Elevated levels of “forever chemicals” have been detected in groundwater beneath several Perdue Farms facilities in Salisbury, the company said last week.

In letters sent to more than 500 residents within a half-mile of the impacted sites just east of the Eastern Shore city, Perdue requested access to test homeowners’ private wells for the compounds, called per- and polyfluoroalkyl substances, or PFAS.

Perdue has pledged to fund the testing, which is to be completed by a third-party contractor, and to ship bottled water to residents’ homes upon request.

A massive class of human-made chemicals, PFAS have been used for decades to create heat-, stain- and water-resistant products, from raincoats and nonstick pans to food packaging and dental floss. Once they enter the environment, the compounds are long-lasting and difficult to remediate, and several PFAS compounds have been linked to health harms such as cancer, prompting increasingly stringent federal limits for their concentrations in drinking water.

The source of the groundwater contamination at Perdue has yet to be determined, the poultry company’s vice president of environmental sustainability Drew Getty said. But officials are searching for answers, and the testing is ongoing, Getty said.

The company has used firefighting foam on the site, as part of its fire suppression system, Getty said. Some firefighting foams have been found to contain harmful PFAS, causing contamination at military testing facilities, airfields and fire training facilities.

At Perdue, the last known release of any foam was a small amount — an accidental release about six years ago, Getty said.

“We’re investigating the historical use of that firefighting foam on site — the releases and when those were — to understand what if any impact that may have on the results that we’re seeing,” he said.

The impacted facilities are part of Perdue AgriBusiness, on a campus that includes an office building, hatcheries, a feed mill, a soybean extraction plant, an oil refinery and grain storage infrastructure. Many of those buildings, located in the area of Zion Church Road, run on private wells, and are connected with a Perdue wastewater plant, Getty said.

Perdue Farms CEO Kevin McAdams said in an interview that the PFAS contamination is an “emerging issue” for the multinational corporation.

“For us, this is all about doing the right thing,” McAdams said. “We want to be very open, very transparent to prioritize safeguarding the health and safety of our community.”

The company is “working diligently” and in collaboration with the Maryland Department of the Environment, to find the source of the contamination, McAdams said.

“Yes, we’re going back through all of our records. Yes, we’re going back through all known things that have occurred on the site. Yes, we’re engaging even retirees to understand what did or didn’t happen there,” McAdams said.

Workers at impacted Perdue facilities have been offered bottled water, Getty said. But several of the impacted buildings already have treatment technology installed to reduce PFAS levels coming out of the tap, he said. McAdams said he addressed the company’s associates and took their questions during a town hall meeting last week.

MDE first discovered elevated PFAS levels in the wastewater at the Perdue facility in September 2023, agency spokesman Jay Apperson said in an email. The results were 694 parts per trillion of PFOS and 40 parts per trillion of PFOA.

For PFOA and PFOS, the EPA considers no amount to be truly safe for drinking water. But the agency has set an enforceable limit for public water systems at 4 parts per trillion. According to the federal Centers for Disease Control and Prevention, increased exposure to PFOA and PFOS can cause ailments such as kidney and testicular cancer, lower birth weights, high cholesterol and changes in liver enzymes.

Groundwater results for the Perdue site, received in January, ranged from below federal limits to 1,370 parts per trillion for PFOS, Apperson said. Then, Perdue drilled new wells closer to its property line for testing, and those results, received in late August, also showed a range of levels, from below the drinking water standard to elevated levels (1,300 parts per trillion for PFHxS). The drinking water standard for that compound is 10 parts per trillion.

About 14% of Maryland’s community drinking water systems have PFAS levels in their water that would be in violation of the EPA standard. Systems have until 2029 to come into compliance.

Private wells do not fall under the rule. But states such as Maryland have begun assessing well water to determine the risks. In recent weeks, several Maryland schools using well water made headlines for elevated PFAS levels.

“PFAS is an emerging area of concern in Maryland and across the nation. We appreciate Perdue’s cooperation in addressing this matter and helping to protect the health and well-being of the community,” said Maryland Department of the Environment Secretary Serena McIlwain.

In July, the agency reached an agreement for Perdue to pay $12.5 million for separate air pollution violations at its Salisbury soybean facility.