Consultation outcome

Summary of responses and government response

Updated 14 September 2023

Introduction

In the Environment Act 2021 (“the Act”) government introduced a requirement for sewerage undertakers to monitor sewerage assets and the impact they have on their local environment. The Act also requires sewerage undertakers to publish data from event duration monitors (EDMs) in near real time. The two duties in the Act place a renewed focus on monitoring the receiving waters and increasing public transparency of those impacts.

This consultation on continuous water quality monitoring and event duration monitoring outlines the government’s proposals to enhance the monitoring of storm overflow and final effluent discharges. This is in addition to the current monitoring programme where 91% of storm overflows are monitored by EDMs. We will reach 100% cover by the end of this year.

This summary is a high-level overview of the main themes from the consultation responses.

Summary

83 consultees were invited to take part in the consultation. This was a variety of organisations including relevant academics, industry representatives, environmental non-governmental organisations and companies that produce supply chain monitoring technologies. 40 organisations responded to the consultation.

Each question below highlights whether respondents answered ‘Yes’, ‘Yes with conditions’, ‘No’, or ‘Unclear’. ‘Unclear’ means an answer was provided that was not clearly supportive or unsupportive of the specific proposal in the question.

Part 1: Event duration monitoring

Question 1: Are you content to allow for equipment failure, so long as sewerage undertakers are required to take all reasonable steps to address any failures as soon as possible?

33 respondents answered this question:

• 94% of respondents either answered ‘Yes’ (15%) or ‘Yes with conditions’ (79%)
• 6% answered ‘No’

Themes

94% of respondents agreed there should be allowances for equipment failure. The reasons provided included power failure and natural problems that arise from operating in challenging environments. 52% of respondents highlighted that sewerage undertakers perform appropriate monitoring and maintenance of equipment so that any faulty equipment can be addressed promptly. 36% of respondents requested further clarification on the proposed regulations, including what constitutes “reasonable steps” and the time limit to address the failure by.

Government response

Government would like all equipment to be constantly operating. In reality, government agrees that there will be instances where equipment will fail, but believes these issues should be rectified as soon as possible. However, sewerage undertakers should target 100% performance of their monitoring and reporting. We do not feel that government can specify how long is a reasonable amount of downtime, as this will depend on the specific circumstances of a failure.

Question 2: Are you content near real-time event duration monitor reporting will apply everywhere it is technically feasible?

32 respondents answered this question:

• 85% of respondents either answered ‘Yes’ (38%) or ‘Yes with conditions’ (47%)
• 6% answered ‘No’
• 9% of respondents provided unclear responses

Themes

31% of responses argued that there is a need to allow for exceptions in circumstances where real-time reporting is not practicably possible due to physical barriers to safe access. 22% of respondents asked for clarification of what constitutes “technically feasible”. 19% of respondents suggested that where the cost of installation might be unusually high, this could also fall within the exceptional circumstances.

Government response

Government understands that there will be areas where event duration monitoring reporting is not technically feasible. Government also cannot define every parameter of feasibility, and installation costs do not constitute an exceptional circumstance. However, water companies should continue to push for 100% EDM reporting. Ofwat will provide an incentive to companies reporting 100% of the time, as outlined in their most recent consultation: Updating the storm overflows performance commitment definition for the 2024 price review (PR24) – our decision

Part 2: Continuous water quality monitoring

Question 1: Should the objectives include any additional aims? Yes or No. If Yes, what additional objectives should be included?

33 respondents answered this question:

• 85% of respondents answered ‘Yes’ (3%) or ‘Yes with conditions’ (82%)
• 15% answered ‘No’

Themes

42% of respondents suggested that additional sources of pollution should be measured, including the impacts of farming and mining. 36% of responses highlighted the way the data that is collected in this programme is presented and its accessibility to the public.

Government response

The monitoring programme is targeted at sewage pollution. Where other sources of similar pollution are present, monitors will pick these up. Defra is leaving scope for innovation within this programme and will consider other pollutants in further water company investment cycles.

The technical guidance states that this data must be made publicly available in near real time (within one hour) and in a common format. This will help to meet the programme objective of increasing public understanding.

Question 2: Are UPM FIS the appropriate standards against which to benchmark the programme for storm overflow impacts? If not, why?

