Virginia lawmaker proposes new limits on data center generator emissions

Legislation brought forward by State Del. John Chilton McAuliff seeks to tighten rules on backup generators at data centers and expand requirements for environmental oversight, according to the Virginia State House.

The proposed bill, HB507, was introduced on Jan. 14, 2026, during the 2026 regular session and is titled: “Data centers; permit requirements, emission limits for certain engine-generator sets.”

The following summary is based on the bill’s text and clarifies its proposed requirements.

The legislation would permit data centers to operate backup generators that emit carbon dioxide only in emergency situations. Those generators would need to meet at least EPA Tier 4 or Tier 2 requirements combined with selective catalytic reduction, with a limit of 500 operational hours annually. Beginning July 1, 2027, data centers would be directed to rely first on energy storage for at least two hours before turning to such generators in grid emergencies. The measure also includes notifying nearby property owners about extended generator use, mandating both continuous and monthly public emission reporting, establishing monitoring near large generator clusters, evaluating cumulative impact on public health in partnership with the Health Department, alerting schools about specific emission permit applications nearby, and giving state agencies the authority to develop related regulations.

Rep. John Chilton McAuliff (Democrat-30th District), Rep. JJ Singh (Democrat-26th District), and Rep. Joshua E. Thomas (Democrat-21st District), plus an additional cosponsor, introduced the legislation.

McAuliff has sponsored eight other measures since this session began.

He holds a degree from the University of Richmond, earned in 2014.

Voters elected McAuliff, a member of the Democratic Party, to the Virginia State House in 2026 for the 30th House District, succeeding Geary Higgins.

The legislative process in Virginia starts with the introduction of a bill in either the House of Delegates or the Senate. It is then assigned to committees for discussion and consideration. If it clears committee, it proceeds to debate and voting by the full chambers. To reach the governor’s desk, both the House and Senate must pass it. The governor can then sign, veto, or let the bill automatically become law. Virginia’s legislature meets in regular session each year starting the second Monday in January, with lawmakers considering hundreds of bills—though not all become law.