1. Scope 

1.1 Applicability

This guidance applies to water companies operating in Wales, which includes:

• Water and sewerage companies: Dŵr Cymru Welsh Water (DCWW), Hafren Dyfrdwy (HD) 
• New appointments and variations (NAVs)
• Water only companies (WOCs)

For the purposes of this document:

• “You/your” refers collectively to all water companies
• “We/us/our” refers to Natural Resources Wales (NRW)

1.2 Coverage 

It applies to actual or potential (likely to take place) pollution incidents that may impact controlled waters, land, or air arising from your assets or activities. Emissions from anaerobic digestion plants can typically cause pollution to air. Water discharges from the assets listed below are most likely to pollute controlled waters and land:

• wastewater treatment works (WwTWs)
• storm overflows (SOs)
• sewage pumping stations (SPSs)
• emergency overflows (EOs)
• rising mains
• foul and surface water sewer network lines
• water treatment works (WTWs)
• water supply distribution system
• sludge and waste-handling operations

1.3 Discharge types

This guidance applies to:

• permitted discharges, where statutory notification requirements exist under the Environmental Permitting (England and Wales) Regulations 2016 (EPR) permit conditions. This guidance sets out how to comply with the requirements in permit condition 4.3 and Schedule 5 
• unpermitted and non-permittable discharges
• polluting discharges from operations under the Water Industry Act 1991

1.4 Polluting discharges

Pollutants include substances found in, but not limited to, the following:

• crude and storm sewage effluent 
• trade effluent, including hazardous substances
• sewage sludge
• chlorinated water
• process effluent and sludge from water treatment operations
• chemicals
• suspended solids from excavations, repairs and scouring

1.5 Responsibility

You have statutory duties for pollution incidents that involve your assets and activities, more detail is in section 3 Your duties. We will assign the incident record to you unless you provide clear evidence that you are not responsible for the pollution incident. More detail about the polluter, is in section 26 Review the polluter.

When we record an incident, we are not necessarily deciding liability for any offences that may have been committed.

We expect you to report pollution incidents you may observe when you carry out your daily duties. For example, if you see any type of polluting matter (not necessarily sewage) entering a river from a surface water outfall, you should report it. We may need to carry out investigations independently or jointly, to gather evidence and identify the polluter.

2. Definitions, offences and incident categorisation

2.1 Definition of a pollution incident A “pollution incident” is defined in the Water Special Measures Act (WSMA) within the Water Industry Act (WIA) as follows: “For the purposes of this section, references to pollution incidents that are attributable to the system of an undertaker:

(a) are references to discharges from any structure or apparatus comprised in that system of any content which may be harmful to health or the quality of the environment, but

(b) do not include references to discharges of treated effluent in accordance with an environmental permit (including any conditions to which it is subject).”

We will use the term “polluting discharges” in this document. This refers to any water discharge that causes pollution and should be self-reported whether the discharge is permitted or not.

2.2 Definition of a duplicate report

These are multiple reports of the same discrete occurrence.

If we receive multiple reports that relate to the same polluting discharge, for example from a cracked foul sewer on the same date and time, we will treat the first report as the master incident and link any subsequent reports to it.

Duplicates are identified and linked as they arise. If we overlook a record we should have duplicated, email ICC to contact the lead officer to discuss: icc@cyfoethnaturiolcymru.gov.uk

Duplicate reports are not the same as duplication requests.

2.3 Definition of a recurring pollution incident

A recurring pollution incident is a repeat polluting discharge with the same root cause. Each polluting discharge should be recorded as a separate incident record. However, if we have agreed action is being taken to resolve a known problem, it may be considered a recurring pollution incident. This may apply when the same issue reoccurs in the same location, with the same root cause, but at different times. Requests to duplicate records can be submitted in these circumstances, but only if the criteria apply. More information is provided in section 27 Request to duplicate.

2.4 Definition of controlled waters

This guidance applies to any incident that affects controlled waters. “Controlled waters” are defined in Section 104 of the Water Resources Act (WRA) 1991 and include: • inland freshwaters – can be natural, artificial, above or below ground and include rivers, lakes, ponds and reservoirs • groundwaters – water contained in underground strata. • coastal waters – landward of the baseline, including enclosed docks • relevant territorial waters – within three nautical miles of the baseline Section 104 of the WRA (1991) states that any reference to the waters of a lake, pond, river or watercourse also includes the bottom, channel or bed, even if it is “for the time being dry”. For example, a dry ditch that is part of a river system and normally carries water during wet periods is a controlled water. An isolated field drain that only collects surface runoff is not. Controlled water does not include a public sewer or any sewer or drain that connects to a public sewer.

2.5 Definition of a water discharge activity

Under Regulation 35 (1) Schedule 21 3(1)(a) of EPR 2016, a water discharge activity is defined as: • “(a) the discharge or entry to inland freshwaters, coastal waters, or relevant territorial waters of any (i) poisonous, noxious, or polluting matter, (ii) waste matter, or (iii) trade effluent or sewage effluent Contents page Page 10 of 40 • (b) the discharge from land through a pipe into the sea outside the seaward limits of relevant territorial waters of any trade effluent or sewage effluent”

2.6 EPR (2016) offences

Under EPR 2016 the following apply: • Regulation 38 (1)(a)(b) details the requirement to have a permit for a water discharge permit and to comply with its requirements • Regulation 38 (2) details that it is an offence not to comply with a permit See our website for information about our Enforcement and sanctions policy.

2.7 WIA (1991) offences

Under the WIA the following apply: • Section 165 (3) refers to steps you must take to ensure the effluent is free of polluting matter, as soon as reasonably practicable (ASARP) • Section 165 (8) requires you to comply with the consent See our website for information about Enforcement and sanctions policy.

2.8 Pollution impacts to multiple receptors

We record principal and secondary receptors, but pollution can impact more than two.

Examples of receptor types are listed below: 

• controlled waters (surface water, groundwater, coastal waters, territorial waters) 
• fisheries
• land (includes agricultural, conservation areas, designated sites)
• amenity
• commerce
• potable abstractions
• ecology
• hydromorphology
• air
• human health

We require information about the receptor types in self-reports. More information about this is in section 6. 6 Self-report receptors.

2.9 Pollution impact categorisation

We use four categories to assess the actual impact of a pollution incident:

• category 1 (major): major adverse effect or damage to the environment, people or property, or to our assets, operation or reputation
• category 2 (significant): significant adverse effect or damage to the environment, people or property, or to our assets, operation or reputation
• category 3 (minor): minor adverse effect or damage to the environment, people or property, or to our assets, operation or reputation
• category 4 (no impact): substantiated occurrence with no impact or risk of minor harm

Water discharges such as sewage and other trade effluent contain polluting substances. When they enter controlled waters outside of compliance with their permit or consent, they will have at least a minor impact on the environment.

More detailed information about when to self-report pollution incidents is in section 4 Self-report scenarios and our role.

There are occasions when you may not need to self-report. More information is in section 6.7 Self-report polluting discharges to land and groundwater exclusions.

2.10 As soon as reasonably practicable

As soon as reasonably practicable (ASARP) means acting without undue delay. In this guidance, it applies to the timing of self-reports, communications and to taking prompt, practical steps to implement required actions.

