[en] The San Francisco Regional Water Quality Control Board recently established mass limits on discharges of selenium to the San Francisco Bay from several petroleum refineries. The refineries had been working independently to develop control strategies, including both source control and treatment options, for removal of selenium from their discharges. By January 1992, over fifty different combinations of treatment technologies, wastewater streams, and pretreatment steps had been investigated to determine their effectiveness and feasibility as selenium removal processes. No treatment process studied could achieve the required mass limits without serious negative environmental consequences, such as generation of large amounts of hazardous sludge. To better facilitate the development of a feasible selenium treatment process, the six Bay Area refineries shared results of their studies and identified several technologies that, with further work, could be developed further. This additional work is currently being carried out as part of a joint selenium treatability study sponsored by the Western States Petroleum Association. A review of the previous source control and treatment studies, along with a description of the current treatability studies will be discussed

[en] An alternate approach to EPA's proposed methods for predicting the bioconcentration of effluent constituents was assessed. Integrated field and laboratory exposures were used to evaluate the bioaccumulation of hydrocarbons and trace metals from refinery effluents in the San Francisco Bay/Delta. Field bioaccumulation and laboratory bioconcentration were analyzed in mussels, oysters and fish at a range of dilutions reflecting effluent distribution in the environment. These studies allowed a rigorous evaluation of a number of factors which normally confound the quantification of bioaccumulation of refinery effluent associated compounds. Specific trace element and hydrocarbon analytes were targeted for measurement using techniques which provide detection at levels below the limits in currently accepted methods. Effluents, receiving waters and tissues were analyzed for aromatic hydrocarbons by multiple selected ion monitoring GC/MS. These methods allowed the quantification of parent compounds as well as specific petrogenic alkylated naphthalenes and phenanthrenes and dibenzothiophenes at very low levels in effluents and tissues. A suite of trace elements was also analyzed using ICP-MS methods. The results of those studies are discussed and compared with EPA's proposed methods

[en] Assessing the contribution of various sources to contaminant bioaccumulation in aquatic organism presents a number of challenges. The use of effluent-specific chemical markers would greatly facilitate identification of sources of contaminants found in aquatic organisms. Two classes of compounds were investigated for use as effluent-specific markers for petroleum industry discharges: alkylated polycyclic aromatic hydrocarbons (PAH) and rare earth elements (REE). Alkylated PAHs, specifically methyl and dimethyl naphthalenes, methyl and dimethyl phenanthrenes, and dibenzothiophene, appear to have excellent potential as effluent-specific markers for petroleum industry discharges. They are not associated with combustion sources, are abundant in crude oil and certain refined petroleum products, and were at detectable concentrations in bivalves exposed to refinery and produced water discharges. Three alkylated PAHs were detected in both refinery and produced water effluents, but not in receiving water samples from a highly urbanized estuary. REEs are incorporated into cracking catalysts used in refiners and would also appear to be excellent candidates for specific markers of refinery effluents. However, concentrations of REEs in a tertiary-treated refinery effluent were near or below detection and no significant bioaccumulation of REEs was observed for bivalves and fish

[en] Public concern regarding the presence of persistent, bioconcentratable compounds in fish and shellfish has led the petroleum industry to investigate methods for the measurement of bioconcentratable compounds in refinery effluents. Research has focused on developing methods to measure polycyclic aromatic hydrocarbons (PAHs) and other hydrocarbons directly in the effluent and in bivalves exposed to refinery effluents in the field and in the laboratory. Results from a multi-refinery study in the San Francisco Bay Area using selective ion monitoring GC/MS-MS indicated that alkylated and non-substituted 2--3 ring PAHs are rarely present in refinery effluents at concentrations greater than 100 ng/L. Higher MW PAHs were rarely detected. PAHs did not substantially bioconcentrate in bivalves exposed in the laboratory to refinery effluent and reference sea water. Total PAHs were generally less than 50 μg/g in the effluent-exposed bivalves. A comparison of the waste water treatment facilities at each refinery suggest that biological treatment already required by existing regulations is sufficient to reduce PAH concentrations to these low levels