Your county health department
Oklahoma 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 Environmental Quality: private well testingGetting your well water tested in Oklahoma
Use a lab Oklahoma certifies, or a mail-in kit. Across the state, the ones worth testing for are arsenic, nitrate and uranium, plus bacteria every year.
About 811,000 people in Oklahoma get their water from a private well, about 2 in 10 residents.
Three ways to get tested, cheapest first.
A lab Oklahoma 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 OklahomaA 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 OklahomaWhat turns up in Oklahoma 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.
Arsenic21%57 of 278Nitrate13%242 of 1,830Uranium9%17 of 194Manganese5%53 of 1,130Fluorideunder 1%4 of 1,147Radon0%0 of 41Lead0%0 of 162
GermsTest every year, whatever the chart says
Coliform bacteria27%6 of 22StainsNot a health risk
Iron stains14%152 of 1,123
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 Garfield County (about 3 in 10 wells), Kingfisher County (about 3 in 10 wells), Harper County (about 3 in 10 wells).
- Arsenic shows up most in Cleveland County (about 6 in 10 wells), Oklahoma County (about 2 in 10 wells).
- Uranium shows up most in Pottawatomie County (about 2 in 10 wells).
Find your county.
5 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 Oklahoma: people on wells and typical depth
| County | People on private wells | Share of residents | Typical well depth |
|---|---|---|---|
| Oklahoma County | 80,195 | 10% | 180 ft |
| Cleveland County | 44,875 | 15% | 180 ft |
| Pottawatomie County | 29,577 | 41% | 160 ft |
| Grady County | 24,988 | 46% | 150 ft |
| Logan County | 24,838 | 50% | 180 ft |
| Garfield County | 22,729 | 36% | 47 ft |
| Creek County | 22,178 | 31% | 164 ft |
| Canadian County | 21,552 | 14% | 120 ft |
| Delaware County | 21,327 | 53% | 320 ft |
| Tulsa County | 20,025 | 3% | 80 ft |
| Lincoln County | 19,801 | 59% | 170 ft |
| Rogers County | 19,143 | 20% | 118 ft |
| Cherokee County | 18,607 | 40% | 215 ft |
| McClain County | 18,433 | 44% | 140 ft |
| Le Flore County | 16,130 | 34% | 165 ft |
| Payne County | 15,859 | 19% | 141 ft |
| Mayes County | 15,611 | 40% | 163 ft |
| McCurtain County | 14,789 | 48% | 145 ft |
| Carter County | 14,548 | 30% | 140 ft |
| Osage County | 14,312 | 31% | 150 ft |
| Bryan County | 14,281 | 31% | 140 ft |
| Sequoyah County | 13,360 | 34% | 190 ft |
| Stephens County | 13,282 | 31% | 140 ft |
| Wagoner County | 12,983 | 16% | 85 ft |
| Muskogee County | 12,539 | 19% | 140 ft |
| Comanche County | 12,313 | 10% | 120 ft |
| Pittsburg County | 12,014 | 27% | 140 ft |
| Adair County | 11,097 | 57% | 200 ft |
| Okmulgee County | 11,045 | 30% | 165 ft |
| Pontotoc County | 10,987 | 29% | 160 ft |
| Seminole County | 10,508 | 45% | 190 ft |
| Garvin County | 9,788 | 38% | 111 ft |
| Caddo County | 9,470 | 35% | 120 ft |
| Ottawa County | 9,076 | 30% | 382 ft |
| McIntosh County | 8,579 | 45% | 120 ft |
| Atoka County | 7,766 | 55% | 122 ft |
| Pawnee County | 7,172 | 46% | 160 ft |
| Washington County | 6,877 | 13% | 68 ft |
| Choctaw County | 6,549 | 46% | 120 ft |
| Kay County | 6,403 | 15% | 37 ft |
| Pushmataha County | 6,155 | 57% | 160 ft |
| Haskell County | 6,140 | 53% | 150 ft |
| Okfuskee County | 5,859 | 52% | 160 ft |
| Woodward County | 5,846 | 29% | 80 ft |
| Craig County | 5,779 | 41% | 230 ft |
| Custer County | 5,551 | 19% | 160 ft |
| Marshall County | 5,381 | 35% | 151 ft |
| Kingfisher County | 5,380 | 35% | 67 ft |
| Hughes County | 4,911 | 37% | 160 ft |
| Beckham County | 4,841 | 22% | 100 ft |
| Love County | 4,643 | 46% | 130 ft |
| Johnston County | 4,469 | 44% | 160 ft |
| Latimer County | 3,969 | 42% | 160 ft |
| Major County | 3,941 | 51% | 70 ft |
| Murray County | 3,826 | 28% | 175 ft |
| Noble County | 3,764 | 34% | 100 ft |
| Nowata County | 3,719 | 40% | 160 ft |
| Washita County | 3,558 | 33% | 120 ft |
| Kiowa County | 3,540 | 42% | 45 ft |
| Jackson County | 3,266 | 13% | 51 ft |
| Texas County | 3,184 | 15% | 308 ft |
| Blaine County | 2,983 | 34% | 65 ft |
| Beaver County | 2,568 | 51% | 180 ft |
| Dewey County | 2,420 | 54% | 120 ft |
| Coal County | 2,412 | 46% | 158 ft |
| Roger Mills County | 2,319 | 67% | 115 ft |
| Woods County | 1,956 | 23% | 60 ft |
| Alfalfa County | 1,889 | 33% | 50 ft |
| Cotton County | 1,789 | 32% | 68 ft |
| Greer County | 1,726 | 31% | 60 ft |
| Jefferson County | 1,528 | 29% | 120 ft |
| Grant County | 1,406 | 34% | 43 ft |
| Tillman County | 1,291 | 19% | 40 ft |
| Ellis County | 1,249 | 33% | 200 ft |
| Harper County | 957 | 29% | 80 ft |
| Cimarron County | 800 | 35% | 247 ft |
| Harmon County | 631 | 25% | 87 ft |
Questions people ask about well water in Oklahoma
Does Oklahoma require private wells to be tested?
Oklahoma 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 Oklahoma?
Otherwise, use a lab certified by Oklahoma 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 Environmental Quality.