Eastern Mainline Project

On 30 October 2014, TransCanada PipeLines Limited (TransCanada) submitted an Application to the National Energy Board (NEB) for the proposed Eastern Mainline Project (Project). TransCanada filed project amendments on 17 December 2015.

The Project would consist of approximately 279 km of new gas pipeline and related components and would be constructed in four sections beginning near Markham, Ontario and finishing near the community of Brouseville, Ontario. About 203 km of the proposed 279 km pipeline would be installed adjacent to existing pipeline, railway and public highway rights-of-way. The Project would also include new and modified compression facilities at existing compressor stations along the proposed route.

The Project would enable TransCanada to continue to meet its commercial obligations following the proposed transfer of certain Canadian Mainline facilities to Energy East Pipeline Ltd. for the conversion of those facilities to crude oil from natural gas service (Asset Transfer). The Asset Transfer makes up a portion of the Energy East application. TransCanada is not, in this application, seeking approvals pursuant to Part IV of the NEB Act, relating to recovery of the cost of the Project through tolls.

If regulatory approval is obtained, TransCanada is proposing to start construction of the Project in Q3 2017 and anticipates the Project to be in-service by 31 March 2019.

The Application includes physical activities listed in the Regulations Designating Physical Activities (Regulations) under the Canadian Environmental Assessment Act, 2012 (CEAA 2012). As a result, the NEB anticipates that the proposed Project will be a designated project for the purposes of CEAA 2012 for which the NEB will be the responsible authority.

Once the NEB deems the Project Application to be sufficiently complete, the NEB will post a Notice of Commencement for the start of the CEAA 2012 environmental assessment and update any of the Project details above as necessary.

The NEB will also establish a public hearing process under the NEB Act to review the Application that will include a process for public participation.

TransCanada’s Application for the Project as well as further details regarding the NEB’s Hearing Process and Application to Participate Process can be found on the NEB’s website.

Consultation and Cooperation with Other Jurisdictions

Section 18 of the CEAA 2012 provides that, as the responsible authority for this Project, the NEB must offer to consult and cooperate with respect to the environmental assessment (EA) of the Project with any jurisdiction referred to in paragraphs (c) to (h) of the definition of “jurisdiction” in CEAA 2012 subsection 2(1) if that jurisdiction has powers, duties or functions in relation to an assessment of the environmental effects of the designated project. 

If you believe you are such a jurisdiction under CEAA 2012 section 18, please self-identify with the NEB describing how you meet the definition of jurisdiction and explain your relevant EA power, duty or function, as well as the activities your jurisdiction plans to undertake to exercise your powers, duties or functions to complete an EA of this designated project.  The Board’s assessment process often includes steps that might be relied upon by other jurisdictions that have EA powers, duties or functions, or may be able to provide other opportunities for cooperation with the EA process of eligible jurisdictions if timely notice is provided.  Accordingly, please write to the NEB as soon as possible and, in any event, no later than 10 days prior to the deadline for applying to participate with this information, so that opportunities can be explored.  

All correspondence should be addressed to the Secretary of the Board and filed by fax (1-877-288-8803), through the NEB’s e-filing tool (on the NEB’s website [www.neb-one.gc.ca] under Submit Applications and Regulatory Documents, then File a Letter of Comment), or mailed in hard copy to:

National Energy Board
517 Tenth Avenue SW
Calgary, Alberta  T2R 0A8


Latest update

October 10, 2017 - The assessment process has been terminated.


External links

Please note that access to external websites is provided solely as a courtesy. Users should be aware that the information offered by non‑Government of Canada websites that are not subject to the Official Languages Act might be available in only one language.


National Energy Board
517 Tenth Avenue SW
Calgary, Alberta T2R 0A8
Telephone: 1-800-899-1265
Email: easternmainline.processhelp@neb-one.gc.ca

  • Location

    • Belleville (Ontario)
    • Bowmanville (Ontario)
    • Brockville (Ontario)
    • Brouseville (Ontario)
    • Cobourg (Ontario)
    • Kingston (Ontario)
    • Markham (Ontario)
  • Nature of Activity

    • Oil and Gas
  • Assessment Status

  • Proponent

    TransCanada PipeLines Limited
  • Authorities

    • National Energy Board
  • Assessment Type

    Environmental assessment under CEAA 2012
  • Reference Number


This map is for illustrative purposes. The markers represent the approximate locations based on available data. More than one marker may be identified for a given assessment.

Nearby assessments

...within 200 kilometres
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