EXPERIENCE SUMMARY

Dr. Rex Bryan a geostatistician with over 35 years of experience with both the mining and environmental sectors. In the environmental sector, he is the author of EPA’s Data Usability and Risk Assessment. (DURA) guidance document’s sampling section. Dr. Bryan is an expert witness for the DOJ in the use of multivariate statistics, sampling theory and geostatistics in contaminant mapping. In the mining sector, Dr. Bryan is an authority in 3-D geologic modelling, data quality assurance, ore grade control and resource/reserve estimation. He has a doctorate from Colorado School of Mines in Mineral Economics, with graduate degrees in Geology from Brown University and Business Administration from Michigan State University. His undergraduate degree is in Electrical Engineering also from MSU. He is a NI43-101 Qualified Person (QP) and a JORC Competent Person (CP). He has worked on mining projects around the world including the United States, Canada, Slovakia, Indonesia, Australia, Mexico, Panama, Brazil and Chile. The commodities include copper, gold, silver, uranium, molybdenum, rare earths, coal, phosphate and lithium. He is the current resource QP for the Nevada Copper Corporation’s Pumpkin Deposit (USA, copper, gold, silver); Vista Corporation’s Mt. Todd project (Australia, gold); AUC LLC’s Reno Creek ISR project (USA, uranium). Early in his career, Dr. Bryan helped develop many of the geostatistical estimation techniques and computer programs used today.

Qualified Person Reports

Pumpkin Copper Deposit, Yerington, Nevada. (2010, 2015) Nevada Copper Corporation, 43-101 Resource calculations as a QP for a major copper and iron deposit in the western U.S. Use of dynamic kriging techniques to follow the changing anisotropy of copper.

Yerington Pit and MacArthur Projects, Yerington, Nevada. (2010, 2013) Quaterra Resource Corporation, 43-101 compliant resource statements as QP for the two copper projects.

Geostatistical Estimation of Gold at the Mt. Todd Mine, Vista Gold Corp., Northwest Australia (2013). Sub-vertical mineralization. Mineralized package within core, hanging wall and footwall zones. Modeled impact of future resource category with proposed drilling site. Currently the QP for the resource

Kuriskova and Huta Nova Uranium Projects, Slovakia (2011, 2013). 43-101 compliant resource statements as QP for uranium projects in East-Central Slovakia. Statistical analysis was used to compare and accept Communist era data using modern Tournigan drill results.

Geostatistical Modeling of Awak Mas Gold deposit, Vista Gold Corp., Indonesia (2012) Used Geostat and Gemcom to estimate gold within complex 3-D ore zones. Variograms calculated within 3-D rotated zones. JORC compliant resources as Competent Person (CP).

Uranium resource estimation, Black Range Minerals, Taylor Ranch, Colorado (2012). QP for a 43-101 compliant uranium resource estimation in central Colorado. Lenticular and strata bound sandstone and braided stream sediments hosted mineralization was estimated using ordinary kriging within interpreted wireframes.

Geostatistical Estimate of the Mineral Resources of the Los Gatos Project, Chihuahua, Mexico, (2012), QP,Cerro Los Gatos, Esther Zone and Update of the mineral resources to reflect drilling that Sunshine Mining Company.

Technical Report Addendum: Mineral Resource of the Amapola Zone (January 2012). Amapola Zone resource estimates in a Technical Note. New mineral resources to reflect drilling that Sunshine Mining Company.

Reno Creek Preliminary Feasibility Study–Amended (May 2014). Preliminary Feasibility Study (PFS) for the Reno Creek ISR Uranium Project located in the Powder River Basin of Wyoming (Project). The new PFS was prepared for AUC LLC (AUC), the operator of the project.

Preliminary Economic Assessment of the Back Forty Project, Michigan, USA. (July 2014). Geology and Resource QP for a VMS Deposit in Michigan’s Upper Peninsula. Prepared for Aquila Resources Inc.

Expert witness and EPA Studies

Expert Witness, Clark Fork Superfund, Anaconda/Butte/Clark Fork (U.S. vs. ARCO), Montana. Developed and managed a sampling and analysis plan to characterize extent of metal contamination in regional soils around Anaconda. Independently validated earlier work by EPA/several PRP contractors. Developed a powerful sampling and statistical technique to estimate directly background metal concentrations at individual sampling sites. Managed the sampling and analysis program. Developed a litigation-quality database for all solid media samples at the Clark Fork Superfund Sites. Developed kriged estimate maps of arsenic, cadmium, copper, lead and zinc contamination in soils and stream sediments for the area from Butte to Missoula, Montana.

