Sewage Spill and Data Centers Threaten Potomac

American Rivers has named the Potomac River the most endangered river in the United States for 2026, citing a major sewage spill earlier this year and the rapid expansion of water-intensive data centers in the watershed. The announcement was made on April 14, 2026, in Washington, D.C., with Betsy Nicholas, president of the Potomac Riverkeeper Network, highlighting the threats to water quality and availability. The sewage spill, which occurred on January 19, 2026, along Clara Barton Parkway in Montgomery County, Maryland, involved the collapse of the Potomac Interceptor sewer line. This incident released an estimated 200 to 300 million gallons of untreated sewage into the Potomac River and the C&O Canal, leading to bacteria levels near the spill site nearly 12,000 times the safe recreational limit. DC Water, which operates the interceptor, constructed a bypass system, and the Environmental Protection Agency was designated as the lead agency for federal involvement. Environmental advocates are also raising alarms about the unchecked growth of data centers, particularly in Northern Virginia's "Data Center Alley," where hundreds of facilities already exist and up to 1,000 are projected. Concerns include increased stormwater runoff, chemical spill risks, hazardous materials management, groundwater withdrawals, and flood potential, especially as many proposed sites are upstream of drinking water intakes. Pat Calvert, Virginia conservation director for American Rivers, emphasized the need for immediate action to prevent detrimental redefinition of the river. Nicholas and other advocates are calling for lawmakers and regulators to conduct thorough investigations into data centers' water use, associated toxins, and community impacts before approving new construction. They also stress the urgent need for investment in aging wastewater infrastructure, highlighting the Potomac Interceptor failure as a clear indicator of systemic issues. Southern Maryland residents in Calvert, Charles, and St. Mary’s counties, who depend on the Potomac, monitor upstream conditions due to potential impacts on drinking water, fishing, and bay restoration efforts.