IMPERIAL PROJECT
DRAFT ENVIRONMENTAL IMPACT STATEMENT/
ENVIRONMENTAL IMPACT REPORT
VOLUME I
SUMMARY
PURPOSE OF THIS DOCUMENT
This Draft Environmental Impact Statement (EIS)/Environmental Impact
Report (EIR) has been jointly prepared by the U.S. Bureau of Land Management
(BLM), which is the Lead Agency with respect
to compliance with the National Environmental Policy Act (NEPA) and its
implementing regulations, and the Imperial County Planning/Building Department
(ICPBD), which is the Lead Agency responsible for compliance with the California
Environmental Quality Act (CEQA) and its applicable regulations, to analyze
the environmental effects of the Proposed Action, which consists of the
Imperial Project, an open-pit, heap-leach, precious metal mine proposed
by Glamis Imperial Corporation, and the "overbuilding" of an existing
utility electrical transmission line to deliver the necessary electrical
power to the Imperial Project.
This Draft EIS/EIR has been revised from, and either replaces, pursuant
to NEPA, or is a recirculation of, pursuant to CEQA, the November 1,
1996 Draft EIS/EIR for the Imperial Project. Since November, 1996, substantial
revisions have been made in the Proposed Action by the Applicant. Additional
environmental field data have also been collected under the direction of
the Lead Agencies, and additional analyses and assessments of the environmental
effects of the Proposed Action have been conducted.
The purpose of this joint EIS/EIR is to inform decision-makers in all agencies
required to approve authorizing actions and the public generally regarding:
the anticipated significant environmental effects of the Proposed Action;
the possible ways to mitigate these significant effects of the Proposed
Action; and reasonable alternatives which could feasibly reduce those identified
significant environmental impacts of the Proposed Action to below the level
of significance. The information in an EIS or EIR does not control an agency's
discretion on a project. However, under CEQA, the state or local agency
must adopt feasible mitigation measures or alternatives within its jurisdiction
if they would avoid significant environmental effects identified for the
Proposed Action. This EIS/EIR also provides, in Table S.1,
the identified areas of controversy and the issues to be resolved.
This Draft EIS/EIR has been prepared as two (2) separate volumes, which
together comprise the entire document. Volume I contains the Summary,
the Table of Contents, Chapters 1 through 11, and
Appendix A of the Draft EIS/EIR, the Imperial Project Reclamation Plan
(including several attachments to the Reclamation Plan). Volume II
contains Appendices B through O of the Draft EIS/EIR. Both Volumes
of this Draft EIS/EIR are available for public review at the BLM's
El Centro Resource Area Office, the Imperial County Planning/Building Department,
and the libraries listed in the front of this volume of the Draft EIS/EIR.
PROPOSED ACTION
Glamis Imperial Corporation (Glamis Imperial) has proposed the development
of the Imperial Project (Project), an open-pit, heap-leach, precious metal
mine and processing facility located in eastern Imperial County, California,
approximately 45 miles northeast of El Centro, California and 20 miles
northwest of Yuma, Arizona (Figure S.1). The Project mine and
associated processing facilities would be constructed on unpatented mining
claims located on public lands administered by the U.S. Bureau of Land Management
(BLM), El Centro Resource Area Office, of the
California Desert District, which are located within portions of Sections 31,
32 and 33, Township 13 South, Range 21 East, and Sections 4,
5, 6, 7, and 8, Township 14 South, Range 21 East, San Bernardino
Baseline & Meridian (SBB&M) (Figure S.2). The Project would
be located south of State Route 78 and north of Interstate Highway
8, and would be accessed via Ogilby Road, a secondary paved road, and Indian
Pass Road, a County-maintained dirt road. Some light-weight vehicles could
occasionally access the Project area via BLM
Route A278, Hyduke Road.
The Project area consists of a Project mine and process area and a Project
ancillary area. The 1,571-acre Project mine and process area would be completely
fenced and contain three (3) open pits, two (2) waste rock stockpiles,
two (2) soil stockpiles, five (5) drainage diversion channels,
an administration office and maintenance shop facility area, a heap leach
facility (consisting of a heap leach pad and process ponds), a precious
metal recovery plant, an electric substation and emergency generator, and
internal haul and maintenance roads and electrical distribution lines. These
facilities would result in approximately 1,302 acres of surface disturbance
(Figure S.3).
