Castle Mountain Venture (Viceroy Gold Corporation) CASTLE MOUNTAIN MINE SAN BERNARDINO COUNTY, CALIFORNIA
MINE PLAN AND RECLAMATION PLAN Ver.2.1 (90M-013) California Mine ID NO. 91-36-0015
Prepared by: Castle Mountain Venture Castle Mountain Mine 911 American Pacific Drive., Ste. 190 Henderson, NV 89014
January 2, 2019 Castle Mountain Mine January 2019 Mine Plan and Reclamation Plan
TABLE CONTENTS
DESCRIPTION PAGE NO
1.0 SUMMARY ...... 1-1 1.1 Introduction and Background...... 1-1 1.2 Mine Ownership and Prior Approvals ...... 1-1 1.3 Purpose and Need ...... 1-2 1.4 Organization of this Mine Plan/Reclamation Plan ...... 1-4 1.4.1 Description – Site, Access, and Property ...... 1-7 1.4.2 Background and Current Status of Operation ...... 1-10 1.4.2.1 Early History – Hart Mining District ...... 1-10 1.4.2.2 Operations (1990 – 2001) ...... 1-11 1.4.2.3 Operations (2001 – 2012) ...... 1-13 1.4.2.4 Operations (2012 – Present) ...... 1-13 1.4.3 Permitting ...... 1-14 1.4.3.1 Permitting (1988 – 1990) ...... 1-14 1.4.3.2 Permitting (1995 – 1998) ...... 1-14 1.4.3.3 Permitting (Present) ...... 1-15 1.5 General Description of Approved Plan of Operations ...... 1-15 1.5.1 General Permit Conditions ...... 1-15 1.5.1.1 1998 Plan Amendments ...... 1-15 1.5.1.2 2013 Plan Amendments ...... 1-16 1.5.2 Layout of Open Pits, Overburden Sites and Heap Leach Pad Areas ...... 1-16 1.5.3 Site Boundary ...... 1-23 1.5.4 Frequency of Monitoring at Piute Spring and Groundwater Elevation Monitoring ...... 1-23 1.5.5 Rock Staining and Placement of Cover Material ...... 1-26 1.5.6 Vegetation Salvage Requirement and the Revegetation Review Committee ...... 1-26 1.6 Project Stipulations (BLM) and Conditions of Approval (County) ...... 1-28
2.0 MINING PLAN ...... 2-1 2.1 Introduction ...... 2-1 2.2 Major Mine Components ...... 2-4 2.3 Production Schedule ...... 2-6 2.4 Mine Operations ...... 2-8 2.4.1 Growth Media Removal ...... 2-8 2.4.2 Mining...... 2-9 2.4.2.1 Pit Design ...... 2-9 2.4.2.2 Operations...... 2-12 2.4.2.2.1 Pit Characteristics ...... 2-12 2.4.2.2.2 Mining Equipment ...... 2-21 2.4.2.2.3 Mining Procedures ...... 2-21 2.4.3 Staged Development ...... 2-22 2.4.3.1 Stage 1 Through 5C (June 1991 to March 31, 1998) ...... 2-26 2.4.3.1.1 General Description ...... 2-26
i Castle Mountain Mine January 2019 Mine Plan and Reclamation Plan
TABLE CONTENTS (cont.)
DESCRIPTION PAGE NO
2.4.3.2 Stages 5A Through 5F ...... 2-26 2.4.3.2.1 General Description ...... 2-26 2.4.3.2.2 Stage 5A ...... 2-27 2.4.3.2.3 Stage 5B ...... 2-27 2.4.3.2.4 Stage 5C ...... 2-27 2.4.3.2.5 Stage 5D ...... 2-27 2.4.3.2.5.1 Oro Belle, Hart Tunnel and Jumbo Pits ...... 2-32 2.4.3.2.5.2 North and South Clay Pit Reclamation Areas ...... 2-32 2.4.3.2.5.3 Other Overburden Stockpile Areas ...... 2-32 2.4.3.2.5.4 Heap Leach Pad Area ...... 2-32 2.4.3.2.5.5 Mine Facilities ...... 2-33 2.4.3.2.6 Stage 5E ...... 2-33 2.4.3.2.7 Stage 5F...... 2-33 2.4.3.3 Stage 6 ...... 2-33 2.4.3.3.1 General Description ...... 2-33 2.4.3.3.2 Open Pit Mining Activities ...... 2-37 2.4.3.3.3 North and South Clay Pit Reclamation Areas ...... 2-37 2.4.3.3.4 Other Overburden Stockpile Areas ...... 2-44 2.4.3.3.4.1 Mine Facilities ...... 2-44 2.4.3.3.4.2 Heap Leach Pad Area ...... 2-45 2.4.3.3.4.3 Onsite Roads (Including Overland Conveyor) ...... 2-45 2.4.3.3.5 Stage 7 Through 8 ...... 2-46 2.4.3.3.6 Stage 9 ...... 2-46 2.4.4 Mine Product Characterization ...... 2-46 2.5 Ore Processing ...... 2-47 2.6 Water Impoundments and Diversions ...... 2-47 2.7 Utilities and Supplies ...... 2-48 2.7.1 Water Requirements and Supply ...... 2-48 2.7.2 Other Utilities and Structures ...... 2-50 2.7.3 Supplies ...... 2-51 2.7.4 Water Containment, Treatment, and Disposal ...... 2-55
3.0 RECLAMATION PLAN ...... 3-1 3.1 Introduction ...... 3-1 3.2 Purpose and Use of the Reclamation Plan ...... 3-1 3.3 Statutory and Regulatory Requirements ...... 3-2 3.4 Goals and Objectives of the Reclamation Plan...... 3-2 3.5 Land Use ...... 3-3 3.5.1 Existing Land Use ...... 3-3 3.5.2 Post – Mining Land Use ...... 3-4 3.6 Evaluation of Reclamation Success ...... 3-7 3.6.1 Updated Reclamation Strategy and Standards ...... 3-7
ii Castle Mountain Mine January 2019 Mine Plan and Reclamation Plan
TABLE CONTENTS (cont.)
DESCRIPTION PAGE NO
3.7 Revegetation Research Program ...... 3-9 3.7.1 Areas of Revegetation Research ...... 3-10 3.7.2 Vegetation Inventory...... 3-10 3.7.3 Revegetation Review Committee ...... 3-12 3.8 General Criteria for Reclamation...... 3-12 3.9 Reclamation Schedule ...... 3-14 3.9.1 Staged Reclamation Schedule ...... 3-14 3.9.1.1 Stages 1 through 4 (October 1990 to March 31, 1995) ...... 3-17 3.9.1.2 Stages 5A through 5F ...... 3-17 3.9.1.3 Stages 6 and 7 ...... 3-18 3.9.1.4 Stage 8 ...... 3-18 3.9.1.5 Stage 9 ...... 3-18 3.9.2 Temporary Suspension of Operations ...... 3-19 3.10 Maintenance and Management of Reclaimed Areas ...... 3-19 3.10.1 Fencing and Protection From Herbivory ...... 3-19 3.10.2 Monitoring and Maintenance ...... 3-19 3.11 Decommissioning of Facilities ...... 3-20 3.11.1 Mine Pits and Overburden Piles ...... 3-20 3.11.2 Crushing Plant, Comminution Circuit and Conveying Systems ...... 3-20 3.11.3 Solution Tanks, Basins, and Piping ...... 3-20 3.11.4 Heap Leach Piles ...... 3-22 3.11.5 Processing/Administration Structures ...... 3-22 3.11.6 Other Facilities...... 3-22 3.11.7 Roads ...... 3-23 3.12 Existing Vegetation ...... 3-23 3.13 Post-Mining Topography and Public Safety ...... 3-23 3.13.1 Topography ...... 3-23 3.13.2 Public Safety ...... 3-29 3.14 Post-Mining Hydrology ...... 3-29 3.14.1 Surface Water ...... 3-29 3.14.1.1 Mine Pits and Overburden Sites ...... 3-29 3.14.1.2 Crushing and Processing Facilities, Heap Leach Pad and Solution Tanks/ Basins ...... 3-31 3.14.1.3 Leachate from Ore, Protore and Overburden...... 3-31 3.14.2 Groundwater ...... 3-31 3.14.3 Drainage, Erosion, and Sedimentation Control ...... 3-35
4.0 RECLAMATION ASSURANCE ...... 4-1 4.1 Introduction ...... 4-1
5.0 SUPPLEMENTAL INFORMATION ...... 5-1 5.1 Introduction ...... 5-1
iii Castle Mountain Mine January 2019 Mine Plan and Reclamation Plan
TABLE CONTENTS (cont.)
DESCRIPTION PAGE NO
5.2 Environmental Documentation ...... 5-1 5.2.1 Permitting (1988-1990) ...... 5-1 5.2.2 Permitting (1995-1998) ...... 5-2 5.3 Permitting (2018) ...... 5-2 5.4 Permits and Regulatory Requirements ...... 5-3 5.4.1 Regional Water Quality Control Board (RWQCB) Order ...... 5-3 5.4.2 Streambed Alteration Agreement – California Department of Fish & Wildlife ...... 5-3 5.4.3 Desert Tortoise Habitat Compensation and Other Issues ...... 5-4 5.4.4 Mojave Desert Air Quality Management District ...... 5-4 5.5 Vested (Mining) Right ...... 5-4
6.0 REFERENCES ...... 6-1
APPENDICES
A San Bernardino County Conditions of Approval (July 22, 2013) B Bureau of Land Management Record of Decision & Stipulations (March 13, 1998) C RESERVED – California Regional Water Quality Control Board WDR D RESERVED – California Fish & Wildlife Dept., Streambed Alteration Agreement E United States Department of the Interior Fish and Wildlife Service Biological Opinion (February 20, 1998) F California Office of Mine Reclamation Letter – Reclamation Standards Success (February 12, 2012) G RESERVED H California Office of Mine Reclamation – Conditions Modification Approval (Sept. 9, 2010) I Dr. Sam Bamberg MEMO (August 13, 2018) J Dr. Sam Bamberg MEMO (April 2018) K San Bernardino County Letter – Adjustment to Revegetation Standards (July 2002) L Addendum Report to Castle Mountain Project Plan for Ground Water Monitoring and Contingency Water Supply to Piute Spring (February 2019) (to be supplied)
SHEET POCKETS
Sheet 1 of 2 – Approved Amended Mine Plan, Reclamation Plan and Cross Sections – January 2019
Sheet 2 of 2 – Updated Mining and Reclamation Plan and Plan of Operations – January 2019
iv Castle Mountain Mine January 2019 Mine Plan and Reclamation Plan
LIST OF TABLES
TABLE PAGE NO
1-0 Updates to 2018 Mine/Reclamation Plan, ver. 2.1 ...... 1-5 1-0A 2018 Change in Assessed Impact of the Approved Operations ...... 1-6 1-1 Proven, Probable and Possible Ore Reserves ...... 1-18 1-2 Comparison of Area of Disturbance ...... 1-20 1-3 Public and Private Land ...... 1-22 1-4 Castle Mountain Mine – Patent Lands ...... 1-24 1-5 Standards of Success of Castle Mountain Mine Revegetation Program ...... 1-28 1-6 County Conditions of Approval and BLM Project Stipulations ...... 1-29
2-1 Estimated Annual Production ...... 2-7 2-2 Production Stages and Chronological Relationships ...... 2-23 2-3 Incremental Acreage Distribution By Stage ...... 2-24 2-4 Incremental Growth Media Removal ...... 2-25 2-5 Seasonal Water Use ...... 2-48 2-6A Estimated Air Contaminant Emissions – Proposed Action – 2004 Operations...... 2-52 2-6B Estimated Air Contaminant Emissions – Proposed Action – 2018 Plan Update ...... 2-53 2-6C Comparison of Onsite Prime Power Generation Equipment ...... 2-54 2-7 Anticipated Wastes to be Generated at the Castle Mountain Mine ...... 2-55
3-1 Vegetation Type and Characteristics ...... 3-8 3-1A Five-Year and Ten-Year Density and Diversity Goals ...... 3-8 3-2 Reclamation Stages and Chronological Relationships ...... 3-15 3-3 Incremental Acreage at Approved Full Mine Development to be Prepared for Revegetation by Stage ...... 3-16 3-4 Estimated Growth Media Salvage by Location ...... 3-27 3-5 Groundwater Monitoring Results – Abandoned Wells...... 3-33 3-6 Groundwater Monitoring Results – (2018) Replacement Wells ...... 3-33 3-7 Piute Spring Outlet Flow ...... 3-33
v Castle Mountain Mine January 2019 Mine Plan and Reclamation Plan
LIST OF FIGURES
FIGURE PAGE NO
1-1 Site Location and Access ...... 1-8 1-2 Land Ownership and Site Boundary Modifications ...... 1-9 1-3 Aerial View of Castle Mountain Venture Gold Mine ...... 1-12 1-4 1996 Mining Plot Plan ...... 1-19 1-5 End of Stage 5D – 2018 Mining Plan Update ...... 1-21 1-6 Groundwater Monitoring Sites ...... 1-25
2-1 Schematic Mine Operation Flow Diagram ...... 2-2 2-2 1996 Mining Plot Plan ...... 2-5 2-3 Growth Media Stockpile Locations ...... 2-10 2-4 Original Lesley Ann Pit Design and Pit Profile ...... 2-13 2-5 Lesley Ann Partial Pit Plan (Partially Backfilled) at the End of Phase I ...... 2-14 2-6 Lesley Ann Pit Cross Sections as Excavated and as Partially Backfilled ...... 2-15 2-7 Phase I OBHT Pit Design ...... 2-17 2-8 Phase I OBHT Pit Design Cross-Section B-B’ and C-C’ ...... 2-18 2-9 Phase I Jumbo Pit Design ...... 2-19 2-10 Jumbo Put Design Cross-Section D-D’ and E-E’ ...... 2-20 2-11 Mine Status at End of Stage 5A ...... 2-28 2-12 Mine Status at End of Stage 5B ...... 2-29 2-13 Mine Status at End of Stage 5C ...... 2-30 2-14 Mine Status at End of Stage 5D (2018 Mining Plan Update) ...... 2-31 2-15 Mine Status at End of Stage 5E ...... 2-34 2-16 Mine Status at End of Stage 5F ...... 2-35 2-17 Preliminary Mine Status at End of Stage 6 ...... 2-36 2-18 Oro Belle – Hart Tunnel Phased Pit Design (Plot Plan) ...... 2.38 2-19 Oro Belle – Hart Tunnel Phased Pit Design (A-A Cross-Section) ...... 2-39 2-20 Oro Belle – Hart Tunnel Phased Pit Design (B-B Cross-Section) ...... 2-40 2-21 Jumbo Phased Pit Design (Plot Plan) ...... 2-41 2-22 Jumbo Phased Pit Design (A-A Cross-Section) ...... 2-42 2-23 Jumbo Phased Pit Design (B-B Cross-Section) ...... 2-49
3-1 Lanfair Valley Recreational, Environmental, and Wilderness Management Features ...... 3-5 3-2A Recontoured Overburden and Heap Leach Pad Slopes ...... 3-21 3-2 End of Phase II ...... 3-24 3-2B Stage 6 (Phase II) Cross-Sections A-C...... 3-25 3-2C Stage 6 (Phase II) Cross-Sections D-F ...... 3-26 3-3 Soil Mapping Units ...... 3-28 3-4 In-Pit Catchment Area, and 100 Year Flood Plain ...... 3-30 3-5 Groundwater Monitoring Sites W-19, W-37 and W-38 ...... 3-32
4-1 Surface Disturbances as of March 1997 ...... 4-2 4-1A Surface Disturbances as of 2018 ...... 4-3
vi 1.0 SUMMARY
1.1 INTRODUCTION and BACKGROUND
Castle Mountain Venture (“CMV” or, “the Company”) is a California General Partnership between Viceroy Gold Corporation (“Viceroy”) and Telegraph Gold Inc. CMV retains 100 percent ownership of the Castle Mountain Mine (“CMM”) and submits this 2018 update to the existing Plan of Operations, and Mine Plan and Reclamation Plan for the Castle Mountain Mine ("Mine"), Ver.2.0 (90M-013), which was last revised June 1998 (“1998 Plan”). This update (the “2018 Plan update”) retains similar formatting and text from the 1998 Plan and other prior versions.
Like the prior versions of the mine plan, the 2018 Plan update will act as a combined federal Plan of Operations (“POO”) and county Mine Plan and Reclamation Plan for previously authorized mining activities at the Mine. This 2018 Plan update will function jointly as the POO and the Mine Plan and Reclamation Plan and therefore, those documents may be referred to interchangeably throughout this update document.
The purpose of this 2018 Plan update is to: (1) provide updated context for previously approved activities that have either been completed or adjusted (pursuant to agency authorization) since 1998; and (2) account for scheduling adjustments related to mining operations and reclamation. This 2018 Plan update will include discussions of the following subjects and events, among others: (1) the 2007 transfer and re-designation of more than 1,000-acres of the Mine, from public land previously managed by the Bureau of Land Management ("BLM"), to private lands now owned by CMV; (2) the successful completion of certain phases of land reclamation ; and (3) positive changes in mining economics.
This 2018 Plan update continues to authorize all activities at the Mine pursuant to the approvals that were previously issued by the County of San Bernardino (“the County”) and the BLM. As discussed below, this 2018 Plan update does not introduce new operational elements that could be interpreted as significant in scale and/or whose environmental effects have not been previously analyzed through one of the multiple comprehensive environmental assessments that have been completed in accordance with the National Environmental Policy Act ("NEPA") and the California Environmental Quality Act ("CEQA").
1.2 Mine Ownership and Prior Approvals
The Mine is owned by CMV, a California General Partnership between Viceroy Gold Corporation (“Viceroy”) and Telegraph Gold Inc.
CMV, through parent company Equinox Gold Corporation, and Viceroy, remains the legal owner/operator of the Mine, as has been the case since the approval of the original mining Conditional Use Permit (“CUP)”) and joint POO/Mining and Reclamation Plan in 1990 (“1990 Plan”). For consistency, references in this 2018 Plan update to either Viceroy or CMV may be used interchangeably and both company names refer to CMV as the operator of the Mine.
Activities at the Mine are authorized by multiple agencies, including the BLM and the County. The BLM authorizes mining on public land pursuant to its multiple-use mandate, the Mining Law of 1872, and the
Castle Mountain Mine Plan and Reclamation Plan 1-1 January 2, 2019 Federal Land Management and Policy Act of 1976, as amended ("FLPMA"), pursuant to environmental analyses that were previously completed in accordance with NEPA. The County’s Land Use Services Department regulates mining within the County, and serves as the lead agency pursuant to the State of California Surface Mining and Reclamation Act (“SMARA”), pursuant to environmental analyses that were previously completed in accordance with CEQA.
In 1990, the BLM and County approved the 1990 Mine and Reclamation Plan to build and operate the Mine in far east San Bernardino County, California, which, at the time, was approximately 2,735-acres. During the approval process, the BLM and County prepared a joint Environmental Impact Statement(“EIS”)/Environmental Impact Report(“EIR”) ( (the "1990 EIS/EIR") in accordance with NEPA and CEQA, respectively.
Thereafter, in 1998, the BLM and County approved an amendment to the 1990 Plan (the “1998 Plan”) to expand the size of the Mine to encompass a total project area of 3,910-acres. During the amendment process, the BLM and County again prepared a joint EIS/EIR (the "1997 EIS/EIR") in accordance with NEPA and CEQA.
As discussed below, both the original 1990 Plan and 1998 Plan contemplated the operational and reclamation-related activities discussed herein. Accordingly, no additional discretionary approvals are necessary.
1.3 PURPOSE and NEED
The purpose of this 2018 Plan update is to describe the next phases of mining and reclamation programs that will be conducted throughout the life of the Mine pursuant to prior approvals previously issued by the agencies, along with an updated schedule for the programs. This 2018 Plan update combines and incorporates the provisions and programs described in the original 1990 Plan and the amended 1998 Plan, and provides updates related to the following subjects and events:
Land Status changes – Title to land covering most of the active Mine site has changed over the past 20 years; this includes the transfer of a large tract of public land parcels by BLM to CMV. These land patents were approved by the Federal government in 2007 and, as a result, the amount of activity on public lands has been greatly diminished; the remaining activity on public lands is mostly located on the western half of the approved heap leach pad site and north overburden site. This update to land status is addressed in more detail at section 1.4.3 of this Plan. Completed Land Reclamation – Based on successful revegetation research programs and reclamation over the past 20 years, various conditions of approval and stipulations are being updated in the 2018 Plan update, as discussed below. As background, successful attainment of the revegetation standard was considered a major focal point of the reclamation plan approved for the site in 1990 and amended in the 1998 Plan. This focus was exemplified through the prior adoption of more than 30 conditions of approval and stipulations1 regarding revegetation of the Mine site. At the time of adoption, the requirements deemed most critical was the unprecedented scope of revegetation research and plant salvage that was required. It is fair to say no other operating mine in the country could claim to match the time and money expended by CMV to further the study the reclamation of arid lands. These conditions were appropriate
1 See Appendices A and B for the full list of County and BLM project conditions of approval and stipulations.
Castle Mountain Mine Plan and Reclamation Plan 1-2 January 2, 2019 for the time because the agencies were still developing an understanding of strategies related to the successful revegetation of arid mine lands that would meet or exceed modern reclamation standards, especially for challenging sites such as those located in the arid California Mojave Desert. This knowledge gap for successful reclamation of desert mine lands has since been filled, due in large part to the successful research and revegetation conducted at the Mine. Because of these successes, it is appropriate to update some of the conditions of approval and stipulations that no longer apply or have already been completed; specific updates are addressed on Table 1-6 and sections 1.3.6 and 3.6 to 3.8 of the reclamation section of this plan. Mining Schedule and Protore Stockpile Processing– This 2018 Plan update describes the resumption of mining, based upon already described mining activities and previously established, but slightly re-ordered phasing, focusing initially on processing of ore stockpiles. The approved 1998 Plan amended the phased mine schedule approved in the original 1990 Plan. The schedule estimated in the 1998 Plan divided the mining into Phase I, comprising mining Stages 5A to 5F, and Phase II, comprising mining and reclamation Stages 6, 7, 8, and 9. As discussed in the approved 1998 Plan, the ultimate implementation and completion of each stage was to be dependent upon multiple factors, including mine engineering and economic factors. For instance, before mining was halted in May 2001 (due to poor economic factors for gold), Stage 5C was the last fully completed mine Stage, with Stages 5D, E, and F only partially completed. Acknowledging that the mine plan schedule can adjust based on these changing factors (in this case economics), CMV in 2001 did not complete authorized mining but instead shifted activity to complete Stages 6, 7, 8, and 9, which focused on the processing of ore stockpiles and land reclamation. This 2018 Plan update continues to implement this established concept of mine scheduling based on engineering and market economics and is why this update discusses the resumption of mining at Stage 5D, the last authorized mine stage not already completed. It is also why the first mining action of this stage will be the processing of ore stockpiles, including backfilled protore, which -was not economic to process in 2001 but is economic to process under this plan update. The original 1990 Plan estimated the processing of ore stockpiles at Stage 7, but due to market economics, this was later adjusted to occur at Stage 6. This 2018 Plan update additionally adjusts the mine schedule to reflect market and engineering conditions that now promote the processing of existing low grade protore stockpiles to occur at the onset of resumed mining in Stage 5D. The material backfilled into the Lesley Ann pit is the largest stockpile of protore on site with an estimated quantity of 40-million tons total ore. The phased mine schedule and processing of backfilled protore is discussed in more detail throughout section 2.0. but specifically section 2.4.3. Increased Operational Efficiency Modifications – The actions discussed in this 2018 Plan update constitute previously authorized actions, or a modification or update of these actions to implement additional efficiencies or conservation measures such as water or mineral resource conservation. These efficiencies result in a smaller scope of operations in comparison to those already approved and are not considered substantial changes. Thus, these activities will not cause significant environmental impacts not previously assessed during prior NEPA and CEQA review. For example, whereas the 1998 Plan detailed that the mining operation would include blasting, ore hauling, overburden stockpiling, crushing, conveying, milling, heap leaching and finally gold recovery, the mining operation contained in this 2018 Plan update only includes ore hauling, limited overburden stockpiling (most material is considered protore), heap leaching and final gold recovery. In short, the 2018 Plan updates will result in operational efficiencies that will have a net effect of lessening the environmental impacts already assessed, mitigated, and authorized at the Mine. These 2018 Plan updates and updated resource impact assessments are contained in sections 2.0 and 5.0 of this 2018 Plan update, respectively.
Castle Mountain Mine Plan and Reclamation Plan 1-3 January 2, 2019 Conditions of Approval and Stipulations Modifications – Because of the reduced scale of the mine operation outlined in this 2018 Plan update, certain conditions of approval and stipulations no longer apply under the current planned scope of activity; but, any applicable conditions and stipulations would remain in effect if those activities are undertaken in the future. The conditions of approval and stipulations that require updates are found in Table 1-6 and section 1.11 of this 2018 Plan update. Mine Schedule Extension – This 2018 Plan update seeks a 10-year extension of the 1998 Plan to account for the time required to complete the remaining authorized mining and reclamation activities detailed in mining Stages 5D through 9 of the approved 1998 Plan. The County, on July 22, 2013, approved a revision to the 1998 Plan that extended the plan by five years to December 31, 2025. Thus, the ten-year extension would further extend the Mine Plan and Reclamation Plan, as well as the POO, to December 31, 2035. The extension of the mine schedule of operations is further discussed in section 1.3.1.2.
To increase the readability of this 2018 Plan update, specific actions which require update under this 2018 Plan update are shown for reference below in Table 1-0.
1.4 ORGANIZATION OF THIS MINE PLAN/RECLAMATION PLAN UPDATE
This 2018 Plan update is a continuation of the original approved 1990 Plan, and the 1998 Plan approved as ver. 2.0 in June 1998 and revised in 2013 with the extension of the mine schedule to 2025. As before, this 2018 Plan update remains designated as "90M-013"; but, for clarification, and as referenced above, it is further titled “2018 Plan update (ver. 2.1, 90M-013)”.
Minor modifications are incorporated into this 2018 Plan update and mostly present a reduction in the previously-authorized scope of mining and mining related activity when compared to the activities authorized by the 1998 Plan. These changes are the result of technological and process efficiencies, and mine plan adjustments due to changing economics of the operation, specifically from the large rise in the price per ounce of gold by approximately 330 percent from 1998 market conditions. As discussed in the 1998 Plan, this increase in the price of gold presents an opportunity where most of the material then recognized as overburden, though conceptualized as protore2 in the approved 1998 Plan, can now be processed on a heap leach pile in a manner that is economically viable. The mine plan updates included in this 2018 Plan update will cumulatively lessen the environmental impacts from the operation analyzed by the BLM and County and approved in 1990, 1998, and more recently in 20133. Particular attention is focused to ensure this 2018 Plan update does not cause a significant effect not analyzed in the previous EIS/EIRs or cause an exceedance or a substantially more severe effect of the impacts analyzed and deemed significant by prior NEPA and CEQA analyses conducted in 1990 (Castle Mountain Project, September 1990) and 1997 (Castle Mountain Mine Expansion Project, October 1997). These prior analyses summarized impacts into the categories represented below in Table 1-0A.
Section 2.0 of this 2018 Plan update discusses the processing of existing ore stockpile as the next activity that will occur at Mine. The estimated mine schedule reflects that this activity should occur during Stage 5D since the Stage 5C was the last fully completed stage before mining was halted in May 2001.
2 Protore is an altered rock mass or primary mineral deposit having uneconomic concentration of minerals. Protore can turn into an economic deposit with advanced technology and/or increase of resource economics (i.e. price of gold). 3 San Bernardino County approval of Mining CUP and Reclamation Plan extension to December 31, 2025.
Castle Mountain Mine Plan and Reclamation Plan 1-4 January 2, 2019 Table 1-0 2018 Plan Update Minor Modifications Sections of Mine Plans with Covered by Relevant Discussions Prior Updated Action Description of Impact This 2018 NEPA/CEQA 1998 Plan Plan Update Analysis? (ver.2.0) (ver.2.1) Sections 2.1 And 2.4.3 No increase to mining rate, land disturbance or mine pit Mining of (Backfilled) Protore YES boundary, or site emissions previously analyzed in 1990 and BLM Stipulation Section 2.4.3 Stockpile by "Run-of-Mine" 1997 EIS/EIRs #10 County Condition #101 No increase to continued groundwater extraction via existing well network previously approved and analyzed in 1990 and 1997 EIS/EIR. 20 years of Lanfair basin groundwater elevation Continued operation of a network of monitoring data show no effect from mining on regional ground water monitoring wells similar aquifer or Piute Springs. The report, Addendum Report to in function to those described in the Castle Mountain Project Plan for Ground Water Monitoring Section 1.4.4 report, Castle Mountain Project Plan YES 4 and Contingency Water Supply to Piute Spring (Feb. 2019) Section 1.4.4 for Ground Water Monitoring and addresses compliance through the new network of ground Appendix L Contingency Water Supply to Piute water monitoring wells. The reconfigured network of Spring (Aug. 1990) monitoring wells described in this Plan update will continue to satisfy the original intent for monitoring mining related ground water withdrawal and its impact, if any, on the regional Lanfair water basin and specifically on Piute Spring. Mandate for the Revegetation Review Committee and site Revegetation Research and the Revegetation Research has been met and proven by Not Applicable Section 1.4.6 Section 1.4.6 Revegetation Review Committee (RRC) successful mine reclamation and revegetation completed to date5 .
4 The Addendum Report is currently under review and will be submitted as Appendix L. The finding of the Addendum Report confirms that a new network of ground water monitoring wells is as protective of regional ground water supply as the prior network of wells. 5 See Appendix F – Feb. 2012 Letter from OMR to County of San Bernardino
Castle Mountain Mine Plan and Reclamation Plan 1-5 January 2, 2019 Table 1-0A 2018 Assessed Impact of Approved Operations IMPACT Change in Assessed Impact as a Result of this 2018 Plan Update As Assessed in 1997 EIS/EIR As Confirmed in 2018 CATEGORY (Technical report referenced, where applicable) No Change Geology Less than significant. Less than significant. No modification to mining methods and no new lands proposed for mining No Change Less Than Significant. Monitoring of the Lanfair aquifer and Piute No increase in water use is proposed. 625-725 acre/ft of groundwater approved in Plan for Water Continued use of groundwater will not impact Piute Springs from 1988 to 2018 confirm no extraction annually from Lanfair basin from 1990 to 2020 Springs. Neither surface nor groundwater quality would impacts observed to regional water basins Resources (Addendum Report to Castle Mountain Project Plan for Ground Water Monitoring and be affected by the Proposed Action or Piute Springs Contingency Water Supply to Piute Spring, February 2019) No Change No modification to add additional land disturbance outside that approved by 1998 Less Than Significant. Revegetation standards attained in 20126 . Mine/Reclamation Plan. Continued implementation of successful revegetation methods Vegetation Mitigate by extensive plant salvage and revegetation Revegetation of the site confirmed developed at the site. research and implementation successful (2012 OMR letter to County confirming CMV has met the reclamation standards, Appendix F) (2017 Fall Blooming Special Status Plant Survey for Castle Mountain Venture) (2018 Spring Blooming Season Special Status Plant Survey for Castle Mountain Venture) No Change Less Than Significant. No modification to land disturbance outside that approved by 1998 Mine/Reclamation Plan. Mitigate by monitoring, site exclusion fence, Less than significant. No change to BLM Continued implementation of wildlife protection measures. Wildlife implementation of protection measures, and purchase Special Status species density on site. 7 Desert Tortose-(Castle Mountain Mine Presence/Absence Survey and Density Estimate, 2017) of compensatory habitat and closure of cattle grazing Compensatory habitat provided in 1994. Golden Eagle-(Castle Mountain Mine Project, 2018 Golden Eagle Nesting Surveys) allotments Bats-(Mine Surveys for Bats and Other Wildlife at Castle Mountain Mine Project, 2018) No Change Significant and Unavoidable. Mitigation reduces While likely still significant, increased Site equipment will conform to California Tier 4 standards for diesel emissions and continued emissions and total emissions do not exceed significance technological innovation and stricter implementation of air quality regulations and emission reduction measures will result in no Air Quality thresholds adopted by MDAQMD and assessed in the emission regulations will decrease substantial change from emissions approved on Table 3.6-4 of 1997 Draft EIS/EIR for Castle EIR/EIR emissions Mountain Mine Expansion (EIR Conformity Emissions Summary, Castle Mountain Venture; Ramboll 2018) Significant and Unavoidable. Mitigate through land No Change While likely still significant, land Visual contouring to resemble natural topography and No additional modification to approved land disturbance is proposed. Visual impact will be reclamation and revegetation proven decrease rigid geometrics of heap leach and overburden less than that estimated in 1990 and 1998 due to the successful reclamation of the historic Impacts extremely successful piles. Revegetation will lessen visual impact. clay quarries which were among the most distinct features regionally. No Change Cultural No impact to eligible site and/or treatment to eligible sites completed Less Than Significant No impact to eligible sites. Resources (Class III Cultural Resources Inventory of 1,091 Acres for the Castle Mountain Venture Project; ASM Affiliates 2018) No Change Land Use Less Than Significant Consistent with land use plans 8, 9 Consistent with land use policy’s, see notes 10 and 11 below. Implementation of applicable Conservation and Management Actions (CMAs) from DRECP. No Change Hazards Less Than Significant Less Than Significant Continued implementation of regulations and mitigations in 1998 Plan approvals
6 See Appendix F - 2012 letter from OMR to San Bernardino County confirming attainment of species density and diversity goal for entire site. 7 Extensive species assessments including rare plants, golden eagle, desert tortoise, and bats conducted in 2017 and 2018 and confirm conditions are consistent with biological assessment results determined during prior NEPA/CEQA impact assessments. 8 Desert Renewable Energy Conservation Plan (BLM, September 2016) recognizes the Castle Mountain Mine as an Existing High Priority Mineral Operations Exclusion Area. 9 Castle Mountain National Monument proclamation (Executive Order, February 2016) recognizes the operation of the Castle Mountain Mine Area as a valid existing right.
Castle Mountain Mine Plan and Reclamation Plan 1-6 January 2, 2019 Section 3.0 discusses the successful land reclamation and revegetation that has been completed to date. This update also includes updates to the reclamation strategy and success standards, which were previously modified by the County. These modifications were authorized through a County letter in July 2002, and a California Department of Conservation – Office of Mine Reclamation (“OMR”) report, Castle Mountain Mine Vegetation Analysis, November 2000. These changes and correspondence are detailed further in section 3.6.1.
This 2018 Plan update is consistent with the format of the approved 1998 Plan and is similarly organized into five major sections: the introduction, the mine plan, the reclamation plan, financial assurance, and other information related to the Castle Mountain Mine. This 2018 Plan update should be considered an update to the original mine plan approved in 1990, and amended in 1998.
The information in this document incorporates the changes that were described in the Company’s Plan Amendment Application, ver. 1.1a, as modified by the environmental analysis, the County’s approval of the modified plan on November 6, 1997 and BLM’s approval of the modified plan on March 13, and July 1, 1998; all of which comprise the final approved 1998 Plan, ver. 2.0. This 2018 Plan update is a continuation of the approved 1998 Mine/Reclamation Plan ver.2.0, after retirement of the Interim Management Plan (“IMP”) that has been in place since 2013 and also to reconcile mine plan updates, which are schedule adjustments due to the positive change in the market economics for gold since 1998.
