Pipeline/South Pipeline pit expansion project : final supplemental environmental impact statement

2004·161.1 MB·English

by  United States. Bureau of Land Management. Battle Mountain Field Office

BUM LIBRARY
88067141
United States Department of the Interior
Bureau of Land Management
Battle Mountain Field Office
Battle Mountain, Nevada December 2004
Pipeline/South Pipeline Pit Expansion Project
Final Supplemental Environmental nvn-067575 01-ia)
(
Impact Statement nvo63-eisoi-70
Nevada DepartmentofWildlife
MISSION STATEMENT
The Bureau ofLand Management is responsible for the stewardship ofour public lands. It is
committed to manage, protect, and improve these lands in a manner to serve the needs ofthe
American people for all times. Management is based upon the principles ofmultiple use and
sustainedyieldofournation’sresourceswithintheframeworkofenvironmentalresponsibilityand
scientifictechnology.Theseresourcesincluderecreation,rangelands,timber,minerals,watershed,
fishandwildlife,wilderness, airand scenic, scientific, andculturalvalues.
EISNUMBER:NV063-EIS01-70
PLAN OFOPERATIONSNUMBER: NVN067575(01-1A)
BLM/BM/PL-05/003+1793
PIPELINE/SOUTH PIPELINE
PITEXPANSIONPROJECT
FINALSUPPLEMENTAL
ENVIRONMENTALIMPACT STATEMENT
Lead Agency: U.S. DepartmentofInterior
Bureau ofLandManagement
BattleMountainFieldOffice
CooperatingAgency: NevadaDepartmentofWildlife
ProjectLocation: LanderCounty,Nevada
SEIS Number: NV063-EIS01-70
Plan ofOperations Number: NVN-067575(01-1A)
Correspondenceon this SEIS
Should beDirected to: PamJamecke
ProjectManager
BureauofLandManagement
BattleMountainFieldOffice
50BastianRoad
BattleMountain,Nevada 89820-1420
[phone]
ABSTRACT
CortezGoldMinesproposestoextendgoldminingoperationsatthePipeline/SouthPipelineMine
withintheGoldAcresMiningDistrictinLanderCounty,approximately30milessoutheastofBattle
Mountain, Nevada. The Pipeline/South Pipeline Pit Expansion Project (ProposedAction) would
modifytheexistingPlanofOperationsandincludeanexpansionoftheexistingopenpitinstages,
theexpansionoftheexistingwasterockdisposalsites,theincreaseinheightoftheheapleachpads,
and waste rock dumps, as well as the sequential backfilling of a majority ofthe open pit and
developmentofanewwasterockdump. TheProposedActionwouldoccurwithinthepreviously
approvedsurface disturbance footprint, all ofwhich is public landadministeredbythe Bureau of
LandManagement.Miningoperationsareexpectedtooccursevendaysaweek,24hoursaday,for
uptoanadditionalsevenyears.ThisFinalSupplementalEnvironmentalImpactStatementanalyzes
the environmental effects ofthe Pipeline/South Pipeline Pit Expansion Project, the No Action
Alternative, andtheComplete BackfillAlternative.
ResponsibleOfficial forthe SEIS: GeraldM. Smith
FieldManager
BattleMountainFieldOffice
1066O.FinalSEIS.V1.wpd
ThisPageIntentionallyLeftBlank.
