GLOCESTER, R.I. — Before this summer, Brandy Bates couldn’t have explained what per- and polyfluoroalkyl substances, also known as PFAS, were, where they came from, or why the Environmental Protection Agency considers them harmful.

But a few months later, she knows how to interpret PFAS test results and is up to speed on the latest research into how exposure to these chemicals — which are found in many items, from waterproof fabric to nonstick coatings to firefighting foam — may impact the effectiveness of a person’s immunizations. The chemicals are also believed to cause an increased risk of some cancers, including prostate, kidney, and testicular, reduce the ability of the body’s immune system to fight infections, and lead to developmental delays in children.

Although her family has spent generations living on their Glocester farm — her ancestors have held the land since George Washington was alive — Bates didn’t know that the company that has been next door to the property for decades, FM Global, had polluted their water with PFAS, which break down very slowly and can build up in people, animals, and the environment over time.

Five wells on the Bates property tested above the maximum PFAS contaminant level set by the Rhode Island departments of Environmental Management and Health.

According to DEM spokesperson Evan Lacross, the wells’ water tested between 25 and 215 parts per trillion (ppt). The acceptable PFAS limit in Rhode Island is 20 ppt, and some research suggests that any exposure can pose health risks.

FM Global is an insurance company that has a research facility near the Bates property. There they test products against conditions such as earthquakes, hurricanes, fires, and explosions. In the process of testing, the company has used fire-retardant foams that could be the source of the contamination.

“As part of state-required water testing, PFAS was recently detected at three residential properties near FM’s Glocester research campus. We take this matter seriously, and we’re working closely with the [DEM] and environmental experts to determine the source of the PFAS,” Robert Julavits, FM’s vice president of strategic communications, told ecoRI News in a statement. “In the meantime, FM is providing the homeowner with water supplies and in-home water filtration systems. We are in close contact with DEM and are committed to keeping the community updated as we learn more.”

Bates said she found out about the contamination after FM asked if it could install monitoring wells on her family’s property.

Initially, Bates thought that it was a “win for us,” an easier way to get water for her horses. But then, through FM and DEM, she was notified that the wells could contain PFAS and she should probably avoid drinking the water.

The process of testing “felt like a massive crime scene was going on,” Bates said.

The people testing the wells wore gloves and had to let the water run for certain periods of time before they could take samples. Bates guessed they spent 8 hours sampling.

A few weeks later she missed a call from FM and came home and found her steps covered with containers of potable water.

Sitting in her kitchen, next to a water cooler given to the family by FM, Bates described the period since the discovery as stressful.

At first she thought the only prohibition on water use would be drinking from the tap, but she soon realized that she couldn’t cook with the water. She even stopped eating her own chickens’ eggs or using her hot tub out of an abundance of caution.

She said right after finding out, she would sometimes forget about the contamination until a pot of pasta was already cooked and ready for dinner.

FM recently installed a point-of-entry treatment system in Bates’ home and a barn that is supposed to filter out the PFAS. The company said it will continue monitoring the water quality.

“We’ve been drinking this water forever. We have no clue what’s coming down the line,” said Bates, referring to future health issues the PFAS exposure could potentially cause.

She’s also not sure how the exposure has impacted her animals. One young horse Bates rescued from a kill pen is sick, and she doesn’t know if the water may have caused the illness. She’s having trouble finding studies or researchers that dive into the effects of forever chemicals on animals.

“It’s a matter of letting nature take its course,” she said of the horse’s fate.

On top of the health concerns, Bates said she is worried about her property values. Will someone want to buy a farm with a contaminated well, she wonders.

Since the death of her father, Bates said she has been investing in the Glocester property, putting up new buildings and barns.

“We put our money in the land,” she said.

Living near FM had never bothered her before. Sure, it was a little bright on the campus at night, she said, but she could always look west if she wanted to see the stars.

“It’s been a lot,” she said, calling the past few months “really frustrating” and “heartbreaking.”

Her neighbors are also concerned, although no one else’s wells have so far tested above the state PFAS threshold.

“DEM is currently overseeing a broader environmental investigation of the FM Research Campus,” LaCross wrote in an email to ecoRI News, “to determine the full nature and extent of PFAS contamination in and around the campus.”