Forest Ranch couldn’t wait four months. After devastating wildfires destroyed this Butte County community, residents needed underground power infrastructure rebuilt fast–but 5.5 miles of volcanic lava cap, dense rock, and narrow residential streets stood between them and grid reliability. Conventional trenching projected a sixteen-week timeline. CPNA delivered in 5.  

When PG&E and C&C Utility Inc. approached CPNA for a 5.5-mile underground installation in Forest Ranch, Butte County, the project carried high stakes. This fire-scarred community needed reliable underground infrastructure quickly, but conventional trenching methods projected a four-month timeline. The utility needed integrated cable installation services capable of accelerating grid hardening work without prolonging disruption to residents still rebuilding from devastating wildfires. 

The Challenge: Geological Complexity in a Residential Zone 


Native soils comprised mostly of dense layered rock, cobble, sandstone, and volcanic lava cap—conditions that reduce the effectiveness of standard trenching equipment and extend installation timelines. Frequent switchbacks and narrow residential access points further limited equipment maneuverability, compounding the difficulty of maintaining consistent production. These combined obstacles drove the four-month conventional timeline that would have prolonged construction activity in Forest Ranch, a community rebuilding confidence in utility infrastructure after devastating wildfires. PG&E required one-pass trenching contractors capable of consistent daily production through these geological and logistical constraints while minimizing project footprint. 

CPNA's Solution: Integrated Technology for Extreme Conditions 


CPNA deployed its specialized one-pass trenching system, combining excavation, HDPE conduit placement, and backfilling into a single continuous operation. The integrated approach eliminated multiple equipment passes and crew mobilizations. CPNA's trencher maintained an average production rate of 1,600 feet per day through the dense rock formations, utilizing precision depth control to achieve consistent 3.5-foot cover throughout the installation. By screening and utilizing native soils for backfill—including the challenging rock and cobble material—CPNA eliminated imported sand requirements, reducing truck traffic and material procurement delays in the residential environment. 

Measurable Results: Accelerated Timeline, Community Approval 


CPNA completed the trenching activity in five weeks, delivering the project eight weeks ahead of schedule. Phase 1 finished three weeks ahead of the contracted timeline, with all conduit successfully installed at the specified depth. Local residents responded positively to the rapid pace and minimal disruption, prompting PG&E to advance additional work packages in the area. Faster installation reduced community exposure to construction and accelerated grid hardening objectives in this high fire-risk zone. Eliminating imported backfill reduced truck trips through residential streets. 

Strategic Takeaway: Speed Through Complexity 


This Forest Ranch project demonstrates how specialized one-pass trenching contractors deliver superior outcomes when geological complexity intersects with aggressive timelines and community sensitivity. CPNA's integrated approach eliminated the inefficiencies of traditional underground cable installation while maintaining consistent production through extreme soil variations. The eight-week schedule acceleration translated to cost savings through reduced overhead and faster project closeout, while minimizing community disruption in a region where wildfire risk makes underground infrastructure essential for utility reliability. 

Ready to accelerate your next utility grid hardening project? Contact CPNA to learn how our one-pass trenching solutions deliver schedule certainty in challenging terrain. 

Project Specifications: 

  • Location: Notre Dame, Forest Ranch, Butte County, CA 

  • Scope: 5.5 miles of 4" HDPE conduit 

  • Installation Depth: 3.5 feet of cover 

  • Soil Conditions: Dense layered rock, cobble, sandstone, lava cap 

  • Production Rate: 1,600 linear feet per day average 

  • Schedule Performance: 8 weeks ahead of baseline, Phase 1 completed 3 weeks early