The Wurtsmith AFB Aquifer Below the Cold War Battlefield

The front line of the Cold War was military bases like Wurtsmith Air Force Base; occupying a seven square mile patch of land adjacent to the quiet beach community of Oscoda, Michigan. Oscoda is on the east side of the state, only 194 roadway miles north of Detroit. Van Ettan lake forms the north-east border of the former base. To the south and through Clark’s Marsh and Tuckers Swamp is the Ausable River. Less than a mile to the west and through the middle of Oscoda Township, is the Great Lake Huron. Connecting all the surface waterways is the aquifer. A distinct 50-foot deep mixture of water, dirt, sand, and stone beginning roughly 15-feet below the surface. At the bottom of the aquifer is a thick bed of impermeable clay. I remember flying B-52 missions over this pristine water environment in the late 1980s. I can still see in my mind’s eye a setting yellow-orange sun sparkling off all the windswept waterways as I came in for a landing. A truly majestic view! From the air it is undeniable, Michigan’s greatest natural resource is its fresh water. A resource every American should protect.

The federal government began using this land in the 1920s. As our nation’s air power emerged, a small airfield appeared. Ten months after the end of World War II, this Army Air Field became Oscoda Air Force Base as the newly minted Air Force began to form. No one knew at the time a cold war would begin and then last 44 years (1947-1991). As the allied battle lines in Europe and the Pacific made victorious retreats, new battle lines slowly emerged across the deep rural communities of the United States. These new encampments grew in stature and responsibility as nuclear deterrence took shape, reflecting phrases like “Peace through Strength” and “Mutual Assured Destruction.” The new threat was Russian expansionism and the cold war was in full swing when Oscoda Air Force Base became Wurtsmith Air Force Base on February 15, 1953. Wurtsmith’s Strategic Air Command (SAC) Cold War mission would last 38-years. Make no mistake, towns like Oscoda were the frontline of a cold war, where the Atlantic Ocean became a neutral zone in a high stakes stand-off for global influence.

Firefighter Foam Basics: 3M’s AFFF Light Water

This was the backdrop in 1970 when a firefighter foam called Light Water became available on military installations across the United States. This firefighter foam was already in use on warships and Navy coastal installations roughly five years earlier. The name of the firefighter foam itself, designed in the research laboratories of the United States Navy and manufactured in the beginning by the 3M Company for the Department of Defense, engenders trust, as if made from something familiar and safe. However, the active ingredient of Light Water, a fluorinated substance is neither safe nor familiar. Fluorinated substances have properties of a neurotoxin and are dubbed the ‘forever chemical.’ A nickname that foretells its durability and lasting impact on society. Light Water would be sprayed and dumped onto the Wurtsmith ground and then seep into the soil in egregious amounts as firefighters doused petroleum fires in a training pit and when they calibrated and cleaned their dispensing equipment. Time and distance calibrations of the spraying equipment and the disposal of excess foam likely dispensed more firefighter foam onto the ground then any used in training. In addition to training, calibration, and cleaning, the firefighter foam was sprayed during real emergencies. 

I saw this firsthand when a KC-135A crashed and was completely engulfed in flames midway down the right side of a Runway 25 approach. It was a windy Thursday with a 10-knot crosswind gusting to 18-knots on October 11, 1988. I remember mission planning a B-52G training sortie that day when the entire 524th Bombardment Squadron building shook and vibrated just before 2:30 pm. We all ran to the edge of the flight line as dark clouds of smoke billowed up in the air while strong winds arced the fire and smoke over the front of the aircraft. We watched helplessly from a distance and listened to the radio chatter as frustrated firefighters emptied their firefighting foam. The firefighters were just finishing up training at the nearby fire pit and were on the scene in minutes. Six crewmembers lost their lives that day, including Captain William G. Russell who flew a B-52 mission with me the week before. William was a respected B-52G Radar Navigator and guest KC-135A crewmember that day. Ten passengers in the back of the aircraft from the 8th Air Force Staff Assistance Visit Team miraculously escaped out the back, as a fireball traveled overhead and curled back under their feet. In honor of our fellow warriors and fallen friends, their names are listed here; Captain Jeffrey Giles, Captain Gerald Earhart, Captain David Greene, Lieutenant Scott Szuter, Airman First Class Robert Parham, and Captain William Russell.

The approved Department of Defense firefighter foams made available to Wurtsmith while it was operational, were from the 3M Company, National Foam, and Tyco/Ansul. The 3M Company was the sole supplier from roughly 1967 to 1973. After 1973 and until Wurtsmith Air Force Base officially closed June 30, 1993, any three of the approved chemical manufactures could have made the firefighter foam constituents found in the former Wurtsmith Air Force Base aquifer today. The practice of disposing of fighter fire foam on the ground at Wurtsmith ended in 1992 after the Michigan Department of Natural Resources (MDNR) informed the base that butyl carbitol, making up roughly 20% of the firefighter foam mixture, was a pollutant. You don’t hear about this chemical. Butyl Carbitol is toxic to humans. Although butyl carbitol breaks down in the environment, it is likely that this chemical reached the water faucets on base in harmful amounts given the proximity of the wells to the firefighter foam disposal site. 