27 respondents answered this question:

• 52% of respondents answered either ‘Yes’ (15%), or ‘Yes with conditions’ (37%)
• 37% answered ‘No’
• 11% of respondents provided unclear responses

Themes

52% of responses highlighted that there would be limitations on the data collected if Urban Pollution Management Fundamental Intermittent standards (UPM FIS) were used to benchmark the programme against. This featured in both ‘Yes’ and ‘No’ answers. Responses stated that impacts from agriculture and other pollutant sources would not be captured within this standard. 37% of respondents suggested that the UPM FIS standard is reliant on data modelling and not appropriate for this programme.

Question 3: Are UPM FIS the appropriate standards against which to benchmark the programme for sewage treatment work final effluent discharge impacts? If not, why?

27 respondents answered this question:

• 26% of respondents answered either ‘Yes’ (7%), or ‘Yes with conditions’ (19%)
• 70% of respondents answered ’No’
• 4% of respondents provided unclear responses

Themes

59% of responses highlighted that the UPM FIS standards aren’t appropriate for continuous discharges. This was a view provided by all water companies who responded. The reasons cited were that UPM FIS standards are designed for intermittent and not continuous discharges and therefore should not be used as a standard for regulatory compliance.

Grouped government response to questions 2 and 3

UPM FIS provides a broad overview of river health with specific focus on river toxicology. It will provide an appropriate standard for storm overflow impacts, measuring key impacts such as levels of dissolved oxygen, temperature and pH values, turbidity and levels of ammonia.

One of the objectives set out in the technical guidance is that the monitoring undertaken should be linked to existing regulatory standards. UPM FIS is the most appropriate existing regulatory standard, and it is not feasible within the scope of this programme to design a new bespoke standard of water quality.

To confirm, UPM FIS will not be used for regulatory compliance from sewage treatment works. Where a cluster contains both continuous storm overflows and wastewater treatment works, UPM FIS will remain the standard to benchmark the programme against.

Question 4: Should Defra explore in future (when technically feasible) if and how nitrates can be monitored in freshwater sites? Yes or No. If Yes, why?

35 respondents answered this question:

• 77% answered either ‘Yes’ (60%) or ‘Yes with conditions’ (17%)
• 17% of respondents answered ‘No’
• 6% of respondents provided unclear responses

Themes

40% of responses expressed nitrate monitoring is needed to fully understand the impact of nitrates on the environment. 34% of responses argued that nitrate monitoring is already feasible, for example using optical sensors. 29% of respondents argued that Defra should consider local factors and that a blanket approach to nitrate monitoring wouldn’t be beneficial. 14% of respondents argued that nitrate monitoring should only be explored if there is a legal requirement to act upon the data.

Question 5: Would you support, where technically feasible, the inclusion of nitrate monitoring at wastewater treatment works for freshwater sites in catchments caught by nutrient neutrality rules – for example, in the Tees, the Broads or Stodmarsh? If so, why?

33 respondents answered the question.

• 82% of respondents answered either ‘Yes’ (27%) or ‘Yes with conditions’ (55%)
• 12% of respondents answered ’No’
• 6% of respondents provided unclear responses

Themes

24% of responses highlighted the increased understanding that would be gained by monitoring nitrates at wastewater treatment works. 15% of respondents also highlighted that the monitoring of nitrates would only be possible or appropriate where a Nitrate Standard applies. 9% of respondents raised the cost and resourcing involved in measuring nitrates in this way. One academic specifically explored the inclusion of nitrate sensors and highlighted their increased costs and complexity.

Grouped government response to questions 4 and 5

With current available technology, we are unable to monitor nitrates at a cost-effective level. Their inclusion would significantly increase costs to the programme and subsequently bill payers in the PR24 period and beyond. This would be the case in both freshwater sites and for wastewater treatment works.

Government has not decided to include nitrate monitoring in this programme. However, Defra will continue to explore opportunities to do this in the future and appreciates respondents highlighting appropriate technology.

Question 6: Is the 24-hour lag sufficient for all watercourses? Yes or No. If No, should the lag be longer or shorter and why?

33 respondents answered this question:

• 39% of respondents answered either ‘Yes’ (15%) or ‘Yes with conditions’ (24%)
• 55% of respondents answered ‘No’
• 6% of respondents provided unclear responses

Themes

64% of respondents argued that the appropriate duration of the lag time should be determined on a case-by-case basis. 21% of responses included concerns over the power requirements and costs for a lag time of this length.

