WINDHAM — Last month, turbid water flowed into Cobbetts Pond for three to four hours due to a decision made without town input. Last night, officials from the state Department of Transportation said it wouldn't happen again.
"We're not going to allow that without consultation to the town," Commissioner George Campbell said.
The pumping of dirty water from Route 111 into Dinsmore Brook violated a work permit for the Interstate 93 widening and could mean penalties for general contractor Middlesex Corp.
The decision to pump the water into the brook, which leads to the pond, was made by the state and Middlesex employees at the construction site off Exit 3.
There are two main retention ponds at the site, one on the east side of I-93 south near Dunkin' Donuts and the other on the west side near the Middlesex trailers, according to Peter Stamnas, project manager for the I-93 widening.
The pond on the west side was not holding water due to fractures in the rock caused by blasting for the project. The water flowed into the other pond, flooding it.
There also is a smaller retention basin just north of the pond on the east side that failed about 11 p.m. on Feb. 25 — the same day a major storm hit the region.
The water spilled out across Route 111, closing the road.
"As the failure started, the road started filling up really fast," Jay Levine, DOT supervisor for the I-93 widening, said after last night's meeting at the Community Development building.
That's when officials decided to pump the water into Dinsmore Brook, thinking Route 111 needed to be cleared for emergency access. Fire Chief Tom McPherson said his department was not "at the table" during that discussion.
"Whenever we've got a closure on 111, we are not going to open that closure unless we get the town's permission that it was a safety issue," Campbell said.
The DOT commissioner said the state Department of Environmental Services told him more water could be pumped into Cobbetts Pond in the wake of this week's storm to clear Route 111, but he refused to exceed turbidity guidelines again unless asked to by the town.
But many at the meeting, attended by numerous residents along with DES Deputy Commissioner Michael Walls, still had concerns about the I-93 construction.
Parts of Route 111 remained closed last night, and the two major retention ponds were at capacity, Levine said, storing 7 million gallons of water thanks to the latest rainstorm.
Between storms, workers blasted at the site to provide additional capacity in the pond on the west side of I-93 south, and sealed the leaks. That pond is still not at its intended size, and is expected to be completed this summer.
Kathleen DiFruscia of the Cobbetts Pond Improvement Association asked whether the site could handle another 100-year storm.
"Not if it came tomorrow," Levine said.
That prompted Selectman Ross McLeod to ask when the site could handle more water.
Levine and Stamnas said they could not answer that question. Treatment with flocculants, which separate sediment from the water so it can be removed, began yesterday. That should speed up the process, cleaning the water so it can be pumped out of the basins, the DOT officials said.
"You're not leaving me with any confidence that this project can withstand another 10-year event," McLeod said.
Walls said he was at the construction site Monday during the storm.
"It was clear to me that the contractors and the DOT were doing everything humanly possible to respond to the events of two weeks ago," he said.
When asked whether a restoration plan would be appropriate, Wells said he was not sure if it is feasible for the area.
Campbell said it would be up to the DES, and the attorney general's office, to find the right mix of restoration, mitigation and fines to respond to the incident.
Resident Bud Sweetser said he first expressed concern about sediment getting into the pond — which kills local vegetation and helps problematic exotic vegetation grow — in 1997.
At recent weekly meetings, it was debated whether there was enough water storage, Sweetser said.
The state should be committed to cleaning up the pond, he said.
"This is the state's water," Sweetser added. "It's our waterfront and our homes, but it's the state of New Hampshire's water."
Campbell said the site contained all the rainwater from this week's storm.
DiFruscia asked whether the DOT could guarantee there would be no more water violations.
"The best we can do is explain to you what happened," Campbell said, and how they are working to prevent it. "The proof of it is how we responded to it with this storm."
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