Super fund Post - Deci si on Proposed H an
JIS Superfund Site
South Brunswick, Middlesex County, New Jersey
July 2009
PURPOSE OF POST-DECISION PROPOSED PLAN
This Post-Decision Proposed Plan describes the proposed
fundamental changes to the August 1995 Record of Decision
(ROD) issued by the United States Environmental Protection
Agency (EPA) with concurrence by the New Jersey
Department of Environmental Protection (NJDEP) for the
Jones Industrial Sanitation (JIS) Landfill Site (Site) located in
South Brunswick, New Jersey.
The remedy specified in the 1995 ROD required the extraction
and on-site treatment of contaminated groundwater in the
primary plume, upgrade of the existing landfill cap to a
modified NJDEP hazardous waste cap, provision of an
alternate water supply to residents with potentially
contaminated wells, and implementation of a groundwater
monitoring plan to monitor the primary and secondary plumes,
the latter as it naturally attenuates over time. A water line had
been installed by potentially responsible parties (PRPs) for
this Site in the early 1990's to provide an alternate water
supply to potentially impacted residents.
Since the 1995 ROD, PRPs have completed the design of the
groundwater extraction and treatment system for the primary
plume, upgraded the existing landfill cap, and regularly
monitored groundwater in both the primary and secondary
plumes. In 2005, the PRPs also began operating a
biosparging pilot project along the landfill's eastern boundary
to determine whether this technology, which was not widely
employed at the time of the ROD, was an effective remedial
measure for treatment of contaminated groundwater. In this
Post-Decision Proposed Plan, EPA is proposing that the
existing biosparge pilot project replace the groundwater
extraction and treatment remedy for the primary plume that
was selected in the 1995 ROD. All other aspects of the
original remedy, including the monitored natural attenuation of
the secondary plume, would continue to function as described
in the 1995 ROD.
This Post-Decision Proposed Plan was developed by EPA in
consultation with the NJDEP. EPA is issuing this Post-
Decision Proposed Plan as part of its public participation
responsibilities under Section 117(a) of the Comprehensive
Environmental Response, Compensation, and Liability Act
(CERCLA) of 1980, as amended (commonly known as the
federal "Superfund" law), and Sections 300.430(f)(2) and
300.435(c) of the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP). The Plan is being provided
to inform the public of EPA's preferred remedy and to solicit
public comments pertaining to the remedial alternatives
evaluated, including the preferred alternative.
Mark Your Calendar
July 30,2009 - August 28,2009: Public Comment Period
on the Proposed Plan.
August 18, 2009 at 7:00 pm: The U.S. EPA will hold a
Public Meeting to explain the Proposed Plan. The meeting
will be held in the main meeting room at the South
Brunswick Municipal Building at 540 Ridge Road in
Monmouth Junction, New Jersey.
For more information, see supporting documents for
this Post-Decision Proposed Plan, which are available
at the following locations:
South Brunswick Public Library
110 Kingston Lane
Monmouth Junction, NJ 08852
Tel. (732)329-4000x7286
Hours: Monday - Friday: 8:30 am - 4:30 pm
USEPA-Region II
Superfund Records Center
290 Broadway, 18th Floor
New York, NY 10007-1866
(212)637-4308
Hours: Monday - Friday: 9am - 5pm
Written comments on this Proposed Plan should be
addressed to:
Edward Als
Remedial Project Manager
JIS Superfund Site
U.S. Environmental Protection Agency
290 Broadway, 20th Floor
New York, New York 10007-1866
Telephone: (212)637-4272
Telefax: (212)637-3966
Email address: als.ed@epa.gov
The nature and extent of the contamination at the Site and
the alternatives summarized in this Post-Decision Proposed
Plan are further described in the May 19, 2009 Focused
Feasibility Study (FFS) Report. EPA and NJDEP encourage
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the public to review this document to gain a more
comprehensive understanding of the Site and the Superfund
activities that have been performed at the Site.
The remedy described in this Post-Decision Proposed Plan is
the preferred amended remedy for the primary plume.
Changes to the preferred remedy or a change from the
preferred remedy to another remedy may be made if public
comments or additional data indicate that such a change will
result in a more appropriate remedial action. The final
decision regarding the selected remedy will be made after
EPA has taken into consideration all public comments. EPA is
soliciting public comment on all of the alternatives considered
in this Post-Decision Proposed Plan.
COMMUNITY ROLE IN SELECTION PROCESS
EPA and NJDEP rely on public input to ensure that the
concerns of the community are considered in selecting an
effective remedy for each Superfund site. Similarly, EPA also
relies on public input when proposing fundamental changes to
a remedy previously selected. To this end, this Post-Decision
Proposed Plan and all supporting reports have been made
available to the public for a public comment period which
begins on July 30th, 2009 and concludes on August 28th,
2009.
