Environmental assessment [of] a proposal by Cominco American Resources, Inc. for a garnet placer mine near Alder, Montana

48 Pages·1992·0.91 MB·English

by  Cominco American Resources, Inc

s
622.2927
LJpcar
1992
DEPARTMENTOFSTATELANDS
STANSTEPHENS,GOVERNOR CAPITOLSTATION
STATE OF MONTANA1
[phone] June18, 1992 HELENA,MONTANA59620
DearReader:
EnclosedforyourreviewisanEnvironmentalAssessment(EA)preparedbythe
DepartmentofStateLands(DSL). ThisEAevaluatesaproposalbyComincoAmerican
PubliccommentonthisEAwillbereceivedbytheagenciesuntil5:00p.m.July6,
1992. CommentsshouldbeabouttheadequacyoftheEAinassessingissues,new
informationnotconsideredthatmayinfluencetheanalysis,andclarification. Comments
shouldbespecific. TheDSLwillusethesecomments,theEA,andtheapplicationtomake
afinaldecisiononthepermit. Thedecisionmaybetoapprovetheproposal,ortodenythe
proposal.
Apublicmeetinghasnotbeenscheduledforthisproject. Writtencommentsshould
besentto:
BobWinegar
HardRockBureau
MontanaDepartmentofStateLands
CapitolStation
Helena,MT59620
Thankyouforyourtimeandconsideration. PleasecallDepartmentofStateLands
(444-2074)ifyouhaveanyquestions.
Sincerely,
7/ SWTPDOCUMENTSCOLLECTION
RobertC.Winegar JUL211992
EnvironmentalProgramSupervisor ""1™*SWELIBRA*
HardRockBureau
ReclamationDivision
JG/ns
Enclosure PLEASE RETUR
f
ANEQUALOPPORTUNITYEMPLOYER"

ENVIRONMENTALASSESSMENT
APPLICANT: ComincoAmericanResources.Inc.
TYPEOFOPERATION: Placerminingandgravityseparationofgarnetsforabrasive
LOCATION: Sections4.9.and 10.T6S.R4W COUNTY: Madison
PERSONPREPARINGE.A.: JoeGurrieriandRobertWineoar
APPLICATIONCOMPLETE: Mav20.1992 E.A.COMPLETE: June18.1992
Date Date
POTENTIALIMPACTS
AFFECTEDENVIRONMENT A B C LONG SHORT AMPLIFICATION
TERM TERM
PHYSICALENVIRONMENT
1. TOPOGRAPHY X X X
2. GEOLOGY:Stabilitv X
3. SOILS;Qualitv.Distribution X X X
4. WATER: Quality;Quantity; X X X
Distribution
5. AIR;Quality X
6. UNIQUE.ENDANGERED.FRA- X X X
GILE,orLIMITED
environmentalresources
BIOLOGICALENVIRONMENT
1. TAEQRURAETSITCR;IAsLp.eciAeVsIAaNn,dand X X X
habitats
2, VEGETATION;quantity, X X X
quality,species
3. AGRICULTURE;grazing,crops X
production
HUMANENVIRONMENT
1. SOCIAL;structuresandmores X
2. CULTURALunioueness, X
diversity
3. POPULATION:ouantitvand X
diversity
4. HOUSING:guantitvand X X
distribution

POTENTIALIMPACTS
AFFECTEDENVIRONMENT A B C LONG SHORT AMPLIFICATION
TERM TERM
5. HUMANHEALTH&SAFETY X
6. COMMUNITY&PERSONAL X
INCOME
7. EMPLOYMENT;auantitvand X X X
distribution
8. TAXBASE;localandstatetax X
r©v©nuG
9. GOVERNMENTSERVICES: X
demand
10.INDUSTRIAL,COMMERCIAL X
andAGRICULTURALactivities
11.HISTORICALand X X
ARCHAEOLOGICAL
12.AESTHETICS X X
13.ENVIRONMENTALPLANSand X X x
GOALS;localandregional
14.DEMANDSonENVIRON- X
water,airandenergy
15.TRANSPORTATION:networks X
andtrafficflows
PUBLICINVOLVEMENT:PublicNotice(February27-March12.1992) PublicCommentPeriodcloses:July6.1992
ALTERNATIVESCONSIDERED: NoAction.ProposedAction
COMPLIANCESTATUS: NoviolationsinpasthistorywithCominco
RECOMMENDATIONSCONCERNINGPREPARATIONOFANEIS: Notnecessaryatthislevelofdisturbance
OTHERGROUPSORAGENCIESCONTACTEDORWHICHMAYHAVEOVERLAPPINGJURISDICTION:
RPruebsyerVvaaltlieoynCOofnfisceer;vaMtoinotnaDniastrDiectp;arMtomnetnatnaofDHeepaalrthtmaenndtEonfvFiirsohn,mWeinltdallifeSc&iePnacrekss;-StWaatteerHisQtuoarliictyBureau;
ArmyCorpsofEngineers
INDIVIDUALSORGROUPSCONTRIBUTINGTOTHISEA:DepartmentofStateLands
A: SignificantUnavoidableImpacts
B: Insignificantasaresultofconditionedmitigation
C: Insignificantasproposed
Signature

