Parkland Corp. has released a review into an unplanned shutdown of its Burnaby, B.C., refinery in January that blanketed parts of Metro Vancouver with a foul stench.

The review released last week says unusually cold weather triggered a series of events leading to the release of a noxious odour that generated more than 100 complaints from residents.

It says the cold weather resulted in a shutdown on Jan. 12, but as crews spent days trying to get the facility back online, they detected a 鈥渟trong odour鈥� on the morning of Jan. 21, followed by a 鈥渓oud pop鈥� and a 鈥済reen-black鈥� plume being emitted from the refinery鈥檚 stacks.

It says the problems 鈥渕ay have been caused by improper closing, valve leakage, or foulant in the system.鈥�

The site was evacuated of non-essential personnel, emergency responders were notified and public advisories were issued soon after, the report says, but 鈥渂roader stakeholder consideration would have improved communications.鈥�

In a written statement, the City of Burnaby says it it鈥檚 pleased to see Parkland taking steps to address the release of emissions, and to improve communications with the public and other stakeholders.

鈥淲e look forward to seeing these recommendations put into action,鈥� the statement said.

Parkland鈥檚 report says it wasn鈥檛 until March 29 that normal operations at the refinery resumed.

The report also says the length of the January cold snap caused problems with instruments at the refinery, hampering sensors that 鈥渄id not have a history of being susceptible to freezing.鈥�

As the odour blanketed parts of Metro Vancouver, the regional federation of municipalities said the air contained elevated contaminant levels but didn鈥檛 breach pollution standards.