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Home My WebLink AboutAppendix B (I-B) Engineering Design Report for WSB-1 Pre-feasibility Engineering Design Report for Water Storage Basin 1 Kings Mountain Mining Project Rev04 ABRIDGED Report: Only the WSBA Pre-feasibility Engineering Design Report is included. The WSBA Design Sheets are included in Appendix B of Appendix C (Design Sheets); The WSBA (stability) Calculation Package document is provided in Appendix C of Appendix G (Geotechnical Stability Reports and Calculations). The WSBA characterization report has been excluded but may be made available upon request. Effective Date: April 19, 2024 Report Date: April 19, 2024 Report Prepared for Albemarle Corporation AALBEMARLEn 4250 Congress Street, Charlotte, NC28209 Report Prepared by srk consulting SRK Consulting (U.S.), Inc. 999 17t" Street, Suite 400 Denver, CO 80202 SRK Project Number: USPR000576 Albemarle Document Number: KM60-EN-RP-9121 North Carolina Firm License Number: C-5030 Signed by Qualified Persons: R. Breese Burnley, P.E. (#055362) Reviewed by: Joshua B. Sames, P.E. SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page ii Executive Summary SRK has prepared this Preliminary Engineering Design report for Water Storage Basin 1 (WSB-1) at the Kings Mountain Mining Project. The site is located in a humid subtropical climate with variable precipitation and temperature.The ore deposit is a lithium-bearing pegmatite intrusion along the Kings Mountain shear zone, a regional structural feature. The site contains several legacy waste rock and tailings facilities, as well as a pit lake. Albemarle proposes to reconstruct the original Foote Minerals Chem tailings impoundment embankment to form WSB-1 to be used during proposed mining operations to manage site stormwater runoff, treated PAG contact water, NAG contact water and pit dewatering. A low-level outlet, suitable to maintain a minimum pond volume and retention time,will be constructed for sediment control.WSB- 1 will be used to limit discharge of contact waters during upset conditions and will serve as a collection node for all contact waters generated at the site that are to be generally suitable for discharge to Kings Creek. A detailed water balance was developed to aid in operational planning for water management across the site —the water balance is described in the SRK report titled Technical Report 2023 Prefeasibility Study, Surface Water: Water Balance Development Report, Kings Mountain Mining Project (SRK, 2024). The original pond was constructed to a crest elevation of 850 ft amsl with compacted fill. A concrete- lined trapezoidal spillway was constructed to exit the impoundment area at elevation 845 ft amsl,which was the original control on pool elevation during operations. A portion of the embankment at the original flowline was removed in the early 2000's down to 820 ft amsl and collected stormwater flows were allowed to flow through the original impoundment footprint. The elevation of the current exit at 820 ft amsl allows for storage of several feet of water and the area has been more recently referred to as WSB-1. To support the preparation of preliminary designs for reconstruction of the original embankment to form WSB-1, SRK completed a site investigation and laboratory testing campaign in two phases(2022 and 2023-24). SRK's report in Appendix A titled Waste Storage Basin 1 (WSB-1) Pre-feasibility Site Characterization Report (SRK, 2024) defines the current understanding of site and material characterization in support of the current design phase. To construct the proposed WSB-1 configuration, the following modifications are proposed to enable the future use of the impoundment as a water storage basin. The preliminary design drawing set in Appendix B shows grading plans and details illustrating the following proposed actions. 1. Clear and grub existing vegetation growth and roots from the existing embankment and proposed expanded design footprint. 2. Reinstate the original embankment by placing and compacting suitable general fill in the embankment breach, including the formation of a lower permeability internal core and compacted fill or rockfill outer zones. Sources of required construction materials will be identified in the next phase of design and will include considerations such as geochemical and geotechnical suitability for the intended use. RBB/JBS KM_WSB-1—Prelim EngDesign_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page iii 3. Install low-level outlet works to facilitate decanting the pool to a predetermined elevation such that normal pool operations allow for both sediment retention and storm storage (refer to Section 5.4). 4. Replace the existing concrete-lined spillway, providing for an outlet at the northwestern corner of the new WSB-1 impoundment at 843 ft amsl, and including energy dissipation measures as required at the downstream end to prevent undue erosion. 5. Construct a gravel blanket drain along the downstream face of the embankment and under the proposed downstream embankment buttress. The top of the blanket drain will extend to 845 ft amsl and be covered with compact general fill to widen the embankment crest and improve access conditions (final crest width to be determined). 6. Construct a compacted fill buttress as shown on the design drawings to improve the predicted stability of the embankment and anchor the new blanket drain section on the downstream embankment face. Slope stability analyses have been prepared to support the current conceptual design of the TSF and are described in detail in the technical memorandum in Appendix C titled Kings Mountain Water Storage Basin WSB-1 Preliminary Slope Stability Memorandum (SRK, 2024). The design concept at this stage of the Project includes a relatively robust embankment design based on the results of slope stability analysis and the current understanding of both the original embankment construction materials and the foundation characteristics.Additional analyses will be completed in later stages of design and will incorporate the results of currently on-going laboratory testing and future characterization work deemed necessary at the next phase of design. RBB/JBS KM_WSB-1—Prelim EngDesign_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page iv Table of Contents 1 Introduction.................................................................................................................. 1 1.1 Property Location................................................................................................................................1 1.2 Property History ..................................................................................................................................1 1.3 Project Overview.................................................................................................................................3 1.4 Project Approach.................................................................................................................................3 1.5 Owner's Information............................................................................................................................4 1.6 Engineer's Information ........................................................................................................................4 1.7 Dam Inventory Information..................................................................................................................4 2 Site Environment ......................................................................................................... 5 2.1 General Description ............................................................................................................................5 2.2 Climate................................................................................................................................................5 2.2.1 Temperature............................................................................................................................5 2.2.2 Evaporation .............................................................................................................................5 2.2.3 Precipitation.............................................................................................................................6 2.2.4 Storm Frequency.....................................................................................................................7 2.3 Wind Patterns......................................................................................................................................9 2.4 Geology...............................................................................................................................................9 2.5 Hydrogeology....................................................................................................................................11 2.6 Surface Water...................................................................................................................................15 3 Geotechnical Characterization ................................................................................. 18 3.1 Site Investigation...............................................................................................................................18 3.2 Laboratory Testing ............................................................................................................................18 4 Calculations and Engineering Design...................................................................... 