F. GEOLOGY, SEISMICITY, AND SOILS

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1 This section describes the project site s geologic conditions based on a site inspection, published and unpublished geologic reports and maps, and a site-specific geotechnical report. 1 This section also assesses potential impacts from surface-fault rupture, ground shaking, liquefaction and lateral spreading, slope failure, expansive and corrosive soils, mineral resources, and subsidence. Mitigation measures for significant impacts are provided, when appropriate. 1. Setting The site s existing conditions related to geology and seismic conditions, and associated hazards, are described below. a. Seismic and Geologic Conditions. The following section describes the primary geologyrelated characteristics of the site. (1) Topography. The project site is located in an urbanized area approximately 7.5 miles south of San Francisco Bay in the Santa Clara Valley on nearly flat valley floor alluvial deposits. The existing ground surface slopes gently to the northeast, with elevations ranging from approximately 145 feet above mean sea level (msl) in the northeast to 175 feet msl in the southwest across a horizontal distance of approximately 3,000 feet. Calabazas Creek, which has been channelized, passes through the southeast portion of the site. 2 (2) Geology and Soils. The project site is located near the center of the Coast Range Geomorphic Province of Northern California. This region is dominated by northwest-southeast trending ranges of low mountains and intervening valleys. 3 The Santa Clara Valley floor consists of alluvial fans derived from the Santa Cruz Mountains (to the south and southwest). The geology at ground surface consists of Holocene age (up to approximately 11,000 years old) and Pleistocene age (up to approximately 2 million years old) alluvial fan (deposited by gravitational means) and fluvial (deposited by moving water) deposits, with artificial fill along the Calabazas Creek channel. 4,5 The Geotechnical Interpretive Report prepared for the project site indicates that the site is underlain by alluvial deposits to a depth of approximately 240 feet below the ground surface (bgs). The alluvial deposits consist of interbedded layers of granular and cohesive soils that are laterally discontinuous. Bedrock was not encountered. Groundwater levels measured in six piezometers (devices used to measure groundwater) and multiple borings drilled during geotechnical explorations indicated groundwater ranged from approximately 54 to 68 feet bgs. 6 1 Arup, Apple Campus 2 Geotechnical Interpretative Report. Issue 3. April U.S. Geological Survey, Cupertino Quadrangle 7.5 series Topographic Map. Revised California Geological Survey, 2002a. California Department of Conservation. Note 36, California Geomorphic Provinces. December. 4 U.S. Geological Survey, Geological Map and Map Database of the Palo Alto 30 x 60 Quadrangle, California. 5 California Geological Survey, no date. California Department of Conservation. Seismic Hazard Zone Report 068, Seismic Hazard Zone Report for the Cupertino 7.5-Minute Quadrangle, Santa Clara County, California. Website: gmw.consrv.ca.gov/shmp/download/evalrpt/cup_eval.pdf (accessed September 21, 2011). 6 Arup, 2013, op. cit. P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 289

2 The soils underlying the site have been mapped as urban land by the National Resources Conservation Service (NRCS). All five soil complexes identified by the NRCS on the project site are well drained and present on slopes less than or equal to 2 percent. 7 (3) Mineral Resources. The City of Cupertino mineral resource map classifies the northwest portion of the project site area as Mineral Resource Zone (MRZ) 3, or an area containing mineral deposits the significance of which cannot be evaluated from available data. The southeast portion of the site is not classified as a mineral resource zone. 8 The California Department of Mines and Geology (now named California Geological Survey) classifies the project site as an area where adequate information indicates that no significant mineral deposits are present, or where it is judged that little likelihood exists for their presence. 9 (4) Seismic Conditions. The site is located in the seismically active San Francisco Bay Area. The main feature generating the seismic activity in the region is the tectonic plate boundary between the North American and Pacific lithospheric plates. Locally, this boundary is referred to as the San Andreas Fault Zone (SAFZ), which includes the San Andreas Fault and numerous other active faults. Movement of the plates relative to one another results in the accumulation of strain along the faults, which is released during earthquakes. The SAFZ includes numerous active faults found by the California Geological Survey under the Alquist-Priolo Earthquake Fault Zoning Act (A-PEFZA) to be active (i.e., to have evidence of surface rupture in the past 11,000 years). Active faults in the San Francisco Bay Area zoned under the A-PEFZA include the San Andreas, Hayward-Rodgers Creek, Calaveras, Maacama, West Napa, Concord-Green Valley, Greenville, Sargent, and San Gregorio-Seal Cove faults. The closest A- PEFZA faults to the project site are the San Andreas Fault, located approximately 6 miles southwest, and the Hayward-Rodgers Creek Fault, located approximately 10 miles northeast. 