Suncor said about 1,400 of its employees would be deployed for regular maintenance at its Edmonton refinery.
"Although this maintenance work may result in an increase in flaring, noise and traffic related to Suncor’s operations, necessary precautions have been taken to ensure these disruptions are kept to a minimum," the company said in a statement Monday.
The refinery in 2011 celebrated its 60th anniversary of operations. It's designed to process 142,000 barrels of oil sands per day into light oils.
The company said it made the necessary arrangements to ensure its meeting its supply obligations to its customers during the maintenance period.
Last year, the company reported a release of water mixed with what it said was a biodegradable cleaning product. Suncor said the release had no impact on wildlife.