Government response

Defra is unable to legislate for the lag on monitoring on a case-by-case basis, due to the variation of site-specific factors. A backstop of 24 hours has been determined as a safe lag time that will include the majority of watercourses and ensure the data captured is as accurate as possible. Research conducted by Defra and the Environment Agency highlighted that, when taking an average of width, combined with a low flow rate, the approximate time needed for water to sufficiently flow downstream to a monitor is 12 hours. In accounting for other factors such as weather impacts and variations in flow rate, a 24-hour lag is deemed appropriate.

Question 7: Is using the maximum point of harm arising from ammonia the right approach, rather than dissolved oxygen? Yes or No. If No, why not?

30 respondents answered this question:

• 37% of respondents answered either ‘Yes’ (20%) or ‘Yes with conditions (17%)
• 43% of respondents answered ‘No’
• 20% of respondents provided unclear responses

Themes

57% of responses supported measuring dissolved oxygen either instead of or alongside ammonia. Those that supported using dissolved oxygen highlighted it as a better measure of ecological harm in rivers. 50% of responses highlighted the distance from event to impact, highlighting that ammonia is more suited to fixed monitoring installations at the point of mixing. Respondents who provided additional information outside of the parameters of the question, confirmed measuring ammonia as an appropriate approach, highlighting the opportunity for cost savings.

Government response

Defra will continue to use the maximum point of harm arising from ammonia as the key determinant for siting. Whilst we recognise the benefits in the measurement of dissolved oxygen, the variables that impact dissolved oxygen mean that it is too difficult to determine the maximum point of harm. Season, river flow conditions, temperature and dilution will all impact dissolved oxygen. Using ammonia as a parameter is more suited to fixed monitoring installations at the point of mixing, making it appropriate for this programme.

Question 8: Is the rule of “not more than 500m downstream from the point of cross-sectional mixing” appropriate? Why?

30 respondents answered this question:

• 33% of respondents answered either ‘Yes’ (6%) or ‘Yes with conditions’ (27%)
• 57% of respondents answered ‘No’
• 10% of respondents provided unclear responses

Themes

57% of respondents identified that the rule was not appropriate due to the site-specific considerations needed when placing monitors at sites. 43% of respondents highlighted the importance of other river characteristics, such as the transfer of final effluent via ditches or drains.

Question 9: Would the 500m rule be better expressed as a ratio based on the width of the watercourse? Why?

32 respondents answered this question:

• 25% of respondents answered either ‘Yes’ (9%) or ‘Yes with conditions’ (16%)
• 66% of respondents answered ‘No’
• 9% of respondents provided unclear responses

Themes

44% of respondents raised other watercourse features that would help determine the appropriate monitoring distance. For example, flow velocity, seasonal variations, and the nature of contaminants. 38% of responses noted that setting a requirement based on river width may lead to the monitor needing to be placed in an area that isn’t accessible, particularly in narrow watercourses.

Grouped government response to questions 8 and 9

We understand that there will be site-specific characteristics that will impact the distance downstream for cross-sectional mixing. However, a standardised rule must be in place to assure data validity.

The 500m (0.31 miles) rule was calculated as follows.

Most rivers in England are less than 50 metres wide at their widest point. Using the formula of 10 times the width of the river would provide a mixing zone of 500m (0.31 miles). This is as defined in the UPM FIS standards located here: http://www.fwr.org/UPM3/Section2.pdf.

By allowing a maximum of an additional 500m (0.31 miles) downstream, water companies will be able to have greater flexibility when placing monitors. The rule also ensures that the downstream monitor remains within a reasonable distance on wider watercourses to assure data validity. Given the responses to questions 8 and 9, the rule will not be amended.

Question 10: Should there be any other site-specific considerations? If so, which?

31 respondents answered this question:

• 81% of respondents either answered ‘Yes’ (32%) or ‘Yes with conditions’ (49%)
• 16% of respondents answered ‘No’
• 3% of respondents provided unclear responses

Themes:

48% of responses to this question referenced features that prevent monitoring. These included the presence of artificial barriers (weirs, dams and reservoirs) and areas with additional planning restrictions, such as world heritage sites. 42% of responses referenced location sensitives and watercourse characteristics. For example, where bed sediment had been disturbed by high volumes of fishing or boat traffic.