Clark Fork River Reach A Phase I Investigation. (Tetra Tech project for the Montana Department of Environmental Quality). Performed a study to determine the efficient sampling for arsenic, copper and zinc contamination in river sediments. Statistical comparison was done to determine the efficacy of field-portable x-ray fluorescence (FPXRF) with traditional laboratory results. Results indicated that FPXRF was significantly accurate in the determination their combined concentration above a trigger of 500 mg/kg. This allowed for FPXRF to support an efficient sampling and remediation protocol.

Expert Witness, Chromium Contamination, DOJ, Odessa, Texas. Expert Witness for the United States Department of Justice (DOJ), U.S. v. Bell Petroleum (Odessa I): Provided expert witness support in geostatistics and geochemistry. Analyzed chromium data for a site in Odessa Texas. Reviewed prior depositions, testimonies, RI/FS reports. Identified and investigated weaknesses in prior expert testimony. Developed counter arguments to refute defendant’s critical expert testimony on extent of chromium contamination at site, allocation of responsibility among PRPs, and extent of clean-up required.

Expert Witness Mine Sampling, Sherman Howard, Candelaria, Nevada. Sherman and Howard Law, Argentum Consolidated Mines vs. Occidental Minerals Corporation, Candelaria Partners, Congdon and Carey: Opinion for the Defendants as an expert in statistical analysis and geostatistics, particularly as applied in the mining industry to sampling, weighing, and the testing of ore for grade control.

Expert Witness, Circle K Lust, EPA, Denver, Colorado. 1993, Circle K Bankruptcy. Developed an expert opinion for the DOJ regarding the calculations for an underground storage tank (UST) Environmental Reserve by Circle K Corporation’s contractor, ERM-Southwest. Developed a Monte Carlo simulation to estimate the probability distribution and upper bound of required reserves based on probability distributions for: potential third-party liability costs; direct removal costs; and soil and groundwater remediation costs. Derived a value seven times larger than that of Circle K Corporation’s contractor for the required Environmental Reserve at a 95% upper confidence level.

California Gulch Superfund Site, DOJ/EPA, Leadville, Colorado. Assist with technical oversight of all PRP sampling and analysis plans for soils. Developed maps depicting extent and source of soil contamination. Supported the DOJ and EPA in making a case that historic mining, milling and smelting produced inappropriately high levels of lead, cadmium, zinc and arsenic. Developed and implemented protocols for using field-portable x-ray fluorescence (FPXRF) along with laboratory grade XRF and CLP measurements. He is a principal author of “Almost Read-Time Run-and-Gun” mapping of heavy metals using global positioning systems (GPS), geostatistics and fPXRF. He has worked with the Environmental Management Laboratory in Las Vegas (EMSL/LV) and the Chief Remedial Project Manager, for the California Gulch Superfund Site.

Smuggler Mountain Superfund, EPA/DOJ, Aspen, Colorado. Performed contaminant mapping using indicator kriging to estimate area of contamination on properties of individual PRP. Smuggler Mountain NPL Site, Aspen, Colorado (EPA). Mapped historic mine waste material found to have elevated concentrations of lead, using standard CLP protocol and field portable X-ray fluorescence (FPXRF). At a determined action line of 1000 mg/kg lead in soils, efficient sampling and mapping methods were developed and implemented. Performed jointly by Geostat and Camp Dresser and McKee.

Navy Clean, Military Bases, USA. Bryan developed technical sampling guidance for the EPA under contract with DynCorp Corporation in Alexandria, Virginia. He was trained as an instructor in Data Quality Objectives and supported the EPA’s Quality Assurance Management Staff. Dr. Bryan has been a Project Manager and Principal Scientist on retainer for DynCorp. He has provided facilitation partnering between DOD and EPA, and risk-based performance-measure development for the RIFS at Yuma Marine Corps Air Station Superfund Site (Navy Clean Program) and at Barstow, El Toro and San Diego, California, and at the naval facilities in Honolulu, Hawaii. Efforts included extensive review of existing site characterization and RIFS background documents.

