By Julie Gordon
VANCOUVER, Oct 10 (Reuters) - Canada'sEnbridge Inc said on Wednesday it had approval to restart operations on a 30-inch natural gas pipeline in northern British Columbia, after a fire in an adjacent line led to disruptions for refineries in the U.S. state of Washington.
The company isolated and depressurized a 36-inch pipeline, which carries gas to the Pacific Northwest, after it ruptured on Tuesday evening causing gas to ignite. An adjacent 30-inch pipeline was also depressurized for safety.
The company has begun a process that will last several hours to return the line to service and plans to gradually bring the pressure up to about 80 percent of normal operating capacity.
Once this is safely completed, some of the capacity would be restored, Enbridge said.
Royal Dutch Shell had said it was "proactively shutting units down" at its Puget Sound refinery in Washington state due to the incident and Phillips 66 said it was adjusting operations at its Ferndale refinery, also in Washington state.
FortisBC, British Columbia's energy utility, declared force majeure on Wednesday on several of its rate schedules which informed shippers their delivery of gas was being curtailed.
The company estimates about 70 percent of its roughly 1 million customers could lose gas supply due to the incident.
FortisBC earlier asked customers to avoid non-essential use of gas and said there could be service disruptions. Puget Sound Energy, Washington state's energy utility, issued a similar notice.
Enbridge earlier said it was maintaining a 1 km (0.6 mile) evacuation zone around the site and was working with regulators on investigating the cause of the incident.
NEB said it had sent a team to the site and was working with the company and other affected parties on the emergency response and investigation.
The rupture occurred near the city of Prince George in British Columbia's northeast. About 100 people were evacuated from their homes in a nearby Aboriginal community on Tuesday as a precautionary measure. There were no injuries.
Shares of Enbridge closed down 2.3 percent at $42.61 on the Toronto Stock Exchange as the broader Canadian energy index slipped 3.7 percent on falling oil prices.