Cleanup crews continued working yesterday as county officials began taking steps to ensure that an oil spill such as the one that sent 450 gallons of diesel fuel into a tributary of Liberty Reservoir on Friday won't happen again.
A generator repair company was at the spill site at Snowden Creek to determine how to fix the county's emergency generator system that malfunctioned, sending fuel into the stream.
Wayne Lewns, chief of Carroll's Bureau of Utilities, said the county plans to install a check valve on the generator system and a concrete curb around the system and its fuel tanks to reduce the chance of oil spills.
A power outage Friday afternoon in the Eldersburg area caused a county-owned sewage pumping station at 6764 Marriottsville Road to shut down.
The emergency generator system, powered by diesel fuel, kept the system going until power was restored. But the switch controlling the flow to the fuel tank failed to shut off, causing the tank to overflow into the stream, said Quentin Banks, a spokesman with the Maryland Department of the Environment.
The department's Emergency Response Division and county firefighters contained the fuel before it reached public drinking water, Mr. Banks said.
For the past two days, Clean Harbors Environmental Services of Baltimore has been working at the spill site to continue the cleanup effort begun by state and county workers.
Members of the state's Emergency Response Division and county firefighters were alerted to the spill Saturday afternoon by a homeowner n the area, Mr. Banks said.
Workers placed containment materials in the stream to absorb and block the oil.
Due to the large quantity of fuel in the stream, the county had to hire the private firm, Clean Harbors, to remove the materials used to contain the oil.
"A couple gallons our folks could have removed themselves," Mr. Banks said. "But because there was so much spilled, we didn't have the wherewithal to remove it."
The power failure that led to the spill occurred at 1:46 p.m. Friday. The failure sent a signal to the emergency generator, which kept the pumping station operating until the power returned at 2:55 p.m., Mr. Lewns said.
But the switch on one of the fuel tanks became stuck, which caused the fuel to continue pumping and overflow into the stream.
After power was restored, a visual inspection of the sewage pumping station and generator system by county utility bureau maintenance workers indicated that the equipment was functioning properly, Mr. Lewns said.
Workers wouldn't have been able to detect a problem unless they had taken the fuel tanks apart, he said.