More widespread groundwater and surface water contamination has been discovered on and near the Duluth Air National Guard base from the chemicals known as PFAS — the stuff left behind by firefighting foam, nonstick cookware, Scotchgard and other products.
Several sites on and near the base now exceed state standards for human health for PFAS levels, and one homeowner near the base is getting bottled water from the state after levels found in the home's well exceeded state standards.
The findings were highlighted in a 442-page report by a private contractor, Los Angeles-based AECOM, produced for the Department of Defense and given to the Minnesota Pollution Control Agency earlier this year. The report was obtained by the News Tribune through a public information request.
The initial investigation found enough PFAS, believed to be a human carcinogen, so that a follow-up investigation will be conducted, base officials said. But the Duluth site is just one of hundreds of military bases across the nation that has problems with PFAS chemical contamination, so-called "forever chemicals" because they never break down in the environment or in human tissue. It remains unclear when the additional study will be conducted, let alone any cleanup if that is warranted.
In an Aug. 27 letter to U.S. Air Force officials regarding the Duluth base contamination, PCA officials said they agree that the initial investigation “indicates significant releases of the PFAS contaminants” related to firefighting chemicals used on the base that “further investigation and response actions are necessary."
It’s been known for years that PFAS chemicals are found in aircraft firefighting foam, which has been used extensively for training at the Duluth base for decades. Officials at the 148th Fighter Wing of the Minnesota Air National Guard that operate the base say they are moving to eliminate the foams containing PFAS chemicals.
“The higher concentrations of PFAS have been detected near suspected source areas,” namely where the foams were used and stored at the air base, which opened in 1948, said Mark Elliott, who is tracking the issue for the Minnesota Pollution Control Agency. The Air Force has provided the PCA with a full copy of the report and has been cooperating with state officials as the process moves forward.
Traces of the chemicals were found in a nearby creek leading north out of the base and in Rice Lake, just north of the base, more than a decade ago. Now the stuff has been found underground near several structures on the base itself. It’s also been confirmed again in Rice Lake and now in Miller Creek, in underground water in the area and in surface water ponds, swamps and creeks on and near the base.
“The concentrations of PFAS chemicals detected in many of the groundwater samples and surface water samples on the base exceed the (state of Minnesota’s) health-based guidance values,’’ Elliott noted.
“We’d definitely like to see more investigation into how its spreading to streams and groundwater off-site,’’ Elliott added later.
The contamination also has infiltrated one well for a private home north of the airport at levels above those considered safe for humans to consume. The homeowner has been provided with alternative drinking water by the PCA. The PCA and Minnesota Department of Health have been sampling nearby private drinking water wells since 2010. With the exception of the one well, “all wells sampled so far have concentrations below MDH’s health-based guidance values for PFAS,’’ Elliott said.
The Duluth base will have to get in line if and when funding is approved for additional study and cleanup on military sites. In September, military leaders told Congress that “forever chemical” contamination costs are likely to surpass their original $2 billion estimate as Congress works to push the Department of Defense to clean up contaminated water near bases across the country.
The Department of Defense has identified at least 425 military sites where water has been contaminated by PFAS in levels above federal standards. But there are another 401 military installations where lower levels of PFAS remain in the water that may be above state but not federal standards.
The followup study at the Duluth base, called a remedial investigation, “will be nationally ranked based on a risk assessment, and addressed with funding after all the SI reports (nationally) are complete with consideration to the risk levels to human health,’’ Maj. Ryan Blazevic, bio-environmental engineer for the 148th, told the News Tribune.
Both the Environmental Protection Agency and Congress have been mulling new PFAS actions, but neither have formed any formal plan as yet. The groups called on elected officials at the state and national levels to take quick action to stop the flow of chemicals into the environment and keep the chemicals away from humans and wildlife.
Studies have documented multiple effects, including cancers in highly exposed groups — especially testicular and kidney cancers — as well as impacts to the immune system and metabolism. Evidence also indicates that elevated PFAS in wildlife can lead to developmental and reproductive problems, the groups noted.
In the Great Lakes region, elevated levels of PFAS have been found in insect-eating birds such as tree swallows, in deer, in fish and in fish-eating birds including great blue herons and bald eagles. PFAS chemicals have spurred fish consumption advisories in some areas and, in Michigan, a do not eat advisory for deer meat in at least one county because a local wetland is contaminated with PFAS.
Other Minnesota contamination
Small amounts of PFAS also have been found in some wetlands and creeks, and some private drinking water wells, in western Duluth near the aircraft firefighter training facility operated by Lake Superior College. Minnesota Pollution Control Agency officials say those chemicals were below safe drinking water standards and are no longer being used at the site. It appears the PFAS chemicals were only used there from 1994 to 1996.
“Based on the sediment and water samples collected during this assessment, the elevated levels of PFAs detected in the creek and wetland sediment and surface water samples do not appear to be impacting the nearby drinking water supply wells at or above drinking water standards,’’ PCA officials concluded in a 2011 report on the issue.
Several other sites statewide also have been targeted for testing due to PFAS contamination near fire training facilities and airports.
Advancing sensing technology has allowed scientists to detect the stuff at much smaller concentrations. In April the Minnesota Department of Health lowered the health-based advisory values to 15 parts per trillion, down from the previous level of 27 parts per trillion set two years ago. The levels are used to determine whether water from public systems and private wells is safe to drink.
Since 2002, state officials have issued nearly 1,100 private well advisories due to PFAS levels.
Minnesota's 3M Company manufactured PFAS at its plant in Cottage Grove, Minn., for decades beginning in the 1950s. 3M legally disposed of waste containing PFAS in landfills in the eastern suburbs of the Twin Cities metro area. The chemicals leached into the groundwater in nearby cities like Woodbury, Oakdale, Cottage Grove and Lake Elmo. The state sued 3M in 2010 and the case was settled in 2018 when 3M agreed to pay $850 million to provide safe drinking water and clean up contamination near its eastern Twin Cities manufacturing facility.
The Wisconsin Department of Natural Resources last week reported that PFAS chemicals have contaminated creeks in Dane and Monroe counties as well as portions of the Mississippi, Wisconsin and Menominee rivers. The DNR said it will release PFAS data on the St. Louis River in coming weeks.
What are PFAS?
Per- and polyfluoroalkyl substances (PFAS) are a group of chemicals that includes PFOA, PFOS, GenX and many other chemicals. PFAS — commonly associated with fire-retardant chemicals and non-stick cookware — have been manufactured and used in a variety of industries around the globe, including in the United States, since the 1940s. PFOA and PFOS have been the most extensively produced and studied of these chemicals. Both chemicals are very persistent in the environment and in the human body — meaning they don’t break down and they can accumulate over time. There is evidence that exposure to PFAS can lead to adverse human health effects.
Studies indicate that PFOA and PFOS can cause reproductive and developmental, liver and kidney, and immunological effects in laboratory animals. Both chemicals have caused tumors in animals. The most consistent findings are increased cholesterol levels among exposed populations, with more limited findings related to low birth weights for infants, effects on the immune system, cancer and thyroid hormone disruption.
PFAS can be found in:
- Food packaged in PFAS-containing materials, processed with equipment that used PFAS, or grown in PFAS-contaminated soil or water.
- Workplaces, including production facilities or industries (e.g., chrome plating, electronics manufacturing or oil recovery), that use PFAS.
- Living organisms, including fish, animals and humans, where PFAS have the ability to build up and persist over time.
Source: U.S. Environmental Protection Agency