PERFORMANCE OF A WET WEATHER TREATMENT FACILITY FOR CONTROL OF COMBINED SEWER OVERFLOWS
Efforts aimed at reducing combined sewer overflow (CSO) pollutant loads on the Muddy Creek receiving waters in Cincinnati, OH have been undertaken in recent years. This includes an investigation of the treatment performance of a flow-through wet weather treatment facility (WWTF) using off-line sedimentation tanks, fine screens and chemical disinfection (which was inactive during this study). Calculations using hydrographs and water quality samples collected at the WWTF during rain events established the mass of BOD5, COD and TSS removed. Most pollutant removal was achieved through settling and storage in the treatment tanks, with removal efficiencies of 20-50% for BOD5 and 25-70% for TSS commonly observed. Owing to the high pollutant concentration in the early stages of the rain event, first-flush containment, or capturing and conveying the early portion of the runoff event to the WWTP, was the most efficient treatment method for every storm. Nevertheless, unacceptable levels of total coliform and E. coli were measured entering the creek, stressing the need for disinfection.
School:University of Cincinnati
School Location:USA - Ohio
Source Type:Master's Thesis
Keywords:combined sewer overflow sedimentation basins tanks first flush stormwater treatment storage tank
Date of Publication:01/01/2003