JOHNSON COUNTY, Ind. — The children fell ill, one by one, with cancers that few families in this suburban Indianapolis community had ever heard of. An avid swimmer struck down by glioblastoma, which grew a tumor in her brain.

Four children with Ewing’s sarcoma, a rare bone cancer. Fifteen children with acute lymphocytic leukemia, including three cases diagnosed in the past year.

As cases mounted, parents started to ask: Could it be something in the air or water?

Their questions led them to an old industrial site in Franklin, the Johnson County seat, that the federal government had ordered cleaned up decades ago. Recent tests have identified a carcinogenic plume spreading underground, releasing vapors into homes.

Now, families in a county that voted overwhelmingly for President Donald Trump are making demands of his administration that collide directly with one of his main agendas: the rolling back of health and environmental regulations.

On Wednesday, a group representing dozens of concerned parents called for a federal investigation by the Environmental Protection Agency’s Office of Inspector General into why Franklin’s toxic plume of trichloroethylene, or TCE, persists.

The group accuses the EPA of “serious mismanagement” and “significant delays” at the site, even after the dangers became apparent.

Families across the political spectrum have spoken out against the Trump administration’s drive to weaken restrictions on TCE, a colorless fluid used by as many as four-fifths of the nation’s 65,000 dry cleaners, as well as about 2,200 factories and other facilities. Decades ago, it was used at the Franklin site.

Twice last year, parents traveled to Washington to urge the administration to stick with stronger controls.

“We are done begging,” said Kari Rhinehart, the mother of Emma Grace Findley, the 13-year-old swimmer who developed brain cancer and died in 2014. “We are demanding the EPA finish what it started and place these restrictions on TCE and other dangerous toxins.”

The EPA confirmed that the chemicals were present near the Franklin site and said that fewer than 10 of 37 homes it had tested had potential air quality issues. The agency said its testing was continuing and that, if necessary, homes would be fitted with devices to clean the air.

Declaring TCE “carcinogenic to humans by all routes of exposure,” the Obama administration had sought to restrict two of its riskiest uses, as a stain remover and as a degreaser, and had marked it for further review, potentially to ban the chemical altogether. It had also moved to strengthen cleanup rules for hundreds of sites believed to be contaminated.

But at the urging of industry groups, the Trump administration has stalled some of those moves. In 2017 it indefinitely postponed the proposed bans on risky uses, leaving as many as 178,000 workers potentially exposed. It also scaled back a review of TCE and other chemicals.

In Johnson County, a parents group co-founded by Rhinehart, If It Was Your Child, has traced at least 58 childhood cancer cases since 2008. At 21.7 cases of pediatric cancer per 100,000 children, Johnson County’s rate puts it in the 80th percentile among counties nationwide. Both the national and Indiana average are fewer than 18 pediatric cancers per 100,000 children.

“You don’t expect to see so many cancers in a relatively small community,” said Dr. Paolo Boffetta, professor in environmental medicine and public health at the Icahn School of Medicine at Mount Sinai in New York. Even so, he stressed that there was little research linking childhood cancers to TCE. “This doesn’t mean an association doesn’t exist,” he said. “But studies have not been able to confirm it.”

The TCE contamination has been traced to a former factory that, for years, discharged industrial wastewater into a municipal sewer. Amphenol, an electronics maker based in Wallingford, Connecticut, became responsible for the cleanup after acquiring the site, although it no longer owns the property.

In June, tests by an environmental group detected the chemical in the air at two homes and in outdoor air near the site. The findings prompted more tests by local and state government officials, including one by Franklin that found levels more than 250 times state limits around a sewer near the homes. In November, the EPA identified a plume of contamination stretching beyond the site toward nearby homes.

Trouble Beneath the Grass

The state investigators who descended on Jennifer Clark’s house in October drilled into her basement floor. They sought signs that chemicals in the ground were turning into a vapor and rising into her home.

Her daughter Chelsea learned when she was 12 that she had acute lymphoblastic leukemia, a cancer of the blood and bone marrow. After chemotherapy, Chelsea, now 18, is in remission; she dreams of working in the beauty industry.

But over the summer, the Clarks received daunting news. Tests at their home on behalf of the Franklin parents group detected TCE levels more than 18 times federal limits.

Testing is tricky. Indeed, later tests showed lower levels in the house. Still, the Clarks, who live about a mile and a half from the former industrial site, remain worried.

Amphenol agreed to a cleanup in 1990, installing a “pump and treat” system that was supposed to control the contamination. For decades Amphenol pumped out groundwater, but contamination remained.

One Home, Two Families, Two Cancers

Two girls lived, several years apart, in the same Franklin apartment about a mile from the toxic site. Both developed cancer, one at age 8 and the other at 14.

“You can’t go anywhere, or do anything, without meeting someone who’s been affected,” said Angela Brennan, whose daughter, Karley, was one of those girls. In 2012, the family learned that Karley had cutaneous T-cell lymphoma, a cancer affecting the skin. Later that year, 14-year-old Madison Newton was told that she had an aggressive form of pilocytic astrocytoma, which causes tumors in the brain and spinal cord.

Karley, who turns 15 this week, is in remission. Madison died in 2015.

Many members of If It Was Your Child in the Franklin area play down the politics. Nevertheless, their demands come at a time when the Trump administration has weakened the rules that could prevent another Franklin.

“It’s not a political fight for us,” said Stacie Davidson, a Trump voter who co-founded the parents’ group with Rhinehart (who didn’t vote for Trump). Davidson said, “His loosening of EPA regulations, it’s infuriating.”

Davidson learned in 2014 that her stepson, Zane, who was 10 at the time, had a rare form of leukemia. He is in remission.

Still, she said, she did not regret her vote. “Trump’s a businessman. There are great things he can do for our country. But he’s used to building high-rises for money,” she said. “He’s not as environmentally savvy. Our hope is that he surrounds himself with people who are more knowledgeable.”

Looking to the Future

Johnson County bills itself as the festival county. In December, it hosted a holiday parade and a drive-through Nativity with live actors. A technology park is soon opening in Franklin.

Recently, though, Rhinehart has been thinking of the past. Four Christmases ago, her daughter Emma Grace suffered two severe seizures.

“She said, ‘Mommy, something’s not right,’ and I knew we weren’t going to get much more time,” Rhinehart said, recalling their final conversation. “I gave her some medication and she drifted off to sleep.”

This article originally appeared in The New York Times.