Keystone Pipeline Now Operational

CALGARY, ALBERTA--(Marketwire - May 13, 2011) - TransCanada Corporation (TSX:TRP) (NYSE:TRP) (TransCanada) today announced it has re-started its Keystone Pipeline system. The line has been closed since May 7 following an above-ground incident at a pump station in Sargent County, North Dakota.

More than 30 workers and their equipment have been on site at the Ludden Pump Station. Three hundred and ninety three barrels of oil have been recovered out of an estimated 500 barrels. Three hundred cubic yards of contaminated soil will be removed to an approved location and replaced with clean soil and gravel. The majority of the clean-up should be finished by the weekend.

"TransCanada has taken this incident very seriously. We have fully communicated details regarding the incident and our corrective actions to our U.S. regulator PHMSA in ensuring the steps we have taken will enable us to safely re-start the pipeline," said Russ Girling, TransCanada president and chief executive officer. "We reacted quickly, shutting down the line within a few minutes of detecting a drop in pressure, demonstrating our safety systems work effectively."

All government agency notifications were made in a timely manner and in accordance with regulatory requirements. Under the guidance of the North Dakota Department of Health, crews have spent the last week cleaning up the oil that was released on our property and some oil mist that drifted into a nearby field.

The oil release was caused by a faulty three-quarter inch fitting – approximately the diameter of a garden hose. TransCanada has re-inspected all similar fittings at its pump stations in the United States and Canada and we have taken proactive steps to install sturdier fittings as a precaution.

TransCanada is working with federal and state regulatory agencies, being open and transparent with all information and cooperating with the agencies and officials to ensure their questions have been answered and their concerns met.

With the re-start today, TransCanada will be able to move all volumes nominated by our customers for the month of May.

With more than 60 years experience, TransCanada is a leader in the responsible development and reliable operation of North American energy infrastructure including natural gas and oil pipelines, power generation and gas storage facilities. TransCanada's network of wholly owned natural gas pipelines extends more than 57,000 kilometres (35,500 miles), tapping into virtually all major gas supply basins in North America. TransCanada is one of the continent's largest providers of gas storage and related services with approximately 380 billion cubic feet of storage capacity. A growing independent power producer, TransCanada owns, or has interests in, over 10,800 megawatts of power generation in Canada and the United States. TransCanada is developing one of North America's largest oil delivery systems. TransCanada's common shares trade on the Toronto and New York stock exchanges under the symbol TRP. For more information visit: www.transcanada.com.

TransCanada
Media Enquiries:
Terry Cunha/Shawn Howard
403.920.7859 or 800.608.7859

TransCanada
Investor & Analyst Enquiries:
David Moneta/Terry Hook/Lee Evans
403.920.7911 or 800.361.6522
www.transcanada.com