The massive coal tailings plume in the Athabasca River may be “dissipated,” according to the provincial government, but concerned scientists and health professionals say its lasting effects on the river and delta are only just beginning.
Watershed scientist Kevin Timoney said government officials are downplaying the potential for long-term impacts from the coal slurry on the environment by claiming there is no longer cause for concern.
“Depending on particle size, solids are settling to the bed of the Athabasca River at different distances downstream from the spill. Because the benthic life in the sediments form the basis for the aquatic food web in the river and its delta, this large spill has the potential to cause harm for years to come. The entire river downstream of the spill may be affected,” Timoney said.
“With high river flows next spring and summer, deposited contaminants will be remobilized and move farther downstream where they will settle again and be remobilized in the future, which will result in pulses of contamination. A portion of the contaminated sediments will accumulate in the Athabasca River delta and adjacent Lake Athabasca and its environs. Fishes and water birds may be harmed, as may humans who harvest them.”
The Alberta government reported Monday that the 670,000 cubic-metre plume of coal tailings, released into the environment on Oct. 31, was no longer distinguishable from normal background levels of river water downstream of Fort McMurray, prompting GNWT Environment officials to announce “there is no longer a threat to Northern waters.”
According to provincial officials, the contaminants attached to the suspended particles – which include heavy metals like cadmium and mercury, along with cancer-linked polycyclic aromatic hydrocarbons (PAHs) – are back at below background levels and no longer exceed water quality guidelines for the protection of aquatic life, as well as drinking water.
The province expects the environmental protection order, issued to the company on Nov. 19, to mitigate any future release into the environment during spring freshet.
In the NWT, water monitoring continues on the Slave River at the Fort Smith water intake. A spring sampling plan is to be developed over the winter, according to the GNWT.
Timoney said the province’s water quality results leave out a major part of the story. He said monitoring and emergency response efforts should have included sediment sampling, since most of the contaminants released in the slurry were attached to the solids rather than in the process water.
“Release of water quality information without sediment and toxicology results serves to underestimate the impacts,” he said.
Timoney is not the only one concerned. Physicians in the lower Athabasca region, Dr. John O’Connor and Dr. Esther Tailfeathers, also recently voiced their concern with the lasting effects of the spill in a joint statement.
“As physicians devoted to providing care to downstream residents for many years, we are appalled at the indifference this government exhibits towards the original inhabitants of this province, while going out of its way to support industry,” they said.
Investigation into spill still underway
The Alberta Energy Regulator’s (AER) investigation into how the berm holding back the coal tailings at Sherritt International’s Obed Mountain mine failed remains underway, AER spokesperson Darin Barter told The Journal in an email.
He said the AER will not issue updates as the investigation progresses, but will release the results publicly once the investigation is complete.
Barter would not release documents tied to the AER’s pre-spill inspection of the mine, which was undergoing remediation at the time of the break, stating that information would inform part of the overall investigation.
However, Barter said the Obed mine had been inspected on five occasions since 2011, with the most recent occurring on Oct. 3, 2013. The results of those inspections were normal.
“The AER found no non-compliance issues that would have required enforcement action and documentation during these inspections,” he said.
According to Barter, the tailings pond contained water and “small amounts of unrecovered coal (usually in the form of ultrafine particulates), clay/rock/mineral deposits, and flocculent, which is used as a thickener.”
He was unable to give a more detailed analysis, though results from Environment and Sustainable Resource Development showed the presence of aluminum, barium, cadmium, chromium, lead and mercury in the spill, along with numerous PAHs, the majority of which exceeded limits for aquatic life and drinking water within the first 40 km of the spill’s movement into the Athabasca River.