The Suncor refinery in Commerce City responded to charges that “toxic levels” of PFAS chemicals were found in Sand Creek, adjacent to and downstream of the refinery.

“There is no doubt that Colorado has a big PFAS problem,” said Caitlin Miller, an attorney with Earthjustice, an environmental nonprofit organization. “Our study shows that Suncor is a significant source of the PFAS found in both Sand Creek and the South Platte.”

PFAS chemicals have been 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 refinery’s emergency response teams, under former owners, most likely used PFAS chemicals in the form of aqueous film-forming foam to combat fuel fires. It is unknown how much foam the refinery’s previous owners used on fires or for training.

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.

“The communities surrounding the refinery have faced disproportionate health impacts and threats from Suncor for far too long,” Miller said in a statement in April. “It is time for the Colorado Department of Public Health & Environment (CDPHE) to issue the strongest possible water discharge permit that prohibits Suncor from discharging any more PFAS.”

In a statement to The Denver Gazette, Mita Adesanya, spokeswoman for Suncor, said: “We believe the presence of PFOS/PFOA at the Commerce City Refinery is due to the historical use of Class B firefighting foam, typical of an industrial site like ours. We are in the process of determining a permanent water treatment system to be installed in alignment with the requirements of our water permit.”

She added: “Suncor Energy replaced the old firefighting foam with ATC-AFFF Class B foam that complies with the U.S. Environmental Protection Agency’s PFOA Stewardship Program – 2015 Requirements and does not include any materials on Colorado’s ‘Hazardous Constituent’ list. This foam is used for emergencies only, and to date we have not used it. The refinery’s Emergency Response Team (ERT) uses water during its fire training exercises.”

Meg Parish, permit section manager for the Colorado Department of 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.

Parish said the limit is the result of a new rule from the Water Quality Control Commission that sets 70 parts per million for PFAS discharges as the limit statewide. She said there are 30 permits subject to that limit.

“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,” Miller said. “What we know about PFAS and the health dangers posed by these toxic pollutants has dramatically changed in the last six years. EPA itself is in the process of revising these Health Advisory Levels, and we expect that EPA will significantly lower them.”

But the EPA has not yet issued new health advisory levels for PFAS, and health advisories are not regulatory limits — they are to advise state agencies on what EPA considers safe exposures.

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).”

But a review of the registry’s PFAS website by The Denver Gazette on Friday says high levels (not low 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.

The registry also says: “At this time, scientists are still learning about the health effects of exposures to mixtures of different PFAS. Additional research may change our understanding of the relationship between exposure to PFAS and human health effects.”

Because of their widespread use and their persistence in the environment, PFAS are found in the blood of people and animals all over the world and are present at low levels in a variety of food products and in the environment. No definitive level of exposure that results in disease in humans has been cited by the EPA.

Miller said Suncor and the state should both do more by way of dealing with existing discharges of PFAS.

“We’ve asked the Division to strengthen Suncor’s final permit to ensure it provides necessary protections for surface waters and downstream communities, while Suncor has urged the Division to weaken its final permit,” Miller said. “Suncor has opposed including more stringent limits (in) its final permit despite the fact that the EPA Health Advisory Levels that served as the basis of the Division’s proposed PFAS limits for the draft permit are now outdated and too high to be protective.”