New Hampshire has just become the first state to finalize drinking water maximum contaminant levels (MCLs) for PFOS and PFOA, two of the best known and studied PFAS (per- and poly-fluoroalkyl substances), setting levels for those compounds at 15 ppt (parts per trillion) and 12 ppt respectively, effective October 1, 2019. New Hampshire also adopted MCLs for PFHxS at 18 ppt and PFNA at 11 ppt. These actions, which were expeditiously moved through the New Hampshire decision-making processes, now predate final action on New Jersey’s proposed MCLs of 13 ppt for PFOS and 14 ppt for PFOA. New Jersey also already has the first formal PFAS MCL, for PFNA at 14 ppt.
MCLs have the effect of requiring public water supply systems to sample for and remove contamination above the set level. They can also serve as ARARs (Applicable, Relevant and Appropriate Requirements) for Superfund remedial cleanups within states where they apply.
The MCL setting process requires consideration of the costs of implementation, and New Hampshire’s action is accompanied by its estimates of costs and impacts. For example, New Hampshire estimates that compliance with the MCL will cost its public water suppliers $190 million over the next two years, and that if private well owners choose to treat to the same levels (which is not required) the costs would add $71 million.
Taken together, New Hampshire’s actions and those of other states that are setting maximum authorized levels in drinking water well below EPA’s “action level” for PFOS and PFOA (70 ppt), indicate changing approaches to evaluating risk. The states appear to be considering recent toxicity data and/or newly available exposure information, while also expanding their focus beyond the PFOS and PFOA.
It also is apparent that these states are not waiting for the outcome of pending federal draft legislation that, if enacted, will have significant potential to affect the developments in PFAS regulation at the federal level. Two competing versions of substantial PFAS provisions in the U.S. Senate and House Department of Defense Authorization bills are awaiting a Conference Committee to resolve differences.
Both of these states and a number of others are also pursuing litigation, cleanup strategies, sampling programs, funding programs, and other strategies to tackle known and emerging PFAS challenges.
In the rapidly changing PFAS space, things are not slowing down.