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Lead in Colorado well water, by county

By the Tested Water teamLab data from the USGS and EPA Water Quality Portal, 2000 to 2026Updated November 8, 2026

Lead is widespread, over the limit in 15% or more of tested wells, in 1 of the 13 Colorado counties with 10 or more tested wells. A county's share tells you how likely a problem is nearby. Only a test of your own well tells you what's in it.

Find a lead test See every county

These tests sample the groundwater, and lead rarely comes from the ground. In a home it mostly comes from plumbing: old solder, brass fittings and some older pumps. So a county's share can't tell you about your pipes. Test a first-draw sample, water that sat in the pipes overnight, from the tap you drink from.

How Colorado compares with the rest of the country

Across Colorado, about 1 in 26 tested wells had lead over the EPA action level of 15 µg/L (23 of 593). Across all tested wells in the US it's under 1 in 50. So lead turns up in Colorado wells about 3 times as often as in the country as a whole, and a test is worth adding even if your county isn't on the list below.

Why it matters: It harms children's growing brains. The CDC says no amount in a child's blood is known to be safe.

Lead in tested wells, county by county

Share of each county's tested wells with at least one result over the EPA action level of 15 µg/L. Counties need 10 or more tested wells to be listed. Widespread means 15% or more, worth checking 5 to 15%, rare under 5%.

CountyWells testedWells over the limitLevel
Lake County 93
16% 15 of 93
 Widespread
Eagle County 34
12% 4 of 34
 Worth checking
Rio Blanco County 25
4% 1 of 25
 Rare
Arapahoe County 58
0% 0 of 58
 Rare
La Plata County 56
0% 0 of 56
 Rare
El Paso County 40
0% 0 of 40
 Rare
Adams County 31
0% 0 of 31
 Rare
Douglas County 31
0% 0 of 31
 Rare
Elbert County 30
0% 0 of 30
 Rare
Park County 26
0% 0 of 26
 Rare
Montrose County 25
0% 0 of 25
 Rare
Weld County 22
0% 0 of 22
 Rare
Montezuma County 15
0% 0 of 15
 Rare

27 more Colorado counties have 1 to 9 tested wells for lead, too few to rate.

Download this table (CSV) · Free to reuse under CC BY 4.0

Where to get your well tested for lead in Colorado

1

Free testing, with limits

Colorado tests private wells for PFAS for free, but not for anything else. Check which tests it includes before you count on it for lead.

Colorado's private well page
3

A mail-in kit

Fill the bottles at your kitchen tap and mail them back. We mark the kits that include lead.

Compare kits

Keep reading about wells in Colorado

Questions people ask about lead in Colorado

Is there lead in Colorado well water?

Lead is widespread, over the limit in 15% or more of tested wells, in 1 of the 13 Colorado counties with 10 or more tested wells. Across Colorado, about 1 in 26 tested wells had lead over the EPA action level of 15 µg/L (23 of 593). Across all tested wells in the US it's under 1 in 50. So lead turns up in Colorado wells about 3 times as often as in the country as a whole, and a test is worth adding even if your county isn't on the list below.

Where can I get my well tested for lead in Colorado?

Colorado tests private wells for PFAS for free, but not for anything else. If that doesn't cover you, use a lab certified by Colorado for drinking water, or a mail-in kit that includes lead from a certified lab.

See Colorado's list of certified labs, or compare mail-in kits.

Where these numbers come from

  • Lab tests: Water Quality Portal (USGS and EPA), well samples since 2000. A well counts as over if any of its tests was over the EPA action level of 15 µg/L. Wells tested for studies and monitoring, not a random sample of homes.
  • Likely overstated: our own check of who tested the wells, when and where. How we check.
  • State programs and links: Department of Public Health and Environment.