Environmental Stewardship

Solar panels at Davis-Monthan Air Force Base, Ariz., collect sunlight. The Davis-Monthan solar array project, on 170 acres of underutilized land, makes it the largest of its kind on any Defnese Department installation. (U.S. Air Force photo/1st Lt. Sarah Ruckriegle)

Davis-Monthan Air Force Base is committed to being good environmental stewards by making it an important part of our mission. Through the base's aggressive pollution prevention, restoration, natural resources conservation, and environmental compliance initiatives, we continue to fully integrate environmental considerations into all phases of operations and comply with all applicable federal, state, local, and Air Force environmental laws and regulations.

By promoting a truly cross-functional approach to environmental stewardship, DM will ensure that the responsibility for protecting and enhancing our environment rests not with one office or squadron, but with the entire 355th Wing.

PFOS/PFOA Overview

PFOS Quote

Davis-Monthan Air Force Base and the Air Force Civil Engineer Center (AFCEC) remain committed to working with regulatory partners to address potential impacts of Per- and polyfluoroalkyl substances (PFAS) in Tucson’s drinking water that may have resulted from Air Force mission activities. In alignment with the Department of Defense’s response to the issue,  the Air Force has taken considerable steps to identify, respond to and prevent the spread of PFAS, and that work continues today.

Beginning in 2015, AFCEC began a series of inspections and investigations sampling water and soil at Davis-Monthan AFB, as well as private wells one mile down gradient of the installation, to assess the presence of Perfluorooctanoic Acid (PFOA) and Perfluorooctane Sulfonate (PFOS), two PFAS compounds used in many industrial and consumer products. The data collected from these ongoing efforts is shared with Tucson Water, the Arizona Department of Environmental Quality (ADEQ) and the Environmental Protection Agency (EPA) during recurring collaborative working groups to help guide the whole-of-government approach needed to address this issue.

PFOS and PFOA were used in legacy formulas of aqueous film-forming foam, commonly used by commercial industries and the armed services to extinguish petroleum fires associated with aircraft emergencies. Davis-Monthan AFB transitioned to a new formula of the foam in 2016 that meets both military specification requirements for firefighting and the goals of the EPA’s PFOA Stewardship Program. It contains no PFOS and only trace amounts of PFOA, and is not used in training activities. The only time the installation’s emergency responders would use this foam is in the event of a fuel fire. If used, preventive actions would be taken to limit the release of PFOA into the environment.

More recently, AFCEC awarded a contract in June 2020 for a Remedial Investigation at Davis-Monthan AFB to further study the nature and extent of PFOS and PFOA impact in the area. This effort began in April 2021 and will include ongoing sampling of surface water, groundwater, sediment and soil on the base through the fall of 2024. AFCEC, Davis-Monthan and Air National Guard personnel have been working with the ADEQ, Tucson Water and the Tucson City Council holding public forums in February and June 2021 to inform residents of the planned activities associated with the investigation, and briefed congressional staffers on the Air Force’s response to PFOS/PFOA in the Tucson community.

Additionally, based on sampling data provided by Tucson Water and ADEQ, AFCEC further expanded its site inspection to test private wells within two miles down gradient of the installation.

While these compounds are not regulated, the Air Force is taking proactive measures, led by AFCEC, to ensure drinking water that may have been impacted by mission activities meets the EPA's Lifetime Health Advisory of 70 parts per trillion for PFOS and PFOA. The service-wide effort is guided by the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA) and state laws. The CERCLA clean-up process allows the Air Force to evaluate unacceptable risk to human health and the environment and plan for a range of responses prioritized within its environmental program.

The Air Force will continue to take aggressive action and work with community and regulatory partners to identify and implement long-term solutions for drinking water.

For more information on the Air Force’s response to PFOS and PFOA please visit http://www.afcec.af.mil/WhatWeDo/Environment/Perfluorinated-Compounds/ or contact Air Force Installation and Mission Support Center Public Affairs at 1-866-725-7617 or AFIMSC.PA.Workflow@us.af.mil.

For questions relating to Davis-Monthan AFB, please contact the 355th Wing Public Affairs Office at (520) 228-3406 or 355WGPA@us.af.mil.

