California regulators approve SDG&E’s proposed 230-kV substation expansion project

According to the commission’s order, the project includes building – within the company’s fee-owned property – a new 230/69-kV air insulated substation (AIS) at the existing 69/12-kV Artesian substation site

The California Public Utilities Commission in a recent decision granted – in conformance with certain mitigation measures – San Diego Gas & Electric a permit to construct the Artesian 230-kV Substation Expansion Project in San Diego County, Calif.

The project consists of:

  • Building – within the company’s fee-owned property – a new 230/69-kV air insulated substation (AIS) at the existing 69/12-kV Artesian substation site
  • Relocating, rebuilding, and expanding – within the company’s fee-owned property adjacent to the existing Artesian substation site – the existing 69-kV facility with a new substation
  • Looping in the existing 230-kV Transmission (TL) 23051 into the new 230-kV substation yard at the Artesian substation
  • Reconductoring an existing double-circuit 69-kV power line – 2.2 miles – located between the Artesian and Bernardo substations, including the replacement of existing wood pole structures with new steel pole structures as needed, as well as removing some existing pole structures from service
  • Building new underground 69-kV powerline getaways – 0.8 mile – outside the existing Artesian and Bernardo substations
  • Minor distribution line upgrades, including removing existing distribution underbuild and wood pole structures
  • Minor modifications to the existing Bernardo – 2.1 acres- and Rancho Carmel – 1.3 acres – substations within the existing footprint

The commission added that SDG&E’s stated purpose for the proposed project is to build a new substation to meet the mandatory NERC reliability criteria and mitigate existing NERC thermal violations identified in the Poway Area Load Pocket; alleviate existing 69-kV congestion at the Sycamore Canyon 230/138/69-kV substation; and locate proposed facilities within existing transmission corridors, SDG&E rights of way (ROWs), and utility owned property.

The project will be located in the western portion of the county, with elements within the City of San Diego and unincorporated County of San Diego, the commission said, adding that the project will also use an existing staging yard located within the City of Escondido.

The commission said that based on its review of the final initial study and mitigated negative declaration (IS/MND), it finds that the project will have either no significant impacts or less than significant impacts with respect to aesthetics; agriculture and forestry resources; air quality; energy conservation; geology, soils, and seismicity; greenhouse gas emissions; hydrology and water quality; land use and planning; mineral resources; population and housing; public services; recreation; transportation and traffic; as well as utilities and service systems.

The commission said that while the project has potentially significant impacts with respect to biological resources, cultural resources, hazards and hazardous materials, as well as noise and vibration, with the implementation of the measures identified in the Artesian Substation Project Final MND Mitigation Measures, the potentially significant impacts are reduced to less-than-significant levels.

The Final MND Mitigation Measures note, among other things, that vegetation clearance in habitat for listed bird species will be conducted outside the nesting season – Sept. 1 through Jan. 31.

The commission noted in its order that the Substation Field Management Plan (FMP) Checklist for the project proposes certain measures to reduce the electromagnetic field (EMF) levels from the substation’s facilities, including keeping high current devices, transformers, capacitors, and reactors away from the substation property lines by bringing into the substation property as much as possible.