IV. ENVIRONMENTAL IMPACT ANALYSIS D. GEOLOGY & SOILS

1. INTRODUCTION

This Section describes the geologic conditions at and near the project site and identifies the types of geotechnical hazards associated with development of the project site. The following analysis is based upon the Summary of Preliminary Geotechnical Feasibility Evaluation dated March 15, 2007, prepared by Moore Twining Associates, Inc. for the proposed project. A copy of this evaluation is provided in Appendix IV.D-1 to the EIR.

2. ENVIRONMENTAL SETTING

A. Regulatory Setting

i) State of

The State of California adopted the 2007 California Building Code, Volumes 1 and 2, which is based in part on the 2006 International Building Code, on January 1, 2010. These regulations include provisions for site work, demolition, and construction, which include excavation and grading, as well as provisions for foundations, retaining walls, and expansive and compressible soils. The California Building Standards Commission is currently undergoing the 2010 annual code adoption cycle. The California Building Standards Commission will receive proposed code changes from the Department of Housing and Community Development, the Division of the State Architect – Access Compliance, the Division of the State Architect - Structural Safety, the Office of the State Fire Marshal and the Office of Statewide Health Planning and Development for code change consideration in the 2011 Annual Code Adoption Cycle. The proposed code change submittals include the text of the proposed changes and justification, and are reviewed in phases, which will conclude with the adoption of the 2011 California Building Codes on January 1, 20111

The California Seismic Safety Commission was established by the Seismic Safety Commission Act in 1975 with the intent of providing oversight, review, and recommendations to the Governor and State Legislature regarding seismic issues. The commission’s name was changed to Alfred E. Alquist Seismic Safety Commission in 2006. Since then, the Commission has adopted several documents based on recorded , such as the 1994 Northridge , 1933 Long Beach earthquake, the 1971 Sylmar earthquake, etc. Some of these documents are listed as follows:

• Research and Implementation Plan for Earthquake Risk Reduction in California 1995 to 2000, report dated December 1994; • Seismic Safety in California’s Schools, 2004, “Findings and Recommendations on Seismic Safety Policies and Requirements for Public, Private, and Charter Schools,” report dated December 1994;

1 Buildings Standards Commission, Department of General Services, website: http://www.bsc.ca.gov/prpsd_chngs/pc_09_annual_cycle.htm, February 28, 2011.

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-1 City of Los Angeles January 2012

• Findings and Recommendations on Hospital Seismic Safety, report dated November 2001; • Commercial Property Owner’s Guide to Earthquakes Safety, report dated October 2006; and • California Earthquake Loss Reduction Plan 2007–2011, report dated July 2007.

The Alquist-Priolo Geologic Hazards Zone Act (the “Alquist-Priolo Act”) was enacted by the State of California in 1972 to address the hazards and damage caused by surface rupture during an earthquake. The Alquist-Priolo Act has been amended ten times and renamed the Alquist-Priolo Earthquake Fault Zoning Act, effective January 1, 1994. The Alquist-Priolo Act requires the State Geologist to establish “earthquake fault zones” along known active faults in the state. Cities and counties that include earthquake fault zones are required to regulate development projects within these zones.

The Seismic Hazard Mapping Act of 1990 (the “Seismic Act”) was enacted, in part, to address seismic hazards not included in the Alquist-Priolo Act, including strong ground shaking, landslides, and liquefaction. Under the Seismic Act, the State Geologist is assigned the responsibility of identifying and mapping seismic hazards zones.

The State of California Geological Survey (formerly known as the California Division of Mines and Geology), adopted seismic design provisions in Special Publication 117 Guidelines for Evaluating and Mitigating Seismic Hazards in California on March 13, 1997, and was revised as Special Publication 117A on September 11, 2008.

ii) City of Los Angeles

The City of Los Angeles (the “City”) adopted the 2007 California Building Code, together with the 1997 Uniform Building Code (UBC) and a series of City amendments on January 1, 2010 as the City of Los Angeles Building Code (the “Building Code”), Volumes 1 and 2. Volume 2 of the Building Code includes provisions for: 1) Foundations, Retaining Walls, and Expansive and Compressible Soils in Chapter 18; 2) Site Work, Demolition, and Construction in Chapter 33; and 3) Grading, Excavation, and Fills in a special Chapter 70 developed by and for the City. Together, the provisions in Volumes 1 and 2 of the Building Code address issues related to site grading, cut and fill slope design, soil expansion, geotechnical investigations before and during construction, slope stability, allowable bearing pressures and settlement below footings, effects of adjacent slopes on foundations, retaining walls, basement walls, shoring of adjacent properties, and potential primary and secondary seismic effects.

