The council maintained the sewage system in its district as agent for the statutory authority, the Severn Trent Water Authority. It operated, maintained and repaired the sewers. As sewage authority, it received raw sewage into its sewers. On the occasion in question one of the sewers became blocked. The sewage flowed into the stormwater drainage system and into the River Avon.
Held: The Council had not done any positive act which caused the pollution. If it had known of the blockage it might have been liable for ‘knowingly permitting’ but it could not be liable for causing. Negligent inactivity which fell short of a positive act was insufficient to be a ’cause’ of pollution.
Gazette 16-Sep-1992,  1 WLR 125
Water Act 1989 107(1)
England and Wales
Disapproved – Empress Car Company (Abertillery) Ltd v National Rivers Authority HL 22-Jan-1998
A diesel tank was in a yard which drained into a river. It was surrounded by a bund to contain spillage, but that protection was over ridden by an extension pipe from the tank to a drum outside the bund. Someone opened a tap on that pipe so that . .
Restricted to its facts – National Rivers Authority v Yorkshire Water Services Ltd HL 21-Nov-1994
The defendant sewerage undertaker received sewage, treated it in filter beds and discharged the treated liquid into the river. One night someone unlawfully discharged a solvent called iso-octanol into the sewer. It passed through the sewage works . .
These lists may be incomplete.
Updated: 18 February 2021; Ref: scu.90635