There is a need for an Independent Audit and Action by Defra if effluent recycling is to proceed
It is of significant concern that Southern Water has given residents and councillors the impression that the effluent recycling plants will be designed and operated under a highly regulated process, when the reality is that they will NOT.
- The Environment Agency has confirmed that they will only be able to regulate a very limited number of parameters in the final discharge water to the river, reservoir and coastal waters. Many of the contaminants of most concern that can pass through the treatment process will not have permit levels applied to protect the environment.
- The Drinking Water Inspectorate (DWI) will have minimal involvement in the effluent recycling plant. They will not routinely or regularly audit the plant.
The Water Matter communities concerns regarding the lack of regulatory control for effluent recycling were set out in our letter to the Secretary of State in April 2026. A copy of this letter,, with personal details redacted, can be read by clicking the image below:
Please refer to Appendix A of the letter, Section 1 for more detail on the regulatory gap, and Section 2 where the minimal role of the Drinking Water Inspectorate (DWI) is explained, along with actions needed by Defra (Section 2.2), including the control measures that need to be made mandatory if effluent recycling were to proceed.
Instead, the effluent recycling plant will be designed, built, operated, monitored and self- regulated by Southern Water or its contractors. Given the low level of public trust in water companies, the repeated failure of traditional treatment plants, reporting failures and pollution incidents, it is completely inappropriate to allow a company like Southern Water to self-regulate the complex effluent recycling treatment process which is new technology to the UK for public water supply.
As many water quality concerns associated with the effluent recycling plant will NOT be dealt with adequately by our regulators under existing legislation, it is essential that Defra review international good practice and regulate to ensure additional control measures for effluent recycling are made mandatory in the UK. This should include;
- Requirement for a risk assessment to be undertaken in the sewer catchment of every planned effluent recycling plant, and action taken to reduce hazards at source.
- Requirement for regular ongoing review with a full review at least every 5 years of the sewer catchment risk assessment, and to use the information obtained to implement a continuous program of improvement in relation to enhanced contaminant source control actions, and optimising the treatment processes to minimise risk to the environment and public health.
- Requiring the formation of an independent Source Control Steering Committee of approved competent experts. To be responsible for confirming the adequacy of the sewer catchment risk assessment, approving the list of actions to reduce risks, monitoring progress, and reporting back to the Regulators/ Local Authority on progress and any concerns.
- Requiring the formation of an Independent Scrutiny Panel to audit the effluent recycling plant design, construction, operation and monitoring data. The independent panel should meet at least twice a year and provide an annual report to Regulators/Local Authority, including any recommendations for action.
This ongoing independent scrutiny is essential given that the water industry in the UK is privately owned, operating as a monopoly on a for-profit model, and the regulatory gaps in UK legislation which was not designed to manage effluent recycling. Public trust in effluent recycling will never be achieved without robust independent scrutiny.
International examples of such control measures including the requirement for independent panels in other countries to monitor effluent recycling plants are provided in Appendix B of the letter to the SoS. These examples are taken from World Health Organisation Guidance on effluent recycling.
Independent scrutiny is essential given Southern Water’s poor track record with £90 million in fines for pollution incidents, and £126 million in penalties for the manipulation and misrepresentation of regulatory data over water treatment works.