Well Water Nerd

Well water testing in Colorado

Nobody tests a private well unless the owner does. In Colorado, the public record says to start with nitrate, uranium, PFOA, 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
    Nitrate
    40% of 5,831 local samples were above the limit.
  2. 2
    Uranium
    33% of 2,485 local samples were above the limit.
  3. 3
    PFOA
    25% of 85 local samples were above the limit.
  4. 4
    PFOS
    18% of 85 local samples were above the limit.
  5. 5
    Arsenic
    8% of 5,744 local samples were above the limit.

Test your Colorado well for nitrate, uranium and PFOA

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. Drinking water lab certification from CDPHE lists every lab certified for drinking water in Colorado. Call ahead: some take walk-in samples, some ship bottles.

The Colorado State Public Health Laboratory ships free sample bottles to well owners and tests private water for total coliforms and E. coli for a fee, while its water chemistry testing is temporarily suspended. Details from the state

Free or low-cost testing: Through the CDPHE PFAS Testing and Assistance Program, anyone with a private well in Colorado can apply for a free mailed PFAS test kit, with a free filter for households whose results exceed EPA standards, while supplies last. How to get it

For questions about your well, Private well water and your health at CDPHE 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
Logan CountyUranium90%
Morgan CountyUranium75%
Montrose CountyUranium65%
Arapahoe CountyUranium65%
Prowers CountyArsenic64%
Weld CountyNitrate58%
Denver CountyUranium52%
Mesa CountyUranium49%
Fremont CountyUranium47%
Rio Blanco CountyFluoride47%
El Paso CountyNitrate46%
Bent CountyArsenic41%
Otero CountyArsenic35%
Montezuma CountyArsenic35%
Jefferson CountyUranium32%
Douglas CountyUranium28%
Saguache CountyArsenic26%
Elbert CountyUranium26%
Garfield CountyArsenic23%
Adams CountyUranium19%
Alamosa CountyArsenic16%
Pueblo CountyUranium15%
Eagle CountyArsenic13%
Chaffee CountyFluoride10%
Boulder CountyUranium9%
La Plata CountyFluoride7%
Archuleta CountyArsenic7%
Moffat CountyCopper5%
Las Animas CountyFluoride4%
Delta CountyFluoride3%
Summit CountyCopper3%
Grand CountyFluoride2%
Park CountyUranium2%
Gunnison CountyArsenic2%
Kiowa CountyFluoride2%
Routt CountyLead1%
Baca CountyFluoride0%
Cheyenne CountyFluoride0%
Conejos CountyFluoride0%
Custer CountyFluoride0%
Kit Carson CountyFluoride0%
Lake CountyFluoride0%
Larimer CountyArsenic0%
Rio Grande CountyCopper0%
Washington CountyFluoride0%
Yuma 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 Colorado

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.

What are you worried about?

The test is free and there is no obligation. No company is named yet; your details stay with us until one joins for your area, and we log the time and address of this request.

Common questions

What should I test my well for in Colorado?

Start with nitrate, uranium, PFOA. 40% of 5,831 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 Colorado?

Use a lab certified for drinking water. CDPHE 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 Colorado?

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 Colorado State Public Health Laboratory ships free sample bottles to well owners and tests private water for total coliforms and E. coli for a fee, while its water chemistry testing is temporarily suspended.

Is there free well water testing in Colorado?

Through the CDPHE PFAS Testing and Assistance Program, anyone with a private well in Colorado can apply for a free mailed PFAS test kit, with a free filter for households whose results exceed EPA standards, while supplies last.

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.