trt report alfreton brook outfall safari final

Outfall Safari An audit of the surface water outfalls in the urban parts of the Alfreton Brook and Oakerthorpe Brook Catchments, Derbyshire

February 2018

TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 2

Revision History

Revision Ref / Date Issued Amendments Issued to Draft v1.0 N/A Trent Rivers Trust

Draft v 1.1 9.1.2018 Partners STW, EA for comment

Final Draft v2 19.2.2018 Julie Wozniczka Partners STW, EA for final comment

Final 26.2.2018 Julie Wozniczka

Acknowledgements

This project, funded by The Esmee Fairbairn Foundation, and part of The River Starts Here!

project, has been delivered by Trent Rivers Trust (TRT), in partnership with Severn Trent

Water (STW) and the Environment Agency (EA). It would not have been possible without the

help of all the dedicated volunteers who collected the data and Alan Graham’s input for TRT.

Special thanks go to Michelle Walker at The Rivers Trust for her invaluable technical support

and to Joe Pecorelli of the Zoological Society of London, who first developed the Outfall Safari

methodology and generously shared his time and methods to help us adapt the survey for the

Alfreton Brook.

The ongoing input and interest from Chris Mulligan and Zara Turtle at Severn Trent and Paul

Reeves and Mark Cunningham at the Environment Agency has been instrumental to the

success of this project. We look forward to continued partnership working to improve the water

quality in these important tributaries of the River Derwent.

Julie Wozniczka

Senior Project Manager

Trent Rivers Trust


Contents

1 Executive Summary.................................................................................................... 4

2 Introduction ................................................................................................................ 4

3 Aims ........................................................................................................................... 6

4 Method ....................................................................................................................... 6

5 The App...................................................................................................................... 7

5.a Conversion of outfall assessment to impact scores ............................................. 8

5.b Reporting and thresholds .................................................................................... 9

5.c Data Processing .................................................................................................. 9

6 Results ....................................................................................................................... 9

7 Volunteer feedback .................................................................................................. 23

8 Discussion ................................................................................................................ 25

9 Future Surveys ......................................................................................................... 26

10 Conclusions .......................................................................................................... 26

11 Contact details ...................................................................................................... 27

12 References ........................................................................................................... 27

13 Appendix – River Friendly Business Awards ......................................................... 27


1 Executive Summary

Alfreton Brook (also known as Normanton Brook and Nunn Brook) is one of the most polluted

tributaries of the River Derwent, affecting water quality downstream. Detailed monitoring has

identified diffuse urban pollution as a key cause. Eight volunteers and two staff surveyed the

urban 22km of the watercourses using a semi-quantitative method recorded on a bespoke

App. 101 outfalls were recorded, of which 28 showed signs of pollution. In this report the

results are mapped and the polluted outfalls presented in a table with photographs, grid

reference and outfall score.

The method was agreed and the survey carried out in close collaboration with the Environment

Agency and Severn Trent Water so that the data can help to inform their plans to reduce

pollution of these brooks.

2 Introduction

Misconnected wastewater pipework, cross-connected sewers and combined sewer overflows

are a chronic source of pollution in urban rivers, sending pollution, via outfalls, into the nearest

watercourse. At the moment there is no systematic surveying of outfalls in rivers to identify

sources of pollution and to notify the relevant authorities. The Outfall Safari is a survey method

devised to address this evidence gathering and reporting gap. It was created by the Citizen

Crane project steering group which consists of staff of Thames Water, Environment Agency

(EA), Crane Valley Partnership, Friends of River Crane Environment, Frog Environmental and

the Zoological Society of London (ZSL). It was first used on the River Crane in 2016.

Alfreton Brook (also known as Nunn Brook and Normanton Brook) is a tributary of the River

Amber, which, in turn, flows in to the Derbyshire Derwent and the River Trent. It is impacted

by coal mining, many industrial estates, the M1 and A38 and several towns and villages. It

brings polluted water to the River Amber, whose water quality is poorer downstream. In terms

of the Water Framework Directive (WFD), it fails to reach Good Ecological Status or Potential

for fish (Moderate), invertebrates (meaning insects etc. - Moderate), macrophytes (meaning

aquatic plants etc - Poor). Chemically it fails for Dissolved Oxygen (Moderate) and

Phosphorous (Poor) which can be linked to pollution from misconnections and sewers.

The Trent Rivers Trust and Environment Agency (EA) have conducted detailed monitoring of

water quality for over 3 months at 9 points along Alfreton Brook (Environment Agency, 2018,

Draft). This has shown that the main pollution sources appear to be along Alfreton Brook itself

and not its tributaries, which include Westwood Brook. As well as some major point sources


of pollution, there is a background level of pollution that is likely to be related to the sewerage

system and misconnections.

