Toxicity identification evaluations of produced‐water effluents

Abstract

Abstract-Toxicity identification evaluations (TIEs) were performed on 14 produced-water (PW) samples of various salinities from inland and offshore oil-and gas-production facilities operated by different companies in Wyoming, Texas, California, and Louisiana (USA) to evaluate the efficacy of TIE procedures in determining potential toxicants in PW effluents. The research involved acute (24-and 48-h) freshwater and marine toxicity tests on whole PW and PW fractions generated by standard U.S. Environmental Protection Agency and PW-specific fractionation schemes. Factors influencing PW TIEs were investigated, such as the effect of salinity in selecting fractionation manipulations, the effect of toxicity test replication (i.e., reproducibility) in distinguishing changes in toxicities between whole PW and its fractions, and the suitability of different test species in PW TIEs. The results obtained and lessons learned from conducting these PW TIEs are presented in this article. Components, or fractions, contributing to toxicity differed for each PW with no specific fraction being consistently toxic. For most PW samples, toxicity attributed to any one fraction represented only part of the toxicity of the whole sample. However, no more than two fraction types were identified as potential toxicants in any sample. Potential toxicants identified during this study, besides salinity, included acidic and basic organic compound class fractions, particulates removed by filtration at pH 11, ammonia, hydrocarbons, hydrogen sulfide, material removed by pH change, and volatile compounds.

Chemical, Physical, and Risk Characterization of Natural Gas Storage Produced Waters

“…Microcrustaceans, Ceriodaphnia dubia Richard, were chosen as the assessment species for this study because they are sensitive to many constituents commonly found in NGSPWs and are routinely used in toxicity testing required by NPDES permits (USEPA 1995;Sauer et al 1997). C. dubia, commonly named 'water fleas', are freshwater arthropods that occur in littoral areas of lakes, ponds, and marshes throughout the world.…”

Field Validation of Toxicity Tests to Evaluate the Potential for Beneficial Use of Produced Water

“…Other sources of toxicity include major ion imbalances, hydrocarbons, ammonia, and hydrogen sulfide (Boelter et al 1992;Sauer et al 1997;Elias-Samlalsingh et al 2004). Gulley et al (1992) and Mount et al (1992) found that toxicity resulting from major ion salinity could be accurately predicted and accounted for using statistically-derived ion toxicity models.…”

“…Of those studies that have assessed the effects of produced water on freshwater organisms, elevated ion concentrations, organics and ammonia have been identified as the primary constituents causing observed toxicity (Ho and Caudle 1997;Sauer et al 1997), and each of these components could be significantly modified upon entering a receiving system. However, field studies that validate these laboratory-based effects are practically nonexistent.…”

Ecological and human risk assessment of long-term produced water discharge to the ocean at the Sonda de Campeche, Gulf of México

“…Produced water is an inextricable part of the hydrocarbon recovery processes; yet, it is by far the largest volume waste stream associated with hydrocarbon recovery (Sauer et al 1997;Balaam et al 2009;Fakhru'l-Razi et al 2009). …”