A Minneapolis startup just demonstrated 99.99% PFAS destruction on groundwater from a Minnesota Pollution Control Agency remediation site in Lake Elmo.
A Minneapolis startup just demonstrated 99.99% PFAS destruction on groundwater from a Minnesota Pollution Control Agency remediation site in Lake Elmo. The result is technically meaningful, but the more interesting story may be what it implies for the cost of cleaning up one of Minnesota's most persistent environmental problems.
PFAS contamination in the Twin Cities east metro is one of the largest groundwater pollution stories in the country. Beginning in the 1950s, PFAS-containing waste was disposed of at 3M disposal sites in Oakdale, Woodbury, and Cottage Grove, as well as the former Washington County Landfill in Lake Elmo. The chemicals leaked into local aquifers, eventually contaminating drinking water for an estimated 140,000 to 170,000 Minnesotans across a contamination area of roughly 150 square miles. In 2018, the State of Minnesota reached an $850 million settlement with 3M to fund drinking water remediation and natural resource projects in the affected communities.
Much of the response has focused on safe drinking water and long-term contamination management. Municipalities have extended water lines, installed granular activated carbon filtration, and switched contaminated wells to deeper aquifers. The technology works, but it does not destroy PFAS. It captures and concentrates the contamination, which then has to be sent somewhere else, typically a landfill or high-temperature incinerator. PFAS in a landfill remains PFAS. Incineration carries its own concerns about incomplete destruction and air emissions.
The unsolved problem in PFAS remediation has always been the final step: actually breaking the chemical down.
PFAS refers to a family of about 15,000 synthetic chemicals built around carbon-fluorine bonds. Those bonds are among the strongest in organic chemistry, which is also why these compounds are so useful. They repel water, oil, and stains, and they do not degrade. PFAS is found in firefighting foam, semiconductor manufacturing, nonstick coatings, food packaging, waterproof apparel, and thousands of other products.
The same persistence that makes PFAS commercially valuable makes it environmentally dangerous. The chemicals accumulate in soil, water, fish, and human blood. Studies have linked exposure to higher cholesterol, thyroid disease, immune suppression, and certain cancers. The Minnesota Department of Health has issued fish consumption advisories for Lake Elmo and dozens of other water bodies in the state, specifically because of PFAS levels.
Until recently, few technologies had shown a credible path to permanent PFAS destruction at field-relevant scale and cost, especially as part of an integrated remediation workflow.
Claros Technologies was founded in Minneapolis in 2018 and is based in Northeast Minneapolis. The company operates two divisions: ClarosLabs, an ISO/IEC 17025-accredited analytical laboratory focused on PFAS detection and quantification, and ClarosTech, which develops the destruction technology itself.
The core product is ClarosTechUV, a UV photochemical system designed to be deployed at the end of an existing capture-and-concentrate workflow. The process works in three stages. First, foam fractionation concentrates the PFAS from a large volume of contaminated water into a much smaller volume of high-loading concentrate. Second, filtration removes solids. Third, proprietary photosensitizer reagents are added, and the mixture is exposed to UV light. The reagents generate reactive species that cleave the carbon-fluorine bonds, converting the PFAS into inorganic fluoride, a measurable mineralized end product that can be managed as part of the treatment process. The system is designed as a closed loop, with reagents recycled back into the destruction process and clean water returned to the source.
The conceptual advantage is straightforward. Existing technologies separate PFAS from water but do not destroy it. ClarosTechUV is positioned as the final-step destruction technology that completes the cycle.
The Minnesota Pollution Control Agency provided Claros with 55 gallons of foam fractionation concentrate generated from the treatment of approximately one million gallons of contaminated groundwater and surface water from the Lake Elmo site. The raw concentrate was a difficult test sample. It contained roughly 28-30 mg/L of PFOS and 9-10 mg/L of PFOA, with total PFAS near 40 mg/L measured as total organic fluorine. The water was so turbid that UV transmittance was effectively zero.
Claros ran the concentrate through three reactor scales: a 0.1-liter small-scale reactor, a 1-liter bench-scale reactor, and a commercial-scale system that processed approximately 30 gallons of clarified concentrate. The commercial-scale results are the most relevant for real-world deployment.
The performance held, and in some cases improved, as the system scaled. According to the technical summary, Claros attributes this to higher UV photon density per unit volume in the commercial reactor design, which is a significant finding because many environmental treatment technologies degrade in performance when moved out of laboratory conditions.
The destruction percentage is a technical milestone. The cost figure may be the more important data point for the broader market. According to the white paper, the destruction step costs less than the energy alone used by the upstream foam fractionation step. That is a meaningful change in the economics of PFAS remediation.
The current model in the east metro and across the country is that PFAS is captured, then managed indefinitely. The captured material remains a liability, and the management cost continues for as long as the contamination persists, which for PFAS is effectively forever. If destruction can be done at a small fraction of the capture cost, the economics shift toward permanent remediation rather than indefinite management.
The order of magnitude is what matters. Claros says it has now treated more than one million gallons of PFAS-impacted water across laboratory, pilot, and commercial deployments, including a 170,000-gallon optimization run with Daikin America in late 2025. The Lake Elmo study extends that record into groundwater remediation, which is a much larger addressable market than industrial process water.
There is a quiet symmetry in this story that is hard to miss. The contamination was created in Minnesota, by a Minnesota company, in plumes that affect Minnesota drinking water. The settlement is administered by Minnesota agencies. And the company demonstrating destruction at commercial scale is also based in Minnesota, with its commercial reactor tested on water from one of the remediation sites tied to the original 3M plume.
As permanent PFAS destruction becomes a commercial market, Minnesota has a credible claim to being the place where it was first demonstrated at a meaningful scale.
The full Claros technical summary is available on the Claros Technologies website. The original article is here
