CALGARY - More than 20 groups are calling for a public inquiry into the safety of oilsands extraction techniques that use steam.

The organizations made their demand to the Alberta Energy Regulator on Tuesday as bitumen continues to ooze out of the ground at a project owned by Canadian Natural Resources Ltd. (TSX:CNQ).

The groups say CNRL's Primrose East project, 250 kilometres northeast of Edmonton, isn't the first example of a unexplained failure of an oilsands operation like Primrose.

"It is time for a broader discussion of the safety and regulation of steam injection given these recurring events," said Greenpeace campaigner Mike Hudema said in a news release.

"The AER needs to reassure the Alberta public and other stakeholders that it has the regulations in place to prevent similar incidents from occurring in the future."

About half of current oilsands production comes from in-situ methods that pump steam deep underground to soften the tarry bitumen and enable it to flow through to the surface. The rest comes from open-pit mining of the oilsands.

The depth of the oilsands deposit is one of the factors that determines which method is used, but the trend has been towards more in-situ extraction methods.

The in-situ method will eventually account for about 80 per cent of the oilsands extractions, said Carolyn Campbell, of the Alberta Wilderness Association.

"Therefore, it's important that we get this right," Campbell said in the groups' statement.

To extract bitumen at Primrose, Canadian Natural uses a method called high pressure cyclic steam stimulation, sometimes described as "huff and puff." It involves injecting steam into a reservoir through a well, letting it soak for awhile and then drawing the softened bitumen to the surface through the same well.

The extraction method, which companies have used for decades, involves fracturing the rock to let the steam through, but not so much that it allows bitumen to flow to the surface.

A more common technique is steam-assisted gravity drainage, or SAGD, which pumps steam into one well and uses another well below it to bring the bitumen to the surface.

Though cyclic steam stimulation has grabbed the most headlines recently, the environmental coalition wants the Alberta Energy Regulator to examine both techniques.

CNRL says faulty old wellbores are to blame for the Primrose East leak, though the AER says it still doesn't know the cause.

An investigation by Alberta's energy watchdog into a similar 2009 leak at Primrose said a potential cause could have been "geologic weaknesses in combination stresses induced by high-pressure steam injection."

But Canadian Natural has said it's unlikely that damaged caprock was behind that spill and the more recent one, which was first detected in late June, about the time that heavy rains caused severe flooding further south.

The damage at Primrose East has been contained to a 13.5-hectare area and the company has been cleaning up an estimated 20 barrels — nearly 3,200 litres — that continues to seep out every day at ever-declining rates.

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  • CFB Cold Lake, CNRL

    A bitumen leak was reported at a Canadian Natural Resources oilsands operation in the weapons range part of the RCAF base in June 2013.

  • CFB Cold Lake, CNRL

    Company officials said the leak - at what it calls its Primrose operation - was caused by faulty machinery at one of the wells, affected an area of approximately 13.5 hectares and released as much as 3,200 litres of bitumen each day.

  • CFB Cold Lake, CNRL

    Preliminary tallies put the death toll from the leak at 16 birds, seven small mammals and 38 amphibians. Dozen were rescued and taken to an Edmonton centre for rehabilitation.

  • CFB Cold Lake

    As of early August 2013, more than 1.1 million litres of bitumen had been pulled from marshlands, bushes and waterways.

  • CFB Cold Lake, CNRL

    Although CNRL could not say when the leak may finally be stopped, it estimates it will likely cost more than $40 million to clean up.

  • <em>Click through for other recent spill in Alberta</em>

  • Plains Midstream

    Little Buffalo band member Melina Laboucan-Massimo scoops up July 13, 2012 what appears to oil from the pond shoreline near the site of a 4.5 million-litre Plains Midstream pipeline leak detected April 29, 2011. Photos taken at the site and released by Greenpeace of Alberta's second-worst pipeline spill suggest at least part of the site remains heavily contaminated despite company suggestions that the cleanup is complete.

  • Plains Midstream Canada

    A boat passes by a boom stretching out to contain a pipeline leak on the Gleniffer reservoir near Innisfail, Alta., Tuesday, June 12, 2012. Plains Midstream Canada says one of their non-functioning pipelines leaked between 1,000-3,000 barrels of sour crude near Sundre, Alberta, on June 7 and flowed downstream in the Red Deer river to the reservoir.

  • Plains Midstream Canada

    Debris pushes up against a boom as it stretches out to contain a pipeline leak on the Gleniffer reservoir near Innisfail, Alta., Tuesday, June 12, 2012.

  • Plains Midstream Canada

    A boom stretches out to contain a pipeline leak on the Gleniffer reservoir near Innisfail, Alta., Tuesday, June 12, 2012. Plains Midstream Canada says one of their non-functioning pipelines leaked between 1,000-3,000 barrels of sour crude near Sundre, Alberta, on June 7 and flowed downstream in the Red Deer river to the reservoir.

