Do New Vapor Rules in NJ Affect Your Project?

NJDEP LogoToday, January 17, 2013: NJDEP published major changes to guidance and standards pertaining to Vapor Intrusion. Vapor Intrusion is defined as the migration of volatile chemicals from the subsurface into overlying buildings through subsurface soils or preferential pathways (such as underground utilities). This pathway has been the driver for many off-site investigations, public notifications and costly indoor air testing since the NJDEP’s initial guidance came out in 2007.

Just released on the NJDEP’s Vapor Intrusion web page is the revised Vapor Intrusion Technical Guidance document and updates to the 2007 Vapor Intrusion Screening Levels (VISL). Finally, the web page also features Johnson & Ettinger (J&E) Model spreadsheets that were updated to reflect toxicity changes in the new VISL.

Here are just some of the changes:
Naphthalene and 2-methylnaphthalene have been added to the VISL tables. At this time, the laboratory capacity to analyze naphthalene and 2-methylnaphthalene using the preferred USEPA Method TO-17 is limited (only one certified laboratory). Therefore, the Department will not require the collection and analysis of naphthalene and 2-methylnaphthalene until July 16, 2013.

A factor of 10 has been incorporated into the calculation of the health-based ground water screening values for additional petroleum related contaminants (not reflected in the March 2007 tables) to account for degradation of the contaminants in the unsaturated zone. The additional petroleum related contaminants include: 1, 3-butadiene; cyclohexane; n-hexane; 2-methylnaphthalene; naphthalene; and styrene.

Five contaminants have been eliminated from the VISL tables due to the absence of inhalation toxicity information. These chemicals include: 1, 3-dichlorobenzene; 1, 2- dichloroethene (cis); 1, 2- dichloroethene (total); 2-chlorotoluene; and tertiary butyl alcohol (TBA).

Changes to many previously regulated compounds, including increases in groundwater screening levels for tetrachloroethylene (aka PCE) (up to 31 ug/l from a prior standard of 1 ug/l) and trichloroethylene (TCE) (up to 2 ug/l from a prior standard of 1 ug/l) for example, were also made.

Consult your LSRP regarding how these changes affect your project, or feel free to contact REPSG directly at

An Introduction to Vapor Intrusion Investigations in New Jersey

 For the New Jersey Department of Environmental Protection (NJDEP), 2012 has been a banner year. Here at REPSG, we have really had to stay on our toes to ensure that allNew Jerseysites are adhering to current regulatory guidance, form submittal requirements, and rules.

In January 2012, the new Vapor Intrusion Technical Guidance was finalized, providing lots of new details for the investigation of vapor intrusion into indoor air. Additionally, the Technical Requirements for Site Remediation (7:26E) was finalized in May 2012, providing the last word in receptor evaluation of populations being potentially impacted by harmful vapors. Now that all of the changes have been finalized, Suzanne Shourds and I plan to tackle the topic of vapor intrusion in an upcoming series of blog articles. We will be discussing the ins and outs of vapor intrusion as well as our own experiences with sites in New Jersey that have addressed potential vapor intrusion. These posts will cover vapor intrusion screening levels, receptor evaluations, the stages of a vapor intrusion investigation (groundwater, soil gas, and indoor air), mitigation, and the special requirements associated with Immediate Environmental Concerns and Vapor Concerns.ew Jersey Department of Environmental Protection (NJDEP), 2012 has been a banner year. Here at REPSG, we have really had to stay on our toes to ensure that all New Jersey sites are adhering to current regulatory guidance, form submittal requirements, and rules.

To get things started, let’s take a look at Vapor Intrusion Investigation Triggers, Screening Levels, and Receptor Evaluation (Stage 1).

When conducting a Site Investigation, the first step to take to address potential vapor intrusion is to identify a source, as well as a potential pathway (typically impacted groundwater) and possible receptors. Identification of all these components triggers the need for a Vapor Intrusion Investigation (Stage 2), addressed in the next blog post on this topic).

