Moose River Water Main Bridge Crossing

The primary transmission mains feeding the Town of St. Johnsbury’s central pressure zone cross the Moose River along Route 2. Due to age, the condition of the existing water main bridge crossings had deteriorated into disrepair leaving only a single HDPE 8-inch crossing with limited capacity sleeved through the previous cast iron main.  To improve capacity and resiliency of the Bridge Crossing the Town contracted with Dufresne Group to design a 16-inch pre-insulated and heat traced crossing to be suspended from the bridge structure adjacent to the bridge deck. The project included abutment modifications, structural support installation, and interconnections to the existing transmission infrastructure on both sides of the bridge.

Construction was carefully phased to limit interruption to the existing service area which required coordination with a large industrial user in the project area, and public outreach by the Town. The new bridge crossing abandons the existing crossings which were suspended beneath the bridge deck and provides a single crossing of increased capacity. The crossing can now be easily inspected and isolated.

The project utilized funding provided by USDA Rural Development, including a 25% grant. During construction 185 linear feet of water main was added to the project to maximize the benefit of the grant funding.