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Third Powerplant Generating Units Overhaul Activities
FONSI and Environmental Assessment

The Bureau of Reclamation has released the Finding of No Significant Impact (FONSI) and Final Environmental Assessment (EA) for the Third Powerplant Generating Units Overhaul activities at Grand Coulee Dam located on the Columbia River about 90 miles west of Spokane, Wash.

The six generating units that comprise the Third Powerplant (TPP) have been in continuous service since the mid 1970s and have experienced age-related problems resulting in power outages and reduced reliability. Grand Coulee’s TPP was constructed between 1966 and 1974.

The Final EA’s four alternatives include:

  • Alternative A - No Action
  • Alternative B - the Preferred Alternative calling for the TPP overhaul and construction of a separate material storage building
  • Alternative C - TPP Overhaul with expansion of the powerplant for material storage
  • Alternative D - TPP Overhaul with Expansion of the powerplant and a separate material storage building.

The Preferred Alternative will take about 10 years to complete. During that time, Reclamation estimates that the economic impacts for the five-county area and the region will vary in proportion to the government’s annual expenditures. The majority of the output, employment, and income impacts are due to wages earned by the workforce involved in the construction.

Reclamation made a Draft EA publicly available in October 2009 with copies sent to governmental agencies, elected officials, Native American tribes, and the interested public. Comments received are addressed in the FONSI and Final EA.



05/2012 Third Powerplant Generating Units Overhaul Activities EA Final Addendum PDF 328 kb
01/2012 Third Powerplant Generating Units Overhaul Activities EA Addendum PDF 46 kb
05/2010 Third Powerplant Generating Units Overhaul Activities Final EA and FONSI PDF 2.90 mb
10/2009 Third Powerplant Generating Units Overhaul Activities Draft Environmental Assessment PDF 2.02 mb

William Smout
(208) 378-5250

Bureau of Reclamation
1150 North Curtis Road, Suite 100
Boise, Idaho 83706-1234


Last Update: February 4, 2015 7:33 AM