Colorado
PFAS mapping
Colorado PFAS mapping
The Colorado Department of Public Health and Environment (CDPHE) publishes a series of three maps of sampling for per- and polyfluoroalkyl substances (PFAS), and a separate model map of where groundwater may be more vulnerable to PFAS. CDPHE says the map series shows results from multiple sampling projects where water, leachate, soil, sediment and fish tissue have been sampled for PFAS in Colorado.
In a Phase I ESA
ASTM E1527-21 does not name PFAS sampling data among its standard record sources. The maps show where the state has looked and what it found, and CDPHE states their limits plainly.
| Map | What CDPHE says it shows |
|---|---|
| PFAS sample results map | Locations where projects evaluated water, soil, sediment, leachate or fish for PFAS |
| PFAS concentration map | The level of PFOA and PFOS combined at each sampling location, from projects that sampled water, soil and sediment |
| PFAS private well and sample grid map | Results from projects where private wells or groundwater were sampled, to help private well users assess their relative risk |
Five details shape how to use them.
- They are not complete. CDPHE says the maps show sampling supported or required by CDPHE and do not include all sampling efforts by outside entities.
- A point is not a source. CDPHE says not all points on the maps are places where PFAS are being released into the environment, and that some facilities may contain and properly dispose of PFAS releases.
- Zero does not mean absent. Samples below detection limits are labeled as zero, though CDPHE says the true value may be somewhere between zero and the detection limit.
- The water samples are raw water. CDPHE says the water samples represent untreated raw water and do not have to meet the drinking water maximum contaminant levels. The maps include five compounds: PFOA, PFOS, PFHxS, PFNA and GenX chemicals.
- The data comes by project. CDPHE says the datasets cannot be downloaded from the maps because some data contains confidential information, and posts them on the page by project and medium. The projects it lists include Department of Defense site investigations, permit monitoring reports, preliminary assessment and site investigation data, and corrective action site screening of groundwater and leachate. For a property near a mapped point, find the project the point came from.
CDPHE says the map series was last updated in July 2026.
The contamination evaluation map is a different kind of thing. CDPHE calls it a model that estimates where there may be a higher vulnerability to PFAS contamination in groundwater, built from sampling results and from potential and known PFAS sources. It predicts at the county level, and CDPHE says it cannot tell you with certainty whether groundwater is contaminated in a given area. Do not cite it as a finding about a property.
CDPHE says the Water Quality Control Commission adopted a PFAS Narrative Policy, Policy 20-1, in July 2020, that the policy was renewed in 2025, and that it describes how the department regulates these chemicals in Colorado lakes, streams and other waters.
Where to look a site up
- CDPHE's PFAS sampling efforts across the state page links the three maps, the datasets, a description of the datasets and a how-to guide.
- CDPHE's PFAS contamination evaluation map page explains the model.
Getting the file
The pages read do not say how to request the reports behind a sampling project. CDPHE gives cdphe_pfas@state.co.us for questions. Where a mapped project belongs to one of its divisions, each division keeps its own records; its Public records page lists the route for each.
Sources
Colorado Department of Public Health and Environment pages, read October 7, 2026, no modified date shown: