The documents — a draft environmental assessment and a draft finding of no significant impact — examine the conversion of an existing warehouse at 13290 W. Sweetwater Ave. into a facility that would hold up to 1,500 detainees and employ roughly 676 staff across three shifts around the clock, according to the draft assessment. The reports are not final; a 30-day public comment period began Monday, and DHS says it will consider those comments before making a final decision.

The draft finding states that with water measures in place, the project "would not significantly affect the quality of the human environment." It also notes that construction and operations would bring jobs and spending to the area.

However, the draft assessment acknowledges that the facility could increase calls for police, fire, and emergency medical services, rating those effects as "minor to moderate." That characterization is disputed by Surprise City Councilman Chris Judd, who represents District 6, where the site is located.

"They said there's potential impact on our public safety services, but they're unsure how much," Judd said. "Surprise is going to comment on that because our fire chief and our police chief believe the impact's gonna be greater than what they've been stating it's gonna be."

Water is another flashpoint. The drafts project the facility would require about 190,000 gallons per day on average, with an anticipated peak demand of approximately 215,000 gallons. To serve the facility, Surprise would need to build a new city well about five years earlier than planned and modify a planned arsenic-treatment expansion, according to the draft assessment. The facility would pay for the work, and the city would build it.

Under Surprise's rules for high water users, Judd said, the city must provide service if the facility covers the cost of the work and replacement water. "We've been saying the same thing from day one: the only way this stops is because the feds decide to stop," he said.

Brent Peak, co-chair of Northwest Valley Indivisible, a group opposing the facility, said the reports fail to address what he considers the site's biggest problem: the potential effects of a chemical warehouse across the street, identified in documentation as Rinchem Company, LLC.

The draft assessment says the detention center would likely have detainees shelter in place during an off-site chemical release because the building has a closed-loop HVAC system. But Peak argues that conclusion is premature.

"Rinchem has filed a risk management plan with the EPA that one of our volunteers was able to look at and research. That risk management plan is never cited in this review," Peak said. He added that DHS is putting off a shelter-in-place plan without first knowing for certain whether sheltering in place would work there.

"If they think that they can kick the can down the road about putting together an adequate shelter-in-place system without even determining whether or not there is a possible way to adequately shelter in place under those circumstances, they are not doing their due diligence here," he said.

The draft reports arrive amid ongoing legal scrutiny. Arizona Attorney General Kris Mayes filed a lawsuit challenging the facility in April, claiming DHS and ICE failed to conduct or make required environmental reviews before development. The Arizona Attorney General's Office told ABC15 it does not have a comment yet on the draft findings.

The public comment period, which started Monday, gives residents and local officials 30 days to weigh in before DHS finalizes its environmental determination. For Surprise, the stakes include not only environmental and public safety concerns but also the city's water infrastructure and its limited leverage over a federal project that local leaders say they cannot block on their own.