Get your water tested.
The short answer
A lab test is the only way to know what is in your own tap or well. Use a lab your state certifies for the test you want: certification is test by test, from bacteria to lead to PFAS.
Call first. The lab will say which bottles to use, how to take the sample and how soon it has to arrive, and whether it takes samples from homeowners at all.
By state
Each state’s own list of labs certified to test drinking water, with their cities and, where the list gives them, phone numbers and what each is certified for.
- Alabama64 labs · 31 in the state
- Alaska37 labs · 24 in the state
- Arizona49 labs · 23 in the state
- California145 labs · 108 in the state
- Colorado54 labs · 26 in the state
- Connecticut86 labs · 20 in the state
- Delaware13 labs · none in the state
- Florida212 labs · 141 in the state
- Georgia43 labs · 15 in the state
- Hawaii12 labs · 2 in the state
- Idaho33 labs · 10 in the state
- Illinois30 labs · 19 in the state
- Indiana81 labs · 53 in the state
- Iowa36 labs · 17 in the state
- Kansas47 labs · 18 in the state
- Louisiana48 labs · 20 in the state
- Maine53 labs · 19 in the state
- Maryland92 labs · 38 in the state
- Massachusetts81 labs · 44 in the state
- Michigan193 labs · 173 in the state
- Minnesota24 labs
- Mississippi5 labs
- Missouri64 labs · 44 in the state
- Montana36 labs · 15 in the state
- Nebraska5 labs
- Nevada52 labs · 14 in the state
- New Hampshire63 labs · 15 in the state
- New Jersey89 labs · 39 in the state
- New Mexico44 labs · 23 in the state
- New York161 labs · 61 in the state
- North Carolina112 labs · 73 in the state
- Ohio76 labs · 51 in the state
- Oregon91 labs · 34 in the state
- Pennsylvania108 labs · 53 in the state
- Puerto Rico12 labs · 7 in the state
- Rhode Island6 labs · 5 in the state
- South Carolina36 labs · 17 in the state
- South Dakota16 labs · 4 in the state
- Tennessee37 labs · 13 in the state
- Texas80 labs
- Utah60 labs · 29 in the state
- Vermont46 labs · 6 in the state
- Virginia145 labs · 82 in the state
- Washington84 labs · 47 in the state
- West Virginia50 labs · 23 in the state
- Wisconsin156 labs · 132 in the state
- Wyoming12 labs
Other states and territories
TapBuff hasn’t read these lists yet: American Samoa, Arkansas, District of Columbia, Guam, Kentucky, North Dakota, Northern Mariana Islands, Oklahoma and U.S. Virgin Islands. EPA’s table of state certification programs links each state’s own list, and some states test well water at a public lab of their own.
Sources: each state’s own list, named and dated on its page, read from Oct. 10, 2026 to Oct. 17, 2026; EPA’s Drinking Water Laboratory Certification Program and its State Certification Programs That Certify Laboratories to Conduct Drinking Water Analyses. A lab certified by more than one state, or listed under more than one spelling, counts once in the total. How labs are listed here.
Where to go next
- Testing a private wellWhat to test for every year, what else depends on where you live, and reading the results.How to test well water
- Testing your tap for leadWhat your own plumbing can add, and what to do before the results come back.Lead in tap water
- What a test costsWhat state and university labs charge, where testing is free, and the fees beyond the test.What a water test costs
- What your utility foundLook up your ZIP code for your utility’s results against EPA’s limits.Your water, by state