A public meeting will be held during the public comment
period at the South Brunswick Municipal Building at 540 Ridge
Road in Monmouth Junction in South Brunswick, New Jersey
on August 18th, 2009at 7:00 PM to describe the proposed
changes in the original remedy and to receive public
comments.
Comments received at the public meeting, as well as written
comments received during the public comment period, will be
documented in the Responsiveness Summary section of the
ROD amendment, which is the document formalizing
selection of the amended remedy.
SCOPE AND ROLE OF ACTION
The primary objective of this Post-Decision Proposed Plan is
to present a preferred alternative to the original groundwater
treatment remedy for the primary plume, in order to amend
the 1995 ROD for the JIS Superfund site. The remedial
action goal for this planned amendment is the long-term
protection of human health and the environment, while the
remedial action objectives are:
• to prevent unacceptable exposure of human receptors to
contaminants of concern (COCs) through ingestion, direct
contact or inhalation of COCs in the primary plume of
groundwater;
• to restore the aquifer to groundwater conditions that are
consistent with the contemplated use of the aquifer within
a reasonable period of time.
Previously, the following elements of the 1995 ROD have
been implemented:
1) upgrade of the existing landfill cap to a modified
NJDEP hazardous waste cap;
2) installation of a security fence around the landfill to
restrict access to the cap;
3) provision of an alternate water supply (water main
extension/connections) to residents with potentially
contaminated wells downgradient of the landfill;
4) performance of a quarterly monitoring program to
track natural attenuation of COC concentrations in
the groundwater; and
5) design of a groundwater extraction and on-site
treatment and discharge system
In addition, PRPs (specifically, the JIS Performing Parties
Group) implemented a pilot project in 2005 with the
permission of the EPA and the NJDEP to evaluate in-situ
biosparging technology as a potentially better alternative to
the extraction and treatment technology selected in the
1995 ROD. The in-situ biosparging pilot project involves
carefully pumping air into the groundwater along the
eastern perimeter of the landfill to facilitate biological
degradation of the COCs "in-situ", or in place, so that
groundwater need not be pumped out of the ground,
treated, and put back into the ground. The data collected
since commencement of the pilot suggests that biosparging
is a feasible technology, given the conditions at the JIS
Landfill, and merits a comparison with the extraction and
treatment system previously selected in the ROD, but not
yet implemented.
EPA has developed this Post-Decision Proposed Plan to
evaluate the following four alternatives addressing the
primary plume of groundwater contamination:
1) No Action;
2) Monitored Natural Attenuation (MNA) with
Institutional Controls;
3) Biosparging with MNA and Institutional Controls;
and
4) Hydraulic Containment/Collection with On-site
Treatment, Aquifer Reinjection, MNA and
Institutional Controls.
SITE BACKGROUND
Site Description
The JIS Landfill site is located on Cranbury South River
Road (Route 535) in South Brunswick Township, Middlesex
County, New Jersey (See FIGURE 1). The Site includes a
landfill immediately east of the New Jersey Turnpike, an
inactive borrow pit, and a solid waste recycling facility. The
north side of the Site borders an agricultural field, while the
south side adjoins a horticultural nursery. Additional
agricultural fields as well as residential areas of Monroe
Township and the Borough of Jamesburg are located east
of the Site.
Site Geoloqv/Hvdroqeoloqy
The Site is situated in the northeastern portion of the New
Jersey Coastal Plain. The Coastal Plain is a
southeastward-thickening wedge of unconsolidated
sediments dipping from the Fall Line, which is the northeast
to southwest trending fault line extending through the
EPA Region 2 - August 2009
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central portion of New Jersey, southeast toward the Atlantic
Ocean. Surface water bodies in the Coastal Plain are fed by
surface water runoff and groundwater discharge. The degree
of groundwater discharge to surface water depends on the
surface water elevation relative to groundwater elevations.
Near major pumping centers, streams and rivers may lose
water to underlying aquifers where the groundwater level in
the aquifer is depressed by pumping. In some instances,
lakes near major pumping centers have been dammed to
retain surface water, promoting surface water infiltration to
groundwater to help sustain groundwater pumping. Regional
groundwater flow within the Coastal Plain aquifer system is
sustained by recharge from precipitation infiltration in aquifer
outcrop areas and leakage through semi-confining beds. The
average annual precipitation rate in the central portion of the
Coastal Plain is approximately 45 inches per year. In aquifer
outcrop areas, precipitation through the unsaturated zone to
the water table is a major source of water to the aquifers.
