Private Well Water Testing in Missouri

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

Missouri private-well risk summary

Counties covered

115

Missouri counties with modeled risk data.

People on private wells

area estimate

868,973

estimated across covered Missouri counties.

Average arsenic risk

area estimate

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

Missouri counties

Find a Missouri-certified testing lab

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

Missouri certified labs

Already tested your well? Get a free plain-English reading

Upload your well water lab report (PDF or a photo) and our team will email you a full, plain-English reading of every result — free. Educational only, never medical advice.

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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.

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By TapWaterData Editorial