Well Water Testing Guide for Colorado
Where to test, what to test for, what it costs, and Colorado-specific programs for private well owners.
CDPHE State Lab
The Colorado Department of Public Health and Environment (CDPHE) State Public Health Laboratory offers water testing services for private well owners. They currently provide bacterial testing (Total coliforms and E. coli). Water chemistry testing has been temporarily suspended.
Drop-off: Samples can be dropped off at participating local public health agencies for courier transport to the lab. Call your local agency to make arrangements.
Ship to: CDPHE Lab - Sample Receiving, 8100 E Lowry Blvd, Denver, CO 80230-6928 (overnight shipping required due to EPA holding time restrictions).
Certified Testing Labs
CDPHE certifies private laboratories for drinking water analysis. Not all labs offer the same tests. Here are labs serving Colorado well owners:
- Colorado Analytical Laboratory Brighton, CO. CDPHE-certified for inorganic drinking water analysis — metals (including copper, lead), cyanide, fluoride, nitrate/nitrite, and coliform bacteria. Offers a "Domestic Water Quality" test package for homeowners.
- GeoWater Services Serving Front Range mountain communities since 2001. Full-service private well consulting including water quality testing. Specializes in Evergreen, Conifer, Bailey, and mountain areas. Tests for radon in water.
- Weld County Department of Public Health and Environment Laboratory Greeley, CO. Water testing laboratory supporting northern Colorado communities. Contact for current test menu and pricing.
- SDC Laboratory Alamosa, CO. Serves the San Luis Valley. Has extensive experience with arsenic testing in valley wells.
- CDPHE Certified Lab List The state maintains a full list of certified drinking water labs. Check this list for labs near you and their specific testing capabilities.
CSU Extension Water Testing
Colorado State University Extension offers water quality education and testing resources through its county offices. CSU Extension's Environmental Quality Laboratory provides microbiological testing of water. Contact your county Extension office for local programs — some counties offer periodic testing events or subsidized testing for well owners.
What Does Testing Cost?
| Test | Typical Cost | Notes |
|---|---|---|
| Coliform / E. coli bacteria | $30-$75 | Basic safety test. Should be done annually. |
| Domestic water quality package | $150-$300 | Bacteria, nitrates, minerals, metals, pH, TDS. Good baseline. |
| Individual contaminants (arsenic, uranium, radon) | $40-$125 each | Add-on tests for specific concerns. |
| Radon in water | $40-$100 | Requires special sample collection (no agitation). |
| PFAS panel | $200-$500 | Emerging contaminant; not all labs offer this. |
CDPHE charges extra for rush orders (2x normal cost, excluding bacteria). Check the CDPHE lab fees page for current state lab pricing.
What Should You Test For?
CDPHE recommends baseline water quality testing for wells with no previous testing history. After obtaining a baseline, test annually at minimum.
Every Year
- Coliform bacteria and E. coli
- Nitrate and nitrite
- pH
At Least Once (and after any changes)
- Arsenic — especially in the San Luis Valley and areas with volcanic geology
- Uranium — naturally occurring in Colorado's crystalline and sedimentary formations
- Radon — essential for mountain wells. See our radon guide.
- Fluoride, iron, manganese — common in Colorado groundwater
- Calcium, copper — CDPHE specifically recommends these
Additional Testing Triggers
- You just purchased the property — always test before relying on a well
- Any change in taste, odor, or appearance
- Flooding or heavy rain/snowmelt events
- You're near oil and gas operations — test for methane and VOCs
- You're near agricultural operations — test for nitrates and pesticides
- Well was recently repaired, deepened, or had pump work
- Unexplained gastrointestinal illness in the household
Community-Specific Recommendations
| Area | Priority Tests Beyond Basics |
|---|---|
| Black Forest / Falcon | Iron, manganese, TDS (deeper wells have higher TDS) |
| Evergreen / Conifer / Bailey | Radon, uranium, iron, flow rate measurement |
| Woodland Park / Divide | Radon in water (!), uranium |
| San Luis Valley | Arsenic (essential), uranium, tungsten, manganese |
| Weld County rural | Nitrates (annually), methane, selenium |
| Douglas County outskirts | Radium, uranium, radon |
| Park County | Heavy metals panel, PFAS (if near known sources), radon |
| Western Slope (Mesa, Garfield) | Selenium, methane (Garfield), TDS, arsenic |
How to Collect a Sample
- Use the container provided by the lab (sterile containers required for bacteria)
- For bacteria: do NOT pre-rinse. Remove the aerator. Run cold water 2-3 minutes before collecting.
- For radon: use the special collection method — water must be collected without agitation
- For chemical tests: run water 2-3 minutes, then fill the container
- Keep samples cool (not frozen) and deliver within 24 hours for bacteria
- Label: name, address, date, time, sample location
- CDPHE requires overnight shipping — FedEx, UPS, or USPS
Jefferson County Mandatory Testing
Jefferson County has mandatory well water quality testing requirements. If you're buying or selling property with a well in JeffCo, check the county requirements for specific testing mandates.
Sources
- CDPHE — Water Testing Services for Non-Water Providers
- CDPHE — Drinking Water Lab Certification Program
- CSU Extension — Private Wells for Home Use (Fact Sheet 6.700)
- Colorado Analytical Laboratory — Inorganic Drinking Water Analysis
- Jefferson County — Mandatory Well Water Quality Testing Requirements
- Colorado Environmental Public Health Tracking — Private Well Water Dataset