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Regulatory matters and revenues subject to refund | 9 Months Ended
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Sep. 30, 2011
Regulatory matters and revenues subject to refund [Abstract] |
Public Utilities Disclosure |
17. | Regulatory matters and revenues subject to refund
| On May 20, 2011, Montana-Dakota filed an application with the NDPSC requesting advance determination of prudence that the addition of the air quality control system at the Big Stone Station, to comply with the Clean Air Act and the South Dakota Regional Haze Implementation Plan, is reasonable and prudent. A hearing is scheduled for November 29, 2011, and an order is expected in early 2012.
| On July 7, 2011, Montana-Dakota filed for an advance determination of prudence with the NDPSC on the construction of an 88-MW simple cycle natural gas turbine and associated facilities projected to be in service in 2015. The turbine will be located on company owned property that is adjacent to Montana-Dakota's Heskett Generating Station near Mandan, North Dakota, and would be used to meet the capacity requirements of Montana-Dakota's integrated electric system service customers. The capacity will be a partial replacement for third party contract capacity expiring in 2015. Project cost is estimated to be $85.6 million. An order is expected in the first quarter of 2012.
| In August 2010, Montana-Dakota filed an application with the MTPSC for an electric rate increase. Montana-Dakota requested a total increase of $5.5 million annually or approximately 13 percent above current rates. The requested increase included the investment in infrastructure upgrades, recovery of the investment in renewable generation, the costs associated with Big Stone Station II and the significant loss of wholesale sales margins. Montana-Dakota requested an interim increase of $3.1 million or approximately 7.4 percent. On February 8, 2011, the MTPSC approved an interim increase of $2.6 million or approximately 6.28 percent, effective with service rendered February 14, 2011. On May 9, 2011, Montana-Dakota and intervenors to the case filed a settlement agreement with the MTPSC at the interim increase level. The MTPSC held a hearing on the settlement on June 29, 2011, and approved the settlement agreement on July 26, 2011. Final rates were implemented effective with service rendered September 1, 2011.
| On March 21, 2011, the WUTC filed a complaint against Cascade, alleging safety violations in the operations of its natural gas distribution system. For more information, see Note 18.

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