PFAS and Drinking Water Quality

Did you know that your water agency tests and treats water thousands of time per year to ensure it meets some of the highest water-quality standards in the world before it reaches your tap?

In fact, the quality of your water is governed by the United States Environmental Protection Agency Safe Drinking Water Act, which requires all public water systems to notify customers annually regarding the quality of the water they receive. In addition, California has stringent standards for water that each water agency must adhere to.

From time to time, we may hear about contaminants in water that are affecting local, national and worldwide water quality, including recent news stories on perfluoroalkyl and polyfluoroalkyl chemicals – also known as PFAS. But what are these chemicals and how did they get into our water?

What are PFAS?

PFAS are prevalent in thousands of products we use every day, including non-stick cookware, firefighting foams, dental floss and stain resistant household coatings on carpets and upholstery. It’s also found in our water; however, water agencies don’t put these chemicals into our water, but over time they have entered our waterways through manufacturing, landfills and wastewater discharge.

Known as “forever chemicals,” PFAS are very hard to breakdown and treat (clean) in our water supply. While some PFAS have been linked to adverse health effects and scientific study is still ongoing, there are some preliminary state and federal regulations for these contaminants.


How Do We Monitor PFAS?

In California, the State Division of Drinking Water (DDW) has a “notification level” and a “response level” for water agencies. The notification and response levels are known as Public Health Goals set by the state and established based on extensive testing – even studying the impacts on people who have been exposed to certain contaminants. While these goals are instrumental in guiding drinking water laws and protecting human health, it is important to note that the EPA has yet to set a national regulatory limit for PFAS.

The Notification Level (NL) requires a water agency to notify government officials when PFAS in the water exceeds the set NL. In California, the NL for perfluorooctanoic acid (PFOA) is 5.1 part per trillion (ppt); the NL for perfluorooctane sulfonate (PFOS) is 6.5 ppt. The Response Level (RL) requires agencies to take action for readings above 10 parts per trillion (ppt) for PFOA and 40 parts per trillion (ppt) for PFOS.

The guidelines are part of DDW’s statewide effort to assess the scope of water supply contamination by PFOS and PFOA.

The response level guidelines will be compared to a quarterly running annual average of sample results.

The CA DDW recommends that the water agency remove the well from service or provide treatment if it exceeds that amount. In the coming months, California may even tighten restrictions on RLs for PFOA and PFOS. For context, a ppt is a microscopic amount and is akin to one drop of water in the Pasadena Rose Bowl.

PFAS notification and response levels in CA are some of the most rigorous in the US; each state is in charge of setting its own levels.

National regulatory limits are set by the EPA and known as “maximum contaminant levels” (MCL) for drinking water. When contaminants in water exceed the MCL, this information must be reported to customers and the state. It is also noted in each agency’s annual Water Quality Report.


How Do We Treat For PFAS?

Thanks to improvements in technology, water agencies can detect and treat for substances, such as PFAS, at a faster rate. The ways that PFAS in our water supply can be removed or treated include  granulated activated carbon, reverse osmosis or ion exchange; removing affected water sources from service; or blending affected water with unaffected water supplies.

What’s Next?

DDW has indicated it will issue a new compliance sampling order in the near future. In addition, many water agencies are studying long-term treatment options for this contaminant.

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