The group, called the Office for Environmental Protection, blamed several agencies and gave them each two months to respond with steps to fix their problems. After then, the OEP may sue them.

Discharges of untreated waste into public waters in recent years triggered outrage among Britons and prompted citizen scientists to conduct their own testing regimes because they don’t trust companies to keep the environment safe.

“The core issue identified in our investigation is the circumstances in which the regulatory system allows untreated sewage discharges to take place,” Helen Venn, the watchdog’s chief regulatory officer, said in a statement. “We interpret the law to mean that they should generally be permitted only in exceptional circumstances.”

The 2 1/2-year probe found that companies were releasing concentrated sewage when it wasn’t raining — a practice known as dry spilling.

The issue plagued the Conservative Party before its defeat in this year’s general election by the Labour Party. Prime Minister Keir Starmer has promised to crack down on the discharges, and his government assumed the power to ban bonuses and bring criminal charges against company executives, a spokesperson said Tuesday.

Regulator Ofwat is investigating all 11 English and Welsh companies for spills from treatment works. That’s running in parallel with a criminal investigation by the Environment Agency.

However, the watchdog blamed Ofwat, the agency and the Department for Environment, Food and Rural Affairs for contributing to the crisis. It accused the agency of drafting guidance that didn’t reflect the intent of the law and failing to ensure companies complied.

In addition, Ofwat and the rural affairs department, known as Defra, failed their responsibilities to issue enforcement orders against unlawful sewage spills, the report said. Defra also allegedly didn’t ensure companies complied with emissions controls.

The Environment Agency has made significant progress in addressing the issues identified by the watchdog and is consulting on updates to permitting and regulations for storm overflows, a spokesman said.

Ofwat is actively taking steps to remedy the issues, a spokesperson said.

Defra didn’t immediately respond to a request for comment.