Dura Risk Assessment, EPA, Alexandria, Virginia. He is a principal author of sampling within the EPA’s revised Data Usability for Risk Assessment Guidance Document (DURA). He is currently authoring the sampling appendix for the Integrated Environmental Uptake Biokinetic (IEUBK) Lead Model. Both guidance’s receive extensive use by EPA, other federal agencies and environmental contractors designing site risk assessment.

Integrated Biokinetic Lead Uptake Model, EPA, and Washington, D.C. Developed sampling protocols for lead contamination in soil, air, water, and food to be used with EPA’s Lead Integrated Biokinetic Uptake Model.

Lead Speciation Bioavailability, EPA, Leadville, Colorado. Developed mapping techniques to illustrate “relative bioavailability” of chemicals of concern over the sites. Coordinate with hydrogeology, speciation, and air modeling experts.

Risk Assessment at Midnite Uranium Mine, URS and the United State Environmental Protection Agency (USEPA), Spokane Indian Reservation, Spokane, Washington. Using modern statistical methods, complex chemical and radiometric data was developed to determine reasonable background levels for an extensive array of COPCs (Cadmium, Chromium Cobalt, Lead, Radium 228, Lead 210, Thorium 227/228/230, and Uranium 234/235) found at a historical uranium mine on the Spokane Indian tribal lands.

Environmental Statistics Calculation, Saint Anthony West Property, Lakewood, Colorado. Over 50 chemicals analyzed within ground water, soils, sediments, and seeps. The study used EPA approved methods such as a determination of underlying distribution (Shapiro-Wilks), upper confidence, and upper prediction limits. Compared site areas with down-gradient levels of contamination using Wikoxon-Rank Sum.

Johnson and Ettinger Model, Walsh & Associates, Denver, Colorado. The Mountain View GTE site is near San Francisco and has a groundwater plume from old industrial facility and landfill. The plume has shown to have volatile organic compounds (VOC). EPA Region IX has concern that the calculated potential vapor emissions into homes above the plume may not be conservative enough. To help in this the CDOT model is being carefully reviewed.

Denver Radium Site, ESC Corp, Denver, Colorado. Denver Radium Site, remediation, risk sampling. EPA Region VIII required that the soil contaminated by uranium and radium is removed from the Shattuck site with a 95 percent confidence level. Geostatistical modeling allowed for remediation plans to be tailored in such a way that this level of assurance was met.

Other Studies

Assessment of Rare Earth Elemental Contents in Select US Coal Basins Final Report. Bryan was a joint author on several studies for the United States Department of Energy’s National Energy Technology Laboratory evaluating coal-based rare earth elements (REE). The study was used to support the DOE Report to Congress summarizing the opportunities and challenges of recovering REE elements from coal and coal by-products. This report summarizes the results of the review and compilation of published information concerning the geology, geochemistry, and resource estimates of select coal basins in the United States, with emphasis on REEs. These data were evaluated with respect to criteria that could be useful in defining “sweet spots” of these metals in coals and associated waste rock and/or ash. To accomplish this, five western States (Arizona, Colorado, Montana, New Mexico, and Montana) and four eastern States (Pennsylvania, West Virginia, Virginia, and Kentucky) were chosen for study. The United States Geological Survey (USGS Coal Quality (CoalQual) Database was used extensively in this evaluation

Study on the Utilization of Portable XRF Spectroscopy as Screening Tool for REEs in Coal and Coal Waste Products Final Report, Dr. Bryan was a joint author on several studies for the United States Department of Energy’s National Energy Technology Laboratory evaluating coal-based rare earth elements (REE). The report summarizes a study of the effectiveness of applying X-Ray fluorescence (XRF) spectrometer analysis as a field screening method to rapidly and economically evaluate coal and coal waste products to determine their potential to contain rare earth elements (REE).

Mineral Economists, UNIDO/Code/CO, Jamaica/Chile. Bryan consulted with the Jamaica Bauxite Institute and the United Nations Industrial Development Organization (UNIDO). Consulted on environmental compliance regulations for bauxite mining in Jamaica for the United Nations Industrial Organization (UNIDO). He has lectured and consulted to the Jamaica Bauxite Institute in Kingston, Jamaica on bauxite estimation. Advisor to the National Copper Company of Chile (CODELCO) on how best to meet United States and European environmental standards and is consulting on the design of a large scale arsenic containment system at CODELCO’s Chuquicamata Mine in the Atacama Desert.