Recharge in the aquifer outcrop areas creates a generalized
radial groundwater flow pattern toward the Atlantic Ocean.
Groundwater flow directions are also influenced locally by
municipal and industrial groundwater pumping from individual
aquifers.
Two major aquifers exist beneath the Site: the Old Bridge
Sand and the underlying Farrington Sand. Both aquifers are
major sources of potable water in Middlesex County. In the
vicinity of the Site, these aquifers are separated by the
Woodbridge Clay formation, which serves to contain
groundwater within the Old Bridge Sand aquifer. Locally,
groundwater flows in an east-southeasterly direction.
Manalapan Brook, to the east of the Landfill, is a discharge
point for shallow groundwater, while deeper groundwater
continues flowing east beneath the Brook.
At the time of the 1995 ROD, groundwater contamination from
the JIS Landfill was categorized into primary and secondary
plumes, both of which were characterized by similar
contaminants; however, concentrations measured in the
primary plume have historically been much higher than those
in the secondary plume (30,558 parts per billion (ppb) total
volatile organic chemicals (VOCs) in the primary plume
compared to 894 ppb in the secondary plume at the time of
the 1995 ROD).
The predominant COC in the primary plume is benzene, but
there are many other contaminants present as well. These
COCs exist in a relatively narrow band of contaminated
groundwater no wider than 1,000 feet in both the primary and
secondary plumes.
Groundwater monitoring since 1995 has confirmed that
natural attenuation of contaminants in the secondary plume is
occurring, confirming the appropriateness of monitored
natural attenuation as the remedy selected in the 1995 ROD
for the secondary plume.
Site History
The JIS property was originally a farm. In 1950, Grandview
Construction Corporation bought the property and began soil
excavation activities. By 1951, the property was being used as
a borrow pit for the construction of the New Jersey Turnpike.
In 1955, Jones Road Material Company purchased the
property and began landfilling operations on part of it. From
the 1960's through the early 1970's, the landfill accepted a
large variety of municipal and industrial wastes. In July
1975, the EPA responded to complaints regarding
contamination of drinking water by sampling a residential
well located next to the Site. The results led to an
expanded monitoring program and ultimately to the
conclusion that the landfill was the source of significant
groundwater contamination east of the landfill.
NJDEP thereupon ordered the JIS owners and operators to
cease all landfilling activities. Through subsequent court
action, disposal of chemical or hazardous substances at the
JIS Landfill was banned, although other specified wastes
were still allowed. The Site was placed on the National
Priorities List of Superfund Sites on September 1, 1983.
In 1985, the Superior Court of New Jersey ordered that the
landfill be closed. JIS subsequently installed a solid waste
cap over the landfill, while EPA provided bottled water to
affected residents. These residents remained on bottled
water until they were permanently connected to the
municipal water system in 1992.
A Superfund remedial investigation (Rl) was initiated in
October 1986 by B&V Waste Science and Technology
Corporation and eventually completed, along with a
Feasibility Study (FS) and a baseline risk assessment, in
1993. The Rl was intended to characterize the nature and
extent of contamination and evaluate the integrity of the
landfill cap. The FS identified and screened remedial
technologies and alternatives to address the contamination
at the Site, while the baseline risk assessment
characterized potential risks to human health and the
environment in the absence of additional remedial actions.
The EPA then issued a ROD with NJDEP concurrence in
1995 that selected a remedy which included the actions
discussed under SCOPE AND ROLE OF ACTION, above.
As part of the selected remedy, EPA included a
groundwater extraction and treatment remedy for the
primary plume of groundwater that was to be constructed
on and downgradient of the JIS property.
SUMMARY OF GROUNDWATER CONDITIONS
The plume of COCs emanating form the JIS Landfill
consists of a "primary" plume and a "secondary" plume.
The groundwater in the primary plume is classified as Class
II, meaning that it is designated as a potable water supply.
The primary plume, as historically documented, includes
contaminated groundwater which originates beneath the
landfill and extends in an easterly direction approximately
5,000 feet. As the COCs in the primary plume move in an
easterly direction with the natural groundwater flow, they
also migrate toward the bottom of the Old Bridge
Formation, which is about 100 feet thick. This formation is
underlain by a low permeability clay layer that defines the
base of the aquifer. The primary COC present in the
primary plume is benzene, which historically comprised
about two-thirds of the organic COC mass present in the
aquifer. Other significant COCs are from the
chlorobenzene series of compounds that comprise the
majority of the remaining organic COCs. Manganese
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comprises more than 99% of the inorganic COC mass
present in the primary groundwater plume; however, arsenic,
although present at much lower levels, is the primary
inorganic COC due to its toxicity.
