Six months after Suncor Energy’s oil refinery contaminated Sand Creek and nearby property, obstacles remain in containing the pollution, and a full cleanup may be years away.

Current data show that surface-water levels of benzene at the point where the creek meets the South Platte River are still much higher than standards for drinking water, but remain stable. And the source of the leak — a pipe within the refinery — is fixed.

But one health department official says a “mass of contamination” continues to dissolve into the groundwater, and isolated pockets of pollution — much of it underground — are spread over large areas within the refinery and off-site, making it difficult to locate. While the state health department has tapped various methods of remediation, officials say it will take another two months to determine their effectiveness.

Walter Avramenko, head of the state’s Hazardous Waste Corrective Action Unit, said it took two decades to study and remedy historical contamination at the refinery, part of a 75-year-old industrial site, and come up with a long-term management plan.

“It took only a short period of time to reverse all those gains, and we’re not planning to wait another 20 years to fix it. We’re pushing the refinery very hard,” Avramenko said. “This is a very difficult, complex hydrogeologic environment for which there are no easy solutions.”

Suncor and health officials don’t know how long and at what rate the refinery pipe was leaking, making it impossible to determine how much liquid was released. However, the health department characterizes the spill as “serious and significant.” Over the past few months, 785,320 gallons of contaminants — about the amount that could fill an Olympic swimming pool — have been pulled from the groundwater. That doesn’t include the pollution that already went into Sand Creek.

Suncor vice president John Gallagher said the refinery “fell short” of its commitment to the community and its employees to operate in a safe and environmentally responsible manner. Suncor, he said, has met all the deadlines and requirements issued by the Colorado Department of Public Health and Environment.

Refinery outage not expected

“We believe that the permanent solutions being installed and operated … will effectively isolate liquid hydrocarbons, manage the plume of contaminated groundwater and dramatically lower the contamination in Sand Creek,” he said in an e-mail.

Suncor, which bought the refinery from Conoco nine years ago and processes 90,000 barrels of crude oil a day, is on the hook for the cleanup costs. Spokeswoman Lisha Burnett said the company would spend “what it takes.” She also said a “refinery outage or shutdown” to remediate the contamination will not be necessary.

Critics, including WildEarth Guardians, point out that Canada-owned Suncor has had problems in the past. Most recently, it was fined $2.2 million for air-quality violations at the refinery.

“We can’t keep putting Band-Aids on the problems every few years,” said Jeremy Nichols, climate and energy program director of the nonprofit environmental group. “Suncor made a huge mess. Are they cleaning it up? Yes. But if this goes on for months, maybe they should shut down the refinery to clean it up.”

By the time a fisherman noticed an oil sheen on the surface of Sand Creek on Nov. 27, both Suncor and the health department had known for months that polluted groundwater from the refinery was contaminating large areas on- and off-site and that the “situation is not under control,” according to a health department summary of events.

Between 2009 and April 2011, pollution was found at various sites: between an underground barrier wall and Sand Creek; between the refinery and a Metro Wastewater Reclamation District plant; in wells on Metro property; and in a pond in the refinery’s northwest corner. The pollution included benzene, an organic compound. Long-term benzene exposure can cause anemia and leukemia, according to the Agency for Toxic Substances and Disease Registry. Symptoms often take years to appear.

Although Suncor and the state took investigative and corrective actions along the way, by May 2011, health officials characterized the situation as “deteriorating.” In August, Suncor noticed an oil sheen on the surface of Sand Creek.

Different sources of pollution



Not all the pollution came from the same source. One leak stemmed from a corroded pipe. It was fixed but then broke again, causing the August seep into Sand Creek. The pipe was repaired again and the sheen disappeared.

Chemical fingerprinting tracked the pond pollution back to the area of Tank 55 in the refinery. Although the leaking pipe was fixed in February 2011, health officials would later learn that it had caused widespread contamination both on and off site.

“At that time, there was nothing to suggest an imminent threat,” Avramenko said. “(But) we were seeing evidence of things happening in different areas. I wanted the facility to take a more holistic approach. Something bigger was happening.”

On Oct. 26, the health department gave Suncor deadlines to contain and stabilize contamination and mandated an investigation into off-site pollution, records show. It wasn’t in time.

