Baltimore County has had its second sewage spill in a week - this time 190,000 gallons that poured into waterways in Dundalk before the spill was stopped yesterday.
The spill, which began Sunday, lasted through yesterday morning because a pumping station alarm system failed to work, county officials said.
"The alarm did not go off," said Elise Armacost, a county spokeswoman. "[Workers] found it when they went on a routine check this morning."
The raw sewage flowed into School House Cove and Bear Creek, Armacost said. Officials from the county's Department of Environmental Protection and Resource Management posted warning signs along the affected waterways yesterday afternoon.
Yesterday's spill was at the North Point Village Pumping Station, said county officials, who dealt with a 5 million-gallon spill into the Gunpowder Falls last week.
As they did with last week's spill, officials said any fish caught in the waterways since Sunday should be thrown away. They also warned against boating in the area for fear of human contact with bacteria in the sewage.
"We don't want people to have contact with the water unless we can assure them it's safe," Armacost said.
Yesterday's spill was the second-largest in the county among 103 reported since the state began tracking discharges last year.
The county has called the recent spills isolated incidents, but environmental groups said they are examples of a deteriorating sewer infrastructure.
Andrew Fellows, Chesapeake program director for Washington-based Clean Water Action Inc., pointed to Baltimore's recent federal agreement to pay $900 million for system improvements as the largest indication of the need to bolster the systems.
"There is a vast water infrastructural illness, of which local incidents like the Baltimore County spill are a significant symptom," Fellows said.
County officials said yesterday's spill differed significantly from last week's Gunpowder Falls discharge. County public works officials said a mechanical failure at the pumping station at 7618 Battle Grove Ave. is being blamed for yesterday's spill.
They are trying to determine what caused the 20-hour Gunpowder Falls spill, which occurred when a valve was sheared off a pump.
Public works officials have found rocks in the Gunpowder pumping system in Perry Hall, which they think might have damaged the equipment, officials said. Foreign objects typically enter the sewer system when people drop them into one of the county's 90,000 manholes, they said.
County environmental officials said yesterday that testing of the Gunpowder Falls has shown bacteria levels gradually decreasing.
"It's what we've wanted to see and what we expect to see," said Bill Clarke, program manager for the county Department of Environmental Protection and Resource Management.
Officials said yesterday that the county maintains 3,000 miles of pipe and handles 100 million gallons of effluent every day. All pumping stations are on a regular preventive-maintenance schedule, and many areinspected every other day.
"This is unusual," Armacost said. "I can't remember two overflows in one week."
Last year, 60,000 gallons of sewage spilled into Bens Run when a power failure shut down the Randallstown pumping station.