Two publicized incidences on U.S. dairy farms have raised concerns and interest in the industry regarding an “emerging contaminant” commonly referred to as PFAS.
Natzke dave
Editor / Progressive Dairy

To begin addressing those concerns and explore the potential impact on dairy farms and the industry as a whole, the American Dairy Coalition (ADC) recently hosted a webinar: “Rising concerns about PFAS causing some states to push for broader testing on farms with biosolids.” The webinar featured Leah Ziemba, a partner and agribusiness/food and beverage co-chair with the law firm Michael Best, and Matthew Schroeder, senior environmental engineer with the Dragun Corporation.

Ziemba and Schroeder will be featured in a similar program sponsored by ADC, set for Oct. 3, beginning at noon (Central time zone), in conjunction with World Dairy Expo in Madison, Wisconsin.

ziemba leah

schroeder matt

PFAS: What is it?

The topic is as complex as the name: Per- and polyfluoroalkyl substances (PFAS) are a group of man-made chemicals that includes perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). U.S. manufacturers have voluntarily phased out PFOA and PFOS, replacing them with less toxic alternatives. The most common of these replacement chemicals are commonly referred to as GenX and ADONA. Recent testing of these replacement chemicals has shown that they also carry health concerns, and some states are developing standards for one or more of the replacement chemicals.

Numbering more than 5,000 chemicals, chances are, you come in contact with PFAS every day. Many have been manufactured and used in a variety of industries around the globe since the 1940s. With their ability to repel water and oil, resistance to temperature changes and friction-reduction properties, PFAS are in everything from stain- and water-repellent fabrics and carpeting, nonstick products (e.g., Teflon), paints, cleaning products, sunscreen, dental floss, food and consumer product packaging, and fire-fighting foams.


In addition to the commonality of those products in our daily lives, PFAS are now prevalent in the environment, including water, soil and air. Due to their persistence and solubility in water, PFAS are very mobile. Heaviest environmental contamination from PFAS is usually found near manufacturing sites using them to produce products and places where certain fire-fighting foams (A-FFF) have been used, especially military bases.

From the environment, PFAS find their way into plants and human and animal body tissues and blood. Widespread testing of blood has found almost everyone has some level of PFAS. PFAS are also bioaccumulative: When they get in a human body, animal or plant, they tend to accumulate in protein instead of being processed and eliminated through waste streams.

Despite their prevalence, the risks posed by PFAS are not well understood. While they don’t break down quickly, they do change and may become a different chemical in the environment. Their unique properties mean there are challenges never encountered with other contaminants.

“For a lot of other contaminants, we can either do something to destroy the chemical in place or encourage Mother Nature to do the job for us,” said Schroeder. “For PFAS, that’s not realistic right now.”

There are three ways to practically remove PFAS from water through filtering or absorption, Schroeder explained. Most common ways use granular activated carbon or ion exchange systems or reverse osmosis. Cost depends on the volume of water treated and what the level of PFAS contamination is in the water.

The only economical way to destroy PFAS is incineration. In most cases, once the filtering/absorption process is completed, the concentrated volume of PFAS is taken to an incinerator and destroyed.

With contaminated soil, the process is to incinerate it or encapsulate it and seal it in a landfill site to prevent it from getting into the environment. Or, the soil can be “washed,” with the water collected and treated using methods mentioned above.

PFAS doesn’t stick to soil or organic materials very well, making it unlikely “binders” – commonly used by dairy farmers to address high mycotoxin levels in feed sources – would have much positive effect.

And, once PFAS is in food or milk, there’s no good method for removing it.

Understanding the toxicology

From a risk standpoint, toxicological information is still being developed, and there’s a lack of firm information about what levels can be considered “safe.” There is evidence that exposure to PFAS at low levels may lead to adverse human health impacts, affecting growth and learning in children, fertility or hormonal levels in women, cholesterol levels and some cancers. And, Schroeder said, because PFAS don’t break down naturally in the environment, it creates a “legacy effect” that doesn’t go away.

While some aspects of PFAS science have yet to catch up, testing for them is advancing, with the ability to detect their presence down to one part per trillion (one grain in an Olympic-sized swimming pool filled with sand).

However, there is currently only one EPA-approved method for testing PFAS, and it only applies to drinking water. And, few laboratories are certified to test for PFAS. While feed and forage testing labs can identify another potential contaminant found in dairy feed sources, mycotoxins, don’t expect those labs to run PFAS tests any time soon.

“Whenever we’re testing anything else – groundwater, soil, milk or someone’s blood, we’re using a modified method that isn’t really a method accepted by EPA,” Schroeder said. The use of differing methods can create inconsistencies in testing and results, making it difficult to compare data from one sample to another or one contamination site to another. “And, because we’re trying to test for these things at really low levels – parts per trillion – there is also a high potential for cross contamination when we’re sampling. There’s a whole list of things you have to keep away from the sampling procedure – things like rain gear or sunscreen – or risk the potential of false positives.”

Dairy farms are ‘public face’ of issue

Two U.S. dairy farms have been “the public face” of the PFAS issue. Located at opposite ends of the country, the sources of PFAS contamination also differ.

The story of Art and Renee Schaap’s Highland Dairy, near Clovis, New Mexico, appeared in the April 19, 2019, issue of Progressive Dairy. The 4,000-cow dairy was located near the Canon Air Force base with a known PFAS contamination issue. (Read: Poisoned wells: New Mexico dairy dumps milk while dealing with toxins in drinking water by Karena Elliott.)

Water and silage ingested by the cows were identified as sources of PFAS contamination. Testing showed water ingested by the dairy cattle was 35 times higher than the EPA health advisory of 70 parts per trillion. The farm was depopulated and the farm is no longer operating in that location.

