90,000 tonnes of muddy sediment hit trout creeks

Coal-mine owner Sherrit reveals extent of Oct. 31 spill near Hinton

About 90,000 tonnes of muddy sediment poured into two trout creeks when the containment pond was breached at the Obed coal mine northeast of Hinton on Oct. 31, according to figures released by mine owner Sherritt International on Friday.

The company released this first estimate of the large amount of sediment — clay, sand, coal particles — contained in the wall of waste water that poured into the Apetowun and Plante Creeks and eventually the Athabasca River.

More than 670,000 cubic metres of waste water quickly overwhelmed the two creeks, eroded the banks for at least five kilometres and spread the sediment into the nearby forest.

The company says that its water testing shows — as does provincial testing — that water in the Athabasca River is safe to human health, though at several places the contaminant levels from heavy metals in the first three days exceeded waterquality guidelines.

“Total metals concentrations exceeded water quality guidelines at several locations following the release,” says Sherritt.

The release also says fish in the Athabasca River have not been affected. There is no mention in the release of the impact on fish in the two smaller creeks near the point of release from the pond.

“Preliminary results show that the sediment in the Athabasca River had no measurable impact on fish,” says the release. That conclusion was reached after trout survived in a laboratory test in a tank with water as cloudy as the plume of waste water flowing down Athabasca River.

University of Alberta biologist Greg Goss said he was “very happy” the company released its water test results and said he appreciates the company is working hard to mitigate the damage from the spill.

He also agreed with the company that the toxicity of some heavy metals was low as the company and Alberta Environment contend.

But he said that large amounts of muddy sediment would definitely damage fish and fish eggs in the trout creeks and in the Athabasca River.

“The creek is still a water body and it has fish and it’s not used to 90,000 tonnes of sediment,” said Goss, noting that trout go back to breed in the stream where they were born.

Goss also suggested it is too early to conclude there is no damage to fish in the Athabasca River. Looking for dead fish is not the only sign of impact on the species, he said.

So far, there’s been no information from the department of fisheries and oceans on any damage to fish, he added.

Goss also said he’d like to seem more detail on how the testing was done.