The Building Code also addresses ground-disturbing activities, such as grading, that are codified in the Los Angeles Municipal Code (LAMC). Specifically, Chapter IX, Article 1, Section 91.7006 outlines regulations specific to the import and export of materials. Additionally, Section 91.7010 outlines regulations specific to excavations required for project construction, while Section 91.7011 outlines regulations specific to the import of fill materials to a project site. Erosion control and drainage guidelines are set forth in Section 91.7013, and regulations pertaining to flooding and mudflows are set forth in Section 91.7014. Lastly, Section 91.7016 outlines regulations specific to soil stability.

The City Grading Division of the Department of Building and Safety (Building and Safety) has also adopted Rules of General Application, a series of Grading Standards that supplement the requirements of the Building Code. The Rules of General Applications include specific requirements of seismic design, slope stability, grading, foundation design, geologic investigations and reports, soil and rock testing, and

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-2 City of Los Angeles January 2012

groundwater. Building and Safety is responsible for implementing the provisions of the Building Code and Grading Standards.

The City requires that firms performing geotechnical investigations, sampling, and testing have their laboratory certified by the Building and Safety Materials Control Section.

The City’s primary seismic regulatory document is the Safety Element of the City’s General Plan, adopted November 26, 1996. The City’s regulations incorporate the State’s requirements. The objective of the Safety Element is to better protect occupants and equipment during various types and degrees of seismic events. In the City’s Safety Element, specific guidelines are included for the evaluation of liquefaction, tsunamis, seiches, non-structural elements, fault rupture zones, and engineering investigation reports. The City’s Emergency Operations Organization helps to administer certain policies and provisions of the Safety Element. The Emergency Operations Organization is a City department with representatives from all City agencies. The Administrative Code, Emergency Operation Organization Master Plan, and associated Emergency Operation Organization plans establish the chain of command, protocol, and programs for integrating all of the City’s emergency operations into one unified operation. Each City agency in turn has operational protocols, as well as plans and programs, to implement Emergency Operation Organization protocols and programs. A particular emergency or mitigation triggers a particular set of protocols that are addressed by implementing plans and programs. The City’s Emergency Operations Program encompasses all of these protocols, plans, and programs. The Safety Element goals, objectives, and policies are broadly stated to reflect the comprehensive scope of the Emergency Operation Organization.

B. Existing Conditions

i) Geologic Setting

The project site is located in the Los Angeles Basin in the northernmost part of the province near the boundary between the Transverse Ranges and Peninsular Ranges geomorphic provinces. The Transverse Ranges geomorphic province is characterized by east-west trending mountain ranges that include the Santa Monica Mountains. The southern boundary of the province is marked by the Santa Monica, Hollywood, Raymond, Sierra Madre, and Cucamonga faults. The Peninsular Range province is characterized by northwest/southeast trending alignments of mountains and hills and intervening basins, reflecting the influence of northwest trending major faults and folds controlling the general geologic structural fabric of the region. This province extends northwesterly from into the Los Angeles Basin and westerly into the offshore area, including Santa Catalina, Santa Barbara, San Clemente, and San Nicolas islands. This province is bounded on the east by the San Jacinto fault zone.

