Spill went undetected from January to March 2015, releasing about 1.4 million litres of condensate.
Rupture last July spilled 225,000 litres of heavy oil mixed with diluent onto the bank of the North Saskatchewan River.
Investigations into the cause of the incident are still ongoing.
Company ordered to pay $350,000 in penalties for produced water pipeline spills.
A landowner – not TransCanada’s spill detection system – noticed the spill Apr. 2.
Alberta Energy Regulator says company faces a maximum penalty of $3.1 million.
Company says the affected area is about 16,000 square metres, mostly along the pipeline’s route.
Metals including selenium, boron and arsenic found at twice the recommended levels.