A joint venture between a Verona-based firm and a Canadian company has led to promising results in an expanding pilot project aimed at removing PFAS in targeted military and civilian sites at the Dane County Regional Airport on Madison’s East Side.
A three-part remediation process utilizing a bio-absorbent “sponge,” microbes that break down complex chemicals in soil and electrodes to generate oxygen supply reduced dangerous concentrations of PFAS in controlled, long-term tests on airport grounds.
The acronym PFAS is short for perfluoroalkyl and polyfluoroalkyl substances, of which there are about 4,700 different compounds worldwide. Two are known threats to human health when there is significant exposure in drinking water over time.
Those compounds are PFOA and PFOS, which was used in fire-fighting foam at the airport and the adjacent National Guard air base for training purposes beginning in the early 1970s until a decade or so ago. The chief danger from PFAS pollutants there comes from plumes that can reach water sources beyond the airport grounds.
Tests were conducted successfully in private laboratories in 2020 and 2021 and later in controlled conditions on a 1,600-square-foot test site at the airport and in separate holding tanks.
Progress demonstrated through the Dane County Regional Airport pilot was highlighted during the Water Council’s “Water Leaders Summit,” held Oct. 5-6 in Milwaukee. Data from the Dane County Airport grounds tests is being shared with the state Department of Natural Resources.
In addition, ORIN Technologies and its partner, Fixed Earth Innovations of Fort St. John, British Columbia, Canada, have been approached by federal elected officials and other researchers to learn more.
“Projects like this prove that Wisconsin continues to lead the way in water innovation, technology and stewardship. We are thrilled that innovation from two of our members could help protect the Great Lakes and other precious freshwater resources that are vital to our citizens,” said Dean Amhaus, president and CEO of The Water Council.
“While some people believe the most toxic PFAS compounds can never be remediated, this testing process is thus far indicating otherwise,” said Tom Still, president of the Wisconsin Technology Council. “These tests show use of aerobic technologies to remediate so-called ‘forever’ chemicals” can work at this scale, and potentially be scaled for broader uses in Wisconsin and beyond.”
The three-part approach has continually degraded PFAS effects in groundwater within the treatment areas. The average 97% removal rate is significant because of possible changes in existing U.S. Environmental Protection Agency rules at both the federal and state levels.
The process is aerobic versus anaerobic, meaning oxygen produced from the electrodes continues the removal process over time. The private remediation firms first used a combination of Bioavailable Absorbent Media (BAM©); an inorganic oxidant compound; and PFAS degrading bacteria in multiple injection locations.
BAM is a carbon-based “sponge” with a unique honeycomb-like structure that draws in contaminants, retains them, and minimizes surface microfilm buildup that could resist continued absorption. An electrokinetic system continues to supply oxygen to support microbial activity and PFAS degradation.
The EPA has set lifetime exposure maximum at 70 parts per trillion in drinking water. That’s based on drinking eight glasses of water, every day, for a lifetime. Such limits could be made stricter by regulators to fall between 20 parts per trillion and 4 parts per trillion, depending on varying state and federal approaches.
The testing was conducted through a joint venture, Onur Solutions, which is a partnership of ORIN Technologies and Fixed Earth Innovations.
Distributed through the Wisconsin Technology Council News Service.