PG&E Gas Transmission Line 109 Canada Road, Bunker Hill, and Crystal Springs Pipeline Replacement Project
The proposed project would involve replacing a combined total of approx. 4.7 miles of existing underground natural gas pipeline across San Francisco Public Utilities Commission (SFPUC) Peninsula Watershed lands within unincorporated San Mateo County. The pipeline replacement would occur the following three segments:
1. The Canada Road segment, which includes two sections, separated by the Pulgas Balancing Reservoir, that run along the east side of Canada Road and west of I-280 from just south of SR 92 to just north of Edgewood Road.
2. The Bunker Hill segment, which beings at the Half Moon Bay Valve lot just west of Lexington Ave. and White Plains Court, then continues across Bunker hill Drive and terminates just west of Laurel Hill Drive.
3. The Crystal Springs segment, which runs parallel to I-280, north of the San Mateo Creek Canyon to a point north of Black Mountain Road and Hayne Road intersection.
The proposed project route is entirely within SFPUC Watershed lands - used for water collection, storage, and quality protection - that are off limits to the public, except along hiking trails that were jointly established by the SFPUC, U.S. Dept. of the Interior, Caltrans, and San Mateo County. This pipeline replacement is part of PG&E's company-wide pipeline modernization and safety program to improve the reliability and facilitate future maintenance of its larger transmission pipelines. Specifically, the existing pipeline would be replaced with 24- and 3-inch diameter pipe to facilitate future pipeline integrity testing using an automated in-line inspection tool called a "pig." The new pipeline would be installed by a combination of cut-and-cover open trench construction, with each trench segment measuring approx. 4-6 feet wide and approx. 6.5 to 8 feet deep, and horizontal directional drilling in certain locations. Once the new pipeline has been installed, the existing pipeline would be filled and abandoned in place. The construction period is expected to last approx. 15 months for all three segments and 5-7 months per segments.