Baltimore City Sinkhole and Emergency Water Main Repair

On March 18, 2021, the City of Baltimore DPW received notification of a water main leak inside a CSX Transportation tunnel that runs beneath Howard Street in Baltimore, Maryland. The city contacted EBA Engineering, Inc. (EBA), who already had a contract in place with the city to provide urgent need water engineering services. A visual inspection determined that the infiltration encompassed extensive dripping, seeping, and flowing water across roughly 200 ft of the tunnel. During a meeting with the entire response team, including the city, CSX, EBA, and the city’s on-call contractor, a decision was made to identify the source of the water leak and begin repairs immediately. Finding a water leak of unknown origin is not an easy task—finding one within the maze of utility lines and other structures located along Howard Street was akin to finding a needle in a haystack. After several weeks of aboveground inspections, followed by CCTV inspections and reviews, were unsuccessful, the city retained Pure Technologies, Ltd., to perform a SmartBall leak detection survey that identified three water main leaks from a 16-in. water main located under the Maryland Transportation Authority (MTA) Light RailLink tracks in Howard Street. With a size between 2 gallons per minute (gpm) and 10 gpm, one leak was significant, while the other two, at a size of less than 2 gpm, were suspected to be feature related. The city tasked EBA with design, permitting, and oversight of the leak repairs to avoid a catastrophic tunnel failure. During efforts to address the largest leak, the contractor discovered a 16-ft by 22-ft void under the MTA light rail tracks and extending down to the CSX tunnel. Repair of the two smaller leaks then required a challenging tunnel design and construction under the MTA light rail tracks. Despite multiple challenges, the city and its on-call design consultant and contractor fostered a strong collaboration to rapidly plan, design, and execute the repairs.