Water Companies and the Environmental Agency (EA) are by law responsible for the quantity and quality of effluent discharged into the seas or rivers (watercourses). As a consequence they must control the amount and type of effluent entering into treatment works to
a finite capacity. Should this capacity be exceeded pollution would be transferred into the watercourses. Industry, with its diversity of trade effluent is the most difficult to control and where high volumes of polluting effluent are generated, companies may be required to monitor and control their discharge.