Spills detailed in documents
New information released on Cantung Mine spills, but amounts still unknown
April Hudson
Northern News Services
Thursday, June 9, 2016
TTHENAAGO/NAHANNI BUTTE
Two spills at the Cantung Mine site, overseen by North American Tungsten Corporation Ltd., have been detailed in reports posted to the Mackenzie Valley Land and Water Board.
Inspectors took this photo of quarry water overwhelming erosion and sediment control barriers on the bank of the Flat River. - NNSL file photo
|
In mid-May, federal inspectors from Indigenous and Northern Affairs Canada discovered the spills, along with a host of other issues including torn linings and leaking waste drums. The spills included a leaking pipe from a diesel tank and quarry water running into the Flat River.
The Flat River spill contravened two conditions of the mine's land use permit, including installing erosion control structures and immediately reporting spills. In a May 19 letter to the GNWT, North American Tungsten senior environmental co-ordinator Kyle Conway said the spill involved "an unauthorized release of sediment-loaded meltwater into the Flat River."
An overview of the spill states although sediment fencing existed between the quarry and the river, it was so inundated with sediment and in need of repair that it failed to stop water that had collected in the quarry from the spring melt. As that water pooled, it overcame the barrier and poured into the river.
To stop the spill, staff at the mine site began pumping the water away from the area. They also constructed a 30-metre earth berm, with a height of 1.5 metres, to prevent further water and sediment from entering the river.
As an extra measure, staff installed sediment fencing on the shoreline between the berm and the river.
A spill report filed with the territorial Department of Environment and Natural Resources on May 12 lists the spill amount as unknown.
The second spill, whose amount is also listed as unknown, involved a leaking pipe running from a diesel tank to a fuel transfer shack.
A spill report was filed with Environment and Natural Resources on May 11 and a follow-up report on the Mackenzie Valley Land and Water Board is dated May 27.
The follow-up report states an "unknown volume of diesel contaminated water was released to the ground" because of faults in plugs on the fuel line, which had been compromised during the winter due to freezing and thawing. However, the contamination was contained and staff temporarily repaired the pipe with hose clamps and tape.
"While contaminated soil was being removed, a liner was discovered below the piping which is believed to have prevented contaminated waters from migrating from this area," states the report.
Water in the containment area was contaminated with diesel. North American Tungsten will either treat the water on-site or ship it out for treatment and disposal.
The company will be bringing in a contractor to repair the leak as well as any damage to the liner.
