NJDEP Proposed Rule Update: PFAS Added to Contaminant Testing Requirements

The proposed rule would potentially usher in a future of broad testing for certain PFAS at New Jersey remediation sites.

On March 17, 2025, New Jersey Department of Environmental Protection (DEP) released a Rule Proposal Notice (Proposed Rule) to change New Jersey state site remediation and water quality standards by:

• Replacing the interim specific ground water quality criterion for hexafluoropropylene oxide dimer acid and its ammonium salt (collectively known as GenX) with a ground water quality standard (GWQS) of 0.02 micrograms per liter (μg/L)¹  
• Replacing its interim remediation standards for soil and soil leachate for perfluorononanoic acid (PFNA), perfluorooctane sulfonic acid (PFOS), perfluorooctanoic acid (PFOA), and GenX (as well as methanol with final standards)²
• Adding GenX, PFOA, PFNA, and PFOS (as well as 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD)) to the list of contaminants that must be tested for at sites “when contaminants are unknown or not well documented”³

If the Proposed Rule is adopted, DEP’s codification of the interim standards into final standards would impact the regulated community, particularly with respect to GenX. Additionally, the inclusion of PFAS in the default list of compounds that must be sampled for in remediations may have significant implications for potentially contaminated sites in New Jersey.

Proposed Additions to New Jersey Site Remediation and Water Quality Standards

• GenX Groundwater Quality Criterion/Standards. Per N.J.A.C. 7:9C, DEP is proposing to replace the interim specific groundwater quality criterion of 0.02 μg/L with a specific ground water quality criterion of 0.02 μg/L, a practical quantitation level (PQL) of 0.0075 μg/L, and a specific ground water quality standard of 0.02 μg/L.⁴
• PFAS Soil/Soil Leachate Remediation Standards. DEP is proposing to amend the remediation standards in N.J.A.C. 7:26D to establish soil and soil leachate remediation standards for GenX, PFNA, PFOA, PFOS. Specifically, (a) the currently existing interim soil remediation standards for the Ingestion‐Dermal Exposure Pathway — Residential, Ingestion‐Dermal Exposure Pathway — Nonresidential and Soil Remediation Standards for the Migration to Ground Water Exposure Pathway and (b) the currently existing soil leachate remediation standards for the Migration to Ground Water Exposure Pathway would be codified as promulgated standards. In other words, there is no numerical change in the standards proposed for these pathways/media. See the table below for what the final standards would be if accepted.
• Analytical methods for PFAS are still evolving. For instance, DEP notes in its rule proposal that the New Jersey Department of Health lab is not certified to test for GenX and acknowledges analytical sensitivity issues with US Environmental Protection Agency Method 1633, which is used for multiple environmental media.⁵
• Proposed Addition of Certain PFAS to Quality Assurance Requirements. DEP is proposing to add GenX, PFOA, PFNA, and PFOS (as well as 2,3,7,8-TCDD) to the list of contaminants in N.J.A.C. 7:26E-2.1(c)1ii. DEP’s proposal explains that this list contains contaminants that must be analyzed in all media when contaminants in an area of concern are unknown or not well documented. DEP is proposing to add these substances to the list because “they have been widely used or are prevalent in the State.”⁶

Potential Implications of the Proposed Rule for Companies

The Proposed Rule would require sampling for GenX, PFNA, PFOS, and PFOA (as well as 2,3,7,8-TCDD) at sites subject to N.J.A.C. 7:26E “when contaminants are unknown or not well documented.”⁷ This change has the potential to greatly expand the number of remediation sites subject to sampling for these PFAS. Potentially responsible parties (PRP), licensed site remediation professionals (LSRP), and DEP would all need to consider what constitutes sufficient documentation of contaminants at a site in this context. In the absence of sufficient documentation or knowledge of contaminants at a site, a PRP would be required to perform PFAS sampling. Therefore, the Proposed Rule would increase — potentially significantly — the number of sites undertaking such sampling.

As PRPs become responsible for assessing or addressing risks associated with the listed PFAS, higher assessment, investigation, remediation, and monitoring costs may follow, particularly as the existing and proposed remediation standards are extremely low. LSRPs would, likewise, have an independent obligation to ensure that these requirements are met. This is compounded by the fact that PFAS are generally considered to be ubiquitous throughout the environment, and requiring widespread sampling for them at remediation sites is likely to lead to widespread detections. Further, given the broad use and distribution of PFAS in the environment, it would likely be difficult and expensive to trace these materials to their sources, assuming tracing is possible. As a result, allocating responsibility for this contamination would present a complex challenge, if the detected concentrations are not treated as background contamination. In addition, the Proposed Rule has the potential to impact sites at various stages of remediation, as any site where contaminants are unknown or are not well documented could be subject to sampling for GenX, PFNA, PFOS, and PFOA (as well as 2,3,7,8-TCDD). Therefore, it is prudent to establish the scope of relevant contaminants at sites where these contaminants are not known to be of concern as early as possible. In the transactional context, entities should be aware of potentially increased requirements that contaminated sites would undergo sampling and then remediation for these PFAS.

With respect to the proposed remediation standards, DEP notes that “the proposed amendments are unlikely to result in a cost differential as the proposed standards hold the same values as the interim standards.”⁸ Nevertheless, this proposal to finalize the standards reflects DEP’s continued focus on PFAS, and it appears likely that interim and final standards for additional PFAS will follow. In addition, facilities subject to the New Jersey Pollutant Discharge Elimination System and other permits that apply New Jersey GWQS may also see rising costs as they are required to monitor and potentially treat for GenX. Finally, practitioners will need to stay abreast of evolving analytical methods as PQLs and reporting limits may be adjusted as test reliability data develops.

Next Steps

The Proposed Rule could lead to significant increased costs for the regulated community, therefore, these parties should engage through the public comment process or otherwise prepare for the potential enactment of the Proposed Rule.

DEP is accepting comments at http://www.nj.gov/dep/rules/comments until May 16, 2025. If you are interested in providing oral testimony or submitting written comments at the virtual public hearing, you may email DEP with your name, organization, telephone number, and email address at csrr_rules@dep.nj.gov until 5 p.m. Eastern on April 16, 2025. A public hearing will be held the following day on April 17, at 1 p.m.

Latham & Watkins will continue to monitor developments around the proposed rule.

This blog post was prepared with the assistance of James Clark in the New York office of Latham & Watkins.

1. N.J.A.C. 7:9C-1.7(c)2ii; Proposed Rule 7:9C, Appendix Table 1. ↩︎
2. N.J.A.C. 7:26D-6.3; Proposed Rule 7:26D, Appendix 1, Tables 1-6. ↩︎
3. Proposed Rule 7:26E2.1(c)1.ii. ↩︎
4. N.J.A.C. 7:9C-1.7(c)2ii; Proposed Rule 7:9C, Appendix Table 1. ↩︎
5. N.J.A.C. 7:26D-6.3; Proposed Rule 7:26D, Appendix 1, Tables 1-6; Proposed Rule at 8, 11. ↩︎
6. Proposed Rule 7:26E2.1(c)1.ii; Proposed Rule at 4. ↩︎
7. Proposed Rule 7:26E2.1(c)1.ii. ↩︎
8. Proposed Rule at 14. ↩︎