Study Reveals Suncor PFAS Pollution in Surface Water and Municipal Drinking Water Systems

Groups call for CDPHE to issue strongest possible water discharge permit for refinery


Perry Wheeler, Earthjustice, (202) 792-6211,

A new study conducted by Westwater Hydrology LLC connects PFAS pollution in Sand Creek and the South Platte River, as well as river water used by Commerce City, Brighton, Thornton, Aurora, and other municipal drinking water systems, to the Suncor refinery in Denver. The study found that Suncor’s 2021 discharges from just one outfall, 020, account for 16-47% of the total PFAS loading in Sand Creek and 3-18% of the total PFAS loading in the South Platte.

Municipalities, including Commerce City, Brighton, Thornton, and Aurora, utilize water intake wells along the South Platte downstream of Suncor. Due to the hydrology of the river and the underlying aquifer, any PFAS in the river gets drawn into the drinking water system when it enters these intake wells. The South Platte is also a major source of agricultural irrigation water; Suncor’s PFAS pollution is likely taken up by crops, creating another exposure point for the humans and animals that consume them.

“The communities surrounding the refinery have faced disproportionate health impacts and threats from Suncor for far too long,” said Caitlin Miller, senior associate attorney with Earthjustice’s Rocky Mountain office. “This facility continues to pollute the air that people breathe and the water that they drink with relative impunity. 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.”

The PFAS levels studied at Outfall 020 do not account for additional pollution from Suncor’s other outfalls, including process water and stormwater outfalls, which only add to the overall impacts to Colorado’s waterways and drinking water.

CDPHE’s Water Quality Control Division has put forth a draft water permit that reduces the amount of PFAS that Suncor can discharge but fails to limit it to levels that are safe. Suncor installed a temporary treatment system in October 2021 to reduce its PFAS discharges at Outfall 020, but even with these measures in place, 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).

In its initial comments on the draft permit, Suncor requested that CDPHE dramatically weaken the pollution limits and monitoring requirements in its final permit for multiple pollutants, including PFAS.

“We have endured pollution to our sources of life through environmentally-racist policies in Commerce City for so long without restoration that even state and federal agencies have normalized trauma to our communities without protection or regulation from extractive industries,” said Renée Millard-Chacon, co-founder and executive director of Womxn from the Mountain, an Indigenous Womxn-led nonprofit based out of Commerce City. “However, we are all connected, and it is never okay to harm disproportionately impacted communities this way, including our future generations, without respecting our right to live and thrive without severe environmental degradation for an economic gain that has never benefited residents’ health.”

PFAS are toxic pollutants that persist in our bodies and the environment for decades. Drinking water is one of the most common routes of exposure to PFAS. Studies of the best-known PFAS have shown links between the chemicals and kidney and testicular cancer, as well as endocrine disruption in people.

The EPA recently objected to Suncor’s draft Title V air permit, finding that CDPHE failed to scrutinize changes to the company’s operations, including those that allow the company to emit even more harmful pollution into surrounding communities. EPA’s objection directs CDPHE to no longer rubberstamp proposed changes to the refinery’s operations.

Read the study: Surface Water PFAS Evaluation – Suncor Energy USA Inc., Commerce City Refinery, Colorado


Update: August 2, 2022

When it was released, the Westwater Hydrology report indicated that South Adams County Water and Sanitation District (SACWSD) had at least one intake well – Well 119 – impacted by Suncor’s PFAS discharges. It found that these PFAS discharges could therefore impact Commerce City drinking water. Since releasing the report, we have learned and verified that this well is not hooked up to SACWSD’s general municipal supply, but rather provides underground irrigation water for portions of Commerce City.

SACWSD has created a dual water system for its northern service area where one set of water infrastructure supplies potable drinking water and another separate system supplies non-potable underground irrigation water. Irrigation water, including irrigation water for domestic use, in the area north of 96th Avenue and east of Highway 2 is impacted by Well 119. This remains a concern if residents use the water for home vegetable or fruit gardens.

The new information about Well 119 does not change any of the other conclusions in the report.

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