On Wednesday, DC mayor Muriel Bowser broke ground at the McMillan Sand Filtration Site, home to one of DC’s most well-known development battles. The project will transform the neighborhood east of Howard University, adding 655 new housing units, a park, commercial space, and expanded offices for the nearby Children’s Hospital.

Update: As of this afternoon, DC’s Court of Appeals has halted the McMillan redevelopment despite rulings from the Zoning Commission and Historic Preservation Review Board saying it could move forward.


The McMillan groundbreaking. All photos by the author unless otherwise noted.

Located at the southwest corner of North Capital Street and Michigan Avenue, McMillan was built at the turn of the century to purify the Washington Aqueduct. Water percolated through four feet of sand in 25 underground vaults to filter out undesirables. The iconic silos were used to store replacement sand above ground.

The site was obsolete by the late 20th century and declared surplus in 1986. It has sat vacant since then, fenced off and waiting for a new purpose.


McMillan’s silos.

The groundbreaking comes after years of heated debate about what to do with the decommissioned site. The group leading the charge, called Friends of McMillan Park have been vocal in their opposition to the project because it it would mean removing many of the underground sand vaults.

Friends of McMillan have been working in the courts since 2014 to stall the project. They’ve also run a very vocal yard-sign campaign.


You’ve probably seen one of these in DC. The sand filtration site has never actually been a park, though. Photo by Jonathan Neeley.

However, others point out that the site has been fenced off and publicly inaccessible since World War II, so the demolition is not actually a huge public loss. In fact, the restoration of sand vaults #28 and the creation of a walking museum are a net win for the site.

In the architectural rendering from Vision McMillan Partners below, you can see how the project will appear when looking southeast.


Image from Vision McMillan Partners.

The two buildings to the right will be office space for Children’s Hospital (located across the street). Housing units and commercial space are in the middle, and a park is at the far left. The sand silos are prominently featured down the two parallel courts.


There’s still a bit of sand left over in the silos.

Many of the historic elements of the old water facility will be retained. The site’s landscape architecture plan will incorporate all 20 of the iconic sand silos, four of the regulator houses and 12 stationary sand washers.


12 stationary sand washers will be saved.

The redevelopment will also save sand vault #14 in its entirety, but planners haven’t settled on what to use it for. The underground vaults stretch for acres underneath the grassy fields of McMillan Park, and look like the cross between a parking garage and an old catacomb. They’ve excited urban explorers for years and they’ve been a big part of the case not to develop at McMillan, but they don’t have a logical (or realistic) use, apart from sand filtration.

According to Joaquin McPeek of the Office of the Deputy Mayor for Planning and Economic Development, “We have not established a use for Cell 14 at this time. It is under DC Water control for a few more years until the First Street Tunnel Project is complete. We will then go through a community engagement and entitlement process to establish its use.”

The other vaults have to go because their century-old concrete walls don’t have rebar reinforcing bars and could collapse.

Construction is set to begin in the summer of 2017. Vision McMillan Partners has some cool architectural images of how the finished project will look on their website.

Crossposted from Architect of the Capital.