What is PFAS?
Perfluoroctanesulfonic acid (PFAS), a class of carbon-fluorine chain organic chemicals typically found in low concentrations in media and wastewaters, is a human health concern generally and is receiving a lot of attention in other states. For example, North Carolina is testing all public water system intakes/wells for PFAS. Michigan has required every publicly owned treatment works (POTW) to test its influent and effluent for PFAS. This month, Maine is requiring all POTWs which land apply biosolids to have their biosolids tested for PFAS.
So where does PFAS come from? It can come from food packaging containing materials, processed with equipment that used PFAS or PFAS contaminated soil or water. It can also be found in common household products like state and water repellent fabrics, nonstick products like Teflon, polishes, waxes, paints, and cleaning products. Some PFAS chemicals are no longer manufactured in the United States, but they are still produced internationally and imported in products such as carpet, leather, clothing, rubber and plastics.
The wastewater industry has generally been supportive of water plant intake and POTW effluent screening sampling. If it is in source water, it will likely pass through to finished water so knowing the concentrations in source water is prudent. If POTW effluent sampling is low, the industry does not necessarily see the need for an industrial user sampling. However, down gradient groundwater well sampling at a landfill may be prudent to ensure no groundwater user impacts are occurring related to any potential groundwater contamination from the landfill.
Like any emerging pollutant parameters, we do not yet have from EPA and/or the state fully developed standards or threshold levels for PFAS. However, for general reference EPA’s Safe Drinking Water Act threshold for the combination of PFOS and PFOA, two specific PFAS chemical compounds, is 70 parts per trillion.
Due to these health concerns and because of the continuing nature of interest and regulatory activity for these pollutant parameters, the Association of Missouri Cleanwater Agencies, which St. Joseph is a member, pulled together several documents that may be of interest either for background or for purposes of sampling and analysis considerations. Most of those are from Michigan, given that MDEQ has been particularly active on this front. One is from Maine. These guidance documents address analytical methods. Note, the EPA regulations under 40 CFR Part 136 address EPA approved analytical methods and Part 136 does not include a method for any PFAS compounds. This does not mean the methods referred to are in any way inappropriate when used in conjunction with a good lab QA program.
PFAS, as an evolving pollutant of concern, has been on the Public Works radar screen for several years now, which was one of the factors that led the City Council several years ago to begin to develop a system for biosolids disposal that did not rely on farm field application into the future.
While testing protocols are still being developed for each of the many types of PFAS, some interim methods have been established and knowing where Missouri falls, and St. Joseph within the state, will be key down the road.