3. Your duties

3.1 Duties under the Urban Waste Water Treatment Regulations (UWWTR) 1994

You must:

• provide and maintain collection systems that effectively convey urban wastewater to treatment plants
• ensure the design, construction and maintenance of these systems meet Directive requirements and prevents pollution
• take account of wastewater treatment needs, population growth, and environmental protection objectives
• comply with monitoring and reporting duties

This duty applies to all agglomerations where urban wastewater is generated, and includes infrastructure serving domestic, industrial, and surface water sources. Failure to maintain adequate networks may result in enforcement action from us, under either or both, the UWWTR (1994) and EPR (2016).

3.2 Statutory responsibilities for pollution incidents

You have duties under the Water Industry Act (WIA) 1991. These include amendments introduced by the Water Special Measures Act (WSMA) 2025 and related legislation. You must:

• maintain your assets to prevent pollution and ensure your infrastructure operates securely, efficiently, and properly. This includes preventing water infiltration and ensuring sewers are free flowing and free from obstructions such as tree roots
• meet environmental obligations:
  • prevent pollution of controlled waters
  • respond to incidents without delay
  • comply with the EPR (2016) and WIA (1991)
     
• control trade effluent discharges into public sewers:
  • authorise all discharges through valid trade effluent consents
  • set and enforce appropriate conditions
  • check compliance
  • stop unauthorised or non-compliant discharges that may damage sewerage infrastructure, disrupt treatment, or impact the environment

4. Self-report scenarios and our role

This section describes provides a summary of the type of water discharges you should self-report. It also provides information for when we will issue a Compliance Assessment Report (CAR) following our investigations. We may issue warnings for permit breaches on a CAR, but if a different enforcement response is appropriate for a regulated site, we will communicate in writing.

4.1 Polluting discharges from regulated sites (non- compliant)

A permitted or consented water discharge can have an environmental impact when the requirements of them are not met. We will record self-reports about polluting discharges and score them as non-compliant with the EPR permit on a CAR. We will regulate non-compliant WIA consented discharges by referring to our Enforcement and Sanctions policy. We will not send a CAR as they are a regulatory tool to assess compliance with EPR permit conditions.

4.2 Polluting discharges from regulated sites

Some polluting discharges may comply with EPR permit conditions but may still cause an environmental impact. For example, a discharge from a permitted emergency outfall (EO) during an emergency, as defined in the permit condition. We will investigate these polluting discharges when they are self-reported. We may assess the discharge as compliant on a CAR, if applicable. We may identify actions where appropriate, which may include the need to vary the permit.

4.3 Non-permitted discharge types from a regulated site (non-compliant)

Some polluting discharges from a permitted outfall do not comply with permit conditions because the water discharge type is not permitted. You should self-report them. For example, a discharge of crude sewage from a storm overflow outfall when the permit only allows a discharge of storm sewage, or a rainfall-dependent discharge from an outfall permitted solely for discharge in an emergency. We will record non-permitted polluting discharges and assess them as non-compliant on a CAR if they come from an outfall that has an EPR permit for a different discharge type.

4.4 Unpermitted and non-permittable polluting discharges

You should self-report polluting discharges, such as unpermitted and non-permittable ones. We will record them on our system and our response will be in line with our Enforcement and Sanctions policy. We will not report our findings in a CAR as there is not an EPR permit for these types of discharges. An example of an unpermitted water discharge includes a storm overflow on the network that does not have an EPR permit for a water discharge activity. An example of a non-permittable polluting discharge is a release of crude sewage from a break in a foul sewer. We do not issue EPR permits for this type of discharge.

5. Information sources

These examples may help identify issues that you need to self-report.

You should provide detail about the source of information and provide supporting evidence in your report.

Examples include, but are not limited to:

• visual observations by you or those working on your behalf
• sample data from operator self-monitoring (OSM) or operational monitoring
• telemetry alarms
• flow meter readings that record flow passed forward for treatment
• monitoring data from event duration monitors (EDM) records flows to the environment
• monitoring data from EDMS monitors that record flows into storm tanks
• reports from third parties such as members of the public (MOP), emergency services, local authorities

We may report a pollution incident that you should have self-reported if we become aware of it. This may include a numeric breach, an issue we observe during a planned site inspection or following a review of data during an audit.

6. Self-report requirements

6.1 When to self-report

We expect you to self-report as soon as reasonably practicable (ASARP). This is normally within two hours from when you become aware of a polluting discharge, or when an issue is likely to lead to a release of a polluting discharge that may cause an environmental impact. Where telemetry provides a reliable indication of a pollution risk, we expect you to self-report ASARP.

However, there may be some circumstances when self-reports are not necessary. More detail is in section 6.3 When you may not need to self-report and section 6.7 Self-report polluting discharges to land and groundwater exclusions.

When you self-report you should provide the appropriate level of detail for each pollution incident. Refer to Annex 1 Pollution incident self-report, updates and notification checklist, for the information we expect self-reports to contain.

See section 6.11 Self-report channels on how to self-report to us.

6.2 Self-reports from EPR permitted sites (Schedule 5)

When a water discharge activity is permitted by an EPR permit it normally has the self-report condition 4.3 that refer to requirements in Schedule 5. Permit condition 4.3 says to notify us (self-report) if the discharge may lead to significant pollution.

You should apply a precautionary approach to self-reports from a permitted site, to comply with the permit condition. This is because the environmental impact is not determined at the time of report, so the pollution incident has the potential to lead to significant pollution.

Refer to Annex 1 Pollution incident self-report, updates and notification checklist to assist you to provide the right level of information to comply with permit condition 4.3 and Schedule 5. You should also refer to information specified in the permit, when you selfreport.

For releases of polluting discharges from an EPR permitted asset:

• condition 4.3 requires you to self-report ASARP
• Schedule 5 Part A requires you to self-report, with supporting information within 24 hours maximum. You must also complete part B of Schedule 5 in the EPR permit

Annex 3 Timeframes for pollution incident correspondence describes communication timeframes.

6.3 When you may not need to self-report

In the following situations, you may not need to self-report if you:

• detect an issue but do not have evidence of a polluting discharge
• can respond quickly and prevent a polluting discharge
• are confident that pollution has not occurred (e.g., telemetry communication issue only)

You also do not need to self-report if the groundwater exclusion applies, see 6.7 Selfreport polluting discharges to land and groundwater exclusions. However, if discharges to groundwater (whether the self-report exclusion applies or not) are secondary to a more significant water discharge activity elsewhere, you should include detail about them in the self-report. Provide a plan and annotate the location of additional releases to land, to provide an overview of a pollution incident. Refer to section 6.7.1 Specific guidance for hydraulic overload.

6.4 New information in updates (not in a new self-report) 

In certain circumstances you will not need to self-report again. You may be able to include new information as part of an update. Always include the primary pollution incident reference in the update.

For example, an update may be appropriate when you have sent information about a numeric sample exceedance or failure for one parameter from an OSM sample and you need to report the results of another parameter, as the results came through later. This would only apply if both results are from the same OSM sample. Refer to section 11.2 OSM and UWWTR sample results for more information.