RCRA Statistics, BFI, Denver, Colorado. Managed a project to assist Browning-Ferris Industries (BFI) in the areas of RCRA groundwater regulations, water compliance issues, statistical tests of compliance, analysis of monitoring data, and repositioning of monitoring wells. This project involved water quality assessment, evaluation of hydrogeology, and the use of GIS and advanced statistical applications. Prepared analyses and reports assisting BFI in meetings with state/federal RCRA regulators.

Air Pollution Compliance by Blending Coal, Tennessee Valley Authority (TVA), Tennessee. To meet the required lbs. /MMBTU SO2 discharge, low sulfur coal is generally required. Old coal piles operating as LIFO inventory have produced a large nucleus of high-sulfur coal. Appropriate modeling of the inventory pile will allow blending so that this poorer quality coal can be burned. This technique will turn a present liability into an asset for TVA’s older power generation stations.

Financial Risk, California Petroleum Properties, Location. Potential remediation costs were estimated for aging petroleum reserves in southern California. Monte Carlo and Decision Tree analysis was applied to estimate the probable levels of remediation costs. Dr. Bryan developed the analysis strategy and was the principal programmer for the project.

Aberdeen, North Carolina, pesticide sampling and cleanup, URS Corp, Aberdeen, North Carolina. An intensely contaminated industrial site which operated through the 1940’s to 1970’s was mapped at various depth intervals. Indicators of characteristic contamination were developed using vertical depth to level of contamination. Geostat Systems, Acad12 and ArcInfo were used to determine required minimum sampling amounts and locations to map Toxiphene, which is the principal chemical of concern.

Publications and Talks

Bryan, R.C., Richers, Andersen, Ackman, Gray, February 16, 2015 Study on the Utilization of Portable Hand-Held XRF Spectroscopy as a Screening Tool for Rare Earth Elements in Coal and Coal Waste Products. US Dept. of Energy, National Energy Technology Laboratory (NETL). https://edx.netl.doe.gov/ree/?p=1428

Bryan, R.C., Richers, Andersen, Gray, January, 2015 Assessment of are Earth Elemental Contents in Select United States Coal Basins. US Dept. of Energy, National Energy Technology Laboratory (NETL). https://edx.netl.doe.gov/ree/?p=1385

Bryan, R.C. Kurtz, and Paul Meno. 2000. Contaminated Soils, Geostatistical Evaluation of Indoor Air VOC’s above a Chlorinated Hydrocarbon Ground Water Plume, Sediments and Water Conference, University of Massachusetts, Amherst. October.

Bryan, R.C. November, 1994. Sampling with kriging error in mind with Leadville Case study, Superfund Mine Waste Conference.

Wangerud, K., Bryan, R.C. September, 1994. High-Density Soil Sampling and Analysis Using Field Portable X-Ray Fluorescence and optimized Risk-Integrated Mapping of Lead Contamination. Second Int. Symposium on Environmental Contamination in Central and Eastern Europe, Budapest, Hungary.

Bryan, R.C. (co-author). June, 1994. Guidance for Planning for Data Collection in Support of Environmental Decision Making Using the Data Objective Process.

Bryan, R.C. March, 1994. DQO/G-4 and Sampling Efficiencies, unpublished report to EPA, Honolulu Hawaii.

Bryan, R.C., (co-author). February, 1994. Human Health Risk-Based Criteria for Decision Making at MCAS Yuma, Final, SWDIV NavFac Engineering Command.

Bryan, R.C. December, 1993. Yuma DQO Case Study, report to QAMs, EPA document.

Bryan, R.C. November, 1993. DQO’s and Yuma, DQO facilitation notes of Yuma..

Bryan, R.C. November, 1993. Arsenic Disposal in a Cell Having a Single Layer Containment Membrane in the Montecristo Region.

Bryan, R.C. August, 1993. Geostatistical Analysis and Mapping of Depth of Contaminants at the Denver Radium Site.

Bryan, R.C., Kurtz, J. July, 1993. Nature, Extent and Source of Contamination at the California Gulch NPL Site.