For this Post-Decision Proposed Plan, data from eleven well
locations in the primary plume were evaluated to determine
human health risks, contaminant attenuation and othertrends
associated with the COC concentrations in the primary plume.
These well locations are MW3, MW5, MW7, MW10, MW16,
MW18, MW20, MW23, MW30, MW34, and MW41.
Concentrations of benzene, the major COC for the JIS site,
showed large downward trends between the years 2000 and
2007. Ten of eleven well locations (some of which included
multiple samples from various depths) recorded either static
or significantly diminishing concentrations of benzene during
that period of time. For 1,4-dichlorobenzene and arsenic,
which are two other important COCs for the Site, declining
concentration trends were not as readily apparent, which may
be due to the relatively low concentrations recorded. In 2007,
arsenic concentration levels exceeded applicable
groundwater criteria in 5 out of 25 samples, with a maximum
concentration of 34.7 parts per billion (ppb); however, the
other four exceedances were marginal. 1,4-dichlorobenzene
only slightly exceeded groundwater criteria in 2 of 25 samples
that same year (maximum concentration 170 ppb). See
TABLE 1 for a complete list of cleanup criteria for the JIS site.
Under the direction of NJDEP and EPA, the PRPs are also
currently performing an investigation of soil vapor intrusion
within the area that could potentially be affected by the
primary plume of contamination. Further east of the primary
plume is an area characterized as the secondary plume. This
plume, as described in the 1995 ROD and refined by
additional investigation, begins approximately 5,000 feet
downgradient from the JIS Landfill site (near Rhode Hall
Road and well MW-20) and extends beyond Henrietta Road
into the area of the Manalapan Brook. The secondary
plume area underlies vacant, agricultural, commercial and
residential properties.
Since the monitored natural attenuation portion of the 1995
remedy continues to be effective in reducing contaminant
concentrations in the secondary plume, the subject of this
Post-Decision Proposed Plan is the primary plume of
contamination only.
SUMMARY OF SITE RISKS
To support the amended remedy, EPA performed a
supplemental risk analysis to estimate the current and
future effects of contaminants on human health and the
environment. This supplemental risk evaluation is designed
to show whether amended remedial action is warranted.
The cancer risk and non-cancer health hazard estimates in
the supplemental risk analysis are based on current future
reasonable maximum exposure scenarios and were
developed by taking into account various health protective
assumptions about the frequency and duration of an
individual's exposure to chemicals selected as COCs, as
well as the toxicity of these contaminants. Cancer risks and
non-cancer health hazard indexes (His) are summarized
below (please see the text box on the following page for an
explanation of these terms).
EPA Region 2 - August 2009
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WHAT IS RISK AND HOW IS IT CALCULATED?
Human Health Risk Assessment:
A Superfund baseline human health risk assessment is an analysis of
the potential adverse health effects caused by hazardous substance
releases from a site in the absence of any actions to control or mitigate
these under current- and future-land uses. A four-step process is
utilized for assessing site-related human health risks for reasonable
maximum exposure scenarios.
Hazard Identification: In this step, the chemicals of potential concern
(COPCs) at the site in various media (i.e., soil, groundwater, surface
water, and air) are identified based on such factors as toxicity,
frequency of occurrence, and fate and transport of the contaminants
in the environment, concentrations of the contaminants in specific
media, mobility, persistence, and bioaccumulation.
Exposure Assessment: In this step, the different exposure pathways
through which people might be exposed to the contaminants in air,
water, soil, etc. identified in the previous step are evaluated. Examples
of exposure pathways include incidental ingestion of and dermal
contact with contaminated soil and ingestion of and dermal contact
with contaminated groundwater. Factors relating to the exposure
assessment include, but are not limited to, the concentrations in
specific media that people might be exposed to and the frequency and
duration of that exposure. Using these factors, a "reasonable
maximum exposure" scenario, which portrays the highest level of
human exposure that could reasonably be expected to occur, is
calculated.
Toxicity Assessment: In this step, the types of adverse health effects
associated with chemical exposures, and the relationship between
magnitude of exposure and severity of adverse effects are determined.
Potential health effects are chemical-specific and may include the risk
of developing cancer over a lifetime or other non-cancer health
hazards, such as changes in the normal functions of organs within the
body (e.g., changes in the effectiveness of the immune system).
Some chemicals are capable of causing both cancer and non-cancer
health hazards.
