VA HB507

Requires data center permit applications submitted on or after July 1, 2026, to meet emission limits equal to or less than Tier 4 equivalent engine-generator sets

Defines "Tier 4 equivalent" gen-sets as requiring selective catalytic reduction for nitrogen oxides control, diesel oxidation catalyst for carbon monoxide control, and diesel particulate filter for particulate matter control

Applies to permits issued by the Department of Environmental Quality under Chapter 13 of Title 10.1, including general permits

Preserves the Department's authority to impose more stringent emission limits than Tier 4 equivalent standards when determining Best Available Control Technology or other federal standards

Targets backup generators at data centers, which are defined by reference to the existing tax code definition in § 58.1-3506