Bismarck (CSi) On a 2-1 vote, the ND PSC has approved the design of a natural gas rate increase for Montana-Dakota Utilities.

PSC Chairman Brian Kalk agreed with the AARP in opposing how the increase was structured.

In December of 2013 the PSC had approved a rate increase that allowed MDU to increase revenues by 4 percent, or $4.25 million, and how that would be collected from customers was decided on Wednesday.

Under the approved rate design, MDU residential customers will pay $17.51 per month in customer charges. That’s an average increase of $2.17 per month.

Officials say most customers won’t see their bills increase because they’ve been paying an interim rate hike since November 17, 2013.

However, customers may notice the difference in the breakdown of charges on their bills.

MDU wanted to double the fixed charge to residential customers from about $9 to $18 and eliminate a separate distribution delivery charge. The AARP testified against such a large flat-rate increase, urging the PSC instead to land roughly in the middle at a fixed charge of $13.60.

Commission Chairman Kalk said he agreed with that approach.

Commissioner Julie Fedorchak said MDU customers who have natural gas service for a single use, such as a grill or to heat a shop, are most likely to notice the higher fixed charge.

MDU serves 99,000 natural gas customers in 76 communities in North Dakota, including Jamestown, Valley City, Bismarck, Devils Lake, Dickinson, Minot, and Williston. About 87 percent of those are residential customers.