The Sunrise Powerlink is an approximately 120-linear-mile electrical transmission line and related features which traverse a wide variety of land types, including remote desert, high-relief mountains, commercial, industrial, and residential properties.
Initially Geosyntec was contracted to perform a Phase I ESA for the project to fulfill the compliance requirements dictated by the existing EIR approved by the California Public Utilities Commission. The ESA was performed on an expedited basis and included voluminous data review, extensive reconnaissance, and an innovative report, which consolidated the findings into a GIS database to provide the client with a user-friendly, comprehensive, and concise deliverable. Subsequently, based on the findings and quality of the Phase I ESA, significant follow-up work was awarded, listed below. The most significant tasks centered around maintaining and documenting compliance with the complex stormwater-related requirements for the more than 400 lattice tower sites, 20 temporary construction yards, six miles of twin trenches, and new construction of a large substation in a mountainous setting. At the peak of project implementation, up to 30 Geosyntec professionals and technicians provided construction stormwater monitoring services and general project support.
Geosyntec's Scope of Services
- Phase I ESA for 120-mile transmission corridor and associated construction yards.
- More than 40 addenda to the initial ESA for due diligence for subsequent property evaluations.
- Geotechnical site evaluations including seismic profiling to assess rippability for trenching, test thermal resistivity of backfill material, and review blast plans.
- Water study to evaluate available water resources for project construction, including groundwater, potable, raw, and reclaimed water.
- Facilitating acquisition of reclaimed water with various water purveyors and regulatory agencies.
- 10 Phase II soil and/or groundwater investigations to characterize the nature and extent of existing contamination, and provide remedial cost estimates to demolish constructed features, remove contaminated materials, and restore impacted properties to their pre-developed conditions.
- Contaminated site assessment and mitigation at five impacted sites acquired for the project.
- Designed and installed erosion control BMPs to prevent notices of violations on properties purchased for the project.
- Prepared Hazardous Materials Business Plans (HMBPs) and Spill Prevention Control and Countermeasure (SPCCs) Plans for construction yards during construction.
- Evaluated the presence of springs and wells within one mile of the construction activities for use in blasting calculations during construction.
- Provided stormwater and hazardous materials compliance monitoring throughout construction.
- Prepared and provided hazardous materials management and stormwater management cross-training to project staff.
- Coordinated with client, purveyor, and agency personnel (including city and county municipalities, Caltrans, US Forest Service, US Bureau of Land Management, private landowners, Department of Defense, Native American Reservations, and State land agencies) to develop the approval pathway to allow the use of reclaimed water outside of defined service area boundaries, spanning multiple RWQCB jurisdictions which is not known to have been previously performed.
- Addressed erosion control challenges in complex settings and topography in rural areas with site specific assessment performed in the field by Geosyntec staff.
- The scale, phasing, and duration of the project required significant documentation and methodical record keeping demonstrate continued compliance to the CPUC and other inquiring agencies.
- Based on the client's observation of our outstanding project management and work product, the client tasked Geosyntec to manage three other SDG&E subcontractors to coordinate the presentation of findings to the California Public Utilities Commission.
- Geosyntec continues to be a multidisciplinary resource for the client and serve as an on-call consultant ready to respond to emerging and changing client needs throughout the service area.
- Based on Geosyntec's performance during the planning and construction of the Sunrise Powerlink, Geosyntec continues to provide additional services to the client for upcoming projects.
- Location: Southern California
- Client: San Diego Gas & Electric
- Project Practice Areas: Environmental Management, Geotechnical
- Type of Facility: Utility Corridor
- Services Provided: Phase I ESAs, Geotechnical Site Evaluations, Water Resources Evaluations, Phase II Soil and Groundwater Assessments, Contaminated Soil Management Planning, Erosion Control Design and Installation, Regulatory Coordination, Health and Safety Training, Resource Mapping, Contaminated Site Mitigation
- Type of Work: Geotechnical
- Governing Regulation: Environmental