Quick answer
About 366,000 people in Mississippi (12.3% of residents) got their water from private wells in 2010, according to USGS estimates. Mississippi State Department of Health runs the state’s private well guidance. We didn’t find a free statewide well testing program in Mississippi. Certified labs charge for each test, and some county health departments offer lower-cost bacteria and nitrate tests.
- People on private wells
- 365,855
- Share of residents
- 12.3%
- Rank among states
- 33rd
- Well users modeled above 10 µg/L arsenic
- 2.6%
Where to get your well tested in Mississippi
- Mississippi State Department of Health: Private Well Water Testing, the state’s guidance for private well owners.
- Certified laboratories in Mississippi. Use a lab certified for drinking water, so results are reliable.
Free or low-cost testing
We didn’t find a free statewide program in Mississippi. 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 Mississippi 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 |
|---|---|---|---|
| Jackson County | 34,594 | 24.8% | 2.4% |
| Harrison County | 31,500 | 16.8% | 3.9% |
| Marshall County | 22,060 | 59.4% | 2.9% |
| Pearl River County | 18,118 | 32.4% | 2.6% |
| Hancock County | 16,763 | 38.2% | 2.3% |
| Lincoln County | 15,003 | 43.0% | 4.0% |
| Tate County | 13,754 | 47.6% | 2.4% |
| George County | 13,586 | 60.2% | 2.7% |
| Pike County | 10,230 | 25.3% | 2.9% |
| DeSoto County | 9,116 | 5.7% | 2.4% |
| Stone County | 8,113 | 45.6% | 4.1% |
| Lowndes County | 7,856 | 13.1% | 1.7% |
Show all 82 counties
| Lauderdale County | 7,172 | 8.9% | 1.0% |
| Union County | 7,079 | 26.1% | 1.5% |
| Amite County | 6,362 | 48.5% | 4.0% |
| Walthall County | 6,315 | 40.9% | 3.0% |
| Benton County | 5,589 | 64.0% | 2.0% |
| Marion County | 5,121 | 18.9% | 3.0% |
| Washington County | 4,666 | 9.1% | 3.5% |
| Newton County | 4,500 | 20.7% | 1.0% |
| Lafayette County | 4,497 | 9.5% | 1.5% |
| Panola County | 4,395 | 12.7% | 2.0% |
| Hinds County | 4,297 | 1.8% | 3.2% |
| Greene County | 4,157 | 28.9% | 1.6% |
| Lamar County | 4,142 | 7.4% | 2.8% |
| Wayne County | 4,007 | 19.3% | 1.9% |
| Bolivar County | 3,843 | 11.3% | 2.7% |
| Monroe County | 3,804 | 10.3% | 1.0% |
| Rankin County | 3,520 | 2.5% | 2.4% |
| Pontotoc County | 3,049 | 10.2% | 1.0% |
| Clarke County | 2,864 | 17.1% | 1.0% |
| Noxubee County | 2,858 | 24.8% | 1.2% |
| Sunflower County | 2,803 | 9.5% | 1.9% |
| Tippah County | 2,773 | 12.5% | 1.4% |
| Perry County | 2,764 | 22.6% | 2.7% |
| Leflore County | 2,646 | 8.2% | 2.0% |
| Leake County | 2,618 | 11.0% | 1.6% |
| Forrest County | 2,553 | 3.4% | 2.6% |
| Lee County | 2,539 | 3.1% | 1.0% |
| Alcorn County | 2,354 | 6.4% | 1.0% |
| Attala County | 2,316 | 11.8% | 2.6% |
| Itawamba County | 2,297 | 9.8% | 1.0% |
| Simpson County | 2,293 | 8.3% | 2.7% |
| Franklin County | 2,250 | 27.7% | 3.9% |
| Jones County | 2,111 | 3.1% | 2.0% |
| Madison County | 2,038 | 2.1% | 2.2% |
| Coahoma County | 1,991 | 7.6% | 2.0% |
| Neshoba County | 1,974 | 6.7% | 1.3% |
| Clay County | 1,957 | 9.5% | 1.0% |
| Tallahatchie County | 1,733 | 11.3% | 3.6% |
| Grenada County | 1,635 | 7.5% | 3.4% |
| Carroll County | 1,571 | 14.8% | 3.5% |
| Copiah County | 1,539 | 5.2% | 3.8% |
| Yazoo County | 1,503 | 5.4% | 3.8% |
| Adams County | 1,477 | 4.6% | 2.8% |
| Tunica County | 1,473 | 13.7% | 2.0% |
| Covington County | 1,369 | 7.0% | 2.0% |
| Lawrence County | 1,348 | 10.4% | 3.0% |
| Scott County | 1,346 | 4.8% | 1.0% |
| Chickasaw County | 1,319 | 7.6% | 1.0% |
| Prentiss County | 1,288 | 5.1% | 1.0% |
| Humphreys County | 1,237 | 13.2% | 2.4% |
| Holmes County | 1,211 | 6.3% | 2.9% |
| Tishomingo County | 1,083 | 5.5% | 1.0% |
| Warren County | 992 | 2.0% | 5.3% |
| Wilkinson County | 929 | 9.4% | 4.5% |
| Smith County | 889 | 5.4% | 1.6% |
| Sharkey County | 888 | 18.1% | 3.0% |
| Oktibbeha County | 881 | 1.8% | 1.7% |
| Jefferson Davis County | 832 | 6.7% | 2.7% |
| Quitman County | 718 | 8.7% | 2.0% |
| Calhoun County | 716 | 4.8% | 1.0% |
| Yalobusha County | 684 | 5.4% | 2.2% |
| Jasper County | 541 | 3.2% | 1.0% |
| Kemper County | 516 | 4.9% | 1.0% |
| Choctaw County | 511 | 6.0% | 2.0% |
| Winston County | 485 | 2.5% | – |
| Webster County | 469 | 4.6% | – |
| Montgomery County | 425 | 3.9% | – |
| Issaquena County | 399 | 28.3% | – |
| Claiborne County | 349 | 3.6% | – |
| Jefferson County | 292 | 3.8% | – |
Counties with the highest modeled arsenic share: Warren County (5.3%), Wilkinson County (4.5%), Stone County (4.1%), Lincoln County (4.0%), Amite County (4.0%).
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 Mississippi offer free well water testing?
We didn’t find a free statewide well testing program in Mississippi. Certified labs charge for each test, and some county health departments offer lower-cost bacteria and nitrate tests.
Who oversees private wells in Mississippi?
Mississippi State Department of Health (Private Well Water Testing) 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 Mississippi?
USGS estimates about 366,000 people, or 12.3% of the population in 2010. That ranks 33rd of the states covered by the estimate.
What should I test my well for in Mississippi?
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.