SoCal Gas Dig 10 Anomaly Repair

SoCal Gas Dig 10 Anomaly Repair

The applicant, SoCal Gas, is requesting a Coastal Development Permit, Case No. 22CDH-00000-00002, for the inspection and repair of a 215-foot long section of Line 247 (L247) running within the bed of Dos Pueblos creek, which contains anomalies detected in previous investigations. Repair will include installation of stopple fittings and the temporary 12-inch diameter bypass line for isolation of the inspection/replacement segment, dewatering of the creek, excavation and replacement of the 215-foot section of L247 under the creek, followed by backfilling of the trench, and restoration of the site. The area will return to pre-project contours and vegetation will be restored. Equipment and staging will occur within two laydown yards on either side of the excavation site. Access is provided from Highway 101 and existing travel routes to the SoCal Gas easement on Calle Real and private roads. Excavation will occur within SoCal Gas easement and all impacts will be temporary. No new roads are proposed. The Project is necessary to comply with U.S. Department of Transportation Pipeline Hazardous Materials and Safety Administration, Office of Pipeline Safety and the California Public Utilities Commission (CPUC) regulations to conform with the Pipeline Safety and Improvement Act of 2002. Anomaly Repair. Excavation of L247 will occur in an approximately 215-foot-long, 15-foot-wide, and 15-foot-deep trench, using hand tools, a backhoe and excavator. The western staging area (7,100-sf) closest to the excavation workspace is within a previously disturbed agricultural access road and is located on APN’s 079-080-039 and 079-140-056. The use of the 12-ft-wide workspace parallel to and directly south of the existing access road will require clearing vegetation to accommodate equipment movement and staging. A water diversion plan and dewatering plan will be implemented to provide safe access to the pipeline below the creek bed, and limit work within ponded or flowing water. The 215-ft segment of the pipeline will be removed and replaced in-kind. Upon completion of repairs, the pipeline will be covered with fine material to protect it during backfill and minimize erosion. The channel bed will be returned to pre-project contours and vegetation will be restored consistent with the Habitat Restoration Plan (HRP). Stopple Fittings/Temporary Bypass Line. Installation of two stopple fittings will allow for isolation of the inspection/replacement segment of the pipeline by installing a temporary 12-inch above-ground bypass pipeline (bypass) to allow for the continued service of regional natural gas during project construction. Work includes installing an upstream stopple (600-ft east of Dos Pueblos Creek) on APN: 079-140-034 and downstream stopple (directly west of Dos Pueblos Creek) on APN: 079-080-039. The upstream (east) stopple will be accessed through an existing ranch road off private Bear Road. The stopple installation will occur within the eastern laydown yard. The laydown yard for the eastern stopple will be 1.43-acres (62,500-sf) located in grazed agricultural fields dominated by mustard plant. A 150-ft by 150-ft bypass workspace and a 25-ft workspace on either side of the bypass is proposed to accommodate equipment access. The upstream eastern stopple will be located entirely within existing agricultural rangeland devoid of native trees and outside of the Dos Pueblos Canyon Creek Environmentally Sensitive Habitat (ESH). The downstream (western) stopple is proposed entirely within the 7,092-sf western laydown yard. Temporary excavation of each stopple will be 8 to 10-ft wide by 15 to 17-ft long to a depth of up to 10-ft (up to 63-cubic-yards each). The stopples and temporary pipeline bypass between the stopples will be installed before the anomaly repair and removed after Line 247 is put back into service. The stopple areas and workspaces will be backfilled and hydroseeded/stabilized consistent with the HRP and Stormwater Pollution Prevention Plan (SWPPP). Dewatering. A Water Diversion plan was submitted to provide safe access to the pipeline below the creek bed, and limit work within ponded or flowing water. Any groundwater encountered during excavation will be hauled off site to approved disposal facilities or discharged to the ground/surface water as authorized under the Statewide General Order for Discharge from Natural Gas Utility Construction, Operation, and Maintenance Activities (Order 2017-0026-DWQ). Best management practices (BMPs) will be implemented during construction and will include, but not be limited to, prevention of track out, dust control with water, straw wattles or silt screens to prevent erosion and sedimentation, and secondary containment around equipment. Impacts to ESH and Trees. Excavation work will occur within Environmentally Sensitive Habitat and will temporarily impact 0.17-acres of coastal ESH and 0.05-acres of Inland ESH. One western sycamore tree is proposed for removal and will be replaced at a 10:1 ratio. Three avocado trees must be removed to accommodate equipment and will be replaced when the project is completed. One oak tree may be trimmed to allow for equipment access. The branch is less than 20% of the tree canopy and will result in minor encroachment. Impacts to fourteen arroyo willow trees will be replaced with 140 willow sprigs within the SoCalGas easement. The measures included in the Biological Resources Assessment are proposed as part of the project description for consistency with the Gaviota Coast Plan, existing regulations, and SoCalGas Best Management Practices. Total area of disturbance of the project will be 3.28-acres (142,877-sf) including workspaces and laydown yards. Approximately 1,918-cubic-yards of temporary cut entirely within the existing easement is proposed for removal, including approximately 1,792-cubic-yards of cut for Anomaly Repair (215-ft long, 15-ft wide, and 15-ft deep trench) and up to 63-cubic-yards for each stopple fittings (8-10 ft x 15-17 ft x 10-ft each, two stopple fittings). The project is anticipated to take approximately 12 weeks to complete. Equipment to be used for the excavation includes an excavator, backhoe, front loader, side boom, crane or heavy lift, gang truck, flatbed truck, welding truck, pickup truck, portable equipment such as generators and air compressors, crew trucks, and portable restrooms. Extended night and weekend work with lighting may be required up three days for the hydrotest and tie-in. All elements of the anomaly repair will be underground. The stopple fittings and temporary bypass will protrude above ground temporarily for the duration of construction and will be removed.

Goleta

Santa Barbara

Unincorporated

Santa Barbara