Risk Characterization: This step summarizes and combines outputs
of the exposure and toxicity assessments to provide a quantitative
assessment of site risks for all COPCs. Exposures are evaluated
based on the potential risk of developing cancer and the potential for
non-cancer health hazards. The likelihood of an individual developing
cancer is expressed as a probability. For example, a 10"4 cancer risk
means a "one-in-ten-thousand excess cancer risk"; or one additional
cancer may be seen in a population of 10,000 people as a result of
exposure to site contaminants under the conditions identified in the
Exposure Assessment. Current Superfund regulations for exposures
identify the range for determining whether remedial action is
necessary as an individual excess lifetime cancer risk of 10"4 to 10"6,
corresponding to a one-in-ten-thousand to a one-in-a-million excess
cancer risk. For non-cancer health effects, a "hazard index" (HI) is
calculated. The key concept for a non-cancer HI is that a "threshold"
(measured as an HI of less than or equal to 1) exists below which non-
cancer health hazards are not expected to occur. The goal of
protection is 10"6 for cancer risk and an HI of 1 for a non-cancer
health hazard. Chemicals that exceed a 10"4 cancer risk or an HI of 1
are typically those that will require remedial action at the site and are
referred to as Chemicals of Concern or COCs in the final remedial
decision or Record of Decision.
Human Health Risk Assessment
The Site is currently zoned for commercial use and contains a
closed landfill and a recycling facility. The area around the
Site is mixed-use (commercial and residential) in nature.
Future land use is expected to remain the same. Since the
landfill portion of the Site was capped in 2000, the
supplemental risk evaluation considered exposure to
contaminated groundwater (ingestion and inhalation) by
adults and children only. Currently, residents and
businesses in the area are served by municipal water.
However, groundwater is designated by the State as a
potable water supply, meaning it could be available for
drinking in the future.
The supplemental risk evaluation considered those
compounds identified as COCs in the 1995 Baseline
Human Health Risk Assessment for the Site: 1,3-
dichlorobenzene, 1,4-dichlorobenzene, benzene,
methylene chloride, tetrachloroethylene, arsenic, copper
and lead. Recent data (2000 and 2007) from eleven
monitoring wells in the primary plume were used to evaluate
exposure. EPA's statistical analysis of the groundwater
sampling data estimated that exposure to concentrations of
the COCs identified above would result in an excess lifetime
cancer risks and non-cancer health hazard indices of 6.9 x
10"3 and 61 for the future adult and child resident combined.
The risk and hazard is primarily driven by benzene, which
had an exposure point concentration of 2,663 ppb. This
concentration also exceeds the Federal and State
maximum contaminant level (MCL).
These cancer risks and non-cancer health hazards indicate
that there is potential risk to potentially exposed populations
from direct exposure to groundwater. For these receptors,
exposure to benzene in groundwater results in an excess
lifetime cancer risk that exceeds EPA's target risk range of
10"4 to 10"6 and an HI above the acceptable level of 1. It is
EPA's current judgment that the preferred alternative
identified in this Post-Decision Proposed Plan is necessary
to protect public health or the environment from actual or
threatened releases of hazardous substances into the
environment.
Ecological risk was not evaluated for this Post-Decision
Proposed Plan for the primary plume, since there are no
potential surface water discharge areas associated with the
primary plume. Previous ecological risk evaluations,
including a Baseline Ecological Evaluation (BEE) and a
more recent Screening Level Ecological Risk Assessment
(SLERA), have been performed for downgradient surface
discharge areas associated with the secondary plume.
These evaluations concluded that there are no significant
ecological effects caused by the secondary plume's
discharge to the surface in wetland areas.
REMEDIAL ACTION OBJECTIVES
Remedial action objectives (RAOs) are media-specific goals
to protect human health and the environment. RAOs are
based on available information and standards such as
applicable or relevant and appropriate requirements
(ARARs), to-be-considered (TBC) guidance, site-specific
risk-based levels established in the risk assessment, and
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the reasonably anticipated future land use for the area of the
primary plume of groundwater contamination.
The remedial actions that were evaluated in the FFS address
groundwater impacted by COCs in the primary plume. The
following RAOs have been established for groundwater:
• to prevent unacceptable exposure of human receptors to
COCs through ingestion, direct contact or inhalation of
COCs in the primary plume of groundwater;
• to restore the aquifer to groundwater conditions that are
consistent with the contemplated use of the aquifer within
a reasonable period of time.
Cleanup Levels
Cleanup levels are typically developed based on Federal and
State promulgated ARARs, risk-based levels, background
levels, and guidance values. Cleanup levels are then used as
a benchmark in the technology screening, alternative
development and screening, and detailed evaluation of
alternatives presented in the subsequent sections of the FFS
Report. Cleanup levels for groundwater are shown in TABLE
1.
