anything developed at the Joe Mamo lot at North Capitol & Florida Avenue NW will undergo design review by the HPRB

Note that the McMillan site borders, but is not part of, the Bloomingdale Historic District.  The McMillan Sand Filtration site is its own historic district.  

The Joe Mamo lot on the northwest corner of North Capitol Street NW and Florida Avenue NW IS within the Bloomingdale Historic District.

There have been no development permits from DCRA issued for the site.

Therefore, any development plans for the site will undergo review by the Historic Preservation Review Board (HPRB).  

The new construction on the site, since it will be built after the historic district's period of significance, will be considered non-contributing.