4.d. geology and soils...4.d. geology and soils august 2016 los angeles county department of public...

LosAngelesCountyDepartmentofPublicWorks Harbor‐UCLAMedicalCenterCampusMasterPlanProjectSCH#2014111004 4.D‐1

4.0 ENVIRONMENTAL IMPACT ANALYSIS D. GEOLOGY AND SOILS

1. INTRODUCTION

Thissectiondescribesexistingconditionsandtheregulatoryframeworkassociatedwithgeologyandsoilsandanalyzesthepotential impactsoftheProjectregardingfaultrupture,seismichazards,groundshaking,liquefaction,soilerosionorthelossoftopsoil,expansivesoils,andlandform/landslideintheunincorporatedLosAngelescommunityofWestCarsonandintheProjectvicinity.Informationinthissectionisbasedontheanalysis and findings provided in the Preliminary Geotechnical Evaluation for the Harbor‐UCLA MedicalCenterMasterPlan(GeotechnicalReport),preparedbyNinyo&Moore,April2015.TheGeotechnicalReportisincludedinAppendixCofthisDraftEIR.

2. ENVIRONMENTAL SETTING

a. Regional Geology

TheProjectSiteis locatedwithinthePeninsularRangesGeomorphicProvinceofsouthernCalifornia. Thisgeomorphic province encompasses an area that extends approximately 125 miles from the TransverseRangesandtheLosAngelesRiverBasinsouthtotheMexicanborderandbeyondanotherapproximately775milestothetipofBajaCalifornia.ThePeninsularRangesprovincevariesinwidthfromapproximately30to100miles is characterized by northwest‐trendingmountain range blocks separated by similarly trendingfaults.

ThepredominantrocktypethatunderliesthePeninsularRangesprovinceisaCretaceousageigneousrock(granitic rock) referred to as the Southern California batholith. Older Jurassic age metavolcanic andmetasedimentary rocks and older Paleozoic limestone, altered schist, and gneiss are present within theprovince.Cretaceous‐agemarinesedimentaryrocksandyoungerTertiary‐agerockscomprisedofvolcanic,marine,andnon‐marinesedimentsoverlietheolderrocks.MorerecentQuaternarysediments,primarilyofalluvialorigin,comprisethelow‐lyingvalleyanddrainageareaswithintheregion,includingtheareawheretheHarbor‐UCLAMedicalCenterProjectSiteislocated.

The Project is situated in the Los Angeles Basin, a region divided into four structural blocks that includeupliftedzonesandsynclinaldepressions.Thestructuralblocksaregenerallyboundedbyfaultsystems.TheProjectsiteissituatedinthesouthwesternblockoftheseawardpartofthebasinwhichisboundedbytheNewport‐Inglewoodzoneofdeformation.Thisblockisacombinationoffoldsandfaultsandischaracterizedbyoverlappingstaggeringanticlinalhills. Newport‐InglewoodandPalosVerdesare themajoractive faultsystemslocatedinproximitytotheProjectsite.Thepredominanttectonicactivityassociatedwiththeseandotherfaultswithintheregionaltectonicframeworkisright‐lateral,strike‐slipand/orreversemovement.

b. Site Geology

RegionalgeologicmapsindicatethattheProjectsite isunderlainbylatetomiddlePleistoceneagealluvialfloodplaindepositsgenerallycomprisedofdissectedgravel,sand,siltandclay‐bearingalluvium.

4.D. Geology and Soils August 2016


(1) Groundwater

Thesiteislocatedwithinthewestcoastsub‐basinoftheLosAngelesCoastalGroundwaterBasin. HistoricgroundwatermonitoringwelldatafromtheStateofCaliforniaWaterResourcesControlBoard’sGeoTrackerWebsite1werereviewedforwellslocatedonadjacentpropertieseastandnorthoftheProjectsite.Basedonthe groundwatermeasurements in thesewells from 2007 to 2014, groundwater levels at these locationshave ranged fromapproximately48 to60 feetbelow theground surface. TheLosAngelesCountySafetyElementindicatesthatthehistorichighgroundwaterinthevicinityoftheProjectsite isapproximately30feetdeep. Groundwaterlevelsmaybeinfluencedbyseasonalvariations,precipitation,irrigation,soil/rocktypes,groundwaterpumping,andotherfactorsandaresubjecttofluctuations.Shallowperchedconditionsmaybepresentonsite.

(2) Faulting and Seismicity

The Project site is located in a seismically active area, as is the majority of southern California and thepotentialforstronggroundmotionatthesiteisconsideredsignificant.Surfacefaultruptureistheoffsetorrupturingofthegroundsurfacebyrelativedisplacementacrossafaultduringanearthquake.AccordingtothepreliminaryGeotechnicalReport(AppendixC),theProjectsiteisnottransectedbyanyknownactiveorpotentiallyactive faults. However,earthquakeeventsononeof theactiveorpotentiallyactive faultsneartheProjectSitecouldresult instronggroundshaking,whichcouldaffect theHarbor‐UCLAMedicalCentercampus.

TheProjectisnotlocatedwithinaStateofCaliforniaEarthquakeFaultZone,althoughtheactiveNewport‐Inglewoodfaultislocatedapproximately3.4milesnortheast.Figure4.D‐1,RegionalFaultLocations,showstheProject locationrelativetotheprincipal faults intheregion. Blindthrustfaultsare low‐angle faultsatdepthsthatdonotbreakthesurfaceandare,therefore,notshownonFigure4.D‐1.Table4.D‐1,PrincipalRegional Active Faults, lists selected principal known active faults, including blind thrust faults, withinapproximately30milesofthecenteroftheProjectareaandtheirmaximummomentmagnitude(Mmax)2.

According to theGeotechnicalReportprepared for theproposedProject, the site is not locatedwithin anareaconsideredsusceptibletoliquefaction(Figure4.D‐2,LiquefactionSeismicHazardZones). Inaddition,thepotentialforliquefactionatthesiteisconsideredrelativelylowbasedonrecentgroundwaterdepthsof48to60feetinthesitevicinity.

