How did PFAS from Peterson Air Force Base reach local drinking water?

What happened at Peterson Air Force Base?

Foam use and contamination found   Steps that ended or treated it

1. 1970sFrom this decade onward the base used AFFF firefighting foam for training. ATSDR
2. 2013PFAS found in municipal wells downhill from the base. ATSDR
3. 2015In October, Fountain shut down its wells and switched to Pueblo Reservoir water. City of Fountain
4. 2016Between January and November, Security and Widefield took the affected wells offline. ATSDR
5. 2017Widefield installed ion exchange treatment. The Security Mobile Home Park had been on bottled water since 2016. In November, it got a treatment system. ATSDR
6. 2018In June, Fountain began treating its groundwater with granular activated carbon supplied by the Air Force. City of Fountain
7. 2021Security's own ion exchange plant went online in April. Security Water District
8. 2021On July 26, Peterson Air Force Base was renamed Peterson Space Force Base. U.S. Space Force
9. 2022On October 13, Fountain's new treatment plant at Aga Park began serving residents. Colorado Springs Gazette The city describes it as an ion exchange plant. The temporary filters were then taken out of service.
10. 2023In November, the Air Force put its spending on the response at $103 million . That covered treatment plants in Fountain, Security and Widefield. It also covered monitoring and home filters for private wells.

Some entries name a month, others only a year. That is how precisely the records state it; we have not filled in the gaps. The likely source is firefighting foam used at the base.

How much PFAS was measured?

The Department of War (officially still the Department of Defense) publishes its test results for off-base drinking water. For Peterson, the published results run from December 2021 to March 2026. Highest results, in ng/L:

The three maxima without a qualifier come from sampling points listed without a treatment system. The PFOS result is sample FC18539-1, taken September 3, 2024, analysed by EPA Method 1633. The three highest estimates were all sampled in July 2023. That is not necessarily what came out of a tap.

How do these results compare with the limits?

The federal limits and the changes the EPA has proposed are kept on one page. So is what they mean for older samples: How do PFAS results compare with the limits? None of these values decides whether someone has a legal claim.

What do the numbers show?

In the Department's data, most results marked after treatment were not detected. For PFOS, PFHxS and PFOA, none of them came without a qualifier. Six were low estimates ("J"), between 0.64 and 1.8 ng/L. All others were not detected. For about half of them, the detection limit was 8 ng/L or higher. There, "not detected" only means below that level. Some short-chain PFAS did come through treatment: PFPeA up to 214 ng/L, PFBA up to 84. The EPA has set no drinking water limit for these two. So these records do not show that every treated sample was below 2 ng/L. They also do not prove how well a given plant works.

Water before treatment is still high. The 1,130 figure is from September 2024. In August 2025, 712 ng/L of PFHxS was measured before treatment, at a system that treats its water. Sampling runs to March 2026.

Which water systems were affected?

Your provider's name was on your bill. Each public system also has a PWSID.

All three PWSIDs come from the City of Fountain's 2026 water quality report (PDF). It carries Widefield's report alongside its own. Security publishes its own report. System status comes from ATSDR.

Is the water safe to use now?

Security Water District has treated its groundwater since April 2021. Security's 2025 water quality report lists none of the six regulated PFAS above the 2.0 ng/L reporting limit. That record covers recent years only. It says nothing about the water before the wells were shut down in 2016.

ATSDR tested three of the public systems. These are Security Water District, Widefield Water and Sanitation District and the Security Mobile Home Park. ATSDR took tap water samples there in September 2020 and reported in 2022. Measured against the EPA's 2016 health advisory, it stated that their customers did not need an alternative water source. Since October 2022, Fountain has treated its groundwater at an ion exchange plant in Aga Park. For today's water, your utility's annual quality report is the current record.

Fountain's newest report covers 2025. It lists three short-chain PFAS from testing for unregulated contaminants (page 10). The highest values were 33.8 ng/L for PFBA, 76.7 for PFPeA and 50.8 for PFHxA. Each comes from 14 samples. No other PFAS appears in that list. The EPA has set no drinking water limit for these three. The report does not say where in the system the water was sampled.

Private wells are the exception. There is no utility behind them, so no utility monitoring and no annual report. Still, something was done. The Air Force tested private wells near the base and supplied filters to some households. For a well that was not part of that programme, testing is the only way to know.

Can you shower, cook and clean with PFAS water?

Drinking and cooking are the routes that matter most. The EPA says showering and washing are unlikely to add much to your risk. Skin, steam, boiling and filters are covered on one page: What does PFAS exposure do to health?

Were volatile PFAS found here?

