From the outset of Project planning, Trans Mountain developed routing principles to guide our routing decisions. When determining the route, we took into consideration community land use, including residences, commercial, recreation and parks, and environmentally sensitive areas, including water crossings, wetlands and wildlife.

With the aid of community input, along with environmental, engineering and economic studies, the new pipeline will follow the existing right-of-way for 73 per cent of the route. An additional 16 per cent will follow existing utility corridors and the final 11 per cent of the new pipeline will be built away from the existing pipeline to accommodate urban development occurring since 1953.

The Lower Mainland has seen considerable change in the past six decades since the original Trans Mountain pipeline was built. This is why we chose to route the expanded pipeline away from residential neighbourhoods and parallel the Trans-Canada Highway instead through the cities of Coquitlam and Burnaby. By following this existing transportation corridor, we will reduce impacts to a significant number of residents and existing infrastructure. The route through the Lower Mainland has been approved by the Canada Energy Regulator and construction is scheduled to begin in the coming months.

At Trans Mountain, we take our commitment to environmental protection seriously. As part of the Expansion Project, substantial work has gone into determining environmental impacts and mitigation methods to reduce the impact to the environment. Our goal is to protect the environment, have as little impact as possible and, where possible, ensure we are returning the land to its original function. 

Tree Removal 

For 900 metres, the expanded Trans Mountain pipeline will follow The Trans-Canada Highway, on privately owned lands, north of BNSF railway in Burnaby. Pipeline construction in this area will take place primarily using a narrow open-cut trench method as this method requires the least amount of temporary workspace. To accommodate construction and the safe operation of the new pipeline, forestry crews are required to clear land and remove trees located along the pipeline right-of-way and temporary workspace, also referred to as the construction footprint.

The newly installed Trans Mountain pipeline will be constructed between the rail and highway corridors

This work complies with necessary approvals, permits and Project Environmental Protection Plans and will be monitored by experienced environmental inspectors. In addition, qualified forestry professionals will be on-site during key activities to provide oversight of tree and forest health protection measures to minimize potential impacts to adjacent forested ecosystems and landscapes.

A 10-metre permanent right-of-way, as well as temporary workspace ranging from 20 to 30 metres, will be required in this area for construction and access. Trans Mountain’s typical pipeline right-of-way is 18 metres wide, however, recognizing the value placed on green space in urban communities, the permanent right-of-way for the new pipeline will be reduced to 10 metres.

Although the pipeline easement itself will not be replanted with replacement trees, the temporary workspaces where trees are removed will be reforested once construction is complete.

Trans Mountain is required by federal regulation to achieve aerial clearance and access along the pipeline corridor to ensure the safe operation, maintenance and integrity of the pipeline. While trees will not be re-planted within the 10-metre right-of-way, this area will be revegetated with compatible native grasses and an ecologically appropriate mix of native, low growing shrubs and herbaceous species.

Whether it’s the pipeline easement or temporary workspace areas, Trans Mountain has developed its ecosystem-based reclamation plans with considerations for the native grasses, plant and tree species found naturally in the local area and are included within or adjacent to the construction footprint. We will work with the municipality to develop reclamation plans that meet their interests to the extent practicable.

Stream Crossings

Within this area, the Project crosses Lost/Austin Creek and Holmes Creek. Trans Mountain recognizes the importance of these streams within an urban setting and has long-standing positive working relationships with local streamkeeper groups who successfully nurture streams and the fish species they support within this watershed.

A lot of time and care has gone into determining construction methodology and environmental precautions during Project construction to protect streams. Both Lost/Austin Creek and Holmes Creek will be crossed using the isolated watercourse crossing method. This is where stream flow is temporarily diverted around the crossing location for a short duration while trenched construction occurs across the watercourse. Once the trench is constructed and the pipe is installed, the trench is backfilled and channel bed and banks restored, and the water is restored to its natural channel. For smaller watercourses, a typical diversion may be as short as a few hours or up to a few days. During this type of construction, if the watercourse is fish-bearing, fisheries biologists will salvage fish from the isolated area and release them upstream. Water quality is also monitored during and after construction in all fish-bearing watercourses.

As with tree removal, this work complies with necessary approvals, permits and Project Environmental Protection Plans, including a Riparian Habitat Protection Plan, and will be monitored by experienced environmental inspectors.

Wildlife Protection

Teams have worked diligently in the field collecting survey data on the forested areas in the construction footprint to identify potential impacts to any number of environmental features, including fish and wildlife habitats and overall ecological function.

Trans Mountain’s Pipeline Environmental Protection Plan (EPP) is a compilation of environmental protection procedures, mitigation measures and monitoring commitments related to pipeline construction. It’s been developed to communicate environmental procedures and measures to the Project pipeline construction and inspection personnel in a clear and concise format. Its objective is to avoid, reduce or mitigate potential adverse environmental effects from construction, including pre- and post-construction phases.

The Pipeline EPP includes detailed environmental alignment sheets that provide site-specific information pertaining to the environmental and socio-economic setting for each kilometre of the construction footprint. The alignment sheets include information on the type of habitat present, as well as any terrestrial features, such as wildlife, that are present.

Trans Mountain has more than 60 environmental protection and management plans relating to specific aspects of construction.


Post-construction environmental monitoring is a key aspect of our environmental plans. As well, there’s an ecosystem-based reclamation management plan outlining general reclamation measures applicable to all lands disturbed by the Expansion Project construction footprint.

The plan provides mitigation measures pertaining to pre-construction and construction activities that can affect reclamation once construction is complete. It also provides reclamation measures pertaining to natural regeneration; seed mixes; seed application techniques; native plant material procurement; bio-stabilization and erosion control.

Once reclamation is complete, the land is monitored for a minimum of five years. If the land hasn’t recovered — for example, if native plants or shrubs are struggling to re-establish themselves — Trans Mountain will amend the area as needed and reseed or replant to ensure vegetation establishment is successful.