10 Additional faults in the project site vicinity also have the potential to generate seismic shaking, including the Monte Vista-Shannon fault zone located along the northeast margin of the Santa Cruz Mountains. 11,12 Regional active and potentially active faults are shown on Figure V.F-1. 7 Natural Resources Conservation Service, U.S. Department of Agriculture. Web Soil Survey. Website: websoilsurvey.nrcs.usda.gov/app/homepage.htm (accessed September 16, 2011). 8 Cupertino, City of, City of Cupertino General Plan, Website: index.aspx?page=709 (accessed September 21, 2011). 9 California Department of Mines and Geology, Mineral Land Classification: Aggregate Minerals in the San Francisco-Monterey Bay Area. Updated California Geological Survey, California Department of Conservation. Alquist-Priolo Earthquake Fault Zone Maps. Website: (accessed November 10, 2011). 11 U.S. Geological Survey, EHP Quaternary Faults. Website: geohazards.usgs.gov/qfaults/map.php (accessed November 10, 2011). 12 U.S. Geological Survey, Earthquake Hazards Program, Database Search for Monte Vista-Shannon Fault Zone. Website: geohazards.usgs.gov/cfusion/qfault (accessed November 10, 2011). P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 290

3 H unti ng Creek - Berryess a a a M a a c a r n F San Andrea s Fault l t u ierr a n Santa Rosa R od g re e r ek F s C St. Helena Napa Sc Bl o k Boundary Petaluma au l t W. Napa Green Valley Fult a Fult a Ful a t Concord Oakland San Francisco M. t Diablo Ha ywa rdfu a lt Tr hus tfa ult Ca l Gr een Pacific Ocean at Project Site ve r a s Fa VeronaFault vi ll e F Las P sitas o ault Fault Seal C ove-san G regor iofaul t San Jose Monte Vista-Shannon Fault u l O r t iga li ta F a t u l FIGURE V.F miles 20 Active Fault - Fault has evidence of surface displacement within the past 11,000 years (dashed where inferred) Potentially Active Fault - Fault has evidence of surface displacement in the past 1.6 million years, but not within the past 11,000 years Seismic Source without Surface Rupture SOURCES: USGS, DATABASE OF POTENTIAL SOURCES FOR EARTHQUAKES LARGER THAN MAGNITUDE 6 IN NORTHERN CALIFORNIA., OFR CALIF. GEOLOGIC SURVEY, FAULT-RUPTURE HAZARDS IN CALIFORNIA, SPECIAL PUBLICATION 42: INTERIM REVISION CALIFORNIA DIVISION OF MINES AND GEOLOGY, FAULT ACTIVITY MAP OF CALIFORNIA AND ADJACENT AREAS, GEOLOGIC MAP 6. I:\COC1101 Apple Campus 2\figures\EIR\Fig_VF1.ai (6/29/12) Apple Campus 2 Project EIR Regional Faults

4 In a fact sheet published in 2008, the U.S. Geological Survey (USGS) estimated that there is a 59 percent probability that between 2008 and 2037 a 6.7 or greater magnitude earthquake will occur along the Southern San Andreas Fault. The probability of a 6.7 magnitude or greater earthquake was estimated to be 31 percent along the Hayward-Rodgers Creek Fault and 7 percent along the Calaveras Fault. 13 b. Seismic and Geologic Hazards. The following section describes the types of seismic and geologic hazards that could occur in the vicinity of the site. (1) Surface Rupture. Surface rupture occurs when the ground surface is broken due to fault movement during an earthquake. The location of surface rupture generally can be assumed to be along an active major fault trace. No active faults have been mapped at the project site, and no portion of the site is located within an A-PEFZ or within a fault zone mapped by the County of Santa Clara. 14 Therefore, the potential for fault rupture at the site is considered negligible. (2) Ground Shaking. Ground shaking is a general term referring to all aspects of motion of the earth s surface resulting from an earthquake, and is normally the major cause of damage in seismic events. The extent of ground shaking is controlled by the magnitude and intensity of the earthquake. Magnitude is a measure of the energy released by an earthquake; it is assessed by seismographs that measure the amplitude of seismic waves. In the past, the common standard for measurement of magnitude (M L ) by geologists and earthquake seismologists was the Richter Scale. However, due to limitations of the instrumentation used to measure Richter magnitude, moment magnitude (M W ) is now most commonly used to characterize seismic events. Moment magnitude is determined from the physical size (area) of the rupture of the fault plane, the amount of horizontal and/or vertical displacement along the fault plane, and the resistance of the rock type along the fault to rupture. The moment magnitude can be calculated following an earthquake or estimated for an expected earthquake if the fault rupture area and displacement and rock properties can be estimated accurately. Therefore, the magnitudes of expected earthquakes in the San Francisco Bay Area are reported as moment magnitudes. Intensity is a subjective measure of the perceptible effects of seismic energy at a given point and varies with distance from the epicenter and local geologic conditions. The Modified Mercalli Intensity Scale (MMI) is the most commonly used scale for measurement of the subjective effects of earthquake intensity (Table V.F-1). Intensity can also be quantitatively measured using accelerometers (strong motion seismographs) that record ground acceleration at a specific location. Ground acceleration is a measure of force applied to a structure under seismic shaking. Acceleration is measured as a fraction or percentage of the acceleration under gravity (g). The San Andreas Fault is considered capable of generating a moment magnitude (M W ) 7.9 earthquake (similar to the 1906 San Francisco 13 U.S. Geological Survey, Forecasting California s Earthquakes What Can We Expect in the Next 30 Years, USGS Fact Sheet Website: pubs.usgs.gov/fs/2008/3027/ (accessed September 20, 2011). 2011). 14 Santa Clara, County of, Fault Rupture Hazard Zones. Website: (accessed November 10, P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 292

