Plans by an Alberta company to drill a sour oil well Wednesday in a hamlet southwest of Edmonton has led to accusations from parents that the firm is breaking a promise not to do such work while children are at school.

Highpine Energy was supposed to start drilling the well this weekend near the hamlet of Tomahawk, about 100 kilometres southwest of Edmonton.

But work was three days ahead of schedule, and the company had planned to start drilling late Tuesday. A delay means the work will now start Wednesday after students have gone home. 

The well is about seven kilometres from Tomahawk school, which has 130 students from kindergarten to Grade 9. 

Parents were told about the change in plans in a letter sent home with students earlier this week.

"I'm very, very discouraged right now," said Anita Berger, a resident with two children at the school.

"I'm just so disappointed in Highpine because they had consistently said they would make some efforts to drill while school is not in session and to me they've made absolutely no efforts to drill while school is not in session," she said. 

"I guess clearly we can't trust anything they've said."

Toxic gas feared

Berger is worried an accident could release toxic gas in the area.

But Highpine Energy has defended its safety record, saying it has drilled almost 100 wells in the area without any incidents.

Christian Vernados, consultation supervisor for Highpine Energy, said Tuesday the company's agreement with the Parkland School Division allows drilling to take place during school hours if "reasonable efforts can't be met."

"We have a provision in there having school buses on standby, so in the event of an emergency the buses are available to evacuate the school," he said.

Work is expected to be completed before the start of school Thursday. Buses will be in front of the school all day in case the work isn't done on time.   

But Berger said the prospect of an evacuation could be terrifying for the students.

"These are kids and they have no idea how to handle this kind of hazard, this kind of potential threat," she said. "I mean, they see this as a threat and it scares them."

Highpine Energy is doing more than what is required by Alberta's Energy Resources Conservation Board (ERCB) because the well is located outside the three-kilometre emergency planning zone, ERCB spokesperson Bob Curran said Wednesday.  

"The regulations in Alberta around sour gas are the strictest in the world," Curran said. "Above and beyond that, this company has chosen to put in place things that are actually not required."

Those measures include monitoring the air around the school, and drilling as if the company were dealing with a "critical sour well," even though it is not, Curran said.

Highpine Energy has an application before ERCB to drill more sour oil wells in the area.

These wells will be even closer to Tomahawk School, within three kilometres.

The application for the wells was opposed by the Parkland School Division and the fire chief of Parkland County during ERCB hearings in late September and early October. Berger and a group of local residents have also campaigned against the wells.

A decision on the application is expected within weeks.

With files from John Archer