The Syncrude oilsands plant 40 kilometres north of Fort McMurray, Alta., is closed until a problem with foul-smelling emissions is solved. ((CBC))

ASyncrude bitumen processing plant has been ordered by the Alberta Environment Department to shut downanddeal withfoul-smelling emissions that have prompted complaints from nearby residents.

Residents of Fort McKay and Fort McMurray say the Mildred Lake planthas been spewingodours the last few days. The plant is 40 kilometres north of Fort McMurray.

The department ordered Syncrude to "immediately"shut down its new flue gas desulphurization unit and the equipment attached to it.

The environmental protection order said the shutdown was directed "as a precautionary measure" following "numerous" complaints of poor air quality and "new health symptoms." A departmental investigation is underway.

The shutdown should be completed sometime Thursday evening.

Syncrude hasbeen ordered to come up with an action plan to fix the odour problem. That plan must be approved before Syncrude will be allowed torestart itsflue gas desulphurization unit.

In a statement on its website, Syncrude said it is consulting with outside experts and has already taken steps to reduce the potential for future foul-smelling emissions. Syncrude says the odour complaints are related to the start-up of its expansion project.

"Syncrude considers all odour concerns to be a serious matter, and treats them as such," it said.

Syncrude is the consortium of energy companies that is developing the oilsands deposits in northern Alberta.