The discovery of contaminated soil has pushed back the reopening of the Washington Monument until August/NPS file

Completion of the new security screening building for the Washington Monument in the District of Columbia has been delayed for mitigation of possibly contaminated soil in the construction area, which means the monument isn't expected to be ready for visitors before August.

The monument has been closed since August 2016 to both construct the new screening facility and modernize the elevator that takes visitors to the 500-foot observation level. The modernization of the elevator is substantially complete, with just final testing and certification of the safety systems remaining.

The potentially contaminated soil is below the ground surface and poses no risk to public health. The soil in question was likely introduced in the 1880s as the monument was being completed, according to the National Park Service. Due to the necessary mitigation efforts, the reopening of the Washington Monument is now expected to take place in August. A specific date will be announced as the work progresses.