PIPELINE/SOUTH PIPELINE
PITEXPANSIONPROJECT
FINALSUPPLEMENTAL
ENVIRONMENTALIMPACT STATEMENT
TABLEOFCONTENTS
ACRONYMSANDABBREVIATIONS
xi
EXECUTIVESUMMARY ES-1
PurposeofthisDocument ES-1
ProposedAction ES-1
CompleteBackfillAlternative ES-3
NoBackfillAlternative ES-4
NoActionAlternative ES-4
AlternativesEliminatedfromDetailedConsideration ES-4
ImportantIssuesandImpactConclusions ES-4
BUMPreferredAlternative ES-5
1 INTRODUCTION:PURPOSEOFANDNEEDFORACTION 1-1
1.1 IntroductionandLocation 1-1
CGM
1.2 Projects 1-1
1.2.1 ExistingandPreviouslyApprovedCGMFacilitiesandOperations 1-1
1.2.2 ProposedAction 1-2
1.3 PurposeofandNeedforAction 1-7
1.4 BLMResponsibilitiesandRelationshiptoPlanning 1-7
1.4.1 ResourceManagementPlan 1-7
1.4.2 SurfaceManagementAuthorizationsandRelevantPlans 1-8
1.4.3 SiteReclamation Requirements 1-8
1.4.4 CyanideManagementPlanRequirements 1-9
1.4.5 LocalLandUsePlanningandPolicy 1-9
1.5 AuthorizingActions 1-9
1.6 EnvironmentalReviewProcess 1-9
2 EXISTINGFACILITIES 2-1
2.1 Introduction 2-1
2.2 ApprovedOpenPits 2-1
2.3 ApprovedDewateringManagement 2-4
2.3.1 MineDewateringandDisposalOperations 2-4
2.3.2 DewateringInducedSubsidenceManagement 2-4
2.4 ApprovedWasteRockDumps 2-15
2.5 ApprovedOreProcessingFacilities 2-16
2.5.1 Pipeline/SouthPipelineMillFacility 2-16
2.5.2 Pipeline/South PipelineTailingsandHeapLeachFacility 2-16
2.5.3 SouthAreaHeapLeachFacility 2-16
2.5.4 GoldAcresHeapLeachFacility 2-16
2.5.5 CortezCFBRoasterandtheCortezCILMillTailingsFacility 2-17
2.6 ApprovedSupportActivities 2-17
2.6.1 SupportFacilities 2-17
2.6.2 WorkForce 2-17
2.6.3 MobileEquipment 2-18
2.6.4 WaterSupplyandConsumptiveUse 2-18
2.6.5 PowerSupplyandUtilities 2-18
2.6.6 WasteDisposalandSanitarySystem 2-19
2.6.7 ChemicalStorageand HazardousMaterialsManagement 2-19
2.6.8 Roadsand HaulRoads 2-19
2.6.9 GravelPits 2-19
2.6.10 Fencing 2-19
1066O.FinalSEIS.V1.wpd
CortezGoldMines Pipeline/SouthPipelinePitExpansionProject
Final SupplementalEnvironmentalImpactStatement
2.6.11 HealthandHumanSafety 2-20
2.7 Exploration 2-20
2.8 Reclamation 2-20
2.9 CGMEnvironmentalProtectionMeasures 2-20
CGM
2.10 SustainabilityActivities 2-22
3 DESCRIPTIONOFALTERNATIVES,INCLUDINGTHEPROPOSEDACTION 3-1
3.1 ProposedAction 3-1
3.1.1 MiningandDevelopmentActivities 3-3
3.1.2 Pipeline/SouthPipelineOpenPitExpansion 3-4
3.1.3 WasteRockDisposal 3-12
3.1.4 OreProcessingFacilities 3-13
3.1.5 OtherProjectActivities 3-13
3.1.6 MobileEquipment 3-14
3.1.7 Reclamation 3-14
3.1.8 MonitoringandReclamationSuccessEvaluation 3-15
3.1.9 EnvironmentalProtectionMeasures 3-15
3.2 AlternativestotheProposedAction 3-16
3.2.1 NoActionAlternative 3-17
3.2.2 CompleteBackfillAlternative 3-18
3.2.3 NoBackfillAlternative 3-18
3.2.4 AlternativesConsideredand EliminatedfromConsideration 3-19
3.2.5 BLMPreferredAlternative 3-19
4 AFFECTED ENVIRONMENTANDENVIRONMENTALCONSEQUENCES 4-1
4.1 Introduction 4-1
4.2 GeologyandMineralResources 4-1
4.2.1 RegulatoryFramework 4-1
4.2.2 AffectedEnvironment 4-1
4.2.3 EnvironmentalConsequencesandMitigationMeasures 4-10
