Draft environmental impact statement : Newmont Mining Corporation's south operations area project amendment

450 Pages·2000·74.1 MB·English

by  United States. Bureau of Land Management. Elko District

383671 )epartment of the Interior
«rv
Bureau of Land Management
Elko Field Office
Elko, Nevada September 2000
DRAFT
Environmental Impact Statement
Newmont
Mining Corporation's
South Operations Area Project Amendment
MissionStatement
The Bureau ofLand Management is responsiblefor thestewardship ofour public lands.
Itiscommittedtomanage,protect,andimprovetheselandsinamannertoservetheneeds
oftheAmericanpeopleforalltimes. Managementisbasedupontheprinciplesofmultiple
use and sustained yield ofour nation’s resources within a framework ofenvironmental
responsibility and scientific technology. These resources include recreation, rangelands,
timber, minerals, watershed, fish and wildlife, wilderness, air and scenic, scientific, and
cultural values.
BLM/EL/PL-00/015+1793.4
United States Department of the Interior
BUREAU OF LAND MANAGEMENT
Elko FieldOffice
3900 East Idaho Street
Elko, Nevada89801-4611
http://www.nv.blm.gov
InReplyReferTo:
1793.4/3809
N16-81-009P
Dear Reader:
Enclosed for your review and comment is the Draft Environmental Impact Statement (DEIS) for
Newmont Gold Co.’s South Operations Area Project Amendment. The DEIS serves to analyze
the effect ofcontinuing mining and dewatering operations for ten years beyond the current
permit. The South Operations Area Project consists of the Gold Quarry, Mac, and Tusc open pit
gold mine, mill, and dewatering facilities, and is located approximately 6 miles northwest of
Carlin, Nevada.
A separate report entitled Cumulative Impact Analysis of Dewatering and Water Management
Operations for the Betze Project, South Operations Area Project Amendment, and Leeville
Project analyzes the cumulative effects ofdewatering from the three major dewatering projects
on the Carlin Trend. This report is available from the Bureau of Land Management, Elko Field
Office, or on the internet at www.nv.blm.gov/elko.
This DEIS addresses those concerns identified by the BLM or raised during public scoping from
June 16 through July 18, 1997. The BLM, in conjunction with all interested parties, will propose
mitigation measures to address incremental impacts which are over and above what was
addressed in the 1993 South Operations Area Project EIS.
Following the 60 day public review and comment period, a Final EIS will be prepared. It will
include mitigation measures that address both predicted direct impacts from Newmont’s mining
and dewatering operations, as well as for predicted cumulative impacts from the Newmont
dewatering operations in relation to other active and proposed dewatering operations on the
Carlin Trend. These other operations include the Barrick operations at the Betze/Post open pit
mine and Newmont’ proposed Leeville underground mine.
s
Public comments on the DEIS will be accepted during a 60-day comment period ending October
A
31, 2000. public meeting to accept verbal and written comments is scheduled for September
BLM
26, 2000 at 5:00 P.M. at the Elko Field Office. Comments on the DEIS should be
submitted to: Bureau of Land Management, Elko Field Office, Attention: Roger Congdon, EIS
NV
Coordinator, 3900 Idaho St., Elko, 89801.
The Final EIS may be published in an abbreviated format so please retain this draft document for
future reference. Your interest in the management ofpublic lands is appreciated. If you have any
questions, please contact Roger Congdon, EIS coordinator at [phone].
Sincerely,
Helen Hankins
Field Manager
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DRAFT
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ENVIRONMENTAL IMPACT STATEMENT c.x
NEWMONT MINING CORPORATION
SOUTH OPERATIONS AREA PROJECT AMENDMENT
LEAD AGENCY
U.S. Department of the Interior
Bureau of Land Management
Elko Field Office
Elko, Nevada
PROJECT LOCATION
Elko and Eureka Counties, Nevada
COMMENTS ON THIS DRAFT ENVIRONMENTAL
IMPACT STATEMENT (EIS) SHOULD BE DIRECTED TO:
Roger Congdon, Project Lead
Elko Field Office
Bureau of Land Management
3900 East Idaho Street
Elko, NV 89801
DATE DRAFT EIS WAS MADE AVAILABLE
TO THE ENVIRONMENTAL PROTECTION
AGENCY AND THE PUBLIC
September 2000
1
,
DATE BY WHICH COMMENTS SHOULD BE
RECEIVED BY THE BUREAU OF LAND MANAGEMENT
October 31 2000
,
ABSTRACT
The Draft Environmental Impact Statement analyzes impacts associated with a proposal to continue and
expand gold mining operations on the South Operations Area Project site in northeastern Nevada.