Some PFAS, the neutral precursors, can pass from water into air. How much depends on the compound. In ordinary drinking water, PFOS, PFOA and PFHxS hardly evaporate. Why that is is explained on the topic page.

The Peterson data answers part of the question. The Department of War tests for some of these precursors too. The data holds 499 results for each of the four precursor compounds. In every one, the compound was not detected. Their detection limits were mostly about 4 ng/L for NEtFOSA and NMeFOSA, and about 18 ng/L for NEtFOSE and NMeFOSE. A related compound, PFOSA, was detected in 49 of 981 results, the highest 8 ng/L. We make no claim about how much of it reaches the air.

What we will not claim: that this settles inhalation. These substances can also travel in airborne droplets rather than as vapour. We found no published measurement of shower air in these communities. What can be said: the main compounds found here hardly evaporate from drinking water. Four precursors tested were not found, and one related compound was found at low levels. Not every precursor was tested.

What is known about PFAS and health?

The federal health agency ATSDR reports that studies suggest links between certain PFAS and several conditions. They include kidney and testicular cancer. The IARC has rated two of them. It classifies PFOA as carcinogenic to humans and PFOS as possibly carcinogenic. The full list, and what it means, is on one page: What does PFAS exposure do to health?

How do the AFFF lawsuits apply to Peterson?

The AFFF cases are grouped before one federal judge as MDL 2873. Handling the foam at work and drinking contaminated water are separate exposure routes. At Peterson, both can apply. The base trained with the foam, and the foam reached town wells. The timeline above shows both.

Which conditions the lawsuits cover, and which are under review, is kept on one page: What are the AFFF lawsuits? What the work route asks for is explained under What if you handled the foam at work?

Which other PFAS sites have we documented?

• Willow Grove and Warminster, Pennsylvania — Horsham, Warminster, Warrington, North Wales, Aqua and private wells
• Fairchild Air Force Base and the West Plains, Washington — Airway Heights and private wells

Every place page uses the same method. We use the Department of War's own test results and name public water systems by PWSID. Dates are as precise as the record.

Where does this page's information come from?

• Security Water District — Water Quality Report for 2025
  The utility's own report. Confirms PWSID CO0121775, the ion exchange plant from April 2021, and current PFAS results.
• ATSDR — PFAS Exposure Assessment: El Paso County, Colorado
  Detection dates, affected systems, current status.
• ATSDR — PFAS sites, Region 8
  Names firefighting foam at the base as the likely source.
• Department of War — Off-Base Drinking Water PFAS Testing Results
  The measurement data. Query results have no permanent link, so the full query is stated on this page. Retrieved September 23, 2026. Our copy of the file can be downloaded.
• City of Fountain — Water Quality
  Well shutdown in 2015, carbon treatment from 2018.
• City of Fountain — 2026 Drinking Water Quality Report, data for 2025 (PDF)
  One document with the reports of Fountain (CO0121275), Widefield (CO0121900), Security (CO0121775), the Fountain Valley Authority and Colorado Springs Utilities. Source for all three PWSIDs. Fountain's PFAS results for 2025 are on page 10 of its report. They are given in µg/L; we converted them to ng/L.
• Colorado Springs Gazette — Fountain's Aga Park treatment facility, February 2023
  Start of service on October 13, 2022.
• City of Fountain — Water Fund operations
  The plant at Aga Park as an ion exchange groundwater treatment plant.
• KRDO — Fountain shows off new treatment facility, February 2023
  Temporary filters taken out of service.
• CBS Colorado — Air Force funding water treatment in Fountain
  Carries the Air Force’s written statement. The Air Force issued it to the newsroom; we found no version published by the Air Force itself.
• KRDO — PFAS in private wells near the base
  Private well sampling, and the Air Force’s written statement on its spending and on filters for private wells. Again a press statement with no official publication we could find.
• Colorado Public Radio — Air Force confirms foam toxins leached into groundwater
  Colorado health officials on the absence of any other identified source, as reported at the time. We found no CDPHE document stating it directly.
• U.S. Space Force — Peterson, Schriever, Cheyenne Mountain cultivate a new identity
  The official account of the renaming ceremony on July 26, 2021.
• EPA — Steps you can take to reduce your risk
  Showering, dishes, filter certification.
• ATSDR — How PFAS impacts your health
  The health associations reported for PFAS.
• US District Court, District of South Carolina — MDL 2873
  The court's page for the AFFF lawsuits. Conditions, exposure routes and proof requirements are set out on the PFAS topic page.

We link a source at the point each claim is made. One set of figures has no permanent link at its source: the Department of War's data. So we state the full query and publish our copy of the data. If a link is broken or a source has been superseded, tell us.