4.3 WaterResources-WaterQuantity 4-18
4.3.1 RegulatoryFramework 4-18
4.3.2 AffectedEnvironment 4-19
4.3.3 EnvironmentalConsequencesandMitigationMeasures 4-79
4.4 WaterResources-WaterQuality 4-174
4.4.1 RegulatoryFramework 4-174
4.4.2 AffectedEnvironment 4-174
4.4.3 EnvironmentalConsequencesandMitigationMeasures 4-185
4.5 AirResources 4-222
4.5.1 RegulatoryFramework 4-222
4.5.2 AffectedEnvironment 4-225
4.5.3 EnvironmentalConsequencesandMitigationMeasures 4-228
4.6 VisualResources 4-264
4.6.1 RegulatoryFramework 4-264
4.6.2 AffectedEnvironment 4-265
4.6.3 EnvironmentalConsequencesandMitigationMeasures 4-266
4.7 AuditoryResources 4-273
4.7.1 RegulatoryFramework 4-273
4.7.2 AffectedEnvironment 4-273
4.7.3 EnvironmentalConsequencesandMitigationMeasures 4-276
4.8 SocioeconomicValues 4-280
4.8.1 RegulatoryFramework 4-280
4.8.2 AffectedEnvironment 4-281
4.8.3 EnvironmentalConsequencesandMitigationMeasures 4-312
4.9 EnvironmentalJustice 4-319
4.9.1 RegulatoryFramework 4-319
iv 1066O.FinalSEIS.V1.wpd
TableofContents
4.9.2 AffectedEnvironment 4-319
4.9.3 EnvironmentalConsequencesandMitigationMeasures 4-321
4.10 WildlifeandFisheriesResources 4-323
4.10.1 RegulatoryFramework 4-323
4.10.2 AffectedEnvironment 4-324
4.10.3 EnvironmentalConsequencesandMitigationMeasures 4-326
4.11 RelationshipbetweentheLocalShort-Term UsesoftheHuman Environment
andtheMaintenanceandEnhancementofLong-TermProductivity 4-331
4.12 Irreversible/IrretrievableCommitmentofResources 4-331
4.13 EnergyRequirementsandConservationPotential 4-331
5 CUMULATIVEIMPACTS 5-1
5.1 Introduction 5-2
5.2 PastActions 5-3
5.2.1 MiningandExploration-RelatedActions 5-3
5.2.2 UtilitiesandCommunityActions 5-3
5.2.3 OtherDevelopment/UseActions 5-3
5.3 PresentActions,IncludingProposedActions 5-7
5.3.1 MiningRelatedActions 5-7
5.3.2 UtilitiesandCommunityActions 5-8
5.3.3 OtherDevelopment/UseActions 5-9
5.4 ReasonablyForeseeableFutureActions 5-10
5.4.1 MiningRelatedActions 5-10
5.4.2 UtilitiesandCommunityActions 5-12
5.4.3 OtherDevelopment/UseActions 5-13
5.5 EvaluationofPotentialProposedActionCumulativeImpactsandMitigation 5-15
5.5.1 GeologyandMineralResources 5-15
5.5.2 WaterResources 5-16
5.5.3 AirResources 5-22
5.5.4 VisualResources 5-23
5.5.5 AuditoryResources 5-25
5.5.6 SocioeconomicValues 5-25
5.5.7 EnvironmentalJusticeEffects 5-27
5.5.8 WildlifeResources 5-28
5.6 NoBackfdlAlternativeImpactAnalysis >. 5-29
5.7 CompleteBackfillAlternativeImpactAnalysis 5-29
5.8 NoActionAlternativeImpactAnalysis 5-29
6 PUBLICCOMMENTSANDRESPONSETOCOMMENTS 6-1
7 CONSULTATION,COORDINATION,ANDLISTOFPREPARERSFORPREPARATION
OFSEIS 7-1
7.1 PublicParticipation 7-1
7.2 SupplementalEnvironmentalImpactStatementPreparation 7-1
7.3 DraftSupplementalEnvironmentalImpactStatementDistribution 7-2
7.4 FinalSupplementalEnvironmentalImpactStatementDistribution 7-2
7.5 ListofPreparers 7-7
7.5.1 BureauofLandManagementEISTeam 7-7
7.5.2 Enviroscientists,Inc.EISTeam 7-8
7.5.3 CooperatingAgencies 7-8
7.5.4 OtherInformationContributors 7-8
8 REFERENCESANDGLOSSARY 8-1
8.1 References 8-1
8.2 Glossary 8-10
