GRANDE PRAIRIE, Alta. -- An energy company says a pipeline from a gas facility has been shut down after it leaked an estimated 500,000 litres of produced salt water in northwestern Alberta.

Produced water is a byproduct of oil and gas development.

Calgary-based NuVista Energy Ltd. says staff identified the leak on Monday through the company's pipeline monitoring system.

The Alberta Energy Regulator website says the leak is due to a pipeline failure 70 kilometres south of Grande Prairie.

It says no impacts to wildlife have been reported.

NuVista says crews are working to skim off any contaminated fluid for safe disposal.

"Our top priority is to ensure the safety of people, protection of the environment, and fish and wildlife," said Jonathan Wright, NuVista Energy's president and CEO in a release Thursday.

"We will ensure a full and proper cleanup and will investigate to ensure learnings and to avoid any recurrence."

The cause of the leak has not yet been determined.