At Fred Stone’s Stoneridge Farm in Arundel, Maine, the contamination culprit is believed to be the long-term (1983-2004) cropland application of biosolid sludge from two municipal wastewater treatment plants. That led to elevated PFOS levels in soil and water ponds in cattle pastures.

When PFAS in wastewater are discharged to a treatment plant, PFAS generally pass right through and end up either in the biosolids, which may be spread on farm fields, or in the discharged water. In the soil and water, the compounds are taken up by plants used for livestock feed. The herd can also be exposed to PFAS through contaminated drinking water.

In March, the Maine Department of Environmental Protection (DEP) announced it was requiring the testing for PFAS of all sludge material licensed for land application in the state. At a presentation to the state PFAS task force meeting in June, test results of various sites found PFAS in groundwater, soil, drinking and surface water, sediment, sludge and fish.

Regulatory patchwork

Just as PFAS compounds are complex, so are efforts to regulate them.

At the federal level, the EPA issued provisional drinking water health advisories setting maximum levels of 400 parts for trillion for PFOA and 200 parts per trillion for PFOS in 2009. In 2016, EPA released a nonbinding drinking water advisory level of 70 parts per trillion combined for PFOA and PFOS.

In 2019, an “EPA Action Plan” laid out potential federal actions. Under that plan, the EPA will begin to consider setting a maximum contamination level (MCL) for drinking water. Also included are increased monitoring of drinking water sources, as well as more research and communications related to health risk.

The agency is also considering whether or not PFAS should be classified as a hazardous substance, opening up an entirely new suite of federal statutes to allow state and federal governments to require for hazard analysis and critical control point (HACCP) cleanup on sites that have PFAS contamination above certain thresholds.

Even if EPA moves forward with setting a MCL, the process could take eight to 10 years. Some states and environmental groups have been frustrated with what they perceive as slow action. As a result, most current regulatory activity is at the state level, and some municipalities are attempting to monitor and regulate PFAS of their individual water supplies.

Lacking one enforceable standard creates regulatory challenges, especially when a contamination problem crosses a state line and is regulated differently on the other side of the border.

“‘Contamination’ means something different in each state,” said Ziemba. “The state regulatory parameters are very much a patchwork.” For example, New Jersey and California have set maximum PFAS limits at 13-14 parts per trillion. In Colorado and Michigan, the maximum limit is 70 parts per trillion. A handful of other states are somewhere in between.

Many states are in the middle of the process, looking to other states to see what they are doing. Not only are states setting drinking water standards, but some states are becoming aggressive in regulating PFAS levels in other consumer products.

“The trend is for more aggressive regulation at the state level – creating a national patchwork that makes it difficult to develop a consistent risk management message, confusing to consumers and the general public,” said Ziemba.

Is food testing next?

Since there are groundwater, surface water and soil standards being proposed, can regulation of food be far off?

“There’s always a possibility, but I think we’re a long way off from something like that. The science just doesn’t exist,” said Ziemba.

Dairy product sampling for PFAS actually started in 2012. There are limited labs – perhaps only one, according to Ziemba – with protocols to test for PFAS in milk and/or dairy products.

The industry has been asking the EPA for clarity and share risk communication details that are necessary in order to assure consumers that dairy products remain safe.

The FDA’s most recent testing (October 2017) looked at a full range of food products, although the sample size was small. Researchers found PFAS in everything they tested at low levels. It should be noted a lot of the testing was done in areas where known PFAS environmental contamination issues existed, and identification of PFAS contamination in food was not surprising.

In a statement, the FDA said, “This sample size is limited and cannot be used to draw definitive conclusions. Based on the best available current science, the FDA has no indication that these substances at the levels found in the limited sampling present a human health concern.”

But even though food regulation may not be imminent, companies are asking suppliers regarding protections to their supply chain. Companies are already asking for – and there are even companies marketing – “PFAS-free” packaging. The state of Washington has enacted a law that restricts PFAS in paper food wrappers if alternatives exist.


In some cases, “citizen scientists” take their own samples or send samples to laboratories not experienced in analytical methods, leading to increased confusion. With so many unknowns, emotional reactions are heightened to any type of knowledge or detection of PFAS, even at very low levels.

With emotion comes lawsuits, and some settlements have already reached millions of dollars.

“PFAS is a plaintiff attorney’s hotbed,” Ziemba said. “Environmental groups are now focused on PFAS issues. Even though many of the environmental groups are very localized, they are spread across the U.S., and their network is well-connected. They share resources very well with each other; what they learn or their tactics and press materials they use to advocate for change in one community will be shared with another. They are well-funded and good at obtaining publicity.”

Does a dairy producer have any recourse if they are forced to depopulate the dairy herd or are dropped by their milk buyer over contamination concerns?

Maybe, said Ziemba. Like a lot of legal answers, most cases would be fact-specific. There are state and federal legislative efforts to provide some financial support for recourse.

Bringing a lawsuit against entities that contaminated their land is a possibility, but lawsuits are expensive. Dairy farmers should also review their rights under any contractual agreements with municipalities regarding biosolid spreading.  end mark

To register for the ADC program at World Dairy Expo, click here.

Schroeder has created a two-minute video, “PFAS and Agriculture.”

For additional information, email Leah Ziemba and Matt Schroeder.  

PHOTO 1: Leah Ziemba is a partner and agribusiness/food and beverage co-chair with the law firm Michael Best.

PHOTO 2: Matthew Schroeder is a senior environmental engineer with the Dragun Corporation. Courtesy photos.

Dave Natzke