NYSDEC Issues Revised Guidance for PFAS Sampling and Analysis

Earlier this month, the New York State Department of Environmental Conservation (NYSDEC) just released its new “Guidance for Sampling and Analysis of PFAS Under NYSDEC’s Part 375 Remedial Programs January 2020 (“PFAS Guidance”).  The purpose of the PFAS Guidance is to establish procedures for sampling PFAS and for determining if PFAS is a contaminant of concern for a particular site requiring remediation.  The PFAS Guidance is not yet available on the NYSDEC website but has been distributed to consultants working on sites subject to one of the DEC remedial programs.

Since the NYSDEC has not yet established Ambient Water Quality Standards (AWQS) and Soil Cleanup Objectives (SCOs) for PFAS , the PFAS Guidance states that the NYSDEC will determine on a case-by-case basis if PFAS-contaminated media will be subject to remediation.

The PFAS Guidance states that all future workplans should include PFAS sampling and analysis procedures that conform to the PFAS Guidance analysis will be required for sampling of soil, groundwater, surface water, and sediment but not soil vapors. The field sampling procedures for the various media are set forth in the appendices. Appendix B establishes the sampling protocols for soils, sediments or other solids. Appendix C sets forth the sampling protocols for non-potable groundwater monitoring wells. Appendix D contains the methodology for sampling PFAS in surface water, Appendix E applies to PFAS sampling of private water supply wells and Appendix F for collecting PFAS samples from fish tissue. Laboratories analyzing environmental samples for PFAS must hold ELAP certification for PFOA and PFOS in drinking water by EPA Method 537.1 or ISO 25101

Appendix G of the PFAS Guidance contains a list of 19 PFAS substances that are to be initially analyzed for all remedial program sites. This PFAS Analyte List may be adjusted or refined  for a particular site depending on investigative results.

Water Sample Results

The PFAS Guidance states that PFAS will be a potential contaminant of concern in groundwater or surface water requiring further assessment when PFOA or PFOS is detected in any water sample at or above 10 ng/L (ppt).

In addition, NYSDEC indicates that further assessment of water may be warranted if either of the following screening levels are met:

  • any other individual PFAS (not PFOA or PFOS) is detected in water at or above 100 ng/L; or
  • total concentration of PFAS (including PFOA and PFOS) is detected in water at or above 500 ng/L

Soil Sample Results

The PFAS Guidance states that for purposes of delineation and remedy selection,  soil samples should be tested using the Synthetic Precipitation Leaching Procedure (SPLP) and the leachate analyzed for PFAS. Soils exhibiting SPLP results above 70 ppt for either PFOA or PFOS (individually or combine) are to be evaluated during the cleanup phase.

The PFAS Guidance notes that the SPLP leachate criteria is based on the Maximum Contaminant Levels (MCL) proposed for drinking water by New York State Department of Health. Thus, the SPLP criteria may be updated based on future federal or state regulatory standards.

NYSDEC indicates in the PFAS Guidance that remedial parties have the option of analyzing samples concurrently for both PFAS in soil and in the SPLP leachate to minimize project delays.

Testing for Imported Soil

The PFAS Guidance states that soil imported to a site for use in a soil cap, soil cover, or as backfill must be tested for PFAS in general conformance with DER-10, Section 5.4(e) for the PFAS Analyte List (Appendix F) using the analytical procedures discussed below and the criteria in DER-10 associated with SVOCs.

  • If PFOA or PFOS is detected in any sample at or above 1 µg/kg, then soil should be tested by SPLP and the leachate analyzed for PFAS.
  • If the SPLP results exceed 10 ppt for either PFOA or PFOS (individually) then the source of backfill should be rejected, unless a site-specific exemption is provided by DER.

PFAS Sampling For Sites Subject Site Management

For sites that were previously remediated and are now under site management, the PFAS  Guidance says PFAS will need to be analyzed to determine if modification to any components of the SMP is necessary (e.g., monitoring for PFAS, upgrading treatment facilities, or performing an RSO).

Thus, much like MTBE sites in the 1990s and chlorinated sites in the early 2000s, it is possible that sites that have received certificate of completion may become subject to reopeners where PFAS was not previously assessed and site management sampling identifies PFAS as a contaminant of concern. As the noted American philosopher Yogi Berra once said, “It Aint Over Till its Over.”

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