The R-407 Program came to fruition due to one of the wettest winters in Northern California in recent history. After one of Pacific Gas and Electric Co.’s (PG&E’s) 36-in. transmission lines was found exposed for 30 ft in Petroleum Creek, an integrity management flag was immediately triggered. PG&E selected Barnard Pipeline Inc. to perform the pipeline relocation. The project took place in an environmentally sensitive area and involved the replacement and relocation of 303 ft of pipeline under Petroleum Creek, in addition to the preparation of an extensive streambed remediation plan.
Name of Project: R-407 Program
Category: Oil and Gas Pipeline
Contractor: Barnard Pipeline Inc.
Owner: Pacific Gas & Electric Co.
City/State Project: Dunnigan, California
The project team was able to expedite all of the applicable permits and mobilized to the site on Aug. 7, 2017. PG&E required an accelerated schedule to meet the mandatory gas clearance on Sept. 19, 2018. To meet this schedule, Barnard crews worked diligently to clear the right of way (ROW), excavate over 6,000 cubic yards of material, and fabricate and hydro-test the new piping.
To complete the gas clearance, Barnard used cross compression equipment to evacuate the gas from Line 400 (L-400) and then repacked it following the successful clearance. Barnard then installed and anchored concrete mats over the newly installed L-400. With the pipeline adequately anchored, Barnard backfilled and compacted L-400. Barnard then recontoured the streambanks of Petroleum Creek and installed 1,454 tons of ½-ton and ¼-ton rock slope protection (RSP) along the recontoured banks to ensure bank stability and prevent future erosion. The project finished with zero at-fault dig-ins or line strikes, and zero OSHA recordable incidents.
One of the largest challenges faced by the project team was the relationship between the PG&E easement and the Western Area Power Administration (WAPA) easement. The easements paralleled each other and only allowed for a 10-ft horizontal offset between the existing L-400 and the newly installed L-400. Due to the proximity and the 24-ft depth of excavation, Barnard implemented a combination of sloping and shoring systems, which was essential for ensuring the full support of the existing L-400 throughout construction. Once Barnard executed the gas clearance, the abandoned segment of L-400 was safely removed.
Another challenge faced throughout construction was an irrigation outflow point located 200 ft directly upstream from the construction site. The irrigation outflow discharged thousands of gallons of water daily, which in turn flowed directly toward the pipeline excavation. Barnard could not shut off the irrigation system due to the impacts it would have on the local farming community at harvest time. To prevent the water from flooding the excavation, Barnard installed a water bypass system that spanned the length of excavation. Barnard then diverted the water and discharged it further downstream where it no longer interfered with construction.
Barnard’s subcontractors on the R-407 Program included: Milbar Hydro-Test Inc., Cal Inc., Atlas Tree Surgery Inc., PSC Environmental Services LLC, Guida Surveying Inc., Larry Jenkins Trucking Inc. and Nordic Industries. Key suppliers on the project were Submar Inc. and United Rentals Inc.
All of the subcontractors were hand selected and invaluable to the overall project success. Each subcontractor displayed extensive knowledge in their respective trades and genuinely cared about the final result of the work. Throughout the duration of the project, Barnard maintained open communication, which resulted in effective scheduling and a project completed ahead of schedule. The excellent performance provided by all subcontractors benefited the success of Barnard and contributed to the success PG&E has in the community.
As the General Contractor, Barnard had the responsibility of selecting safe, reliable and affordable subcontractors and suppliers. Each subcontractor selected on this project had developed a quality relationship with Barnard on previous projects and exhibited quality performance. Barnard takes pride in working alongside selected subcontractors and incorporating them into the project team. Prior to performing any work, Barnard provided all subcontractors with a project-specific orientation and had them attend PG&E Veriforce onboard training. This effort brought everyone together to work toward the common goal of improving the community’s safety and making PG&E one of the safest and most reliable utilities in the nation.
One of most successful attributes of the R-407 Program was having it conducted with zero safety incidents. Barnard places a special emphasis on every aspect of safety and requires the same from all subcontractors. The commitment to safety from all of the subcontractors on this project was exemplary. The following descriptions illustrate how each subcontractor and supplier assisted with the overall success of the project.
Milbar Hydro-Test Inc. conducted the 8-hour strength test and assisted Barnard crews in the dewatering and drying operations. Cal Inc. completed the removal of the asbestos pipe coating that was found to be 2 percent on L-400.
Atlas Tree Surgery removed more than 400 almond trees within the PG&E ROW and mulched the trees onsite with a tub grinder. They then removed and disposed of the mulched material.
PSC Environmental Services provided precautionary emergency spill response vacuum trucks during the gas clearance. Guida Surveying Inc. performed all field surveys, and then compiled and produced the final as-built package for all newly installed piping.
Larry Jenkins Trucking provided the trucking of aggregates and sand to the main isolation point at Buckeye Station. Nordic Industries provided the RSP and trucking services required for the streambed remediation.
Submar provided the concrete mats and handling frame for the streambed stabilization. United Rentals provided the trench shields, trench boxes and speed shores that Barnard used during the excavation process. These suppliers were able to meet all requested timelines for material delivery and provided quality products.
Since becoming a PG&E Alliance Partner in 2013, Barnard has completed hundreds of projects throughout California. The R-407 Program is a true testament of PG&E and Barnard’s continued commitment to executing successful transmission line upgrades that improve the safety of communities.
Barnard recognized early in the planning stage that Petroleum Creek was an environmentally sensitive area requiring the utmost attention. The project team held numerous site walks and developed a plan to execute work with minimal disturbance to Petroleum Creek. Barnard completed the project with zero environmental compliance issues or notice of violations, and developed a great rapport with environmental governing agencies.
Barnard also recognized that construction would take place during the almond harvest, which led to regular correspondence with almond orchard owners. From these discussions, Barnard established alternate access routes to avoid any impacts on the almond harvest.
Additionally, Barnard greatly increased the level of safety for the community by rerouting L-400 to an adequate depth. While installing L-400, Barnard also reinforced the streambanks to ensure that water in Petroleum Creek flows within its established boundaries, preventing flooding in surrounding areas. The project team’s due diligence in the planning stage set the foundation for a successful and beneficial project.
Tags: Barnard Pipeline Inc., June 2019 Print Issue, PGandE, pipeline integrity, Pipeline Relocation
This article previously appeared in Utility Contractor, a sister publication of North American Oil & Gas Pipelines.