9 INDEX 9-1
10660.FinalSEIS.V1.wpd
CortezGoldMines Pipeline/SouthPipelinePitExpansionProject
Final SupplementalEnvironmentalImpactStatement
LISTOFTABLES
TableES-1: SummaryofPotentialEnvironmentalEffects,MitigationMeasures,andResidual
Impacts ES-7
Table1.5.1: SummaryofPermitsandApprovalsRequiredforthePipeline/SouthPipelineProject 1-12
Table2.1.1: SummaryofPlansofOperationsandEnvironmentalAnalysisDocumentsforCortez . .
GoldMinessinceFebruary2000 2-2
Table2.1.2: SummaryofPipeline/SouthPipelineApprovedSurfaceDisturbance 2-3
Table2.6.1: ApprovedMobileEquipment 2-18
Table3.1.1: SummaryofApprovedandProposedSurfaceDisturbance 3-2
Table3.1.2: PlannedMobileEquipment 3-14
Table4.3.1: EstimatedAverageAnnualWaterBudgetfor2001 4-47
Table4.3.2: WellsandWaterRightswithinFiveMilesoftheProjectArea 4-78
Table4.3.3: SummaryofConsumptiveWaterLosses 100YearsAfterMining 4-96
Table4.4.1: SummaryofProjectAlluvialGroundWaterChemistry 4-181
Table4.4.2: SummaryofProjectBedrockGroundWaterChemistry 4-182
Table4.4.3: StandardsforToxicMaterialsApplicabletoDesignatedWaters 4-186
Table4.4.4: ComparisonofMaturePitLakeChemistry 100YearsafterMiningtoWaterQuality
Standards 4-207
Table4.5.1: FederalandStateAmbientAirQualityStandardsforCriteriaPollutants 4-223
TTaabbllee44..55..23:: AAnmnbuiaelntAvPeMra10gMeoPniMto10rMionngiDtaotrainfgrDoamtSaitfero1Am,SSiittee1IAB,,Saitned1SBi,tea2ndASite2Aforthe 4-231
Years 1997to2001 4-232
Table4.5.4: AirPollutantsandApplicableAveragingTimesfortheAirQualityModeling 4-241
Table4.5.5: BackgroundValuesforCriteriaPollutants 4-243
Table4.5.6: ListofSourcesAnalyzedfortheSouthPipelineProject 4-244
Table4.5.7: HighestModeledAirPollutantConcentrationsfromtheProposedActionatReceptor
PointsAccessibletothePublic 4-254
Table4.5.8: HighestModeledAirPollutantConcentrationImpactsfromtheProposedActionatthe
DefinedSensitiveReceptors 4-255
Table4.5.9: HighestModeledAirPollutantConcentrationsfromtheNoBackfillAlternativeat
ReceptorPointsAccessibletothePublic 4-261
Table4.5.10: HighestModeledAirPollutantConcentrationImpactsfromtheNoBackfillAlternative
attheDefinedSensitiveReceptors 4-262
Table4.5.11: HighestModeledAirPollutantConcentrationsfromtheNoActionAlternativeat
ReceptorPointsAccessibletothePublic 4-263
Table4.5.12: HighestModeledAirPollutantConcentrationImpactsfromtheNoActionAlternative
attheDefinedSensitiveReceptors 4-264
Table4.6.1: BLMVisualResourceManagementClasses 4-265
Table4.7.1: RelativeScaleofVariousNoiseSources 4-274
Table4.7.2: AverageSoundLevelsforEquipmentandMineOperations 4-276
Table4.8.1: Actual,Present,and ProjectedPopulationsoftheStudyAreaandStateofNevada .... 4-284
Table4.8.2: 2000AgeDistributionofStudyAreaandStateofNevadaPopulations 4-285
Table4.8.3: 2000EthnicCompositionofStudyAreaandStateofNevadaPopulation 4-286
Table4.8.4: 1999IncomeLeveloftheStudyAreaComparedwiththeStateofNevadaBasedon
aSample 4-288
Table4.8.5: PersonsBelowPovertyLevelbyRaceintheStudyAreaComparedwiththeStateof
Nevada(1989) 4-289
Table4.8.6: EmploymentbyIndustryinStudyAreaCounties,September2000toSeptember
2001 4-290
.
