Teck Resources held a water quality open house on Tuesday, October 29 at the Fernie Senior’s Drop-in Centre to speak with residents about safety, water quality, and environmental considerations pertinent to its Elk Valley operations. Nic Milligan, Manager, Social Responsibility with Teck, began the evening with an important reminder for Elk Valley residents to have their furnaces maintained and serviced, as the onset of winter increases the risk of potentially fatal carbon monoxide poisoning, particularly with older or poorly maintained furnaces.
Dan L’Heureux, Director, Water Strategy at Teck Resources then lead a discussion about active water treatment at the West Line Creek tank-based plant.
“We came to discover that while the plant was working very well to remove total selenium and nitrate, some of the selenium that was left in our effluent was not of the species that we expected and more bioavailable than we expected,” he explained. “And so we needed to understand what that meant and what we could do about it. What it meant was, the facility that we built and put to work wasn’t having as much of a benefit as we wanted. Selenium was still being up-taken into benthic invertebrates and fish tissues.”
L’Heureux said that with expert help, Teck was able to select an advanced oxidation process to remove the problem selenium type.
“We are now about one year in,” he explained. “The advanced oxidation process is doing the job we wanted. We are meeting our water quality parameters. The tissue concentrations are at the level of benchmarks. That’s a great new story for us.”
In addition to tank-based water treatment technology, which is being deployed at other Teck mines, the company is using saturated rock fill (SRF) a system that involves filling in mined-out open pits with waste rock, allowing the pit to become naturally water saturated, then removing nitrate and selenium from the water using similar biological processes as tank based water treatment. The SRF system is advantageous over traditional valley based waste rock piles, which historically allowed mine influenced water to drain into the watershed. SRF consumes fewer overall resources and has and has an extended operating life.
“It’s very exciting how well it’s working,” said L’Heureux. “We are operating up to 10 million litres per day. We are removing 95 percent of the selenium and nitrate, which is the same performance, or similar performance, to the West Line Creek [tank based] facility.
Matt Gay, Manager, Water Quality with Teck, said the company is looking at six more water treatment projects over the next 10 years, prioritizing SRF.
“We’ve also identified another technology that is somewhere in between saturated rock fill and tank based treatment,” he explained.
Teck is actively conducting other water quality and aquatic health research studies, sampling at approximately 100 stations in the Elk Valley.
Teck’s water quality plan, Five Year Update, states “To date, regional monitoring indicates that current levels of selenium and other substances are not impacting populations of fish or birds.”
The company is also investing $30 million this year in over 20 research and development projects including alternative treatment technologies, nitrate prevention, and waste rock covers.
Lindsay Watson, Lead Fish Habitat Management with Teck is collaborating with regulators and Ktunaxa Nation (Elk Valley Fish and Fish Habitat Committee), on work to create new fish habitat to ensure healthy fish populations.
“To date, more than 75,000 m2 of fish habitat, and 10km of stream length have been created or rehabilitated, while 47.5 hectares of land adjacent to the river have been planted since 2016,” she said in a statement.
“Most of the projects are located in the Upper Fording River within the Fording River Operations mine boundary. Other projects are in Line Creek, Grave Creek, Michel Creek and the Elk River. Teck fish habitat rehabilitation and creation objectives are to improve fish passage for multiple life stages, restore channel form and function and increase habitat complexity, create and rehabilitate tributary habitat, and re-establish riparian ecosystems.”