[Federal Register Volume 60, Number 205 (Tuesday, October 24, 1995)]
[Notices]
[Pages 54508-54509]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-26295]



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DEPARTMENT OF THE INTERIOR
Bureau of Land Management
[NM-030-7122-03-8546]


Proposed Expansion of the Continental Mine in Grant County, New 
Mexico

AGENCY: Bureau of Land Management (BLM), Interior.

ACTION: Notice of Intent to Prepare an Environmental Impact Statement 
(EIS) and Notice of Scoping Meeting.

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SUMMARY: Pursuant to Section 102(2)(C) of the National Environmental 
Policy Act (NEPA) of 1969, as amended, the BLM, Las Cruces District 
Office, will be directing the preparation of an EIS to be prepared by a 
third party contractor. The EIS will describe the potential impacts of 
Cobre Mining Company's proposed Continental Expansion Project at its 
Continental Mine located approximately 3 miles north of the town of 
Hanover in Grant County, New Mexico. The proposed development would 
occur partially on patented Cobre land and partially on Federal land 
administered by the BLM and the U.S. Forest Service (USFS).
    The public is invited to participate in the planning process. A 
public scoping meeting will be held at the following time and location:

TIME/DATE/LOCATION: 7:00 p.m., November 15, 1995, Grant County 
Courthouse Bldg., Third Floor Conference Room, 201 North Cooper Street, 
Silver City, New Mexico.

DATES: Written comments on the scoping process will be accepted through 
November 27, 1995.

ADDRESSES: Comments should be sent to Chuck O'Donnell, BLM, Las Cruces 
District, 1800 Marquess, Las Cruces, New Mexico 88005.

FOR FURTHER INFORMATION CONTACT: Chuck O'Donnell, BLM Las Cruces 
District Office, at (505) 525-4373.

SUPPLEMENTARY INFORMATION: On April 12, 1995, Cobre Mining Company 
submitted a Plan of Operations (POO) to expand mining activities at the 
Continental Mine. It was determined by the BLM that the preparation of 
an EIS would be required for these operations. A Memorandum of 
Agreement (MOA) between Cobre Mining Company, the BLM, and the USFS 
outlining the responsibilities of each party has been executed.
    Cobre is currently engaged in mining ore using open pit and 
underground mining methods. The primary production metal is copper, 
with the potential for zinc, silver, gold and magnetite recovery as a 
by-product. Ore is crushed and processed via milling on-site. Tailings 
material generated in the milling process is discharged to an on-site 
tailings pond.
    The copper mineralization within the Hanover Mountain deposit is 
predominantly chalcocite, and is economically recoverable by acid heap 
leaching techniques, followed by solvent extraction (SX) and 
electrowinning (EW) to produce cathode copper.
    Development of Hanover Mountain will take place on land owned by 
Cobre, and will eventually extend onto BLM land. Expansion of the 
Continental pit and underground working will occur on or beneath 
property owned by Cobre, and on or beneath land administered by BLM and 
the USFS.
    Proposed activities and facilities for the Continental Expansion 
Project include: open pit mining at Hanover Mountain, expansion of the 
Continental open pit, development of additional underground mining 
operations, ore crushing and conveying, waste rock disposal, heap 
leaching, solvent extraction, electrowinning, ancillary facilities, 
including a truck stop, change rooms, water supply, electrical 
substation and power distribution.
    The Hanover Mountain ore body will be mined using conventional open 
pit mining techniques and equipment. The planned rate of ore mining of 
Hanover Mountain is 10 million tons per year. The primary waste rock 
disposal area for the Continental Expansion Project is located west of 
Hanover Mountain. Waste rock disposal for current mining operations 
occurs on two waste rock dumps located south and east of the current 
Continental Pit. Placement of approximately 88 million tons of waste 
rock is planned on 233 acres, of which 179 acres are administered by 
the BLM. Additional waste rock capacity of a combined 82 million tons 
is planned on Cobre patented land. Waste rock will also be used to 
stabilize leach pad sites, for haul roads and process facilities, and 
to shape and stabilize existing mine waste rock dumps. Ore from the 
proposed Hanover Pit will be delivered to a primary crusher. Crushed 
ore will be stockpiled and reclaimed to a secondary crushing plant. 
Crushing facilities will be located north of the existing office 
facilities on Cobre patented land.
    Ore crushed to nominal one-inch size will be conveyed and stacked 
onto a lined leach pad. A drip emitter or spray irrigation system will 
be placed over the ore pile, and acidic solution will be percolated 
through the ore for 90 to 120 days. A pad liner and drainage pipes will 
collect and drain the solution to a pregnant leach solution (PLS) pond. 
The PLS will be pumped to a SX/EW facility for copper recovery.
    The primary area for leaching will be the Fierro area, with a 
design capacity of approximately 92 million tons. The Fierro leach pad 
will be developed in phases, with the initial phase taking place on 
Cobre property. Later phases of development will expand the 177-acre 
leach pad to include 50 acres of land administered by the BLM. 
Additional leaching capacity of up to 89 million tons may be developed 
south of the existing Continental Pit, which encompasses 67 acres of 
BLM land.
    The SX/EW plant will be located entirely on Cobre patented land on 
the east side of County Road 3-5, north of the Fierro town site.
    As the Hanover Pit expands toward its design limit, it will become 
necessary to re-route drainage from the upper portion of Hanover Creek 
around mining 

