PFAS Mapping


This map shows results from multiple sampling projects where water, soil, sediment, and fish have been sampled for PFAS in Colorado.

  • This map shows sampling supported or required by CDPHE and does not include all sampling efforts by outside entities.
  • Not all points on the map are places where PFAS are being released into the environment. Some facilities may be containing and properly disposing of PFAS releases.
  • The map includes PFOA, PFOS, PFBS and GenX chemicals. The EPA released new or updated health advisories for these four PFAS in June 2022.
  • Samples that were below the limit of detection are labeled as zero, though their true value may be somewhere in between zero and the detection limit.
  • Users can find more information about the data from each project in the map’s layer descriptions.
  • This map will be updated as more information becomes available.

PFAS Concentration Map

To help us decide the most important places to sample for PFAS, we developed a map to predict where there may be a higher risk of PFAS contamination in groundwater. This map is a model that uses many sources of information to predict PFAS levels in areas where we do not have data.


How the map was created

We created the map using test results from various sampling efforts and potential and known PFAS sources. We also included information that may impact how PFAS travel in the environment, like yearly rainfall and elevation. Using existing data, we “trained” the map to predict the risk of PFAS contamination in areas we have not yet sampled.

The map will improve over time

Our intent is to continue to update the map, show the need to collect more PFAS-related data, and continue to identify target areas for sampling. As we add more location-specific information about PFAS in the environment and the different types of PFAS sources, the map will become better at predicting PFAS risk.

Using the map to make decisions

Based on this version of the map, we developed a list of focus areas for sampling. These include higher-risk:

  • Schools and mobile home parks that have their own water systems.
  • Public water systems that have not yet been sampled for PFAS.
  • Areas that have high-density private wells and are in close proximity to potential PFAS sources.

The map also tells us we need to test:

  • Near potential PFAS sources where we have minimal sampling information.
  • Areas where we have minimal sampling information, making it harder to predict PFAS risk.

PFAS prediction map (based on data available as of January 2023)

This map predicts a very general risk of PFAS groundwater contamination by county. Clicking on a specific county gives more information about the risk in that county.

What the map tells you

This map can tell you if you live in a county or region that has a higher risk of PFAS in groundwater. This risk is related to how many people live in an area, the results of sampling in the area, and how many potential PFAS sources are in that area. The map is a model that predicts the risk of finding PFAS in groundwater at the county level.

What the map doesn’t tell you

  • The map cannot tell you with certainty if the groundwater is contaminated in a given area. It is based on the best information we have, but since there is not enough data, sometimes it will be less accurate.
  • This map cannot tell you if you are exposed to PFAS. If groundwater around you is contaminated with PFAS, it does not necessarily mean your drinking water is contaminated with PFAS. That depends on where your drinking water comes from. For example, some Front Range water providers get their water from reservoirs in the mountains.
  • The map shows risk at the county level and it can only show the general pattern across the whole county. Within one county, some areas will have a higher risk and some areas will have a lower risk. This is identified by the text box descriptions as you place your mouse over the county.
  • The map cannot tell you whether you or your community is at risk of health impacts due to PFAS.

What you can do

Because some data contains confidential information, you cannot download the datasets directly from the map. You can access the data used in the map at the links below.



Ask questions. Share your PFAS data.
Email cdphe_pfas@state.co.us