(3) Landslides

Landslides,slope failures,andmudflowsofearthmaterialsgenerallyoccurwhereslopesaresteepand/ortheearthmaterialsaretooweaktosupportthemselves.Earthquake‐inducedlandslidesmayalsooccurduetoseismicgroundshaking.AreviewofgeologicmapsdidnotrevealanypastlandslidesattheProjectsite.In addition, the Project Site has been extensively developed and is primarily covered with pavement,hardscape,andbuildingsandstructures.TheProjectSitealsoincludessomesmallgradedslopesassociated

1 State of California Water Resources Control Board. http://geotracker.waterboards.ca.gov/gama/

gamamap/public/default.asp?CMD=runreport&myaddress=harbor+ucla+medical+center%2C+carson%2C+ca.Accessed,April,2015

2 Cao, et al., 2003. The Revised 2002 California Probabilistic SeismicHazardMaps. http://www.conservation.ca.gov/cgs/rghm/psha/ofr9608/Pages/Index.aspx,Accessed,April2015

FIGURERegional Fault Loca ons

Harbor-UCLA Medical Center Master Plan 4.D-1Source: Ninyo and Moore Geotechnical and Environmental Sciences Consultants, April 2015.

0 10 Miles

N

P C R

FIGURELiquefac on Seismic Hazards Zone Map

Harbor-UCLA Medical Center Master Plan 4.D-2Source: Ninyo and Moore Geotechnical and Environmental Sciences Consultants, April 2015.

0 2000 Feet

N

P C R

August 2016 4.D. Geology and Soils


withlandscapingandpedestrianareas.Anon‐siteareanorthwestoftheExistingHospitalTowercontainsaslope thatdescendsapproximately25 feet toward theedgeof thebuilding. This slope is landscapedandlinedat thebottomedgewithadrainage system. According to theGeotechnicalReport, thepotential forfuturelandslidesormudflowstoaffectdevelopmentswithintheProjectareaisrelativelylow.

(4) Site Soils

ExposedmaterialsatthesurfaceoftheProjectsiteincludeclaysandsiltysandysoils.Sandysoilstypicallyhavelowcohesion,andhavearelativelyhigherpotential forerosionfromsurfacerunoffwhenexposedincutslopesorutilizednearthefaceoffillembankments.Surfacesoilswithhigheramountsofclaytendtobelesserodibleastheclayactsasabindertoholdthesoilparticlestogether.

Soilerosionreferstotheprocessbywhichsoilorearthmaterialisloosenedordissolvedandremovedfromitsoriginallocation.ErosioncanoccurbyvaryingprocessesandmayoccurintheProjectareawherebaresoil is exposed towindormovingwater (both rainfall and surface runoff). Theprocesses of erosion aregenerally a function of material type, terrain steepness, rainfall or irrigation levels, surface drainageconditions,andgenerallanduses.

Table 4.D‐1

Principal Regional Active Faults

Fault Approximate Fault Distancea to Site

Miles (Kilometers)

Maximum Moment Magnitude

(Mmax)

Newport‐Inglewood(LosAngelesBasin) 3.4(5.5) 7.1PalosVerdes 307(5.9) 7.3PuenteHillsBlindThrust 10.3(16.5) 7.1UpperElysianParkBlindThrust 16.7(26.8) 6.4SantaMonica 16.9(27.1) 6.6Elsinore 18.1(29.1) 6.7Hollywood 18.6(30.0) 6.4Malibu 19.1(30.7) 6.7Anacapa‐Dume 19.8(31.9) 7.5Raymond 20.5(32.9) 6.5Verdugo 22.2(35.7) 6.9SanJoaquinHillsBlindThrust 22.7(36.5) 6.6SierraMadre 26.9(43.3) 7.2SanJose 27.8(44.7) 6.4Clamshell‐Sawpit 29.3(47.1) 6.5

a USGS, 2008 Source: Ninyo & Moore, 2015



(5) Subsidence

Subsidenceischaracterizedasasinkingofgroundsurfacerelativetosurroundingareas,andcangenerallyoccurwheredeepsoildepositsarepresent.Subsidenceinareasofdeepsoildepositsistypicallyassociatedwith regionalgroundwaterwithdrawalorother fluidwithdrawal from thegroundsuchasoil andnaturalgas.Subsidencecanresultinthedevelopmentofgroundcracksanddamagetosubsurfacevaults,pipelinesandotherimprovements.

Historically, subsidencehasoccurred in theCityofLongBeach,but isnotknown tohaveoccurredat theProject site. The County of Los Angeles Safety Element (1990) does not indicate mapped areas ofsubsidence.AccordingtotheGeotechnicalReport,thepotentialforsubsidenceintheProjectareaislow.

(6) Compressible/Collapsible Soils

Compressible soils are generally comprised of soils that undergo consolidation when exposed to newloading,suchasfillorfoundationloads.Soilcollapseisaphenomenonwherethesoilsundergoasignificantdecrease in volume upon increase in moisture content, with or without an increase in external loads.Buildings,structures,andotherimprovementsmaybesubjecttoexcessivesettlement‐relateddistresswhencompressiblesoilsorcollapsiblesoilsarepresent.

The Geotechnical Report states that the Project area is underlain by older alluvial deposits which aregenerallyunconsolidated,reflectingadepositionalhistorywithoutsubstantialloading,andmaybesubjecttocollapse.Older,undocumentedfillsoilsrelatedtopreviousdevelopmentmaybepresentattheProjectSiteand,ifso,maybepotentiallycompressibleorcollapsible.Duetothepresenceofpotentiallycompressibleorcollapsible soils at the site, the potential exists for differential settlement, which can destabilize areas ofhardscapeorbuildingcomponents.

(7) Expansive Soils

Expansive soils includeclayminerals thatare characterizedby theirability toundergosignificantvolumechange (shrink or swell) due to variation in moisture content. Sandy soils are generally not expansive.Changes in soil moisture content can result from rainfall, irrigation, pipeline leakage, surface drainage,perchedgroundwater,drought,orother factors. Volumetricchangeofexpansivesoilmaycauseexcessivecracking and heaving of structures with shallow foundations, concrete slabs‐on‐grade, or pavementssupportedonthesematerials.

AccordingtotheGeotechnicalReport,near‐surfacesoilsintheProjectsitearegenerallyclayeyandsandysiltsoils.Sandysoilstypicallyhavealowexpansionpotential.However,clayeysoilsaretypicallyexpansive.

