California PUC Approves Undergrounding of Tehachapi Transmission Line Through Chino Hills

The California Public Utilities Commission has granted the request of the City of Chino Hills to underground a segment of Southern California Edison’s Tehachapi Renewable Transmission Project, finding that the design of the above ground line effectively ignores community values and places an unfair and unreasonable burden on residents. 

Currently, the 3.5 mile segment of the 500 kV transmission line running through Chino Hills consists of massive transmission towers reaching 195-198 feet tall (more than double the height of the prior 75 foot structures) and set in a narrow 150-foot right of way.  Today’s decision rectifies that disproportionate burden and finds that it is in the public interest to construct an underground alternative based on a single circuit, two cables per phase design using cross linked polyethylene cable. 

The cost estimate of undergrounding in Chino Hills is approximately $224 million, including offset for Chino Hills’ financial contribution of real property, which is valued at approximately $17 million.

Said CPUC President Michael R. Peevey, “It’s the dawn of a new era in transmission line planning in this state.  In urban and suburban areas, we have to look anew at how we site transmission lines, and carefully weigh their role in fulfilling the state’s energy goals against their impact on community values.  I know undergrounding costs more, but I believe in this instance the costs are manageable and relatively minor considering the overall well-being of the populace in doing so.”