Severn Trent Water is conducting detailed investigations, using modelling and sondes and

has supported the Outfall Safari as a potentially valuable additional source of data.

The much smaller Oakerthorpe Brook faces similar issues. It also flows to the Amber south,

and although it less monitored as for WFD purposes it forms part of the River Amber water

body.

The Trent Rivers Trust has been working on a project called ‘The River Starts Here!’ since

2015 bringing together businesses, communities and other organisations to make these

brooks cleaner, more enjoyable and richer in wildlife.

fig 1. Map of the Derbyshire Derwent catchment showing Alfreton and Oakerthorpe Brook catchments.

By working in the headwaters we hope to be

able to make a tangible impact on the water

quality in these tributaries, which are just as

much a source of the River Derwent as are

the clean reservoirs of the Peak District. By

doing this we aim to contribute to improving

the water quality of the River Derwent and

Trent. The project is illustrated below.

‘The River Starts Here!’ is supported by the

Derbyshire Derwent Catchment Partnership,

comprising some 40 partners including STW,

EA and TRT.

Fig 2. ‘The River Starts Here! project area


3 Aims

The aims of the Alfreton Brook Outfall Safari were to:

record and map the dry weather condition behaviour of surface water outfalls in the urban

parts of Alfreton Brook and tributaries and Oakerthorpe Brook.

assess the impact of the outfalls and report those that are polluting to the Environment

Agency and Severn Trent Water

build evidence on the scale of the problem of polluted surface water outfalls in the wider

area

recruit more volunteers and further engage existing volunteers in the work of the Trent

Rivers Trust and The River Starts Here! project.

4 Method

The survey of outfalls was conducted between the 9th October and 6th December 2017. Eleven

people took part in the Outfall Safari, comprising nine volunteers and two members of TRT

staff. Volunteers were trained at the Hilcote Community Centre on 4th October 2017. Training,

which was given by TRT and STW included:


an overview of water quality issues in the Alfreton Brook catchment

information on outfalls and how they become polluted

instruction on how to assess each outfall using the project App and how to upload

information to the database

a health & safety briefing and signing of the risk assessment

During the training, groups of volunteers were assigned lengths of brook to survey. Further

coordination of survey dates and reaches was conducted by the volunteer group on a closed

Facebook group set up specifically for the Outfall Safari. Groups of volunteers were free to

conduct the survey of their reach when convenient to them, within the survey period, provided

there had been no rain for 48 hours prior to survey.

A period of 48 hours of no rain is required before any survey work as rainfall and high surface

water flows can obscure the negative impacts of outfalls by washing away sewage fungus,

discoloured sediments and rag. In addition, many Severn Trent Water outfalls should only

convey rain water. Therefore, any flow in dry weather conditions, no matter how small, was of

concern to STW.

The survey work was conducted from the riverside path or banks. The risk assessment for

riverside outfall surveying highlighted that volunteers should not enter the river channel to

undertake the survey. In addition to personal protective equipment (PPE) volunteers took a

printed handout, designed to help with ranking the impacts of each outfall, a smart phone or

tablet loaded with a specially created data entry App and printed maps showing known surface

water outfalls and Combined Sewage Overflows.

5 The App

For ease of data collection from the river, the volunteers used an app created in Epicollect5

(https://five.epicollect.net ). Created by researchers at Imperial College, Epicollect is free and

openly available. Once a project is set up in Epicollect5 it provides an app for remote data

collection and upload, usable on GPS enabled smart phones, and a web portal to access and

download the data. The outfall assessment form created in the app consisted of eleven

questions for volunteers to fill in at each outfall. The questions were taken from the form that

ZSL developed for the River Crane, adapted in consultation with Severn Trent Water and the

Environment Agency, and are shown in Table 1.


Table 1 – Questions used in the Epicollect App to assess each outfall and their corresponding Impact Score

Question Options score

1. Volunteer name

2. Date of survey

3. GPS location

4. Photo of the outfall

5. Description of the nearest landmark

6. Which bank is the outfall on (when looking downstream)

7. Ranking of the discharge coming out of the outfall

a. No Flow

b. Trickle

c. Low Flow

d. Moderate Flow

e. High Flow

8. Ranking of the visual impact of the outfall

a. No visible effect 0

b. Within 2m of outfall 2

c. Impact 2 to 10m 4

d. Impact 10 to 30m 6

e. Impact greater than 30m 10

9. Ranking of the aesthetics of the outfall

a. No odour or visible aesthetics 0

b. Faint smell, slight discolouration 2

c. Mild smell, mild discolouration, small coverage of sewage fungus

4

d. Strong smell, strong discolouration, large coverage of sewage fungus and/ or litter

6

e. Gross smell, gross sewage 10

10. Is there any sewage related debris visible? Y/N

11. Other signs of pollution free text N/A

5.a Conversion of outfall assessment to impact scores

To assist with prioritisation of the outfalls, the Environment Agency in London had provided a

method of converting the assessment data to a numeric impact score for each outfall. This

was adopted for this study after consultation with the addition of a presence/absence question


for sewage related debris. These scores are shown in the right hand column in Table 1. The

scores for questions 8 and 9 were added to give an Impact Score.