CERCLA Section 121(b)(1), 42 U.S.C. Section 9621 (b)(1),
requires that remedial actions must be protective of human
health and the environment, cost-effective, comply with other
statutory laws (ARARs), and utilize permanent solutions and
alternative treatment technologies and resource recovery
alternatives to the maximum extent practicable. Section
121(b)(1) also establishes a preference for remedial actions
which employ, as a principal element, treatment to
permanently and significantly reduce the volume, toxicity, or
mobility of the hazardous substances, pollutants, and
contaminants at a site.
The objective of the FFS was to identify and evaluate cost-
effective remedial action alternatives which would minimize
the risk to public health and the environment resulting from
groundwater contamination in the primary plume. A summary
of the four groundwater remediation alternatives that were
evaluated for this Post-Decision Proposed Plan is presented
below. Detailed descriptions of these alternatives can be
found in the FFS report:
Groundwater Remedial Alternatives
alternative would also not include long-term groundwater
monitoring, although existing engineering controls would
remain in place.
Alternative GW1 - No Action
Capital Cost
Operation & Maintenance
(O&M) Initial Annual Cost
Present Worth Cost
Duration of Operation
$0
$0
$0
N/A
The "No Action" alternative is considered in accordance with
NCP requirements and provides a baseline for comparison
with other alternatives. If GW1 was selected, the biosparge
pilot would be turned off and no additional remedial actions
would be implemented under this alternative. Groundwater in
the primary plume would not be actively addressed, although
natural attenuation processes would continue to occur. This
Alternative GW2 - MNA with Institutional Controls
Capital Cost
O&M Initial Annual Cost
Present Worth Cost
Duration of Operation
$10,000
$37,200
$391,000
30 years
In GW2, a long-term groundwater monitoring program
would be performed to evaluate the continuing
effectiveness of the natural attenuation processes in
restoring groundwater quality. Data from the ongoing
monitoring program have demonstrated that significant
natural attenuation of groundwater contaminants is currently
taking place in the primary plume and that chemical
concentrations are generally lower than those that existed
when the ROD was issued in 1995.
The groundwater monitoring program would consist of both
hydraulic and water quality monitoring. The purpose of the
hydraulic monitoring program would be to confirm that the
groundwater flow patterns do not change overtime resulting
in unexpected conditions that could adversely affect
groundwater remediation. Groundwater quality monitoring
would be performed to track the reductions in the COC
concentrations overtime, evaluate the continuing favorable
conditions for natural attenuation, and confirm the
protectiveness of the remedy.
Conceptually, the groundwater monitoring network would
consist of 8 existing groundwater monitoring well nests, and
groundwater samples would be analyzed on a semi-annual
or annual basis for 30 years. Details of a long-term
monitoring plan would be reviewed and approved by EPA
and NJDEP.
GW2 would also include engineering and institutional
controls. There are engineering controls already in place at
the Site i.e., landfill cap, fencing, alternate water supply,
etc., which would be supplemented with institutional
controls.
The engineering and institutional controls on potable water
usage include the following:
i) public water has been provided to the residents
in the primary plume, secondary plume and the
surrounding area;
ii) a CEA would be established by NJDEP; and
iii) groundwater-use controls would be put in
place.
Alternative GW3 - Biosparging with MNA and
Institutional Controls
Capital Cost
O&M Initial Annual Cost
Present Worth Cost
Duration of Operation
$0*
$301,000
$4,560,000
30 years
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'Capital costs in the amount of $1,969,219 were expended in 2005 to construct
the biosparge pilot project.
GW3 consists of biosparging on or immediately adjacent to
the JIS site along with MNA and institutional / engineering
controls.
Biosparging involves the controlled injection of oxygen (either
pure or as a component of air) directly into the groundwater
allowing natural microorganisms to biodegrade the COCs.
The injection of oxygen also causes inorganic compounds
(primarily manganese and iron) to precipitate out of solution,
thereby reducing the mobility of some inorganic COCs as well.
A biosparging pilot project is currently operating at the JIS
Landfill in the primary plume since 2005 which has proven to
be effective in reducing COC concentrations. The biosparge
injection system is comprised of 40 well nests located along
the eastern i.e., hydraulically downgradient, boundary of the
JIS Landfill site. The current pilot project is uniformly
distributing oxygen across the width and depth of the primary
plume, thereby creating an aerobic treatment zone that is
effectively addressing the COCs. Alternative GW3 also
includes addressing the primary plume area downgradient of
the injection system through MNA. Data from the pilot project
shows that the aerobic treatment zone created by the injection
system has been expanding eastward along with natural
groundwater flow and can therefore be reasonably anticipated
to supplement the MNA downgradient of the injection system.
