National Mall Fuel Cleanup Efforts Continue as Officials Assess Long-Term Environmental Impact.
WASHINGTON, D.C. (AP) — What began as a routine maintenance operation has escalated into a major environmental remediation project, as National Mall fuel cleanup efforts remain underway following the discovery of a significant underground fuel leak beneath the iconic greenspace.
The leak was first detected by National Park Service personnel on Monday, when a monitoring system alerted them to irregularities in soil vapor levels near the basement of the Smithsonian’s National Museum of American History. Subsequent investigation revealed that an aging, decommissioned fuel storage tank, believed to be a remnant of a 1960s-era heating system, had suffered a structural failure, releasing an estimated 1,500 gallons of heating oil into the surrounding soil.
Authorities evacuated a three-block radius of the central Mall area, including sections of the adjacent National Museum of Natural History, as a precautionary measure. No injuries have been reported. The environmental contractor, CleanHarbors Environmental Services, has been mobilized under a $1.2 million emergency contract to contain and extract the contaminated soil.
The primary response phase began on Tuesday, involving the excavation of approximately 80 cubic yards of petroleum-saturated earth. A secondary phase, scheduled to commence next week, will involve groundwater monitoring and the installation of a sub-slab depressurization system beneath the Smithsonian museum to prevent vapor intrusion.
Officials are investigating the cause of the tank failure, with preliminary assessments pointing to corrosion due to a lack of cathodic protection. The National Park Service has pledged a comprehensive review of all historic underground storage infrastructure on federal property in the capital region.
The cleanup is expected to take at least two weeks, but officials warn that full remediation of the aquifer system could extend for months. The National Mall will remain partially closed to the public during that period, with specific path closures and detours in effect around the 12th Street and Madison Drive corridor.