Bryan, R.C. January, 1993. Estudio Tecnico y Ambiental De la administracion de la Ceniza Volante y de Escorias En la Central Electrica de EDELNOR en Mejillones, Chile.

Bryan R.C. September, 1992. Strategies in Obtaining Site-Specific Data for the UBK Lead Model, Toxic Integration Branch, Environmental Protection Agency.

Bryan, R.C., Price, J. April, 1992. Development of Data Quality and Project Planning Objectives. Seminar U.S. Navy, Southwest Division, Naval Facilities Engineering Command. April.

Bryan R.C. (co-author). April, 1992. Guidance for Data Usability in Risk Assessment (Part A)., U.S. Environmental Protection Agency.

Bryan, R.C. February, 1991. The Evolution of Proven, Probable and Possible. Ore Reserves, Joint SME/CMA Conference.

Jamison, D.B., Bryan, R.C. September, 1990. Geostatistical Approach to Blending Sodium in Coal. Technical Paper, Mining Engineering Magazine.

Bryan, R.C. May, 1990. Overview of Ten Years of Geostatistics. Symposium of Computer Applications to the Mining Industry.

Bryan, R.C., Lopez, W.A. May, 1990. The Indicator Kriging Approach for Highly Erratic Deposits. Symposium of Computer Applications to the Mining Industry.

Bryan, R.C. November, 1989. Honest Abe – Guilty Until Proven Innocent (GUPI). Future Trends in Sampling Risk, 5^th Annual Hazardous Materials Management Conference.

Bryan, R.C., Myers, J.C. June, 1989. Innovative Sampling Strategies for Site Assessment. Proceeding of the HAZMAT Conference.

Bryan, R.C., Myers, J.C. 1987. Sampling Strategies for Site Evaluation. Conference and Exhibition proceedings on Hazardous Wastes and Hazardous Materials.

Bryan, R.C., Splitstone, D. 1986. Risk Qualified Mapping of Polychlorinated Dibenodioxin (PCDD) Contamination. Proceedings of the symposium on solving hazardous waste problems.

Bryan, R.C. 1986. Grade Control Using Microcomputers at Candelaria Mines. Conference proceedings on ore reserve estimation methods, models a reality. Sherman and Howard, Law Firm.

Bryan, R.C., Myers, J.C. November, 1985. Three Dimensional Response Surfaces in Coal Washability.

Bryan, R.C. 1985. Geostatistical Use, Methods, and Results – Smuggler Mountain Site, report to the Environmental Protection Agency.

Bryan, R.C., Myers, J.C. May, 1984. Geostatistics – Environmental Solutions from the Mining Industry. Mines Magazine, Colorado School of Mines. May.

Myers, J.C., Bryan, R.C. 1984. Geostatistics Applied to Toxic Wastes… A Case Study. Geostatistics for Natural Resources Characterization Part 2. G. Verly, M. David, eds. Dordrecht, Holland: D. Reidel Publishing Company. P. 893-901.

Bryan, R.C., Ellis, T. 1982. Economic Sensitivity Analysis using Geostatistics. Application of Computer and Operations Research in the Mineral Industry. T.B. Johnson and R. Barnes, eds. Baltimore: Port City Press.

Bryan, R.C., Roghani, F. 1982. Applications of Conventional and Advanced Methods to Uranium Ore Reserve Estimation and the Development of a Method to Adjust for Equilibrium Problems. Application of Computer and Operations Research in the Mineral Industry. T.B. Johnson and R. Barnes, eds. Baltimore: Port City Press.

Bryan, R.C. 1980. PhD Dissertation: Enhanced Ore Estimation using Multi-Factor Co-kriging. Colorado School of Mines.

PROFESSSIONAL AFFILIATONS

Society of Mining Engineers, Registered Member #411340

PROFESSIONAL EMPLOYMENT HISTORY

President, Geostat Systems LLC, 2015

Senior Geostatistician, Tetra Tech, 2007 to 2015

Geostatistician, Gustavson Associates, 2006 to 2007

Consultant, Rex Bryan Ph.D, 2003 to 2006

Environmental Statistician, Dames & Moore / URS, 1999 to 2003

Geostatistician, Viar / DynCorp / CSC, 1994 to 1999

Director, Geostat Systems (GSI), 1980 to 1994

Geostat Systems

Resume: Rex C. Bryan, BSEE, MBA, Ph.D.