WINDHAM — Water woes continue for Cobbetts Pond after storm water collection basins failed at the Exit 3 construction site and dirty water poured into the pond for at least 36 hours late last week.
The latest water violations are being investigated by the state Department of Environmental Services and might result in fines for general contractor Middlesex Corp., according to state officials.
Middlesex spokesman Jose Nieto said the New Hampshire Department of Transportation is handling the matter and he had no comment.
Problems started last week when storms dropped at least 41âÑ2 inches of rain, filling the large detention basin along Route 111 near Castleton Banquet Center, said Jay Levine, DOT supervisor for the Interstate 93 widening project.
Construction workers pumped water from the detention area to another one across the street near the Middlesex Corp. trailers, but it leaked and water flowed back to the original detention pond, he said.
Workers then directed water from the first detention pond to another collection basin, north of the Middlesex pond, but it, too, leaked and water coursed back to the original collection basin, Levine said.
He said blasting might have opened fissures in the ledge at the bottom of the collection ponds, causing leaks.
Water streamed across Route 111 and the road was closed for about six hours overnight Thursday, he said. Crews pumped excess water into tank trucks and emptied them into a DOT quarry in Londonderry, he said.
After the fierce windstorm dropped trees and knocked out power to the town it became clear Route 111 needed to be open for fire and police personnel to respond to emergencies. DOT and Middlesex employees decided, collectively, to pump storm water from the full primary detention pond into Dinsmore Brook, which empties into Cobbetts Pond, Levine said.
Water was directed into Cobbetts Pond from late Thursday night until Saturday night. That is what the water violations stem from, Levine said.
Andy Chapman of the DES said the case is being talked about at the agency. He confirmed that water violations occurred, but had no more to say.
Derek Monson, spokesman for the Cobbetts Pond Improvement Association, has plenty to say.
"It's another blow to Cobbetts," he said.
Excess sediment on the pond's bottom feeds aquatic plants, reducing the oxygen level. The continued flow of sediment comes at a time when the association is gaining traction with pond restoration.
"We're very angry about it," Monson said.
This is the third major incident, he said. The first time was during the December 2008 ice storm when rain-driven erosion from the Exit 3 reconstruction project caused an estimated 1,000-foot plume in the pond, according to the DES. The second major incident was last spring when sediment washed into the pond.
Monson said transportation officials were warned by the DES to create more detention pond capacity, but they didn't heed the advice.
Levine said the DOT had enough detention space, but officials weren't aware of the leaks.
Selectmen will discuss the problem Monday. Chairman Galen Stearns said the board will want to know what plans were in place to respond to heavy rain, whether the plans were followed, and whether everyone who should have been notified was contacted.
Peter Stamnas, manager of the I-93 widening, said the department is seeking ways to ensure more storm water collection.
Monson said he can only hope the problem is solved, given the frequency with which major storms have hit the area in recent years.
"We get these things, it seems, every year," he said.
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