Gregory O'Neal, P.G., and Adam Taylor, P.G.

Regulatory Risk–Informed Procedures for PFAS Sampling, Data Management, and Remediation

Gregory O'Neal, P.G., Senior Geologist, and Adam Taylor, P.G., Senior Geologist, WSP USA, Inc.

Regulatory Risk–Informed Procedures for PFAS Sampling, Data Management, and Remediation  Per‑ and polyfluoroalkyl substances (PFAS) present a unique regulatory risk profile due to their chemical persistence, evolving toxicity benchmarks, and rapidly expanding federal and state regulatory frameworks. As enforceable standards advance across drinking water, groundwater, surface water, and soil programs, the timing and structure of PFAS sampling, data collection, and remedial response have become as critical as the analytical results themselves.  From a regulatory perspective, PFAS sampling programs must be designed to support not only current requirements but also foreseeable future thresholds, including enforceable maximum contaminant levels, mixture‑based risk metrics, and site‑specific cleanup criteria. Decisions regarding when and how data are generated—such as distinguishing among characterization, compliance, confirmation, and remedial monitoring phases—directly influence regulatory interpretation, enforcement posture, and a site’s ability to transition efficiently toward closure. Equally important, PFAS data collection strategies must incorporate clearly defined data quality objectives, contamination avoidance controls, and robust metadata management to ensure long‑term usability as analytical methods, detection limits, and regulatory expectations continue to evolve.  PFAS remediation decision‑making further requires a risk‑based screening framework that integrates exposure pathways, land and water use, regulatory jurisdiction, and remedy implementability. Rather than relying on prescriptive technology selection alone, a regulatory risk‑informed approach emphasizes adaptable remedial strategies, treatment‑train compatibility, and long‑term stewardship considerations that remain resilient under regulatory uncertainty.  This presentation will demonstrate how risk‑informed planning across sampling, data management, and remediation supports defensible environmental assessment, accelerates regulatory decision‑making, and reduces business and legal risk. Case examples will illustrate how structured approaches to characterization, fate and transport, risk assessment, and remedy selection can expedite site closure while maintaining flexibility to accommodate emerging contaminants, evolving standards, and redevelopment objectives.

Greg O'Neal is an Assistant Vice President and licensed professional geologist with 26 years of experience in field hydrogeology, soil and groundwater contamination assessment, and remediation design. His experience also covers environmental site assessments, water-well design, SPCC planning, and remediation of chlorinated solvent, petroleum, and phosphogypsum-related impacts.