Government response

Water companies should consider local and site-specific factors in the final siting of monitors. The 500m (0.31 miles) rule should allow for sufficient flexibility when placing monitors. Defra recognises the issues raised by respondents in this question and will amend the technical guidance to include the following:

Downstream monitors:

Local and site-specific factors should also be considered in final siting of downstream monitors. Factors that may need to be considered include:

• river features or geography, including catchment type, variable annual flow, sources dilution, and other sources of diffuse pollution
• the influence of other pollutant sources on data
• health and safety considerations for access for maintenance or repair
• the presence of artificial barriers – weirs, dams, reservoirs, culverted watercourses
• areas with additional planning restrictions
• areas with high flood risk

Question 11: Would this rule be better if expressed as below? If Yes, why or why not? “Where there are two or more assets with overlapping mixing zones within 250m of one another in a single length of watercourse, these can be considered a cluster and monitored by one pair of monitors.”

30 respondents answered this question:

• 30% of respondents either answered ‘Yes’ (10%) or ‘Yes with conditions’ (20%)
• 40% answered ‘No’
• 30% of respondents provided unclear responses

Themes

47% of respondents suggested a case-by-case approach to assessing mixing zones. They noted that mixing zones will be dependent on factors such as flow rate and the presence of other pollutant sources. 17% of respondents, including industry bodies, environmental NGOs and academics, highlighted installation practicalities and cost as issues to consider. 17% of respondents agreed with the proposed rule and noted that it is expressed clearly and ensures that monitors can be placed where full mixing has occurred.

Government response

Defra has noted the most common theme referencing a case-by-case approach. A joint response from academics at the Swiss Institute of Aquatic Science and Technology specifically highlighted the benefits of a larger clustering zone (up to 3km or 1.86 miles) in this programme. This highlighted the cost-saving of using a larger clustering zone, allowing further funding to be used to address broader regional impacts on watercourses as well as measuring variables such as rainfall.

We will update the clustering range rule in the technical guidance to the following:

Where there are two or more discharge outlets within up to 1km (0.62 miles) of one another in a single length of a watercourse, these can be considered a cluster and monitored by one pair of monitors. The downstream monitor for a cluster should be placed at the point of cumulative cross-sectional mixing for the last asset in the cluster. This will naturally mean that the first asset in a cluster will be further away from the downstream monitor. To assure quality of the data, the downstream monitor should be no more than 500m (0.31 miles) downstream from the point of cross-sectional mixing for the first asset in the cluster.

No other European country recommends placing the monitor more than 1km (0.62 miles) downstream. By amending the clustering range, water companies will have greater flexibility when placing monitors without compromising on data quality. This will also reduce the overall number of monitors needed, addressing concerns raised around installation practicalities and costs.

Question 12: Do you agree with the proposed cap of 10 on clustering? If not, why not, and what should the cap be?

32 respondents answered this question:

• 44% of respondents answered either ‘Yes’ (16%) or ‘Yes with conditions’ (28%)
• 47% of respondents answered ‘No’
• 9% of respondents provided unclear responses

Themes

38% of respondents highlighted that location of outflows should be considered in the placement of monitors. 25% of responses centred around the need for clarity, with many respondents asking for justification or evidence to explain the proposed cap of 10.

Government response

Government has considered the responses provided to this question. Due to other updates that are being made to the technical guidance following this consultation, including the extension of the clustering range, we will continue with the proposed cap of 10 on clustering. This will ensure that clusters are able to be clearly identified, whilst allowing for sufficient flexibility when placing clusters of monitors.

Question 13: Is it reasonable to require sewerage undertakers to attribute the source of a breach of standards to a particular asset? Why?

34 respondents answered this question:

• 58% of respondents answered either ‘Yes’ (32%) or ‘Yes with conditions’ (26%)
• 26% of respondents answered ‘No’
• 15% of respondents provided unclear responses

Themes

38% of responses centred around being able to hold responsible parties to account for mitigation of the issue. 24% of respondents argued that it should not be solely the responsibility of water companies to investigate all impacts on waterways.

Government response

Government will continue with the investigatory duty outlined in the technical guidance. The duty is drafted in recognition of the public interest in knowing which discharge is causing ecological harm within a reasonable timescale. The duty to investigate is intended to allow sewerage undertakers to better understand their networks.

