City officials on Wednesday approved a revised bridge design study, which may allow bids on the project to be sought this September, according to Mayor Donnalee Lozeau.
The Manchester Street Bridge, which crosses the Pennichuck Brook between Nashua and Merrimack, has been on the municipal red list of substandard bridges since 2008 because of structural deficiencies. The new bridge will have a larger paved width, safer cross slope, updated railing, a sidewalk and improved drainage over the drinking water reservoir, according to Stephen Dookran, city engineer.
"This has been in the works for a while," said Dookran. "Our hope is that if we get some good bids, we will begin construction in the fall, with work continuing for maybe 10 to 12 months."
On Wednesday, the aldermanic Finance Committee unanimously approved a revision to the current contract with CLD Consulting Engineers, which has been working on the new bridge design. The original bridge study and design contract was approved at $135,666, but has increased over time to $238,057 because of additional environmental requirements.
On Wednesday, committee members authorized a contractual increase of $13,826 to address and complete even more environmental items, including the state's wetlands permit and seeking approval from the Nashua Conservation Commission.
"Is this bridge actually ever going to get built?" Alderman-at-Large David Deane asked the mayor, stressing that concerns with the bridge were raised at least 13 years ago.
Lozeau acknowledged the delay, saying it was not on the list of priorities for Merrimack. There have also been multiple design drafts experimenting with various bridge heights, added Lozeau. According to the mayor, the original bridge will be kept intact underneath the new bridge construction.
"The old bridge is showing a lot of deficiency. It has structural deficiencies in the stone foundation and the superstructure," said Dookran, adding city staff and engineers have been working with the state Division of Historical Resources and the Department of Environmental Services to mitigate the design's impact on existing wetlands.
Dookran said preliminary cost estimates of the bridge construction are about $2.7 million.
An archeological study was also requested for the site, as it was originally believed that there may have been some Native American artifacts buried in the area, according to minutes from a previous Zoning Board of Adjustment meeting in 2010.
The New Hampshire Department of Transportation is funding 80 percent of the design contract, while the city of Nashua is contributing 15 percent of the cost and the town of Merrimack is contributing 5 percent. The two communities needed to replace the narrow jack-arch bridge that was built in 1935, while also minimizing impacts to the Pennichuck Reservoir, according to the CLD Consulting Engineers' website.
"The existing bridge and roadway approaches are too narrow for the traffic Manchester Street experiences," the site says.