Teck Trail Operations has looked into what was behind that pollution plume over the Kivcet furnace last month.
The incident was caused by a voltage imbalance that caused power supply interruption to the control system within the smelter.
The company says control measures have been put in place to help prevent interruption of the control systems should a similar incident occur.
The discharge of highly visible zinc and lead gases on July 21st lasted about an hour but Teck says they did not result in their permitted levels being exceeded.