Arkansas well water by county: arsenic and nitrate
Modelled arsenic and nitrate for private-well users in every Arkansas county, what to test for, and where to find a certified lab. Private wells aren’t covered by the Safe Drinking Water Act.
All 75 counties
- Benton CountyWell users 23,900Arsenic about 1 in 100Nitrate 0.1 mg/L
- Garland CountyWell users 21,900Arsenic about 1 in 100Nitrate 0.1 mg/L
- Washington CountyWell users 20,100Arsenic about 1 in 100Nitrate 0.3 mg/L
- Faulkner CountyWell users 16,000Arsenic about 2 in 100Nitrate 0.1 mg/L
- Pope CountyWell users 14,400Arsenic about 2 in 100Nitrate 0.2 mg/L
- Baxter CountyWell users 14,200Arsenic about 1 in 100Nitrate 0.1 mg/L
- Miller CountyWell users 13,600Arsenic about 1 in 100Nitrate 0.1 mg/L
- White CountyWell users 13,200Arsenic about 2 in 100Nitrate 0.2 mg/L
- Hot Spring CountyWell users 13,000Arsenic about 1 in 100Nitrate 0.1 mg/L
- Boone CountyWell users 12,200Arsenic about 1 in 100Nitrate 0.2 mg/L
- Conway CountyWell users 11,500Arsenic about 2 in 100Nitrate 0.4 mg/L
- Polk CountyWell users 11,300Arsenic about 1 in 100Nitrate 0.2 mg/L
- Pulaski CountyWell users 11,200Arsenic about 1 in 100Nitrate 0.2 mg/L
- Greene CountyWell users 11,100Arsenic about 2 in 100Nitrate 0.2 mg/L
- Saline CountyWell users 10,300Arsenic about 1 in 100Nitrate 0.1 mg/L
- Carroll CountyWell users 9,600Arsenic about 1 in 100Nitrate 0.1 mg/L
- Hempstead CountyWell users 9,000Arsenic about 1 in 100Nitrate 0.0 mg/L
- Marion CountyWell users 8,900Arsenic about 1 in 100Nitrate 0.1 mg/L
- Logan CountyWell users 8,200Arsenic about 3 in 100Nitrate 0.2 mg/L
- Cleburne CountyWell users 8,000Arsenic about 2 in 100Nitrate 0.1 mg/L
- Randolph CountyWell users 7,700Arsenic about 1 in 100Nitrate 0.3 mg/L
- Sevier CountyWell users 7,600Arsenic about 1 in 100Nitrate 0.1 mg/L
- Crawford CountyWell users 7,500Arsenic about 1 in 100Nitrate 0.1 mg/L
- Madison CountyWell users 7,200Arsenic about 1 in 100Nitrate 0.1 mg/L
- Fulton CountyWell users 7,000Arsenic about 1 in 100Nitrate 0.3 mg/L
- Independence CountyWell users 6,800Arsenic about 1 in 100Nitrate 0.2 mg/L
- Lonoke CountyWell users 6,700Arsenic about 1 in 100Nitrate 0.1 mg/L
- Craighead CountyWell users 6,500Arsenic about 2 in 100Nitrate 0.2 mg/L
- Ashley CountyWell users 6,300Arsenic about 1 in 100Nitrate 0.0 mg/L
- Scott CountyWell users 6,300Arsenic about 2 in 100Nitrate 0.1 mg/L
- Yell CountyWell users 6,300Arsenic about 2 in 100Nitrate 0.3 mg/L
- Montgomery CountyWell users 6,300Arsenic about 1 in 100Nitrate 0.1 mg/L
- Sebastian CountyWell users 6,200Arsenic about 2 in 100Nitrate 0.1 mg/L
- Howard CountyWell users 6,100Arsenic about 1 in 100Nitrate 0.1 mg/L
- Sharp CountyWell users 5,900Arsenic about 1 in 100Nitrate 0.1 mg/L
- Pike CountyWell users 5,500Arsenic about 1 in 100Nitrate 0.1 mg/L
- Stone CountyWell users 5,100Arsenic about 1 in 100Nitrate 0.1 mg/L
- Van Buren CountyWell users 5,100Arsenic about 2 in 100Nitrate 0.2 mg/L
- Columbia CountyWell users 5,000Arsenic about 1 in 100Nitrate 0.1 mg/L
- Franklin CountyWell users 5,000Arsenic about 2 in 100Nitrate 0.3 mg/L
- Johnson CountyWell users 4,900Arsenic about 3 in 100Nitrate 0.2 mg/L
- Clark CountyWell users 4,900Arsenic about 1 in 100Nitrate 0.1 mg/L
- Ouachita CountyWell users 4,600Arsenic about 1 in 100Nitrate 0.2 mg/L
- Little River CountyWell users 4,500Arsenic about 1 in 100Nitrate 0.3 mg/L
- Nevada CountyWell users 4,100Arsenic about 1 in 100Nitrate 0.1 mg/L
- Perry CountyWell users 4,100Arsenic about 1 in 100Nitrate 0.1 mg/L
- Izard CountyWell users 3,800Arsenic about 1 in 100Nitrate 0.2 mg/L
- Jackson CountyWell users 3,400Arsenic about 1 in 100Nitrate 0.2 mg/L
- Lawrence CountyWell users 3,300Arsenic about 1 in 100Nitrate 0.2 mg/L
- Grant CountyWell users 3,300Arsenic about 1 in 100Nitrate 0.1 mg/L
- Searcy CountyWell users 3,300Arsenic about 1 in 100Nitrate 0.1 mg/L
- Bradley CountyWell users 2,900Arsenic about 1 in 100Nitrate 0.1 mg/L
- Lafayette CountyWell users 2,700Arsenic about 1 in 100Nitrate 0.1 mg/L
- Newton CountyWell users 2,600Arsenic about 1 in 100Nitrate 0.1 mg/L
- Clay CountyWell users 2,500Arsenic about 2 in 100Nitrate 0.3 mg/L
- Prairie CountyWell users 2,400Arsenic about 1 in 100Nitrate 0.0 mg/L
- Chicot CountyWell users 2,400Arsenic about 2 in 100Nitrate 0.0 mg/L
