(Adds NuVista comment)
CALGARY, Alberta, Aug 19 (Reuters) - The Alberta Energy Regulator is investigating a leak on a NuVista Energy pipeline in northern Alberta that spilled 100 cubic meters, roughly 629 barrels, of oil and water and natural gas emulsion, the regulator said on Wednesday.
The leak on the pipeline, 50 kilometers (30 miles) northeast of Rainbow Lake, was first identified by a helicopter crew during an aerial surveillance flight on Friday, and covered an area approximately 70 by 100 metres.
Bob Curran, director of public affairs at the Alberta Energy Regulator, said NuVista shut in the line and a clean-up was under way. AER staff are on site investigating the spill.
There has been no impact to wildlife reported.
NuVista Chief Executive Jonathan Wright said the company responded within minutes of the leak being reported and is cooperating with the AER and local First Nations representatives.
It has not yet determined the cause of the spill.
The company said special equipment will be used to skim off any contaminated fluid.
Last month an oil sands pipeline owned by CNOOC subsidiary Nexen Energy leaked 31,500 barrels of bitumen emulsion in northern Alberta, drawing fierce criticism from environmentalists. (Reporting by Nia Williams; Editing by Nick Zieminski)