The shale boom that has provided the Pacific Northwest region stocked with natural gas at consistently affordable prices, the Northwest Gas Association (NWGA) said in its latest newsletter.

“Over the past year, NWGA member utilities have adjusted rates downward as a reflection of continued falling prices [spurred by robust shale production],” said Dan Kirschner, executive director of the regional trade association covering Idaho, Oregon and Washington.

Typical of actions throughout the region, Oregon regulators recently reduced gas utility rates for the upcoming winter, noting that Portland-based NW Natural’s rates will drop about 11%, saving typical residential customers about $4/month.

The Oregon Public Utility Commission (PUC) said commercial rates should drop 12.6% and industrial about 21%. PUC-approved rate changes were similar for the state’s other two gas utilities. Spokane, WA-based Avista Utilities’ Oregon customers will see similar decreases for the residential (12.6%), commercial (16.2%) and industrial (22.3%) sectors. And Cascade Natural Gas customers will see 6.6%, 7.5% and 13.5% rate decreases for the same three respective customer groups.

On Thursday the Washington Utilities and Transportation Commission (UTC) decreased gas rates for Puget Sound Energy’s customers in six counties by 15.4%, effective Sunday (Nov. 1), offering an average monthly savings of more than $12. The UTC said Avista’s gas customers in eastern Washington will see similar rate decreases.

In Idaho, rates for customers of Intermountain Gas Co. declined an average of 5.7%, effective Oct. 1. The Idaho Public Utilities Commission (PUC) approved the company’s annual purchased gas cost adjustment (PGA), adjusting rates up or down every annually to account for the portion of wholesale gas supply expense that changes every year.

“Lower wholesale prices for natural gas and a decrease in transportation costs billed to Intermountain by its supplier, Northwest Pipeline GP, contributed to this year’s reduction,” the regulators said. The $15.3 million passed on to customers is about a 6.1% decrease to customers who use natural gas for space and water heating, a 3.56% decrease to those who use natural gas for space heating only and a 5.6% reduction for commercial customers.

With the latest adjustments, Intermountain’s combined residential and commercial rates are 35% lower than in 2005, a utility spokesperson said.