BALTIMORE, Md.— A federal district court judge granted Maryland’s request for a preliminary injunction yesterday afternoon, ordering the U.S. Department of Homeland Security to stop major construction activities at the proposed Williamsport warehouse detention center site. The Center for Biological Diversity and partners in March supported Maryland in its lawsuit challenging the detention center.

The order blocks the Department of Homeland Security and Immigration and Customs Enforcement from moving forward with construction or renovations at the warehouse, which the federal government planned to convert into an immigration detention facility housing up to 1,500 people at once. The agencies had failed to conduct legally required environmental reviews and would have begun construction already if not for Maryland’s lawsuit.

“This injunction is a monumental victory for the environment and local communities,” said Laurel Jobe, an attorney at the Center. “By stopping all construction and renovation, the court has taken a critical step toward preventing a dangerous project from moving forward without proper environmental safeguards. The Trump administration can’t ignore the law when people’s health and vital ecosystems and vulnerable species are at risk of harm.”

The Center and Earthjustice previously submitted an amicus brief in support of Maryland’s lawsuit, outlining several concerns about the project’s potential threats to endangered species, water quality, air pollution, traffic and public health and safety. Judge Brendan A. Hurson granted the Center’s motion to file the brief, officially accepting it as part of the court record.

The Center raised serious concerns about the facility’s projected additional wastewater and sewer requirements if the detention facility were to be functional. There is a severe risk of sewage overflows from the facility, which risks degrading water quality across the Potomac watershed. The Potomac River was recently deemed the most endangered river in the country. Increased levels of fecal matter, E. coli and other harmful pathogens would threaten drinking water and public health for communities downstream and further degrade this already vulnerable watershed.