Comment submitted by Michael Lengefeld

Lee Zeldin Administrator Environmental Protection Agency 1200 Pennsylvania Avenue NW Mail Code: 1101A Washington, DC, 20460 Re: Comments on Extending the Compliance Deadline for the PFOA and PFOS Maximum Contaminant Levels (Docket (EPA-HQ-OW-2025-1742) Dear Administrator Zeldin, I write to oppose finalization of the proposed PFOA/PFOS Compliance Extension Rule (along with the proposed PFAS Rescission Rule). Together, these rules would strip enforceable drinking water protections for four “forever chemicals” and delay enforcement of the two that remain regulated, without any new scientific finding that the underlying health risks have changed. The rules also impose disproportionate, under-examined harms on Tribal communities, who face the greatest barriers to independently filling the gap EPA would leave behind. I. The Compliance Extension Rule Prolongs Known Exposure to PFOA and PFOS •Two more years of exposure above EPA's own health-based limit. The rule keeps the PFOA/PFOS MCL at 4.0 parts per trillion (ppt) but lets water systems obtain a federal exemption pushing the compliance deadline from April 2029 to April 2031. Every day of that extension is a day EPA's own risk assessment says residents may be drinking water above the level EPA has determined necessary to protect health. •The mitigation trigger is set at three times the enforceable limit. Under the proposal, only systems at or above 12 ppt — three times the 4.0 ppt MCL — must take short-term mitigation action during the exemption period. Systems between 4 and 12 ppt can legally take no additional action for up to two more years. •The rule shifts the burden to residents rather than utilities. Exempted systems satisfy their obligations through notices and Consumer Confidence Reports, meaning it is left to individual residents — many without easy access to alternative water sources — to learn of ongoing contamination and independently reduce their own exposure. Both Rules Disproportionately Harm Tribal Communities •Tribal water systems will likely get pushed into the delay, not the funding they need. Tribal water systems are already underfunded and behind on infrastructure compared to state-run systems. Adding a federal extension option makes it more likely Tribes will end up taking the extra two years instead of getting the money and help they need to meet the original 2029 deadline. •Dropping the combined-chemical standard ignores how Tribal members are actually exposed. A 2026 study of tribal waters in Montana found PFAS in fish that people rely on for subsistence and recreational fishing, and found some wells near streams with unsafe levels. The Hazard Index standard EPA wants to rescind was the one rule that added up exposure from multiple PFAS chemicals at once. Without it, there's no single measure that reflects the fact that many Tribal members are exposed through their water and their food at the same time. •Tribal water is already the least tested for PFAS. Studies and EPA's own testing project in the Pacific Southwest show that Tribal water systems, especially private wells, have not been tested as thoroughly as other water systems. Rolling back the rules for four of the six PFAS chemicals could mean less funding and less priority for testing and cleanup help tied to those chemicals — making an already bad testing gap worse. •Rescinding the rule adds extra paperwork just for Tribes. Under the Safe Drinking Water Act, Tribes (like states) will have to file paperwork to update their own water programs once the federal rule is rolled back. Tribal environmental offices are often small, with limited staff and legal resources, adding a significant additional burden. •Tribes have the least ability to replace the protection EPA is taking away. States with bigger budgets and legal teams may be able to write their own, stricter water rules to replace what EPA rescinds. Most Tribal nations don't have those same resources, so when EPA pulls back a federal protection, Tribal members are left more exposed than people living in states that can step in. •EPA closed the office that used to handle this kind of outreach to Tribes. EPA shut down its Office of Environmental Justice and External Civil Rights in 2025 — the office that used to help coordinate consultation with Tribes on rules like this. EPA should explain how it is getting real input from Tribes without that office in place. Thank you for your consideration. Mike Lengefeld, PhD Sources: Institute for Tribal Environmental Professionals, EPA Proposed Recission notice (itep.nau.edu); PFAS in tribal waters of Montana, Environmental Science: Processes & Impacts (2026); EPA Pacific Southwest PFAS Tribal Drinking Water Sampling Project.