Firefighters train to extinguish aircraft fires
Firefighters use extinguish a helicopter fire during a training exercise in 2007. Photo credit: U.S. Army Photo (Photo Credit: Patrick Hodges) VIEW ORIGINAL

ABERDEEN PROVING GROUND, Md. -- National Groundwater Awareness Week takes place March 6-12. Groundwater is an important natural resource for more than a third of the U.S. population that relies on it as their drinking water source. Per- and polyfluoralkyl substances, or PFAS, are potential groundwater contaminants that have been receiving increased public attention and regulatory scrutiny in recent years.

PFAS have recently found their way into the news and into our collective vocabulary. PFAS are a group of man-made chemicals that have been used worldwide since the 1940s, and became common ingredients in many products due to their stain resistant, water proof and non-stick properties. Consumer products that may contain PFAS include food packaging materials, nonstick cookware, and stain resistant coatings for clothing and carpeting and personal care products, such as dental floss.

PFAS are commonly referred to as ‘forever chemicals’ because they do not easily breakdown under typical environmental conditions. There are as many as 4,000 chemically distinct PFAS. Two persistent PFAS of special interest are perfluorooctane sulfonate, or PFOS, and perfluorooctanoic acid, or PFOA.

We know that we don’t want this alphabet soup in our drinking water, but what do we know about these ‘forever chemicals’?

PFOS and PFOA are present in some formulations of firefighting foam known as aqueous film forming foam, or AFFF. AFFF is used at Department of Defense facilities, commercial airports and some local fire departments, because it is very effective in quickly extinguishing fuel fires.

The DOD investigates releases associated with past usage of AFFF and determines the appropriate cleanup actions based on risk. These investigations include assessing potential off-installation migration of PFOS and/or PFOA into drinking water. The DOD’s priority is to quickly address PFOS and PFOA from DOD activities found in drinking water at levels above the U.S Environmental Protection Agency health advisories, also called HAs.

The DOD no longer discharges AFFF during maintenance, testing, or training operations on military installations worldwide; for the past 5 years, the military only uses AFFF to respond to real-world emergency events. Research efforts are ongoing to develop an acceptable PFAS free replacement for AFFF that meets the performance requirement of current AFFF products.

When humans ingest PFAS (by eating food or drinking water contaminated with PFAS), the PFAS is absorbed and can accumulate in the body to a level that can potentially cause adverse health effects. Animal studies show that high concentrations of PFOA and PFOS can cause reproductive, developmental, liver, kidney and immunological effects. Research involving humans suggests that reductions in vaccine response, increased cholesterol levels, reproductive effects, thyroid issues, increased risk of kidney or testicular cancer and decreased birth weights may be correlated with high serum levels of some PFAS. To learn more about potential health effects and ongoing exposure assessments and health studies, visit the Agency for Toxic Substance and Disease Registry.

The EPA develops HAs to provide information on contaminants that can occur in drinking water and cause human health effects. When both PFOA and PFOS are found in drinking water, the combined concentrations of PFOA and PFOS should be compared with the 70 parts per trillion health advisory level. For perspective, this concentration is equivalent to one droplet of water in 20 Olympic sized swimming pools. The EPA says this health advisory level offers a margin of protection for all Americans throughout their life from adverse health effects resulting from exposure to PFOA and PFOS in drinking water.

The EPA’s Fifth Unregulated Contaminant Monitoring Rule (UCMR5), which will require all drinking water systems serving more than 3,300 individuals to collect occurrence data for 29 PFAS substances, was finalized Dec. 20. Under the UCMR5, the EPA will also include a representative number of samples from water systems servicing fewer individuals. The EPA believes this monitoring effort is a key action to guide science-based decision making for future PFAS drinking water regulations.

According to the EPA, Lifetime HAs replaced provisional HAs developed in 2009 after the science evolved. The EPA’s health advisory levels were calculated to offer a margin of protection against adverse health effects to the most sensitive populations: fetuses during pregnancy and breastfed infants. The health advisory levels are calculated based on the drinking water intake of lactating women, who drink more water than other people and can pass these chemicals along to nursing infants through breastmilk. Unlike other EPA health standards, such as the drinking water maximum contaminant levels, or MCLs, the HAs are recommended exposure thresholds but are not enforceable standards.

Since the current EPA lifetime HA standard was set in 2016, some states have set more stringent lifetime HAs while other states have promulgated more stringent MCLs for PFAS chemicals in drinking water. At the time this article was developed, the lifetime HAs of 70 ppt were in effect. However, discussions are currently underway in early 2022 to possibly lower the PFOS and PFOA lifetime HAs.

“In practice, when PFOS and PFOA are detected above the EPA lifetime HA, the DOD remediates their drinking water systems to ensure consumers are not being exposed to levels above the HA,” said Matthew Waterbury, Army Public Health Center hydrologist.

In 2016, following the issuance of the EPA’s lifetime HA, the U.S. Army Public Health Center began assisting the Army’s Installation Management Command with the testing of Army-owned drinking water systems. This initial testing, along with subsequent testing, identified several U.S. Army Installation Management Command water systems where PFOS/PFOA concentrations exceeded the EPA lifetime HA.

The detection of PFOS/PFOA above the EPA lifetime HA at several installations led to implementation of various remedies to reduce or eliminate PFAS exposure to consumers.

“These remedies included short-term provision of bottled water and long term actions such as closing contaminated wells, purchasing municipal water, or installing treatment systems to remove PFAS,” said Waterbury. “Granular activated carbon filter systems have been effective as a treatment process to remove PFAS from drinking water.”

PFAS Study
Dan Casey, left, lead field operations engineer, and Brad Geisman, pilot engineer for Emerging Compounds Treatment Technologies (ECT2), discuss a water filtration system being used to remediate polyfluoroalkyl substances (PFAS) from contaminated groundwater at the fire training area of Wright-Patterson Air Force Base, Ohio on Sept. 29, 2020. U.S. Air Force personnel from the 88th Air Base Wing Civil Engineer Group are leading the pilot study of new remediation techniques that can remove and destroy the PFAS, some of which were formerly used in aircraft fire fighting foam. (U.S. Air Force photo by Ty Greenlees) (Photo Credit: Tyler Greenlees) VIEW ORIGINAL

As the drinking water monitoring program continues, APHC continues to coordinate with installations and the APHC Laboratory Sciences Directorate to receive water samples for testing and also maintains PFAS data in the Defense Occupational and Environmental Health Readiness System (DOEHRS). There are currently thousands of PFAS water test results associated with more than 500 drinking water systems in DOEHRS. In addition, the APHC Toxicology Directorate has been involved in investigational studies about PFAS and its health effects.

In 2020, the DOD expanded the PFAS drinking water monitoring program to include non-DOD owned drinking water systems, such as privatized water systems and purchased purveyor water systems. In addition, the DOD has invested more than $1.5 billion in PFAS related research and cleanup activities. This current DOD research effort may be one of the largest of its kind.

In addition to finding effective fluorine-free substitutes for AFFF, this current DOD effort also includes research into how to detect, treat and respond to PFAS found in the environment, with the aim of accelerating the cleanup response. To date, the DOD has obligated nearly $1.2 billion for cleanup at 699 installations and National Guard facilities. The DOD estimates that the future costs at these known sites will exceed $2 billion.

APHC has developed a fact sheet on PFOS and PFOA with frequently asked questions for consumers.

The Army Public Health Center focuses on promoting healthy people, communities, animals and workplaces through the prevention of disease, injury and disability of Soldiers, military retirees, their families, veterans, Army civilian employees, and animals through population-based monitoring, investigations, and technical consultations.