BETA completed the design and construction oversight of approximately 3,000 feet of new 20-inch water transmission main to service the Route 9/Route 90 Economic Development Zone (EDZ) area. The project’s purpose was to ensure that the EDZ has adequate domestic and fire water service to meet existing and future water demands. Additionally, the project also provides system redundancy, since the EDZ is currently fed from a single 20” water main.
The project spanned two communities (Framingham, MA and Southborough, MA) and had a multitude of stakeholders, requiring extensive coordination by BETA. Stakeholders included Framingham and Southborough Conservation Commissions and Public Works Depts., MassDOT (state roadway), MADEP (wetlands / water quality certification), MWRA (project located near Southborough facility), Mass. Dept. of Conservation and Recreation (DCR), Tennessee Gas Company, and Genzyme Corporation (project located near major R&D park).
Stony Brook Bridge/River Crossing: BETA determined that the existing bridge could not support the transmission main and associated construction activities, so proposed that the water main be constructed adjacent to the bridge. To minimize the environmental impacts associated with construction at the river crossing and the sensitivity of adjacent wetlands, while also crossing two high pressure gas transmission mains, the water main was successfully installed, utilizing the horizontal directional drill (HDD) method.
Culvert Replacement: In accordance with the MassDOT design standards, the new culvert was designed to convey flow from a 50-yr storm event. Due to flow restrictions in the downstream infrastructure, the allowable flow through the new culvert could not exceed the maximum flow through the existing culvert, currently limited to a 2-yr storm event. To limit the allowable flow, the culvert was outfitted with a restrictor plate with bottom elevation of the plate set at the water level associated with a 2-yr storm.
- 2,200 LF of 20” DICL water main
- 700 LF of 20” fused PVC AWWA C-905 pipe, installed by horizontal directional drilling (HDD)
- 100 LF 8” DICL water main (Town of Southborough, MA)
- Replacement of twin 3’x3’ stone culverts with a 3’x6’ precast concrete box culvert