This report represents the second in a series of studies of sewage treatment basins undertaken in order to determine the relative importance of major sources of pollutants found at the influent of publicly-owned treatments works (POTWs). The general categories of residential, commercial and industrial have been identified as appropriate classifications for this study. This second study was carried out in the drainage basin of the Coldwater Creek treatment plant in the metropolitan St. Louis, Missouri area. In contrast to the predominantly residential character of the Muddy Creek basin in Cincinnati, the Coldwater Creek basin area had a reasonable amount of flow from commercial and industrial sources in addition to the residential flow. The relative flow from these source types in the basin was: Residential: 78%, Commercial: 10%, Industrial: 12%.