PFAS/PFOS/PFOA – Please read in its entirety
NYSDEC Emerging Contaminant (PFAS) Sampling Initiative
Some North Castle residents have been contacted by the NYS Department of Environmental Conservation (DEC) with a request to test your private well for what is called “emerging contaminants”. This is a New York State-wide initiative to analyze representative groundwater samples and identify if emerging contaminants are present. The DEC does not provide the location of the private wells they are testing to the Town nor do they provide the results of the testing.
I know this sounds concerning and I have discussed this topic at past Town Board meetings and included in emails, including that my own well was tested and I’m happy to share the results, as a way to lessen your concerns. Although our home well tested just over the permissible limit of 10 parts per trillion (“ppt”), NYSDEC is providing mitigation in the next few months in the form of Carbon Filters and a UV light, which will reduce the level below 10 ppt. And by the way, when my tap water was tested after my reverse osmosis system, it tested below 10 ppt.
The following info will give you some background on this issue along with links to the related agency websites. There is alot here, and the whole country and world is continuing to learn about this topic. As we progress, we’ll most likely conduct public forums to educate residents and answer questions. In advance, the Town has created a landing page on the Town Website where we will continue to add information for your reference, including my comments from last week’s meeting. Additionally, the Town has a proposal from Langan Engineering to help guide the us through this very complicated and lengthy process, along with providing corrective action plans for any of our water districts (ie: common wells) that test above 10 ppt. As I announced at the last meeting, NYSDEC is still testing our water district wells, and at the moment have determined that one well in WD2 tested above 10 ppt, but that well is not in use at this time. Each affected water district user in any district will be advised via mail, once the letters are approved by the Westchester County Board of Health.
PFAS – So what exactly are they?
Per- and Polyfluoroalkyl substances (PFAS) compounds are unique, synthetic chemicals, created by the US chemical industry starting in the 1940’s. They have both water and oil repelling properties. Upwards of 4,700 PFAS compounds are known to exist worldwide. Perfluorooctanoic Acid (PFOA) and Perfluorooctanesulfonic Acid (PFOS) are the two most commonly found PFAS compounds in water. (I know, these acronyms are difficult to get your arms around).
Where they came from:
We owe much of the waterproof and oil / stain resistant advances to PFAS compounds. PFAS provide waterproof properties of rain proof outerwear, oil / stain repelling properties for furniture, carpets, pots & pans, clothing, and many other consumer household product uses. They are used to manufacture polytetrafluoroethylene (PTFE or Teflon) and have been used as an additive in firefighting foam for gas and jet fuel fires.
The unique chemical properties that enable PFAS compounds to repel water and oil contribute to their persistence. They do not break down in nature. Traditional wastewater and drinking water treatment systems cannot always remove PFAS, although in my own home, my reverse osmosis system does.
Why this is an issue now:
It took many years for the scientific community to develop methods and instruments to accurately analyze contaminants down to the part per trillion (ppt) level. Over time, low level PFAS was identified as a contaminant of concern and by the mid- 2000s, in response to health community concerns, PFAS was added to the USEPA's process for analyzing unregulated contaminants.
By 2016, United States EPA adopted drinking water health advisory limits for PFOA and PFOS of 70 parts per trillion (ppt). It is important to note that the EPA limits are advisory guidance values, i.e., they are non-enforceable.
The EPA and other Federal agencies continue to analyze PFAS and in April 2021, the EPA recommitted to reducing the risks associated with PFAS compounds by establishing a PFAS Action Council and they are taking actions to assess over 29 (this number increases with further study) most commonly identified PFAS compounds found in water.
Why the NY standard is higher than the USEPA guidance values:
In parallel with USEPA and federal agency assessments, over 20 states have been performing their own occurrence and health effects analysis research and are evaluating and adopting strict limits, e.g., in 2018, NJ adopted PFOA and PFOS limits of 14 ppt and 13 ppt.
When NYS adopted the 10 ppt MCL from 70 ppt, they noted that the MCLs were set at levels well below those that have caused health effects in laboratory animal studies and that the MCLs offer a large margin of protection, and exceedances do not signal immediate health risks though exceeding the MCL does signal the need for water systems to take action to reduce exposure. NYS acknowledges that it could take several years to upgrade water treatment processes where required.
Summary
If all of this sounds complicated, it is. But this issue is literally being dealt with around the globe; this is not just a North Castle issue. We’ll continue to educate you. And the state, country, and globe will deal with this together.
