BPA’s 500 kV Grizzly Substation is located in central Oregon and was originally constructed in the 1950’s.  Serving the ever-increasing power needs of the Oregon and West Coast region, BPA commissioned an upgrade of the existing infrastructure.

Team Members

Bonneville Power Association

PAR Western Line Contractors

Crux Subsurface

Crux’s Role

Crux is well versed in substation and underground work – providing an extensive understanding of safe operations within an energized and confined environment – and was contracted to complete the full civil scope.  This included installation of 14 two-foot diameter drilled pier foundations; wreck out of 48 existing concrete foundations; installation of 35 pad and pier type foundations; excavating approximately 1,000 linear feet of conduit trench and installing approximately 6,000 lineal feet of conduit; concrete coring existing vaults for conduit installation; backfilling and compacting conduit trench once completed; and installing yard rock after foundation installation.

Outages were limited only to the specific bays being actively worked on, leaving the remainder of the substation energized.  To mitigate the safety risks, Crux ensured Qualified Electrical Workers were onsite to observe work and enforce Minimum Approach Distances.

Additional challenges included encountering more underground utilities than anticipated due to inaccurate mapping.  These issues were mitigated by contracting a private utility company to scan all work locations before breaking ground, as well as by potholing foundation locations to ensure the excavator did not strike a live utility.

The project is currently in-progress and expected completion is in the summer of 2024.

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