What ARE pfos and pfoa?

Per- and Polyfluoroalkyl Substances, or PFAS, are a group of manmade chemicals used for a wide variety of residential, commercial and industrial purposes including: nonstick cookware, stain-resistant fabric and carpet, some food packaging and firefighting foam.

In 2016, the Environmental Protection Agency established health advisory levels in drinking water for two types of PFAS - perfluorooctane sulfonate (PFOS) and perfluorooctanoic acid (PFOA). The EPA has not established regulatory standards for PFOS and PFOA, but evolving science has identified potential risk to humans and regulatory standards are under consideration.

PFOS/PFOA Timeline

1970

The Air Force began using a legacy formula of aqueous film-forming foam (AFFF) to extinguish petroleum fires such as those associated with burning aircraft. AFFF is an extremely efficient extinguishing method for widely used across commercial industries and the armed services to extinguish petroleum fires associated with aircraft emergencies. It is also known to have contained PFOS and PFOA.

2009

The U.S. Environmental Protection Agency (EPA) issued provisional health advisories for PFOS and PFOA.

2010

AFCEC launched a comprehensive Preliminary Assessment process to identify Department of Defense installations with fire training areas, emergency response locations, and aircraft crash sites where AFFF had likely been used.

2015

AFCEC concluded its Preliminary Assessment at Davis-Monthan, identifying three areas of interest for investigation. These areas of interest include the DM Fire Training Area near the southeastern end of the DM flight line, a storm-water outfall canal located on the north end of the flight line and four historical crash sites along the length of the flight line where AFFF had been deployed.

2016

The EPA established a lifetime health advisory (LHA) level of 70 parts per trillion for PFOS and/or PFOA. The LHA does not include other PFAS compounds and is only applicable to exposure to PFOS/PFOA via the consumption of drinking water. The LHA is non-regulatory and not enforceable.

Davis-Monthan transitioned from the legacy formula of AFFF to a new formula that meets both military specification requirements for firefighting and the goals of the EPA’s PFOA Stewardship Program. It contains no PFOS and only trace amounts of PFOA, and is not used in training activities. The only time the installation’s emergency responders would use this foam is in the event of a fuel fire. If used, preventive actions would be taken to limit the release of PFOA into the environment. The last time any version of AFFF was used at Davis-Monthan was in 2006, when the 355th Civil Engineer Squadron’s fire department employed it in response to an aircraft emergency on the flight line.

Nine on-base water supply well samples were collected and six tap water sources were tested, which resulted in no detection for PFOS or PFOA.

2017

The Air Force completed enterprise-wide sampling of drinking water to ensure supplies met EPA guidelines. This initial work, coupled with the 2010 Preliminary Assessment has resulted in the Site Inspections that have taken place at installations across the country in recent years, including at DM, and the continued work that is ongoing today.

2017-2018

An initial Site Inspection was conducted, the results of which were released in February 2019. This inspection involved soil samples and groundwater samples collected from the areas of interest identified during the 2015 preliminary assessment. Zero of the groundwater samples taken tested above the EPA’s LHA level of 70 parts per trillion.

2019

Two additional monitoring wells were installed within 100-Acre Wood Park near the northwest boundary of the base. This was accomplished through an agreement between the Air Force, Tucson Water, Pima Flood Control and Tucson Parks and Recreation to minimize impact to the environment while optimizing the ability to obtain accurate groundwater data. 

Sample data taken from these wells was released by AFCEC as an addendum to the Site Inspection report in June 2019. PFOS and PFOA were detected at 935 parts per trillion at one well and 14,400 parts per trillion at the second for a combination of PFOS and PFOA, with the concentrations decreasing with depth.

In October, AFCEC initiated a contract for an expanded Site Inspection to test private wells located within one mile down gradient of the installation.

2020

Davis-Monthan and AFCEC identified 14 potential private wells within one mile down gradient of the installation. Every effort was made to contact the well owners to inform them of the EPA’s LHA for PFOS/PFOA, that potential PFOS/PFOA source areas had been identified at Davis-Monthan and to request permission to collect samples from their wells. Two wells were sampled, and neither tested above the EPA’s LHA.

