What You Need to Know

• Stricter Standards for Many Constituents: NJDEP adopted more stringent ground water remediation standards for 52 constituents, with seven—including vinyl chloride, a contaminant commonly found in plumes of chlorinated solvents—tightened by an order of magnitude, significantly impacting remediation requirements.
• Impact on Active and Closed Cases: These changes affect both active and closed remediation cases that address contaminants with newly lowered standards.
• Phase-In Guidance Issued: NJDEP released two guidance documents outlining conditions under which the prior standards may be applied to active cases, provided certain deadlines and criteria are met.
• Reopening of Closed Sites: Closed remediation cases may be reopened if the applicable revised standard has been reduced by an order of magnitude as compared to the standard in applied in the remediation and renders previous cleanups insufficient to protect human health or the environment.

The New Jersey Department of Environmental Protection (“NJDEP” or the “Department”) proposed revisions to its Ground Water Quality Standards (“GWQS”) on January 2, 2024. Exactly one year later, on January 2, 2025, NJDEP finalized the regulation amending or establishing ground water quality standards for 73 constituents within Class II-A ground water. These new standards became effective on February 3, 2025, and are the current ground water remediation standards (“GWRS”) under N.J.A.C. 7:26D-2.2, subject to the phase in period discussed below.

The adopted rule established more stringent standards for 52 constituents,  including trichloroethylene (“TCE”), tetrachloroethylene (“PCE”), 1,1-Dichloroethylene (“DCE”), polychlorinated biphenyls, benzene, cobalt, and vinyl chloride. Of these 52 constituents for which the Department adopted more stringent standards, the standards for seven decreased by an order of magnitude: 1,1-biphenyl, cobalt, cyanide (free), 1,3-dichlorobenzene (meta), heptachlor epoxide, methoxychlor, and vinyl chloride. The order of magnitude change in the vinyl chloride remediation standard is particularly significant because vinyl chloride is present at many contaminated sites as a breakdown product of the formerly common solvents TCE and PCE. On the other hand, the standards for 12 constituents became less stringent and NJDEP did not change the GWQS for nine constituents. Additionally, NJDEP established standards for dimethyl phthalate and 4-Chloro-3-methylphenol, which are less stringent than the current interim generic ground water quality criteria for these constituents.

The GWQSs will have significant impacts on both active and closed remediation cases across the state, especially for sites where constituents are present and their standard has been amended by an order of magnitude.

With respect to active remediation cases, the Department has issued two guidance documents discussing how the GWQS will be phased-in. First, NJDEP published Phase-In Period for Use of Ground Water Remediation Standards N.J.A.C. 7:26D, v. 3.0, updating the phase-in timeframes in N.J.A.C. 7:26D-1.4(b) that have been applied to past changes to the GWRS. A person responsible for the remediation (“PRCR”) can use the GWRS in effect before February 3, 2025 for its remediation case if the old standard is not greater than or equal to an order of magnitude than the newly adopted GWRS; a remedial action workplan or remedial action report is submitted before August 3, 2025, which is either certified by an LSRP or approved by the Department; and the PRCR completes the remedial action within the appropriate regulatory timeframe.

Second, NJDEP published its Phase-In Guidance for Initial Ground Water Remedial Action Permit Applications that include Contaminants where the Ground Water Remediation Standard changed by an Order of Magnitude. NJDEP explained that for new Initial Ground Water Remedial Action Permit (“RAP”) applications submitted (or postmarked) before August 3, 2025, it will review the application using the GWRS in effect prior to February 3, 2025. NJDEP explained that it would include in its approval of the RAP that the order of magnitude remedial action protectiveness evaluation needs to be completed prior to and submitted with either the first Remedial Action Protectiveness/Biennial Certification Form or an application for a RAP modification, whichever occurs first. Conversely, if a RAP application is withdrawn or deemed administratively or technically incomplete, the remediation must be conducted using the newly adopted GWRS.

For remediation cases that are currently closed, the case may be reopened if the remediation standard for a constituent present in ground water has decreased by an order of magnitude as compared to the standard used to remediate the site and the previous remediation poses a risk to the environment and human health. See N.J.S.A. 58:10B-13.e. The type of use remedy employed at the site dictates when the order of magnitude evaluation must be completed to determine whether the current remedy is protective or additional remediation is necessary. For sites subject to a restricted use remedy, the evaluation must be conducted as part of the next biennial remedial action protectiveness certification. If the site has an unrestricted use remedy, the evaluation would be conducted when the site “re-enters” the Contaminated Site Remediation and Redevelopment program, for example, if there is a new ISRA trigger for the site.

Licensed Site Remediation Professionals and persons responsible for conducting the remediation should be cognizant of these changes and consider how they may affect any of their active or inactive remediation cases and how they may take advantage of the phase-in period to be grandfathered under the old ground water remediation standards.

For more information, please contact the author, Amelia Whiting, at awhiting@riker.com or any attorney in our Environmental Practice Group.