Risk-Based Guidance for Treated Produced Water Reuse: Progress and Opportunities
Citation:
Thimons, S., C. Danforth, P. Xu, J. Butler, AND M. Jahne. Risk-Based Guidance for Treated Produced Water Reuse: Progress and Opportunities. Presented at 2023 WateReuse Symposium, Atlanta, GA, March 05 - 08, 2023.
Impact/Purpose:
Risk-based guidance for reuse of treated produced water outside the oilfield relies on hazard identification and exposure assessment using best-available information. This session presents new perspectives and novel approaches for conducting risk assessments to inform guidance on reuse treatment targets while linking current efforts to previous recommendations. Attendees will: Learn how researchers have identified and prioritized constituents of concern in produced water and outlined remaining questions based on data gaps. Gain understanding of the current state of research to characterize produced water local to New Mexico. Recognize challenges regarding the evaluation of a risk assessment framework tailored to a complex industrial wastewater from a consortium of interested parties in the oil/gas field. Be introduced to on-going efforts from US EPA including regionally focused research and the development of tools to help characterize produced water for reuse opportunities.
Description:
In the United States, onshore oil and gas extraction operations generate an estimated one trillion gallons of produced water annually, making it the largest waste stream associated with upstream development of petroleum hydrocarbons by volume. Produced water is defined as the incidental byproduct from hydrocarbon exploration that contains production and maintenance chemicals along with naturally occurring geogenic compounds from the local geology. Currently, discharge of this waste is prohibited east of the 98th meridian, and permitted west under 40 CFR § 435.51, 435.52 so long as said effluent is put to “use in agricultural or wildlife propagation” at a discharge limit of 35 mg/L for “oil and grease”. Complex compositional analysis of treated or produced water is limited. The lack of unified, nationwide wastewater management schemes and lack of characterization methodologies for complex wastewater mixtures to inform fit-for-purpose treatment and reuse have been identified as research priorities at the state and federal level. This panel features perspectives from industry, government, academic and NGO sector researchers regarding the state-of-the-science for risk-based guidance of treated produced water reuse. After a brief introduction to the unique nature of produced water, we present perspectives from each party to better understand underlying issues regarding reuse of produced water. Guidance from the Ground Water Protection Council’s Produced Water Report is benchmarked against a comprehensive literature review of field and laboratory studies to highlight existing human toxicity and ecotoxicological data gaps. Survey sites in New Mexico are then referenced, focusing on analytical assessment to identify relevant compounds from these sites. Additionally, the development and implementation of a risk-based framework using new and existing data from local (New Mexico and Texas) and national (United States) sources targeting identification, reduction, and management of environmental and human health risks is discussed. Finally, we present details regarding the on-going efforts by EPA Regions and its Office of Research and Development to improve characterization of produced water using next generation, non-targeted analysis techniques. The session will close with a moderated panel discussion and audience Q&A. Collectively, this session will familiarize attendees with the state of science regarding risk-based management of produced water reuse and provide a knowledge base to support ongoing implementation of these approaches.