Buried Treasure!
The Vaulted Caverns
Under the surface of the park are twenty underground "filter cells," each about an acre in size.
Much of McMillan's magic hides buried beneath its surface.
Under the surface of the park are twenty underground "filter cells," each about an acre in size.Graceful archways form a colonnade as you descend the ramp into this underground marvel.
Water flowed into the chambers, slowly percolating through about eight feet of sand and several layers of gravel. It was then extracted, providing purified drinking water for our growing Capital.
Prior to McMillan, water was carted in from the Washington aqueduct untreated!
Notice the stratification on the surface. Years of water flowing in and out of the cells has caused much of the concrete to harden, much like petrified wood, strengthening its structural integrity.
McMillan's cutting-edge technology was a public health breakthrough in municipal water purification.
