EPA's Final PFAS Drinking Water Rule: The Most Consequential Environmental Regulation in a Decade
The U.S. Environmental Protection Agency has finalized the National Primary Drinking Water Regulation (NPDWR) for six PFAS compounds — the most health-protective drinking water standards ever promulgated under the Safe Drinking Water Act. The rule sets MCLs of 4 parts per trillion (ppt) for PFOA and PFOS individually, a combined hazard index of 1.0 for mixtures of PFNA, PFHxS, HFPO-DA, and PFBS, and individual MCLs of 10 ppt for PFNA and PFHxS.
For New York — where the State already established 10 ppt PFOA and PFOS MCLs in 2020 — the federal rule adds a new and even more stringent compliance layer. On Long Island, documented PFAS detections in the Nassau-Suffolk sole-source aquifer at multiple municipal wellfields now exceed both the federal and state MCLs, triggering urgent compliance and source investigation activity that directly implicates industrial PFAS users throughout Nassau and Suffolk Counties.
Compliance Timeline and Requirements for New York Public Water Systems
Public water systems have five years from the rule's effective date to achieve compliance, including mandatory milestones: initial PFAS monitoring in year one, annual consumer notification for any detections at or above MCLs, and implementation of treatment measures by the compliance deadline.
For Nassau and Suffolk County water providers already confronting PFAS-impacted wellfields, the rule creates immediate capital planning urgency. Granular activated carbon (GAC) filtration and high-pressure membrane systems — the primary treatment technologies capable of achieving the new MCLs — require capital investment ranging from tens to hundreds of millions of dollars for major municipal systems. Water districts must begin engineering assessments, procurement planning, and State Revolving Fund or WIFIA financing applications immediately.
CERCLA Cost-Recovery Liability for Long Island Industrial PFAS Users
The drinking water MCL rule dramatically increases the financial exposure of industrial companies with historical PFAS use in New York. Water utilities facing hundreds of millions in treatment costs have already filed — and won — CERCLA Section 107(a) cost-recovery actions against upstream industrial PFAS users. The theory is direct: industrial PFAS releases contaminated source water aquifers, forcing utilities to install expensive treatment systems to meet regulatory standards.
Long Island water districts are uniquely well-positioned to pursue these claims given the aquifer's sole-source status. Industries with significant Long Island PFAS use histories — aerospace and defense manufacturing, electronics fabrication, metal finishing, commercial laundry, and AFFF users — face material CERCLA cost-recovery exposure. Companies that have not yet conducted a privileged assessment of their historical PFAS use should do so before NYSDEC or a water utility makes first contact.
Insurance Coverage Assessment for PFAS Claims
New York industrial companies facing PFAS-related demands should immediately assess their insurance portfolio for responsive coverage. Pre-1986 comprehensive general liability (CGL) policies — issued before standard pollution exclusions became prevalent — may cover PFAS contamination claims. Environmental Impairment Liability (EIL) policies may provide additional protection depending on specific policy language and coverage trigger theory.
Coverage analysis for long-tail PFAS claims in New York must account for applicable trigger theories, the scope of pollution exclusions under New York law, and multi-year allocation methodologies. Engaging New York environmental coverage counsel before responding to any demand or government notice is essential to preserving insurance rights.
Key Takeaways for New York Water Systems and Industrial Companies
EPA's final PFAS drinking water rule creates concrete, immediate obligations. Water utilities must begin capital planning now. Industrial companies with any historical PFAS use must assess CERCLA exposure before demands arrive. Insurers must prepare for a wave of coverage claims driven by the massive cost of PFAS treatment infrastructure across New York.
Rigano LLC advises Long Island water utilities, industrial companies, and environmental insurers on PFAS drinking water compliance, CERCLA liability defense, and insurance coverage disputes. Contact our Long Island environmental law office for a comprehensive PFAS exposure assessment.