Water Industry Act 1991

Under the Water Industry Act, companies wishing to discharge trade effluent to foul sewer must hold a consent from the local sewerage undertaker (normally the regional water company). Charges may be levied according to effluent nature, concentration and volume.

Again, conditions will be imposed on the consent, and monitoring to ensure compliance may either be undertaken by the sewerage undertaker or the site itself. Failure to comply with the consent conditions, or the lack of a consent altogether, would be an offence under the WIA.

The system of consents allows treatment works to budget for the type of substances that they will have to treat. Unconsented discharges may contain substances which cannot be treated effectively and which will therefore pollute the discharge of effluent into controlled waters from the treatment works. In addition, treatment works rely on bacteria to break down incoming effluent and sewage. Unusual chemicals entering the works may damage the bacteria and reduce the efficiency of the plant.