  • Plains Midstream

    A boom stretches out to contain a pipeline leak on the Gleniffer reservoir near Innisfail, Alta., Tuesday, June 12, 2012. Plains Midstream Canada says one of their non-functioning pipelines leaked between 1,000-3,000 barrels of sour crude near Sundre, Alberta, on June 7 and flowed downstream in the Red Deer river to the reservoir.

  • Plains Midstream Canada

    A photographer snaps a boom stretching out to contain a pipeline leak on the Gleniffer reservoir near Innisfail, Alta., Tuesday, June 12, 2012. Plains Midstream Canada says one of their non-functioning pipelines leaked between 1,000-3,000 barrels of sour crude near Sundre, Alberta, on June 7 and flowed downstream in the Red Deer river to the reservoir.

  • Plains Midstream Canada

    A boom stretches out to contain a pipeline leak on the Gleniffer reservoir near Innisfail, Alta., Tuesday, June 12, 2012. Plains Midstream Canada says one of their non-functioning pipelines leaked between 1,000-3,000 barrels of sour crude near Sundre, Alberta, on June 7 and flowed downstream in the Red Deer river to the reservoir.

  • Plains Midstream Canada

    A worker slows traffic while a boom stretches out to contain a pipeline leak on the Gleniffer reservoir near Innisfail, Alta., Tuesday, June 12, 2012. Plains Midstream Canada says one of their non-functioning pipelines leaked between 1,000-3,000 barrels of sour crude near Sundre, Alberta, on June 7 and flowed downstream in the Red Deer river to the reservoir.

  • Plains Midstream Canada

    A no swimming sign along the banks of the Gleniffer reservoir while a boom stretches out to contain a pipeline leak on the lake near Innisfail, Alta., Friday, June 12, 2012. Plains Midstream Canada says one of their non-functioning pipelines leaked between 1,000-3,000 barrels of sour crude near Sundre, Alberta, on June 7 and flowed downstream in the Red Deer river to the reservoir.

  • Plains Midstream Canada

    Oil from a pipeline leak coats a pond near Sundre, Alta., Friday, June 8, 2012. Plains Midstream Canada says one of their non-functioning pipeline leaked between 1,000-3,000 barrels of oil.

  • Plains Midstream Canada

    Oil from a pipeline leak coats a pond near Sundre, Alta., Friday, June 8, 2012. Plains Midstream Canada says one of their non-functioning pipeline leaked between 1,000-3,000 barrels of oil.

  • Plains Midstream Canada

    Oil from a pipeline leak coats a pond near Sundre, Alta., Friday, June 8, 2012. Plains Midstream Canada says one of their non-functioning pipeline leaked between 1,000-3,000 barrels of oil.

  • Plains Midstream Canada

    Tracks pass through oil on the banks of the Gleniffer reservoir after a pipeline leak near Sundre, Alta., on Friday, June 8, 2012. Plains Midstream Canada says one of their non-functioning pipelines leaked between 1,000-3,000 barrels of oil.

  • Enbrige's Athabasca pipeline

    Approximately 1,450 barrels of oil spilled from a pumping station along Enbridge’s Athabasca pipeline in June 2012. The spill occurred approximately 24 kilometres from Elk Point, Alta., a village located 200 kilometres northeast of Edmonton.

  • Lake Wabamun

    Wreckage from the August 3rd train derailment and subsequent oil spill is seen lining the shore of Lake Wabamun on Monday, August 8, 2005, as clean-up continues.

  • Lake Wabamun

    Wreckage and black oil from the August 3rd train derailment and subsequent oil spill are seen lining the shore and waters of Lake Wabamun on Monday, August 8, 2005, as clean-up continues.

  • Lake Wabamun

    White absorbent boom is seen lining the shores of Lake Wabamun, Alberta, as the clean-up effort from the August 3rd train derailment and subsequent oil spill continues on Monday, August 8, 2005.

  • Lake Wabamun

    Wreckage and black oil from the August 3rd train derailment and subsequent oil spill are seen lining the shore and waters of Lake Wabamun on Monday, August 8, 2005, as clean-up continues.

  • Lake Wabamun

    Wreckage and black oil from the August 3rd train derailment and subsequent oil spill are seen lining the shore and waters of Lake Wabamun on Monday, August 8, 2005, as clean-up continues. Lake Wabamun was severely polluted when a train carrying heavy oil derailed on August 3, 2005, spilling much of it's load into the lake.

  • Lake Wabamun

    Rail cars leak bunker fuel oil, meters from summer homes bordering Lake Wabamun, after a freight train derailed, in this August 3, 2005 file photo, near the town of Wabamun, Alta. Canadian National Railway faces an environmental charge stemming from the train derailment and oil spill at a popular Alberta lake last summer.