This 2018 Plan update also accounts for the recent decision on July 22, 2013, by the County to extend the life of the approved 1998 Plan to December 31, 2025. This 2018 Plan update amends the approved 1998 Plan to account for the 2013 County extension of the Mine/Reclamation Plan. A further extension request is made in this 2018 Plan update, to extend the proposed schedule of operation for both the Mine Plan and Reclamation Plan, and the POO, by 10 years to December 31, 2035. This extension is necessary to complete the remaining authorized mining and reclamation detailed in mine Stages 5D through 9 of the approved 1998 Mine Plan and updated in this 2018 Plan update.
1.4.1 DESCRIPTION – SITE, ACCESS, and PROPERTY
The Castle Mountain Mine is an open pit gold mine located in the Mojave Desert about 100 miles east of Barstow, California, and about 70 miles south of Las Vegas, Nevada, near the eastern border of California in San Bernardino County. Elevations range from 4,100 to 5,100 feet above mean seal level (msl). Precipitation averages 8 inches per year. Temperatures range from below freezing during occasional cold periods in the winter, to as high as 110 degrees F in the summer. The location of the Castle Mountain Mine is shown in Figure 1-1.
Road access to the mine site is via an 18-mile gravel road that connects to Nevada State Highway 164 (Nipton Road), seven miles west of Searchlight, Nevada. BLM issued Viceroy Special Use Permits (CA-28869 and NV-54089) for the construction of an adjacent overhead power transmission line. Site access through this route was authorized as the mitigated alternative site access route during the public scoping process for the 1990 FEIS/EIR. The road, then formerly known as the Castle Mountain Mitigated Access Route (CMMAR), is now more generally known as the Walking Box Ranch access road and is still maintained by the Company and also open to public access.
Secondary road access is provided by a nine-mile dirt road that connects the mine site to a gravel road maintained by San Bernardino County, at Barnwell, California. This road is known as the Hart Mine access road.
Castle Mountain Mine Plan and Reclamation Plan 1-7 January 2, 2019
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L A C N E I A D A V F A I N R O
Castle Mountain Mine Lat: 35.27758587° N Lon: 115.09941887° W
N E V A D A
San Francisco C A L I F O R N I A
Map Area
San Bernardino County Los Angeles
San Diego
Mojave National Preserve 0 4.3 (National Park Service)
MILES Approved Mine Boundary (1997 EIS/EIR) Source: Unigrid-map-of-Mojave-National-Preserve Designated Area Roads SITE LOCATION and ACCESS Castle Mountains National Monument CASTLE MOUNTAIN MINE (National Park Service) County of San Bernardino, California LILBURN FIGURE 1-1 C O R P O R A T I O N
C A N L E FI V A O D R A A I N
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PROJECT SITE
Approved Mine Boundary Castle Mountain Mine Area (BLM Managed) 0 1.5 Castle Mountains National Monument (National Park Service) LAND OWNERSHIP and MILES Source: Lilburn Corp., April 2017 (TAG). Mojave National Preserve (National Park Service) PROJECT SITE BOUNDARY BLM data: LandStatus_v10.gdb.zip Modified: 01/06/2017 CA State Lands CASTLE MOUNTAIN MINE Private Lands County of San Bernardino, California
LILBURN C O R P O R A T I O N
LEGEND FIGURE 1-2 The site boundary, in relation to the public lands survey, is shown in Figure 1-2. The project site comprises 2,609 acres of public lands (unpatented mining claims) administered by the BLM and 1,301 acres of private lands (patented mining claims) administered by the County. The site boundary description includes all or portions of Sections 13, 14, 22, and Sections 23 through 26, Township 14 North, Range 17 East; Lots 19 through 22 of Section 18, the Southwest Quarter of the Southwest Quarter of Section 19 and the West Half of the West Half of Section 30, Township 14 North, Range 18 East, San Bernardino Base and Meridian. Of the 3,910 total acres of project land, approximately 1,375 acres are currently authorized (through Phase II of the approved mine 1998 Plan) for land disturbing activity, the majority of which occur on 1,000 acres of private land but also approximately 375 acres of public land (mostly heap leach pad expansion area). This represents a pronounced shift from prior site operations which largely occurred on public land. This significant change resulted from the Department of the Interior approval of the Company’s mineral patent applications10 in 2007. The result of this change in land status is that now, the majority of current authorized mine activity and oversight formerly conducted by the BLM (federal) has shifted to the County (state).
1.4.2 BACKGROUND and CURRENT STATUS OF OPERATION
1.4.2.1 EARLY HISTORY – HART MINING DISTRICT
Gold mining began in the region in 1907 with the discovery of high grade gold by Jim Hart, along with Bert and Clark Hitt. As word of the discovery spread, hundreds, and ultimately thousands of people migrated to the area from the surrounding towns of Searchlight, Nevada, and Needles, California, and formed the town of Hart. Although Hart lost most of its 1,500 residents by 1918, the 1930s saw a resurgence of mining activity, this time focused on high quality clay, kaolin, and perlite from mine claims owned by, among others, the Standard Sanitary Manufacturing Company. Clay quarrying continued sporadically through the early 1980’s. See Larry M. Vredenburgh, Gary L. Shumway, & Russell D. Hartill, Desert Fever: An Overview of Mining in the California Desert Conservation Area (1981).
During the early 1900s, the Oro Belle, Hart, and Valley View mines were the most successful of the early gold mines near Hart. Of the high-quality clay and kaolin deposits discovered, south of the town of Hart, the Standard Sanitary Manufacturing Company mined and exported clay from 1933 to 1986. A second mine located by H.F. Coors was known as the C-1 (or Milma patent) clay mine, which operated from 1925 to 1986 and was located adjacent to the town of Hart. A third deposit known as the Huntington Tile clay mine was operated until 1974 (Minerals in the East Mojave National Scenic Area, 1990). North of the Hart town site and extending to the Nevada border exist many known perlite deposits that have been mined sporadically. By 1953, the perlite-bearing belt was controlled by three operators on the California side: Lewis Cox from Las Vegas; the More-Lite Minerals Corporation, Riverside, California; and the L.S. Whaley Lumber Company. Perlite from the More-Lite quarry in California was trucked to both Ivanpah and Searchlight on route to the company’s Riverside plant where the material was processed. Whether transportation was to Ivanpah or Searchlight, use of the historic area roads was nonetheless required. See State of California, Division of Mines, 49 California Journal of Mines and Geology Nos. 1-2, at 185-87 (Jan.-Apr. 1953).
10 MPA CACA-24570, CACA-29997 and CACA-30912
Castle Mountain Mine Plan and Reclamation Plan 1-10 January 2, 2019 1.4.2.2 OPERATIONS (1990 – 2001)
The Company’s exploration activity under Viceroy began in the Hart Mining District in 1984. The mining operation received state and federal agency mine permit approvals in the Fall of 1990. Preproduction mining in the first open pit (Lesley Ann) commenced in June 1991, and first gold production in February 1992.
The Castle Mountain Mine, throughout this period of operation, was one of the largest producers of gold in California, providing year-round employment for a work force of over 200 people. The operation was completely self-sufficient, providing its own water, sewerage and sanitation services, trash disposal and access road construction and maintenance. Property tax payments to the County exceeded $500,000 annually, and annual claim holding fees paid to the BLM exceeded $200,000.
As of June 1997, approximately 633 acres of surface disturbance had taken place. Reclamation to this same time period totaled approximately 21 acres on the South Overburden Pile. The Company conducted reclamation in accordance with the SMARA, California Public Resources Code, Section 2710 et seq., as further defined in the County's Conditions of Approval for the 1990 Mine/Reclamation Plan (dated October 7, 1990); and BLM's requirements outlined in 43 CFR 3809.l-5(c)(5) and further defined in the stipulations of the Record of Decision (dated October 31, 1990). Detailed reclamation practices and procedures for the Castle Mountain mine were further defined in the first version of the Mine Plan and Reclamation Plan (August 1990), designated as 90M-013.
In 1998, through two Records of Decisions (1998 RODs), the BLM approved the Castle Mountain Mine Plan Amendment with updated stipulations; and the County approved the revised 1998 Mine/Reclamation Plan in January 1998 for the expansion of mining activities on an additional 490 acres. The aerial photograph, Figure 1-3, shows the Castle Mountain Mine as of December 1996 as compared to the site in 2017 showing most of the land reclamation and revegetation complete.
The Company continued to provide financial assurance for reclamation of the site throughout this period. The reclamation obligation was reviewed annually, and the financial assurance adjusted accordingly. The principal amounts of the Company’s financial assurance during this period were $2.5 million, to cover estimated reclamation costs for the cumulative acreage scheduled to be disturbed through the end of 2020 and closure of the heap leach pad.
Mining under the expanded operation continued until May 2001, at which point mining was halted by Viceroy; the heap leach pile was rinsed, drained, and reclassified as a Group C (inert overburden) Mine Waste by 2010. Due to the potential for a prolonged stoppage of active mining, land reclamation operations, which had already begun, became the primary focus for the operation by 2001. The total period of active mining extended over 10 years from 1991 to 2001.
As of 200111, approximately 760 acres of land surface had been disturbed, out of 1,375 acres of total permitted land disturbance. Additional detail on total land disturbance total is included in Table 1-2. Due to the stoppage of mining by May 2001, land reclamation commenced and was mostly completed by 2007, with some additional minor re-seeding on the heap leach pile and with monitoring extending to 2012. Detailed reclamation practices and procedures for the Castle Mountain Mine were originally defined in the 1990 Mine Plan and Reclamation Plan (August 1990: # 90M-013, ver.1.0), and later
11 May 2001 represented the peak of land disturbance.
Castle Mountain Mine Plan and Reclamation Plan 1-11 January 2, 2019 1996 Aerial View of Project Site 2017 Aerial View of Project Site
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17
5
1 Lesley Ann Pit 9 Heap Leach Pad
2 Oro Belle/Hart Tunnel Pit 10 Gold Recovery Plant
3 Low Grade Ore Stockpile 11 Process Solution Storage Tanks
4 South Overburden Site 12 Stormwater Overflow Basin
5 Administration Office 13 Growth Media Stockpile
6 Crushing Plant 14 South Clay Pit Reclamation Area
7 Haul Road and Overland Conveyor 15 North Overburden Site
8 Comminution Circuit 16 North Clay Pit Reclamation Area 0 1,500’
FEET 17 Maintenance and Contractor Area Source: Castle Mountain Venture AERIAL VIEW of CASTLE MOUNTAIN VENTURE GOLD MINE CASTLE MOUNTAIN MINE LILBURN County of San Bernardino, California C O R P O R A T I O N FIGURE 1-3 amended as the 1998 Mine Plan and Reclamation Plan ver.2.0, in June 1998 after approval of Mine expansion. However, there were some key elements missing from those approved Plans simply because the baseline vegetation data had not been finalized which made it impossible to define revegetation success standards. The County (and OMR) approved standards were defined by 2002 and are now available for inclusion into this 2018 Plan update and are presented on Table 3.1A in the reclamation section of this plan. There will also be some adjustments regarding reclamation made in this 2018 Plan update due to the pronounced success of reclamation plans implemented and later modified as site revegetation proceeded at the site. This 2018 Plan update will follow past practice and is referenced as ver.2.1 of the Castle Mountain Mine Plan and Reclamation Plan (#90M-013). Additional reclamation and revegetation details are included in section 3.0 of this 2018 Plan update.
1.4.2.3 OPERATIONS (2001 – 2012)
Site operations throughout this period mostly consisted of heap leach pad rinsing, land reclamation and revegetation monitoring during the latter six years of operation. Most site reclamation was complete and met revegetation success criteria by 2012. Additional detail regarding land reclamation and revegetation are contained in section 3.0.
Also during this time, the Department of the Interior reached a decision on the company’s pending mineral patent application and approved the transfer of 1,038 acres of previously designated public land to patent land in the name of Viceroy Gold Corporation.
1.4.2.4 OPERATIONS (2012 – PRESENT)
With substantial land reclamation complete by 2012, the Company submitted an Interim Management Plan (IMP) to the County to manage site operations which consisted of preparing for additional mineral exploration at the mine site. The County approved an extension of the 2013 IMP for an additional five years on April 13, 2018. In anticipation of renewed mining at the site, the Company applied for and received BLM approval for two mine plan of operation modifications for continued mineral exploration at the mine site in 201312. A third mineral exploration program, Phase III Exploration Drilling Program, was approved on September 11, 201813.
The County, in July 2013, approved a revision to the 1998 Plan for an extension of mine activities by an additional five years until December 31, 2025. This 2018 Plan update seeks a further 10-year extension of the 1998 Plan to 2035, to accommodate for the time necessary to complete the remaining mining and reclamation detailed in mine Stages 5D through 9 of the approved 1998 Plan. The company recently received BLM authorization for a third phase of exploration drilling at the site which could expand the defined mineral resource.
The company continues to provide financial assurance cost estimates (“FACEs”) and Financial Assurance in the form of bonds for reclamation and closure of the site. The reclamation obligation is reviewed annually, and the financial assurance is adjusted accordingly. The principal amounts of the company’s financial assurance are currently $406,918.20, to cover estimated reclamation costs for the cumulative acreage scheduled to be disturbed through the end of 2018.
12 BLM, DOI-BLM-CA-D090-2013-DNA, February 2013; BLM, DOI-BLM-CA-D090-2013-0105-DNA, September 2013 13 BLM, DOI-BLM-CA-D090-2018-0037-EA
Castle Mountain Mine Plan and Reclamation Plan 1-13 January 2, 2019 1.4.3 PERMITTING
1.4.3.1 PERMITTING (1988 – 1990)
The Company filed a Plan of Operations with the BLM and a Mine/Reclamation Plan with the County to conduct mining at the Castle Mountain Mine in March 1988. The application outlined a project that included mining of the Lesley Ann/Jumbo Pits and the Oro Belle pit, the construction of heap leach pads, ore crushing facilities, gold recovery plant, access road, and buildings for maintenance and administrative activities. The plan called for mining of approximately 90 million tons of material – approximately 30 million tons of ore and 60 million tons of overburden. The nominal rate of ore mining was set at 11,500 tons per day. The application defined a project area of 2,735 acres with an estimated surface disturbance of 890 acres.
The project was deemed a major, significant environmental impact requiring the agencies to prepare a combined EIS/EIR as prescribed by NEPA and the CEQA. In February 1989, a Draft EIS/EIR was made available to the public. Hearings were conducted and public comments on the DEIS/DEIR were taken from March 1989 until May 1989. In June 1989, the Desert Tortoise was designated an endangered species. This required the preparation of a Biological Assessment ("BA") that outlined the anticipated effects of the project on the desert tortoise. The BA was submitted to the U.S. Fish and Wildlife Service (“FWS”) in January 1990. In August 1990, FWS issued a Biological Opinion (“BO”) (6840 CA-CA-932.1) (1-6-90-F-24) with a “no jeopardy” ruling on the BA. This decision was based on mitigation measures required of Castle Mountain Venture. In September 1990, the Final EIS/EIR received approval from the BLM and the County.
The BLM and the County approved the 1990 Plan in October 1990. The County and State of California designated the approved 1990 Plan as 90M-013 with a California Mine ID NO. 91-36-0015.
1.4.3.2 PERMITTING (1995 – 1998)
In 1995, after additional exploratory drilling and after the Company negotiated a new contract with the mining contractor, the Company outlined an expanded mine program. The Company incorporated the expanded mine program into a Plan Amendment Application that was submitted to the County and the BLM in May of 1995. A modification of the Plan Amendment Application was submitted to the agencies August 14, 1997 as Plan Amendment Application (Mine Plan and Reclamation Plan) ver. 1.1a for additional mining activities on 490 acres and an extension of the estimated project schedule to the year 2020.
In summary, this plan consisted of additional mining in the Jumbo Pit, the Oro Belle pit, a pit contiguous to the Oro Belle called the Hart Tunnel pit, and pit in the South Extension area (an extension of the Lesley Ann pit). In addition, planning called for placement of overburden in a new area identified as the North Overburden Area; and consolidation of the heap leach pads into one leach pad. The mining plan called for maintaining the mining rate at 11,500 tons of ore per day; and therefore, the need to change the existing infrastructure was eliminated. The plan also included a continuance of all the existing environmental programs. Details of this mining plan and corresponding reclamation plan, as modified by the permitting process, are described in Sections 2.0 and 3.0 of this 2018 Plan update.
The agencies determined that the expanded plan could have the potential to result in a significant environmental impact, thus requiring preparation of an EIS/EIR before the new mine plan could be
Castle Mountain Mine Plan and Reclamation Plan 1-14 January 2, 2019 approved. The agencies proceeded with the preparation of these documents and issued a Final EIS/EIR in October 1997. The County approved the application in November 1997 and the BLM followed with an approval in March of 1998 and a second approval in July 1998 that included the North Overburden Stockpile. The FWS also updated their BO (1-8-97-F-37) and determined a “not likely to jeopardize” ruling and that no critical habitat would be affected. The approvals resulted in modifications and additions in the 1990 Mine/Reclamation Plan that included among others, clarification of overburden slope requirements, requirements on placement of overburden cover material, and requirements to modify the straight-line geometrics of the overburden and heap leach pile shapes to blend with the natural topography. These revisions were incorporated into the 1998 Plan, ver.2.0.
1.4.3.3 PERMITTING (Present)
In 2012, the California Department of Conservation, Office of Mine Reclamation14(OMR), determined the Company met the prescribed land reclamation and revegetation standards for plant density and diversity as of 2012 and the Company subsequently submitted an IMP to the County to maintain site permits in good standing. Concurrently, Plan modifications were submitted to BLM Needles Field Office to continue mineral exploration at the site.
The County, in July 2013, approved a revision to the 1998 Plan for an extension of mine activities by an additional five years until December 31, 2025.
The Company received BLM approval of renewed mineral exploration in February 2013 (DOI-BLM-CA- D090-2013-DNA), for expanded mineral exploration in September 2013 (DOI-BLM-CA-D090-2013-0105- DNA), and again in September 2018 (DOI-BLM-CA-D090-2018-0037-EA). These authorizations confirmed that prior BLM mine authorizations approved in 1990 (EIS No. 890053) and expanded in 1998 (BLM Record of Decision CACA31137; EIS No. DES 97-10) were still in full force and effect and that additional NEPA analysis was not required for activities at the project site that proceed in accordance with the approved plans.
1.5 GENERAL DESCRIPTION OF APPROVED PLAN OF OPERATIONS
1.5.1 GERNERAL PERMIT CONDITIONS
1.5.1.1 1998 PLAN AMENDMENTS
As mentioned above, the 1998 Plan approved revisions to the original 1990 Plan issued by the County and BLM. Briefly, these revisions included:
• revising the location, size and configuration of disturbances associated with the open pits, overburden sites, and heap leach pad. • utilizing a portion of the additional overburden that would be produced in mining the additional ore deposits to sequentially backfill the Lesley Ann, Jumbo and South Extension pits; • adjusting the Site Boundary, to incorporate the adjacent 150 acre Milma patented placer mining claim now owned by Viceroy, and moving the north and west boundaries outwards by approximately one-quarter to one-half mile, respectively;
14 See Appendix F – Feb. 2012 Letter from OMR to County of San Bernardino
Castle Mountain Mine Plan and Reclamation Plan 1-15 January 2, 2019 • reducing the frequency at which stream flows and water quality at Piute Spring are monitored; • modifying the requirement to stain freshly exposed rock surfaces; • and other amendments to the Conditions of Approval and Stipulations related to reclamation.
The approved operation involves a total site disturbance of 1,375 acres-this is exclusive of the North and South Clay Pit Reclamation Areas, which are 48 acres and 36 acres, respectively.
1.5.1.2 2013 PLAN AMENDMENTS
The 2013 County amendment to the Mining CUP and Reclamation Plan effectively extended the approved 1998 Plan schedule until December 31, 2025, and this 2018 Plan update reflects that extended project schedule.
This 2018 Plan update will not deviate from prior permit conditions applicable to the approved 1998 Plan, unless explicitly stated in this plan (see Table 1-0) and subsequently approved by the BLM or County (or both), respective of jurisdiction. Granted, certain permit conditions may now be redundant or no longer applicable due to the lesser scope of this 2018 Plan update from earlier approved mine and reclamation plan versions; these changes will be addressed throughout this 2018 Plan update, but also specifically in section 1.11 and on Table 1-6.
1.5.2 LAYOUT OF OPEN PITS, OVERBURDEN SITES and HEAP LEACH PAD AREAS
The 1998 Plan identified additional ore reserves delineated through exploration programs which are in close proximity to the ore deposits for which the Company had been authorized to mine. The sequence and manner in which the ore deposits will be mined will achieve optimum environmental and operational efficiencies. While the 2018 Plan update does not identify additional ore reserves in the form of new hardrock ore discoveries, it does target increased ore reserves and stockpiles that remained at the site or were backfilled into the Lesley Ann pit up until the halt of active pit mining in May 2001. The potential for future mining of low-grade ore stockpiles was foreseen by the mine operators and was specifically built into their strategy for site reclamation. This possibility was also recognized by the agencies as they established this concept (protore stockpiling for future use) in the conditions of approval for the project. For example, County Condition of Approval #101 states: “Following project completion, the Lesley Ann/Jumbo and Oro Belle pits shall be accessible for potential recovery of low grade ore”; while BLM Project Stipulation #10 states: “Protore shall be separated in the overburden pile to the extent possible.”
The market price for gold in 2018 is more than 330% above the price range from 1998 to 2001, and this price increase allows for the mining of stockpiled ore and protore. This 2018 Plan update details how the stockpiled and backfilled ore will be processed as Run-of-Mine(ROM)15 ore on the Heap Leach Pad. A change to more positive market economics (for gold) and authorization of future processing of the ore/protore stockpiles by the approved 1998 Plan was thoroughly described in multiple sections of the 1998 Plan. These discussions include the statements found in approved 1998 Plan sections:
15 Run-of-Mine generally means excavated ore will not undergo any crushing or milling and will be transported directly to the heap leach pile for leaching.
Castle Mountain Mine Plan and Reclamation Plan 1-16 January 2, 2019 2.1 INTRODUCTION: “Low-grade ore and protore (the latter material contains a lower concentration of gold) excavated from the pit is stored in stockpiles for potential processing at a later time, when improvements in prices and/or technology can allow profitable treatment of such material for additional gold recovery. The Company intends to process these stockpiles after the high grade materials have been processed. However, if at that time, conditions are such that the protore stockpiles would not be profitable to process, their upper surface would be prepared for revegetation. Since the protore stockpiles would be a resource that could become economic at some future date, and due to the limited amount of growth media available, growth media would not be placed on the protore stockpiles as part of the reclamation program.” 2.4.2.2.1 PIT DESIGN: “As is customary in the mining industry, in order to maximize the recovery of the contained gold, pit design will be evaluated several times during the course of mining in response to these changing factors”, and; “Because these factors are to some extent interdependent, and metal prices and costs are variable, the bench levels shown above are estimates. Final elevations could vary by perhaps 100 or 200 feet from the estimates shown.” 2.4.2.2.1 PIT CHARACTERISTICS: “As is typical of most mining operations, more precise data will be generated as operations proceed, leading to engineering refinements and other modifications to operational plans in future years. All material departures from the procedures described herein will be submitted to the appropriate governmental agencies for approval prior to implementation.” 2.4.3 STAGED DEVELOPMENT: “Mining is a dynamic process and must be responsive to changes in economics and geotechnical factors. As with most major projects, changes will occur throughout the life of the operation.” 3.2 PURPOSE and USE OF THE RECLAMATION PLAN: “The activities described in this Reclamation Plan are based on a detailed engineering assessment of the current ore reserves at Castle Mountain. What must be kept in mind, however, is that the determination of ore reserves is a complex exercise involving a myriad of economic and technical factors. As these factors change over time, estimated ore reserves can also change. Changes that may occur to these factors subsequent to the agencies’ approval of the Plan Amendment Application could warrant a reassessment of the procedures and schedules discussed in this Reclamation Plan.” 3.5.3 POST – MINING LAND USE: “Mining will be an appropriate second use of the site, and the mine’s reclamation program is structured in a manner so as to not unduly restrict or impede such future use. Gold mineralization is disseminated at Castle Mountain with no sharp physical demarcation between ore and overburden. In such circumstances the material is mined to an economic “cut-off” grade. The walls and floor of the pit contain gold mineralization in concentrations that are uneconomic to mine under current (1998) conditions. However, future improvement in technology (or lower unit costs that might be achieved with improved technology) and/or a higher gold price might allow the operator to mine these areas and increase the ultimate recovery of the resource.”
These statements are important because they highlight both the flexibility required of a successful mine plan, and how that flexibility is even more warranted for a low-grade disseminated gold ore body such as that found at Castle Mountain where the extent of recoverable resources will change depending on changing economics. Additionally, the 1998 Plan authors note that reserves will change over time, dependent on market conditions, and specific to the Castle Mountain Mine, this means that much of the low-grade disseminated ore, referred to as “overburden stockpile” in the approved Plan and used to backfill the Lesley Ann pit, is an ore resource16 that will be removed and processed economically on a heap leach pad. Throughout the remainder of this 2018 Plan update, protore stockpiled in the Lesley Ann pit for future processing will be referred to as backfilled protore stockpiles. Removal of the
16 NI 43-101 Technical Report on the Preliminary Feasibility Study for the Castle Mountain Project (August 2018)
Castle Mountain Mine Plan and Reclamation Plan 1-17 January 2, 2019 backfilled protore stockpile and ROM processing of this low-grade disseminated ore will be the first stage of resumed mining at the Lesley Ann pit and is expected to consume the remaining available mine schedule, or until approximately 2025. This does not represent a modification to the approved 1998 Plan because there is no proposal to expand mining beyond those limits already approved (vertically or laterally) and, as described above, the approved 1998 Plan contemplated this future potential for an operation once mining economics had recovered from the industry lows seen in the late 1990’s. Section 2.0 of this 2018 Plan update will further detail processing of the backfilled protore stockpiles.
The 1990 Plan originally authorized open pits, heap leach pads and overburden sites were designed to accommodate up to 30 million tons of ore (ore reserves and protore) and 60 million tons of overburden. It’s estimated that only approximately half or about 37 million tons of ore have to date been placed on the heap leach pad. The 1998 Plan authorized enlarged open pits, heap leach pads and overburden sites designed to accommodate up to 71 million tons of ore, and 223 million tons of overburden. In 1998, it was estimated that of the 223 million tons of overburden, approximately 95 million tons would be sequentially backfilled into the Lesley Ann, Jumbo, and South Extension pits. See Table 1-1. This backfill of protore stockpiles into the Lesley Ann pit was completed and all but the upper benches of the original pit are noticeable today. No backfilling of Jumbo ever began at the site.
Table 1-1 Proven, Probable and Possible Ore Reserves (In Millions of Short Tons) Mine Plan Ore Over-burden Total Strip Ratio 1990 Plan: Jumbo South/Lesley Ann and Jumbo 21 50 71 2.38 Oro Belle 9 10 19 1.11 Sub Total 30 60 90 2.00 1997 – 98 Plan: Jumbo South/Lesley 26 82 108 3.15 Ann/South Extension Oro Belle, Jumbo and Hart Tunnel 36 141 177 3.92 Sub Total 62 223 285 3.60 2018 – 2025 (Phases I & II ): Lesley Ann/South Extension 0 0 0 0 Lesley Ann low-grade backfilled ore 18 33 51 1.7 stockpile Oro Belle, Jumbo and Hart Tunnel 0 0 0 0 Sub Total 18 3317 51 1.7 Total 100 283 393 2.4 (avg.)
As mentioned above, the permitted acreage of disturbance for this 2018 Plan update is estimated to be 1,375 acres (no change from the 1998 Plan), exclusive of the North and South Clay Pit Reclamation Sites, as compared to 890 acres previously approved in the 1990 Plan. The estimated cumulative acreage of land that could potentially be disturbed, as approved in the 1998 RODs and County approvals, under this 2018 Plan update, is shown in Table 1-2. The layout for the extended mine life from the approved 1998 Plan is shown in Figure 1-4 (1996 Mining Plan). The portions of Figure 1-4 highlighted with diagonal stripes are areas of disturbance that are incremental to the areas approved in the original 1990 Plan,
17 This volume has already been counted as overburden when it was mined and stockpiled in the Lesley Ann pit.
Castle Mountain Mine Plan and Reclamation Plan 1-18 January 2, 2019
REV: 10/17/2018 1 REV: Page: Mining Plot Plan (TAG) File: F1-5 CMV-1996
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
0 1,500’
FEET Source: Castle Mountain Venture 1996 MINING PLOT PLAN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 1-4 C O R P O R A T I O N
Mojave National Preserve (National Park Service)
Approved Mine Boundary (1997 EIS/EIR) Designated Area Roads
Castle Mountains National Monument (National Park Service) LEGEND were approved by the agencies in 1998, but where mining has not yet been completed18, or only partially completed. The portions of Figure 1-4 highlighted with a herringbone pattern are the areas approved in 1990 for use as heap leach pad sites though it was later agreed the Company would not develop these areas as heap leach pad sites and would instead join and expand to the west the existing heap leach piles.
Table 1-2 Comparison of Area of Disturbance (acres) 1998 Plan 1998 Plan 2018 Phase II Area 1990 Plan Phase I Phase II (cont’d.) Open pits 135 198 307 307 (no change) Overburden storage sites 300 432 516 516 (no change) Leach pads 330 313 421 421 (no change) Growth media piles/nurseries 70 41 50 50 (no change) Roads 30 49 48 48 (no change) Crushing area, administration building, parking, mine contractor’s 15 15 15 15 (no change)19 shop, and warehouse Process and basin areas 10 14 18 18 (no change) TOTAL AREAS 890 1,062 1,375 1,375 (no change)
Additionally, the approved 1998 Plan did not include changes to the mine surface plant, crushing plant, overland conveyor system, processing facilities, access road, overhead electrical transmission line, ground water supply system, and administration area, compared to those facilities defined in the 1990 Plan. Although the design of these facilities are not changed by this 2018 Plan update, site reclamation carried out from 2001 to 2006 decommissioned most of these facilities and this 2018 Plan update will re-establish some of those approved facilities (see Figure 1-5). However, because mining proposed in this 2018 Plan update will be Run-of-Mine, many of the facilities approved for the site will not be required and not re-established at this time. This does not prohibit those facilities from use at a future time, only that under this update under the 2018 Plan there is no need, due to the smaller scale of the operation.
The facilities which will not be re-established at this time include:
Comminution Circuit Crushing Plant Overland Conveyor Mine Shop Building
18 Phase II of the 1998 Mine Plan (ver. 2.0) was not initiated when site reclamation began in 2001. Mining will resume at the Phase I, Stage 5D of the mine plan which corresponds with the remaining mining approved by the June 1998 mine Plan. 19 Disturbance for crushing will not occur during Phase II continued operations.
Castle Mountain Mine Plan and Reclamation Plan 1-20 January 2, 2019 File: F2-14A CMV-F2-14A CMV-MINE STATUS at END of STAGE 5D (TAG) Page:1 REV: 10/17/2018
Desert Tortoise Fence
Desert Tortoise Fence
Gold Processing Plant to be Re-established 2018 Source: Castle Mountain Ventures, 2018. Approximate Area of Heap Leach Pad Expansion (Portion to Overlap Existing Reclaimed Area) Backfill/Protore to be Mined (Removed) and Hauled to Heap Leach Pad END of STAGE 5D - 2018 MINING PLAN UPDATE North Nursery to be Established CASTLE MOUNTAIN MINE County of San Bernardino, California Desert Tortoise Fence
LEGEND 1998 Approved Mine Plan Boundary LILBURN FIGURE 1-5 C O R P O R A T I O N 1998 Approved Facilities Approved facilities that will be re-established to conduct Phase I and Phase II mining include:
Administration Trailers – Already present and located on patent land. Mine Maintenance area – (Not an overland structure) and located on patent land. Gold Recovery Plant – Includes Process Solution Tank/Basins and Stormwater Basins. All located on patent land. Heap Leach Pad – Phase II approved expansion of the prior heap leach pad will occur on both public and patent land.
Refer to Table 1-3 for additional detail regarding mine facilities and land status.
Table 1-3 Public and Private Land20 (acres) Phase I Phase I Total Total Disturbed Disturbance Type Disturbance21 Disturbance Disturbance Lands (2025)22 (pre-patents) (post-patents) Permitted23 24 Public Patent Public Patent Public Patent TOTAL
Mine pits 142.5 47.5 10 180 10 190 307
Overburden sites 228 2325 5 246 22 264 516
Heap Leach pad area 239 0 10 229 118.5 302.5 421
Growth media 70 0 2.5 67.5 2.5 67.5 98 storage/nurseries/Roads Crushing area, administration building, parking, mine shop, 7 8 0 15 0 15 15 warehouse Process and stormwater basin 18 0 0 18 0 18 18 areas
SUBTOTAL 704.5 78.5 27.5 755.5 153 857 1,375
% Ownership 90% 10% 4% 96% 15% 85%
TOTAL SURFACE DISTURBANCE 783 783 1,010 1,375
20 Mineral Patents received in from 2007 to 2009 (see Table 1-4, Castle Mountain Mine Patent Land) 21 Phase I was completed in 2001 which was the peak year for land disturbance 22 2025 denotes the estimated end of Phase II mining 23 1998 ROD/CUP 24 Public refers to land managed by the Bureau of Land Management 25 This total does not include 60 acres of disturbance attributed to historic clay quarrying and reclamation by the Company
Castle Mountain Mine Plan and Reclamation Plan 1-22 January 2, 2019 1.5.3 SITE BOUNDARY
At the time the 1990 Draft EIS/EIR for the 1990 Plan was issued, the Milma Patent (See Figure 1-2) was owned by a third party. The north line of the site boundary was therefore drawn to exclude the Milma Patent. Shortly before the 1990 Final EIS/EIR was issued, Viceroy was able to negotiate terms for the purchase of the Milma Patent, and subsequently acquired that parcel in December 1990.
Reclamation of the abandoned clay quarry on the Milma Patent was discussed in the 1990 Final EIS/EIR for the 1990 Plan and approved by the County. The County's Condition of Approval No. 94 (and BLM's equivalent 1990 ROD Stipulation No. 77) states, in part: " ... The Applicant shall incorporate reclamation of the adjacent North Clay Pit, located offsite, into the Mine/Reclamation Plan.” Reclamation at both the North and South Clay Pits has been completed.
This 2018 Plan update remains unchanged regarding the project boundary approved in the 1998 Plan, and similarly covers 1,375 acres. However, land ownership within the project boundary has changed significantly since the 1998 Plan went in effect as of June 1998. Table 1-3 shows the land ownership changes which resulted from the DOI approval of the various mineral patent applications filed by the Company during the early 1990’s. Table 1-4 lists CMV patented lands. By the end of 2025, this 2018 Plan update estimates that approximately 1,000 acres of the total 1,375 acres will see some form of approved disturbance, and of these disturbed lands, approximately 85% (857 acres) will occur on private land.
