The chemicals—linked to cancer, thyroid disease, and ulcerative colitis—have been detected in a type of fertilizer used on farms throughout the state. The photo shows a cow munching on grass in a field.
(Photo by Waldemar Brandt/Unsplash)

Editor’s note: This story is part of an ongoing collaboration between Environmental Health News and PublicSource on PFAS contamination in Pennsylvania and was funded in part through the Bridge Pittsburgh Media Partnership.

In 2016, Fred Stone made a discovery that threatens to ruin the Maine dairy farm that’s been in his family for more than a century: His cow’s milk contained exorbitant levels of chemicals that have been linked to illnesses including cancer, thyroid disease, obesity and ulcerative colitis.

“Since our nightmare started in November of 2016, our losses have been running between 415 and 425 dollars a day, 365 days a year,” Stone, 63, told EHN. “Before all this, my wife and I had been hoping to retire soon.”

“I can’t overstate what kind of toll this has taken on my family and my farm and myself,” he added. “This has ruined our lives.”

The chemicals contaminating Stone’s milk were PFAS (per- and polyfluoroalkyl substances), a class of chemicals that includes more than 4,000 individual chemicals with similar properties. The Maine Department of Environmental Protection (DEP) announced earlier this year that they’d traced the source of the contamination to Stone’s use of biosolids—a fertilizer made from treated sewage sludge—on the fields where he grows hay to feed his cows. 

Stone was shocked. 

“The last time we applied biosolids was in 2004,” he said. “That’s over 15 years ago. But I found out they call these things ‘forever chemicals’ for a reason. They layer and build up over time.”

PFAS have been used in products like stain- and water-resistant clothing, nonstick pots and pans, firefighting foam, carpets and furniture. They don’t break down naturally, and are increasingly showing up in drinking water throughout the United States as a result. 

PFAS contamination of food is an emerging threat. In addition to being detected in dairy milk in several states, a recently-released study revealed the Food and Drug Administration has found PFAS compounds in everything from sweet potatoes, leafy greens and pineapples to seafood, meat, and chocolate cake, and experts say the use of contaminated biosolids on farm fields is likely a primary source of food contamination. Produce grown in soil contaminated with PFAS uptake the chemicals into their roots, fruit, and leaves, which humans and animals eat.

PFAS can find their way into biosolids through contaminated water used in sewage treatment plants, contaminated waste entering sewage treatment plants from industrial sites that use the chemicals in their operations, or from contaminated feces and urine that’s been excreted by people drinking contaminated water or eating contaminated food. 

Pennsylvania has already identified at least 23 sites of PFAS contamination, and officials are struggling to address the threat of contaminated drinking water throughout the state. A DEP spokesperson told EHN that given the agency’s limited resources, the Pennsylvania PFAS Action Team hasn’t even begun to consider tackling potential food contamination yet. 

Meanwhile, the use of biosolids in the state is widespread: Approximately 94,000 dry tons of biosolids from 51 sewage treatment plants, many of which are located near known or suspected sites of PFAS contamination, were applied to farm fields throughout Pennsylvania in 2018 alone. None of it was required to be tested for PFAS. 

Since Pennsylvania launched its biosolids program in 1989, at least 750,000 tons of biosolids have also been applied to more than 4,500 acres of land across the state through the mine reclamation project. None of that material has been tested for PFAS either, and experts believe that if contaminated, those biosolids could potentially contribute to contaminated water and food throughout the state.

Biosolids and PFAS contamination in Pennsylvania

Click the arrows in the upper left to see the map’s legend. View an interactive version of this map. Learn more about the data.

(Credit: Map by Jared Kohler)

“PFAS-laden biosolids pose a risk for runoff, and many reclaimed mines are later farmed, so that could be another potential route of PFAS contamination,” said Colin O’Neil, legislative director for the Environmental Working Group, a nonprofit that conducts research and advocacy related to environmental health and conducts extensive research on PFAS.

“Diet is believed to be one of the major sources of PFAS contamination in humans,” O’Neil told EHN, noting that tainted food packaging or the use of contaminated water in food production can also result in PFAS in food. 

“Biosolids aren’t the only source of food contamination, but they’re likely a major one. Roughly seven million tons of biosolids are produced in the U.S. each year. Nearly half of it is applied to fields, and there are currently no federal regulations requiring PFAS testing. It’s pretty alarming.”

