Select a city below to view local well water testing services in your area. Each city page lists providers offering lab testing, field sampling, or mail-in well water tests.
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Colorado's high-altitude terrain, from the Rocky Mountain peaks to the Eastern Plains, creates diverse groundwater conditions that affect well water quality across the state. Whether you're in a mountain community, a Front Range suburb, or rural agricultural land, understanding your water is an important part of well ownership.
The Colorado Department of Public Health and Environment is clear about one thing: they do not regulate water quality for private water wells. Unless your well meets the definition of a regulated public water system (serving 25+ people or 15+ connections), the state leaves water quality responsibility entirely with the owner.
What makes Colorado interesting is that 'mandatory' testing often comes through the back door-via county public health departments and permit conditions. Some counties require well water testing as a condition of septic (OWTS) permits. Real estate transactions commonly involve testing driven by lenders or buyers rather than state law. If you're wondering whether you need to test, start by checking with your county public health department.
Colorado does not have a statewide mandate requiring private well water testing for property transfers or routine ownership. The state's Department of Public Health and Environment explicitly states that it does not regulate water quality for private wells.
However, mandatory testing commonly occurs through local permitting processes. Many Colorado counties require raw well water testing-typically for total coliform and nitrate-as a condition of an on-site wastewater treatment system (OWTS/septic) permit. If you're building a new home, adding a septic system, or making certain property improvements, your county may require a well water test before final approval.
Real estate transactions in Colorado often involve well water testing, but this is typically driven by lenders and buyers rather than state law. Mortgage lenders-especially for FHA, VA, and USDA loans-frequently require water quality documentation. Many buyers also request testing as part of their inspection process, even when not technically required.
The bottom line in Colorado: testing requirements are often county-specific. Jefferson County, El Paso County, Boulder County, and others each have their own environmental health departments with potentially different requirements. Always check with your local county public health department to understand what applies to your situation.
The baseline testing recommended everywhere applies in Colorado: total coliform bacteria and E. coli to check sanitary integrity, plus nitrates which pose risks to infants and pregnant women. These should be tested annually as a matter of good practice.
Colorado's diverse geology creates regional variations in water quality. Mountain communities may deal with naturally occurring metals from mineralized rock formations. Agricultural areas on the Eastern Plains may have elevated nitrate levels. Some areas have naturally occurring radionuclides like uranium or radium, depending on local geology.
If you're at higher elevations with older mining activity nearby, testing for heavy metals like arsenic, lead, and manganese may be prudent. Colorado has a long mining history, and legacy contamination can affect groundwater in some areas. Your county health department or a local lab can advise on contaminants of concern in your specific region.
Consider expanding your testing if you notice changes in taste, odor, or appearance; after flooding or well repairs; if you're near agricultural operations; or if household members have specific health concerns. Hard water is common in parts of Colorado, so minerals like calcium and magnesium may be worth testing if you're experiencing scaling or taste issues.
Every year
For new wells and every 3-5 years thereafter
Based on location and local guidance
Well water testing costs in Colorado depend on what you're testing for and which lab you use. Basic bacteria and nitrate tests-the most common panel for permit compliance-are generally affordable. Adding metals, radionuclides, or comprehensive panels increases the cost.
County health departments sometimes partner with labs to offer testing at reduced rates, particularly for the basic parameters required for permits. Check with your county environmental health department to see what's available in your area. Some counties maintain lists of certified labs that regularly work with local property owners.
Turnaround time follows typical patterns: bacteria results within a few days (samples are time-sensitive), chemical tests for nitrates and metals within 5-10 business days. If you're testing for a permit or real estate closing, make sure you factor in adequate time. Some tests-like bacteria-have strict holding periods and need to reach the lab within 24-30 hours.
Colorado's varied geography means lab access differs by location. Front Range communities have many local lab options. More remote mountain or rural areas may require shipping samples, which adds time and logistical complexity for time-sensitive tests like bacteria.
When choosing a testing provider in Colorado, consider whether your testing is for permit compliance, real estate, or general peace of mind. For permit-related testing, your county may have specific requirements about which labs are acceptable or which parameters must be tested.
Look for laboratories certified for drinking water analysis in Colorado. Certified labs follow standardized methods and quality controls that ensure accurate, defensible results. Some labs accept walk-in samples at their facilities; others offer mail-in services or work with sampling services.
Field sampling services can be valuable in Colorado, especially for remote properties or if you're not comfortable collecting samples yourself. These services handle proper collection technique and chain of custody, which matters for official documentation. They can also advise on what to test based on your location.
Treatment companies sometimes offer testing, but remember their primary business is selling equipment. If a treatment company recommends expensive systems based on their test, consider getting independent verification from a certified lab before investing.
For mountain properties or areas with known mining history, choose a lab that can test for a range of heavy metals at appropriate detection limits. Not all panels are equal-make sure the lab can detect contaminants at levels that matter for drinking water standards.
Quick answers to common questions about testing well water in Colorado, from county requirements to finding certified labs.