CALGARY - To help quell concerns about the proposed Northern Gateway project, Enbridge will enhance the pipeline's wall thickness in sensitive areas, the company announced Friday.

"We recognize there are concerns among some Aboriginal groups and the public about pipeline safety, particularly around sensitive habitats in remote areas," said Janet Holder, executive vice-president of Western access.

"And after years of consultation with stakeholders and after personally attending many of the regulatory hearings for Northern Gateway, it has become clear to me we have to do everything we can to ensure confidence in the project."

As a result, Enbridge will increase the pipeline's wall thickness at water crossings, along with upping the number of remotely-operated isolation valves and increasing in-line inspection surveys to at least 50% above the current standard.

"These isolation valves will be placed on each side of major tributaries to the Fraser, Skeena, Kitimat and Athabasca Rivers to provide enhanced protection in sensitive habitats," Holder said.

Dual leak detection systems will also be installed and pump stations will be staffed in remote areas 24/7.

"This will further enhance on-site monitoring, security and rapid response," Holder said.

Cost of the upgrades is expected to run between $400 and $500 million, Holder said.

The thickness of the pipeline will be increased significantly, engineering manager Ray Doering said.

"For the 36-inch diameter oil pipeline, the current design has an average .67 inch wall thickness, which is about 17 millimetres," he said.

"We're looking at several potential design enhancements, potentially including reducing the operating stress of the pipeline, which wold provide an overall wall thickness increase really, from one end of the pipeline to the other, likely in the range of about 10%.

"And we're looking at increasing wall thickness over and above that in sensitive areas as well."

The Northern Gateway project would see a 1,177 km pipeline stretch from Bruderheim, Alta. to Kitimat on the northern B.C. coast.