PFAS Wastewater Sampling Guidance: Leave the Sharpies and Post-It Notes at the Office

The Michigan Department of Environmental Quality (MDEQ) recently issued guidance on wastewater sample collection for PFAS (per- and polyfluoroalkyl substances). The wastewater sampling guidance can be used for compliance with the new PFAS Industrial Pretreatment Program (IPP) requirements. 

The wastewater PFAS sampling guidance covers sampling equipment, equipment decontamination, sample collection and handling, field clothing, personal protective equipment (PPE), and sample shipment.  Grab sampling and automatic composite sampling are discussed in the MDEQ guidance.  Grab sampling is the preferred method for PFAS wastewater collection. Automatic composite, because of the increased potential for cross-contamination, should only be used if grab sampling is not an option.

One interesting take from the guidance includes a table of prohibited and allowable items and materials for sample collection.  Because of their potential for PFAS cross- contamination during the sampling process, Sharpie®-type markers, Post-It Notes®, Teflon®, Gore-Tex™, and Tyvek® are a few of the items on the prohibited list. 

Earlier this year, the MDEQ also released the list of PFAS compounds that should be analyzed as part of the IPP.  The list is considered a minimum list of PFAS compounds. Merit Laboratories performs testing for all of the PFAS compounds listed in the MDEQ IPP PFAS directive.  The list of IPP PFAS compounds includes:

• Perfluorotetradecanoic acid (PFTeA)
• Perfluorotridecanoic acid (PFTriA)
• Perfluorododecanoic acid (PFDoA)
• Perfluoroundecanoic acid (PFUnA)
• Perfluorodecanoic acid (PFDA)
• Perfluorononanoic acid (PFNA)
• Perfluorooctanoic acid (PFOA)
• Perfluoroheptanoic acid (PFHpA)
• Perfluorohexanoic acid (PFHxA)
• Perfluoropentanoic acid (PFPeA)
• Perfluorobutanoic acid (PFBA)
• Perfluorodecanesulfonic acid (PFDS)
• Perfluorononanesulfonic acid (PFNS)
• Perfluorooctanesulfonic acid (PFOS)
• Perfluoroheptanesulfonic acid (PFHpS)
• Perfluorohexanesulfonic acid (PFHxS)
• Perfluoropentanesulfonic acid (PFPeS)
• Perfluorobutanesulfonic acid (PFBS)
• Perfluorooctanesulfonamide (PFOSA)
• Fluorotelomer sulphonic acid 8:2 (FtS 8:2)
• Fluorotelomer sulphonic acid 6:2 (FtS 6:2)
• Fluorotelomer sulphonic acid 4:2 (FtS 4:2)
• 2-(N-Ethylperfluorooctanesulfonamido) acetic acid (N-EtFOSAA)
• 2-(NMethylperfluorooctanesulfonamido) acetic acid (N-MeFOSAA)

Merit is Michigan’s PFAS environmental laboratory, analyzing wastewater, groundwater, drinking water, and other sample matrices at our laboratory in East Lansing, Michigan. Merit offers two analytical options for PFAS: ASTM D7979 with Isotopic Dilution and EPA 537.  Please contact Merit Laboratories for assistance on your PFAS testing needs.