Trumbull County, Ohio: drinking water report. Trumbull County borders Mahoning County in northeast Ohio, with Warren as the county seat and about 197,000…
Trumbull County borders Mahoning County in northeast Ohio, with Warren as the county seat and about 197,000 residents. The Mahoning Valley Sanitary District and Warren Water Department serve most of the population, drawing from Mosquito Creek Reservoir and the Mahoning River. Like its neighbor, Trumbull County's identity was built on steel – Republic Steel, Copperweld, and others operated massive facilities here through the 1970s.
The steel industry's shutdown left contaminated sites across the county. According to Ohio EPA's 2024 property assessment records, Trumbull County has 24 brownfield sites with confirmed groundwater contamination, primarily from heavy metals, chlorinated solvents, and petroleum products. The Warren city wellfield sits downgradient from several of these former industrial properties.
The Youngstown-Warren Regional Airport spans both Trumbull and Mahoning counties and has confirmed AFFF firefighting foam use. Ohio EPA's 2024 PFAS sampling found combined PFAS at 21 ppt in monitoring wells near the airport. The EPA's UCMR5 program detected PFAS in the Warren public water supply at levels that will require treatment under the new federal MCLs.
Trumbull County's industrial past means contamination is widespread but concentrated along the Mahoning River corridor and near former mill sites. Municipal water treatment addresses most regulated contaminants, but the sheer density of contamination sources raises the value of household filtration.
Check your water for data specific to your system. Reverse osmosis handles both the industrial legacy compounds and PFAS found in this area. Our water filter guide compares systems by certified removal rates. Pull your detailed report for historical data, and visit our Ohio page for statewide patterns.