The Municipal Environmental Research Laboratory of the U.S. Environmental Protection Agency funded an extramural research program to (1) develop sensitive analytical methods capable of analyzing municipal wastewaters and sludges for 114 organic priority pollutants and (2) survey 25 publicly owned treatment works for the toxic organics. Development of the analytical methods and results of the survey are discussed. Plant selection criteria included plant size and type, geographical location and industrial contributions to the municipal wastewater. Raw wastewaters, primary effluents, final discharges and sludges were sampled. The majority of the plants were found to have between 20 and 50 priority organics in their raw influents and 10 to 30 priority organics in their final discharges. Only 15 compounds were found at concentrations above 1 micrograms/l in wastewaters (or 1 mg/kg in sldge) at least 80 percent of the time in raw wastewaters and at least 50 percent of the time in final plant discharges and sludges. Significance of the findings as related to proposed Water Quality Criteria for both toxic organics and metals are addressed.