19 4.1 Design Basis.....................................................................................................................................19 4.2 Proposed Project Layout...................................................................................................................19 4.3 WSB-1 Design...................................................................................................................................21 4.4 WSB-1 Operational Summary...........................................................................................................22 4.5 WSB-1 Slope Stability.......................................................................................................................23 4.6 Hydrology and Hydraulic Design.......................................................................................................23 4.7 Dam Breach Analyses.......................................................................................................................23 4.8 Technical Specifications and Construction Quality Assurance Plan ................................................24 4.9 WSB-1 Closure .................................................................................................................................24 5 Operation, Maintenance, and Surveillance Manual................................................. 25 6 Erosion and Sediment Control Plan......................................................................... 26 6.1 Temporary and Permanent Controls.................................................................................................26 RB B/J BS KM_WSB-1_Prelim Eng Design_Report_USPR000576_Rev03.docx Ap ri 1 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page v 6.2 Maintenance Requirements..............................................................................................................27 6.3 Responsible Parties..........................................................................................................................27 6.4 Vegetation Stabilization Plan ............................................................................................................27 7 References.................................................................................................................. 28 Disclaimer........................................................................................................................ 30 Copyright ......................................................................................................................... 30 List of Tables Table 2-1: Excerpted Tables showing Site-Specific Study and Annual Return Intervals Results......................8 Table 3-1: Laboratory Testing Summary Table................................................................................................18 Table 4-1: Key Contact Water Pond Input Parameters....................................................................................23 Table4-2: Engineering Drawing List ................................................................................................................23 List of Figures Figure1-1: Location Map....................................................................................................................................2 Figure 2-1: Average Monthly Evaporation..........................................................................................................6 Figure 2-2: Annual Precipitation .........................................................................................................................7 Figure 2-3: Wind Rose Data in the Vicinity of Kings Mountain...........................................................................9 Figure24: Project Geology Map......................................................................................................................10 Figure 2-5: Locations of Drilled Boreholes for Hydrogeological Study.............................................................12 Figure 2-6: Locations of Monitoring Wells/Points.............................................................................................13 Figure 2-7: Locations of Completed Hydraulic Tests .......................................................................................14 Figure 2-8 Conceptual Hydrogeologic Model of Kings Mountain Pit Area .......................................................15 Figure 2-9: Groundwater Levels Contours .......................................................................................................15 Figure 2-10: Existing Streamflow Network and Monitoring Points ...................................................................16 Figure 4-1: Preliminary Kings Mountain Mining Project Site Map....................................................................20 Appendices Appendix A: Water Storage Basin 1 (WSB-1), Pre-feasibility Site Characterization Report, Kings Mountain Mining Project (SRK, 2024) Appendix B: Preliminary Design Drawing Set Appendix C: Slope Stability Calculations for Preliminary Design of Water Storage Basin 1 RB B/J BS KM_WSB-1_Prelim Eng Design_Report_USPR000576_Rev03.docx Ap ri 1 2024 SRK Consulting(U.S.),Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page vi List of Abbreviations The US Customary System for weights & units has been used throughout report for site specific data (unless otherwise stated). Rock mass classification schemes and geotechnical analysis figures may be referenced in their original metric units. Abbreviation Unit or Term Albemarle Albemarle Corporation ADS advanced drainage systems amsl above mean sea level ARDML acid rock drainage and metal leaching AWA Applied Weather Associates b s below ground surface BMP best management practice CMP corrugated metal pipe CPEP corrugated polyethylene pipe CWMP contact water management pond CY cubic yard o degree of de rees Fahrenheit DEQ Department of Environmental Quality DMS dense media separation FOR engineer-of-record ft foot m gallons per minute HDPE high-density of eth lene 1-85 Interstate 85 OF inflow design flood IFC issued for construction KMMP kings mountain mining project KMSZ kings mountain shear zone MAC Mining Association of Canada NC DEHNR North Carolina Department of Environment, Health and Natural Resources NCSCC North Carolina Sedimentation Control Commission NOAA National Oceanic and Atmospheric Administration OMS operation, maintenance,and surveillance < less than % percent PAG potentially acid generating PCPE perforated corrugated polyethylene PMP probable maximum precipitation SRK SRK Consulting (U.S.), Inc. Terracon Terracon Consultants Inc. TSF tailings storage facility USDA FS U.S. Department of Agriculture Forest Service wsb water storage basin RBB/JBS KM_WSB-1_Pre11mEngDesign_Report_USPR000576_Rev03.docx Ap ri 12024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 1 1 Introduction Kings Mountain Lithium Mine (the Project) is an existing open pit lithium mining operation located in the city of Kings Mountain, North Carolina, in the southeastern United States. The Project is a lithium pegmatite deposit that is currently being investigated for redevelopment by Albemarle Corporation (Albemarle)as part of a prefeasibility-level analysis. Albemarle commissioned SRK Consulting (U.S.), Inc. (SRK) to develop a prefeasibility-level design for Water Storage Basin 1 (WSB-1) to manage contact water and stormwater flows for the proposed reactivation of the Project. WSB-1 is located south of Highway 85 in the site where the legacy Foote Mineral Company Chem tailings facility was located—currently referred to as WSB-1. The current level of characterization, design and analysis is of sufficient detail to both support a prefeasibility-level economic analysis and provide a basis for mine permitting. Future detailed design phases will be completed to support dam safety permitting and construction. 1.1 Property Location Situated in Cleveland County, the mine is approximately 35 miles west of Charlotte, North Carolina. Located amidst rolling hills of the Piedmont Plateau, the Project is in a predominantly rural setting within the city of Kings Mountain. The mine site covers a significant land area, which includes both the proposed extraction areas and associated processing infrastructure. Figure 1-1 shows the location and extent of the mine. 1.2 Property History The following summary highlights the history of the site, compiled from records available to SRK: • Mining started in 1883 with the discovery of cassiterite, a tin-bearing mineral, within the outcropping pegmatites. • Subsequently, open pit mining for tin occurred sporadically between 1903 and 1937 (Horton and Butler, 1988). • Between 1943 and 1945, under the sponsorship of the U.S. government, Solvay established a processing plant and mined for spodumene from the outcropping pegmatites(Garrett,2004). • In the early 1950s, Foote, a subsidiary of Newmont Mining Corporation, purchased the property and began open pit mining (assumed at the beginning of 1955)and extracting lithium from the spodumene. • In 1993, exploration and mining operations ceased when the open pit bottom reached approximately 660 feet(ft) above mean sea level (amsl). • In early 1994, an open pit lake started to form due to rebounding groundwater, and the pit lake reached an elevation of 817 ft amsl (as of January 2023). • During the groundwater recovery period (1994 to present), water was sporadically pumped from Kings Mountain pit lake to a nearby quarry(Martin Marietta)to support quarry operation. • Albemarle acquired the site in 2015, resuming exploration and mine development activities. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 2 _. ire �dlSlill L? 4ti � 1 � A� BlUe Ridge �7A1 o- Parkway Anerrw,� o� + oak Grave 4*r4'+wy t Mountain Yfeh G Kings MlauntaiA I I CraLrders M l{jP,.yp I Mounlain 61e:� Kings I Perk Mountain A eraale Project 5fdoeallle + it prr r heville South Maun[al ns 5tate Park Mao-resville �nbe zf North Cde6lina _ Gastonia fS pCharlotbe -- 4 4' UT --——— `T Ctr 7 l�r tl Spartanburg 5 Gi'f+Plivi�IN r. ��¢� T73f[ South Carolina 4 5 14 15 2G 7E Source:Google Earth,2023(modified by SRK) Figure 1-1: Location Map RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 3 1.3 Project Overview The Project ore deposit is a Lithium-bearing rare-metal pegmatite intrusion that has penetrated along the Kings Mountain shear zone, a regional structural feature known to host multiple lithium bearing pegmatites along its trend. The pegmatite field at Kings Mountain is approximately 1,500 ft wide at its widest point in the historic pit area and narrows to approximately 400 to 500 ft in width at its narrowest point south of the historic pit. The field has a lithium mineralization strike length of approximately 7,500 ft and is predominantly contained in the mineral spodumene.The spodumene pegmatite bodies exhibit a texture-based variation in lithium grade, spodumene grain size, mineral alteration, and rock hardness. After dewatering the historic pit, the lithium deposit is to be mined using conventional open pit mining techniques. Blasting will fragment the ore and waste rock where it will be loaded and hauled to either the processing facilities (ore) or the waste storage facilities (overburden). The current plan includes mining in the existing pit and expanding the pit to the southwest. Ore would be drilled, blasted, loaded, and transported by haul truck to a new processing plant at a rate of—2.98 million tons per annum of ore (-8,150 tons per day) and processed to produce 385 to 440 thousand tons per annum of spodumene concentrate.The concentrate will be filtered to approximately 11% moisture by weight and transported off site for further refinement into lithium hydroxide monohydrate at a separate facility. Tailings from the spodumene concentrate process will be filtered to approximately 10 to 15% moisture content by weight and transported off-site to a nearby facility for disposal. A portion of the waste rock with economic value as aggregate will also be transported off-site for sale. 1.4 Project Approach The approach to WSB-1 preliminary design has included the following steps to date: 1. Research and compilation of available information regarding existing site conditions and facilities, including the original Foote Mineral "Chem" tailings facility. 2. Site characterization via geophysical methods and diamond core, air rotary, and sonic drilling methods, including sample testing and laboratory characterization. 3. Preliminary design and material balance calculations, including slope stability analyses. 4. Stormwater management system design. To support the preparation of preliminary designs for WSB-1 and other site facilities, SRK completed a site investigation and laboratory testing campaign in two phases (2022 and 2023-24). SRK's report titled Waste Storage Basin 1 (WSB-1) Pre-feasibility Site Characterization Report(SRK, 2024), a copy of which is included in Appendix A for reference, describes the implementation and results of the geotechnical site investigation completed to date, including drilling, in situ and laboratory testing, and collection of disturbed bulk samples, relatively undisturbed modified California split-spoon samples, and laboratory testing results for selected samples. The laboratory testing program of the current characterization phase was still underway at the time of report preparation. The application for a dam safety permit must include detailed drawings and calculations suitable to support Issued for Construction (IFC)drawings and supporting technical components of a construction bid package. It is anticipated that most of the detailed design work will be carried out in 2024, with RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 4 initial construction activities beginning in 2026 pending the successful completion of a number of separate permitting processes. 1.5 Owner's Information Albemarle owns the Kings Mountain Mining Project. Contact information for the Owner is provided below. • Ryan McClusky, Director Mine Planning Albemarle Corporation 348 Holiday Inn Drive Kings Mountain, NC 28086 Email: ryanmcclusky@albemarle.com Phone: (503) 734-6553 1.6 Engineer's Information The certifying design engineer for the preliminary design presented in this report is SRK Consulting (U.S.), Inc., represented by R. Breese Burnley, North Carolina registered Professional Engineer #055362. SRK is doing business in North Carolina as SRK Consulting (North Carolina), P.C. under North Carolina Firm License Number C-5030. Contact information for the design engineer's representative is provided below. • R. Breese Burnley, P.E. SRK Consulting (North Carolina), P.C. c/o Legalinc Corporate RA Services 8480 Honeycutt Road, Suite 200-V295 Raleigh, NC 27615 Email: rburnley(jr�srk.com Phone: (775) 828-6800 1.7 Dam Inventory Information The proposed WSB-1 design will be a modification of existing dam CLEVE-006 subject to the requirements of the North Carolina Administrative Code under Subchapter 2K— Dam Safety. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 5 2 Site Environment 2.1 General Description The Project is located in southwestern North Carolina, USA, near the city of Kings Mountain on the Interstate 85 (1-85) transit corridor, approximately 33 miles west of the city of Charlotte (Figure 1-1). The property is located at approximately 35 degrees (°), 13 minutes north latitude and 81°, 21 minutes west longitude. The site contains several historic waste rock areas, river diversion, and tailings facility. None of these show any signs of active acid rock drainage or metal precipitation except for some iron precipitates, which are probably related to corroded steel associated with drainage pipes discharging to the diversion creek around the pit. Most facilities are heavily vegetated, and none of the vegetation shows signs of metal or acid stress. 2.2 Climate The Project is situated within the Koppen-Geiger Cfa climate classification (Kottek, 2006), which describes a continental type of climate without a dry season.Temperatures during the warmest months are above 72 degrees Fahrenheit(°F), and temperatures in the coldest months are between 27°F and 65°F. Average monthly precipitation varies between 3 and 5 inches. Average annual precipitation is 42 inches, with an even distribution of rainfall throughout the year and an average annual snowfall of 4 inches. Southwestern North Carolina is prone to thunderstorms during the summer and ice storms during the winter. 2.2.1 Temperature The climate of the Project vicinity is humid subtropical with hot summers and mild winters.The monthly temperature ranges from a minimum of around YF in January to a maximum of around 104°F in August,with an average temperature of around 60°F. Legacy data show that temperatures in the area have been increasing, with an average rise of 0.3°F per decade since 1970, or roughly 1.7°F from 1895 to 2020. Climate change is expected to further contribute to this warming trend, potentially impacting surface water conditions, such as increased evaporation rates and altered streamflow patterns. Predictive climate models suggest further warming in the future, potentially resulting in more frequent and severe heatwaves and droughts. 2.2.2 Evaporation Evaporation rates at the Project vary based on temperature, humidity levels, wind speed, and solar radiation. Legacy data show that evaporation rates are highest in summer, averaging around 6 to 7 inches per month, and lowest in winter, with around 2 to 3 inches per month (Figure 2-1). Overall, average annual evaporation ranges from 55 to 65 inches. Evaporation impacts surface water availability by contributing to water loss from lakes, rivers, and streams. Factors such as vegetation cover, land use practices, and soil moisture levels influence evaporation variability. Climate models predict that evaporation rates will continue to increase in the future due to warming temperatures and changes in precipitation patterns. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 6 s 7 6 0 5 Y o 0.4 7 W s 3 1= o 1 0 January February March April May June July August September October November December Clemson Univ Chesnee 7 WSW Chapel Hill 2 W — — —Average GOIdSim Figure 2-1: Average Monthly Evaporation 2.2.3 Precipitation Precipitation totals at the Project vary throughout the year. Based on the last 30 years, the area typically receives between 41 to 55 inches of rainfall annually (Figure 2-2), with precipitation being distributed relatively evenly throughout the year without a clear wet or dry season. The region is susceptible to extreme precipitation events, such as tropical storms and hurricanes, which can bring heavy rainfall and cause flooding. RBB/J BS KM_WSB-1_Prel1mEngDesign_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 7 Distribution of Precipitation 80 _ 70 v to — L y � 8 - 0 0 50 a 5 e 40 y 30 T 4 CCC 20 a z C 10 a p January February M—h April May June July August September October November December Annual Total 2.59G5% 5%-10% ■10%-25% ■25%-50% ■Median ■50%-75% ■75%-90% ■90%-95% 95%-97.5% Annual Precipitation ao ro r 60 c 50 t 40 a`30 20 0 1925 1930 1931 1940 1945 1950 1955 1950 1%5 1970 1925 19 0 19 5 1990 1995 2000 2005 2010 2015 2020 Figure 2-2: Annual Precipitation 2.2.4 Storm Frequency Storms encountered at the Project vary in frequency and intensity throughout the year. For example, a 100-year, 24-hour storm event produces, on average, 7.96 inches of precipitation (National Oceanic and Atmospheric Administration (NOAA), 2023). The region experiences thunderstorms, tropical storms, and hurricanes, which can bring heavy rainfall and high winds. Thunderstorms, which are the most common type of storm in the area, see peak activity in July and August. Factors such as temperature, humidity, wind patterns, and topography influence storm occurrence. These storms can impact surface water availability and quality by causing flooding, erosion, and sedimentation. Climate change could increase the frequency and intensity of storms in the future, posing higher risks of flooding and erosion. Applied Weather Associates (AWA) completed the Site-Specific Probable Maximum Precipitation Study for Kings Mountain Mining Operations, North Carolina(AWA,2022)for the Kings Mountain basin in North Carolina. AWA utilized a storm-based approach to derive the site-specific probable maximum precipitation (PMP) depths to update the PMP depths originally developed in hydrometeorological reports developed by the National Weather Service. Table 2-1 shows Tables 10.4 and 10.5 excerpted from AWA (2022), which show the results of the site-specific study with annual return intervals to 1:10,000 years and beyond. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 -Kings Mountain Mining Project Page 8 Table 2-1: Excerpted Tables showing Site-Specific Study and Annual Return Intervals Results Table 10.4: King% Mountain hasin AEP for 6-,24-,And 72-hour PMP Kings Mounuin AEP Estimate PMP(in) AEP ARI 6hr 28.5 2.5 F9 39,829,769 24hr 32.4 1.09'7 9,144,104 72hr 32.4 3.93'7 2,540,551 Table 10.5: Kings Mauntain hstsin a.erall frequent~• analysis for 6,24-,and 72-hour pr Kings Mnt Frequency Analysis 6-hour 24-hour 72-hour ARI AEP AEP 50% 5% 95% 50% 5% 95% 50% 5% 95% 1.01 0.99010 9.91 1.0 0.9 1.1 2.0 1.8 2.2 2.4 2.2 2.6 2 0.5000D 5.01 2.3 2.1 2.5 3.6 3.4 3.9 43 4.0 4.6 5 0.2000D 2.01 3,2 2.9 3.4 4.8 4.4 5.1 5.7 5.2 6.1 10 0.10000 1.01 3.8 3.5 4.1 5.5 5.1 6.0 6.6 6.1 7.1 25 0.04000 4.0 4.7 4.3 5.0 6.6 6.1 7.2 7.9 7.3 8_5 50 0.02000 2.C) 53 4.9 5.8 7.5 6.9 8.2 8.9 8.2 9.7 100 0.01000 1.01 6.0 5.5 6.7 8.4 7.7 9.2 9.9 9.1 10.9 200 0.00500 5.01 6.3 6.2 7.6 93 8.3 10.4 11.0 10.1 123 500 0.00200 2.01 7.9 7.1 8.9 10.6 9.6 12.1 12.6 11.4 143 1,000 0.00100 1.0' 8,7 7.$ 10.1 11.7 10.4 13,5 1-1.9 12.4 16,0 5,000 0.0002D 2.0 d 10.9 9.5 13.1 14.4 12.5 17.2 17.1 14.9 20.4 10,000 0.00010 1.0° 11.9 10.3 14.5 15.7 13.5 19.1 18.6 16.0 22.6 100,000 0.00001 1.c) 15.9 13.1 20.5 20.4 16.9 26.5 24.2 20.0 313 1,000,000 0.000401 1.c) 20.5 16,3 28.3 26.2 20.7 36.1 31.0 24.5 42.7 10,000,000 0.0000401 1.0' 26.2 19.9 38,7 33.1 25.0 48.6 39.1 29.7 57.8 100r000,000 0.00000001 1.01 33.1 24.0 52.5 41.3 29.9 65.5 48.9 35.4 77.6 1,000,000,000 0.000000001 1.01 41.4 28.6 70.7 51.2 35,3 97.4 60.6 41.9 103.5 10,000,000,000 0.0000000001 1.010 51.4 33.9 94.7 63.1 41.5 1161 74.7 49.2 137,5 Source:AWA,2022 AWA (2022) also included a site-specific climate change assessment to "understand and quantify whether the climate change projections related to temperature, moisture, and precipitation are expected to change significantly in the future (through 2100), and whether those changes would warrant a change to the currently derived PMP depths." The results of the study indicate "an increase in precipitation and temperature in the future" with "the most likely outcome regarding precipitation over the basin going forward is that the mean annual and seasonal amount will increase, but the individual extreme events will stay within the range of uncertainty currently calculated" (AWA, 2022). The site-specific water balance prepared to inform water management requirements across the site considers the results of the site-specific climate study and is described in detail in SRK's Technical Report 2022 Prefeasibility Study, Surface Water: Water Balance Development(SRK, 2023a). RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 9 2.3 Wind Patterns Wind rose data were obtained from the North Carolina Department of Environmental Quality (DEQ) Air Quality Portal available online at https://airgualitV.climate.ncsu.edu/wind/. Figure 2-3 presents wind rose data for the Shelby Municipal Airport, located about 13 miles west of Kings Mountain, and for the Gastonia Municipal Airport, located about 13 miles east of Kings Mountain. The data for both sites indicates the predominant wind direction is out of the north and northeast, with a good portion of the winds out of the south and southwest. Wind rose for KAKH in Gastonia,NC Wind rose for KEHO in Shelby,NC For Feb 1,1999 m May 24, For Jan 3,200A m May 24,2@3 93%of date available) N N vr,n IJpe - .. 75% \ NE .4 5.1. \ 1 \ ENE WNW -I- 4� W — E W E 44_ I9 z l Wipdel¢mpni: ;- , w, s Ca1m W nda cQ mpH: s 251 of observations Wind Speed: fit mph7 t.T mpM1 �15 mpn �J uu Wind Speed_ •sto7mpn 1omismp n •>.mpn �,m,�aaa. „ z mpn mpn 1s mpn ,u 05m7 mph 10 to 15mph >_20 mph Source: DEQ Air Quality Portal, https://airquality.climate.ncsu.edu/wind/ Figure 2-3: Wind Rose Data in the Vicinity of Kings Mountain 2.4 Geology The following summary of the geology of the project area is based on information contained in the SEC Technical Report Summary Assessment (SRK, 2021). The Kings Mountain mining district is located in the central part of the Piedmont Plateau. The plateau ranges in elevation from 750 to 1,050 ft amsl. The rocks of the Piedmont Plateau are both igneous and sedimentary in origin, with various grades of weathering. The metasedimentary rocks include assemblages of gneissic and schistose rocks. Figure 2-4 shows regional geology. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 10 ...- .e �ar� M .i•• IF' UST OF MAP UNITS ' i.. Jf /._" . ((�a w k: �� I.VMTA PILI]MOn I'LiYf]iFD Yi.'IAMONPFIIC R9Q(5 -� "/' /r"•i � 0 6'`d'� CL AmPhlbdro lCamMlan or NcoPmrvmmlc) "onMauoNre uhlu Cmnbrfen or Aruuminomk) `.T{�/ b-1.strew(c—b— N.owwe. 14 1, MINDS MIXINfNN SI.QIIF:Y(.F. - (N F N I+ e 1 r / Ia.J�.b. aJan uuPm1e 1 Ili$%• I •T.,. A� (7tloriAe Ph:ll APPROXIMATE > r" r {: � �I.� FOOTPRINT OF t, rmmn "" F' ✓'o ! '- mn Mvh4 manber at Upon Brmrch hnlwm.l rumel PROP OSFA- B-1 ® Geffiy Mah4 Mambr -'... � ]G�♦� ��i. Innury imkaaoa gxr!ffie Source:SRK,2021 Figure 2-4: Project Geology Map The Kings Mountain deposit lies within North Carolina's tin-spodumene belt and is located within a larger-scale shear zone (the Kings Mountain Shear Zone (KMSZ)). The shear zone is a northeast- striking, steeply to moderately dipping zone of ductile and semi-brittle deformation. The zone is at least 37 miles long and is no more than a few hundred feet wide. The shear zone is a boundary between two terrains within the Piedmont Plateau, including the Kings Mountain and Inner Piedmont Belts. The belts are described as: • Kings Mountain Belt: Located east of the KMSZ and composed primarily of meta-sedimentary rocks (quartzite, conglomerate, and marble) associated with mica schists (meta-sedimentary and meta-volcanic in origin), as well as the High Shoals Granite • Inner Piedmont Belt: Located west of the KMSZ and composed primarily of mica gneiss and mica schist(commonly with low undulatory dips).At a local scale,this includes the Cat Square terrane, which is represented by muscovite schist and amphibolite, which have been intruded by the weakly foliated Cherryville Granite and its associated pegmatite stocks, including spodumene pegmatites. Surface exposures within the Project area are limited to exposed areas around historical mine workings.The remainder of the property is either blanketed under a deeply weathered saprolite profile, rarely preserving any remnants of the protolith, or overlain by waste rock or stockpiles from the earlier operations. Units of the Cat Square terrane (Inner Piedmont) dominate the property and host the spodumene pegmatite ore deposits. The eastern limit of the former open pit mine coincides with the KMSZ, and as a result, units belonging to the Blacksburg Formation were largely observed from drill core. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 11 2.5 Hydrogeology The Prefeasibility Study, Hydrogeologic Characterization, Kings Mountain Project(SRK, 2023f) report describes the groundwater conditions for the site. SRK collected opportunistic hydrogeologic data during an existing exploration drilling program in 2018. Although the exploration targets were not selected based on hydrogeologic characterization, insight gained from testing and monitoring equipment installations, significantly advanced the understanding of the groundwater system for the project. This program included packer isolated interval testing, vibrating wire piezometer(VWP) installations, and construction of water level monitoring equipment in diamond core holes (stub wells, open core holes, existing wells, VWP's). Data loggers were installed to measure water levels in select stub wells, all VWP's, existing wells, and pit lake. Two barometric pressure transducers were installed in the southern end of the pit and at the north wall. In late 2021 SRK began developing a prefeasibility hydrogeologic characterization program to evaluate the shallow and deep groundwater systems that started in the second half of 2022. In addition, the geotechnical (tailings and waste rock) characterization program was included in this scope of work to expand the data collection opportunities across the site. The field program consisted of monitoring well installation screened across the overburden (native, tailings, and waste rock), saprolite, weathered bedrock, and terminating in competent unweathered bedrock to evaluate the shallow groundwater system. Monitoring wells were installed to evaluate the deep groundwater system by drilling across the overburden sequence and into competent bedrock before installing a grouted conductor casing. Using a smaller diameter bit,the lower section was drilled to depths greater than 500 feet below ground surface (ft bgs)and left as open hole.Additional larger diameter pumping wells were installed to stress the shallow groundwater