Kansas well water by county: arsenic and nitrate
Modelled arsenic and nitrate for private-well users in every Kansas county, what to test for, and where to find a certified lab. Private wells aren’t covered by the Safe Drinking Water Act.
All 105 counties
- Sedgwick CountyWell users 40,800Arsenic about 5 in 100Nitrate 3.6 mg/L
- Reno CountyWell users 16,100Arsenic about 6 in 100Nitrate 3.8 mg/L
- Butler CountyWell users 13,700Arsenic about 5 in 100Nitrate 0.5 mg/L
- Leavenworth CountyWell users 7,600Arsenic about 2 in 100Nitrate 0.3 mg/L
- Finney CountyWell users 5,400Arsenic about 6 in 100Nitrate 6.6 mg/L
- Sumner CountyWell users 5,200Arsenic about 3 in 100Nitrate 6.3 mg/L
- Harvey CountyWell users 5,200Arsenic about 7 in 100Nitrate 1.4 mg/L
- Barton CountyWell users 5,000Arsenic about 4 in 100Nitrate 6.0 mg/L
- McPherson CountyWell users 4,900Arsenic about 3 in 100Nitrate 2.0 mg/L
- Douglas CountyWell users 4,500Arsenic about 2 in 100Nitrate 0.5 mg/L
- Ellis CountyWell users 4,400Arsenic about 4 in 100Nitrate 5.9 mg/L
- Riley CountyWell users 4,400Arsenic about 2 in 100Nitrate 0.6 mg/L
- Dickinson CountyWell users 4,300Arsenic about 2 in 100Nitrate 1.8 mg/L
- Ford CountyWell users 4,200Arsenic about 3 in 100Nitrate 4.0 mg/L
- Shawnee CountyWell users 4,200Arsenic about 3 in 100Nitrate 0.8 mg/L
- Pottawatomie CountyWell users 4,100Arsenic about 2 in 100Nitrate 0.7 mg/L
- Cowley CountyWell users 3,900Arsenic about 6 in 100Nitrate 2.0 mg/L
- Marion CountyWell users 3,400Arsenic about 4 in 100Nitrate 1.9 mg/L
- Geary CountyWell users 3,200Arsenic about 3 in 100Nitrate 0.6 mg/L
- Saline CountyWell users 3,000Arsenic about 3 in 100Nitrate 3.2 mg/L
- Franklin CountyWell users 2,900Arsenic about 2 in 100Nitrate 0.4 mg/L
- Kingman CountyWell users 2,900Arsenic about 4 in 100Nitrate 7.6 mg/L
- Jefferson CountyWell users 2,500Arsenic about 2 in 100Nitrate 0.5 mg/L
- Jackson CountyWell users 2,400Arsenic about 2 in 100Nitrate 0.6 mg/L
- Wabaunsee CountyWell users 2,400Arsenic about 4 in 100Nitrate 0.7 mg/L
- Cherokee CountyWell users 2,300Arsenic about 3 in 100Nitrate 0.1 mg/L
- Brown CountyWell users 2,300Arsenic about 2 in 100Nitrate 1.5 mg/L
- Morris CountyWell users 2,300Arsenic about 6 in 100Nitrate 0.7 mg/L
- Pratt CountyWell users 2,100Arsenic about 3 in 100Nitrate 9.7 mg/L
- Rice CountyWell users 2,000Arsenic about 4 in 100Nitrate 5.0 mg/L
- Lyon CountyWell users 2,000Arsenic about 4 in 100Nitrate 1.6 mg/L
- Gray CountyWell users 2,000Arsenic about 4 in 100Nitrate 5.6 mg/L
- Montgomery CountyWell users 1,900Arsenic about 3 in 100Nitrate 1.0 mg/L
- Seward CountyWell users 1,800Arsenic about 4 in 100Nitrate 5.4 mg/L
- Ottawa CountyWell users 1,800Arsenic about 3 in 100Nitrate 1.6 mg/L
- Thomas CountyWell users 1,800Arsenic about 6 in 100Nitrate 9.3 mg/L
- Miami CountyWell users 1,700Arsenic about 1 in 100Nitrate 1.3 mg/L
- Norton CountyWell users 1,700Arsenic about 4 in 100Nitrate 5.0 mg/L
- Nemaha CountyWell users 1,600Arsenic about 2 in 100Nitrate 0.6 mg/L
- Phillips CountyWell users 1,600Arsenic about 3 in 100Nitrate 5.1 mg/L
- Stafford CountyWell users 1,600Arsenic about 4 in 100Nitrate 6.7 mg/L
- Doniphan CountyWell users 1,500Arsenic about 3 in 100Nitrate 2.7 mg/L
- Clay CountyWell users 1,500Arsenic about 3 in 100Nitrate 2.2 mg/L
- Atchison CountyWell users 1,500Arsenic about 2 in 100Nitrate 0.7 mg/L
- Marshall CountyWell users 1,500Arsenic about 2 in 100Nitrate 0.5 mg/L
- Cloud CountyWell users 1,400Arsenic about 4 in 100Nitrate 2.7 mg/L
- Washington CountyWell users 1,300Arsenic about 2 in 100Nitrate 1.8 mg/L
- Pawnee CountyWell users 1,300Arsenic about 3 in 100Nitrate 5.1 mg/L
- Grant CountyWell users 1,300Arsenic about 11 in 100Nitrate 3.3 mg/L
- Haskell CountyWell users 1,200Arsenic about 5 in 100Nitrate 4.1 mg/L
- Johnson CountyWell users 1,200Arsenic about 2 in 100Nitrate 0.6 mg/L
- Stevens CountyWell users 1,100Arsenic about 7 in 100Nitrate 5.5 mg/L
- Ellsworth CountyWell users 1,000Arsenic about 3 in 100Nitrate 2.9 mg/L
- Osage CountyWell users 1,000Arsenic about 2 in 100Nitrate 0.9 mg/L
- Sherman CountyWell users 1,000Arsenic about 5 in 100Nitrate 6.8 mg/L
