Quick answer
About 533,000 people in Kentucky (12.3% of residents) got their water from private wells in 2010, according to USGS estimates. Kentucky Energy and Environment Cabinet, Division of Water runs the state’s private well guidance. We didn’t find a free statewide well testing program in Kentucky. Certified labs charge for each test, and some county health departments offer lower-cost bacteria and nitrate tests.
- People on private wells
- 532,677
- Share of residents
- 12.3%
- Rank among states
- 23rd
- Well users modeled above 10 µg/L arsenic
- 2.7%
Where to get your well tested in Kentucky
- Kentucky Energy and Environment Cabinet, Division of Water: Water Well Information for Home Owners, the state’s guidance for private well owners.
Free or low-cost testing
We didn’t find a free statewide program in Kentucky. Certified labs charge per test; county health departments sometimes offer lower-cost bacteria and nitrate tests.
Mail-in lab kits are another option when no local lab is convenient. See well water test kits for what home kits can and can’t tell you.
What to test for
- Every year: total coliform bacteria and nitrate.
- Before buying equipment: pH, hardness, iron, manganese and, if there’s a smell, hydrogen sulfide.
- Based on location: arsenic, uranium and radon, PFAS, and lead in older plumbing.
Private wells by county
Estimated people relying on private wells in each Kentucky county in 2010, the share of residents that represents, and the modeled share of well users with arsenic above 10 µg/L. These are USGS model estimates (2010 population), not measurements of any well. Arsenic is hidden for counties with fewer than 500 well users.
| County | People on wells | Share | Arsenic >10 µg/L |
|---|---|---|---|
| Pike County | 40,258 | 61.9% | 2.5% |
| Letcher County | 16,295 | 66.5% | 2.3% |
| Floyd County | 14,537 | 36.8% | 2.2% |
| Perry County | 14,047 | 48.9% | 2.1% |
| Whitley County | 13,936 | 39.1% | 2.0% |
| Harlan County | 13,518 | 46.2% | 1.1% |
| Knott County | 13,492 | 82.5% | 2.0% |
| Graves County | 12,281 | 33.1% | 2.1% |
| Calloway County | 12,015 | 32.3% | 2.0% |
| Hardin County | 10,875 | 10.3% | 1.2% |
| Johnson County | 10,707 | 45.8% | 2.3% |
| Clay County | 10,487 | 48.3% | 1.9% |
Show all 120 counties
| Morgan County | 10,151 | 72.9% | 2.6% |
| Knox County | 9,969 | 31.3% | 2.0% |
| Lawrence County | 9,492 | 59.8% | 2.2% |
| Greenup County | 9,393 | 25.4% | 3.2% |
| Breathitt County | 8,914 | 64.2% | 2.1% |
| Meade County | 8,819 | 30.8% | 1.4% |
| Carter County | 8,368 | 30.2% | 2.4% |
| Casey County | 8,210 | 51.5% | 1.8% |
| Leslie County | 7,825 | 69.2% | 1.7% |
| Christian County | 7,707 | 10.4% | 1.1% |
| Magoffin County | 7,402 | 55.5% | 2.0% |
| Russell County | 7,356 | 41.9% | 1.5% |
| Grayson County | 7,307 | 28.4% | 1.4% |
| Bell County | 7,055 | 24.6% | 1.3% |
| Breckinridge County | 6,908 | 34.4% | 1.5% |
| Pulaski County | 6,813 | 10.8% | 1.6% |
| Adair County | 6,650 | 35.6% | 1.7% |
| Marshall County | 6,390 | 20.3% | 2.2% |
| McCracken County | 5,781 | 8.8% | 3.2% |
| Larue County | 5,639 | 39.7% | 2.0% |
| Bullitt County | 5,609 | 7.5% | 16.8% |
| Martin County | 5,597 | 43.3% | 2.2% |
| Laurel County | 5,312 | 9.0% | 2.0% |
| Allen County | 5,248 | 26.3% | 2.0% |
| Logan County | 5,223 | 19.5% | 2.0% |
| Elliott County | 5,036 | 64.1% | 2.0% |
| Lewis County | 5,021 | 36.2% | 4.4% |
| Wayne County | 4,954 | 23.8% | 1.6% |
| Barren County | 4,792 | 11.4% | 1.2% |
| Henderson County | 4,747 | 10.3% | 10.1% |
| Metcalfe County | 4,719 | 46.7% | 1.2% |
| Daviess County | 4,613 | 4.8% | 6.4% |
| Monroe County | 4,359 | 39.8% | 1.0% |
| Jefferson County | 4,324 | 0.6% | 11.3% |
| Wolfe County | 4,266 | 58.0% | 2.3% |
| Jackson County | 4,200 | 31.1% | 2.0% |
| Todd County | 4,029 | 32.3% | 1.6% |
| Hart County | 4,026 | 22.1% | 1.2% |
| Ballard County | 3,994 | 48.4% | 4.0% |
| Boyd County | 3,979 | 8.0% | 2.2% |
| McCreary County | 3,314 | 18.1% | 1.2% |
| Taylor County | 3,295 | 13.4% | 1.3% |
