The Department for Environment, Food and Rural Affairs (Defra), the Environment Agency, and water services agency Ofwat may have broken environmental law, according to an investigation by the Office for Environmental Protection (OEP).
This possible failure is in relation to the regulation of combined sewer overflows (CSO), which the OEP had been investigating following a complaint alleging failures to comply with legal duties relating to the monitoring and enforcement of the management of sewage. 
The OEP believes that there may have been failures to comply with environmental laws by all three of the public authorities and has issued Information Notices to each of them setting out the details of those possible failures. 
The three authorities have two months to respond to the notices by setting out their response to the allegations and what steps, if any, they’ll take in relation to them.
Environmental Audit Committee chair, Rt Hon Philip Dunne MP, said this investigation confirms committee findings from January 2022.
“In January 2022 the Environmental Audit Committee reported that there were ‘multiple potential points of failure in the regulatory arrangements for monitoring, governance and enforcement of water quality’,” he said.
“The OEP’s information notice today, issued after a thorough investigation, tends to confirm this sorry state of affairs.”
Investigation
Helen Venn, OEP’s chief regulatory officer, believes that the issue at its core is misinterpretation of “key points of law”.
“The core of the issue is that where we interpret the law to mean that untreated sewage discharges should generally be allowed only in exceptional circumstances, such as during unusually heavy rainfall, it appears that the public authorities may have interpreted the law differently, permitting such discharges to occur more often,” she said.
“This then has consequences for the regulatory activity that follows. The guidance provided by government to regulators, and the permitting regime they put in place for the water companies, possibly allow untreated sewage discharges to occur more regularly than intended by the law without risk of sanction.
“This is what has created the possible failures to comply that we have identified. 
“Clarifying this point will ensure future efforts to improve water quality are built on a solid foundation. We will consider the responses from all three public authorities in detail before deciding next steps,” she added.
Three public authorities
A Defra spokesperson has said that while it does not agree with the OEP’s initial interpretations, it will continue to work “constructively” with the OEP on this issue.
“The volume of sewage discharged is completely unacceptable,” the spokesperson added
“That is why we are the first government in history to take such comprehensive action to tackle it, driving forward more investment, stronger regulation and tougher enforcement – and it’s why we are introducing a legally binding target to reduce storm overflows.”
“We welcome this investigation from the Office for Environmental Protection and we share their ambition to drive improvements in water quality,” a spokesperson for the Environment Agency said.
“We will always take action against companies that do not follow the rules or those that are deliberately obstructive. We have secured fines of over £150 million and are conducting our largest ever criminal investigation into potential permit non-compliance at sewage treatment works.”
An Ofwat spokesperson also welcomed the OEP’s considerations, “particularly on the clarity of responsibilities for the protection of the environment and we will work with them as their investigation moves forward”.
“Our position at Ofwat remains clear, water companies’ performance on the environment is simply not good enough,” the spokesperson added.
“We will keep pushing for the change and the improvements that the public rightly expects and where we can learn lessons or do things better, we will do so.”
Alleged environmental law failures
For Defra, the potential failures relate to the requirements of urban waste water legislation, water quality legislation, and Defra’s duty to make enforcement orders where sewerage companies fail to comply with their own duties to effectually deal with sewage.
For the Environment Agency, the potential failures relate to the requirements of urban waste water legislation and the Agency’s resulting role in devising guidance, setting permit conditions for CSOs, and reviewing and enforcing of such conditions.
For Ofwat, the potential failures relate to its interpretation of sewerage undertakers’ duties to effectually deal with sewage and Ofwat’s duty to make enforcement orders where sewerage undertakers fail to comply with such duties.