Latest Mount Polley water sample results show high turbidity and copper levels.
According to results from the latest water samples from Quesnel River off the Likely Bridge, water quality continues to show turbidity levels above the B.C. drinking water guidelines and total aluminum above Health Canada drinking water guidelines.
The findings are consistent with previous results and the sampling taken Nov. 19, states the Ministry of Environment in an information bulletin issued Tuesday.
Results for aquatic life show total copper levels exceed the chronic water quality guidelines. Chronic guidelines are based on the average of five samples collected over a 30-day period. Long-term monitoring and testing is necessary to help better determine and understand any potential long-term impacts to aquatic life.
According to the ministry, the increased turbidity at the Likely Bridge is the result of the complete breakdown of a thermocline (water temperature gradient) in Quesnel Lake as a result of the annual fall overturn of the lake.
Fall overturn occurs when warm surface water of the lake cools allowing the cooler and deeper waters to mix with the surface water of the lake.
Interior Health said all chemical sampling on surface water located outside of the impact zone meets safety guidelines.
Residents using surface water are advised to treat water for pathogens (germs) found naturally in surface water.
Residents unable to treat their water should boil all water used for drinking, washing of fresh fruits and vegetables and making ice for one minute or use water from an alternate potable water source.
The information bulletin stated that Mount Polley Mining Corporation, responsible for the tailing breach which released an estimated 25 million cubic metres of mine water and sediment into Quesnel Lake Aug. 4, has committed to deliver water to residents drawing water from Quesnel Lake during this period of high turbidity.
Full-time and seasonal residents on Quesnel Lake rely on the lake for their source of water, both drinking and household.
As of Sept. 23, 2014, the Quesnel River off Likely Bridge site has been established as a federal/provincial trend monitoring site and is being sampled weekly.
All results and explanations are publically available on the Ministry of Environment’s dedicated Mount Polley site: http://www.env.gov.bc.ca/eemp/incidents/2014/mount-polley.htm.