The IGSTA allowed me to travel to mine sites near Lillooet, Likely, Lytton, and Quesnel in June 2019, where I collected between five and ten samples per site to identify the mercury hotspot locations on each mine site. 

Travel Report: Tara Limothei

Tara Limothei, a master's student in the School of Resource and Environmental Management, received an Indigenous Graduate Student Travel Award (GIRTA) to further her research in different mine sites in British Columbia. 

August 27, 2019
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The Indigenous Graduate Student Travel Award (IGSTA) allowed me to complete research integral to my master’s project, currently titled: “Quantifying Gold-Rush Era Mercury Contamination in the Fraser Basin.”  

I became interested in mercury contamination during research I was doing on the environmental effects of modern placer mining, also called artisanal or small-scale gold mining. This work was commissioned by First Nations Women Advocating Responsible Mining. Many First Nations in BC are concerned about how placer mining is affecting the environment, and some have even banned the activity from their traditional territories. Placer mining has been more or less continuous since the start of the gold rush in 1858, and despite hundreds of operating mines there is next to no scientific research on how this activity affects our shared environment.

Mercury is a well-known contaminant that can cause severe ecological and human health issues at low concentrations. It bonds with gold and has been used in placer mining to increase yields for millennia. Mercury was used by placer miners in B.C. during the gold rushes; B.C.’s 1897 Annual Report of the Minister of Mines records that one mine near Likely lost 793 kg of mercury that year. There are more than 500 gold-rush era mine sites in the Fraser basin, and while mercury use is mentioned in the aforementioned annual reports, no specific quantity is reported. Thus, there could be hundreds of old placer mine sites contaminated with mercury within the Fraser basin. This raises a host of potential research questions: Which mines used mercury? How much mercury was used? Is mercury still present at those sites? If present, is mercury sequestered in tailings, or entering the ecosystem? Are current miners disturbing legacy mercury deposits? If mercury is entering the ecosystem, is it converting to methylmercury? If it is converting to methylmercury, are there ecosystem or human health effects? Attempting to answer all these questions is well beyond the scope of a Resource and Environmental Management 699 project. Therefore, I am focussed on the first three questions, identifying the location of potentially contaminated sites and quantifying the amount of mercury potentially used at these sites.

To accomplish this, my research has two parts: First, I am doing historical research to figure out how much mercury was imported to B.C. and used in placer mining during the gold rush period (roughly 1958 – 1930). Second, I am collecting and testing sediment samples at 20 mine sites in the Fraser basin to see what proportion of gold-rush era miners used mercury, and if mercury use can be predicted by the mining method used.

The IGSTA allowed me to travel to mine sites near Lillooet, Likely, Lytton, and Quesnel in June 2019, where I collected between five and ten samples per site to identify the mercury hotspot locations on each mine site. Samples were sent to ALS Laboratories in Burnaby, B.C. Along the way, I met up with experienced locals who were able to show me the locations of local mine sites and how to read the remains of sites to identify the locations of infrastructure, so I could identify and test likely mercury hotspots.

This project will help us understand the location and severity of mercury contaminated sites in the Fraser basin, pointing to the areas where current mining activity should be restricted pending further investigation and environmental remediation. These results will inform current placer mining permits, land use planning, and cumulative impact assessments. I will report the results to First Nations Women Advocating Responsible Mining, who requested this study.