July 11, 2024. Yesterday, the Environmental Management Commission’s Groundwater and Waste Management Committee voted to recommend against moving forward with groundwater standards for five of eight per and poly-fluorinated substances (PFAS)  included in a Department of Environmental Quality (DEQ) rulemaking proposal. It  may be an unprecedented decision to reject health-based standards that would also provide regulatory relief to business and protect property values.

DEQ has proposed two sets of PFAS rules for EMC adoption.  One rule package proposes groundwater standards for eight  per and poly-fluorinated substances (PFAS)  prevalent in the state — PFOS, PFOA, GenX, PFBS, PFNA, PFHxS, PFBA, and PFHxA. The second rule package proposes parallel surface water standards for the same substances.  Both sets of rules establish health-based standards for ingestion of the substances in drinking water. The surface water standards also take fish consumption into consideration since PFAS can bioaccumulate in fish tissue. Scientific research has documented that these substances are toxic; accumulate in the human body;  and persist in the environment for long periods of time. Some have been identified as a likely cancer risk in humans.

Surface water standards would largely be enforced through discharge limits on industrial and municipal wastewater systems identified as potentially significant PFAS sources. The groundwater standards would be used as to set remediation goals for cleanup of PFAS contamination in groundwater; limit permitted releases of PFAS to groundwater;  and as the health threshold for providing alternative water supplies to the owners of contaminated wells.

The two sets of rules have moved slowly through the EMC committee process. Yesterday, the EMC’s Groundwater and Waste Management Committee debated whether to recommend that the full EMC send the entire groundwater rule package of eight PFAS standards out to public notice as the next step in rule-making. The committee declined to do that and instead voted to recommend that the EMC move forward with only three of the eight standards — those for PFOA, PFOS and GenX.  The committee recommendation would have the paradoxical result of rejecting health-based standards for the other five substances even though the new standards would actually reduce regulatory burden on business and potentially benefit private property owners who have detectable levels of  PFAS in their groundwater.

Background on N.C. groundwater standards.  First some background on how N.C. groundwater standards work. The EMC has adopted specific health-based groundwater standards for a number of contaminants. In the absence of a specific standard for a contaminant,  EMC rules provide that the groundwater standard will be the  “practical quantification limit” (PQL) for the contaminant. In lay language, the PQL means the level of the contaminant that can be detected using existing technology.

Today, PFAS detected in groundwater is regulated based on the detection limit for each substance;  the EMC has not adopted  a specific health-based groundwater standard for any PFAS.  Release of PFAS to groundwater above the detection limit without a permit is a violation of the groundwater rules and the detection limit serves as the goal for remediation of PFAS- contaminated groundwater.  The rules proposed by DEQ would establish health-based groundwater standards for the eight PFAS substances listed above. If adopted by the EMC, those health-based standards would replace use of the detection limit as the enforceable groundwater standard for purposes of remediation, permitting, and public health response.

Comparison of the proposed health-based standards to detection limits. DEQ  has calculated numerical health-based standards for each of the eight PFAS substances based on toxicity and/or increased cancer risk associated with ingesting the substance in drinking water. For two of the substances  — PFOS and PFOA — DEQ proposed a health-based standard that is  lower than the current detection limit. As a result, the detection limit for PFOS and PFOA would continue to be the enforceable groundwater standard since it isn’t  possible to enforce a standard below detectable levels. (The  health-based standards for PFOS and PFOA  could  become enforceable in the future if  technology advances to detect lower levels of those substances.)

For the other six PFAS substances, the proposed health-based standard would be higher than the detection limit for each substance — in some instances, significantly higher.   Adoption of those standards would  protect public health,  but  actually result in a less stringent regulatory standard than using the detection limit.  That would  benefit  a business  required to remediate contamination by one of those PFAS substances  in groundwater because the ultimate groundwater cleanup goal would be relaxed by comparison to a goal based on the detection limit.

Using the  proposed health-based standard for those substances could also benefit the owners of private wells with  PFAS levels above the detection limit but below the proposed health-based standard. Those well owners would be reassured that the level of  PFAS in their well does not pose a health risk that requires an alternative water supply.  It would also  remove a cloud over their property that could affect its value since PFAS in the groundwater would no longer exceed the  state regulatory standard.

Committee action. The majority in committee today voted to recommend that the full EMC move forward with health-based standards only for PFOS, PFOA and GenX. It was difficult to discern from the discussion any clear rationale for the recommendation to abandon adoption of health-based standards for the other five PFAS when those standards would have provided greater clarity on health risk; reduced the regulatory burden on business; and protected  property values.

Next steps.  The committee asked DEQ to provide a revised fiscal analysis of the rule package based on adoption of standards for just three of the eight PFAS. The full EMC could then vote (possibly in September) on whether to send the groundwater rule-making package out to public notice. The EMC can accept the committee recommendation or decide to go out to notice  with the larger package of groundwater standards proposed by DEQ. The EMC would make a final decision on adoption of some or all of the proposed groundwater standards after considering comments received in response to the public notice.