On a smaller scale, according to the 7 ½-minute Series Topographic Quadrangle (Hollywood, California), produced by the United States Geological Survey (USGS), the project site is at an elevation of about 350 feet above mean sea level.

ii) Subsurface Geology at the Project Site

Five test borings have been drilled at the project site, and the locations are depicted on Figure IV.D-1 (Soil Boring Location Map). The test borings were advanced to depths ranging from 21 ½ to 50 ½ feet below site grade. Fill soils, to a depth of three feet, were found in Boring 4. The fill soils consisted of very stiff silty clay. The near surface soils consisted of medium stiff to very stiff clays and sandy clays from near ground surface to depths ranging from 10 to 20 feet below site grade. Underlying the near

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-3 City of Los Angeles January 2012

surface clay soils, the soils generally consisted of various interbedded layers of silty sands and lean clays to the maximum depth explored of 50 ½ feet below site grade. An expansion index (E.I.) test indicated that the near surface clays in this area had a medium potential for expansion (E.I.=80). The near surface clays in this area also exhibited low to high compressibility characteristics, low swell potential, and low shear strength.

iii) Groundwater

Groundwater was encountered in the test borings at depths of 44 feet below site grade. Based on Seismic Hazard Zone Report 026 published by the California Geological Survey, the historical high ground-water level was between 40 and 50 below the ground surface.

iv) Faulting & Seismicity

The numerous faults in include active, potentially active, and inactive faults. The criteria for these three major groups are based on criteria developed by the California Geological Survey for the Alquist-Priolo Earthquake Fault Zoning Program. The project site is not included in a State of California Alquist-Priolo Earthquake Fault Zone or a City of Los Angeles Fault Rupture Study Area.2

By definition, an active fault is one that has had surface displacement within Holocene time (about the last 11,000 years). A potentially active fault is a fault that has demonstrated surface displacement of Quaternary age deposits (last 1.6 million years). Inactive faults have not moved in the last 1.6 million years. The fault closest to the project site is the Santa Monica Fault. This fault is located approximately 0.8 mile north of the project site and is potentially active. In addition, the is located approximately 1.1 miles north of the project site. An Alquist-Priolo Fault Rupture Study Area has been established for the Hollywood Fault, surrounding it approximately one-eighth of one mile on either side.3 The Hollywood Fault is considered active by the State Geologist and the City of Los Angeles considers it active for planning purposes.

1) Faults

a) Santa Monica Fault

The active Santa Monica fault, a left lateral reverse oblique fault, is located approximately 0.8 mile north of the project site. The Santa Monica and Hollywood fault zone form a portion of the Transverse Ranges Southern Boundary fault system. The Transverse Ranges Southern Boundary fault system also includes the Malibu Coast fault to the west of the Santa Monica fault and the Raymond and Cucamonga faults to

2 ZIMAS, website http://zimas.lacity.org/, November 29, 2010. 3 ZIMAS, website http://zimas.lacity.org/, November 29, 2010.

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-4 Source: Moore Twining Associates, Inc., March 5, 2007.

Figure IV.D-1 Soil Boring Location Map City of Los Angeles January 2012

the east of the Hollywood fault. The Santa Monica fault zone is the western segment of the Santa Monica-Hollywood fault zone. The fault zone trends east-west from the Santa Monica coastline on the west to the Hollywood area on the east. Urbanization and development within the greater Los Angeles area has resulted in a poor understanding of the lateral extent, location, and rupture history of the Santa Monica fault zone. However, the surface expression of the Santa Monica fault zone includes fault- related geomorphic features, offset stratigraphy, and ground water barriers within late Quaternary deposits. Research indicates that the Santa Monica fault zone is separated into an east segment and a west segment, divided by the West Beverly Hills Lineament. The east segment of the Santa Monica fault zone is not considered active. However, the west segment of the fault is considered active. Although the west segment of the Santa Monica fault is considered active, it has not yet been included in a State of California Special Studies (Alquist-Priolo) Earthquake Fault Zone. The project site is not included in a City of Los Angeles Fault Rupture Study Area.

b) Hollywood Fault

The active Hollywood fault, a left-lateral, reverse oblique fault, is located about 1.1 miles north of the project site and approximately trends east-west along the base of the Santa Monica Mountains from the West Beverly Hills Lineament in the West Hollywood-Beverly Hills area to the Los Feliz area of the City. The fault is a ground-water barrier within Holocene sediments. Studies by several investigators have indicated that the fault is active, based on geomorphic evidence, stratigraphic correlation between exploratory borings, and fault trenching studies.

