Work is underway at a base camp for migrants in Brighton Park on Dec. 1, 2023. (WTTW News)

State officials stopped construction on a “winterized base camp” designed to house at least some of the nearly 1,000 migrants now living at police stations and O’Hare International Airport on Monday, as state environmental officials continued their review of an environmental assessment of the nine-acre site that found soil contamination.

Work will not resume Tuesday, while the review of the 800-page report by Illinois Environmental Protection Agency officials continues, said Jordan Abudayyeh, a spokesperson for Gov. J.B. Pritzker.

“We’re hopeful we will have more information tomorrow,” Abudayyeh said late Monday.

Earlier on Monday,Abudayyeh told WTTW News that state officials“had questions” about the report they were working through.

Mayor Brandon Johnson said late Fridaythe report by Terracon Consultants determined the site near 38th Street and California Avenue is safe to use as a temporary shelter as long as contaminated soil is removed and a stone barrier of at least six inches covers the entire nine-acre site.

Read the full report.

Tests were performed in 16 locations on the site, and soil, groundwater and soil gas samples were taken and analyzed, according to the report.

Mercury was found in one location on the site, and the soil in that area was removed and disposed of, according to the report.

In another location, the organic compound bis(2-ethylhexyl)phthalate was found, the report said. That compound is used in the manufacturing of polyvinyl chloride, a rigid yet flexible plastic. That soil has yet to be removed and disposed of, according to a statement from the mayor’s office.

At multiple locations on the site, the tests found evidence of two semi-volatile organic compounds and four metals that exceeded limits considered safe for residential use, according to the report.

That prompted city officials to require that the entire site “be covered with imported clean stone from a quarry and compaction of the stone to a minimum thickness of six inches throughout the site. The stone layer will be periodically inspected and maintained,” the report said.

The city will pay the owners of the lot $91,400 per month to lease the land, under the terms of an agreement reached in October.

The base camp will have separate tents for sleeping, case management services, dining, showers and bathroom facilities. The Brighton Park base camp will open to house 500 people and expand to as many as 2,000 people, officials said. A second base camp for migrants is expected to be built at 115th and Halsted streets, officials said.

Once the new shelter is up and running, most of those who move in will be allowed to stay for no more than 60 days, under new rules announced by Johnson.

GardaWorld Federal Services will operate the base camps under a contract with state officials, who will have earmarked $65 million cover the cost of the base camp and open another shelter at a vacant CVS drugstore in Little Village.

Contact Heather Cherone:@HeatherCherone| (773) 569-1863 |[email protected]