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Hacienda TOD Standards and Design Guidelines Initial Study substantial evidence of a known fault Refer to Division of Mines and Geology Special Publication 42. ii) Strong seismic ground shaking% X iii) Seismic - related ground failure, incliding liquefaction? X iv) Landslides? X b) Result in substantial soil erosion or the loss of topsoil? X c) Be Located on a geologic unit or soil that is unstable, or that X would become unstable as a result of he project, and potentially result in on- or off -site landslide, lateril spreading, subsidence, liquefaction or collapse? d) Be located on expansive soil, as defined in 'liable I8 -1 -B of the Uniform Building Code (1994;, creating substantial risks to X life or property? e) 1lave soils incapable of adequately supporting the use of X septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of ■'asle water? Environmental Setting The three project sites arc located on relatively flat land. The City has referred to the Public Safety Element of the Pleasanton General Plan and to the geotechnical investigation prepared for the Hacienda Business Park before its development' to analyze whether the project sites are located in areas of seismic activity. The three sites are located in the vicinity of the known bit. Diablo Fault, although they are not in any landslide zone or in an Alquist Priolo Special Study Zone (Figures 5 -1, 5 -2, and 5 -5 of the Public Safety Element). The sites are in an arca designated as "Severe to Violent" for relative intensity of ground shaking by the California Geological Survey and are listed in a liquefaction zone in the California Geological Survey Seismic Hazards Zonation Program (Figures 5 -3 and 5 -4 of the Public Safety Element of the General Plan). Regarding expansive soils, the three sites have the potential to contain such soils. Significance Criteria The impact questions above constitute the significance criteria for this environmental topic. Discussion of Checklist Items Less - than - Significant Impacts. The project vicinity has a relatively high susceptibility to seismic shaking. The greatest seismic risks for the area are from a large earthquake on the Calaveras fault on the Pleasanton Ridge flank, and to s. slightly lesser extent, large magnitude earthquakes on the more distant Calaveras fault segments, as well as on the Calaveras, Concord, Greenville, Hayward, or San Andreas faults. Such events could cause extensive damage to structures and infrastructure. Because the site vicinity is located in an area susceptible to liquefaction and expansive soils, the potential exists for development due to the proposed zoning change to be subject to these hazards. Thus the project sponsor of development of the site would have to submit geotechnical or soils studies at the time development is proposed on any of the three project sites, if required to update the existing analysis conducted in 1981. 2 Wahler Associates, Geotechnical Engineer, "Preliminary Gcotechnical Investigation, Hacienda Business Park, Pleasanton, California," June 1981. Draft, Subject to Revision 13 2/11/2011