Efforts are underway to restore service to 37,000 customers in eastern Washington and northern Idaho in the wake of the “largest natural gas outage” in Avista’s history.

A worker using an excavator in the vicinity of Colfax, Wash., dug into the Williams Northwest Pipeline the afternoon of Nov. 8, according to the Washington Utilities and Transportation Commission, which regulates private, investor-owned electric and natural gas utilities.

“We cannot emphasize enough that it is important and required to call 811 before excavating,” said Amanda McCarthy, assistant director of communications for the commission. “If you are planning on digging or excavating a piece of land, you must call 811 before beginning the project. You never know what utilities lay just below the ground surface.”

McCarthy did not yet have an estimate for the cost of the damage.

Penalties under Washington state dig laws include the possibility of criminal punishment and civil fines.

“We are still completing the investigation, which will help us determine next steps,” McCarthy said.

The damaged gas pipeline supplies Avista’s natural gas for the region.

The damage resulted in natural gas outages for Avista customers in the areas of Pullman, Moscow, Albion, Palouse, Uniontown, Colton, Genesee, Troy, Bovill, Deary, Asotin, Lewiston and Clarkston. 

Gas company crews went home to home on the Palouse in eastern Washington and northern Idaho to manually shut off natural gas meters.

“The impact of this incident has affected an estimated 37,000 customers,” Avista stated. “The restoration process involves many steps that will take time to ensure the safety of our customers and our employees.”

Avista anticipated being able to start the relight of natural gas appliances as soon as possible Nov. 10, the company said in a post on Facebook. “Once the relight process starts, the complete natural gas restoration for Avista customers is estimated to be three to five days.”

Shutting off the meters is a required step to prepare the system before relighting can take place. To assist Avista crews, the company encouraged home and business owners to make sure any gates leading to natural gas meters are unlocked.

“Once the gas has been shut off, do not turn it back on,” Avista said. “Only Avista can turn it back on.”