Another example may include when you have self-reported the sample results from an operational sample because a level of concern has been reached and take additional operational samples during the same pollution incident. Sample results from ongoing monitoring should be shared in updates.

Refer to section 27.3.1 Assets with EDM.

6.5 Consistent self-report approach (EPR and non-EPR)

This guidance supports consistent and complete self-reports about polluting discharges. It supports compliance with EPR condition 4.3 and Schedule 5 Parts A(a), A(b), A(c) and Part B. We expect you to provide the same level of detail about polluting discharges when:

• an EPR permit has condition 4.3
• an EPR permit does not include condition 4.3 (yet)
• they are from an unpermitted asset (waste or clean water)
• they are non-permittable discharges 

This requirement is to maintain regulatory consistency.

6.6 Self-report receptors

When you submit a self-report, include the receptor types that the pollution incident could or has, impacted. You should list all that apply but indicate those you consider to be the principal and secondary receptors. A detailed list of receptors is in 2.8 Pollution impacts to multiple receptors.

For example, if sewage effluent escapes from a rising main onto a field and flows over land and enters a watercourse, include surface water as the principal receptor and land as the secondary. Include other receptors in the self-report where appropriate, such as groundwater and if it is within, or near to a designated site or Site of Scientific Interest (SSSI) for example.

6.7 Self-report polluting discharges to land and groundwater exclusions

Polluting discharges to land can impact a range of receptors. They can affect:

• groundwater (controlled water) – through infiltration into soil 
• surface waters (controlled water) – over land or via subsurface flow 
• land – can affect amenity, commercial use, ecology, or human health 

You do not need to self-report to land if the polluting discharge is so small in quantity and concentration that it will not cause deterioration in groundwater quality.

However, if any of the following apply you should self-report:

• the polluting discharge to land is significant, persistent, or extensive
• the polluting discharge enters surface water or impacts amenity
• a large volume could be released (for example, from trunk sewers or rising mains)
• the polluting discharge is highly concentrated such as during “prolonged dry weather” or contains hazardous trade effluent
• the discharge location is sensitive which includes if it is:
  • within a Source Protection Zone 1 (SPZ1) or in an area with high groundwater vulnerability
  • within 50 metres of a private drinking water borehole
  • in or near to, a designated site such as Special Area of Conservation, Special Protection Area, Ramsar site or Site of Special Scientific Interest (SSSI)

6.7.1 Specific guidance for hydraulic overload

If there are multiple polluting discharges along the same sewer line all caused by hydraulic overload, you should reference all discharges to land within the self-report for the main polluting discharge, which may be from an emergency overflow (EO) at a sewage pumping station (SPS). You do not need to send separate self-reports for the smaller discharges from upstream sewer chambers to land, or groundwater, if there is a direct connection. Refer to information in section 6.3 When you may not need to self-report.

6.8 Self-report recurring polluting discharges

You should self-report even if we have agreed to duplicate recurring polluting discharges. You should always self-report a pollution incident if it happens outside of the agreed duplication criteria in an Incident Action Plan (IAP). Refer to section 27 Request to duplicate recurring pollution incidents. There are exceptions to the requirement to self-report recurring pollution incidents separately, refer to section 27.3.1 Assets with EDM. This section provides more information about repeat water discharge activities from overflows with EDM installed. Also refer to section 27.3 Incident Action Plan (IAP).

6.9 Extreme weather

You should self-report polluting discharges that occur during extreme wet weather such as heavy rainfall events, flood events or during a named storm. You should maintain planned capability to manage the impacts of flood events, high winds, heat, drought, snow, and ice. You should prevent the release of polluting discharges, mitigate environmental impacts, and restore assets affected. You should self-report the release of polluting discharges which involve a submerged permitted asset due to flooding as the Schedule 5 Part A (a) requirement is likely to be relevant. You should provide the specified information in Annex 1 Pollution incident selfreport, updates and notification checklist. Refer to section 22 Flooded assets.

6.10 Power outage

You should self-report polluting discharges from permitted assets that occur due to issues with the supply of electricity and tell us if you have complied with the conditions in the permit. You should maintain capability to manage mains power blips, surges and outages. We will assign you as the polluter for that incident record.

6.11 Self-report channels

You should self-report polluting discharges to our Incident Communication Centre (ICC) and provide the relevant detail in Annex 1 Pollution incident self-report, updates and notification checklist. If there are delays gathering information and you want to ensure you are the first to report, call ICC on 0300 065 3000 to give an overview, then email full details to icc@cyfoethnaturiolcymru.gov.uk. Provide all updates in writing.

6.12 Self-report checklist

See Annex 1 Pollution incident self-report, updates and notification checklist for required and suggested information. Not all fields apply to every incident.

Use the same checklist for self-reports about polluting discharges from permitted, consented, unpermitted and non-permittable assets. If you follow the checklist, you will comply with information requirements in EPR permit condition 4.3 and Schedule 5 where relevant. We expect you to apply the same standards of communications for all polluting discharges, even if they are not authorised by an EPR permit.

6.13 Submit clear and timely information

Your self-report and updates must include information that is:

• gathered and submitted promptly, ideally before we complete our assessment
• representative of the pollution incident, for example, photos, on-site sample results
• submitted without delay, start with initial detail, proposed mitigation, additional updates and how you intend to prevent a recurrence (Part B Schedule 5)
• complete and summarised, include all receptors (refer to section 6.6 Self-report receptors), cover impact, pollution risk, and root cause

6.14 Provide timely updates and a final report

You should provide timely updates as information becomes available and submit a final report within 14 days from the self-report. This report should confirm the outcome of the investigation and remedial measures. By exception, we may consider extending the timeframe for you to submit the final update. We will record the environmental impact based on information available and requested. We will assess compliance with permit conditions where applicable.

Refer to Annex 3 Timeframes for pollution incident correspondence.

6.15 Do not report maintenance activities that do not have environmental risk

Do not self-report planned or unplanned maintenance activities that pose no environmental risk, unless we have agreed otherwise in writing. If circumstances change and there is a risk of pollution, you must self-report.

Keep a record of all maintenance actions and make them available on request. We may ask for these records during an investigation, inspection, audit, or liaison meeting.

Refer to section 6.3 When you may not need to self-report for other examples.

When you direct flow into storm tanks for maintenance and this does not result in a discharge to the environment, continue to notify us already agreed. We will use this information when we assess Flow Passed Forward (FPF) compliance to discount flows detected by EDMS as appropriate. Refer to Annex 1 Pollution incident self-report, updates and notification checklist and include relevant details about your actions. Make sure your submission is clearly marked as a notification, rather than a self-report. However, if this maintenance activity leads to a discharge to the environment, you must self-report it. Refer to section 12.3 Storm overflow with storm tank(s) and EDMS.

7. Incident response requirements

7.1 Stop polluting discharges, remediate and mitigate

We expect you to stop the pollution incident as soon as you can, take action to identify the root cause and remediate the impact. If the polluting discharge has an Incident Action Plan (IAP) in place, we expect you to implement mitigation measures to reduce the frequency of pollution incidents, whilst waiting for the long-term resolution.

More information about IAPs is in section 27 Request to duplicate recurring pollution incidents and Annex 2 Incident Action Plan checklist template.

7.2 Protect public health and the environment

We expect you to mitigate the environmental impact and clean up polluting matter to protect public health and the environment.

7.3 Prevent recurrence

We expect you to take all reasonable steps to prevent a recurrence and reduce the environmental impact. We expect you to update your management systems, maintenance schedules and IAPs where relevant.

7.4 Resolve root cause

If the root cause is not related to maintenance and cannot be resolved immediately, you should implement a resolution and implement mitigation measures to reduce the environmental impact. Agree the resolution with us using an IAP, as detailed in section 27 Request to duplicate recurring pollution incidents and Annex 2 Incident Action Plan checklist template.

8. Our responsibilities when we receive reports

8.1 What we will do

We have a statutory duty to regulate environmental activities under EPR 2016 and UWWTR 1994. We do this by ensuring compliance with permits and treatment standards. Our priority is environmental protection and pollution control. Ofwat is responsible for enforcing economic and service-related duties under WIA 1991.

We will:

• record pollution incidents to build a picture of their extent, impact, and duration
• inform you of reports about your assets or activities, subject to General Data Protection Regulation (GDPR)
• record pollution incidents we identify or those you did not self-report
• investigate and gather evidence when appropriate
• use third party information where relevant
• assess and substantiate pollution incidents
• categorise the actual environmental impact using our Incident Categorisation Policy.
• recover investigation costs under the “Polluter Pays Principle” which apply whether we attend or not
• check compliance with EPR permits and record breaches on a CAR
• score permit breaches based on the potential environmental impact (this may differ from the pollution incident category)
• consider our enforcement response in line with our Enforcement and sanctions policy
• close the incident record within 30 days (or within 90 days if extended), or by the end of February for the previous year (whichever is sooner)
• reopen incident records only to correct factual errors or add significant new evidence that materially changes the understanding of the pollution incident
• report pollution incident data in EPA metrics and other regulatory frameworks

Refer to Annex 3 for Timeframes for pollution incident correspondence.

9. Data quality and cooperation

9.1 Ensure accuracy and completeness

You must ensure all data you submit is accurate and complete, whether for a self-report, an update, or a notification.

9.2 Handle personal data lawfully

Both parties must follow organisational policies and procedures to comply with the UK GDPR when handling personal data. This includes ensuring data is shared securely, only when necessary, and managed in line with legal and regulatory obligations. We must comply with these requirements when handling personal data.

9.3 Provide supplementary information when required

We expect you to cooperate and provide information when requested. If you do not, we may use statutory powers, under Section 202 of the WRA 1991 for unpermitted discharges and regulation 60 of the EPR for permitted discharges, to require supplementary information.

9.4 Support regulatory reporting

We will publish pollution incident data and water company performance as part of the annual environmental performance report (EPA). You will also use pollution incident data to produce Pollution Incident Reduction Plans (PIRPs) and Implementation Reports as required by the Water Special Measures Act (WSMA) 2025.

9.5 Resolve discrepancies cooperatively

Both parties must cooperate to resolve any discrepancies in categorisation or factual reports. We will consider all information, valid requests to review, and escalation appeals. Where mutual agreement cannot be reached, our decision will be final.

9.6 Resolve premises type differences

The premises type is a key component of pollution incident data. Raise any differences with the lead officer promptly so they can be discussed and resolved.

10. Substantiate a pollution incident record

10.1 Use of reliable evidence to substantiate

We will substantiate a pollution incident record if we receive credible evidence that it is occurring or has occurred. This includes photographs, video footage, or information from reliable sources such as you, our colleagues, emergency services, anglers, voluntary groups, or multiple reports from different MOPs.

On occasions we will substantiate a report when there is no evidence of an environmental impact. For example, if you self-report a newly identified unpermitted storm overflow which is not discharging at the time. However, in this example, you will need to self-report it again if a water discharge activity occurs.

10.2 Always substantiate self-reported polluting discharges

We will substantiate a pollution incident if you self-report a polluting discharge to controlled waters but refer to section 6.7 Self-report polluting discharges to land and groundwater exclusions.

Wastewater assets self-report guide

11. Treated final effluent from WwTWs – EPR

11.1 Schedule 5 permit requirements for numeric limits

You must self-report permit non-compliances from a WwTW that may lead to significant pollution to the environment. You must comply with condition 4.3 and the requirements of Schedule 5. You should apply a precautionary approach to comply with this condition as the impact to the environment cannot be determined at the start of a pollution incident. Refer to Annex 1 Pollution incident self-report, updates and notification checklist and Schedule 5 prompts, so that you submit the information required to comply.

We set numeric limits for the quality of final effluent in permit conditions to protect the receiving water. There is potential for polluting discharges when the numeric limits are exceeded or breached. Self-report these types of issue to ICC, provide information in Schedule 5 and copy in our compliance mailbox.

Refer to section 6.2 Self-reports from EPR permitted sites for additional information about polluting discharges from sites that have an EPR permit. In most circumstances for LUT exceedances and numeric breaches you should provide information in Schedule 5 of your permit as specified in parts A (a) and A (b) and submit part B later. You may also need to provide information specified in part A (c).

Below is a list of some typical examples for when to self-report potentially polluting discharges for sites that have numeric limits. This list is not exhaustive.

11.2 OSM and UWWTR sample results

Self-report potential non-compliances as described in this section as you receive the sample results. If a second parameter from the same prescheduled sample should also be self-reported, you can send this additional information in an update to the original selfreport. Correspondence about exceedances or breaches of numeric limits should be sent to ICC and copied to the relevant compliance mailbox: • DCWW should copy in: OSM_DCWW@cyfoethnaturiolcymru.gov.uk • HD should copy in: hafrendyfrdwy@cyfoethnaturiolcymru.gov.uk

11.2.1 Look Up Table (LUT) exceedances

When you receive a sample result that indicates an LUT exceedance for a parameter from a prescheduled OSM sample, you should self-report this as specified in section 11.1 Schedule 5 permit requirements for numeric limits and section 11.2 OSM and UWWTR sample results and provide information listed in Annex 1 Pollution incident self-report, updates and notification checklist. There may be situations where you should self-report prior to receipt of OSM sample results, such as if you find a level of concern has been reached from operational samples, refer to section 11. 3 Operational samples (not OSM) and level of concern.

11.2.2 LUT failures

When an LUT failure has occurred, you should self-report this. Ensure it is clear in the selfreport that it is an LUT failure. Refer to permit condition 4.3 and Schedule 5. You should confirm if the sample frequency will increase from reduced to normal in the self-report.

11.2.3 Maximum limit breaches

When a maximum limit has been breached you should self-report this. Refer to permit condition 4.3 and Schedule 5. You should also confirm if the sample frequency will increase from reduced to normal in the self-report.

11.2.4 Minimum limit breaches

Minimum limit breaches normally apply to pH only. You should self-report a permit breach to comply with condition 4.3 and Schedule 5.

11.3 Operational samples (not OSM) and level of concern

You may monitor the water quality from the final effluent discharge point at a WwTW outside of the scope of pre-scheduled OSM samples. This may apply to water discharge activities from a WTW for similar reasons.