1.5.4 FREQUENCY OF MONITORING AT PIUTE SPRING and GROUNDWATER ELEVATION MONITORING
The 1998 approved Plan revised monitoring frequency at Piute Springs to quarterly monitoring. For almost 20 years, extensive groundwater elevation and water quality monitoring have been conducted throughout the Lanfair basin between the Mine and Piute Springs, the latter of which is located approximately 15 miles southeast from the Mine and the water wells remain in use by the Company. The 1990 Plan approved an annual average extraction of 725 acre/feet of groundwater. By 1998, after approximately a decade of extraction at this rate, no mine related impact (sustained water elevation decrease) had been recorded outside the immediate vicinity of the extraction wells (i.e. cone of influence/depression). Groundwater elevation monitoring wells used by the Company, and approved by the compliance report, “Plan for Groundwater Monitoring and Contingency Water Supply ” (August 1990), included wells W-3, W-19, W-37, W-38, and PS-2; although PS-2, W-37, and W-38 are often noted as the official monitoring wells for site ground water levels (see Figure 1-6). Similarly, there have been no chronic mine impacts to water quality. Following approval of the 1998 Plan, the average annual groundwater extraction rate was decreased to 625 acre/feet while groundwater elevation and quality monitoring continued until most elevation and groundwater quality monitoring was halted in conjunction with the stoppage of mining (per BLM agreement) between 2003 and 2006 for most locations. Almost 20 years of data collection has shown no Mine-related impacts to Piute Springs and the greater Lanfair regional water basin; this finding is in line with the results of multiple investigations conducted from 1987 to 2001 by both the Company and the agencies.
Castle Mountain Mine Plan and Reclamation Plan 1-23 January 2, 2019 Table 1-4 Castle Mountain Venture – Patent Lands Patent Acres Year Patented Patent Number Original Issuee Oro Belle Oro Belle Mines and 33.64 1914 424670 Company Oro Belle Fraction lodes Oro Belle Mines Oro Belle Lode 1 20.236 1918 649101 Company Standard Sanitary Pacific Clays 59.592 1939 1101406 Manufacturing Company Milma Patent 150.0 1942 1113695 Herman F. Coors 2007 04-2007-0004 Viceroy Gold 2007 Mill Sites 772.5 (FHFC-1991) (CACA-29997) Corporation 2007 04-2007-0003 Viceroy Gold 2007 Lodes26 206.746 (FHFC-1991) (CACA-24570) Corporation 2007 04-2007-0005 Viceroy Gold 2007 Water Wells 53.74 (FHFC-1991) (CACA-30912) Corporation 2009 04-2009-0009 Viceroy Gold 2009 Appeal Decision 5.0 (FHFC-1991) (CACA-29997) Corporation
LAND TOTAL 1,301.454
The five monitoring wells listed above were all permanently abandoned during mine reclamation activities that occurred around 2005 so further use of them is not possible. Additionally, it is unlikely replacement monitoring wells cand be installed at the exact same locations because while the Company still retains the unpatented mine claims at these locations, they are now situated within the Mojave National Preserve, whereas in 1988 when these wells were originally installed, the land was managed by the BLM. The Preserve is administered by the National Park Service who, by policy, is typically not as amenable to authorizing the scale of disturbance which would be required to reinstall wells at these former locations.
This 2018 Plan update proposes that groundwater elevation monitoring will now be conducted among a network of five new monitoring wells. Three of the new monitoring wells (2017-1MW, 2017-2MW and 2017-3MW) are already in place north and south of the heap leach pad area and two more (2018-1MW and 2018-2MW) will be installed further south and west to replace original wells W-37 and W-38. A replacement for PS-2 is not proposed at this time but with approval by the Park Service, CMV proposes to continue Piute Springs water flow and quality monitoring.
26 The use of the lands described in this patent, and any mining activities therein are subject to such reasonable regulations as may be prescribed by the Secretary of the Interior to protect the scenic, scientific and environmental values of the public lands of the California Desert Conservation Area against undue impairment, and to assure against pollution of the streams and waters within said area.
Castle Mountain Mine Plan and Reclamation Plan 1-24 January 2, 2019 W-45P NEVADA CALIFORNIA REV: 12/05/2017 1 REV: Page: .CDR (TAG) W-14P W-3P W-18P
W-19P
2017-3MW
2017-2MW
F3-5 CMV-GROUNDWATER MONITORING SITES MONITORING File: F3-5 CMV-GROUNDWATER 20171-1MW 2018-1MW
W-37 2018-2MW
W-38
PS-2
Source: Castle Mountain Ventures, 2018.
Approved Mine Boundary Groundwater Monitoring Site and Name 0 2 2018-2MW GROUNDWATER Water Supply Wells MILES W-14P Monitoring Wells (Abandoned) MONITORING SITES W-38 CASTLE MOUNTAIN MINE County of San Bernardino, California
LILBURN C O R P O R A T I O N
LEGEND FIGURE 1-6 The continued operation of a network of monitoring wells, as previously approved and analyzed in 1990 and 1997 EIS/EIR and as reconfigured in conjunction with this Plan Update, which will continue to satisfy the original intent for monitoring mining related groundwater withdrawal and its impact, if any, on the regional Lanfair water basin and specifically on Piute Springs. An analysis of the continued operation and reconfiguration of the well network is included with the report, Addendum Report to Castle Mountain Project Plan for Ground Water Monitoring and Contingency Water Supply to Piute Spring, included in Appendix L of this 2018 Plan update.
1.5.5 ROCK STAINING REQUIREMENT AND PLACEMENT OF COVER MATERIAL
The rock staining requirement has been waived by both the BLM and County,27 and prior discussion has been omitted.
Final slopes shall be contoured as described further in this Plan (Section 3.0) and shall incorporate, to the extent available, a final covering of darker material that blends with the surrounding landscape.
1.5.6 VEGETATION SALVAGE REQUIREMENT AND THE REVEGETATION REVIEW COMMITTEE
The 1990 Draft EIS/EIR acknowledged that reestablishment of desert vegetation to pre-disturbance cover and composition would be a lengthy process, and that a reclamation program could not be successful in the absence of a successful revegetation component. To facilitate revegetation, the agencies stipulated that the Company implement a multi-faceted revegetation research program that included, amongst other things:
Establishing quantifiable goals for density and diversity of perennial species. For land disturbance completed up until the cessation of mining in 2001, permits required reclamation to re-establish 15% of native plant diversity and 21% of native plant density ten years following mine closure. These standards were attained in February 201228. This stipulation should be considered met on reclaimed lands and these standards will be used for future revegetation. Identification of dominant species to be used in revegetation. With the completion of the various revegetation research trials and results from actual successful revegetation, it has been determined that while cactus/succulents do present good revegetation diversity, they are not dominant species. The specific plant species which qualify as dominant include29: o Creosote bush o Four-wing saltbush o California buckwheat o Rabbitbrush and any plant with a yellow flower o Herbaceous perennials and grasses
The Company, the agencies and several interest groups agreed in late 1990 to form a Revegetation Review Committee. The mandate for the committee would be to review the annual revegetation report Viceroy was required to file with the agencies, to advise the Company what actions it might take to
27 See Appendix H – OMR letter, September 9, 2010 28 See Appendix F - OMR letter, dated February 17, 2012 confirming attainment of reclamation standards. 29 See Appendix I - Samuel A. Bamberg, PhD, memorandum dated August 13, 2018
Castle Mountain Mine Plan and Reclamation Plan 1-26 January 2, 2019 increase the success of its revegetation efforts, and to advise the BLM and the County as to adjustment which should be made to the revegetation standards. This 2018 Plan update confirms that those mandates have now been satisfied.30
Much of the original (1990 – 2001) mine related disturbance reclamation and revegetation approved by the agencies has been successfully completed. A 2012 letter from OMR stated that the reclamation goals had been achieved that year; the letter is included as Appendix F. Prior versions of this mine Plan placed much focus on revegetation of the site due to the known complexity of successful land revegetation of arid mine lands and because such little research had up until that point been the focus for regulatory agencies. The original mine underwent approvals during the late 1980’s, when there was less information available regarding successful revegetation programs for lands characterized by the specific challenges (i.e. revegetation in the Mojave Desert) present on the Castle Mountain Mine site and from which both the industry and agencies could draw conclusions and establish reclamation goals. From this known lack of available scientific data came some of the project stipulations found in the 1990 and 1998 mine conditions of approval31. Because that information gap is no longer present today (the mine was successfully reclaimed) many of these former project conditions and stipulations no longer apply to this 2018 Plan update32, though the invaluable information which resulted from those stipulated programs will continue to be employed at the site during all present and future reclamation and revegetation. Most of this information derived from the past revegetation success at the Site has been the result of continued collaboration with the experts that implemented and monitored the revegetation effort at Castle Mountain. Dr. Samuel Bamberg was the lead arid lands ecologist who reviewed the original reclamation plan, reviewed initial reclamation began in 2001, authored the revegetation monitoring reports and monitored reclamation and successful attainment of the revegetation density and diversity standards. Much of the updated information in these sections comes directly from Dr. Bamberg, as well as the report, Castle Mountain Mine, San Bernardino County, Ca, Research and Reclamation 1990-2005, Summary Reports, authored by associate Dr. Ingrid E. Bamberg in December 2005.
To date, the reclamation and environmental stewardship conducted at the Castle Mountain Mine has been recognized across industry, among the agencies, and environmental groups as one of the best examples of successful reclamation of mined lands in an arid climate. Select recognition includes:
1990 – During public hearing at the County Planning Commission, California environmental community (represented by Sierra Club Legal Defense Fund) hailed the reclamation plan as state-of-the-art, precedent-setting, and a model for future reclamation planning; 1990 – Recipient of the California Mining Association “Excellence in Reclamation Award” for the Reclamation Plan for the Castle Mountain gold mine; 1992 – BLM designated Castle Mountain gold mine as a “showcase” for demonstrating responsible multiple use of public lands administration by the BLM; 1995 – Recipient of the BLM “Health of the Land Award” to Viceroy for its commitment to using innovative technical procedures to protect environmental resources.
30 See 11 TH Annual Revegetation Report (page 2), January 2002 31 The County attributed 117 Conditions of Approval as mitigation measures for the approved action. The BLM attributed 104 Project-Stipulations as mitigation measures for the approved action. 32 See Table 1-6 and/or section 1.10 of this Plan for a list of the Conditions that have been updated from this Plan.
Castle Mountain Mine Plan and Reclamation Plan 1-27 January 2, 2019 2000 – CMV worked closely with staff from California Office of Mine Reclamation to validate and, where needed, amend the revegetation strategy at the site. Final product was the report: Castle Mountain Mine Revegetation Analysis in Nov. 2000. 2012 – OMR recognizes that revegetation success standards have been met for the last remaining reclamation area at CMM, the heap leach pad. Even though the consensus was that it would take at least 10 years to meet reclamation standards given the arid climate, the heap leach pad area achieved revegetation standards in about 6-years, due to innovative revegetation techniques employed at the site.
To reiterate, the mandate of the Revegetation Review Committee (“RRC”) was to further the success of the future revegetation effort and help advise on the appropriate revegetation standards. Because these standards were affirmed by the County and OMR in their November 2000 report33, later attained by 2012, and because the same roadmap for future revegetation success will be implemented, there is no further need for the existence of the RRC. This is similar for additional site revegetation research, insofar as the goal of the research programs was the establishment of correct reclamation and revegetation procedures which would achieve the density and diversity standards set for the site. (See Table 1-5 for the final revegetation reclamation standards approved by OMR in 2000.) Now that those standards and procedures are set, the need for additional research will not be included in this 2018 Plan update. This does not necessarily mean that no revegetation research will occur at the site if there is a real need , but that it is no longer appropriate for this condition to remain as a project stipulation For a complete summary of revegetation research conducted on site and discussion regarding the final Revegetation Committee meeting on January 2002, see the attached memo from Dr. Sam Bamberg34 35
Table 1-5 Standards of Success for Castle Mountain Mine Revegetation Program Standards of Success 5 Year 10 Year Density (# of perennial plants/acre) 255 895 Richness (total # species on site) 536 1837
1.6 PROJECT STIPULATIONS (BLM) and CONDITIONS OF APPROVAL (County)
Both the County and BLM assigned specific conditions to the actions approved in both the original 1990 Plan and again in the 1998 Plan. BLM assigned 104 Project Stipulations (“Stipulations”) and the County assigned 117 Conditions of Approval (“Conditions”). Some of the County and BLM Conditions and Stipulations mirror each other but others are unique conditions that pertain to each specific agency. Because of the updates that have occurred at the site, as discussed in this 2018 Plan, some of these requirements simply no longer apply and therefore, have been updated and included in Table 1-6 and section 3.0. Table 1-6 contains those agency requirements where updates are required, and details the proposed Condition or Stipulation change, and a related explanation for each change. Proposed in this table is the deletion of ten former requirements, amendment to eight others, and a notation to one requirement. Deletions and updates are presented below in through the use of strikeouts.
33 Castle Mountain Mine Vegetation Analysis, Office of Mine Reclamation, November 2000. 34 See Appendix J-Memorandum, Current Status of Revegetation Research Programs, Castle Mountain Mine, April 2018 35 See also, Castle Mountain Mine, Research and Reclamation, 1990-2005 Summary Report, December 2005 36 5 species equal 4% of baseline vegetation richness after five years. 37 18 species equal 15% of baseline vegetation richness after 10 years.
Castle Mountain Mine Plan and Reclamation Plan 1-28 January 2, 2019 Table 1-6 County Conditions of Approval and BLM Project Stipulations 1998 2018 Agency-# Conditions of Approval (County) Condition / Stipulation and/or text update Project Stipulations (BLM) This conditional use approval is for the establishment of Mining Conditional Use Permit and Reclamation Plan No. 90M-013 (hereafter "Mine/Reclamation Plan") for the Castle Mountain Project. The Project is an open pit gold mine operation on 265 1,301acres of patented mining claims and a reclamation plan on the entire 3,910- As of 2007, the Project is located on 1,301 acres of patented mining SBC-1 acre project site located approximately 100 miles east of Barstow, claims. California. A copy of these Conditions, the Mine/Reclamation Plan, the Mitigation Compliance Program, and the Plan for Groundwater Monitoring and Contingency Water Supply for Piute Spring shall be kept on site during the operation. The Mine/Reclamation Plan shall be effective for a maximum of 35 years, expiring on December 31, 2025 2035. The Conditional Use Plan requests change to December 31, 2035 to allow additional time SBC-2 Permit shall be in effect as long as the Mine/Reclamation Plan is valid (10 years) for land reclamation. and the operation is in compliance with the Mine/Reclamation Plan and Conditions of Approval. If the mining, reclamation, or operating procedures change from those outlined in the Mine/Reclamation Plan, an amendment shall be filed and approved before such changes are made effective. A Updates to approved Mine Plan and Reclamation Plan, (90M-013) SBC-4 Revised Final Mine Plan and Reclamation Plan shall be submitted ver.2.0 have been submitted to the County. Once approved, the within 90 days of approval which combines the final approved updated Plan will be referred to as Plan ver. 2.1 procedures of the 1997 Plan Amendment with the 1990 approved plan into a single comprehensive document. Project water requirements shall be minimized by the following Water conservation will be further enhanced to include: operational procedures: a. Crushing the ore to reduce leaching time so that less water a. No crushing or over-land conveying of ore is planned while BLM-12 will be circulated and evaporation will be reduced. processing only ROM material. Water conservation will be (SBC-39) b. Employing drip irrigation to distribute solution directly to the increased through this operation as less water will be used in heap leach surfaces; use of sprinkler systems during the the crushing/conveying operations. operational phase of each leach pad is prohibited. b. Coarser nature of the ROM ore entrains less water in the
Castle Mountain Mine Plan and Reclamation Plan 1-29 January 2, 2019 heap leach pile, about 40% less; c. Drip irrigation lines on the heap leach will be buried to further limit evaporative water loss. The Operator shall comply with the "Addendum Report to Castle The 1998 approved Plan revised monitoring frequency at Piute Mountain Project Plan for Ground Water Monitoring and Springs has been changed to quarterly monitoring. For almost 20 Contingency Water Supply to Piute Spring" (August, 1990; revised years, extensive groundwater elevation and water quality monitoring Feb. 2019) and Castle Mountain Expansion Project FEIS (October, have been conducted throughout the Lanfair basin between the mine 1997) which require: site and Piute Springs, the latter located approximately 15 miles a. Water levels in monitor wells W-3, W-19, W-37, W-38, and PS- southeast from the mine site and the water wells currently in use by 2 2017-1MW, 2017-2MW, 2017-3MW, 2018-1MW and 2018- the Company. The 1990 Plan approved an annual average extraction 2MW and stream flows and water quality at Piute Spring shall of 725 acre/feet of groundwater. By 1998, after approximately a be monitored quarterly until the end of mining operations or decade of extraction at this rate, no mine related impact (sustained reclamation activities which use groundwater, or as water elevation decrease) had been recorded outside the immediate determined by mutual agreement between the BLM and the vicinity of the extraction wells (i.e. cone of influence/depression). Operator. Groundwater elevation monitoring wells used by the Company and approved by the “Plan for Groundwater Monitoring and Contingency b. In the event groundwater levels in monitor well 2018-2MW Water Supply ” (August 1990) included wells W-3, W-19, W-37, W- W-37 begin to approach the level predicted by the 38, and PS-2; although PS-2, W-37, and W-38 are often noted as the BLM-13 hydrogeologic modeling completed for the EIS, an additional official monitoring wells for site ground water levels. Similarly, there (SBC-40) monitor well (W-40) shall be developed south of monitor well have been no chronic mine impacts to water quality. Following 2018-2MW W-37. This well shall be monitored with the same approval of the 1998 Plan, the average annual groundwater frequency as 2018-2MW W-37. The location of the new well extraction rate was lowered to 625 acre/feet while groundwater will be approved by the BLM and potentially NPS before elevation and quality monitoring continued until most elevation and installation. groundwater quality monitoring was halted in conjunction with the
stoppage to site mining (per BLM agreement) between 2003 and c. In the event groundwater levels in monitor well 2018-2MW W-37 reach the level anticipated by the hydrogeologic 2006 for most locations. Almost 20 years of data collection has modeling completed for the EIS, the hydrogeologic model shown no mine related impacts to Piute Springs and the greater shall be recalibrated and the characteristics of the Lanfair Lanfair regional water basin which is in line with multiple Valley aquifer shall be reevaluated. The modeling report and investigations conducted from 1988 to 2001. other information shall be submitted to the BLM for its consideration and decision as to whether additional mitigation The five monitoring wells listed above were all permanently measures are necessary. abandoned during reclamation activities that occurred around 2005 so further use of them is not possible. Additionally, it is highly d. BLM's decision as to whether additional mitigation measures unlikely replacement monitoring wells could be installed at the exact
Castle Mountain Mine Plan and Reclamation Plan 1-30 January 2, 2019 are necessary shall be circulated for public review and same locations because while the Company still retains the comment prior to implementation. unpatented mine claims at these locations, they are now situated within the Mojave National Preserve whereas in 1988 when these If water level declines in monitor well 2018-2MW W-37 ·exceed the were originally installed the land was managed by the BLM. The drawdown predicted by the hydrogeologic modeling before BLM's Preserve is administered by the National Park Service who, by policy, decision respecting additional mitigation measures (if any) becomes is typically not as amenable to authorizing the scale of disturbance final, the Operator shall reduce its groundwater pumping rates in which would be required to reinstall wells at these former locations. accordance with the provisions of the groundwater monitoring plan. This 2018 Plan update proposes that groundwater elevation monitoring will now be conducted among a network of five new monitoring wells. Three of the new monitoring wells (2017-1MW, 2017-2MW and 2017-3MW) are already in place north and south of the heap leach pad area and two more (2018-1MW and 2018-2MW) will be installed further south and west to replace original wells W-37 and W-38. A replacement for PS-2 is not proposed at this time but with approval by the Park Service, CMV proposes to continue Piute Springs water flow and quality monitoring.
This replacement network of monitoring wells will serve the original purpose for monitoring mining related groundwater withdrawal and its impact, if any, on the regional Lanfair water basin and specifically on Piute Springs. A technical review and acceptance of these new monitoring wells into the network of ground water monitoring wells at Castle Mountain Mine is included with the report, Addendum Report to Castle Mountain Project Plan for Ground Water Monitoring and Contingency Water Supply to Piute Spring. This addendum report is also included in Appendix L of this 2018 Plan update. The Operator shall continue to develop its has completed the goals of Revegetation research will likely continue at the site though in a the revegetation research program based upon information provided reduced capacity and at the discretion of the mine operator. by a qualified expert in desert flora mine reclamation and Research will continue where there is room for specific improvement BLM-21 revegetation. The goals of the formerThis research program included: to the Reclamation Plan but is no longer a specific Stipulation or (SBC-48) shall include, but not be limited to the following measures: Condition of Approval because all of the revegetation research goals a. Review of all available materials describing methods and have been met and findings implemented at the site; this ultimately success rates of revegetation programs employed on other resulted in the successful reclamation of the site by 2012.
Castle Mountain Mine Plan and Reclamation Plan 1-31 January 2, 2019 lands in the arid west to determine the best available procedures. All of the research conducted to date is catalogued in one or more of b. Development of a research methodology and a schedule for the eleven Annual Revegetation Reports that Viceroy (CMV) implementation of the revegetation program for submittal to submitted to the agencies; the 11th and final report was submitted in the BLM and the County. January 2002. Additionally, over 20 formal research projects have c. Revegetation success shall be determined by measuring the been summarized in the report: Castle Mountain Mine, San density and diversity of perennial species. "Density II here Bernardino County, California; Research and Reclamation, 1990-2005 means the number of live perennial individuals per unit area; Summary Report (December 2005)38. These formal research projects "diversity" here means the number of perennial species (with that have been published represent only a subset of the total live individuals) per unit area. The ten-year goal for density, research conducted at the site. Many projects are not listed or using only perennial species, will be 21% as compared to discussed in much detail owing to limited formal reporting, failure of undisturbed control sites. "Control sites are defined at the plant survival due to drought or grazing, laboratory errors and end of this subparagraph. Using a sigmoidal curve, the five- departure of personnel. Additionally, numerous observations have year goal for density will be 6% of the control. The ten-year grown out from formal research projects and these observations goal for diversity will be 15%, expressed as a similarity index have led to reclamation insights that have helped guide reclamation of the control. The five-year goal for diversity, based on a and revegetation techniques. These observations and insights are sigmoidal curve, will be 4%, expressed as a similarity index of detailed in section 10 of the above referenced summary report. the control. The standard control sites against which any revegetation area is assessed for density and diversity shall A more recent assessment of cumulative revegetation research was be a subset of the approximately 300 plots which were prepared in 2018 by the expert ecologist contracted to manage site established immediately prior to the onset of mining revegetation, Dr. Sam Bamberg. That report, Current Status of operations. The subset shall be those plots most closely Research Programs, Castle Mountain Mine, (April 2018), is listed in similar in topographic position to the revegetated area, and Appendix O. the vegetation data originally collected on that subset shall ordinarily be the data set used as the standard. Any two Finally, on July 12, 2002, the County issued its final reclamation members of the Revegetation Review Committee may, adjustment, Adjustments to the Revegetation Standards for Castle however, request that the standard be a data set from the Mountain Mine. This County report noted the following: current year instead of from the past. In such a case it is The objective of the reclamation plan was to minimize likely that only some fraction of the original 300 plots will environmental impacts of the mining activities through an have remained undisturbed and be relocatable in order to integral revegetation research program designed to develop take the current year's plant cover data. That is, the subset specific revegetation techniques for the project. A dedicated available for resurvey will be smaller than the original. This research program was required because little was known at
38 See Appendix N – Research and Reclamation Summary Report (December 2005)
Castle Mountain Mine Plan and Reclamation Plan 1-32 January 2, 2019 remaining number of plots is termed the “subsubset". The the time regarding revegetation of mined lands in the standard sub-subset shall be those plots which have Mojave Desert. Information gained from research during the remained undisturbed, have been permanently marked so mine’s operation has been used to facilitate a…”revegetation that they are relocatable, and whose topographic position is program that will, over time, establish plant communities most closely similar to that of the revegetation plot. with species composition and plant densities similar to those d. Stockpiling of available soil. Redistribution of these soils over now existing on undisturbed areas at the mine site.” disturbed areas shall be done following completion of Application of viable seed at known quantities, in activities on an area. Studies shall be initiated to determine conjunction with revegetation techniques developed from where available soil would be most effectively used. the 10 years of research at the mine is being utilized to e. Identification of dominant species to be used in revegetation. achieve the reclamation goals. Salvaging of individual plants amenable to transplantation shall be completed and such plants will be kept in nursery The 11 years of mining operations and revegetation research at the areas for replanting on reclaimed areas to provide a mine have been completed as of May 2001. Results of the research continuous seed source. The goal will be to transplant at program were reported in eleven Annual Revegetation Reports (1991 least 25 percent of barrel cactus and 25 percent of the to 2001) submitted to the County. The mine was monitored for 10 following species with the size classification shown: years (2002 to 2011) during final reclamation, and reported in a series of 10 Annual Monitoring Reports. Information in these (i) Joshua Tree - 3 to 10 feet in height, unbranched or with reports resulted in sufficient research data from which to now set few branches; those performance standards that will be applicable throughout the (ii) Mojave Yucca - well developed, single-stemmed plants duration of successful vegetation at the site monitoring. The density that have not developed a vertical trunk; standard is set at the values presented in the CUP conditions as 21% (iii) Blue Yucca - well developed, single-stemmed plants that of the general vegetation type, and the diversity standard as clarified have not developed a vertical trunk; in this review as 15% of all native perennial species identified on the (iv) Barrel Cactus - plants no smaller than 8 inches in mine site. The OMR stated that the mine was successfully reclaimed diameter and no taller than 14 inches. by 2012.
For the purpose of these Stipulations:
(1) transplant of plants salvaged during site clearing operations shall mean the placement of such plants into their final revegetation sites on reclaimed areas and (2) bond release shall be determined solely by the density and diversity goals specified in Stipulation 21(c), notwithstanding failure to achieve the 25 percent
Castle Mountain Mine Plan and Reclamation Plan 1-33 January 2, 2019 transplanting goal specified in this subparagraph.
f. The nursery will continue to support the revegetation research program and mine reclamation. g. A plan shall be developed to coordinate and phase revegetation efforts in accordance with mining and processing operations. The goal will be to initiate revegetation procedures within six months following completion of project activities over an area. h. Potential invasion of exotic species shall be monitored. If exotic species densities exceed levels of these species on non-disturbed areas at the project site, a weed control program acceptable to the County and the BLM shall be implemented. i. Employment of reseeding, transplantation, fertilization, and watering procedures determined appropriate for each disturbed area in the program methodology. j. Evaluation of the benefits of removing, shredding, and composting vegetation that would otherwise be lost. k. Ground preparation procedures shall include ripping and harrowing of compacted soils. Intervening areas between planted soil islands on overburden waste dump deck surfaces shall be ripped to decrease compaction and improve rainfall infiltration, reduce runoff and provide a suitable seed bed for plant dispersal. l. Implementation of a monitoring program to verify revegetation results, based upon the goals for diversity and density.
(1) The revegetation bond for any specific area will not be released until the Applicant demonstrates, based on a full 10 years of monitoring of the revegetation of that area, including at least two full years in which the vegetation is completely self-sufficient that the density and diversity
Castle Mountain Mine Plan and Reclamation Plan 1-34 January 2, 2019 standards set forth in Stipulation No. 21(c) have been met. Baseline vegetation analysis has been conducted at the mine site since 1991 and is documented in each of the 11 Annual Revegetation reports.
Baseline standards were further re-assessed beginning in 1998 and concluded with the California OMR report, Castle Mountain Mine Vegetation Analysis, completed in November 2000. This OMR report was completed with cooperation from the mine operator and made changes to the final approved reclamation and revegetation methodology employed at the site during final reclamation.
Finally, on July 12, 2002, the County issued its final reclamation adjustment, Adjustments to the Revegetation Standards for Castle Baseline vegetation measurements have been completed and Mountain Mine. This County report noted the following: accepted by the County and OMR. These same standards will be used The objective of the reclamation plan was to minimize for all future site reclamation. Shall be completed as part of the environmental impacts of the mining activities through an BLM-22 vegetation research program prior to surface disturbing activities. A integral revegetation research program designed to develop (SBC-49) draft report of all baseline vegetation measurements shall be specific revegetation techniques for the project. A dedicated completed within one year of approval and a final report shall be research program was required because little was known at submitted within two years of approval. the time regarding revegetation of mined lands in the Mojave Desert. Information gained from research during the mine’s operation has been used to facilitate a…”revegetation program that will, over time, establish plant communities with species composition and plant densities similar to those now existing on undisturbed areas at the mine site.” Application of viable seed at known quantities, in conjunction with revegetation techniques developed from the 10 years of research at the mine is being utilized to achieve the reclamation goals. The 11 years of mining operations and revegetation research at the mine have been completed as of May 2001. Results of the research program were reported in eleven Annual Revegetation Reports submitted to the County. Information in these reports resulted in
Castle Mountain Mine Plan and Reclamation Plan 1-35 January 2, 2019 sufficient research data from which to now set those performance standards that will be applicable throughout the duration of successful vegetation at the site monitoring. The density standard adopted by the County is listed on Table 3-1A of this 2018 Plan update. This condition has been satisfied. Research on the propagation of dessert grasses by salvage and by seed was conducted at the site and findings contained in the Annual Revegetation Reports and The project revegetation program shall collect and provide data on subsequent Annual Monitoring reports until 2011. Cumulative data BLM-26 revegetation and recovery of the onsite desert grassland unusual on revegetation, including dessert grasses, was compiled and (SBC-51) plant assemblages (UPA) and provide such data to the BLM to updated with new information in a final site vegetation report supplement UPA monitoring and planning strategies. compiled by California Office of Mine Reclamation (OMR) in collaboration with the mine operator, in the report: Castle Mountain Mine Vegetation Analysis (November 2000). This report established final reclamation standards. Fencing shall be used to exclude livestock from revegetated areas, BLM-31 such that grazing can be accommodated. The Operator shall be The condition has been removed. The are no longer any open (SBC-55) responsible for removing these fences following reclamation, as grazing allotments adjacent to the project area. determined. by the BLM. Stipulation 54 has been re-introduced into this Plan update to allow, in the interim, for on-site generated power. Stipulation has been further amended to allow diesel power generators. Propane based [Stipulation 54 is omitted as permanent on-site power is supplied by generators were in use at the site in the 1990’s but diesel generators a ·power lines approved by the BLM.] meeting Tier 4 Final requirements have been proven as the cleaner BLM-54 On-site power shall be generated using diesel or natural gas emitting alternative. Section 2.7.2 of this Plan addresses the generators. significance of using diesel power generators in place of propane as assessed and approved in the 1990 Plan and ROD and CUP authorizations. Diesel power generators are the environmentally preferred alternative over propane powered generators. Rock staining solutions shall be used on the upper mine pit walls Rock staining was attempted at the site during a number of field BLM-76 where necessary, as determined by the BLM and the County, to trials. It was later determined39 rock staining would not be a viable (SBC-93) reduce the contrast of light-colored rock exposed by mining activities alternative for site reclamation.
39 See Appendix H – OMR letter, September 9, 2010.
Castle Mountain Mine Plan and Reclamation Plan 1-36 January 2, 2019 and where visible above prevailing grade. These solutions shall be specifically colored to reduce the contrast between the pit walls and the surrounding undisturbed slopes. Any waiver of the rock-staining requirements would be made by the BLM and County Staff with a prior 15-day notice to interested members of the public. BLM-83 The Operator shall construct and maintain fencing to restrict cattle The condition has been removed. There are no longer any open (SBC-97) from operational areas and access roads where required by the BLM. grazing allotments adjacent to the project area. BLM-84 Grazing lessees shall be compensated by the Operator for livestock The condition has been removed. There are no longer any open (SBC-98) killed or injured by vehicles driven by project employees. grazing allotments adjacent to the project area. Cattle guards shall be installed and maintained by the Operator at The condition has been removed. There are no longer any open BLM-85 points where cattle control fences cross the access roads. grazing allotments adjacent to the project area. If project activities inhibit use of watering facilities by cattle, the The condition has been removed. There are no longer any open BLM-86 Operator shall provide alternate water sources, in accordance with grazing allotments adjacent to the project area. requirements of the BLM. The Operator shall, within one year of this approval, construct the viewpoint at the Castle Mountain Project Site, approved August 18, 1993, describing past and present gold mining operations in the area. The interpretive site will be located at a point overlooking both the BLM-88 old Hart Townsite and the Lesley Ann Pit. The site shall include At the request of NPS40, this Stipulation has been rescinded. (SBC-99) descriptive information about the permitting process, agencies involved in that process, measures taken to protect the environment, current mining operations, and the history of the Hart Mining District. This descriptive information shall be approved by the BLM. It is understood by the BLM that the terms of the Settlement Per the terms of the Settlement Agreement, the role of the Agreement have been met and there is no further role for the former Revegetation Review Committee (RCC) is to: Revegetation Review Committee.: Review the Annual Revegetation Report to make a. The Applicant has established a Revegetation Review recommendations to further improve the effectiveness of BLM-101 Committee in January 1991. That Committee consists of an Viceroy’s revegetation programs and research efforts, and to; (SBC-112) arid lands revegetation expert, a geologist/hydrologist and Advise the agencies whether to make adjustments to the an arid lands ecologist, three representatives of the revegetation goals of density and diversity contained in the environmental community and one representative each of approved Mine Plan and Reclamation Plan. the County, BLM and the State Division of Mines and
40 See Appendix H – OMR letter, September 9, 2010
Castle Mountain Mine Plan and Reclamation Plan 1-37 January 2, 2019 Geology, and the Applicant. Because the research mandate adopted by the County and BLM has b. The Committee will confer annually to discuss the annual been completed; and because the County and OMR made their final revegetation reports filed by the Applicant in order to reclamation adjustments in their respective reports, Adjustments to interpret the information contained in these reports; advise the Revegetation Standards for Castle Mountain Mine (July 2002) and the Applicant of actions it might take to increase the success Castle Mountain Mine Vegetation Analysis (November 2000), no of its revegetation efforts; and advise the County and BLM as further reclamation adjustments are warranted. to adjustments which should be made to the revegetation standards. Considering these above goals have been met, which also proves c. The Committee will produce a written report by June 1 of they can be met again for future mine reclamation, there is no each year. further role or need for an RRC. This is further emphasized by the d. The Operator has made provisions for the reimbursement to actions of the RRC as the members agreed at the last scheduled Committee members of the costs associated with meeting in 2002 to continue their oversight and comment function participation in the Committee during the revegetation monitoring period from 2002 to 2011. However, no further comment or confirmation of the annual monitoring reports submitted by CMV was ever delivered by the RRC members to CMV or the agencies after 2002. In conclusion, the purpose of the RRC was finished in 2002 and its mandate (as defined in the Settlement Agreement) satisfied. In the event that evaluation of the Historic Hart townsite (CA-SBr- 3060H) leads to a determination that the property is eligible for Hart was determined not eligible for NRHP and CRHR. See BLM NRHP and CRHR inclusion, the Operator shall complete an Record of Decision, July 1, 1998, page 3 regarding the findings of the appropriate data-recovery program, with the following performance Class III level cultural survey over the Milma Patent: standards:
SBC-110 a. Define, recover, and analyze, with respect to relevant “In 1997 this site was subjected to rigorous recordation and testing in (BLM-99) research and historical issues, representative samples of the order to complete the evaluation of this site for the National Register archaeological materials and information contained within of Historic Places. The site was determined Not Eligible and the North significant depositional loci subject to adverse impact. Overburden Site will have No Effect on historic properties eligible for Document results of the undertaking in a comprehensive report listing on the National Register of Historic Places.” detailing the research context, investigative methods, findings, and consequent recommendations of the data-recovery program.
Castle Mountain Mine Plan and Reclamation Plan 1-38 January 2, 2019 2.0 MINING PLAN
2.1 INTRODUCTION
This Section provides a description of the approved (1990 and 1998) Mine Plan while also providing updates to the Mine Plan which are the result of extensive reclamation conducted at the site and a positive change in mining economics which has fostered resumed mineral exploration and mine development at CMM. This 2018 Plan update also includes the activities that have occurred at the Castle Mountain mine site since the initial approvals were issued in the Fall of 1990. The modified mine plan allows the Company to integrate the mining of newly identified reserves and ore stockpiles into the previously approved mining operation at Castle Mountain, that is efficient, while also capitalizing on the more favorable economics for mining the low-grade disseminated gold bearing ore that is pervasive through the mine site.