“Between October and November, material migrated onto Metro’s property from the general area of the refinery,” said Rob Beierle, the health department environment-protection specialist tasked with overseeing Suncor’s cleanup.

And again into Sand Creek.

The U.S. Environmental Protection Agency launched an emergency response. Almost immediately, benzene levels in the creek measured 24,000 times the drinking-water standards. That was also 23 times times higher than the “warm-water aquatic life” standard.

Suncor does not have a permit to discharge any level of pollutants in the creek.

The situation now indicated “human health and the environment are in immediate peril,” wrote Avramenko in a Dec. 1 letter to Suncor. The state and Suncor, he added, seemed to have “limited understanding of the contamination present at the refinery,” which was “evidently more extensive and mobile than originally believed.”

Suncor was required to conduct daily inspections along the creek, monitor indoor air at the Metro plant and investigate contamination under the plant, among other things.

The wastewater plant had to temporarily close a technical services building and employees had to wear respirators because of toxic vapors. Additionally, pollution under the plant — Suncor doesn’t know if the source is the same as what entered Sand Creek or old contamination — permeated a plastic pipe that brought drinking water into the refinery. About 675 Suncor employees and contractors were blood-tested; however, the results are “considered private and confidential,” Gallagher said.

“At this time we do not know that anyone drank contaminated water,” he said. “Results indicated only two of the locations that were sampled from across the refinery showed benzene at levels higher than drinking-water standards,” he said.

Employees have been provided bottled water and the pipe was replaced with metal.

The Occupational Safety and Health Administration is investigating worker conditions. Herb Gibson, OSHA’s Denver-area director, said he could not provide further details.

The material on Metro’s property was chemically identical to the contamination found earlier that year in the pond, which was traced to a broken pipe near Tank 55. That escaped liquid — similar to gasoline — didn’t flow in a straight line, Avramenko said. Instead, it scattered into pools throughout the refinery. Along the way, it dislodged old, previously immobile contaminants from the industrial site and dispersed them, he said.

Pockets of pollution seeped out of the refinery through a gap between two underground walls: one along the Burlington Ditch and the other along Sand Creek. While much of the refinery was dammed, this area was thought to have little contamination and was never sealed, Beierle said.

Contamination remediation

Although the Suncor site requires extensive cleanup, the No. 1 priority cited by both Suncor and the health department is to remediate contamination that escaped the refinery.

But doing that is not as easy as scooping it up like a skimmer in a pool.

First, it’s liquid. Second, the contamination is made up of both floating and dissolved material.

Finally: “It’s in oily form. As it moves, blobs break off the main body and are left behind. The blobs dissolve in water, but not fast,” said Kenneth Reardon, a chemical and biological engineering professor at Colorado State University. ” It’s very difficult to get in and find the little blobs, especially since they are underground.”

Reardon said it’s hard to predict where contamination is going. The soil is not perfectly layered like a terrarium. Instead, some layers are mixed together, and water moves through it at different speeds, making its path hard to forecast.

Relatively insoluble in water, the compounds, including benzene, that were recently released tend to spread laterally and form a layer on top of the water. Health officials refer to this floating material, along with a soup of other organic compounds, as “free phase.”

Suncor trenched an underground hanging wall to fill in the gap where the contamination escaped the refinery. That wall stops the free phase, which is then pumped out of the water and back to the refinery. Any residual free phase is stopped at a second wall. Dissolved contaminants flow underneath both walls but are extracted before hitting the creek through an air-sparging and soil vapor-extraction system.

Currently, free phase has stopped flowing into the creek, but dissolved contamination continues, health officials said.

A new, unrelated leak was found two weeks ago. Gallagher said the “material is well-contained within refinery property.”

Gallagher also said he believes the trenching and treatment systems will successfully isolate the contamination and lower the benzene levels in Sand Creek. The health department, however, is more cautious.

“We’re going to monitor, adjust, monitor, adjust, monitor and then, by summer, hopefully we will be able to say, yes, it’s working, or no, it’s not,” Avramenko said.

While there is a lot of remediation technology available, “every site is different and every technology will behave differently as a result of different conditions and different environments,” he said.

Karen E. Crummy: 303-954-1594 or kcrummy@denverpost.com