The water quality near the site of the massive tailings-pond breach this week meets drinking-water standards, according to preliminary test results, but the long-term impact on fish habitats and other wildlife remains unknown.
A water-usage ban will remain in place until additional testing is completed.
Jennifer McGuire, executive director of regional operations at the B.C. Ministry of Environment, delivered the news Thursday afternoon at a public meeting in the rural community of Likely. With her were Premier Christy Clark, Energy and Mines Minister Bill Bennett and Interior Health medical health officer Trevor Corneil.
Medical health officers and water specialists collected samples from three sites at Quesnel Lake and looked at pH levels, turbidity, suspended and dissolved solids, E.coli, dissolved metals and more, Ms. McGuire said.
"All results came back meeting the requirements for Canadian and B.C. drinking-water standards," she said to applause from residents. "This is very good news."
But she likened the preliminary assessments to a blood glucose test for diabetics: "You can stick [a needle] in and get a number back … but if you want a real workup on your hemoglobin and blood count, it's got to go to a lab. Our samples have to go to a lab where they are run through special equipment."
With transportation factored in, some of those tests – which will ideally shed some light on the long-term impacts of the disaster – can be expected in three days. Other testing will continue for some time, she said.
The tailings-pond dam at Imperial Metals' Mount Polley mine burst early Monday morning, spewing millions of cubic metres of mining waste into the Cariboo district's waterways and triggering a local state of emergency. A water-usage ban has left up to 300 residents dependent on bottled water and refilling jugs from communal tanks. Residents are also advised not to swim or bathe in the water, or feed it to pets or livestock.
Dr. Corneil said the ban will remain in place until Polley Lake – which drains into Quesnel Lake – can be tested as well.
The area around Polley Lake has been unstable, which has hampered water-testing efforts to date. Mr. Bennett said Imperial Metals has a ministry-approved plan to pump some water out of Polley Lake into neighbouring pits to mitigate the risk of tailings coming loose and rushing into Hazeltine Creek.
Since 2012, the Ministry of Environment has conducted 14 inspections on the Mount Polley mine site, issuing five warnings. On Wednesday, Mr. Bennett had refuted reports that there had been red flags at the mine over the years, noting only one of the five warnings related to water levels.
"I've been told on numerous occasions that this company was 'repeatedly warned about the water levels in their tailings pond,' " he said. "That is not true; that is not the case. … This company has been warned once about water levels in its tailings impoundment. This company has had five directives from government about issues around the mine site, one of which dealt with the water levels in the tailings pond."
According to records obtained from the Ministry of Environment, the four other warnings were for "bypassing treatment works" in April, when spring melt blocked a pump system and resulted in effluent overflow; failing to submit data for groundwater monitoring wells in both January and April of 2012; and failing to report excess effluent height for the perimeter pond in August, 2012. In the August incident, the perimeter pond overflowed, releasing about 150 cubic metres of waste water.
Mr. Bennett also rejected the claim that cuts to environmental staff at the B.C. government may have contributed to the disaster. A 2011 report by the Environmental Law Centre at the University of Victoria on environmental enforcement and securities at B.C. mines found "successive staff and budget cuts have had significant impacts on their enforcement capabilities."
According to the 2012 annual report of the chief inspector of mines, inspections plummeted from 2,021 in 2001 to 449 in 2003, climbing slowly over the years to reach 1,163 in 2012. In 2011, just 628 mine inspections were carried out.
"I know that the inspections of tailings ponds are as frequent today as they were five years ago," Mr. Bennett had said Wednesday. "This is not an issue of not having enough inspectors on the ground."
Imperial Metals has not made president Brian Kynoch available for an interview with The Globe and Mail.