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PFAS

PFAS, short for perfluoroalkyl and polyfluoroalkyl substances, are chemical compounds manufactured and used for decades to repel water, grease and oil. They can be found in many common products, including fire-fighting foam, carpets, clothing, nonstick cookware, food packaging, plastic coating, dental floss and some high-end ski waxes.

The chemicals don’t easily break down, earning themselves the nickname the “forever chemicals.” Research by the Centers for Disease Control and Prevention show most people in the United States have been exposed to some PFAS. Research suggests exposure to high levels of certain PFAS may lead to health impacts.

Denver Water is committed to providing a clean, safe water supply for our customers that meets or goes beyond state and federal drinking water standards. Our water quality experts have been studying the evolving information about the chemicals and are involved in discussions with legislators, state and local regulators and other utilities on how to best find, control, remove and prevent PFAS contamination in water.

We also have tested for PFAS-related compounds in the source water that comes into our treatment plants and the drinking water that leaves our treatment plants since 2017 and have not detected anything above the Environmental Protection Agency’s proposed regulatory limits.

FAQs

How can PFAS get into the water supply?

Because PFAS is so widely used, the chemicals can get into the water cycle in a number of ways.

Firefighting foam can seep into groundwater supplies. PFAS-containing products in landfills can break down and the chemicals can leach out of the landfill. When PFAS-containing products — such as cookware, cosmetics or water-resistant clothing — are washed with water, trace amounts of the chemicals can be carried down the drain and into the community’s wastewater system.

How is PFAS in drinking water regulated?

Because the chemicals are in so many products used every day and don’t break down on their own, surveys by the Centers for Disease Control and Prevention show that most people in the United States have been exposed to some PFAS. Current scientific research suggests exposure to high levels of certain PFAS may lead to adverse health outcomes; more research is underway.

At the same time, a spotlight has been put on the water and wastewater industries to remove these widely used chemicals from our environment, even the trace amounts that may appear in the water system.

The Environmental Protection Agency's regulatory approach to PFAS compounds in drinking water has evolved over the years, including a health advisory in 2016 on two kinds of PFAS (called PFOA and PFOS), and a second, interim health advisory in 2022. Learn more about EPA health advisories.

In March 2023, the EPA proposed the first-ever national standard to limit PFAS in drinking water. The proposed standard covered six PFAS compounds, with limits set for PFOA and PFOS, and a combined limit for the other four compounds (PFNA, PFHxS, PFBS and GenX). Learn more here.

The EPA’s proposed PFAS regulation would require public water systems to: 

  • Monitor for six specific PFAS compounds in our drinking water. 
  • Notify the public if the levels of the six regulated PFAS compounds are above EPA’s regulatory limits.
  • Reduce the levels of these six PFAS compounds in drinking water if test results are above the EPA’s regulatory limits. 

At the state level, in 2022 Colorado’s Gov. Jared Polis signed a new law (House Bill 1345) that will gradually restrict the sale of PFAS in consumer products, as well as fluids used in the extraction of oil and gas products, starting as early as 2024.

The new state law will prohibit the sale or distribution in Colorado of products that contain PFAS, such as cosmetics, carpets or rugs, fabric treatments, food packaging and juvenile products. Cookware that contains PFAS will have to carry a label.

What is Denver Water doing about PFAS?

Denver Water is committed to ensuring a clean, safe water supply for our customers that meets or goes beyond state and federal drinking water standards. Our water quality experts have tested for PFAS-related compounds in the source water that comes into our treatment plants and the drinking water that leaves our treatment plants since 2017 and have not detected anything above the Environmental Protection Agency’s proposed regulatory limits.

Also, our water quality experts and scientists have been closely studying the evolving information about these chemicals and preparing for solutions in case future test results are above the EPA’s regulatory limits.

We also have been involved in discussions with legislators, state and local regulators and our sister utilities on how to best find, control, remove and prevent PFAS contamination in water.

Denver Water PFAS testing

Our water quality experts have tested for PFAS-related compounds in the source water that comes into our treatment plants and the drinking water that leaves our treatment plants since 2017 and have not detected anything above the Environmental Protection Agency’s proposed regulatory limits. The results below are sampling results from 2023.

