Well Water Nerd

Well water testing in Missouri

Nobody tests a private well unless the owner does. In Missouri, the public record says to start with arsenic, PFOA, nitrate, then bacteria every year. Below: what to order, where, what it costs, and the county-by-county results that set the order.

What to test for first

  1. 1
    Arsenic
    13% of 2,937 local samples were above the limit.
  2. 2
    PFOA
    9% of 53 local samples were above the limit.
  3. 3
    Nitrate
    6% of 11,815 local samples were above the limit.
  4. 4
    PFOS
    4% of 53 local samples were above the limit.
  5. 5
    Lead
    4% of 2,785 local samples were above the limit.

Test your Missouri well for arsenic, PFOA and nitrate

Certified lab analysis of your own tap water, bottles and prepaid return shipping included. The Essential well panel covers arsenic, uranium, nitrate, lead, copper, manganese, iron, sodium and bacteria; radon and PFAS are add-ons.

Order the Tap Score well water test kit, from $209Already tested? Upload the report

Just want bacteria checked first? Tap Score coliform and E. coli test, $99. Coliform and E. coli are the tests every well needs every year.

Want a quick look before paying for a lab? Home well water test strips on Amazon check hardness, iron, pH and nitrate in minutes. They are a screen, not a result: arsenic, bacteria, uranium and PFAS need a certified lab.

Affiliate links: the merchant pays us a commission and the price is the same for you. It does not change what the data above says. As an Amazon Associate we earn from qualifying purchases.

Where to get it tested

Three routes, and all of them work. A mail-in kit from a certified lab is the simplest: the lab ships bottles, you fill them at the kitchen tap, and results come back by email. The full panel above is $209.

A local certified lab is the second route. Certified Laboratories from Missouri DNR lists every lab certified for drinking water in Missouri. Call ahead: some take walk-in samples, some ship bottles.

The Missouri State Public Health Laboratory tests private well water for total coliform and E. coli bacteria using collection kits available from local public health agencies, with a $10 handling fee per sample. Details from the state

For questions about your well, Private Drinking Water at Missouri DHSS is the official source.

Already have results? Get the lab report read line by line, $29.

Testing by county

The contaminant most often over its limit in each county's public record, highest share first. Open a county for the full test list and its towns.

CountyTest first forOver the limit
Gentry CountyNitrate33%
Holt CountyNitrate31%
Nodaway CountyNitrate29%
Cass CountyNitrate26%
Bates CountyNitrate26%
New Madrid CountyLead23%
Lincoln CountyFluoride21%
Clay CountyArsenic19%
Hickory CountyLead19%
Daviess CountyNitrate19%
Henry CountyFluoride16%
Clark CountyNitrate15%
Iron CountyArsenic14%
Carroll CountyNitrate13%
Vernon CountyNitrate13%
Adair CountyLead13%
Butler CountyNitrate12%
Dallas CountyLead12%
Mississippi CountyNitrate11%
Webster CountyLead10%
Ralls CountyNitrate10%
St. Louis CountyArsenic9%
Platte CountyArsenic9%
Ray CountyNitrate8%
Jasper CountyLead8%
Lewis CountyArsenic8%
Pike CountyFluoride8%
Cape Girardeau CountyArsenic7%
Barry CountyLead7%
Marion CountyNitrate7%
Grundy CountyLead6%
Shannon CountyLead6%
Oregon CountyLead6%
Stoddard CountyNitrate6%
Franklin CountyLead6%
Livingston CountyNitrate6%
Jefferson CountyLead6%
Chariton CountyNitrate6%
Knox CountyLead5%
Montgomery CountyFluoride5%
Cole CountyLead5%
Phelps CountyLead5%
Boone CountyLead5%
Newton CountyLead5%
Camden CountyLead5%
St. Francois CountyFluoride5%
Madison CountyFluoride4%
Carter CountyNitrate4%
Christian CountyLead4%
Moniteau CountyNitrate4%
St. Charles CountyFluoride4%
Cooper CountyNitrate4%
Scott CountyNitrate4%
Washington CountyLead4%
Polk CountyLead3%
Johnson CountyLead3%
Dunklin CountyNitrate3%
Ozark CountyLead3%
Douglas CountyLead3%
Saline CountyLead3%
Cedar CountyNitrate3%
Callaway CountyLead3%
Crawford CountyNitrate3%
Greene CountyLead3%
Howell CountyLead2%
Randolph CountyLead2%
Ste. Genevieve CountyUranium2%
Morgan CountyLead2%
McDonald CountyArsenic2%
Wright CountyLead2%
Stone CountyLead2%
Gasconade CountyNitrate2%
Perry CountyLead2%
Dent CountyLead1%
Reynolds CountyFluoride1%
Pettis CountyLead1%
Texas CountyLead1%
Lawrence CountyLead<1%
Dade CountyNitrate<1%
St. Clair CountyArsenic<1%
Andrew CountyLead0%
Atchison CountyLead0%
Audrain CountyLead0%
Barton CountyFluoride0%
Benton CountyArsenic0%
Bollinger CountyFluoride0%
Buchanan CountyLead0%
Caldwell CountyLead0%
Clinton CountyLead0%
Howard CountyLead0%
Jackson CountyLead0%
Lafayette CountyLead0%
Macon CountyNitrate0%
Maries CountyLead0%
Miller CountyFluoride0%
Osage CountyFluoride0%
Pemiscot CountyFluoride0%
Pulaski CountyFluoride0%
St. Louis CountyLead0%
Taney CountyNitrate0%
Warren CountyArsenic0%
Wayne CountyLead0%

Closer than the county: see the sampled wells near your address.

Free, no obligation

Get on the list for a free in-home water test in Missouri

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Common questions

What should I test my well for in Missouri?

Start with arsenic, PFOA, nitrate. 13% of 2,937 local samples were above the limit. Add total coliform bacteria and nitrate every year for any private well.

Where can I get my well water tested in Missouri?

Use a lab certified for drinking water. Missouri DNR keeps the list of certified labs. A mail-in kit from a certified lab works anywhere in the state.

How much does well water testing cost in Missouri?

A full mail-in panel from a certified lab costs $209 (Tap Score well water test kit). A bacteria-only test costs $99 (Tap Score coliform and E. coli test). The Missouri State Public Health Laboratory tests private well water for total coliform and E. coli bacteria using collection kits available from local public health agencies, with a $10 handling fee per sample.

How often should a private well be tested?

Bacteria and nitrate every year. A full panel once, then again after flooding, a change in taste, smell or color, work on the well, a new baby in the house, or a nearby result above the limit. Contaminants that come from the rock, like arsenic, radon and uranium, change slowly, so one good test and a check every few years is enough.