Well Water vs. City Water: Key Differences and Testing
How private well water differs from municipal supply and what to test for.
The fundamental difference
City water is regulated by the EPA under the Safe Drinking Water Act. Your utility tests it, treats it, and publishes annual results. Private well water has no federal regulation. You are responsible for testing and treatment. About 43 million Americans use private wells.
What to test for
Annual testing for coliform bacteria, nitrate, pH, and TDS is recommended. Test for arsenic, radon, lead, and PFAS at least once. Hardness testing determines whether you need a softener. Testing after heavy rain or flooding is also important.
Common well water issues
Iron and manganese staining, sulfur smell (hydrogen sulfide), bacterial contamination, and high hardness. Treatment typically requires multiple systems. See our softener vs. filter guide.