(8) Corrosive Soils

ThegeologicenvironmentoftheProjectsitecouldincludesoilconditionspotentiallycorrosivetoconcreteandmetals.Corrosivesoilconditionsmayexacerbatethecorrosionhazardtoburiedconduits,foundations,andotherburiedconcreteormetal improvements. Corrosivesoilscouldcauseprematuredeteriorationoftheseundergroundstructuresorfoundations.



c. Regulatory Setting

Thefollowingsubsectionsdiscussthevariouscodes,regulationsandpoliciesapplicabletogeologyandsoilsatthefederal,stateandlocallevels.

(1) Federal

(a) National Earthquake Hazards Reduction Program Reauthorization Act of 2004

TheEarthquakeHazardsReductionAct{(PublicLaw95‐124,42U.S.C.7701et.seq.),asamendedbyPublicLaws101614,105‐47,106‐503,and108‐360.}wasenactedin1977to“reducetheriskstolifeandpropertyfrom future earthquakes in the United States through the establishment andmaintenance of an effectiveearthquake hazards and reduction program.” To accomplish this, the Act established the NationalEarthquakeHazardsReductionProgram (NEHRP). Theprogramwas significantly amended inNovember1990 by NEHRP, which refined the description of agency responsibilities, program goals, and objectives.NEHRP’s mission includes improved understanding, characterization, and prediction of hazards andvulnerabilities; improvement of building codes and land use practices; risk reduction through post‐earthquake investigation and education; development and improvement of design and constructiontechniques;improvementofmitigationcapacity;andacceleratedapplicationofresearchresults.TheNEHRPdesignates the Federal Emergency Management Agency (FEMA) as the lead agency of the program andassigns itseveralplanning,reports,andcoordinatingresponsibilities. ProgramsunderNEHRPinformandguideplanningandbuildingcoderequirementssuchasemergencyevacuationresponsibilitiesandseismiccodestandardssuchasthosetowhichtheProjectwouldberequiredtoadhere.

InOctober2004,NEHRPwasreauthorizedtodevelopeffectivemeasuresforearthquakehazardreduction;promote the adoptionof earthquakehazards reductionmeasuresby government agencies, standards andcodesorganizations,andothersinvolvedinplanningandbuildinginfrastructure;improvetheunderstandingofearthquakesandtheireffectsthroughinterdisciplinaryresearch;and,develop,operate,andmaintainboththeAdvanced National Seismic System (ANSS)and the George E. Brown, Jr.Network for EarthquakeEngineeringSimulation(NEES). TheactalsodirectedthatNEHRPsupportdevelopmentandapplicationofperformance‐based seismic design (PBSD). It also established an Advisory Committee on EarthquakeHazardsReduction (ACEHR)thatwill assess scientific and engineering trends; programeffectiveness; andprogrammanagement, coordination, and implementation. ANEHRP InteragencyCoordinatingCommittee(ICC)wasalsoestablishedtooverseeNEHRPplanning,management,andcoordination.

(2) State

(a) Alquist‐Priolo Earthquake Fault Zoning Act

The Alquist‐Priolo Earthquake Fault Zoning Act (Public Resources Code Section2621‐2624, Division 2,Chapter 7.5) was enacted in 1972 to address the hazard of surface faulting to structures for humanoccupancy.3 The primary purpose of the Alquist‐Priolo Earthquake Fault Zoning Act is to prevent theconstructionofbuildingsintendedforhumanoccupancyonthesurfacetracesofactivefaults.TheAlquist‐Priolo Earthquake Fault Zoning Act requires the State Geologist to establish regulatory zones, known as“earthquake fault zones”, around the surface traces of active faults and to issuemaps to assist cities andcounties in planning, zoning, and building regulation functions. Local agenciesmust enforce the Alquist‐

3 TheActwasoriginallyentitledtheAlquist‐PrioloGeologicHazardsZoneAct.



PrioloEarthquakeFaultZoningActinthedevelopmentpermitprocess,whereapplicable,andmaybemorerestrictivethanstatelawrequires.TheActrequiresthat,priortoapprovalofaproject,ageologicstudybeconductedtodefineanddelineateanyhazardsfromsurfacerupture. AgeologistregisteredbytheStateofCalifornia,withintheleadagency’sorganizationorretainedbytheleadagencyfortheproject,mustpreparethisgeologic report. A50‐footbuilding setback fromanyknown traceof anactive fault is required. TheAlquist‐Priolo Earthquake Fault Zoning Act and its regulations are presented in California Department ofConservation, California Geological Survey, Special Publications (SP) 42, Fault‐rupture Hazard Zones inCalifornia.

(b) Seismic Hazards Mapping Act

TheSeismicHazardsMappingActof1990(PublicResourcesCodeSection2690‐2699)addressestheeffectsofstronggroundshaking, liquefaction, landslides,andotherground failuresdue toseismicevents. UndertheSeismicHazardsMappingAct, theStateGeologist isrequiredtodelineate“seismichazardzones.” TheState Mining and Geology Board provides additional regulations and policies to assist municipalities inpreparing the Safety Element of their General Plan and encourage land use management policies andregulationstoreduceandmitigatethosehazardstoprotectpublichealthandsafety.UnderPublicResourcesCodeSection2697,citiesandcountiesshallrequire,priortotheapprovalofaproject located inaseismichazardzone,ageotechnicalreportdefininganddelineatinganyseismichazard.

Statepublicationssupporting therequirementsof theSeismicHazardsMappingAct include theCaliforniaGeologicalSurveySP117,GuidelinesforEvaluatingandMitigatingSeismicHazardsinCalifornia,andSP118,RecommendedCriteria forDelineatingSeismicHazardZones inCalifornia. Theobjectives of SP117 are toassistintheevaluationandmitigationofearthquake‐relatedhazardsforprojectswithindesignatedzonesofrequired investigations and topromoteuniformandeffective statewide implementationof the evaluationandmitigationelementsof theSeismicHazardsMappingAct. SP118implementstherequirementsof theSeismicHazardsMappingActintheproductionofProbabilisticSeismicHazardMapsfortheState.