Until recently, the approximately 15 kilometer-long Hollywood fault zone was considered to be expressed as a series of linear scarps and faceted south-facing ridges along the south margin of the eastern Santa Monica Mountains and the Hollywood Hills. Multiple recent fault rupture hazard investigations have shown that the Hollywood fault zone is located south of the faceted ridges and bedrock outcrops along Sunset Boulevard. Active deposition of numerous small alluvial fans at the mountain front and a lack of fan incision suggest late Quaternary uplift of the Santa Monica Mountains along the Hollywood fault zone. The fault dips steeply to the north and has juxtaposed Tertiary and Cretaceous age (1 to 150 million years old) rocks over young sedimentary deposits of the northern Los Angeles Basin. The Hollywood fault zone has not produced any damaging earthquakes during the historical period and has had relatively minor micro-seismic activity.

v) Slope Stability

A landslide area, as identified by the State of California, is an area that is located in the general area of sites that possess the potential for earthquake-induced rock falls, slope failure, and debris flow. The project site is located approximately one mile south of the Hollywood Hills, but is not located immediately adjacent to any mountains or steep slopes. The project site is not located within any landslide areas mapped in the available public geologic maps.4 Furthermore, according to the Safety Element of the General Plan of the City of Los Angeles, the project site is not within a Landslide Inventory or Hillside areas.5 Lands specified as hillside are identified to be located in or in close

4 State of California, Department of Conservation, Seismic Hazard Zones Maps: State of California Seismic Hazard Zones, Hollywood Quadrangle, website: http://gmw.consrv.ca.gov/shmp/download/pdf/ozn_holly.pdf, November 29, 2010. 5 City of Los Angeles, Department of City Planning, General Plan of the City of Los Angeles, Safety Element, Exhibit C, Landslide Inventory & Hillside Areas, June 1994.

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-6 City of Los Angeles January 2012

proximity to a hillside mountainous area and are subject to developmental regulations relating to guidelines required to mitigate hillside area hazards. The project site is not located in a hillside area and is therefore not subject to the Hillside Ordinance. The project site is located in an area that is topographically flat, sloping gently toward the south-southwest, no hillsides exist on or near the site, and there is no potential for landslides to occur on or near the site.

vi) Liquefaction/Lateral Spreading and Seismic-Induced Settlement

Liquefaction is the process in which saturated, silty to cohesionless soils below the groundwater table temporarily lose strength during strong ground shaking as a consequence of increased pore pressure during conditions such as those caused by earthquakes. The vast majority of liquefaction hazards are associated with sandy soils and silty soils of low plasticity. Potentially liquefiable soils must be saturated or nearly saturated to be susceptible to liquefaction. Significant factors that affect liquefaction include water level, soil type, particulate size and gradation, relative density, confining pressure, intensity of shaking, and duration of shaking. Liquefaction potential has been found to be the greatest where the groundwater level is shallow and submerged loose, fine sands occur within a depth of about 50 feet or less. Liquefaction potential decreases with increasing grain size and clay and gravel content, but increases as the ground acceleration and duration of shaking increase. Liquefaction is therefore more likely to occur in sand dune areas. Structures founded on or above potentially liquefiable soils may experience bearing capacity failures due to the temporary loss of foundation support, vertical settlements (both total and differential), and undergo lateral spreading.

Soils at the project site include fill and other materials consisting of medium to very stiff clays and sandy clays from near the ground surface to 10 to 20 feet below ground surface (bgs). Beneath theses clays, soils generally consist of various interbedded layers of silty sands and lean clays.

According to the Safety Element of the General Plan of the City of Los Angeles, the project site is in a liquefiable area.6 However, liquefaction and seismic settlement analyses were conducted based on soil properties identified by test borings and laboratory testing. The analysis was based on groundwater depths of 40 feet bgs, an earthquake magnitude of 6.5, and an average peak ground acceleration of 0.70g. The results of these analyses indicated that the subsurface soils encountered were not subject to liquefaction below the groundwater elevation.7 Therefore, the potential for liquefaction is considered low.