You should self-report any findings from monitors or other sampling equipment when a parameter reaches a level of concern.

For parameter with permitted limits, a level of concern is:

• twice the permitted LUT limit where the receiving water is sensitive or in low flow conditions during prolonged dry weather, for example
• or three times the permitted LUT limit in other circumstances
• or any reading above the maximum (or below the minimum) limits specified in the permit

On occasions you should self-report operational results that reach a level of concern when there is not a numeric limit in the permit. For example, turbidity is often measured as an indicator of suspended solids and overall water quality. Schedule 5 Part A(a) requires you to self-report any “emission of a substance not controlled by an emission limit which has caused, is causing or may cause significant pollution”. Part A(b) requires detail about samples taken and the results.

11.4 Visual observations (final effluent or inlet of WwTW)

You should self-report if you or someone working on your behalf, observes poor water quality when an OSM sample is taken from the final effluent discharge point. Do not wait for the sample results. You should take photographs (timestamped) and take operational samples of the discharge at the same time. It may be appropriate to take samples upstream and downstream of the water discharge at the same time as the OSM ones. Refer to Annex 1 Pollution incident self-report and updates checklist.

If the self-report from your visual observations leads to a numeric compliance issue from the OSM sample taken, you must self-report the OSM sample results to comply with permit condition 4.3 and Schedule 5. However, as the pollution incident is on record, you can submit the OSM sample results in an update. However, you must provide all the information specified in Schedule 5 to comply with the permit.

Refer to section 2.2 Definition of a duplicate report.

If you observe poor water quality leaving site from the final effluent discharge point, outside of a pre-scheduled OSM sample, you should self-report it ASARP. You should follow the procedure described when visual observations are self-reported when an OSM sample is taken. Refer to Annex 1 Pollution incident self-report and updates checklist.

You should always share available site data relevant to the issue in the self-report or update and comply with the requirements in Schedule 5 of your permit.

If you observe an issue at the inlet of a WwTW, that may impact its performance, you should self-report and investigate. You should share water quality data available and any on site sample results, when they are taken from the final effluent discharge point. You should report the findings of your investigations ASARP.

11.5 No flow

If you find there is no discharge of final effluent during a prescheduled OSM sample visit, or during any routine checks, you should investigate the reason. There may be a legitimate reason, which you should provide as part of your usual “no flow” evidence submissions. Or you may need to investigate issues within the WwTW, or on the sewer network. You must self-report other water discharge activities that may occur elsewhere from the site or on the network and the reason for a “no flow” OSM sample.

11.6 Disinfection

Some WwTWs have tertiary treatment such as ultraviolet (UV) light or membrane filters to disinfect the treated final effluent.

11.6.1 UV day dose failure

You should self-report UV day dose failures in line with condition 4.3 and Schedule 5 of your permit. You should self-report on a precautionary basis to comply with the requirements of the permit and so that we can assess the impact.

A UV “day failure” is when no more than 10% of measurements taken consecutively during any 24-hour period from midnight to midnight fall below the 50% dose limit specified in the permit. This may occur because of an unplanned loss of power, or a mechanical failure for example. We will assess the impact from UV “day failures” based on the impact to human health and amenity.

Refer to section 6.3 When you may not need to self-report for examples of when you may not need to self-report an issue. If your prompt investigations find there was a telemetry error or a data loss issue and you are confident the effluent was receiving UV treatment, you do not need to self-report it. You should keep records such as backup logs, manual readings and other relevant information about these type of issues. Information and evidence should be made available on request. If the issue reoccurs you should take action to resolve it to reduce the risk of a pollution incident in the future.

12. Storm overflows (SOs) at WwTW – EPR

Refer to section 27.3.1 Assets with EDM for self-report requirements in certain circumstances.

12.1 Non-compliant discharges from storm overflows

You must self-report a discharge from a storm overflow (SO) when it is not compliant with permit conditions. Reasons may include but are not limited to:

• a blockage in the foul line
• the storm tank contents were not returned ASARP prior to the next rainfall event
• a screen has been blinded which causes a discharge from that asset, or another one
• when data shows the FPF (or FFT) is below the permit limit

Include sufficient detail in your self-report to comply with permit condition 4.3 and Schedule 5 requirements.

12.2 Compliant discharges from storm overflows with an environmental impact

On occasions, you should self-report a pollution incident when a discharge from an SO may cause significant pollution, even if it is compliant with the permit conditions. This may include visual observations such as a visible plume or the release of rags or sewage debris, for example. The water discharge activity may be permitted but the screen dimensions are not fit for purpose. In this situation the permit may need to be varied and a new screen with smaller dimensions installed.

Members of the public may report water discharge activities from storm overflows that are compliant with their permits. In this situation the report will be recorded on our system by ICC and we will assess compliance with the permit conditions. We may request data from you to enable us to do this. The water discharge may be compliant with the conditions of the permit, but there is an impact to amenity.

12.3 Storm overflow with storm tank(s) and EDMS

An EDMS (EDM storm) monitor detects the flow into the storm tank. If the FPF is not achieved and it is likely to lead to a non-compliant discharge from an SO or has led to a water discharge, you should self-report it. This may also apply if the storm tank has not been emptied ASARP and there is a discharge. You should submit EDM data, EDMS data, storm tank level data, FPF data, and other information we will require to assess compliance when you self-report it.

Refer to section 6.15 Do not report maintenance activities that do not have environmental risk for more information if the flow is intentionally directed to the storm tank(s).

12.4 Storm overflow from a Last in Line Overflow (LiLO) SPS

You must self-report a discharge from an SO sited at a last in line overflow (LiLO) connected to a sewage pumping station (SPS) if the discharge is not compliant with the permit conditions. Provide the appropriate amount of information for us to assess compliance in line with permit condition 4.3 and Schedule 5 of the permit.

13. Emergency overflows (EOs) at a WwTW or SPS – EPR

Refer to section 27.3.1 Assets with EDM for self-report requirements in certain circumstances.

13.1 Consolidated in a WwTW permit or a separate SPS permit

Emergency discharges are permitted from Emergency Overflows (EOs) during an emergency, as defined in the EPR permit. Refer to section 6.10 Power outage for information about power supply issues.

However, you are required to self-report all discharges from an EO, whether they are compliant or non-compliant with the permit conditions. Crude sewage may be discharged during an emergency. Whilst the permit authorises the discharge, it has the potential to cause significant pollution. You should self-report them in line with condition 4.3 and Schedule 5.

Where appropriate we expect you to mitigate the environmental impact of the discharge in line with the SPS Key Protection Measures (KPM) in place. If the discharge is compliant with the permit conditions and the KPM (if applicable), we will not record a permit breach on the CAR.

A discharge from a permitted EO is not permitted if the discharge is rainfall dependent and not because of an emergency. Guidance Note GN021 Unpermitted storm overflows (uSOs), details our approach to permit uSOs if the option is available. When you have provided evidence to show that an EO was not originally designed as an SO, we will not normally permit an SO discharge from this asset. You must self-report the incident in line with condition 4.3 and Schedule 5. The EO must be brought back into compliance within an agreed timeframe.

14. Storm overflows on the network – EPR

For discharges from emergency overflows due to rainfall, refer to section 13 Emergency overflows (EOs) at a WwTW or SPS – EPR.