The Project ancillary area (Figure S.2) would include up to four (4)
ground water production wells, a buried water pipeline, a new 92 kV/13.2 kV
transmission line, and relocated portions of Indian Pass Road; these facilities,
of which only the water wells would be fenced, would result in approximately
38-acres of surface disturbance.
The Proposed Action would consist of the Project activities described above,
together with the overbuilding of an existing 34.5 kV utility electric
transmission line, which is necessary to transmit the electrical energy
necessary for the Project. The existing 34.5 kV transmission line would
be overbuilt with a 92 kV transmission line in an area called the overbuilt
92 kV/34.5 kV transmission line corridor. This overbuilt 92 kV/34.5 kV
transmission line corridor begins immediately south of Interstate Highway 8
at Sidewinder Road, and continues approximately sixteen (16) miles
to its intersection with Indian Pass Road (Figure S.2). Overbuilding
the existing 34.5 kV electric transmission line would result in approximately
22 acres of surface disturbance.
Up to 150 million tons of ore would be mined and deposited on the
leach pad where the precious metals would be leached. Up to 300 million
tons of waste rock would be mined and deposited in the waste rock stockpiles
or the mined-out portions of two (2) of the open pits. Mining activities
would be performed 24 hours per day, seven (7) days per week.
The daily mining rate would typically be 130,000 tons per day, and
range between zero (0) and 200,000 tons per day. The mine would
commence operation in 1998, after the acquisition of all required approvals.
Operations would terminate in approximately the year 2017, although reclamation
activities may continue beyond that date.
Mining of the three (3) pits would be phased, and would each include
drilling, blasting, loading and hauling. Ore would be hauled, without crushing,
to the heap leach pad to be leached of the precious metals with a dilute
process solution containing sodium cyanide. The heap leach pad would be
lined with synthetic materials as an engineered, zero-discharge facility
with leak detection systems, in conformance with the requirements of the
California Regional Water Quality Control Board, Colorado River Basin Region.
The leached precious metals would be recovered from the dilute cyanide process
solution in the process plant, and shipped off-site as gold doré
for further processing. Waste rock would be placed on either the two (2)
waste rock stockpiles, located adjacent to the pits, or into one (1)
of two (2) of the previously mined-out open pits. The West Pit would
be the first pit mined, followed by the Singer Pit, followed by the East
Pit (Figure S.3); both the West Pit and the Singer Pit and would
be entirely backfilled with waste rock under the Proposed Action.
Up to four (4) ground water production wells would be drilled and completed
to provide the Project average water requirements of approximately 1,200 acre
feet per year (afy). These wells would be
drilled in a 1.5-mile section of the Project ancillary area known as the
ground water well field area (Figure S.2). The produced ground
water would be pumped to the Project mine and process area via a buried
pipeline.
Peak Project electrical power demand of up to eight (8) MW would
be provided from the utility grid. This would require the overbuilding of
an existing Imperial Irrigation District (IID) 34.5 kV transmission
line for approximately sixteen (16) miles from Interstate Highway 8
near Sidewinder Road to Indian Pass Road near Ogilby Road (Figure S.2),
to create an overbuilt 92 kV/34.5 kV transmission line, also owned
by the IID. At that point, the IID would construct a new 92 kV transmission
line, within the Project ancillary area adjacent to Indian Pass Road, for
approximately 3.7 miles to a mine substation built within the Project
mine and process area. A new 13.2 kV distribution line would also be
underbuilt on the same transmission line poles as the new 92 kV transmission
line from the Project mine and process area to provide power to the Project
ground water well pumps located in the ground water well field area along
Indian Pass Road. A 750 kW" diesel-powered emergency electric
generator would be located in the Project mine and process area.
An approximately 6,000-foot section of Indian Pass Road would be realigned
approximately 1,000 feet to the west of the Project mine and process
area to allow for the safe passage of traffic during the mining of the West
Pit (Figure S.3), and the intersection of Indian Pass Road with
Ogilby Road would be slightly realigned. The relocated portion of Indian
Pass Road would be returned to approximately its original location once
the West Pit had been backfilled. Several ephemeral drainage channels located
within the Project mine and process area would be permanently diverted around
Project pits within the Project mine and process area (Figure S.3),
although all diversions would return the diverted water to the same major
ephemeral drainage system, still within the Project mine and process area.
