This report presents the results of a study of wastewater effluent characteristics of refineries in Washington State, compiled for NOAA as part of an Environmental Assessment of Northern Puget Sound and the Strait of Juan de Fuca. The purpose of the study was to describe in detail the types of petroleum and petroleum derivatives that potentially could reach the waters of Puget Sound. This was achieved through the collection and summary of available information on the chemical characteristics, amounts processed, and final disposition of crude oils, refined products, and wastewater effluents associated with the six Puget Sound refineries. Sources for this information included the literature, federal and state government agencies, the petroleum industry, and academic institutions. The report describes the amounts and types of petroleum and its derivatives handled by Puget Sound refineries and the amounts typically reaching marine waters. Further, the refining and waste treatment processes employed by the area refineries are described in detail.