Private Wells: Your Annual Testing Schedule and What to Look For

If you get your water from a private well, the EPA does not test it. There's no utility behind your tap — just you, your pump, and whatever's in the aquifer below your property. The CDC recommends an annual baseline test, but that's a floor, not a ceiling. Here's the schedule to actually follow.

Test every year

• Total coliform bacteria and E. coli — indicators of contamination from septic, animals, or surface water

• Nitrates — especially critical if you have an infant in the home

• pH and total dissolved solids — early signs of plumbing corrosion or aquifer change

Test every 3 to 5 years

• Heavy metals (lead, arsenic, copper, manganese)

• Volatile organic compounds (VOCs) if you live near industry, gas stations, or dry cleaners

• Radon in water — especially in granite-bedrock regions like the Northeast

Test immediately if any of these happen

1. The taste, color, or smell of your water changes

2. Anyone in the household has unexplained gastrointestinal illness

3. There's been flooding, a chemical spill, or new construction nearby

4. You replace your pump or any major plumbing component

What to do with results

Don't panic at one bad result — retest first. Bacterial contamination usually means your well needs shock chlorination. Persistent metals or chemicals usually mean a treatment system: filtration, ion exchange, or reverse osmosis depending on what's elevated. A certified lab report tells you exactly which treatment matches the contaminant.