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How much selenium is in the Elk River?

Based on my thirty two years of experience with selenium work throughout the western US and now this Canadian add-on, this in my mind is one of the most significant selenium inputs to a water body that I’ve experienced in my career.

David Naftz

Geologist, USGS, Helena MT

Don’t believe your eyes. The Elk appears to be a lovely, clear gravel bed river. To the undiscerning terrestrial eye, there’s nothing wrong with it. To the aquatic creatures that live in the clear cocktail of mining contaminants, it’s a bit of a problem. And it’s been a problem for many years.

I emphasize “cocktail” because there isn’t just one contaminant. There are many. And while we can try to quantify the impact of each one individually using peer-reviewed science from short-term lab experiments, no one knows what happens when an aquatic animal has to *live* in all of them. Do we need to lower the safe level for each contaminant? Or, counter-intuitively, can we raise it? Do the effects from each one add up? Do the impacts multiply? No one knows.

Imagine ingesting the maximum daily safe dosage of Advil. Safe? Now chug your caffeine maximum safe intake. Still OK? Throw in the maximum safe daily limit of copper and finish with a daily max chaser of chromium, retinol and, just for fun, selenium. How safe do you feel? Now do that every day for the rest of your life. Including your reproductive years. And please record everything. The chronic toxicity of that particular cocktail in humans is currently unknown. Cocktails create uncertainty.

So, keeping the cocktail caveat in mind let’s look at selenium in the Elk River.

We’ve been recording selenium increasing at the mouth of the Elk since 1984. In the early 1990’s selenium levels in the Elk River breached the BC guideline for aquatic life (2 µg/L). This guideline, updated in 2014, is based on an extensive review of the scientific literature on selenium impacts to fish, birds and aquatic invertebrates (Beatty and Russo, 2014). It is the maximum level of selenium that theoretically won’t threaten aquatic life.  It’s a conservative “pollute-to” number that the lower Elk blew past twenty years ago.

Upstream the situation is worse. At Sparwood, near the major pollution inputs from the Fording River, Line and and Michel Creeks, the average level of selenium in 2014 exceeded even the BC drinking water quality guideline.

Again, give the Elk River points for style. This unfolding aquatic trauma was—and still is—invisible to the human eye. A person could be tempted into make-believing it’s not happening.

However, a person with scientific knowledge, experience and a different vantage point can be more objective. The selenium that travels down the Elk River ends up in the trans-boundary reservoir, Lake Koocanusa where it is finally diluted to a level below the BC aquatic life guideline level. Last summer I spoke with several scientists in the US and Canada. One of them was David Naftz, a geologist with the United States Geological Survey in Helena, MT. Selenium is one of his specialties.

“Based on my thirty-two years of experience with selenium work throughout the western US and now this Canadian add-on, this in my mind is one of the most significant selenium inputs to a water body that I’ve experienced in my career. What puzzles me is the lack of public concern over what’s coming into Lake Koocanusa and the potential implications for this pretty important water body.”

Next: What selenium does. Does it cause operculum deformities in fish?

Literature Cited

J.M. Beatty and G.A. Russo. 2014. Ambient water quality guidelines for Selenium Technical Report Update
ISBN 978-0-7726-6740-3 Available at: http://www2.gov.bc.ca/gov/content/environment/air-land-water/water/water-quality/water-quality-guidelines/approved-water-quality-guidelines