Newmont has been mining at this location since 1981, and, in 1993 as a result of the South Operations
Area Project EIS Record of Decision, has implemented an extensive Mitigation Plan which has proven
effective in mitigating potential impacts and in some cases, improving environmental conditions. The
annual progress reportforthe Mitigation Plan is provided as an appendixtothis document. The Proposed
Action includes: (1) additional mining to approximately 350 feet below the currently approved operating
level of the Gold Quarry open pit mine, (2) continuing to dewater the mine and discharge groundwater
(less than 30,000 gallons per minute) directly into Maggie Creek six miles above the confluence with the
Humboldt River, (3) expand waste rock disposalfacilities and leachfacilities, and (4) constructassociated
ancillary facilities. Two alternatives to the Proposed Action are analyzed in the document. The Agency
Preferred Alternative includes Alternative 1 - Proposed Action with Backfilling the Mac pit. Aconsiderable
portion of the Draft Environmental Impact Statement addresses and analyzes impacts associated with
incremental dewatering issues and the resulting expanded cone of depression.
Responsible Official for DEIS:
Manager, Elko Field Office
UNIT CONVERSION TABLE
From To Multiply By
Area
acres square feet 43,560
square miles acres 640
Volume
acre-feet gallons 325,829
gallons cubic feet 7.48
Flow
cubic feet per second (cfs) gallons per minute (gpm) 449
gpm acre-feet per year 1.61
cfs acre-feet per year 724
Concentration
parts per million (ppm) milligrams per liter (mg/L) 1
mg/L micrograms per liter (pg/L) 1000
Loads
tons per day (tpd) tons per year (tpy) 365
tpy pounds per day 5.48
Cover photographs, clockwise from top, left: Maggie Creek; Coyote Creek; oblique aerial view of
Gold Quarry site; and Bighorn sheep on the Ivanhoe mine site. (Bighorn sheep do not occur at the
Gold Quarry site.)
SUMMARY
Newmont Mining Corporation (Newmont) extend the time period during which existing
submitted a Plan of Operations describing impacts would continue.
proposed activities for the South Operations
Area Project Amendment (SOAPA) in March Newmont began mining at the Gold Quarry
1997. The proposal would amend the existing Mine in 1981 under a Plan of Operations (as
PlanofOperationsN16-81-009P. The Bureau amended). In 1992, Newmont filed a Plan of
of Land Management (BLM) reviewed the Operations Amendment with the BLM Elko
AmendmentanddeterminedthattheProposed Resource Area Office proposing to expand
Action hadthe potential to resultin significant mining atthe site (Plan ofOperationsN16-81-
environmental impacts andthatpreparationof 009P). Newmont also changed the name of
an Environmental Impact Statement (EIS) the operation to South Operations Area
would be necessary. Project.
Newmont proposes activities that would Existing operations at the Gold Quarry site
BLM
support continued operation and expansion of were analyzed by the in 1993 (BLM,
BLM
existing gold mining and processing at its 1993). Subsequently, the issued a
South Operations Area Project in Eureka and Record ofDecision approving the project and
ElkoCounties,Nevada; sixmilesnorthwestof requiring the implementation ofan extensive
Carlin. The South Operations Area Project is mitigation plan developed by Newmont and
located on both private lands owned or the BLM (BLM, 1993). That mitigation plan
controlled by Newmont and on public lands contained numerous, specific actions to be
administered by the BLM. taken to mitigate potential impacts to riparian
and wetland areas, springs and seeps, streams
This EIS describes components of, reasonable and rivers, aquatic habitat and fisheries,
alternatives to, and environmental threatened, endangered andcandidate species,
consequences of implementing the SOAPA. livestock grazing, terrestrial wildlife, soils,
Direct, indirect, and cumulative impacts on vegetation, visual resources, and recreation
A
the affected environment have been analyzed and wilderness. major element of the
for the Proposed Action and alternatives. The mitigation plan was the Maggie Creek
impacts described inthis document will be the Watershed Restoration Project and its
basis for a decision regarding the Proposed extensive requirements formonitoring, which
Action or alternatives and selection of are described inthis document. Anothermajor
appropriate mitigation. No distinction has element of the mitigation plan was the
been made between impacts occurring on reclamation and revegetation plan, which is
public versus privatelyowned landthatwould described in Chapter 2.
result from the possible federal authorization.
The SOAPA would not cause any new kinds The BLM recently prepared a Cumulative
ofimpacts(withcertainexceptions)butwould Impact Analysis report (BLM, 2000b) to
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Summary
address potential cumulative dewatering and ofthe open pit would be 139 acres. Mining
discharge impacts associated with Barrick’s for the SOAPA would continue through the
Betze ProjectandNewmonfsproposed South year 2011 and ore processing would continue
Operations Area Project Amendment and through 2016.
Leeville Project. The results of this analysis
are summarized in Chapter 5 ofthis EIS. The DeepeningoftheGoldQuarrypitwouldresult
analysis may result in the implementation of in further mining below the regional
mitigationmeasurestoaddressthe cumulative groundwater table and would require
impacts of the groundwater pumping and installation of additional dewatering wells to
water management operations of these three keep groundwater out of the mine pit.
BLM
mines. The will identify monitoring Dewatering would result in pumping and
programs and mitigation measures in discharging water in excess of Newmont’s
conjunction with the affected parties; water needs at the South Operations Area.
monitoring and mitigation measures will be Newmont proposes to pump water at rates of
specified in the Final EISs for the three less than 30,000 gallons per minute (gpm),
projects. treat the water to State ofNevada standards,
and discharge the waterto Maggie Creeknear
SUMMARY OF THE PROPOSED the mine site. Dewatering activities would
ACTION cease at the conclusion ofopen pit mining in
the year 2011.
The Proposed Action would provide for the
Wasterockgeneratedduringminingwouldbe
expansion ofminingatthe GoldQuarryMine.
disposed at the existing Gold Quarry North
Total incremental disturbance in the South
Waste Rock Disposal Facility, the Gold
Operations Area associatedwith the Proposed
Quarry South Waste Rock Disposal Facility
Action would be 1,392 acres, of which 553
and the James Creek Waste Rock Disposal
acres are private lands and 839 acres are
Facility. Waste rock disposal at the South
public lands. The disturbed area would
Waste Rock Disposal Facility would require
include the mine pit, leach pads, waste rock
an expansion of approximately 235 acres.
disposal facilities, haul roads, and ancillary
Waste rock placed on the North Waste Rock
mine facilities associated with the Proposed
Disposal Facilitywoulddisturb approximately
Action. These areas compare with the South
439 acres. The James Creek Waste Rock
Operations Area Project analysis of 2,047
DisposalFacilitywoulddisturbapproximately
acres of public land, 5,913 acres of private
255 acres. The total waste rockproduction for
land, and a total surface disturbance of7,960
the amendment would be 408 million tons.
acres.
These acreages represent an approximate 50
percent increase in the area ofexisting waste
Mining and processing operations would
rock disposal facilities.
result in recovery ofoxide and sulfide ores by
deepening the existing Gold Quarry pit
Combined oreproduction forthe expandedpit
approximately 350 feet. Incremental is expected to be about 118 million tons. Of
disturbance area associatedwith development
this amount, approximately 57 million tons
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Summary
would be oxide and mill-grade sulfide ore. 2 including process and stormwater ponds
The remaining 61 million tons would be low- would disturb 163 acres of public lands and
grade sulfide ore. would contain approximately46 million tons.
The proposed open pit expansion would Newmont proposes to construct an expansion
require relocating 30 million tons of tailing to the Refractory Leach Facility to provide an
from the James Creek tailing facility to the ammonium thiosulfate leach pad for heap
Mill 5/6 tailing facility. The tailing would be leaching the carbonaceous sulfidic refractory
moved by dredging and surface mining ore in lifts without removing it from the pad.
techniques. This represents the removal of This proposed Refractory Leach Facility
186 surface acres ofold tailing. expansion would disturb an additional 108
acres ofpublic land and 219 acres ofprivate
The existing oxide leach facilities inthe South land.
Operations Area would be expanded to
accommodate the low grade oxide and Tailinggeneratedbythe ore processingwould
biooxidized sulfidic refractory ore from the continue to be disposed at the existing Mill
proposed Gold Quarry pit expansion. The 5/6 tailing facility. No additional acreage
South Area Leach facility expansion would would be disturbed for expansion of the
consist ofa southern extension ofthe existing tailing storage facility.
Non-Property Leach Pad and construction of
the Property Leach Pad 2. The leach pads Proposed reclamation activities at the South
would continue to be stacked in lifts to a Operations Areawould include neutralization
maximum height of 300 feet. Process and ofprocess solutions, regrading ofdisturbance
stormwaterponds wouldbe constructeddown areas, replacement of topsoil, and seeding,
gradient of the proposed leach pads. The fertilizing, andmulching. The mine pit would
proposed leach pads would share the same not be reclaimed; however, the pit would be
process and stormwater ponds. All ponds fenced or bermed.
would be fenced in compliance with Nevada
(NDOW) PROJECT ALTERNATIVES
Division ofWildlife specifications.
Changesto leachingoperationswouldinvolve
the addition of approximately 487 acres, or Alternatives identified in this EIS were
about 40 percent more leaching area.
developed in response to issues raised during
BLM
public scoping and review of the
The Non-Property Leach Pad would be
Proposed Action. Alternatives selected for
expanded along its existing southern edge and detailed review in the EIS were based on one
would disturb 1 82 acres ofpublic lands. The primary issue related to potential impacts
expansion would buttress against the existing
resulting from the Proposed Action. This
Non-PropertyLeachPad andwouldultimately issue is feasibility of backfilling open mine
contain approximately 245 million tons. The pits to be consistent with Nevada
Property Leach Pad 2 would be operated
Administrative Code (519A.250) concerning
independently from the existing Property
solid minerals reclamation standards and
Leach Pad. The proposed PropertyLeach Pad
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Summary
policystatements outlinedinthe Federal Land Mine would not expand beyond the currently
Policy Management Act (PL 94-579, 43 USC approved Plan ofOperations.
1701).
SUMMARY OF IMPACTS
Two alternatives were developed to address
this issue. In addition, the No Action
Detailed analysis of potential impacts and
Alternative was also carried through analysis.
mitigationmeasures arepresentedinChapters
The alternatives are as follows.
4 and5, Consequences ofthe ProposedAction
and Alternatives and Cumulative Effects
Mac
Alternative 1 - Backfilling the Analysis, respectively. The following is a
Pit summary of potential impacts, by resource,
resulting from implementation of the
This alternative includes backfilling of the Proposed Action and alternatives. Impacts in
Mac open pit with waste rock generated from this EIS address only the incremental effects
the GoldQuarrypitexpansion. Backfillingthe ofthe proposed expansion and do not repeat
Mac pit would reduce the size of the waste the impacts analyzed in the original EIS
rock disposal facilities by six acres. Total (BLM, 1993).
disturbance forthis alternativewouldbe 1,386
PROPOSED ACTION
acres with ,247 acres reclaimed.
1
Alternative 2 - Modified Waste Geology and Minerals
Rock Disposal Facility Design
Newmont’sproposedamendmentwouldmove
This alternative would modify the Gold 526 million tons of waste rock and ore from
Quarry South Waste Rock Disposal Facility the Gold Quarry pit to waste rock disposal
by substituting some ofthe horizontal hauling facilities, leach processing facilities, and a
distance for additional elevation in an attempt tailing storage facility. Relocation of these
to have a smaller “footprint” for the facility rock materials would modify landscape and
A
(50 acres less). smaller footprint would topography of the South Operations Area.
reduce the disturbance associated with a new Several million ounces of gold would be
diversion channel west ofthe disposal facility extracted from the geologic resource.
by three acres. Total disturbance for this
alternative would be 1,339 acres with 1,200 One sinkhole has been documented to-date in
acres reclaimed. the area affected by dewatering at the Gold
A
Quarry mine. sinkhole was discovered in
No Action Alternative July 1996 along Maggie Creek that
temporarily captured the Maggie Creek flow.
Expansion of the SOAPA mining facilities Although development of the sinkhole is
likely related to mine-induced drawdown, the
would not be approved. The Gold Quarry
mechanism for development ofthis sinkhole
is not completely understood. Available
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