Environmental assessment for Cable Mountain Mine, Inc. application for amendment no. 003 to state operating permit no. 00134 operating and reclamation plan

16 Pages·1992·0.29 MB·English

by  Cable Mountain Mine, Inc

s
622.2927
L3eapgf
1992
DEPARTMENTOFSTATELANDS
STANSTEPHENS,GOVERNOR CAPITOLSTATION
STATE OF MONTANA
[phone] HE1L6E2N5AE,LEMVOENNTTAHNAAVES9N6U2E0
July 8, 1992
Dear Reader:
Enclosed for your review is an Environmental Assessment (EA)
parteesparaedprobpyostahle DbyepaCrabtlmeentMouonftaSitnateMinLea,ndsInc(DtSLo)e.xpTahned tEhAeemvianlue-
permit area.
Public comment on this EA will be received by the DSL until
5:00 p.m. July 29, 1992. Comments should be about the adequacy
of the EA in assessing issues, new information not considered
that may influence the analysis, and clarification. Comments
should be specific. The agencies will use these comments and
agency responses, the EA, and the application for amendment to
make a final decision on the permit. The decision may be to
approve the proposal, deny the proposal, or approve the proposal
with modifications.
A public meeting is scheduled for 7:00 p.m. on July 23,
1992, in the Anaconda Deer Lodge County Courthouse. Written and
verbal comments will be accepted. Comments will also be accept-
ed by phone (444 - 2074) or by letter to:
Bob Winegar
Montana Dept. of State Lands
Capitol Station
Helena, MT 59620
Thank you for your time and consideration.
Sincerely,
Robert C. Winegar STATEDOCUMENTSCOLLECTION
Program Supervisor
Hard Rock Bureau
Reclamation Division SEP 41992
MONTANASTATELIBRARV
HEJ.E1N5A1,5MEO-N6TtAhNAAVE5.9620
"ANEQUALOPPORTUNITYEMPLOYER"

ENVIRONMENTALASSESSMENT
APPLICANT: CableMountainMine.Inc.
TYPEOFOPERATION: PlaceGoldMine
LOCATION: Sec. 10, 15,T5N,R13W COUNTY: DeerLodge
PERSONPREPARINGE.A.: WayneJepson.BobWinegar.PeterWerner
APPLICATIONCOMPLETE: June2. 1992 E.A.COMPLETE:
Date Date
POTENTIALIMPACTS
A B C LONG SHORT AMPLIFICATION
TERM TERM
PHYSICALENVIRONMENT
1. TOPOGRAPHY X X SeePage4
2. GEOLOGY:Stability X X SeePage4
3. SOILS:Oualitv.Distribution X X SeePage5
4. WATER: Quality;Quantity; X X SeePage5
Distribution
5. AIR;Quality X X SeePage5
6. UNIOUE.ENDANGERED.FRA- X
GILE.orLIMITEDenvironmental
resources
BIOLOGICALENVIRONMENT
1. TERRESTRIAL,AVIAN,and X
AOUATIC:speciesandhabitats
2. VEGETATION:quantity,quality, X X SeePage5
species
3. AGRICULTURE;grazing,crops X
production
HUMANENVIRONMENT
1. SOCIAL:structuresandmores X
2. CULTURALuniqueness,diversity X
3. POPULATION;quantityand X
diversity
4. HOUSING:quantityand X
distribution
5. HUMANHEALTH&SAFETY
—

POTENTIALIMPACTS
A D C LONG SHORT AMPLIFICATION
TERM TERM
6. COMMUNITY&PERSONAL X
INCOME
I7. EMPLOYMENT;quantityand X
distribution
8. TAXBASE;localandstatetax X
revenue
9. GOVERNMENTSERVICES; X
demand
10.INDUSTRIAL.COMMERCIAL X
andAGRICULTURALactivities
11.HISTORICALand X X SeePage5
ARCHAEOLOGICAL
12.AESTHETICS X
13.ENVIRONMENTALPLANSand X
GOALS:localandregional
14.DEMANDSonENVIRON- X
water,airandenergy
1 15.TRANSPORTATION;networks X
andtrafficflows
PUBLICINVOLVEMENT: PublicReviewofE.A.
ALTERNATIVESCONSIDERED: Seeattacheddiscussiononpage6.
COMPLIANCESTATUS:
RECOMMENDATIONSCONCERNINGPREPARATIONOFANEIS: AnEISisnotnecessaryforthislevelof
OTHERGROUPSORAGENCIESCONTACTEDORWHICHMAYHAVEOVERLAPPINGJURISDICTION:
INDIVIDUALSORGROUPSCONTRIBUTINGTOTHISEA:
A: SignificantUnavoidableImpacts
B: Insignificantasaresultofconditionedmitigation
C: Insignificantasproposed
Signature (J
2

BACKGROUND
AnapplicationforanamendmenttoOperatingPermit00134was
receivedbytheDepartmentofStateLandsonMarch 16, 1992,fromCable
MountainMines, Inc. (CMI). CMIisaCaliforniaCorporationheadquarteredat
5143SunsetBoulevard,LosAngeles,California. Theproposedplacermining
expansionislocatedonprivateland 13mileswestofAnaconda,Montana,
alongtheupperCableCreekdrainage. ThemineareaisinSees. 10and 15,
T5N, R13W(Figure 1).
TheminewaspermittedJuly6, 1988,for93.6permitacresand51.2
acresofdisturbance. Amendment001 (April 18, 1989)reducedthepermitto
54.8acresandaddedamercuryamalgamationcircuit. Amendment002
(August24, 1990)furtherreducedthedisturbanceandpermitto34.8acres.
Thisapplication wouldadd23.5acrestotheexistingpermitacresforatotalof
58.3permitacresand 15acrestodisturbanceforatotalof49.8disturbance
acres.
PROPOSAL
CMIproposestominegoldbearingplacergravelsfromanundisturbedarea
northwestofthepreviouslypermittedarea. Orewouldbeminedfromazone
approximately20-30feetdeep.Theplanofoperationswouldbetorecover
goldbyconventionalgravitymethods;sortingandsizingofgravelsbytrommel
andscreens,andconcentratingbysluiceandjigs.
Accordingtotheexistingpermit,thewashplantcanprocess2000cubic
yardsperday. Thetotalpredictedvolumetobeprocessedovera4yearmine
lifewas800,000cubicyards. Themaximumamountofmaterialexpected
fromtheproposedexpansionareais581,000cubicyards(12acresX30feet
deep). Therefore,thisamendmentcouldpotentiallyextendthelifeofthis
miningprojectbyaboutthreeyears. Theproductionratestatedinthe
applicationis 1,000cubicyardsperdayfortheexpansionarea. Thisarea
wouldbeminedconcurrentlywiththecurrentlypermittedminearea; an
additional 1000cubicyardsperdaywouldcomefromthecurrentmineareato
maintainthewashplantproductionrate.
Miningintheproposedamendmentareawouldproceeduphillfromthe
existingpermitboundary. Gravelwouldbehauledfromthehillsidedowntothe
existingwashplantforprocessing. Thisgravelwouldbecombinedwithgravels
minedfromthecurrentlypermittedminingarea. Coarsematerial (+ 2inch)
wouldbedumpedacrosstheupperendoftheminepitinthelowermining
area,formingadambehindwhichasettling/filtration pondwouldbecreated.
Whenthispondfillswithsedimentandthecoarsebarrierceasestoactasa
filter,anewpondwouldbeconstructeddowngradientoftheoldpond,as

mininginthelowerregionproceedsdownhill. Meanwhile,additionalwashplant
rejectwouldbehauledbackuphilltotheproposedmineareatobackfillthepit
inthatarea. Slurrytransportofrejectmaterialcouldbeincorporatedintothe
mineplanfortheamendmentareaintheinitialstagesofminingwhenthepitis
stillrelativelyclosetotheprocessingplant. Overburdenstockpileswouldbe
limitedto8000Icy,andprocessplantrejectto30,000Icyatanygiventime
regardlessofwhetherminingoccursintheexistingpermitarea,theamendment
area,orboth.
Oreprocessingwouldrequireamaximumof2000gallonsperminute
(gpm)waterthroughput. Waterwouldberecycledbut400gpmmakeupwater
(calculatedbyDSL)wouldberequired. Themakeupwaterwouldbesupplied
byminepitinflowandbyinflowintothesettlingpondsatthewashplant.
Mercuryamalgamationofgoldoreispermittedintheoriginalplan. The
sameproceduresandmonitoring requirementswouldapplytothisamendment.
Employmentandequipmentrequirementswouldremainaspermittedin
theoriginalplan.
RECLAMATION
Overburdenandsoilmaterialwillbestockpilednexttotheminepit. This
overburden,alongwithoverburdenandrejectmaterialfromthewashplantand
lowerminearea,wouldbebackfilledintotheminepitasthepitadvances. The
sizeoftheopenpitwouldbeapproximately200'x70'x30',without-of-hole
overburdenlimitedto8000Icyatanygiventime. Gradingwouldbeconducted
toproducesmalldozerdepressionstocontrolrillingandreducetherunoff
energyoftheslope. Soilwouldthenbereplacedandseededwithagrass
mixture. Slashmaterialswouldbescatteredoverthereclaimedarea.
AMPLIFICATION OFENVIRONMENTAL FACTORS
PhysicalEnvironment
Topography: Thetopographyoftheareawouldbealteredduringthe
operationallifeofthemine. Thisalterationwouldconsistoftheminepit,
topsoilandoverburdenstockpiles,andrejectpile. Alldisturbanceswouldbe
regradedtoapproximateoriginalcontoursduringreclamation.
Geology: Excavation,processing,andbackfilling ofthegravelwillcausesome
swellingofthenaturallycompactedmaterial. Thiswillslowlysettleafter
reclamation. Nostabilityproblemsareanticipatedasaresultofthisprocess.