Private Well Water Testing in Ohio

County-by-county USGS area-risk estimates for private wells across Ohio — arsenic exceedance probability and private-well population — plus how to test your own well at a Ohio-certified laboratory.

Ohio private-well risk summary

Counties covered

Ohio counties with modeled risk data.

People on private wells

area estimate

1,823,086

estimated across covered Ohio counties.

Average arsenic risk

area estimate

average modeled chance a well exceeds 10 µg/L arsenic across covered counties.

Ohio counties

Find a Ohio-certified testing lab

Get your well tested at a Ohio-certified laboratory. We list certification programs by state.

Ohio certified labs

These figures are USGS area estimates: statistical groundwater models describing how likely elevated contaminant levels are across a county. They are not designed to predict the concentration in any single well. Only testing your own well reveals its water quality.

All well-water states Well water testing near me — full guide Data & methodology

By TapWaterData Editorial