A teammate looks into a 300-foot stretch of the Washington Aqueduct's Old Conduit after it was upgraded with carbon-fiber. Washington Aqueduct crews have been conducting repairs and updates to sections of the utility's First Conduit, commonly referred to as the "Old Conduit," located under MacArthur Boulevard, since November 2023. The Old Conduit is a 12-mile-long circular tube structure carrying water from the Potomac River near Great Falls to the Dalecarlia Reservoir. The conduit was placed in regular service in July 1864 and — thanks to the qualified professionals that have overseen its operations and maintenance throughout the past 160 years — remains a vital component to providing drinking water for approximately 1 million citizens in the DC area.