Regulation of combined sewer overflows (CSOs)

Summary

An investigation into the roles of Ofwat, the Environment Agency and the Defra Secretary of State in the regulation of combined sewer overflows (CSOs) in England.

More information

Our investigation found that there had been failures to comply with environmental law by each of the three public authorities relating to the regulation of network CSOs. Decision notices were issued to them setting out the actions required to address the non-compliances. We welcomed responses from them which showed positive action to address the concerns raised and significant progress being made.