Groundwater and PFAS


EPA releases draft toxicity assessment for two PFAS chemicals; seeks public input

Nov 16, 2018, 07:02 AM by Pat Levak
Release of the draft toxicity values provides an opportunity for NGWA to provide comments during a 60-day public comment period.

The U.S. Environmental Protection Agency released draft toxicity values for chemicals known as GenX and perfluorobutane sulfonic acid (PFBS) — chemicals in the PFAS family used as replacements for PFOA and PFOS.

GenX and PFBS were seen as potentially safer alternatives to PFOA and PFOS, but the draft toxicity values proposed highlight exposure to these alternatives is also harmful.

The draft toxicity values provide EPA’s best assessment as to how much of the chemicals are acceptable before adverse health impacts may occur. Assessing toxicity represents the first step in determining whether additional action to protect public health should be taken.

The EPA announced it does not have plans to regulate these chemicals at this time, but will provide the information to state, tribal, and local governments to help them take any local action necessary.

Release of the draft toxicity values provides an opportunity for NGWA to provide comments during a 60-day public comment period reinforcing the Association’s message that more federal regulatory certainty is needed for certain PFAS chemicals, including PFBS and GenX.

If interested in working with NGWA to prepare comments, or if you would like information on how to submit your own comments, to the EPA, please contact NGWA Director of Government Affairs Lauren Schapker at

NGWA guidance document


NGWA published Groundwater and PFAS: State of Knowledge and Practice, a guidance document on per- and polyfluoroalkyl substances (PFAS). Created by 36 NGWA volunteers who spent 1100 hours on it over 12 months, it is a comprehensive eight-part piece exploring the potentially hazardous, and widely discussed, compounds in groundwater and soil. NGWA published the document to identify the known science and knowledge related to per- and polyfluoroalkyl (PFAS) compounds. It summarizes the fate, transport, remediation, and treatment of PFAS, as well as current technologies, methods, and field procedures.


PFAS in Groundwater Workshop: The Professional’s Challenge
December 5, 2019

NGWA PFAS expert

seth-kelloggSeth Kellogg, PG, a senior geologist at Geosyntec Consultants,​ was elected to the board of the Scientist and Engineers Section of NGWA in 2016. She has 25 years of experience in evaluating complex contaminant hydrogeology and groundwater/surface water interactions, including large groundwater and sediment sites in New York and New Jersey. As PFAS have emerged as environmental concerns, Kellogg has been working with NGWA to advance the industry’s understanding and implementation of best practices. She has presented and published on the technical and regulatory challenges of PFAS contamination, including coauthoring NGWA’s Groundwater and PFAS: State of Knowledge and Practice (NGWA Press 2017). In May 2018, Kellogg was recommended by members of the NGWA Board of Directors to represent the Association at the U.S. Environmental Protection Agency National Leadership Summit on PFAS. Kellogg’s leadership on PFAS has also included several presentations educating industry professionals on the fragmented PFAS regulatory framework, PFAS characterization challenges, and the complexities of PFAS fate and transport. She also served as a program adviser and facilitator for NGWA’s PFAS in Groundwater Workshop that was held in August 2018.