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I’m playing a bit of catch-up here, but the plans to redevelop the former McMillan Sand Filtration Site cleared a major hurdle on Thursday when the Historic Preservation Review Board voted unanimously to advance the project. The development team, Vision McMillan Partners, hopes to build a mixed-use complex on the long-vacant 25-acre site, with housing, retail, medical offices, a large park, and an incorporation of the existing sand towers that currently resemble a cross between an alien landscape and the Shire. But the developers have faced persistent opposition from a group calling itself Friends of McMillan Park that is resisting large-scale development in favor of more parkland.

HPRB had previously expressed skepticism toward the plans, but this time was more complimentary. Board member Maria Casarella called the latest designs a “very, very thoughtful and serious response to what we established,” while Rauzia Ally said they were “very tangible and commendable.” They signed off on the Historic Preservation Office staff report that considered the designs a “significant improvement over previous versions.”

But as Mike DeBonis points out, the fight is far from over. Because HPRB found that substantial demolition of the underground portions of the site would need to take place in Vision McMillan’s plans, the project will have to be approved by the so-called mayor’s agent—-an official appointed by the mayor to weigh in on projects that require significant alteration of historic assets. The mayor’s agent for at least the duration of fiscal year 2014 is J. Peter Byrne, a Georgetown Law professor who was appointed in 2011 after grumbling from preservationists and development skeptics that the then-mayor’s agent, Office of Planning Director Harriet Tregoning, was too pro-development and shouldn’t be wearing those two powerful hats at once.

And then, since the site was once federally owned, the federal Advisory Council on Historic Preservation will also weigh in, followed by the Zoning Commission (the site still needs to be rezoned before construction can begin), the D.C. Council (to surplus the land), and HPRB once again for a final review. Which is to say that opponents will have a lot of chances to raise objections.

But given the slog that the redevelopment process has been thus far, the conditional stamp of approval from HPRB represents a pretty significant step forward. At long last, the realization of an inhabited McMillan may be on the horizon.

Here’s an animated rendering of what Vision McMillan expects the site to look like:

Renderings courtesy of Vision McMillan Partners