Introduction U.S. petroleum refiners have consistently reported water pollution abatement technology and waste control practices in order that this type of information will be readily available for all interested parties both within and outside the oil industry (1 thru 5). The nationwide effort to establish water quality criteria and the supplementary plans for implementation@ in accordance with the 1965 Amendments to the Federal Water Pollution Control Act@ stimulated the American Petroleum Institute in 1967 to initiate a comprehensive industry-wide survey of current oil refinery waste control practices and performance. It was intended that this survey would update available data and provide a more comprehensive picture of refinery effluent quality than had previously been published. The stated purposes of the 1967 API Survey were as follows: a. To provide the petroleum industry with valid data on refinery effluent loads and current waste control practices. b. To develop reliable data on waste control performance to permit realistic comparisons of waste load characteristics between refineries with similar amounts of downstream processing complexity and waste load potential. c. To permit comparison of effluent control for typical types of refineries under varying conditions of waste treatment and control. d. To establish a realistic basis for development of good practices in refinery water pollution control.