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OH

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Ohio Water Quality

698

Utilities in database

11.7M

Residents served

2

With open violations

328

PFAS monitored

Quick Answer

Ohio public drinking water is served by 698 EPA-tracked water systems, providing service to approximately 11.7 million residents through public utilities. 2 of those systems currently have open health-based violations on record in the EPA federal database. 328 systems have official PFAS monitoring records from the EPA UCMR 5 program (2023–2025). About 12% of OH residents use private wells, which fall outside federal utility compliance monitoring.

2 Ohio water systems have open health-based violations recorded in EPA SDWIS. An open violation means a contaminant exceeded a federal limit and the violation has not been formally resolved in the federal database. Check individual utility pages for current status.

Open Health-Based Violations in Ohio

Records sourced from EPA SDWIS. A record may be under review or resolved at the utility level but not yet updated in federal records. Water Utility Report does not determine whether water is safe to drink.

Drinking Water in Ohio

Ohio draws water from Lake Erie and inland rivers. Lead contamination in older housing stock — particularly in cities like Toledo and Cleveland — is a documented concern. Agricultural runoff contributes nitrate loading near Lake Erie. Several communities near industrial sites have documented PFAS detections. Ohio EPA holds primary enforcement authority.

Utilities in Ohio

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Key Contaminant Concerns in Ohio

These contaminants appear most frequently in Ohio utility records or pose elevated risk in this region based on EPA data.

high

PFAS

Per- and polyfluoroalkyl substances (PFAS) are a class of over 12,000 synthetic chemicals characterized by strong carbon-fluorine bonds that resist degradation. The two most studied — PFOA (perfluorooctanoic acid) and PFOS (perfluorooctane sulfonic acid) — have been phased out of U.S. manufacturing but persist widely in the environment.

EPA limit: 4 ppt

high

Lead

Lead is a naturally occurring heavy metal that was widely used in plumbing infrastructure until it was banned for new installations in 1986. An estimated 9.2 million lead service lines still connect homes to public water mains across the United States, along with millions of homes with lead solder in their internal plumbing. Critically, a utility's water quality report can show zero detected lead at the treatment plant while your specific tap still delivers elevated lead — because the contamination happens inside the distribution system and your home's plumbing, not at the source.

EPA limit: 15 ppb (action level)

moderate

Nitrates

Nitrate (NO₃⁻) is a nitrogen-containing compound that forms naturally through the decomposition of organic matter. At elevated concentrations — almost always caused by human activity — nitrate is converted in the digestive system to nitrite, which then reacts with hemoglobin to form methemoglobin, a form of hemoglobin that cannot carry oxygen. In the body, nitrite also reacts with amines in food to form N-nitroso compounds (nitrosamines) — known carcinogens classified by the IARC as Group 2A (probable human carcinogens). The United States applies over 23 million tons of nitrogen fertilizer annually, making agricultural runoff the dominant source of nitrate contamination in U.S. groundwater.

EPA limit: 10 mg/L

moderate

DBPs

When utilities add chlorine to water to kill pathogens, it reacts with dissolved organic matter — leaves, algae, soil — to produce disinfection byproducts (DBPs). Over 600 DBPs have been identified. The EPA regulates two groups: total trihalomethanes (TTHMs, including chloroform) and haloacetic acids (HAA5). DBP levels tend to be highest in surface water systems and in warm months when organic matter is elevated.

EPA limit: 80 µg/L (TTHMs) / 60 µg/L (HAA5)

City Water Reports in Ohio

Tap water quality pages for Ohio cities — violations, PFAS records, utility profiles, and official source links.

Ohio PFAS Watchlist — all utilities with official records

Independent Water Testing

Find a certified lab in Ohio

Utility compliance records show what water systems report to the EPA. An independent test from a certified laboratory confirms what's actually in your tap water. Ohio labs can test for PFAS, lead, nitrates, bacteria, and dozens of other contaminants.

Explore Water Quality in Ohio

Common Questions About Ohio Drinking Water

Ohio Water FAQs

Data sources: Utility compliance and violation data from EPA SDWIS (Safe Drinking Water Information System). PFAS monitoring records from EPA UCMR 5 (Unregulated Contaminant Monitoring Rule 5, 2023–2025). Contaminant data from EPA and ATSDR public references. This page summarizes public records — it is not a compliance determination. Methodology →

Last updated: 2025-01-10