EDMONTON - The Transportation Safety Board says a replacement rail that broke caused a CN train to derail two years ago and spill oil into a popular Alberta lake.

The Aug. 3, 2005, accident dumped more than 700,000 litres of bunker C oil and chemicals onto the shore of Lake Wabamun west of Edmonton.

A report by the safety board released Thursday says management of the oil spill would have been more efficient if CN had better co-ordinated its emergency response plan.

It also says a better Alberta emergency response plan would have mitigated the impact of the spill.

The safety board is calling for the federal Transport Department to establish minimum standards for the quality and strength of maintenance rails and to establish standards for replacing rails.

The board also reiterated a recommendation made in 1993 for the department to reassess Canadian rail procedures and equipment used for testing tracks.

"In sports it is widely held that the best defence is a good offence,'' Wendy Tadros, chairman of the safety board, said as the report was released.

"A good offence to prevent rail failures means doing three things: ensuring more accurate rail testing, discarding fatigued rail and ensuring replacement rail can carry the load.''

CN President E. Hunter Harrison praised the safety board report and said the corporation has already taken some steps to prevent similar accidents.

He did not comment on any of the board's specific recommendations.

"The TSB report reflects a very thorough investigation of the unfortunate accident we experienced at Wabamun,'' Harrison said in a release.

"We made several commitments to clean up the lake to agreed environmental standards, to fairly and promptly compensate those affected, and to work with all stakeholders to restore full use of the lake.''

Just over a month ago, health officials were still warning people not to go into the lake if they see oil, tar balls or oiled aquatic vegetation.

A separate report to Ottawa prepared by people who live near the lake year-round said CN appeared to be more concerned with getting trains moving on the line than in protecting the lake's ecosystem.

The residents said CN did not respond quickly enough to the accident and suggested the federal government should review train speeds and the stability of rail lines to prevent future derailments.

Resident David Hardy said he is pleased with the Transportation Safety Board's findings. But he cautioned that people who live near rail lines won't be safer until the federal government and the rail industry act on the recommendations.

"If they are acted upon we will be satisfied,'' he said.