I'd like to thank local geologist Chris DeWitt for the chemistry lesson in his recent My Turn (Empire, Nov. 15). Not being a big fan of chemistry, I was surprised to learn that hazardous-sounding chemicals - like potassium amyl xanthate and methyl isobutyl carbinol - used in gold mining are relatively harmless compounds, posing little threat whatsoever to the Dolly Varden, midges, and lowly amphipods that call Lower Slate Lake home. Mr. DeWitt also expertly assures us the tailings toxicity studies show that the mine's tailings are not only relatively benign from a biological standpoint, but contain far fewer heavy metals than the area's natural sediments. We should all be left feeling comforted knowing the Kensington Mine tailings are not toxic, or at least not chemically toxic. But this is where Mr. DeWitt uses some selective semantics himself.
I think it's safe to say most people associate the word toxic with some nasty chemical, like organophosphate pesticides or the frog slime that Natives down in South America apply to their poison arrows. After all, most definitions of "toxic" include words like carcinogenic or poisonous and conjure up images of glowing liquids in Erlenmeyer flasks. There's another way to define toxic, however: any substance that causes unwanted side effects. I would argue that pouring a slurry of crushed rock into Lower Slate Lake for 10 or more years will have very undesirable physical side effects on the fish that live there. Namely, those fish will die - all of them - and so will the fish in every other lake the mining industry in Alaska decides is a cheap place to hide their waste.
I wonder how Mr. DeWitt would like having his morning cup of coffee interrupted by the disposal of four and a half million tons of fine-grained intrusive plagioclase feldspar slurry dumped on his home.
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