Assessing Seismic Retrofit for Pipelines within a Residential Neighborhood
Penitencia Delivery Main and Penitencia Force Main Seismic Retrofit Project | San Jose, CA
LSA prepared CEQA documentation (IS/MND), as well as, technical studies for traffic and noise to assess construction-related impacts, for the repair/replacement of portions of three pipelines and related vault structures between Grossmont Drive and Vista Del Mar in the City of San Jose, California. The project elements include repair/replacement and/or demolition of facilities that are critical to operation of the Penitencia Water Treatment Plant, owned and operated by the Santa Clara Valley Water District (District). The facilities are located at the toe of the Penitencia Creek Landslide and have incurred damage related to landslide creep.
The objective of the proposed project is to seismically retrofit the pipelines and related infrastructure to accommodate both the creep and potentially extensive seismically-induced movements of the landslide. The proposed project is located within a residential neighborhood and adjacent to an existing school. The Initial Study/Mitigated Negative Declaration addressed potential construction impacts on neighboring residents, including air quality, noise, and traffic; impacts to biological resources associated with pipeline dewatering into Sierra Creek, and visual and land use impacts associated with construction of new infrastructure within the pipeline alignment. The District approved the proposed project and adopted the IS/MND in September 2015.
As a subsequent task, LSA prepared a Streambed Alteration Agreement for the California Department of Fish and Wildlife to address the discharge of water from pipeline dewatering into Sierra Creek, which flows into Berryessa Creek and eventually into Coyote Creek.