Photo by Mr. T in DC

The McMillan San Filtration Site, which stretches along North Capitol Street from Channing Street to Michigan Avenue NW, has long stood as a testament to the city’s history. The former water treatment plant, built in 1905, has sat unused since the mid-1980s; redevelopment plans for the site are only now in the works—albeit slowly.

In recent years D.C. has allowed tours of the site’s 20 acres of underground vaults, but as the Post reports, those were recently discontinued over safety concerns:

Earlier this month, the D.C. government’s real estate director, Jeff Miller, e-mailed John Salatti, one of the Bloomingdale activists who have led the recent tours. Miller wrote that due to concerns about the “safety and stability of portions of the site,” the only access given to the site will be for “survey, stabilization work, or other development-related studies.” The locks were changed, making Salatti’s key useless.

…

Jose Sousa, a spokesman for the city economic development office, suggested that it’s unusual and unwise to give private citizens like Salatti the keys to a 25-acre piece of city property without much supervision. “We have to basically regulate access to the site to maintain safety and security at that location,” he said.

In a press release, Salatti promised that he would work to get the tours of the site back on.

“Tours have been safely conducted at this D.C.-registered historic site for over 20 years,” he said. “In the last year alone, over a thousand people have toured the site in all kinds of weather without out any incident. We are taking this up with the Department of General Services as well as with our elected officials and the Deputy Mayor for Planning and Economic Development.”