Home Water Report

Private wells

Private well water testing: what to test, and how often

No one tests a private well but its owner — wells sit outside the federal lead and PFAS rules. Here is the plain EPA/CDC schedule, and when to stop and test right away.

By Home Water Report Research Desk · EPA/CDC-sourced · not a substitute for your local health department

A private well head and a labeled water sample bottle in a backyard

Here is the part well owners often miss: private wells are not regulated by the EPA under the Safe Drinking Water Act. The lead rule, the PFAS rule, the annual water reports — those cover public water systems. If you are on a well, you are the water utility, and testing is your job.

Test every year

EPA and CDC recommend testing a private well at least once a year for the basics:

  • Total coliform bacteria — a core safety indicator; many labs also report E. coli or fecal coliform if the result suggests fecal contamination.
  • Nitrate — especially important where there is agriculture or septic nearby; a serious risk for infants.
  • pH and total dissolved solids (TDS) — corrosion and general water-quality signals.

Add a broader panel periodically

Beyond the annual basics, test for local contaminants of concern on a longer cycle — every few years, or when you first move in. Depending on your area, that may include lead, arsenic, mercury, radium, VOCs, pesticides, herbicides, or other local chemicals; EPA also flags metals near mining, landfills, factories, gas stations, or dry-cleaning operations. Your county or state program can tell you what is common where you live — see heavy metals in water.

Test immediately when something changes

  • There is a known groundwater or drinking-water problem in your area.
  • Conditions near the well change — flooding, land disturbance, or new construction or industrial activity.
  • You repair or replace any part of the well system.
  • You notice a change in taste, odor, or color.
  • Someone in the home is pregnant or nursing, or you have infants or elderly residents — test more often, since they are more vulnerable.

Use a state-certified lab

For results that matter — bacteria, nitrate, metals — use a state-certified laboratory, not a hardware-store strip. Your county or state drinking-water program keeps a list of certified labs and often the recommended test package for your area. The finding-a-lab guide walks through who to call.

Lead and wells

On a private well, lead is usually a house plumbing problem rather than a municipal lead-service-line problem: EPA flags household plumbing or service lines that contain lead, corrosion, low/high pH, solder, and fixtures as reasons to test for lead and copper. If you have older plumbing, include lead in your panel; if it shows up, use a point-of-use filter certified to NSF/ANSI 53 for lead at drinking and cooking taps. See how to test for lead and the certified-filter picks.

Sources