Washington, D.C. Water Quality: Yesterday
The earliest settlers of Washington, D.C. relied on local springs for their drinking water, like City Spring, Caffery’s Spring, Franklin Park (now Judiciary Square), and Smith Spring (now the McMillan Reservoir). The earliest documentation of drinking water infrastructure in Washington, D.C. is from 1808. Residents living in the 600 block of Pennsylvania Avenue NW paid to “convey” water from the city spring to their neighborhood using wooden pipes. A year later, city planners appropriated $300 of public funds to build pipes to convey water from Caffery’s Spring to the northwestern Pennsylvania Avenue area. This system was extended each year until 1850. When a congressionally funded engineering study identified the Potomac River as Washington D.C.’s future drinking water source, the U.S. Army Corps of Engineers designed and built the structures and facilities that became the Washington Aqueduct.
The influx of new residents during WWII put a strain on D.C.’s water system, leading the District Engineer, the U.S. Engineering office, and the Engineer Commissioner of D.C. to submit a report to Congress with plans to construct, improve, and add on to the existing water system. This report has guided the modifications of D.C.’s drinking water system ever since.
In the early 2000s, Washington D.C.’s drinking water was found to have had high levels of lead that could be traced to the replacement of chlorine with chloramine during the water treatment process. Chloramine has been found to leach lead from corroding pipes and solder and dissolve it in the flowing water. Washington D.C.’s water municipality found that adding corrosion inhibiting chemicals, like orthophosphate, could help prevent lead leaching from infrastructure. However, as recent as 2010, the Centers for Disease Control has found high levels of lead in residents’ drinking water.