09/21/2013 05:00 EDT | Updated 11/21/2013 05:12 EST

Air Advisory In Alberta Issued After Power Dips At Refineries Near Edmonton

burning and smoking oil flare

EDMONTON - Health officials in northern Alberta have issued an air quality advisory after a power failure forced refineries in the Edmonton area to flare off extra gas, creating clouds of thick black smoke.

Alberta Health Services says the advisory is precautionary, and applies to people with pre-existing respiratory conditions such as asthma, or heart conditions.

AltaLink, which supplies power to the area just east of Edmonton known as "refinery row," says earth-moving equipment damaged a line early Saturday.

Company spokesman Scott Schreiner says it caused a voltage dip rather than a complete failure, but it affected operations for a number of industrial customers.

Schreiner says no one was hurt.

Full power was restored later in the morning, but some refineries say extra flaring could continue throughout the weekend.

John Huntzinger, director of site operations at Keyera Alberta EnviroFuels, said the voltage dip required the facility to shut down. That meant it needed to vent off hazardous energy, or pressure.

"All of our systems performed as intended to control the situation," Huntzinger said, noting any additional flaring had been completed by Saturday afternoon.

The Imperial Oil Strathcona Refinery said it a recorded message left on a community update line that all of the refinery's processing units are in a safe position following the power interruption.

"Neighbours can expect to see increased flaring and noise over the next 24 to 48 hours as all unit operations are returned to normal. We apologize for any inconvenience this may cause," the message stated.

Suncor reported on the update line that it was experiencing "process upsets" that may create a higher flame on its flarestack as well as increased noise.

The air quality advisory affects Edmonton as well as communities to the north.

Alberta Health Services says most healthy people don't need to be concerned, but that people with pre-existing conditions may notice a worsening of symptoms and should adjust their activities accordingly.

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