Apache Canada Ltd. reported one of its operator's discovered the leak on Oct. 25 at its Shekilie field northwest of Zama City and the line was immediately shut in.
The company also says an investigation found the leak began on Oct. 3 and the amount of waste water that leaked was about 1.8 million litres.
Waste water that is extracted during oil and natural gas operations contains oil, salt and other minerals.
Darin Barter of Alberta Energy Regulator confirms Apache reported the leak on Oct. 25 and says the agency won't be able to confirm the amount that spilled until it completes its investigation.
Apache also says it has revised the volume of waste water that spilled from its pipeline in the same area in May to 15.4 million litres, up from its original report of 9.5 million litres.
In a news release dated Oct. 18, Apache it has determined that the pipeline started leaking on May 5, but it wasn't discovered to be leaking until June 1.
Apache says the cause of the pipeline failure was stress corrosion cracking.
It says it was "installing real-time monitoring with SCADA (supervisory control and data acquisition) to the existing four water injection systems across Apache's Zama operations area."
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