.2: Estimated cuttings for containment and shipping to shore from three future Corrib wells

Section III (12.25”) m3 (tonnes)

Section IV (8.5”) M3 (tonnes)

Total m3 (tonnes)

Dry cuttings 555 (1470) 216 (570) 771 (2040) Mud on Cuttings 237 (348) 93 (117) 330 (465) Oil on Cuttings 147 (117) 57 (45) 204 (162) Assumptions: Washout: 12.25” washes out to 13” (13%), 8.5” washes out to 9” (12%). Rock density of approx 2.65. “Oil on cuttings” is the part of the mud which is the organic base fluid, and volumes provided above are those which are theoretically extractable from the “mud on cuttings”.

The impact of seabed disposal of water-based mud coated cuttings is discussed in Sections 7, 8 and 9 of this EIS. There will be no further discharge of organic based muds in the Corrib Field.

Solid general wastes likely to be generated during the offshore development operations include plastics, scrap metal, non-hazardous drums and segregated recyclables. Table 15.3 presents an estimate of the quantities anticipated to be produced during this phase.

Potential impacts associated with the disposal of general waste during this phase of the project are not anticipated to be significant, due to their non-hazardous nature.

In contrast to the above, the potential impact could be significant if special wastes entered the environment. Special solid wastes which could be generated during the offshore operations (excluding the oil-based cuttings described earlier in this section), include batteries and hazardous drums. Estimates of theses wastes and their quantities are presented in Table 15.3. These figures are based on waste production quantities from three proposed development wells.


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Table 15.3: Solid waste production from drilling and completion operations1

Type of Waste Quantity Recycling Potential General Scrap Metal 33 tonnes yes Drums 1650 drums yes Tins and Jars 1.65 tonnes yes Wood 58.24 m3 yes Plastic bottles 11.65 m3 yes Paper/ card etc. 291 kg yes Hazardous Batteries 1165 kg yes Spent lube oil 3339 litres limited Oily residues 13976 litres limited Oily Filters 70 filters limited Oily Rags/ Gloves 233 kg no Clinical First Aid – Bandages, Syringes etc.

388 kg no

Assumption: The volume of waste stream arisings have been estimated from generic industry generation rates from previous drilling and completion operations and assume maximum drilling and completion programme durations of 60 days and 25 days respectively.

15.2.5.2 Pipeline and Umbilical and Discharge Pipeline

Several waste streams will be generated during laying of the offshore pipeline, umbilical and discharge pipe, as follows:

Plastic wastes

Plastic caps are used to protect the pipes internally from damage. Once the pipe is ready for welding and laying, the plastic caps are discarded. These can be disposed of as general waste in a skip on the laybarge. However, it is possible for the plastic caps to be returned to the supplier for reuse or recycling. There will be no impact from these items.

Metal Wastes

The pipe sections will be welded together on the barge. This operation can be done manually or by machine. Small pieces of weld metal will be generated and disposed of as general waste, or recycled if practicable.

The pipe edges are bevelled prior to welding. This can either be done on the barge, or at the point of manufacture. If carried out on the barge, swarf waste will be created. The pre-prepared bevelled areas will have to be prepared prior to welding. Grindings will be created from preparing the weld areas. The pipe is coated in concrete and corrosion inhibitor material and is smoothed prior to laying. The grindings can be disposed of as general waste.

1-Special wastes will remain on board vessels and will be handled according to local regulations at the port where the vessel returns. In event that such a port is in Ireland, the waste will be transferred to and handled by a licensed waste contractor1


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A filling material is used over the weld areas to protect the pipe. When filling this space, shutters are used to contain the material. These shutters have to be disposed of. These are made of metal and can be disposed of as general waste.

There would be a small impact on the environment if these wastes were not managed properly.

Packaging

Many of the materials brought on to the laybarge will have associated packaging, including wooden pallets, cardboard boxes, steel and plastic banding and plastic wrappings. All of these can be disposed of as general waste. There is the potential for recycling or reuse of many of these materials.

There would be a small impact on the environment if these wastes were not managed properly.

15.2.5.3 Landfall and Sruwaddacon Crossings

Several waste streams will be generated from the landfall and Sruwaddacon crossing operations, as follows:

Excavated Material

Seabed trenching will be carried out using a backhoe. The excavated material will be side cast for subsequent replacement as part of the reinstatement process.