5 earthquake). 15 An earthquake of this magnitude on the San Andreas Fault could generate very strong seismic shaking (MMI VIII) at the project site. 16 Table V.F-1: Modified Mercalli Scale a Intensity Effects v, b cm/s g c M d I. Not felt. Marginal and long-period effects of large earthquakes. 3 II. Felt by persons at rest, on upper floors, or favorably placed. III. Felt indoors. Hanging objects swing. Vibration-like passing of light trucks Duration estimated. May not be recognized as an earthquake. 4 IV. Hanging objects swing. Vibration-like passing of heavy trucks; or sensation of a jolt like a heavy ball striking the walls. Standing motor cars rock. Windows, dishes, doors rattle. Glasses clink. Crockery clashes. In the upper range of IV, wooden walls and frame creak V. Felt outdoors; direction estimated. Sleepers wakened. Liquids disturbed, some spilled. Small unstable objects displaced or upset. Doors swing, close, open. Shutters, pictures move. Pendulum clocks stop, start, change rate. 5 VI. Felt by all. Many frightened and run outdoors. Persons walk unsteadily. Windows, dishes, glassware broken. Knickknacks, books, etc., off shelves. Pictures off walls. Furniture moved or overturned. Weak plaster and masonry B cracked. Small bells ring (church, school). Trees, bushes shaken (visibly, or heard to rustle). 6 VII. Difficult to stand. Noticed by drivers of motor cars. Hanging objects quiver Furniture broken. Damage to masonry D, including cracks. Weak chimneys broken at roof line. Fall of plaster, loose bricks, stones, tiles, cornices (also unbraced parapets and architectural ornaments). Some cracks in masonry C. Waves on ponds; water turbid with mud. Small slides and caving-in along sand or gravel banks. Large bells ring. Concrete irrigation ditches damaged. VIII. Steering of motor cars affected. Damage to masonry C; partial collapse. Some damage to masonry B; none to masonry A. Fall of stucco and some masonry walls. Twisting, fall of chimneys, factory stacks, monuments, towers, elevated tanks. Frame houses moved on foundations if not bolted down; loose panel walls thrown out. Decayed piling broken off. Branches broken from trees. Changes in flow or temperature of springs and wells. Cracks in wet ground and on steep slopes. 7 IX. General panic. Masonry D destroyed; masonry C heavily damaged, sometimes with complete collapse; masonry B seriously damaged. General damage to foundations. Frame structures, if not bolted, shifted off foundations. Frames cracked. Serious damage to reservoirs. Underground pipes broken. Conspicuous cracks in ground. In alluviated areas, sand and mud ejected, earthquake foundations, sand craters X. Most masonry and frame structures destroyed with their foundations. Some wellbuilt wooden structures and bridges destroyed. Serious damage to dams, dikes, embankments. Large landslides. Water thrown on banks of canals, rivers, lakes, etc. Sand and mud shifted horizontally on beaches and flat land. Rails bent slightly XI. Rails bent greatly. Underground pipelines completely out of service. >1.2 XII. Damage nearly total. Large rock masses displaced. Lines of sight and level distorted. Objects thrown into the air. Table notes included on next page. 15 U.S. Geological Survey, Earthquake Hazards Program. Website: geohazards.usgs.gov/cfusion/ hazfaults_search/disp_hf_info.cfm?cfault_id=1abcd (accessed March 22, 2012). 16 Association of Bay Area Governments, ABAG Earthquake Shaking Scenario, Entire San Andreas (1906 Quake) Magnitude 7.9. Website: gis.abag.ca.gov/website/shaking-maps/ viewer.htm (accessed September 16, 2011). P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 293

6 a From Richter (1958). b Average peak ground velocity, centimeters per second (cm/s). c Average peak acceleration (away from source). d Richter magnitude correlation. Notes: Masonry A, B, C, D. To avoid ambiguity of language, the quality of masonry, brick or otherwise, is specified by the following lettering (which has no connection with the conventional Class A, B, C construction). Masonry A: Good workmanship, mortar, and design, reinforced, especially laterally, and bound together using steel, concrete, etc; designed to resist lateral forces. Masonry B: Good workmanship and mortar, reinforced, but not designed to resist lateral forces. Masonry C: Ordinary workmanship and mortar; no extreme weaknesses such as non-tied-in corners, but masonry is neither reinforced nor designed against horizontal forces. Masonry D: Weak materials, such as adobe; poor mortar; low standards of workmanship; weak horizontally. Source: Baseline, Estimates of the peak ground acceleration have been made for the project site and its surroundings based on probabilistic models that account for