ABSTRACT
Sampling is the most important factor in every wastewater analyses. Since the wastewater analyses will be dependent upon the composite samples, care must be taken to insure that the composite sample is a valid sample. The combined sewers hydraulically overloaded new wastewater treatment plants, causing violations of effluent discharge permits. Normally, the separate storm sewers have no discharge during dry periods unless groundwater leaks into the sewers or illegal connections exist, allowing domestic wastewaters or industrial wastewaters to enter the storm water sewers. The relative volumes of municipal wastewater and storm water runoff determine the characteristics of combined sewer overflows when the overflow events occur. Normal procedures divide the wastewater characteristics into physical characteristics, chemical characteristics, and biological characteristics. The overflow from combined sewers has different characteristics than the discharge from separate storm water sewers. The local topography determines the characteristics of the pollutants found in rural runoff.
