A coalition of concerned groups led by the Keepers of the Athabasca watershed protection organization is doing its own testing of sediment in the Athabasca River.
The Obed response group is trying to track any movement of contaminated sediment that may have been deposited by a coal slurry plume that made its way up the Athabasca River late last year.
The coalition, which includes Ecojustice, MiningWatch Canada and First Nations, hopes to monitor sediment movement for years to come.
“Our goals are twofold,” said Keepers of the Athabasca member Donna Mendelsohn. “Yes, we do want to know what’s in the sediment without having to rely on the company monitoring. The other thing is, we’d like to be somewhat prepared … to see community monitoring happen along the river from now on.”
The Keepers sampled seven sites earlier this month. The sites stretched from the Town of Athabasca almost to the spill’s source, the Obed Mountain Mine near Hinton (approximately 547 km upstream). The group collected three to five 250-mL samples from each site by drilling through the ice. The 31 samples have been sent to commercial labs and to the University of Alberta to be tested for mercury, heavy metals (including toxins like arsenic) and polycyclic aromatic hydrocarbons (PAHs can be carcinogenic and mutagenic).
As of press time, Mendelsohn was unsure when all the sediment test results would be back.
Other members of the coalition have taken the lead on testing sediment downstream from Athabasca.
“We’re seeing government take a somewhat hands-off approach to monitoring,” said Mendelsohn, noting that monitoring from now on will be up to consultants hired by the company responsible for the Obed Mountain Mine, Sherritt International.
“They emphasized the plume,” said Keepers member Harvey Scott of the government and Sherritt’s focus after the slurry spill. “That was never our greatest concern.”
If seven sample sites along a 500-km-or-so stretch of river doesn’t sound like a lot, it’s worth noting that Alberta Environment and Sustainable Resource Development (ESRD) took fewer sediment samples than that and over an even greater distance: six samples over an approximately 600-kilometre stretch of the river.
The ESRD collected its river sediment samples in November and noted that at one sampling site 30 km upstream of the Town of Athabasca, arsenic and chromium were at concentrations above guideline limits. (The ESRD uses freshwater sediment Interim Sediment Quality Guidelines, or ISQGs, where possible.)
However, ESRD limnologist Dr. Colin Cooke stated the arsenic and chromium exceedances were likely not related to the spill.
The ESRD also noted exceedances of 10 types of PAHs in sediment at sites 19 km and 22 km from the spill along the riverbed.
Sherritt has conducted sediment and soil samples of its own. The company has tested 256 samples to date: some soil surrounding the spill site, some sediment, and some deposited solids from the spill.
Sherritt has acknowledged that in some tested areas, high concentrations of arsenic, iron, zinc, and molybdenum were found; however, the company believes these high concentrations are “an anomaly that appears to be naturally occurring.”
The company has highlighted one type of PAH as exceeding a guideline that Mendelsohn criticizes for not being conservative enough (the “probable effect levels” guideline).
On its website, Sherritt states its investigation into these substances of “possible concern,” as well as cleanup of the sediment in two affected creeks, is ongoing.
Sherritt has collected 12 sediment samples from the Athabasca River as of press time and plans to collect more over the summer; it does not yet have an end date for when it will cease to monitor the sediment in the river.
The ESRD has also stated it is awaiting test results of four sediment samples from the Obed mine site and the two affected creeks (not the river). The ESRD hopes analyses of those four samples will allow the ESRD to then “‘fingerprint’ sediment released by the Obed spill and distinguish it from other sources of sediment in the Athabasca River,” said Cooke.
Two Athabasca-based scientists helped with the Keepers’ initial sampling, and a professor at U of A has allowed access to two labs there, but the lion’s share of the work is up to a small group of volunteers.
Scott said it is challenging to collect sediment from a river bottom when the river is frozen: you have to contend with ice on the surface, which must be drilled through (the Keepers used a hand-powered auger and chisel), and once you’re through, you have to contend with gravel and rocks on the river bottom.
“You know generally where the (sediment) deposition takes place: on the slow side of the river. So it’s on the inside of a bend,” he said.
That rule of thumb doesn’t guarantee success, though.
“Up in Smith, the first three holes we dug, it was solid rock on the bottom: either shale or sandstone.”
But by drilling the holes and collecting the samples before break-up on the river, “We have sort of a baseline measure before the ice scours the bottom,” said Scott.
Mendelsohn noted the Keepers wanted to take samples closer to the spill site, but, “There was no encouragement at all as far as letting us get onto the mine site.”
The closest they got, she said, was driving to a public road that crosses one of the affected creeks, Plante Creek, and hiking upstream from there.
Paying for testing will be the next challenge. Scott said testing for PAHs is $300 per test, while mercury tests are about $50 to $80 each.
$5,000 has been raised for the project so far.
“We’re already way over budget,” said Scott, though he remained hopeful that more funds would be collected to sustain the project.
“If we get the money together, we’ll test at least once a year and see how far it goes,” he said. That long-term view is key, he and Mendelsohn agreed, as the concern is that toxins will gradually be taken up by benthic life on the riverbed and make their way up the food chain.
Scott said it’s likely much of the contaminated sediment was too heavy to be carried very far initially.
“Every time there’s a freshet in the spring … this stuff will be picked up and moved. Eventually, we’ll get higher and higher concentrations here and right down the river,” said Scott.
Scott acknowledged Sherritt’s cleanup efforts on slurry-affected creeks that feed into the Athabasca River. Those efforts have included the installation of sediment traps and a silt fence, as well as removal of some sediment with excavators.
“Hopefully they catch most of it,” he said.
Mendlsohn noted that because of that dredging, though, “It was kind of a crapshoot for us whether we’d get useful samples out of (Plante Creek).”
She said whether the Keepers get conclusive results from any of sediment tests or not, “We know that significant amounts of contaminants did enter the Athabasca River.”
She said even “sketchy” data from the ESRD and Sherritt have already shown this to be true. However, she said, “There is nowhere near enough sampling being done.”
Most importantly, she said, “There’s no confidence that the company or the government will tell us the truth about the impacts of this spill.”
The real story, say the Keepers, is in the sediment now.