Seismic settlement is often caused by loose to medium-dense granular soils densified during ground shaking. Uniform settlement beneath a given structure would cause minimal damage. However, due to variations in distribution, density, and confining conditions of the soils, seismically-induced settlement is generally non-uniform and can cause serious structural damage. Seismic settlement can occur in saturated and unsaturated, loose, and unconsolidated materials. Although the amount of settlement is anticipated to be minimal (¾ to 1¼ inches of total settlement and 5/8 inches in 30 feet of differential settlement), seismic-induced settlement risks associated with development within the bedrock are considered potential.

6 City of Los Angeles, Department of City Planning, General Plan of the City of Los Angeles, Safety Element, Exhibit B, Areas Susceptible to Liquefaction, October 1993. 7 Moore Twining Associates, Inc., Summary of Preliminary Geotechnical Feasibility Evaluation Proposed Target Store and Retail Space SWC of Sunset Boulevard and Western Avenue Hollywood, California, March 15, 2007.

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-7 City of Los Angeles January 2012

vii) Tsunamis, Inundation, Seiches, and Flooding

Since the project site is not located in close proximity to a contained body of water, there is no potential impact associated with a seiche or tsunami. Additionally, the project site is not located in a potential tsunami zone.8 Furthermore, the project site is not located downslope of any large bodies of water that could adversely affect the project site in the event of earthquake-induced dam failures or seiches (wave oscillations in an enclosed or semi-enclosed body of water). The project site is not in an Inundation and Tsunami Hazard Area of the City. The project site is not located within a flood zone, including, but not limited to, the 100-year flood zone or 500-year flood zone as designated by the Federal Emergency Management Agency (FEMA).9

viii) Subsidence

The project site is not within an area of known subsidence associated with fluid withdrawal (ground water or petroleum), peat oxidation (natural decay of organic peat materials), or hydrocompaction (compression of soils due to the introduction of water).

ix) Expansive Soils

Expansive soils are clay-based soils that tend to expand (increase in volume) as they absorb water and shrink (lessen in volume) as water is drawn away. If soils consist of expansive clays, foundation movement and/or damage can occur if wetting and drying of the clay does not occur uniformly across the entire area. The near surface clays on site have an expansion index of 80 indicating a medium potential for expansion.10 The UBC mandates that special foundation design consideration be employed if the Expansion Index is 20, or greater (UBC Table 18-1-B).

3. ENVIRONMENTAL IMPACTS

A. Thresholds of Significance

As set forth in the L.A. CEQA Thresholds Guide, the determination shall be made on a case-by-case basis, considering the following factors:

a) A project would normally have a significant geologic hazard impact if it would cause or accelerate geologic hazards, which would result in substantial damage to structures or infrastructure, or expose people to substantial risk of injury;

b) A project would normally have significant sedimentation or erosion impacts if it would;

i) Constitute a geologic hazard to other properties by causing or accelerating instability from erosion; or

8 City of Los Angeles Department of City Planning, General Plan, Safety Element, Exhibit G, Inundation & Tsunami Hazard Areas in the City of Los Angeles, March 1994. 9 City of Los Angeles Department of City Planning, General Plan, Safety Element, Exhibit F, 100-Year & 500-Year Flood Plains in the City of Los Angeles, March 1994. 10 Moore Twining Associates, Inc., Summary of Preliminary Geotechnical Feasibility Evaluation Proposed Target Store and Retail Space SWC of Sunset Boulevard and Western Avenue Hollywood, California, March 15, 2007.

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-8 City of Los Angeles January 2012

ii) Accelerate natural processes of wind and water erosion and sedimentation, resulting in sediment runoff or deposition which would not be contained or controlled on-site.

