This is the second in a series of articles discussing issues relating to the quality of water provided by OCWA—Central New York’s Water Authority.

Today’s article focuses on three human-made substances generally referred to as “emerging contaminants”–1,4-Dioxane,  PFOA (or perfluorooctanoic acid) and PFOS (or perfluorooctanoic sulfontate).  These particular chemicals are important to OCWA and its customers because New York State recently became one of the first states in the nation to adopt drinking water standards regulating them.


I,4-Dioxane is a chemical whose main use (90 percent) was as a stabilizer in solvents such as TCA, paint strippers, greases and wax. Use of TCA was phased out under the 1995 Montreal Protocol and the use of 1,4-dioxane as a solvent stabilizer was terminated.  Since that time, I,4-Dioxane has been found in groundwater at sites throughout the United States (importantly, all of OCWA’s principle water sources rely on surface water, not groundwater).

PFOA and PFOS are two of the most well-known members of a family of compounds known as PFAS (or per- and polyfluoroalkyl substances).  They are manufactured substances used in the creation of many products that are part of our daily lives, such as non-stick, stain resistant, and water repellant projects, as well as fire-fighting foam.

Drinking Water Regulations

Currently, the U.S. Environmental Protection Agency (EPA) does not regulate any of the three contaminants.  EPA did issue health advisories in 2016, however, setting guidance levels for PFOA and PFOS at 70 parts per trillion in drinking water.  To put that in context, one part per trillion is roughly the equivalent of one droplet of water in an Olympic-sized swimming pool.  So, 70 parts per trillion would be about 70 droplets.  The EPA has no guidance on 1,4-Dioxane.

The new New York State regulations set the maximum contaminant level (MCL) of 1 part per billion for 1,4-Dioxane, and 10 parts per trillion for PFOA and PFOS.  The new regulations also require public water systems in the state to regularly test and monitor these chemicals, regardless of size.

Impact on OCWA Water Supply

Although not currently required to do so, OCWA has tested for all three emerging contaminants in our water supplies.  As part of EPA’s requirement to periodically (every 5 years) monitor various unregulated contaminants, we tested both our Otisco Lake and Lake Ontario sources for 1,4-Dioxane several years ago.  All samples came back as non-detected.

We’ve also been testing on a quarterly basis for PFOA and PFOS.  We are happy to report that all of the results have come back well below the aggressive new standard being set by New York State.

Finally, OCWA is currently conducting a study to evaluate the effectiveness of its granular activated carbon filtration systems in removing PFOA and PFOS from its principle surface water supplies.  Scientific research has shown these systems to be effective at removing a host of potential contaminants from drinking water, including PFOA and PFOS.