When the U.S. government turned over more than 600 acres of the former Loring Air Force Base to the Aroostook Band of Micmacs in 2009, the land was so polluted it was categorized as a federal superfund site.
While many of the toxins have been removed, concerning levels remain in the soil and water.
It turns out that when it comes to neutralizing at least one group of toxic chemicals, the solution may be planting cannabis. Lots of it.
Ongoing research by members of the Micmac Nation and the group Upland Grassroots, along with scientists in Connecticut and Virginia, is looking at the ability of industrial hemp to extract perfluorooctanesulfonic acid — PFOS — from the soil.
PFOS, along with inorganic per- and polyfluoroalkyl substances, or PFAS, are often referred to as “forever chemicals.” They are used in industrial and household products and have been found to pose health risks in humans.
The research explores one possible way to address the worsening problem of forever chemicals across the state. Dangerous levels of PFAS and PFOS have been found in Maine’s deer meat, chicken eggs, dairy milk, soil and groundwater. Those discoveries have left health and resource agencies scrambling to find ways to identify, mitigate and remove the health hazards. If it works, planting hemp would be the first known solution for absorbing forever chemicals from soil.
David Madore, deputy commissioner of the Maine Department of Environmental Protection, said the research fits in well with ongoing work at his department.
“The DEP is actively looking for ways to manage, treat, and dispose of PFAS in soils because there is no clear and cost effective solution at this time,” Madore said. “With the research being done at Loring, hemp may turn out to be an option [and] we support this and other efforts to find a solution to the PFAS problem and welcome opportunities for future collaboration.”
In their research, the group at Loring planted several small plots of industrial hemp in soil known to contain PFAS and PFOS. Once the hemp had matured, it was harvested and sent to Sara Nason at the Connecticut Agricultural Experiment Station, a state-run scientific research facility.
“The idea was to see if fiber hemp can clean PFAS from the soil at Loring and find out what the hemp does with the chemicals,” Chelli Stanley of Upland Grassroots said.
Using plants to extract toxins and heavy metals from the soil is known as phytoremediation. Stanley co-founded Upland Grassroots specifically to look at ways to use hemp for that process.
The concentration of PFOS in the soil decreased in the Loring hemp plots, according to Nason. Data also showed that several PFAS chemicals had accumulated in the hemp plants’ tissue.
Loring Air Force Base in Limestone was closed in 1995 under the federal base realignment and closure act. The land reinstated to the Micmac tribe included a tank farm of five fuel storage tanks that held 13 million gallons of jet fuel, and a coal handling station.
There are more than just PFAS and PFOS chemicals at Loring, but Stanley said they were selected because they fit in with existing research at the Connecticut Agricultural Experiment Station.
Richard Silliboy, vice chief of the Micmac tribe, said the tribe wants to know the extent of the pollution at Loring.
“Some of that land that was given to us by the Air Force was very questionable,” he said. “They say they did a lot of cleaning up, but no one really knows what their idea of cleaning up was.”
The Maine Department of Environmental Protection is still inspecting how widespread the problem is, having identified 34 municipalities around Maine for PFAS sampling between now and 2023.
The agency is focusing its investigation on soils and private well groundwater. Where dangerous levels are found in private groundwater, the state will supply homeowners with bottled water until an appropriate filtration system can be installed.
The Legislature has set a deadline for all testing by the end of 2025. Meanwhile, state officials are conducting more tests on deer throughout the state.
The Maine Center for Disease Control and Prevention will continue to test dairy, poultry and other food items as needed where dangerous levels of PFAS and PFOS are identified.
“We have met with state environmental and agriculture officials to talk about hemp as a solution,” Stanley said. “They are really interested and it’s amazing to me how proactive they are being in wanting to get this under control.”
The next step is determining where in the hemp plant the chemicals end up, and what happens to them.
“We need to find out if the plant breaks the chemical down,” Stanley said. “Or if it just sequesters it, is there a solution to get the chemicals by using the hemp for something?”
Researchers plan to follow up by planting a much larger crop of hemp this summer at Loring. The size of the plots was limited by the amount of water researchers could haul in. The water at Loring was too polluted to use.