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Puget Sound Energy electric transmission project

Covington - Berrydale 230 kV transmission line

Spring 2009 project completion
  • PSE completed construction of the new $13 million Covington-Berrydale 230 kV line in May 2009.
Project overview

To improve electrical system reliability in South King County, Puget Sound Energy built a 230 kilovolt (kV) transmission line as well as re-routed an existing 115 kV transmission line. The two-phase project creates a loop system to increase reliability and meet growth of the Covington area for years to come. In a loop system, electricity can be delivered to the same point from different paths in case one path is out of service. We completed phase one of the project, re-routing of the existing 115 kV line, in November 2007. We began construction on our second phase, the new 230 kV transmission line that runs between the PSE Berrydale substation and the BPA Covington substation, in August 2008.

Download full-size map
Project map (785 KB PDF)
What is a transmission line?

Transmission lines are key elements in the electrical distribution system. The lines safely transport high voltage electricity from power generation sources like dams and wind generating facilities to substations in local communities. Transmission normally takes place at voltages of 55 kV and higher.

Download information

Download these PDF files for more detail on PSE's Covington-Berrydale electric transmission project. 
Press release (3/30/08)
Media advisory (28 KB PDF)
Thank you letter (262 KB PDF)
Construction notice, Aug. 2008 (177 KB PDF)
Project update, June 2008 (1 MB PDF)
Meeting invite, June 2008 (207 KB PDF)
Project update, March 2007 (181 KB PDF) 
Project  map (785 KB PDF)
Loop diagram (708 KB PDF)
Pole diagram (590 KB PDF)