Mercury Loss from Gold Rush Era Placer Mines in the Fraser Basin
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Mercury Loss from Gold Rush Era Placer Mines in the Fraser Basin by Tara Lamothe Hons. BSc. Biogeography, University of Toronto, 2004 Project Submitted in Partial Fulfillment of the Requirements for the Degree of Master of Resource Management, Planning in the School of Resource and Environmental Management Faculty of Environment © Tara Lamothe 2020 SIMON FRASER UNIVERSITY Fall 2020 Copyright in this work rests with the author. Please ensure that any reproduction or re-use is done in accordance with the relevant national copyright legislation. ii Approval Name: Tara Lamothe Degree: Master of Resource Management, Planning Title: Mercury Loss from Gold Rush Era Placer Mines in the Fraser Basin Examining Committee: Chair: Jonathan Boron PhD Candidate Cliff Atleo Senior Supervisor Assistant Professor Frank Gobas 2nd Reader Professor Date Defended/Approved: January 18, 2020 iii Abstract Gold-rush era mercury loss at mine sites in the Fraser Basin was investigated. 109 soil and sediment samples were collected from suspected hotspots on 15 legacy placer mine sites and tested for total mercury. 89% of sites that had clearly discernable signs of mining had at least one test sample that exceeded all control samples taken during the study, suggesting that mercury use was widespread during B.C.’s Fraser and Cariboo gold rushes. An estimated 17,768 to 247,665 kg was lost in the Fraser Basin between 1858 and 1910, calculated by relating mercury loss to different records of gold extraction. Historical records show that 26,749 kg of mercury was shipped to B.C. from California between 1860 and 1883, and mercury imports into Canada between 1882 and 1899 exceeded expected mercury needs for gold amalgamation practices. Keywords: Mercury, methylmercury, placer mining, gold-rush, gold mining, ASGM, amalgamation, mercury imports, contaminated sites, British Columbia environmental history, Barkerville, Quesnel, Fraser River. iv Dedication Dedicated to those who eat what the lands and waters provide. Also dedicated to my dad, who taught me to fish, who shared wonder in the earth, trees and sky, and who patiently answered what must have been rather annoying strings of “but why” questions. v Acknowledgements This project was supported by many people. I returned to university with 4 and 6-year- old children in tow and could have not done this project without Tyler Ammerlaan, whom in addition to taking on extra parenting responsibilities, also provided invaluable support as an unpaid and intrepid research assistant. My kids have also gamely put up with being deposited at grandparents and dragged along on working camping trips. Dr. Cliff Atleo, my supervisor, has been unfailingly supportive. Thank you! I also want to thank Dr. Frank Gobas, who provided insight and direction to simplify and steer my research. I am grateful for the funding and support of The Firelight Group, especially Dr. Ginger Gibson, and the encouragement and support of First Nations Women Advocating Responsible Mining, especially Jacinda Mack and Cindy Charleyboy. Thanks also to the Fair Mining Collaborative, especially Amy Crook, who initially handed me a project on placer mining and encouraged me to follow the rabbits. A number of people helped steer me in the right direction and overcome roadblocks, in particular, big thank yous to Michael Kennedy, Darwin and Sue Baerg, Dr. Vicky Marlatt, Sue Zillwood, Dr. Mary- Ellen Kelm, Lawrence Joiner, Mr. Mundell, and Meghan Burton. This study also owes a debt to the work of Andrew Nelson, Michael Kennedy, and Michael Church. Without their painstaking work mapping placer mine sites and compiling data on mining methodologies, this study would not have been possible. Thank you to the UniverCity community and University Highlands Elementary for being a wonderful nest for our 20 months in the big city. And also, Hillary Atleo, for keeping me sane! I am also grateful for the millennia of stewardship of the WSÁNEĆ people, on whose land I live, work, and raise my family as an uninvited settler. I also want to acknowledge that field work for this project was conducted on sites in S’ólh Téméxw (Stó:lō), Nłeʔkepmx Tmíxʷ (Nlaka’pamux), Tsilhqot’in Nen, St̓ át̓ imc Tmicw (St’at’imc), Secwepemcúl’ecw (Secwépemc), and Dakeł Keyoh (ᑕᗸᒡ ᗲᘏᑋ). Finally, I would like to thank my parents, who always encouraged curiosity and the big questions. vi Table of Contents Approval .............................................................................................................................. iii Abstract ............................................................................................................................... iv Dedication ............................................................................................................................v Acknowledgements ............................................................................................................. vi Table of Contents ............................................................................................................... vii List of Tables ....................................................................................................................... ix List of Figures.......................................................................................................................x List of Acronyms ................................................................................................................. xi Glossary ............................................................................................................................. xii Preface / Self Location ...................................................................................................... xiii Chapter 1. Introduction ................................................................................................. 1 1.1. Health and Ecosystem Effects of Mercury .............................................................. 2 1.2. Historical Documentation of Mercury Use in B.C. ................................................... 4 1.3. Study Overview ........................................................................................................ 6 Chapter 2. Mine Site Testing ........................................................................................ 7 2.1. Methods ................................................................................................................... 9 2.1.1. Mine site selection ............................................................................................ 9 2.1.2. Sampling and testing ...................................................................................... 12 2.1.3. Data Analysis .................................................................................................. 14 2.2. Results and discussion for mine site sampling ..................................................... 16 2.2.1. Soil & Sediment Quality Guidelines ............................................................... 22 2.2.2. Limitations and caveats .................................................................................. 24 2.2.3. Conclusions for mine site sampling................................................................ 25 Chapter 3. Estimated Mercury Loss .......................................................................... 26 3.1. Introduction ............................................................................................................ 26 3.2. Overview of methods to determine mercury loss .................................................. 26 3.3. Method for estimating mercury loss during B.C.’s gold rushes ............................ 28 3.4. Results and Discussion ......................................................................................... 38 3.4.1. Bullion Pit Calculated Mercury Loss............................................................... 38 3.4.2. Cariboo Region Calculated Mercury Loss ..................................................... 39 3.4.3. Fraser Basin Calculated Mercury Loss .......................................................... 40 Chapter 4. Discussion and Recommendations ........................................................ 43 4.1. Discussion on potential impacts ............................................................................ 43 4.2. Mercury monitoring in B.C. .................................................................................... 45 4.2.1. Further Research ............................................................................................ 49 4.3. Recommendations ................................................................................................. 50 4.4. Conclusion ............................................................................................................. 52 References ....................................................................................................................... 53 vii Appendix A Mine test sample descriptions and results ........................................ 64 Appendix B ...................................................................................................................... 72 Selected Maps of Mine Sites Sampled ............................................................................. 72 viii List of Tables Table 2.1 Mine site locations and descriptions 10 Table 2.2 Levene test for homsedacity and Shapiro test for lognormality of total mercury concentration samples in regional groups 16 Table 2.3 Sample size, mean,