B. Project Construction and Operation Impacts

i) Seismic Fault Rupture

As discussed previously, the project site is not located in an Alquist-Priolo Earthquake Fault Zone. The closest active fault is the Santa Monica fault, located approximately 0.8 mile north of the project site. Based on the available geologic data, active or potentially active faults with the potential for surface fault rupture are not known to be located beneath or projecting toward the project site. The potential for surface rupture at the project site due to fault plane displacement propagating to the ground surface during the operation of the proposed project is considered low, and no significant impacts related to seismic fault rupture would occur.

ii) Strong Seismic Ground Shaking

The project site is located in a seismically active region, and future users on the project site would be exposed to seismic groundshaking. Seismic groundshaking could damage the buildings, parking areas, and utility infrastructure. However, the proposed construction would be consistent with all applicable provisions of the City of Los Angeles Building Code and the recommendations of the Geotechnical Study. Conformance with current Building Code requirements would minimize the potential for structures on the project site to sustain damage during an earthquake event. The proposed project would thus not cause or accelerate geologic hazards or expose people to substantial risk of injury. Furthermore, although the project site is located within approximately 0.8 mile of the Santa Monica Fault, and nearby many other faults on a regional level, the potential seismic hazard to the project site would not be higher than in most areas of the City of Los Angeles or elsewhere in the region. Therefore, risks from seismic groundshaking would be less than significant.

iii) Erosion and Topsoil

1) Construction

The proposed project would include the export of up to 8,000 cubic yards of material from the project site. During construction, grading and excavation would expose minimal amounts of soil for a limited time, allowing for possible erosion. However, due to the temporary nature of the soil exposure during the grading and excavation processes, substantial erosion would not occur. The project site is relatively flat and excavation of the project site would be limited to that necessary for the installation of foundations and utilities. All grading activities require grading permits and haul route approval (see Section II.5, Discretionary Actions and Approvals, of this EIR) from the Los Angeles Department of Building and Safety, which include requirements and standards designed to limit potential impacts to acceptable levels. In addition, on-site grading and site preparation must comply with all applicable provisions of Chapter IX, Division 70 of the Los Angeles Municipal Code, which addresses grading, excavations, and fills.

The majority of the area surrounding the project site is completely developed and would not be susceptible to indirect erosional processes (e.g., uncontrolled runoff) caused by the proposed project. During construction, the proposed project would be required to prevent the transport of sediments from the project site by stormwater runoff and winds through the use of appropriate Best Management

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-9 City of Los Angeles January 2012

Practices (BMPs). These BMPs will be detailed in a Stormwater Pollution Prevent Program (SWPPP), which must be acceptable to the City Engineer and in compliance with the latest National Pollutant Discharge Elimination System (NPDES) Stormwater Regulations. With implementation of the applicable grading and building permit requirements and the implementation of applicable BMPs, less-than- significant impacts would occur related to erosion or loss of topsoil.

2) Operation

The project site is currently occupied by a Department of Water and Power (DWP) electrical substation, a surface parking lot, and approximately 59,561 square feet of vacant one-story commercial buildings, all of which would be demolished under the proposed project. As the project site has been previously graded and improved for the development of these uses, the presence of topsoil is not anticipated. The proposed project would develop the project site with pervious and impervious surfaces including structures, paved areas, and landscaping. As such, the proposed project would not leave soils exposed at the project site or substantially increase the rate and amount of erosion occurring at the project site. Therefore, operational impacts related to erosion and the loss of topsoil would be less than significant.

iv) Liquefaction/Lateral Spreading and Seismic-Induced Settlement

As discussed previously, liquefaction is the process in which saturated, silty to cohesionless soils below the groundwater table temporarily lose strength during strong ground shaking as a consequence of increased pore pressure during conditions such as those caused by earthquakes. Liquefaction and seismic settlement analyses were conducted based on soil properties identified by test borings and laboratory testing. The results of these analyses indicated that the subsurface soils encountered were not subject to liquefaction below the groundwater elevation.11 With respect to lateral spreading, construction would comply with the City of Los Angeles UBC, which is designed to assure safe construction and includes building foundation requirements appropriate to the conditions present at the project site. Additionally, the Geotechnical Study prepared for the proposed project has identified construction and building requirements. The proposed project would comply with existing regulations, and would implement all site-specific requirements identified in the Geotechnical Study (see Appendix IV.D-1 to this EIR). Thus, risks associated with liquefaction/lateral spreading during operation of the proposed project would not occur. Therefore, impacts associated with liquefaction or lateral spreading would be less than significant.

