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Well Test Results Checker
Type the numbers from your lab report. For each one you'll see the official benchmark it's usually compared with, which kind of benchmark that is, a link to the source, and the guide to read next.
Educational only. This is not a safety determination. The checker compares numbers; it can't tell you whether your water is safe to drink. EPA's limits are written for public water systems, not private wells, and one sample is a snapshot. Confirm results with a state-certified lab and talk to your local health department about what they mean for your household.
Private by design: the checker runs entirely in your browser. Nothing you type is sent to us or anyone else, and nothing is saved.
How to use it
- Enter only what's on your report. Leave the rest blank.
- Pick the unit your lab used. mg/L is the same as ppm; µg/L is the same as ppb (1 mg/L = 1,000 µg/L).
- If the lab wrote a "less than" value, type it with the sign, like
<0.001. If it says ND (not detected), typeND. - Kinds of benchmarks: an MCL is EPA's enforceable health-based limit for public water systems. An action level (lead, copper) triggers treatment steps for public systems. A secondary standard is a non-enforceable guideline for taste, odor, staining or corrosion. A health advisory is non-enforceable EPA guidance. Hardness and radon in water have no federal standard, so we show a USGS classification and state examples. See how to read your results for more.
What the checker doesn't cover
- Other contaminants. Labs and states test for more than this list, such as volatile organic compounds, PFAS, gross alpha and radium. Ask your health department which tests make sense where you live.
- Stricter state limits. Some states set their own limits. New Jersey's arsenic limit, for example, is stricter than EPA's (see the arsenic guide).
- Your household. Infants, pregnancy and health conditions can change what a result means for you. That's a conversation for your doctor or health department.
Next steps
- How to read your well water test results
- Best way to test well water (finding a state-certified lab)
- Whole-house vs. point-of-use treatment
- Private Well Testing Checklist (free printable)
Sources
Benchmarks were checked against these pages on October 22, 2026:
- U.S. EPA, National Primary Drinking Water Regulations: MCLs for nitrate, nitrite, arsenic, uranium and fluoride; lead and copper action levels (including the 0.010 mg/L lead action level from November 1, 2027); total coliform and E. coli.
- U.S. EPA, Secondary Drinking Water Standards: iron, manganese, copper, pH, TDS, sulfate, chloride and fluoride.
- U.S. EPA, Drinking Water Health Advisory for Manganese (2004).
- U.S. Geological Survey, Hardness of Water.
- U.S. EPA (archive), Proposed Radon in Drinking Water Rule (1999, never finalized).
- Vermont Department of Health, Radon in Drinking Water.
- NHDES, Well Water Information Workshop (radon advisory level).