Castle Mountain mine is characterized as an open pit, heap leach gold mine, which historically has processed 4 million tons of ore annually. The process to recover gold is illustrated in Figure 2-1. While the procedures employed are common to the mining industry, the Castle Mountain Mine has been recognized for implementing innovative measures that offer both economic and environmental benefits. This trend toward innovative and sustainable practices continues with this 2018 Plan update as many of the proposed modifications are the result of greater efficiencies and resource conservation realized by the mining and heap leach processes specific to CMM; these will be further detailed in section 2.2. The past measures included the use of large steel solution storage tanks to contain the leaching solutions, and the installation of a Comminution (also known as a “grinding”, or “milling”) Circuit to extract more of the gold contained in the higher-grade ores. The Comminution Circuit achieves higher gold recoveries, without the need to construct and operate tailings impoundment facilities. Tailings facilities have been historically associated with such a circuit. As noted in section 1.4.2, at this time the Comminution Circuit will not be re-established in this 2018 Plan update.
The first step in recovering gold at Castle Mountain involves excavating the ore. The ore is covered with rock or alluvium that does not contain precious metals. This requires the removal and disposal of the unmineralized materials at the designated overburden sites. After the orebody is exposed, ore grade material is excavated and either delivered to the crusher, where it is reduced to the size of pea gravel or transported directly to the Heap Leach Pad using haul trucks. At this time, this 2018 Plan update does not propose to re-establish the crushing operation or the overland conveyor.
The 1998 Plan used an extensive crushing and overland conveying operation to crush ore to 3/8” in size and convey that crushed ore out to the Heap Leach Pad. This 2018 Plan update aims to establish a more efficient operation while maximizing conservation of site resources, especially water and power resources. The crushing and conveying processes explained in the 1998 Plan consumed a significant portion of site power supply and water use, up to 200 gallons per minute (gpm). Additionally, recent pilot testing has shown that ROM ore (uncrushed ore) will require 36% less water for use in the drip irrigation leaching of the ore on the Heap Leach Pad. This efficiency is evident from
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LEGEND SCHEMATIC MINE OPERATION FLOW DIAGRAM CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN C O R P O R A T I O N FIGURE 2-1 0 1,500’
FEET Source: Castle Mountain Venture laboratory testing which has shown that a coarser ore, which exerts less surface tension through less surface area, does not retain the same volume of water as would be the case with a smaller ore size, similar to 3/8 inch that was used in past operation. Additionally, pilot scale gold recovery of a leach pile consisting of ROM ore size has still proven very successful with recovery predicted at about 65%. Similarly, a significant portion of the site energy demand from prior operations came from the crushing and conveying circuits. With those demands removed, the site will use significantly less power; enough of a reduction that on-site generated power is more efficient, less costly, and with fewer environmental impacts than re-establishing the former overhead 69kV powerline that fed power to the site. Site power requirements and impacts are detailed in section 2.7.2 of this 2018 Plan update.
Prior to off-loading at the heap leach pad, lime and moisture are selectively added to each haul truck load of the ROM ore to adjust the ore pH to a slightly basic concentration.
Low-grade ore and protore (the latter material contains a lower concentration of gold) excavated from the pit is stored in stockpiles for potential processing at a later time, when improvements in prices and/or technology can allow profitable treatment of such material for additional gold recovery. The Company intends to process these stockpiles after the high-grade materials have been processed. However, if at that time, conditions are such that the protore stockpiles would not be profitable to process, their upper surface would be prepared for revegetation. Since the protore stockpiles would be a resource that could become economic at some future date, and due to the limited amount of growth media available, growth media would not be placed on the protore stockpiles as part of the reclamation program.
The approved 1998 Plan was correct to recognize that past stockpiled low grade ore or protore could one day be economically processed for additional gold recovery. The current largest source of stockpiled protore is the backfill that was sequentially stockpiled in the Lesley Ann pit up until 2001. This resource is referred in this 2018 Plan update as backfilled protore stockpiles (i.e. ROM ore). Extensive exploration and modeling occurred over the past five years to confirm this backfilled protore stockpile is of high enough gold concentration for the increased gold economics to now allow the processing of this material, which again, was recognized as a future possibility by the approved 1998 Plan (see 1998 Plan, section 2.1.5).
Leach-grade ore is heaped onto a leach pad that is underlain by a synthetic liner system. A dilute sodium cyanide solution (125 to 150 ppm (parts sodium cyanide per million parts water)) is distributed across the top of the heap by drip irrigation. Drip emitters will be buried by an additional layer of ROM ore to limit evaporative water loss and as an additional benefit, the buried solution lines will further prevent wildlife from contacting cyanide leach solution. The solution percolates through the material, dissolving the gold in the ore. The pregnant (gold-bearing) solution drains from the heap into pipes located immediately above the synthetic liner, and then flows by gravity in pipes to the pregnant solution storage tank.
Pregnant solution is pumped from the storage tank through pipes to the gold recovery plant where vessels containing activated carbon adsorbs the gold from solution. After the gold has been adsorbed onto the carbon, the now “barren” solution flows by gravity to the barren solution storage tank where cyanide is added before the barren solution is recycled to the heaps to continue the leaching process. The solutions are continuously recycled, and the process operates with no discharge to the environment.
Castle Mountain Mine Plan and Reclamation Plan 2-3 January 2, 2019 The gold-bearing carbon is chemically treated to release, or “strip”, the gold from the carbon; which is then reactivated for reuse, using heat, followed by an acid wash to remove lime from the reactivated carbon. The gold-bearing strip solution, more concentrated than the original pregnant solution, is treated by electrolysis in an electrowinning cell. In the cell, gold is electrically plated onto steel wool. Any silver that was dissolved and carried into the pregnant solution follows the gold through the process and is also plated onto the steel wool. After electrowinning, the impure gold/silver residue is washed from the steel wool, dried and melted in a furnace. The resulting project is a bar of alloy gold and silver, referred to in the industry as a “dore” bar. The dore is then sold or shipped to a refinery for further purification.
2.2 MAJOR MINE COMPONENTS
The major components of the Castle Mountain mine as approved by the County and the BLM are illustrated in Figure 2-2. This arrangement of the major components was selected and approved based upon numerous considerations, including:
Location of mineral deposits and open pit mining activities. Pit locations and configurations are dictated by the geology of the orebodies as defined by exploratory drilling. Overburden Storage and past Crushing Facilities were located near mining operations to minimize haul distances. The South Overburden Site is partially surrounded by low hills, which screen the site from views in most directions. Former Heap Leach Pad and Comminution Circuit were located on gentle slopes at lower elevations. This minimizes the amount of grading needed to achieve gravity flow of solutions from the base of the pad. These facilities are also located to minimize disruptions to natural drainages and are outside the flood plain for the 100-year 24-hour flood event. Solution Storage Tanks and Gold Processing Plant are located downslope from the heap leach pad, again, to allow solution draining from the ore heap to flow by gravity, minimizing pumping cost and the length of pipes handling solution flow.
The open pits, heap leach pads and overburden storage sites described in this plan are designed to accommodate up to approximately 71 million tons of ore, and 128 million tons of overburden. An additional 95 million tons of overburden would be sequentially backfilled into the Lesley Ann, Jumbo and South Extension pits. As of 2018, approximately 37 million tons of ore has been placed on the heap leach pad and 97 million tons of overburden have been placed at the north and south overburden sites. This means that approximately 34 million tons of approved heap leach pad expansion capacity remains available for remaining Phase I and II mining, as well as a minimum of 31 million tons of overburden capacity.
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Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
0 1,500’
FEET Source: Castle Mountain Venture 1996 MINING PLOT PLAN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-2 C O R P O R A T I O N
Mojave National Preserve (National Park Service)
Approved Mine Boundary (1997 EIS/EIR) Designated Area Roads
Castle Mountains National Monument (National Park Service) LEGEND The on-site acreage permitted for disturbance is 1,375 acres, there is no change from the approved 1998 Plan.
2.3 PRODUCTION SCHEDULE
Exploration and associated geological studies undertaken since the Fall of 1990 identified additional minable (proven) reserves in the Oro Belle, Jumbo, and Lesley Ann pits. More recently, and recognized in this 2018 Plan update, backfilled protore stockpiles will be processed as additional reserves from the approved mine footprint of the Lesley Ann pit. This activity is in line with the 1998 Plan which explains stockpiled material would be processed during stage 5F and 6(see section 2.3, ¶ 11) as well and County (Condition #10141) and BLM (Stipulation #1042) requirements specific to stockpiling and accessibility of ore and protore stockpiles.
Certain other mineralized structures, whose presence was suspected but not confirmed in 1990 in areas beyond the planned boundaries of the Lesley Ann, Oro Belle and Jumbo pits, were categorized as proven reserves in the approved 1998 Plan. Mining of additional ore found between the Oro Belle and Lesley Ann pits in the Hart Tunnel area and below the floor of the Oro Belle pit was proposed to result in the north and east highwalls of the Oro Belle pit moving a considerable distance to the southeast. Mining of additional ore beneath the floor of the Jumbo deposit was approved to be deeper and larger laterally, compared to the Oro Belle and Jumbo pits configured in 1990 Plan. While these aspects of the approved 1998 Pan are currently authorized actions, mining of these features is not currently included in this mine 2018 Plan update which focuses on the processing of existing ore stockpiles, though implementation of these approved actions will be available for inclusion in future mine plans when hard-rock mining recommences.
In addition to adding to the ore reserves in the Oro Belle and Jumbo areas, the exploration effort identified two other deposits, the South Extension and the Lucky John. These are adjacent to the south and west walls of the Lesley Ann pit. These deposits have still not been mined as of this 2018 Plan update and while these deposits are authorized to be mined, this 2018 Plan update focuses on the processing of existing ore stockpiles.
The approved 1998 Plan divided the mining program into two phases. Phase I includes mining the reserves in the Oro Belle-Hart Tunnel (OBHT) and Jumbo pits, and Phase II includes mining of the South Extension pit and expanded operations in the Jumbo and Oro Belle-Hart Tunnel pits. Due to the significantly higher stripping ratios (over-burden to ore) in Phase II, compared to Phase I, Phase II will only proceed under a favorable combination of metal prices, metallurgical recoveries and operating costs. Total material mined by phase and stage (i.e., time period) is shown in Table 2-1.
As of May 2001, mining Stage 5C was the last fully implemented stage for Phase I of the estimated mine schedule authorized in the 1998 Plan. Some features from the approved 1998 Plan associated with Stages 5D, 5E, 5F, and 6 were not fully implemented by May 2001, while other aspects such as mining in Oro Belle pit were completed (vertical extent) through to Stage 5F. For example, a major component of Phase I Stage 5D included a westward expansion of the heap leach pile and this expansion did not occur. Likewise, when active hard-rock mining was halted, certain elements of the Phase II mine plan were
41 County Condition of Approval #101: Following project completion, the Lesley Ann/Jumbo and Oro Belle pits shall be accessible for potential recovery of low grade ore. 42 BLM Project Stipulation #10: Protore shall be separated in the overburden pile to the extent possible.
Castle Mountain Mine Plan and Reclamation Plan 2-6 January 2, 2019 implemented even though completion of all mining approved through Phase I Stage 5F had not been completed. These elements of Phase I Stage 5D, 5E and 5F, as well as elements of expanded mining approved for Phase II Stage 6 of the authorized 1998 Plan did not occur in succession (as estimated in the 1998 Plan). Instead, stage activities were implemented according to engineering and market economics, and until processing was halted in 2001 due to the same unfavorable economics. This 2018 Plan update follows the same standard established in the 1998 Plan where the remaining approved, but incomplete, activities detailed in Phases I and II mine plans are now due to commence in late 2019 as a result of stable economics which promotes the profitable processing of these remaining known ore reserves, as well as ore reserves proposed (by the approved 1998 Plan) as protore to be profitably processed at a future time when the market price for gold increases.
The quantity of materials mined annually is governed by the overburden removal ratio, however this 2018 Plan update does not propose any substantial increase to the currently approved mining rate and total quantity processed. Generally, mining will be scheduled for two 10-hour shifts per day, operating six or seven days per week, to achieve a maximum 120 hour per week. The processing facilities operate continuously, 24 hours per day, seven days per week.
The mine was authorized to use overburden from the Jumbo and pits to reclaim the North Clay Pit Reclamation Area. This activity commenced in Stage 5A during the First Quarter of 1996 and is considered complete.
During Stage 5B, approximately 5.2 million tons of overburden from the Oro Belle and Jumbo deposits were placed in the North Clay Pit Reclamation Area. Subsequent overburden from Oro Belle and Jumbo was placed in the Lesley Ann Pit.
Table 2-1 Estimated Annual Production (Quantities in Millions of Tons) Stages Time Pit(s) Overburden/Ore Incremental Cumulative Stage 5D 6 years to 2025 Lesley Ann (backfill) 5 na 30
The approved 1998 Plan discusses the backfilling of the Lesley Ann and Jumbo pits. Backfilling of the former pit was completed but for background, the original text from the approved 1998 Plan will be presented in the paragraph below:
“Sequentially backfilling of the Lesley Ann Pit with Overburden from the OBHT and Jumbo pits will be done in the two mining phases. Phase I would start in the second half of Stage 5B, and would continue into the first half of Stage 5F, at which time sequential backfilling would be suspended until mining of the South Extension Pit had been completed. An estimated 21.7 million tons of overburden from the OBHT and Jumbo pits would partially backfill the Lesley Ann pit during State 5F. Sequential backfilling of this pit would then be halted when the toe of the overburden reaches approximately the 3900-foot elevation, so as to permit construction of a haul road out of the South Extension Pit. This haul road will ascend the southwest side of the Lesley Ann Pit. As a consequence, material sequentially backfilled into the Lesley Ann Pit during Stages 5B through 5F will have to be placed in a manner that will not interfere with construction of this haul road, which will occur during the latter half of Stage 5F. By the time backfilling is temporarily halted, approximately 32 acres of level surface will have been created at approximately the 4450-foot elevation over the north half of the Lesley Ann Pit. Sequential backfilling of the Lesley Ann
Castle Mountain Mine Plan and Reclamation Plan 2-7 January 2, 2019 Pit will be completed in Stage 6, after the South Extension deposit is mined out, using an additional 14.8 million tons of overburden mined from the OBHT Pit for this purpose.”
The Lesley Ann pit backfilled with low-grade disseminated ore stockpiled within was mostly complete by 2000.
Phase II mining was approved to involve the development of an open pit to mine the South Extension deposit, a push-back of the pit highwalls in the Jumbo Pit and a push-back of the north and east highwalls of the OBHT Pit. These activities were approved to initiate Stage 6. As explained above, this 2018 Plan update does not foresee mining of these features at this time under the 2018 Update plan.
Stockpiled materials were approved to be withdrawn from the stockpiles during Stage 5F and Stage 6, to augment ore production from the various pits. This 2018 Plan updates the prior mine schedule to process ore/protore stockpiles (including from the Lesley Ann pit) during Stage 5D. This is possible due to the positive change in mining economics since 2001. Leaching of materials on the pads will continue through Stage 7; and the leach pads will be rinsed and decommissioned during Stage 8. Reclamation and monitoring will continue through Stage 9. Based on this 2018 Plan update, Stage 9 should end before 2035.
2.4 MINE OPERATIONS
2.4.1 GROWTH MEDIA REMOVAL
Significant reclamation and revegetation research has occurred at CMM up to 2002, and one result of those efforts is that it has been confirmed that the importance of growth media for use as a transplanting media for vegetation has not resulted in the vegetation success that was originally assumed in the original 1990 and amended 1998 Mine and Reclamation Plans. Test plots on the South Overburden were seeded in 1998, with plot 4 receiving growth media and plot 5 receiving no growth media; the results were profound with almost no germination in test plot 4 and good germination in test plot 5. It was thought that the more rough surface of test plot 5, since the course overburden material was only ripped, provided a better seed bed to help lock seeds in place and prevent dispersal from wind and other weather related erosional forces. This research resulted in a change to the reclamation strategy whereby growth media was placed in mounds (or islands) and then ripped/mixed into the overlying course overburden material. This approach proved successful and will be retained during future reclamation at CMM; and while this strategy requires less growth media stockpiles, this 2018 Plan update still includes the salvage of growth media, but appropriately places lesser importance on this element of the overall reclamation strategy.
Two soil surveys have been conducted over the mine site: the first in November 1989; the second, on the Milma Patent (North Clay Pit) in May 1994. The reports provide estimates of the depth of growth media that could be salvaged at various locations around the site.
Through Stage 5C, approximately 686,000 cubic yards of growth media had been salvaged from the following areas:
Lesley Ann/Jumbo Pits South Overburden Site Heap Leach Pad area Solution Storage area Crusher/warehouse Processing Plant area
Castle Mountain Mine Plan and Reclamation Plan 2-8 January 2, 2019 The location of the growth media stockpiles are shown in Figure 2-3.
Growth media suitable for revegetation, as described in the soil reports, will continue to be salvaged in campaigns coordinated with ongoing operations. Salvaging growth media in this manner minimized the amount of land that will be disturbed prior to the time at which a particular tract is needed for placement of material. Moreover, in some instances, campaigning growth media removal will allow material salvaged from on area to be placed directly on sites that have been prepared for reclamation, with no double handling.
For the operations proposed in this 2018 Plan update, the principal undisturbed area to be developed will be approximately 150 acres on the west side of the existing heap leach pad within the approved 1998 Plan heap leach pad footprint. Based on past growth media salvaging in this area, the growth media depth averaged approximately 18 inches. Therefore, approximately 314,000 cubic yards of growth media will be salvaged from this area for future revegetation. Portions of this 150-acres may not be salvageable so the amount of growth media salvaged may be less. This is further detailed in Section 3.0.
2.4.2 MINING
2.4.2.1 PIT DESIGN
Pit designs at the Castle Mountain mine are at different stages. Designs are based on density of exploratory drill holes in the respective pit areas, estimated value and distribution of the mineralization, and related economic and geotechnical factors. Most of these factors are subject to change during the life of the mine. As is customary in the mining industry, in order to maximize the recovery of the contained gold, pit design will be reevaluated several times during the course of mining in response to these changing factors.
The Castle Mountain mine consists of a number of discrete deposits. To some degree, the projected highwalls surrounding these deposits overlap. Where this happens, the individual pits will coalesce into a single large excavation sharing a common upper pit wall, dividing at depth into discrete pit bottoms separated by low internal saddles. Based on the present understanding of the deposit’ geometry, the lowest benches forming the floor of each of the pit areas are anticipated to have elevations as follows:
Floor Elevation Floor Elevation Floor Elevation Pit Area (feet msl) (feet msl) (feet msl) 2018 Actual Phase I Phase II Condition South Extension N/A 3800 N/A Lesley Ann 3780 N/A N/A Jumbo 3820 3820 4,030 Hart Tunnel 4080 4080 4,250 Oro Belle 4200 3920 4,200
Castle Mountain Mine Plan and Reclamation Plan 2-9 January 2, 2019 File: F3-2 CMV- GROWTH MEDIA STOCKPILE LOCATIONS (TAG) Page:1 REV: 10/17/2018
Source: Castle Mountain Ventures, 2018.
GROWTH MEDIA STOCKPILE LOCATIONS CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-3 C O R P O R A T I O N The pit boundary configurations and lowest bench elevations are determined primarily by complex interrelationships involving geologic and economic factors, including ore grade, overburden removal ratio, metallurgical recoveries, mining and production costs, capital expenditures and projected sales revenues. Because these factors are to some extent interdependent, and metal prices and costs are variable, the bench levels shown above are estimates. Final elevations could vary by perhaps 100 or 200 feet from the estimates shown above.
Metallurgical recoveries have an important influence on pit design. Estimated metallurgical recoveries are derived from laboratory tests of representative ore samples and are the best estimates prior to having actual operating data for evaluation. These estimates are continually compared to recoveries actually achieved during the life of the operation. An increase in projected recoveries could result in the need for expanded pit boundaries, as mineralization in the walls or floor of a pit that was previously uneconomic could become profitable to mine. Reduced costs or a higher gold price would have an effect similar to higher metallurgical recoveries. These themes recognized by the approved 1998 Plan are the contribute to the purpose of the updates contained in this 2018 Plan update, in that the higher gold price we see now has a profound influence on pit design and when stockpiled material is processed. The approved mine plan recognized that stockpiles of low-grade ore and protore might not be processed during Phase I or even during Phase II mining as market conditions dictate when stockpiles of varying gold concentrations can be processed, especially material considered protore. The necessary economic factors are now in place to profitably process the remaining stockpiles of material authorized for processing in the approved 1998 Plan, including the backfilled protore stockpile contained mostly within the Lesley Ann pit.
Current Lesley Ann pit designs will be refined and optimized as backfill protore stockpile is removed for processing and also as data from further “definition” drilling is integrated into existing mine models, to better determine the extent of mineralized material in the pits and to more accurately predict ore reserves. However, the vertical and lateral definition of the pit will not extend beyond what was approved in the 1998 Plan, in short, the backfilled protore will be removed and processed leaving the resulting Lesley Ann pit in the same state (vertical/lateral extent) as it was prior to backfilling.
Pit slopes and bench heights are influenced by geotechnical characteristics and grade control considerations. Bench heights of 20 feet were used in the Lesley Ann Pit, and this height is also proposed for the Jumbo and OBHT pits.
Rock in the Lesley Ann Pit was very competent. As a result, the walls were progressively steepened as mining proceeded on lower benches. Walls in the upper portion of the Lesley Ann Pit were sloped at 45 degrees, but slope angles on most of the walls in the lower portion of the pit are 54 degrees or more. Initial mining of the stockpiles detailed in this 2018 Plan update will generally follow the existing mine pit bench contour as was in place when mining was halted in 2001.
The approved 1998 Plan made changes to the degree to which pit walls were adjusted based on the competency of the rock that was encountered during mine. While extensive hardrock mining of pit benches is not envisioned in this 2018 Plan update, the former discussion related to pit bench slope angles is maintained in this plan for reference:
“Steepening the Lesley Ann Pit walls as mining progressed into lower levels allowed those levels to be larger than originally designed. Consequently, it was possible to mine mineralization adjacent to, but outside the originally
Castle Mountain Mine Plan and Reclamation Plan 2-11 January 2, 2019 planned Lesley Ann Pit walls at lower elevations within the pit, without expanding the area of surface disturbance beyond that originally approved. The effect of steepening the pit walls is shown in Figure 2-4.
The Lesley Ann Pit was excavated leaving a safety bench 30 to 35 feet wide at every third or fourth bench. The width of the safety benches, and the vertical separation between benches, determine the overall pit wall slope.
The Oro Belle, Hart Tunnel and Jumbo deposits have been designed with 52 degree interramp wall slopes initially. These slopes may be steepened, depending on an assessment of the competence of the wall rock, absence of faulting, et cetera, after the first several benches in these pits have been mined. The use of any angle greater than 52 degrees will be supported by a slope stability analysis. The rock exposed after the benches have been excavated will allow a more detailed assessment of pit wall stability. It is anticipated that the safety benches will be 20 to 30- feet wide, depending on slope angle, spaced vertically every 60 to 80 feet. In poorly consolidated or clay altered zones, safety benches will be wider, and/or placed at more frequent intervals, thereby reducing the overall slope angle to that needed to assure slope stability.”
Although water was not encountered during exploration drilling within pit areas, down to depths of 400 feet, water did begin to infiltrate into the Lesley Ann pit when the floor of the pit reached the 3920 foot elevation. In retrospect, the apparent lack of water within the planned pit boundaries, indicated by exploration drilling, was likely the result of a combination of factors—the aquifer in the Lesley Ann Pit area is located in low permeability crystalline rocks, the smaller diameter drill holes did not provide sufficient surface area, and the high air pressure used for drilling.
2.4.2.2 OPERATIONS
2.4.2.2.1 PIT CHARACTERISTICS
An estimated 307 acres of open pit areas will ultimately be created through Phase II by mining the deposits at Castle Mountain.
The proposed mining and reclamation sequence is based upon economic considerations, known engineering information and environmentally sound procedures. As is typical of most mining operations, more precise data will be generated as operations proceed, leading to engineering refinements and other modifications to operational plans in future years. All material departures from the procedures described herein will be submitted to the appropriate governmental agencies for approval prior to implementation. It is important that the approved 1998 Plan recognized that not only economic and resource factors can influence the proposed sequence for mining and reclamation but also that the most environmentally sound procedures are employed throughout this process. This consideration to environmental factors plays a significant role for introducing the updates contained in this 2018 Plan update, which is largely to process the backfill protore stockpile before continuing on with the more resource intensive processes of the approved 1998 Plan.
The approved 1998 Plan pit design and a cross-section for the Lesley Ann deposit are shown in Figures 2-5 and 2-6, respectively, and as partially backfilled at the end of Phase I. The cross section shows the original surface topography, the location of the pit highwall and the surface topography after partial backfilling. Figure 2-6 shows the Lesley Ann pit design once the backfilled protore stockpile has been removed. You will note that the footprint of the pit does not exceed the lateral or vertical limit of approved mining.
Castle Mountain Mine Plan and Reclamation Plan 2-12 January 2, 2019
REV: 10/17/2018 1 REV: Page: Ann Pit Design (TAG) Lesley File: F2-4 CMV-Original
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
0 1,500’
FEET Source: Castle Mountain Venture ORIGINAL LESLEY ANN PIT DESIGN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-4 C O R P O R A T I O N
Mojave National Preserve (National Park Service)
Approved Mine Boundary (1997 EIS/EIR) Designated Area Roads
Castle Mountains National Monument (National Park Service) LEGEND
REV: 10/17/2018 1 REV: Page: Ann Phase 1 (TAG) File: F2-5 CMV-Lesley
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
0 1,500’ FEET LESLEY ANN PIT PLAN Source: Castle Mountain Venture (PARTIALLY BACKFILLED) at the END of PHASE 1 CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-5 C O R P O R A T I O N
Mojave National Preserve (National Park Service)
Approved Mine Boundary (1997 EIS/EIR) Designated Area Roads
Castle Mountains National Monument (National Park Service) LEGEND File: F2-6 CMV-LESLEY ANN CROSS SEC (TAG) Page:1 REV: 10/17/2018
Source: Castle Mountain Ventures, Oct. 2018
LESLEY ANN PIT CROSS SECTIONS CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-6 C O R P O R A T I O N The following paragraph relates to partial sequential pit backfilling that was proposed, though not required by permit, for select pits at the mine site. Since active mining was halted during Phase I mining in May 2001, the backfilling discussion to follow was never fully implemented; Lesley Ann pit was backfilled with protore up to approximate surface elevation of 4,400 feet; Jumbo however, was not backfilled at all and the South Extension was not mined by 2001 and so no backfilling occurred there. The backfilling plan as proposed by the approved 1998 Plan included the following:
“Pending completion of mining in the South Extension Pit, the Lesley Ann pit will be partially backfilled, using overburden mined from the Jumbo and OBHT pits. This will be accomplished initially by dumping overburden over the northwest edge of the Lesley Ann pit, so the toe of the backfilled material advances in an easterly direction across the north half of the Lesley Ann pit. As additional overburden is backfilled, the toe of the backfilled material will advance in a southerly direction, across the floor of the Lesley Ann pit. Once the far edge of the pit has been reached, sequentially pit backfilling will halt so that backfilled overburden would not rest against the South Extension Pit (i.e. the South Extension Pit “daylights” on the south highwall of the Lesley Ann pit) which would be mined during Phase II.
When the Castle Mountain Project was approved in 1990, backfilling the Lesley Ann pit was not proposed. As shown in Figure 2-4, mineralization remained in the pit walls just beyond the planned pit boundary. The pits were conservatively designed, with a 45 degree slope angle for stability. Had the deposit been mined according to this design, the mineralization outside the planned pit boundary would have remained accessible for future mining, in the absence of backfilling.”
The 1998 Plan assumed that the remaining mineralization beside or beneath the Lesley Ann pit would not likely be economic to extract under any reasonably foreseeable circumstances. As a consequence the Lesley Ann pit was backfilled, using overburden mined from the OBHT and Jumbo open pits, and while known to contain low concentrations of gold, at less than $400 per ounce, it would not have been economical for this resource to have been processed in 2000, thus its use as backfill for the mine pits. This reinforces a theme of this 2018 Plan update, that successful mine plans are generally considered fluid documents that can and will change as the need and economics of the operation change. Regardless, even the approved 1998 Plan did not foresee such a pronounced increase to the price of gold to where it is today ($1,250 per ounce), and at which price not only is further processing possible in the Lesley Ann pit, but also that the backfill in the pit is stockpiled protore that will now be profitably processed on the heap leach pad.
The 1998 Plan Phase I pit design and two cross-sections for the OBHT pit are shown in Figure 2-7 and Figure 2-8. Similar designs for the Phase I Jumbo pit are shown in Figure 2-9 and Figure 2-10. While this 2018 Plan update does not propose extensive hardrock mining in the OBHT or Jumbo pits, that mining is authorized by the approved 1998 Plan and those authorizations will be retained in this 2018 Plan update.
Conservative estimates were used in developing the designs for the OBHT and Jumbo pits. More optimistic assumptions concerning wall rock stability, metallurgical recoveries and economic factors could result in larger pits, encompassing more of the mineralized rock adjacent to the planned pit boundaries. Should these factors arise during the mining of these pits, the walls will be steepened, in much the same manner as the walls of the Lesley Ann pit were steepened in light of more definitive information.
Haul roads from the mine pits to the overburden disposal areas and Heap Leach Pad are about 60 feet wide to permit two-way travel for haul trucks, plus an additional 15 feet for safety berms and drainage ditches. The only exception to this would be the haul road from the upper benches of the Hart Tunnel Pit. This road would traverse existing topography to the North Oro Belle Overburden Site, where it would intersect the northwest boundary of the OBHT pit. This road would be single land with turnouts,
Castle Mountain Mine Plan and Reclamation Plan 2-16 January 2, 2019
10/17/2018 1 REV: Page: (TAG) and 100 YEAR FLOOD PLAIN and 100 YEAR FLOOD PHASE 1 OBHT PIT DESIGN File: F2-7 CMV-
Source: Castle Mountain Ventures; June 1998.
PHASE 1 OBHT PIT DESIGN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-7 C O R P O R A T I O N Source: Castle Mountain Ventures; June 1998.
PHASE 1 OBHT PIT DESIGN CROSS SECTIONS B-B’ and C-C’ CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-8 C O R P O R A T I O N REV: 10/17/2018 1 REV: Page: (TAG)
PHASE 1 JUMBO PIT DESIGN File: F2-9 CMV-
Source: Castle Mountain Ventures; June 1998.
PHASE 1 JUMBO PIT DESIGN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-9 C O R P O R A T I O N Source: Castle Mountain Ventures; June 1998.
PHASE 1 JUMBO PIT DESIGN CROSS SECTIONS CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-10 C O R P O R A T I O N and would be used only during the mining of the upper benches of the Hart Tunnel pit, during the second half of Stage 5B. Grades of in-pit haul roads are held to a maximum of ten percent.
2.4.2.2.2 MINING EQUIPMENT
The following is a list of major units of equipment used for mining operations at the mine:
Number of Units Description Nominal Size 4 Blasthole drills 2.5 – 6.75 inch 4 Loading units 13 cubic yds. 3 Road graders 16-G class 3 Bulldozers D9 class 1 Wheeled dozer 834 class 3 Water trucks 4 – 10,000 gallons 1 AN/FO truck 10 tons 2 Lube and oil trucks 35 tons 13 Pickups ½ ton 15 Haul trucks 85 to 120 ton
The actual number of units in use from time to time may be less than that shown above, in light of the changing overburden removal ratios and haulage distances from the various pits to the overburden storage sites, ore/protore stockpiles and the Heap Leach Pad.
The mine maintenance shop, administrative offices, fuel depot or powder magazine facilities, are the same as approved in the 1990 Plan, although the powder magazine will be relocated at some point, as the North Overburden Site will be expanded into the area currently occupied by these facilities during later mining stages of Phase II.
2.4.2.2.3 MINING PROCEDURES
Most ore and consolidated overburden will not require drilling and blasting prior to loading as most material processed under this updated 2018 Plan will utilize Run-of-Mine (ROM) procedures. This means that the stockpiled (backfill) ore is in its natural unprocessed state, except that it has already been blasted. While drilling and blasting of ore bearing rock is not, at this time, an anticipated activity of this 2018 Plan update, it remains an approved activity per the approved 1998 Plan and could occur in the future. When those activities are required, these materials are drilled on a set pattern, and representative samples of drill cutting are taken as each hole is drilled. Samples are assayed and then categorized as high grade ore, leach-grade ore, low grade ore, protore, or overburden. After blasting, the broken rock is classified into one of the above categories and flagged appropriately, so that the loader operator knows its destination.
Blast hole drilling is done using either rotary or percussion blast hole drills. Explosive materials used include AN/FO blasting agents, water resistant slurries, and cap sensitive primers. Time-delay blasting procedures are used for controlled production blasting of overburden and ore. Blasting occurs as often as six days per week averaging 180 blast holes per blast. All blasts take place during daylight hours. It is intended that a minimum of one production day of material be blasted in advance for loading purposes.
Castle Mountain Mine Plan and Reclamation Plan 2-21 January 2, 2019 No problems have been encountered due to blasting, as the closest residences are approximately eight miles from the pit areas.
Blasted and broken materials are loaded into haul trucks using front-end loaders and/or shovels.
2.4.3 STAGED DEVELOPMENT
Development of the Castle Mountain mine was separated into 10 stages for the purposes of the original 1990 Plan and approved 1998 Plan. The same structure has been followed in developing the production schedule in this 2018 Plan update. It should be noted that the exact schedule of staged development can change with changing mining economics, as has been explained throughout the approved 1998 Plan, and flexibility was incorporated into the Mine Plans to ensure the schedules presented therein were/are subject to modification. However, the original Stage 7, as approved in the 1998 Plan, which was to have been used to process stockpiled lower grade ore, was adjusted such that those activities occurred at Stage 6. Accordingly, the 1998 Plan proposed stockpiled materials would be used to augment mine production during Stage 6. As a result, activities that previously were designated to occur in Stages 8, 9, and 10, will instead occur in the renumbered Stages 7, 8, and 9, respectively. Additionally, this updated 2018 Plan recognizes that the approved 1998 Plan was not fully implemented due to the economics that were present at the time when mining halted in 2001. At that time, mining was suspended at approximately Phase I, Stage 5D. After April 2001, the Company processed some ore stockpiles (Stage 6) which were economical to work but left other protore stockpiles. Completing leaching and rinsing of the heap leach pile ore (Stage 7) continued in parallel with work to satisfy the reclamation and revegetation requirements of Stages 8 and 9. That the operator was not required (by the agencies) to formally modify the approved 1998 Plan as mining economics dictated a reordering of stage implementation, is recognized in this updated 2018 Plan. Similarly, this 2018 Plan update does not propose to alter the scope and scale of staged mine development as authorized in the approved 1998 Plan, but it does need to account for the fact that stockpiles remain at the site, that processing of stockpiles is an authorized action, and that an efficient mine plan which is mindful of environmental resources, requires that these stockpiles should be processed first, before any future mining is contemplated that might expand the footprint of the pit walls beyond their 2001 footprint, creating new land disturbance. Mining will continue under this 2018 Plan update with Stage 5D as the first stage implemented because it was the last stage not fully completed, per the approved 1998 Plan. Furthermore, as the approved 1998 Plan adjusted the sequence of stockpile processing from Stage 7 to Stage 6, this 2018 Plan update similarly adjusts that sequence to process stockpiles during Stage 5D instead of Stage 6. It is estimated that it will require the remaining proposed mining schedule (to 2025) to process the existing ore/protore stockpiles at the site. Only after the processing of stockpiles is completed will already approved hardrock mining again be considered (including drilling and blasting) under Stage 5F and/or 6.