Additionally, seismic settlement can occur in saturated and unsaturated, loose, and unconsolidated materials. Although the amount of settlement is anticipated to be minimal (¾ to 1¼ inches of total settlement and 5/8 inches in 30 feet of differential settlement), this settlement needs to be incorporated into project design to minimize potential impacts. The proposed project would implement all of the site-specific requirements identified in the Geotechnical Study (see Appendix IV.D-1 to this EIR). With incorporation of these site-specific requirements, seismic settlement impacts would be less than significant.

11 Moore Twining Associates, Inc., Summary of Preliminary Geotechnical Feasibility Evaluation Proposed Target Store and Retail Space SWC of Sunset Boulevard and Western Avenue Hollywood, California, March 15, 2007.

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-10 City of Los Angeles January 2012

v) Tsunamis, Inundation, Seiches, and Flooding

As discussed above, tsunamis are large ocean waves that usually result from submarine earthquakes. Additionally, the project site is not located in a potential tsunami zone.12 Therefore, impacts related to tsunami would be less than significant.

Also as discussed above, seiches are oscillations generated in enclosed bodies of water that can be caused by an earthquake. Furthermore, the project site is not located downslope of any large bodies of water that could adversely affect the project site in the event of earthquake-induced dam failures or seiches. Therefore, impacts related to inundation as a result of seiche or breached upgradient reservoir would be less than significant.

Finally, as previously discussed, according to the City of Los Angeles Environmental and Public Facilities Maps of the Safety Element of the General Plan, Exhibit F, the project site is not located in a mapped 100-year or 500-year flood plain. As such, impacts related to a 100-year or 500-year flood upon the project site would be less than significant.

vi) Subsidence

Groundwater and petroleum are not currently being extracted from the project site and would not be extracted as part of the proposed project. Thus, subsidence as a result of such activities would not occur. Thus, earth materials underlying the project site would not be subject to subsidence. Therefore, impacts associated with subsidence would be less than significant.

vii) Expansive Soils

As discussed previously, expansive soils are clay-based soils that tend to expand (increase in volume) as they absorb water and shrink (lessen in volume) as water is drawn away. The near surface clays on the project site have an expansion index of 80 indicating a medium potential for expansion.13 However, construction of the proposed project would be required to comply with the City of Los Angeles UBC and the 2010 California Building Code, which include building foundation requirements appropriate to site- specific conditions. The UBC mandates that special foundation design consideration be employed if the Expansion Index is 20, or greater (UBC Table 18-1-B). Therefore, because the project site has an expansion index of 80, which exceeds the expansion index of 20 identified by the UBC, the project would utilize alternate foundation systems such as drilled pier and gradebeam systems or driven piles and structural gradebeam systems. With compliance with the Los Angeles Building Code and implementation of all site-specific requirements identified in the Geotechnical Study (see Appendix IV.D- 1 to this EIR), impacts associated with expansive soils would be less than significant

4. CUMULATIVE IMPACTS

Geotechnical impacts related to future development in the Hollywood area would involve hazards related to site-specific soil conditions, erosion, and ground-shaking during earthquakes. The impacts on each site would be specific to that site and its users and would not be common or contribute to (or

12 City of Los Angeles Department of City Planning, General Plan, Safety Element, Exhibit G, Inundation & Tsunami Hazard Areas in the City of Los Angeles, March 1994. 13 Moore Twining Associates, Inc., Summary of Preliminary Geotechnical Feasibility Evaluation Proposed Target Store and Retail Space SWC of Sunset Boulevard and Western Avenue Hollywood, California, March 15, 2007.

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-11 City of Los Angeles January 2012

shared with, in an additive sense) the impacts on other sites. In addition, development on each site would be subject to uniform site development and construction standards that are designed to protect public safety. Therefore, cumulative geology and soils impacts would be less than significant.

5. MITIGATION MEASURES

IV.D-1. The proposed project shall be designed and constructed in accordance with the recommendations provided in a full Geotechnical Study, which shall be approved by the Department of Building and Safety prior to issuance of building and grading permits.

6. LEVEL OF SIGNIFICANCE AFTER MITIGATION

With implementation of the mitigation measure listed above, project impacts with regard to geology and soils would be less than significant.

Target at Sunset and Western IV.D. Geology & Soils Page IV.D-12