Your county health department
Arizona doesn't run a statewide free testing program that we know of. Some county health departments still test wells or sell kits, so call yours first.
Department of Health Services: private well testingGetting your well water tested in Arizona
Use a lab Arizona certifies, or a mail-in kit. Across the state, the ones worth testing for are arsenic, nitrate, fluoride, uranium and manganese, plus bacteria every year.
About 651,000 people in Arizona get their water from a private well, about 1 in 11 residents.
Three ways to get tested, cheapest first.
A lab Arizona certifies
The state's list of labs certified for drinking water. Many sell bottles you pick up or get by mail, and their results count for a home sale or loan.
Labs certified by ArizonaA mail-in kit
Order online, fill the bottles at your kitchen tap and get results by email in about a week. Full well tests run about $210 to $220.
Compare kits for ArizonaWhat turns up in Arizona wells.
Share of tested wells over the limit, from lab tests the USGS, EPA and state agencies collected since 2000. Your own well needs its own test.
Arsenic23%542 of 2,320Nitrate14%234 of 1,719Fluoride11%267 of 2,528Uranium10%28 of 280Manganese8%217 of 2,566Radon1%10 of 748Lead1%21 of 2,189
GermsTest every year, whatever the chart says
Coliform bacteria31%57 of 184StainsNot a health risk
Iron stains12%293 of 2,534
Rare: under 5%Worth checking: 5 to 15%Widespread: 15%+
Lab results: Water Quality Portal (USGS and EPA)
Where it shows up most
- Nitrate shows up most in Maricopa County (about 1 in 4 wells), Yuma County (about 1 in 4 wells), Pinal County (about 2 in 10 wells).
- Arsenic shows up most in Yuma County (about 6 in 10 wells), Maricopa County (about 1 in 3 wells), Graham County (about 3 in 10 wells).
- Uranium shows up most in Maricopa County (about 2 in 10 wells), Pima County (about 1 in 9 wells).
Find your county.
6 counties have a full report with local test results and well depths.
No full report for that county yet. The statewide results above still apply, and so do the three ways to get tested.
Every county in Arizona: people on wells and typical depth
| County | People on private wells | Share of residents | Typical well depth |
|---|---|---|---|
| Maricopa County | 146,769 | 3% | 400 ft |
| Pinal County | 98,488 | 23% | 480 ft |
| Pima County | 70,129 | 7% | 380 ft |
| Yavapai County | 69,599 | 29% | 305 ft |
| Navajo County | 55,863 | 52% | 370 ft |
| Apache County | 54,146 | 82% | 280 ft |
| Coconino County | 32,281 | 22% | 220 ft |
| Cochise County | 28,180 | 22% | 284 ft |
| Yuma County | 27,403 | 13% | 190 ft |
| Gila County | 21,393 | 40% | 170 ft |
| Mohave County | 20,006 | 9% | 278 ft |
| Graham County | 10,315 | 27% | 120 ft |
| La Paz County | 10,255 | 62% | 150 ft |
| Santa Cruz County | 4,215 | 9% | 280 ft |
| Greenlee County | 2,365 | 25% | 130 ft |
Questions people ask about well water in Arizona
Does Arizona require private wells to be tested?
Arizona doesn't require routine testing of existing private wells. Keeping a well safe is up to the owner, so test for bacteria and nitrate every year.
Where can I get my well water tested in Arizona?
Otherwise, use a lab certified by Arizona for drinking water. The state's list is linked on this page.
Where these numbers come from
- How many people use wells: EPA estimates from the 2020 Census.
- Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000.
- State programs and links: Department of Health Services.