These stages are further described in Table 2-2. The stages are separated based on the interrelationships between pre-production development and plant construction, mining, placement of ore, low grade ore, protore, and overburden, and reclamation efforts. It is additionally amended to reflect those stages where activities have been completed or where the estimated schedule has been adjusted. This description is based on the current operational plan. Mining is a dynamic process and must be responsive to changes in economics and geotechnical factors. As with most major projects, changes will occur throughout the life of the operation.
Disturbed acreage are shown in Table 2-3; and the estimated quantities of growth media that would be salvaged from those acreages are shown in Table 2-4. Section 3.9 of this document describes how reclamation activities are being integrated with mining operations.
Castle Mountain Mine Plan and Reclamation Plan 2-22 January 2, 2019 Table 2-2 Production Stages and Chronological Relationships Estimated Estimated End Status Stage Start (proposed) (as of 2018) Stage 1 June 1991 February 1992 Completed Stage 2 March 1992 March 1993 Completed Stage 3 April 1993 March 1994 Completed Stage 4 April 1994 March 1995 Completed Stage 5A 43 April 1995 March 1996 Completed Stage 5B44 April 1996 March 1997 Completed Stage 5C April 1997 March 1998 Completed Mining not completed in Oro Belle and Jumbo; December Activities Not Completed Stage 5D April 1998 2025 Mining not completed in Oro Belle and Jumbo; December Activities Not Completed Stage 5E April 1999 2025 Mining not completed in Oro Belle and Jumbo; December Activities Not Completed Stage 5F April 2000 2025 Mining was halted in May 2001, and stockpiles (that could be Activities Not Completed economically processed) completed by December 2001. Stage 645 April 2001 Resumed ore/protore stockpile processing complete by December 2025 Original leaching activities completed 2004; Resumed leaching Activities Not Completed Stage 7 2025 complete by December 2027 Original leach pad decommissioned 2005; Resumed leach pad Activities Not Completed Stage 8 2027 decommissioned by 2028 Stage 946 2027 Reclamation completed by December 2035 Activities Not Completed
43 Mining activities in Jumbo and Oro Belle deposits were initiated in Stage 5A. 44 Mining in the Lesley Ann pit was completed in February 1996. 45 In the event the South Extension pit and/or mineralization surrounding the OBHT and Jumbo pits proves to be economic to mine, Stage 6 will overlap with Stage 5F. Stages 7 through 9 will be postponed for the length of time Stage 6 is in operation. 46 Stage 9 involves revegetation activities in the leach pad area after the leach pad has been detoxified and the solution storage tanks and the stormwater basins have been dismantled and removed (See Section 3.9.1.5). Stage 9 will commence within six months after decommissioning and will end after the tenth growing season following the initial plantings on these areas.
Castle Mountain Mine Plan and Reclamation Plan 2-23 January 2, 2019
Table 2-3 Incremental Acreage Distribution By Stage Area Disturbed Cumulative Stage Stage Stage Stage Stage Stage Stage 5 Cumulative Stage Cumulative through 5A 5B 5C 5D 5E 5F Subtotal Through 6 through Stage 4 Stage 5 Stage 6 Lesley Ann/Jumbo Pits 90 10 10 18 5 0 0 43 133 15 148 Oro Belle/Hart Tunnel Pits 0 8 15 6 36 0 0 65 65 61 126 South Extension Pit 0 0 0 0 0 0 0 0 0 33 33 North Overburden Site47 0 0 22 0 70 93 15 200 200 9 209 South Overburden Site 214 0 0 0 0 0 0 0 214 93 307 Crushing Area 10 0 0 0 0 0 0 0 10 0 10 Solution Storage Area 6 0 0 2 0 0 2 4 10 4 14 Process Plant Site 4 0 0 0 0 0 0 0 4 0 4 Administration Site48 5 0 0 0 0 0 0 0 5 0 5 Heap Leach Pad49 120 34 37 39 52 0 31 193 313 108 421 Site Roads50 28 10 5 0 5 0 1 21 49 -1 48 Growth Media Storage 20 3 4 4 4 1 5 21 41 9 50 Areas
TOTALS 497 65 93 69 172 94 54 547 1,044 331 1,375 Source: 1998 Mine Plan
47 North Overburden Site does not include 28 acres of North Clay Pit Reclamation area and 36 acres of the South Clay Pit Reclamation area. 48 Administration area disturbance includes shop and warehouse areas 49 Heap leach pad disturbance includes 2 acres occupied by Comminution Circuit 50 Site roads include overland conveyor and powder magazine areas
Castle Mountain Mine Plan and Reclamation Plan 2-24 January 2, 2019
Table 2-4 Incremental Growth Media Removal (cubic yards) Cumulative Cumulative Cumulative Stage Stage Stage Stage Stage Stage 5 Area Disturbed Through Stage 5E Through Stage 6 Through 5A 5B 5C 5D 5F Subtotal Stage 4 Stage 5 Stage 6 Lesley Ann/Jumbo Pits 78,000 0 8,000 5,000 4,000 0 0 17,000 95,000 0 95,000 Oro Belle/Hart Tunnel 0 0 0 0 0 0 0 0 0 0 0 Pits South Extension Pit 0 0 0 0 0 0 0 0 0 11,000 11,000 North Overburden Site 0 0 0 0 226,000 0 0 226,000 226,000 0 226,000 North Oro Belle Site 0 0 0 0 0 0 0 0 0 0 0 South Overburden Site 229,000 0 0 0 28,000 0 0 28,000 257,000 0 257,000 Crushing Area 12,000 0 0 0 0 0 0 0 12,000 0 12,000 Solution Storage Area 14,000 0 0 5,000 0 0 5,000 10,000 24,000 10,000 34,000 Process Plant Site 10,000 0 0 0 0 0 0 0 10,000 0 10,000 Administration Site 1,000 0 0 0 0 0 0 0 1,000 0 1,000 Heap Leach Pad 160,000 96,000 77,000 81,000 399,000 0 0 653,000 813,000 0 813,000
TOTALS 504,000 96,000 85,000 91,000 653,000 0 5,000 934,000 1,438,000 21,000 1,459,000
NOTE: Growth media has been salvaged and used for past reclamation through in general Stage 5. Approximately 150,000 cubic yards of growth media are currently stockpiled on-site for future reclamation, mostly left over from the 2006 reclamation of the heap leach pad which didn’t require growth media for the slopes or top of the heap leach pad area.
Castle Mountain Mine Plan and Reclamation Plan 2-25 January 2, 2019 2.4.3.1 STAGE 1 THROUGH 5C (JUNE 1991 TO MARCH 31, 1998)
2.4.3.1.1 GENERAL DESCRIPTION
Stage 1 to 5C operations have been completed and only the general description of these activities will be included below for background. For a full description of each of these stages, refer to 1998 Plan.
Stage 1 to 5C General Description:
“Stage 1 commenced in June 1991 and ended with the commissioning of the Primary Crusher in February, 1992. Stages 2, 3, 4, 5A, 5B, and 5C were each of 12 months duration; with Stage 5C ending March 31, 1998.
During Stage 1 the Crushing Plant, Overland Conveyor, Shop, Process Plant, Administration, and Heap Leach Pad areas were cleared and graded, and the facilities in those areas were constructed. In addition, the primary access road (Walking Box Ranch Road) connecting the mine site to the regional highway grid was completed.
One major modification to the approved 1988 Plan of Operations and the original Plan 90M-013 concerned the supply of electrical power. The mine was approved on the basis of on-site generation of power using propane-fired engine/generator sets. In the Fall of 1991, alternative arrangements were concluded, and the operation was able to purchase utility power from Nevada Power. BLM and the County approved this change, and an overhead transmission line was built paralleling the Walking Box Ranch access road.
A second significant modification was the construction, during Stage 3, of the Comminution Circuit. This facility is authorized to process up to 1,750 tons per day of higher grade crushed ore, in order to enhance gold recoveries from such material. Viceroy's June 1992 application to construct this facility (located within an area of the heap leach pad already approved for disturbance) was approved by the BLM and County.”
2.4.3.2 STAGES 5A THROUGH 5F
2.4.3.2.1 GENERAL DESCRIPTION
Stages 5A to 5C operations have been completed and only the general description of these activities will be included below for background. For a full description of each of these stages, refer to the 1998 Plan.
Stage 5A to 5C General Description:
“Stage 5 will consist of six substages, each substage, except Stage 5F, being 12 months long. Stage 5A started April 1, 1995, with the commencement of preproduction activities (principally plant salvage) within those portions of the Oro Belle and Jumbo deposits authorized for disturbance pursuant to the Fall 1990 approvals issued by the County and BLM. It is presently anticipated that Stage 5F would end sometime during the Third Quarter of 2001, when the OBHT and Jumbo pits reach their planned Phase I pit boundaries.
This Plan (ver. 2.0 of 90M-013) incorporates enlargement of the areas approved for open pit mining, to accommodate the updated designs of the Oro Belle and Jumbo deposits, and to mine the Hart Tunnel deposit. Individually, the pits created in mining these deposits in Phase I are smaller than the Lesley Ann Pit. As a result, space on the working levels inside these pits will be cramped, requiring careful coordination of mining crews and equipment.
Given the presence of gold mineralization in the rock outside the planned Phase I pit boundaries of the Jumbo, Oro Belle, and Hart Tunnel deposits, the pit boundaries could expand beyond the presently designed pit limits under favorable economic conditions as a Phase II mining operation. Phase II will involve "push-backs" of the highwalls of the Jumbo Pit, and the north and east highwalls of the OBHT Pit, in order to gain access to deeply seated ore zones that lie outside the Phase I OBHT and Jumbo pit boundaries. Phase II will also involve development of the South Extension Pit.
Phase II mining of the Jumbo, Oro Belle, Hart Tunnel and South Extension deposits will occur during Stage 6, during the years 2001 through 2009. Implementing Phase II mining will postpone the commencement date of Stages 7, 8 and 9.
Castle Mountain Mine Plan and Reclamation Plan 2-26 January 2, 2019 A campaign involving the sequential backfilling of the Lesley Ann Pit commenced in the second half of Stage 5B. An estimated 21. 7 million tons of overburden from the OBHT and Jumbo pits will be used through Stage SF to partially backfill this pit. See Figure 2-5 and 2-6. The lowest 120 feet of the Lesley Ann Pit (up to the 3900 foot elevation) will be backfilled. Above the 3900 foot elevation, only the northernmost portion of the pit will be filled, up to about the 4450 foot 'elevation (The southern portion of the Lesley Ann Pit above the 3900 foot elevation will be kept clear to allow access to mine the South Extension deposit). Partially backfilling the Lesley Ann Pit in this manner will create about 32 acres of level surface areas. Later additional overburden material from the OBHT pit expansion in Phase II will be placed on this surface. Therefore, placement of growth media and revegetation of this area will be delayed until Stage 6.
2.4.3.2.2 STAGE 5A
Phase I, Stage 5A operations have been completed and the description of these activities has been omitted from this 2018 Plan update (see Figure 2-11). Please refer to the 1998 Plan for a description of these activities.
2.4.3.2.3 STAGE 5B
Phase I Stage 5B operations have been completed and the description of these activities has been omitted from this 2018 Plan update (see Figure 2-12). Please refer to the 1998 Plan for a description of these activities.
2.4.3.2.4 STAGE 5C
Phase I Stage 5C operations have been completed and the description of these activities has been omitted from this 2018 Plan update (see Figure 2-13). Please refer to the 1998 Plan for a description of these activities.
2.4.3.2.5 STAGE 5D
Phase I Stage 5D operations are incomplete and the description of these completed activities has been omitted from this 2018 Plan update (see Figure 2-14). Please refer to the approved 1998 Plan section 2.4.3.2.D for a complete description of these completed activities.
Activities authorized but not completed under this Stage of the mine plan includes westward expansion of the Heap Leach Pad, expansion of the North Overburden Stockpile, additional mining in the OBHT and the Jumbo pits, and realignment of a new haul road from the OBHT. As describe in section 2.4.3 of this Plan update, the remaining proposed mining activity for Stage 5D will be the processing of backfilled protore stockpile that was sequentially backfilled into the Lesley Ann pit up until mining was suspended at this Stage of the mine plan (Phase I, Stage 5D) in 2001. Processing of ore/protore stockpiles was approved to occur at Stage 6, but current mining economics and resource conservation requires an adjustment to the proposed mine schedule to process stockpile material during Stage 5D. These ore stockpiles must be moved (processed) before the mine pit expansions approved from Stage 5F to 6 can occur and the most efficient and environmentally conscious strategy for processing these ore stockpiles is the run-of-mine(ROM) operations described in the preceding sections of this 2018 Plan update.
The excavation of ROM ore stockpile does not require any drilling or blasting and the removal and transport of this ore will occur on private land parcels. Haul roads will largely overlay prior haul road locations, with slight modifications within the Lesley Ann ore stockpile area which is already highly disturbed mine land. Figure 2-14 shows the mine plot plan after Stage 5D mining of backfilled protore
Castle Mountain Mine Plan and Reclamation Plan 2-27 January 2, 2019
F2-11 CMV-Mine Stat at end of 5ABC Stage File: F2-11 CMV-Mine 10/17/2018 1 REV: Page: (TAG)
Stage 5A Mining is Complete
MINE STATUS at END of STAGE 5A CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-11 C O R P O R A T I O N
F2-11 CMV-Mine Stat at end of 5ABC Stage File: F2-11 CMV-Mine 10/17/2018 1 REV: Page: (TAG)
Stage 5B Mining is Complete
MINE STATUS at END of STAGE 5B CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-12 C O R P O R A T I O N
F2-11 CMV-Mine Stat at end of 5ABC Stage File: F2-11 CMV-Mine 10/17/2018 1 REV: Page: (TAG)
Stage 5C Mining is Complete
MINE STATUS at END of STAGE 5C CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-13 C O R P O R A T I O N File: F2-14A CMV-F2-14A CMV-MINE STATUS at END of STAGE 5D (TAG) Page:1 REV: 10/17/2018
Desert Tortoise Fence
Desert Tortoise Fence
Gold Processing Plant to be Re-established 2018 Source: Castle Mountain Ventures, 2018. Approximate Area of Heap Leach Pad Expansion (Portion to Overlap Existing Reclaimed Area) Backfill/Protore to be Mined (Removed) and Hauled to Heap Leach Pad END of STAGE 5D - 2018 MINING PLAN UPDATE North Nursery to be Established CASTLE MOUNTAIN MINE County of San Bernardino, California Desert Tortoise Fence
LEGEND 1998 Approved Mine Plan Boundary LILBURN FIGURE 2-14 C O R P O R A T I O N 1998 Approved Facilities stockpile from the Lesley Ann pit. It should be noted that the approved 1998 Plan assumed that sequential backfilling of the Lesley Ann pit would be ongoing at Stage 5D which was proposed to begin March 1999. Only one element of Stage 5D was completed by 2000, that being mining in the Oro Belle pit to its proposed pit depth. The majority of approved Stage 5D activities were not completed by the time operations were suspended in 2001 by the mine operator, and at which time backfilling of Lesley Ann pit was complete. This delay before implementation of the major components of this stage supports the understanding that even these approved mine stages represent a best estimate and the exact schedule will change as mining advances and mine economics fluctuate, and that these types of scheduling fluctuations do not represent major or even minor changes to the approved 1998 Plan, but are innate to any mine plan.
2.4.3.2.5.1 ORO BELLE, HART TUNNEL and JUMBO PITS
This 2018 Plan updates the Stage 5D plan details to focus on removing backfilled protore stockpile from the Lesley Ann pit.
2.4.3.2.5.2 NORTH and SOUTH CLAY PIT RECLAMATION AREAS
[Section omitted from this 2018 Plan update.]
2.4.3.2.5.3 OTHER OVERBURDEN STOCKPILE AREAS
Growth media coverage for the North and South Overburdens sites is estimated at 6 to 12 inches thick. However, as it will be explained in section 3.0, the successful reclamation strategy contained in this 2018 Plan updated places less correlation between the availability of growth media and the success of revegetation and reclamation. In any event, there is abundant growth media stockpiles still present that were not used during the reclamation from 2001 to 2006. During this substage, based on growth media volume estimates on Table 2-4, there may be 25 acres of disturbance in the South Overburden Site with 28,000 remaining cubic yards of growth medial scheduled for salvage. The North Overburden Site, during this substage, may see up to 160 acres of disturbance with 158,000 cubic yards of growth media scheduled for salvage. The amount of growth media scheduled for salvage in the Lesley Ann pit areas is minimal due to reclamation that has already occurred. During prior reclamation, growth media was not applied as a soil layer on top of reclaimed areas but mounds that were then mixed in with overburden rock material. Because of this strategy, it will be almost impossible to salvage more growth media.
2.4.3.2.5.4 HEAP LEACH PAD AREA
Approximately 44-million tons of ore bearing material will be placed on the pad during this substage. This material will be placed in approximate 50-foot lifts. About 150-acres of desert grassland-creosote bush scrub-Joshua tree woodland will be disturbed in expanding the heap leach pad within its approved footprint in this substage. It should be noted that successive, and approved, heap leach pad expansions estimated to occur from Stage 5D to Stage 6, with this schedule adjustment, will now all accrue during Stage 5D to accommodate the processing of backfilled protore stockpiles; this is estimated to consume the remaining approved capacity of the heap leach pad. Based on an estimated growth media volume from Table 2-4, approximately 399,000-cubic yards of growth media will be salvaged from this area. This 2018 Plan update does not alter this approved heap leach expansion area and is planned to occur in 2019. Since the former Regional Water Quality Control Board (“RWQCB”) Waste Discharge Requirement
Castle Mountain Mine Plan and Reclamation Plan 2-32 January 2, 2019 (“WDR”),which authorized operation of the heap leach pad, was rescinded in 2010, a new WDR will need to be approved and in place prior to operation of the heap leach pad under this 2018 Plan update.
2.4.3.2.5.5 MINE FACILITIES
Certain approved mine facilities were reclaimed during the substantial mine reclamation from 2001 to 2012. During this stage, these facilities will be re-established including the Heap Leach approved expansions, the Processing Plant, the Water Basins (adjacent the Processing Plant) and the Fleet Maintenance area. Only the Heap Leach Pad expansion authorized for Stage 5D will partially occur on public land managed by the BLM.
2.4.3.2.6 STAGE 5E
Phase I, Stage 5E operations as described in the approved 1998 Plan (see Figure 2-15) have been halted under this 2018 Plan update and will not be completed until processing of existing site ore stockpiles is complete. For a complete description of actions authorized in these stages, please refer to section 2.4.3.2.E through 2.4.3.3 of the currently approved 1998 Plan.
2.4.3.2.7 STAGE 5F
Phase I, Stage 5F operations as described in the approved 1998 plan (see Figures 2-16) have been suspended under this 2018 Plan update and will not be completed until processing of existing site ore stockpiles is complete. This activity is estimated to occur until 2025 which is the current end of the mining schedule. If at that time after the processing of stockpiles, there is additional schedule remaining in the mine plan, then the Company will decide whether to complete the authorized mine pit expansions detailed for Stage 6. For a complete description of actions authorized in these stages, please refer to section 2.4.3.2.E through 2.4.3.3 of the currently approved 1998 Plan.
2.4.3.3 STAGE 6
2.4.3.3.1 GENERAL DESCRIPTION
Assuming economic conditions warrant, mining in the South Extension and expanding the Jumbo and OBHT pit boundaries to recover additional mineralization adjacent to the planned Phase I boundaries, Phase II of the mining plan will be implemented as Stage 6. This stage is no longer expected to start until the processing of ore/protore stockpiles is complete which is tentatively expected to end by 2025. At that time, and similar in approach with the approved 1998 Plan, the economics will be reassessed to determine if mining Stage 6 is feasible. Additionally, as detailed in section 2.4.3.2.5 for Stage 5D, protore stockpile processing that was forecast for Stage 6 has been adjusted to Stage 5D. This 2018 Plan update assumes active mining of stockpiles and/or hardrock ore reserves will be completed by 2025 at which time reclamation may begin if plans for additional mine Plan changes have not been submitted to the agencies. The configuration of the pits, overburden sites and Heap Leach Pad at the conclusion of Stage 6 is shown in Figure 2-17 and reflects changes requested by the County Planning Commission, i.e., modifications to the configuration of the North Overburden Area
Prior to initiating any Phase II expansion work, the Company will present data to the County and BLM as related the mine design and reclamation plans. (See Appendix A, Conditions of Approval, No. 113.) Submittal of this 2018 Plan update to the agencies satisfies this requirement.
Castle Mountain Mine Plan and Reclamation Plan 2-33 January 2, 2019 REV: 10/17/2018 1 REV: Page: (TAG)
MINE STATUS at END of STAGE 5E at END of STAGE MINE STATUS
File:
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
MINE STATUS at END of STAGE 5E CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-15 C O R P O R A T I O N REV: 10/17/2018 1 REV: Page: (TAG)
MINE STATUS at END of STAGE 5F at END of STAGE MINE STATUS
File:
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
MINE STATUS at END of STAGE 5F (Completion of Phase 1) CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-16 C O R P O R A T I O N REV: 10/17/2018 1 REV: Page: (TAG)
PRELIMINARY MINE STATUS at End of 6 Stage MINE STATUS PRELIMINARY
File:
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
PRELIMINARY MINE STATUS at End of Stage 6 CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-17 C O R P O R A T I O N 10/17/2018 1 REV: Page: (TAG)
PRELIMINARY MINE STATUS at End of 6 Stage MINE STATUS PRELIMINARY
File:
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998. ORO BELLE/HART TUNNEL PHASED PIT DESIGN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-18 C O R P O R A T I O N File: F2-19 CMV-Oro Belle hart Tunnel Phase Pit (TAG) Page:1 REV: 10/17/2018
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
ORO BELLE/HART TUNNEL PHASED PIT DESIGN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-19 C O R P O R A T I O N File: F2-19 CMV-Oro Belle hart Tunnel Phase Pit (TAG) Page:1 REV: 10/17/2018
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
ORO BELLE/HART TUNNEL PHASED PIT DESIGN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-20 C O R P O R A T I O N
10/17/2018 1 REV: Page: (TAG) F2-21 CMV-JUMBO PHASED PIT DESIGN File: F2-21 CMV-JUMBO
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
JUMBO PHASED PIT DESIGN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-21 C O R P O R A T I O N File: F2-22 CMV-JUMBO PHASED PIT DESIGN (TAG) Page:1 REV: 10/17/2018
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
JUMBO PHASED PIT DESIGN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-22 C O R P O R A T I O N Early in Stage 6, push-back of the pit highwalls in the Jumbo pit and the east highwall of the OBHT pit will be completed, so that the more deeply-seated ore in these deposits can be made accessible for mining. The effect of a Phase II expansion of the OBHT pit is shown graphically in Figures 2-18 through 2-22. During the push-back of the OBHT pit highwall, the overburden placed in that area during Stage 5B will be removed. Concurrently, the South Extension deposit will be mined.
During Stages 1 through 5F, stockpiles of various grades of mineralized material mined from the Lesley Ann, OBHT and Jumbo pits will have been built on top of the South Overburden Site and on the lowest terrace in the South Clay Pit Reclamation Area. The total tonnage of material ultimately placed in these stockpiles depends on economic considerations and the nature of gold mineralization within the pits. The remaining volumes of this stockpiled material, in conjunction with backfilled protore stockpiles will be processed in Stage 5D, as defined in previous sections of this 2018 Plan update.
2.4.3.3.2 OPEN PIT MINING ACTIVITIES
While the general development of the mine during Stage 6 will be similar to earlier stages, the approved 1998 Plan explained that detailed engineering for the South Extension pit and the OBHT pit expansion cannot proceed until considerably more drilling of these deposits has occurred.
Conceptually, access to the South Extension pit will be provided by excavating ramps into the southernmost portion of the Lesley Ann pit, where by this stage, processing of the backfilled protore stockpiles should be completed to expose the original bench elevations of the Lesley Ann pit. Ore from the South Extension pit will be transported to the Primary Crusher using a haul road ascending the southwest wall of the Lesley Ann pit, or if further ROM processing is still necessary, then directly out to the heap leach pad. Ore will be dumped directly into the Primary Crusher, or it will be placed in nearby stockpiles, or transported directly to the heap leach pad if no crushing is required. Overburden will be placed in the north end of the South Overburden Site (see Figure 2-17).
The push-backs of the pit walls in the OBHT and Jumbo pits will result in the disturbance of an additional 61 and 15-acres, respectively. As most of this activity will occur in steep terrain with limited opportunities for growth media salvage, the amount of growth media that can be salvaged prior to the start of the push-backs would be limited, probably amounting to no more than 10,000-cubic yards.
Preparing the South Extension pit for mining will disturb an additional 33-acres, and result in the salvage of approximately 11,000-cubic yards of growth media.
During the push-back of the east highwall of the OBHT pit, overburden material will be transported to the North Overburden Site using temporary haul roads constructed along the east and north sides of the pit. From the northwest side of the OBHT pit, a haul road will descend to the west, to the top of the overburden previously placed on the North Clay Pit Reclamation Area of the North Overburden Site.
2.4.3.3.3 NORTH and SOUTH CLAY PIT RECLAMATION AREAS
The approved 1998 Plan explained that processing of stockpiled low grade ore and protore from the storage area atop the South Clay Pit Reclamation area and in the vicinity of the Primary Crusher will occur throughout Stage 6. Revised scheduling already reflects this will now occur during Stage 5D, but prior reference to crushing this material has been removed, and as it was established as a contingency
Castle Mountain Mine Plan and Reclamation Plan 2-37 January 2, 2019 measure in the approved 1998 Plan can be hauled directly to the heap leach pad, placed on the uppermost lift of crushed ore, then leached.
The plans for reclamation of the historic clay pits did commence as proposed by earlier versions of the mine plan and is now considered complete. This remaining section will however still be included in this updated 2018 Plan to provide some background:
The BLM’s approval of Viceroy’s initial application for a Plan of Operations to develop the Castle Mountain Project was appealed by several environmental organizations in late 1987. Those approvals had been based on an Environmental Assessment. In light of the appeals, the agencies elected to prepare an Environmental Impact Statement and an Environmental Impact Report. While these documents were being prepared, Viceroy met, on numerous occasions, with representatives of the groups that had filed the appeals. Viceroy agreed to implement a number of measures suggested by the environmental organizations to address several of their specific concerns, but the parties were unable to reach agreement on the request that Viceroy agree to backfill the open pits that would be created by its mining activities. Viceroy’s position was that such a requirement would render the project uneconomic.
At the request of the BLM, the Department of the Interior’s Bureau of Mines prepared an analysis of the economic effects of requiring backfilling on a hypothetical, open pit mining operation in the desert southwest. The analysis demonstrated that for the mine model used by the Bureau of Mines’ study, with a gold price of $400 per ounce gold and a 15 percent rate of return on capital investment, backfilling would make an otherwise profitable operation unprofitable, resulting in a negative net present value.
In light of this result, the environmental organization and Viceroy negotiated an arrangement whereby Viceroy would contribute $2 million to a trust fund to be used for environmental enhancement activities in return for the environmental organizations agreeing not to appeal approval of the Castle Mountain Project. The “Settlement Agreement”, dated November 7, 1990, stated that moneys in the trust fund would be used “…for one or more of the following purposes,…”
(1) On-site Environmental Enhancement Activities. Conducting environmental enhancement activities on areas affected by mining operations at the project, not excluding partial recontouring and revegetation of the Oro Belle pit. Such on-site activities shall be coordinated with Viceroy so as not to interfere with mining operations under Viceroy’s then approved mining plan in the area of such activity. (See the “Settlement Agreement” for other terms of this item.)
(2) Off-site Environmental Enhancement Activities. Conducting environmental enhancement activities on areas disturbed by mining operations which are located in the East Mojave National Scenic Area other than the project.
(3) Land Acquisition. Acquisition of lands located in the East Mojave National Scenic Area which are of value as wildlife habitat, scenic areas, recreational areas, or other purposes which similarly enhance natural values. Any lands so acquired shall be held in a manner which is consistent with their perpetual preservation from development (other than development which is consistent with the value of the lands for the purposes stated in the first sentence of this paragraph). (See the “Settlement Agreement” for other terms of this item.)
Subsequent to the establishment of the trust fund, the environmental groups advised Viceroy of their intention to use the funds to finance activities within the third category, specifically the placement of overburden within the Oro Belle pit, to assist in the recontouring of that pit.
It is difficult at this time to quantify the tonnage of overburden that could be backfilled into the Oro Belle pit, since it depends on two items:
1) the amount of money in the trust fund when active mining in the Oro Belle pit stops, which in turn depends on the rate of return the trust funds can generate from the $2 million investment portfolio,
and,
2) the unit cost of operating a fleet of front end loaders and haul trucks to load and transport overburden from the North Overburden Site to the pit area.
Castle Mountain Mine Plan and Reclamation Plan 2-43 January 2, 2019
In order to accommodate the foregoing operation, Viceroy reclamation activities on a portion of the North Overburden Site, covering, perhaps, 30-acres, will be deferred for 12 to 18 months after mining activities in the Oro Belle pit are finished, to allow the backfilling operation to be completed. Thereafter, Viceroy will proceed to reclaim and revegetate the area used as a source of backfilling material.
2.4.3.3.4 OTHER OVERBURDEN STOCKPILE AREAS
Overburden sorted from the backfill protore stockpile at the Lesley Ann pit during Stage 5D and any other material mined from the expanded OBHT and Jumbo pits in later years will be placed first in the South Overburden Site, and then if required also in the North Overburden Site, immediately west of the Jumbo pit. Overburden from the South Extension pit, if this pit is mined during Phase II (12.3-million tons) will be placed in the South Overburden Site. The North Overburden Site will expand by about 9-acres as a result of this activity.
If mining of the South Extension pit does occur, it will take place during the first 24 months of Stage 6, where 12.3 million tons of overburden from the South Extension pit will be placed in the South Overburden Site which will ultimately cover 307 acres, in substantial conformity with the 300 acres that are presently permitted for disturbance in this area. This material will be placed, in part, in the north end of the South Overburden Site, in an area that was approved for disturbance in the 1990 Plan approvals.
The 1998 Plan included a general discussion of mine pit backfilling throughout this section of the plan; those references have been omitted from this 2018 Plan update because backfilling was completed in 2000 and that material is considered protore stockpile. Additionally, backfilling will occur in the future to the extent conditions merit but additional reference in this Plan is not warranted. The agencies have long recognized that backfilling at the CMM site is not a requirement under the 1990 and/or 1998 Plans, but rather a voluntary action by the operator.
2.4.3.3.4.1 MINE FACILITIES
Except as noted, expansion of the mine facilities, other than what was approved in the original 1990 Plan and/or 1998 Plan is not anticipated.
The larger the heap leach pad area, the greater the volume of water that must be retained within solution handling system during a precipitation event. Additional basin capacity will be added from time to time during Stage 6, as the heap leach pad increases in size. The larger pad area will capture a greater volume of water from a precipitation event. Over several days following a precipitation event, the retained water will be used in the leaching process, in lieu of fresh water.
Any additional basins will be constructed adjacent to the existing basins in the Process Plant Area. Basins typically occupy two or three acres each. Excavation of such basins will produce between 4,000 and 8,000-cubic yards of growth media per basin. The growth media will be added to existing stockpiles in the immediate vicinity. Vegetation in this area is desert grassland/creosote bush scrub/Joshua tree woodland.
Castle Mountain Mine Plan and Reclamation Plan 2-44 January 2, 2019 2.4.3.3.4.2 HEAP LEACH PAD AREA
The area approved for the Heap Leach Pad will accommodate the ore scheduled for production through the end of Phase II. This 2018 Plan update does not propose any changes to the maximum approved footprint for the heap leach pad which Table 1-3 lists as 421 acres.
Expansion of the consolidated leach pad towards the northwest will occur in phases throughout Stage 5. This 2018 Plan update notes Stage 5D as only partially complete; specific to the Heap Leach Pad, its approved westward expansion estimated to occur during stage 5D did not occur before mining stopped in 2001;that expansion is now proposed to occur in anticipation of the onset of resumed Stage 5D mining, and is estimated to occur during the 3rd Quarter 2019. If additional pad space is required, it will be provided by further expanding the leach pad towards the southwest as has already been approved and estimated to occur through Stage 6, by the 1998 Plan. The expansion(s) will occur in soils mapping unit 1. Growth media in this area is expected to average approximately 18-inches in depth. Accordingly, each acre of additional disturbance during Stage 6 would generate approximately 2,400-cubic yards of growth media. This material will be stockpile on the south and north side of the consolidated leach pad. Additionally, and prior to the halt of mining in 2001, the perimeter fence and desert tortoise exclusion fences were not installed around the approximate 100-acre west expansion area for the heap leach. The southernmost 52 acres of this area will be the first heap leach pad expansion area under Stage 5D. To prepare this land for Heap Leach Pad expansion, the Company has already received BLM authorization to complete the desert tortoise exclusion fence around this 100-acre expansion area (completed as of September 2018).
General management, design and construction of the expanded heap leach pad will be similar to the practices followed with the initial heap leach pad, incorporating design specifications approved by the RWQCB for the existing leach pad. Final engineering design to accommodate site specific conditions could result in some modification to the shape and orientation of the expanded heap leach pad from that shown. The detailed engineering design for each pad expansion will be submitted for review and approval by the RWQCB.
2.4.3.3.4.3 ONSITE ROADS (INCLUDING OVERLAND CONVEYOR)
This 2018 Plan update includes reference to an overland conveyor which was approved in the original 1990 Plan and fed crushed ore from the Crushing Plant to the Mill and/or Heap Leach Pad. While this remains an approved action, this facility is not currently proposed for Stage 5D operations of resumed processing of protore stockpiles. Reference to the overland conveyor system will remain in this 2018 Plan update but re-installation is not planned at this time.
During the reclamation carried out between 2001 and 2006, the California side of the main access road (Walking Box Ranch Road) was decreased from two lanes of traffic to a single lane but the road in Nevada remained a two-lane dirt road. It’s likely that at some point during the implementation of this 2018 Plan update, that the road section in California will be widened back to its original width approved in the original 1990 (and 1998) Plans. Any additional approvals required by the BLM or any other agency will be in place before the road is widened.
Castle Mountain Mine Plan and Reclamation Plan 2-45 January 2, 2019 2.4.3.3.5 STAGE 7 THROUGH 8
After Stage 6, no further ore will be added to the Heap Leach Pad, but circulation of barren solution through the heaped ore will continue, to extract additional gold during Stage 7. Operating activities in Stage 8 will be limited to circulation of rinse water through the leach pads to displace residual leaching solution and reduce cyanide concentrations to the levels specified in the Waste Discharge Requirement (WDR) issued by the Regional Water Quality Control Board (RWQCB).
The length of time circulation of barren solution will continue is uncertain, but experience at other operations suggests economic quantities of gold could continue to leach from heaped ore for as much as 24 to 48 months after the last gold-containing material is placed on the pad.
