WESTON -- A State Police dive team ended its search today in the Charles River for a steel collar that held two pipes together before Saturday's massive water main break, but a contractor will launch a dredging operation tomorrow morning, authorities said.
Victor L'Esperance, head of emergency planning and security management for the MWRA, said a private contractor will begin dredging the sediment Wednesday morning rom that part of the river and continue searching for the collar, weather permitting.
He said the dredging has been approved by the Army Corps of Engineers, the state Department of Environmental Protection, and the Weston Conservation Commission.
He added that while the collar was not recovered today, divers had found a few pieces of metal that analysts will look at to see if they are connected to the leak.
The collar, officials say, is in two pieces, with a combined circumference of about 31 feet, and weighs at least a ton.
Freeman estimated that the sediment pile juts out about 20 feet from the river's edge on one side of the bridge and 8 to 10 feet on the other.
Because of its weight, the collar would not be lifted out of the water, according to State Police Lieutenant William Freedman, the diving unit commander.
Instead, he said, they would mark one or both pieces for the Massachusetts Water Resources Authority, which will analyze the pieces as part of the investigation into the catastrophic leak.
He said divers had about five or six feet of underwater visibility for most of the day and metal detectors were also brought in for the search.
Trooper Anthony Vorias, one of the divers who went below the surface of the river, said that while they have not found the collar, they have seen debris dating back decades.
"You start going back in time," he said, adding that during his sweep of the river he saw old Coke and Pepsi bottles and a half-buried shopping cart, among other items.
Those early sightings lead Vorias to believe that authorities will find the collar if it has not washed farther down the river.
"When you find the little stuff, you know you're going to see the larger things," he said.
And the little stuff helps divers navigate. Vorias said he turns bottles upside down underwater to keep track of his whereabouts -- if he passes an upturned bottle, he knows that he's recently gone through the area.
"It's like mowing a lawn underwater," he said. "But it's not like you can see your trail."
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