Update -- TransCanada Places Final Section of 2017 NGTL Expansion Program into Service

CALGARY, Alberta, April 03, 2018 -- Media Advisory – TransCanada Corporation (TSX:TRP) (NYSE:TRP) (TransCanada) today announced its Northwest Mainline Loop-Boundary Lake pipeline has been placed into service, completing the final section of its 2017 Expansion Program on the NOVA Gas Transmission Ltd. (NGTL) System. With the completion of winter construction activities, the 2017 Expansion Program represents a $1.7 billion investment in Canadian natural gas infrastructure, and connects low-cost, clean-burning natural gas from northwest Alberta and northeast British Columbia to the NGTL System.

The 2017 Expansion Program added approximately 230 kilometres (km) of new pipeline and additional compression facilities and increased the NGTL System capacity by approximately 500 million cubic feet per day. In addition, it generated an estimated $800 million in labour income during the construction phase and will add an estimated $1.2 billion in gross domestic product in Canada.

“We continue to focus on optimizing the competitiveness of the NGTL System and services and expanding our established transportation network to connect growing volumes of Western Canadian Sedimentary Basin natural gas to markets across North America,” said Tracy Robinson, TransCanada’s senior vice-president and general manager, Canadian Gas Pipelines. “Projects like the 2017 NGTL Expansion program demonstrate our strong focus on future growth opportunities for producers and we are working with industry to address their needs for long-term, safe and reliable transportation service.”

The 2017 Expansion Program is part of TransCanada’s commitment of more than $7 billion in near-term growth capital to the NGTL System that will, subject to regulatory approvals, allow the company to increase its delivery capacity of clean-burning natural gas on the system by 2.5 billion cubic feet per day by 2021. Completion of the 2017 Expansion Program follows consecutive, successful, over-subscribed open seasons to connect growing basin supply to downstream markets across North America, as well as a negotiated revenue requirement settlement that provides NGTL customers with cost certainty for 2018-2019.

The NGTL System is an extensive natural gas pipeline system in Western Canada that is comprised of approximately 24,320 km of pipeline and associated facilities.

With more than 65 years' experience, TransCanada is a leader in the responsible development and reliable operation of North American energy infrastructure including natural gas and liquids pipelines, power generation and gas storage facilities. TransCanada operates one of the largest natural gas transmission networks that extends more than 91,900 kilometres (57,100 miles), tapping into virtually all major gas supply basins in North America. TransCanada is a leading provider of gas storage and related services with 653 billion cubic feet of storage capacity. A large independent power producer, TransCanada currently owns or has interests in approximately 6,100 megawatts of power generation in Canada and the United States. TransCanada is also the developer and operator of one of North America’s leading liquids pipeline systems that extends approximately 4,900 kilometres (3,000 miles), connecting growing continental oil supplies to key markets and refineries. TransCanada’s common shares trade on the Toronto and New York stock exchanges under the symbol TRP. Visit TransCanada.com to learn more, or connect with us on social media and 3BL Media.

FORWARD-LOOKING INFORMATION

This publication contains certain information that is forward-looking and is subject to important risks and uncertainties (such statements are usually accompanied by words such as "anticipate", "expect", "believe", "may", "will", "should", "estimate", "intend" or other similar words). Forward-looking statements in this document are intended to provide TransCanada security holders and potential investors with information regarding TransCanada and its subsidiaries, including management's assessment of TransCanada's and its subsidiaries' future plans and financial outlook. All forward-looking statements reflect TransCanada's beliefs and assumptions based on information available at the time the statements were made and as such are not guarantees of future performance. Readers are cautioned not to place undue reliance on this forward-looking information, which is given as of the date it is expressed in this news release, and not to use future-oriented information or financial outlooks for anything other than their intended purpose. TransCanada undertakes no obligation to update or revise any forward-looking information except as required by law. For additional information on the assumptions made, and the risks and uncertainties which could cause actual results to differ from the anticipated results, refer to the Fourth Quarter 2017 Financial Highlights release and 2017 Annual Report filed under TransCanada's profile on SEDAR at www.sedar.com and with the U.S. Securities and Exchange Commission at www.sec.gov.

Media Inquiries:
Shawn Howard  
403.920.7859 or 800.608.7859

TransCanada Investor & Analyst Inquiries:
David Moneta / Stuart Kampel
403.920.7911 or 800.361.6522