The B.C. Ministry of the Environment has ordered the Mount Polley mine northeast of Williams Lake, B.C. to stop discharging effluent into Hazeltine Creek.
The provincial order comes only a day after residents said they witnessed slurry being pumped from Polley Lake near the mine downstream into Hazeltine Creek and Quesnel Lake.
The mine breach released 17 million cubic metres of water and more than seven million cubic metres of slurry — much more than the original estimate when the spill occurred Aug. 4.
In an emailed statement, the environment ministry says it also witnessed the tailings pond effluent being discharged into Hazeltine Creek during an inspection Sept. 4.
The province says the mine has not discharged any more slurry into the creek since then and it has ordered the company not to do so in the future.
"This advisory is the first step of an escalating enforcement response to a violation of the Environmental Management Act," the province warns in a letter to the company.
B.C. says it is also concerned the mine is still in a vulnerable position.
"While discharges have stopped since the Sept. 4, 2014, inspection, ministry staff are concerned future rain events will trigger further discharges," the ministry said.
The letter orders the mine to immediately install sediment control systems to ensure tailings pond capacity is sufficient to handle a "one in 10 year 24-hour rainfall event."
Residents concerned
On Monday, residents of the small British Columbia community of Likely, downstream from the mine breach said they didn't believe the provincial government was dealing with the disaster and were were concerned their questions weren't being answered.
One resident with a three-year-old and a six-year-old said she drew their drinking water at the cottage from Quesnel Lake and said the potentially toxic slurry should be removed from the watershed altogether.
Test results last week showed levels of copper, iron, manganese, arsenic, silver, selenium and vanadium in excess of provincial standards near the spill site but the ministry said similar testing last spring also found concentrations above guidelines.
Before and after: slide your cursor across the image
On mobile? Click here to read non-compliance letter from the province