The Trump administration's Environmental Protection Agency is considering a rule change that would let individual US states decide how much public input is required before permits are granted for smaller polluting facilities, including gas plants and diesel generators increasingly used to power data centres. Campaigners warn this could strip away opportunities for communities to learn about, or object to, new polluting projects near them, at a time when data centre expansion is already generating significant local opposition across the country.

Under the Clean Air Act, "major" pollution sources face strict federal and state review with mandatory public hearings, while "minor" sources—a broad category spanning dry cleaners to gas and diesel engines—currently have lighter but still EPA-mandated public participation requirements. Because enforcement of these rules already varies by state, campaigners such as Keri Powell of the Southern Environmental Law Center point to states like Georgia and Kentucky, which have relatively strong notification processes, as places where communities could lose vital early warning about projects like data-centre gas plants if the federal requirement is scrapped. The EPA says the change would not alter emissions standards themselves, only who controls the timing and extent of public consultation, and held a public hearing on the proposal on Wednesday.