Richland County, Ohio: drinking water report. Richland County in north-central Ohio has a population of about 124,000, centered on Mansfield.
Richland County in north-central Ohio has a population of about 124,000, centered on Mansfield. The city draws water from reservoirs on the Clear Fork and Black Fork of the Mohican River. The county's manufacturing base – auto parts, steel products, and electronics – provided economic stability for decades but also left contamination at multiple sites across the Mansfield area.
The former Mansfield Lahm Airport/Air National Guard Station has confirmed PFAS contamination from AFFF firefighting foam. According to the Ohio EPA's 2024 PFAS investigation, monitoring wells near the airport showed PFOS at concentrations up to 85 ppt. The contamination plume extends toward nearby residential wells.
The EPA's UCMR5 data shows PFAS detections in the Mansfield water system at levels below current action thresholds. Industrial solvent contamination from legacy manufacturing sites adds TCE and other VOCs to the groundwater picture. A 2023 Ohio EPA remediation report documented four active cleanup sites in Richland County involving chlorinated solvents.
Mansfield's reservoir-fed supply avoids the worst of the groundwater contamination, but residents on private wells – particularly near the airport or former industrial sites – should test for both PFAS and VOCs.
Check your water for monitoring data on your area. For PFAS and VOCs, reverse osmosis provides the broadest household protection. Our water filter guide covers systems for multi-contaminant scenarios. Pull your detailed report for historical data, and visit our Ohio page for statewide context.
Drinking water is one exposure route. These federal datasets also cover Richland County, OH.
The EPA places Richland County, OH in Zone 1 - the EPA's highest-risk category, where the predicted average indoor radon level is above 4 pCi/L. Zone maps predict an area's radon potential from geology and existing indoor readings; they say nothing about a specific house. Testing is the only way to know your own level.
74% of homes in Richland County, OH were built before 1980, and 26% before 1950. Residential lead paint was banned in 1978, so housing age is the strongest available proxy for lead-paint exposure. This describes the county's housing stock, not any one home.
Modelled annual fine-particle pollution (PM2.5) in Richland County, OH averages 7.9 µg/m³, within the EPA's annual standard of 9 µg/m³. These are CDC modelled county estimates rather than readings from a specific monitor.
How radon zones work · Air quality by county · Lead exposure guide