DEQ Launches Air Quality Monitoring in Ashburn’s Data Center Alley

The Virginia Department of Environmental Quality (DEQ), with a grant from the Environmental Protection Agency, has initiated an air quality monitoring program in Loudoun County's Data Center Alley, home to the world's largest concentration of data centers. This project was launched in response to residents' concerns about emissions from data center backup generators and natural gas turbines, with the goal of determining if further monitoring is necessary. The first phase, which began in February, involved placing five air sensors in eastern Loudoun, followed by two more in April, bringing the total to 22 identified sites for sensor placement including residential and industrial areas. The second phase will involve relocating these sensors to Prince William County in June, where similar resident concerns about data center impacts exist. Initial data collected since March 3 through April 23 indicates that most pollutant levels, including carbon monoxide and nitrogen dioxide, are well below national ambient air quality standards. However, two instances of PM2.5 readings exceeding the national standard of 35 micrograms per cubic meter were recorded: one in the Newberry community in Sterling around April 12, reaching over 50, and another near Stuart Weller Elementary School in Ashburn, nearing 35. This monitoring effort comes amidst conflicting reports regarding data center emissions. The Piedmont Environmental Council (PEC) earlier commissioned a study by Michael Cork, which estimated that constant use of natural gas turbines, such as those at a Vantage data center in Sterling, could lead to $53 million to $99 million annually in health-related damages, projecting 3.4 to 6.5 additional deaths per year. These estimates were based on the highest legally allowed emissions, not actual measured levels. PEC President Chris Miller emphasized that cumulative impacts of emissions are often overlooked. However, the DEQ has released additional data disputing the PEC report's findings, stating it overstated actual emissions from the Vantage data center by aggregating all turbines and generators as a single source and using outdated ambient air quality data. Vantage Vice President of Global Marketing Mark Freeman affirmed the company operates well below permitted emission limits. Nicole Riley of the Data Center Coalition criticized such "misleading claims" as attempts to slow essential digital infrastructure growth. The PEC responded, clarifying their study focuses on health impacts, while DEQ's report addresses compliance with regulations.