Turner Valley - Tests show methyl mercury levels down

Okotoks Western Wheel
November 30, 2005
Vol 31 No 17
By Laurel Nadon
Staff reporter

The most recent tests by Alberta Environment show that methyl mercury levels have decreased in the Sheep River downstream from the Turner Valley Gas Plant, but residents say the results don’t conclusively show the river is safe.
Results from Nov. 8 samples show a decrease in methyl mercury levels, especially in the Sheep River at Black Diamond which went from 0.21 ng/L (nanograms per litre) detected in samples from Oct. 26 to 0.05 ng/L detected in samples from Nov. 8.
The results from the Turner Valley and Black Diamond raw water show 0.09 ng/L detected at each location on Oct. 26 with no detection on Nov. 8.
The Calgary Health Region has reviewed these initial results and determined that the total and methyl mercury concentrations do not suggest a public health risk.
“I’m relieved the levels are low and my hope is they continue to test, but we can’t formulate an opinion based on two results,” said Linda Abrams, a concerned resident from Okotoks and business owner in Black Diamond. “Everyone’s dancing around because they didn’t find it, but how do they know they won’t find it tomorrow? Even if the levels are being reduced, it’s still there.”
Abrams said the low levels could have been caused by a variety of things. If the bacteria, which is necessary to cause methylation in the mercury, is low because its food source isn’t as readily available due to the season, then it may affect the result.
Another cause could be reduced water flow which decreases the potential amount of mercury released into the water.
While these potential reasons are speculation, Abrams said one thing is clear: there is still some methyl mercury in the water.
She said the results simply mean that on that particular day, methyl mercury wasn’t found at some sites. She wants to see consistent tests to develop a baseline of what typical levels are for the area.
“Just because they didn’t find any in the sample that day, it doesn’t mean it’s not there,” Abrams said.
Methyl mercury levels could have been diluted from runoff or snowfalls meaning the results don’t show the Sheep River is free of methyl mercury, said Black Diamond Councillor Michel Jackson, who pushed for council to begin testing drinking water for methyl mercury at its last meeting on Nov. 16.
“I’m under the impression that maybe there is no methyl mercury coming from the plant, but it just might be naturally occurring in the whole water system,” Jackson said. “It’s something that’s unpleasant, but I feel pretty confident that all the data we’ve been given says something’s there and any amount is something to worry about.”
He pointed out that scientists have determined the amount of methyl mercury they believe to be safe. The Canadian Council of Ministers of the Environment (CCME) has drinking water standards which state that the maximum allowable amount for methyl mercury in water is 4 ng/L. However, the footnotes of the CCME states that this level may not be a protective level.
“Underneath that (4 ng/L), we should feel safer, but there could be reasons for concern,” Jackson said.
He said he trusts that drinking water is still safe as Alberta Environment is monitoring the situation and sharing their findings with the towns and the Calgary Health Region.
A detailed analysis of the latest results weren’t released until last week. Martin Foy, district compliance manager for Alberta Environment, confirmed at a town meeting in Turner Valley on Nov. 1 that low levels of methyl mercury were discovered in the Oct. 26 samples. Samples were taken at six locations on Oct. 26 and Nov. 8.
Samples were sent to the Alberta Research Council (ARC), a lab accredited for methyl mercury by the Canadian Association for Environmental Analytical Laboratories (CAEAL).
Alberta Environment will continue to sample the Sheep River with a final analysis and report generated once the sampling program is complete.
The Towns of Black Diamond and Turner Valley will soon begin testing their drinking water for methyl mercury.