GW3 includes a long-term annual groundwater monitoring
program to evaluate the effectiveness of the remedial action
in restoring groundwater quality. The groundwater monitoring
program would consist of both hydraulic and water quality
monitoring in the existing monitoring well network. The
purpose of the hydraulic monitoring program is to confirm that
the groundwater flow patterns do not change over time
resulting in unexpected conditions that could adversely affect
groundwater remediation. Groundwater quality monitoring
would be performed to track the reductions in COC
concentrations over time, evaluate the continuing favorable
conditions for natural attenuation, and confirm the
protectiveness of the remedy. Conceptually, the groundwater
monitoring network would consist of 20 existing groundwater
monitoring well nests, and groundwater samples would be
analyzed on a semi-annual or annual basis for 30 years.
Details of a long-term monitoring plan would be reviewed and
approved by EPA and NJDEP.
As part of GW-3, the present biosparge pilot system would be
considered a full-scale remediation and operated for an
estimated 10 years or longer if impacted groundwater
exceeding cleanup levels continues to be released from
beneath the capped landfill. MNA of low-level, contaminated
groundwater beyond the range of the treatment system would
continue for an estimated 30 years.
GW3 also includes the engineering and institutional controls
described in GW2. The engineering and institutional controls
on potable water usage include the following:
i) public water has been provided to the residents in
the primary plume, secondary plume and the
surrounding area;
ii) a CEA would be established by NJDEP; and
iii) groundwater-use controls would be put in
place.
Alternative GW4 - Hydraulic Containment/Collection
With On-site Treatment, Aquifer Reinjection, MNA and
Institutional Controls
Capital Cost
O&M Initial Annual Cost
Present Worth Cost
Duration of Operation
$4,743,450
$1,150,500
$13,301,000
30 years
GW4 is the extraction and treatment remedy that was
selected in the 1995 ROD for the primary plume. It consists
of hydraulic containment and groundwater extraction from
the primary plume with on-site treatment and discharge of
the treated groundwater back into the aquifer. The
treatment system would utilize chemical oxidation,
precipitation, pH adjustment, and filtration/clarification to
address high inorganic concentrations and air stripping to
remove VOCs. Air emissions may need to be treated to
meet ARARs for air pollutants, but the preliminary
assessment performed during the design phase suggested
that it probably would not be necessary.
The extraction well system, as designed, would contain and
recover impacted groundwater. The pumping rate
necessary to achieve hydraulic containment is estimated to
be on the order of 350 to 450 gallons per minute. The
system would require a series of extraction wells and a
treatment facility constructed on the landfill property.
Treated water would be discharged back into the aquifer on
neighboring properties due to space and hydraulic
constraints. Treatment residues would be disposed of off-
site at a permitted facility.
The pump and treat system that has already been designed
for the JIS Landfill site is applicable for use in the primary
plume; however, several modifications to account for
specific treatment plant and pumping locations would need
to be finalized prior to implementing the design.
GW-4 includes a long-term annual groundwater monitoring
program to evaluate the effectiveness of the remedial action
in restoring groundwater quality. The groundwater
monitoring program would consist of both hydraulic and
water quality monitoring. The purpose of the hydraulic
monitoring program would be to confirm that the
groundwater flow patterns do not change overtime resulting
in unexpected conditions that could adversely affect
groundwater remediation. Groundwater quality monitoring
would be performed to track the reductions in COC
concentrations overtime, evaluate the continuing favorable
conditions for natural attenuation, and confirm the
protectiveness of the remedy. Conceptually, the
groundwater monitoring network would consist of 20 existing
groundwater monitoring well nests, and groundwater
samples would be analyzed on a semi-annual or annual
basis. Details of a long-term monitoring plan would be
reviewed and approved by EPA and NJDEP.
It is estimated that the extraction and treatment system
would be actively operated for 10 years, or longer if
EPA Region 2 - August 2009
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impacted groundwater exceeding cleanup levels continues to
be released from beneath the capped landfill, with MNA of
low-level, contaminated groundwater beyond the range of the
treatment system continuing for 30 years.
GW4 also includes the engineering and institutional controls
proposed in GW2. The engineering and institutional controls
on potable water usage include the following:
i) public water has been provided to the residents in
the primary plume, secondary plume and the
surrounding area;
ii) a CEA would be established by NJDEP; and
iii) groundwater-use controls would be put in place.
EVALUATION OF ALTERNATIVES
In selecting a remedy for a site, EPA considers the factors set
forth in CERCLA §121, 42 U.S.C. §9621, by conducting a
detailed analysis of the viable remedial alternatives pursuant
to the NCR, 40 CFR §300.430(e)(9) and OSWER Directive
9355.3-01. The detailed analysis consists of an assessment
of the individual alternatives against each of nine evaluation
criteria and a comparative analysis focusing upon the relative
performance of each alternative against those criteria:
• Overall protection of human health and the
environment addresses whether or not a remedy
provides adequate protection and describes how risks
posed through each exposure pathway (based on a
reasonable maximum exposure scenario) are
eliminated, reduced, or controlled through treatment,
engineering controls, or institutional controls.
