RESEARCH PRIORITIES TO REDUCE ENVIRONMENTAL AND HEALTH RISK OF EXPANDED PRODUCED WATER USE (Invited Presentation)

Oil and gas development in the United States generates over a trillion gallons of produced water each year, the majority of which is managed using underground injection for disposal or enhanced recovery. Some arid western states are undertaking efforts to expand use of produced water inside and outside the oilfield to reduce demands on freshwater. Challenges to such uses of produced water include its high variability in quality and volume, insufficient storage and transportation infrastructure, and poorly understood chemical and toxicological characteristics.

We will present a database of chemicals detected in produced water. The database includes EPA approved methods for measuring the concentration of these chemicals in the environment, human and ecological toxicity values, and an overview of existing state and federal regulatory programs that could potentially apply to produced water use and discharge, focusing initially on water quality criteria and standards. The database contains 181 citations that characterized produced water, resulting in the identification of over 1350 unique chemicals found in produced water samples collected across North America. Of these chemicals, only about eight percent are included in surface water quality regulations, indicating that existing standards and criteria offer some understanding of produced water constituents of concern, but major gaps remain. Furthermore, over half of produced water chemicals have not been the subject of a toxicity study, and most do not have health-based reference values needed to conduct a risk assessment. By combining these data, we have developed a database that brings to light missing information about possible constituents of concern in produced water. This information, in turn, highlights potential research needs. Such research is critical for informing health-protective policy about produced water use.