Downstream communities worrieed yesterday over the effect on their drinking water supplies of about 20 million gallons of sewage that have spilled from a Hagerstown treatment plant since Saturday.
Meanwhile, Hagerstown public works officials scrambled to get their disabled sewage treatment plant, which discharges into a Potomac River tributary, back in full operation.
Brunswick, the first community downstream that draws drinking water from the river, closed its Antietam Creek intake pipes about 11 p.m. Tuesday "as a precautionary measure," said Kevin Brawner, the Frederick County town's director of public facilities. He said they had no indications of trouble, but wanted to be "on the safe side."
The town has about a six-day supply of water for its 6,000 customers in a reservoir and a storage tank, he said.
At the same time, a spokesman for the Maryland Department of the Environment said the Washington area's water supply probably won't be affected by the spill.
About 90 percent of the harmful bacteria in the sewage will have died by the time the vastly diluted spill reaches the nation's capital, said MDE's John Verrico.
"We'd be looking at [bacteria] levels below what we treat for normally," said Liz Kalinowski, spokeswoman for the Washington Suburban Sanitary Commission, which draws 110 million gallons a day from a spot 70 miles downstream from the mouth of Antietam Creek.
She and others said they would carefully monitor water coming into their plants. The plume from the spill is expected to reach the Washington area this weekend.
The Hagerstown treatment plant was knocked out Saturday after industrial solvents from an unknown source killed the bacteria that help remove the germs in sewage, allowing about 5.7 million gallons of partially treated wastewater to enter Antietam Creek daily.
MDE investigators began interviewing local businesses yesterday and probing sewer pipes to learn how chemicals strong enough to knock out the plant got into the system.
Hagerstown began treating its sewage with chlorine Monday as a temporary measure until the plant is operating normally. The chlorine, which kills germs but also fish, is removed before the waste is discharged into the creek.
The water near the outfall remained foamy yesterday but wasn't as bad as it was Saturday, said Jim Kline of the Maryland Bass Federation.
Since the 1960s, when it was so polluted some feared to touch its waters, the Potomac has begun to return to life as a result of environmental laws and costly sewage plant upgrades.
MDE records show more than 650 sewage spills in the Potomac in the last year, totaling more than 98 million gallons. Most came from Allegany County communities with old treatment systems.