North Dakota well water by county: arsenic and nitrate
Modelled arsenic and nitrate for private-well users in every North Dakota county, what to test for, and where to find a certified lab. Private wells aren’t covered by the Safe Drinking Water Act.
All 53 counties
- Burleigh CountyWell users 7,900Arsenic about 9 in 100Nitrate 0.3 mg/L
- Ward CountyWell users 5,700Arsenic about 7 in 100Nitrate 0.1 mg/L
- Morton CountyWell users 5,000Arsenic about 5 in 100Nitrate 0.3 mg/L
- Cass CountyWell users 4,400Arsenic about 13 in 100Nitrate 0.0 mg/L
- Stark CountyWell users 4,000Arsenic about 6 in 100Nitrate 0.8 mg/L
- Ramsey CountyWell users 3,600Arsenic about 9 in 100Nitrate 0.0 mg/L
- Stutsman CountyWell users 3,500Arsenic about 6 in 100Nitrate 0.2 mg/L
- Benson CountyWell users 3,300Arsenic about 10 in 100Nitrate 0.1 mg/L
- Richland CountyWell users 3,100Arsenic about 8 in 100Nitrate 0.1 mg/L
- McLean CountyWell users 3,100Arsenic about 5 in 100Nitrate 0.1 mg/L
- McKenzie CountyWell users 3,000Arsenic about 4 in 100Nitrate 0.2 mg/L
- Williams CountyWell users 2,800Arsenic about 7 in 100Nitrate 0.3 mg/L
- Rolette CountyWell users 2,600Arsenic about 6 in 100Nitrate 0.1 mg/L
- Mountrail CountyWell users 2,200Arsenic about 7 in 100Nitrate 0.1 mg/L
- McHenry CountyWell users 2,100Arsenic about 9 in 100Nitrate 0.1 mg/L
- LaMoure CountyWell users 2,000Arsenic about 6 in 100Nitrate 0.1 mg/L
- Ransom CountyWell users 1,900Arsenic about 5 in 100Nitrate 0.4 mg/L
- Dickey CountyWell users 1,800Arsenic about 10 in 100Nitrate 0.2 mg/L
- Mercer CountyWell users 1,800Arsenic about 5 in 100Nitrate 0.5 mg/L
- Bottineau CountyWell users 1,800Arsenic about 5 in 100Nitrate 0.0 mg/L
- Dunn CountyWell users 1,700Arsenic about 5 in 100Nitrate 0.5 mg/L
- Cavalier CountyWell users 1,600Arsenic about 4 in 100Nitrate 0.1 mg/L
- Barnes CountyWell users 1,500Arsenic about 7 in 100Nitrate 0.3 mg/L
- Kidder CountyWell users 1,400Arsenic about 8 in 100Nitrate 0.3 mg/L
- Sargent CountyWell users 1,400Arsenic about 8 in 100Nitrate 0.1 mg/L
- Pierce CountyWell users 1,300Arsenic about 7 in 100Nitrate 0.1 mg/L
- Walsh CountyWell users 1,300Arsenic about 5 in 100Nitrate 0.2 mg/L
- Emmons CountyWell users 1,300Arsenic about 8 in 100Nitrate 1.0 mg/L
- Grand Forks CountyWell users 1,300Arsenic about 7 in 100Nitrate 0.5 mg/L
- Oliver CountyWell users 1,200Arsenic about 4 in 100Nitrate 0.7 mg/L
- Hettinger CountyWell users 1,200Arsenic about 6 in 100Nitrate 0.9 mg/L
- Grant CountyWell users 1,200Arsenic about 5 in 100Nitrate 0.6 mg/L
- Sioux CountyWell users 1,100Arsenic about 7 in 100Nitrate 0.2 mg/L
- Foster CountyWell users 940Arsenic about 5 in 100Nitrate 0.1 mg/L
- Bowman CountyWell users 900Arsenic about 5 in 100Nitrate 0.7 mg/L
- Pembina CountyWell users 900Arsenic about 6 in 100Nitrate 0.2 mg/L
- Logan CountyWell users 890Arsenic about 4 in 100Nitrate 0.3 mg/L
- Nelson CountyWell users 870Arsenic about 5 in 100Nitrate 0.1 mg/L
- Towner CountyWell users 850Arsenic about 7 in 100Nitrate 0.0 mg/L
- Adams CountyWell users 840Arsenic about 6 in 100Nitrate 0.5 mg/L
- Wells CountyWell users 810Arsenic about 6 in 100Nitrate 0.1 mg/L
- Divide CountyWell users 770Arsenic about 8 in 100Nitrate 0.3 mg/L
- McIntosh CountyWell users 760Arsenic about 6 in 100Nitrate 0.6 mg/L
- Sheridan CountyWell users 750Arsenic about 6 in 100Nitrate 0.0 mg/L
- Burke CountyWell users 740Arsenic about 7 in 100Nitrate 0.1 mg/L
- Griggs CountyWell users 710Arsenic about 5 in 100Nitrate 0.4 mg/L
- Eddy CountyWell users 610Arsenic about 5 in 100Nitrate 0.2 mg/L
- Billings CountyWell users 600Arsenic about 7 in 100Nitrate 0.3 mg/L
- Slope CountyWell users 570Arsenic about 5 in 100Nitrate 0.3 mg/L
- Golden Valley CountyWell users 500Arsenic about 4 in 100Nitrate 0.3 mg/L
- Traill CountyWell users 360Arsenic about 12 in 100Nitrate 0.1 mg/L
- Renville CountyWell users 340Arsenic about 7 in 100Nitrate 0.0 mg/L
- Steele CountyWell users 300Arsenic about 8 in 100Nitrate 0.4 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
North Dakota Department of Environmental Quality lists the laboratories certified to test drinking water in North Dakota.
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.
North Dakota 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 North Dakota?
About 96,900 people across 53 North Dakota counties, by the USGS 2010 estimate. USGS models place about 6,700 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 North Dakota?
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 North Dakota?
North Dakota Department of Environmental Quality keeps the list of laboratories certified to test drinking water in North Dakota. Only use laboratories that are certified to do drinking water testing. (EPA)