Water and chemicals from firefighting foam and other sources


On June 15, 2022, the Environmental Protection Agency announced an update to health advisories for four PFAS chemicals by lowering the level of acceptable amounts present in drinking water (PFOA, PFOS, PFBS, and GenX). These chemicals are known to have negative impacts on human health and the environment. This page has information for water consumers as well as water providers to learn more about these chemicals. 


How do these chemicals enter drinking water?

Person filling water glass at kitchen sink.

There are many ways for these chemicals to enter drinking water. In Colorado, we are especially concerned about toxic firefighting foams containing these chemicals. If firefighting foam is left on the ground after putting out a fire, this may allow PFAS chemicals to sink through the soil into groundwater or run off into rivers and streams.


What should I do to make sure my drinking water is safe?

If you receive a water bill, then you are connected to a public drinking water system. If your water bill is included in rent or association dues, contact the manager to determine which system provides your water. If you do not receive a bill, you could be served by a private well.


If you are served by a public water system

Some water systems participated in a sampling project in 2020 to test for these chemicals and you can view the results. We recommend following up with your water system because they may have changed their treatment methods since this project took place.

We will continue to work with public water systems that may be impacted by the updated health advisories. We will help them assess their PFAS data, and then inform customers and evaluate options if PFAS levels are higher than the health advisory. 



If you have a private well

If you use well water for drinking, cooking food like soup or rice, or gardening, we recommend testing your well water for PFAS chemicals. EPA has a list of labs that can test for these chemicals. We recommend testing for as many PFAS contaminants as the lab offers. Please note the number of labs that can test for these chemicals changes, so this list may not be the most current.

Searchable list of accredited laboratories (search by method 537.1 or 533)

EPA list of certified labs.

Tell the lab you want to test your drinking water for PFAS. A test usually costs between $300 and $500.

For help interpreting lab results, please contact the department's toxicology hotline:




What if my water has PFAS levels over the health advisory?

The EPA’s 2022 health advisory for PFAS in drinking water includes levels for PFOA at 0.004 parts per trillion (ppt), PFOS at 0.02 ppt, PFBS at 2,000 ppt, and GenX at 10 ppt.

You can reduce exposure by using at-home water filters or using an alternate source of water for drinking and cooking. While many at-home water filters exist, they haven’t all been certified to remove PFAS. Look for manufacturers that have demonstrated the water filter can remove PFAS to non-detectable levels (see in-home treatment information sheet). Using bottled water is an individual choice, but CDPHE cannot verify that all bottled water is below PFAS health advisories. Reverse osmosis is a treatment that will remove PFAS. Choosing a brand that has this language on the bottle is important in selecting bottled water. Before choosing bottled water, consider the negative environmental impacts.

Other water sources include bottled water or water treated under the sink by a reverse osmosis system (see in-home treatment information sheet). If you or your family are concerned about your health, contact your health care provider and talk with them about PFAS (see guidance document). 

Learn about health effects on our health web page


Additional information for drinking water providers

The department is partnering with water systems and following the steps outlined by EPA including assessing the situation, informing the public about confirmed PFOA and PFOS levels above the health advisories and taking steps where possible to reduce PFAS levels in tap water. 

We strongly recommend that all public water systems (even those without PFAS detections) keep their customers updated on their PFAS-related activities, including all sampling results (even if PFAS aren't detected) and any potential PFAS reduction steps. We are working in partnership with water systems with confirmed PFOA and PFOS results above laboratory minimum reporting levels to provide direct public notification to their customers (see Consumer Drinking Water Notice). Considering the low levels of the updated health advisories, it is helpful to know whether these chemicals are present even if the concentration cannot be accurately measured by the laboratory. Both the department and water systems should request that the laboratory provide data to the lowest level they are capable of detecting. 

This document provides current information on coordination with Colorado public water systems in response to the June 2022 EPA health advisories and this document contains answers to some frequently asked questions. 


Consumer Drinking Water Notice

When contaminants in drinking water exceed the EPA health advisory with confirmed detectable concentrations (above the laboratory minimum reporting level) for per- and polyfluoroalkyl substances (PFAS) the department recommends that the water system inform the public. The information provided should include the sample results and an explanation of the significance of the sample results. To assist in these efforts, the department is providing this Consumer Drinking Water Notice template that water systems can choose to use. The notice is also available in Spanish.  


Public Water System Status Document

The department is partnering with water systems and following the steps outlined by EPA including assessing the situation, informing the public about confirmed PFAS levels above the health advisory and taking steps where possible to reduce PFAS levels in tap water. 

This document provides current status information on coordination with Colorado public water systems. 



From 2023 to 2025, large public water systems and some smaller ones must monitor for 29 PFAS and lithium under the EPA’s Unregulated Contaminant Monitoring Rule (UCMR). EPA uses the UCMR to collect data on contaminants in drinking water that do not have health-based standards. These data help EPA determine whether future health research and/or regulation is needed.

UCMR test results are available on EPA’s website. Water systems also must share information with customers about contaminants they detect.