Private wells
Arkansas well water: who's on a well and what to test for
People on private wells
120,600
Homes on wells
4.4%
Est. above arsenic limit
1,200
Every Arkansas county
Sorted by people on private wells. Arsenic and nitrate are modeled for typical wells in the county, not measured at yours; depth is the median of domestic well records.
| Baxter County | 11,700 | 30% | 1.1% | 0.1 | 300 ft |
| Carroll County | 7,600 | 28% | 1.2% | 0.1 | 396 ft |
| Benton County | 6,200 | 2% | 1.2% | 0.1 | 382 ft |
| Miller County | 5,800 | 14% | 1.2% | 0.1 | 170 ft |
| Fulton County | 4,900 | 41% | 0.9% | 0.3 | 260 ft |
| Marion County | 4,800 | 32% | 1.3% | 0.1 | 340 ft |
| Randolph County | 4,300 | 25% | 1.3% | 0.3 | 280 ft |
| Saline County | 3,700 | 3% | 0.8% | 0.1 | 125 ft |
| Izard County | 3,700 | 22% | 1.0% | 0.1 | 260 ft |
| Montgomery County | 3,400 | 40% | 0.9% | 0.1 | 140 ft |
| Sharp County | 2,800 | 16% | 1.1% | 0.1 | 293 ft |
| Polk County | 2,500 | 13% | 0.9% | 0.2 | 125 ft |
| Faulkner County | 2,500 | 2% | 1.9% | 0.1 | 135 ft |
| Union County | 2,200 | 6% | 1.1% | 0.1 | 230 ft |
| Boone County | 2,200 | 6% | 1.2% | 0.2 | 350 ft |
| Crittenden County | 2,200 | 4% | 2.9% | 0.2 | n/a |
| Lafayette County | 2,100 | 31% | 1.1% | 0.1 | 160 ft |
| White County | 1,800 | 2% | 2.1% | 0.1 | 140 ft |
| Pope County | 1,700 | 3% | 2.4% | 0.2 | 140 ft |
| Crawford County | 1,700 | 3% | 1.2% | 0.1 | 153 ft |
| Sebastian County | 1,600 | 1% | 2.0% | 0.1 | 160 ft |
| Hempstead County | 1,600 | 9% | 0.9% | 0.0 | 160 ft |
| Drew County | 1,500 | 8% | 1.4% | 0.1 | 68 ft |
| Mississippi County | 1,400 | 3% | 2.7% | 0.3 | 33 ft |
| Madison County | 1,400 | 10% | 1.2% | 0.1 | 278 ft |
| Ashley County | 1,400 | 8% | 1.4% | 0.0 | 103 ft |
| Scott County | 1,400 | 15% | 1.6% | 0.1 | 130 ft |
| Chicot County | 1,300 | 6% | 2.1% | 0.0 | 110 ft |
| Little River County | 1,300 | 10% | 1.3% | 0.3 | 75 ft |
| Ouachita County | 1,300 | 6% | 1.0% | 0.2 | 76 ft |
| Lonoke County | 1,200 | 2% | 1.2% | 0.1 | 115 ft |
| Pike County | 1,200 | 10% | 0.8% | 0.1 | 120 ft |
| Garland County | 1,100 | 1% | 1.0% | 0.1 | 130 ft |
| Yell County | 1,100 | 6% | 2.0% | 0.3 | 120 ft |
| Columbia County | 950 | 5% | 1.0% | 0.1 | 65 ft |
| Pulaski County | 930 | 0% | 1.2% | 0.2 | 140 ft |
| St. Francis County | 910 | 4% | 1.7% | 0.0 | 100 ft |
| Phillips County | 890 | 5% | 3.3% | 0.0 | n/a |
| Washington County | 860 | 0% | 1.4% | 0.3 | 260 ft |
| Nevada County | 830 | 12% | 0.9% | 0.1 | 165 ft |
| Clark County | 770 | 3% | 0.9% | 0.1 | 125 ft |
| Lawrence County | 760 | 5% | 1.2% | 0.2 | 220 ft |
| Stone County | 750 | 6% | 1.1% | 0.1 | 130 ft |
| Searcy County | 740 | 10% | 1.2% | 0.1 | 200 ft |
| Johnson County | 730 | 4% | 2.6% | 0.2 | 125 ft |
| Desha County | 730 | 7% | 2.5% | 0.0 | 420 ft |
| Newton County | 730 | 11% | 1.2% | 0.1 | 295 ft |
| Howard County | 730 | 5% | 0.9% | 0.1 | 165 ft |
| Logan County | 730 | 3% | 2.6% | 0.2 | 130 ft |
| Van Buren County | 720 | 4% | 2.0% | 0.2 | 120 ft |
| Lincoln County | 700 | 7% | 1.3% | 0.1 | 36 ft |
| Poinsett County | 680 | 3% | 2.4% | 0.1 | n/a |
| Independence County | 650 | 2% | 1.3% | 0.2 | 110 ft |
| Craighead County | 630 | 1% | 2.0% | 0.2 | 135 ft |
| Cleburne County | 620 | 2% | 1.7% | 0.1 | 192 ft |
| Grant County | 570 | 3% | 1.0% | 0.1 | 125 ft |
| Sevier County | 560 | 4% | 0.9% | 0.1 | 145 ft |
| Hot Spring County | 510 | 2% | 0.9% | 0.1 | 125 ft |
| Franklin County | 510 | 3% | 2.2% | 0.3 | 160 ft |
| Jefferson County | 500 | 1% | 1.3% | 0.1 | 122 ft |
| Perry County | 480 | 6% | 1.5% | 0.1 | 148 ft |
| Lee County | 460 | 7% | 2.1% | 0.0 | n/a |
| Prairie County | 450 | 6% | 1.3% | 0.0 | 120 ft |
| Cleveland County | 430 | 5% | 1.1% | 0.0 | n/a |
| Dallas County | 420 | 7% | 1.0% | 0.1 | 120 ft |
| Jackson County | 420 | 3% | 1.4% | 0.2 | 110 ft |
| Conway County | 390 | 2% | 2.4% | 0.4 | 110 ft |
| Greene County | 320 | 1% | 1.9% | 0.2 | 150 ft |
