EPA found that the level of forever chemicals in drinking water should be ZERO
A friend just emailed me a question about EPA’s proposed drinking water standard (known as an “MCL” for “Maximum Contaminant Level”) for “forever chemicals” (e.g. PFOA, PFAS, et al).
He could not find it and asked me what was the cancer risk level that the EPA MCL was based upon.
EPA has an “acceptable cancer risk” range policy based on individual lifetime cancer risks. The risk range is one in 10,000 (10(-4)) to one in a million (10 (-6)). The federal law allows EPA to consider costs in setting an MCL.
This EPA policy can and likely would be weakened under a Trump 2.0 Project 2025 EPA. The EPA risk policy is applied across the board (air, water, drinking water, Superfund, RCRA, et al), so the rollback would have huge impacts on public health.
NJ has a more stringent cancer risk legislative standard of one in a million. The NJ law does not authorize consideration of costs in setting those standards. Trump’s EPA can’t touch that, only the NJ Legislature can.
Accordingly, for many chemicals, the NJ MCL is more stringent than the US EPA national MCL.
In the case of “forever chemicals”, the NJ DEP 13 – 14 ppt MCLs reversed this historical reality and is LESS stringent than the proposed EPA 4 ppt MCL. Therefore, DEP will need to revise their MCL to lower it to meet the EPA national MCL when (and if) that MCL becomes effective.
In addition to cancer risks, forever chemicals have a host of other negative health and developmental impacts.
So, in answering my friends question, I found that the EPA MCL is NOT based on the acceptable cancer risk policy. The real basis has not been reported by the media and the public does not understand what is really going on.
Instead, it is based on the most sophisticated laboratory technology that can reliably quantify the level of forever chemicals in the drinking water.
This is important, because EPA found that the level of forever chemicals should be ZERO. That level is known as a “Maximum Contaminant Level Goal” (MCLG).
Here are the scientific and regulatory findings that form the basis of the EPA proposed 4 ppt MCL:
Just follow the logic of points 1 – 3 (verbatim excerpts from the EPA proposal, highlights mine):
1. “Based upon a consideration of the best available peer reviewed science and a consideration of an adequate margin of safety, EPA proposes a MCLG of zero for PFOA in drinking water.
2. “Under section 1412(b)(4)(B) of SDWA, EPA must generally establish an enforceable MCL as close to the MCLG as is feasible, taking costs into consideration. The Agency evaluates feasibility according to several factors including the availability of analytical methods capable of measuring the targeted compounds in drinking water and examining available treatment technologies capable of contaminant removal examined under laboratory and field conditions.
3. “In this evaluation, EPA determined that 4.0 ppt is the lowest concentration that PFOA and PFOS can be reliably quantified within specific limits of precision and accuracy during routine laboratory operating conditions. EPA has historically called this level the “practical quantitation level,” also known as a PQL (USEPA, 1987). Under UCMR5, EPA published MRLs of 4.0 ppt each for PFOA and PFOS (USEPA, 2022g). As described in the UCMR 5 rulemaking, this reporting level is the minimum quantitation level that, with 95 percent confidence, can be achieved by capable analysts at 75 percent or more of the laboratories using a specified analytical method (i.e., Method 533 and 537.1, discussed in more detail in section VIII of this preamble). Based on the multi-laboratory data acquired for the UCMR 5 rule, EPA has defined the PQL for PFOA and PFOS to be equal to the UCMR 5 MRL of 0.0000040 mg/L or 4.0 ppt. “
So there you have it. As usual, the reality is far worse than the press or environmental groups tell you it is.
Hope this helps.