PG&E Northeast San Jose Transmission Reinforcement Project

Project Description

(Proposed Project as described in PG&Eís September 1999 Supplemental Proponentís Environmental Assessment)

The proposed project is intended to expand PG&Eís capacity to provide electric service to the northeast San Jose area.  The project would require construction of several components, which are described in more detail below:  

  • Construction of a new, 24-acre combined transmission substation (230/115 kV) and distribution substation (230/21 kV), called Los Esteros Substation

  •  Construction of a 7.3-mile-long, 230 kV double-circuit transmission line from Newark Substation to the new Los Esteros Substation, by the summer of 2000.

  • New 21 kV connections from Los Esteros Substation to local distribution circuits to serve future local growth.

  • Modification of the Newark Substation to accommodate the new 230 kV transmission line.

  • Replacement of a segment of an existing, 115 kV single-circuit wood pole line with a double-circuit, steel pole line.

  • Connection of the Los Esteros Substation to the 115 kV system with four 115 kV power line circuits.

Los Esteros Substation.  The proposed Los Esteros Substation site is located on the north side of State Route 237, between Zanker Road and Coyote Creek.  The site would occupy the northern 24 acres of a 54-acre property that is currently occupied by greenhouses, agricultural facilities, and buildings that house residents engaged in agricultural work.  The substation would be an unattended, remote-controlled facility that would require periodic maintenance.  The substation would initially consist of three 230/115 kV transmission transformers, circuit breakers, bus, capacitors, and controls.  Ultimately, a fourth 230/115 kV transformer would be installed.

PG&E also plans to install four 230/21 kV transformer banks at the Los Esteros Substation on the west side of the proposed 24-acre substation site.  Each transformer bank would serve three 21 kV distribution circuits that connect into the 21 kV distribution system.  These twelve 21 kV circuits are planned for connection to existing or future distribution lines in the area of the Los Esteros Substation.  Distribution substation banks would be added to the substation when the load is projected to exceed capacity.  PG&E anticipates this will occur within the next ten years.

230 kV Transmission Line.  The proposed project includes the construction of a 7.3-mile-long; 230 kV double-circuit transmission line from the Newark Substation to the new Los Esteros Substation.  PG&Eís Proposed Route parallels existing PG&E 115 kV power lines for approximately two miles of its 7.3-mile length and then diverges easterly.  The route crosses property owned by Catellus Corporation south of the Auto Mall Parkway, two Cargill Salt Company (Cargill) salt ponds, the westerly edge of the Bayside Business Park, the Fremont Airport property, the Santa Clara Valley Water Districtís Coyote Creek Flood Control Channel, and the San Jose/Santa Clara Water Pollution Control Plant (WPCP) property north of State Route 237.

Newark Substation Modification.  The 230 kV bus structure within the existing Newark Substation yard would be extended to accommodate the new 230 kV transmission line.  The area that would be occupied by the new equipment is within the existing footprint of the substation and is currently used as a storage area for heavy electrical equipment.  PG&E would relocate this equipment to another facility to make room for the modification.

115 kV Power Lines.  The Los Esteros Substation would be connected to the 115 kV transmission system via four 115 kV power lines:  Los Esteros to Kifer Power Line, Los Esteros to Trimble Power Line, Los Esteros to Montague Power Line, and Agnews Tap Line.  This would be achieved, in part, by utilizing 115 kV power lines to be built as part of the North San Jose Area Capacity Increase Project (Nortech Project) for which the commission has issued a Permit to Construct.  PG&E plans to follow existing power lines and utilize double-circuit steel poles in order to minimize the creation of new power line corridors to the greatest extent possible.  

  • Los Esteros to Kifer and Los Esteros to Trimble 115 kV Power Lines.  PG&E would install two 115 kV power lines from the Los Esteros Substation to the Trimble to Kifer 115 kV Loop at the Zanker Road/State Route 237 interchange.  PG&E will connect into the Trimble to Kifer 115 kV Loop north of State Route 237 and east of Zanker Road.  

  • Los Esteros to Montague 115 kV Power Line.  This power line would utilize a 2.4-mile segment of the Trimble to Kifer 115 kV Loop along Zanker Road, which is planned to be built by as a double circuit line by the summer of 2000 as part of the North San Jose Area Capacity Project.  Four-tenths of a mile of 115 kV power line would be constructed between the new Los Esteros Substation and the northeast corner of the Zanker Road/State Route 237 intersection and 1.4 miles of double-circuit replacement line would be constructed along Trimble Road and Montague Expressway.

  • Agnews 115 kV Tap Line.  The existing Agnews 115 kV Tap would connect into the new Los Esteros Substation.  This would shorten the tap from 2.9 miles to 1.2 miles.

Alternatives Considered in the Proponent's Environmental Assessment (PEA)

The PEA included in PG&E Application presents several alternatives for routing of the 230kV transmission line and for the substation site.  The following transmission line alternatives are presented:  

  • Combined Overhead/Underground 230kV Route Alternative: three miles of overhead lines; 9.9 of miles underground lines through residential and industrial areas of Milpitas.  

  • Westerly 230kV Route Alternative: seven miles of overhead line, paralleling existing 115kV lines along 5 miles, and crossing water and salt ponds for about half of its length.  This route crosses a portion of the Don Edwards San Francisco Bay National Wildlife Refuge.  

  • Newby Island Route Alternative: same as proposed route for first 3.8 miles, but turns east south of the Newby Island landfill, then south through WPCP property.  

  • Interstate 880 Alternative: Same as the proposed route for first 1.7 miles, then turning east and generally paralleling I-880 on the west side along the Bayside Business Park.  Rejoins the proposed route just north of the Fremont Airport property.  

  • New Generation Alternative: Interconnection with a 600 Megawatt (MW) generation plant near the Los Esteros Substation site with additional 115kV transmission upgrades.  

  •   No Project Alternative: A description of the environmental impacts that would result if the project were not constructed.  

The PEA also evaluates several alternative substation sites in the northeastern San Jose area.

EIR Alternatives:  PG&Eís alternatives will be evaluated, and additional alternatives will be considered to determine which alternatives will be studied in the EIR.  Input received during the scoping process will be considered in making this determination.

Information Sources:  

  • PG&E, Proponent's Environmental Assessment, Northeast San Jose Transmission Reinforcement Project, CPUC A. 98-07-007  

  • PG&E, Supplemental Proponentís Environmental Assessment, Northeast San Jose Transmission Reinforcement Project, CPUC A. 99-09-029  


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