The city of Hastings in Minnesota has sued 3M over alleged PFOA contamination in five public drinking-water wells, claiming emissions from the company’s nearby Cottage Grove plant polluted groundwater serving about 23,000 people.
The civil complaint, filed in Dakota County District Court on 26 August, seeks to recover the cost of treating the water and alleges that 3M knew for decades about the health and environmental risks associated with perfluorooctanoic acid, or PFOA.
Hastings operates six wells and supplies water to more than 7,500 customers. The city says five are above the US Environmental Protection Agency’s enforceable limit of four parts per trillion for PFOA and PFOS, introduced in April 2024.
Hastings sues 3M over water treatment costs
The city is planning three treatment plants using granular activated carbon and ion-exchange filters. Hastings estimates the construction bill at about $69 million, with a further $1 million a year needed to operate the systems.
Construction on the first plant began in 2025 and, subject to funding, the three facilities are expected to be completed by late 2027 or early 2028, according to information published by the city.
Hastings says it is bringing the claim because existing financial support will not cover the full cost of protecting its water supply. The city has already received or expects to receive money through Minnesota’s 2018 settlement with 3M, but says further funding is needed.
A 2025 report by the Minnesota Pollution Control Agency found sufficient evidence to trace contamination in Hastings’ Well No. 5 to 3M’s Cottage Grove site. The report said Well No. 5 was the only Hastings well to have received that designation at the time, while investigations into the others continued.
Alleged route of PFOA contamination
The lawsuit claims 3M manufactured PFOA at its 865-acre Cottage Grove facility from the 1940s until 2002 and produced more than 2.5 million pounds of finished goods there between 1976 and 1998.
Hastings alleges that the plant released substantial quantities of the chemical through smokestacks and other air emissions, at a time when effective controls were not in place. The complaint cites an internal meeting in 1978 which allegedly recorded that the production cells had no air scrubbers.
It also refers to figures reported by the Agency for Toxic Substances and Disease Registry, which said 3M had estimated that 1,950 pounds of PFOA compounds were released from vent stacks at the plant in 1997 alone.
According to the city’s account, the wells lie south-east of the factory and prevailing winds carried PFOA towards Hastings. The chemical was allegedly deposited on the ground before seeping through porous soil into shallow groundwater supplying the wells.
The complaint further points to the chemical composition found in Hastings’ water, arguing that the presence of both linear and branched forms of PFOA is consistent with material manufactured by 3M.
PFOA is a synthetic substance that can persist in the environment for long periods. The EPA says exposure to PFOA and related PFAS chemicals has been associated with serious health effects, including some cancers, liver damage and impacts on the immune and developing systems.
3M rejects city’s decision to litigate
3M said the lawsuit was “unfortunate” and argued that it had led efforts to address PFAS contamination.
The company said it stopped manufacturing certain long-chain PFAS in 2000 and had completed its commitment to end all PFAS manufacturing worldwide by the end of 2025.
It also pointed to an $850 million commitment made in 2018 to mitigate PFAS contamination in Minnesota, including in communities in the state’s east metropolitan area. In 2024, 3M announced a $10.3 billion commitment to help public water suppliers across the United States which had detected PFAS or did so in future.
“3M remains willing to engage with the City to discuss any legitimate concerns it may have,” the company said.
The lawsuit also cites 3M’s position that trace levels of PFOA in Hastings’ wells are safe based on decades of research and that studies show no adverse effects at the low levels found in people and the environment.
The claims made by Hastings have not been tested at trial. The case will determine whether 3M is legally responsible for the contamination and the city’s treatment costs.