Once impacted groundwater with concentrations above the NJDEP’s Groundwater Vapor Intrusion Screening Levels is identified and delineated, all buildings (homes, apartments, commercial spaces, warehouses) and structures (garages, utility vaults, sheds) within 30 feet of petroleum-based impacts (including free product) and/or within 100 feet of non-petroleum-based groundwater impacts (including free product) must be considered potential receptors of vapor intrusion impacts and incorporated into the investigation.       A receptor must be present in order for there to be a potential vapor intrusion concern. This includes consideration of future receptors. Once the trigger is identified, the property owner has 150 days to conduct sampling of the identified receptors. Prior to conducting this sampling, all receptors must be characterized to identify building or structure use, size, and details (such as the presence of a basement).

Additional site triggers for a vapor investigation include: soil gas or indoor air data above Vapor Intrusion Screening Levels, a wet basement or sump containing free product or groundwater impacted with volatile compounds, methane-generating conditions, any other situation threatening health and safety that is related to vapor/indoor air.

Have a question about vapor intrusion investigation triggers? Leave a comment below or please feel free to contact me at Please check back soon for our follow up article on Stage 2: Vapor Intrusion Investigation.

Vapor Encroachment Explained

In a Phase I Environmental Site Assessment (ESA) report, these days you are likely to see an evaluation of vapor encroachment conditions at the site. If you haven’t, you will. The upcoming update to ASTM’s Phase I Standard proposes to treat vapor encroachment like any other source of contamination, and thus a routine component of environmental due diligence.  So, what is it?

Think of vapor encroachment as a cousin of vapor intrusion.

According to the EPA, vapor intrusion occurs when there is a migration of volatile chemicals from contaminated groundwater or soil into an overlying building. Evaluation of vapor intrusion identifies contamination sources on- site. Vapor encroachment, on the other hand, also considers off-site sources. Think of vapor encroachment as a screening tool.

Vapor encroachment screening identifies releases in the vicinity of the subject property and, based on the contaminant plume, evaluates the likelihood of vapors migrating to the subsurface of the subject property. Vapors, in this case, consist of any chemical of concern (COC); and their presence or likely presence constitutes a vapor encroachment condition (VEC). The ASTM standard for this screening (E2600-10) uses a two-tiered approach (not to be confused with the EPA’s three-tiered vapor intrusion guidance!)

Tier 1 of vapor encroachment screening uses state and federal database records to identify those sites with the potential to affect subsurface vapor conditions. Much like the radius search for a Phase I report, Tier 1 employs a 1/3 mile radius for releases of non-petroleum products, and a 1/10 mile radius for releases of petroleum products. If a VEC cannot be ruled out, i.e. there are open sites within the search distance, then on to Tier 2.

Tier 2 starts out as a non-invasive records review. If you’re lucky, the state will have regulatory files for sites identified in Tier 1, and those files will contain the location of the source and contaminant plume. Based on the relation of the plume to the subject property, it is possible to rule out a VEC. If you don’t have access to plume info, or, if a VEC cannot be ruled out non-invasively, the next option is sampling – of soil, soil gas, and/or groundwater.

Ultimately, there are four possible outcomes of a vapor encroachment screen: 1) VEC exists; 2) VEC likely exists; 3) VEC cannot be ruled out; or 4) VEC can be ruled out. In the context of a Phase I ESA, the environmental professional determines if a VEC represents a recognized environmental condition (REC) for a specific site.

As vapor intrusion receives more attention from regulators, vapor encroachment screening can be a useful tool to delineate vapor concerns originating on-site and off. The intent is to provide an evaluation of vapor in the soil, thus refining the determination of vapor that may end up indoors. Some agree, some disagree, either way it is here to stay. Have you found vapor encroachment screening to provide insight or headaches? Leave a comment below, and please feel free to contact me at with your vapor encroachment questions.