The active ingredient in the legacy firefighter foam was perfluorooctane sulfonate (abbreviated PFOS and pronounced ‘pea-foss’). The firefighter foam was sold containing 3% or 6% of fluorinated substances. Although PFOS was the desired chemical in the design of the military firefighter foam mixture, only 70% of the fluorinated substances created were actually PFOS. The other 30% were similar fluorinated substances like perfluorooctanoate (abbreviated PFOA and pronounced ‘pea-foe-uh’) and perfluorohexane sulfonate (abbreviated PFHxS). Studies record that no samples remain of the firefighter foam made prior to 1989 to determine the exact mixture of fluorinated substances released into the environment.  Even if we did have a sample to test, the composition of fluorinated substances in firefighter foam was different from year to year. This is partly because the Electrochemical Fluorination (ECF) process used to make PFOS was not pure. To complicate things further some of the larger fluorinated substances, once in the aquifer, broke apart to make different and smaller fluorinated substances. Knowing the exact fluorinated substances entering the aquifer is likely not as important as the composition and amount left behind in the aquifer.  What remains in the groundwater is a slow fading snapshot, an echo of the past, and a source of ongoing contamination as the poisons migrate into the Oscoda surface waterways and surrounding community wells.

What makes PFOS a special ingredient in firefighter foam is its surfactant quality. Surfactants are useful at home and in industry, designed to reduce the surface tension of a liquid in which it is dissolved. This quality is never more visible when PFOS is aerated or agitated in water to create a foam, which is visible today as boat motors and wave action creates a bright white foam on the surface and shores of Van Etan Lake bordering the former Wurtsmith Air Force Base. You are already familiar with the unique quality of surfactants because you use soap. The soapy bubbles you create in water attracts and binds with grease and dirt so you can rinse away the resulting soap-grime mix. Light Water acts similarly. PFOS bubbles in the firefighter foam bind with the surface of petroleum, creating a barrier between the petroleum and the air above. The petroleum can’t burn without oxygen.  Again, you can draw on your experience to understand this principal. If you throw plain water on a grease fire, the burning grease fire spreads everywhere as the burning grease, now on top of the water, spreads rapidly-a disaster! Throw water on a grease fire once, and you will never do this again. In comparison, aerating 3M’s AFFF concentrate with water creates a foam that rests (floats) on top of petroleum (burning or not). From the perspective of the casual observer, the PFOS treated water appears to float on top of the petroleum giving water the appearance it is now lighter than regular water. Hence the name, Light Water. 3M discontinued the use of PFOS and the like in 2002. Unfortunately, other US manufactures took advantage of 3M existing the market, but stopped making these substances by 2015, as the potential liability of health outcomes overtook any profit motive. A year later, the US banned the import of PFOS. It is hard to believe any government official or PFAS manufacturer can say with a straight face we have no evidence that the PFAS in these legacy firefighter foams are harmful to humans.

1970-2020: Oscoda Community: The second group of people harmed by the firefighter foam are the Oscoda Township families and visitors exposed to contaminates leaking past the former Wurtsmith boundaries, which continues to this day. Two of the larger PFAS groundwater plumes are impacting the surrounding communities and requires immediate action to stop the migration of the plumes into the surface waterways and community wells. 

The ‘Horseshoe Plume’ is the second largest plume and is being naturally drawn into Van Etten Lake, where agitated water from wave action and boats is creating a white foam with a PFAS concentration over 200,000 ppt. The white foam is visible along the lake’s recreational shoreline and is the most significant plume impacting the local community. The harm is not only environmental. Tourists and investors avoid the contaminated Van Etten Lake, which is 1) impacting the livelihood of local businesses (merchants and rentals); 2) destroying property values bordering the lake as well and reducing property values in the greater Oscoda area; 3) poisoning nearby community wells today and wells in the future as the plume continues to grow in size. The horseshoe plume was created by the disposal of AFFF from 1982 to 1992 (10 years). As of this writing the USAF has agreed to place a line of purge wells to prevent PFAS from being drawn into Van Etten Lake from the Horseshoe Plume.

The ‘Clark’s Marsh Plume’ is the largest plume and is being naturally drawn into the Ausable River leading to Lake Huron. The amount of PFAS in the marsh is egregious with concentrations in the 1,000,000 ppt and upward. This Plume is migrating to the Ausable River and is carried directly to Lake Huron. The environmental harm is off the charts as fish, bugs, flora, and wildlife consume and share the poison. The economic harm is in the wake of this poison as it travels to Lake Huron, impacting fishing, local businesses, house values, and community wells. The Clark’s marsh plume was created by the disposal of AFFF from 1972 to 1997 (25 years) from the base sewer system and is further impacted by PFAS from the fire pit plume. The Clark’s Marsh plume will be more challenging to contain and clean up and will likely require significant planning by government and local officials before deploying a viable purge system.

There are roughly five smaller PFAS plumes, slowly transiting the aquifer toward the surface waterways that will eventually require attention.