Department of Environmental Quality withdraws proposed variance for data centers

The Department of Environmental Quality is withdrawing its proposed temporary variance to allow data centers to use backup generators during potential strains on the electric grid.

DEQ proposed the variance in January after PJM Interconnection, the regional electric grid Virginia is connected to, flagged in its five-year forecast an increased demand for electricity due to data center development. The proposal would have suspended short-term air emission limits through July 31 in areas where PJM issued warnings of acute strains on the transmission system, allowing data centers to run the generators temporarily. 

“Given further discussion with stakeholders and public comment on the proposal, DEQ believes that these issues are now being addressed between the data centers, the utilities, and the regional transmission organization,” an April 12 announcement from the agency read.

The proposal initially encompassed the counties of Loudoun, Prince William and Fairfax, but was scaled back to Loudoun following pushback during a public hearing in which Northern Virginia residents expressed health, environmental and noise concerns.

Also at the hearing was Josh Levi, president of the Data Center Coalition (DCC), who had requested the variance be narrowed to Loudoun, where Dominion had given “assurance that the impact of the transmission constraint” would be limited. But on March 27, Levi sent a letter to DEQ asking for the withdrawal of the variance altogether, citing “unresolved technical, federal regulatory and operational challenges.”

“Due to these issues, no DCC member has indicated they would use the variance,” Levi wrote. 

Allison Gilmore, vice president of the Data Center Coalition, declined to provide more details on what led to DEQ withdrawing the permit. Dominion did not immediately respond to a request for comment. 

The region of Loudoun County known as Data Center Alley is home to the largest concentration of data centers in the world, where almost 300 data centers in Northern Virginia support 70% of the world’s internet traffic.