Glossary · Health & indoor air

Well water testing

Also called: well water test · private well testing · well testing · drinking water test

Lab testing of water from a private well for bacteria and chemicals, done on a regular schedule and after floods or repairs.

What it means

Basic tests look for coliform bacteria, including E. coli, which signal contamination from the surface or from sewage. Which chemicals to test for, and how often, depends on local geology and land use, so ask your local or state health department. Follow the lab's sampling instructions.

Why it matters in an audit

A home health screen flags whether a well test is due, especially before buying, after flooding, or when someone in the household is vulnerable.

Typical numbers

Reference values with their sources. Your auditor’s report gives the figure for your own house.

What Value Source
Safe microbial result (EPA) No E. coli and no total coliforms per 100 mL epa.gov ↗
US EPA Test at least once a year for total coliform bacteria, nitrates, total dissolved solids and pH; more often with infants, older adults, or pregnant or nursing household members epa.gov ↗

Sources