multiple seismic sources. Under these models, consideration of the probability of expected seismic events is incorporated into the determination of the level of ground shaking at a particular location. The expected peak horizontal acceleration (with a 10 percent chance of being exceeded in the next 50 years) generated by any of the seismic sources potentially affecting the area, including the project site, is estimated by the California Geological Survey as approximately 0.6 to 0.7g. 17 Shaking amplification for geologic materials underlying the project site area has been estimated to be moderate to moderately high. 18 This level of ground shaking at the project site is a potentially significant hazard. (3) Liquefaction and Lateral Spreading. Liquefaction is the temporary transformation of loose, saturated granular sediments from a solid state to a liquefied state as a result of seismic ground shaking. In the process, the soil undergoes transient loss of strength, which commonly causes ground displacement or ground failure to occur. Since saturated soils are a necessary condition for liquefaction, soil layers in areas where the groundwater table is near the surface have higher liquefaction potential than those in which the water table is located at greater depths. Recent geotechnical explorations indicate the depth to groundwater at the project site ranges between approximately 54 to 68 feet bgs, and historically high groundwater has been reported to be from 45 to 55 feet bgs. 19 Regional liquefaction hazard mapping indicates that the site is within a zone considered to be subject to moderate to low liquefaction susceptibility and low liquefaction hazard. 20 The project site vicinity has been mapped in conformance with the Seismic Hazards Mapping Act (discussed further below under Regulatory Framework ). A Seismic Hazard Zone for liquefaction has been identified for the area immediately adjacent to Calabazas Creek, in the southeast portion of the site, indicating a 17 California Geological Survey, California Department of Conservation. Probabilistic Seismic Hazards, Peak Ground Acceleration. Website: (accessed September 22, 2011). 18 Association of Bay Area Governments, Earthquake and Hazards Program, Geologic Materials Shaking Amplification Maps. Website: quake.abag.ca.gov/shaking/amplification (accessed September 20, 2011). 19 Arup, 2013, op. cit. 20 Association of Bay Area Governments, Liquefaction Susceptibility Map. Website: quake.abag.ca.gov/ liquefaction (accessed September 20, 2011). P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 294

7 liquefaction investigation is required in this area by the State of California. 21 Santa Clara County has also mapped the vicinity of Calabazas Creek on the project site as a Liquefaction Hazard Zone. 22 Liquefaction assessment results estimate liquefaction-induced settlement in the Calabazas Creek area to be about 0.5 inches. 23 The required liquefaction assessment would be completed as part of the design-level geotechnical report required by Mitigation Measure GEO-1, discussed below under Impacts and Mitigation Measures. The City would review and approve the geotechnical report prior to issuing grading or building permits. Lateral spreading is a form of horizontal displacement of soil toward an open channel or other free face, such as an excavation boundary. Lateral spreading can result from either the slump of lowcohesion unconsolidated material, or more commonly, by liquefaction of either the soil layer or a subsurface layer underlying soil material on a slope. 24 The lateral spreading hazard tends to mirror the liquefaction hazard for a site. Lateral spreading was evaluated in the geotechnical report, and was not considered to be a potential issue since liquefaction is not expected to not occur in the layers above the bed of the creek channel. 25 (4) Landslides. Slope failure can occur as either rapid movement of large masses of soil (landslide) or imperceptibly slow movement of soils on slopes (creep). The primary factors influencing the stability of a slope are the nature of the underlying soil or bedrock, the geometry of the slope (height and steepness), and rainfall. The presence of historic landslide deposits is a good indicator of future landslides. Landslides are commonly triggered by unusually high rainfall and the resulting soil saturation, by earthquakes, or a combination of these conditions. The City of Cupertino is mapped as Category 1, (stable areas of less than 5 percent slope and not underlain by landslide deposits). 26 There are no Seismic Hazard Zones for landslides on the project site, indicating a geotechnical investigation addressing potential landslide hazards would not be required by the State of California. 27 Slope stability issues on relatively flat sites are generally related directly to construction activities such as spoil and dirt stockpiling, and trenching and sub-surface excavation activities. (5) Settlement and Differential Settlement.Settlement or differential settlement may occur when loads, such as structures or fill, are placed on compressible subsurface materials (including imported fill) or if improvements straddle the boundary between different types of subsurface materials (e.g., a boundary between native soil and fill). Although differential settlement generally occurs slowly enough that its effects are not dangerous to inhabitants, it can cause significant building damage over time. The project site has been developed and it would be expected that some settlement has occurred in the past due to existing and historical structural loads. Portions of the project site that 21 California Geological Survey, 2002b. California Department of Conservation. State of California Seismic Hazard Zones, Cupertino Quadrangle, Official Map. September Santa Clara, County of, Santa Clara County Geologic Hazard Zones. Website: (accessed November 10, 2011). 