PIERRE, S.D. (KELO) — South Dakota customers who buy electricity from Otter Tail Power will pay a little less starting September 1.

The state Public Utilities Commission on Tuesday approved a revised rate schedule. The average residential customer using 1,000 kilowatt-hours per month will see a monthly decrease of approximately $3.29, according to a memo from the commission’s staff.

Among the South Dakota communities served by Otter Tail Electricity are Astoria, rural Blue Dog Lake, Brandt, Britton, Bruce, Bushnell, Castlewood, Claire City, Clear Lake, Corona, De Smet, Dempster, Eden, Egan, Elkton, rural Enemy Swim Lake, Erwin, Gary, Grenville, Hammer, Hayti, Hetland, Hillhead, Kidder, Labolt, Lake City, Lake Norden, Lake Preston, Marvin, Milbank, New Effington, Newark, Nunda, Oldham, Ortley, Peever, rural Pickerel Lake, Revillo, Rosholt, Roslyn, Rutland, Sisseton, South Shore, Stockholm, Strandburg, Summit, Toronto, Trent, Twin Brooks, Veblen, Victor, Ward, Waubay, Wentworth, White Rock and Wilmot.

Otter Tail is using revenue from a phase-in rider to recover costs from adding the Merricourt (N.D.) wind project, the Astoria (S.D.) natural-gas project, the Ashtabulla III (N.D.) wind project and advanced grid infrastructure projects.

Commissioner Chris Nelson asked whether Otter Tail’s customers will see a “whip-saw” effect from higher rates next year. The Merricourt expense should stay the same, commission analyst Brittany Mehlhaff answered. “But we will see other costs going up,” she acknowledged.

Commission chair Kristie Fiegen said she was “grateful” for the addition of the Astoria gas plant and more large-user revenue flowing in. Regarding the current decrease, Fiegen said, “That’s always nice to see.”