Tested Water

Arsenic in Ohio well water, by county

Arsenic is widespread, over the limit in 15% or more of tested wells, in 6 of the 14 Ohio counties with 10 or more tested wells. A county's share tells you how likely a problem is nearby. Only a test of your own well tells you what's in it.

How Ohio compares with the rest of the country

Across Ohio, about 2 in 10 tested wells had arsenic over the EPA limit of 10 µg/L (74 of 475). Across all tested wells in the US it's about 1 in 9. So arsenic turns up somewhat more often in Ohio than in the country as a whole. Check your county below.

Why it matters: Drinking it for years raises the risk of skin, bladder and lung cancer.

Arsenic dissolves out of certain rocks and old sediments, so it can be high even where nobody has polluted anything.

Arsenic in tested wells, county by county

Share of each county's tested wells with at least one result over the EPA limit of 10 µg/L. Counties need 10 or more tested wells to be listed. Widespread means 15% or more, worth checking 5 to 15%, rare under 5%.

CountyWells testedWells over the limitLevel
Licking County 19
53% 10 of 19
Widespread
Preble County 34
38% 13 of 34
Widespread
Shelby County 35
29% 10 of 35
Widespread
Stark County 12
25% 3 of 12
Widespread
Greene County 18
17% 3 of 18
Widespread
Franklin County 12
17% 2 of 12
Widespread
Geauga County 21
14% 3 of 21
Worth checking
Miami County 15
13% 2 of 15
Worth checking
Montgomery County 27
11% 3 of 27
Worth checking
Hamilton County 11
9% 1 of 11
Worth checking
Butler County 17
6% 1 of 17
Worth checking
Clark County 18
6% 1 of 18
Worth checking
Tuscarawas County 24
0% 0 of 24
Rare
Champaign County 14
0% 0 of 14
Rare

65 more Ohio counties have 1 to 9 tested wells for arsenic, too few to rate.

Download this table (CSV) · Free to reuse under CC BY 4.0

Where to get your well tested for arsenic in Ohio

1

Your county health department

Ohio doesn't run a statewide free testing program that we know of. Some county health departments test wells or sell kits, so call yours first.

Ohio's private well page
3

A mail-in kit

Fill the bottles at your kitchen tap and mail them back. We mark the kits that include arsenic.

Compare kits

Keep reading about wells in Ohio

Questions people ask about arsenic in Ohio

Is there arsenic in Ohio well water?

Arsenic is widespread, over the limit in 15% or more of tested wells, in 6 of the 14 Ohio counties with 10 or more tested wells. Across Ohio, about 2 in 10 tested wells had arsenic over the EPA limit of 10 µg/L (74 of 475). Across all tested wells in the US it's about 1 in 9. So arsenic turns up somewhat more often in Ohio than in the country as a whole. Check your county below.

Where can I get my well tested for arsenic in Ohio?

Use a lab certified by Ohio for drinking water, or a mail-in kit that includes arsenic from a certified lab. Some county health departments test wells too, so call yours first.

See Ohio's list of certified labs (a PDF list), or compare mail-in kits.

Where these numbers come from

  • Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000. A well counts as over if any of its tests was over the EPA limit of 10 µg/L. Wells tested for studies and monitoring, not a random sample of homes.
  • Likely overstated: our own check of who tested the wells, when and where. How we check.
  • State programs and links: Department of Health.