5.b Reporting and thresholds

Any outfall with an Impact Score ≥ 10 was reported directly from the river to the Environment

Agency’s Incident Hotline and Severn Trent Water. Those scoring 0 are shown with a green

flag, 1 to 9 as amber and 10 or over as red. These thresholds were decided jointly with STW,

and it was very positive that STW were keen to know about all polluting outfalls scoring over

0. STW were also keen to know if any sewage related debris was present, and this is shown

on the same maps on a presence or absence basis.

Further analysis is provided in the Discussion section.

5.c Data Processing

Outfall data were checked to remove double entries and mapped using ArcGIS Desktop in the

maps below.

6 Results

The volunteers photographed, located and assessed a total of 101 outfalls. Of this total 28

showed some signs of pollution and scored ˃ 0 and of these 7 were significantly polluting with

a score ≥ 6. The locations of these outfalls are shown in Maps 1 to 8. The details of the outfalls

with an impact score of > 0 are given in Table 2 and their numbers are shown on the yellow

or red flags in the maps below.

The full 2017 Alfreton Brook Outfall Safari dataset is available from Trent Rivers Trust.

Figure 3

Contains Environment Agency information

© Environment Agency and/or database

right. Contains Ordnance Survey data ©

Crown copyright and database right 2017


Figure 4

Contains Environment Agency information © Environment Agency and/or database

right. Contains Ordnance Survey data © Crown copyright and database right 2017


Figure 5




Figure 6




Figure 7

Contains Environment Agency information © Environment Agency

and/or database right. Contains Ordnance Survey data © Crown

copyright and database right 2017


Figure 8




Figure 9



Outfalls inaccessible due to building work


Figure 10




Figure 11



Table 2 Details and photos of outfalls shown in figures 1 to 9. Only outfalls with an impact score of > 0 are included in the table

ID Location NGR Bank Outfall Score Photo

4 David Nieper school Alfreton SK4130455170 Right 4

7 David Nieper school Alfreton SK4132655196 Left 4 Not recorded

11 Thurston Way SK4420158968 Right 4

27 U/s Ball Hill Rd SK4488756768 Right 4

30 Outfall below sports pitches SK4478856660 Left 12


33 Source of stream. Bridge. Henry crescent

SK4224255375 Left 2

34 Ds Hilcote road bridge SK4502357742 Right 6

37 Hilcote Miners Welfare SK4527757788 Right 4

38 Henry Crescent off Flowery Lees Lane Alfreton

SK4221555440 Left 4

39

Parallel to bollard in footpath next to water treatment works SK44975747

SK449574 Right 6 Not recorded

47 Industrial estate SK4210956459 Left 4


48 Industrial estate SK4194256552 Right 2

53 B6025 SK4135156911 Left 2

55 B6025 SK4132456899 Left 6

56 B6025 bridge to sewage works ind estate

SK4123756859 Left 2

57 Blue coloured factory, pylon SK4614258435 Left 2

59 Railway SK4209256748 Left 10


62 Railway viaduct SK4238157375 Right

4

64 Non SK4295357640 Right 2

77 Behind Hilcote Community Centre


86 Opposite wind turbine near Blackwell lane

SK4608458538 Left 4

87

Down stream from wind turbine between Blackwell lane and Blackwell trail

SK4612958428 Left 4

91 Home foods Brookside Way. SK4654058107 Right 6


93

West of Severn Trent treatment works Common Road.

SK4687758175 Right

2

94 Bottom of Common Road west side.

SK4687758175 Left 2

96

Opposite entrance to South Normanton Sewage Treatment Works


98

Manhole near footpath across from bridge 30m


101 HELP footbridge SK4573557777 Left 4

7 Volunteer feedback

The volunteers were asked to give feedback on:

What went well? What could be improved? Any advice for next time? Any other comments?


Four volunteers and one staff member gave feedback. All enjoyed the experience and felt the

training was good. The handout was found to be useful, and ‘contributing to an important

project’ was motivating.

Needing to have 48 hours without rain meant that volunteers had to rearrange and be very

flexible. The Outfall Safari would not suit volunteers who prefer a regular activity, but attracted

people who did not want a regular commitment and preferred a ‘task anad fiinish’ project.

Facebook did not suit everyone, and Whatsapp is worth considering in future. Having two

methods of communication (plus email) seems unavoidable. GHelp with map reading wold

have been useful for some volunteers, and integrating STW maps showing outfalls with OS

maps wold be helpful. Now that TRT has the GIS layers for the STW maps this should be

possible in future.