Where you intend to apply for a permit, for an unpermitted storm overflow further to the investigations required in Guidance Note GN021 Unpermitted storm overflows (uSOs), refer to section 15 Unpermitted discharges from an SO or EO – EPR.

If an SO does not have direct links with a WwTW, it may have a pass forward flow (PFF) meter, rather than an FPF meter which should be referenced in the permit. The PFF  should be achieved before the SO should operate. It is a non-compliant discharge if EDM detects a discharge to the environment and the PFF is not met. You should self-report this. Information should be provided to comply with permit condition 4.3 and Schedule 5.

14.1 Storm overflow from an SPS with a storm tank and, or, a wet well

You should self-report non-compliant discharges from this type of asset. They are noncompliant if they discharge outside of permit conditions. There should be a flow meter for the PFF. You should self-report when the PFF is not met, the storm tank fills and EDM detects a discharge to the environment. Telemetry alarms in a wet well should notify you so that you can prevent a discharge.

15. Unpermitted discharges from an SO or EO – EPR

The following examples do not have an EPR permit but we expect you to apply the self-report requirements detailed in EPR permit condition 4.3 and Schedule 5 as stated in section 6.5 Consistent self-report approach (EPR and non-EPR).

15.1 Unpermitted storm overflows (uSOs)

If there is a rainfall dependent discharge from an outfall that does not have an EPR permit to discharge storm sewage, this is an unpermitted water discharge activity. You should self-report polluting discharges from these outfalls.

Guidance Note GN021 Unpermitted storm overflows details our approach to legalise the water discharge activity. From January 2026 you must self-report “known” as well as “newly identified” uSOs. We will consider duplication where appropriate, whereby at least one record per year is captured if an IAP is accepted. We expect you to mitigate pollution while you investigate options for solutions.

If an EO operates as a storm overflow you should refer to section 13 Emergency overflows (EOs) at a WwTW or SPS – EPR.

15.2 Unpermitted emergency discharges

You must self-report if there is a water discharge activity because of an emergency when there is not an EPR permit in place. We expect you to take action to minimise any environmental impact.

16. Non-permittable discharge (not EPR) – sewer, rising main, SWO

16.1 Foul sewer or network lid

You should self-report all water discharge activities from this non-permittable infrastructure, unless groundwater exclusion applies, or the discharges can be recorded on the self-report or update for the main polluting discharge to surface waters, refer to section 6.3 When you may not need to self-report.

16.2 Rising main

You should self-report all discharges from rising mains. As the flow is pressurised, any damage to the rising main pipework has the potential to cause significant pollution to controlled waters which includes groundwater and land.

16.3 Self-report polluting discharges from a surface water outfall (SWO)

If you observe or become aware of a polluting discharge from an SWO, such as sewage or another pollutant type, you should self-report it. If you are confident you are not the polluter, make this clear in your report to ICC so that we can investigate the pollution incident. Refer to section 1.5 Responsibility about sharing information and joint investigations depending on the pollutant and polluter.

16.3.1 Investigate polluting discharges from SWOs

If you own the surface water line and suspect the pollution incident is within your remit to investigate and resolve, after you have self-reported it, you should investigate the polluter and resolve the issue. If a third party is responsible, you should share the relevant information with us, subject to GDPR.

16.3.2 Include network-related details

If the discharge from the SWO is due to an issue in your wastewater network, include this detail in your self-report. Refer to section 21 Dye tracing.

16.3.3 Refer to misconnection guidance

Refer to section 20 Misconnections for our expectations related to misconnections.

Water supply assets self-report guide 

17. Treated process effluent discharge at WTW – EPR 17.1 OSM – numeric permits

A WTW can have an EPR permit for a range of water discharge activity types. Common water discharges are from the filter backwash, analyser wastewater, wastewater from the maintenance of granulated activated carbon (GAC) or “run to waste” water discharge activities.

If the permit contains numeric limits and OSM sample results demonstrate a numeric breach, you must self-report this. Refer to Annex 1 Pollution incident self-reports and update checklist for the information we need to assess the impact. You must comply with the requirements of EPR permit condition 4.3 and Schedule 5. You will need to submit detail in Part A(a) and A(b) as well as Part B when appropriate. 

Numeric breaches in WTW EPR permits are normally limited to minimum (e.g. pH) and maximum values. Look up table (LUT) exceedances and LUT failures do not apply to WTW permits with numeric limits. 

17.2 Operational samples, level of concern

You may monitor the water quality from the discharge point outside of the scope of prescheduled OSM samples. You must self-report your findings and described in the same way as for WwTWs in section 11.3. Operational samples (not OSM) and level of concern.

17.3 Visual observations (discharge point or inlet of WTW)

You should self-report if your visual observations of the discharge, if the water discharge appearance causes concern. Particularly if you suspect the water discharge is unlikely to comply with numeric limits in the permit. This includes during an OSM prescheduled sample visit and your observations during routine checks or maintenance operations. You should self-report a malfunction of equipment which has, is or may cause a pollution incident as specified in Part A(a) of Schedule 5 and complete Part A(b) if you can share sample data.

17.4 No flow

If there is no discharge of final process effluent when you take a prescheduled OSM sample or otherwise, you should investigate why. If a discharge is not expected (e.g. there may be batch treatment processes onsite) you do not need to self-report this. If you expect a water discharge activity to take place but it is not, you should investigate and self-report any unpermitted discharges that may occur elsewhere at the WTW, to comply with permit condition 4.3 and Schedule 5.

18. Non-permittable discharge from water the distribution network

A non-permittable asset is one that could result in a water discharge activity, but we would not grant an EPR permit or WIA consent to allow it.

18.1 Water distribution assets

This network does not have EPR permits to authorise water discharge activities. You should self-report water discharge activities from these asset types when they occur. The water in this network can contain high levels of chlorine, fluoride, or other chemical residues from the water treatment process. Pipes on the distribution network are pressurised and if they burst, they can mobilise sediment.

Refer to section 6.6 Self-report receptors and section 6.7 Self-report polluting discharges to land and groundwater exclusions. 

18.2 Pumping station emergency discharges

Under some circumstances a discharge may be made in an emergency from a WTW without the benefit of an EPR permit. You should self-report them to us with the appropriate amount of information for to us to be able assess the impact as there is risk of pollution to the environment.

18.3 Untreated (raw) water

You should self-report water discharge activity from a source of untreated water. Refer to Annex 1 Pollution incident self-reports and updates checklist to for type of information you should submit for us to assess the environmental impact. It is likely that this type of water discharge activity will mobilise sediment and suspended solids. This type of water discharge activity is likely to have an environmental impact.

19. Water Industry Act (WIA) discharges

We issue WIA consents for discharges made from the water distribution and storage network, which includes discharges from reservoirs.

19.1 Section 165 WIA consented discharges

You do not need to apply for a consent from us if the water discharge is from a pipe less than 229mm in diameter. You should provide ICC 48 hours’ notice of the water discharge and specify how you intend to prevent pollution to the environment, such as reducing the amount of chlorine in the discharge. You should provide the appropriate amount of information specified in Annex 1 Pollution incident self-report, updates and notification checklist and state that the information is a notification, rather than a self-report. You should self-report a pollution incident if the discharge has an impact on the receiving environment.

