Sewage Pipeline Work Undertaken at Pennyfield
Repair work continues in the aftermath of the Potomac Interceptor sewage spill, notably at Pennyfield Lock where DC Water identified significant deterioration of the pipeline. However, paddlers report that the work is not interfering with taking out on the boat ramp nor with parking at Pennyfield.
Describing the Pennyfield project, DC Water said, "Recent inspections found areas of the pipe that need urgent repair, including worn concrete, corrosion, and exposed steel reinforcement," but added, "There is no current emergency, overflow, or impact to drinking water." Construction of a temporary bypass was completed July 9. Next to be undertaken will be emergency repairs inside the pipe.
Pennyfield is about 2 miles upstream from a major drinking water intake facility. "Although the findings identified in this section warranted moving this work to the top of DC Water's repair priorities," the agency said, "the most deteriorated portion of the pipe is fully encased in concrete, which reduces the risk of failure and the likelihood of an impact to public water supplies." On a typical dry weather day, DC Water said, the section being worked on at Pennyfield carries an average of 6 million gallons of wastewater and connects to the main trunk of the Potomac Interceptor.
Other Interceptor repair sites are located near the pipeline collapse site at Rock Run (Cabin John), Dulles International Airport, Broad Run (Loudoun County), and the DC-Maryland border along Clara Barton Parkway.
Meanwhile, in a July 2 update, DC Water said:
• it would continue daily Potomac River water quality testing through July 31, and then would coordinate with the Maryland Department of the Environment (DOE) to determine frequency of further testing.
• at the collapse site, C&O Canal cleanup was nearly complete, and soil testing was being done in coordination with the National Park Service.
Chair Hugh Hilliard told the CCA Board at its June 29 meeting that he believes the repair and cleanup activities have been going well, as demonstrated by water test results showing low levels of bacteria except after heavy rainfall events. Hugh and Grace Hassler have been meeting with the CLEAR Potomac coalition of groups, the Board minutes noted.
However, Montgomery County health officials have not lifted their advisory that contact should be avoided with the riverbed and shoreline in the area from Lock 11 down to and around Minnie's Island (see "Montgomery County Lifts Sewage Advisory--Except for Lock 10 Area Shoreline," Cruiser, May-June 2026, which includes links for obtaining water quality information). So there still is no joy for paddlers who are wondering when Lock 10 can resume its role as a favorite Potomac takeout.
For More Information
"DC Water Completes Bypass For Emergency Sewer Repairs At Pennyfield Lock," DC Water, July 10
"Montgomery County Lifts Sewage Advisory--Except for Lock 10 Area Shoreline," Cruiser, May-June