CONSTRUCTION ACTIVITY DETAILS
As part of the Trans Mountain Expansion Project, extensive work has been conducted to determine environmental impacts and mitigation measures to reduce those impacts. Our goal is to protect the environment, have as little impact as possible and, where we do have an impact, ensure we return the land to a similar function.
We completed field studies between 2012 and 2018 along the pipeline corridor studying a wide range of environmental features, including wildlife, fisheries, plants, species at risk or species of special status, soils, heritage resources, traditional land use and air and greenhouse gas emissions. Following the field studies, we conducted extensive analysis to predict the effects associated with the Project, including those that could be caused by construction, operations, decommissioning or abandonment, as well as potential accidents and malfunctions. The information and analysis was used to develop our unique Environmental Protection Plans.
Mitigation strategies for avoiding or reducing potential environmental effects will be employed at all stages of the project. For more information about environmental mitigation methods and our Environmental Protection Plans, visit transmountain.com/environmental-protection-plans.
Stockpile Sites and Construction Yards
In 2017, Trans Mountain began preparing and activating two sites in Yellowheadto support construction related activity: (i) Northgate and (ii) Edson. These sites are being used for:
Preparing a Right-of-Way
- Delivery and storage of construction materials and equipment, including stockpiling and staging of pipe
- Installation of temporary office buildings or trailers to support construction crews building the pipeline and associated facilities
- Transportation of materials and equipment to and from the site
There are a number of steps involved in preparing the right-of-way for the arrival of construction crews and equipment, including clearing, flagging and installing temporary infrastructure. They include:
- Alberta One Call, locating and marking of all buried facilities
- Flagging and staking the right-of-way and any temporary workspace required for construction
- Installation of signage
- Clearing trees and vegetation from pre-approved areas essential for construction
- Disposing or burning of unsalvageable timber, like branches, tree limbs or shrubs left behind from clearing
Throughout these activities, we will implement environmental mitigation measures outlined in our Environmental Protection Plans. For more information, please view our Environmental Protection Plans at transmountain.com/environmental-protection-plans Utility Relocation
In some areas, where new right-of-way areas are required, Trans Mountain will work collaboratively with TELUS and/or BC Hydro to relocate utilities. This should not impact your services but you may see work crews in your area. Pipeline Construction
Once clearing is complete and access to the right-of-way has been established, crews will perform a series of steps within the construction footprint to facilitate installation of pipe in the ground:
- Remove topsoil and grade the surface to prepare for the arrival of bigger equipment and delivery of pipe segments
- Remove pipe from delivery trucks and lay down along right-of-way
- Weld pipe segments together and apply a protective coating
- Perform non-destructive examinations to ensure quality of welds
- Dig a trench and lower in pipe sections
- Backfill the trench to bed and protect the pipe
- Clean up and restoration activities. These include returning the right-of-way to its original grade, replacing any topsoil and replanting vegetation.
Where the pipeline crosses a body of water, one of three methods of construction will be used. The techniques for each are site-specific:
- Isolated method
- The stream is temporarily dammed and rerouted through temporary pumps or using piping often referred to as a flume. The pipe is then installed using conventional construction techniques before the dam is removed and the stream returned to its normal flow path. Great care is taken to preserve the environmental features around the stream, such as the wildlife and aquatic habitat provided within the riparian zone.
- Trenchless method
- This method leaves the bed and banks relatively undisturbed. A horizontal directional drill is used to drill under the watercourse, creating a path to pull the pipe back through. Horizontal directional drilling is only possible in the right geotechnical conditions and requires special environmental measures to be put in place.
- Open cut method
- If the other techniques cannot be used for environmental or geotechnical reasons, we will use an open cut crossing of the watercourse. Open-cut watercourse crossings trench directly through the watercourse following the conventional construction methodology.
Engineering feasibility assessments have been made to determine the most suitable crossing techniques to be used at each water crossing. Regulatory guidelines and standards will apply to all crossing methods, as will appropriate erosion and sediment control measures to ensure the safety of the body of water.
Learn more about pipeline construction and watercourse crossings at transmountain.com/building-a-pipeline Horizontal Directional Drilling
There will be Horizontal Directional Drilling (HDD) or Direct Pipe completed in the following areas:
- Highway 16 & Range Road 40
- Pembina River
- McLeod River
- Wolf Creek
- Highway 16 & CN Railway (Direct Pipe)
- Sundance Creek
- Hardisty Creek
HDD technique is used where the pipeline crosses roads and railways, for select watercourse crossings, and in places with restricted workspace such as in some urban or residential areas. This technique involves set up of a drill rig on one side of the crossing and equipment along the drill path. The pipe is assembled and welded on the opposite side to the drill setup, with the pipe string connected to the drill assembly and pulled back through the drill path. The Direct Pipe technique is similar to HDD, except the pipe is assembled and welded on the same side as the drill setup.
For more information on Horizontal Direction Drilling, please visit transmountain.com/building-a-pipeline Performing a Hydrostatic Test
Before the pipeline is ready to transport oil, a hydrostatic test is performed. A hydrostatic test is a way pipelines can be tested for strength and leaks. The test involves filling the pipe system with water and increasing pressure of the pipe to the specified test pressure. Should there be any leaks or weaknesses, they can be identified through this test and rectified. Hydrostatic testing is the most common method employed for testing pipes. Valve Installations
Valves are installed at intermediate locations as required by the pipeline design and the Canadian Standards Association pipeline code. The valves are used once the line is operational to shut off or isolate part of the pipeline. Valve installation will take place along the pipeline route once hydrostatic tests are completed. Pump Station Construction
Pump stations contain electric motors to drive the pumps that maintain the pressure and flow rate in the pipeline. Eleven new pump stations will be added along the route and one new pump station will be added on the existing pipeline. Ten of the new pump stations will be added at existing pump station facilities.
Construction of the pump stations involves the following steps within the pump station footprint:
- Site preparation, including clearing of any vegetation and installing fencing
- Install piles and pour concrete
- Mechanical equipment installation
- Piping and tie-ins (welding)
- Construction of structural steel and buildings
- Electrical installation and instrumentation
- Insulation and pre-commissioning
- Clean up and restoration activities
Pump station construction activities will take place over an 8- to 10-month period (timing subject to change)
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In the event of a pipeline emergency or to report odours, call 24 hours 1.888.876.6711