The Idaho Public Utilities Commission approved Intermountain Gas Company’s purchased gas adjustment that will lower gas bills by about 10 percent for residential customers and 11.9 percent for commercial customers on Oct. 1, according to a Sept. 26 press release. The annual adjustment reflects changes in the costs incurred by the utility to purchase, store, and transport gas needed to serve its customers. The utility attributed the change to factors including lower transportation costs and a decrease in the weighted average cost of gas. Benefits stemming from the company’s management of storage and capacity rights on pipeline systems, as well as changes in federal and state corporate income tax laws contributed to the change. Some industrial customers are expected to see an increase in rates. Intermountain Gas is a subsidiary of MDU Energy Capital LLC.