This is part three in a series of articles about DC’s water supply. Be sure to also check out the Washington Aqueduct and the Lydecker Tunnel Fiasco.

Typhoid epidemics regularly swept across Washington at the turn of the century as the population increased and industrial pollution worsened. A chief culprit was the city water supply. The unfiltered Washington Aqueduct carried a stream laced with bacteria and a notorious amount of Potomac mud, described by a contemporary Washington Post reporter as a “Seal-brown mixture of water and real estate.”

Shortly after the new city reservoir was completed at Howard University, Congress authorized funds for an adjacent filtration site to address the public health situation.

The facility relied entirely on sand to clean the water; at the time this method scaled better and was more cost effective than using chemicals.

“Raw water” came in from the reservoir next door and slowly percolated through the sand in 25 vaulted underground cells before making its way out into District taps. The four foot lining of sand actually did a remarkable job at removing bacteria and sediment from the water.