"The MCS recognises that Combined Sewer Overflows (CSO) are necessary to avoid sewage flooding roads or people's houses, and that diffuse pollution is an entrenched and difficult problem, " Mr Bell said.

BBC: NEWS | UK | Heavy rains 'pose bathing risk'

The contribution of diffuse sources of pollution to bathing water failures, both rural and urban, is being investigated.

BBC: Beaches 'need to improve'