Table4.8.7: TopEmployersbyNumberofEmployeesforElko,EurekaandLanderCounties 4-291
Table4.8.8: LaborForceStatisticsfortheStudyAreaComparedwiththeStateofNevada 4-293
Table4.8.9: HousingCharacteristicsoftheStudyAreaandStateofNevada,2000 4-294
Table4.8.10: EmergencyServicesServingStudyAreaCountiesandCommunities 4-299
Table4.8.11: Enrollment,CapacityandTeachingStaffforSchoolsintheElkoCountySchool
District 4-305
vi 1066O.FinalSEIS.Vl.wpd
TableofContents
Table4.8.12: HistoricStudentEnrollmentandTeachingStaffLevelsinStudyAreaSchool
Districts 4-305
Table4.8.13: Enrollment,CapacityandTeachingStaffforSchoolsintheEurekaCountySchool
District 4-306
Table4.8.14: Enrollment,CapacityandTeachingStaffforSchoolsintheLanderCountySchool
District 4-307
Table4.8.15: RevenuesandExpendituresinStudyAreaCounties,1999and2000(indollars) 4-310
Table4.8.16: AssessedValuationandTaxRevenueDistributionofNetProceedsofMineralsby
StudyAreaCounty 4-311
Table4.8.17: MiningPropertyValuationasaPercentageofTotal PropertyintheStudyArea
Counties 4-311
Table4.12.1: IrreversibleandIrretrievableCommitmentofResourcesbytheProposedAction 4-332
Table5.1.1: SummaryofActivitiesThatMayCumulativelyAffectResources 5-4
Table5.1.2: SurfaceDisturbanceAssociatedwithProjectswithintheCumulativeEffectsStudy
Area 5-5
vii 1066O.rinalSEIS.Vl.wpd
CortezGoldMines Pipeline/SouthPipelinePitExpansionProject
Final SupplementalEnvironmentalImpactStatement
LISTOFFIGURES
Figure1.1.1: GeneralLocationMap 1-3
Figure1.1.2: ProjectAreaMap 1-5
Figure2.2.1: ProjectAreaFacilitiesMap 2-5
Figure2.3.1: SubsidenceManagementComponentsMap 2-7
Figure2.3.2: PreliminaryZoningofEarthFissureRisk 2-11
Figure3.1.1: Stage8PlanViewPipeline/SouthPipelineOpenPit 3-5
Figure3.1.2: Stage8CrossSectionAtoA’throughPipeline/SouthPipelineOpenPit 3-5
Figure3.1.4 Stage9PlanViewPipeline/SouthPipelineOpenPit 3-6
Figure3.1.5: Stage9CrossSectionAtoA’throughPipeline/SouthPipelineOpenPit 3-6
Figure3.1.3: Stages8and9PlanViewofOpenPitWestRimRevision 3-7
Figure3.1.6: Stage10PlanViewPipeline/SouthPipelineOpenPit 3-9
Figure3.1.7: Stage10CrossSectionAtoA’throughPipeline/South PipelineOpenPit 3-9
Figure3.1.8: Stage11 PlanViewPipeline/SouthPipelineOpenPit 3-10
Figure3.1.9: Stage11 CrossSectionAtoA’throughPipeline/South PipelineOpen Pit 3-10
Figure3.1.10: Stage12PlanViewPipeline/SouthPipelineBackfdledPitandtheGapOpenPit 3-11