(c) Title 24 California Building Standards Code

The California Buildings Standards Commission (Commission) is responsible for coordinating, managing,adopting,andapprovingbuildingcodesinCalifornia.OnJuly12014,the2013CaliforniaBuildingStandardsCode(CBSC)becameeffectiveandupdatedallpriorcodesunderCaliforniaCodeofRegulations(CCR)Title24. The State of California providesminimum standards for building design through the 2013 CaliforniaBuilding Code (CBC), a component of the 2013 CBSC. Chapters 16 through 18 of the 2013 CBC regulatestructuraldesign, structural testsand inspections,andsoilsand foundations. TheCBCapplies tobuildingdesignandconstructioninthestateandisbasedonthefederalUniformBuildingCode(UBC),whichisusedwidelythroughoutthecountry(generallyadoptedonastatebystateordistrictbydistrictbasis).TheCBC,whichhas beenmodified for California conditions, contains numerousprovisions that aremore stringentthan those in theUBCbecauseofCalifornia’s seismicandenvironmental conditions. According toSection1613 of the CBC, “[e]very structure, and portion thereof, including nonstructural components that arepermanentlyattachedtostructuresandtheirsupportsandattachments,shallbedesignedandconstructedtoresisttheeffectsofearthquakemotionsinaccordancewithASCE7."4

4 ASCE7isadocumentpublishedbytheAmericanSocietyofCivilEngineers(ASCE)thatspecifiesminimumdesignloadsforbuildings

andotherstructures.



(d) Senate Bill 1953: The Alquist Hospital Seismic Safety Act

Senate Bill (SB) 1953, signed into law on September 21, 1994, is an amendment to the Alfred E. AlquistHospital Seismic Safety Act of 1983 and is California’s Hospital Seismic Safety Law.5 The 1983 Actwas aresponse to the damage to hospitals in the 1971 Sylmar quake, and the amendment resulted fromassessmentofdamage tohospitals following the1994Northridgeearthquake. SB1953 (Chapter740) asamended ischaptered intostatute inSections130000through130070of theCaliforniaHealthandSafetyCode. SB 1953 was a result of failures to nonstructural components of hospitals that were built inaccordancewith the structural provisions of the Act. SB 1953 amended the Act to address the issues ofsurvivabilityofbothstructuralandnonstructuralcomponentsofhospitalbuildingsafteraseismicevent.SB1953 ensures that by 2030 California hospitalsmust be capable of remaining operational after a seismiceventorothernaturaldisaster.Consistingoftwoparts,thelawrequireshospitalstofixorreplacebuildingswith structural problems that may cause them to collapse in an earthquake. Secondly, non‐structuralfeatures suchaselectrical,mechanical,plumbingand fire safetysystemsmustbeanchoredandbracedsotheydonotbecomefallinghazardsandathreattolifeintheeventofadisaster.LicensedacutecarefacilitiessuchastheExistingHospitalTowerhavemorestringentrulesregardingmeetingseismicstandardsby2030than sub‐acute care facilities. To achieve compliancewith the requirements of SB1953before2030, theProjectisproposedtobuildaNewHospitalTowercompliantwithSB1953tohouseacutecarefunctions.

(3) Local

(a) Los Angeles County General Plan Update (2035)

California Government Code Section 65300 requires general plans to include “a safety element for theprotectionofthecommunityfromanyunreasonablerisksassociatedwiththeeffectsofseismicallyinducedsurfacerupture,groundshaking,groundfailure,tsunami,seiche,anddamfailure;slopeinstabilityleadingtomudslides and landslides, subsidence and other geologic hazards known to the legislative body; flooding;andwildlandandurbanfires.”Assuch,theLosAngelesCountyGeneralPlanUpdate(2035)SafetyElement(Chapter 12) addresses hazards which must be considered in the physical development of the County,including seismic, geologic, erosion; flooding; hazardousmaterials; noise control; and emergency/disasterpreparedness.ApplicablegoalsandpolicesfromtheSafetyElementareidentifiedbelow:

GoalS1:Aneffectiveregulatorysystemthatpreventsorminimizespersonalinjury, lossof lifeandpropertydamageduetoseismicandgeotechnicalhazards.

PolicyS1.1: Discourage development in SeismicHazard andAlquist‐PrioloEarthquakeFaultZones.

PolicyS1.2:Prohibittheconstructionofmoststructuresforhumanoccupancyadjacentto active faults until a comprehensive fault study that addresses the potential for faultrupturehasbeencompleted.

Policy S1.3: Require developments to mitigate geotechnical hazards, such as soilinstabilityandlandsliding,inHillsideManagementAreasthroughsitinganddevelopmentstandards.

5 Office of Statewide Health Planning & Development. California’s Hospital Seismic Safety Law (2005). Available at

http://www.oshpd.ca.gov/fdd/seismic_compliance/SB1953/SeismicReport.pdf,accessedonJuly19,2016.



PolicyS1.4:Supporttheretrofittingofunreinforcedmasonrystructurestohelpreducetheriskofstructuralandhumanlossduetoseismichazards.

GoalS2:Aneffectiveregulatorysystemthatpreventsorminimizespersonalinjury,lossoflife,andpropertydamageduetofloodandinundationhazards.

PolicyS2.1:DiscouragedevelopmentintheCounty’sFloodHazardZones.

PolicyS2.2:Discouragedevelopmentfromlocatingdownslopefromaqueducts.

Policy S2.3: Consider climate change adaptation strategies in flood and inundationhazardplanning.

PolicyS2.4:Ensurethatdevelopments locatedwithintheCounty’sFloodHazardZonesaresitedanddesignedtoavoidisolationfromessentialservicesandfacilitiesintheeventofflooding.

PolicyS2.7:Locateessentialpublicfacilities,suchashospitalsandfirestations,outsideofFloodHazardZones,wherefeasible.

3. ENVIRONMENTAL IMPACTS

a. Methodology

ThetechnicalanalysessupportingtheimpactconclusionsinthefollowingsectionarebasedontheanalysiscontainedinthePreliminaryGeotechnicalEvaluationReportpreparedbyNinyo&Moore(AppendixCofthisDraftEIR).TheconclusionsinthePreliminaryGeotechnicalEvaluationReportwereprimarilyderivedfromthefollowingtasks:

Review of readily available topographic and geologic maps, published geotechnical literature,geologicandseismicdata,soildata,groundwaterdata,aerialphotographs,andin‐houseinformation;

ReviewofgeotechnicalaspectsofProjectplansanddocumentspertainingtothesite;

GeotechnicalsitereconnaissancebyarepresentativeofNinyo&MooreconductedonFebruary16,2015,toobserveanddocumenttheexistingsiteconditionsattheProjectsite;

Compilationandanalysisofexistinggeotechnicaldatapertainingtothesite;

AssessmentofthegeneralgeologicconditionsandseismichazardsaffectingtheareaandevaluationoftheirpotentialimpactsontheProject;

Preparationofreportpresentingtheresults,aswellasconclusionsregardingtheProject’sgeologicand seismic impacts, and recommendations to address the impacts to be included in theenvironmentalplanningdocuments;and

ReportpreparationpresentingresultsandconclusionsregardingtheProject’sgeologicandseismicimpacts,andrecommendationstoaddresstheimpactstobeincludedintheenvironmentalplanningdocuments.