At the time the commitment was made to apply leaching solutions to the ore using drip irrigation rather than “rainbird”-type impulse sprinklers (to minimize ponding and the risk of avian exposure to cyanide solutions), it was anticipated that drip irrigation would be less effective in leaching the side slopes. When a trial recontouring of the southwest side of the existing pad was undertaken in early 1996, leach solution was applied to the slope after it had been recontoured. Additional quantities of gold were extracted, confirming previous predictions that drip irrigation procedures are only partially effective in leaching the ore within the sloping sides of the Heap Leach Pad. It is anticipated that two to three years will be required to complete the leaching and rinsing of side slopes after they are graded as part of the initial reclamation procedures for the Heap Leach Pad.
During Stage 7, the process plant, the solution storage tanks and stormwater basins will continue in service, but other facilities, such as pit haul roads will be taken out of service. Once the equipment occupying these sites has been removed, reclamation efforts on these sites will commence, and reclamation activities previously started in earlier years on the overburden sites will be intensified.
Stage 8 will commence when the circulation of barren solution is halted. Rinse water will then be circulated through the heaps until residual cyanide levels meets RWQCB specifications. This could take several months. Oxidizing chemicals may be added to the rinse water to accelerate the detoxification process. During this stage, the solution storage tanks and stormwater basins will continue in service.
2.4.3.3.6 STAGE 9
Stage 9 will commence after the leach pad, solution storage tanks and stormwater basins have been decommissioned. Activities during this Stage are discussed in the Reclamation Plan (Section 3 of this document).
Stage 9 ends when reclamation activities have been completed. Based on present information, Stage 9 would end prior to the year 2035.
Topographic and hydrologic conditions when Stage 9 is complete are described in Sections 3.10 and 3.11, respectively.
2.4.4 MINE PRODUCT CHARACTERIZATION
Historic drilling at the far north end of the Oro Belle deposit to better define the extent of the mineralization zone in that area once encountered ore-grade material that was noted as having remnant
Castle Mountain Mine Plan and Reclamation Plan 2-46 January 2, 2019 sulfide mineralization present. Under certain conditions, if the sulfidic ore oxidizes, it can cause a condition known as acid rock drainage (“ARD”). The quantity of the sulfidic gold-bearing ore in the Oro Belle deposit is limited. Since this material will be placed on the heap leach pad (where lime and cement are used to maintain high pH levels) ARD conditions are not likely to arise. Any acid generated is likely to be neutralized by the lime, cement and alkaline nature of the rest of the ore on the heap leach pad. Additionally, the Company has conducted over 300,000 feet of mineral exploration drilling over the past five years and it has been rare to even find trace amounts of sulfide mineralization. See the Final EIS/EIR, Response to Comments to amend County Mine Plan and Reclamation Plans, October 1997, pp. 7-11 to 7-15 for more discussion on this matter.
2.5 ORE PROCESSING
The discussion in the original 1990 Plan (at page 2-44 and Figures 2-12, 2-13 and 2-14, and at pages 2-45, 2-46 and 2-47) describes the crushing and conveying circuit, the heap leach system, and the gold recovery system that are approved at the mine site. Additionally, pages 27, section 2.1.9 of the approved 1998 Plan discusses the Comminution Circuit. This 2018 Plan update does not propose to operate many of the approved ore processing facilities outlined above (Crushing and Conveying Circuit, or the Comminution Circuit) due to the increased efficiencies and overall increased resource conservation strategy discussed throughout this 2018 Plan update.
Gold recoveries at Castle Mountain using heap leaching techniques range from 5 to 75 percent, depending on which pit the ore is obtained from.
In June 1992, the Company submitted an application to the agencies seeking permission to construct a Comminution Circuit on a 2-acres site on the heap leach pad. The facility would process up to 1,750 tons per day of the higher grade portions of the ores at Castle Mountain. Approvals were received several months later, and the facility commenced operation in July 1993. This facility was decommissioned and reclaimed by 2006 and while it is an authorized facility, this 2018 Plan update does not propose to re-establish it at this time.
Crushed ore and/or run-of-mine ore is delivered to the Heap Leach Pad either on the Overland Conveyor or via haul truck and stacked on the heap leach pad to continue the leaching process. This alternate option for ore delivery to the Heap Leach Pad is recognized in the approved 1998 Plan. The approved 1998 Plan also discusses the general operation of the former Comminution Circuit and while this circuit is an approved facility, it is not currently proposed for Stage 5D resumed processing of protore stockpiles. Nonetheless, reference to the Comminution Circuit will remain in this 2018 Plan update even though it is not planned for operations proposed by this 2018 Plan update. If this circuit is warranted in the future, the high-grade portion of ore will divert to the Comminution Circuit. This ore is milled, or “ground” in cyanide solution and partially leached. The slurry is then thickened and filtered, to separate gold-bearing solution from the leached ore residue. This solution flows by gravity to the gold recovery plant, while the filtered residue (which still contains recoverable gold values) is agglomerated with the low-grade portion of the ore, and stacked on the Heap Leach Pad.
2.6 WATER IMPOUNDMENTS and DIVERSIONS
With the exception of two areas, precipitation falling on the mine site drains from the area in existing ephemeral drainages. The exceptions are the open pits, and areas which are underlain by the liners associated with heap leaching activities.
Castle Mountain Mine Plan and Reclamation Plan 2-47 January 2, 2019 The open pits are located at or near the crest of their respective watersheds. The watersheds cover approximately 407-acres as shown in Figure 2-23.
Although the pits constitute approximately 75 percent of this watershed area (307-acres), water entering the pits would have little effect on the volume of downstream flows. Surface water flowing from the mine site could ultimately reach Sacramento Wash, which drains the northeastern portion of Lanfair Valley. The drainage area feeding Sacramento Wash cover approximately 240-square miles (153,000-acres). The 407-acres of watershed that may potentially be affected by the development of the open pits, and the 421-acres that would ultimately be covered by the Heap Leach Pad each represent less than 0.3 percent of the Sacramento Wash watershed.
The main processing facilities are located on the alluvial fan portions of the mine site. Facilities have been sited to conform to the topography, to minimize earthwork, and to avoid interfering with the major ephemeral water courses that cut across the alluvial fan. Accordingly, flows (which occur only during of following large storm events) in the main drainage through the site have not been affected by construction of the mine processing facilities. Some V-ditches will be installed to divert surface sheet- flow around the immediate proximity of the heap leach pad and other structures.
No impoundment structures will be constructed to intercept storm water flowing in any of the dry washes. Storm water falling on areas underlain by synthetic liners at heap leach pad and Process Plant are directed to the emergency solution storage and storm water basins. These basins are between 20 to 25 feet deep.
2.7 UTILITIES and SUPPLIES
2.7.1 WATER REQUIREMENTS and SUPPLY
The Mine’s water needs are primarily to supply the heap leach process and for dust control. The percentage of total water used for dust control will be noticeably lessened during resumed Stage 5D operations due to efficiencies realized from operating the run-of-mine process which doesn’t require the Crushing and Conveying circuits. Daily water requirements vary throughout the year, due to changes in temperature and evaporation. Approximate water usage during the summer and winter seasons as anticipated in the initial planning for the Castle Mountain Project is shown in Table 2-5.
Table 2-5 Seasonal Water Use Water Use Summer (gpm) Winter (gpm) Moisture retained in heap piles 175 175 Evaporation loss: Heap Piles 160 95 Evaporation loss: Solution 10 5 Storage Area Dust Control 100 65 Miscellaneous, including domestic, equipment washdown, 50 50 etc. TOTALS 495 390 ANNUAL AVERAGE 450 gpm, or 725-acre feet/year
Castle Mountain Mine Plan and Reclamation Plan 2-48 January 2, 2019
10/17/2018 1 REV: Page: (TAG) F2-23 CMV-IN-PIT CATCHMENT AREA and 100 YEAR FLOOD PLAIN AREA and 100 YEAR FLOOD CATCHMENT File: F2-23 CMV-IN-PIT
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
IN-PIT CATCHMENT AREA and 100 YEAR FLOOD PLAIN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 2-23 C O R P O R A T I O N Actual experience has shown that water requirements to be considerably less than 725-acre feet/year. Water consumption during the first five years of operation was less than 525-acre feet/year; and consumption from mid-1996 through to the year 2010 did not exceed 625-acre feet/year. The water consumption during the 10-year revegetation-monitoring period at the conclusion of mining operations is expected to be less than 2.5-acres feet/year.
Water is supplied from a series of ground water wells in a main well field located about 2 miles northwest of the Mine site. Water is delivered from each well site to the main pipeline via a buried pipe in the well service road. The main pipeline is an 10 inch line buried in the shoulder of the Hart Mine access road extending from the West Well Field to the site. Water is stored adjacent to Well W-15 in a 250,000 gallon tank. Additional water has historically been provided by mine dewatering wells located throughout the Mine area and it will continue to be the case that water from these wells, known as the East Well Field, will augment supply from the existing West Well Field.
Water wells for the West Well Field include up to 15 water wells which were drilled from approximately 1986 to 1997. The individual bore holes and well installations were authorized by San Bernardino County through water well permit applications. Where well installation occurred on public land, Plan of Operations and/or Right of Way temporary use permits were authorized by the BLM. Where well installation occurred on State land, managed by the State Lands Commission, lease agreements were authorized by the Commission. Bore holes which were developed into active water production wells for the mine were perfected for use through the authorizations described above, the established California water rights doctrine of beneficial use as documented by First Notice Ground Water Extraction filings with the State Water Control Board which were obtained by CMV for water wells. Annual filings of water use with the State have continued for each water well from the date of the original First Notice of Ground Water Extraction to the most recent annual filing in May 2017.
2.7.2 OTHER UTILITIES and STRUCTURES
The original 1990 Plan approved the use of on-site power generators to supply site power. Shortly after the agencies issued final approvals for the operation in 1990, the Company reached an agreement with Nevada Power to install a 69-kV overland power transmission line to the site along the main access road; this action was authorized as a modification to the approved mine Plan and impacts assessed through a separate Environmental Assessment. The mine purchased electrical energy from Nevada Power Company until the power line was removed during land reclamation in 2011. It is likely that the Company will apply for the reinstatement of the prior right-of-way to reinstall the overland power line but until that time, power will be generated onsite, as was originally assessed for the project through the 1990 EIS/EIR (Castle Mountain Project, Final EIS/EIR, August 1990) and as recognized on the 2013 revision (and extension) of the Mining CUP approved by the County. These reviews assessed the impacts estimated from on-site generated power supply from propane fueled generators. The subsequent 1997 EIS/EIR removed air emissions associated with onsite power generation due to accessibility to commercial grid power, with one emergency diesel engine evaluated as part of onsite operations. The approved emission limits as estimated in the 1997 EIS/EIR are shown in Table 2-6A.
Even with the reduced scope of onsite power generation evaluated in the 1997 EIS/EIR (emergency backup generation only), a current assessment prepared by Ramboll US Corporation (“Ramboll”) has concluded that air emissions estimated under this 2018 Plan update are expected to be below all criteria air pollutants (CAPs) levels evaluated in the 1997 EIS/EIR. In addition to the reduced scope of operations in the 2018 Plan, recent advancements in clean diesel technology, and the 2018 Plan’s commitment to
Castle Mountain Mine Plan and Reclamation Plan 2-50 January 2, 2019 diesel-fuel based power generating units meeting Tier 4 Final emission requirements lead to these reduced levels of air emissions. A comprehensive emissions inventory based on the proposed operations under this 2018 Plan update is shown in Table 2-6B below. Site emission estimates in this 2018 Plan update are cumulatively lower than those analyzed in the 1997 EIS/EIR and approved in the resulting County CUP and BLM ROD51.
In summary, proposed operations in this 2018 Plan update, do not represent a quantitative increase of site emissions estimated during the 1997 environmental impact analyses conducted through the NEPA and CEQA processes, but are in fact cumulatively estimated to be lower.
To further demonstrate the advancements in diesel fuel technology and the reduced air impacts from the selection of Tier 4 diesel-fueled power generators, Table 2-6C shows emissions as presented in the 1990 EIS/EIR (all propane-fueled generators) against those estimated for the 2018 Plan update. As shown below, emissions are significantly lower for almost all pollutants.
Telecommunications are provided by a private microwave facility installed at the mine.
Ancillary structures, which include a laboratory, lunch room and change room buildings, are located near the gold recovery plant. An administration building is located at the southern terminus of the Walking Box Ranch access road. These buildings have been furnished with water, heat, and sewerage to conform to requirements of the County Building and Safety Department and Department of Environmental Health Services (DEHS). A parking lot is located in the Administration area, for use by employee van pool vehicles, company vehicles, and visitors. Provisions have been made for access and parking for handicapped persons.
The Shop facility is located with the Contractor’s Area south of the South Clay Pit Reclamation Area. This shop is used for vehicle maintenance, with office space for administration and warehousing space for equipment parts. A truck ready line and other vehicle parking is located nearby.
2.7.3 SUPPLIES
Activities at the Castle Mountain mine require the receipt, storage and handling of chemicals and explosives, and the treatment and disposal of wastes generated at the site. Some of the waste materials are classified as hazardous waste.
Fuels and oils are stored onsite. Tanks for these fuels and oils are installed on prepared foundation enclosed with berms adequate secondary containment to contain the contents of the tanks in the event of a leak or rupture, as determined by the County Fire Department-Hazardous Materials Division. Storage facilities for reagents such as sodium or calcium cyanide and hydrochloric acid also include secondary containment for spills.
51 BLM RECORD OF DECISION (CACA31137), March 13, 1998; and San Bernardino County CUP, Revised Mining and Reclamation Plan (90M-013), January 27, 1998
Castle Mountain Mine Plan and Reclamation Plan 2-51 January 2, 2019 Table 2-6A Estimated Air Contaminant Emissions – Proposed Action – 2004 Operations (52,53) Pounds Per Peak Day Tons Per Year Emission Source
ROG NOx SOx CO PM10 ROG NOx SOx CO PM10 Onsite Stationary Exhaust and Fugitive
Sources Blasting 255.0 30.0 1,005.0 19.1 2.3 75.4 Ore Processing Equipment ------195.6 ------22.2 Emergency Generator, Misc. Equipment 3.3 20.6 0.0 9.4 0.3 0.6 3.7 0.0 1.7 0.1 Diesel Storage and Transfer Losses 0.4 ------0.1 ------
Onsite Mobile Exhaust Sources
Diesel-Powered Equipment Exhaust 76.7 2345.0 150.8 470.6 70.2 12.0 367.8 23.7 73.7 11.1 Gasoline-Powered Equipment Exhaust 2.4 1.3 -- 2.0 -- 0.5 0.2 -- 0.4 --
Onsite Fugitive Dust Sources
Mining Operations (Drilling, Blasting, Loading) 168.7 25.5 Haul Roads 26.0 4.0 Ore and Overburden Dumping 119.4 17.9 Wind Erosion (Disturbed Areas, Stockpiles) 12.0 2.3
TOTAL 82.8 2,621.9 180.8 1,487.0 592.2 13.2 390.8 26.0 151.2 83.1
52 Operational parameters, emission factors, and assumptions used to prepare emissions summarized in this table are documented in Appendix F of the 1997 Castle Mountain Mine Expansion Project Draft EIS/EIR, March 1997. The “Blasting” emissions category was added in the Final EIS/EIR, October 1997. 53 Estimated emissions summarized in this table are calculated assuming full implementation of the mitigation measures described in Section 3.6-2.
Castle Mountain Mine Plan and Reclamation Plan 2-52 January 2, 2019 Table 2-6B Estimated Air Contaminant Emissions – Proposed Action – 2018 Plan Update (54) Pounds Per Peak Day Tons Per Year Emission Source
ROG NOx SOx CO PM10 ROG NOx SOx CO PM10
Onsite Stationary Exhaust and Fugitive Sources
Blasting ------Ore Processing Equipment ------6.8 ------0.6 Combustion Sources 3.4 43.8 7.1 13.2 3.2 0.6 6.8 0.9 1.9 0.4 Diesel Storage and Transfer Losses 0.1 ------0.027 ------Onsite Mobile Exhaust Sources Diesel-Powered Equipment Exhaust 17.5 220.3 1.1 273.6 5.1 2.3 33.5 0.17 33.9 0.8 Gasoline-Powered Equipment Exhaust ------Onsite Fugitive Dust Sources Mining Operations (drilling, blasting, loading) 133.0 11.4 Haul Roads55 147.9 24.8 Ore and Overburden Dumping 201.9 7.0 Wind Erosion (Disturbed Areas) 72.3 3.5 2018 Plan Update TOTALS 21.5 264.1 8.2 286.8 570.2 2.9 40.3 1.0 35.9 48.5
82.8 2621.9 180.8 1,487.0 592.2 13.2 390.8 26 151.2 83.1 Conformance with 1997 EIS/EIR Estimate 56 YES YES YES YES YES YES YES YES YES YES
54 Estimated emissions summarized in this table are calculated assuming full implementation of the mitigation measures described in the 1998 BLM ROD and County CUP 55 The significant increase seen in fugitive PM10 emissions from haul road travel is primarily due to a methodology change when calculating a lb/VMT emission factor. Emissions estimated under the 2018 Plan update follow the methodology outlined in current MDAQMD guidance for Dust Entrainment from Unpaved Roads. This methodology factors in the weight of vehicles traveling on the roadways, while the methodology utilized in the 1997 EIS/EIR only accounts for the number of wheels on a given vehicle. This results in significantly different emission factor estimates. For example, for haul truck travel, the uncontrolled PM10 emission factor utilized to estimate emissions under the 2018 Plan Update is 2.9 lb/VMT versus 0.3 lb/VMT used in the 1997 EIS/EIR. 56 See Table 2-5.1 above, Table 3.6-4 from the Castle Mountain Mine Expansion Project Draft EIS/EIR, March 1997, or Table 3.6-4 REVISED from the Castle Mountain Mine Expansion Project Final EIS/EIR, October 1997.
Castle Mountain Mine Plan and Reclamation Plan 2-53 January 2, 2019
Table 2-6C Comparison of Onsite Prime Power Generation Equipment Pounds Per Peak Day Tons Per Year Emission Source
ROG NOx SOx CO PM10 ROG NOx SOx CO PM10
Onsite Stationary Power Generation
Emission Estimate – 1990 EIS/EIR57 235.0 352.5 0.5 587.4 02.3 42.9 64.3 0.1 107.2 0.4
Emission Estimate – 2018 Plan Update 2.9 25.7 0.7 8.7 1.1 0.5 4.7 0.1 1.4 0.2
57 See Table 3.2 from the Castle Mountain Project Supplement to Draft EIS/EIR, January 1990.
Castle Mountain Mine Plan and Reclamation Plan 2-54 January 2, 2019 Explosives and other blasting agents are stored in facilities constructed and maintained in accordance with Federal and local permit requirements.
Chemical reagents are brought to the site by various suppliers.
2.7.4 WASTE CONTAINMENT, TREATMENT, and DISPOSAL
The mine generates solid and liquid wastes from construction, operation of equipment, and gold processing facilities. Wastes are stored, recycled, or disposed of in accordance with rules and regulations set forth by the DEHS and the California Department of Toxic Substances Control (DTSC) and in a manner acceptable to the BLM and the County. Wastes generated on site are listed in Table 2-7.
Table 2-7 Anticipated Wastes to be Generated at the Castle Mountain Mine Waste Generated Waste Type Disposal Procedure Refuse—food, garbage, glass, Domestic waste Recycled—Remaining waste plastic, paper, wood, metal disposed at a Class I or II (Nevada or Arizona) landfill Tires Industrial Waste (non- Recycled or stockpiled for hazardous) disposal (after shredding) Hydrocarbon (contaminated Industrial Waste (non- Removed to Class I (Nevada) waste) hazardous) landfill Waste Oil Industrial Waste (CA hazardous Recycled (licensed recycler) waste) Lead contaminated laboratory Industrial Waste (RCRA Recycled (licensed recycler) or wastes, solvents, waste paints Hazardous Waste) disposed at a licensed TSDF58 Batteries, light bulbs, Universal Waste Recycled – Remaining wastes electronics, etc. disposed at a licensed TSDF
Wastes considered hazardous are both solids and liquids, such as waste oils and fuels from vehicles, solvents, and certain processing chemicals and their containers, lead contaminated cupels and small volumes of reagents used in laboratory testing. Used oils and other water hydrocarbon products are stored in tanks located in a containment area. Other wastes are recycled or packaged and disposed offsite by a licensed waste disposal contractor who hauls these items to an approved recycler or disposal site. Where possible, processing chemicals and laboratory reagents are neutralized onsite (when not considered treatment) and incorporated into the barren solution system. Chemical containers are rinsed and either returned to the supplier for reuse or sent to an approved disposal site.
Haulage of hazardous wastes is by licensed carriers only. Following haulage, the hazardous wastes are incinerated, treated, recycled, or placed in an approved hazardous waste landfill facility. Final disposition of the Mine’s hazardous wastes depends on the type of waste, and is in accordance with the rules and regulation for waste disposal set forth by the DEHS and DTSC.
Where feasible, non-hazardous wastes are recycled, including items which are used in larger quantities, such as metal. Used tires are sent back to the suppliers when possible or stockpiled for proper
58 Treatment, Storage, and Disposal Facility
Castle Mountain Mine Plan and Reclamation Plan 2-55 January 2, 2019 disposal—this would most likely involve shredding and disposal in a Class I or II (Nevada) landfill. Recyclers leave empty containers at the site, pick them up when full, and recycle the products. To ensure that all recyclable products are deposited in the correct location, a written policy has been established dictating disposal locations for the various waste types.
Non-hazardous wastes are temporarily stored onsite in refuse bins and ultimately disposed of in a Class I or II (Nevada) landfill. Haulage to an approved landfill facility is in approved waste containers.
Domestic waste water from the Process Area, Crusher, Shop Area, Administration Area and greenhouse/nursery complex is disposed in septic tanks and leach fields adjacent to each of these areas. These disposal facilities are designed and constructed according to requirement of the DEHS. Portable toilets are used in areas not served by the main sanitary facilities, such as the mine pit. Maintenance of portable toilet facilities and septic tanks is contracted to a licensed septic pumper.
The gold processing and extraction circuit operates as a closed system. Rain which falls on the pads enters the process circuit or evaporates. The heap leach solution storage system is sized to RWQCB specifications to accommodate precipitation run-off.
Spent analytical reagents discharged from the assay laboratory area are neutralized in the chemical neutralization sump of the processing plant, then transferred to the barren solution tank. Solutions containing cyanide chemicals discharged from the assay lab report to the process area sump, which in turn goes to the barren solution tank.
Castle Mountain Mine Plan and Reclamation Plan 2-56 January 2, 2019 3.0 RECLAMATION PLAN
3.1 INTRODUCTION
The BLM and the County are the agencies having permit approval authority respecting activities that result in site disturbances at the Castle Mountain gold mine. In the fall of 1990, the BLM and the County approved CMV’s application to develop an open pit/heap leach gold mine at Hart, in eastern San Bernardino County. Those approvals were based on a Plan of Operations Viceroy submitted to BLM in March 1988, a Mining/Reclamation Plan submitted to the County, and an EIS/EIR on the Castle Mountain Project prepared for the agencies by an independent environmental contractor.
This 2018 Plan update is an update of the approved 1998 Mine Plan and Reclamation Plan, 90M-013, dated June 1998. It is now designated as 90M-013, ver.2.1.
3.2 PURPOSE and USE OF THE RECLAMATION PLAN
The activities described in this Reclamation Plan are based on a detailed engineering assessment of the current ore reserves at Castle Mountain. What must be kept in mind, however, is that the determination of ore reserves is a complex exercise involving a myriad of economic and technical factors. As these factors change over time, estimated ore reserves can also change. Changes that may occur to these factors subsequent to the agencies’ approval of the Plan Amendment Application could warrant a reassessment of the procedures and schedules discussed in this Reclamation Plan.
The purpose of this Chapter (the “Reclamation Plan”) is to discuss the procedures and practices that were and continue to be employed by CMV in order to meet Federal, State and County regulations for the reclamation of sites disturbed by mining operations at the Castle Mountain gold mine. In turn, responsible agencies, including the BLM, County, and other will use this Reclamation Plan as a basis to review and evaluate the updated reclamation program at the Castle Mountain gold mine. This update will be based on those reclamation techniques employed from 1996 through 2006 during interim and final reclamation (testing, research, and implementation) that were successful in reclaiming the site by 2012. The Plan will discuss those procedures that worked well, and those that did not succeed in adequate revegetation.
Updates are required to the 1998 Plan because the economic and technical factors at the site have changed, and while much of the site has achieved successful reclamation, gold reserves still remain stockpiled, both in the backfill and overburden but also in unmined hard-rock ore. The goal of this 2018 Plan update has been to account for those economic changes which will allow for the mining that has been authorized by the agencies (in 1998 and again in 2013), while also accounting for the very successful land reclamation that has occurred at the site. As noted above, this change in economics is also the driver for the realignment of project schedules to where approved mining can resume, even though much reclamation has already occurred. Because successful reclamation is present at the site, better techniques and procedures for this reclamation plan are included since we have the foresight to now know which of the reclamation strategies employed at the site worked and which did not. The recognition of those successful techniques will be fully employed in this 2018 Plan update for future site reclamation.
Castle Mountain Mine Plan and Reclamation Plan 3-1 January 2, 2019 The nature and size of the disturbances described in this Reclamation Plan are based on the planned pit and stockpile boundaries, which in turn determine the planned size of the heap leach pad and overburden sites. However, in estimating the outside perimeter of areas that could potentially be disturbed, the increased volumes of ore and overburden materials that could be produced assuming an expansion of the pit boundaries under reasonably foreseeable circumstances have been considered. No changes are proposed in this 2018 Plan update, that would exceed the lands approved for surface disturbance per the approved 1998 Plan.
As with any large, multi-year project, there will be changes to planned reclamation procedures over the life of the mine. In addition to changes arising from permitted alterations of operating activities, procedural changes in planned reclamation as a result of information developed by the Company’s onsite revegetation research and/or changes in Federal/State regulations could also require changes to this Reclamation Plan. Recognizing this, the County incorporated annual reporting and mine planning requirements into the permits. (See Appendix A, Condition No. 12)
A mitigation compliance monitoring program has been implemented for the Mine. It incorporates the County’s Conditions of Approval and the BLM’s Stipulations. (See Appendix A and B).
3.3 STATUTORY and REGULATORY REQUIREMENTS
Reclamation of areas disturbed by the Castle Mountain gold mine are required to comply with reclamation requirements set out in the Federal Land Policy Management Act (“FLPMA”), California state requirements in SMARA, and County regulations.
3.4 GOALS and OBJECTIVES OF THE RECLAMATION PLAN
The goals and objectives of this Reclamation plan are as follows:
1) To promote revegetation of disturbed areas as an integral and concurrent function of the mining and reclamation program. 2) To ensure that materials excavated during mining operation are placed in a manner that does not pose a hazard to public health and safety, creates a naturally appearing topography, and minimizes subsequent shaping and recontouring needed to avoid erosion. 3) To implement a revegetation program that will, over time, establish plant communities with species composition and plant densities similar to those now existing on undisturbed areas at the mine site, with a proactive program to exclude non-native species. 4) To outline programs that will create the physical and biological conditions required for plants to grow without continued cultural inputs such as irrigation, tillage, or fertilization subsequent to the completion of mining operations. 5) To enhance the visual appearance of the area by reducing , where warranted, visual contrasts caused by excavations and road cuts. 6) To establish microhabitats providing cover and nesting opportunities for desert vertebrates.
Castle Mountain Mine Plan and Reclamation Plan 3-2 January 2, 2019 Those procedures that worked well during interim and final reclamation (1996 to 2012) are as follows:
Overburden and heap leach material placement to mimic natural topography. Rough grading to control and direct water and control erosion. Water management to direct water to catchment basins was important for vegetation growth and survival. Fine grading into microcatchment basins to promote germination, growth, and survival of seedlings and transplants. Collecting and sowing locally collected bulk native seed. Seeds were sown using both aerial seeding for large areas, and hand seeding on smaller sites. Transplanting was successful for a limited number of species, including cacti (barrel cactus) and succulents such as small Yucca species. Protection of reclaimed areas until vegetation is established. Monitoring and maintenance until reclamation standards are met.
The following programs and procedures had limited or no success and while may have been incorporated into prior reclamation at the mine site, should not be the focus of future core reclamation strategy:
Salvage and transplanting most plant species including Joshua trees. Failure and death of transplants was 75% or greater, and some plants species (such as black brush) had no survival. Propagation of plants in the greenhouse and garden were successful, but transplanting to reclaimed areas had limited success. Results of the research program, while there were many, most could not be applied to site reclamation or revegetation techniques that were successful. Salvage and stripping of “topsoil” (growth media”) had limited effect on the growth of plant species when reapplied to reclaim sites. The desert soils are highly weathered, with poor nutrients status and water retention. Monitoring of reclamation areas with reapplied growth media revealed mostly weeds with little native vegetation density.
3.5 LAND USE
3.5.1 EXISTING LAND USE
Since the passage of Public Law 103-433 (the California Desert Protection Act) on October 31, 1994, public lands within most of the Lanfair Valley have been managed by the National Park Service (“NPS”) as part of the Mojave National Preserve (“Preserve”). In passing Public Law 103-433, the Congress specifically provided:
1) that all private lands (other than lands owned by Catellus Corporation) in a twelve township area in Lanfair Valley bounded on the southwest by Township 11N, Range 15E and on the northeast by Township 13N, Range 18E, San Bernardino Base and Meridian are excluded from the Preserve; 2) that Viceroy’s claims are excluded from the Preserve, and
Castle Mountain Mine Plan and Reclamation Plan 3-3 January 2, 2019 3) that grazing of domestic livestock on lands within the Preserve shall continue to be exercised at no more than the current level, subject to applicable laws and National Park Service regulations.
The borders of the Preserve, the Castle Mountain National Monument (“Monument”), CMV’s claim block, the perimeter of the Castle Mountain mine site within the claim block, and several points of interest in northern Lanfair Valley are shown in Figure 3.1.
BLM continues to be the federal agency responsible for administering the lands covered by the majority of the Company’s claim block, although a number of mine claims are located on both the Monument and Preserve; operations on some of these claims could fall under 36 CFR 9A, otherwise known as the “Mining in the Parks Act”. The claim block is zoned as multiple-use Class L (limited) by BLM. Mining is one of the multiple-use activities allowed in Class L zones. Mining is also allowed under County zoning regulations.
All of the grazing allotments that once bordered the mine lands have since been removed, mostly by Viceroy as the company purchased and retired those rights.
Recreational use at the mine site most often involves unorganized, informal activities such as sightseeing. The evidence of past mining activities at Hart attracts sightseers, rockhounds, and other recreationalists. The current mining operation also attracts a considerable number of visitors.
The historic Hart Mining District at the south end of the Castle Mountains has been the scene of mining activities almost continuously for more than 100 years. Gold, silver and clay are the principal minerals mined. Much of the townsite built during the 1907-1910 gold rush was subsequently obliterated by fire and clay quarrying activities, the latter of which commenced in the 1920s.
The nearest occupied residences are at the OX Ranch, nine miles southwest, and two houses at Barnwell, 8.5 miles west.
3.5.2 POST – MINING LAND USE
Uses of the site include mining, recreation, and wildlife habitat. The latter two uses have been altered or temporarily interrupted on approximately 1,500 acres because of the present mining activities on the site. Fencing and gating restrict access by the public, and some wildlife. This exclusion policy will continue for several years after completion of mining operations, to enable newly revegetated areas to recover without disturbance.
(1) Recreation – Most visitors to Hart travel there for rock-hounding, touring the East Mojave Heritage Trail and to view the ongoing activities at the Castle Mountain gold mine. Historic features of the area are discussed in East Mojave Heritage Trail, Ivaanpah to Rocky Ridge (Casebier 1988).
(2) Wildlife – Species in the area is typical of the eastern Mojave Desert, in particular those species associated with the dominant creosote bush scrub and Joshua tree woodland series habitats. With the exception of the desert tortoise, there are no threatened or endangered plant or animal species on site. The US Fish and Wildlife Service (“FWS”) issued “No Jeopardy” Biological Opinions for the Castle Mountain Project regarding the desert tortoise in August of 1990 and again in 1998. During the construction phase, the areas scheduled for land disturbance were
Castle Mountain Mine Plan and Reclamation Plan 3-4 January 2, 2019
REV: 10/17/2018 1 REV: Page: (TAG) Features.CDR Rec File: F3-1 Lanfair Valley
L A C N E I A D A V F A I N R O
Castle Mountain Mine Lat: 35.27758587° N Lon: 115.09941887° W
N E V A D A
San Francisco C A L I F O R N I A
Map Area
San Bernardino County Los Angeles
San Diego
Mojave National Preserve 0 4.3 (National Park Service)
MILES Approved Mine Boundary (1997 EIS/EIR) Source: Unigrid-map-of-Mojave-National-Preserve LANFAIR VALLEY Designated Area Roads RECREATIONAL FEATURES Castle Mountains National Monument CASTLE MOUNTAIN MINE (National Park Service) County of San Bernardino, California
LILBURN LEGEND FIGURE 3-1 C O R P O R A T I O N fenced with tortoise proof fencing. The fenced areas were then “cleared” by authorized biologists. This practice and procedure has been used for expansions of the heap leach pad and will be used for future expansions.
(3) Mining – Mining will be an appropriate second use of the site, and the mine’s reclamation program is structured in a manner so as to not unduly restrict or impede such future use. Gold mineralization is disseminated at Castle Mountain with no sharp physical demarcation between ore and overburden. In such circumstances the material is mined to an economic “cut-off” grade. The walls and floor of the pit contain gold mineralization in concentrations that are economic to mine under current (2018) conditions, though there are zones that are uneconomic to mine even at current gold prices. However, future improvement in technology (or lower unit costs that might be achieved with improved technology) and/or a higher gold price might allow the operator to mine more of these areas and increase the ultimate recovery of the resource.
The following factors control post-mining land uses of the site:
(1) Compatibility With Adjacent Land Uses – Congress encourages mineral development consistent with the principles developed in the Mining and Mineral Policy Act, 1970 (30 U.S.C. 21a). When Congress passed the California Desert Protection Act in October 1994, it recognized the socioeconomic benefits of the Mine and excluded Viceroy’s mining claims from the Mojave National Preserve. The BLM, though in a few cases NPS, has retained management authority for public lands within the Viceroy claim block.
(a) Castle Mountains National Monument – Presidential Proclamation created the Castle Mountains National Monument (“Monument”) on February 12, 2016; Monument lands are administered by the NPS. The Monument surrounds the Castle Mountain Mine project area on all sides but a buffer of BLM land remains as a buffer between the Monument and the mine area to the North, West, and South. While the Monument proclamation does close those lands contained therein from mineral entry, it is subject to valid existing rights. Additionally, the Monument proclamation identifies and recognized the validity of mining for those areas of the Castle Mountain Mine area that are operating under valid Plans of Operation (i.e. Mine/Reclamation Plan).
2) Zoning Restrictions and County General Plans – BLM administered lands in Lanfair Valley are designated as Multiple Use Class-L (limited) lands. Mining, livestock grazing, recreation, and wildlife habitat are all activities authorized on Class-L lands. The County has designated the Castle Mountains as a Mineral Resource Zone 2 area, which ensures that other forms of development proceed in a manner that is compatible with the presence of significant minerals.