The topsoil excavated for the construction of the underground installation will be reused locally, or sent to landfill for use as a daily cover or a restoration soil.

Neither of the above mentioned construction spoils will be classified as waste.

Construction Materials

Concrete or timber foundations constructed to hold the winches in position will be removed and disposed of following operation. An underground installation will be built onshore. Normal construction waste will be generated including steel, polystyrene and other similar building materials. All of these material types are classified as general waste. If not managed properly, they would have a moderate impact on the environment.

Metal Wastes

Welding of the pipeline onshore will be done manually. Small pieces of weld metal and welding rod remnants will be generated. They will be disposed of as general waste, or recycled, if praticable, to avoid any impact on the environment.


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15.2.5.4 Operations

During operation of the offshore sections of the Corrib development, there will be very little waste generated on a normal basis. If well intervention works are required, the types of waste involved will be the same as those for initial drilling. Therefore no impacts are expected from this phase of the development.

15.2.5.5 Decommissioning

When the offshore development is decommissioned, some elements will be removed from the seabed, including the wellheads, manifolds and the infield pipelines and associated umbilical network. The main waste type produced during this decommissioning will be metal, the majority of which can be recycled as scrap.

In addition to the above, all recovered equipment and materials arising from decommissioning will, where suitable, be refurbished and re-used or disposed of, in accordance with national and international regulations in force at the time.

Some parts of the development (ie. the pipeline) could be left on the seabed to minimise disturbance to the local marine environment and this will also reduce the amount of waste brought back to shore.

Onshore the underground installation will be decommissioned and the area reinstated. This will involve the disposal of building materials used in its construction.

Decommissioning activities will ensure that all installations, equipment and pipelines are removed in such a way as to comply with any legislation that is in place at the time of decommissioning.

15.2.6 Do-Nothing Scenario

If the offshore development did not proceed, no waste would be generated and therefore, there would be no waste to dispose of.

15.2.7 Mitigation Measures

15.2.7.1 Waste Management Plan

Enterprise will produce a Waste Management Plan as part of the detailed design. This will ensure rigorous management and control of the wastes generated from the offshore development phases.

In particular the procedure will set out how Enterprise will:

• collect and minimise waste generation;


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• reuse or recycle wherever possible;

• separate, store and contain securely and label all wastes;

• nominate someone to be responsible for waste management at the Terminal;

• employ suitably licensed waste contractor(s) for disposal purposes;

• audit the licence(s) of the waste contractor(s) and check their disposal site(s); and

• monitor and periodically audit the waste management system and activities.

15.2.7.2 General Waste Disposal

General wastes produced offshore will be shipped ashore for disposal or further treatment. The nearest major port to the offshore development is in Co. Donegal. From here (or wherever the support vessels come ashore) a licensed waste haulier will transport the wastes to the place of disposal. The landfill sites/ waste transfer disposal centres to be used will be determined by the waste contractor.

15.2.7.3 Special Waste Disposal

The potential impacts associated with the disposal of special waste have been minimised, as far as reasonably practicable. Where waste is generated, it will be securely stored, removed, transported and ultimately disposed of, in line with the relevant regulations.

Due to the limited facilities available for treatment/ disposal of special waste within the Republic of Ireland, it is possible that special waste may have to be exported via road and sea to continental Europe for treatment/ disposal at appropriately licensed facilities.

By dealing with these wastes in a legally responsible manner, there will be no impact on the environment.

15.2.8 Predicted Impacts of the Proposed Development

15.2.8.1 Drilling

Waste streams generated during drilling will be categorised onboard at source, for the purpose of segregation and temporary storage prior to shipment to shore for treatment or disposal at an approved facility. Table 15.3 shows that the majority of the waste produced during the drilling operations can be recycled.

The only wet cuttings that will be disposed of as waste will be those contaminated with LTOBM. These will be containerised and taken by supply vessel to shore. They are transported to a processing plant where the


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oil is thermally removed from the cuttings. The oil could be recovered as distillate. Uses may be found for the oil-free processed rock material.

There will, therefore, be no impact on the local environment from LTOBM drill cuttings.

15.2.8.2 Field Facilities

The structures to be laid on the seabed will be transported to the Field pre-constructed, there will, therefore, be relatively little construction waste generated. Any minor fabrication works that are required are likely to result in the production of small amounts of metal waste. This will be returned to shore for disposal as general waste, general waste will also be generated from normal operation of the vessels.

