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Private Well Water Testing by County
Roughly 43 million Americans rely on private wells, which are not covered by the Safe Drinking Water Act — testing is the owner's responsibility. We pair USGS area-risk models with EPA Water Quality Portal samples to show county-level arsenic and nitrate risk, then point you to a state-certified lab to test your own well.
Browse by state
- Alabama
- Alaska
- Arizona
- Arkansas
- California
- Colorado
- Connecticut
- Delaware
- Florida
- Georgia
- Hawaii
- Idaho
- Illinois
- Indiana
- Iowa
- Kansas
- Kentucky
- Louisiana
- Maine
- Maryland
- Massachusetts
- Michigan
- Minnesota
- Mississippi
- Missouri
- Montana
- Nebraska
- Nevada
- New Hampshire
- New Jersey
- New Mexico
- New York
- North Carolina
- North Dakota
- Ohio
- Oklahoma
- Oregon
- Pennsylvania
- Rhode Island
- South Carolina
- South Dakota
- Tennessee
- Texas
- Utah
- Vermont
- Virginia
- Washington
- West Virginia
- Wisconsin
- Wyoming
- District of Columbia
Well-water tools & guides
- Well water symptomsRotten-egg smell, stains, cloudy or salty water — what to test for.
- What to test forA guide to the right test panel for your situation, symptom, or annual check.
- Interpret your test resultsEnter your own lab numbers and see how they compare to EPA limits.
- Data & methodologyThe USGS/EPA/USDA sources behind every county and what each model means.
- FHA loan well testFHA private-well water-test requirements before closing.
- VA loan well testVA private-well water-test requirements before closing.
- USDA loan well testUSDA private-well water-test requirements before closing.
Common well-water contaminants
What each contaminant is, how common it is in private wells, and how to test for it.
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.
Need whole-house or professional water treatment?
For the problems a pitcher or under-sink filter cannot fix — scale, rust and black staining, sulfur smell, well contamination, or test results you cannot explain. Tell us what is happening and we will connect you with a local water-treatment professional.
By TapWaterData Editorial
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