Norwich considers fix for polluting bridge
Published: 11-27-2024 5:31 PM |
NORWICH — After years of temporary fixes, the Selectboard is seeking a long-term solution to prevent a contaminant from leaking from the deck of Moore Lane Bridge into Bloody Brook.
During paving at some point, the timber on the bridge deck was treated with an excessive amount of the sticky tar substance to make the pavement adhere to it, according to a report prepared by Stantec, an international engineering company with offices in Vermont and New Hampshire.
Now, when the bridge gets wet or the weather heats up, the petroleum-based asphalt emulsion drips down the sides of the bridge into the water below, a Stantec structural engineer said during a Selectboard meeting on Tuesday.
The report, which was prepared by a Stantec structural engineer, featured four potential long-term solutions for the town to consider, including tearing down the bridge and not replacing it.
“There’s this continued school of thought that how we should be handling climate (change) is to be decommissioning, to find ways to possibly remove expensive fossil fuel based infrastructure,” board member Roger Arnold said. “I’m curious about the bridge option and while I’m sure we will be looking into replacing this bridge in a vehicular way, we probably shouldn’t be.”
Other options that the engineering consultants said the town could consider are:
Maintaining the current containment system, installing a membrane on top of the bridge deck to prevent water from leaking in and mobilizing the emulsion, and building a replacement bridge.
“I don’t think I’m the only person in town who’s tired of patching this problem,” board member Priscilla Vincent said during the meeting.
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Two homes reside on Moore Lane, a short street near Huntley Meadows athletic fields that connects Beaver Meadow Road and Turnpike Road. Removing the bridge would not deny access to the homes, but lengthen residents’ routes by a few minutes.
Instead of accepting one of the four options included in the report, the board and residents suggested exploring another option: Rebuilding the bridge as a pedestrian and bike path closed to vehicular traffic.
Norwich Deputy Fire Chief Matt Swett told the board that closing the bridge to vehicles would not affect the fire emergency response.
“If one of Norwich’s goals is to be more of a walkable town, I think that bridge has a lot of value to it and gets a lot of use,” he said.
Arnold said he would like to see a traffic study, which was not included in the report, before making any decisions to decommission the bridge.
As outlined by the report, the town has been attempting to tackle this issue since at least 2021 when a tarp was fashioned to the underside of the bridge deck to temporarily contain leakage.
In June 2022, the town hired environmental consultant, Murray & Masterson Environmental Services, to collect water and sediment samples and test the emulsion. They found the emulsion contained high levels of naphthalene, fluoranthene, and benzo(a)pyrene, exceeding residential standards.
Also in 2022, the town spent $62,000 on installing “a more robust containment system,” consisting of two layers of absorbent fabric and plywood sheathing across the bottom of the bridge deck. In 2023, the town once again observed breakthrough emulsion dripping down the bridge.
Over the summer, a trough made out of timber with an oil-absorbent medium in it was installed along the abutments to catch the contaminant as it drips down. It is not clear if the trough is stopping all of the emulsion from reaching the brook or not according to the report.
“I’m not in favor of continuing with the ongoing maintenance of the absorbent material,” Mary Layton, the board’s vice chairwoman, said. “It seems to have become compromised and it has to continue to be maintained and it’s costly.”
Maintaining the current containment system is estimated to cost up to $10,000 annually and last five to 15 years. Replacing the bridge, however, is estimated to cost $700,000, and funding will not be easy to come by since the bridge does not have structural issues and still has an estimated remaining service life of 15 to 30 years.
No decisions about the bridge were made at Tuesday’s meeting. The board encouraged residents to send in their opinions in the form of written comments and even floated the idea of putting the decision up to the town in a vote.
“This is way too big of a decision to spring on the town the week of Thanksgiving,” Peter Orner, who lives near the bridge and has pressed town officials for action, said. “This issue needs more time and more input from the public.”
Town Manager Brennan Duffy requested Stantic return to the board with information about a non-vehicular bridge option.
Emma Roth-Wells can be reached at erothwells@vnews.com or 603-727-3242.