Verification of the Water Quality Impacts of Combined Sewer Overflow

摘要

The purpose of this study was to identify the source and mechanism of the water quality impacts in the Milwaukee River following wet weather discharges. Monitoring surveys have demonstrated that there is often a rapid decline in dissolved oxygen following combined sewer overflow discharge events in the lower portions of the river. Water quality modeling of the river with Harper's water quality model indicate that the loadings from combined and storm sewer discharges are not sufficient to cause the observed rapid declines in DO. The results of laboratory and field investigations indicate that bottom sediments within the lower river are a significant sink for DO and are linked to the rapid loss of DO. The mechanism of this rapid DO decline is the scouring of sediment oxygen demanding materials by submerged CSO outfalls.