Data and conclusions from the analyses in the Preliminary Geotechnical Evaluation Reportwere used todetermine potential impacts from the Project to and from the site geology and soils parameters. These



impacts were compared against the Thresholds of Significance set forth below to determine the level ofsignificanceofpotentialimpacts.

b. Thresholds of Significance

Thepotential forgeologic impacts isbasedonthresholdsderivedfromtheCounty’sInitialStudyChecklistquestions, which are based in part on Appendix G of the State CEQA Guidelines. These questions are asfollows:

(VI) Geology and Soils. Would the project:

a) Exposepeopleorstructurestopotentialsubstantialadverseeffects,includingtheriskofloss,injury,ordeath,involving:

1) Ruptureofaknownearthquake fault,asdelineatedon themostrecentAlquist‐PrioloEarthquakeFaultZonemapissuedbytheStateGeologistfortheareaorbasedonothersubstantial evidence of a known fault (refer toDivision ofMinesandGeology SpecialPublication42);

2) Strongseismicgroundshaking;

3) Seismicallyrelatedgroundfailure,includingliquefaction;or

4) Landslides.

b) Resultinsubstantialsoilerosionorthelossoftopsoil.

c) BelocatedonageologicunitorsoilthatisunstableorthatwouldbecomeunstableasaresultoftheProject and potentially result in an on‐site or off‐site landslide, lateral spreading, subsidence,liquefaction,orcollapse.

d) Be located on expansive soils, as defined in Table 18‐1‐B of the UBC (1994), or corrosive soils,creatingsubstantialrisktolifeorproperty.

e) Havesoilsthatwouldbeincapableofadequatelysupportingtheuseofseptictanksoralternativewastedisposalsystemswheresewersarenotavailableforthedisposalofwastewater.

The Initial Study determined that the Project would have a less than significant impact with respect toChecklistquestionVI.e).Accordingly,thisenvironmentaltopicisnotevaluatedinthisEIR.

Basedontheabovefactors,theProjectwouldhaveapotentiallysignificantimpactonGeologyandSoilsifitwould:

GEO‐1: Exposepeopleorstructurestopotentialsubstantialadverseeffects,includingtheriskofloss,injury,ordeath,involving:

1) Ruptureofaknownearthquake fault,asdelineatedon themostrecentAlquist‐PrioloEarthquakeFaultZonemapissuedbytheStateGeologistfortheareaorbasedonothersubstantial evidence of a known fault (refer toDivision ofMines andGeology SpecialPublication42).



2) Strongseismicgroundshaking.

3) Seismicallyrelatedgroundfailure,includingliquefaction.

4) Landslides.

GEO‐2: Resultinsubstantialsoilerosionorthelossoftopsoil.

GEO‐3: Belocatedonageologicunitorsoilthatisunstableorthatwouldbecomeunstableasaresultof the Project and potentially result in an on‐site or off‐site landslide, lateral spreading,subsidence,liquefaction,orcollapse.

GEO‐4: Belocatedonexpansivesoils,asdefinedinTable18‐1‐BoftheUBC(1994),orcorrosivesoils,creatingsubstantialrisktolifeorproperty.

c. Project Characteristics or Design Features

TherearenospecificProjectDesignFeaturesthatrelatetogeologyandsoilsontheProjectSite.However,theProjectwouldcomplywithallapplicablebuildingrequirementsrelatedtogeologyandsoilconditions.Recommendations from theGeotechnicalReportwould be incorporated into theProject. In addition, theconstructionplansforacutecarefacilitiesproposedaspartoftheProjectwouldbereviewedandapprovedbytheCaliforniaOfficeofStatewideHealthPlanningandDevelopment(OSHPD).

Also,withregard to impactspertaining tosoilerosionor the lossof topsoil, theProjectwould implementnumerousBMPsasdetailed in theWaterQualityManagementPlan (WQMP) for theProject. TheanalysisbelowreferstoSection4.G.,HydrologyandWaterQuality,ofthisDraftEIRforalistingoftheBMPsproposedfortheProject.

d. Project Impacts

ThresholdGEO‐1: WouldtheProjectexposepeopleorstructurestopotentialsubstantialadverseeffects,including the risk or loss, injury, or death, involving earthquake fault rupture, seismic shaking, groundfailure,orlandslides?

ImpactStatementGEO‐1: TheHarbor‐UCLACampus issubject toseismicshakingdue to its location in theseismicallyactivesouthernCaliforniaregion.Basedonsubsurfacegeologicconditionsandthedepthtogroundwater, thepotential for substantialadverse effectsdue to fault ruptureandground failure isrelativelylow,butimpactsarenonethelesspotentiallysignificant.

(1) Fault Rupture

Aspreviouslystated,theProjectsiteisnottransectedbyanyknownactiveorpotentiallyactivefaults.TheactiveNewport‐Inglewood fault is located approximately 3.4miles northeast and the active Palos Verdesfaultislocatedapproximately3.7milessouthwestoftheestimatedcenteroftheProjectsite.TheProjectisnotlocatedwithinaStateofCaliforniaEarthquakeFaultZone;therefore,thepotentialforsurfaceruptureatthesiteisrelativelylowandisconsideredalessthansignificantimpact. However, lurchingorcrackingofthegroundsurfaceasaresultofnearbyseismiceventsispossible.Thisisapotentiallysignificantimpact.



(2) Seismic Ground Shaking

TheHarbor‐UCLACampus is locatedwithin a seismically active region, and thus thepotential for seismicgroundshakingexistsatthesite.However,thelevelofgroundshakingatagivenlocationdependsonmanyfactors,includingthesizeandtypeofearthquake,thedistancefromtheearthquake,andsubsurfacegeologicconditions. The type of construction also affects how particular structures and improvements performduringgroundshaking.

