Thermalito Pumping-Generating Plant Fire Restoration

Location: Oroville, CA

Owner: California Department of Water Resources (DWR)

Contract: $21.6 Million

Role: General Contractor

Delivery Method: Design-Bid-Build

Result and Benefit to Client

A quality project was delivered safely, on time, and within budget. DWR has reduced their energy costs, and they saved $2 million due to Monterey Mechanical’s equipment recommendations.

Project Description

A devastating fire burned out of control for nearly 48 hours on Thanksgiving Day 2012 at the 84-MW Ronald B. Robie (Thermalito) Pumping-Generating Plant, which was operated by the California Department of Water Resources (DWR). Although there were no injuries to plant personnel, 2014 revenue loss from hydroelectric generation was estimated at $6.5 million to $10.5 million. There was no damage to the bottom two floors of the structure.

Thermalito has five floors with the top two above ground. There are four units in its underground powerhouse complex, a 36-MW Kaplan type generator, and three 27-MW Francis type pump-generators.

Monterey Mechanical’s scope consisted of:

  • Cleaning all fire-impacted mechanical and electrical equipment
  • Start-up related services of essential systems
  • Design and construction of a replacement HVAC system
  • Design and construction of a lighting system
  • Structural repair of spalled and delaminated concrete and masonry
  • Cleaning of four disassembled turbine generators

Challenges | Solutions

Monterey Mechanical faced numerous challenges in restoring the Thermalito plant after a major fire burned for almost 48 hours. One challenge was how to protect workers and the environment during removal of 3800 cubic yards of fire-damaged debris, while recycling 350,000 pounds of scrap metal, and treating 905,000 gallons of contaminated water.

Monterey Mechanical developed a Hazardous Substance and Disposal Plan with a Certified Industrial Hygienist to assure protection of present and future workers as well as the environment.

DWR asked if we could find a way to reduce the high energy costs the state was incurring. Monterey Mechanical led value engineering efforts working closely with engineering firms to develop an energy and cost-efficient lighting and HVAC system. DWR is realizing ongoing savings through these new systems.

Monterey Mechanical recommended that DWR purchase equipment they were renting for power and climate control, which saved the agency approximately $2 million.

Awards and Commendations

Wayne Wolfe
Project Safety Office
California Department of Water Resources

“Great job to the contractor’s staff for ensuring a safe work environment at THPP. Safety is a team effort and it is shown at THPP what a collaborative effort can accomplish.”