Intermountain Gas Co. wants to reduce the rates of residential customers who use natural gas for both water and space heating by 3.1 percent or about $1.51 per month effective Oct. 1, according to Idaho utility regulators.

For residential customers who use natural gas for space heating only, the proposed decrease is 0.4 percent or about 17 cents a month. For commercial customers, the proposed decrease is also 3.1 percent, or about $6.46 per month. These adjustments would lower the company’s annual revenue by $6 million.

Intermountain also has proposed a one-time credit of $3.7 million to customers in December as a result of credits that accrued before the purchased gas cost adjustment last February. For residential customers who use natural gas for both space and water heating, the one-time credit would be about $29.85. Residential customers with gas space heating only would get a credit of about $19.40. Commercial customers would get about $129.80.

The Idaho Public Utilities Commission will take comments through Sept. 20. Comments are accepted via email at www.puc.idaho.gov by clicking on "Comments & Questions About a Case." Fill in the case number (INT-G-12-01) and enter your comments. Comments also can be mailed to P.O. Box 83720, Boise, ID 83720-0074 or faxed to (208) 334-3762.