23 Arup, 2013, op. cit. 24 Rauch, Alan F., EPOLLS: An Empirical Method for Predicting Surface Displacements Due to Liquefaction- Induced Lateral Spreading in Earthquakes, Ph. D. Dissertation, Virginia Tech, Blacksburg, VA. 25 Arup, 2013, op. cit. 26 Nilsen, T. H., Wright, R. H., et al., Relative Slope Stability and Land-use Planning in the San Francisco Bay Region, California. USGS Professional Paper California Geological Survey, 2002b, op. cit. P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 295

8 contain loose or uncontrolled (non-engineered) fill may be susceptible to differential settlement. The proposed project is not located within a Santa Clara County compressible soil hazard zone. 28 (6) Expansive and Corrosive Soil. Expansion and contraction of volume can occur when expansive soils undergo alternating cycles of wetting (swelling) and drying (shrinking). During these cycles, the volume of the soil changes markedly. As a consequence of such volume changes, structural damage to buildings and infrastructure may occur if the potentially expansive soils are not considered in building design and during construction. This is of particular concern for structures supported in near-surface soils. The project site soils consist of of interbedded layers of granular soils (sand and gravel) and cohesive (silt and clay) soils. 29 Granular soils are non-expansive, silt has a low expansion potential, and clay can range from low to high expansion potential. Soils with moderate to high expansion potential are classified as expansive soils and construction would require appropriate engineering. 30 Soil testing for corrosion potential has been performed. Chemical tests on soil samples for chlorides, sulfates, ph and Redox Potential indicate the soils tested are non-corrosive. However, chemical tests on soil samples and in-situ measurements of resistivity (a function of soil moisture) indicate the soils tested are moderately corrosive to severely corrosive. Site soils are therefore considered to be moderately corrosive to severely corrosive with respect to bare steel or ductile iron, and proposed structures may require corrosion protection. 31 (7) Subsidence. Subsidence is the lowering of the land-surface elevation. The mechanism for subsidence is generally related to groundwater pumping and subsequent consolidation of loose aquifer sediments. The primary hazards associated with subsidence are increased flooding hazards and damage to underground utilities. Other effects of subsidence include changes in the gradients of stormwater and sanitary sewer drainage systems in which the flow is gravity-driven. Historical subsidence in the vicinity of the project site has been reported to be from approximately 0.5 to 1 feet. 32 c. Regulatory Framework. This section includes a discussion of applicable geology-related policies and regulations. (1) Federal Regulations National Earthquake Hazards Reduction Program. The National Earthquake Hazards Reduction Program (NEHRP) was established by the U.S. Congress when it passed the Earthquake Hazards Reduction Act of 1977, Public Law In establishing NEHRP, Congress recognized that earthquake-related losses could be reduced through improved design and construction methods and practices, land use controls and redevelopment, prediction techniques and early-warning systems, coordinated emergency preparedness plans, and public education and involvement programs. The four basic NEHRP goals are: Develop effective practices and policies for earthquake loss reduction and accelerate their implementation. Improve techniques for reducing earthquake vulnerabilities of facilities and systems. 28 Ibid. 29 Arup, 2013, op. cit. 30 Natural Resources Conservation Service, 2010, op. cit. 31 Arup, 2013, op. cit. 32 Santa Clara Valley Water District, Lines of Equal Subsidence, Santa Clara Valley, North County, Website: cf.valleywater.org/media/pdf/permanente/ecr_permanente_subsidence.pdf (accessed September 21, 2011). P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 296

9 Improve earthquake hazards identification and risk assessment methods, and their use. Improve the understanding of earthquakes and their effects. Several key federal agencies contribute to earthquake mitigation efforts. The four primary NEHRP agencies are: National Institute of Standards and Technology (NIST) of the Department of Commerce National Science Foundation (NSF) United States Geological Survey (USGS) of the Department of the Interior Federal Emergency Management Agency (FEMA) of the Department of Homeland Security Implementation of NEHRP priorities is accomplished primarily through original research, publications, and recommendations to assist and guide State, regional, and local agencies in the development of plans and policies to promote safety and emergency planning. (2) State Regulations. State regulations are discussed below. California Building Code. The 2010 California Building Code (CBC), which refers to Part 2 of the California Building Standards Code in Title 24 of the California Code of Regulations, is based on the 2009 International Building Code. The 2010 CBC covers grading and other geotechnical issues, building specifications, and non-building structures. The City of Cupertino has adopted the 2010 CBC as the reference building code for all projects in the City. 33 The City of Cupertino Building Department is responsible for reviewing plans, issuing building permits, and conducting field inspections. (Project buildings would conform to the 2010 CBC; the proposed bridge would comply with American Association of State Highway and Transportation Officials (AASHTO) and California Department of Transportation design standards.) The CBC requires that a site-specific geotechnical investigation report be prepared by a licensed professional for proposed developments of one or more buildings containing more than 4,000 square feet of interior space to evaluate geologic and seismic hazards. Developers of buildings with 4,000 square feet or less of interior space are also required to prepare a geologic engineering report, except for one-story, wood-frame and light-steel-frame buildings of Type V construction that are located outside of the Alquist-Priolo Earthquake Fault Zone. The purpose of a site-specific geotechnical investigation is to identify seismic and geologic conditions that require project mitigation, such as those related to surface fault ruptures, ground shaking, liquefaction, differential settlement, lateral spreading, expansive soils, and slope stability. Requirements for a geotechnical investigation are presented in Chapter 16 Structural Design and Chapter 18 Soils and Foundation of the 2010 CBC. The geotechnical investigation report would be reviewed by the City of Cupertino Building Department prior to issuance of building permits, to ensure compliance. 33 Cupertino, City of, Website: (accessed March 22, 2012). P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 297

10 Alquist-Priolo Earthquake Fault Zoning Act. Surface rupture is the most easily-avoided seismic hazard. The A-PEFZA was passed by the California Legislature in December 1972 to mitigate the hazard of surface faulting to structures designed for human occupancy. The project site is not located within the A-PEFZA. Seismic Hazards Mapping Act (SHMA). In 1990, following the 1989 Loma Prieta earthquake, the California Legislature enacted the SHMA to protect the public from the effects of strong ground shaking, liquefaction, landslides and other seismic hazards. The SHMA established a Statewide mapping program to identify areas subject to violent shaking and ground failure; the program is intended to assist cities and counties in protecting public health and safety. The SHMA requires the State Geologist to delineate various seismic hazard zones and requires cities, counties, and other local permitting agencies to regulate certain development projects within these zones. As a result, the California Geologic Survey is mapping SHMA Zones and has completed seismic hazard mapping for the portions of California most susceptible to liquefaction, ground shaking, and landslides: primarily the San Francisco Bay area and Los Angeles basin. The vicinity of the project site has been mapped in conformance with the SHMA. 34 (3) City of Cupertino General Plan. Policy 6.1 of the Health and Safety Element states: Evaluate new development proposals within mapped potential hazard zones using a formal seismic/ geologic review process. Use Table 6-D of this Hazards Analysis to determine the level of review required Impacts and Mitigation Measures The analysis of the impacts related to geology, soils, and seismicity that could result from implementation of the proposed project is presented below. This section begins with the criteria of significance, which establish the thresholds for determining whether a project impact is significant, and identifies less-than-significant and potentially significant geology, soils, and seismicity impacts/hazards associated with the proposed project. Mitigation measures are provided to reduce significant impacts to a less-than-significant level. a. Criteria of Significance. The project would have a significant geology, soils, or seismicity impact if it would: Expose people or structures to substantial risk of loss, injury, or death involving: Rupture of a known active or potentially active earthquake fault, as delineated on the most recent A-PEFZ Map issued by the State Geologist for the area, or based on other substantial evidence of a known fault; Strong seismic ground shaking; Seismic-related ground failure, including liquefaction; or Landslides; Result in substantial soil erosion or loss of topsoil; 34 California Geological Survey, 2002b, op. cit. 35 Cupertino, City of, City of Cupertino General Plan, , Health and Safety Element. Website: (accessed September 21, 2011). P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 298

11 Be located on a geologic unit or soil that is unstable, or that would become unstable as a result of the project, and potentially result in an on- or off-site landslide, lateral spreading, subsidence, liquefaction, or collapse; Be located on expansive soils (as defined in Table 18-1-B of the 1994 Uniform Building Code) or corrosive soils, creating substantial risks to life or property; Result in the loss of availability of a known mineral resource that would be of value to the region and the residents of the State; or Result in the loss of availability of a locally-important mineral resource recovery site delineated on a local general plan, specific plan or other land use plan. A criterion regarding septic tanks and alternative wastewater disposal systems is not included since the project would be served by municipal wastewater lines. b. Less-Than-Significant Impacts. This section discusses the less-than-significant impacts of the project. (1) Active or Potentially Active Earthquake Fault. The most recent A-PEFZ maps indicate that the nearest active fault to the project site is the San Andreas Fault peninsula segment, located approximately 6 miles to the southwest. 36 Based on USGS fault maps, no potentially active faults underlie the site. 37 The proposed project would therefore not be expected to be affected by rupture at the site of a known active or potentially active fault. (2) Mineral Resources. The project site is classified as an area where adequate information indicates that no significant mineral deposits are present, or where it is judged that little likelihood exists for their presence. 38 The project would therefore not result in the loss of availability of a known mineral resource of value locally or to the region or State. The project site is not identified in a planning document as being a locally-important mineral resource recovery site. (3) Slope Stability. The project site is in an area mapped by the City of Cupertino as stable with regard to landslides, 39 and there are no Seismic Hazard Zones for landslides on the project site. Therefore, a geotechnical investigation addressing potential landslide hazards would not be required by the State of California. 40 The project would require approximately 1,690,000 cubic yards of excavation (net) and 1,620,000 cubic yards of fill (net) for Phase 1 and Phase 2 combined. Phase 1 would result in a balanced site and Phase 2 would require approximately 150,000 cubic yards of soil to be exported from the site. Phase 1 would require approximately 45,000 cubic yards of top soil import and Phase 2 would require an import of 5,000 cubic yards, for a total top soil import of 50,000 cubic yards. 36 California Geological Survey, Alquist-Priolo Earthquake Fault Zone Maps, 2011, op. cit. 37 U.S. Geological Survey, Earthquake Hazard Program Quaternary Faults, 2011, op. cit. 38 California Department of Mines and Geology, 1987 updated 1996, op. cit. 39 Nilsen, T. H., Wright, R. H., et al., 1979, op. cit. 40 California Geological Survey, 2002b, op. cit. P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 299

12 The project grading plan would result in the construction of berms around the perimeter of the campus and north of the Main Parking Structure. However, these berms would be appropriately compacted and landscaped, and would not pose significant slope stability hazards. The Main Building would have two sub-grade levels. The geotechnical report anticipates and the project plans indicate that an excavation approximately 35 feet deep would be required and a permanent retaining structure would be constructed. 41 Other proposed sub-grade structures on the site would be subject to similar retaining structures, thus reducing potential instabilities to a less-than-significant level. (4) Subsidence. The proposed project would not be expected to contribute to regional subsidence since groundwater extraction for water supply is not proposed. (5) Erosion. Long-term erosion hazards are also not expected since most of the site is currently paved, and with implementation of the project would remain paved or covered by structures and landscaping. In addition, with the exception of the provision of fencing and maintenance access, no construction would occur within the 50-foot buffer around Calabazas Creek, and the riparian zone would be planted with primarily native plants, including those that conform to California Native Plant Society guidance and the Santa Clara Valley Water District s Qualifying Plant List. Therefore, project-related construction activities would not be expected to result in substantial erosion around Calabazas Creek. It is therefore unlikely that the project would result in geology, soils, or seismicity impacts related to fault rupture; mineral resources; slope stability; subsidence; or erosion. These impacts are considered less than significant. c. Significant Impacts. Two significant impacts that would require mitigation have been identified and are described below. Impact GEO-1: Occupants of the development proposed as part of the project would be subject to seismic hazards. (S) All structures in the Bay Area could be affected by ground shaking in the event of an earthquake. The amount of ground shaking depends on the magnitude of the earthquake, the distance from the epicenter, and the type of earth materials between the receptor and the epicenter. Violent ground shaking is expected at the project site during predicted earthquakes on the San Andreas and other active regional faults. This level of seismic shaking could cause extensive non-structural damage in buildings at the site. In addition, limited structural damage may occur. The following mitigation measure would reduce the potential hazards associated with seismic activity to a less-than-significant level. Mitigation Measure GEO-1: Prior to the issuance of any site-specific grading or building permits, a design-level geotechnical report shall be prepared and submitted to the City of Cupertino Building Department for review and approval and in accordance with adopted City standards. The structural designs shall adhere to the 2010 California Building Code (CBC) or the appropriate building code, as adopted by the City of Cupertino. Examples of the kinds of measures that would typically be used to meet these requirements include pile-supported foundations, use of pre-stressed concrete materials, slab reinforcement, compaction specifications, drainage requirements, use of control joints, and appropriate safety factors. The report 41 Arup, 2013, op. cit. P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 300

13 shall identify specific building techniques appropriate for minimizing damage from seismic events, including liquefaction and lateral spreading. In addition, the following requirement for the geotechnical and soils report shall be met: The seismic hazard analysis presented in the geotechnical report shall include an evaluation of liquefaction hazards in the Calabazas Creek area, and shall conform to the California Division of Mines and Geology recommendations presented in the Guidelines for Evaluating and Mitigating Seismic Hazards in California. 42 Design review for the project shall include evaluation of fixtures, furnishings, and fasteners with the intent of minimizing collateral injuries to building occupants from falling fixtures or furnishings during the course of a violent seismic event. All design criteria and specifications set forth in the design-level geotechnical report shall be implemented as a condition of project approval. This report shall address the final specifications for design and construction intended to limit the effects of seismic hazards to structures and utilities, including but not limited to: foundation design, driven piles, utility corridor design, excavation subgrade preparation, fill materials and compaction specifications, retaining walls and concrete pavement specifications, and drainage and dewatering design. This report shall be completed as a condition of approval of the vesting tentative map or adoption of the development agreement. (LTS) Impact GEO-2: Damage to structures or property could result from expansive or corrosive soils. (S) Site excavation for sub-grade structures would occur throughout the project site, including at the locations of the Main Building, Corporate Auditorium, Corporate Fitness Center, Phase 2 Buildings, Central Plant, Main Parking Structure, and North Tantau Parking Structure. Excavated soil is intended to be reused within the project site to the maximum extent possible. The project site soils include some soils with moderate to high expansion potential, and construction would require appropriate engineering. Chemical tests on soil samples and in-situ measurements of resistivity indicate the soils tested are moderately corrosive to severely corrosive. Therefore, proposed structures may require corrosion protection. 43 Implementation of the following mitigation measure would reduce the impact from potentially expansive or corrosive soils to a lessthan-significant level. Mitigation Measure GEO-2: The design-level geotechnical report shall include recommendations for foundations and improvements, including sidewalks, parking lots, and subsurface utilities, that take into consideration the potential effects of expansive and corrosive soils. The report shall be submitted to the City of Cupertino Building Department for review and approval. All design criteria and specifications set forth in the design-level geotechnical report shall be implemented as a condition of project approval. (LTS) 42 California Geological Survey, Guidelines for Evaluating and Mitigating Seismic Hazards in California, CGS Special Publication Arup, 2013, op. cit. P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 301

14 d. Cumulative Impacts. The proposed project would not contribute considerably to any cumulative impacts related to geology, soils, and seismicity. Development of the proposed project in conjunction with other past, present, and reasonable foreseeable future development would increase the number of individuals that could be exposed to regional seismic risks in the seismically active San Francisco Bay Area. However, this cumulative risk would be reduced to a less-than-significant level through the implementation of the requirements of modern building codes and practices. In addition, new structures could be built on areas of expansive and/or corrosive soils. However, these impacts are confined to specific development sites (i.e., they would not contribute to any cumulative impacts) and are not expected to be significant once incorporation of standard geotechnical mitigation measures have been implemented. P:\COC1101 Apple 2 Campus\PRODUCTS\DEIR\Public\5f-Geology.doc (06/03/13) PUBLIC REVIEW DRAFT 302