system. Pumping tests were performed ranging from minutes, hours, and up to 7 days. Spinner logging was performed in all accessible wells to evaluate the distribution of transmissivity across the screen (water producing zone in open holes) intervals. Between 2018 and 2023, a total of 104 boreholes were used for hydrogeological data collection, with combined total drilled length of 46,280 ft. Drilled borehole locations are shown in Figure 2-5. Types of drilling included: • 35 diamond core holes • 10 rotary boreholes • 45 sonic boreholes RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 12 S; i +' EaE++D cnenaeraalon onlons 0 De,nonn Dnm�,za,e • ROM,y Dnano,zo2a ��-� DRAfT D,,I,iV Melnoe D- ♦ Dv—D"IbM2023 o SO-0,111inG.2022 p„M,�a�, , tsrk,:In s.r'•nci AALBEMARLE • cvr?Du o Romry onloae,lsra "� ---^w ♦ Dla,mnn Dning.201i O Rolsry DnlhnB?022 mamawa °'.MMAif ,fINGSMWNTNN MfNMIG PROTECT ��'� -wIRfNwan Figure 2-5: Locations of Drilled Boreholes for Hydrogeological Study A groundwater monitoring system was installed at the site starting in 2018, continuing through 2023 to evaluate changes over time for groundwater, pit lake, surface water, and atmospheric pressure. SRK collected water level data from a variety of locations, including: • 34 boreholes where water levels were collected during drilling and before grouting. • 19 open diamond core holes equipped with surface casing and left open to the final depth drilled. • 15 stub wells installed in selected diamond open holes for long-term water level monitoring (a stub well is constructed by lowering 2-inch diameter well casing, equipped with a cement basket attached at the bottom into competent bedrock ranging in depth from 30 to 100 ft below ground surface [bgs], with open hole depths up to 2000 ft bgs • 4 pumping wells, 2 deep monitoring wells (greater than 400 ft deep), 22 monitoring wells, and 1 temporary well. • 5 grouted-in-place Vibrating Wire Piezometers (VWPs). • 8 historical wells found within the project boundaries (built circa 1974). All accessible stub wells and two of the historical wells were equipped with data-logging pressure transducers. All downhole instrument data (apart from grouted-in VWPs) were verified with manual measurements using a water level measuring tape. Figure 2-6 shows the locations of all monitoring points. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 13 w..,.w y-w.a•e.w �ar.wi.,mn O aw w...x,e o meao oao,aoauoo ... ... � Ha.ryc..wn nue •oo..�w.,w,e O em vw..>oz, Srk Iq DMAFr o�.�.� • AALBEMARLE �wm r�,v,e mrKem -,.un>,ve KinGS YpuNrw wninG MlaEtT Figure 2-6: Locations of Monitoring Wells/Points A total of 124 hydraulic tests were completed across the site using diamond core holes, open boreholes, existing wells, pumping wells, and monitoring wells. Figure 2-7 shows the hydraulic test locations. The distribution of hydraulic testing performed includes: • Packer isolated interval - 26 • Slug - 51 • Short-term pumping - 15 • Long-term pumping - 7 • Spinner logging in of all accessible wells—25 RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 14 r - Y - srk "RA FT AALBEMARLE •� KRGS NONf7M1 MhRa('PROJECT Figure 2-7: Locations of Completed Hydraulic Tests A conceptual hydrogeological model (CHM)corresponds to a simplified,schematic model which allows for a clearer understanding of the hydrogeological system at a particular site. The main components of the CHM that affect flow and water levels are grouped and synthesized to represent all elements of the hydrogeological regime. The CHM forms the basis for numerical models, as the latter are mathematical representations of the former. A schematic representation of CHM components at Kings Mountain are represented in Figure 2-8. In general terms, the conceptual hydrogeological model subdivides the groundwater system into two main components, namely, surficial regolith and deeper bedrock. The upper regolith, composed of overburden, saprolite and weathered bedrock, is considered to be the high hydraulic conductivity component in the system (0.1 to 0.5 ft/day). Most of the drawdown from mining is understood to occur in the surficial regolith, both historically and during future mining. The historical recovery of the pit lake is believed to be mainly through recharge and flow in the surficial regolith. In contrast, hydraulic testing in the bedrock suggests low to medium hydraulic conductivity(1 x10-4-0.3 ft/day),with hydraulic conductivity decreasing with depth. Flow in the bedrock is expected to be mostly controlled by fractures, which are mostly present at shallower depths close to the weathered zone. Therefore, mining operations are likely to affect water levels in the deep bedrock component to a lesser extent than in the overlying regolith. In addition to these components, hydraulic testing identified two major water-bearing lineaments in the bedrock, at geological contacts east and west of the Kings Mountain pit. These lineaments have been labeled the Southeast and Northwest Shear Contact Zones, respectively, and have shown hydraulic conductivities similar to, or higher than, those observed in the regolith. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Repor[_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 15 nPh,I,t,�Metes I„o.. e a 51 P h ,30y g tt' d 1 PRI -- — --=1 11f K %M t OP Pt_k -h t - n8 13 t ] t I .e. p 1 oA t -d 2 s -The bottom g _ a t ._s. I ... Ills 7CA I t ttl f m Ma:�te_e_e -1-"-:]_=p"_ i,Ma'etta anarry K,= t_ .ei rtarre -T_-he,�.ate� Hegdith:c-i st e"p"I a -=Ia- eeble E33It rr t a, —t CL--' It I ."I t t P11 + - s t e_- -t e 3 the I sxcvxo t 7 ISJ Water tah1 t k-S=s - hp fthe current �) Bedrock)yd auhc totdtttvly.l "IlI sia Al I f3 I-i n ing}.ater level-n nearby ove T-, t t g stl. -.,t 4;t t 3 14f Water Ta ble 1203s I,P:- _-P-=-.,illI a=ei tac==a 285 ft-I F: _ .i_a-d_-st Kcecre seswth oep.ho e.o the absence of f'i::,I I'_. at:he ce-te: J... .. :,ll,ee:e e:.:.tt ra.b 7--'dd:a.:'I' I Haman ana �•- -tl __,1 -lurs un'.as theme=-eces as readily, sl Shear Cot ti ;South t dNorthwest):Asl'gh th n C—t I parcel,1— I __-, I n=ake level_ -=1'rt ---d I -eld�taracter=at on_shear Contaetmne K ——————————————- -- --":he ;1st:::a, Figure 2-8 Conceptual Hydrogeologic Model of Kings Mountain Pit Area SaacM2z-a3a 1. 916. 7 SN1M22-424 a - 8m.97 KM -41 5 M2• SN 22-4 t3 Q. o 525 ,33 M •382 M22- 67 23 N 2 41 SIN 2-385 23 29 Q786.5 •375 SHKM22-437 a679.456 sNK 22• WSB-1 SNK1422J35 p 3. $21.325 SIN 22-396 ,9 .791 I rr/ N 22 0 SNK 2i33 Rr' .df SNKM22 41:, _fiF 832.3 627.618 ❑ Figure 2-9: Groundwater Levels Contours 2.6 Surface Water Surface water hydrology and stormwater control system design at the site are described in detail in SRK's Surface Water Management Report, Kings Mountain Mining Project, North Carolina (SRK, 2023d), and the following sections are incorporated from that report. R BB/J BS KM_WSB-1_Prelim Eng Design_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 16 The natural drainage network in the vicinity of the Project is heavily influenced by historical and active mining activities. The contributing watersheds to the Project area are roughly defined by Battleground Avenue to the north, Tin Mine Road to the west, Church Road to the south and east, and Cardio Hill, a legacy rock storage facility, to the northeast. The drainage network consists of two main drainages and several constructed water bodies, as shown on Figure 2-10. AI k' Y eir 2s Source:SRK,2023d Figure 2-10: Existing Streamflow Network and Monitoring Points Kings Creek passes through the Project area from northeast to southwest. Upgradient of the Project, Kings Creek is intercepted by the Martin Marietta Quarry Pit. Water intercepted by the Martin Marietta Quarry Pit is pumped out on a regular basis and discharged into Kings Creek. The pumping system was recently upgraded to a capacity of 2,500 gallons per minute (gpm). As Kings Creek enters the Project area, it is routed under the current Albemarle Research Building in a 620-ft long, 4-ft-diameter corrugated metal pipe (CMP) culvert. After exiting the culvert, Kings Creek flows to the southwest and joins with flows from the South Creek Reservoir before crossing under I- 85 in three, 7-ft-wide by 10-ft-high concrete box culverts. Flowing south, Kings Creek joins with flows from WSB-1 before flowing off the Project area to the southwest. South Creek begins northwest of the Project area in an area of residential neighborhoods. The creek flows generally southwards as it passes the existing Foote Mineral Tailings Impoundment before RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 17 entering the South Creek Reservoir, formed as part of the legacy mining activities in the area. Runoff from the historical tailings impoundment does not discharge directly to South Creek, but meteoric water infiltrating into and through the tailings likely reports to South Creek and South Creek Reservoir. The recently upgraded spillway from the South Creek Reservoir consists of two 32-inch-diameter high- density polyethylene (HDPE) culverts through the embankment. The culverts flow into a rock down- chute that joins Kings Creek. Kings Creek Pit Lake is formed in the historical Kings Mountain Pit and does not currently contribute surface water flows to the stream network. The current pit lake elevation is approximately 817 ft amsl and would need to rise approximately 40 ft before overflowing from the pit into Kings Creek. There are several small, manmade ponds in the Project area which generally contribute to the Kings Creek drainage system. The most notable of these ponds is Pond #1, a historical water management structure used by the existing industrial activities to manage stormwater runoff from the Project area. Pond #1 collects water from the site and infrequently discharges through a culvert under the railroad spur into Kings Creek. WSB-1 is formed by the historical Foote Minerals Chem tailings impoundment south of 1-85. Post- mining, the embankment was breached down to an elevation of approximately 820 ft amsl, and flows exiting WSB-1 flow freely over a rock spillway, joining with Kings Creek approximately 1,500 ft downstream of the lake.The area below the confluence of Kings Creek and WSB-1 outflow is currently blocked by a beaver dam, forming a large marshy area in the drainage and resulting in localized flooding. Streamflow at the Project site is continuously monitored at the two locations. Monitoring point KMSW- 3 is a legacy concrete and steel plate weir designated as Weir#3 located on Kings Creek below the confluence with South Creek and upstream of the culvert crossing under 1-85. Monitoring point KMSW- 8 is located at the outlet of South Creek Reservoir,just upstream of the confluence with Kings Creek. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 18 3 Geotechnical Characterization 3.1 Site Investigation A sonic drilling program was designed by SRK and completed by Terracon Consultants Inc. (Terracon),from August to December 2022 using truck and track mounted sonic drill rigs. 53 boreholes were drilled to depths ranging from 55 to 501 ft bgs. Figure 2-4 above shows borehole locations and illustrates the primary focus of the 2022 field program around the existing Foote Mineral TSF north of 1-85 and the Chem tailings impoundment (WSB-1)south of 1-85. A second characterization program was implemented in 2023 and 2024 and included another round of drilling and laboratory testing that included nine boreholes within the WSB-1 facility area. Final borehole depths range from 90 to 162.5 ft bgs. The boreholes were drilled using two sonic drill rigs, one truck-mounted and the other track-mounted. Continuous sampling was performed during drilling by either collecting the bagged sonic samples in between penetration resistance tests, and by collecting hammer-driven split-spoon modified California (ModCal) and SPT samples every 5 to 10 ft during drilling. The results of the site investigation are described in detail in SRK(2024) in Appendix A. 3.2 Laboratory Testing Laboratory testing was completed on selected bulk and split-spoon samples of site foundation soils from both phases of site characterization in Terracon's Charlotte, North Carolina, geotechnical testing laboratory and other specialty testing laboratories as necessary. Table 3-1 summarizes the type and number of laboratory tests for material characterization.The results of the laboratory testing completed to date are presented in SRK(2024) in Appendix A Table 3-1: Laboratory Testing Summary Table Test Procedure 2022 Quantity 2023-24 Quantity Moisture content ASTM D2216 111 39 Atterberg limits ASTM D4318 102 38 Wash 200 ASTM C117 101 41 Sieve analysis ASTM D6913 101 41 Hydrometer ASTM D7928 16 41 Unit weight ASTM D7263 16 3 Standard proctor ASTM D698/D1557 4 0 Flexible wall permeability ASTM D 5084-90 METHOD C 1 0 CU triaxial test ASTM D4767 9 0 Consolidation ASTM 2435 3 0 Unconfined compression (rock) ASTM D 7012 3 2 RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 19 4 Calculations and Engineering Design 4.1 Design Basis The design for WSB-1 is based on the following criteria and industry standards and the operational requirements described in subsequent sections: • North Carolina Administrative Code Subchapter 2K— Dam Safety • Global Industry Standard on Tailings Management(GISTM, 2020) • Canadian Dam Association's Dam Safety Guidelines (CDA, 2013) and Technical Bulletin: Application of Dam Safety Guidelines to Mining Dams (CDA, 2019) • IRMA Standard for Responsible Mining IRMA-STD-001 (IRMA, 2018; Section 4.1.3.) For the purposes of pre-feasibility level design, WSB-1 is considered to be a "Class C" dam in accordance with Title 15A of the North Carolina Administrative Code, Section 02K.0105 based on the potential downstream consequences. Refer to Section 4.7 below for a discussion of dam breach analyses and a formal determination of dam classification. The design criteria should be reviewed and updated as additional site and material characterization data become available during later phases of the project. 4.2 Proposed Project Layout Figure 4-1 presents the Project layout, showing the relative locations of the major components of the Project. The Project is bisected northeast to southwest by I-85. The headwaters of Kings Creek are located immediately northeast of the site, and the creek leaves the Project area at the southern side. The Phase 1 open pit outline is shown in the northeast area of the Project, along with the ultimate (Phase 4) pit extents. Haul roads are shown connecting the pit to the rock storage facility: RSF-X located south-centrally for potentially acid generating(PAG)waste and RSF-A located in the southwest for non-PAG waste.The haul roads will also connect to the non-processing infrastructure(NPI)located in the northwest portion of the site and the ore sorting area and the ore stockpiles located on the east side of the Project, just north of 1-85. A bridge over 1-85 will connect the ore stockpile area to the processing area, located immediately south of 1-85. South of the processing area, WSB-1 will collect all contact water produced within the Project area before being discharged from the site. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 PERIMETER N POND 71 LAYDOWN AREA PERIMETER / ' '•� POND 72 /•'' _ '�, %�'' PROPERTY LINE GROWTH MEDIA / - � '�•.% �. ❑ STORAGE LAYDOWN AREA TRUCK MAINTENANCE /' �� ❑ SHOP MINE PIT WAREHOUSE- �• Opq G�PG _EXISTING ROM PAD NATURAL GAS FACILITY/LABORATORY \, �-• � — , LINE RE-ROUTE 1 r, o -- READY LINE - ' HAUL ROAD 'S ❑o . '\ /,,/ /'' % / CONCENTRATE �kk�_L , ;% / RAIL LOADOUT ^ -�__ _„•' �'� �� EXISTING 11 PROCESS BOOSTER PUMP FACILITY ' � .. / / %• �"- OVERBURDEN STORAGE OVERBURDEN -- .--��' �'- -� _ - FACILITY 2 (OSF-2) � SED POND 1 �;,/ ,< 15 STOCKPILE r/ / / STORAGE FACILITY 1 (OSF-1) WETLAND AREA RAIL CAR � � �, t� /' SETBACK FUELING STATION / ❑ & INFRA STORAGE❑ SOUTH CREEK MUD POND#2 ❑ CRUSHING FACILITIE CULVERT ❑ _ •-� �� GRADE TO DRAIN 4. O �- OSF-1 WATER - KING' S CREEK �✓ % .�� / MANAGEMENT PONDS � CONCENTRATE TRUCK - LOADING BUILDING SOUTH CREEK _ = % a HAUL ROAD , d PROPOSED ROCK -- FILL CHECKDAM �• �- �❑❑❑❑❑❑ � � ROCK --� STORAGE v •�•.— �� FACILITY X � 5 / CONCENTRATOR FACILITIES � I � ❑�i�� i� I I I ill I I I I I I� I I I I I I I �� / / �O'9\•„� ROCK WRC POND 51 6 STORAGE Z \,\ FACILITY A OJ�� 5 / / ❑i� WATER STORAGE /. / BASIN 1 (CURRENT / OUTLINE) � WRC POND 61 - EXISTING 230kV loo, POWERLINE ALIGNMENT OSF-3 WATER \ MANAGEMENT POND \ - WETLAND AREA SETBACK PROPOSED WATER STORAGE !- ---/ Iool EMBANKMENT VERBURDEN STORAGE / FACILITY 3 (OSF-3) LAYDOW \ �� MAX WATER LEVEL •� %' YARD ❑ PMP EVENT PROPOSED TOE (845 FT AMSL) Al BUTTRESS \ %❑ 'lollIlool , 230/24.9KV ELECTRICAL PROPOSED _ SUBSTATION SPILLWAY ❑ REVISIONS DESIGN: EL/JO REVIEWED:JO PREPARED BY: DRAWING TITLE: ISSUE: REV. DESCRIPTION DATE DRAWN:EL APPROVED:JO OPEN PIT AND MINE FACILITY SIMPLIFIED SITE DATE: 1 ISSUED FOR CLIENT REVIEW 05/09/2023 srk consultingCOORDINATE SYSTEM: 2 ISSUED FOR CLIENT REVIEW- NEW SITE LAYOUT 07/24/2023 MAP EXHIBIT 6/19/2024 ISSUED FOR CLIENT REVIEW- NEW MINE PLAN NC83F PREPARED FOR: SRK PROJECT NO.: REVISION: 3 08/24/2023 ISSUED FOR CLIENT REVIEW-SURFACE WATER PROJECT: USPR576.800 7 0 250 500 1000 4 08/30/2023 KINGS MOUNTAIN 5 ISSUED FOR CLIENT REVIEW 08/30/2023 DRAWING NO. FEET g ISSUED FOR CLIENT REVIEW 09/15/2023 IF THE ABOVE BAR .1 Operated by:ALBEMARLE MINING PROJECT KINGS MOUNTAIN MINING PROJECT 7 RE-ISSUED FOR PERMITTING 06/19/2024 DOES NOT MEASURE 1 INCH, FIGURE 1 -2 FILE NAME: Site Map_Rev 8_Simplified_Linked.dwg THE DRAWING SCALE IS ALTERED Albemarle-Lithium C:\Users\elynn\SRK Consulting\NA USPR000576 Albemarle Corporation Kings Mountain 2022 Pre Feasibility Study-GIS\04 CAD\20240619_Simplified SiteMap\Site Map_Rev 8_Simplified_Linked.dwg SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 21 4.3 WSB-1 Design The original Foote Minerals Chem tailings impoundment embankment was constructed to a crest elevation of 850 ft amsl.A concrete-lined trapezoidal spillway was constructed to exit the impoundment area at elevation 845 ft amsl, which was the original control on pool elevation during operations. A portion of the embankment at the original flowline was removed in the early 2000's down to 820 ft amsl and collected stormwater flows were allowed to flow through the original impoundment footprint. The elevation of the current exit at 820 ft amsl allows for storage of several feet of water and the area has been more recently referred to as WSB-A A portion of the original tailings is still present in the southwest corner of the site against the original embankment. The original concrete-lined spillway is still in place and in most areas is in serviceable condition, though there are sections where the original concrete has been undercut and broken. To convert the existing configuration, Albemarle proposes to implement the following modifications to enable the future use of the impoundment as a water storage basin. The preliminary design drawing set in Appendix B shows grading plans and details illustrating the following proposed actions. 1. Clear and grub existing vegetation growth and roots from the existing embankment and proposed expanded design footprint. 2. Reinstate the original embankment by placing and compacting suitable general fill in the embankment breach, including the formation of a lower permeability internal core and compacted fill or rockfill outer zones. Suitable sources of required construction materials will be identified in the next phase of design. 