S.W.COLE was retained by Power Engineers in 2012 to provide subsurface explorations and geotechnical engineering for this proposed National Grid electrical transmission project. The project included construction of 345 kV electrical lines along existing transmission line corridors and upgrading the Millbury 3 Substation in Millbury, MA and the Sherman Road Substation in Burrillville, RI. The general alignment spanned about 38 miles through the towns of Millbury, Sutton, Northbridge, Uxbridge, Millville, MA and North Smithfield and Burrillville, RI. Our work included 80 test borings and 57 test probes along the transmission line corridor and at substation expansions.
Given the length of the alignment, varying surficial terrain and features made access to the project sites difficult. Access was limited by steep terrain, wetlands, subsurface gas pipelines and right-of-way abutters. S.W.COLE’s scope of work for the project required extensive pre-planning and coordination with the project team and stakeholders. Prior to mobilization to the site, pre-planning involved ground reconnaissance for access for drilling equipment and safety and environmental training. Access through wetlands and over pipelines was accomplished by contracting with a timber matting company to place temporary protective matting for hundreds of feet to numerous exploration locations. Weekly forecasts of our drilling locations were required to be reported to the project’s public relations personnel for providing project abutters the required 20 day notice before nearby explorations began. Environmental compliance involved protection of wetlands and surface water, containment of drilling wash fluid and use of biodegradable hydraulic fluids in the drilling equipment.
The exploration work on this project was accomplished in two phases, spanning from April to July 2012 and October to December 2012. Project progress and coordination was managed by S.W.COLE via weekly teleconferences with personnel from Power Engineers, National Grid, environmental consultants and pipeline personnel.