Prepared for: 
California Public Utilities Commission 
Energy Division 

September 1998 

Prepared by: 
Aspen Environmental Group 
Agoura Hills, California 
(Contract No. PS-1624) 




Southern California Edison (SCE) has filed an application for a Permit to Construct Electrical Facilities with Voltages Between 50 kV and 200 kV (A.97-12-049) with the California Public Utilities Commission (Commission).  SCE specifically requests the authority to construct a new substation, replace power poles, and string new power lines to service the Six Flags Magic Mountain amusement park adjacent to Feedmill Road on the west side of the Santa Clara River in northwestern Los Angeles County.  This is regulated pursuant to General Order (GO)131-D which governs CPUC-regulated utilities.  As required by the California Environmental Quality Act (CEQA), the Commission assessed the potential environmental impacts of the proposed project as part of its decision to grant or deny SCE's application.  Based on this assessment from the Initial Study, this Mitigated Negative Declaration has been prepared. 


The proposed project involves the construction of a new substation, the replacement of power poles, and the stringing of new power lines to increase electrical service for the Six Flags Magic Mountain Amusement Park in Valencia, California.  A new 66/16 kilovolt (kV) substation would be constructed in the parking lot of the amusement park adjacent to Feedmill Road on the west side of the Santa Clara River.  A 66 kV power line would span the Santa Clara River, the Old Road, and Interstate 5 and new power lines would be added to existing poles along Avenue Stanford and Avenue Hall in the City of Santa Clarita (Interstate 5 is the boundary between the City of Santa Clarita and unincorporated Los Angeles County). A portion of the new power lines would be located within the boundaries of the City of Santa Clarita, while the new substation and the majority of the new power poles would be constructed within unincorporated territory of Los Angeles County. 


The proposed 66/16 kV chain-link fenced substation would be located approximately 1,100 feet from the west bank of the Santa Clara River and would occupy a 45-foot by 83-foot area with one 29-foot switchrack and one 15-foot switchrack with two circuit breakers. 

Proposed 66kV Power line 

The proposed 66kV tap line will require the construction of 3,210 feet of single circuit line, and the double circuiting of 2,890 feet of existing line, for a total distance of 6,100 feet (1.15 miles).  The proposed project requires the installation of nine 75 foot-high wood poles and three 85 foot-high tubular steel poles. The  power lines will tap into a Southern California Edison (SCE) transmission line east of Pardee Substation and then be strung along existing power poles on the north side of Avenue Hall.  Then the proposed power line would be strung along existing poles on Avenue Stanford (heading southeast) for 1,590 feet, and new poles would be added along the edge of existing parking lots located at rear of commercial and industrial businesses on the west side of Avenue Stanford.  From the new poles, the proposed power line turns southwest again and crosses Interstate 5 and the Old Road, and continues across the Santa Clara River along more new poles.  Here, the conductor on an existing 16kV system will be transferred onto the new poles.  After crossing the river, the proposed power line and the transferred conductor enter the Six Flags Magic Mountain property.  The proposed power line continues across a gravel parking lot to Feedmill Road.  The south side of Feedmill Road is a paved parking lot and the proposed power lines would terminate at the proposed Colossus substation, approximately 1,100 feet from the west bank of the Santa Clara River.  At Feedmill Road, the transferred conductor will be split off to the existing 16kV pole system, and the 66kV line will enter the station as described below. 

Relocation and Removal of 16 kV Conductor and Poles 

The existing 16 kV conductor that currently crosses the Santa Clara River, south of the proposed project, will be relocated and placed on the poles installed for the proposed 66kV project.  The 16 kV conductor will then be strung across the Six Flags Magic Mountain parking lot to an existing 16kV pole that is located adjacent to Feedmill Road.  The poles and 16 kV conductor that were previously used will be removed. 


The Initial Study (attached) was prepared to assess the potential effects on the environment of the construction of the substation, the placement of new poles, the removal of old poles, and the stringing of new power lines, and the respective significance of those effects.  The Initial Study was based on information taken from Southern California Edison's Application (December 31, 1997) and Amendments to the Application (March 6 and April 22, 1998) for a permit from the California Public Utilities Commission, pursuant to CPUC General Order 131-D.  Within the Amendments to the Application, mitigation measures addressing potentially significant impacts identified within the application of December 31, 1997, were proposed by the applicant which have been incorporated into the project description. 

Based on the Initial Study, the proposed project will have less-than-significant effects or no impacts in the areas of: 

Air Quality 
Cultural Resources 
Energy & Mineral Resources 
Geological Problems 
Land Use and Planning 
Mandatory Findings of Significance 
Population and Housing 
Public Services 
Utilities & Service Systems 
The Initial Study indicates that the proposed project would have potentially significant impacts in the areas of: 

- Biology 

- Hazards 

Each of the impacts identified as potentially significant can be mitigated to avoid the impact or reduce it to a less-than-significant level.  The mitigation measures, which SCE has agreed to include in the project, are as follows: 


Potential habitat for Peirson's morning glory may exist within the project site.  Potential impacts would be reduced to non-significance by implementation of the following measure: 

B-1 If Peirson's morning glory are located within the construction area, plants will be marked with a 1-2 foot tall metal pole at the time of surveying, and flagging shall be attached to each pole to ensure specimens are avoided during construction.  Workers will be instructed in writing to avoid walking, driving, or parking near these flagged poles. 

A portion of the proposed project is located adjacent to the riparian zone of the Santa Clara River.  Riparian areas are noted for their use as migration corridors by wildlife.  Disturbance to wildlife during tree topping will be minimized through implementation of the following measure: 

B-2 Trimming of trees may only take place from September 30 to March 31. 


The proposed project will require the temporary closure of Interstate 5 in the early morning hours to pull conductor across the freeway (SCE, 1997).  Implementation of the following measure would decrease the chances of a conflict with emergency response and action plans and avoid potential impacts: 

H-1 SCE shall ensure that affected state and local emergency service agencies are notified of the freeway closure at least two weeks in advance.  SCE shall coordinate with each affected agency as needed to ensure that alternative emergency response and evacuation routes are available during the period of freeway closure.  Emergency service agencies shall be provided with name and telephone number of a SCE contact person who will be responsible for coordinating construction activities related to the freeway closure. 

Based on the analysis of Initial Study and the mitigation measures identified therein and incorporated into the project, the Commission should find that the project will not have a significant effect on the environment. 

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