You should provide the appropriate level of detail listed in Annex 1 Pollution incident self-report, updates and notification checklist. 

19.2 Section 166 WIA consented discharges

You must apply for a consent from us to discharge from a pipe when the diameter is 229mm or more. Most Section 166 WIA consents are valid for a specific timeframe.

Regular discharges from reservoir scour valves are either for maintenance purposes, or to check the scour valve works or during an emergency. A consent for a discharge from a scour valve may be valid for a 5-year period. You should assess the risks from the discharge and act to minimise environmental impact for each water discharge.

You should provide 48 hours’ notice before the discharge and submit information about the asset type, nature of the discharge and mitigation measures. This process is detailed in section 19.1 Section 165 WIA consented discharges.

If you fail to notify us 48 hours in advance, you should self-report the activity.

You should self-report a polluting discharge if your operations have an impact to any type of receptor, refer to section 6.6 Self-report receptors. The discharge may have a measurable impact downstream if sediment has been mobilised or if dissolved oxygen is lower than you expected. You should self-report if the discharge causes injury to fish, or other aquatic life or if it impacts gravel beds for fish spawning grounds.

You should provide information listed in Annex 1 Pollution incident self-report, updates and notification checklist so we can assess the environmental impact. 

19.3 Sludge and waste-handling operations

You should self-report if you cause pollution to controlled waters when you manage sludge or other waste types from your assets. You should provide information listed in Annex 1 Pollution incident self-report, updates and notification checklist so we can assess the environmental impact. Other types of pollution incidents

20. Misconnections 

20.1 Your responsibilities

For misconnections on surface water outfalls (SWOs) you are responsible for, you should:

• self-report and investigate to identify the source of the misconnection
• take action to stop the pollution
• use dye tracing where appropriate to confirm pollution pathways – refer to section 21 Dye tracing
• provide regular updates to us throughout the investigation

If the source cannot be confirmed within section 24 - Review timescales the pollution incident report remains attributed to you. 

20.2 Duplication

If you receive further reports, self-report them and if they relate to the same outfall, we may consider duplication if the pollution incident meets the duplication criteria in section 27 Request to duplicate recurring pollution incidents.

20.3 Multi-year investigations

If your investigation spans calendar years, you must provide evidence the source is not from your sewerage assets. Only then will we consider closing the incident record as an unidentified third party for that calendar year.

If the polluter was not identified and the pollution incident record states you were responsible, you should self-report the pollution incident for the new calendar year to record the continued investigations. You should continue doing this until the polluter is identified. 

20.4 New misconnection to the same SWO

If pollution reoccurs after identified misconnections have been rectified, you must: • self-report a new incident each calendar year • repeat the investigation and self-report process 

21. Dye tracing

21.1 Self-report and planning

You should self-report before you dye trace. This is to ensure transparency and responsible use. Before you proceed with a dye test, check for any downstream events or amenities that could be impacted. Confirm whether the dye tracing is part of an ongoing investigation (e.g. a misconnection investigation) where a report has already been recorded. It may be that the dye trace self-report can be duplicated to the original one if appropriate.

21.2 Third party attribution

If the investigation confirms a third party is responsible, you should provide supporting evidence to enable the correct polluter to be identified. We may take action if appropriate.

21.3 Public reports

If the presence of dye is reported by a member of the public, we will record this on our system. We will assess it as a minimum category 3 amenity impact. We will attribute you as the polluter if our investigations find you were responsible for the release of dye.

22. Flooded assets

22.1 Definition

You should refer to section 6.9 Extreme weather and when to self-report flooded assets.

Flooded assets are when infrastructure you are responsible for is submerged, malfunctions and is uncontrollable due to extreme flooding. This includes treatment works, pumping stations or network infrastructure. These events may result from severe storms, fluvial flooding, groundwater rise, or coastal surges that exceed your reasonable capacity to prevent or manage pollution. 

22.2 After a flood event

After a flood event ends, you must:

• inform us once an asset is fully restored
• submit an IAP if restoration is delayed, refer to section 27.3 Incident Action Plan (IAP)
• be aware that our records may reflect restoration progress

Request to review – polluter and category 

23. Review principles

23.1 Our responsibilities

Under the Regulators’ Code we must ensure we have clear information and guidance to demonstrate our regulatory approach is transparent. We are also required to provide a route of appeal if you disagree with our regulatory decision.

23.2 Reviews are the exception

You should self-report accurate and timely information so we can assess the impact of a pollution incident and identify the correct polluter. A request to review our decision should be a rare occurrence. You should not treat them as routine.

23.3 When to submit a request to review

You should only submit a request to review when you can provide clear evidence that supports a change to our records. This may include identifying a:

• different category, see section 25 – Category review
• different polluter, see section 26 – Polluter review 

23.4 How to submit a request to review

• If we have agreed a process with you, use that to submit your request • If we do not have a process in place, contact the lead officer directly.

23.5 Timeliness

Share evidence promptly, ideally before we complete our assessment and close the pollution incident record. Refer to Annex 3 – Timeframes for pollution incident correspondence.

23.6 Our approach

To keep the process transparent and robust, we will:

• allow a reasonable timeframe for you to contact us
• apply timescales strictly
• reject review requests if evidence is insufficient or any of the criteria are not met

23.7 If we reject your proposed change

We will explain our decision. You may escalate the review if you disagree with our conclusion and have strong supporting evidence to support it.

23.8 Final decision

If the escalated review also rejects the change request, our decision is final.

24. Review timescales

Summarised in Annex 3 – Timeframes for pollution incident correspondence.

24.1 Submit requests to review

You must submit any review requests within 14 days of us confirming the incident assessment. This confirmation will be provided in writing such as when we send regular pollution incident datasets. If you submit requests promptly it will help us to review contemporaneous evidence and allows further information to be gathered within a timely manner.

24.2 Request an extension

You may request a 14-day extension, but only if you: • submit the request in writing to the lead officer and their team inbox before the initial timeframe • explain why more time is needed • include completed actions, outstanding tasks, and proposed timeframes

24.3 Further extensions

By exception, we may agree to a further extension, up to a maximum of 60 days from the notification date. The relevant Environment Team Leader must approve this due to the potential impact on external reports.

24.4 Annual cut-off

All requests to review and escalations must be resolved by 28 February for the previous calendar year because of the EPA and PIRP report process. 

24.5 Missed timeframes

If you do not provide evidence within the agreed timeframe, we will categorise the incident and assign the polluter based on the information provided.

25. Review the impact category

25.1 Category 1 and 2

If we categorise a pollution incident as Category 1 or 2, we may review our decision where you provide additional evidence that may indicate that the environmental impact was lower than the original assessment.

25.2 No review option for Category 3

Do not submit requests to review the category where we have assessed the discharge to controlled waters as Category 3. We will consider most water discharge activities into the environment to have a minimal impact. The exceptions are detailed in section 6.7 Self-report polluting discharges to land and groundwater exclusions and 6.3 When you may not need to self-report.

