By way of background, in 2016 the New York State Department of Environmental Conservation (NYSDEC) listed two long-chain per- and polyfluoroalkyl substances (PFAS)—PFOA and PFOS—as hazardous substances. However, NYSDEC did not publish a remedial standard for PFOA or PFOS at the same time. Instead, beginning in the spring of 2018, the NYSDEC began collecting information regarding the extent and scope of PFOA and PFOS, and 19 additional PFAS compounds, at existing and new state Superfund and Brownfield Cleanup Program (BCP) sites across New York State. Existing sites were informed via letter, rather than through a public rulemaking process, that they were required to perform groundwater sampling for these emerging contaminants using the United States Environmental Protection Agency's (EPA) Method 537.1 for a target analyte list of twenty-one PFAS. In many cases, sites had already completed remediation and received regulatory closure. Similarly, new remedial sites were informally told that participants were required to perform groundwater sampling and subsequent soil sampling if PFAS were identified in groundwater.

Fast forward to February 2019 when the NYSDEC announced in a memorandum that it had drastically expanded the sampling requirements for PFAS and 1,4-dioxane, and outlined its preferred laboratory methodology. New state Superfund and BCP sites are now required to sample all environmental media, including soil, groundwater, surface water, sediment and, in certain scenarios, animals and biota for the twenty-one PFAS compounds and 1,4-dioxane. Additionally, NYSDEC now requires PFAS and 1,4-dioxane to be assessed during the remedy selection process, and to be included as part of the long term monitoring performed after remediation is complete. In addition, soil imported to a site for use in a soil cap, soil cover, or as backfill must be sampled for PFAS and 1,4-dioxane in general conformance DER-10. Although, it is unclear if sites will be prohibited from using imported soil containing any PFAS or 1,4-dioxane, or if a certain maximum concentration will be chosen.

NYSDEC's February 2019 memorandum states that the preferred sampling method remains EPA's Method 537.1. However, NYSDEC may, in certain circumstances, require two additional laboratory methods during investigation—Synthetic Precipitation Leaching Procedure (SPLP) by EPA Method 1312 to determine the potential of soil contaminants to leach to groundwater, and Total Oxidizable Precursor Assay (TOP Assay) to test for the risk of certain PFAS to transform through oxidation into other PFAS with more known health risks.

Once NYSDEC develops remedial standards, NYSDEC may require sites that have identified PFAS or 1,4-dioxane, even those that were previously closed, to perform additional remediation. It is unclear if remedial standards will address only PFOA and PFOS, or if they will address all of the PFAS that parties are required to sample. Thus, owners and potential owners of sites contaminated with PFAS or 1,4-dioxane face added cleanup costs on the horizon. At a minimum, parties can expect to have more expensive investigation and long-term monitoring costs then they may have planned for.

Lastly, it is likely that NYSDEC will change its PFAS sampling requirements after EPA issues new laboratory analysis methodologies this summer. As described in EPA's Technical Brief, there are no validated standard EPA methods for analyzing PFAS in surface water, non-potable groundwater, wastewater, or solids. According to EPA's PFAS Action Plan, it is in the process of finalizing two new laboratory methods that deal with 24 additional PFAS compounds, all of which are short-chain PFAS and could not be analyzed under Method 537.1. The first method, Draft Method SW-846 8327, is a direct injection analytical protocol for preparing and analyzing the 24 short chained PFAS in groundwater, surface water, and wastewater effluent. EPA estimates that Draft Method 8327 will be published for review this summer. The second forthcoming method, Draft Method SW-846 8328, is a solid-phase extraction/isotope dilution (SPE-ID) method for the same 24 short-chain PFAS analyzed in Draft Method 8327. EPA intends to add additional PFAS to Method 8328. This method includes solid matrices and non-drinking water aqueous matrices. EPA is awaiting external validation for Method 8328, which is expected to begin this summer.

As more analytical methods are developed and validated we can expect more states will follow New York's lead requiring more and more sampling and analysis for the myriad PFAS compounds across all environmental media. No longer will the PFAS phenomenon be limited to drinking water.