A site‐specific analysiswas conducted toevaluate thepotential levelsof groundshaking that couldoccur.The2013CBCrecommendsthatthedesignofstructuresbebasedonspectralresponseaccelerationsinthedirectionofmaximumhorizontalresponse(5percentdamped)havinga1percentprobabilityofcollapsein50 years. These spectral response accelerations represent the Risk‐Targeted Maximum ConsideredEarthquake(MCER)groundmotion.Thehorizontalpeakgroundacceleration(PGA)thatcorrespondstotheMCERforthesitewascalculatedat0.65gusingtheUSGSweb‐basedseismicdesigntool(USGS,2014).Themapped and design PGA were estimated to be 0.62g and 0.43g, respectively, using the USGS (2014)calculatorandtheAmericanSocietyofCivilEngineers7‐10Standard.Thesegroundmotionestimatesdonotincludenear‐source factors thatmaybeapplicable to thedesignof thestructureson‐site. BasedonthesePGAestimates,groundshakingat theHarbor‐UCLACampuscouldhaveapotentially significant impactonpeopleandproposedbuildingsontheHarbor‐UCLACampus.

(3) Liquefaction

According to the Seismic Hazard Zones Map, the Harbor‐UCLA Campus is not in an area susceptible toliquefaction;historichighgroundwaterdepthsof48to60feetintheProjectvicinitylimitthepotentialforliquefactionthatcouldadverselyaffectProjectbuildingsandstructures.However,thesitecouldbesubjectto seismically‐induced soil settlement, which could have a significant impact on people and proposedbuildingsontheHarbor‐UCLACampus.

(4) Landslides

TheProjectSitehasbeenextensivelydevelopedand isprimarilycoveredwithpavements,hardscape,andstructures. It also includes some graded slopes associated with landscaping. An area northwest of theExistingHospitalTowercontainsalandscapedslopethatdescendsapproximately25feettowardtheedgeofthebuildingandislinedatthebottomedgewithadrainagesystem.Inaddition,therehavebeennohistoriclandslides at the site. Therefore, the potential for future landslides ormudflows to affect developmentswithintheProjectsitearenotanticipatedandnosignificantimpactsareexpected.SlopescreatedforfuturedevelopmentswithintheProjectareawillbedesignedtoreducethepotentialforlandslidesormudflows.

ThresholdGEO‐2: Would the Project result in a significant impact if it would result in substantial soilerosionorthelossoftopsoil?

Impact Statement GEO‐2: Compliancewith the County’sNational Pollutant Discharge Elimination SystemthroughimplementationofaStormWaterPollutionPreventionProgramforerosioncontrolwouldberequired during Project construction and with County’s Low Impact Development (LID) ordinancerequirements during operations. Impacts related to soil erosion and loss of soilwould be less thansignificant.



Aspreviouslystated,thematerialsexposedatthesurfaceoftheProjectsiteincludeclaysandsiltysandsoils.Sandysoilstypicallyhavelowcohesion,andhavearelativelyhigherpotentialforerosionfromsurfacerunoffwhenexposedincutslopesorutilizednearthefaceoffillembankments.Surfacesoilswithhigheramountsofclaytendtobelesserodibleastheclayactsasabindertoholdthesoilparticlestogether.

FutureconstructionattheProjectsitewouldresultingroundsurfacedisruptionduringexcavation,grading,and trenching thatwouldcreate thepotential forerosion tooccur. However,asdescribed inSection4.G.,HydrologyandWaterQuality,anyprojectinvolvinggradingofanareagreaterthanoneacreisrequiredtoapply for aNationalPollutantDischargeElimination Systempermit from theLosAngelesRegionalWaterQuality ControlBoard. This permit requires preparation and implementation of a StormWater PollutionPrevention Program (SWPPP) incorporating Best Management Practices (BMPs) for erosion control.Specifically,constructionactivityresultinginalanddisturbanceofoneacreormore,orlessthanoneacrebut part of a larger common plan of development, must obtain the Construction Activities StormwaterGeneralPermit.Constructionactivitiesincludeclearing,grading,excavation,stockpiling,andreconstructionofexistingfacilitiesinvolvingremovalandreplacement.Positivesurfacedrainageshouldbeaccommodatedat project construction sites to allow surface runoff to flow away from site improvements or areassusceptible to erosion. To reducewind‐related erosion,wettingof soil surfaces and/or covering exposedroundareasandsoilstockpilescouldbeconsideredduringconstructionoperations,asappropriate.Theuseof soil tackifiers may also be considered to reduce the potential for wind related soil erosion.Implementation of BMPs would ensure that water‐ and wind‐related erosion would be confined to theconstructionareaandnottransportedoff‐site.Inaddition,thetopographicgradientsattheProjectSitearerelativelygentle.Therefore,potentialsoilerosionimpactsduringconstructionwouldbelessthansignificantandnomitigationisrequired.

BMPsrelatedtoongoingdrainagedesignandmaintenancepracticeswouldbe includedintheSWPPPandimplementedtoreducesoilerosionduringoperationoftheproposedProject.Examplesoftheseprocedurescould include surface drainagemeasures for erosion due towater, such as the use of erosion preventionmatsorgeofabrics,silt fencing,sandbagsandplasticsheeting,andtemporarydevices. Soilerosionduringoperationcanalsobemitigatedthroughdesignproceduressuchasappropriatesurfacedrainagedesignofroadways and facilities to provide for positive surface runoff. These design procedures would addressreducing concentrated run‐off conditions that could cause erosion and affect the stability of Projectimprovements.

Additionally, as discussed inmore detail in Section 4.G., Hydrology andWater Quality, of this Draft EIR,buildout of the Harbor‐UCLA Master Plan Project would increase the amount of pervious area on theCampus.However,theProjectwouldbebuiltoutincompliancewiththeCounty’sLowImpactDevelopment(LID)ordinance,whichrequiresnewdevelopment to include featuresandpractices thatprovidephysical,biological,andchemicalcontrolsthatremovepollutantsfromstormwaterrunoffgeneratedonaprojectsite.Typical LID features include bioretention or infiltration, which are intended to reduce and slow peakstormwaterflowsdischargedoff‐sitecomparedtoexistingconditions.SincetheseandotherLIDcompliancepracticesand featurearea intended toprevent,amongotherpotential impacts,erosionandsedimentationconveyedbystormwateranddischargedtooff‐sitestormdrain infrastructureandreceivingwaterbodies,compliancewith County LID requirementswould prevent erosion of soil on the Project Site. Accordingly,following Project buildout, operational impacts related to erosion of on‐site soil would be less thansignificant.



