Colorado county well guide

Well Water in Jefferson County, CO: Testing, Contractors and Rules

About 7,862 households in Jefferson County, 4% of the county, rely on a private well. Nobody tests that water unless the owner does.

Labs within 40 milesLicensed contractors
4%of households on a private well
Share on wells, county vs state
Jefferson County4%
Colorado average11%
11licensed contractors serve the county
4 mito the nearest certified lab, SGS North America, Inc. – Wheat Ridge
Nostatewide test required when a home is sold

Most of Jefferson County is on public water, but an estimated 7,862 households still rely on a private well. This page covers the rules, labs and licensed contractors that serve them.

Local rules for wells in Jefferson County

Colorado permits the well but not the water. In Jefferson County that means a DWR permit and a licensed driller, and no required water test at any point. The state’s recommendations and the free PFAS program are below.

At a glance

Water test for a new wellNot required statewide

A DWR well permit is required before drilling and contractors must notify DWR before construction, but no water quality test is required by the state.

Water test when a home is soldNot required statewide

No statewide requirement. Lenders often require a test; some counties recommend one at transfer.

What the state recommends

CDPHE recommends yearly testing for coliform bacteria and nitrate, and a broader panel (metals, uranium, radon, fluoride, hardness) every few years. Colorado groundwater commonly has naturally occurring uranium, radon and fluoride.

Free or low-cost testingAvailable

Colorado offers a free PFAS testing program for private wells. Several county health departments (Weld, El Paso, La Plata, Mesa, Pueblo, Routt, Gilpin, Northeast Colorado) run certified labs that accept homeowner samples.

Getting your water tested near Jefferson County

10 certified labs within 40 miles serve Jefferson County, starting with Eurofins Denver in Arvada (in the county). Each card below shows whether the lab takes homeowner samples and which tests it is certified for.

10 certified labs within 40 miles

Licensed well contractors serving Jefferson County

11 licensed contractors serve Jefferson County, including Alpine Remediation, Inc. and Arvada Pump Co. Inc. Each profile carries the state license number and the date we checked it, and the filters below sort them by drilling, pump work or treatment.

Well depth and water chemistry

What comes up with the water depends on the aquifer. A first full panel tells you which of them apply to your well.

Typical well depth

Varies by location. Check the state well record search for logs of nearby wells.

Contaminants to test for
  • Uranium
  • Radon
  • Fluoride
  • Nitrate
  • Hardness
  • Coliform bacteria
  • Arsenic (some basins)

Neighboring counties: Denver County, Adams County, Broomfield County, Arapahoe County.

What well work costs in Jefferson County

Basic bacteria and nitrate test$25 to $75lab fee, homeowner sample
Full panel lab test$150 to $400metals, VOCs, radiologicals
Well inspection$250 to $550flow, pressure, visual, water test
Submersible pump replacement$1,200 to $4,500parts and labor
Pressure tank replacement$400 to $1,200installed
Whole-house treatment system$800 to $6,000softener, iron filter, UV, RO
New well drilled$5,500 to $25,000about $25 to $65 per foot
Shock chlorination$80 to $300or about $20 as a DIY job

National ranges from published 2025 to 2026 contractor pricing. Local quotes vary with depth, access and materials.

Questions Jefferson County well owners ask

How many homes in Jefferson County are on a well?

About 7,862, or 4% of households, based on Census housing data and state well surveys. The share is highest outside the towns with public water.

Where is the closest certified lab to Jefferson County?

Eurofins Denver in Arvada, inside the county. It accepts homeowner samples.

Do I need a permit to drill a well in Jefferson County?

Yes. A permit from the Colorado Division of Water Resources is required before any drilling.

What does a well test cost near Jefferson County?

A bacteria and nitrate test runs $25 to $75 at most certified labs; a full panel with metals is $150 to $400. County health department labs charge less than commercial labs, and PFAS testing is free through the state.