New Ground Water Quality Standards: What do they mean for your site in New Jersey?

These standards may apply to sites undergoing remediation as well as sites that have been closed

If you’re wondering what the New Jersey Department of Environmental Protection’s (NJDEP’s) updated Ground Water Quality Standards (GWQS) mean for you, here are some key points GZA has been discussing with clients.

Background

NJDEP amendments to the GWQS changed the criteria for 73 compounds, including 50 that were made more stringent. Of those, the GWQS of seven compounds have been decreased by an Order of Magnitude (OOM) or more. Effective February 3, 2025, these standards apply to Class II-A groundwater, which is essentially all groundwater in New Jersey. It has been estimated that thousands of sites, both active and closed, may be impacted.

What are the Order of Magnitude compounds?

The seven compounds for which standards have been decreased by an OOM or more—at least 10x more stringent—are: 1,1-Biphenyl; Cobalt; Free Cyanide; 1,3-Dichlorobenzene; Heptachlor Epoxide; Methoxychor; and Vinyl Chloride.

How do these new standards change what is required at my site where remediation is underway?

• If your remedial action workplan (RAW) or remedial action report (RAR) is submitted by August 3, 2025, the former GWQS remain in effect, except for those seven compounds with OOM changes. It is imperative that an evaluation be completed for those seven compounds to determine if groundwater concentrations remain in compliance and protective of human health and the environment. If they do not meet the new standards, additional investigation and/or remediation may be required.
• At sites where the RAW/RAR have not been submitted by August 3, 2025, the new GWQS will apply. 

An RAO was issued for my site – will the case be reopened?

There has been much discussion in the environmental community in the short time since the GWQS were published as well as in the comments/responses of the newly published GWQS about potential “reopener” triggers for cases that have been closed, i.e., have a Response Action Outcome (RAO) or No Further Action (NFA). Indeed, the science of each site varies, and environmental consultants will work closely to advise their clients appropriately as these scenarios are further explained by the NJDEP.

Thus far, in response to multiple comments included in the February 3, 2025 New Jersey Register publication of the new GWQS regarding the potential for cases with a final remediation document to be reopened, the NJDEP response has included the following information:

• For sites with a Restricted-Use RAO or Limited Restricted-Use RAO with an approved Groundwater Remedial Action Permit, an OOM evaluation for the seven compounds noted above must be conducted and included with the next Biennial Certification submittal. Depending on the results of that evaluation, additional actions may be required.
• If a site has been closed with an unrestricted RAO or an unrestricted NFA, the OOM evaluation would be required if/when the site “re-enters” the NJDEP’s Contaminated Site Remediation and Redevelopment Program (formerly named the Site Remediation Program), which could be prompted by a property transaction or other triggers. 

What are the most common constituents for which standards have been made more stringent?

In addition to Vinyl Chloride (one of the seven compounds for which the standard has decreased by an OOM), three of the 50 compounds for which standards have become more stringent and which are very commonly found on contaminated sites in New Jersey include: Benzene; Tetrachloroethene; and Trichloroethene. These compounds are often present in groundwater at sites in New Jersey impacted by historical uses such as dry cleaners, gas stations/auto repair shops, and industrial and manufacturing facilities that used solvents in their operations, to name a few.

What if the site I am considering purchasing is contaminated?

Environmental due diligence, including a Preliminary Assessment (PA) and, if necessary, a Site Investigation (SI), remains critical for buyers in New Jersey to make informed property transaction decisions. This investigatory process demonstrates that the buyer has conducted “all appropriate inquiry” and entitles the buyer to “innocent purchaser defense” under the Spill Act; this can protect the buyer from responsibility for additional evaluation requirements or costs associated with the new GWQS. Compliance with the new GWQS is the responsibility of the Person Responsible for Conducting Remediation (PRCR), as determined by New Jersey’s Spill Act and/or Brownfield Act.

Questions?

GZA has prepared for the promulgation of these amendments and is advising clients whose sites may be impacted. Please contact us if we can assist you.