ThresholdGEO‐3:WouldtheProjectresultinasignificantimpactifitwouldbelocatedonageologicunitorsoilthatisunstableorthatwouldbecomeunstable,potentiallyresultinginanon‐siteoroff‐sitelandslide,lateralspreading,subsidence,liquefaction,orcollapse?

ImpactStatementGEO‐3:BuildoutoftheHarbor‐UCLACampuscouldresultinpotentiallysignificantimpactsrelatedtodifferentialsoilsettlementandliquefactionbeneathproposedbuildings,duetothepresenceofalluviumandpossibleundocumentedfill,andrelativelyshallowdepthstogroundwaterbeneaththeCampus.Subsidencehazardswouldbelessthansignificant.

(1) Subsidence

Aspreviouslystated,historicsubsidenceisnotknowntohaveoccurredontheHarbor‐UCLACampusanditdoes not lie within a mapped subsidence area according to the County of Los Angeles Safety Element.Therefore, the potential for subsidence on the Project site is relatively low. Subsidence hazards duringconstructionandoperationwouldbealessthansignificantimpact.

(2) Compressible/Collapsible Soils

The Project area is underlain by older alluvial deposits which are generally unconsolidated, reflecting adepositionalhistorywithoutsubstantial loading,andmaybesubject tocollapse. Olderundocumented fillsoils related to the previous development at the Project Site may also be potentially compressible orcollapsible.Duetothepresenceofpotentiallycompressible/collapsiblesoilsatthesite,thereisapotentialfor differential settlement, which could cause damage to Project improvements. This is a potentiallysignificantimpact.

(3) Shallow Groundwater

Proposed construction activities in the Project area would include excavation and site grading for newmedical, office and retail structures, pedestrian areas, landscaping, open space areas, and parking areaimprovements. Areas of shallower perched groundwater may be encountered during excavations.Groundwater levels may be influenced by seasonal variations, precipitation, irrigation, soil/rock types,groundwaterpumping,andotherfactorsandaresubjecttofluctuations.Ifwetorsaturatedsoilconditionsareencounteredduringexcavation, instability couldoccurandpresent a constraint to the constructionoffoundations.Thisisapotentiallysignificantimpact.

ThresholdGEO‐4:WouldtheProjectresultinasignificantimpactifitwouldbelocatedonexpansivesoil,asdefinedinTable18‐1‐BoftheUBC(1994),orcorrosivesoils,creatingsubstantialrisktolifeorproperty?

ImpactStatementGEO‐4:BuildoutoftheHarbor‐UCLACampuscouldresultinpotentiallysignificantimpactsrelated to expansive and corrosive soils beneath proposed buildings, based on the underlying soiltype(s).



(1) Expansive Soils

Aspreviouslystated,thenear‐surfacesoilsintheProjectsitearegenerallyclayeyandsandysiltsoils.Clayeysoilsaretypicallyexpansivewhenwetted,andcouldhaveanadverseeffectonproposedProjectbuildings.Thisisapotentiallysignificantimpact.

(2) Corrosive Soils

TheProjectsite is located inageologicenvironmentthatcouldpotentiallycontainsoilconditionsthatarecorrosive toconcreteandmetal,whichcouldcauseprematuredeteriorationofundergroundstructuresorfoundations.Thisisapotentiallysignificantimpact.

4. CUMULATIVE IMPACTS

ThestudyareaconsideredforcumulativeimpactsencompassestheareasthatcouldbeaffectedbyHarbor‐UCLAMasterPlanProjectactivitiesaswellasbyotherprojectswhoseactivitiescoulddirectlyorindirectlyaffectthegeologyandsoilsoftheProjectSite.Alloftheidentifiedrelatedprojectswouldbebuiltinthesameseismicallyactiveregionandcouldexperiencegroundshakingandotherseismicallyrelatedhazards,similarto theProject. Thoseprojectswouldalsobe subject to applicable seismic standards, safety requirementsand,standarddesignspecificationtokeeppotentialriskofdamagefromseismicandothergeologichazardsto an acceptable level. Geologic and soil impacts are generally site‐specific and there is little, if any,cumulative relationship between development projects. Adherence to all relevant plans, codes, andregulationswith respect to project design and constructionwould reduce project‐specific and cumulativegeologic impacts. Therefore, the Harbor‐UCLA Medical Center Campus Master Plan Project, consideredtogetherwithrelatedprojects,wouldnotresultinacumulativelyconsiderablecontributiontocumulativelysignificantgeologyandseismicityimpacts.

During construction of the proposed and related projects, grading and excavation have the potential toexpose soils in thearea towindandwatererosion, resulting ina lossof soils. AsdiscussedaboveunderImpactStatementGEO‐2,anyprojectinvolvinggradingofanareagreaterthanoneacreisrequiredtoapplyfor a NPDES permit, which requires the use of BMPs for erosion control. Compliance with NPDESrequirements would minimize potential soil erosion impacts for the proposed and related projects.Moreover, compliance with the County’s LID ordinance would ensure features and practices intended toreduce, amongother impacts, sedimentation in stormwaterdischarge,wouldbe incorporated intoProjectdesignandoperations.Therefore,theHarbor‐UCLAMedicalCenterCampusMasterPlanProject,consideredtogetherwithrelatedprojects,wouldnotresultinacumulativelyconsiderablecontributiontocumulativelysignificantsoilerosionimpacts.

OperationoftheproposedandrelatedprojectswouldnotchangethegeologicpropertiesoftheProjectarea.Seismicandothergeologichazardscouldstillpotentiallyimpacttheproposedandrelatedprojectsastheyarelocatedinaseismicallyactiveregion.However,theseriskswouldnotincreaseordecreaseasaresultoftheproposedand/orrelatedprojects.Therefore,operationoftheHarbor‐UCLAMedicalCenterMasterPlanProject, considered together with the related projects, would not result in a cumulatively considerablecontributiontocumulativelysignificantimpactswithrespecttogeology,soilsandseismicity.