In Maine, following the discovery that biosolids were to blame for tainted dairy milk, legislators temporarily halted all land application of biosolids, set an enforceable limit for PFAS in milk, and started testing milk from a handful of sludge producers from across the state to assess the scope of the problem. The full results of that testing aren’t in yet, but at last count, sludge at 18 out of 22 producers tested exceeded the state’s threshold for PFAS contamination.

PFAS contamination is most commonly seen in waste from industrial sites in industries associated with the chemicals’ use, like paper mills, electroplating facilities, tanneries, and carpet manufacturers. But municipal waste can also become contaminated.

“It’s possible for PFAS contamination to show up in a sewage treatment plant if their pipes connect to any residential areas where PFAS contamination has occurred,” O’Neil said. “Water is interconnected, and we know that most drinking water and wastewater treatment plants are ill-equipped to filter out PFAS chemicals.”

Some states have also issued “Do Not Eat” warnings after high levels of PFAS were detected in fish and deer near known sites of contamination. The Pennsylvania DEP is not equipped to address that issue at this time, either, Elizabeth Rementer, a spokesperson for the agency, told EHN.

“Because this is a relatively new issue in the area and, until recently, our lab could not analyze for PFAS, testing for PFAS in fish, game, biosolids or sludge for PFAS contamination is not part of our Water Quality Network sampling program at this time,” Rementer said. She added that there are currently no EPA-approved methods for testing PFAS in fish, game, biosolids or sludge. 

In the city of Geneva, IL, fertilizer supplements are provided to local farmers at no cost through the City Land Application of Biosolids Program. (Photo by City of Geneva/Flickr)

In Maine, officials sent all of their samples to a California-based laboratory, Vista Analytical, which remains one of the few facilities in the country equipped to perform this kind of analysis. They also published information on their analysis methods and a list of all the labs the Maine DEP has approved to perform PFAS testing of water, soil and biosolids.

If a producer of biosolids wanted to test biosolids for PFAS before releasing them to farms, Rementer said, they “could contract with a lab to perform the testing.”

The widespread use of biosolids that have never been tested for contamination makes it virtually impossible to avoid PFAS in food—even if you’re only eating organic.

“It’s pretty much impossible to shop your way out of potential PFAS contamination,” said Patrick MacRoy, the deputy director of the Environmental Health Strategy Center, a Maine-based nonprofit that helped bring the issue of PFAS in dairy milk to light. “While organic farms cannot use sludge, prior to the conversion from conventional to organic, sludge could have been applied. The incredible persistence of PFAS means they could still be impacting those now organic farms.” 

He added, “I suppose one could try to identify and buy direct only from farms without a history of any sludge application, but that’s obviously not a practical solution. What is more practical is for consumers to insist that governments actually test farms, agricultural products, and not allow the use of contaminated sludge.”

‘If they don’t look for the problem, they won’t find it’

Biosolids are essentially chemically-cleaned human feces. They’re made by extracting the solid waste from raw sewage and treating it to adjust PH levels and remove bacteria, viruses, parasites, and heavy metals. 

The final product is nutrient-rich and supposedly harmless, which is why it’s frequently used as fertilizer—though some Pennsylvanians have previously taken their complaints about the smell of biosolids used on farms near their homes all the way to the state Supreme Court. 

Fred Stone said the Maine DEP offered incentives to participate in the state’s biosolids program.

“We were encouraged by DEP to spread biosolids on our land,” he said. “They said it was our civic duty to do it, and they were paying us to spread it. We did everything to the letter of the law. In our permit, it states that they can’t contaminate our land, but they did. And now they’re refusing to do anything about it.”

He said the agency told him they’ve run out of money for testing and cleanups, and the family is, as he puts it, “S.O.L.” Stone’s attorneys are working to recoup costs from the suspected original sources of pollution, but it’s a complicated case that’s unlikely to be resolved anytime soon. 

The family has also received some payments from the U.S. Department of Agriculture’s Farm Service Agency for dumping their contaminated milk, but it hasn’t been enough to keep them afloat, and Stone said the checks mysteriously stopped arriving in January. The Stones have managed to lower the PFAS levels in their dairy milk by giving their cows clean feed and water, but not enough to sell it.