Once the field facilities are operational, very little waste will be produced. It should be noted that small amounts of waste will be produced during maintenance operations. This waste will be retained on board the vessels carrying out the maintenance.

There will be no impact from the waste generated during the installation or operation of the field facilities. Aqueous discharges during operation are discussed in Section 9 of this EIS.

15.2.8.3 Pipeline and Umbilical and Discharge Pipeline

Once the pipeline, umbilical and discharge pipe are operational, very little waste will be produced. It should be noted that small amounts of scale could be produced during maintenance operations. This waste will arise in the Terminal and therefore, is discussed in detail in the Terminal EIS. There will also be some solid waste generated by vessels carrying out survey or maintenance work along the pipeline route. This waste is held on board and there will no impact from this.


Once the landfall and Sruwaddacon crossings are operational, no waste will be produced.


The predicted impacts will be the same as those discussed in the potential impacts (Section 15.2.5.5).


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15.2.9 Monitoring

15.2.9.1 Drilling

A person will be nominated during the drilling programme to ensure waste materials are handled, stored and disposed of correctly. Frequent checks will be made to ensure that waste management procedures are being followed.

15.2.9.2 Construction

A person will be nominated on the laybarge and at the landfall and Sruwaddacon crossings to ensure waste materials are handled, stored and disposed of correctly. Frequent checks will be made to ensure that waste management procedures are being followed.

15.2.9.3 Operation

Very little waste generation is anticipated during this stage of the project therefore monitoring has not been proposed.


During decommissioning, a range of monitoring procedures will be agreed with the Department of the Marine and Natural Resources, based upon the environmental requirements in force at that time.

15.2.10 Reinstatement and Residual Effects

The options for final abandonment of the project will be the subject of a study approximately five years prior to the last gas date. This will allow sufficient time to investigate recycle and reuse options of the materials used in the project.

15.3 Traffic Impact Assessment

15.3.1 Introduction

In May 2001, RSK Environment commissioned Oscar Faber to undertake a traffic impact assessment of land based traffic, for the construction and operational aspects of the offshore section of the proposed Corrib Field development.

In addition, RSK carried out desk-based research on the vessel movements (i.e. marine traffic) for this section of the Corrib Field development.


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15.3.2 Study Methodology

In order to complete the study of the onshore traffic impacts, a number of routes in the study area were examined, which would possibly be impacted by the construction of the landfall along with the Sruwaddacon Bay crossings.

This study took the following issues into account:

• suitability of the surrounding road network to cater for the additional traffic generated during the construction section of the landfall and Sruwaddacon crossings;

• the number of movements by both land and sea for construction of the pipeline;

• concerns of the local residents and businesses regarding traffic generated by the proposed development, as expressed during the public consultation phase of this project;

• remedial measures required to allow the development to be constructed in a safe manner; and

• a proposed Traffic Management Plan to reduce the levels of traffic on the road, particularly at peak hours, and minimise the impact of the development on the residents and the environment.

This traffic impact assessment addresses the three areas of pipeline construction namely, the offshore sector, nearshore sector, and the landfall and Sruwaddacon crossings. In addition, all operations within 30 m of the high water mark are summarised, in order to identify their impacts.

In terms of the offshore traffic movements, information was gathered from a number of sources including Jee Associates (2000) and Boelens et al. (1999).

15.3.3 Receiving Environment

15.3.3.1 Existing Offshore Traffic

The main vessel traffic activity is that associated with fishing with vessels, either on passage or actually engaged in fishing.

Fishing activity in the offshore area consists mainly of vessels trawling for whitefish, with sizes ranging from 55 ft (25 tonnes) to 85 ft (400 tonnes). There are also large concentrations of small inshore vessels along the Sligo/North Mayo coast which undertake gill netting, pot fishing (seabed) and drift netting (surface). These vessels range from a few tons to around 15 tons, and work from 6 to 9 months of the year. As well as Irish vessels, there are occasionally vessels originating from Scotland, Norway, Spain and France.

There is a 12-mile limit preventing the larger offshore fishing vessels from entering the nearshore areas to fish for certain species, namely mackerel and herring.


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There are no major ferry ports or any major shipping channels in the study area (Dames and Moore, 1996). Boelens et al. (1999) support this view and it can be seen in Figure 15.1 that all the major shipping activity on the west coast of Ireland is concentrated south of Galway or north of Sligo, thus excluding the Corrib Field area.

