More than three million gallons of raw but diluted sewage spilled into the Patapsco River and Jones Falls during and after Tuesday's near-record downpour, city officials reported Friday.
An overflow at the Patapsco Wastewater Treatment Plant in Wagner's Point dumped about three million gallons into the river before it was stopped after nearly five hours, the Department of Public Works said.
Another overflow at a pumping station at Patapsco Avenue and Shell Road, less than a half mile away, spilled 170,300 gallons of untreated sewage into the river before it was halted early Thursday, the department said.
A third major overflow in the 1900 block Falls Road discharged 23,050 gallons of sewage into the Jones Falls before it was fixed Tuesday night, city officials said. Repair crews also responded to a number of other, smaller overflows, officials added.
Public Works had reported overflows at the sewage plant and on Falls Road Tuesday evening after rains abated, but provided few details at the time. One spill was said to be ongoing, while the other was "believed to exceed 10,000 gallons."
The department's release Friday said the volume of stormwater runoff from the 6.3-inch rainfall Tuesday — the second highest one-day total ever for the city — overwhelmed storm drains and infiltrated the city's sanitary sewer system, causing lines to back up and overflow.
City officials have been working since 2002 under a federal consent decree to fix Baltimore's overflow-prone sewer system, a major source of pollution rendering the city's streams and harbor unswimmable. The effort, projected to cost $1 billion, is supposed to be complete by 2016.
The sewage spilled on Tuesday exceeds the combined overflows reported by the city to the Maryland Department of the Environment for all of 2012, 2013 and this year through late July.