“We don’t have any income, and I’m not sure what we’re supposed to do with the cows,” Stone said. “We’ve been breeding these same cows in our family for generations, but we’re at the point where we’re thinking about killing them all. We just don’t know what to do.”

Pennsylvania farmers have also been encouraged to participate in the biosolids program since its launch in 1995, and have been promised that it’s safe. 

“We are all responsible for generation of biosolids,” the DEP’s webpage for the biosolids program states. “Pennsylvanians produce an estimated 2.2 million tons of wastewater solids, or sewage sludge and residential septage, each year, nearly a quarter of a ton per household… In order to ensure safe use of biosolids, Pennsylvania’s regulatory program focuses on setting strict standards for biosolids quality before land application and requiring generators to be more responsible.”

The Food and Drug Administration has found PFAS compounds in everything from sweet potatoes, leafy greens and pineapples to seafood, meat, and chocolate cake, and experts say the use of contaminated biosolids on farm fields is likely a primary source of food contamination.
The Food and Drug Administration has found PFAS compounds in everything from sweet potatoes, leafy greens and pineapples to seafood, meat, and chocolate cake, and experts say the use of contaminated biosolids on farm fields is likely a primary source of food contamination. (Photo by Arnaldo Aldana/Unsplash)

DEP spokesperson Rementer said that in addition to reducing the cost of fertilizer, “some farmers are paid to allow land application to occur on their farms.” She also noted that disposing of biosolids always costs money, and that “generally, land application is the most cost-effective way for a generator to deal with their biosolids.”

The DEP generates a small amount of revenue from the program—in 2018, the agency issued 51 biosolids permits with application fees of $500 each to sewage treatment facilities, so the total fees collected would have been $25,500. 

Land appliers, which serve as middlemen between some biosolids producers and farmers, also generate profits from the application of biosolids on farmlands. Land appliers often contract with many sewage treatment facilities and farms, so they may contribute to biosolids being applied to fields far from the source where they were generated, which can make it difficult to track down the original source if PFAS contamination is found in soil or produce down the line.

Like most states with biosolids programs, Pennsylvania requires treated sewage sludge be tested for pathogens, heavy metals, and other common contaminants before being spread on farm fields. But public health officials didn’t know PFAS were a threat until recently, and most farmers in the state remain unaware that there’s cause for concern.

“We have not heard from a single farmer voicing concern about PFAS,” Mark O’Neill, a spokesperson for the Pennsylvania Farm Bureau, told EHN. “The criteria for biosolid suppliers to meet under DEP rules are very specific and strict, and farmers rely on suppliers and the agency to ensure that the standards are being met.”

EHN also reached out to a number of sewage treatment facilities located near known contamination sites throughout the state to ask if they’d ever tested their sewage sludge or biosolids for PFAS. Most of them declined to answer our questions or didn’t respond to requests for comment. Two, the Allegheny County Sanitary Authority (ALCOSAN) in Pittsburgh, and the North Middleton Authority Biosolids Treatment Authority in Central Pennsylvania, stated only that they’ve never conducted any PFAS testing. 

“State agencies looking to address this issue should start by identifying farms where sludge has been applied and get some soil testing done to determine if there’s a problem,” MacRoy with the Environmental Health Strategy Center said.

“This needs to be done in a way that doesn’t hurt farmers,” he added. “The land application of sludge was encouraged by federal, state, and often municipal governments as a cost-saving measure, and we can’t just leave farmers holding the bag for cleanup and lost income.”

Stone wasn’t required by law to test his dairy milk for PFAS—he voluntarily tested his milk after learning that a nearby water supply had been contaminated. And despite his family’s struggles, he feels it was the right thing to do.

“As much hell as my wife and my family are going through, it was the right decision,” he said. “I could not live with myself if I thought someone was consuming milk or produce from our farm that made them get sick or die.”

“I’ve had people tell me, ‘you made a big mistake—you should’ve just kept your mouth shut,’” he added. “But as far as I know, it’s a crime to knowingly sell adulterated food. And we knew there might be an issue. So what were we supposed to do?”

When asked what advice he’d offer Pennsylvania farmers concerned about potential PFAS contamination, Stone didn’t hesitate. 