Figure 15.1: Important shipping ports around the coast of Ireland showing total cargo handled (millions of tonnes per year) in 1995 (Boelens et al., 1999)

15.3.3.2 Existing Road Network Inventory

As shown in Figure 15.2, the proposed landfall at Dooncarton is located some 2.0 km north of Pollatomish Village and 4.3 km north of Inver Village. Three possible routes can connect the R314 to Pollatomish.

The L243 extends from the crossroads at Barnatra through Inver to Pollatomish and reconnects with the R314 at Bellagelly. The route has an average width of the 5.5 m, with the narrowest section approximately 4.5 m wide. The road pavement is in good condition, however, some additional improvements and local widening would be desirable. It was noted that the route caters for a significant amount of heavy vehicle movements


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particularly in relation to peat extraction and tree felling operations. Varying horizontal and vertical alignments reduce the safe passing distances, and at a number of locations, vehicles are required to pull onto the soft margin to allow on-coming traffic to pass. The route is fronted by a significant number of houses particularly between Inver and Pollatomish.

The L1203 runs between Glenamoy and Portacloy. The route has an average width of approximately 6 m and is single carriageway over its full length. Agricultural lands, used primarily for peat extraction purposes, front the route with very few houses. The carriageway is in reasonable condition. However, local pavement improvements would be desirable at some locations.

The L5245 connects the L1203 to Glenamoy to Rossport. This is a 5 m single carriageway route which terminates at the slipway in Rossport. The route is fronted by a significant amount of housing and becomes narrower towards Rossport Village.

The above routes are shown in Figure 15.2.

Figure 15.2: Study area road network

15.3.4 Characteristics of the Proposed Development

15.3.4.1 Drilling

Drilling activities will take place from a drilling rig which is serviced by supply vessels which provide bulk supplies. Helicopters will provide crew changes and any emergency equipment and components.


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15.3.4.2 Field Facilities

These will all be situated on the seabed at approximately 350 m depth. There will, therefore, be no impact upon fishing vessel movements, however, there will be seabed exclusion zones covering the central field facilities and satellite wellheads (approximately 3 km2 in total). No fishing will be allowed over these areas of seabed.

15.3.4.3 Pipeline and Umbilical and Discharge pipeline

The pipeline, umbilical conduit (from landfall to approximately 1000 m from shore) and outfall line will be laid using a dynamically positioned (DP) laybarge. The outfall line will be attached to the gas pipeline to the discharge point, and installed by the pipelay vessel. The umbilical will be laid from the end of the conduit in Broadhaven Bay, to the Corrib Field by an umbilical lay vessel. The operation will be assisted by various support and supply vessels and helicopters.


Potential road impacts arising during the course of this construction phase, will result from the construction related traffic, i.e. the movement of plant, labour and materials, and any abnormal loads which may need to be brought to the construction site. The majority of this machinery and personnel will arrive by road.

15.3.5 Potential Impact of the Proposed Development

15.3.5.1 Offshore

In order to construct the offshore section of the pipeline, i.e. from the Corrib Field to Broadhaven Bay, a specialist pipelay vessel will be required. This vessel will measure 300 m x 40 m with a draught of 14 m and a displacement of 77,000 tonnes. All operations associated with the construction of the pipeline will be undertaken from this vessel, which will be supported by a number of smaller vessels supplying pipe lengths and other materials.

The umbilical lay vessel and the umbilical trenching vessel will be used in May/June 2003 to lay and bury the umbilical out to the Corrib Field.

The potential impacts from this activity on existing traffic are not seen as being significant.

15.3.5.2 Nearshore

Following the detailed identification of the proposed pipeline route, it is proposed to commence construction in March 2002. The seagoing equipment to be utilised during this stage of construction will include a self-elevating


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platform, backhoe dredger with support vessels and a split hopper barge, which will remain in the bay from March to June 2002. The dredger and platform will remain in the bay until September 2002, although at times they will be on stand-by and may seek anchor or mooring locally. All these vessels will occasionally use up to four anchors in a holding pattern to hold position. It is not possible to schedule these movements, as they will be ad-hoc and dictated by the weather. The crews may use local people and vessels for ferrying people and small equipment from Ballyglass, which is accessible at all states of the tide and has a davit. Rossport, opposite the landfall, could also be used. A number of additional small support vessels may also be required.

