Controls on trade effluent: discharge consents
A company that wishes to release effluent directly to controlled waters or indirectly- by surface water drains needs to have a consent from the EA. This will detail the amount and the type of discharges that are deemed acceptable. The consent parameter (eg pH and Chemical oxygen demand (COD) are ascertained through studying their likely effect upon controlled water quality that will receive the discharge.
The conditions attached to the consent by the EA will generally be (schedule 10: Water Resources Act 1991)
Discharges to sewers
A consent system also exists for effluent discharges to sewers. It is the sewerage undertakers (the water companies) that are charged with the regulation of this. Parameters are set to protect the sewers and the tretament works. Parameters and limits are given to the company from the sewerage undertaker using a discharge consent.