The finding is a procedural milestone for the project, which would be built in the northwest Valley. Under federal rules, a finding of no significant impact allows an agency to proceed without a more exhaustive environmental impact statement, provided the public has a chance to weigh in.

The release of the draft assessment opens a public comment period, giving Surprise residents and others a formal opportunity to scrutinize the agency's conclusions before they are finalized. Details such as the exact site, construction timeline and the scope of the environmental review were not immediately available in the agency's announcement.

The project comes as immigration detention capacity has become a flashpoint nationally. Proponents argue that processing centers are needed to handle arrivals and reduce backlogs, while critics raise concerns about conditions inside detention facilities, the strain on local infrastructure and the environmental consequences of large-scale construction in fast-growing suburban communities.

For Surprise, a city that has expanded rapidly over the past two decades, the proposal raises questions about water use, traffic and land use at a time when residents are already contending with the pressures of growth. The draft finding asserts that those effects would not rise to the level of significance, but the comment period will test that conclusion.

Residents who want to participate can review the draft documents through the Department of Homeland Security and submit comments during the public window. The agency will then decide whether to finalize the finding or revise its analysis in response to public input.