El Paso County (CO) near Peterson Air Force Base

El Paso County near Peterson Air Force Base

PFAS Exposure Assessment Community Level Results

In 2019, the Centers for Disease Control and Prevention (CDC) and the Agency for Toxic Substances and Disease Registry (ATSDR) started exposure assessments (EAs) in communities near current or former military bases known to have had per- and polyfluoroalkyl substances (PFAS) in their drinking water. Individuals who participated in the EAs provided blood and urine samples to CDC/ATSDR for analysis. We sent letters to participants that included their individual lab results. An example letter of the test results letter and the community level results are available here pdf icon[PDF – 565 KB].


Use and spills of aqueous film forming foam (AFFF) containing PFAS occurred at the Peterson Air Force Base primarily during firefighting training exercises. The PFAS traveled into the groundwater eventually affecting nearby water systems in El Paso County, CO.

Testing in 2013 and 2014 found PFAS in the Widefield WSD. PFAS were first detected in the Security WD and Security MHP in 2014 and 2016, respectively. These three drinking water systems had customers with sustained PFAS exposures greater than the current EPA health advisory. In 2016, all three systems took active measures to reduce PFAS exposure to customers. Based on information available to the ATSDR, drinking water supplies from all three systems currently meet federal PFAS guidelines.

In 2018, a health study, PFAS Assessment of Water and Resident Exposure (PFAS-AWARE), tested PFAS levels in approximately 200 people in El Paso County. Approximately 50 participants were retested in 2019. Information can be found online at pfas-aware.org.

CDC/ATSDR’s exposure assessment is different from the PFAS-AWARE study. The exposure assessment will help public health professionals better understand the overall PFAS exposure in your community (not just for those who participate) and may provide information to help communities across the nation. The exposure assessment will also test children older than 3 years old; the PFAS-AWARE study was limited to adults. You can participate in the exposure assessment even if you participated in the PFAS-AWARE study.

In 2019, CDC/ATSDR established a cooperative agreement with researchers at the Colorado School of Public Health (Colorado SPH) at the University of Colorado Anschutz Medical Campus to conduct a health study, called the Colorado Study of Community Outcomes from PFAS Exposure (CO-SCOPE). This study is part of a larger program, the ATSDR PFAS Multi-site Study (MSS), which aims to expand the knowledge between PFAS exposure and health outcomes among different populations. To learn more about the differences between the exposure assessment, and the PFAS-AWARE and CO-SCOPE health studies see click here pdf icon[PDF – 213 KB].

Sampling Area 

CDC/ATSDR identified a random selection of households exposed to PFAS in their drinking water above the Environmental Protection Agency’s (EPA’s) current health advisory level. This includes residents within the Security-Widefield area served by of households served by the drinking water systems of Security Water District (WD), Security Mobile Home Park (MHP), and the western portion of the Widefield Water and Sanitation District (WSD). Choosing a random selection of households to participate will help estimate exposure for all community members, even those not selected to participate.

All individuals living in selected households were eligible to participate if they:

  • Were 3 years of age or older (children were included in the exposure assessment only if we had consent from a parent or legal guardian)
  • Did not have a bleeding disorder and were not anemic, which would have precluded a blood draw
  • Had lived in the sampling area for at least one year before November 10, 2016
The image shows the boundaries of the sampling frame in the Security-Widefield area


CDC and ATSDR began an exposure assessment in the Security-Widefield area in August 2020. Recruitment lasted about five weeks and CDC/ATSDR conducted the biological and environmental sampling in September 2020.

CDC/ATSDR completed the analysis of the biological samples. Individual results were mailed to participants May 7, 2021. CDC/ATSDR will write a final report summarizing the findings and recommendations for the community and present the results at a public meeting.

El Paso Exposure Assessment Timelineimage icon

Page last reviewed: May 20, 2021