Virginia’s Department of Environment Quality (DEQ) is requiring Microsoft pay $2.5 million for exceeding air quality standards last summer. This is the largest civil penalty a data center has been ordered to pay, DEQ officials told the Loudoun Times-Mirror.
According to the DEQ, the local electrical substation in Microsoft’s Leesburg data center experienced a catastrophic failure in July 2025. As a result, the company ran 62 emergency engines for seven days; DEQ found these exceeded fuel and emissions limits.
In October 2025, Microsoft claimed that the reported emissions were based on a “worst-case calculation methodology.” It stated a different methodology they conducted would provide more accurate results. The company said based on historical data from the electricity provider, it was “confident that an event like this will not recur.”
The facility is permitted to emit up to 94.67 tons of nitrogen oxides, 6.86 tons of organic volatile compound, and 655,850 gallons of diesel fuel. The data center emitted 102 tons of nitrogen oxides, 11.6 tons of volatile organic compounds, and used 1.19 million gallons of fuel from October 2024 to October 2025, DEQ spokesperson Irina Calos told the Loudoun Times-Mirror.
DEQ is ordering Microsoft to pay $99,000 of the fine to the Virginia Environmental Emergency Response Fund. The other $2.4 million will go toward additional air quality monitoring equipment for DEQ’s Supplemental Environmental Project. This includes an air quality monitor station and air quality sensors.
Feature image, kubais/stock.adobe.com
