Test results released Tuesday show a host of noxious chemicals and metals made their way into the Athabasca River after last month's massive coal-mine spill near Hinton, Alta.
Alberta's environment department has now ordered Coal Valley Resources Inc. and Sherritt International Corp. to make detailed plans for cleaning up the spill from the Obed Mountain mine, and to take steps to prevent any further pollutants from entering the Athabasca – the province's longest river – from the creeks near the mine site.
Alberta's chief medical officer of health, Dr. Jim Talbot, released a statement Tuesday saying he's confident that at no time was there a risk to drinking water. However, as a precaution, water treatment plants are still being asked to refrain from using river water "when the plume is near."
A report from the province's environment department also released Tuesday said government scientists continue to evaluate the "potential long-term human health impacts from the Obed Mountain mine release to this drinking water source and to fish and wildlife." Water quality guidelines for some pollutants were exceeded as far as 40 kilometres from the release.
On Oct. 31, a dike failed at Sherritt's Obed Mountain mine water storage pond, releasing 670,000 cubic metres of water – along with clay, mud, shale and coal particles – into creeks that flow into the Athabasca River. The Athabasca originates in the Rocky Mountains, and flows in a northeasterly direction through a number of Alberta communities including Whitecourt and Fort McMurray, as well as the province's oil-sands region. All downstream were told not to drink the water. The spill was contained by Nov. 4.
After examining Tuesday's report, retired but still renowned University of Alberta water scientist David Schindler said he agreed there likely is no risk to drinking water but there were "some big exceedances of very toxic chemicals," including metals such as silver, zinc, arsenic, lead and cadmium.
"The spill is a pretty large one, even by international standards," he said. "Fortunately, I would say the river is also larger than many that spills have gone into."
Sherritt released a statement late Tuesday saying testing is proceeding, and remediation began as soon as the pond was secured.
"We are deeply concerned about what's happened here and we are committed to making this right," Sean McCaughan, Sherritt's senior vice-president for coal, said in a news release.
"We began our testing the morning after this happened and, to date, these samples have indicated that the sediment travelling downstream in the Athabasca River poses no risk to human health or safety."