A total of 208 POTWs from four flow rate categories were selected for sampling and analysis. EPA contract personnel collected the samples which were analyzed for a total of 412 analytes. These analytes include every organic, pesticide, dibenzofuran, dioxin and PCB for which EPA has gas chromatography and mass spectrometry (GC/MS) standards. The remaining pollutants are inorganic. Pollutants were also selected based on: 1) the CWA Section 307(a) priority pollutants, 2) toxic compounds highlighted in the domestic sewage study, and 3) Resource Conservation and Recovery Act (RCRA PL94-580) Appendix VIII pollutants.