| Lincoln County | 3,229 | 13.0% | 2.5% |
| Carlisle County | 2,925 | 57.3% | 3.3% |
| Caldwell County | 2,923 | 22.5% | 2.3% |
| Nelson County | 2,908 | 6.7% | 11.0% |
| Livingston County | 2,866 | 30.1% | 2.0% |
| Crittenden County | 2,743 | 29.4% | 2.9% |
| Hickman County | 2,706 | 55.2% | 4.0% |
| Webster County | 2,642 | 19.4% | 5.1% |
| Clinton County | 2,637 | 25.7% | 2.0% |
| Ohio County | 2,601 | 10.9% | 3.5% |
| Green County | 2,496 | 22.2% | 1.3% |
| Rowan County | 2,270 | 9.7% | 3.4% |
| Hancock County | 2,011 | 23.5% | 2.0% |
| Owsley County | 1,984 | 41.7% | 2.0% |
| Lyon County | 1,933 | 23.3% | 2.0% |
| Butler County | 1,927 | 15.2% | 4.5% |
| Trigg County | 1,789 | 12.5% | 1.0% |
| Rockcastle County | 1,757 | 10.3% | 3.5% |
| Menifee County | 1,739 | 27.6% | 3.4% |
| Lee County | 1,738 | 22.0% | 3.0% |
| Fleming County | 1,677 | 11.7% | 6.9% |
| Hopkins County | 1,602 | 3.4% | 4.6% |
| Washington County | 1,597 | 13.6% | 1.6% |
| Bath County | 1,534 | 13.2% | 8.5% |
| Powell County | 1,486 | 11.8% | 3.0% |
| Shelby County | 1,465 | 3.5% | 3.6% |
| Union County | 1,451 | 9.7% | 18.3% |
| Clark County | 1,434 | 4.0% | 1.9% |
| Boone County | 1,392 | 1.2% | 5.0% |
| Warren County | 1,342 | 1.2% | 2.2% |
| Edmonson County | 1,284 | 10.6% | 2.0% |
| Bourbon County | 1,262 | 6.3% | 1.9% |
| Cumberland County | 1,234 | 18.0% | 2.0% |
| McLean County | 1,222 | 12.8% | 7.5% |
| Muhlenberg County | 1,221 | 3.9% | 4.3% |
| Madison County | 1,200 | 1.4% | 2.0% |
| Marion County | 1,161 | 5.9% | 1.3% |
| Scott County | 1,096 | 2.3% | 1.9% |
| Estill County | 1,069 | 7.3% | 3.0% |
| Montgomery County | 1,013 | 3.8% | 4.6% |
| Oldham County | 1,010 | 1.7% | 9.9% |
| Boyle County | 994 | 3.5% | 1.1% |
| Mercer County | 942 | 4.4% | 1.8% |
| Henry County | 923 | 6.0% | 5.1% |
| Owen County | 910 | 8.4% | 4.4% |
| Spencer County | 904 | 5.3% | 3.9% |
| Kenton County | 889 | 0.6% | 6.8% |
| Campbell County | 865 | 1.0% | 4.9% |
| Fulton County | 863 | 12.7% | 5.0% |
| Jessamine County | 799 | 1.6% | 2.6% |
| Nicholas County | 794 | 11.1% | 3.0% |
| Fayette County | 790 | 0.3% | 1.9% |
| Grant County | 775 | 3.1% | 4.0% |
| Garrard County | 770 | 4.6% | 2.5% |
| Anderson County | 745 | 3.5% | 2.8% |
| Mason County | 712 | 4.1% | 2.1% |
| Woodford County | 663 | 2.7% | 2.8% |
| Franklin County | 640 | 1.3% | 5.0% |
| Simpson County | 609 | 3.5% | 2.0% |
| Gallatin County | 601 | 7.0% | 5.5% |
| Harrison County | 569 | 3.0% | 2.4% |
| Trimble County | 511 | 5.8% | 3.0% |
| Carroll County | 474 | 4.4% | – |
| Pendleton County | 471 | 3.2% | – |
| Bracken County | 442 | 5.2% | – |
| Robertson County | 192 | 8.4% | – |
Counties with the highest modeled arsenic share: Union County (18.3%), Bullitt County (16.8%), Jefferson County (11.3%), Nelson County (11.0%), Henderson County (10.1%).
After you get results
Enter your numbers in the test results tool to see what needs treating and in what order. The guide to reading a well water test explains units and limits.
Common questions
Does Kentucky offer free well water testing?
We didn’t find a free statewide well testing program in Kentucky. Certified labs charge for each test, and some county health departments offer lower-cost bacteria and nitrate tests.
Who oversees private wells in Kentucky?
Kentucky Energy and Environment Cabinet, Division of Water (Water Well Information for Home Owners) publishes guidance for private well owners. Private wells aren’t covered by the federal Safe Drinking Water Act, so testing and treatment are up to the owner.
How many people use private wells in Kentucky?
USGS estimates about 533,000 people, or 12.3% of the population in 2010. That ranks 23rd of the states covered by the estimate.
What should I test my well for in Kentucky?
Test every year for total coliform bacteria and nitrate, plus pH, hardness, iron and manganese before buying equipment. Ask the state program or a certified lab about local concerns such as arsenic, uranium or PFAS.