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Biofilm—Jefferson Memorial to get a high-tech cleaning

Jefferson Memorial, Washington DC

The Jefferson Memorial in Washington, DC stands elegantly on the edge of the Tidal Basin framed by the capital’s famous cherry trees. The pantheon-like structure was completed in 1943 and the bronze statue of Jefferson within was added in 1947. Constructed of white marble from the state of Vermont, in recent the surface of the memorial’s dome began taking on a black tint that the National Park Service initially thought to be caused by pollution from automobile traffic; the city’s primary roadways across the Potomac River to Virginia—14th Street and Interstate 395—pass directly east of the memorial. More recent analysis, however, showed the cause is actually bacteria that create was is known as biofilm, notoriously difficult to remove. After numerous tests, the National Park Service has settled on a high-tech method to clean the memorial, removing the biofilm with little or no damage to the marble stone


Lasers to the rescue! Slime & grime set to be removed from Jefferson Memorial

By Mike Valero and Eliana Block


July 5, 2017

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