This is our third post on poly- and perfluoroalkyl substances (PFAS), that ubiquitous and troublesome family of 5,000 “contaminants of emerging concern.” In this post: the risk of PFAS in public drinking water systems, and the current state of affairs in Vermont.
In Vermont, concern spiked after the 2016 discovery of PFOS and PFOA, two of the oldest and best-researched PFAS, in private wells in the Bennington area. The contamination was determined to be due to pollution by Saint-Gobain Performance Plastics, which recently agreed to a $40 million settlement with the state. One result was that, during the 2019 session, the Vermont Legislature gave PFAS close attention, emerging with Act 21, signed by Gov. Scott. The bill:
- Requires testing of all public drinking water systems by December 1, 2019 (specifically, 650 public community water systems and non-transient, non-community water systems serving 25 or more people over a period of 6 months per year);
- Establishes a drinking water health advisory level of 20 parts per trillion, in aggregate, of five PFAS, which, if exceeded, requires publication of a “do not drink” advisory and planning for remediation;
- Mandates research into potential sources and impacts of PFAS over the next five years;
- Gives the Vermont Agency of Natural Resources authority to establish drinking and surface water MCLs by, at the latest, January 1, 2024.
- Full information on Act 21 and the Agency’s actions is available at https://dec.vermont.gov/pfas/pfoa
But is there really a significant risk to public drinking water systems?
The U.S. EPA’s “Third Unregulated Contaminant Rule Data Summary” of January, 2017 (surveying PFOA, PFOS, and four other PFAS from 2011 to 2016) reports on tests at 4,920 public water systems. Very few tested as at or above minimum reference levels, ranging from .1% of sites for PFBS to 1.9% of sites for PFOS and 2.3% for PFOA.
On the other hand, that data is now three years old; only six types of PFAS were surveyed; and the health reference MCLs of 70 ppt were much higher than Vermont’s 20 ppt.
More recently — May, 2019 — the Environmental Working Group and Northeast University, using data from the Pentagon and local water utilities, reported PFAS contamination at 610 sites in 43 states, including some public drinking water systems.
Michigan, with 192 known contamination sites, was the most-impacted; however, of the 65 sites found to have MCLs over the federal limit of 70 ppt in a study conducted by the state in 2018, none were municipal systems. (Three school water systems did show contamination; the rest were military-related, industrial, firefighting, or mining sites.)
But the data keeps coming in – and it merits close attention. The August 30, 2019 Orange County Register reports finding “reportable levels” of PFAS in 11 source wells operated by Southern California public drinking water agencies – levels that will require remediation (and alternate water sourcing) under newly-legislated limits. In Los Angeles County, 32 of 138 county wells exceeded limits, resulting in closure of 4 wells.
The best solution for PFAS is prevention and interception at high-concentration sites. But can these “forever chemicals” be eliminated from water that’s already contaminated?
Yes. Granular activated charcoal filters and reverse osmosis are being used to successfully remove PFAS in Michigan, California, and elsewhere. Of course, water quality professionals and regulators have to ask: But at what cost, to whom?
New research developments also have promise, as high-tech solutions are being devised to address the problem. At the international CleanUp 2019 conference, as of this writing being held in Australia (Sept. 8 – 12), the company AECOM unveiled DE-FLUOROTM, a process of electrochemical oxidation that removes 90% to 100% of PFAS.
Admittedly, only time will tell if the technology proves viable, affordable, workable in diverse contexts, and without unforeseen effects of its own. But AECOM is likely only the first major corporation to be drawn by the lure of marketable — profitable — remediation products/processes.
All of which leaves us wondering what we can expect from the current round of testing in Vermont. The answer: Like everything else about PFAS, we’ll just have to wait and find out!
GMWEA would love to hear from water system operators and administrators about their experiences with the testing process! Please send perspectives to Daniel Hecht, executive director, at email@example.com.
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