BEMIDJI, Minn. — Efforts by the city of Bemidji to address chemicals found in groundwater are continuing.
The Bemidji City Council on June 21 approved an incentive program for 19 property owners in the Bardwell Park neighborhood. To the west of the neighborhood is an area owned by the city with several wells providing water to the municipal system.
For more than a decade, the city has been aware of chemicals, commonly referred to as PFAS (perfluorinated alkylated substances), in that area's groundwater and subsequently, in the wells. The chemicals were formerly used in firefighting foams and likely originated at the adjacent Bemidji Regional Airport, which has been a training ground for local fire departments.
According to a statement from the Minnesota-based company 3M, the developer of the chemicals, the type of PFAS in Bemidji is called AFFF (aqueous film forming foam). The specific chemical was developed by the United States Navy in the early 1960s with support from 3M.
"It was a critical tool that served an immediate need for our service members facing life-threatening challenges in live combat missions and training exercises during the Vietnam War," 3M stated.
The risks that come from PFAS are still under review by health agencies and scientists, but studies have been done over the last two decades.
3M in a statement said "the weight of scientific evidence from decades of research does not show the PFOA (perfluorooctanoic acid) or PFOS (perfluorooctane sulfonic acid) cause harm in people at current or past levels. This includes studies monitoring 3M employees, who were typically exposed to higher levels of these materials than the general population.
"Public health data support this conclusion," 3M said. "For example, the Minnesota Department of Health has tracked the levels of PFAS in the blood of residents of the east metro area since 2008. In February 2018, after a decade of study, MDH provided an update on its findings, reporting that the overall cancer rate in Washington County was virtually identical to the statewide average, notwithstanding historically elevated levels."
On its website, though, MDH does note that in some studies, higher levels of PFAS in a person's body were associated with higher cholesterol, changes to liver function, a reduced immune response, thyroid disease and increased kidney and testicular cancers.
"It's a very large group of chemicals and some of them can accumulate in humans," said MDH Toxicologist Helen Goeden. "On health effects, we have some information on epidemiology studies. They look at humans who have been exposed to these compounds. There are challenges in evaluating humans because it's not a controlled study and some of the effects we think are linked to PFAS have other causes."
The causality of health impacts is something not yet proven and was cited in 3M's communication. As part of its statement, 3M referenced the following quote from the Centers for Disease Control and Prevention's Agency for Toxic Substances and Disease Registry: "Although a large number of epidemiological studies have examined the potential of perfluoroalkyls to induce adverse health effects, most of the studies are cross-sectional in design and do not establish causality. Based on a number of factors, the available epidemiological studies suggest associations between perfluoroalkyl exposure and several health outcomes. However, cause-and-effect relationships have not been established for these outcomes."
Additionally, 3M states "while some studies may find links or associations with possible health outcomes, this is not the same as causation."
According to Goeden, causality is difficult to demonstrate in humans.
"We're not taking people and putting them in a controlled environment where the only thing they're exposed to is the PFAS compounds, we can't do those studies," Goeden said. "Additionally, some of the health effects, like cholesterol, are impacted by diets.
"Immune suppression is one of the effects that we have the strongest weight of evidence because we see it in multiple epidemiology studies with humans," Goeden said. "If you see something consistently and repeatedly in different populations and it seems to be associated with the same exposure, it adds to the weight of evidence. It's like cigarette smoking and lung cancer. It takes a certain amount of evidence before you can come close to saying 'we believe these two dots are connected.'"
On the CDC's website related to the matter, the agency states that while it's difficult to show the substances cause health conditions in humans, "scientific studies have shown that exposure to some PFAS in the environment may be linked to harmful health effects in humans and animals."
According to Goeden, the chemicals have the biggest impact when they build up over several years.
"If exposed over a long period of time, we have clear evidence that the accumulated chemicals are transferred through the placenta to a fetus," Goeden said. "It can also be transferred through breast milk for infants. Because it's accumulated, it can be more significant. The water guidance we have developed for PFAS over time has been based on keeping levels in infants lower."
In 2000, 3M made the decision to phase out production of PFAS, including products relying on AFFF.
In 2018, the state of Minnesota settled a lawsuit against 3M for $850 million. The case was launched in 2010, alleging the company's production of PFAS had damaged drinking water and natural resources in the Twin Cities metro area. According to a state-operated website, after legal expenses, $720 million from the settlement will be invested in water projects in the Twin Cities.
During the years of the lawsuit, the city of Bemidji was made aware of new health and environmental standards related to PFAS set by the state. In response, the city began exploring options, such as drilling a new well.
Because no suitable alternatives were found, the city moved forward with a facility to remove the chemicals being pumped from the wells. To assist with construction costs, the city was awarded $10.19 million from the state Legislature in the form of a 2020 bonding bill. Around the same time as the bonding bill was passed in a fall special session, the city took legal action against 3M.
In March, a settlement was reached between the city and 3M, with the company contributing $12.5 million to the treatment facility and related costs. One of those costs is the incentive program approved by the council.
Remediation and monitoring
3M said it has "voiced support for regulating PFOA and PFOS under the Safe Drinking Water Act, including establishing maximum containment levels that are rooted in rigorous, reliable science."
On its website, 3M notes that it has invested more than $200 million in global PFAS remediation action. This includes testing and cleanup in areas where PFAS were manufactured and disposed of.
"The levels of PFOA and PFOS in people are declining," 3M stated. "Reduced exposure to these materials is evidenced in a series of studies that have occurred over the past 15 years involving the measurement of these compounds in the blood of the U.S. general population."
Todd Johnson, an engineer for the MDH's Drinking Water Protection Program, said five municipal systems across the state are actively removing PFAS. Moving forward, Johnson said the agency is looking to test more of Minnesota's waters for the chemicals.
"As we've learned more about these chemicals, our guidance has changed, meaning more communities are impacted," Goeden said. "Our message is that these are ubiquitous and here in Minnesota they've been on our radar for some time. We've devoted a lot of resources to looking at these compounds and trying to make sure we protect the citizens of the state."