The wastewater spill near Zama City, Alberta, at 9.5 million litres, is North America's biggest in recent history.

The spill, first spotted June 1, has leaked oil, water and other chemicals out of Apache's wastewater pipeline, and is the third major spill in the area, The Globe and Mail reports.

The leak happened less than 100 kilometres from the Northwest Territories border, and 20 kilometres from Zama City, and has affected more than 42 hectares - about the size of 52 CFL fields.

The spill is Alberta's tenth largest "produced water" spill since 1975, Global News reported.

In that time, Apache has been responsible for 949 spills - 517 of which have been produced water spills.

Produced water is a salty chemical that contains hydrocarbons, radioactive material and additional substances, Global reports.

Bob Curren of the resources conservation board said Alberta regulators didn't learn how big the spill was until Tuesday.

"At the outset we were unaware that it was of this extent or volume," Curren said from Calgary. "If we had known that up front we would have made the announcement at that time.

"Once it was determined that the volumes were at this level we immediately moved to issue a news release."

Provincial spokesperson Nikki Booth told CBC Edmonton that both the Alberta Environment Support and Emergency Response Team and the Energy Resources Conservation Board are working with Apache to assess any environmental damage.

“At this point, we're still monitoring wetlands and water bodies near the break so I don't have information on impact on wetlands and water bodies are, but we do know at this point in time there's no indication there's been any impact to the Zama river.”

Greenpeace Canada said the area of the spill is an important wetland and habitat for animals and birds.

"This is a massive spill of toxics into one of the most important wetlands in Canada, if not the world," said spokesman Keith Stewart.

The leak comes after two other major spills in the area, including 800,000 litres of wastewater mixture from Pace Oil and Gas Ltd., and 3.5 million litres of oil from a Plains Midstream Canada pipeline.

James Ahnassay, chief of the Dene Tha First Nation, told the Globe and Mail “every plant and tree died” in the area affected by the Apache spill.

Loading Slideshow...
  • 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.