In June, AFCEC awarded a contract for a Remedial Investigation at Davis-Monthan to further study the nature and extent of PFOS and PFOA impact in the area. This investigation is expected to include ongoing sampling of surface water, groundwater, sediment and soil on the base through the fall of 2024. That sampling will be accomplished through the installation and development of an estimated 24 new monitoring wells, 30 to 45 surface sampling locations and 15 soil boring locations.

2021

In February, representatives from AFCEC and Davis-Monthan briefed members of the Tucson City Council, Tucson Water, ADEQ, City of Tucson staff members and residents of Ward 6 on Air Force actions to date and its ongoing partnerships with city, state and national regulatory organizations to identify, respond to and prevent PFOS/PFOA impacts on Tucson’s drinking water.

In April, initial Remedial Investigation fieldwork began.

In August, AFCEC began its expanded site sampling targeting private wells within two miles down gradient of the installation. AFCEC received permission to test 11 of 19 wells identified in this area. Four were found to be connected to city water, three were not in use and one was used only for irrigation. Multiple attempts to contact the owners of the remaining four wells were made, but no response was received. Results found no detections of PFOS/PFOS in any of the wells sampled.

By the end of September, four monitoring wells were installed in the vicinity of the north end of the base boundary as part of the AFCEC remedial investigation. Information gathered from these monitoring wells will guide the project team towards identifying the source and extent of impact.

Additionally, an Air Force Environmental Services Agreement (ESA) was approved with ADEQ to begin operation of the PFAS pilot demonstration/treatment facility in October that is immediately off-base to the north. This resource allocation will provide funding associated with plant construction and ongoing operations for up to one year. Data will be shared between ADEQ, City of Tucson, and Davis-Monthan in order to determine the effectiveness of the treatment process, gather aquifer data that may be useful in future cleanup efforts, as well as the immediate removal of contaminants to reduce the impact of PFAS in the local aquifer.

Aqueous Film-Forming Foam

Aqueous film-forming foam (AFFF) is a firefighting foam that quickly extinguishes fuel fires on ships and airplanes. The Defense Department is conducting research on this foam because of concerns about adverse health effects.

Why does the DOD use AFFF?

Anywhere there are large amounts of flammable materials, you need to be able to put out fires rapidly to protect human lives. AFFF is used as part of fire suppression systems and in emergency responses at chemical plants, oil refineries and rigs, and notably in aviation operations.

DOD uses this firefighting foam because on ships and on aircraft, the close proximity of people, fuel and munitions can be especially dangerous. AFFF works by quickly spreading out over the surface of the fuel, depriving the fire of oxygen, quickly extinguishing even large fires. The foam also prevents the hot fuel from reigniting. So far, only AFFF that contains PFAS are capable of putting out dangerous fuel fires fast and keeping them out.

Why is the department looking for replacement products?

Research has shown that the same attributes that make PFAS great for fighting fires also make them persist in the environment. There are concerns that the fluorine in these chemicals may have adverse health effects. DOD is looking for new technologies that can do the job without fluorine.

How is DOD funding firefighting foam replacement research?

DOD’s environmental research and demonstration programs; the Strategic Environmental Research and Development Program (SERDP) and the Environmental Security Technology Certification Program fund AFFF replacement research. They work on environmental issues that are of concern to DOD and additional research is needed.

Since fiscal year 2017, DOD has committed $11 million towards research in alternative firefighting technologies. SERDP has provided funding opportunities for basic and applied research and advanced technology development to identify solutions and technologies that use nanotechnology, polymers and more.

AFFF at Davis-Monthan

Davis-Monthan transitioned from the legacy formula of AFFF to a new formula that meets both military specification requirements for firefighting and the goals of the EPA’s PFOA Stewardship Program.  It contains no PFOS and only trace amounts of PFOA, and is not used in training activities. The only time the installation’s emergency responders would use this foam is in the event of a fuel fire. If used, preventive actions would be taken to limit the release of PFOA into the environment. The last time any version of AFFF was used at Davis-Monthan was in 2006, when the 355th Civil Engineer Squadron’s fire department employed it in response to an aircraft emergency on the flight line.