The Montana Public Service Commission recently approved by a 4-1 vote a new natural gas rate for NorthWestern Energy’s 182,000 customers, most of which are in western and central Montana. This is the first permanent rate increase approved by PSC since 2008.

The PSC had approved a temporary rate increase for NorthWestern in March that went into effect April 1. The new and final rate, which is lower than the temporary rate, will go into effect in June. The company will reimburse customers for the difference between the two rates for the months of April and May.

The increase will pay for delivery and storage of natural gas, not the cost of the gas itself, which fluctuates with market prices. Customers on average will see a $3.72 monthly increase over the pre-April 1 rate. The approved rate is 4.6 percent higher than the pre-April 1 rate.

NorthWestern Energy will take in about $11.5 million more from the rate increase, which it says it needs to pay for pipelines and other infrastructure improvements. That’s about $4 million less than the company had requested last fall.