“So I want everybody to be aware of what’s happening in our backyard,” said Scott Denver Jacket, one of the protest organizers .

Roughly 200 people lined I-270 around 4:00 p.m. Saturday, slowing traffic, drawing two Commerce City police cars. They carried signs reading “Lies”, “Got Benzene” and “Suncor Killed This River”.

Since late November, Suncor crews have been working to stop benzene, a known carcinogen linked to cancers such as leukemia, from entering the waterway just before it merges with the South Platte River.

“And now it’s March 10th and there’s a lot of people out here. And they saw what’s happening and it still hasn’t been cleaned up,” Jacket said.

A spokeswoman for Suncor, Lisha Burnett, told 7NEWS “We’re working as quickly, as effectively and as safely as we can.”

Warren Smith, a spokesman for the Colorado Department of Public Health and Environment said Suncor has been “very cooperative, aggressively dealing with the situation.”

Smith said the company has been hanging “slurry walls” and injecting oxygen into Sand Creek in an effort to “eat” the hydrocarbons still being found in water tests.

Smith stressed though that the health department hasn’t received any complaints from public drinking water providers about benzene in their drinking water.

Neither spokesperson could put a deadline on when benzene levels would be back to state standards.