There will be a minor impact on the local marine community from this work, but it will be of short duration. There could be a positive impact, in that local vessels will, where possible, be used to assist with the work.

During construction of the pipeline through Broadhaven Bay there is a possibility that small craft (RIBs) could strike marine mammals and cause physical damage when moving at high speeds.

Most sections of the pipeline to be installed will be stored at a western port such as Killybegs. Due to the large number of pipe sections required, approximately one third will be shipped directly to the pipelaying vessel. The balance will be brought to the port by sea, involving about 6 pipe-carrier movements, and stored in the port area or possibly on barges in the port. This will avoid road traffic movements in the port. The sections will then be shipped directly to the pipelaying vessel by barge as required. It is expected that there will be 25 barge movements between the port and the pipelaying vessel.

There will, therefore, be both positive impacts from the increased activity on the local marine community around the port where the pipe sections are stored, and some negative impacts arising from the disruption during this activity.


In the following sections the traffic generated during the construction of the landfall and Sruwaddacon crossings are discussed.

Plant

From experience on projects of a similar nature, it is estimated that the following equipment will be used for the construction of the landfall, Sruwaddacon crossings and the pipeline in general:

• CPM 600 (250 t) linear winches (x 2);

• CPM 225 (100 t) linear winch (x 1);

• 10 t winches (x 2);


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• nominal 15 t excavators (x 2);



• Cat 572 sidebooms (x 4);

• 20Te dump trucks (x 4);

• JCB 3 (x 1);

• forklift (x 1);

• pipe bevelling machine (x 1);

• pipe bending machine (x 1);

• weld sets (x 12);

• nominal 15 t dozers (x 3);

• Hiab truck (x 1);

• crawler loader (x 1); and

• 2-7 t dumpers (x 6).

Once these machines are brought to the construction site, they will remain within the working width at all times. This will minimise their impact on the surrounding road network.

Labour

In order to construct the pipeline, it is estimated that the maximum number of construction workers at any period throughout the work programme will be 140 persons. This number of workers is likely to generate up to 70 car trips to the site. However, in order to reduce this number of vehicles in the study area, it is recommended in the Traffic Management Plan that a minibus service be provided to ferry the construction workers to and from the construction site.

Abnormal Loads

In the event of abnormal loads, several options exist for their transportation to site. The largest piece of equipment to be delivered will be two 250 tonne capacity winches, which will be used for the landfall pipe pull. It is unlikely that these winches, which weigh up to 30 tonnes, could be transported to the site safely by road, without having a significant impact on the surrounding road network. If road delivery of the winches is not feasible, consideration will be given to delivery by sea.

Onshore Pipeline

In respect of the 8 km of onshore pipeline, the pipe sections will most likely be transported by road from Killybegs to the area over a six month period. It is not expected that there will be a significant impact from these movements.

15.3.6 Do-Nothing Scenario

If the development did not proceed, local road and sea traffic movements would remain unchanged.


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15.3.7 Mitigation Measures

15.3.7.1 Offshore and Nearshore

Enterprise employs a Fisheries Liaison Officer as a contact point between the company and the fisheries interests. The officer is responsible for communicating the construction schedule to the relevant fisheries and maritime organisations throughout the period of the development, in order to enable their members to plan their activities accordingly.

This liaison will also allow the Department of the Marine and Natural Resources to issue appropriate notices, in order that commercial traffic are properly informed of the offshore activities associated with the development.

To minimise the risk of small, fast moving craft colliding with other marine users (including marine mammals) in Broadhaven Bay, the operators will be required to use the minimum safe speed when carrying out operations.


Whilst it is clear from the above assessment that the road network and proposed construction routes can cater for the overall traffic generated by the scheme, Enterprise are anxious to minimise the overall affect on the residents and general environment within the study area. With this in mind, Enterprise will implement a Traffic Management Plan, to actively control the number of vehicles arriving/departing from the development and the time at which they occur, particularly during the construction phase of the project.