“Go out and test,” he said. “Test the milk and test the land. State agencies might not want to test, because if they know that if they don’t look for the problem, then they won’t find it. But it’s better to know the truth.”

The risk extends beyond farms

In total, 195 facilities throughout Pennsylvania hold permits to produce biosolids, and the state generates 300,000 dry tons of biosolids annually, according to the Pennsylvania Legislative Budget and Finance Committee Report on Biosolids from June 2017. 

Roughly 38 percent of those biosolids are applied to farmland. The rest is either incinerated, sent to landfills, or used in mine reclamation projects—all of which can also spread PFAS contamination.

“PFAS can leach out of traditional landfills and once again re-enter surface or groundwater and contaminate the water stream,” O’Neil, of the Environmental Working Group, explained. “And if you don’t incinerate PFAS chemicals at a high enough temperature, you create new PFAS chemicals as air emissions in the process of burning them, which can affect local communities or even travel long distances as particulate matter.”

He added that PFAS that become airborne can also settle and deposit in lakes, rivers, or estuaries and can contaminate rain, and that one study found PFAS air emissions winding up on trees near industrial sources.

A 6-wheeler helps in the land application of biosolids by hauling fertilizers through the farm in Geneva, IL.
(Photo by City of Geneva/Flickr)

How are other states addressing this issue?

Many PFAS experts feel that his problem needs to be addressed at the federal level—and the current administration has been slow to take action

“As far as examining the risk that the PFAS contamination crisis poses for our food supply, [the United States Department of Agriculture’s] involvement has been pretty minimal,” O’Neil said. “That is especially true with regard to the use of contaminated sewage sludge on farm fields.” 

USDA did not respond to our request for comments.

“Ultimately,” O’Neil added, “EPA should be requiring that sewage sludge be tested for PFAS prior to it being spread on farm fields so we don’t make this problem any worse.”

In the meantime, a number of states are ahead of Pennsylvania when it comes to addressing PFAS contamination in drinking water, and some local governments in addition to Maine have recently begun addressing contamination in food. 

Officials in Michigan are systematically testing biosolids at wastewater plants throughout the state. In Wisconsin, the city of Marinette stopped using biosolids on farm fields after high contamination levels were found in wastewater. Lawmakers in New Mexico are scrambling to develop a plan in the wake of PFAS contamination ruining a massive dairy operation near a contaminated military site.

One major hurdle to addressing PFAS contamination in food in Pennsylvania is cost. Officials in the PFAS Action Team have stated that in the absence of federal guidance or funding for PFAS cleanup, state agencies are already having to divert resources meant for cleaning up other toxic chemicals in the state to cover the cost of the PFAS water testing plan. 

MacRoy said the cost of testing biosolids for safety generally falls to the sewage treatment plants that produce it, and suggested it might make sense for states like Pennsylvania to just add PFAS to the list of testing requirements. 

But ultimately, neither farmers nor sewage treatment plants are responsible for this problem.

“Wastewater treatment plants and farmers are going to be unfairly blamed for PFAS finding its way into food,” O’Neil said. “But really the problem originated upstream.”

Awareness about PFAS contamination in food is spreading slowly among policymakers, but leaked reports have revealed that 3M, the company that developed the most ubiquitous PFAS chemicals for use in products like Scotchgard and stain repellents, have known PFAS were contaminating food since at least 2001. The state government of New Jersey has started suing the industries that caused PFAS pollution to recoup the cost of cleanup and testing, rather than putting the burden on taxpayers.

“Unless you can identify the sources that are producing, using, or discharging PFAS pollution that’s going through the pipes to the sewage treatment plant, you can’t turn off the tap,” O’Neil said. “And as long as the tap is on, pollution is going to keep happening.”

The Pennsylvania DEP hopes to identify sources of pollution through its water testing plan and begin to initiate cleanups.

In the meantime, Stone said he’d urge Pennsylvania farmers to stop using biosolids until the state requires PFAS testing prior to land application.

“People can do whatever they want,” he said, “but knowing what I know now, I wouldn’t touch that stuff with a ten-foot pole until I knew for sure whether the material is contaminated or not.”

Correction: An earlier version of this story erroneously stated at what facilities the Maine DEP had found contaminated milk. This testing found contaminated biosolids at 18 out of 22 sludge producers in the state.

Kristina Marusic of Environmental Health News can be reached at

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