Research Project 3: Investigating PFAS across water reclamation facilities and in environmental media

University Of Southern California, Los Angeles CA

Investigators

Abstract

RESEARCH PROJECT 3 (RP3): PROJECT SUMMARY PFAS are ubiquitous in wastewater and many urban groundwater systems due to urban stormwater runoff, Superfund sites, and other industrial emissions, presenting a risk for human exposure through drinking water. While there is a growing scientific basis for regulating PFAS as a class, quantification remains challenging given the (1) reliance of conventional methods on analytical standards for individual compounds and (2) extraction methods from complex environmental matrices remain in development. Methods that analyze PFAS without the use of analytical standards (e.g., aggregate or non-targeted analyses) have yet to be extensively tested. Further, the enormous diversity of PFAS creates challenges to understanding physical and chemical properties that dictate fate and transport in the environment, including in groundwater aquifers, soil, and air. Predictive models of the spatial distribution of PFAS in groundwater are needed to identify communities that are disproportionately affected by PFAS to enable formulation of equitable strategies aimed at minimizing their exposure. Further, many urban areas currently practice or plan to implement indirect potable reuse to supplement traditional water supplies with recycled water. In indirect potable reuse, wastewater is treated to potable water quality, injected or recharged into a groundwater aquifer, and eventually extracted from the aquifer as a source of drinking water. Although the advanced treatment used to convert wastewater into potable quality water significantly reduces PFAS risk, existing PFAS contamination in groundwater aquifers, much of which coincides with Superfund sites, can be mobilized or comingled with high quality recycled water due to changing hydrodynamic conditions resulting from water injection/extraction, potentially decreasing recycled water quality. Existing PFAS contamination in soil and air along with industrial emissions exacerbates groundwater vulnerability, and consequently drinking water, to PFAS. Project 3 aims to address SRP Mandate 3 by developing techniques for extraction of PFAS from complex matrices, improving detection limits, understanding when time-intensive and costly solid phase extraction is necessary, and assessing usefulness of aggregate and non-targeted characterization across diverse sample types. This work will enable quantification of baseline PFAS occurrence across water reclamation facilities (WRFs) and in groundwater aquifers, including contributions from soil and air, to inform development of a PFAS modeling framework that can be used to predict exposure risks. Our specific aims are (1) Multi-factor quantification of PFAS across WRFs, (2) Characterization of PFAS in groundwater including contribution from soil and air, and (3) Prediction of PFAS contamination using a novel fate and transport application-oriented modeling framework. Project 3 addresses the need for comprehensive assessment of PFAS contamination while considering dynamics associated with indirect potable reuse—the future of water management near many SRP sites.