NTPC's Snare Falls hydro unit back online after oil sheen spotted in water for 2nd time this year

A hydro unit that helps powerthe North Slave region in the Northwest Territories is working again after it was taken offline earlier this month following the discovery of an oil sheen near the facilityfor the second time this year.

The Northwest Territories Power Corporation (NTPC) said in a news release Thursday that the Snare Falls Hydro Unit returned to service and is fully functional after carrying out successful tests over the past couple of days.

The unit is part of four generating facilities that makeup the Snare River hydroelectric system which powers Yellowknife, Dettah and Behchok.The aging system has been plagued by costly mechanical issues, curbing its ability to operate at full capacity and the problems keep mounting.

NTPC revealed it has informed regulators that approximately 408 litres of oil has gradually leaked from the Snare Falls unit since June 1.

NTPC says oil in the unit has been replaced with a higher viscosity lubricant as an interim measure to prevent future leaking.

A detailed inspection and any repair work will be completed next year during a period of warmer weather and lower electricity demand, it said.

The unit went offline on Dec. 10. According to NTPC, diesel replacement costs during the shutdown totalled approximately $260,000, though it said the total cost of the shutdown is unknown at this time.

Back in May, the same unit was shut for about three weeks after a similar oil leak.

"Trouble-shooting at a hydro unit is a complex process but our employees and contractors were able to identify and implement a solution fairly quickly," said NTPC president Noel Voykin in a statement.

He said that will help to minimize the cost of the shutdown and avoid the greenhouse gas emissions created by diesel generation during a period of peak demand in the region.