Water testing frequently requested information
For Questions about testing water please contact us:
Environmental Microbiology (bacteria in food or water)
Chemistry (chemicals in food or water)
Please specify the chemistry topic in the email subject line.
Chemistry laboratory voicemail line: 303-692-3048
When to test your well
As a private well owner or well-water consumer, you'll probably use groundwater from your well for drinking, cooking, bathing, doing your family's laundry and watering your garden.
Municipalities are required to test their water supplies regularly to ensure the water is safe to drink. However, because there’s no requirement to test a private well except when it’s first drilled or the pump is changed, you’re responsible for making sure your water is safe.
While most private wells provide a clean, safe supply of water, contaminants can pollute private wells. Because you can't see, smell or taste most contaminants, you should test your water on a regular basis. The types of land uses near your well determine which tests you need to have performed on your water supply.
Read the Water Quality Control Division pamphlet "Drinking Water From Household Wells" to learn how wells are polluted, how to protect them, what pollutants contaminate the water and what testing is needed.
If you own property with a private water supply such as a spring or a well, consult this list for testing suggestions:
- Because bacterial levels in the water can change over time, a coliform test should be performed yearly.
- If there’s farming or livestock ranching in the area, nitrates can be found in areas where fertilizers have been applied or livestock waste is found.
- If children are drinking the water on a regular basis, fluoride levels should be between 1 and 2 milligrams per liter (mg/l). Fluoride levels of less than 1 mg/l may prevent the proper development of teeth and supplements may be needed. Fluoride levels greater than 4 mg/l can lead to a pitting and staining of the teeth caused by fluorosis.
- An odor of rotten eggs indicates the presence of sulfide. This is more of an aesthetic problem than a health concern and can be easily treated with chlorine.
- If the bathroom fixtures are stained by the water, check for the following metals:
- Blue or green stains indicate the presence of copper.
- Red or rust-colored stains indicate iron is present.
- Black stains indicate the presence of manganese or zinc.
- Uranium is naturally occurring in granite formations, which are found throughout Colorado, especially in the foothills. It can be found dissolved in the waters of wells sunk in these areas.
- Testing processes require varying amounts of time, depending upon the test performed. Therefore, allow up to 30 days for chemistry tests, and 24-96 hours for coliform testing. Laboratory staff can assist in evaluating your testing needs and help you develop a water testing plan.
Sampling bottles are specially prepared by the laboratory and are required for performing any testing. Samples taken in any other bottles aren’t accepted because they may be contaminated and ruin the test.
Ordering testing supplies:
- Call our order line at 303-692-3074.
- Water providers and wastewater companies can request supplies through our online order form.
- Private citizens, well owners and realtors can request supplies through our online order form.
Testing supplies are free of charge and will be sent to you via FedEx.
If you’re picking up sample bottles from the lab, go to the entrance marked "Receiving" on the south side of the building. The main entrance at the west side of the building is locked and not available for pickup of sampling bottles.
- Map to the lab and designated entrance.
- Compliance testing schedules, facility name, Public Water System ID (PWSID) and sampling site numbers.
Returning samples to the lab
Some water samples must be delivered to the laboratory within a few hours and in a cooler with an ice pack. Be sure to check the collection instructions provided with your sampling bottles.
Samples can be delivered to the lab in person, or in some cases can be sent to the lab. Samples can be dropped off at the same entrance where bottles are picked up.
If your sample must be delivered to the lab within 24 hours after it was collected, you can use U.S. Postal Service overnight mail or have the samples delivered by any carrier able to deliver it within 24 hours after collection.
To ensure prompt processing, be sure to complete the sample information form included with your sampling bottles. Each sample requires a separate test request form.
Testing turnaround times vary according to the type of test being performed.
Testing processes require varying amounts of time, depending on the test performed. Therefore, allow up to 30 days for chemistry tests, and 24-96 hours for coliform testing. Laboratory staff can assist in evaluating your testing needs and help you develop a water testing plan.
Getting your results
We send results reports via email or the U.S. Postal Service as soon as the tests are completed. Be sure to include your email address on your request for analysis form. If you haven’t received your test results within the sample testing time frame, you can call or email the lab: