4.6 GEOLOGY AND SOILS

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1 The analysis in this Subsection is based, in part, on information contained in four (4) reports prepared by Southern California Geotechnical that assessed the existing surface and subsurface geologic conditions. The report titled Geotechnical Feasibility Study Proposed Commercial/Industrial Development, 95 Acre County Exchange Property, SEC Merrill Avenue and Vineyard Avenue, Chino, California, and dated February 19, 2014, addresses most of the Project site located north of Remington Avenue, including APNs , -02, -07, -08, and -09; ; ; ; and (refer to EIR Figure 2-1, Parcel Identification Map). This report is included as Technical Appendix F1 to this EIR (SCG, 2014a). The report titled Geotechnical Feasibility Study, Proposed Commercial/Industrial Development, 60 Acre Auction Property, South of Remington Avenue at Carpenter Street, Chino, California, and dated March 4, 2014, addresses all of the Project site located south of Remington Avenue, including APNs , -05, -06, -07, -12, -14, -15, and -22; and and -02. This report is included as Technical Appendix F2 to this EIR (SCG, 2014b). The report titled Geotechnical Feasibility Study Lekkerkerker Property SEC Merrill Avenue at Baker Avenue Chino, California, and dated August 19, 2014, addresses the northwestern portion of the Project site, including APNs ; ; ; and This report is included as Technical Appendix F3 to this EIR (SCG, 2014c). The report titled Geotechnical Investigation Proposed Watson Commerce Center East, SEC Merrill and Walker Avenues Chino, California, and dated January 27, 2010, addresses APN , which is located in the southwestern portion of the Project site and abuts Remington Avenue, as well as off-site property that is not a part of the Project site. This report is included as Technical Appendix F4 to this EIR (SCG, 2010). In addition, information used to support the analysis in this Subsection was obtained from the Geology and Soils section (Section 4.6, pp ) of the certified Final Program EIR prepared for the City of Chino General Plan (SCH No ), dated May 21, 2010 (Chino, 2010b), as well as field observations by T&B Planning, Inc. in April 2014 (LaMar, 2014) EXISTING CONDITIONS A. Soils Southern California Geotechnical (SCG) performed visual site reconnaissance and subsurface exploration of the Project site. The soil conditions observed on the Project site are described below. Page 4.6-1

2 Manure Manure was encountered at the ground surface within the cattle pens and several of the wastewater treatment detention basins on-site. Where encountered on-site, manure extended to depths ranging between three inches and two feet below the ground surface (SCG, 2014a, p. 6; SCG, 2014b, p. 7; SCG, 2014c, p. 7; SCG, 2010, p.7). Artificial Fill Artificial fill soils at the ground surface across most of the Project site and extended to depths up to three feet below the existing ground surface. The fill soils encountered by Southern California Geotechnical generally consisted of loose to medium dense fine sandy silts, fine sands, silty fine sands, and clayey silts. At several subsurface testing locations, the artificial soils contain artificial debris including plastic fragments and asphaltic concrete fragments (SCG, 2014a, p. 7; SCG, 2014b, p. 7; SCG, 2014c, pp. 7-8; SCG, 2010, p.8). Alluvium Native alluvial soils were encountered at the ground surface and/or beneath the fill soils and manure at all subsurface testing locations on-site. Native alluvium soils extended to the maximum explored depth at all subsurface testing locations (up to 50 feet below existing ground surface). The surficial alluvial soils generally consist of loose to medium dense fine sands with traces of silt and loose to medium dense silty fine sands, extending to depths up to approximately 15 feet below the existing ground surface. At greater depths the observed alluvium soils generally consist lightly to moderately porous, very soft to very stiff silty clays with occasional strata of medium dense clayey fine sands, fine sands, and fine sandy silts (SCG, 2014a, p. 7; SCG, 2014b, p. 8; SCG, 2014c, p. 8; SCG, 2010, p.8). B. Topography The Project site is relatively flat and slopes gently to the south and southwest at an estimated gradient of less than one- to two-percent. There are no unique topographic features or steep natural or manufactured slopes present on or near the property (SCG, 2014a, pp. 4-5; SCG, 2014b, p. 5; SCG, 2014c, p. 5; SCG, 2010, p.4). The Project site s topographic conditions were previously illustrated on Figure 3-3, USGS Topographic Map. C. Groundwater Free water was not encountered at any subsurface testing location on the Project site. Based on the lack of any water at subsurface testing locations and the moisture contents of the recovered soil samples, Southern California Geotechnical concluded that the static groundwater table beneath the Project site is located in excess of 30 to 50 feet below the existing ground surface (SCG, 2014a, p. 7; SCG, 2014b, p. 8; SCG, 2014c, p. 8; SCG, 2010, p.8). Page 4.6-2

3 D. Seismic Hazards The Project site is located in an area of southern California that is subject to strong ground motions due to seismic events (i.e., earthquakes). The geologic structure of southern California is dominated by northwest-trending faults associated with the San Andreas Fault system. The San Andreas Fault system includes several major branches, including the San Jacinto and Elsinore faults, as well as numerous minor branches. As depicted on Figure 4.6-1, Earthquake Fault Zones, the nearest known active fault is the Chino-Central Avenue Fault, located approximately 3.3 miles to the southwest of the Project site. The Project site also is located approximately 4.5 miles west of the active Elsinore Fault. An active fault is defined by the California Geological Survey as a fault that has experienced surface displacement within the Holocene Epoch (roughly the last 11,000 years). Secondary hazards associated with earthquakes include surface rupture, ground failure, unstable soils and slopes (liquefaction). Each of these hazards is briefly described below. Fault Rupture Fault rupture can occur along pre-existing, known active fault traces; however, fault rupture also can splay from known active faults or rupture along unidentified fault traces. As shown on Figure 4.6-1, no known faults are mapped trending through or toward the site. Furthermore, there are no active or potentially active faults occurring on the Project site. Therefore, the potential for fault rupture on the Project site is very low (SCG, 2014a, p. 10; SCG, 2014b, p. 11; SCG, 2014c, p. 11; SCG, 2010, p.11). Liquefaction Liquefaction is a phenomenon in which loose, saturated, relatively cohesion-less soil deposits lose shear strength during strong ground motions, which causes the soil to behave as a viscous liquid. Liquefaction is generally limited to the upper 50 feet of subsurface soils. Research and historical data indicate that loose granular soils of Holocene to late Pleistocene age below a near-surface groundwater table are most susceptible to liquefaction, while the stability of most clayey material is not adversely affected by vibratory motion (Southern California Earthquake Center, 1999, pp. 5-6). Therefore, in order for the potential effects of liquefaction to be manifested at the ground surface, soils generally must be of Holocene to late Pleistocene age, granular, loose to medium dense, relatively saturated near the ground surface and subjected to a sufficient magnitude and duration of ground shaking. The Seismic Hazards Map for the Corona North, California 7.5 Minute Quadrangle, published by the California Geological Survey (CGS) indicates that the Project site is not located within a designated liquefaction hazard zone. In addition, the subsurface soil conditions encountered at the Project site and the lack of near-surface groundwater are not considered to be conducive to liquefaction (SCG, 2014a, p. 11; SCG, 2014b, pp ; SCG, 2014c, p. 12; SCG, 2010, p.12). Page 4.6-3

4 MONTCLAIR %&'( 10 ONTARIO }þ 60 CHINO PROJECT SITE JURUPA VALLEY Central Avenue Fault }þ 71 CHINO HILLS Elsinore Fault LOS ANGELES }þ Mi. 4.5 Mi. SAN BERNARDINO COUNTY [_ S A N B E R N A R D I N O C O U N T Y # R I V E R S I D E C O U N T Y EASTVALE NORCO %&'( 15 }þ LEGEND 71 }þ60 Project Boundary SOILS }þ 57 Db, Dehli Fine Sand [_ Gr, Grangeville Fine Sandy LoamRIVERSIDE %&'( 15 %&'( 5 }þ }þ KEY MAP HbA, Hanford Sandy Loam, 0 to 2 Percent Hr, Hilmar Loamy Fine Sand ORANGE %&'( 10 }þ 91 }þ 74 CORONA }þ 91 Source(s): RCTLMA (2014), SANBAG (2014), USGS 0 2,250 4,500 9,000 Feet Figure EARTHQUAKE FAULT ZONES Page 4.6-4

5 Unstable Soils and Slopes The Project site is generally flat and does not contain nor is it adjacent to any steep natural or manufactured slopes. As such, the site is not susceptible to seismically induced landslides and rockfalls. E. Slope and Soil Instability Hazards Soil Erosion Erosion is the process by which the upper layers of the surface (such as soils) are worn and removed by the movement of water or wind. Soils with characteristics such as low permeability and/or low cohesive strength are more susceptible to erosion than those soils having higher permeability and cohesive strength. Additionally, the slope gradient on which a given soil is located also contributes to the soil s resistance to erosive forces. Because water is able to flow faster down steeper gradients, the steeper the slope on which a given soil is located, the more readily it will erode. According to the City of Chino General Plan EIR, soils in the Project area are moderately susceptible to water erosion (Chino, 2010b, pp ). Wind erosion can damage land and natural vegetation by removing soil from one place and depositing it in another. It mostly affects dry, sandy soils in flat, bare areas, but wind erosion may occur wherever soil is loose, dry, and finely granulated. According to the City of Chino General Plan EIR, soils in the Project area are moderately susceptible to wind erosion (Chino, 2010b, pp ). Under the existing conditions, the Project site has the potential to contribute windblown soil and sand because portions of the Project site contain are undeveloped with no or little vegetative cover and loose and dry topsoil conditions. Settlement Potential Laboratory testing conducted by Southern California Geotechnical indicates that most of the site s near surface alluvial soil are variable in composition and possess a potential for settlement and/or collapse (SCG, 2014a, pp ; SCG, 2014b, pp ; SCG, 2014c, p. 13; SCG, 2010, p.13). Shrinkage/Subsidence Potential Subsidence is a gradual settling or sudden sinking of the ground surface (i.e., loss of elevation). The principal causes of subsidence are aquifer-system compaction, drainage of organic soils, underground mining, and natural compaction. Shrinkage is the reduction in volume in soil as the water content of the soil drops (i.e., loss of volume). Based the conditions encountered at subsurface testing locations at the Project site, Southern California Geotechnical estimates that removal and re-compaction of the near surface native soils is estimated to result in an average shrinkage of eight to 15-percent. Minor ground subsidence is expected to occur in the soils below the zone of removal, due to settlement during construction activities on the property. Southern California Geotechnical estimates subsidence potential to be Page 4.6-5

6 approximately 0.10 to 0.15 feet (SCG, 2014a, p. 14; SCG, 2014b, p. 15; SCG, 2014c, p. 15; SCG, 2010, p.14). Therefore, the Project site s soils have the potential for shrinkage and subsidence. Soil Expansion Potential Expansive soils are soils that exhibit cyclic shrink and swell patterns in response to variations in moisture content. According to the City of Chino General Plan EIR, the Project site is located in an area with the City with low potential for expansive soils (Chino, 2010b, Figure 4.6-3). Furthermore, based on expansion index testing of soil samples taken from the Project site, Southern California Geotechnical determined that the site s soils have a very low-to-low expansion potential (SCG, 2014a, p. 13; SCG, 2014b, p. 14; SCG, 2014c, p. 14; SCG, 2010, p.13). Landslide Potential The Project site and immediately surrounding properties are flat to gently sloping and contain no steep natural or manufactured slopes; thus, there is no potential for landslides to occur on or immediately adjacent to the site. F. Applicable Environmental Regulations Federal Water Pollution Control Act (Clean Water Act) The Federal Water Pollution Control Act (also known as the Clean Water Act (CWA)) is the principal federal statute that addresses water resources. The provision of the CWA applicable to geology and soils is CWA Section 402, which applies to all construction sites of over one acre in size and, in part, serves to control the potential impacts of erosion. CWA Section 402 authorizes the National Pollutant Discharge Elimination System (NPDES) permit program that covers point sources of pollution discharging to a water body. The NPDES program requires operators of construction sites one acre or larger to prepare a Stormwater Pollution Prevention Plan (SWPPP) and obtain authorization to discharge stormwater under an NPDES construction stormwater permit. State Water Resources Control Board (SWRCB) The State Water Resources Control Board adopts statewide water quality control plans and its nine Resource Water Quality Control Boards (RWQCBs) are required to develop and adopt regional water quality control plans that conform to state water quality policy. The Santa Ana RWQCB s Santa Ana River Basin Water Quality Control Plan is applicable to the Project site; it designates beneficial uses of water bodies to be protected and establishes water quality objectives. South Coast Air Quality Management District, Rule 403 The South Coast Air Quality Management District (SCAQMD) is responsible for enforcing air pollution control measures in the South Coast Air Basin, within which the Project site is located. Rule 403 addresses blowing dust from construction sites and is applicable to the Project due to the potential for wind erosion during Project grading and construction activities. Page 4.6-6

7 Alquist-Priolo Earthquake Fault Zoning Act (CA Pub. Res. Code 2621 et Seq.) The Alquist-Priolo Special Studies Zone Act was signed into law in 1972 and renamed the Alquist- Priolo Earthquake Fault Zoning Act in The primary purpose of the Alquist-Priolo Act is to mitigate the hazard of fault rupture by prohibiting the location of structures for human occupancy across the trace of an active fault. The Project site is not located in or near a designated Alquist-Priolo Earthquake Fault Zone (SCG, 2014a, p. 10; SCG, 2014b, p. 11; SCG, 2014c, p. 11; SCG, 2010, p.11). Seismic Hazards Mapping Act (CA Pub. Res. Code 2690 et Seq.) The Seismic Hazards Mapping Act of 1990 is a statewide seismic hazard mapping and technical advisory program in California to assist cities and counties in fulfilling their responsibilities for protecting the public health and safety from the effects of strong ground shaking, liquefaction, landslides, or other ground failure and other seismic hazards caused by earthquakes. The California Geologic Survey (CGS) is the principal State implementing agency that mapped seismic zones requiring the completion of site-specific geotechnical investigations prior to construction of a development project. California Building Standards Code, Title 24 The California Green Building Standards Code (CCR, Title 24), also known as the CBSC or CalGreen, is the standard from which California buildings derive appropriate building design standards. The International Building Code (IBC) used by the International Conference of Building Officials establishes design and construction standards for buildings and facilities. The CBSC incorporates the IBC as well as other uniform codes into its code standards. All development projects in California are required to comply with CalGreen. City of Chino General Plan The Safety Element of the City of Chino General Plan provides information about natural and human-made hazards in Chino and establishes goals, objectives, and policies to prepare and protect the community from such risks. The Safety Element states that the City shall reduce the risk of geologic hazards to the community by enforcing building codes, requiring the preparation of soils and geologic reports, and using the most current and comprehensive geological hazard mapping available to assist in the evaluation go potential seismic hazards to proposed new development. (Chino, 2010a) City of Chino Building Code The City of Chino Building Code is based on the CBSC and is supplemented with local amendments. The Building Code regulates the construction, alteration, repair, moving, demolition, conversion, occupancy, use, and maintenance of all buildings and structures in the City of Chino. The Building Code is included in Chapter 15 of the City of Chino Municipal Code. (Chino, 2014b, Chapter 15.04) Page 4.6-7

8 City of Chino Municipal Code of the Municipal Code requires development projects to prepare geologic engineering reports to identify site-specific geologic and seismic conditions and provide site-specific recommendations to preclude adverse impacts from unstable soils and strong seismic groundshaking. These reports shall recommend corrective action to preclude any structural damage that may be caused by geological hazards or unstable soils. (Chino, 2014b) BASIS FOR DETERMINING SIGNIFICANCE The proposed Project would result in a significant impact related to geology and soils if the Project or any Project-related component would: 1. Expose people or structures to potential substantial adverse effects, including the risk of loss, injury or death involving: i. Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault; ii. Strong seismic ground shaking; iii. Seismic-related ground failure, including liquefaction; or iv. Landslides. 2. Result in substantial soil erosion or the loss of topsoil; 3. 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 on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse; 4. Be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial risks to life or property; or 5. Have soils incapable of adequately supporting the use of septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of waste water. Page 4.6-8

9 4.6.3 IMPACT ANALYSIS Threshold 1: Would the Project expose people or structures to potential substantial adverse effects, including the risk of loss, injury or death involving: i. Rupture of a known earthquake fault, as delineated on the most recent Alquist-Priolo Earthquake Fault Zoning Map issued by the State Geologist for the area or based on other substantial evidence of a known fault? ii. iii. iv. Strong seismic ground shaking? Seismic-related ground failure, including liquefaction? Landslides? A. Rupture of Known Earthquake Fault There are no known active or potentially active faults on the Project site or trending toward the Project site and the Project site is not located within a mapped Alquist-Priolo Earthquake Fault Zone (SCG, 2014a, p. 10; SCG, 2014b, p. 11; SCG, 2014c, p. 11; SCG, 2010, p.11). Because there are no known faults located on the Project site, there is no potential for the Project to expose people or structures to substantial adverse effects related to ground rupture. No impact would occur. B. Strong Seismic Ground Shaking The Project site is located in a seismically active area of southern California and is expected to experience moderate to severe ground shaking during the lifetime of the Project. This risk is not considered substantially different than the risk to other similar properties in the southern California area. As a mandatory condition of Project approval, buildings on the Project site would be required to be constructed in accordance with the California Building Standards Code (CBSC), also known as California Code of Regulations (CCR), Title 24 (Part 2), and the City of Chino Building Code, which is based on the CBSC with local amendments. The CBSC and City of Chino Building Code provide standards that must be met to safeguard life or limb, health, property, and public welfare by regulating and controlling the design, construction, quality of materials, use and occupancy, location, and maintenance of all buildings and structures, and have been specifically tailored for California earthquake conditions. In addition, the CBSC (Chapter 18) and the City of Chino Municipal Code (Section ) require development projects to prepare geologic engineering reports to identify site-specific geologic and seismic conditions and provide site-specific recommendations to preclude adverse effects involving unstable soils and strong seismic ground-shaking, including, but not limited to, recommendations related to ground stabilization, selection of appropriate foundation type and depths, selection of appropriate structural systems. The Project Applicant has prepared such reports, which are included as Technical Appendices F1 through F4 to this EIR, and the City shall condition the Project to comply with the site-specific ground preparation and construction recommendations contained in these reports. With mandatory compliance with these standard and site-specific design and construction measures, potential impacts related to seismic ground shaking would be less than significant. As such, the Project would not expose people or structures to substantial adverse effects, including loss, injury or death, involving seismic ground shaking. Impacts would be less than significant. Page 4.6-9

10 C. Seismic-Related Ground Failure According to available mapping data and soil conditions encountered at the Project site, the Project is not expected to be subjected to a significant risk associated with seismic-related ground failure, including liquefaction (SCG, 2014a, p. 11; SCG, 2014b, pp ; SCG, 2014c, p. 12; SCG, 2010, p.12). Regardless, as noted above, the Project would be designed and constructed in accordance with the latest applicable seismic safety guidelines, including the standard requirements of the CBSC (Chapter 18) and City of Chino Building Code (Municipal Code Section ). Furthermore, the Project would be required to comply with the site-specific grading and construction recommendations contained within the Project s geotechnical reports (Technical Appendices F1 through F4), which the City would impose as conditions of Project approval, to further reduce the risk of seismic-related ground failure due to liquefaction. As such, implementation of the Project would result in less-than-significant impacts associated with seismic-related ground failure and/or liquefaction hazards. D. Landslides The Project site is relatively flat, as is the surrounding area. There are no hillsides or steep slopes on the Project site or in the immediate vicinity of the site. Upon completion of proposed grading activities, the Project site would feature a very gradual north to south gradient, with elevations ranging from approximately 665 feet AMSL in the northern portion of the Project site to approximately 635 feet AMSL and the southwestern and southeastern portions of the Project site. The Project would not result in the creation of any new slopes on-site, with exception of the approximately eight foot tall manufactured slopes around the perimeter of the proposed water quality/detention basins, which are designed to have a maximum slope gradient of 3:1, and which would be engineered to maximize stability so as to not pose a threat to future site workers or the Project s proposed buildings. Accordingly, development on the subject property would not be exposed landslide risks, and the Project would not pose a landslide risk to surrounding properties. No impact would occur. Threshold 2: Would the Project result in substantial soil erosion or the loss of topsoil? Implementation of the proposed Project has the potential to result in soil erosion. The analysis below summarizes the likelihood of the Project to result in substantial soil erosion during temporary construction activities and/or long-term operation. A. Impact Analysis for Temporary Construction-Related Activities Under existing conditions, the Project site is partially developed with dairies and associated singlefamily residences and agricultural support buildings. The undeveloped portions have been subject to routine maintenance activities (i.e., discing) and other activities (e.g., cow pasture, materials staging) which regularly disturbs on-site soils and subjects them to erosion. Proposed demolition, grading, and construction activities would expose underlying soils beneath the developed portions of the site and would continue to temporarily expose underlying soils on the undeveloped portions of the Page

11 Project site. Exposed soils would be subject to erosion during rainfall events or high winds due to the removal of stabilizing vegetation and exposure of these erodible materials to wind and water. Pursuant to the requirements of the State Water Resources Control Board, the Project Applicant is required to obtain a National Pollutant Discharge Elimination System (NPDES) permit for construction activities, including proposed grading. The NPDES permit is required for all projects that include construction activities, such as clearing, grading, and/or excavation, that disturb at least one (1) acre of total land area. The City s Municipal Separate Storm Sewer System (MS4) NPDES Permit requires the Project Applicant to prepare and submit to the City for approval a Project-specific Storm Water Pollution Prevention Plan (SWPPP). The SWPPP would identify a combination of erosion control and sediment control measures (i.e., Best Management Practices) to reduce or eliminate sediment discharge to surface water from storm water and non-storm water discharges during construction. In addition, the Project would be required to comply with SCAQMD Rule 403, which would reduce the amount of particulate matter in the air and minimize the potential for wind erosion. With mandatory compliance to the requirements noted in the Project s SWPPP, as well as applicable regulatory requirements, the potential for water and/or wind erosion impacts during Project construction would be less than significant and mitigation is not required. B. Impact Analysis for Long-Term Operational Activities Following construction, wind and water erosion on the Project site would be minimized, as the areas disturbed during construction would be landscaped or covered with impervious surfaces and drainage would be controlled through a storm drain system. Implementation of the Project would result in less long-term erosion and loss of topsoil than occurs under the site s existing conditions. The City s MS4 NPDES Permit requires the Project Applicant to prepare and submit to the City for approval a Water Quality Management Plan (WQMP, see Municipal Code Section ). The WQMP identifies an effective combination of erosion control and sediment control measures (i.e., Best Management Practices) to reduce or eliminate sediment discharge to surface water from storm water and non-storm water discharges. The WQMP for the Project prepared by Hall & Foreman (included as Technical Appendices I2 and I3 to this EIR) incorporates Best Management Practices, including water quality/detention basins and vegetative swales, which are effective at removing silt and sediment from stormwater runoff. The WQMP also requires post-construction maintenance and operational measures to ensure on-going erosion protection. Compliance with the WQMP would be required as a condition of Project approval as would the long-term maintenance of water quality features. Therefore, implementation of the proposed Project would not result in substantial erosion or loss of top soil during long-term operation. The Project s impact would be less than significant. Threshold 3: Would the Project 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 on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse? The Project site is relatively flat and contains no substantial natural or man-made slopes under existing conditions. Based on a review of aerial photography (refer to EIR Figure 2-6, Aerial Page

12 Photograph) and field observations collected by T&B Planning (LaMar, 2014), there are no natural or man-made slopes adjacent to the Project site. The Project would not result in the creation of any new slopes on-site, with exception of slopes around the perimeter of the proposed water quality/detention basins (up to eight feet tall). The proposed manufactured slopes would be engineered for long-term stability and would be required to be constructed in accordance with the site-specific recommendations contained within the Project s geotechnical reports prepared by Southern California Geotechnical (Technical Appendices F1 through F4). Accordingly, the Project would result in less-than-significant impacts associated with landslide hazards. Based on laboratory testing of subsurface soils from the Project site, Southern California Geotechnical determined that near surface soils at the Project site have potential for shrinkage/subsidence and collapse (SCG, 2014a, pp ; SCG, 2014b, pp ; SCG, 2014c, pp. 13, 15; SCG, 2010, pp ). However, the Project s geotechnical reports (Technical Appendices F1 through F4) indicate that the site s shrinkage/subsidence and settlement potential would be attenuated through the proposed removal of near surface soils down to competent materials and replacement with properly compacted fill, which is included as a recommendation in the Project s geotechnical reports (SCG, 2014a, pp ; SCG, 2014b, pp ; SCG, 2014c, pp. 13, 15; SCG, 2010, pp ). Through standard conditions of approval, the City would require the proposed Project to implement the recommendations contained within the Project s geotechnical reports into the grading plan for the Project. As such, implementation of the Project would result in less-thansignificant impacts associated with soil shrinkage/subsidence and collapse. Lateral spreading is primarily associated with liquefaction hazards. As noted above under the discussion of Threshold 1, the potential for liquefaction at the site is considered low based on a sitespecific analysis conducted by Southern California Geotechnical, Inc. Accordingly, impacts associated with lateral spreading would not occur. In conclusion, the Project would not 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 on- or off-site landslide, lateral spreading, subsidence, liquefaction or collapse. Impacts would be less than significant. Threshold 4: Would the Project be located on expansive soil, as defined in Table 18-1-B of the Uniform Building Code (1994), creating substantial risks to life or property? As determined by Southern California Geotechnical, the Project site s soils have a very low to low expansion potential (SCG, 2014a, p. 13; SCG, 2014b, p. 14; SCG, 2014c, p. 14; SCG, 2010, p. 13). Accordingly, the Project would not create substantial risks to life or property from exposure to expansive soils. Impacts would be less than significant. [Note: Threshold 4 is based on Appendix G of the CEQA Guidelines and references Table 18-1-B of the 1994 Uniform Building Code (UBC) which has been superseded by the current building code, the 2013 CBSC. The 2013 CBSC references ASTM D- 4829, a standard procedure for testing and evaluating the expansion index (or expansion potential) of soils established by ASTM International, which was formerly known as the American Society for Testing and Materials (ASTM). ASTM D-4829 was used as the standard for evaluating the Project s potential impact related to expansive soils in the above analysis.] Page

13 Threshold 5: Would the Project have soils incapable of adequately supporting the use of septic tanks or alternative waste water disposal systems where sewers are not available for the disposal of waste water? The Project does not propose the use of septic tanks or alternative waste water disposal systems. Accordingly, no impact associated with septic tanks or alternative waste water systems would occur with implementation of the Project CUMULATIVE IMPACT ANALYSIS As noted in the foregoing analysis of the Project s direct impacts, all potential Project-specific impacts related to geology and soils would be precluded through mandatory conformance with the geotechnical recommendations contained within the Project s geotechnical reports (Technical Appendices F1 through F4) and compliance with standard regulatory requirements as part of the Project s design. With the exception of erosion hazards, potential geologic and soils effects are inherently restricted to the areas proposed for development and would not contribute to cumulative impacts associated with other existing, planned, or proposed development. That is, issues including fault rupture, seismic ground shaking, liquefaction, landslides, and expansive soils