As many as 300 workers may be required to construct the Project facilities,
although only a small number of these workers would be working on the Project
or the overbuilt 92 kV/34.5 kV transmission line at any given
time. Approximately 120 full-time workers would be employed to operate the
Project, most working in shifts (about 64 would work on any given day).
Project traffic on Ogilby Road and Indian Pass Road is estimated at approximately
47 light-weight vehicle round trips, and 3.5 heavy truck round
trips, per day. The Project would spend approximately $48 million for initial
capital items, $1.7 million per year in continuing capital expenditures,
and spend $26 million per year in non-capital expenditures including
payroll. The Project would pay sales taxes on expenditures and pay local
property taxes on the assessed valuation of the resources and assets.
Reclamation activities would be conducted by Glamis Imperial in accordance
with the California Surface Mining and Reclamation Act of 1975 (SMARA) and
the federal regulations found at 43 CFR 3809.1-3(d) and 14 CCR 3500.
The proposed Reclamation Plan includes measures for: protecting wildlife
and the public; minimizing erosion and mass failure potential; demolishing
and removing structures; neutralizing process components; regrading the
waste rock stockpiles and heap; revegetating areas of surface disturbance;
and, where feasible, providing for the resumption of pre-mining land uses.
Figure S.4 shows the projected final contours of the principal
features within the Project mine and process area (South Waste Rock Stockpile,
East Waste Rock Stockpile, heap, backfilled West Pit and Singer Pit, and
open East Pit) after the completion of final reclamation.
Glamis Imperial Corporation, a Nevada Corporation, is a wholly owned subsidiary
of Glamis Gold, Inc., also a Nevada Corporation. Glamis Gold, Inc. is a
wholly owned subsidiary of Glamis Gold Ltd., a corporation incorporated
under the laws of the Province of British Columbia, Canada, which is a publicly
traded company on the New York and Toronto Stock Exchanges. Glamis Imperial
Corporation has two (2) sister companies operating gold mines in the
United States. They are Chemgold, Inc., which operates the Picacho Mine
in Imperial County, California, and Rand Mining Company, which operates
the Rand Mine in Kern County, California.
WEST PIT ALTERNATIVE
The West Pit Alternative would mine only the West Pit and the Singer
Pit, and would produce an estimated 150 million tons of mined material.
The West Pit Alternative would eliminate the East Pit, the East Waste Rock
Stockpile, and the East Pit West and East Pit East drainage diversions within
the Project mine and process area. In addition, the size of the leach pad,
the process area, and the haul and maintenance roads would also be reduced
from those within the Project mine and process area, and no more than two (2)
ground water production wells would be required. All of the other components
of the Proposed Action would still be required and would be constructed
and operated as under the Proposed Action. Figure S.5 provides
a general layout of the facilities within the West Pit Alternative project
mine and process area. The total area of surface disturbance within the
West Pit Alternative project mine and process area would be 795 acres,
reduced from the 1,302 acres disturbed under the Proposed Action. Surface
disturbance within the Project ancillary area would be reduced from 38 acres
to 36 acres, and surface disturbance within the overbuilt 92 kV/34.5 kV
transmission line corridor would be unchanged at 22 acres.
Only a small portion of the West Pit would be backfilled with waste rock
from mining of the Singer Pit, and the Singer Pit would not be backfilled,
since the East Pit would not be mined under the West Pit Alternative (see
Figure S.6). Both the South Waste Rock Stockpile and the heap
would be constructed to approximately the same height as under the Proposed
Action.
Mining and processing rates for the West Pit Alternative are assumed to
be the same as those for the Proposed Action, and initial capital costs,
and ongoing capital and operating costs, would also be similar. However,
Project life for the West Pit Alternative would be approximately ten (10)
years, reduced from the approximately twenty (20) years under the Proposed
Action, although final reclamation may continue beyond ten (10) years.
Following the completion of mining, the West Pit Alternative assumes that
all of the same reclamation methods which are to be applied for the Proposed
Action would be undertaken and completed for the West Pit Alternative. Indian
Pass Road would be returned to a location east of and approximately parallel
to the diverted West Pit West Diversion channel, and the assessment of the
probability of the formation of a pit lake after mining would also be conducted
on the West Pit after the completion of mining.
