CASCADE TOWNSHIP, Mich. (WOOD) — Private tests have found PFAS, a likely carcinogen, in the drinking wells of several homes near the Gerald R. Ford International Airport, according to the company that conducted those tests.

Gordon Water Systems has tested 20 private wells not far from the airport, all at the request of residents, in response to a Target 8 report about the Ford’s use of AFFF firefighting foam.

The company said it found PFAS in four of the wells.

While none of the tests found PFAS above the state’s limit for drinking water, some neighbors said the results show a need for more widespread testing.

“I would hope that that expedites any kind of investigation, that there’s a sense of urgency in any of those parties to get going on what’s actually happening, whether there’s contamination going on in our water,” Raul Alvarez, who lives in a neighborhood between the airport and the Thornapple River, said.

Airport officials say they have started investigating but have no immediate plans to test neighboring wells.

Gordon Water Systems Vice President Tom Duisterhof said two of the tainted wells are in the neighborhood of more than 400 homes just east of the airport. Most families in that neighborhood rely on well water. The other two are downstream closer to Ada, near where the Thornapple meets the Grand River, he said. Gordon Water Systems won’t say exactly where due to privacy.

The company charges $300 per test and sends the samples to Pace Analytical EPA-certified labs in Minnesota or Florida.

The highest PFAS level was found nearest the airport. A test result provided by Gordon shows that well with 36.6 parts per trillion of perfluorooctanoic acid, or PFOA, one of the two most-studied PFAS compounds. The test also found 15.5 ppt of another, less-studied compound known as perfluoroheptanoic acid or PFHpA.

The state limit for drinking water is 70 ppt.

The tests can’t show if the PFAS came from the airport or how far it has spread, Duisterhof said.

“It tells me that Mother Nature can carry contaminants in water supplies underground in ways we don’t fully understand,” Duisterhof said.

Already, one of the residents has reported the private findings to the state, according to the Department of Environmental Quality. The DEQ is asking any other residents to report their findings.

The private tests are “useful to MDEQ in building an understanding of the presence and concentrations of PFAS contamination in the area,” DEQ spokesman Scott Dean said in a statement to Target 8.

“There remain many unanswered questions that must be investigated and MDEQ remains committed to understanding the sources of PFAS in groundwater and identifying and mitigating any risks posed to residents,” Dean’s statement continued.

He said DEQ officials met with airport leaders last week to review progress on drilling and sampling.

“Based on the results of sampling and testing on airport property, MDEQ will direct airport officials on next steps in their investigation,” Dean said.

He wouldn’t say if that would include testing private wells.

It was the testing of private wells that determined how far PFAS has spread in northern Kent County, where contamination is blamed on waste from Rockford-based shoe manufacturer Wolverine Worldwide. That has spread to an area six miles long and five miles wide.

Airport officials also wouldn’t say if the private tests would lead them to check neighboring wells.

“The MDEQ encourages residents with any test results to contact their offices,” airport spokeswoman Tara Hernandez wrote in an email to Target 8. “We continue to work with environmental specialists to conduct an investigation of the potential of PFAS exposure at the airport.”

Three former Ford Airport fire chiefs told Target 8 they used AFFF firefighting foam extensively for more than two decades, mostly for training.

It’s the same foam that has contaminated military bases across the country with PFAS.

The PFAS levels aren’t nearly as high as those around former Wolverine Worldwide dump sites in northern Kent County, but already some airport neighbors are using bottled water.

Target 8 recently hired Gordon to test well water at Cascade Township Park, next to the airport. While PFAS was found in more distant private wells, none was found at the park.

“It’s very likely that if there was PFAS foam dumped onto the airport that it would make it over this way, but who knows how deep this well is, who knows if water flows here. There’s a lot in play,” said Chad Lomonaco of Gordon.