Last checked: October 22, 2026

Private wells in Ohio

USGS estimates more people on private wells in Ohio have arsenic above the drinking water standard than in any other state. We found no statewide requirement to test a well when a home is sold, but some county health districts require a point-of-sale inspection. Here's what to check, where to find certified labs and well logs, and who to call. Every fact has a source.

Ohio at a glance

• Who's on a well: USGS estimates about 1.86 million Ohioans supplied their own household water in 2015, about 16% of the state's population.¹
• Home sales: no statewide testing requirement found. The state disclosure form asks about the water source and known problems. Summit County requires a point-of-sale well evaluation.³⁴
• What to test: Ohio State University's Ohio Watershed Network says the Ohio Department of Health (ODH) recommends regularly testing for total coliform, E. coli, nitrate and arsenic.⁶
• Arsenic: USGS estimates about 241,000 Ohioans on private wells may have arsenic over 10 µg/L, rising to about 374,000 during drought.⁹

County pages

• Well water testing in Summit County, OHSummit County's point-of-sale well inspection rule for home sales, what's tested, exemptions, county water sampling, Ohio EPA certified labs, ODNR well logs and contacts, with sources.Last checked 2026-10-22

Ohio counties with the most people on household wells in USGS's 2015 estimates are Summit (about 108,000), Stark (about 99,000), Medina, Geauga and Licking (about 71,000–76,000 each), Fairfield, Trumbull and Wayne.¹ In Geauga County, about 76% of residents were on household wells.¹ We're adding pages for these counties.

Buying a home with a well in Ohio

Disclosure. Ohio's Residential Property Disclosure Form (Ohio Revised Code 5302.30) asks the seller to identify the water source, including a private well, and to disclose known problems with the water supply system or water quality.²³ It isn't a test.

County point-of-sale rules. Ohio EPA says it doesn't regulate private wells and refers owners to their local health department.⁷ Some local health districts have rules for property transfers:

• Summit County Public Health requires a private water system evaluation and a Certificate of Transfer before a property with a well can be sold. A registered contractor tests the flow rate, and a sample goes to an Ohio EPA-certified lab for total coliform and E. coli. The results don't stop the sale. See our Summit County page.⁴
• Ask the county or city health district whether a point-of-sale inspection applies. NACCHO keeps a directory of Ohio local health departments.

Elsewhere, write a well inspection and water test contingency into your offer and add arsenic to the test list. See our homebuyer's guide.

Contaminants to know about

• Arsenic. USGS's national model ranks Ohio first for the number of private well users likely over 10 µg/L.⁹ In Ohio EPA's ambient groundwater monitoring network (not private wells), 16% of wells in sand-and-gravel aquifers were impaired for arsenic and another 17% were on a watch list.⁸
• Bacteria and nitrate. The ODH-recommended tests include total coliform, E. coli and nitrate.⁶
• OSU notes the only enforceable private water standard in Ohio is for bacteria.⁶

Where to test

• Certified labs: Ohio EPA's Combined Lab List (PDF) of certified drinking water labs.⁷
• Local health districts often collect samples or sell kits. Ohio EPA says to contact your local health department about private well testing.⁷

Free and low-cost testing

We didn't find a statewide free testing program for private wells in Ohio. Many county health districts run sampling programs. Summit County Public Health, for example, samples for bacteria, nitrate, lead, copper and arsenic.⁵ Ask your local health district.

Well records

• ODNR well logs: ODNR's Division of Water Resources keeps Ohio's water well logs.⁶ Search well logs or use the water wells map.

Who to call

• ODH Private Water Systems Program: (614) 644-7558, [email protected].⁶
• Local health districts: NACCHO directory of Ohio local health departments.
• OSU Extension: the Ohio Watershed Network's well owner page and extension.osu.edu.⁶

Guides for Ohio well owners

• Buying a home with a well
• Arsenic in well water
• Shock chlorinating a well
• How to read your well water test results