Question 14: Should there be any additional exemptions? How would they benefit the programme?

30 respondents answered this question:

• 67% of respondents answered either ‘Yes’ (13%) or ‘Yes with conditions’ (54%)
• 30% of respondents answered ‘No’
• 3% of respondents provided unclear responses

Themes

47% of respondents called for low risk, or low spillage areas to not be included in the programme, noting the potential for significant cost saving. Respondents suggest sites that demonstrate less than 5 or 10 spills over a year would be able to be deprioritised. 33% of responses mentioned prioritisation based on risk factors. Respondents suggested various ways to prioritise site including frequency of spill events, cost and site conservation importance. Cost and risk balance were cited by 27% of respondents as an important consideration.

Respondents who disagreed argued that it should be possible to put monitoring in place at all sites. One response suggested expanding the distance allowed between overflow sites and monitoring equipment to ensure that data is collected.

Government response

Considering the responses provided, Defra is making the following changes to the programme:

1. We are not including descriptive only permitted treatment works in the programme.
2. We are not including storm overflows which have fewer than 10 spills per year over a 5-year average.

Including the above changes to the programme will significantly reduce the cost of the programme to bill payers. It will also allow for greater deliverability of the programme, with water companies being able to focus efforts on a smaller number of assets in the initial rollout of the programme.

We are also making the following update to the technical guidance:

3. Water companies will be required to have completed rollout of 25% of all sites by 2030. This initial rollout should focus on high priority sites. We expect most water companies should be able to install monitors at 50% of high priority sites within the envelope of a 25% rollout of the total programme.

In order to have the quickest possible impact in its initial rollout, water companies will be able to prioritise sites across the first 5 years of the programme to focus on high spilling assets and higher priority sites. This will also allow for water companies to trial technology, take localised approaches and report learnings back to Defra. High priority sites are as defined in the technical guidance. This will be reviewed in 2027, during the review of the Storm Overflows Discharge Reduction Plan.

Question 15: What data should be included and what is the best way to display this data so that it usefully informs the public or meets your needs?

30 respondents answered this question:

Repeat suggestions are captured in Table 1. This table suggests that most responses consider the visualisation of data to be a key concept as well as a level of interactivity. The need for real-time data alongside long-term data trends were also repeatedly suggested which would allow the public to make informed decisions about waterway use.

Table 1. Common themes in response to Question 15

Theme	Proportion of responses
Data visualisation or interactivity	67%
Real-time data	43%
Long term data (trends)	33%
Regulatory information, for example, thresholds	33%
Summary or explanation	30%
Water quality index	27%
Equipment information	20%
Data reliability	20%
River quality modelling	17%
Location	13%
Weather-based information	13%
Source of breach	13%
Additional resources	10%
Watercourse information	10%
Remediation status	7%

Question 16: What other contextual information is required to ensure that everyone will be able to understand the data?

30 respondents answered this question:

These responses were grouped into themes as seen in Table 2. Respondents felt that the data needs to be interpreted or presented in a visual manner which is easily digestible by the general public. Respondents also indicated that location data of spill events would be important. This links to the public use of waterways and is also important for ensuring accountability for overflow events.

Table 2. Common themes in response to Question 16

Theme	Proportion of responses
Data interpretation or visualisation	67%
Location	43%
Rainfall	33%
Water quality index	30%
Watercourse information	27%
Environmental targets	20%
Biological activity	10%
Instrument information	7%
Other discharges	3%

Grouped government response to questions 15 and 16

Defra has considered the responses and themes raised in these 2 questions. This consultation has highlighted that further consideration needs to be given to how the data collected in the continuous water quality monitoring programme will be used.

Particular consideration will need to be given to how the public will access this data. Defra’s position remains that this should be presented in the form of an interactive national map. We have noted the comments made regarding the data being presented in a visual manner that is easy to use, as well as the ability to pinpoint the exact location of spills. Defra will provide further updates regarding the presentation of this data in due course.

Next steps

We thank all respondents for their participation in the consultation. As has been outlined in this response, we will be making the proposed updates to the technical guidance.

The updated technical guidance will be published on www.gov.uk in due course.
The event duration monitoring and continuous water quality monitoring programmes will continue to be developed in partnership with stakeholders.