STATE OF CALIFORNIA, PETE WILSON, Governor
January 28, 1998
RE: Variance Request #41 - Allow for the relocation of a check valve from station number 3240+81 to 3250+00 (a distance of approximately 900 feet south), Segment 2B.
Dear Mr. Shauers:
We have reviewed the above-referenced variance request and approve your request based on the following factors:
In accordance with Mitigation Measure SS-29**, valves shall be installed along the pipeline alignment at "environmentally sensitive areas, areas of liquefaction/faulting/scour, and at pump stations." The subject check valve has been incorporated into the project design to minimize the amount of oil that could enter Castaic Creek in the event of a spill and potentially impact the biological and hydrological resources of Castaic Creek and the Santa Clara River.
The valve relocation has been requested to accommodate a bridge abutment footing for the future overpass expansion at Biscaliluz Drive proposed by the County of Los Angeles. As proposed, the concrete footing would be installed within Castaic Creek to a subsurface depth of minus 120 feet. In order to clear the subsurface footing and accommodate the technological constraints of a directional drill, a minimum depth of 200 feet, an entry angle of 16o, and an exit angle of 12o would be required for the directional drill. Based on these constraints and the physical constraint for a suitable entry site for drilling operations, the resultant exit point of the directional drill would be approximately 900 feet south of the original valve location; the proposed site of the check valve relocation.
The original check valve location would have allowed a maximum of 247 barrels of oil to enter the creek if the pipeline were to break just north (creek side) of the valve. The proposed valve relocation would increase the potential for a maximum of 702 additional barrels of oil to enter Castaic Creek. However, since the area is relative flat from the valve site to the creek (a distance of approximately 1,800 feet) and since the creek is already bermed directly north of the valve relocation site, it is not anticipated that all of the additional volume of oil would enter the creek (a major rainfall and runoff might however, result in discharge of the oil to the creek).
The following measures shall be implemented:
- All applicable mitigation measures for the project shall be implemented at the subject location.
- Vehicle passage on The Old Road shall be maintained.
- Implementation of this variance in accordance with the provisions noted above shall be verified on a random basis by a CPUC/ANF Environmental Monitor.
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