EPA Air · stack tests by county and year
Air-emissions stack tests in Loudoun County, Virginia, 2025
- 21Stack tests
A stack test measures what a source actually emits, at the stack, against the limit in its permit. Each row below is one stack test recorded against a source in Loudoun County, Virginia during 2025. A facility can appear several times: this is the year’s record of what happened, not a list of places. The sources themselves are on the Loudoun County facility page.
Loudoun County, Virginia, 2025
Air-emissions stack tests in Loudoun County, other years
Air-emissions stack tests recorded in Loudoun County, Virginia, 2025
| Date | Facility | Kind | Agency |
|---|---|---|---|
| 2025-12-19 | DARAB VENTURES ONE, TWO, SIX LLC | Pass | State |
| 2025-12-12 | DIGITAL WESTERN LANDS LLC | Pass | State |
| 2025-12-11 | DIGITAL REALTY (DIGITAL LOUDOUN 3 & 4, LLC) | Pass | State |
| 2025-12-03 | ALIGNED DATA CENTERS IAD03 | Pass | State |
| 2025-11-14 | VANTAGE DATA CENTER VA3 LLC — high-priority violation on file | Pass | State |
| 2025-10-31 | ALIGNED DATA CENTERS IAD03 | Fail | State |
| 2025-10-30 | ZAYO GROUP, LLC | Pass | State |
| 2025-10-29 | AMAZON DATA SERVICES IAD-156, IAD-157, IAD-158, IAD-159, AND IAD-327 | Pass | State |
| 2025-10-23 | COMPASS IAD DATACENTER | Pass | State |
| 2025-10-15 | DIGITAL REALTY (DIGITAL LOUDOUN 3 & 4, LLC) | Pass | State |
| 2025-10-10 | EQUINIX LLC (DC-21/DC-22) | Pass | State |
| 2025-10-09 | QTS INVESTMENT PROPERTIES ASHBURN LLC | Pass | State |
| 2025-10-02 | EQUINIX, LLC - ASHBURN | Pass | State |
| 2025-09-17 | VANTAGE DATA CENTERS VA2 LLC | Pass | State |
| 2025-06-20 | YONDR DATA CENTER | Pass | State |
| 2025-04-30 | MICROSOFT CORPORATION â LEESBURG DATA CENTER (IAD01-02-03-04-05) — high-priority violation on file | Pass | State |
| 2025-04-16 | EQUINIX LLC (DC-21/DC-22) | Pass | State |
| 2025-04-03 | ISKANDER (LC-1A) JAMSHID (LC-1B) KAVEH (LC2) LOHRASP VENTURES (LC3) — high-priority violation on file | Pass | State |
| 2025-04-02 | VANTAGE DATA CENTERS VA2 LLC | Pass | State |
| 2025-03-26 | QTS DULLES, LLC | Pass | State |
| 2025-01-10 | VANTAGE DATA CENTERS VA11, VA12, VA13, VA14, & VA15 | Pass | State |
Dates as filed by the agency that recorded the stack test. Figures from EPA’s ICIS-AIR download.