by Anthony Swift, reposted from NRDC’s Switchboard

Colorado officials fear that vast amounts of petroleum have been leaking into the South Platte River from a broken pipeline at a refinery operated by tar sands producer Suncor.

It is not yet clear how long oil has been leaking into the South Platte River, how much has been spilled or what substance was spilled. State officials are currently testing the water on the South Platte River, a major source of drinking water, wildlife habitat and agricultural water for Colorado and the Midwest. Meanwhile, levels of benzene and volatile organic compounds at the nearby Denver Metro Wastewater plant required a partial closure.

Suncor is the oldest tar sands producers, up to 90% of its production comprised of tar sands bitumen. The company uses its Colorado refinery to process some of the heavy tar sands coming from the Express and Platte pipelines. At a time when companies like TransCanada and Enbridge are proposing to build tar sands infrastructure through our rivers and water resources—and some in Congress are trying to speed up the process by skipping environmental review—this spill provides another sad example of what can go wrong with these projects.

The spill was discovered on Sunday morning by Trevor Tanner, a fisherman who saw sheen on the South Platte River and said the area smelled like a gas station. In his account:

I walked several hundred feet up Sand-Creek and there was an oil sheen the whole way and there was even a weird milky chocolaty sludge trapped in the small back-eddy below the confluence. My fly smelled like gasoline. My fingers smelled like gasoline. I could see micro-currents and upwells in the water column that you usually just can’t see. Something was terribly wrong.

When Mr. Tanner found the hotline number and called it, the spill response coordinator initially wanted him to call back in twenty minutes. On Monday officials from the Environmental Protection Agency (EPA) arrived onsite and Suncor reported a leak. On Tuesday evening Suncor and EPA officials decided to dig a trench. This afternoon, EPA officials announced that three small booms erected on a bank of Sannd Creek appear to be containing the oil and preventing further contamination.

The extent of the contamination is still unclear. If the leak involves tar sands diluted bitumen, the contamination could be more severe. Tar sands diluted bitumen spills are associated with significantly more submerged oil which cannot be contained by surface booms. Spill responders are still struggling to handle the submerged oil at Enbridge’s Kalamazoo oil spill. However, this spill shows the weakness in spill response and is yet another example of the very real risks inherent in tar sands infrastructure projects.

Anthony Swift is an attorney with the International Program at the Natural Resources Defense Council. This piece was originally published at NRDC’s Switchboard blog.