A Manitoba environmental group is blaming the provincial government and others for a spill it says poured "a toxic soup of acidic water and heavy metals" into a northern lake.

The Wilderness Committee says the incident took place at an abandoned mine in Sherridon, Man., which is located about 800 km. north of Winnipeg. Back in August 2009, the province reclaimed the mine and began to clean up seven million tons of mining tailings that were leaching sulfuric acid into a lake.

But the committee says a water treatment plant being used to clean the site broke down late last month, causing a leak into Kississing Lake.

The committee claims the company that runs the treatment plant failed to shut it down for two days after they learned of the malfunction.

As a result, the water now contains dangerous levels of zinc, cadmium, aluminum and copper, according to the committee.

Sherritt Gordon — a mining company - had shut down its copper and zinc mine almost 60 years prior to the project.