A ‘covering letter’ for volunteers to explain to people what they were doing was suggested. A

final ‘mop-up’ of outfalls on private land with the Environment Agency would be helpful in

completing the dataset. There were difficulties in seeing the brooks through vegetation,

despite the safari taking place in October to December. Spring may be the optimum time.

Feedback from the volunteers about the app was that it was mostly easy to use, but there

were some issues with uploading data and photos. Some found that the GPS positional

accuracy improved if the position was taken twice. Future improvements to the questions

could include a third option for bankside as many outfalls were emerging from underground,

and it was also suggested that discolouration and odour are separated in the questions. In

hindsight it wold have been better for all photos to be landscape.

All of those who replied said they would take part in future Outfall Safaris and volunteering

activities for the Trent Rivers Trust.

A feedback session was held for volunteers, with input from TRT, STW, EA and Coal Authority.

This was also a good way of engaging partner organisations in the finding.

I would love to do this again. I

thoroughly enjoyed it would


thoroughly enjoyed it.


thoroughly enjoyed it would

It was a good adventure and

felt worthwhile


8 Discussion

This report represents an audit of how outfalls within the surveyed areas of the Alfreton Brook

and Oakerthorpe Brook catchments were behaving during the survey. However, some outfalls

pollute intermittently and may not have been detected as a problem during the survey.

In total there are 58 km of river in the Alfreton Brook and Oakerthorpe Brook Catchments. This

Outfall Safari surveyed 22km or 38% of this length comprising the urban sections and those

impacted by urban areas. 27 of the 101 outfalls were recorded as having a detrimental impact.

20 were recorded with impact scores of 2-4, 4 with scores of 6-9 (34,39,55,91) and 3 with

scores of ≥ 10 (30, 59 and 96). These were reported to STW, followed up and feedback given.

Figure 12

5 of the outfalls appear, from the photographs, to have ochrous (containing iron oxide)

discharges (27,34,37,59 and 64). Of these 3 (34,37 and 64) are not mapped as STW assets.

Not all of the outfalls with impact scores appear to be associated with Severn Trent Water

assets.

Some outfalls marked as ‘green’ have previously been seen to be polluting. We will monitor

them occasionally and report if polluted.

Not all of the outfalls were accessible. For example several on Map 6 could not be accessed

as it was a building site.

Impact Scores

0 1 to 5 6 to 9 10 or more


9 Future Surveys

Applying a method developed by ZSL for London rivers was a very useful time-saver, as many

of the elements of the London surveys could be replicated for the Alfreton Brook, and we are

very grateful to Joe Pecorelli for all his technical support and guidance in setting up the project.

Rivers Trusts and Catchment-Based Approach partnerships wishing to replicate the

methodology can contact Michelle Walker at The Rivers Trust ([email protected])

for template databases and guidance on setting up the app and GIS database for other

catchments. It is critical to undertake such outfall surveys in consultation with the water

company and EA, in order to design the form to suit local requirements and to agree threshold

scoring. It is hard to make changes to the app once the survey has commenced, so be sure

to agree this with all stakeholders before starting the survey.

10 Conclusions

The Outfall Safari has provided an inventory, with photographs, impact scores and locations

of 101 outfalls, of which over 25% were bringing some pollution to the water courses at the

time of the survey. It has engaged volunteers with this issue and they would be willing and

able to identify and report pollution incidents in future. It has also enhanced working

relationships between TRT and STW, providing a tangible and useful focus which engaged

both operational and strategic staff, as well as consultants carrying out detailed modelling on

their behalf.

The dataset has been shared with STW and EA, and also with the Coal Authority and

researchers at Nottingham Trent and Nottingham University. Feedback from consultants

working for STW and from researchers is that the dataset is a useful resource to complement

their studies.

STW followed up the three ‘red’ outfalls that were reported. The Trent Rivers Trust and

Derwent Catchment Partnership are keen to ensure that all sources of pollution are traced and

dealt with, to improve water quality locally and within the wider Derwent and Trent catchment.

We understand that prioritisation is necessary, and we hope that this study will help to prioritise

activities. We request a response from STW and EA to our findings in relation to all of

the ‘Amber’ and ‘Red’ outfalls.


11 Contact details

Julie Wozniczka (Project Manager), Trent Rivers Trust [email protected]

Michelle Walker (Data and Mapping), The Rivers Trust [email protected]

12 References

Environment Agency, 2018 (draft). WFD Water Quality Investigation: Alfreton Brook,

Derbyshire Analysis & Reporting Team, East Midlands Area

13 Appendix – River Friendly Business Awards

TRT has launched ‘River Friendly Business’ Awards to encourage businesses in the Outfall

Safari area to allow ‘Only Rain Down the Drain’. It has been publicised to over 200 businesses.

trt report alfreton brook outfall safari final

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