PFAS FAQs

PFAS compounds are difficult to detect. Technological advances now allow us to detect concentrations in the parts-per-trillion (ppt) range. The scientific understanding and regulatory response to these compounds are uncertain and rapidly evolving.

While scientific studies into the impacts of PFAS in drinking water are currently limited to a handful of chemicals, the EPA and other organizations are conducting more research.

The most studied PFAS, perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS), have been identified by the EPA as contaminants of concern. Specifically, the EPA currently identifies PFOA as “likely to be a carcinogen,” which is a step below a “carcinogenic” classification. PFOS is currently identified to have “suggestive evidence of carcinogenic potential,” a step below PFOA.

The EPA recently published interim lifetime Health Advisories for PFOA and PFOS. The updated advisory levels, which are based on new science and consider lifetime exposure, indicate that some negative health effects may occur with concentrations of PFOA or PFOS in water at 0.004 parts per trillion (ppt) and 0.02 ppt, respectively. (For reference, the level at which the PFOA Health Advisory is an amount roughly equivalent to traveling 0.6 millimeters on a trip to the sun.) These interim health advisories will remain in place until EPA establishes a National Primary Drinking Water Regulation.

In March 2023, the EPA also published a proposed National Primary Drinking Water Regulation for six (6) PFAS. The proposal establishes the following maximum contaminant levels goals (MCLGs):

• A MCLC for PFOA and PFOS of 0.0 ppt is proposed, and the MCL is proposed to be 4 ppt.
• A MCLG and MCL have been proposed for PFHxS, PFNA, PFBS, and HFPO-DA using a hazard index of 1.0. A hazard index is a tool used to evaluate combined risk from exposure to a mixture of contaminants.

Scientists are studying the health effects of elevated PFAS blood levels and preliminary research indicates that health effects may include types of cancer, high cholesterol, and decreased vaccine response in children. Because of their prevalence in our homes, as well as environmental exposure via the air, water, and dust, virtually every person in America has a detectable level of PFAS in their blood.

Currently, there is no immediate public health risk, and people do not need to stop drinking their water. The state health department will keep providing facts to help inform the public about the latest science.

PWSD’s source waters are a mix of groundwater and surface water that does not come into contact with known PFAS activities.

Consumer products, such as non-stick pans, waterproof clothing, and fast food containers are the largest source of human exposure to this group of chemicals. Additionally, in communities where some industrial and manufacturing activities occur, these chemicals can contaminate water sources.

While PWSD does not produce, manufacture or use PFAS in the treatment of water or wastewater, they do come through our wastewater systems and treatment plants as a byproduct of products that are used in homes and businesses.

With regard to our drinking water supply, PWSD and other water utilities across the country are scheduled to begin monitoring for 29 different PFAS between 2023 and 2025 under the EPA’s fifth Unregulated Contaminants Monitoring Rule (UCMR).

Under the UCMR, every five years the EPA is required to issue a list of unregulated contaminants to be monitored by water systems under the Safe Drinking Water Act. This monitoring provides EPA and other parties with scientifically valid data on the national occurrence of these contaminants in drinking water. As part of the testing, PWSD will report any findings on our annual Consumer Confidence Report. We will rely on the EPA and the Colorado Department of Public Health and Environment (CDPHE) for further guidance on any regulatory updates and necessary actions as science progresses.

With regard to our wastewater operations, future discharge permit requirements could impact PWSD’s pretreatment program, treatment processes, and biosolids program.

If you are concerned about PFAS exposure, it’s recommended that you consider avoiding the following consumer products:

• waterproof clothing (look for water-resistant instead)
• stain-resistant furniture and carpets 
• grease-resistant restaurant containers and wrappers
• non-stick cookware

PFAS Central also maintains a list of PFAS-Free brands and products.

Some home treatment devices (water filters) that meet NSF/ANSI Standards 53 and 58 are certified to remove PFAS. For more information, you can visit NSF International or the Colorado Department of Public Health and Environment. If you choose to use a home treatment device, please remember to follow the manufacturer’s instructions carefully.