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

Transcription

1 Outfall Safari An audit of the surface water outfalls in the urban parts of the Alfreton Brook and Oakerthorpe Brook Catchments, Derbyshire February 2018

2 Revision History Revision Ref / Date Issued Amendments Issued to Draft v1.0 N/A Trent Rivers Trust Draft v Partners STW, EA for comment Final Draft v Julie Wozniczka Partners STW, EA for final comment Final 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 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 2

3 Contents 1 Executive Summary Introduction Aims Method The App a Conversion of outfall assessment to impact scores b Reporting and thresholds c Data Processing Results Volunteer feedback Discussion Future Surveys Conclusions Contact details References Appendix River Friendly Business Awards TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 3

4 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 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 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 4

5 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 2. The River Starts Here! project area 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. TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 5

6 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 9 th October and 6 th December 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 4 th October Training, which was given by TRT and STW included: TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 6

7 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 ( ). 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. TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 7

8 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 9. Ranking of the aesthetics 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 a. No odour or visible aesthetics 0 b. Faint smell, slight discolouration 2 c. Mild smell, mild discolouration, small coverage 4 of sewage fungus d. Strong smell, strong discolouration, large 6 coverage of sewage fungus and/ or litter e. Gross smell, gross sewage 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 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 8

9 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. TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 9

10 Figure 3 Contains Environment Agency information Environment Agency and/or database right. Contains Ordnance Survey data Crown copyright and database right 2017

11 Figure 4 Contains Environment Agency information Environment Agency and/or database right. Contains Ordnance Survey data Crown copyright and database right 2017 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 11

12 Figure 5 Contains Environment Agency information Environment Agency and/or database right. Contains Ordnance Survey data Crown copyright and database right 2017 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 12

13 Figure 6 Contains Environment Agency information Environment Agency and/or database right. Contains Ordnance Survey data Crown copyright and database right 2017 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 13

14 Figure 7 Contains Environment Agency information Environment Agency and/or database right. Contains Ordnance Survey data Crown copyright and database right 2017 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 14

15 Figure 8 Contains Environment Agency information Environment Agency and/or database right. Contains Ordnance Survey data Crown copyright and database right 2017 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 15

16 Figure 9 Outfalls inaccessible due to building work Contains Environment Agency information Environment Agency and/or database right. Contains Ordnance Survey data Crown copyright and database right 2017 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 16

17 Figure 10 Contains Environment Agency information Environment Agency and/or database right. Contains Ordnance Survey data Crown copyright and database right 2017 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 17

18 Figure 11 Contains Environment Agency information Environment Agency and/or database right. Contains Ordnance Survey data Crown copyright and database right 2017 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 18

19 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 SK Right 4 7 David Nieper school Alfreton SK Left 4 Not recorded 11 Thurston Way SK Right 4 27 U/s Ball Hill Rd SK Right 4 30 Outfall below sports pitches SK Left 12

20 33 Source of stream. Bridge. Henry crescent SK Left 2 34 Ds Hilcote road bridge SK Right 6 37 Hilcote Miners Welfare SK Right 4 38 Henry Crescent off Flowery Lees Lane Alfreton SK Left 4 39 Parallel to bollard in footpath next to water treatment works SK SK Right 6 Not recorded 47 Industrial estate SK Left 4 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 20

21 48 Industrial estate SK Right 2 53 B6025 SK Left 2 55 B6025 SK Left 6 56 B6025 bridge to sewage works ind estate SK Left 2 57 Blue coloured factory, pylon SK Left 2 59 Railway SK Left 10 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 21

22 4 62 Railway viaduct SK Right 64 Non SK Right 2 77 Behind Hilcote Community Centre SK Right 2 Not recorded 86 Opposite wind turbine near Blackwell lane SK Left 4 87 Down stream from wind turbine between Blackwell lane and Blackwell trail SK Left 4 91 Home foods Brookside Way. SK Right 6 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 22

23 2 93 West of Severn Trent treatment works Common Road. SK Right 94 Bottom of Common Road west side. SK Left 2 96 Opposite entrance to South Normanton Sewage Treatment Works SK Right 12 Not recorded 98 Manhole near footpath across from bridge 30m SK Right 4 Not recorded 101 HELP footbridge SK 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? TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 23

24 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 ) 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. I I would love to do this again. I thoroughly enjoyed enjoyed it would it. I would It was a love good to do adventure this again. and I thoroughly felt enjoyed worthwhile it would 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. TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 24

25 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 Impact Scores 0 1 to 5 6 to 9 10 or more 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. TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 25

26 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 (michelle@theriverstrust.org) 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. TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 26

27 11 Contact details Julie Wozniczka (Project Manager), Trent Rivers Trust Michelle Walker (Data and Mapping), The Rivers Trust 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. TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 27

28 TRENT RIVERS TRUST ALFRETON BROOK OUTFALL SAFARI 28