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Quality Water Matters: Keeping Our Customers Informed

A tranquil mountain lake flanked by pine-covered slopes under a clear blue sky.

At Roxborough Water and Sanitation District (RWSD) our top priority is providing you with reliable, safe drinking water. That’s why we test our raw-water source and finished waters regularly and comply with every regulation of the Colorado Department of Public Health and Environment (CDPHE) and the U.S. Environmental Protection Agency (EPA). What’s important to know is your drinking water remains safe to drink.

In the fall of 2022, RWSD voluntarily participated in proactive testing for a group of unregulated chemicals scientifically known as per- and polyfluoroalkyl substances or PFAS. This program was designed to help water providers across Colorado and the communities they serve determine if PFAS chemicals are present in the drinking water.

Prior to June 15, 2022, only PFOA and PFOS had advisory limits set at 70 parts per trillion (ppt). (One part-per-trillion would be the equivalent of one drop of water in an Olympic sized pool.) Previous sampling results were below these limits.

On June 15, 2022, the EPA released much lower, interim health advisories for two PFAS compounds – PFOA and PFOS – and issued final health advisories for two new compounds – GenX and PFBS.

The sampling this fall showed PFOA and PFBS present in the drinking water. PFBS was present but well below the final health advisory. The results for PFOA are approximate because the concentrations were below the level a laboratory can precisely quantify PFAS concentrations.

RWSD’S staff is working closely with the Colorado Department of Public Health and Environment (CDPHE) to understand and address this concern and will use the latest and best available technology to monitor and safeguard your drinking water.

PFASInterim Health Advisory:Finished Water Results:Results of Sampling:
PFOA0.004 parts per trillion0.64 parts per trillionThis is above the health advisory. It is an approximate value that is below the level a laboratory can precisely quantify PFAS.
PFOS0.02 parts per trillionNon-detectThis is below the health advisory.
PFASFinal Health Advisory:Finished Water Results:Results of Sampling:
GenX10 parts per trillionNon-detectThis is below the health advisory.
PFBS2,000 parts per trillion0.84 parts per trillionThis is below the health advisory.

What is a health advisory?

A health advisory provides information on substances that can cause negative human health effects. Health advisories are non-enforceable and non-regulatory.

The health advisory levels were calculated to offer a margin of protection for all people, including sensitive populations and ages, against adverse health effects and to consider other potential sources of exposure beyond drinking water (for example, food, air, consumer products, etc.). Because these substances have been used in an array of consumer products, most people have been exposed to them and have them in their system. According to the Centers for Disease Control (CDC), the average concentration (geometric mean) measured in the general U.S. population during 2017-2018 was 1.4 parts per billion (ppb) for PFOA and 4.3 ppb for PFOS.

Research has shown that there may be health effects associated with cumulative exposure to PFAS. Because there are many types of PFAS chemicals, which often occur in complex mixtures and in various everyday products, researchers face challenges in studying them. More research is needed to fully understand all sources of exposure, and if and how they may cause health problems.

What is PFAS?

It is an abbreviation for per- and polyfluoroalkyl substances which are man-made chemicals used in metal plating and a wide variety of consumer products including fire-suppressing foam, carpets, paints, polishes, and waxes. These products were originally created to make our lives easier, as they are resistant to water, grease, and stains. Researchers, however, have found that there may be health effects associated with cumulative exposure to PFAS compounds.

PFAS compounds are difficult to detect. They exist in most products at extremely miniscule levels. It’s only recently that laboratory testing technology could even see them at the levels being discussed.

Technological advances now allow us to detect concentrations in the parts-per-trillion (ppt) range. The health advisory limits, however, are below what can be currently detected. The scientific understanding and regulatory response to these compounds is uncertain but rapidly evolving. This includes potential health implications.

For more information on PFAS, please visit the CDPHE website:

What actions should I consider? What does this mean?

  • People do not need to stop drinking or using RWSD’s tap water.
    • There is not an immediate public health risk, and people do not need to stop drinking their water.
    • CDPHE will keep providing facts to help inform the public on the latest science.
    • There are certain higher risk groups that may want to reduce their exposure (ex: more vulnerable populations).
  • People can reduce their exposure from drinking water by using water treated by an in-home water treatment filter that is certified to lower the levels of PFAS. If you do choose to purchase an in-home water filter, please make sure it is certified. You will want to replace the filter regularly and because our mountain water supply is considered moderately hard, you may need to replace the filter more frequently than the manufacturer’s recommendation. Also do not be alarmed if you notice discoloration on the filter – that just means it’s doing its job and is filtering out the calcium and trace levels of dissolved minerals in the water.
    • It is important to know there are reports of companies using predatory sales tactics to scare customers into paying more than they need to on home water filters.
  • Roxborough Water does not recommend using bottled water, but if you choose to drink bottled water make sure it has been purified with a reverse-osmosis (RO) process.
    • Using bottled water is an individual choice, but there are important concerns with bottled water. CDPHE cannot verify that all bottled water is below PFAS health advisories. Reverse osmosis is a treatment that removes PFAS. We recommend people who use bottled water choose a brand that has been treated using RO and includes this language on the bottle.
    • Additionally, bottled water does not contain fluoride to support oral health, may contain micro-plastics, and creates solid waste and other environmental concerns.
    • Boiling, freezing, or letting water stand does not reduce PFAS levels.

What can be done about PFAS?

RWSD’s staff remains committed to protecting the safety of your drinking water. Our staff has been engaged in numerous discussions with federal, regional, and state levels (including both regulators and elected officials) stressing the importance of appropriately regulating, managing, and remediating PFAS substances. These communications have included the importance of holding those parties who introduced the PFAS into the environment responsible for remediation and clean-up and the importance of prohibiting additional use of PFAS compounds in the manufacture of goods.

Drinking water providers test their product more than just about any other industry. Water quality is highly regulated, primarily through CDPHE, which is responsible for enforcement of EPA’s Safe Drinking Water Act and Clean Water Act. Measuring PFAS in water is easy compared to measuring exposure from other sources of PFAS like clothing, food packaging, or dental floss.

We encourage residents to avoid anything containing PFAS when purchasing consumers goods and new household products. This will help protect your health and prevent the compounds from further entering our environment.

PFAS is a growing national concern, and you can be assured that RWSD, will continue to closely monitor and work with the CDPHE and EPA regulatory agencies. To learn more, you can look to our website ( for evolving information and certainly contact us if you have any questions regarding this or any other water quality issues at RWSD.

About our Water Quality

You can review our current water quality Consumer Confidence Report (CCR) by visiting our Water Quality page below. 

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