Title: Draft Interim Recommendations for Addressing Groundwater Contaminated with PFOA and PFOS
Docket ID: EPA-HQ-OLEM-2019-0229
Comments Close: June 10, 2019
The Environmental Protection Agency “is seeking public comment on a draft set of recommendations for cleaning up groundwater contaminated with” perfluorooctanoic acid (PFOA) and/or perfluorooctane sulfonate (PFOS). “When finalized, the recommendations will provide a starting point for making site-specific cleanup decisions.”
The Environmental Protection Agency is evaluating several sites with groundwater that has been contaminated with PFOA and PFOS. The sites will be evaluated and addressed under federal cleanup programs, including the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA, commonly referred to as “Superfund”) and the Resource Conservation and Recovery Act.
This guidance recommends:
The screening level for PFOA or PFOS individually is 40 ng/L or parts per trillion.
Use of the current health advisory level of 70 parts per trillion for PFOA and PFOS combined as the preliminary remediation goals, where no state, tribal, or other applicable or relevant and appropriate requirements exist.
Responsible parties are expected to address levels of PFOA and/or PFOS over 70 parts per trillion.
Please note: There are two versions of the draft groundwater guide for PFOA and PFOS on the EPA docket. Draft Interim Recommendations for Addressing Groundwater Contaminated with PFOA and PFOS is the version after the Office of Management and Budget review. The other version, named OMB Review Redline Version – Draft Groundwater Guide for PFOA and PFOS, tracks changes made during the Office of Management and Budget (OMB) review process. This summary will mainly be based on the post-OMB review version, but commenters are encouraged to take a look at the tracked changes in the other version too.
Substantial changes were made to the final draft posted for comment. Specifically, the entire section related to Removal Management Levels was deleted. Removal Management Levels are used to support the decision for the Environmental Protection Agency to undertake an action using CERCLA authority and funding. Deleting this section means that the interim guideline “makes no recommendation on concerning what level of contamination requires ‘immediate’ action under Superfund” (JDSUPRA).
Background on PFOA and PFOS
PFOA and PFOS are synthetic fluorinated organic chemicals that belong to a large group called per- and poly-fluoroalkyl substances (PFAS). PFAS have been used in various industrial processes and products such as surface treatment for stain/water resistance, textiles, paper, metal plating and firefighting foams. PFOS and PFOA are highly persistent in the environment and can bioaccumulate in humans. In 2016, EPA finalized a lifetime drinking water health advisory level of 70 ppt for PFOS and PFOA combined.
Role of Screening and Screening Levels
Under regulatory programs like the Comprehensive Environmental Response, Compensation, and Liability (“Superfund”) Act, if the contamination level is below the risk-based screening level, no further action or study is warranted. Risk-based screening level is made by considering both non-cancer effects and carcinogenic effects. For non-cancer effects, a hazard quotient of 0.1 is used “when more than one contaminant is present.” The Environmental Protection Agency (EPA) developed a reference dose when it derived the health advisory level for PFOA and PFOS. Putting this reference dose into the risk equation for a hazard quotient of 0.1 yields a screening level of 40 ppt for each chemical. This level is lower than the level associated with a one-in-a-million excess cancer risk for PFOA and EPA states there is no strong relationship between PFOS and cancer. Therefore, EPA states the screening level derived from non-cancer effect “will be protective for the cancer endpoint as well.”
Preliminary Remediation Goals
Preliminary Remediation Goals are “used to set initial targets for cleanup, which can be adjusted on a site-specific basis as more information becomes available during the remedial investigation/feasibility study (RI/FS) process.” During the remediation process, Preliminary Remediation Goals are often modified based on factors such as “exposure through multiple exposure pathways” or “exposure to multiple chemicals.” EPA recommends using the health advisory level of 70 ppt for PFOA and PFOS combined as the Preliminary Remediation Goal; there is “no other state or tribal laws or regulation that qualify as applicable or relevant and appropriate requirements.” If there is state or tribal law or other “applicable or relevant and appropriate requirements,” those standards are the basis of developing the Preliminary Remediation Goal.
Contributor: Post-doctoral Fellow, Environmental Health