Suncor’s Commerce City oil refinery was accused in March of discharging “large amounts of toxic PFAS” chemicals into Sand Creek, a tributary of the South Platte River, according to Earthjustice, a nonprofit environmental law organization. The organization released a study by Westwater Hydrology of Wheat Ridge.

Last week, Suncor provided The Denver Gazette with a study of its own by Geomega Inc. of Boulder saying the Earthjustice study is “inaccurate, misleading, and should not be relied upon. … (It) is fundamentally flawed and its conclusions regarding Suncor’s PFAS contributions to Sand Creek and the South Platte River are incorrect.”

PFAS are called “forever chemicals” because they do not readily break down over time and can accumulate in both plants and animals.

Used since the 1940s in many consumer products including nonstick cookware, water-repellent clothing, stain resistant fabrics and carpets, cosmetics, firefighting foams and products that resist grease, water and oil, the link to health issues is still unconfirmed.

No definitive level of exposure that results in disease in humans has been cited by the EPA, which says, “current scientific research suggests that exposure to high levels of certain PFAS may lead to adverse health outcomes.”

In an email to The Denver Gazette in early May, Caitlin Miller, senior associate attorney for Earthjustice’s Denver office, said: “The truth of the matter is that Suncor discharges large amounts of toxic PFAS into Sand Creek, and that PFAS makes its way downstream to the South Platte River, which is a major drinking water source for a number of communities.”

“Since October 2021, Suncor’s Outfall 020A contributes only ~2% of the mass of PFAS compounds … in the South Platte River at the confluence with Sand Creek and contributes only ~16% of the mass of these PFAS compounds in Sand Creek, which is not a drinking water source,” Loa Esquilin Garcia, a spokesperson for Suncor, said in a statement.

Geomega says Westwater didn’t consider PFAS contributions from sources upstream of the confluence of Sand Creek and the Platte River, which Geomega says “comprise 89% of the total load to the South Platte River since October 2021.”

Geomega also criticized the Westwater report for overestimating Suncor’s contributions by analyzing data collected before the installation of an interim PFAS water treatment system by Suncor, which is in the design stages of a permanent water treatment plant for the facility.

Garcia also said the Earthjustice report is an “apples and oranges analysis” that includes PFAS compounds not regulated by the Colorado Department of Public Health and Environment.

“Our analysis demonstrates that Suncor’s PFAS contributions are not impacting the South Platte River in any meaningful way,” Garcia continued.

“Suncor is basing its argument on outdated health advisory levels that were set for just two types of PFAS — PFOA and PFOS — back in 2016,” said Miller.

Miller said that even with Suncor’s temporary water treatment, “the pollution remains at toxic levels according to updated toxicity assessments from the Agency for Toxic Substances and Disease Registry (ATSDR) and the U.S. Environmental Protection Agency (EPA).”

A review of the registry’s PFAS webpage by The Denver Gazette says high levels of certain PFAS may (and the registry emphasized “may” on its webpage) lead to a list of health issues, including increased cholesterol levels and an increased risk of kidney or testicular cancer.

“I have only just received the report a few hours ago and have not had enough time to thoroughly review it,” Andy Horn, Principal Hydrogeologist at Westwater Hydrology said in a statement. “However, my preliminary response is that the data used were collected by Suncor themselves; Suncor only recently installed their treatment system which continues to allow substantial quantities of detected PFAS compounds to be discharged into Sand Creek and subsequently the South Platte River.”

Meg Parish, permit section manager for the Colorado Department of Public Health and Environment Clean Water Permit division, said Suncor is not under any limitations for PFAS discharges, but that the division is seeking to impose limits on Suncor’s discharge permit that is in the process of being drafted.

Located in an industrial area on Brighton Boulevard, some 3 miles north of downtown Denver, the plant is a major provider of gasoline, diesel fuel and asphalt in Colorado.

Suncor’s website says it produces about 98,000 barrels a day and contributes $2.5 billion to Colorado’s economy annually. The refinery started operating in 1931, long before dense residential communities were built near it. Suncor acquired the refinery in 2003 and 2005.