THE IMPACTS OF DISCHARGES FROM 2 COMBINED SEWER OVERFLOWS ON THE WATER-QUALITY OF AN URBAN WATERCOURSE

The impacts of combined sewer overflows and surface water outfalls on receiving water quality are assessed by comparing dry weather flow and storm event concentrations of dissolved oxygen, BOD, total and unioni sed ammonia, pH, dissolved copper and total zinc with those recommende d by the River Ecosystem classification guidelines for freshwaters in the UK. The deteriorating conditions during wet weather are identified by water quality falling below the RE2 category for all monitored pol lutants, other than dissolved copper, and reaching the most grossly po lluted condition for BOD and total ammonia. (C) 1997 IAWQ. Published b y Elsevier Science Ltd.