PacifiCorp owns 971 MW of electricity across 37 hydropower facilities in the West. They are committed to providing safe recreational opportunities for visitors and thriving habitats for wildlife alongside reliable power generation facilities. For 15 years, McMillen has been partnering with PacifiCorp to uphold this commitment. Sample projects include improvements to powerhouse facilities, the design and construction of a water treatment facility, the development of new pumped storage options, the demolition and construction of hydraulic structures, and numerous upgrades at fish hatcheries. Additional work is summarized below.
Naughton Water Treatment Plant | Kemmerer, WY
As design-build lead, McMillen provided the design, construction, and commissioning of a new standalone water treatment plant for three cooling tower units. The facility treats the spent cooling water before releasing it into the local environment. Scope included civil site work, piping, electrical, fire protection, mechanical equipment, and all structural aspects.
Yale Dam Fish and Debris Net System | Ariel, WA
McMillen was the design-build lead for a new net system to reduce fish entrainment at Yale Dam. We delivered design, fabrication, permitting, installation, and startup services and self-performed or directly managed construction. The final design featured two net systems, one in the approach channel to prevent bull trout and debris from approaching the spillway and a second net that screened the intake. Both nets can be raised and lowered to adjust to varying water depths. Due to rigorous planning, our team cut the scheduled installation from ten days to three, resulting in reduced outages and financial savings for PacifiCorp.
Lewis River Pump Station Modifications | Woodland, WA
The Lewis River Hatchery’s downstream injection system pump station facility was originally constructed in 1963 with submersible turbine well-style pumps installed in three pump slots. In the 2000’s, these submersible pumps were replaced with new vertical turbine pumps, pump columns, and line shafts, but the original pipe cans were left in service. McMillen discovered the original cans had oversized openings, leading to problematic high-velocity points in the intake screens. Therefore, we developed intake screen modifications to remedy the issues.
Furthermore, continual river undercutting of the intake zone underneath the pumps had undermined previously designed pump and intake screen support assemblies. To provide improved support and proper fish screening of the pumps, we designed new National Marine Fisheries Service-compliant intake screens and support mechanisms. These are more reliable and easier to maintain.
Toketee Intake Trash Rack and Debris Handling | Toketee Falls, OR
McMillen provided engineering, procurement, and construction services for modifications to the trash rack at the Toketee development. The new system was designed to exclude adult bull trout from entering the powerhouse intake and provided an automated debris-handling system. Due to a limited construction footprint, we used a long-reach excavator on a floating barge to remove 20 feet of debris depth in front of the intake. A camera was mounted to the excavator’s boom so the operator could see what needed to be removed via a television mounted in the cab, creating a safer approach to traditional underwater debris removal. Then, our team used a hydraulic crane to lower modular sections into their final positions. The new structure was installed in the wet by 14 divers who performed underwater fit-up and welding around the clock. Our team was offered a 14-day window to complete installation, but we completed the work in 13 days, allowing operations to resume a full day early.
