HOUSTON A petroleum spill near Suncor Energy's Denver-area refinery has been contained and does not come from the Canadian tar sands, the U.S. Environmental Protection Agency said on Thursday.
Earlier this week authorities discovered a petroleum substance oozing into Sand Creek in Commerce City, north of Denver near a refinery operated by Canadian-based Suncor that processes heavy crude oil extracted from the Canadian tar sands.
Suncor said the spill amounts to less than a barrel. According to the EPA, preliminary tests indicate "a gasoline-like substance."
"We're not dealing with tar sands here," EPA spokesman Matthew Allen told Reuters. "It is refined product."
Suncor has constructed a small dam to contain the spill, said Chief Operating Officer Steve Williams, who will become chief executive officer in May.
"It's a very small leak, it's less than one barrel of oil but we are taking it very seriously," Williams told reporters at a news conference in Calgary.
"It's a small leak but we are actively cleaning it up with the authorities," Williams said.
Tests showed no contamination of the South Platte River, which is a major source of drinking water for the Denver area, Allen said. Sand Creek feeds into the South Platte near the refinery.
The spill "is a relatively minor incident that appears to be under control. We're pretty sure we've contained it," Allen said.
Environmental activists had worried the spill might be tar sands oil. Critics say producing oil from Canadian tar sands and importing it into the United States threatens the environment.
The 93,000-barrel-per-day Suncor refinery receives oil from tar sands in Canada by pipeline and refines it into petroleum products.
Construction crews coordinated by Suncor, the EPA and the Colorado Department of Public Health and Environment have built dams, dug ditches and placed floating barriers to trap the spill.
Suncor, Canada's largest oil and gas producer, is the dominant producer of oil from Alberta's tar sands and expects its output to reach 300,000 barrels or more this year.
TransCanada Corp's planned $7 billion Keystone pipeline linking Canadian oil sands output to U.S. refiners on the Texas Gulf Coast has attracted strong opposition from environmental groups.
(Reporting by Bruce Nichols, additional reporting by Scott Haggett in Calgary, editing by Chris Baltimore)