Environmental and Regulatory Compliance

Pine Tree Wind Facility (135 MW) Design-Build

Location: Kern County, California

The Pine Tree Wind Facility is one of the nation’s largest municipally-owned wind power generating facilities. It is located 14 miles northeast of the City of Mojave in Kern County, California, in the rugged and steep terrain of the Tehachapi Mountains. This project included 90 GE 1.5 MW wind turbine generators on a 12-square-mile project site. The design-build delivery approach allowed design and construction work to proceed in tandem during the project’s duration, creating efficiencies of time and cost. This project stands as one of the most complex sites developed in the U.S. to date, from regulatory requirements to civil construction challenges with the remote and mountainous terrain.

DEA’s role as program manager and engineer-of-record included:

  • Led BOP design team for civil, electrical, structural, and geotechnical engineering services.
  • Roadway design of 25 miles of on-site and roadway upgrades to allow large delivery trucks access to the wind facility site. The roads climbed steep, rugged terrain; required specific grade, width, and turning radii; and had switchback guidelines.
  • Ninety individually designed turbine pads providing space for turbine components for full blade assembly as required by the turbine manufacturer’s and owner’s requirements.
  • Timing the design services simultaneously with the roadway systems in order to properly manage on-site surface water and control erosion.
  • Substation and operations and maintenance facilities site design.
  • Structural design, in challenging terrain, of two bridges in sensitive areas near aqueducts that transport water for the City of Los Angeles.
  • Boundary surveys, transmission line ALTA surveys, records of survey, construction surveying, as well as Federal Aviation Administration airspace and military flight plan analysis.
  • Construction engineering and agency coordination, which required stationing resident engineers on-site to provide design and construction quality assurance and checks. The engineers worked with the owners and local agencies to coordinate on-site work with permitting.

Project Awards

  • National Engineering Excellence Silver Award - ACEC Washington, 2010