Find the right water test

How your plan is built

Your plan comes from written rules, not from a chatbot. Each rule says when it applies (for example "private well" or "home built before 1986"), which tests it adds and which public source it is based on. The rules are versioned data, and every plan stores the rules version it was built with, so the same answers always give the same plan.

The yearly baseline for wells. CDC says: "Test your well water at least once every year for total coliform bacteria, nitrates, total dissolved solids, and pH level." EPA gives the same yearly list and adds that you may want to test more often if someone in your home is pregnant or nursing, or if small children or older adults live there. If you have a private well, or you are not sure where your water comes from, these four tests are always in your plan.

Tests for your situation. Other rules add tests for what you tell us: a baby on the way, recent flooding, a smell, taste or stain, the age of your home, a treatment system you want to check, or a contaminant you are worried about. Each test in your plan shows the reason it is there and links to the source. Tests that don't fit your situation are listed as "not prioritized", with the reason, so you can still add them.

Public data as context. For your ZIP code we also look at public data: your water utility's reported testing (from TapWaterData, which draws on EPA's SDWIS database) and USGS model estimates for wells in your county. Model estimates describe an area, not your well, so we label them as estimates. Public data can add a test to your plan. Only a certified lab result tells you what is in your own water.

How labs are chosen

A lab appears in your plan only if all of these are true:

• your state certifies it to test drinking water, and for each test in your plan that has a state certification of its own;
• it says on its own website that it accepts samples from homeowners, and we checked that within the last 90 days;
• your sample can reach it in time, by mail-in kit or by drop-off near you. Bacteria samples have the tightest time limit, so far-away mail-in labs are left out for them.

We then show up to three options: Best value (the lowest total price), Easiest (a mail-in kit with shipping included, when there is one) and Fastest (the shortest stated turnaround). Every other eligible lab is listed below them.

Prices are all-in

Each price is the lab's price for the tests you need, with any fees included. For a mail-in kit that doesn't include shipping, kit shipping is added once per order, not once per test. When a lab doesn't publish a price, we say "price on request" and never rank it as best value.

How WTA makes money

Some labs can be ordered through WaterTestAtlas checkout, and WTA earns money on those orders. That never changes the order of the labs: the ranking doesn't know which labs WTA earns from, and labs you can't order through us are ranked the same way as the rest.

Example plans

Sources (2)

1. Guidelines for Testing Well Water (opens in a new tab)Centers for Disease Control and Prevention · Retrieved Oct 5, 2026
2. Protect Your Home's Water (opens in a new tab)US Environmental Protection Agency · Retrieved Oct 5, 2026