EAST PIT ALTERNATIVE
The East Pit Alternative would mine only the East Pit and the Singer
Pit, and would produce an estimated 300 million tons of mined material.
The East Pit Alternative would eliminate the West Pit, the West Soil Stockpile,
the West Pit West and West Pit East drainage diversions, and the relocation
of Indian Pass Road within the Project mine and process area. In addition,
the size of the leach pad, the South Waste Rock Stockpile, the associated
areas of disturbance, and the haul and maintenance roads would be reduced
from those within the Project mine and process area, and no more than three (3)
ground water production wells would be required. All of the other components
of the Proposed Action would still be required and would be constructed
and operated as under the Proposed Action. Figure S.7 provides
a general layout of the facilities within the East Pit Alternative project
mine and process area. The total area of surface disturbance within the
East Pit Alternative project mine and process area would be 1,126 acres,
reduced from the 1,302 acres disturbed under the Proposed Action. Surface
disturbance within the Project ancillary area would be reduced from 38 acres
to 31 acres, and surface disturbance within the overbuilt 92 kV/34.5 kV
transmission line corridor would be unchanged at 22 acres.
Under the East Pit Alternative, the Singer Pit would be completely backfilled,
and the East Pit would not be backfilled (see Figure S.8). The
South Waste Rock Stockpile and the East Waste Rock Stockpile would still
be constructed to approximately the same height (300 feet) as under
the Proposed Action, but the heap would be constructed to a height of approximately
250 feet.
Mining and processing rates for the East Pit Alternative are assumed to
be the same as those for the Proposed Action, and initial capital costs,
and ongoing capital and operating costs, would also be similar. However,
Project life for the East Pit Alternative would be approximately fourteen (14)
years, reduced from the approximately twenty (20) years under the Proposed
Action. Final reclamation may continue beyond fourteen (14) years.
Following the completion of mining, the East Pit Alternative assumes that
all of the same reclamation methods which are to be applied for the Proposed
Action would be undertaken and completed for the West Pit Alternative. However,
Indian Pass Road would not need to be returned to approximately its original
location since it was not relocated.
COMPLETE PIT BACKFILL
ALTERNATIVE
The Complete Pit Backfill Alternative consists of the complete filling
of all of the open pits with mined material to at least original grade.
After the completion of mining (as described under the Proposed Action),
waste rock would be loaded back into the haul trucks, which would be driven
to the edge of the open East Pit and the waste rock dumped into the pit.
It would require up to approximately 4.33 years (4 years, 4 months)
to move enough waste rock back into the open East Pit to fill it to grade
once mining was complete, and cost up to approximately $100 million.
Because broken rock occupies a greater volume than the same volume of solid
rock, all of the rock mined from an open pit would not fit back into that
same pit. All of waste rock would backfill
all of the pits, and the spent leached ore would remain where originally
placed. The Complete Pit Backfill Alternative would not result in any reduction
of surface disturbance compared to the Proposed Action since the Complete
Pit Backfill Alternative includes completion of the Proposed Action. However,
all of the surface area disturbed by waste rock stockpiles and the East
Pit would be reclaimed "at grade," and not reclaimed as a stockpile
or pit, since the waste rock contents of the stockpile would have been removed
and dumped into the open pits (see Figure S.9).
NO ACTION ALTERNATIVE
If the No Action (no project) Alternative is implemented, the Project
area would remain as is, and present uses in the area, including opportunities
for dispersed recreational activities, would continue. The Project area
would remain available for future commercial gold processing proposals or
for other proposals as permitted by BLM policy
or land use designations.
ENVIRONMENTAL CONSEQUENCES,
MITIGATION MEASURES, AND SIGNIFICANCE
The environmental consequences of, mitigation measures for, and level
of significance of the environmental consequences before and after mitigation
for the Proposed Action and each Alternative identified in this EIS/EIR
are summarized in Table S.1. Detailed discussions
of the environmental consequences of, mitigation measures for, and significance
before and after mitigation of, the Proposed Action and each of the Alternatives,
are provided in Chapter 4 of this EIS/EIR.
|
