SURPRISE, ARIZONA — Arizona Attorney General Kris Mayes filed a lawsuit on Friday seeking to block a proposed Immigration and Customs Enforcement mass detention facility in the city of Surprise, alleging the site sits near hazardous chemicals and lacks required environmental reviews. The proposed facility could house anywhere from hundreds to up to 1,500 individuals.

"The Trump administration has run roughshod over federal law in its rush to expand detention capacity across the country," Mayes said. She had previously foreshadowed the lawsuit, alleging that ICE's plans in Surprise violate environmental and immigration laws.

The lawsuit alleges the Department of Homeland Security and ICE did not conduct or publicize the required environmental reviews before moving forward with the facility. It also alleges the proposed facility violates the Immigration and Nationality Act, which mandates that the federal government arrange for "appropriate" places for immigration detention.

According to court documents, the federal government purchased the warehouse in Surprise for $70 million on Jan. 23 and has since issued contracts for more than $300 million to retrofit the building. The warehouse was constructed as an industrial distribution facility for up to four commercial tenants, not as a space to house hundreds of people.

The warehouse sits directly across the street from a chemical storage facility containing thousands of gallons of hazardous materials, according to court documents. The warehouse itself includes more than 100,000 feet of containerized hazardous materials storage for chemicals used in semiconductor production.

Before purchasing the site, ICE evaluated the use of existing facilities to help minimize environmental impacts. Congress appropriated $45 billion to ICE in July 2025 for single adult alien detention capacity and family residential center capacity, with those funds available for obligation through September 2029.