03-17198. Exira Station Project in Audubon County, Iowa

AGENCY:

Western Area Power Administration, DOE.

ACTION:

Notice of wetlands involvement.

SUMMARY:

The Western Area Power Administration (Western) has been approached by the Western Minnesota Municipal Power Agency (WMMPA) and Missouri River Energy Services (MRES) with a request for interconnection of the Exira Station Project (Project) with Western's electric transmission system. The Project, as proposed, would be a gas-fired (with fuel oil backup) electrical peaking plant with an estimated yearly electrical output averaging less than 50 megawatts (MW). Project construction would expand an existing 0.03-acre pond to approximately 0.18 acres for stormwater and process water retention and develop a new 0.46-acre pond for stormwater retention. This represents a wetland action and Western will prepare a wetland assessment as part of its Environmental Assessment.

DATES:

Comments on the proposed wetland action are due to the address below no later than July 23, 2003.

ADDRESSES:

Comments should be addressed to Mr. Nick Stas, Environment Manager, Upper Great Plains Customer Service Region, Western Area Power Administration, P.O. Box 35800, Billings, MT 59107-5800, fax [phone], e-mail [e-mail].

FOR FURTHER INFORMATION CONTACT:

Mr. Dirk Shulund, Environmental Protection Specialist, Upper Great Plains Customer Service Region, Western Area Power Administration, P.O. Box 35800, Billings, MT 59107-5800, fax [phone], e-mail [e-mail].

SUPPLEMENTARY INFORMATION:

WMMPA and MRES are proposing to construct the Project in Audubon County, near the towns of Exira and Brayton, Iowa. The Project would occupy about 13 acres of a 76-acre parcel that would be owned by WMMPA. The Project would consist of two turbines, each with a net generating capacity of 45 MW. The turbines would also use diesel fuel oil as a backup during unforeseen natural gas curtailments or during times of high natural gas fuel cost. Other major plant features would include a switchyard, a 161-kilovolt (kV) transmission line, and a natural gas interconnection with an existing gas pipeline that crosses the property. The yearly electrical output of the plant would be less than 50 average MW. Electricity generated by the Project would be used to meet MRES customer's peak electrical demand which occurs primarily during the summer.

Western's Creston-Dennison 161-kV Transmission Line crosses the northeast corner of the 76-acre parcel. The electrical output of the plant would be interconnected to this line by a new 2,000-foot long, 161-kV transmission line that would travel almost straight east from the power plant along the northern border of the site. On-site groundwater wells would supply the non-potable water for plant operation. Potable water would be brought to the site as bottled water.

There are two small ephemeral ponds on the site. One is on the west side of the site and is about 0.03 acres. The other pond on the north side of the property is about 0.01 acres in size. All ponds eventually drain to the East Nishnabotna River. Plant process water effluents and stormwater runoff would be discharged to the larger pond, which would need to be expanded. The existing 0.03-acre pond would be excavated to provide a deeper basin and a larger surface area. The proposed action would raise the existing dike on the larger pond sufficient to increase the size of the pond to 0.18 acres. The result would be a 0.15-acre increase of wetland habitat in the project area. The new 161-kV transmission line would span the other pond which would not be impacted by the Project. Also, a new pond would be developed to capture stormwater runoff during construction and operation. The new pond would be constructed by excavating a low area just east of the proposed plant site and creating a berm near the northern property boundary. The resulting pond would be approximately 0.46 acres with a depth of 1 to 2 feet during and after storm events.

In accordance with the Department of Energy's Floodplain/Wetlands Review Requirements (10 CFR part 1022), Western will prepare a wetland assessment and will perform the proposed actions to avoid or minimize potential harm to or within the wetland. The wetland assessment will examine the use of the wetland as a stormwater and waste water retention basin and evaluate avoidance, mitigation, or compensation to minimize loss of wetland habitat. The wetland is located in Audubon County, Iowa, in T. 78 N., R. 35 W., section 31. Maps and further information are available from the contacts listed above.

Dated: June 27, 2003.

Michael S. Hacskaylo,

Administrator.