While early tests on the water from a ruptured B.C. mine-waste pond are promising, an official with the provincial Environment Ministry says more rigorous testing and sampling is needed before the water quality can be fully assessed.

Environment Ministry manager Jennifer McGuire said the initial test results are only based on samples from three locations — two from Quesnel Lake and one from the Quesnel River — and the ministry has not yet taken samples of the silt that spilled from the mine's tailings pond due to safety issues.

McGuire was speaking Thursday afternoon to residents and reporters at a town hall meeting called to discuss the early test results.

She likened the quick, early water test results to a quick blood test for glucose.

Contents from a tailings pond flow down Hazeltine Creek into Quesnel Lake near the town of Likely, B.C., on Tuesday. The pond that stores toxic waste from the Mount Polley Mine had its dam break on Monday, spilling its contents. (Jonathan Hayward/Canadian Press)

"If you get your blood tested and you want to know what your glucose is, you can do a real quick test and prick your finger and get a number back," she told reporters.

"And that's a quick and dirty number — instantaneous. We've been doing some of those samples for pH and conductivity, which are good indicators of the health of the water, but if you want a real workup, it's got to go to a lab."

McGuire said crews have been on the water every day since the tailings pond breached Monday, and many more samples have been collected.

For definitive results, she said, samples need to be run through specialized equipment in certified, clean environments.

"And we're pushing those labs to move stuff through, but it's taking three days."

Polley Lake contamination unknown

Dr. Trevor Corneil, a regional medical health officer, said a decision was made to leave the water-use ban in place because key testing has not yet been done.

"We don't have information from Polley Lake at this time, which drains into what was the tailing pond and then into Quesnel Lake," he said.

A aerial view shows the damage caused by Monday's tailings pond breach at the Mount Polley Mine, which resulted in a ban on using water from the area. (Jonathan Hayward/Canadian Press)

Corneil said Polley Lake is only just now being sampled.

"There is difficulty getting to that lake because of safety concerns," he said. "There is also a concern about that lake breaking the barrier between it and the Hazeltine Creek area, and we don't know what's in that."

"Pre-tests show it was not drinking-water level on all chemicals, so for the time being we're leaving the 'do-not-use' in place until we have results from Polley Lake and see if they meet Canadian drinking water standards and we know the lake is stable and will not breach."

Debris from the tailing pond breach backed up into Polley Lake at the same time the bulk of the pond's effluent went roaring down Hazeltine Creek into Quesnel Lake.

Corneil said officials are being cautious because the tailings pond chemicals can be absorbed though the skin and the stomach.

Energy and Mines Minister Bell Bennett said the main priority over the next few days is to close the breach in the tailings pond and make sure that rain doesn't bring more material down the creek bed.