President Trump calls for federal response to Potomac Interceptor collapse

Crews dewatered the collapsed pipe, cleaned it out and removed debris to assess the extent of the damage to the 60-year-old, 72-inch-diameter interceptor pipe. On Feb. 5, CCTV crews discovered a more pressing complication: a large rock dam 30 feet downstream of the original collapse site. In a published image from the CCTV footage, this blockage appears as one large boulder filling the entirety of the 72-inch pipe, impeding flow. Given the extent of this blockage, DC Water updated its timetable for completion of work, which would now take four to six weeks.

Since the discovery of the second rock dam, DC Water has published daily updates on its website to maintain transparency with the public as it addresses the Potomac Interceptor collapse. This also included the publishing of environmental impact findings, which noted 243 million gallons of untreated wastewater had entered the Potomoac River as a result of the collapse. Of that total flow, 194 million is estimated to have occurred in the first five days of discovering the overflow. At peak, DC Water estimates 40 million gallons entered the Potomac River in a single day, which is roughly 2% of the river's total flow in a daily period.

On Feb. 9 and Feb. 10, the daily updates noted additional overflows, the first of which was deemed significant with "several hundred thousand gallons of wastewater" having flowed into the Potomac River. The second overflow was limited to 5,000 gallons, which DC Water said was contained on site and did not enter the river.

DC Water CEO David L. Gadis published an open letter about the incident on Feb. 11. In his letter he acknowledged the troubling nature of the Potomac Interceptor collapse and overflow, and that he and the organization are committed to environmental responsibility. He underscored that message with calls for consistent and reliable funding for water and wastwater infrastructure for utilities across the U.S., not just DC Water.

"The Potomac Interceptor - more than 60 years old - is a critical regional asset, conveying wastewater from across the metropolitan area to the Blue Plains Advanced Wastewater Treatment Plant," Gadis wrote. "Its failure reinforces why sustained investment and vigilance are essential. DC Water has already committed significant resources to this work, including a $625 million investment to rehabilitate the Potomac Interceptor as part of our 10-year, $10 billion Capital Improvement Program."

Gadis also expressed the value of transparency throughout the process, called on the community to continue providing feedback, and that DC Water leadership would be gathered with the community to engage with questions about the response to the overflow.

By Feb. 16, two new access pits were constructed to allow for planning and removal of the rock dam blocking the flow through the interceptor. Once that rock is removed further assessment can be made and repairs can then begin.