The US EPA Posts a Method for 40 PFAS Compounds Called 1633
On September 2, 2021, The US EPA Office of Water solicited comments on its document, “Analysis of Per- and Polyfluoroalkyl Substances (PFAS) in Aqueous, Solid, Biosolids, and Tissue Samples by LC‑MS/MS” (Draft Method 1633, dated August 2021). The document was posted on the US EPA website (EPA Announces First Validated Laboratory Method to Test for PFAS in Wastewater, Surface Water, Groundwater, Soils | US EPA).
While this document provides meaningful steps forward in terms of formalizing the analysis of 40 PFAS compounds in a variety of matrices (wastewater, surface water, groundwater, soil, biosolids, sediment, landfill leachate, and fish tissue), the document ultimately needs to be proposed as a draft method as part of formal rulemaking. The published version of the method on the US EPA website was based on a single-laboratory method validation; however, the single-laboratory method validation report and supporting data have yet to be posted for review/comment.
Of concern regarding the informal posting of this document, are the following comments included in the background information:
“This draft method can be used in various applications, including National Pollutant Discharge Elimination System (NPDES) permits. The method will support NPDES implementation by providing a consistent PFAS method that has been tested in a wide variety of wastewaters and contains all the required quality control procedures for a CWA [Clean Water Act]. While the method is not nationally required for CWA compliance monitoring until EPA has promulgated it through rulemaking, it is recommended now for use in individual permits.”
Essentially, the posting of this document appears to provide regulatory approval for NPDES permit writers to require the use of this method without first going through formal rulemaking and promulgation. This approach is divergent of US EPA’s normal policy of only using methods that have undergone the rigors of multi-laboratory validation. Yes, US EPA-validated and approved methods are desperately needed given the hysteria around PFAS in the environment, but endorsing use of a draft, single-laboratory validation method seems counterproductive.
With respect to technical merits and potential shortcomings of Draft Method 1633, within the “Notice” section of the online document, the US EPA stated, “Laboratories, regulatory authorities, and other interested parties are encouraged to review the method, and where appropriate, utilize it for their own purposes, with the explicit understanding that this is a draft method, subject to revision.”
Directly responding to that request, Environmental Standards’ Principal and Senior Consulting Chemists were engaged by a number of industry advocacy groups and other industrial parties to review and comment on the draft document. On behalf of those interested parties, on November 11, 2021, Environmental Standards issued formal comments for US EPA consideration. Additional information on Draft Method 1633 will be published in future issues of The Standard.