Metro is seeking a solution to an age-old problem for Red Line stations in Montgomery County.
Since the construction of the underground stations, water has infiltrated through bedrock cracks and into the transit system. Though drainage systems were originally built, an excessive amount of water is entering the 3-mile-long tunnel between the Medical Center and Friendship Heights stations. Aluminum tents have been attached to leaking cracks in the walls to divert water away from the tracks since at least 2003, according to a U.S. Geological Survey study.
Now, with increasing ridership putting pressure on Metro’s maintenance efforts, the Washington Metropolitan Area Transit Authority is seeking a long-term solution.
When the stations were built, three pumping stations were installed in the area to address the issue. Unlike the newer stations on the Glenmont side of the Red Line, Medical Center, Bethesda and Friendship Heights were constructed without a waterproof shell, Metro spokesman Dan Stessel said.
“This part of the Red Line is where we see more water infiltration than anywhere else,” he said.
Metro is now conducting an engineering study to design possible solutions, though Stessel said it will take four to five months to complete. After the study and a peer review are complete, WMATA may decide if service disruptions are necessary.
“We simply don’t know whether a shutdown would be necessary, whether it could be done on weekends [or] whether it could be done with single-tracking,” he said.
Lining the 3-mile tunnel with a synthetic material is a possible solution, Stessel said, but no decisions have been made.
Metro’s current maintenance routine includes pumping out water and sludge, which accumulate at the track’s switches near the Medical Center station.
“It requires continual attention while we’re trying to do other things,” Stessel said.
Water infiltration causes the infrastructure of the system to age prematurely and presents issues for the electrically charged third rail, but it is not a safety issue, he said.