How to Test Your Well Water (Step-by-Step, 2026 Guide)

If you own a private well, no one is testing your water for you. The EPA's drinking-water rules apply to public utilities, not the roughly 23 million U.S. households on private wells. Testing is on you, and the CDC recommends at least an annual check for coliform bacteria and nitrate plus a broader scan every 3 to 5 years.

Step 1: decide what to test for. Every well should be checked for total coliform and E. coli (bacteria), nitrate and nitrite (septic and ag runoff), pH, hardness, iron, and total dissolved solids. Add arsenic if you are in the Western U.S., Maine, or the upper Midwest. Add PFAS if you are within a few miles of a military base, airport, chrome plater, or industrial site. Add radon and uranium in granite regions.

Step 2: pick a testing route. There are three real options, and they answer different questions.

Free state labs: most state health departments will test for coliform bacteria and nitrate for free or under $25 if you mail in a sample using their bottle. Search '[your state] private well testing' to find the program. Best for the annual safety check.

Certified mail-in labs (Tap Score by SimpleLab, National Testing Labs, ETR): $150 to $700 depending on the panel. These run a full ICP-MS scan for 50 to 100+ contaminants including metals, VOCs, and (on premium tiers) PFAS. Best for the comprehensive 3 to 5 year baseline, before you buy a treatment system, or after any nearby industrial or agricultural change.

At-home strip and drop kits: $10 to $40 at any hardware store. They give you fast directional reads on hardness, pH, iron, chlorine, and nitrate. Useful for sizing a softener or iron filter, but not a substitute for certified testing.

Step 3: collect the sample correctly. For bacteria, run the cold tap for 5 minutes, then sterilize the spout with a flame or a 10% bleach wipe, then fill the sterile bottle without touching the inside. For metals, do NOT run the tap first: a first-draw sample catches anything leaching from your plumbing. Ship same-day with the cold pack the lab provides.

Step 4: read the report. Each contaminant has an EPA Maximum Contaminant Level (the legal limit for utilities) and often an EWG health guideline (a stricter advisory). Anything above the EPA limit needs treatment now. Anything above the EWG guideline but below the EPA limit is your judgment call.

Step 5: match results to a treatment. Bacteria or coliform present means a UV purifier and a chlorine shock of the well. Iron over 0.3 ppm or sulfur smell means an air-injection iron filter. Hardness over 7 gpg means a softener. PFAS or arsenic detected means an RO unit at the kitchen sink at minimum. Multiple problems usually need a stacked treatment train, sediment first then iron then softener then UV.

Re-test 30 days after any new system goes in to confirm the numbers actually moved. Then put the annual coliform and nitrate test on your calendar.