In a notice posted Thursday, DC Water said the pipe rupture that sent sewage into the Potomac River will remain difficult to contain as crews work around a newly identified obstacle inside the collapsed sewer line. The local water authority said video inspection showed that a blockage inside the line was “far more significant” than officials initially believed when they announced the breach in January.
The additional work, DC Water said, will add an estimated 4 to 6 weeks to the timeline for getting a system in place to address the spill and begin removing rocks and boulders from the sewer line. DC Water said the inspection revealed a large rock dam about 30 feet (9 meters) from the point of the breach, and that the dam requires treatment before current discharges can be addressed.
The leak started when the 72-inch (183-centimeter) Potomac Interceptor collapsed on Jan. 19, shooting sewage out of the ground and into the Potomac River just north of Washington in Montgomery County, Maryland. DC Water said the spill was causing an estimated 40 million gallons (about 150 million liters) a day of wastewater for about five days after the collapse.
DC Water later said the overflow was not constant. In remarks carried with the notice, Sherri Lewis, a spokesperson for DC Water, said the overflow initially stayed at 40 million gallons a day and that it then shifted as pumps were taken out of service because of clogs linked to items such as wipes and grease, which can reduce pumping capacity. Lewis said that most days, the system had none or only limited overflows.
Lewis said the drinking-water supply was never impacted because the primary intakes for Washington’s water system are upstream of the collapse and are separate from the sewer system. DC Water and the state agency both pointed to separate sampling locations when describing where bacteria levels remained higher near the leak compared with other downstream sites.
DC Water said it has been assessing water quality for bacteria contamination and that while E. coli levels were well beyond safe levels at the site of the leak, levels at other sampling sites downstream into Washington were within safe ranges. In an emailed statement, the Washington Department of Energy and Environment said it continued advising the public and pets to avoid contact with the water until the situation was fully resolved and bacteria levels were reported as safe, adding: “DC drinking water remains safe for everyone to drink and use.”
The notice came amid new calls for public-health advisories related to the Potomac River. The same day, the Potomac Riverkeeper Network and researchers at the University of Maryland said they had found high levels of fecal-related bacteria and disease-causing pathogens in the river and were calling for advisories on recreational use of the water in Washington and Maryland.
Dean Naujoks, the Potomac Riverkeeper and part of an environmental nonprofit, said he was concerned about additional bacterial and pathogenic dangers and criticized DC Water for what he said was misleading information and changing versions of what had transpired.