Edison's TRTP ProposalIn 2002, California Senate Bill 1078 was signed into law requiring all investor-owned utilities to increase their sale of electricity produced by renewable energy sources to 20% by 2010. In 2009 the California Public Utilities Commission (PUC), on a 5-0 vote approved Southern California Edison’s (SCE) Tehachapi Renewable Transmission Project (TRTP).  Designed to bring more renewable energy to the region, the route begins in the Tehachapi Mountains in Kern County, traverses the Antelope Valley, San Gabriel Mountains, San Gabriel Valley, and ends in the Inland Empire. One leg of the TRTP project slices through the Puente-Chino Hills Wildlife Corridor with new taller towers and widened right-of-way. These new 500 kV towers will cause temporary, permanent, and cumulative impacts to the biology and aesthetics of the hills. The PUC failed to require Edison to specify adequate mitigation for impacts to these protected lands.

Farther along the route, the 200 foot tall 500 kV lines were approved to go through several Chino Hills neighborhoods along an existing right-of way (with inactive towers) wide enough only for 220 kV lines.  HFE worked with the City of Chino Hills in a cooperative effort to design an alternate (Alt 4CM) on existing right of way through Chino Hills State Park, the result of which avoided the neighborhoods and reduced the number of existing towers in the Park.


  • Once some towers were erected, the real impacts could be seen and angry residents effectively gained the renewed interest and attention of the PUC.
  • On November 10, 2011 the PUC ordered Edison to take a new look at alternatives through the neighborhoods in the City of Chino Hills and also ordered Edison to stop construction pending a Commission decision on Chino Hills’ Application for Rehearing.
  • HFE supported a new look at the route through the State Park on existing towers as long as adequate mitigation is provided for the temporary, permanent, ongoing, and cumulative impacts.
  • Eventually SCE was required to underground the transmission lines through Chino Hills.


  • In December 2009 the California Public Utilities Commission (CPUC) approved Edison’s TRTP which adds tall new towers and cuts through much of the Puente-Chino Hills Wildlife Corridor.
  • Soon after approval, Edison leapfrogged construction and quickly built the new highly controversial 500 kV towers on a small easement through neighborhoods in the City of Chino Hills.
  • The drawings on paper did not do justice to what the massive towers would actually look like. The new towers caused an uproar in the City. Residents organized and hammered the PUC and SCE.
  • Under attack for the apparent lapses in oversight by the PUC in the PG&E gas explosion in San Bruno in late 2010, PUC President Peevey came to see the new towers near 185 homes and was disturbed by what he saw.
  • As one of only two remaining commissioners and as the overseer of the project, on November 10, 2011 he ordered SCE to look at other alternatives to the towers in the neighborhoods, including undergrounding and the Alternative 4CM route developed with HFE.

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