For Homeowners & Well Owners
If you're on a private well, no one tests your water unless you do. When you do, the lab you choose is the whole ballgame.
What can go wrong before the test even starts
A water test has three parts: collecting the sample, getting it to the lab intact, and analyzing it. Regulatory certification concentrates on the third. But most bad results come from the first two:
- A bacteria sample collected in the wrong bottle, or without the preservative, will read clean when it isn't.
- A sample that sat in a hot truck for a day can lose the very thing you're testing for.
- A sample with no chain-of-custody record could be anyone's water.
DWLCA-certified labs are audited on all three parts, every year, in person.
How to use this site
Ask the lab for its DWLCA number
A certified lab will give you its 8-digit DWLCA certificate number before you send a sample. If it can't, that tells you something.
Check the report when it comes back
Look for the DWLCA seal and 8-digit number. Type it into Verify or scan the QR code. Make sure the lab is In Good Standing and certified for the scope on your report.
Ask who collected the sample
A DWLCA report tells you. If a home inspector or lab courier collected it, they should be on the lab's trained-collector roster. If you collected it yourself, the report will say so.
Speak up if something's off
Wrong number, missing seal, a result that makes no sense — tell us. Every concern is read by a person, and credible ones trigger an unscheduled audit.
What to test for on a private well
General guidance, not a substitute for your local health department's recommendation:
- Every year: Total coliform and E. coli bacteria, nitrate, pH, total dissolved solids.
- Every 3–5 years, or at purchase: Metals (lead, arsenic, iron, manganese), hardness, fluoride, and — depending on your area — radon in water, uranium, and PFAS.
- Any time the water changes taste, color, or smell; after flooding; after well or plumbing work; or if someone in the house is pregnant or has an unexplained illness.