A small leak prompted officials to send workers back to their rooms at Surmont 2.
The Edmonton Journal reports ConocoPhillips stopped operations at the SAGD site, which is 63 kilometres southeast of Fort McMurray.
The hydrochloric acid leak was found at the site’s central processing facility.
The company says it doesn’t pose a risk to the public or environment, but work is on hold until the area is declared safe.
First steam at the site started last month, and oil production is expected in the third quarter.