TABLEOFCONTENTS-AMPLIFICATION
BACKGROUND 1
PROPOSEDMININGPLAN 1
PROPOSEDRECLAMATIONPLAN 4
1. GENERALDESCRIPTIONOFRECLAMATION 4
2. RECLAMATIONPROCEDURESANDPLANOBJECTIVES 4
A. MineSite 5
1. BackfillingandContouring 5
B. MainProcessingandSupportFacilities 5
1. FirstYearStrippingStockpile 6
2. OreStockpile 6
3. SettlingPondsandSettlingPondsStockpile 6
4. +6Meshand-100MeshStockpiles 6
5. FineSand(waste)Stockpile 7
6. SoilStockpile 7
7. PlantSiteRecyclePond 7
8. OfficeTrailer 7
9. RepairShop 7
10. EquipmentYard 8
11. 50-TonStorageBinandConveyor 8
12. FuelStorageFacilities 8
C. Roads,Parking,Utilities,andPipelines 8
D. ReestablishmentofSurfaceWaterFeatures 9
1. ReestablishmentofaPortionoftheAlderGulchCreekChannel . 9
2. ReestablishmentofPondsandAssociatedWetland 11
3. DESCRIPTIONOFRECLAIMEDTOPOGRAPHY 13
A. MainProcessingandSupportFacilities 14
4. RECLAMATIONSCHEDULE 14
AMPLIFICATIONOFAFFECTEDENVIRONMENTALFACTORS 16
1. Topography 16
2. Soils 16
3. Water 16
4. UniqueEnvironmentalResources 17
5. Terrestrial,Avian,andAquaticWildlife 17
6. Vegetation 18
7. Housing 18
8. Employment 18
9. Historical 18
10. Aesthetics 19
11. EnvironmentalPlansandGoals 19
ALTERNATIVES 19
GLOSSARY 20

COMINCOAMERICANRESOURCES,INC.
AmplificationofPotentialImpactstothePhysical,
BiologicalandHumanEnvironmentSections
oftheEnvironmentalAssessment
BACKGROUND
AnapplicationforanOperatingPermitwasreceivedbytheDepartmentofState
LandsonFebruary18,1992,fromComincoAmericanResources,Inc. ComincoAmerican
Resources,Inc.isasubsidiaryofComincoResourcesInternational,Ltd.aCanadian
companyheadquarteredinVancouver,B.C. TheprojectisajointventurewithSunwest
AbrasivesCompany.
TheproposedAlderGulchgarnetplacerminewouldbe9mileswestofVirginiaCity,
Montana,inMadisonCounty. TheminingincludesportionsofSections4,9,and 10,T6S,
R4W(Figure 1).
AgenciesinvolvedinthereviewoftheplanorotherpermitsincludetheRubyValley
ConservationDistrict,DepartmentofFish,WildlifeandParks,DepartmentofStateLands,
DepartmentofHealthandEnvironmentalSciences—WaterQualityBureau,andtheArmy
CorpofEngineers.
PROPOSEDMININGPLAN1
Theproposedplanistoextractgarnetsands,tobeusedforabrasives,fromhistoric
placerminingtailingdredgepiles. Lifeofthemineisestimatedtobeapproximately30
years.Byyearsevenoftheminingoperation,miningandprocessingratesareexpectedto
reachfulldesigncapacityandareprojectedtocontinueuntilcompletionofmining.Mining
andprocessingexperiencegainedduringtheearlyyearsoftheminingoperationmayresult
infutureadjustmentstotheminingtechniquesandratetoassuremaximummining
efficiencyandproductrecovery.
Theminingoperationwouldbegininthewesternportionofthetailingpilesnearthe
mainprocessingplantandprogressintothethickerandhigher-gradetailing.Miningwould
beginwiththeinitialexcavationofastartingpond. Excavationoftailingmaterialwould
likelyinvolvetheuseofabackhoe-typeexcavator.Screeningandpre-concentration
facilitieswouldlikelybelocatedalongtheminepondonthebankoppositetheexcavator
toallowamplespacefortemporarymaterialstockpiles.Duringtheseinitialminingyears
(lowerlevelsofproduction),thecontractormayusetrucksfortheshorthaul(about1,000
feet)aroundtheperimeteroftheactiveminepondtothescreensandportablejig(pre-
concentration)facilities.
1ModifiedfromVolume1 -TextandAppendices. ApplicationforanOperatingPermit
andProposed PlanofOperationsAlderGulchMineProject,MadisonCounty,Montana.
ComincoAmericanResourcesIncorporatedwithassistancefromHydrometrics,Inc.1992.
1