5. MITIGATION MEASURES

ThefollowingmeasureisrequiredtomitigateImpactGEO‐1:

MM‐GEO‐1:AllrecommendationsincludedinthePreliminaryGeotechnicalEvaluationpreparedforthe Project (provided in Appendix C of this Draft EIR) shall be followed. A detailedsubsurfacegeotechnicalevaluationshallbeperformedtoaddresssite‐specificconditionsatthelocationsoftheplannedimprovementsandprovidedetailedrecommendationsfordesign and construction. The geotechnical evaluation shall include the followingmeasures to mitigate potential fault rupture, seismic ground shaking, and liquefactionhazardsidentifiedunderImpactGEO‐1:

Seismicity:Structuralelementsoffutureimprovementsshallbedesignedtoresistoraccommodate appropriate site‐specific groundmotions and conform to the currentseismicdesignstandards.

Liquefaction: An assessment of the liquefaction potential and seismically induceddynamic settlement shall bemade prior to detailed design and construction of theproposedProject.Structuraldesignandmitigationtechniques,suchasin‐situgroundmodificationorsupportingfoundationswithpilesatdepthsdesignedspecificallyforliquefaction,shallbeincluded.

ToevaluatethepotentialliquefactionhazardfortheProject,asubsurfaceevaluationcould be performed. Site‐specific geotechnical evaluations that assess theliquefactionanddynamicsettlementcharacteristicsof theon‐sitesoilsshall includethedrillingofexploratoryborings,evaluationofgroundwaterdepths,andlaboratorytestingofsoils.

Methods for construction in areas with a potential for liquefaction hazard mayinclude in‐situ ground modification, removal of liquefiable layers and replacementwithcompactedfill,orsupportofProjectimprovementsonpilesatdepthsdesignedspecifically for liquefaction. Pile foundations can be designed for a liquefactionhazardbysupportingthepilesindensesoilorbedrocklocatedbelowtheliquefiablezoneorother appropriatemethodsas evaluatedduring the site‐specific evaluation.Additionalrecommendationsformitigationofliquefactionmayincludedensificationby installation of stone columns, vibration, deep dynamic compaction, and/orcompactiongrouting.


MM‐GEO‐2: All recommendations included in thePreliminaryGeotechnicalEvaluationpreparedfor theProject (provided inAppendixCof thisDraftEIR)shallbe followed. Adetailedsubsurfacegeotechnicalevaluationshallbeperformedtoaddresssite‐specificconditionsatthelocationsoftheplannedimprovementsandprovidedetailedrecommendationsfordesign and construction. The geotechnical evaluation shall include the followingmeasurestomitigateunstablesoilhazardsidentifiedunderImpactsGEO‐3:

Compressible/CollapsibleSoilsandSettlement:Anassessmentofthepotentialforsoilsthatarepronetosettlementshallbemadepriortodetaileddesignandconstructionof Project improvements, and mitigation techniques shall be developed, asappropriate,toreduceimpactsrelatedtosettlementtolowlevels.



DuringthedetaileddesignphaseoftheProjectcomponents,surfacereconnaissanceandsite‐specificgeotechnicalevaluationsshallbeperformedtoassessthesettlementpotentialoftheon‐sitenaturalsoilsandundocumentedfill.Thismayincludedetailedsurfacereconnaissancetoevaluatesiteconditions,drillingofexploratoryboringsortest pits, and laboratory testing of soils, where appropriate, to evaluate siteconditions.

Prescribed mitigation measures for soils with the potential for settlement includeremovalofcompressible/collapsiblesoillayersandreplacementwithcompactedfill;surcharging to induce settlement prior to construction of new fills; and specializedfoundation design, including the use of deep foundation systems to supportstructures. Varietiesof in‐situsoil improvement techniquesarealsoavailable,suchasdynamiccompaction(heavytamping)orcompactiongrouting.

Shallow Groundwater: A subsurface exploration shall be performed during thedetailed design phase of future improvements to evaluate the presence ofgroundwater, seepage, and/or perched groundwater at the site and the potentialimpacts on design and construction of Project improvements. Assessment of thepotentialforshallowgroundwaterwouldbeevaluatedduringthedesignphaseoftheProjectandmitigationtechniqueswouldbedeveloped,asappropriate,toreducetheimpacts related toshallowgroundwater to low levels. Therefore,potential impactsdue to groundwater would be reduced with incorporation of techniques such asconstructiondewatering.


MM‐GEO‐3: All recommendations included in thePreliminaryGeotechnicalEvaluationpreparedfor the Project (provided in Appendix C) shall be followed. A detailed subsurfacegeotechnical evaluation shall be performed to address site‐specific conditions at thelocationsoftheplannedimprovementsandprovidedetailedrecommendationsfordesignandconstruction. Thegeotechnical evaluation shall include the followingmeasures tomitigateexpansivesoilshazardsidentifiedunderImpactsGEO‐4.

ExpansiveSoils:Anassessmentofthepotentialforexpansivesoilswillbeconductedduring the detailed design and construction phases of the Project. Mitigationtechniques such as over excavation and replacement with non‐expansive soil, soiltreatment,moisturemanagement,and/orspecificstructuraldesignforexpansivesoilconditionswouldreducetheimpactfromexpansivesoilstolowlevels.

CorrosiveSoils: Anassessmentof thepotential forcorrosivesoilswillbeconductedduring the detailed design phase of the Project through a subsurface evaluationincluding soil testing and analysis of soils at foundationdesigndepths. Laboratorytests would include corrosivity tests to evaluate the corrosivity of the subsurfacesoils. Data will be reviewed by a corrosion engineer and mitigation techniquessuitable fortheproposedProjectwillbeimplementedasappropriate. Mitigationofcorrosive soil conditions could include the use of concrete resistant to sulfateexposure. Corrosion protection for metals used in underground foundations orstructures in areas where corrosive groundwater or soil could potentially causedeterioration could include epoxy and metallic protective coatings, the use ofalternative (corrosion resistant)materials, and selection of the appropriate type ofcement and water/cement ratio. Specific measures to reduce the potential effectswould be developed in the design phase and would reduce impacts related tocorrosivesoilstolowlevels.



6. LEVEL OF SIGNIFICANCE AFTER MITIGATION

Givencompliancewithapplicablebuildingcodesandseismicsafetyrequirements,aswellasimplementationofapplicablemitigationmeasures,impactsrelatedtogeologyandsoilswouldbelessthansignificant.

4.d. geology and soils...4.d. geology and soils august 2016 los angeles county department of public...

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