McMillan Reservoir

“Clean water? In 1900s Washington D.C.? That was a luxury, not a guarantee.” Let’s talk about the McMillan Reservoir, a key player in changing that. Before 1902, when the McMillan Reservoir was completed by the U.S. Army Corps of Engineers, Washington relied on natural springs and later, the Potomac River. But as the city grew, so did its thirst, and these sources became insufficient and unsafe. The McMillan Reservoir, originally called the Howard University Reservoir or Washington City Reservoir, marked a turning point. It was built on the site of Smith Spring, a poignant reminder of the city’s past reliance on unreliable springs. The reservoir’s story is intertwined with the Washington Aqueduct, a marvel of engineering that began delivering Potomac water in 1864. However, simply bringing water into the city wasn’t enough. Sediment and pathogens posed significant health risks. The McMillan Reservoir improved the city’s water supply, but true purification came with the construction of the McMillan Sand Filtration Site in 1905. This innovative system, using slow sand filtration technology, treated a staggering 280 million liters of water per day, significantly reducing the threat of diseases like typhoid. In 1907, the entire site was named after Senator James McMillan, a champion of the project. Sadly, he didn’t live to see the completed reservoir, nor its closure during World War II due to security concerns. The site reopened after the war, and though the original filtration system was eventually replaced, the McMillan Reservoir continues to serve D.C. The old filtration site became a historic landmark and recently reopened as part of the Reservoir District. So, as you stand here, looking at this serene body of water, remember the story of innovation, public health, and the legacy of Senator McMillan, all captured in the McMillan Reservoir.