| Calhoun County | 320 | 7% | 1.3% | 0.1 | 125 ft |
| Arkansas County | 320 | 2% | 1.6% | 0.0 | n/a |
| Monroe County | 310 | 7% | 1.5% | 0.0 | n/a |
| Woodruff County | 300 | 5% | 1.2% | 0.1 | n/a |
| Bradley County | 270 | 2% | 1.3% | 0.1 | 58 ft |
| Clay County | 230 | 2% | 2.5% | 0.3 | n/a |
| Cross County | 210 | 1% | 2.1% | 0.0 | n/a |
Shading: red is among the highest counties nationally, amber the middle, green the lower range. Click a column to sort.
Most well users above the arsenic limit
- Greene County: about 110 people
- Craighead County: about 80 people
- Miller County: about 80 people
- Polk County: about 50 people
- Marion County: about 50 people
Test first, then treat what the test finds
We may earn a commission from links below, at no cost to you. Picks follow the testing order, not who pays. How we make money.
1. Certified lab well test
Start here, every year
A mail-in kit analyzed by a certified lab measures bacteria, nitrate, arsenic, metals and more. Test strips cannot measure arsenic or uranium reliably.
2. Sediment pre-filter
Sand, silt or cloudy water
A 5-micron cartridge after the pressure tank catches sand, silt and rust before they reach fixtures or other filters. Cartridges are cheap and swap every few months.
3. Iron and sulfur filter
Orange stains or rotten-egg smell
Air-injection or oxidizing-media filters remove orange staining and rotten-egg smell. Size one from a lab result for iron, manganese and hydrogen sulfide.
4. UV disinfection system
Coliform bacteria in a test
Inactivates bacteria and viruses; usually for private wells or after boil notices.
5. Under-sink reverse osmosis
Arsenic, nitrate or uranium in a test
The most thorough option for drinking water: PFAS, lead, nitrate, arsenic and more. Look for NSF/ANSI 58.
6. Whole-house well filter
Several problems at once
Multi-stage sediment and carbon for every tap. Add UV if bacteria shows up, and choose stages from your lab results, not a guess.
Questions
Which Arkansas counties rely most on wells?+
By share of homes: Fulton County (41%), Montgomery County (40%), Marion County (32%), Lafayette County (31%), Baxter County (30%). By number of people: Baxter County (11,700), Carroll County (7,600), Benton County (6,200).
Is arsenic a problem in Arkansas wells?+
USGS estimates about 1,200 Arkansas well users have water above the 10 microgram per liter arsenic limit that applies to public systems, the largest numbers in Greene County, Craighead County, Miller County. Arsenic has no taste or smell, so only a lab test finds it.
Do I have to test my well when I sell a house in Arkansas?+
We could not confirm a statewide rule for Arkansas. Check with your county health department. Buyers can still make a lab test a condition of the offer.
How often should I test my well?+
No federal law covers private wells. EPA's drinking water limits apply to public water systems, so testing and treating a private well is up to the owner. EPA and CDC recommend testing at least once a year for coliform bacteria, nitrate, pH and total dissolved solids, and testing for arsenic, uranium, radon and other local concerns based on where you live.
Well-user counts, arsenic and nitrate figures are each a modeled estimate built from national datasets, not a count of tested wells, and well depths summarize drilling records rather than every well. Your own well can be very different from the county average, which is why the only answer for your home is a lab test. Sources: EPA Office of Research and Development, Water Source 2020 (private well estimates by census block); CDC Environmental Public Health Tracking, Well Water Index (from USGS nitrate and arsenic models); USGS, county-level domestic well population with arsenic above 10 micrograms per liter (Ayotte and others, 2017); USGS Synthesized Domestic Well Database for the Conterminous United States (SynDWell-US), McCarthy and others, 2025 (depth, where a county has 30+ usable records).