Statewide Compliance and Testing

• Overall Compliance: The majority of Ohio’s 1,500+ public water systems meet federal Safe Drinking Water Act standards. However, a February 2025 EWG report identified high levels of over 100 contaminants statewide — including disinfection byproducts, nitrates, and PFAS. Over 100 systems have detectable PFAS levels ranging from 5–140 parts per trillion. Check our national water quality checker to compare Ohio data with other states.
• PFAS Regulatory Shift (May 2025): The EPA retained enforceable PFOA/PFOS MCLs of 4 ppt but extended the compliance deadline from 2029 to 2031. Simultaneously, the agency proposed rescinding MCLs for PFHxS, PFNA, GenX (HFPO-DA), and PFBS — drawing criticism from public health groups and triggering likely litigation under the Safe Drinking Water Act’s anti-backsliding provisions. Initial PFAS monitoring for all public water systems is required by April 2027.
• Ohio River PFAS Spike: In July 2025, a U.S. congressman formally petitioned the EPA to address a documented spike in PFAS levels in the Ohio River — a primary drinking water source for millions of Ohio and Kentucky residents. PFAS from Ohio businesses can travel significant distances downstream, compounding contamination risks for communities along the river.

Major Water Sources and Challenges

• Lake Erie System: Serves northern Ohio communities but faces annual harmful algae bloom challenges threatening drinking water for approximately 12 million people. Enhanced monitoring and treatment protocols are required each summer bloom season, adding costs to affected utilities. The 40% phosphorus reduction target agreed with Canada under the Great Lakes Water Quality Agreement remains unmet.
• Ohio River Basin: Primary source for southern Ohio communities, with a documented PFAS spike in July 2025 prompting congressional action. Wright-Patterson Air Force Base near Dayton has recorded PFOS at up to 12.4 ppt — above the 4 ppt federal MCL — contributing to regional contamination concerns.
• Lead Service Line Crisis: Ohio ranks third nationally with approximately 745,000 lead service lines still in use, posing significant health risks particularly to children. The Ohio Lead Line Replacement Act (HB 534), introduced in May 2025 and still moving through the state legislature, would require all public water systems to replace lead service lines within 15 years.

Emerging Contaminant Response

• PFAS Compliance Planning: Utilities must complete initial PFAS monitoring by April 2027 and comply with PFOA/PFOS MCLs by 2031. The EPA launched the “PFAS OUT” initiative in May 2025, providing technical assistance to every public water utility known to need capital improvements for PFAS treatment — though no additional federal funding was announced alongside this programme.
• Treatment Technology Deployment: Ohio water utilities are implementing activated carbon filtration, ion exchange, and reverse osmosis systems for PFAS removal. Dayton — a national leader in PFAS response since 2016 — is working with consulting firm TetraTech to design a cost-effective advanced treatment solution, having secured significant Ohio EPA funding at 0% interest and principal forgiveness.
• Data Centre Discharge Concern: In December 2025, Ohio EPA was found to be considering fast-tracking water discharge permits for data centres — without mandatory PFAS discharge limits or baseline water quality testing — raising new concerns about emerging contamination pathways. Ohio has more data centres than any other Great Lakes state, with at least 217 facilities.

Lake Erie Algae Bloom Impact

• Annual Bloom Challenges: Western Lake Erie continues to experience harmful algae blooms each summer, driven by agricultural phosphorus and nitrogen runoff. Blooms threaten drinking water for approximately 12 million people and require utilities to implement specialised toxin monitoring, potentially switch water sources, and apply enhanced treatment.
• Treatment Cost Impact: Residents served by Lake Erie water systems face additional costs for enhanced bloom-season treatment. The Toledo 2014 water crisis — when microcystin toxins shut off water for 400,000 residents — continues to inform regional preparedness protocols and investment decisions.
• Source Water Protection: The 40% phosphorus reduction target for Lake Erie’s western basin, agreed upon under the 2012 Great Lakes Water Quality Agreement, has not been achieved. Ongoing watershed management and agricultural best management practice programmes continue, but progress is slow relative to the scale of runoff. Track algae bloom-related boil water advisories on our live notice tracker.

Lead Service Line Replacement Initiative

• Legislative Action: The Ohio Lead Line Replacement Act (HB 534), introduced in May 2025, would mandate all public water systems replace lead service lines within 15 years. The bill is moving through the Ohio House of Representatives and still requires Senate approval and the governor’s signature. Meanwhile, nearly 4,000 Ohio children are tested annually for elevated blood lead levels linked to drinking water.
• Municipal Progress: Cities like Akron are targeting lead-free status by 2027; Columbus began comprehensive replacement in 2025; Greater Cincinnati Water Works has replaced over 6,000 lead lines since 2016. Federal EPA rules finalized in 2024 require all lead service lines nationally to be replaced within 10 years.
• Federal Funding: EPA lead service line replacement funding of $3 billion per year (FY2022–2026) under the Bipartisan Infrastructure Law continued into 2025, though the November 2025 release of FY2025 allocations was delayed approximately five months due to administrative issues. Ohio has received $184 million specifically for lead pipe replacement, prioritising disadvantaged communities.

Looking Forward: 2026–2031

Ohio’s water quality landscape faces a pivotal period through 2031 as utilities work toward PFOA/PFOS compliance while simultaneously confronting the third-largest inventory of lead service lines in the nation and persistent Lake Erie algae bloom threats. The Trump administration’s May 2025 decision to rescind MCLs for four additional PFAS compounds introduces regulatory uncertainty for utilities that had planned for broader compliance, though PFOA/PFOS limits remain enforceable. The state’s Ohio EPA is also navigating new pressures around data centre water discharge and PFAS monitoring for emerging sources. Residents in affected areas are strongly encouraged to stay informed via our water quality news feed, use our water quality checker, and review home filtration options certified for PFAS and lead removal.