The key mitigation measures to be implemented as part of the Traffic Management Plan are listed below:

• delays to school buses and peak hour traffic will be avoided by scheduling all trips to the site by site-operatives before 08:00 hrs;

• consideration will be given to the provision of a minibus service to bring site operatives to and from the construction site. This will have the effect of minimising the traffic impact of the proposed development. The minibuses would collect the operatives from their accommodation in the morning before 08:00 hrs and return them in the evening after 18:00 hrs;

• the bulk of deliveries, both plant and materials to the construction site, whenever possible, will be restricted to between 09:30 hrs and 14:30 hrs;

• all signage relating to the proposed construction routes for construction traffic will be positioned clearly and designed to the satisfaction of Mayo County Council. Drivers of vehicles failing to observe the signed routes will initially be given a warning and thereafter be banned from the site; and

• a commitment to reinstate the proposed haul routes following completion of the construction phase, in agreement with Mayo County Council. It is proposed that a pre- and post- construction survey of the routes be


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undertaken and that they be reinstated to their original condition.

Recommended Routes to Construction Sites It is recommended that where possible, construction traffic should be removed from the public road network, by using temporary access roads. As part of the construction methodology detailed earlier in this document, a 40 m working width will be established along the finalised pipeline route. It is proposed that this working width will be used by all construction related traffic, where possible, in order to reduce the impacts of traffic on the surrounding road network.

Where traffic cannot access the crossing points via the working width, the following routes are recommended:

• for traffic destined for the northern side of Sruwaddacon Bay, R314 to Glenamoy; L1203 over Annie Brady Bridge to the L5245; L5245 to the L2451; and thence turn right to the site using the working width; and

• for traffic destined for the Landfall at Dooncarton, site access road to the L243; thence to the temporary access road to the construction site.

These routes are presented in Figure 15.3. A road network assessment has shown that the road network has sufficient capacity to cater for all additional traffic generated by the construction of the proposed pipeline, as the traffic volumes predicted and the low base traffic flows are such that junction capacities will not be exceeded.

Construction Methodology

The impact of the construction on the study area road network will be minimised as a result of the designers’ and contractors’ commitment to reducing the number of movements on the public road network.

For all abnormal loads, Enterprise propose to adopt the policy of delivering the load to site either by sea, or, as a number of smaller units, by road. In the event that remedial measures to the study area road network be required for the movement of abnormal loads, they will be carried out following discussions with Mayo County Council.

In order to reduce the number of movements made during the construction phase of the project, all materials excavated on site will be stored within the working width adjacent to the landfall and Sruwaddacon crossings and where possible, used to backfill the trench at a later date. Therefore, this element of the construction process will not have a significant negative impact on the study area road network by movements involving excavated material.


RSK/H/P/P8069/03/04/01rev01 15-19

Figure 15.3: Recommended routes to construction sites

15.3.8 Predicted Impact of the Proposed Development

15.3.8.1 Offshore

Through ongoing consultation with national organisations, the presence of offshore drilling and installation vessels and associated supply vessels is not predicted to interfere with the fishing industry on the continental shelf adjacent to the Corrib Field. The impact on existing offshore activities is expected to be negligible.

15.3.8.2 Nearshore

The presence of pipelaying vessels and their associated support vessels in Broadhaven Bay will have a short-term impact to the nearshore fishing activities. However, fisheries liaison personnel will be in regular contact with the local fishing groups to inform them of the times of particular operations, in order that they can plan their activities accordingly.

The potential for vessels to strike any marine mammals in the vicinity cannot be eliminated, but, by using the minimum safe vessel speed to carry out operations, it is unlikely that any physical damage to marine mammals will occur.

The impact on existing nearshore activities is expected to be moderate during construction and then negligible during the lifetime of the project.


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The largest impact on the study area road network will arise as a result of the number of trips made by site operatives during the construction phase of the Landfall and Sruwaddacon crossings. However, it has been shown that the proposed study area road network can adequately cater for the volumes of traffic generated in the worst-case scenario. It has also been shown, on the basis of well-founded assumptions, that the impact of heavy goods vehicles on the road network will be minimal, in terms of reserve capacity and queue lengths. It is likely that the main impact will be in relation to pavement maintenance.

15.3.9 Monitoring

Enterprise will ensure that their main contractor and all sub-contracting firms involved in the project adhere to the Traffic Management Plan. Enterprise also propose to monitor the route used by heavy vehicles, as well as the loads they are carrying.

15.3.10 Reinstatement and Residual Effects

It is anticipated that any repair works carried out to the main transport routes, in agreement with Mayo County Council, will result in a better road surface following the construction period than before. In addition, Enterprise is committed to reinstating the pavement, as required, after construction is completed.

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