If you have evidence that the polluting discharge was fully contained on impermeable land or within the sewerage network, we can assess it as Category 4 (no impact). You should share this information with us within 14 days of notification and not through a request to review the category. 

25.3 Impact categories

If we decide to alter the category on the pollution incident record, for example, downgrade the water quality impact, you should be aware that other impact categories, such as amenity or ecology may remain unchanged. Each impact category is assessed independently, and a change for one receptor does not automatically alter others.

26. Review the polluter

26.1 Third party polluters

You must make reasonable efforts to identify any third-party polluters as part of your investigation. If you believe a third party is responsible, provide this information within 14 days of the self-report. If you obtain new evidence after we have completed our assessment, you can request a review of the identified polluter within 14 days of us confirming our assessment.

26.2 Share information

You should pass on third party details, subject to GDPR, so we can consider enforcement options and cost recovery.

26.3 Incident records

We will decide how the pollution incident is recorded on our system. This does not determine legal liability or enforcement action. We may still record permit non-compliances on a CAR and take enforcement action against you, even if a third party is involved. Shared responsibility may be assigned.

26.4 Responsibility criteria

You remain responsible for pollution discharges if the incident:

• could have been anticipated, prevented, or mitigated by reasonable action
• reflects common water industry operations 

Third parties are only responsible where the polluting discharge was unforeseeable to an extraordinary degree. Vandalism may qualify in exceptional cases. 

26.5 Foreseeable items

Items commonly found in the sewerage system are considered foreseeable. You are expected to have systems in place for asset maintenance and public engagement to prevent sewer misuse. You should not submit requests to review the accountability for a polluting discharge involving (but not limited to) the following items, as these will not be accepted:

• drainage rods (domestic or industry)
• fats, oils, and grease
• toilet paper
• sanitary items (e.g. nappies)
• wet wipes (biodegradable or not)
• screwdriver
• drink bottles and cans
• tree roots
• stones
• items that can be flushed in a toilet

These items are the result of common water industry operations and sewer misuse and should be managed through proactive maintenance and education. Other third-party items typically found in sewers may be added to this list. Appeals for other items may still be rejected. 

26.6 Object size and relevance

The size of the object is important in determining third party requests, especially in relation to the sewer diameter. We will reject requests where the object is small relative to the sewer diameter.

26.7 Unforeseeable to an extraordinary degree

We accept that some incidents may be genuinely unforeseeable. In such cases, you must provide detailed evidence as outlined in Annex 1 – pollution incident self-report and updates checklist. 26.8 Misconnections Refer to section 20 Misconnections. 

Request to duplicate recurring pollution incidents

27. Request to duplicate

27.1 Our approach to duplication

We may agree to record future reports of the same recurring pollution incident as duplicates if the impact remains minor and an approved Incident Action Plan (IAP) is in place to identify and resolve the root cause. We will not duplicate pollution incidents that have a major or significant impact.

A recurring incident is defined in section 27.3 Definition of a recurring pollution incident.

If we accept your duplication request, future pollution incidents will be linked to the primary record, the one created before we approve the IAP.

If we reject your request to duplicate, we will explain our decision. You may escalate the request if you disagree with our conclusion and have strong supporting evidence to support it. If we reject the escalated request, our decision is final. Refer to Annex 3 Timeframes for pollution incident correspondence.

You must deliver all actions in the IAP as agreed. If you do not complete the actions by the agreed timeframes or they prove ineffective, we may record each polluting discharge as a separate incident.

If we attend site in response to a report about a pollution incident, that record will not be included as a duplicate one. It will be recorded outside of the duplication process.

If recurring polluting discharges continue into the next calendar year, the duplication process will not continue. At least one pollution incident must be self-reported each calendar year. You must report the first pollution incident when it reoccurs in the next calendar year.

 Approval of an IAP and acceptance of a duplication request does not limit our enforcement response. We may still take action in line with our Enforcement and sanctions policy.

27.2 Duplication criteria

To request duplication, you must provide evidence that all the following criteria are met. We will only approve duplication if these conditions are satisfied:

• the incidents are recurring and likely to occur again because the root cause cannot be resolved promptly
• all incidents occur at the same location or originate from the same asset
• the root cause is the same and cannot be addressed through planned maintenance. Some examples of planned maintenance may include activities such as de-silting or removing tree roots which should be resolved promptly, relining pipework, replacement of mechanical parts
• the impact on any receptor, not just water quality, remains minor. Serious impacts (category 1 or 2) must be reported as separate incidents and the Incident Action Plan should be updated with actions and mitigation measures. For example, an impact may no longer be minor if it recurs during low flows, prolonged dry weather, or lasts significantly longer than expected
• mitigation measures are implemented or planned to minimise environmental impact until the root cause is fully resolved
• once the root cause is confirmed, any issues that can be addressed through planned maintenance are resolved without delay. Investigations may reveal multiple causes: minor repairs should be completed quickly, while major upgrades may take longer. Interim mitigation measures must remain effective until long-term solutions are delivered
• an Incident Action Plan that meets the requirements in section 27.3 Incident Action Plan (IAP) is in place and accepted by us

For assets with EDM see section 27.3.1 Assets with EDM for more detail.

27.3 Incident Action Plan (IAP)

An Incident Action Plan (IAP) sets out how you will investigate, mitigate, and manage a pollution incident that is likely to recur before the root cause can be resolved. Your IAP must:

• be owned and signed off by a budget-holding manager
• be kept up to date, with revisions submitted whenever actions are complete or timescales change for our consideration (acceptance is not guaranteed)
• include all required information as specified in Annex 2 Incident Action Plan checklist template
• record each polluting discharge, even if a self-report is not required, and your response to each incident as agreed in the IAP
• address any planned maintenance issues promptly to reduce the number of polluting discharges while you deliver the long-term solution
• be submitted early, you can submit an IAP after one pollution incident if a repeat is likely

27.3.1 Assets with EDM

Event Duration Monitors provide data about discharges from storm and emergency overflows, where they have been installed. They record all discharges, some of which are short lived. Some are compliant with the permit conditions, others are not. It is not appropriate to individually self-report these polluting discharges as described in this guidance.

To bring the asset into compliance requires investment and resolution that may take many years. When we apply duplication to an asset with EDM, we will agree how and at what frequency you will tell us about the discharges that take place. We may require information from the EDM data in updates after the initial self-report. We will agree the frequency of submitting this information. It is important we have a record of the total number of polluting discharges.

For storm overflows we have agreed for inclusion within the SO programme, the IAP must also:

• demonstrate that the GN021 and GN066 performance classification process is being followed within the required timeframe
• include storm overflow programme tracker updates
• specify dates for performance classification
• specify dates for completion of an Urban Pollution Management (UPM) study, which will inform the scheme design to resolve the root cause

27.4 Examples when duplication may apply

Duplication may be appropriate in any of the following circumstances:

• complex investigations, establishing the root cause involves multiple factors or covers a large geographical area 
• difficult access, the location requires significant planning to access, such as:
  • busy highways
  • railway infrastructure
  • remote or hazardous sites
• long-term investment required, which includes planned maintenance and enhancement is needed to resolve the root cause, for example:
  • groundwater infiltration
  • hydraulic overload
  • surface water or saline intrusion