If your drinking water comes from a public or private well, and you live near a military base, airport, factory, or landfill, there is a good chance your water contains PFAS chemicals. These so-called forever chemicals do not break down in the environment. They accumulate in the human body and have been linked to cancer, liver damage, thyroid disease, and other serious health problems. From a legal liability standpoint, PFAS contamination presents a straightforward but expensive problem: someone allowed these chemicals to get into the groundwater, and someone else now has to clean it up or pay for the damage. The law generally holds the party that caused the contamination responsible, but proving who that is and what they owe is where the real fight happens.
The main legal theory used in PFAS drinking water cases is strict liability. This means you do not have to prove that the company or government entity was negligent or intended to harm anyone. If they released PFAS into the environment and that release caused your water to become contaminated, they are liable. This is because PFAS are classified as hazardous substances under many federal and state environmental laws. The Comprehensive Environmental Response, Compensation, and Liability Act, commonly called Superfund, allows the Environmental Protection Agency to force polluters to clean up contaminated sites, including groundwater, regardless of whether they followed regulations at the time of the release. In court, a plaintiff only needs to show that the defendant’s PFAS got into the water and that the contamination levels exceed safety thresholds.
Negligence claims are also possible but harder to win. To prove negligence, you must show that the polluter knew or should have known that PFAS could harm people or the environment, and that they failed to take reasonable precautions. Given that PFAS have been used since the 1940s and studies showing their toxicity go back decades, many companies and government agencies had plenty of warning. If they did not install containment systems, treat their wastewater, or alert nearby residents, a court can find them negligent. This opens the door for compensatory damages for medical monitoring, property value loss, and even future health treatment costs.
Water suppliers themselves, such as municipal utilities, can also be held liable if they failed to filter out PFAS before delivering water to homes. Some states have set enforceable maximum contaminant levels for PFAS. A water utility that does not test for these chemicals or does not install the required treatment technology can be sued for negligence or even for violating the Safe Drinking Water Act. However, many water suppliers are now caught between a rock and a hard place. They did not create the PFAS problem but are forced to spend millions of dollars on new filtration systems while trying to pass the costs back to the original polluters through contribution claims or third-party lawsuits.
One major complication in PFAS liability is the sheer number of potential defendants. PFAS are used in everything from nonstick cookware to firefighting foam to waterproof clothing. The chemicals come from dozens of different sources, and groundwater moves slowly, so it can be difficult to trace contamination back to a single factory or air base. Courts often handle this by applying joint and several liability, meaning each defendant can be held responsible for the entire harm even if their share of the contamination was small. This is good news for a plaintiff because they only have to sue one deep-pocketed defendant, but it can lead to messy fights between defendants over who pays what share.
Another issue is government immunity. If a military base or federal agency released PFAS, you might think the government is off the hook because of sovereign immunity. But the Federal Tort Claims Act allows private parties to sue the federal government for certain types of negligence, and many states have waived immunity for environmental claims. Additionally, the government itself can be named as a responsible party under Superfund. Several class action lawsuits against the Department of Defense have already resulted in settlements for residents near contaminated bases.
Defendants typically try to avoid liability by arguing that the contamination came from many sources, that the plaintiff does not have enough specific evidence linking their water to the defendant’s product, or that current regulations did not require them to stop using PFAS at the time. They also raise the statute of limitations, claiming that the contamination happened too long ago. But because PFAS are persistent and still being released from landfills and wastewater, many courts have ruled that each day of continued contamination counts as a new harm, restarting the clock.
For anyone whose drinking water has tested positive for PFAS above the levels recommended by health agencies, the practical takeaway is clear. You do not have to prove that the polluter was bad or reckless. You only need to show that they put PFAS into the environment and that it ended up in your tap. Water suppliers can sue back, but the original manufacturers of PFAS—companies like 3M and DuPont—have already faced billion-dollar settlements. The legal system is slow, but the liability is real, and the costs are being shifted to those who profited from these chemicals.
