Practice Areas

Project Types


PG&E Line 401 Capacity Loops Project

This project involved construction of a 42-inch natural gas pipeline in two separate locations: (1) Northern Loop, Modoc County, approximately 5 miles of pipe installation, and (2) Southern Loop, Shasta County, approximately 8 miles of pipe installation. The Line 401 project is a follow-up to the PG&E/PGT Pipeline Project constructed over a decade ago. The Northern Loop is located on Modoc National Forest lands and contains numerous cultural resource sites. Topography is level, but subsurface lava made pipe installation difficult. The Southern Loop is located on private lands, owned by lumbering interests, and contains stream and wetland resources. The topography oscillates between 2,000 to 4,000 feet.

The CPUC allowed use of PG&E/PGT Pipeline Project mitigation measures and compliance plans for Line 401 construction, including required pre-construction surveys for biological resources. New permits were acquired for timber clearing, cultural resource data recovery, stream crossings, extra workspace areas, and roadway usage.

Aspen monitored construction of the project on behalf of the CPUC to ensure compliance with mitigation measures and permit conditions. Aspen filed regular reports to the CPUC on the progress of construction and compliance with mitigation.

Practice areas: Energy

Services provided for this project: