Contents

• Bureau Of Underground Storage Tanks Announces Cooperative Venture
• Alternative Ground Water Sampling Proposals
• Hazsite Database
• Second Printing Of "Known Contaminated Sites In New Jersey"
• New Air Permit Conditions Announced For Soil Vapor Extraction Of Petroleum Hydrocarbons
• Recent Developments May Affect Home Buyers
• NAPL And Aquifer Remediation
• Classification Exception Areas
• Site Remediation Program Focused On Human Health Impacts
• Site Remediation News Alphabetical Index

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BUREAU OF UNDERGROUND STORAGE TANKS ANNOUNCES COOPERATIVE VENTURE

By: Kevin F. Kratina, Chief, Bureau of Underground Storage Tanks

On April 27, 1995, the Bureau of Underground Storage Tanks (BUST) met with most underground storage tank (UST) stakeholders having more than eight cases within the department's Site Remediation Program to announce the "Cooperative Venture".

This alternative case processing plan is intended to increase cooperation between UST owners and operators and the department in pursuing site cleanup compliance with federal and state regulations. These changes should facilitate the department's efforts to maximize the "teamwork approach" with the regulated community, while continuing our mission to protect public health and the environment. The following provides a brief summary of a new approach to the management of regulated UST cases.

The purpose of this initiative is to develop mutually agreed upon schedules for the investigation and remediation for all regulated UST sites based upon site specific conditions and risks to receptors. This initiative will be available to large and small business alike and is intended to accomplish the following:

• Allow up-front identification of cases presenting risks and in need of priority action. Examples of priority cases include, but are not limited to, potable well impacts, vapor threats, surface water discharges, ongoing UST system discharges, free product removal, etc.
  
  
• Work with UST owners and operators' business/economic considerations, while ensuring protection of public health and the environment.
  
  
• Develop a performance based program, similar to the Voluntary Cleanup Program, where responsible parties can prioritize some of their remediations (after appropriate risk evaluation) based upon business/ economic factors. Longer schedules can be developed to complete specific objectives (i.e. completion of a Remedial Investigation, submittal of a complete Remedial Action Workplan, etc.) by following the "Technical Requirements for Site Remediation", N.J.A.C. 7:26E et seq., with less departmental oversite.
  
  
• Reduce administrative paperwork such as routine extension requests, compliance referrals, redundant information submissions, etc., resulting in less cost to the regulated community from consultant and attorney review fees, and ultimately, allow for the department to address more UST cases and prepare for the expected increase in reportable releases as part of the 1998 federal and state UST upgrade deadline.

This plan does not change "how" a responsible party will conduct the required investigation and remediation. The responsible party must continue to follow the "Technical Requirements for Site Remediation", and utilizes the department's most recent soil cleanup criteria and the Ground Water Quality Standards for evaluating the extent of contamination and developing a remedial action workplan.

Under the plan, the responsible party would first be required to assess the actual and/or potential risk posed by the release from the UST system(s). This would also include the immediate completion of critical activities, such as eliminating the source of a continuing discharge, evaluation/mitigation of impacts to potable wells, surface water, utility conduits, and initiating the removal of free product on ground water. Early evaluation of site conditions will ensure adequate protection of public health and the environment, reduce owner/operator liability and provide a basis for developing the schedule for remaining work.

After the completion of the initial risk evaluation and any critical activities, the responsible party would then adhere to a mutually agreed upon schedule for the completion of the remaining remedial investigation and final remedial action. Sites that are deemed a priority, utilizing the Remedial Priority Score and other site specific factors, will continue to be investigated/remediated on an expedited timeframe. In contrast, if a site is shown to pose little or no risk, maximum flexibility will be provided to schedule the remaining activities based upon business/economic factors. As a site progresses with the investigation, the risk (and schedule) may also be adjusted accordingly. This process is very similar to the American Society for Testing and Materials (ASTM-ES38-94) "Emergency Standard for Risk-Based Corrective Action Applied at Petroleum Sites", issued this past summer, and is consistent with the United States Environmental Protection Agency, Office of Solid Waste and Emergency Response (OSWER) Directive 9610.17, issued March 1, 1995, titled "Use of Risk-Based Decision Making in UST Corrective Action Programs."

For owners and operators of multiple sites, a single point of contact with the department will be established; this individual will be responsible for gauging compliance responsiveness. This individual will not be the "case manager," but will work with the assigned case managers and responsible parties to establish the risk of their regulated UST sites and define the schedules for remaining activity, as well as assess overall compliance. As necessary, the department will publish the degree of compliance achieved. For owners and operators of single sites, the case manager will be the point contact.

The department's case managers will stand ready to assist UST owners and operators to ensure complete submittals, monitor case progress, provide guidance for compliance options and provide timely responses to submittals. With over three years of experience in dealing with the "Technical Requirements for Site Remediation," the regulated community is expected to have knowledge of the requirements for investigating and cleaning up sites. This plan incorporates this knowledge and allows for less direct department oversight and cost. This service oriented approach will reinforce this cooperative venture. Most importantly, department case managers will monitor site conditions to carry out the department mission to protect public health and the environment.

It is the UST program's intention to continue the practice of open dialogue and a cooperative approach to assist in achieving compliance at UST corrective action sites. The program is optimistic that this approach will result in a greater number of cleanups being completed with a focus on upfront risk reduction, less department and regulated resources being expended and an improved relationship between our responsible parties and the department. For more information and details on the above, please contact your case manager within the Bureau of Underground Storage Tanks or Kevin F. Kratina at (609) 292-8761.

GENERAL INFORMATION:

Please be sure to include the box number on all mail addressed to the Industrial Site Evaluation Element. Some mail has been received by the element many weeks past the date on the correspondence due to the omission of the box number. The proper way to address mail to the element is:

Section Name or Case Manager's Name
Industrial Site Evaluation Element
CN 028
Trenton, New Jersey
08625-0028

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ALTERNATIVE GROUND WATER SAMPLING PROPOSALS

By: Elaine DeWan, Bureau of Underground Storage Tanks

The Site Remediation Program has received numerous variance requests to use alternative ground water sampling methods either to conduct a remedial investigation of ground water pursuant to Section 4.4 of the Technical Requirements for Site Remediation, N.J.A.C.7:26E (Technical Regulations) or in lieu of installing a permanent ground water sampling well. According to Section 4.4(c) of the Technical Regulations, ground water sampling methods other than those found in the NJDEP Field Sampling Procedures Manual may be used and therefore, a formal variance request is not required. However, if departmental pre-approval is not received (in the form of a Remedial Investigation Workplan (RIW) approval) and an alternative ground water sampling method is used in a manner that cannot withstand a departmental review pursuant to Section 1.6(c) of the Technical Regulations, the responsible party runs the risk of the results being rejected. If you wish to implement an alternate ground water sampling method without departmental approval, all items outlined in Section 1.6(c) of the Technical Regulations shall be submitted in the applicable remedial phase report. NOTE: Typically, alternate sampling techniques have been used successfully at sites as an aide in the delineation of the plume and for the effective placement of monitoring wells. This use is not addressed in this article, since permanent sampling points will be installed.

The alternate sampling methods in lieu of a permanent well should be used only when the contaminants are known and the presence of free floating product is not a concern. Since most of the sampling devices have a short screen interval, the chances of missing the free product layer is high.

Many of the alternate ground water sampling proposals in the form of a variance request or RIW received by the Site Remediation Program do not contain sufficient information for the department to approve the proposal without an exchange of comments between the responsible party and the department. In addition, many of the site/remedial investigation reports submitted where alternate ground water sampling methods have been used do not provide adequate documentation required in Section 1.6(c) of the Technical Regulations. This potentially increases costs both in consultant fees and department oversight. Also, situations involving numerous information exchanges are contradictory to the whole approach of using these sampling methods, specifically, to streamline and expedite investigations.

Prior to preparing a RIW and/or implementing an alternate ground water sampling method, the department's "Alternative Ground Water Sampling Technique Guide", July 1994, should be referred to for the most suitable method based on site specific conditions and parameters to be analyzed. This guide outlines the advantages and limitations for each technique.

The following are the most common deficiencies noted by the department in reviewing variance requests and RIWs utilizing alternate ground water sampling methods:

• Not specifying the sampling method proposed, the specific equipment to be used and how the method is to be applied at the site;
  
  
• Not reporting or proposing a method to determine the depth to the ground water at the site. If the contaminants of concern are lighter than water, which is true for most UST cases, sampling is required across the water table. Therefore, either the depth to ground water needs to be determined and reported in the variance request or a method to determine the depth to water prior to implementing the alternative sampling method should be proposed;
  
  
• Not identifying the subsurface soil profile. Each sampling technique outlines the limitations/capabilities for different types of geologic formations. Therefore, the variance request should include a description of the subsurface soils and the appropriateness of proposed method to the formation;
  
  NOTE: Most techniques are not suitable in silty/clay formations due to low yield and/or smearing of the screen. In addition, these techniques may not be practical in areas of shallow bedrock.
  
  
• Not including a scaled site map indicating the proposed sample locations;
  
  
• Not identifying the parameters to be sampled and analyzed;
  
  NOTE: Most techniques are not suitable for metals due to higher levels of turbidity in the sample collected, biasing the results high.
  
  
• Proposing an inappropriate sample method based on site specific conditions. An example is proposing a method which is limited by potentially causing cross contamination or carrying contamination to a zone not previously contaminated in an area where soil contamination exists;

In closing, when comparing costs of installing permanent wells versus using analternative ground water sampling technique the following should be considered.

• If soils remain in place above the impact to ground water cleanup criteria and a proposal for an alternative soil remediation standard pursuant to N.J.S.A. 58:10B-12(f) is being considered, the department may require more than one round of ground water sampling based on the site specific conditions (i.e. the amount of soil above standard, the depth to ground water, the age of the discharge). The case manager should be contacted to discuss the case specifics.
  
  
• Should any of the parameters analyzed indicate levels above the Ground Water Quality Standards, a permanent well will be required. Therefore, if there is a strong probability that ground water contamination exists at the site, the costs to mobilize twice should be considered before applying for the variance.

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HAZSITE DATABASE

By: George Jaegers, Bureau of Planning and Systems

For many years the Site Remediation Program (SRP) has been gathering a variety of sample data during site remediations, most of which has come into the department in the form of data tables in printed reports. Not only does it take a long time to manually evaluate these reports but long term storage and retrieval of this printed information is both expensive and inefficient.

In an effort to begin shifting away from paper data summaries and into the world of electronic data gathering and analysis, a section was incorporated into the Technical Requirements for Site Remediation, N.J.A.C. 7:26E, which specified the department preference for receiving site data in an electronic format. This preference took the form of the Hazardous Site Information Application, now also known as the HAZSITE Database.

The HAZSITE Database is designed to fulfill several critical needs.

First, it is an easy-to-use repository for all site sampling data, allowing both rapid access to large amounts of data as well as a variety of analytical tools for data analysis. The database application now contains current department soil cleanup criteria as well as groundwater standards, which will allow for easy and rapid analysis of site data as well as automatic comparison to existing cleanup guidelines. This has the potential to significantly reduce the amount of time spent manually searching for samples that exceed specific criteria and will help to ensure that all exceedences are discovered.

Second, the HAZSITE Database is designed to facilitate the integration of all sampling data gathered by the Site Remediation program. Written in Microsoft Foxpro, the HAZSITE Database uses the popular dbf database format, which is not only readily available to the entire environmental user community, but also compatible with our existing Geographic Information System (GIS). When fully implemented, program personnel will have ready access to up-to-date sample information that can be analyzed on a site specific basis or studied using the spatial analysis tools provided by the GIS. The SRP will then have the capability to efficiently look beyond site boundaries to analyze the potential effects of neighboring contamination when making cleanup decisions.

Finally, the HAZSITE Database is a cornerstone of the department Electronic Data Interchange (EDI) initiative. In an effort to more efficiently utilize modern computer capabilities and to increase the timeliness and productive use of department data, the EDI committee was established to encourage the environmental community to begin the transition to electronic data transmittal. The HAZSITE Database is one of the first applications to be made ready for electronic data submission. It has been designed to allow direct uploads of data sent to the department electronically.

Electronic submission can currently be accommodated through two methods. Either a computer disk containing the sampling information can be sent to the department, or the files can be transmitted over phone lines to the new department Electronic Bulletin Board system (BBS). The DEPBBS is just now coming online, and should prove to be an efficient means of not only receiving data from the field, but also making data or other department information available to the public.

For further information regarding the HAZSITE Database, the DEPBBS, or electronic data exchange, please contact George Jaegers or John Abolins in the Bureau of Planning and Systems, at (609) 633-1476, or through the Internet, GEJAEGERS@DEP.STATE.NJ.US or JABOLINS@DEP.STATE.NJ.US The phone number for the DEPBBS is (609) 292-2006.

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SECOND PRINTING OF "KNOWN CONTAMINATED SITES IN NEW JERSEY"

The second printed edition of Known Contaminated Sites in New Jersey (KCSNJ) will become available for purchase in September 1995. The KCSNJ lists sites in the state that have confirmed contamination present at levels greater than the applicable cleanup criteria for soil and/or ground water contamination and includes a separate list of sites with unknown sources of contamination. A full description of the KCSNJ appeared in the Summer 1994 edition of Site Remediation News, Volume 6, Number 2.

Since the first printed edition, published in the fall of 1994, two revised editions were generated in January and May 1995 which were made available on diskette through the New Jersey Department of Environmental Protection's (NJDEP) Maps and Publications Sales Office. The department plans to continue to offer an electronic edition of KCSNJ on a quarterly basis in diskette format. The cost of the new printed edition or the diskette formats (ASCII or as a printable report) is $15.00 for each option selected.

Please direct all purchase requests to: NJDEP Maps and Publications Sale Office, CN 417, Trenton, New Jersey 08625-0417. For more information, you may contact Maps and Publications at (609) 777-1038 or (609) 777-1039.

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NEW AIR PERMIT CONDITIONS ANNOUNCED FOR SOIL VAPOR EXTRACTION OF PETROLEUM HYDROCARBONS

By: Rebecca Jones, P.G., Bureau of Underground Storage Tanks

The Bureau of New Source Review (BNSR) has finalized conditions for soil vapor extraction (SVE) systems at sites with petroleum hydrocarbon contamination. These conditions were the outcome of a cooperative effort between the Industrial Site Evaluation Element (ISEE) and representatives of BNSR to examine ways to streamline permitting and to reduce costs associated with the monitoring of SVE treatment units. Part of this effort also involved a review of a draft version of these conditions by interested parties. Many comments received from this review were incorporated into the final version. As a result, the previous policy of issuing individual permits by treatment unit has been changed to allow the use of thermal oxidation, catalytic oxidation and carbon adsorption units under the same permit. This will allow for smoother transitions between treatment units as influent concentrations decrease during a cleanup. Following the proposal of conditions for internal combustion engines (set for proposal at a later date), only one permit will be needed to control the most common treatment units utilized at SVE sites.

Most notable of the new conditions are those relating to analytical methods and monitoring frequency at sites where thermal and catalytic oxidation units are used. Previously, either a continuous emissions monitor or the monitoring schedule contained in the Bureau of Technical Services' April 1994 "Emission Monitoring Requirements for Petroleum Soil Remediation Projects for Oxidizers" was specified in permits for these units. The new conditions do not require the use of a continuous emissions monitor and have significantly changed the monitoring schedule in the April 1994 document. Monitoring frequency has been reduced from 28 monitoring events during the first three weeks of operation to 6 monitoring events during this period. Unlike previous conditions which required no less than weekly monitoring after three weeks, monthly monitoring is allowed after the tenth week of operation. In addition, laboratory-analyzed canister samples are no longer required. All sampling can be done with portable equipment if the monitoring protocol meets certain conditions (as specified in Attachments 1 and 2 to the permit conditions) and is approved by the Bureau of Technical Services prior to start-up. Previously, eighteen canister samples were required during the first 10 weeks of operation. The BNSR has also allowed for a return to the pre-shutdown monitoring requirements if an operating system is shut down and restarted for reasons other than an exceedance and monitoring results return to within 10% of the pre-shutdown results. These changes are expected to greatly reduce labor and laboratory analytical costs at SVE sites, thus resulting in reduced site remediation costs. Preliminary estimates by consultants place the savings in the monitoring of these systems over a one year period at approximately 60% to 65% less than the cost of implementing the April, 1994 monitoring requirements.

The BNSR has also standardized the emissions requirements by requiring that a unit meet either a removal efficiency of 95% for total volatile organic compounds (VOCs), a concentration limit of either 25 or 50 ppmvd (parts per million per unit volume as calculated on a dry weight basis) of total hydrocarbons depending upon the conditions for the type of unit, or an emission rate of 0.5 lbs/hr total VOCs and 0.1 lbs/hr for toxic substances. This will allow greater flexibility in achieving compliance later in the cleanup as influent concentrations decrease and removal efficiencies decline.

Upon review of the new conditions, it is very likely that many responsible parties will want to revise conditions in existing permits. The BNSR will revise only the conditions for control devices contained in the initial permit application (requests for the addition of new control devices to the permit must be submitted as an alteration). In order to handle the revision requests in the most efficient manner, the BNSR recommends that responsible parties with multiple SVE sites consolidate these requests into a single revision request. All requests shall consist of a letter requesting a revision with site specific information submitted as an attachment. The attachment shall consist of the following seven items for each site where a revision is requested:

1. Applicant
2. Location (including county)
3. Stack Designation
4. BNSR Log No.
5. APC Plant ID and N.J. Stack No. (from form VEM-017, if available)
6. Control Device(s) on permit, with maximum flow rates
7. Minimum temperatures and residence times for catalytic oxidizers (if applicable)

The revision request containing this information shall be submitted to the following address:

New Jersey Department of Environmental Protection
Bureau of New Source Review
Attn: Lou Mikolajczyk
CN 027
Trenton, NJ 08625-0027

Copies of the final conditions and additional information on revising or altering existing permits can be obtained by contacting Richard Gudz of the Bureau of New Source Review at (609) 633-8253.

As a result of these changes, the ISEE anticipates that SVE technology will become more affordable for responsible parties, especially for those with small businesses, due to reduced operational costs and reduced time and effort in permitting these units. The ISEE is continuing to work with the BNSR on issues common to both programs and to improve service to the regulated public.

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RECENT DEVELOPMENTS MAY AFFECT HOME BUYERS

By: Mark Herzberg, Bureau of Community Relations

A recent New Jersey Supreme Court decision requires developers and real estate brokers selling homes to inform prospective buyers about offsite conditions, such as contaminated sites, that might impact property values or pose health and environmental problems to the buyer. The April 25, 1995 decision (Strawn v. Canuso) was unanimous in favor of a group of homeowners in Voorhees Township, Camden County. They had purchased homes in a new development within a half-mile of the Buzby Landfill and were allegedly never told of the nearby site. The class-action case was brought against the developer and the selling agent for the development. The court said both knew of the landfill's hazards but did not disclose them to potential buyers.

As a result of the court decision, legislation has been drafted by Assemblyman George Geist (R-Camden) in an effort to define the responsibilities of the various parties involved. The bill would require the municipal clerk of each municipality to maintain information on various conditions within the municipality's borders. Under the current version of bill, prospective home buyers would be able to access information on contaminated sites, electrical transformer substations, underground gas lines, sewage treatment plants, airport safety zones, and air pollution sources. Every seller, including brokers or builders, of newly constructed residential real estate would be required, at the time of entering into a contract for the sale of the property, to provide the purchaser with a notice of the availability of the information.

Last summer, the Site Remediation Program released an inventory of Known Contaminated Sites in New Jersey. The report contains a listing of over 6800 sites, ranging from leaking residential oil tanks to major Superfund cleanups. The report is available from the DEP's Maps and Publications Sales office at (609) 777-1038.

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NAPL AND AQUIFER REMEDIATION

By: Jeff Story, P.G., Bureau of Ground Water Pollution Abatement

Pursuant to the site investigation and remedial investigation (RI) requirements in the Technical Requirements for Site Remediation, specifically at N.J.A.C. 7:26E-3.6(a)7 and 4.1(b), the horizontal and vertical delineation of contamination for all media must be conducted. This delineation requirement includes proper characterization of the contamination present.

At many industrial facilities the source of groundwater contamination is from product spills or leaks from drums or containment vessels (i.e., tanks) and associated piping. When the drums and tanks are removed, the products remaining in soils can still act as a source of groundwater contamination. These products must either be removed, where practical, or contained (i.e., using physical and/or hydraulic means) when remediating groundwater contamination. This is also true where dissolved contaminant plumes are allowed to be remediated naturally. These products are non-aqueous phase liquids (NAPL) due to their relatively low water solubility. Some products (e.g., gasoline) are lighter than water (LNAPL) and will float on the water table while others (e.g., TCE) are denser than water (DNAPL) and will sink in the aquifer until they encounter a relatively impermeable boundary, such as a clay, that may cause the DNAPL to move laterally (Figure 1). DNAPL pools, if present, will migrate in the direction the impermeable boundary dips, which may not be the same direction that the groundwater flows.

Although NAPL constituents are relatively insoluble, they can dissolve in groundwater at concentrations that can far exceed their specific health-based drinking water-quality standards. NAPL can be present as both mobile, free-phase NAPL (i.e., free product) and as immobile, residual NAPL. Free product occurs when the volume of the product released exceeds the retention capacity of the soils and aquifer materials. Residual NAPL is what remains in the aquifer pores and adsorbed on aquifer solids after mobile, free-phase NAPL has migrated downgradient (or vertically downward, in the case of DNAPL, see Figure 1).

Residual NAPL is left behind due to such factors as wettability, interfacial tension between two immiscible liquids and capillary pressure. LNAPL on a fluctuating water table can also be left behind as residual product. As the water table rises it forces product upward at different rates through different pore sizes where it is separated from the main product body; it is saturated-zone residual product. When the water table falls, some of this product is released back into the product body but a portion of this product is trapped and remains as unsaturated-zone residual product. There is a constant transfer of oil from the mobile to residual state as water-table fluctuations occur (1). It is believed that the overall amount of residual oil released during a water-table fall exceeds the amount of oil trapped during a water-table rise (2).

Wettability describes whether a fluid will "coat" a solid or bead on it. In most cases of DNAPL contamination of aquifers, water is the wetting fluid, which leaves the DNAPLs to form isolated accumulations of nonaqueous liquids ("ganglia") in the pore spaces. Capillary pressure, which increases in finer-grained materials, will suck into the finer (i.e., smaller) pores the wetting fluid (usually water) and repel the non-wetting phase (usually NAPL). This restricts the movement of NAPL to larger pores unoccupied with water (3).

In some cases, spills and leaks result in losses of relatively small volumes of NAPL which result in the presence of only residual NAPL in the aquifer. The residual NAPL can, however, still act as a source of groundwater contamination as it slowly dissolves.

In recent years, much evaluation of conventional groundwater pump-and-treat (P&T) methods has been performed. It has been found that, while P&T can be effective in providing hydraulic control of plumes to prevent their migration, P&T is often not cost-effective when used alone for remediating contaminant plumes, particularly if NAPL is present. In this case, not only would it be difficult to achieve the remediation goals (e.g., groundwater quality standards), it typically takes many more years to remediate the aquifer than originally predicted (e.g., the number of pore volumes needed to be recovered for aquifer remediation may be significantly underestimated). In fact, if NAPL is not removed, conventional P&T remediation could last tens or even hundreds of years because of poor mass-removal rates.

Use of other methods with faster mass-removal rates (e.g., free-product recovery, soil-vapor extraction and air sparging, etc.) in the source area may be critical in accelerating aquifer remediation and achieving groundwater quality standards. (Note that even with source control or removal, it still may not be possible to achieve groundwater quality standards everywhere in the plume. Natural remediation may also be necessary if its use is considered to be protective of human health and the environment). Thus, in order to develop a cost-effective plan to remediate contaminated groundwater, it is essential to determine if NAPL is present and its extent. For these reasons, characterization and delineation of NAPL is recommended by USEPA for all Superfund and RCRA sites (4).

Several methods are available to determine if NAPL is likely to be present in the subsurface. However, it is important that the hydrogeology (e.g., location and extent of confining layers and groundwater flow paths, etc.), as well as the type(s) of contaminants present (e.g., whether LNAPL and/or DNAPL are likely to be present) be well understood before the source-area investigation is undertaken. Information on the hydrogeology (e.g., thickness of confining layers, if any) should first be obtained in areas outside of the suspected source areas. Once the hydrogeology is defined, the subsurface investigation is performed in the source area in such a way as to prevent the unwanted migration of DNAPL into uncontaminated aquifers by, for example, using telescoping drilling techniques.

Groundwater-quality data can lead one to suspect the presence of NAPL if dissolved concentrations are less than 10% (3) or even approach just 1% (5) of their effective water solubility. The use of permanent and temporary monitor wells (e.g., driven well points, HydropunchTM and GeoprobeTM samplers (6)) can be used to delineate NAPL during the RI. The temporary methods can provide relatively rapid and cost-effective collection of groundwater and NAPL samples for horizontal and vertical delineation as well as source identification.

Field screening of subsurface soil samples can also be used to identify, characterize and delineate the presence of NAPL at a site. Field-screening methods can include: visual and olfactory identification of free product, use of organic vapor monitors (e.g., OVA and HnU), "paper bag" and "jar tests" (7), and ultraviolet fluorescence and hydrophobic dyes (8, 9), among others. (Note: Sudan IV, a hydrophobic dye, is a teratogen, so take appropriate precautions.)

Laboratory analysis of soil samples can also indicate the presence of free-phase NAPL, particularly if the contaminant concentrations in the soil are in the percent range or >10,000 mg/kg. Unfortunately, typical lab analyses of soil samples cannot always indicate the presence of residual NAPL. In addition, the field-screening methods discussed above may not be effective either, if residual contents are low or they are distributed heterogeneously throughout the samples.

Fortunately, one can quantitatively evaluate the chemical results of soil samples using a knowledge of chemical partitioning in unsaturated and saturated soils to determine if residual NAPL is likely to be present even in the absence of NAPL pools (10).

In the unsaturated zone, the pore water contaminant concentration (Cw, in mg/L or ug/cm3) is related to the total soil chemical concentration (Ct in ug/g dry weight) for soils as follows:

                     -----------------------------
                    |              CtPb           |
                    | Cw = ---------------------  |
                    |       KdPb + nw + Hc + na   |
                     -----------------------------
                               Equation 1.
where:
Pb  =  soil bulk density
Kd  =  distribution coefficient between pore water and soil solids
       (cm3/g), and
    =  Koc foc (organic carbon-water partition coefficient times the
       fraction of organic carbon in the soil)
nw  =  water-filled porosity (volume fraction)
na  =  air-filled porosity (volume fraction)
Hc  =  Dimensionless Henry's Law Constant

For soil samples in the saturated zone, the air-filled porosity is by definition zero and is removed from Equation 1 as follows:

                     ---------------------
                    |           CtPb      |
                    | Cw = -------------  |
                    |        KdPb + nw    |
                     ---------------------
                            Equation 2.

By using Equations 1 and 2, one can calculate the contaminant concentration in the pore water in both unsaturated and saturated soils, respectively, and compare it to the contaminant's water solubility.

For example, if the TCE concentration in a soil sample (Ct) taken from the saturated zone is 420 mg/kg, nw = 0.3, Pb = 1.86 g/cm3, Koc = 126, and foc = 0.001, then by using Equation 2, Cw = 1500 mg/L, which exceeds the water solubility of TCE of 1100 mg/L. This indicates that TCE is likely to be present as NAPL in the aquifer. This should trigger further investigation to determine if TCE is present in DNAPL pools and where, or if it is present only as residual DNAPL.

Koc values can be found in published data (11, 12). Values for foc can be determined in the laboratory; they typically range from 0.001 to 0.003 for natural subsurface soils (10).

In most cases, NAPL consists of a mixture of many compounds. To more accurately determine the likelihood of the presence of NAPL in the aquifer, the effective solubility of each compound in the mixture should be determined.

The effective solubility (Se) of a compound can be determined from a laboratory analysis of samples of free-phase NAPL collected from the site or it can be estimated based on the percentage of each compound found in the soils or contaminant plume in groundwater. Se is related to solubility as follows:

                     ------------
                    | Se  =  XS  |
                     ------------
                      Equation 3.

where: X is the mole fraction of the compound and S is the pure-phase solubility of the compound. Compound molecular weights can be found in published literature sources such as reference 12 below. As can be seen in Equation 3, the effective solubility is less than the pure-phase solubility. Thus, even when the pore-water concentrations do not exceed S, they can exceed Se, indicating that residual NAPL may be present.

For reference, the equations provided above are contained in an EPA Quick Reference Fact Sheet (13).

Summary:
In order for aquifer remediation to be cost-effective, sources of groundwater contamination must be remediated. In the case of organic compounds, these sources typically are NAPL. Remediation of NAPL requires they first be adequately identified, characterized and delineated. These tasks can be achieved by use of the methods provided in this paper.

References:

1. The Use of Temporary Wells as a Field Screening Tool. EXXON paper submitted to NJDEP, February 28, 1995.
   
   
2. Assessment, Control and Remediation of LNAPL Contaminated Sites- Volume 1--One Day Workshop, presented for API/EPA by Environmental Systems & Technologies, Inc. Blacksburg, VA, Sept.-Oct., 1994.
   
   
3. S.G. Hulling and J.W. Weaver. Ground Water Issue, Dense Nonaqueous Phase Liquids. EPA/540/4-91-002, March 1991.
   
   
4. Considerations in Ground-Water Remediation at Superfund Sites and RCRA Facilities--Update. EPA Directive No. 9283.1-06, May 27, 1992.
   
   
5. Dense Nonaqueous Phase Liquids, A Workshop Summary. Dallas, Texas April 16-18, 1991, EPA/600/R-92/030, February 1992.
   
   
6. Alternative Ground Water Sampling Techniques Guide. NJDEP, July 1994.
   
   
7. SCOPE OF WORK, Investigation and Corrective Action Requirements for Discharges from Underground Storage Tanks and Piping Systems. NJDEP/BUST, September 1990.
   
   
8. Cohen, R.M., A.P. Bryda, S.T. Shaw and C.P. Spalding, Evaluation of Visual Methods to Detect NAPL in Soil and Water. Fall 1992 GWMR
   
   
9. Field Analysis Manual, NJDEP, July 1994.
   
   
10. Feenstra, S., D.M. Mackay, and J.A. Cherry, A Method for Assessing Residual NAPL Based on Organic Chemical Concentrations in Soil Samples. Spring 1991 GWMR.
    
    
11. Jeng, C.Y., D.H. Chen and C.L. Yaws, Data Compilation for Soil Sorption Coefficient. Pollution Engineering, June 15, 1992.
    
    
12. Montgomery, J.H., and L.M. Welkom, Groundwater Chemicals Desk Reference. Lewis Publishers, Inc., 1990.
13. Estimating Potential for Occurrence of DNAPL at Superfund Sites. USEPA Quick Reference Fact Sheet, Publication 9355.4-07FS, January 1992.

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CLASSIFICATION EXCEPTION AREAS

By: Elizabeth Fernandez-Obregon, Bureau of Ground Water Pollution Abatement

On April 17, 1995, SRP's Assistant Commissioner Richard Gimello approved a final guidance document detailing procedures for designation of Classification Exception Areas (CEAs) in accordance with the New Jersey Ground Water Quality Standards (Standards), N.J.A.C. 7:9-6 et seq. The Standards establish a ground water classification system based on a combination of natural characteristics and actual or potential uses and define numeric and narrative criteria for each classification which, when not exceeded, will protect designated ground water uses. Within the context of its various regulatory programs, the department is charged with the responsibility to ensure protection of potable water users and ecological receptors by preserving and where necessary, restoring ground water quality to the applicable criteria established under the Standards.

Because it is recognized that primary aquifer uses based on classification are not always viable within a given area due to permitted discharges or pollution problems, the Standards include a provision which allows the department, under certain circumstances, to except areas from strict application of the Standards for a specified period of time. As defined under N.J.A.C. 7:9-6.6, Classification Exception Areas (CEAs) can be designated only when constituent standards are not or will not be met due to (1) natural groundwater quality; (2) localized effects of a permitted discharge; (3) a pollution remedy conducted pursuant to a department oversight mechanism or regulatory program; or (4) an Alternate Concentration Limit approved pursuant to the New Jersey Pollutant Discharge Elimination System (NJPDES). The department therefore can establish a CEA for a regulated area in cases where former discharges of pollutants have degraded groundwater quality and restoration through natural or active remedial processes is expected to take some time, and for active permitted discharges where exceedence of applicable criteria is reasonable and expected. The department's ability to except contaminated portions of an aquifer from strict application of the Standards for the term of a cleanup will allow the Site Remediation Program to move forward with the remediation of contaminated sites where immediate compliance with the Standards by a given discharge may be infeasible.

Although the department will formally designate CEAs under the authority of an oversight document, regulatory program, or New Jersey Pollutant Discharge Elimination System - Discharge to Ground Water (NJPDES - DGW) permit, the department will require the person responsible for conducting the remediation to submit the information needed to establish the CEA as part of the remedial action approval process. Generally, this information can be included in the proposed Remedial Action Workplan (RAW), or, in cases where a NJPDES - DGW permit is needed, as part of the permit application process. It is emphasized that RAW or No Further Action (NFA) approval will not be given unless the information needed by the department to designate the CEA is submitted. If a RAW will be proposed for groundwater remediation that does not currently included the full extent of the plume, the CEA can be proposed for that portion being remediated. The CEA designation can be modified over time as necessary once additional data on the rest of the plume have been collected.

The three basic components necessary for a CEA designation are (1) an identification of the contaminants exceeding groundwater quality criteria; (2) the horizontal and vertical boundaries of the CEA; and (3) the time expected before the remediation reduces contaminant levels to applicable standards. These components are briefly discussed below. Collection of data required to identify contaminants exceeding standards and define CEA boundaries routinely occurs during the course of a groundwater Remedial Investigation. A list of contaminants exceeding water quality criteria applicable to the aquifer classification area must be included in the CEA description. For all impacted properties, lot and block numbers and latitude and longitude with accuracy to 1/10 of a second must be provided. The lateral boundaries of the CEA should be shown on a USGS 7.5 minute quadrangle map. Off-site migration of a plume into an area where current or future (based on a 25-year planning horizon) groundwater use includes potable, industrial, or agricultural purposes will require accurate mapping of the known and expected migration path of the plume in a Geographic Information System (GIS)-compatible format. Copies of the NJDEP's "GIS - Mapping the Present to Protect New Jersey's Future - Mapping and Digital Data Standards" are available from the NJDEP, Bureau of Revenue, CN417, Trenton, NJ 08625. If off-site plume migration is not expected to occur, the lateral extent of a CEA may be coincident with site boundaries. All affected aquifers must be identified so that the vertical boundaries of the CEA can be defined.

A prediction of the longevity of the CEA generally should be based on analytical or numerical modelling using the most mobile and persistent compounds. Selection of an appropriate groundwater model will depend on site-specific factors including contaminant characteristics (e.g., degradability), properties of the aquifer (e.g., porosity, hydraulic conductivity), and the type of remediation proposed (active or passive). As appropriate, existing monitoring data should be used to verify predictions made using models. The longevity of a CEA established pursuant to a department oversight document or regulatory program will be the projected term of the cleanup. CEAs established under NJPDES-DGW permits will remain in effect for the 5-year term of the permit. Permanent CEAs can be established only when natural groundwater quality exceeds the criteria applicable to the groundwater classification area. The Standards require the department to restrict potable uses in any CEA where Primary Drinking Water Standards, N.J.A.C. 7:10, are exceeded. Therefore, when contaminant levels in a CEA exceed Maximum Contaminant Levels (MCLs), and designated aquifer use based on classification includes potable use, the department will identify the CEA as a Well Restriction Area (WRA). The department ordinarily will not prohibit installation of wells in WRAs but will identify any special installation, construction, or sampling requirements through the department's well permitting program, which is administered by the Bureau of Water Allocation.

The CEA's role as a public notification mechanism is discussed in the department's Response to Comments document for the Ground Water Quality Standards (see 25 N.J.R. 464, 1 February 1993). The primary purpose of establishing CEAs is to provide public notice of the suspension of designated aquifer uses within the affected area for the term of a CEA. Designation of CEAs as defined areas of noncompliance with the Standards due to pollutant discharges, and provision of appropriate notifications of these designations within and outside the department, will ensure that present and future groundwater users are informed that constituent standards within the CEA have been contravened, and that use restrictions apply for the duration of the CEA.

Within the department, the Remedial Lead will provide internal notifications to the Office of Environmental Planning, Bureau of Water Allocation, Environmental Claims Administration and, if necessary, the Bureau of Safe Drinking Water. External notifications must be provided via certified mail by the person responsible for conducting the remediation, prior to RAW or NFA submittal. The level of external notification required is based on existing and future groundwater use within the current and projected pathway of the plume. Groundwater use areas are those locations with current or future (based on a 25-year planning horizon) potable, industrial, and agricultural use. In a non-groundwater use area, the person responsible for conducting the remediation must notify municipal authorities and health agencies of the CEA designation. If the plume has or is expected to migrate off-site in a groundwater use area, individual property owners within the impacted area must be notified in addition to the local governing body and health department. The notifications must inform the appropriate local authorities and property owners of the CEA designation and of any ground water use restrictions in effect for the term of the CEA. The department recommends that the person responsible for conducting the remediation communicate with the remedial lead prior to public notification to discuss CEA boundaries and aquifer use restrictions. As noted previously, CEAs are designated under a NJPDES - DGW permit or pursuant to the authority of an oversight mechanism or regulatory program. Therefore, any specific requirements for routine, ongoing groundwater monitoring to assess the effectiveness of a proposed remedy will be established as part of the remedial decision process for the individual site. Confirmatory groundwater sampling performed prior to expiration of the CEA may be required to verify that remedial efforts have reduced contaminant concentrations within the CEA to applicable standards, depending upon groundwater use in the impacted area.

The department may give conditional No Further Action (NFA) approval in situations where active case management is no longer necessary but exceedence of groundwater quality criteria will continue for the term of the CEA. These sites will remain listed on the Known Contaminated Site List (KCSL) until the person responsible for conducting the remediation demonstrates that applicable standards have been achieved. The department will require confirmatory sampling only in groundwater use areas. However, unconditional No Further Action (NFA) approval will not be given, and CEA designations will not be removed from the KCSL, unless compliance with applicable standards has been verified. A more detailed discussion of the information requirements and procedures for establishing CEAs and WRAs is provided in the "Final Guidance on Designation of Classification Exception Areas." Copies of the guidance document may be obtained by contacting the Bureau of Ground Water Pollution Abatement at (609) 292-8427.

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SITE REMEDIATION PROGRAM FOCUSED ON HUMAN HEALTH IMPACTS

By: Bette Sovinee, Bureau of Planning and Systems, Lisa Serfling, Bureau of Site Management - Wellfield Remediation Section, and Matt Coefer, Bureau of Field Operations - Case Assignment Section

Our highest priority in the remediation of contaminated sites is the protection of human health. The extent of private and public water supplies being impacted from off-site sources resulted in over $600,000 in FY94 being spent for the installation of interim water supplies (such as Point of Entry Treatment Systems or POETS). The concern in the communities is real and the Site Remediation Program (SRP) is poised for action. Additionally, over the past three years, the SRP has approved $22 million from the Hazardous Discharge Bond Fund and the Spill Compensation Fund to provide funding for long-term water supply alternatives for municipalities affected by ground water contamination. Recently, the SRP established an internal set of criteria to ensure the uniform identification, notification and remediation of certain site conditions which pose an acute, direct threat to human health. The SRP refers to those site conditions as Immediate Environmental Concern (IEC) situations. The SRP will address three categories of IECs: potable water, direct contact, and toxic and harmful gas exposures. At present, (June 1995) there are a total of 209 IEC cases within the SRP (192 potable, 2 direct contact, and 15 toxic or harmful gas exposures). By definition, IECs represent a threat to human health and, next to emergencies, are our highest priorities. The SRP is committed to ensuring a prompt response to, and remediation of, these situations and has outlined procedures for ensuring expedited use of public funds should Responsible Parties fail to respond. The remediation of any case using public monies subject, parties responsible for the discharge to liability for three times the cost of the clean up under the NJ Spill Compensation and Control Act.

Persons conducting remediation activities should note the criteria below so that they can assist in the early identification and response to IEC situations and provide early mitigation of the human health impacts. Expedited remedial actions are required if an IEC is identified. These actions include the placement of receptor controls (Point-of-Entry Treatment Systems, fences, ventilation) within 30 days from the confirmation of the IEC condition and expedited remediation of any concern which may represent a continuing source to the IEC condition for expedited remediation.

SRP IEC CRITERIA (effective as of January 1995) A potable water IEC is a condition where there are analytically confirmed contaminants in wells used for potable purposes at levels above applicable standards; and where:

1. There is a known source contaminating any number of actively used public or private water supplies (includes impacts to surface water intakes); or
   
   
2. There is an unknown source contaminating any number of public water supplies; or
   
   
3. There is an unknown source contaminating five or more active private wells in an area which exhibit the same contaminant above applicable standards and are located within approximately 1000' radius of each other.

A direct contact IEC is a condition where there is reasonable potential for either dermal contact, inhalation or ingestion of contaminated materials that could result in an acute human health impact. Determinations of "acute" may rely on a variety of available toxicological references (e.g., Irving Sax, "Destructive Properties of Industrial Materials"). This category of IEC is perhaps the most contentious as there are no standard "triggers" or "thresholds" which define the term "acute." Thus this category is being administered where there is "obvious gross contamination" and evidence of human activity at the site of the contamination.

A toxic or harmful gas exposure IEC is a condition where subsurface contaminants, which are confirmed to have migrated into an occupied or confined space, are producing a toxic or harmful gas resulting in an acute or short-term human health exposure producing an oxygen-deficient atmosphere or resulting in demonstrated physical damage to essential underground services. These are typically instances of product flowing into an apartment building basements. In such an instance, the potential fire and explosion condition would be addressed via an emergency response and, once stabilized, addressing the continuing flow of product would constitute the IEC action. The exception to human health impact is in the instance of product adversely impacting underground conduits which provide, for example, 911 service to the area.

It is the policy of the SRP that case managers notify the municipal and/or county health officials of the presence of an IEC condition within 24 hours of confirmation. The SRP has expertise in its Wellfield Remediation Section (609) 984-5862 of the Division of Publicly Funded Site Remediation and works closely with the Safe Drinking Water program as well. At the request of a municipality, the SRP will conduct community meetings to discuss the appropriate interim measures being taken.

The potable water and toxic or harmful gas exposure IEC cases contain two remedial components which must be addressed before the IEC case designation can be removed or considered closed-out: receptor control and source control. Receptor control measures must be installed within 30 days from the confirmation of the IEC condition. Subsequent to that, it must be evaluated if a continuing source is present which will threaten additional receptors. If such a source exists, then source control measures are to be taken. Oversight of IECs

Once an IEC condition is identified at a site, the person conducting the remediation must respond to the condition and enter into an oversight agreement (control document) with the department. The type of control document prepared depends on whether another control document for the case exists. This is discussed below:

No Prior Control Document: The SRP will issue a directive which specifies the timeframes for addressing the receptor and source controls. The Responsible Party must memorialize their commitment to perform the work by signing a Remedial Action Administrative Consent Order (ACO).

Voluntary Cleanups/Memorandum Of Agreements (MOAs): Cooperative parties conducting remediation under an MOA are not required to enter into alternate control documents. However, if it becomes apparent that the 30 day requirement for the receptor controls will not be met, then more stringent actions will be taken, including the possibility of remediation using public funds.

Industrial Site Recovery Act (ISRA) or Underground Storage Tank (UST) Cases: Both the ISRA and UST rules and regulations provide the de facto control document for these cases since they provide requirements for immediate actions to be taken. The IEC criteria will apply for these instances. Field Directives will be issued by the case managers in order to initiate the 30 day receptor control deadline.

Existing ACOs: Existing ACOs will be reviewed to ensure that language exists regarding the remediation of the IEC condition. If not, the ACO may require modifications.

Information concerning IEC is being provided via the Site Remediation News at this time. It is anticipated that amendments to the Technical Rules will formalize the IEC procedures through rulemaking and public comment.