This story was produced in collaboration with the Food & Environment Reporting Network , a nonprofit investigative news organization.

At Art Schaaps dairy farm in Clovis, New Mexico, sprinklers draw from deep wells to water green fields of sorghum and corn. Near the milking barn Schaap built almost three decades ago, glossy black-and-white cows lap water from a pipe.

Schaap used to ship thousands of gallons of milk each day to milk co-ops and cheese producers, who in turn sold to consumers across the country. But for the last year, he has poured all that milk down the drain.

In September 2018, Schaap got an unexpected visit from an official with Cannon Air Force Base, which adjoins his Highland Dairy property. The official gave him a letter indicating that tests found his well water was contaminated with per- and polyfluoroalkyl substances (PFAS), a group of chemicals that have been linked to reproductive and developmental problems as well as cancer. The chemicals had migrated into Schaaps groundwater from foams used in firefighting exercises on the military base.

Schaap and his family, the letter said, should immediately stop drinking the water.

Schaap, 54, is a third-generation dairy farmer. His family had farmed in the Netherlands and California before moving to New Mexico, and Schaap has been raising cows and crops here since 1992. Air Force officials told him theyd supply his family with bottled water. But he wondered about his cows.

Milk is 90% water, he thought.

It kind of hit me like a rock, he recalled in a recent interview, that my cows are drinking this polluted water.

Testing by the New Mexico Department of Agriculture showed that his milk was contaminated at levels 70 times above a federal advisory health limit for PFAS. The compounds are often called forever chemicals because they dont break down and instead accumulate over time in the environment and the bodies of animals and humans.

When Schaap found out his water was polluted, neither the state Agriculture Department nor the Food and Drug Administration had a protocol for testing milk for PFAS they developed a test expressly for his milk. When Schaap sent his first samples to the Agriculture Department for testing, he made the decision to dump his milk in order to avoid selling a potentially contaminated product.

Schaap has since laid off 35 employees, and his 4,000 cows not to mention his familys health and livelihood are in limbo. Two other dairy farms in Clovis, a town of about 40,000 on the states eastern edge, were also found to have PFAS contamination in their groundwater, and others are concerned about the spreading plume.

Some Clovis dairy farmers have installed filtration systems on their wells, at a cost of about $260,000 per system, with yearly maintenance costs around $50,000. The Schaaps have not the price is simply too high for the level of contamination in multiple wells, with no guarantee of adequate purification.

The farmers say the contamination is an existential threat not only to their livelihoods but to the regions economic future.

Everything has changed, Schaap said. Its not gonna ever be the same.

An Emerging Concern Across The Country

PFAS contamination is a critical concern across the U.S., as the nonprofit Environmental Working Group estimates it has affected over 1,300 locations in 49 states, based on an analysis of state and federal records. That includes more than 400 military sites that used firefighting foam with PFAS compounds, according to the Pentagon .

Industrial manufacture of PFAS, which are used in products like waterproof clothing and nonstick pans, has caused contamination in North Carolina , Michigan , California , Colorado and elsewhere. A highly publicized case of PFAS contamination from a DuPont factory in West Virginia became the basis for the new Hollywood film Dark Waters starring Mark Ruffalo and Anne Hathaway. But Schaaps case, which the small nonprofit news outlet Searchlight New Mexico highlighted earlier this year, is only the second known example of dairy contamination .

The effects of his farms contamination have rippled through the dairy industry, revealing a new vulnerability of the food supply. Most of the milk and other dairy products that Americans consume come from dairy cooperatives made up of thousands of smaller farmers like Schaaps. In 2018, the top 50 dairy co-ops produced an estimated 81% of all milk sold.

PFAS chemicals were first developed in the 1940s as nonstick coatings for cookware, but their resistance to heat, water and oil soon led to widespread use in products like waterproof clothing and industries like electronics manufacturing. Over the last 20 years, a handful of PFAS compounds were phased out of production in the U.S., although they continue to be produced in other countries. Thousands of other PFAS compounds are still manufactured here.

Yet no enforceable federal regulatory level exists for PFAS in anything water, air, soil or food.

That advisory level that New Mexico officials cited when they tested Schaaps water is part of the Environmental Protection Agencys lifetime health advisory for drinking water, which for now is the sole federal PFAS guideline. The EPA threshold is controversial. Some scientists consider it too high to be protective of human health, and because its only an advisory, federal regulators dont enforce it. Out of a massive family of nearly 5,000 PFAS chemicals, with more created each year, the EPA advisory covers just two compounds.