Well Water Nerd

Well water testing in Illinois

Nobody tests a private well unless the owner does. In Illinois, the public record says to start with PFOA, radium (226 + 228), arsenic, then bacteria and nitrate 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
    PFOA
    17% of 30 local samples were above the limit.
  2. 2
    Radium (226 + 228)
    12% of 350 local samples were above the limit.
  3. 3
    Arsenic
    10% of 5,098 local samples were above the limit.
  4. 4
    Nitrate
    9% of 10,010 local samples were above the limit.
  5. 5
    E. coli
    4% of 75 local samples were above the limit.

Test your Illinois well for PFOA, radium (226 + 228) and arsenic

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. Accredited Labs from Illinois EPA lists every lab certified for drinking water in Illinois. Call ahead: some take walk-in samples, some ship bottles.

For questions about your well, Private Water & Closed Loop Wells at IDPH 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
De Witt CountyArsenic72%
Macon CountyArsenic69%
Stark CountyNitrate46%
Bureau CountyArsenic44%
Pulaski CountyArsenic43%
McLean CountyArsenic40%
Morgan CountyNitrate38%
Macoupin CountyNitrate37%
Piatt CountyArsenic32%
Schuyler CountyNitrate29%
Mason CountyArsenic27%
Fulton CountyLead27%
Tazewell CountyArsenic25%
Peoria CountyNitrate25%
Montgomery CountyNitrate22%
Iroquois CountyArsenic22%
Wayne CountyNitrate20%
Sangamon CountyNitrate20%
Shelby CountyNitrate19%
Woodford CountyArsenic19%
Pike CountyNitrate18%
St. Clair CountyNitrate18%
Ogle CountyNitrate17%
Putnam CountyNitrate16%
Scott CountyNitrate15%
Warren CountyNitrate15%
Whiteside CountyArsenic14%
Lee CountyNitrate13%
Logan CountyArsenic13%
Champaign CountyArsenic11%
DeKalb CountyArsenic11%
Vermilion CountyArsenic11%
Carroll CountyNitrate11%
Henry CountyArsenic11%
Randolph CountyLead10%
McHenry CountyArsenic10%
Madison CountyArsenic9%
Winnebago CountyNitrate8%
Mercer CountyNitrate8%
Rock Island CountyNitrate8%
LaSalle CountyArsenic7%
Kankakee CountyNitrate7%
Livingston CountyArsenic7%
Marshall CountyArsenic6%
Boone CountyNitrate5%
Adams CountyNitrate5%
Henderson CountyNitrate3%
Wabash CountyNitrate3%
Will CountyArsenic3%
McDonough CountyLead3%
Christian CountyArsenic3%
Stephenson CountyNitrate3%
Cook CountyArsenic2%
Lake CountyLead<1%
Kane CountyArsenic<1%
DuPage CountyArsenic<1%
Grundy CountyFluoride0%
Jo Daviess CountyFluoride0%
Massac CountyFluoride0%

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 Illinois

We are signing licensed water treatment companies county by county. They test at your tap for free, walk you through the numbers, and quote treatment only if something needs fixing. Nothing is shared until a company joins for your area, and you get an email naming it first.

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Common questions

What should I test my well for in Illinois?

Start with PFOA, radium (226 + 228), arsenic. 17% of 30 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 Illinois?

Use a lab certified for drinking water. Illinois EPA 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 Illinois?

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).

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.