Sorting Through New York PFAS Standards and Guidance

Does the commonly used term “emerging contaminants” really apply to per- and poly-fluorinated alkyl substances (PFAS)? On the one hand, we have been sampling and reporting these contaminants for close to a decade now, and we are finding them in lots of places. On the other hand, what is truly “emerging” is their actual regulation. Although it is now common to see PFAS treatment applied to media such as drinking water and groundwater, the standards and guidance values that drive this need are in a state of flux, and can be confusing. In this blog post, we describe the current situation of various standards and guidance values in New York State.

The New York State Department of Environmental Conservation (NYSDEC) and the New York State Department of Health (NYSDOH) are the departments that regulate PFAS.  Standards become enforceable when they are incorporated into the New York Code of Rules and Regulations (NYCRR). In addition to enforceable standards, these agencies can also issue guidance values that do not have the force of law, but in practice are often used in an equivalent fashion as standards.

NYSDOH has promulgated PFAS drinking water standards in 10 NYCRR Part 5. This regulation sets maximum contaminant levels (MCLs) for drinking water. These regulations are specific to water that is actually used as a drinking water source.  Effective January 2022, Section 5-1.52 of this Part sets drinking water standards for PFOA and PFOS at 10 ng/L (parts per trillion) each. This is a promulgated regulation and water supply systems need to meet, or develop a plan to meet, these standards. In addition, NYSDOH has just proposed additional standards for the PFAS compounds PFDA, PFHpA, PFHxS, and PFNA, although these are not yet promulgated.

In contrast, NYSDEC focuses the concentration of PFAS in environmental media. While it is New York’s policy to consider all groundwater to be Class GA and to be considered suitable for use as drinking water, all groundwater is not drinking water and thus the NYSDOH 10 NYCRR Part 5 standards do not directly apply to groundwater. NYSDEC promulgates groundwater and surface water standards and guidance values in 6 NYCRR Part 703, and separately addresses soil standards and guidance values in 6 NYCRR Part 375. To date, PFAS standards have not been finalized for any of these environmental media. However, standards and guidance values have been proposed and will likely be promulgated in the near future. The groundwater and surface water values are presented in Section 703.5, but also summarized in the easier to use TOGS 1.1.1.

NYSDEC proposed adding PFOA and PFOS guidance values to Part 703 in October 2021. The proposed guidance values are specific to the class of groundwater/surface water. For Class GA, which covers most groundwater in New York, the proposed guidance values are 2.7 ng/L for PFOS and 6.7 ng/L for PFOA. These are lower than the promulgated drinking water MCLs. The guidance values for other classes of water (e.g. various classes of surface water) are higher and are summarized in the proposed updates to TOGS 1.1.1. NYSDEC proposed adding PFOA and PFOS standards for soil in December 2021. The parts of 6 NYCRR Part 375 tabulating soil standards are tables 375-6.8(a) (for unrestricted use) and 375-6.8(b) (for restricted use). These proposed standards range from 0.66 µg/kg for PFOA in unrestricted uses to 600 µg/kg for PFOA in the Industrial (a restricted use) category.

It is important to note that NYSDEC also publishes a separate PFAS guidance document for remedial programs.  Confusingly, this document provides different proposed Protection of Groundwater (another restricted use category) guidance values for PFOA and PFOS compared to those proposed in December 2021. However, both the guidance document and the proposed guidance values indicate that migration from soil to groundwater is subject to further study.

In summary, NYSDOH has made it clear what the standards are for drinking water supplies with promulgated MCLs. In contrast, the standards and guidance values for environmental media are still in the proposal stage and are subject to change prior to promulgation. But in the meantime, NYSDEC uses these values in evaluating contamination decisions at sites throughout the state. Although PFAS is still commonly referred to as an emerging contaminant, we have been addressing the causes and impacts for several years. The presence of PFAS touches many of our services including investigation/remediation, impacts to water supplies, and management at solid waste and wastewater treatment facilities.

For more information related to PFAS standards, guidance values and associated impacts, please contact:

Jon Sundquist, PhD (Investigation/Remediation)

Greg Mosure, P.E., BCEE (Water Supply/Wastewater Treatment)

Chad Hutton (Solid Waste Management)