Board orders study and possible moratorium on large data centers, citing air, water and noise concerns

The Board of Supervisors voted to direct county departments to study the health, environmental and infrastructure impacts of large‑scale data centers and return in 120 days with recommendations — including potential protocols, community benefits and a framework for moratoria in unincorporated areas.

Supervisor Hilda Solis, who authored the motion, said communities in her district had raised serious questions about new hyperscale facilities and asked county departments to marshal expertise across Public Health, Regional Planning, Public Works, Fire and the Chief Sustainability Office.

Public‑health and technical findings: DPH Director Barbara Ferrer highlighted noise, diesel backup generators, air pollutants (including PM2.5 and nitrogen oxides), and increased greenhouse‑gas emissions tied to high‑intensity AI processing. Public Works and the Chief Sustainability Officer flagged grid and water‑supply pressures (public‑comment and staff estimates put single large facilities’ cooling water use in the hundreds of thousands to millions of gallons per day in some configurations) and advised granular modeling for basin impacts. Regional Planning noted that AI‑type hyperscale centers are a different class than older telecommunications server rooms and that the county code currently lacks a specific definition or permitting approach for them.

Public comment: Hundreds of residents, community groups and labor representatives spoke. Community organizations — including environmental‑justice groups, school district representatives and city officials in the San Gabriel Valley — urged a moratorium and stronger siting controls. Labor organizations supported study but urged inclusion of local hiring and community benefits.

Board action and follow‑up: Chair Solis amended the motion to add recommended protocols to safeguard impacted residents and a directive to propose community benefits and fee structures that could offset utility impacts. The board approved the revised motion (4–0). Departments will study siting, water and energy demand, grid and rate impacts, noise and public‑health risks and report back with policy options including possible prohibitions or setbacks and mechanisms for city engagement.

What this means: The action does not immediately ban data centers countywide but requires an expedited assessment and sets the stage for ordinance or moratorium proposals if the study finds disproportionate harms. Dr. Ferrer emphasized that while not all data centers are the same, the county must “cut through misinformation” with clear evidence and protections.