Introduction of PFAS/AFFF to Wurtsmith Air Force Base Groundwater Contamination 1970-1997

Wurtsmith Air Force Base firefighter foam groundwater contamination began in the early 1970s when Aqueous Film Forming Foam (abbreviated AFFF and pronounced ‘a-triple-eff’) first became available. Formulated by 3M specifically for the military, the firefighter foam’s active ingredients are Perfluorooctane Sulfonate (PFOS for short and pronounced ‘pea-foss’), Perfluorooctanoic Acid (PFOA for short and pronounced ‘pea-foe-uh’), Perfluorohexane Sulfonate (PFHxS for short), and roughly sixteen more similarly constructed molecules. The perfluoroalkyl molecules found in the AFFF used at Wurtsmith are only a handful of the similar 4000+ molecules manufactured world-wide for other uses and are collectively called Perfluoroalkyl Substances (PFAS for short and pronounced ‘pea-fass’). The PFAS in AFFF is colorless, odorless, tasteless, and is virtually indestructible in nature, earning the nickname “Forever Chemical”.

Beginning in the early 1980s and for roughly 10-years, firefighter foam was routinely dumped in the grassy areas off the edge of the concrete taxiways (operational apron) on the southeast side of the runway, not far from the fire station. From the surface of the ground, the firefighter foam descended into the aquifer, flowing naturally toward Van Etan Lake and creating a contamination footprint (horse-shoe plume) that remains in the soil strata today. A few years later in March and April of 1985, three new main-wells were put in service a short 500-yards downstream in the aquifer from this active disposal site. The new wells named AF30, AF31, and AF32 supplied the main drinking water for the base via the water tower, which was augmented during peak demand by four nearby supplemental wells. In addition to the “horseshoe plume,” a record of PFAS in the abandoned base water system was discovered in water trapped in fire hydrants and equipment before the main water supply was switched over to a local city water source. The practice of dumping firefighter foam off the edge of the concrete taxiways abruptly ended in 1992 when scientists discovered butyl carbitol, a chemical making up 20% of AFFF, was harmful to humans. As such, the peak base-wide distribution of PFAS and butyl carbitol through the main water supply system lasted 7-years (From 1985 through 1992). Significant residual amounts of PFAS continued to enter the main water supply system for an additional 5-years, until the final 1997 cutover to city water. For 15-years (From 1985 to 1997), PFAS laden tap water entered the drains to continue its journey to the sewer treatment plant where the PFAS was discharged into Clark’s Marsh leading to the Ausable River. The sewer systems sludge and aeration equipment were removed in 1996 and 1997.

The PFAS concentrations from PFOS, PFOA, and PFHxS in 2018/2019 blood samples from two Wurtsmith veterans living on base during the peak 1985 to 1992 PFAS main water supply contamination was ~24,000 parts-per-trillion (ppt). A concentration 3.5X higher than the national average today. Applying a well-known pharmacological equation, our two veterans left Wurtsmith with a staggering blood serum concentration of ~4,000,000 ppt. Based on their tour of duty at Wurtsmith, their average daily exposure was likely 65,000 ppt. This is well above the EPAs daily exposure limit of 70 ppt for PFOS and PFOA combined. In comparison, you would need to consume 70 ppt a day for 30 years to reach a blood serum concentration of about 10,000 ppt. Of particular note is the high concentration of PFHxS in our two veterans, which is 18X higher than the national average today. PFHxS is a likely marker in blood for past exposure to military AFFF.

Drinking water from area specific or stand-alone wells resulted in untold PFAS contamination of those living on base. 

1. Stand-alone well AF22 supplied water to Burkhart Lodge, the visitation center for crews on alert through September 27, 1991. In January 1989, A 500-gallon tank of concentrated AFFF next to building 5306 in the weapons storage area, cracked. The entire 500-gallons of AFFF concentrate entered the groundwater and passed through well AF22 on the way to Van Etten Lake. A couple of years later in 1991, firefighter foam was sprayed during a malfunction of a hangar fire suppression system. The foam was pushed outside the hangar onto the ground.

2.  Stand-alone well AF25 supplied water to the Jet Engine Test Cell (Building 5098) built in 1972. This well was less than 250 yards from the fire pit with a recent recorded peak PFAS concentration of 1,200,000 ppt. The fire pit was a gravel burn pit from 1958-1982 and was replaced by a concrete pit with an oil/water separator after 1982. After the oil was skimmed for disposal, the PFAS laden water went to the sewage treatment plant and was ultimately discharged into Clark’s Marsh leading to the Au Sable River. In 1998, all of the base wells were officially abandoned except AF25, which is used for non-potable purposes today. Per ATSDR 2001 Public Health Assessment, there is no longer an occupant at facility 5098. The building is now being used to store equipment for the fire pit’s new remedial system. Before the oil/water separator was installed in 1982, the open gravel fire pit sprayed AFFF during training from ~1972 to 1982 (10 years) creating an AFFF plume leading to Clark’s Marsh and ultimately the Au Sable river.

3.  Four (4) stand-alone wells supplied water to the Air Force Beach. Well AF7 serviced the North Cottage and well AF8 serviced the South Cottage. Well AF14 serviced building 1135 and the well is roughly collocated with well AF23. All the Air Force Beach wells were contaminated with PFAS from the firefighter foam originating from the Horseshoe Plume.

Three pump and treat plants were installed from 1977 to 1992 to remove volatile chemicals from the groundwater. In the process of drawing water in the aquifer to the many pump and treat system purge wells, PFAS was spread over a larger area underground. In addition, PFAS laden water was pulled out of the ground for thirty to forty years and disposed of in the surrounding lakes, rivers, creeks, marshes, and swamps. 

1. The Arrow Street Pump and Treat System (ASPTS) was developed incrementally beginning in 1977. The purge water was piped to the water treatment system until 1981. In 1982 the Michigan Department of Natural Resource (MDNR) issued a direct discharge permit allowing the purge water to be discharged to the storm sewer leading to Tucker’s Swamp and Van Etan Creek on way to the Ausable River. PFAS is being drawn from the Horseshoe Plume.

2.  The Mission Drive Pump and Treat System (MDPTS) was installed in the mid 1980s and is drawing PFAS in the aquifer from an AFFF plume from outside hanger 5063 where firefighter foam was dispensed during system testing in 1991 and hosed out of the facility.

3.  Benzene Plant Pump and Treat System (BPPTS) was installed in 1992 and is drawing PFAS from the Horseshoe Plume.