- Calhoun CountyWell users 2,200Arsenic about 1 in 100Nitrate 0.1 mg/L
- St. Francis CountyWell users 1,900Arsenic about 2 in 100Nitrate 0.0 mg/L
- Dallas CountyWell users 1,800Arsenic about 1 in 100Nitrate 0.1 mg/L
- Union CountyWell users 1,800Arsenic about 1 in 100Nitrate 0.1 mg/L
- Drew CountyWell users 1,800Arsenic about 1 in 100Nitrate 0.1 mg/L
- Desha CountyWell users 1,700Arsenic about 2 in 100Nitrate 0.0 mg/L
- Jefferson CountyWell users 1,500Arsenic about 1 in 100Nitrate 0.1 mg/L
- Lincoln CountyWell users 1,300Arsenic about 1 in 100Nitrate 0.1 mg/L
- Arkansas CountyWell users 1,200Arsenic about 2 in 100Nitrate 0.0 mg/L
- Cleveland CountyWell users 1,100Arsenic about 1 in 100Nitrate 0.0 mg/L
- Lee CountyWell users 1,100Arsenic about 2 in 100Nitrate 0.0 mg/L
- Mississippi CountyWell users 1,000Arsenic about 3 in 100Nitrate 0.3 mg/L
- Cross CountyWell users 1,000Arsenic about 2 in 100Nitrate 0.0 mg/L
- Poinsett CountyWell users 950Arsenic about 2 in 100Nitrate 0.1 mg/L
- Crittenden CountyWell users 880Arsenic about 3 in 100Nitrate 0.2 mg/L
- Woodruff CountyWell users 810Arsenic about 1 in 100Nitrate 0.1 mg/L
- Monroe CountyWell users 770Arsenic about 2 in 100Nitrate 0.0 mg/L
- Phillips CountyWell users 510Arsenic about 3 in 100Nitrate 0.0 mg/L
Each mark = 1 in 100 well users the model places above 10 µg/L arsenic (scale 0–10)10 mg/L nitrate: the federal limit (MCL) for public systems
- These figures describe the area, not your well. Only a lab test shows what’s in your water.
- CDC says the Well Water Index figures “do not describe risk to individual wells.” (CDC Tracking Network)
- The arsenic model is better at spotting low-arsenic areas than at confirming high ones.
- Well-user counts are 2010 USGS estimates; tract values are averages over each census tract.
- Total coliform bacteriaEvery year
- NitrateEvery year
- Total dissolved solidsEvery year
- pHEvery year
- ArsenicAsk your local health department
EPA: Private Drinking Water Wells · CDC: Guidelines for Testing Well Water
Use a state-certified lab
Arkansas Department of Health lists the laboratories certified to test drinking water in Arkansas.
Screening tells you if something is worth a closer look
A lab result is the number you can act on.
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Lab-certified results
ETR Labs Basic Water Quality Test Kit
ETR Laboratories
50+ substances, including lead, copper, arsenic, nitrate, hardness and coliform bacteria
- Analyzed by Environmental Testing and Research Laboratories (ETR Labs), Leominster, MA · ISO/IEC 17025:2017, ANAB certificate AT-2638
- Turnaround: 2–4 business days after the lab receives it
What it can't tell you: It does not test PFAS, and not every result on the panel falls under the lab's accredited scope.
Screening: quick check, not lab-grade
Watersafe Drinking Water Test Kit
Silver Lake Research
Lead, bacteria, nitrate, copper, iron, chlorine, hardness and pH
- Turnaround: Minutes; the bacteria test can take up to 48 hours
What it can't tell you: Each test gives a yes/no or a rough range, not a lab number, and it cannot detect PFAS or arsenic.
A mail-in kit’s lab is accredited (ISO/IEC 17025) but may not be certified by your state. For a home sale, a loan, or a health-department follow-up, use a state-certified lab.
Arkansas well water
Sources: CDC Well Water Index (2024) · USGS arsenic and nitrate models · USGS domestic well populations · EPA and CDC testing guidance. Data last updated 2026-10-08. All sources →
How many people use private wells in Arkansas?
About 470,700 people across 75 Arkansas counties, by the USGS 2010 estimate. USGS models place about 6,600 of them in areas where wells are likely to be above the 10 µg/L arsenic limit. These are area estimates, not well results.
Are private wells regulated in Arkansas?
The quality and safety of drinking water from private domestic wells are not regulated by the Federal Government under the Safe Drinking Water Act nor by most state governments and laws. (EPA) Testing and treatment are the owner's responsibility.
Where can I get my well tested in Arkansas?
Arkansas Department of Health keeps the list of laboratories certified to test drinking water in Arkansas. Only use laboratories that are certified to do drinking water testing. (EPA)