- Scott CountyWell users 990Arsenic about 4 in 100Nitrate 13.3 mg/L
- Sheridan CountyWell users 990Arsenic about 6 in 100Nitrate 5.5 mg/L
- Meade CountyWell users 990Arsenic about 3 in 100Nitrate 3.6 mg/L
- Coffey CountyWell users 950Arsenic about 2 in 100Nitrate 0.6 mg/L
- Gove CountyWell users 940Arsenic about 5 in 100Nitrate 10.4 mg/L
- Republic CountyWell users 940Arsenic about 3 in 100Nitrate 3.8 mg/L
- Chase CountyWell users 930Arsenic about 7 in 100Nitrate 0.6 mg/L
- Lincoln CountyWell users 910Arsenic about 3 in 100Nitrate 1.8 mg/L
- Smith CountyWell users 910Arsenic about 2 in 100Nitrate 6.0 mg/L
- Rawlins CountyWell users 870Arsenic about 4 in 100Nitrate 6.1 mg/L
- Kearny CountyWell users 850Arsenic about 9 in 100Nitrate 8.4 mg/L
- Rooks CountyWell users 850Arsenic about 3 in 100Nitrate 6.8 mg/L
- Harper CountyWell users 830Arsenic about 3 in 100Nitrate 10.0 mg/L
- Cheyenne CountyWell users 810Arsenic about 4 in 100Nitrate 7.0 mg/L
- Decatur CountyWell users 800Arsenic about 6 in 100Nitrate 6.5 mg/L
- Kiowa CountyWell users 780Arsenic about 3 in 100Nitrate 6.2 mg/L
- Trego CountyWell users 760Arsenic about 4 in 100Nitrate 6.6 mg/L
- Barber CountyWell users 740Arsenic about 3 in 100Nitrate 5.1 mg/L
- Linn CountyWell users 740Arsenic about 1 in 100Nitrate 1.9 mg/L
- Hodgeman CountyWell users 730Arsenic about 3 in 100Nitrate 4.1 mg/L
- Graham CountyWell users 720Arsenic about 5 in 100Nitrate 7.9 mg/L
- Chautauqua CountyWell users 720Arsenic about 2 in 100Nitrate 0.4 mg/L
- Hamilton CountyWell users 700Arsenic about 9 in 100Nitrate 4.7 mg/L
- Ness CountyWell users 690Arsenic about 4 in 100Nitrate 6.1 mg/L
- Greenwood CountyWell users 690Arsenic about 4 in 100Nitrate 0.7 mg/L
- Edwards CountyWell users 680Arsenic about 3 in 100Nitrate 8.1 mg/L
- Osborne CountyWell users 670Arsenic about 2 in 100Nitrate 4.2 mg/L
- Neosho CountyWell users 630Arsenic about 1 in 100Nitrate 0.9 mg/L
- Anderson CountyWell users 620Arsenic about 1 in 100Nitrate 0.9 mg/L
- Rush CountyWell users 590Arsenic about 3 in 100Nitrate 2.8 mg/L
- Wichita CountyWell users 590Arsenic about 5 in 100Nitrate 12.3 mg/L
- Wilson CountyWell users 520Arsenic about 2 in 100Nitrate 1.1 mg/L
- Morton CountyWell users 520Arsenic about 7 in 100Nitrate 6.0 mg/L
- Labette CountyWell users 510Arsenic about 1 in 100Nitrate 0.8 mg/L
- Logan CountyWell users 500Arsenic about 5 in 100Nitrate 8.3 mg/L
- Jewell CountyWell users 500Arsenic about 3 in 100Nitrate 7.0 mg/L
- Woodson CountyWell users 490Arsenic about 2 in 100Nitrate 1.2 mg/L
- Clark CountyWell users 480Arsenic about 3 in 100Nitrate 3.9 mg/L
- Stanton CountyWell users 470Arsenic about 11 in 100Nitrate 4.5 mg/L
- Wallace CountyWell users 470Arsenic about 6 in 100Nitrate 7.2 mg/L
- Wyandotte CountyWell users 470Arsenic about 3 in 100Nitrate 0.2 mg/L
- Bourbon CountyWell users 460Arsenic about 2 in 100Nitrate 0.6 mg/L
- Mitchell CountyWell users 450Arsenic about 2 in 100Nitrate 4.8 mg/L
- Allen CountyWell users 440Arsenic about 2 in 100Nitrate 0.8 mg/L
- Russell CountyWell users 430Arsenic about 3 in 100Nitrate 2.7 mg/L
- Lane CountyWell users 430Arsenic about 7 in 100Nitrate 12.7 mg/L
- Comanche CountyWell users 400Arsenic about 3 in 100Nitrate 4.7 mg/L
- Greeley CountyWell users 370Arsenic about 7 in 100Nitrate 8.9 mg/L
- Crawford CountyWell users 330Arsenic about 2 in 100Nitrate 0.3 mg/L
- Elk CountyWell users 310Arsenic about 3 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
Kansas Department of Health and Environment lists the laboratories certified to test drinking water in Kansas.
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.
Kansas 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 Kansas?
About 242,100 people across 105 Kansas counties, by the USGS 2010 estimate. USGS models place about 9,800 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 Kansas?
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 Kansas?
Kansas Department of Health and Environment keeps the list of laboratories certified to test drinking water in Kansas. Only use laboratories that are certified to do drinking water testing. (EPA)