Current laboratory equipment can reliably detect and quantify compounds down to slightly less than 2 parts per trillion in a sample. Below that level, the tiny trace amounts are so small that test results at these extreme detection limits are only estimations.

The Environmental Protection Agency's regulatory approach to PFAS compounds in drinking water has evolved over the years, including a health advisory in 2016 on two kinds of PFAS (called PFOA and PFOS), and a second, interim health advisory in 2022. Learn more about EPA health advisories.

In March 2023, the EPA proposed the first-ever national standard to limit PFAS in drinking water. The proposed standard covered six PFAS compounds, with limits set for PFOA and PFOS, and a combined limit for the other four compounds (PFNA, PFHxS, PFBS and GenX). Learn more here.

The EPA’s proposed PFAS regulation would require public water systems to: 

  • Monitor for these six PFAS compounds in our drinking water. 
  • Notify the public if the levels of the six regulated PFAS compounds are above EPA’s regulatory limits.
  • Reduce the levels of these six PFAS compounds in drinking water if test results are above the EPA’s regulatory limits. 

A review of the EPA’s proposed PFAS regulation indicates the drinking water Denver Water provides to customers tests well below the EPA’s proposed regulatory limits for the six PFAS compounds included in the agency’s draft rule.

Denver Water will continue testing for PFAS as part of our monitoring protocols. We regularly review our treatment processes and adjust these processes as part of our mission to provide a clean, safe, reliable water supply to our customers.

If PFAS test results go above the EPA’s regulatory limits, Denver Water might be required to add new and potentially costly treatment methods or find alternative sources of water — which isn’t always an available option in the water-starved West.  

Note: The symbol “<” means “less than” and “ppt” means “parts per trillion.”
Denver Water’s PFAS test results* compared to the EPA’s proposed PFAS regulation
PFAS compound Marston Treatment Plant, treated water 2023 Moffat Treatment Plant, treated water 2023 Foothills Treatment Plant, treated water 2023 EPA’s proposed laboratory detection limits EPA proposed regulatory limit for drinking water Does Denver Water exceed the proposed regulatory limit?
GenX <1.9 ppt <1.9 ppt <1.9 ppt 5.0 ppt Weighted combined score** = 1.0 No
PFBS <1.9 ppt <1.9 ppt <1.9 ppt 3 ppt
PFHxS <1.9 ppt <1.9 ppt <1.9 ppt 3 ppt
PFNA <1.9 ppt <1.9 ppt <1.9 ppt 4.0 ppt
PFOA <1.9 ppt <1.9 ppt <1.9 ppt 4.0 ppt 4.0 ppt No
PFOS <1.9 ppt <1.9 ppt <1.9 ppt 4.0 ppt 4.0 ppt No

*Test results through the end of 2023.
**The “weighted combined score” is the weighted sum of the test results of four specific PFAS compounds: GenX, PFBS, PFHxS and PFNA. The EPA calls this a Hazard Index and any sum above 1 for a year would be considered a violation of the EPA’s proposed PFAS drinking water regulations. Learn more about the EPA’s proposed PFAS Hazard Index.

Note 1: Denver Water’s 2023 test results in the above chart reflect the detection limits of our laboratory’s capabilities. The EPA’s proposed laboratory detection and reporting limits for PFAS are higher.

Note 2: Denver Water also monitors its water for PFAS-related compounds that are not included in the EPA’s proposed regulations, as well as other nonregulated emerging contaminants. In 2023, test results of treated water at Marston Treatment Plant indicated a PFAS compound called PFBA at levels around 1.9 parts per trillion, which is at the lower limit of laboratory detection and analysis capabilities. The EPA’s list of compounds in the agency’s proposed PFAS regulation for drinking water doesn’t include PFBA, although that may change in the future. More information about PFBA is available at the EPA’s website.

What can you do about PFAS?

You can help! Learn more about where PFAS is used in our society and about alternative, PFAS-free products that you could use instead. This will not only protect your health, but also reduce the amount of PFAS in circulation.

Several groups are working on lists of PFAS-free consumer goods, including PFAS Central.org.