The latest water samples from Quesnel River off the Likely Bridge on Nov. 19 are consistent with previous results.
Results for water quality show turbidity levels above the British Columbia drinking water guidelines and total aluminum above Health Canada drinking water guidelines.
According to Health Canada, there is no evidence of adverse health effects for aluminum at levels above the guidelines.
Results for aquatic life show total copper levels above the chronic water quality guidelines.
Chronic guidelines are based on the average of five samples collected over a 30-day period. As a result, exceedances in a single sample do not automatically indicate impacts to aquatic life.
Long-term monitoring and testing is necessary to help better determine and understand any potential long-term impacts to aquatic life.
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 reaffirms that 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.
Mount Polley Mining Corporation has committed to deliver water to residents drawing water from Quesnel Lake during this period of high turbidity.
As of Sept. 23, the Quesnel River off Likely Bridge site has been established as a federal/provincial trend monitoring site and is being sampled weekly.
All test results have been shared with local First Nations, the First Nations Health Authority, Interior Health and the Cariboo Regional District.
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.