Working with Water - September 2018


Tucson Water's water quality laboratory

Keeping Your Water Safe from PFOA and PFOS

Tucson Water delivers safe, clean, and high quality water that meets state and federal regulations. The utility also voluntarily monitors the water system for hundreds of contaminants that are not regulated by federal, state, or local governments.

In 2016, the United States Environmental Protection Agency (EPA) issued an updated health advisory for perfluorooctanoic acid (PFOA) and perfluorooctanesulfonic acid (PFOS). The EPA issues health advisories for contaminants that it does not regulate, but which may pose a risk to public health. The current health advisory for PFOA and PFOS is set at 70 parts per trillion – one part per trillion is roughly equivalent to one drop of water in 20 Olympic-sized pools.

What are PFOA and PFOS?
PFOA has been used in the manufacture of consumer goods such as Gore-Tex™, Teflon™, and similar grease- and water-repellent products. PFOS is the key ingredient in Scotchgard™ and numerous stain repellents. Both chemicals have also been used extensively in firefighting and industrial applications. Most of the production and use of PFOA and PFOS has been discontinued in the United States.

Are PFOA and PFOS found in our local groundwater?
Yes, in some areas. PFOA and PFOS have been detected above the 2016 health advisory levels in six wells in Tucson Water’s central well field. These wells have been taken out of service. Six additional wells have registered levels of PFOA and/or PFOS below the health advisory. These wells have been removed from regular service and placed on standby, to be used only in times of emergency or critical need.

Is my drinking water safe?
Yes. The majority of our drinking water comes from recharged and recovered Colorado River water, in which PFOA and PFOS have not been found. And, most of our local groundwater wells have also not been affected. Tucson Water takes a proactive, aggressive approach to protecting public health.

Tucson Water tests for water quality.

What is Tucson Water doing about PFOA and PFOS?

  • Participating in a regional effort with local water providers, state and federal agencies to assess the scope and sources of contamination.
  • Established an internal Tucson Water task force that is developing the most effective ways to test, contain, and remove PFOA and PFOS from all our water sources and drinking water.
  • Shutting down any drinking water wells with PFOA and PFOS levels above the new EPA health advisory.
  • Turning off and placing on standby any wells where PFOA and PFOS are detected at levels below the health advisory.

For more detailed information, visit

Call 520-791-4331 to learn more about Tucson Water's efforts to test, contain, and remove PFOA and PFOS from water sources and drinking water.