A proposed detention center for unaccompanied immigrant children sits on top of land that could pose serious health risks, a report released on Tuesday alleges, including multiple toxic chemicals, heavy metals, and contaminated groundwater.

As part of the Trump administration’s plan to jail undocumented immigrants on military bases, the site at Goodfellow Air Force Base in San Angelo, Texas, is slated to hold up to 7,5000 unaccompanied children. Attorneys with Earthjustice, the nation’s largest nonprofit environmental law organization, say that the proposed location’s status as a former landfill and Superfund site should preclude it from ever being used for housing—particularly for children, who are especially vulnerable to environmental contaminants.

“Public records show the migrant children’s housing site proposed for Goodfellow will be built atop a former landfill, in an area riddled with lead, benzene and other chemicals particularly hazardous to children,” said Lisa Evans, Earthjustice attorney. “This is outrageous.”

In the report, compiled from documents developed by the U.S. Air Force during the Superfund cleanup process and inspections, Earthjustice found that serious potential health risks remain for future residents of the Goodfellow detention center. The contaminants include arsenic, benzene, lead, and PFAS, a pollutant that has been found to affect neurodevelopment and increase risk of learning delays and autism.

Volatile organic compounds, also known as VOCs, have been detected at Goodfellow as well, and have been found to cause damage to human nervous systems, kidneys, and liver—risks that are compounded when the person exposed to the compounds is a child.

Most of the contaminants date back to the site’s use as a landfill, which has since been covered but remains uncapped. Lead-contaminated soil from one section’s former use as a firing range, however, sits directly beneath land the Defense Department hopes to use for detainee housing. Pollution at many of those sites, Earthjustice alleges, has never been fully remediated—and was likely never sufficient to support housing for children.

The Department of Health and Human Services, which oversees the Office of Refugee Resettlement that cares for unaccompanied immigrant children, did not respond to a request for comment on the planned site.

“The Trump administration clearly cannot be trusted with the health and safety of vulnerable migrant children,” said Laura M. Esquivel, director of National Advocacy for Hispanic Federation. “Make no mistake; if plans go forward for these centers, the Trump administration is responsible for yet another cruel, misguided, and intentional action that will compound the irreparable damage to the physical and mental well-being of thousands of migrant children being separated from their parents at the border.”

Esquivel is a lead plaintiff in a lawsuit filed by Earthjustice last August that seeks to compel the government to turn over records relating to the construction of detention facilities on U.S. military bases, including any documents identifying all hazardous waste sites that could harm detainees. Evans said that the suit, filed after the Department of Defense declined to release the documents in response to a request under the Freedom of Information Act, is necessary to accurately determine the potential risk to migrant children.

“We urge the government to immediately turn over all documents related to this immoral plan so the public can get to the bottom of this,” Evans said.

Among the people who have opposed plans to house undocumented children on military bases are U.S. military officers and enlisted personnel, one of whom told The Daily Beast in June 2018 that the plan “smacks of totalitarianism.”

In an Aug. 2018 letter addressed to then-Secretary of Defense Jim Mattis, nearly two dozen retired senior officers urged the Defense Department to rethink the plan, which they wrote would “divert critical defense resources from core military functions, reduce service member readiness, and detract from their ability to protect our homeland and defend our interests abroad.”

In addition to concern that housing children atop a legacy waste site could potentially poison them, advocates for migrant kids have warned that attorneys may not be able to securely represent their clients from inside a military base that serves as an intelligence hub for the U.S. Air Force.

“Even the unrealized risk that communications could be intercepted will likely cause people to self-censor and prevent them from receiving the full benefit of legal counsel,” Amie Stepanovich, a lawyer with the digital-rights group Access, told The Daily Beast last summer.

But without comprehensive investigations and analyses of the current conditions at Goodfellow, using modern scientific standards, advocates said that it is impossible to say for sure what risks the child detainees may face there.

“The Trump administration chooses secrecy, despite the public’s right to know,” said Mark Magaña, president and CEO of GreenLatinos. “Now we must compel the government to respond to our queries and be accountable for the sake of our communities and migrant families.”