Figure3.1.11: Stage12CrossSectionAtoA’throughPipeline/SouthPipelineBackfdledPitandthe
GapOpenPit 3-11
Figure3.2.1: NoActionAlternative 3-17
Figure3.2.2: CompleteBackfdlAlternative 3-18
Figure3.2.3: NoBackfillAlternative 3-19
Figure4.2.1: GeologyofCrescentValley,Nevada 4-3
Figure4.2.2: GeneralizedStratigraphicColumn 4-5
Figure4.2.3: CrescentValleyBedrockElevationMap 4-7
Figure4.2.4: GeneralizedGeologyandGeometryoftheGoldAcresWindow 4-11
Figure4.2.5: SimplifiedGeologicMapofSouthernCrescentValley 4-13
Figure4.3.1: PhysiographicandHydrographicFeaturesofCrescentValley 4-23
Figure4.3.2: AverageMonthlyandAnnualPrecipitationandPanEvaporation 4-25
Figure4.3.3: RegionalWellLocationsandGroundWaterElevationsPriortoPipelineMine
Dewatering 4-31
Figure4.3.4: Pipeline/SouthPipelineProjectAreaGeneralizedGroundWaterElevations,
February2002 4-33
Figure4.3.5: WeeklyAverageCombinedPumpingRate(gpm) 4-35
Figure4.3.6: AeromagneticMapShowingStocksandPlutonsinCrescentValley 4-41
Figure4.3.7: DistributionofPhreatophytesinCrescentValley 4-43
Figure4.3.8: PRISMPrecipitationContoursforCrescentValley 4-49
Figure4.3.9: InfiltrationBasinLocationMap 4-53
Figure4.3.10: InfiltrationBasinLocationMap-HighwayArea 4-55
Figure4.3.11: WaterLevelsattheHighwayInfiltrationSite 4-57
Figure4.3.12: InfiltrationBasinLocationMap-FilippiniArea 4-59
Figure4.3.13: WaterLevelsattheFilippiniInfiltrationSite 4-61
Figure4.3.14: InfiltrationBasinLocationMap-RockyPassArea 4-65
Figure4.3.15: WaterLevelsattheRockyPassInfiltrationSite 4-67
Figure4.3.16: InfiltrationBasinLocationMap-FromeArea 4-69
Figure4.3.17: WaterLevelsattheFromeInfiltrationSite 4-71
Figure4.3.18: InfiltrationBasinLocationMap-WindmillArea 4-73
Figure4.3.19: SimulatedWaterTableatEndofMining,Stages 11 and 12 4-83
Figure4.3.20: IsoplethsofWaterTableDrawdowninBasinFillDepositsatEndofMining,Proposed
ActionStages11 and 12 4-85
Figure4.3.21: WaterTableDrawdowninBasinFillDepositsinSouthernCrescentValleyatEndof
Mining,ProposedActionStages11 and 12 4-87
Figure4.3.22: WaterTableDrawdowninBasinFillDepositsinSouthernCrescentValleyat
TimeofMaximumDrawdownExtent,ProposedActionStage12 4-89
Figure4.3.23: WaterTableDrawdowninBasinFillDepositsinSouthernCrescentValleyat
TimeofMaximumDrawdownExtent,ProposedActionStage11 4-91
viii 1066O.ProofFinalSEIS.V1.wpd