Ohio
Water quality data from the EPA Safe Drinking Water Information System
Water Systems
16,365
Active public water systems
Population Served
11.09M
Residents with piped water
Lead Violations
223
Systems exceeding 15 ppb
Copper Violations
1665
Lead & Copper Rule
Average Lead Level
EPA Action Level: 15 ppb
MCLG (health goal): 0 ppb
Average across 2974 systems with reported lead data.
Violations Detected
1888 water systems in Ohio have reported violations under the Lead and Copper Rule. These utilities are required to notify customers and take corrective action.
Water Systems: Highest Lead Levels
| System Name | City | Population | Lead Level | Status | Sample Date |
|---|---|---|---|---|---|
| DAYTON | 141,407 | 470.00 ppb | Violation | 2026-12-31 | |
| HAMILTON | 52,920 | 12.80 ppb | OK | 1992-12-31 | |
| HAMILTON | 10,080 | 12.80 ppb | OK | 1993-06-30 | |
| CLEVELAND | 326,846 | 11.69 ppb | OK | 2000-12-31 | |
| DAYTON | 236,000 | 10.00 ppb | OK | 1992-12-31 | |
| DAYTON | 184,000 | 10.00 ppb | OK | 1992-12-31 | |
| SALEM | 16,850 | 9.40 ppb | OK | 2025-12-31 | |
| CLEVELAND | 424,027 | 8.60 ppb | OK | 2001-12-31 | |
| CLEVELAND | 352,888 | 8.60 ppb | OK | 2001-12-31 | |
| WESTLAKE | 198,665 | 8.60 ppb | OK | 2001-12-31 | |
| CANTON | 40,000 | 8.10 ppb | OK | 2002-12-31 | |
| CANTON | 107,113 | 8.00 ppb | OK | 2025-12-31 | |
| CINCINNATI | 686,400 | 7.80 ppb | OK | 1992-12-31 | |
| EAST CLEVELAND | 28,500 | 7.38 ppb | OK | 2007-12-31 | |
| MASON | 11,000 | 6.50 ppb | OK | 2004-12-31 |
Showing top 15 of 2883 systems with lead data. Action level: 15 ppb.
Systems With Active Violations
These water systems have exceeded EPA limits and must take corrective action.
CLEVELAND · Pop. 1,308,955
Lead: 0.00 ppb (2024-12-31)
COLUMBUS · Pop. 1,305,946
Lead: 1.20 ppb (2023-12-31)
CINCINNATI · Pop. 750,200
Lead: 2.00 ppb (2025-12-31)
TOLEDO · Pop. 360,000
Lead: 0.00 ppb (2025-12-31)
KETTERING · Pop. 150,207
Lead: 0.00 ppb (2025-12-31)
DAYTON · Pop. 141,407
Lead: 470.00 ppb (2026-12-31)
BATAVIA · Pop. 133,059
Lead: 2.10 ppb (2023-12-31)
YOUNGSTOWN · Pop. 130,530
Lead: 0.00 ppb (2025-12-31)
HAMILTON · Pop. 116,572
Lead: 0.00 ppb (2025-12-31)
CANTON · Pop. 107,113
Lead: 8.00 ppb (2025-12-31)
KETTERING · Pop. 83,033
Lead: 0.00 ppb (2025-12-31)
PAINESVILLE · Pop. 78,379
Lead: 0.00 ppb (2024-12-31)
Water Source Types
Air Quality
GoodAvg AQI
48.2
PM2.5
7 µg/m³
Unhealthy Days
9
Primary Pollutant
Ozone
Source: EPA AirNow & American Lung Association 2024 State of the Air. AQI scale: 0–50 Good · 51–100 Moderate · 101–150 Sensitive Groups · 151+ Unhealthy.
PFAS Contamination
Moderate DetectionPFAS (per- and polyfluoroalkyl substances), known as “forever chemicals,” are a group of synthetic chemicals that persist indefinitely in the environment and human body. The EPA set a maximum contaminant level (MCL) of 4 parts per trillion (ppt) for PFOA and PFOS in April 2024. View national PFAS tracker →
Systems Tested
398
PFAS Detected
162
Detection Rate
40.7%
Exceeding MCL (4 ppt)
36(9.0%)
Highest recorded level: 98 ppt (EPA MCL: 4 ppt). Most widespread contamination region nationally (EWG). Large systems with PFAS above federal threshold (USGS). DuPont Washington Works plant (Parkersburg WV area) impacts Ohio River