Desert Renewable Energy Conservation Plan (“DRECP”) was a major land use plan alignment (for southern California) the California BLM state office signed as a land use plan amendment (“LUPA”) in September 2016. The DRECP is an amendment to the existing land use plans: (1) California Desert Conservation Area “CDCA”), (2) Bishop Resource Management Plan, and (3) Bakersfield Resource Management Plan. The Castle Mountain Mine is located within the CDCA plan and is now located within the amended DRECP area. The DRECP establishes Conservation Management Actions (“CMAs”) as mitigation for impact to select resources or habitat. Mineral resources are also represented as a CMA category (Minerals) and the DRECP recognizes select mining areas as Existing High Priority Mineral Operations Exclusion Areas. The
Castle Mountain Mine Plan and Reclamation Plan 3-6 January 2, 2019 Castle Mountain Mine is one of eight recognized exclusion areas and as such the operator is exempt from all but what are known as the LUPA-WIDE CMA’s.
3) County General Plan – The County has zoned the area for home-sites of not less than 40 acres. Privately owned land within a five to eight-mile radius of the mine site (other than for patented mining claims owned or controlled by Viceroy) is minimal. The Federal government owns most of the surrounding land and all but 1,301 acres of the mine site itself. Given ownership and zoning restrictions, real estate development does not appear to be a realistic post-mining land use.
4) Post-Mining Topography – Site topography after cessation of mining and completion of decommissioning is discussed in Section 3.13. Materials will be placed to ensure long-term stability of overburden and spent ore piles. Final topography will minimize erosion and sedimentation, and enhance water retention and revegetation.
3.6 EVALUATION OF RECLAMATION SUCCESS
Following lengthy discussions with the County, BLM, and State Department of Conservation, Division of Mines and Geology, the Desert Studies Consortium, and representatives of several interest groups, reclamation success, per the 1998 Plan, was to be evaluated on the basis of plant densities and species diversity, as measured against control plots. By letter from the County59, measurement against control plots was removed and instead based off the results from the OMR 2000 vegetation analysis. Density and diversity are readily quantifiable factors that are ecologically meaningful when compared to undisturbed sites.
By definition, density is the number of live perennial individuals per unit area and diversity is the number of different perennial species (with live individuals) per unit area. The density and diversity of species in revegetated areas are now based on the “general vegetation” type specified in the OMR 2000 vegetation analysis report discussed in the next section.
Reclamation strategy and standards were amended in 2002 after OMR, in conjunction with Viceroy, issued the report, Castle Mountain Mine Vegetation Analysis (November 2000) which prompted the County to issue a revegetation standards revision to Viceroy on July 12, 2002, in its document, Adjustments to the Revegetation Standards for Castle Mountain Mine. Final reclamation at the site ultimately followed these updated standards.
3.6.1 UPDATED RECLAMATION STRATEGY and STANDARDS
The updated reclamation strategy is provided in Section 3.4 and presents those programs and procedures that were successful, and those that had limited success. The OMR analysis established four vegetation types: BLACKBUSH SCRUB, GENERAL, WASHES, and ROCKY UPLAND. The vegetation types are further characterized in Table 3-1.
The amended revegetation types at the mine site consists of two major revegetation components and a third more moderate component. Revegetation of colonizer species by native bulk seed collection methods have proven very successful at the site. Colonizer species represent plant species that are
59 See Appendix K: County letter, July 2002
Castle Mountain Mine Plan and Reclamation Plan 3-7 January 2, 2019 Table 3-1 Vegetation Type and Characteristics Topography/Elevation Species Density and Diversity (Non-Grasses) Vegetation High Moderate Low Strong Moderate Low Strong Moderate Low Grasses Aspect Misc. Type Steep Flat Density Density Density Diversity Diversity Diversity SW Blackbush dominant Blackbush X X X Moderate facing Scrub S facing General X X X Low
NONE Washes X X X Strong
W to SW Second in species Rocky X X X Low facing density only to Upland Washes.
Table 3-1A Five-Year and Ten-Year Density and Diversity Goals (Revegetation Success Standards for the Castle Mountain Mine) Standard 5-Year 10-Year Density (# perennial plants/acre) 255 (6%) 895 (21%) Richness (total # species on site) 5 (4%) 18 (15%)
Castle Mountain Mine Plan and Reclamation Plan 3-8 January 2, 2019 found throughout the site regardless of vegetation type and are important due to their ability to germinate and survive in reclaimed mine areas. Bulk seed mixes were collected which, completed implementation of the main component of the revegetation strategy based on bulk collection and distribution of local seed mixes. A minor component to the main revegetation strategy will be continued salvage of cacti and yuccas at the site prior to new land disturbance. While it’s been documented that plant salvage and transplanting is susceptible to high rates of failure and therefore should not represent a major component of the revegetation strategy, the benefit of these surviving transplants as sources for seed has been documented. The prior salvage and transplant practices will continue but will be applied in a scale appropriate to their ancillary role in the larger revegetation strategy for meeting site reclamation standards.
Revegetation of semi-arid areas usually proceeds very slowly, especially during periods of drought, but can be shorter if favorable seasonal rains occur. Revegetation can be expected to improve with the passage of time, owing to continued germination, growth, and the “nurse-plant” effect of established vegetation. Confirmation that viable populations of shrubs, grasses, and forbs have been established will vary and may take several growing seasons. Owing to a variable nature regarding revegetation rates and years required to attain success standards, the County imposed a 10-year post-mining reclamation monitoring period to measure revegetation success. This 2018 Plan update recognizes that under some conditions the standards can be met sooner, and the monitoring period should be able to adapt under these scenarios (i.e. standards have been met) to shorter reclamation monitoring periods. A case in point is the revegetation at the heap leach site which was completed between 2006 to 2007 and where the reclamation standards were achieved by early 2012, by conservative estimates a 7-year period after final reclamation/revegetation to meet the standards.
Revegetation success is established through County prescribed performance standards for the Castle Mountain Mine Site. These standards are determined by measuring the density and diversity of perennial species known or identified at the mine site. Density and diversity goals are established for the 5-year and 10-year monitoring periods. Table 3-1A above presents these 5-year and 10-year goals.
The authorized and proposed mining/processing activities may encompass as many as seven years of operation, followed by a seven to ten-year post-mining reclamation monitoring period. Accordingly, some areas on the site could have over three decades of revegetation data available for use in assessing reclamation success. Reclamation on available areas commenced in 1991.
Revegetation reports concerning reclamation activities at Castle Mountain are prepared annually. The data presented in these reports, and onsite reviews by agency
3.7 REVEGETATION RESEARCH PROGRAM
Castle Mountain Venture established a Revegetation Research Program at the Castle Mountain Mine. The program was directed by a Viceroy employee with a doctorate, and utilized both employees and outside contractors. Since start-up, University and private contractors were used for research, revegetation, and seed collection. Some form of these programs may continue as part of the reclamation program at the mine site. However, because much research has already been completed, which ultimately played a minor part in the successful reclamation conducted at the site, the need for further research will be based on the realistic need for further revegetation enhancements that will further strengthen the revegetation and reclamation program at the site. The County, in its July 2002 letter (page 3)referenced in section 3.6 above, states that:
Castle Mountain Mine Plan and Reclamation Plan 3-9 January 2, 2019
“The 11 years of mining operations and revegetation research at the mine have been completed as of May 2001.”
3.7.1 AREAS OF REVEGETATION RESEARCH
Areas of completed research were many and so have not been included in this 2018 Plan update. However, they can be reviewed in Appendix N to this Plan, which contains the report, Castle Mountain Mine, Research and Reclamation, 1990 – 2005 Summary Report (December 2005).
Research programs have also been reported in the eleven Annual Revegetation Reports published by Viceroy each January 1990 to 2001.
3.7.2 VEGETATION INVENTORY
Vegetation surveys were completed in 1990 and 1991 and resampled in 1996 on the existing flora within and adjacent to the Site Boundary. The sites surveyed included:
• The Hart townsite, former roads, and building sites. • Overburden piles accumulated from the South Clay Pit. • Onsite grazed grassland. • Onsite grazed Joshua tree woodland. • Onsite slopes with blackbush. • Future sites of heap leach pads. • Future locations of overburden. • Future locations of onsite buildings and roads.
The original approved revegetation methodology included a grid survey with 200-meter intervals to sample the site. At each intersection of grid lines, a circular plot (10-meter diameter) was established to determine the baseline diversity and density. Two hundred ninety such grid intersection plots were established initially. Additional plots were established in 1991 and 1996.
By 1999, after a review of the 1990 -1991 plot data and re-analysis in 1996, the doctoral ecologist employed at the site, Dr. Michael Eichelberger, proposed that some of the original (1990-1996) baseline survey data should not be used due to errors and inconsistencies in the baseline data. Additionally, a major assumption of the original system of grid-based sample plots was that there was a “uniform nature of the vegetation” at the mine (Annual Revegetation Report, 1996). This notion of uniformity was rejected by Eichelberger (and later also OMR and the County) as well as the originally perceived importance of slope and aspect particular to each sample plot and corresponding vegetation. Eichelberger insisted the revegetation strategy should focus on the idea of colonizer species and grasses which are found throughout the site, and with somewhat lesser importance on transplanted succulents and cacti. Because of this proposed change to the revegetation strategy, the County asked the California Office of Mine Reclamation (OMR), in conjunction with the site operator, to perform additional studies. OMR completed baseline vegetation analysis in June 2000 and issued their final
Castle Mountain Mine Plan and Reclamation Plan 3-10 January 2, 2019 report, Castle Mountain Mine Vegetation Analysis, in November 2000. The OMR report, which largely confirmed Eichelberger’s findings, concluded the following:
“At the request of San Bernardino County, OMR analyzed existing vegetation data for Castle Mountain Mine in 2000. We found errors and inconsistencies similar to those identified by Eichelberger. These errors included:
• the grid sampling method used previously was not stratified for the various vegetation units at the mine; • perennial grasses were not recorded in 1996 vegetation plots; • stem succulents (cacti and yuccas) were not recorded; and • 1996 plots could not be relocated with a global positioning device.
Based on our analysis, we determined that a field survey of vegetation was needed.”
The conclusion of the OMR report was that changes were required of both the revegetation standards and strategy. Revegetation standards were recommended to include:
• Standards should be prescribed to specific revegetation areas designated as overburden, leach pad, access roads, and pits. • Each revegetation area will be assessed independently of the other revegetation areas. • Revegetation sample plots will be randomly distributed throughout each revegetation area. • Plots will be non-contiguous. • Sample plots will be 100m2 to be consistent with previous sampling data. • A minimum of number of 14 plots will be established per revegetation area for an 80% confidence and precision level. • When compared to one or more native vegetation types, the index of similarity will be at least 15% and the density will be at least 21% for each revegetation area. • Within each revegetation area, any area of 1000m2 or greater that does not meet these standards will be evaluated for the need for remedial measures.
To meet the standards listed above, the OMR report recommended an alteration to the revegetation strategy employed at the mine site. The OMR report proposes adopting two main strategy concepts based on the use of “Colonizer” plant species. Colonizer species, the OMR report explains, can be found throughout the mine in more than one vegetation type and they exhibit a broad ecological amplitude. It was additionally determined that Joshua tree and creosote bush are not prescribed to any individual vegetation type because they are found throughout the entire site and in all vegetation types. Secondary to the broad reach of colonizer species is the segregation of the mine site into four vegetation types: (1) General, (2) Blackbush Scrub, (3) Wash, and (4) Rocky Upland. Each of these four vegetation types has a distinct type of plant species found within its breadth.
The plants that germinate and succeed on mine reclamation sites are a combination of perennial and annual species adapted to continual disturbance such as desert washes. It has been observed on this Site and other reclaimed desert gold mines, that these are often wash species adapted to fresh soil substrates with water requirement of periodic flooding. This type of habitat is being simulated during
Castle Mountain Mine Plan and Reclamation Plan 3-11 January 2, 2019 reclamation by current surface preparation and water enhancement grading for moisture control. The strategy in the OMR report did not identify unique floral assemblages, but determined a high degree of overlap among clusters, which “makes purely unique revegetation prescriptions by vegetation type almost useless” (OMR Nov. 2000, page 17). After reviewing the baseline data, it was determined that the revegetation areas are compared to Cluster3, General type, and that the density and species diversity (richness) standards should be based on cluster (vegetation) type.
Revegetation success will be based on vegetation density and diversity standards listed on Table 3-1A. Note that a success standard for vegetation cover (the downward vertical projection of the vegetative crown to the ground surface), a parameter usually included for revegetation success, was not incorporated (by the County and OMR) into the CMM success standards.
3.7.3 REVEGETATION REVIEW COMMITTEE
The mandate of the Revegetation Review Committee (RRC) has been stated as including the following:
• Review the Annual Revegetation Report to make recommendations to further improve the effectiveness of Viceroy’s revegetation programs and research efforts, and to; • Advise the agencies whether to make adjustments to the revegetation goals of density and diversity contained in the approved Mine Plan and Reclamation Plan.
Because the research mandate adopted by the County and BLM has been completed60; and because the County and OMR made their final reclamation adjustments in their respective reports, Adjustments to the Revegetation Standards for Castle Mountain Mine (July 2002) and Castle Mountain Mine Vegetation Analysis (November 2000), no further reclamation adjustments are warranted at this time.
Considering these above goals (research which aids in attaining density/diversity standards) have been met, which also proves they can be met again during future mine reclamation, there is no further role or need for prior oversite or input provided by the RRC. This is further emphasized by the voluntary lack of any further involvement by the RRC at the site from 2003 to 2012 when reclamation standards were satisfied.
The RRC was sent copies of the annual Revegetation Monitoring Reports beginning in 2002, but no further comment or confirmation of the annual monitoring reports submitted by CMV was ever delivered to the Company or the agencies after 2002. In reliance upon this lack of any response since 2002, CMV is proceeding based on the understanding that the RRC has deemed its mandate complete as of 2003.
3.8 GENERAL CRITERIA FOR RECLAMATION
Whenever practicable, reclamation at the mine will be conducted concurrently with mining activity as areas are released from further mining related activities.
Soil surface conditioning, both physical and biological, is vital for successful reclamation. Species selection, seed collection, planting techniques, fertilization, irrigation, and herbivory control strategies
60 See section 3.7 of this 2018 Plan update
Castle Mountain Mine Plan and Reclamation Plan 3-12 January 2, 2019 are important components of a successful revegetation effort. The original Plan discusses these components in some detail. Accordingly, the interested reader is referred to Section 1.5 of that document for information on the following items:
• Educational program for heavy equipment operators • Experimental garden and nursery • Salvage and transplanting • Seedbank establishment, soil salvage and handling • Land shaping, overburden handling and placement • Soil islands • Seed bed preparation • Seeding and planting sources • Characteristics of recommended species • Seeding and planting methods • Seeding and planting timeframe • Control of weed and exotic species • Fertilization • Irrigation • Mulching
However, it should be noted here, and as discussed in section 3.7.2, that some of the more original standards of the original and 1998 Plan were determined to be commendable experiments but ultimately provided lesser than anticipated impact towards achieving the reclamation standards set by the County and BLM. For instance, great focus was originally placed on the salvage of specific plants, mostly cacti, and by 2002 it was determined that while plant salvage (for later transplant) should still occur, but it should not be the main aspect of revegetation due to the high failure rate of salvaged transplants; instead, emphasis should be placed on vegetative propagation by bulk seeding which has produced very successful results. The County documented this correction in its July 2002 letter61:
“Condition 48C requires that salvaged plants be replanted into reclaimed areas with the objective ‘to provide a continuous seed source’ as an integral part of the revegetation plan. However, a high percentage of the salvaged plants died before being permanently transplanted into the revegetation areas and therefore were not available to provide the continuous seed source as envisioned. About 10,000 salvaged and propagated plants species were transplanted onto portions of the reclaimed mine in November 2001, and will provide some seed. However, revegetation will also be dependent upon successful germination and growth from seeds of these species contained within the revegetation seed mix.”
Plant salvage (as described in condition No. 48C) of areas scheduled for mine disturbance included the following:
Joshua tree – Plants to ten feet in height (and small seedlings under mature trees), unbranched or with few branches that will be planted once when salvaged. Mojave Yucca - Well developed, single stemmed plants that have not developed a vertical trunk.
61 The letter: Adjustments to the Revegetation Standards for Castle Mountain Mine, San Bernardino County, July 12, 2002, can be found in Appendix K.
Castle Mountain Mine Plan and Reclamation Plan 3-13 January 2, 2019 Blue Yucca - Well developed, single stemmed plants that have not developed a vertical trunk. Barrel Cactus - Plants of most sizes were successfully transplanted, and survived well in nursery gardens until planted.
At least 25% of each species in the salvageable size class will be salvaged and placed either into a nursery or preferably directly into a revegetation site.
Propagation techniques, seed and plant inventories, seed collections and other horticultural aspects that are required for successful revegetation were summarized each year in the Revegetation Annual Reports.
3.9 RECLAMATION SCHEDULE
Development of the Castle Mountain gold mine is described in the Mining Plan (Section 2.0 of this document) as a sequence of stages to inform the reader as to the nature of the disturbances.
Reclamation efforts are being implemented at the earliest practicable time. It should be noted however, that CMV has selected minimized surface disturbance while using existing topographic features, where possible, to screen the operation from public view from much of the Lanfair Valley.
3.9.1 STAGED RECLAMATION SCHEDULE
This section of the Reclamation Plan describes how reclamation activities are being integrated with mining operations.
Because mining was halted in June 2001 and major reclamation, revegetation and monitoring proceeded until 2012, this 2018 Plan update must account for a realignment of mining and reclamation schedules. Though as noted in prior sections of the approved 1998 Plan, it was contemplated and planned for in prior Plan versions that this would likely occur.
The original 1990 and 1998 Plans discussed nine stages of reclamation to correspond with the nine stage of mining in the mine plan detailed in section 2 of this Plan. Reclamation has been completed corresponding to the level of mining completeness of each stage. This means that as this mine plan describes how mining of Stage 5D was not completed and mining under this Plan will resume at that point, reclamation will correspondingly resume at that point, for land disturbance associated with resumed mining of protore stockpiles at Stage 5D.
The separation of the stages is based on the interrelationships between the following factors; preproduction mining development and plant construction, mining, placement of ore, low grade ore, protore, and overburden, and reclamation. Estimated acreages to be reclaimed are shown in Table 3-2.
Areas no longer subject to disturbance, will be recontoured (i.e., regrading, surface preparation, et cetera) and planted and or seeded. Table 3-3 summarizes the estimated areas by stage for surface preparation activities (grading, contouring, growth media placement, scarifying, etc.) in each area.
Castle Mountain Mine Plan and Reclamation Plan 3-14 January 2, 2019 Table 3-2 Reclamation Stages and Chronological Relationships End Completed Stage Start (proposed) (as of 2018) Stage 1 June 1991 February 1992 Completed Stage 2 March 1992 March 1993 Completed Stage 3 April 1993 March 1994 Completed Stage 4 April 1994 March 1995 Completed Stage 5A 62 April 1995 March 1996 Completed Stage 5B63 April 1996 March 1997 Completed Stage 5C April 1997 March 1998 Completed Mining not completed in Oro Belle and Jumbo; December Activities Not Completed Stage 5D April 1998 2025 Mining not completed in Oro Belle and Jumbo; December Activities Not Completed Stage 5E April 1999 2025 Mining not completed in Oro Belle and Jumbo; December Activities Not Completed Stage 5F April 2000 2025 Mining was halted in May 2001, and stockpiles (that could be Activities Not Completed Stage 664 April 2001 economically processed) completed by December 2001. Ore/Protore stockpile processing complete by December 2025 Original leaching activities completed 2004; Resumed leaching Activities Not Completed Stage 7 2025 complete by 2027 Original leach pad decommissioned 2005; Resumed leach pad Activities Not Completed Stage 8 2027 decommissioned by 2028 Stage 965 2027 Reclamation completed by December 2035 Activities Not Completed
62 Mining activities in Jumbo and Oro Belle deposits were initiated in Stage 5A. 63 Mining in the Lesley Ann pit was completed in February 1996. 64 In the event the South Extension pit and/or mineralization surrounding the OBHT and Jumbo pits proves to be economic to mine, Stage 6 will overlap with Stage 5F. Stages 7 through 9 will be postponed for the length of time Stage 6 is in operation. 65 Stage 9 involves revegetation activities in the leach pad area after the leach pad has been detoxified and the solution storage tanks and the stormwater basins have been dismantled and removed (See Section 3.9.1.5). Stage 9 will commence within six months after decommissioning and will end after the tenth growing season following the initial plantings on these areas.
Castle Mountain Mine Plan and Reclamation Plan 3-15 January 2, 2019 Table 3-3 Incremental Acreage at Approved Full Mine Development to be Prepared for Revegetation by Stage66 AREA DISTURBED CUMULATIVE STAGE STAGE STAGE STAGE STAGE STAGE STAGE Land Reclaimed and TOTAL THROUGH 5D 5E 5F 6 7 8 967 No New Disturbance STAGE 5C LESLEY ANN/JUMBO PIT 103 45 148 ORO BELLE/HART TUNNEL PIT 18 18 SOUTH EXTENSION PIT 10 10 NORTH OVERBURDEN SITE68 14 249 30 293 SOUTH OVERBURDEN SITE 26 25 25 25 85 0 121 307 CRUSHING AREA 0 10 10 SOLUTION STORAGE SITE 14 14 PROCESS PLANT SITE 4 4 ADMINISTRATION SITE 5 5 HEAP LEACH PAD 261 160 421 SITE ROADS 48 48 GROWTH MEDIA STORAGE 15 10 25 50 AREAS
STAGE SUBTOTALS 40 25 25 25 452 83 0 357 321
CUMULATIVE ACRES 40 65 90 115 567 650 650 1,007 1,328 1,328
66 Physical preparation of disturbed sites will be completed by the end of each stage for the estimated acreage shown for that stage. Staged revegetation activities will commence on each area after ground preparation has been completed. 67 Stage 9 involves revegetation in areas from which buildings have been dismantled and removed following project decommissioning (See Section 3.8, Decommissioning of Facilities). Stage 9 will end after the tenth growing season following initial plantings on the locations involved in project decommissioning, or sooner if standards are met prior to the tenth year. 68 North Overburden site acreage prepared for revegetation includes the North and South Clay Pit Reclamation Areas, respectively 48 acres and 36 acres of disturbance caused by mining activities carried out by other parties have been completed by CMV.
Castle Mountain Mine Plan and Reclamation Plan 3-16 January 2, 2019
Mining is a dynamic process that must be responsive to changing economic conditions and other factors. This is also the case with reclamation. It is not possible to anticipate in advance what modifications to the reclamation program may arise as a result of adjustments to the mining schedule. With this qualification in mind, completed, current and projected reclamation will be by stage.
3.9.1.1 Stages 1 through 4 (October 1990 to March 31, 1995)
Mining and reclamation have been completed for these stages. Refer to the 1998 Plan for the original text of this section.
3.9.1.2 Stages 5A through 5F
Mining and reclamation have been completed for these stages as related to the corresponding level of mining completed by CMV up to June 2001. Refer to the 1998 Plan for the original text of this section.
As described in section 2 of this Plan, mining will resume at the last partially completed mining stage, 5D; and as described under this 2018 Plan update, this stage will focus on the processing of backfilled protore currently in the Lesley Ann pit. Processing of this stockpile will likely consume the remaining mine life as proposed by this 2018 Plan update, at which time either a Plan amendment will be provided to the agencies for continued mining at the site or reclamation will commence.
Reclamation will not be required for Stages 5E, 5F, or 6 unless the mining activities described for these stages occurs. However, mining is a dynamic process that must be responsive to changing economic conditions and other factors which could at a later time require some degree of reclamation which will be addressed with the County if changing conditions warrant the hardrock mining activities included in stages 5E, 5F, and 6.
At the beginning of Stage 9, following the heap leach pad rinsing and detoxification in Stage 8, the slopes will be recontoured to 2.5H: 1 V. Earthmoving equipment will push leached material downslope, away from the crest of the pad, to cover the exposed pad liner, berms, pipe transport trench and road presently encircling the pad. This activity cannot commence at an earlier stage, since the berms, pipe trench and road must remain in service until the heap leach pad is fully decommissioned. Fresh water demand for the mining and processing operations will preclude any significant rinsing and detoxification of the heaps until Stage 8.
The approved EIS and original technical report to the California Regional Water Quality Control Board (RWQCB) indicated a heap height of about 80-feet. In 1993, an application was made to the RWQCB requesting an amendment allowing stacking to 120-feet. On June 2, 1993, approval was granted permitting stacking to the 120- foot height. On March 24, 1997, approval was granted from the RWQCB allowing stacking to 150-feet. Both approvals were granted after a review by the RWQCB of site specific geotechnical reports indicating appropriate factors of safety with the increased heap heights. The increased heap height and a more compact heap leach pad will result in less surface disturbance. With the increased heap height, available areas for concurrent reclamation are reduced because active leaching areas will be ongoing into Stage 5C through 5F.
Castle Mountain Mine Plan and Reclamation Plan 3-17 January 2, 2019 3.9.1.3 Stages 6 and 7
The amount and overall timing for the preparation of disturbed acres for revegetation is dependent on whether mining operations continue beyond Stage 5D. In the event economic conditions are not favorable to proceed with Phase II mining (developing the South Extension or for expansions in the Jumbo and OBHT pits) placement of growth media and other reclamation activities would begin immediately in areas which had been disturbed in prior stages. However, if expansion of OBHT and Jumbo do not occur, reclamation already completed at those areas will remain intact and no further reclamation will be required. The pit floor and haul roads of the Lesley Ann pit, from which backfilled protore has since been removed, would be prepared for revegetation.
Under the Phase II mining scenario described in Chapter 2, in which the South Extension deposit would be mined, and both the Jumbo and OBHT pits would be enlarged, certain areas could be prepared for revegetation while mining activities proceed concurrently in other areas during Stage 6. Mining of the initial South Extension overburden material would complete the South Overburden Site to its 307 acres of total disturbance, and reclamation activities would commence on those portions of that site where overburden was recently placed. Once the Jumbo Pit expansion was completed reclamation activities could commence in earnest on much of the North Overburden Site where fresh material has been placed; for all other undisturbed areas of both overburden sites, the reclamation completed to date will remain intact and no further reclamation will be required of those areas.
The start of Stage 7 will be influenced by the amount of mining activity in Stage 6. During Stage 7, the overburden sites over which ore stockpiles were located will be reclaimed. In general, most areas of disturbance would be in an advanced stage of reclamation during Stage 7, with the exception of the Process Plant and Administration sites, and the Heap Leach Pad. Many of the roads and growth media stockpiles would also still be active. Further leaching of residual gold from ore on the Heap Leach Pad would continue throughout Stages 6 and 7.
3.9.1.4 Stage 8
During Stage 8, no additional areas will be prepared for revegetation but revegetation efforts will continue on sites previously prepared for revegetation. Rinse solutions will be circulated through the heap leach pile to reduce cyanide levels to the closure limits specified by the Colorado River Basin Regional Water Quality Control Board (“RWQCB”).
3.9.1.5 Stage 9
At the outset of Stage 9, the slopes on the Heap Leach Pad will be recontoured to 2.5H: l.0V. The slopes and the top surface of the leach pad will be prepared for revegetation. In addition the remaining areas will be prepared for revegetation. See Table 3-3.
Stage 9 will conclude at the end of the tenth growing season. Plantings of the final revegetation areas will follow decommissioning the Heap Leach Pad, solution storage tanks, and stormwater basins.
Monitoring of the post-mining revegetation program will continue throughout this ten year period.
Castle Mountain Mine Plan and Reclamation Plan 3-18 January 2, 2019 3.9.2 TEMPORARY SUSPENSION OF OPERATIONS
Measures to be implemented in the event CMV temporarily suspends operations (defined as a shutdown for up to 24 consecutive months during which both mining and processing activities have been halted) are discussed in this Section. The objective of these measures would be to protect the environment and the public. Proper arrangements for handling process chemicals, management of process solutions, heap leach piles, and surface drainage would be of particular concern
The most probable cause for a decision to temporarily suspend operations would be a decline in project economics; but other factors, such as a shortage of process reagents, or other conditions of force majeure, could be responsible for this decision.
Security personnel would be attendance on a continuous basis during the suspension, to safeguard the substantial investment in plant and equipment, and to restrict public access to the mine site.
Solution in the leach pile would be allowed to drain into the tanks and the emergency solution storage pond. It would be treated with a strong oxidant, such as hydrogen peroxide, to destroy free cyanide in the solution. The detoxified solution would be used to rinse the pile in order to flush out residual cyanide. This procedure would be repeated several times to lower the cyanide content in the pile to a level stipulated by the RWQCB.
Chemicals used in the gold recovery circuit would be flushed into the solution storage tanks and detoxified as part of the solution detoxification program. Surplus chemicals would be sealed and stored in secured areas.
Interceptor ditches around the leach pad and process area would remain functional. Since the overburden disposal area surfaces will be sloped to the interior at a grade ranging from 0.5 to 1.0 percent, surface water will flow away from, rather than over, the crest. Run-off from the catchment area surrounding the pits would collect on the floor of the pits.
A temporary suspension of operations will not affect reclamation measures outlined in this 2018 Plan update.
3.10 MAINTENANCE AND MANAGEMENT OF RECLAIMED AREAS 3.10.1 FENCING AND PROTECTION FROM HERBIVORY
Perimeter fencing around the mine site will remain following reclamation to restrict access to revegetated areas. Fencing will also restrict public access to the site.
Cages may be used for some transplanted species.
3.10.2 MONITORING AND MAINTENANCE
Viceroy and regulatory agencies including the BLM, State and County annually review the reclamation plan, to evaluate progress, and to establish bonding requirements for the ensuing year.
An annual report on the revegetation program is prepared to document both the successes and failures arising from the Revegetation Research Program and the nature and extent of reclamation activities at
Castle Mountain Mine Plan and Reclamation Plan 3-19 January 2, 2019 the mine during the preceding year. The report becomes part of the public record on file with the BLM and County.
In addition to the inventories to be performed on the control plots as discussed in Section 3.6, vegetation inventories will be performed on reclaimed areas. These inventories will measure density, diversity and other biometric information of perennial species using 100 meter2 plots. Photo point transects will be established to measure visual aspect. Revegetation success on each reclaimed area will be monitored annually for the first two years after planting and at three-year intervals thereafter.
3.11 DECOMMISSIONING OF FACILITIES
3.11.1 MINE PITS AND OVERBURDEN PILES
Reclamation of the open pits will include ripping the pit floors, haul roads leading out of them, application of growth media, and seeding and/or planting.
Rock staining will not be applied as prior rock staining investigations carried out at the site during past reclamation have proved unsuccessful.
Stabilization of post-closure landforms will be achieved through regrading and slope reduction as discussed in Section 3.13.1. This Plan provides flexibility in slope configuration as shown in Figure 3-2A.
The slope of the South Overburden Site and North Overburden Site will be recontoured to an overall slope of 2.0H: to 1.0V.
A limited amount of growth media will be distributed to form soil islands across the tops of overburden sites. As part of the final recontouring of these areas prior to revegetation, microcatchment basins will be created to channel rainfall into certain areas.
3.11.2 CRUSHING PLANT, COMMINUTION CIRCUIT AND CONVEYING SYSTEMS
When mining has been completed and ore stockpiles have been processed, structures and equipment will be disassembled for salvage and removal from the site. Since the Processing Plant and solution handling facilities will have to remain in service until the Heap Leach Pad has been rinsed and decommissioned, the unneeded facilities will be the first items to be dismantled.
Structural steel and sheet metal siding, decking and grates will be sold to a scrap metal dealer. Demolition debris that has no salvage value will be disposed of at an approved landfill for such items.
The foundations for primary facilities have large reinforced concrete structures. These foundations will be buried in place during decommissioning. Foundations for the other minor structures will be buried in place whenever practical.
3.11.3 SOLUTION TANKS, BASINS, AND PIPING
Rinse water or a neutralizing solution will be circulated through the solution storage tanks, piping and heap leach piles, until residual cyanide concentrations are reduced to levels acceptable to the RWQCB. Remaining solutions will be allowed to evaporate. Sludge that has accumulated in the bottom of the
Castle Mountain Mine Plan and Reclamation Plan 3-20 January 2, 2019 File: F3-2A CMV-RECONTOURED OVERBURDEN and HEAP LEACH PAD SLOPES (TAG) Page:1 REV: 10/17/2018
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
RECONTOURED OVERBURDEN and HEAP LEACH PAD SLOPES CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 3-2A C O R P O R A T I O N solution storage tanks and basins will be assayed and if found hazardous will be sent to an approved hazardous waste facility for disposal. If it is determined to be non-hazardous material it will be applied to the heap leach pile.
Solution storage tanks will be disassembled and sold for salvage or scrap value. Concrete ring foundations beneath the tanks will be buried in place when the basins are backfilled.
After the tanks have been removed, the liners in the basins will be freed from anchor trenches, folded in on themselves, and covered with broken concrete from building foundations, slabs, and water-well pads. These materials will then be covered with fill materials, primarily overburden. Final grading of the surface, including application of “soil islands” of growth media, will reestablish approximate pre-mining contours, thus restoring pre-mining drainage patterns in this area.
3.11.4 HEAP LEACH PILES
Spent ore on the heap leach piles will be detoxified by circulating rinse water or a neutralizing solution through the heaps until the residual cyanide concentrations are reduced to levels stipulated in the RWQCB waste discharge permit. After check sampling has confirmed the pile detoxification, spent ore piles will be graded to 2.5H:1.0V slope to assure long-term stability.
Stabilization of post-closure heap landforms will be achieved through regrading and slope reduction as discussed in Section 3.13.1. this Plan provides flexibility in slope configuration as shown in Figure 3-2A.
Some mounding of the heap tops will be done during regrading. This will serve two purposes: (1) small scale reduction of visual contrast with surrounding landforms, and (2) creation of microcatchment hollows and depressions to direct surface flows to selected sites for revegetation purposes.
Process solutions will be evaporated concurrently with heap rinsing and detoxification. Any excess solutions from the gold recovery circuit will be pumped into the tanks and treated in the same manner as heap leach solution.
Surplus reagents will be shipped back to the manufacturer via approved transport. Unsealed, partially- used reagent containers will be dealt with on an individual basis. Nonhazardous or nontoxic reagents will be shipped to a Class III landfill. Toxic and hazardous chemicals will be shipped via a licensed carrier to an approved hazardous waste facility for disposal.
3.11.5 PROCESSING/ADMINISTRATION STRUCTURES
Buildings and structures not needed for continued reclamation and monitoring will be dismantled and removed. Concrete footings, slabs, and foundations will be buried in place or in the basins near the Process Area.
3.11.6 OTHER FACILITIES
Prior to project termination, the BLM will be asked to designate a well for recreational needs, stock water purposes, and wildlife guzzler supply. This would allow water supplies in the Northern Lanfair Valley to be improved without drilling new wells and disturbing additional land. Water wells not needed for irrigation requirements for reclamation at Castle Mountain will be decommissioned at the end of the
Castle Mountain Mine Plan and Reclamation Plan 3-22 January 2, 2019 mine life. Decommissioning will be in a manner that complies with the specifications of the County Department of Environmental Health Services. The wells will be left in a condition that will allow them to be reopened as needs require.
A licensed California driller/contractor will be hired by CMV to perform the required work on wells to be decommissioned. Concrete platforms surrounding each well-head will be demolished and the broken concrete will be placed in the basins at the leach pad area or at other areas acceptable to BLM. Casing removal and plugging will be performed by the driller/contractor. After these tasks have been completed, the well site areas and related service roads will be scarified to eliminate soil compaction and revegetated.
Aboveground utilities will be removed. Underground lines will be capped and covered, and all other equipment and materials will be removed from the site.
3.11.7 ROADS
Site roads, parking lots, and portions of access roads designated by the BLM for closure will be reworked, scarified, and revegetated. As directed by the BLM, CMV will reclaim the Walking Box Ranch access road between the California/Nevada border and the mine site to a single lane of traffic.
