The Enbridge Mainline

Mainline System Capacity

The current average annual capacity on the Mainline System is approximately 3 million bpd out of Western Canada.  A series of pipelines run between Edmonton, Alberta and Superior, Wisconsin and four pipelines extend the system beyond Superior, providing access to markets in Minnesota, Illinois, Indiana, Ohio, Michigan and Ontario. Enbridge also has market access pipelines connected to the Mainline that serve markets in Eastern Canada, Cushing, Patoka and the U.S. Gulf Coast (USGC).

Despite the increasing challenges in permitting major infrastructure projects, between 2013 and 2019 Enbridge successfully placed into service more than 1.265 million bpd of additional system capacity upstream of Superior and more than 1.65 million bpd of additional system capacity downstream of Superior. These projects have enabled production growth from the WCSB and Bakken regions to move to prime markets and have provided Enbridge with the flexibility to optimize the operations of the Mainline System to become even more safe and reliable.

Enbridge Mainline system map
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Recent Expansions

Enbridge delivered a record 2.845 million bpd ex-Gretna in December 2019 by putting the Canadian portion of the Line 3 Replacement Project and other Canadian Mainline optimization projects into service.

Mainline Tankage and Terminalling

In 2018 and 2019, Enbridge continued making upgrades to a number of terminals across the network, with the goal of maximizing throughput and increasing the level of service provided to our customers. This year, Enbridge will continue to support customer-initiated projects, as well as explore further opportunities to optimize the terminalling assets.

Line 3 Replacement Program

After receiving shipper support in 2014 to replace Line 3 from Hardisty to Superior, Enbridge continues to develop the approximately $8.2-billion program to maintain and enhance our Canadian and U.S. Mainline systems. This is the largest project in Enbridge’s history and involves replacing all remaining segments of Line 3 between Hardisty and Superior with 1,660 kilometers (1,031 miles) of new pipe, using the latest available high strength steel and coating technology. The Line 3 Replacement Program (L3RP) will also substantially reduce long-term adverse impacts to landowners and the environment caused by conducting numerous preventative maintenance digs to maintain the line. The L3RP will support the safety and operational reliability of the overall system, enhance flexibility and allow Enbridge to restore 370,000 bpd of capacity and optimize throughput on the Mainline system's overall Western Canada export capacity. When completed, the L3RP will provide landowners and shippers with a new pipeline that restores the historical operating capabilities of Line 3 to move approximately 760,000 bpd in mixed-product service.

Construction of the $5.3-billion Canadian portion of the L3RP is complete; the new line began commercial service in December 2019. Throughout the construction period in Canada, Enbridge has delivered on our commitments and maintained relationships with all our stakeholders including landowners, Indigenous communities, the Canadian Energy Regulator and all levels of government, which was crucial to the completion of the project.

In the United States, the 14-mile Wisconsin segment of the L3RP is complete and was brought into service in 2018. In addition, Enbridge has secured all necessary permits to construct the 13-mile North Dakota segment of the project.

In Minnesota, permits are required before L3RP construction can begin. In early 2020, Enbridge achieved another milestone when the Minnesota Public Utilities Commission approved the revised Final Environmental Impact Statement for the L3RP and reaffirmed the project’s Certificate of Need and Route Permit. The L3RP has strong support in Minnesota, including from communities along the route. Enbridge remains actively involved in the ongoing state and federal permitting processes; remaining requirements are progressing, and Enbridge is expecting to complete the project as expeditiously as possible upon receipt of all outstanding permits.

Upstream of Superior System Enhancements

Beyond Enbridge’s secured slate of projects, the Mainline system is well positioned to offer scalable, low-cost and highly executable expansion projects to meet the transportation needs of industry, particularly in this time of uncertainty. Given the multi-pipeline configuration of the Mainline system, several low-cost system optimization and expansion options are available. These system enhancements can be achieved by employing new crude slates and drag reducing agent injections, as well as minimizing delivery windows across our system. These system enhancements could potentially provide incremental capacity of up to 350,000 bpd ex-WCSB.

Downstream of Superior System Enhancements

Beyond Enbridge’s secured slate of projects, the Mainline system is well positioned to offer scalable, low-cost and highly executable expansion projects to meet the transportation needs of industry, particularly in this time of uncertainty. Given the multi-pipeline configuration of the Mainline system, several low-cost system optimization and expansion options are available. These system enhancements can be achieved by employing new crude slates and drag reducing agent injections, as well as minimizing delivery windows across our system. These system enhancements could potentially provide incremental capacity of up to 350,000 bpd ex-WCSB.

System Optimization

Enbridge continues to review its system configuration to maximize value to customers.

With the significant pressure to add egress out of Western Canada, Enbridge has placed a key focus on increasing pipeline capacity. Since 2015, significant progress has been made to optimize system performance and capacity out of Western Canada, increasing capacity by 600,000 bpd.  This includes incremental capacity of 165,000 bpd offered in 2019 from capacity recoveries on Lines 4 and 2A, putting Canadian Line 3 in service and window optimizations.

The optimization process examines several factors including:

  • Overall system capacity
  • Expected throughput/capacity by commodity/crude slate
  • Maintenance aligned with customer maintenance
  • System reliability
  • Current pressure restrictions
  • Product quality
  • Line-fill requirements
  • Facility interconnection capabilities
  • Power and integrity costs
  • Maximizing scheduling windows
  • Drag Reducing Agent (DRA)

Improvements made on these factors have increased the system operating efficiency and overall throughput offered to industry. The Enbridge Mainline offers a one-of-a-kind system related to shipper optionality and flexibility across North America, which allows quick response to supply/demand disruptions via its multiple pipelines, terminal facilities and access to several markets. Enbridge will continue to optimize the above factors to maximize throughput offered to the market.

Mainline Tolls

Maintaining toll certainty and competitiveness for our customers is a significant focus for Enbridge.

The Enbridge Canadian Mainline system is currently tolled as per the Competitive Tolling Settlement (CTS), a 10-year tolling agreement with shippers that expires June 30, 2021. The CTS provides for a U.S. dollar denominated International Joint Tariff (IJT) for crude oil shipments originating in Canada on the Enbridge Pipelines Inc. (EPI) system and delivered in the U.S. off the Lakehead system. Local rates for service on the U.S. portion of the Mainline system are not affected by the CTS and continue to be established by Lakehead’s existing tolling agreements. Replacing the expired CTS will be a new tolling arrangement that will have a U.S. dollar denominated IJT while providing priority access on a contract basis on the Canadian Mainline. Contracts offered will be available for term lengths of up to 20 years and contain flexible commercial terms for all shippers while providing long-term toll stability and certainty.

The new commercial framework will reserve a minimum 10% of the Canadian Mainline capacity as spot service. Enbridge has submitted the application for the new tolling arrangement to the CER and expects a decision in Q1 2021 at which time Enbridge will hold a subsequent Open Season.