D. Kirk Nordstrom 2013 Roasting arsenopyrite-bearing gold ore for more than fifty years has resulted in nearly 300,000 tons of arsenic trioxide waste at the Giant mine near Yellowknife, NWT, Canada. Most of this has been stored in underground chambers sealed with concrete bulkheads. Seepages from underground drillholes and fractures contain up to 4,000 mg As L-1. Approximately 70% of the total is As(III). The dominant dissolved constituents are As, Ca, Mg, Na and SO4 with low Fe. application/pdf en InfoMine Extremely arsenic-rich, pH-neutral waters from the Giant Mine, Canada text