would involve effects to (and not from) the proposed development, and are specific to on-site conditions. Accordingly, addressing these potential hazards for the proposed development would involve using measures to conform to existing requirements, and/or site-specific design and construction efforts that have no relationship to, or impact on, off-site areas. Because of the site-specific nature of these potential hazards and the measures to address them, there would be no connection to similar potential issues or cumulative effects to or from other properties. As discussed under Threshold 2, measures would be incorporated into the Project s design during construction and long-term operation to ensure that significant erosion impacts do not occur. Other development projects in the vicinity of the Project site (including nearby development projects located within the Cities of Eastvale and Ontario) as well as full General Plan buildout in the City of Chino would be required to comply with similar regulatory requirements as the Project to preclude substantial adverse erosion impacts, such as the need to obtain an NPDES permit and mandatory compliance with the resulting SWPPPs and WQMPs. All development projects in the vicinity of the Project site also would be required to comply with applicable building code ordinances in their governmental jurisdiction, and SCAQMD Rule 403, which would preclude wind-related erosion hazards during construction. Therefore, because the Project would not result in significant erosion impacts, and because other projects within the cumulative study area would be subject to similar requirements to control erosion hazards during construction and long-term operation, cumulative impacts associated with wind and water erosion hazards are evaluated as less than significant. Page

14 4.6.5 SIGNIFICANCE OF IMPACTS BEFORE MITIGATION Threshold 1: Less-than-Significant Impact. The Project would not expose people or structures to substantial adverse seismic risks. The risk of liquefaction on the Project site is low. There are no known active or potentially active faults on the Project site or trending toward the Project site. As with all properties within the southern California region, the Project site is subject to seismic ground shaking associated with earthquakes; however, mandatory compliance with local and state ordinances and building codes including but not limited to the CBSC (Chapter 18) and City of Chino Municipal Code Section would ensure that the proposed structures are developed as required to attenuate the risk to life or property to less-than-significant levels. Threshold 2: Less-than-Significant Impact. The Project would not result in substantial soil erosion or the loss of topsoil. The Project Applicant is required to obtain a National Pollutant Discharge Elimination System (NPDES) permit for construction activities and adhere to a Storm Water Pollution Prevention Plan (SWPPP) as well as SCAQMD Rule 403 during Project construction. With mandatory compliance to these regulatory requirements, the potential for water and wind erosion impacts during construction would be less than significant. Following construction, wind and water erosion on the Project site would be minimized, as the areas disturbed during construction would be landscaped or covered with impervious surfaces and drainage would be controlled through a storm drain system. Furthermore, the Project is required by law to implement a WQMP during operation, which would preclude substantial erosion impacts in the long-term. Threshold 3: Less-than-Significant Impact. There is no potential for the Project to cause on- or offsite landslides or lateral spreading. Potential hazards associated with soils on the site that have the potential for collapse would be precluded through mandatory adherence to recommendations given in the Project s geotechnical reports and mandatory compliance with applicable regulations including, but not limited to the CBSC (Chapter 18) and City of Chino Municipal Code Section would ensure that the proposed structures are developed as required to attenuate the risk to life or property to less-than-significant levels. Threshold 4: Less-than-Significant Impact. Soils on the Project site have a very low expansion potential and have little to no potential to create substantial risks to life or property. Accordingly, soil expansion impacts would be less than significant. Threshold 5: No Impact. The Project would not install septic tanks or alternative wastewater disposal systems. Accordingly, no impact would occur associated with soil compatibility for wastewater disposal systems MITIGATION Impacts would be less than significant; therefore, mitigation is not required. Page