[[Page 54509]]
operations. This may be accomplished through either gravity flow or 
pumping through either a pipeline or a relocated stream channel.
    In order to ensure continued access to lands north of the 
Continental Mine, the expansion of the Hanover Pit will also require 
the relocation of County Road 3-5 around mining operations. Surface 
mining operations currently conducted at the Continental Mine produce 
approximately 10,000 tons of ore per day from the Continental Pit. 
Exploratory drilling has indicated that economic ore reserves 
recoverable by open pit mining techniques occur around the perimeter of 
the existing Continental Pit. Based on these results, the existing pit 
is proposed to be expanded. Expansion of the pit will include 
additional land owned by Cobre, and BLM land, and may also include 
approximately 7 acres of USFS land.
    Cobre also currently conducts underground mining activities at the 
Continental Mine site. Between 2,000 and 5,000 tons per day of ore are 
crushed in an underground crushing facility. The crushed ore is 
transported to the surface and is sent to either the #1 Mill by 
conveyor or to the #2 Mill stockpile by truck for processing.
    Due to the nature and depth of mining activities and the rock 
stability in the mining area, no subsidence has occurred, and none is 
expected to occur.
    Reclamation of the site will comply with BLM provisions of an 
approved reclamation plan and plan of operations. It is anticipated 
that the New Mexico Mining Act regulations will also be instrumental 
for ultimate closure requirements. The BLM and the USFS will determine 
``post mining land use'' for the portions of the pit areas, the waste 
rock dumps, and the leach pads located on Federal land.
    The objective of the reclamation plan will be to minimize public 
safety hazards, and to provide for long-term protection of the 
environment and restoration of the site to a condition consistent with 
planned long-term land use. Major components of the reclamation plan 
are anticipated to include: rinsing the leach heaps to remove residual 
copper-bearing solution; recontouring the top surfaces of the leach 
heaps and the waste rock dumps; removal of buildings, equipment and 
foundations; recontouring roads, building sites and other disturbed 
areas; protection of natural stream channels and permanent diversion 
ditches at strategic points to ensure long-term stability; and blocking 
access to the open pits. An evaluation of the stability of proposed 
slopes of the reclaimed open pit, waste rock dump slopes, and heap 
leach slopes will be performed. After initial dewatering and drying, 
the tailings will be re-contoured and capped.
    The EIS will address the resources of geology and minerals, soils, 
water resources, vegetation, wildlife, range management, air quality, 
visual resources, reclamation, land use, access, recreation, 
wilderness, cultural resources, social and economic values, 
transportation and noise. The BLM has identified the following 
potentially significant impacts as requiring additional analysis: 
quality of post-mining surface and ground water generated by the 
Continental and Hanover open pits; potential impacts to surface and 
ground water from acid mine drainage from the mine's waste rock dumps; 
potential impacts to ground water from the mine's tailings impoundment; 
potential impacts of the diversion of Hanover Creek; potential impacts 
of the re-routing of County Road 3-5.
    Because these issues were determined to require special 
investigation, it is anticipated that the majority of work for other 
resources will be limited to summarizing and incorporating by reference 
data and analyses from existing environmental studies as prescribed in 
40 CFR Sec. 1500.4 and Sec. 1500.5. Additional investigation may be 
indicated for other resources after review of existing data and 
comments received during the scoping process.
    BLM's scoping process for the EIS will include: (1) identification 
of issues to be addressed; (2) identification of viable alternatives; 
and (3) notifying interested groups, individuals, and agencies so that 
additional information concerning these issues can be obtained. The 
scoping will consist of a news release announcing the start of the EIS 
process; letters of invitation to participate in the scoping process; 
and a scoping document which further clarifies the proposed action and 
significant issues being considered to be distributed to those on the 
mailing list and available upon request.

    Dated: October 18, 1995.
Linda S. C. Rundell,
District Manager, Las Cruces.
[FR Doc. 95-26295 Filed 10-23-95; 8:45 am]
BILLING CODE 4310-FB-P