By Peak Johnson
Earlier this month, a terrible wildfire ignited in Canada’s Alberta forest at Fort McMurray. The fire burned more than 420,000 hectares of the forest, leaving behind ash-covered soil that may now feed into Fort McMurray’s water supply.
Preventing the large amount of ash from the wildfire from contaminating the city's drinking water will be a challenge, a University of Alberta scientist told CBC News
"What has us concerned is, all of the run-off after this fire," Uldis Silins, professor of forest hydrology and watershed management with the University of Alberta said. "All the ash and some of the contaminants that are coming off the landscape when we start to get those rains, is going to be washing those materials into the river, right above the city of Fort McMurray."
After a wildfire, water quality can change drastically. Silins, who is among several water scientists working with the Alberta government on a recovery plan for Fort McMurray, told CBC News that the contaminated water would be difficult to treat.
Though rain would provide relief to firefighters who are battling the blaze, it would be a “double-edged sword” for water treatment officials. The reason being that spring showers can wash wildfire contaminants into the Athabasca River, which connects to Fort McMurray's water treatment plant.
And with each additional rainfall, a new wave of contaminants would wash down to the riverbanks. Silins added that nearly 30 kilometers of the Athabasca River bank and more than 100 kilometers of the Clearwater River have been contaminated so far.
"We have very limited experience with these kinds of large, severe wildfires, right on top of a community where you have a water treatment plant,” Silins said.
Thankfully, Fort McMurray's water treatment plant was not damaged. Silins told CBC News that the Fort McMurray treatment plant is well equipped to handle the disaster. It relies on the same technology Calgary uses, which served that city well following the floods of 2013.
Though research is limited, Silins said that the Lost Creek wildfire of 2003 provided scientists some clues about wildfire contamination in rivers. According to his study on the southern Alberta fire, it could be years before the watershed fully recovers.
More than the 80,000 who were displaced by the fire may be allowed to start returning to their homes in June, as part of a phased re-entry plan presented by the Alberta government.
For similar stories visit Water Online’s Source Water Contamination Solutions Center.