People in two communities near Peace River say Baytex Energy's operations are creating powerful gassy smells that are impossible to live with.
Alberta's energy regulator called an inquiry after getting numerous complaints.
The regulator says it will now review what it heard and make recommendations in a report by March 31.
Baytex spokesman Andrew Loosely says the hearings were a rewarding experience and the company looks forward to the regulator's findings.
One former resident, Alain Lebreque, says he had to move his family out of the area because the smells were making them sick.
In an affidavit filed with the Alberta Energy Regulator, one resident complained of symptoms that included severe headaches, dizziness, sinus congestion, muscle spasms, popping ears, memory loss, numbness, constipation, diarrhea, vomiting, eye twitching and fatigue.
Baytex uses an unusual method of heating bitumen in above-ground tanks to extract oil.
Reid Glenn, a mechanical engineer, told the hearing that his personal examination of Baytex's operations suggested vapours were coming off those tanks.
"You can see the leaks on a cold day by where the steam's coming off the top of the tank,'' he said.
Geologists also described the nature of the bitumen that Baytex is drilling for, describing it as being high in sulphur. Sulphur is a common component of smelly chemicals.
Loosely has said the company is continuing its efforts to improve its practices and capture all vapours from the tanks.
Expert reports commissioned by the regulator suggest that Baytex's operations are the likeliest source of the odours.
Families affected by the smells have said they want the hearings to result in new rules for the oilpatch that deal specifically with bad odours. Current regulations only address toxic gases or gases that are released in enough quantity to be worth gathering and selling.
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