3. Install low-level outlet works to facilitate decanting the pool to a predetermined elevation such that normal pool operations allow for both sediment retention and storm storage (refer to Section 5). 4. Replace the existing concrete-lined spillway, providing for an outlet at the northwestern corner of the new WSB-1 impoundment at 843 ft amsl, and including energy dissipation measures as required at the downstream end to prevent undue erosion. 5. Construct a gravel blanket drain along the downstream face of the embankment and under the proposed downstream embankment buttress. The top of the blanket drain will extend to 845 ft amsl and be covered with compacted general fill to widen the embankment crest and improve access conditions (final crest width to be determined). Geotextile or a sand drain may be required on either side of the blanket drain to ensure proper functioning. Note also that the drain material shall be non-potentially-acid-generating and determined in advance to be geochemically and geotechnically suitable for the intended purpose. 6. Construct a compacted fill buttress as shown on the design drawings to improve the predicted stability of the embankment and anchor the new blanket drain section on the downstream embankment face. Note that the purpose of the blanket drain is to intercept any seepage through the original embankment section and to route flows through the blanket drain and under the downstream buttress. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 22 4.4 WS13-1 Operational Summary A significant portion of the watershed between the existing WSB-1 and Interstate 85 is diverted around the ECL. During the development period, the diversions will be removed or directed into WSB-1 and the former TSF embankment will be restored and stabilized. A low-level outlet, suitable to maintain a minimum pond volume and retention time, will be constructed for sediment control. A detailed water balance was developed to aid in operational planning for water management across the site — the water balance is described in the SRK report titled Technical Report, 2023 Prefeasibility Study, Surface Water. Water Balance Development Report, Kings Mountain Mining Project (SRK, 2024). Although not simulated in the model, WSB-1 will be used to limit discharge of storm and contact waters during upset conditions and will serve as a collection node for all storm and contact waters generated at the site that are assumed to be suitable for discharge to Kings Creek. WSB-1 is currently anticipated to accept storm and contact water flows from the following sources: • Pit dewatering flows from the Open Pit Sump • Seepage and runoff from RSF-A • Runoff from ROM Pad Collection Sump (by others) • Unused treated PAG contact water(RSF-X)from the Water Treatment Plan (WTP) In addition, WSB-1 will receive non-contact inflows from: • Runoff from the surrounding watersheds • Direct precipitation on the open water surface WSB-1 will supply makeup water to the Processing Plant, if necessary, and will serve as a backup source for haul road dust control water. Flows exiting WSB-1 will enter the drainage below the pond, which joins Kings Creek south of 1-85, approximately 1,750 ft downstream of the toe of the WSB-1 embankment. Under normal operating conditions, flows exiting WSB-1 will be passively controlled through a low- level outlet works consisting of an 18-inch diameter inclined riser pipe set at approximately 10 ft above the lowest point in WSB-1 and along the upstream embankment slope to 20 ft below the crest of the WSB-1 embankment (which will be completed to elevation 850 ft amsl). Additional riser pipes will be installed at selected elevations such that individual riser pipes may be opened or closed as part of operations to control facility water levels. As also describe above, an emergency spillway is incorporated in the model at elevation 843 ft amsl and is designed to convey the Inflow Design Flood (IDF) (currently considered as the Probable Maximum Precipitation event)with less than two feet of flow depth, resulting in a maximum water level in WSB-1 of 845 ft amsl. The Water Balance model does not simulate the use of the emergency spillway, as it is only utilized during upset conditions when the pond is prevented from discharging water for an extended period of time prior to generating the IDF. Stormwater management at the site is described in further detail in the Surface Water Management Report, Kings Mountain Mining Project (SRK, 2024). Water balance modeling for sitewide water management is described in further detail in the Technical Report, 2023 Prefeasibility Study, Surface Water. Water Balance Development Report, Kings Mountain Mining Project(SRK, 2024). The water balance model includes calculations to determine the amount of flow passing through the vertical riser during normal operations, as well as flow through the spillway under flooding events. The RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 23 model also assumes that WSB-1 is again breached at the end of the mine life, returning the outlet invert to elevation 820 ft amsl for closure. Table 4-1: Key Contact Water Pond Input Parameters Parameter Contact Water Pond Value Pond Base Elevation 820 ft amsl Pond Crest Elevation 850 ft amsl Contributing Watershed 115.92 ac Diverted Watershed 151.81 ac Spillway Invert Elevation 843 ft amsl Low Level Outlet Elevation 830 ft amsl Contributing Watershed 281 ac Spillway Bottom Width 16 ft Riser Pipe Diameter 18" Source:SRK,2023 Engineering drawings were prepared under the direct supervision of R. Breese Burnley (P.E. No. 055362), a Professional Engineer currently registered in the state of North Carolina; Table 4-2 provides the drawing list for these plans. Table 4-2: Engineering Drawing List Drawing Number Title 100 Location Map and Drawing Index 200 Existing Site Topography and Proposed Facilities 201 WSB Embankment Existing and Proposed Topography 300 Water Storage Basin Grading Plan and Sections 301 Water Storage Basin Embankment Details 400 Water Storage Basin Spillway Design 401 WSB-1 Spillway and Stilling Basin Details 4.5 WSB-1 Slope Stability Slope stability analyses have been prepared to support the current conceptual design of the TSF and are described in detail in the technical memorandum in Appendix C titled Slope Stability Calculations for Preliminary Design of Water Storage Basin 1 (SRK, 2024). The design concept at this stage of the Project includes a relatively robust embankment design based on the results of slope stability analysis and the current understanding of both the original embankment construction materials and the foundation characteristics. Additional analyses will be completed in later stages of design and will incorporate the results of currently on-going laboratory testing and future characterization work. 4.6 Hydrology and Hydraulic Design Hydrological evaluation and hydraulic design of the various components of the site stormwater control system design are described in detail in the Surface Water Management Report, Kings Mountain Mining Project, North Carolina (SRK, 2024). 4.7 Dam Breach Analyses High-level dam breach analyses will be prepared in advance of the detailed design and submitted to the North Carolina Department of Energy, Mineral and Land Resources, Land Quality Section's Dam Safety Program as part of an initial request for a Jurisdictional Determination and Hazard Classification RBB/J BS KM_WSB-1_Prelim Eng Desig n_Repor[_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 24 Request. More-detailed dam breach analyses will be prepared following the completion of the detailed design process to verify the results of the original high-level analysis and form the basis of the development of an Emergency Action Plan, as recommended by the Federal Emergency Management Agency in their guidance document titled Federal Guidelines for Dam Safety, available at https://www. fema.gov/sites/default/files/2020-08/eap federal guidelines fema p-64.pdf. 4.8 Technical Specifications and Construction Quality Assurance Plan The detailed design of the TSF will include preparation of a thorough set of technical specifications to guide construction in accordance with the approved design and a detailed construction quality assurance plan to detail required field and laboratory procedures that must be followed to ensure compliance with the technical specifications and approved detailed design. 4.9 WSB-1 Closure Current plans call for removing the portion of the embankment placed to fill the notch in the existing dam to reinstate the current flow conditions at the end of the operational life of the facility. Closure actions will therefore include removal of the new embankment section along the existing creek alignment to the current base elevation of 820 ft amsl. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 25 5 Operation, Maintenance, and Surveillance Manual Albemarle will prepare an Operation, Maintenance, and Surveillance (OMS) Manual for the facility upon completion of the detailed design and permitting. The OMS Manual will outline the data, framework, and procedures that Albemarle staff and authorized contractors will use "to ensure safe design, construction, operation, maintenance, and surveillance" of WSB-1. The OMS Manual will include operating, monitoring, and surveillance requirements described in site environmental and dam safety permits and will be prepared in general accordance with the Mining Association of Canada (MAC) guidance document titled Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities (MAC, 2019). This OMS Manual will be prepared to assist Albemarle in guiding compliance with regulatory requirements and implementing BMPs and will include definition and description of the following: 1. Roles and responsibilities of key personnel assigned to facility management 2. Procedures and processes for managing changes to the OMS manual 3. History of the facility 4. Key components of the facility 5. Procedures required to operate, monitor the performance of, and maintain the facility 6. Requirements for data analysis, reporting, and documentation of facility performance The OMS Manual will also provide direction for stormwater management during operations, storm preparedness in the event of extreme events, and monitoring instrumentation and data evaluation. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 26 6 Erosion and Sediment Control Plan As part of new site construction and commissioning, the design and operational details included in this section, and future detailed facility designs will form the erosion and sediment control plan that is tailored to the final site conditions and the final site management team structure and that complies with the specific requirements of the Erosion and Sediment Control Planning and Design Manual (North Carolina Sedimentation Control Commission (NCSCC), 2013). At a minimum, the erosion and sediment control plan will include the following: 1. Brief narrative 2. Construction schedule 3. Maintenance plan 4. Vicinity map 5. Site topographic map 6. Site development plan 7. Erosion and sedimentation control plan drawing 8. Detail drawings and specifications 9. Vegetative plan 10. Supporting calculations 11. Financial responsibility/ownership form 12. Checklist 6.1 Temporary and Permanent Controls In general, proposed temporary and permanent stormwater management and erosion controls have been designed in accordance with the following requirements of the NC Surface Mining Manual(North Carolina Department of Environment, Health, and Natural Resources (NC DEHNR), 1996): • Temporary diversions, those that function for less than a year, should be designed to carry at least the 10-year design storm for the total drainage area; furthermore: o Temporary diversions require erosion protection. Velocities over 2.5 ft per second may require a temporary liner with supporting design calculations unless the soil is especially erosion resistant. o Sideslopes of the diversion berm should be constructed to 2H:1V or flatter. The slopes then should be immediately seeded. • Permanent ditches and channels, those constructed to function for more than a year and to carry concentrated runoff non-erosively to a predetermined destination, must be designed for the 25-year storm event for the total drainage area; furthermore: o Sideslopes must be 2HAV or flatter. o Grass-lined channels are generally used for slopes less than 5%. o Velocities should not exceed 5 ft per second for established grass-lined channels. o Sharp bends and turns should be avoided. o Velocities over the maximum-allowable design velocity for grass-lined channels require a permanent structural lining, such as riprap. o In cases where velocity allows, riprap may be installed in the bottom of the channel with grass-lined sideslopes to decrease the quantity of riprap needed. Filter fabric or a 6-inch- RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 27 deep sand gravel crushed stone filter must be installed under the riprap to prevent undermining. The filter should extend under the entire area of the riprap lining. o The receiving channel or outlet must be protected from erosion by ensuring that the outlet velocity is minimized. o Outlet protection must be included where necessary. o Channels must be stabilized as soon as possible after construction, and sediment-laden runoff must be diverted away from stabilized channels. o Channels must be inspected after every major rainfall and appropriately repaired. Erosion protection will be provided by constructing sediment control ponds that will receive flows from site facilities. These ponds will receive flows from the contact water channels that will be pumped to WSB-1, which will provide sediment control capacity. 6.2 Maintenance Requirements Maintenance of all erosion and stormwater control features at the site will be the responsibility of Albemarle, who will prepare and maintain a schedule for regular inspection and maintenance. Maintenance will also include system inspection following significant storm events, removal of sediment, debris, and new plant growth from all conveyances and sediment ponds, and repair of damage to the system, as necessary, to ensure proper operation consistent with the design. Maintenance requirements will be explicitly defined in the erosion and sediment control manual and will include a review and update schedule for the plan itself to ensure it complies with the most recent guidance documents, practice, and procedures. 6.3 Responsible Parties Albemarle's site maintenance team will have primary responsibility for implementing the erosion and sedimentation control plan in coordination with the site environmental and capital projects teams. 6.4 Vegetation Stabilization Plan Albemarle will revegetate disturbances associated with WSB-1 construction, operation, and closure with the recommended seed mix in the mine manual. Revegetation and facility closure stabilization will be accomplished in accordance with an approved closure and reclamation plan. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 28 7 References Applied Weather Associates (AWA) (2022). Site-Specific Probable Maximum Precipitation Study for Kings Mountain Mining Operations, North Carolina, Applied Weather Associates, September 2021, KM60-EN-RP-9431. Garrett, D. E. (2004). Handbook of lithium and natural calcium chloride. Elsevier. Horton, J.W. Jr., and Butler, J. R. (1988).The Kings Mountain belt and spodumene Pegmatite District, Cherokee and York Counties, South Carolina, and Cleveland County, North Carolina. Southeastern Section of the Geological Society of America, Neathery TL, Vol. 6. Kottek, M., J. Grieser, J., Beck, C., Rudolf, B., and Rubel, F. (2006). World Map of the Koppen- Geiger climate classification updated. Meteorol. Z., 15, 259-263. DOI: 10.1127/0941- 2948/2006/0130. Mining Association of Canada(MAC)(2019). Developing an Operation, Maintenance and Surveillance Manual for Tailings and Water Management Facilities, Mining Association of Canada, March 2021. National Oceanic and Atmospheric Administration (NOAA) (2023). NOAA Atlas 14 Point Precipitation Frequency Estimates: NC. https://hdsc.nws.noaa.gov/hdsc/pfds/pfds_map_cont.html. North Carolina Department of Environment, Health and Natural Resources(NC DEHNR)(1996). State of North Carolina, Department of Environment, Health and Natural Resources, Surface Mining Manual, February. North Carolina Sedimentation Control Commission (NCSCC) (2013). Erosion and Sediment Control Planning and Design Manual, cooperative between the North Carolina Sedimentation Control Commission, the North Carolina Department of Natural Resources, and the North Carolina Agricultural Extension Service, May. SRK Consulting (U.S.), Inc. (SRK) (2021). SEC Technical Report Summary - Initial Assessment, prepared for Albemarle Corporation, by SRK Consulting (U.S.), Inc., Kings Mountain, North Carolina, December 31, 2021. SRK (2023a). Water Balance Development Report, prepared by SRK Consulting, May 2023. SRK(2023b). Factual Report, Preliminary 2022-23 Geotechnical Characterization for TSF and SWMF Design, Kings Mountain Mining Project, prepared by SRK Consulting, May 2023. SRK (2023c). Technical Report, 2022 Prefeasibility Study, Baseline Geochemistry Characterization, Kings Mountain, prepared by SRK Consulting, May 2023. SRK (2023d). Surface Water Management Report, Kings Mountain Mining Project, North Carolina, prepared by SRK Consulting, May 2023. SRK (2023e). Technical Memorandum, Kings Mountain Tailings Storage Facility, Preliminary Slope Stability Memorandum, prepared by SRK Consulting, May 2023. SRK (2023f). DRAFT Technical Prefeasibility Study, Hydrogeological Characterization, Kings Mountain Mining Project, prepared by SRK Consulting, May 2023. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 29 U.S. Department of Agriculture Forest Service (USDA FS) (2023). Land Areas of the National Forest System. https://www.fs.fed.us/land/staff/lar/LAR2017/FIA_data_products/LAR2017/FIA_ data_products/. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024 SRK Consulting(U.S.), Inc. Pre-feasibility Engineering Design Report,Water Storage Basin 1 —Kings Mountain Mining Project Page 30 Disclaimer The opinions expressed in this Report have been based on the information supplied to SRK Consulting (U.S.), Inc. (SRK) by Albemarle Corporation (Albemarle). These opinions are provided in response to a specific request from Albemarle to do so, and are subject to the contractual terms between SRK and Albemarle. SRK has exercised all due care in reviewing the supplied information. Whilst SRK has compared key supplied data with expected values, the accuracy of the results and conclusions from the review are entirely reliant on the accuracy and completeness of the supplied data. SRK does not accept responsibility for any errors or omissions in the supplied information and does not accept any consequential liability arising from commercial decisions or actions resulting from them. Opinions presented in this report apply to the site conditions and features as they existed at the time of SRK's investigations, and those reasonably foreseeable. These opinions do not necessarily apply to conditions and features that may arise after the date of this Report. Copyright This report is protected by copyright vested in SRK Consulting (U.S.), Inc. It may not be reproduced or transmitted in any form or by any means whatsoever to any person without the written permission of the copyright holder, SRK. RBB/J BS KM_WSB-1_Prelim Eng Desig n_Report_USPR000576_Rev03.docx April 2024