Brunswick Pipeline will be constructed with the utmost care. In the past decade, we have laid more than 1300 kilometers of pipe in Nova Scotia, New Brunswick, Maine, Massachusetts and New Hampshire. That includes the pipeline Spectra Energy Transmission has been operating through Saint John since 2000. Click here to view our Environmental Manual for Construction Projects in Canada

Pipeline construction typically involves the following:

Clearing - Clearing crews brace and cut all fences that cross the right-of-way and install temporary fences and gates where required. They also remove all trees and brush that could become an obstacle for other crews.

Grading - Crews construct access along the right-of-way that will be used by all subsequent crews. In forested areas, the forest soil layer is removed and stored separately from subsoil materials. In agricultural areas, the topsoil is stripped by bulldozers and/or graders so that it is not mixed with the subsoil that is subsequently removed from the trench.

Trenching - A hoe excavator or trenching machine is used to excavate a trench to a depth sufficient to attain the necessary cover over the pipe (approximately 1 metre of cover). The width of the trench is generally twice the diameter of the pipeline.

Where bedrock is encountered, controlled blasting may be required. All blasting activity is conducted according to strict guidelines. Rubber blast mats are used to prevent scattering of rock and debris. Where required, blasting is monitored in the area of existing wells, buildings or other structures. Where required, safety barricades, fences, signs and flashers are put in place around an excavation.

Stringing - Pipe sections are delivered via stringing trucks to the construction site and laid on wooden skids adjacent to the trench.

Watercourse Crossings - All watercourses are flagged prior to clearing to indicate the minimal disturbance zone where equipment and work activities are restricted until the watercourse crossing takes place. Access over watercourses is facilitated by using portable bridges installed to span the watercourse.

Installation of the pipeline under watercourses is typically accomplished by one of three methods: horizontal directional drill (HDD), wet crossing or dry crossing. HDD is conducted by directionally drilling a hole under the watercourse (from bank to bank) and pulling the pipe section through. Wet crossings are constructed directly through the undiverted flow of the watercourse. Dry crossings entail damming of the water and the diversion of flowing water around the construction zone using water pumps and/or culverts. The choice of crossing method depends on the width and depth of the watercourse, flow rate, environmental sensitivities, adjacent land use and soil conditions.

Bending - The pipe is bent to conform to the topography of the pipeline trench.

Welding - The individual joints are welded into one continuous length. The welded joints are inspected and coated with a urethane or a fusion-bonded epoxy material.

Lowering in - Where necessary, the bottom of the pipeline trench is padded with sand to protect the pipeline coating. The pipeline is lowered into the trench using side boom tractors and/or excavators . A tie-in crew makes the final welds to connect the lowered-in sections of pipe.

Backfilling - Soil is backfilled using a drag-line, bulldozer, or excavator. In agricultural areas, subsoil is placed back into the trench and the trench is then covered with topsoil. Excess subsoil is removed and disposed of at an appropriate location. Topsoil is replaced using a drag-line and/or small bulldozers.

Testing - Following backfilling, the pipeline is hydrostatically tested to ensure integrity of the system. This is done by filling the pipeline section with water and pressurizing the system.

Clean-up - During clean-up, crews also repair fences, pick up debris, seed the right-of-way and restore sensitive areas such as steep slopes, ditch banks and watercourse and wetland crossings.