3.12 EXISTING VEGETATION
The original 1990 Plan provides an extensive discussion of the existing vegetation within the Lanfair Valley and the mine site.
Additional discussion can be found in the OMR report, Castle Mountain Mine Vegetation Analysis, listed as Appendix Q to this Plan.
3.13 POST-MINING TOPOGRAPHY AND PUBLIC SAFETY
3.13.1 TOPOGRAPHY
A plan map of post-mining topography of the site at the end of Phase II is shown in Figure 3-2 with cross sections shown on Figures 3-2B and Figure 3-2C. The major permanent topographic changes at the site will those areas where materials have been excavated or deposited during mining operations.
As constructed, the sides of the Heap Leach Pad have slopes of 1.5H: 1.0V. Material will be placed on the pad in five (5) lifts, to an ultimate height of 150-feet. Once the pad has been detoxified the sides will be recontoured to an average slope of2.5H: 1.0V with earthmoving equipment. As a result of the reduction in slope, the toe of the heap will move outward to cover the synthetic liner, berms, and pipe trench.
Along the south face of the South Overburden Site and the North Overburden Site the final slopes will achieve an overall 2.0H: 1.0V slope. Studies performed by consulting geotechnical engineers on overburden materials have determined they will be stable at this slope angle. These slopes were first rough graded for large water catchment areas, and then into micro-catchment basins for water retention and erosion control. These small basins promoted seed germination and continued plant growth due to better moisture retention.
Castle Mountain Mine Plan and Reclamation Plan 3-23 January 2, 2019 File: F2-14A CMV-F2-14A CMV-MINE STATUS at END of STAGE 5D (TAG) Page:1 REV: 10/17/2018
Desert Tortoise Fence
Desert Tortoise Fence
Gold Processing Plant to be Re-established 2018 Source: Castle Mountain Ventures, 2018. Approximate Area of Heap Leach Pad Expansion (Portion to Overlap Existing Reclaimed Area) Backfill/Protore to be Mined (Removed) and Hauled to Heap Leach Pad END of PHASE 2 North Nursery to be Established CASTLE MOUNTAIN MINE County of San Bernardino, California Desert Tortoise Fence
LEGEND 1998 Approved Mine Plan Boundary LILBURN FIGURE 3.2 C O R P O R A T I O N 1998 Approved Facilities File: F3-2A CMV-RECONTOURED OVERBURDEN and HEAP LEACH PAD SLOPES (TAG) Page:1 REV: 10/17/2018
Source: Castle Mountain Ventures, 2018.
CROSS SECTIONS A, B and C CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 3-2B C O R P O R A T I O N File: F3-2A CMV-RECONTOURED OVERBURDEN and HEAP LEACH PAD SLOPES (TAG) Page:1 REV: 10/17/2018
Source: Castle Mountain Ventures, 2018.
CROSS SECTIONS D, E and F CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 3-2C C O R P O R A T I O N Figure 3-3 shows the distribution of growth media throughout the mine site. Because of topography and relative thinness of the growth media, only limited quantities will be salvageable. Table 3-4 shows projected growth media salvaged by area through Stage 6. The applied growth media showed poor plant growth in test areas on the south overburden site and contained mostly weeds due to poor soil conditions. Recommendations based on these results were to place salvaged growth as irregular mounds and rough grade to blend the growth media with overburden or heap leach material to create diverse habitat.
Table 3-4 Estimated Growth Media Salvage by Location Mapping Media Depth Location Cubic Yards Unit69 Range (inches) Average (inches) Heap Leach Pad 18 12-30 18 813,000 Solution Storage Site 34,000 Process Plant Site 10,000 Subtotal Unit 1 857,000 South Overburden Site 3 6-12 8 257,000 North Overburden Site 226,000 Lesley Ann Pit 78,000 Jumbo Pit 27,000 South Extension Pit 11,000 Crushing Plant Site 12,000 Administration Site 1,000 Subtotal Unit 3 612,000 Total 70 , 71 1,469,000
There are rocky slopes on the sides of the mountains immediately north and east of the mine site that have slopes ranging from as steep as 1.5H: 1.0V to less than 3H: 1.0V. Owing to the more than three mile distance between the overburden sites and the nearest road to the south (the East Mojave Heritage Trail), most viewers from this road would be unable to distinguish between surfaces sloped at between 2H: 1.0V and 3H: 1.0V.
This Plan and the Conditions of Approval provide for alternative slopes as described in Section 3.11.1. Having the option to place overburden at the angle of repose, with intermediate benches, provides an alternative to provide long term stability, disturb less land, maximize the amount of growth media available for use on other areas and resemble other existing topographic features in the area.
Roads to be reclaimed in flat topography will be ripped and scarified to eliminate compaction. Bermed material will be replaced, and then seeded. In sloping topography, the material graded to the downslope side of the road will be retrieved with a backhoe and distributed across the width of the road. To the extent practicable, road cuts will be returned to their original contours.
69 Mapping Unit 2 is the dry washes. Since no disturbances occur in the washes, there will be no growth media salvaged within Mapping Unit 2. 70 Mapping Unit 4 has an average growth media depth of 6 inches. However, topography is too steep for earthmoving equipment to attempt salvage within Mapping Unit 4. 71 Mapping Unit 5 is the area in the North and South Clay Pits disturbed by previous clay quarrying activities. There is no salvageable growth media within Mapping Unit 5.
Castle Mountain Mine Plan and Reclamation Plan 3-27 January 2, 2019 REV: 10/17/2018 1 REV: Page: (TAG)
F3-3 CMV-SOIL MAPPING UNITS PRIOR to 1997 File: F3-3 CMV-SOIL
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998. 1 Average 18” of salvagable growth media 2 Dry Wash 3 Average 18” of salvagable Growth Media 4 Too steep to salvage 5 Prenious Clay Pits - No salvagable growth media
SOIL MAPPING UNITS PRIOR to 1997 CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 3-3 C O R P O R A T I O N 3.13.2 PUBLIC SAFETY
Public safety during the operational period is assured by restricting access to operation areas with fences and gates. All visitors are required to register at the security desk, and must adhere to procedures mandated by the Federal Mine Safety and Health Administration (MSHA). No member of the public is allowed unaccompanied access to any working areas of the facility.
Public safety will be addressed after decommissioning by reclamation practices that will include slope stabilization where required, removal of buildings, structures and equipment, and use of barriers such as berms in areas that would otherwise provide vehicle access into mine pits.
When revegetation has been deemed successful, the BLM will determine when fencing should be removed to provide access for authorized uses.
3.14 POST-MINING HYRDROLOGY
3.14.1 SURFACE WATER
3.14.1.1 Mine Pits and Overburden Sites
Surface waters flowing through the mine site have the potential to reach Sacramento Wash, which drains the northeastern portion of Lanfair Valley. The drainage area feeding Sacramento Wash covers approximately 240 square miles (153,000 acres).
The open pits (307 acres) are located at the headwaters of the watershed (407 acres) as shown in Figure 3-4. Surface runoff from this catchment area will flow into the pits. The affected watershed constitutes less than 0.3 percent of the Sacramento Wash watershed. Consequently, the amount of water entering the pits will have little effect on post-mining flow volumes at Sacramento Wash.
The overburden sites, including side slopes, will cover 600 gross acres including clay pit reclamation. As haul trucks discharge material over the edge of the overburden pile, larger rocks tend to advance to the bottom, while smaller rocks remain closer to the top. This natural size segregation creates underdrains beneath the overburden.
The top surface of the South Overburden Site is graded (ranging from 0.5 to 1.0 percent slope) away from the crests, into interior depressions (see Figure 3-4). These depressions, or infiltration basins, have been designed at specific locations, to accommodate the volume of surface run-off generated during a probable maximum precipitation event.
If needed, coarse rock can be dumped on the infiltration basin slopes to inhibit migration of fines. Surface water will flow into the basins, percolate down to the under-drain at the bottom of the pile, and exit into existing dry washes at the toe of the overburden.
Previously, most surface run-off in the South Clay Pit Reclamation Area collected in the abandoned clay quarry. Reclamation of this area involved placing overburden over the quarry, forming three terraces extending up the hillside. The terraces were constructed with a back-slope, to direct surface water on each terrace away from the crest. Post-mining drainage in this area will be similar to the previous
Castle Mountain Mine Plan and Reclamation Plan 3-29 January 2, 2019
10/17/2018 1 REV: Page: (TAG) F3-4 CMV-IN-PIT CATCHMENT AREA and 100 YEAR FLOOD PLAIN AREA and 100 YEAR FLOOD CATCHMENT File: F3-4 CMV-IN-PIT
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
IN-PIT CATCHMENT AREA and 100 YEAR FLOOD PLAIN CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 3-4 C O R P O R A T I O N drainage pattern, i.e., precipitation will drain through the overburden material into the bottom of the former quarry, and then percolate into the regional ground water system.
A similar result will occur when overburden is placed in the North Clay Pit Reclamation Area and the pits that are sequentially backfilled. Water moving through the overburden in the quarry and pit area will drain the bottom of the quarry/pit, then percolate into the regional ground water system. Water descending through overburden in the North Overburden Site outside the catchment area for the former clay quarry will reach the underdrain at the bottom of the overburden and exit into existing dry washes at the toe of the overburden.
3.14.1.2 Crushing and Processing Facilities, Heap Leach Pad and Solution Tanks/Basins
The Administration Area and the Shop Area are located on the alluvial fan portions of the mine site. Locations of facilities were selected to conform to existing topography, thereby minimizing "cut and fill" earthwork and avoiding encroachment into major dry washes. Up gradient of these facilities, sheet flow from major precipitation events are intercepted and diverted by small V-ditches. Except for the perimeter of the Heap Leach Pad area, these ditches will be filled in at decommissioning.
V-ditches installed up-gradient from the Heap Leach Pad during construction to divert sheet-flow around the pad will be left in place, to continue diverting run-off around the decommissioned pad.
Solution storage areas adjacent to the Heap Leach Pad will be reclaimed by backfilling to approximately their original contour and as a consequence will not collect water.
3.14.1.3 Leachate from Ore, Protore and Overburden
Precipitation percolating through spent heap leach ore and overburden materials will not degrade surface water or ground water quality. Samples of ore and overburden have been subjected· to geochemical testing to determine the acid generation potential and extractable metals. The materials are slightly alkaline in nature, will not produce acidic leachate conditions, and the measured concentration of metals dissolved under the Environmental Protection Agency's test procedure were well below the concentrations considered to be of potential concern by the Agencies.
3.14.2 GROUNDWATER
Table 3-5 shows the average annual groundwater levels adjacent to the mine well field as measured at wells W-19, W-37 and W-38, respectively, from 1990 through 2001. Since these wells were abandoned during the reclamation conducted from 2001 to 2006, they have been replaced by wells 2017-2MW, 2017-3MW, 2018-1MW and 2018-2MW, the last two to be drilled in late 2018 (see Figure 3-5). Table 3-6 shows the initial readings from the 2017 monitoring wells.
Water flows at the outlet of Piute Springs have been measured monthly until 1998 when reduced monitoring at a quarterly frequency was approved due to the limited risk posed by the mine operation on Piute Springs (see Table 3-7); this Plan proposes to continue the quarterly flow and water quality monitoring at the springs but that is contingent on agreement and access that will be required from the National Park Service. See Appendices A and B.
Castle Mountain Mine Plan and Reclamation Plan 3-31 January 2, 2019 Figure 3-5 Groundwater Monitoring Sites (2018)
Castle Mountain Mine Plan and Reclamation Plan 3-32 January 2, 2019 Table 3-5 Groundwater Monitoring Results – Abandoned Wells (Depth from Surface to Groundwater in feet) Monitoring Well 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 2004 Annual Average W-19 365.1 365.6 367.7 371.2 375.8 380.0 383.3 386.1 388.1 391.7 392.0 393.3 394.6 396.0 397.1 W-37 614.9 610.3 606.1 599.8 591.6 587.6 584.8 581.9 579.8 575.0 573.0 567.4 572.4 ------W-38 757.0 756.9 756.3 756.7 757.1 757.3 757.7 758.0 758.0 757.7 757.0 756.9 757.0 756.9 ------
Table 3-6 Groundwater Monitoring Results – (2018) Replacement Wells (Depth from Surface to Groundwater in feet) Monitoring Well 2017 2018 Annual Average 2017-1MW 502.3 504.3 2017-2MW 542.5 542.9 2017-3MW 191.0 164.8 2018-1MW ------2018-2MW ------
Table 3-7 Piute Spring Outlet Flow (Spring Flow in Gallons Per Minute) Annual Average 1987 1988 1989 1990 1991 1992 1993 1994 1995 1996 1997 1998 1999 2000 2001 2002 2003 Spring Flow Piute Springs 42.3 41.0 40.8 42.0 35.3 38.2 49.3 47.1 42.7 41.8 48.8 36.0 48.5 77.8 66.3 42.5 38.7 (Outflow) Piute Springs 67.3 82.3 70.5 103 ------186 216 208 186 226 251 195 149 (Flow at Dam)
Castle Mountain Mine Plan and Reclamation Plan 3-33 January 2, 2019 There has been no discernible change in spring flow since pumping at Castle Mountain began in mid- 1991, nor has any change in water quality been observed.
Modeling undertaken in connection with preparation of the Draft EIS/EIR demonstrated that the cone of depression that develops around the well field will have a limited lateral extent and will be eliminated within 30 years after pumping ceases. Recharge to the aquifer is expected to refill the cone of depression within that time.
Drawdown at the monitor wells has been less than predicted in the EIS/EIR modeling. It appears the transmissivity of the aquifer is somewhat lower than the estimate used in the modeling. As a result, while drawdown is more pronounced immediately adjacent to the production wells, the cones of depression are confined to the vicinity of these wells. Because the drawdown is localized to the well field, ground water levels at distances removed from the well field are less pronounced than the modeling predicted.
Sites occupied by Process Facilities, as well as reclaimed roads, the Heap Leach Pad, and Overburden sites, are not expected to affect post-mining hydrologic conditions, since these sites are not a material part of the recharge zone for the local aquifer. Condemnation drilling completed in the leach pad and overburden areas demonstrated that the ground water table in these areas is, on average, at least 550 feet below surface topography.
Heap leach facilities are monitored, using leak detection systems beneath the pad liners, the emergency solution storage basin, and the stormwater basins. The design and installation of these leak detection systems comply with CCR, Title 27, Subchapter 15 regulations, and have been approved by the RWQCB.
The monitoring systems beneath the Heap Leach Pad and the solution storage basins provide the regulatory agencies and Viceroy with the earliest possible warning should a release occur. Three separate leak detection systems have been installed: under the emergency solution storage basin; under each stormwater catchment basin, and the leach pad itself.
Each basin has two plastic liners on either side of a geotextile membrane, to direct any leakage through the top liner to a sump located in the lowest comer of each basin's floor. The sumps are monitored by an 8-inch diameter riser pipe connected to the low point of the system. If necessary, a pump can be inserted into the riser, to dewater the sump prior to remedial action.
The Heap Leach Pad leak detection system is beneath the pad liner and geotextile underliner. The system consists of slotted PVC pipes, which are placed within fill used to level topographic lows within the leach pad site. The system is monitored through a PVC pipe extending through the perimeter berm and connected to a sump and riser pipe assembly.
Should significant seepage indicating a major liner failure be detected from any basin, that basin will be drained for repair. Should significant seepage indicating major liner failure be detected from any pad cell, that cell will be withdrawn from service, or cleared and inspected. Liners and welded seams are inspected, by a third party inspector, for holes, tears, and defects before crushed ore is loaded onto the liners. Areas of the liners requiring repair are repaired or replaced, depending upon the extent of the problem.
Castle Mountain Mine Plan and Reclamation Plan 3-34 January 2, 2019 The collection ditches, exposed areas of the HDPE pad liners, pipelines and diversion systems are thoroughly examined monthly. This is to ensure the integrity and performance of the system.
If groundwater infiltrates into the open pit bottoms, it will be addressed as specified in Conditions of Approval No. 115 and Stipulation No. 104. See Appendices A and B.
Water wells for the West Well Field include up to 15 water wells which were drilled from approximately 1986 to 1997. The individual bore holes and well installations were authorized by San Bernardino County through water well permit applications. Where well installation occurred on public land, Plan of Operations and/or Right of Way temporary use permits were authorized by the BLM. Where well installation occurred on State land, managed by the State Lands Commission, lease agreements were authorized by the Commission. Bore holes which were developed into active water production wells for the mine were perfected for use through the authorizations described above, the established California water rights doctrine of beneficial use as documented by First Notice Ground Water Extraction filings with the State Water Control Board which were obtained by CMV for water wells. Annual filings of water use with the State have continued for each water well from the date of the original First Notice of Ground Water Extraction to the most recent annual filing in May 2017.
3.14.3 DRAINAGE, EROSION, AND SEDIMENTATION CONTROL
The mine pits will be located at or near the crest of their respective watersheds, as described in Section 3.11.1. Any surface water and associated sediment within the perimeter of the in-pit catchment area will collect at the bottom of the pits.
Drainage for the post-mining North and South Overburden sites is discussed in Section 3.11.1. During development of these areas, a gradient ranging between 0.5 and 1. 0 percent will be maintained to ensure surface waters flow away from, rather than over, the crests. To reduce wind erosion, reclamation activities will be initiated as soon as practicable after use of each site is discontinued.
Facilities needed to operate the mine have been constructed outside the 100-year flood plain associated with the dry washes that traverse the site. As a matter of sound engineering practice, any V-ditches and associated berms that may be needed in the future to will be designed to safely accommodate the flows arising from a 24-hour, 100-year storm event with a minimum freeboard of one foot. The slope and alignment of the ditches will be designed to minimize flow velocities and subsequent erosion from flood waters.
Since the terrain in the areas where the facilities have been erected is generally of modest relief, erosion and sedimentation problems are not anticipated.
Solution Storage areas and the Heap Leach Pad have been designed to operate as closed systems. As a result, any sediment would be contained within these areas. The post-mining description of these areas is given in Sections 3.11.3 and 3.11.4
Erosion will be assessed annually. Sites showing evidence of rill and gully erosion will be bermed and terraced. Areas showing evidence of erosion will be graded and seeded prior to the next growing season. The effectiveness of mulching and straw bales will be evaluated in controlling erosion.
Castle Mountain Mine Plan and Reclamation Plan 3-35 January 2, 2019 4.0 RECLAMATION ASSURANCE
4.1 INTRODUCTION
Following the approvals of the operating permits for the Castle Mountain gold mine by the various Federal, State and County agencies, Viceroy arranged for two surety bonds to be posted.
The first bond, in a principal amount of $619,000, was a joint bond posted in favor of the BLM and the County. The second bond, in favor of the Regional Water Quality Control Board, Colorado River Basin region, was in a principal amount of $400,000.
Financial Assurance requirements are discussed in the Conditions of Approval and the Record of Decision. See Appendices A and B.
Financial Assurance requirements are reviewed annually to ensure that adequate coverage of reclamation of land that will be disturbed at the end of each calendar year. Figure 4-1 shows the extent of disturbances at the end of March 1996 and March 1997. Reclamation costs were then estimated to be $1,890,000.
Figure 4-1A shows the estimated extent of disturbances through 2018.
The principal amount of the BLM/County surety bond in place when the current Plan was approved in 1998 was $1,890,000. The Company currently has bonds in place to cover land disturbance associated mineral exploration and site development activities; these bonds total $406,918.20 and will be further reviewed and adjusted as the site transitions from development and mineral exploration to resumed mining.
Castle Mountain Mine Plan and Reclamation Plan 4-1 January 2, 2019
10/17/2018 1 REV: Page: (TAG) F4-1 CMV-SURFACE DISTURBANCES as of DISTURBANCES MARCH 1997 File: F4-1 CMV-SURFACE
Source: Viceroy Gold Corporation Castle Mountain Mine, Mine Plan and Reclamation Plan Ver. 2.0 (90M-013); June 1998.
SURFACE DISTURBANCES as of MARCH 1997 CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 4-1 C O R P O R A T I O N File: F2-14A CMV-F2-14A CMV-MINE STATUS at END of STAGE 5D (TAG) Page:1 REV: 10/17/2018
Desert Tortoise Fence
Desert Tortoise Fence
Source: Castle Mountain Ventures, 2018. LEGEND
Approved Mine Plan Boundary
2018 MINING DISTURBANCES 2018 Mining Disturbance CASTLE MOUNTAIN MINE County of San Bernardino, California LILBURN FIGURE 4-1A C O R P O R A T I O N 5.0 SUPPLEMENTAL INFORMATION
5.1 INTRODUCTION
Castle Mountain Venture (“CMV”) is a California general partnership. Through CMV, Viceroy Gold Corporation (“Viceroy”), a Delaware corporation is authorized to conduct business in California as the Operator of the Castle Mountain gold mine. The mailing address for CMV is 911 American Pacific Drive, Ste. 190, Henderson, Nv 89014.
5.2 ENVIRONMENTAL DOCUMENTATION
5.2.1 Permitting (1988-1990)
The operations at Castle Mountain were reviewed by the BLM and County Planning Department, as the federal and state lead agencies having permitting authority under the NEPA and CEQA, respectively. Under the direction of BLM and County staff, the following environmental documents were prepared and circulated for public comment:
Castle Mountain Project, San Bernardino County, California. Draft EIS/EIR. BLM and the County of San Bernardino, February 1989; State Clearinghouse No. 88062708.
Castle Mountain Project, San Bernardino County, California. Supplement to Draft EIS/EIR. BLM and County of San Bernardino, January 1990; State Clearinghouse No. 88062708.
Castle Mountain Project, San Bernardino County, California. Biological Assessment for the Desert Tortoise. BLM, January 1990.
The extensive public comments on the foregoing documents were taken into consideration and responded to in a Final EIS/EIR entitled:
Castle Mountain Project, San Bernardino County, California. Final EIS/EIR. BLM and the County of San Bernardino, August 1990; State Clearinghouse No. 88062708.
Concurrently, CMV staff, with assistance from the California Department of Conservation, Mined Land Reclamation Division, BLM and the County prepared a report entitled:
Castle Mountain Project, San Bernardino County, California. Mine Plan and Reclamation Plan, August 1990.
Inasmuch as the environmental resources in and adjacent to the Castle Mountain mine site were described in the documents listed in items 1 through 3 above, such information is was incorporated into the 1998 Plan by reference.
Castle Mountain Mine Plan and Reclamation Plan 5-1 January 2, 2019 Chapter 4 of the original 1990 Plan contains a summary of information based upon studies completed for the EIS/EIR documents, organized by the following topics:
Brief History of the Hart Mining District Visual Resources Geologic Setting Water Resources Wildlife Air Resources Cultural Resources
5.2.2 Permitting (1995-1998)
Castle Mountain Mine, Plan Amendment Application, ver. 1.1 a, dated August 14, 1997, prepared by the CMV. Castle Mountain Mine Expansion Project, Draft EIS/EIR, to amend County Mine and Reclamation Plans and modify BLM Plan of Operations, State Clearinghouse No. 95081031, March 1997.
Biological Assessment for Desert Tortoise (Gopherus agassizii). Castle Mountain Mine Expansion Project, Lilburn Corporation, San Bernardino, CA, June 1997.
5.3 Permitting (2018)
No additional permitting is required of the BLM or the County, to resume mining that is already authorized at the site. Modifications of agency authorized actions may be subject to additional NEPA/CEQA analysis if the impacts of proposed modifications have not been thoroughly assessed by prior, similar, analysis.
Regardless, CMV recognizes potential impact that may occur to select resources as authorized actions are performed. These impacts have been assessed by various biological and cultural resource assessments and ultimately through the prior EIS/EIRs; and where necessary have been mitigated through the project conditions and stipulations.
CMV has updated many of the past resource assessments referenced in section 5.2.1 of this Plan. Those specific areas of investigation have included:
RESOURCE REPORT Class III Cultural Resources Inventory of 1,091 Acres for the Castle Mountain Cultural Venture Project; ASM Affiliates, September 2018 2017 Fall Blooming Special Status Plant Survey for Castle Mountain Venture; MBI, January 2017 Rare Plants 2018 Spring Blooming Season Special Status Plant Survey for Castle Mountain Venture; ELMT Consulting, August 2018 Desert Tortoise Castle Mountain Mine Presence/Absence Survey and Density Estimate, 2017 Castle Mountain Mine Project, 2018 Golden Eagle Nesting Surveys; BRC, Golden Eagle (raptors) October 2018
Castle Mountain Mine Plan and Reclamation Plan 5-2 January 2, 2019 RESOURCE REPORT Mine Surveys for Bats and Other Wildlife at Castle Mountain Mine Project; Bats Brown-Berry Biological Consulting, November 2018 Addendum Report to Castle Mountain Project Plan for Ground Water Ground Water Monitoring and Contingency Water Supply to Piute Spring; GLA, February 2019 Air EIR Conformity Emissions Summary, Castle Mountain Venture; Ramboll, 2018
5.4 PERMITS AND REGULATORY REQUIREMENTS
Many of the permits and approvals that the Company must maintain on the Venture's behalf are intended merely to inform a given agency that a certain action will be undertaken, so that the relevant agency may determine the adequate precautions to be taken to ensure public health and safety.
5.4.1 REGIONAL WATER QUALITY CONTROL BOARD (RWQCB) ORDER
The former operation of the heap leach facility was authorized by RWQCB, Order No. 91-002. That Order was rescinded after mining was suspended and was followed by implementation of Closure and Post- Closure Maintenance WDR Order No. R7-2005-0092 on July 6th, 2005. Following successful post-closure monitoring, the heap leach pile was successfully determined closed and no longer a threat to the water and/or land of the state.
The Company is currently drafting a new ROWD application which will be submitted to the Colorado River RWQCB and once approved, the new WDR will authorize operations at the expanded head leach pad.
It has been past practice that the RWQCB Order will recognize that the approved heap leach facility will be extended in stages (or “components”). Accordingly, the RWQCB Order requires that, as the need for additional pad space arises, at least 60 days prior to the commencement of construction of each component, the Company must submit a technical report to the RWQCB for approval by the Executive Officer. The report must include a plan showing in detail the proposed construction of that component.
The RWQCB approval mechanism discussed in item 2 above could be used for approving construction of future leach pad space needed to accommodate the increased tonnage of ore that would be produced under this Plan.
5.4.2 STREAMBED ALTERATION AGREEMENT—CALIFORNIA DEPARTMENT OF FISH & WILDLIFE (CDFW)
The site formerly operated subject to Streambed Alteration Agreement No. 5-554-90 with the CDFG and approved the leach pad design. See Appendix D. Assessments are currently underway to determine if heap leach pad expansion to the fully approved size (421-acres) will impact any drainages under state or federal jurisdiction. If it is determined that jurisdictional drainages are present, the appropriate permit agreements will be in place before any heap leach pad expansion occurs.
Castle Mountain Mine Plan and Reclamation Plan 5-3 January 2, 2019 5.4.3 DESERT TORTOISE HABITAT COMPENSATION AND OTHER ISSUES
Extension of leach pad and overburden storage sites will occur in areas that have been identified as potentially, very, low density tortoise habitat. As a result, a Biological Assessment was prepared as part of the consultation with the U.S. Fish and Wildlife Service (USF & W) and CDFG concerning compensation for habitat that would be affected by the additional disturbances. In November of 1997, the USF&W issued a Biological Opinion with a non-jeopardy decision based certain mitigation measures to be implemented by Viceroy. The 1997 Biological Opinion is attached as Appendix E.
Due to the length of time since the prior Biological Assessment (BA) and resulting Biological Opinion (BO), the Company conducted a large desert tortoise protocol survey in 2017 which covered most of the mine site. The result of that survey was in line with past BA’s conducted at the site and reaffirmed prior findings that while some portions of the site are considered desert tortoise habitat, the habitat is of low quality mostly due to higher land elevations, and the habitat present does not support high or even moderate species density. Historical assessments at the site dating back over 30 years have all generally located one or two live tortoises and indeed the 2017 protocol survey covering over 1,000 acres of the mine site discovered a single live desert tortoise.
Recent informal consultation with the BLM and the Service have indicated that no additional review of the currently approved BO will be required for operations proposed by this mine Plan.
5.4.4 MOJAVE DESERT AIR QUALITY MANAGEMENT DISTRICT
In February 1993, the Mojave Desert Air Quality Management District ("District") amended the Permits to Operate for the Castle Mountain gold mine. The amendment increased the maximum processing rate through the primary crusher to 15,000 tons per day, and 13,200 tons per day through the secondary and tertiary crushers. This is equivalent processing rate of 4.5 million tons per year.
New Authority to Construct (“ATC”) and Authority to Operate permits will be required prior to construction/operation of re-established equipment which require such permits. Those permits will be in place prior to construction of the facilities approved by this Plan.
5.5 VESTED (MINING) RIGHT
The Castle Mountain Mine site is subject to a vested right to conduct surface mining activities at the Site; this right was established by extensive pre-SMARA mining operations that have continued for much of the past 100 years at the Site. These grandfathered property rights attach to and run with the land, and thus have benefitted the successors-in-interest to the Site throughout the past 30 years, including Viceroy and CMV.
Vested rights are defined by, and established pursuant to, the provisions of Section 2776(a) of SMARA, which provides as follows:
"(a) No person who has obtained a vested right to conduct surface mining operations prior to January 1, 1976, shall be required to secure a permit pursuant to the chapter as long as the vested right continues and as long as no substantial changes are made to the operation except in accordance with this chapter. A person shall be deemed to have a vested right if, prior to January 1, 1976, the person has, in good faith and in reliance upon a permit or other authorization, if the permit or authorization was required, diligently
Castle Mountain Mine Plan and Reclamation Plan 5-4 January 2, 2019 commenced surface mining operations and incurred substantial liabilities for work and materials necessary for the surface mining operation. Expenses incurred in obtaining the enactment of an ordinance in relation to a particular operation or the issuance of a permit shall not be deemed liabilities for work or materials."
Section 1.1.2.1 of this Plan describes the extent of mining throughout the last 100 years at the Hart Mining District, a substantial portion of which occurred prior to 1976, and of which the Mine is a major feature. Generally, gold, silver, and high-quality clay (kaolin) represent the mineral resources that have historically been mined throughout the District.
The vested right described herein has been established pursuant to a number of historical pre-SMARA mine operations located within, and subject to property transactions72 affecting the site, including the following:
(1) Gold mining at the Hart District traces back to the Hart gold boom of 1907. As gold booms go, this was a relatively short-lived cycle (1907 to 1918) but at least three successful gold mines did operate up to about 1918. Among these early and profitable mines was Oro Belle No. 1 and No. 2 mines operated by James Hart and the brothers Bert and Clark Hitt. They sold the mines in 1908 and the operation was reorganized by Worth B. Andrews under the Oro Bell Mines Company. It was the Oro Belle Mines Company that patented these mine claims in 1918; the lode mine claim Oro Belle No. 1 was recorded under Patent Number 64910173 and Oro Belle and Oro Belle Fraction lode claims were recorded under Patent Number 42267074. These patents, on which gold was produced and capital expended, are now owned by CMV and the lands which they comprise are located in the middle of the currently existing Oro Belle pit of the Mine.
(2) Clay (kaolin) mining also occurred intermittently, but continuously, in the Hart District from 1929 to the early 1980’s. The first clay quarry, later known as the south clay pit, was situated about a mile south from Hart and adjacent the west side of the old Big Chief gold mine and mill. This clay quarry was operated by the Standard Sanitary Manufacturing Company. The company’s mine claims: Pacific Clay Deposit No. 1, Pacific Clay Deposit No. 2, and Pacific Clay Deposit No. 3, were patented in 1939 under Patent Number 110140675. Operations on these sites continued subsequent to the enactment of SMARA on January 1, 1976, and in December 1997 a reclamation plan was approved by the County for the P.S. Hart Mine (Pacific Clay patent) absent any requirement for a use permit, mine permit, or other land use authorization, thus confirming the existence of a grandfathered vested right to mine in that area. This patent, on which high quality clay was produced and capital expended, and on which vested rights were confirmed by the County, is now owned by CMV and the lands which it comprises are located on the Mine site and where gold mining and/or activities ancillary to gold mining (by CMV) have occurred since 1986. Accordingly, clay and kaolin, and then gold, mining operations have occurred in the Hart District on the same ownership area of the Mine site from 1929 to the present.
72 Many of the historic details from this section are contained in the publication prepared for the Desert District of the BLM, (1980): Desert Fever: An Overview of Mining History of the California Desert Conservation Area 73 Patent details are also shown on Table 1-4 of this Plan. 74 Patent details are also shown on Table 1-4 of this Plan. 75 Patent details are also shown on Table 1-4 of this Plan.
Castle Mountain Mine Plan and Reclamation Plan 5-5 January 2, 2019 (3) Clay (kaolin) was also mined from a deposit directly adjacent to what was left of the abandoned town of Hart, beginning in 1947. This quarry was owned by Herman F. Coors and was situated on what was known as the Milma placer mining claim. This mining claim was patented in 1942 under Patent Number 111369576. In 1981, the County approved a reclamation plan for the C-1 Clay Mine operation on the Milma patent and in the process expressly concluded no use permit, mine permit, or other land use authorization was required by virtue of the mine having existed prior to enactment of applicable mine regulations; thus confirming the existence of a grandfathered vested right to mine in that area. This patent, on which high quality clay was produced and capital expended, and on which vested rights were confirmed by the County, is now owned by CMV and the lands which it comprises are on the Mine site and where gold mining pits are now located and/or activities ancillary to gold mining (by CMV) have occurred since 1986. In conjunction with the mine operations described above, there has been a number of documented mining operations beginning in the 1930s and 1940s, throughout various areas of the overall Mine site, essentially appropriating the entire Mine site as a mining area, and establishing a vested right across a broad area of the Mine site. The County has previously recognized the establishment of vested mining rights in this area through the approval of reclamation plans to continue the mining operations post-SMARA absent the requirement for obtaining mining or use permits, or other land use authorizations.
76 Patent details are also shown on Table 1-4 of this Plan.
Castle Mountain Mine Plan and Reclamation Plan 5-6 January 2, 2019 6.0 REFERENCES
11TH Annual Revegetation Report, Viceroy Gold Corp, Castle Mountain Mine, p.2. (Jan. 2002). Castle Mountain Venture
#49 California Journal of Mines and Geology, p.185-187. (Jan.-Apr. 1953). California Division of Mines
Castle Mountain Expansion Project Final EIS/EIR. (1997). County of San Bernardino and Bureau of Land Management
Castle Mountain Mine, Research and Reclamation 1990-2005 Summary Report. (Dec. 2005). Dr. Bamberg, Ingrid E.
Castle Mountain Mine Vegetation Analysis. (Nov. 2000). California Department of Conservation, Office of Mine Reclamation
Castle Mountain Project Final EIS/EIR. (1990). County of San Bernardino and Bureau of Land Management
Decision Record: DOI-BLM-CA-D090-2013-0020-DAN. (Feb. 2013). Bureau of Land Management
Decision Record: DOI-BLM-CA-D090-2013-0105-DNA. (Sept. 2013). Bureau of Land Management
Desert Renewable Energy Conservation Plan. (Sept. 2016). Bureau of Land Management
Interim Management Plan For Castle Mountain Venture, Castle Mountain Mine. (Dec. 2012). Castle Mountain Venture
NI 43-101 Technical Report on the Preliminary Feasibility Study for the Castle Mountain Project. (Aug. 2018). Equinox Gold Corp
Plan for Groundwater Monitoring and Contingency Water Supply. (Aug. 1990). The Mark Group
Castle Mountain Mine Plan and Reclamation Plan 6-1 January 2, 2019