Compliance with applicable or relevant and
appropriate requirements addresses whether or not a
remedy would meet all of the applicable or relevant
and appropriate requirements of other federal and
state environmental statutes and regulations or
provide grounds for invoking a waiver.
• Lonq-Term effectiveness and permanence refer to
the ability of a remedy to maintain reliable protection
of human health and the environment overtime, once
cleanup goals have been met. It also addresses the
magnitude and effectiveness of the measures that
may be required to manage the risk posed by
treatment residuals and/or untreated wastes.
• Reduction of toxicitv, mobility, or volume through
treatment is the anticipated performance of the
treatment technologies, with respect to these
parameters, a remedy may employ.
Short-Term effectiveness addresses the period of
time needed to achieve protection and any adverse
impacts on human health and the environment that
may be posed during the construction and
implementation period until cleanup goals are
achieved.
Implementability is the technical and administrative
feasibility of a remedy, including the availability of
materials and services needed to implement a
particular option.
• Cost includes estimated capital and operation and
maintenance costs, and net present-worth costs.
State acceptance indicates whether, based on its
review of the RI/FS reports and the Proposed Plan,
the State concurs with, opposes, or has no
comment on the preferred remedy at the present
time.
• Community acceptance will be assessed in the
ROD, and refers to the public's general response to
the alternatives described in the Proposed Plan
and the RI/FS reports.
A comparative analysis of the four groundwater remedial
alternatives, based upon the evaluation criteria noted above,
follows.
Comparative Analysis of Alternatives
Overall Protection of Human Health and the
Environment
GW3 and GW4 would both be protective of human
health and the environment. Each alternative relies
upon existing groundwater flow paths and
contaminant migration routes to achieve COC
treatment. Once COCs reach the locations where
biosparge injections or groundwater extractions
occur, the COCs would be treated.
GW3, currently operating as a full-scale pilot
project, has already begun to reduce chemical
presence in groundwater in the primary plume, with
an associated reduction in potential risk to human
health. As part of GW3, MNA would effectively
address the remainder of the COCs present further
downgradient in the primary plume.
GW4 (Hydraulic Containment / Collection /
Treatment) would effectively reduce the potential
risk to human health and the environment primarily
through containment of contaminated groundwater
and reductions in COC concentrations through
treatment. However, as groundwater is drawn into
the system from areas surrounding the primary
plume, the dilution of the primary plume overtime
would make extraction technology less efficient
than GWS's point-of-contact treatment. Under
GW4, MNA would effectively address the
remainder of the COCs present further
downgradient in the primary plume.
The monitoring performed in conjunction with GW2
(MNA) would also make this alternative protective
of human health. However, since there is no active
treatment, the restoration of groundwater quality
would not be accelerated beyond that which would
EPA Region 2 - August 2009
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be achieved by natural attenuation processes. The
ongoing groundwater monitoring program has
demonstrated that natural attenuation has been
effectively reducing the presence of COCs in the
areas of the primary plume that are beyond the direct
reach of the biosparge pilot system.
Under GW1, which would also include natural
attenuation processes, there would be no monitoring
of the COCs in the primary plume. Since there would
also be no control of contaminated groundwater
migration or active treatment of groundwater COCs,
this uncertainty renders GW1 potentially unprotective.
Compliance with ARARs
EPA and the State of New Jersey have promulgated
health-based protective criteria, which are
enforceable standards for various drinking water
contaminants i.e., chemical-specific ARARs. The
groundwater in the primary plume is classified as
Class II, meaning that it is designated as a potable
water supply.
All the alternatives considered for the primary plume
are expected to achieve compliance with ARARs, but
over different time periods. While both GW3 and
GW4 would achieve chemical-specific ARARs more
quickly in the part of the primary plume nearest to the
landfill, both alternatives still rely on natural
attenuation to complete remediation of the remainder
of the plume. Also, the active component of these
alternatives treats the chemicals as they reach the
injection/extraction point (either through in-situ
treatment in the case of biosparging or through ex-
situ treatment in a groundwater treatment facility in
the case of the pump & treat remedy) thereby
facilitating natural attenuation downgradient of the
system.
Neither GW1 nor GW2 would contain or reduce the
upgradient portion of the primary plume, and
therefore, downgradient natural attenuation of COCs
and attainment of ARARs would take a longer period
of time than either GW3 or GW4.
All alternatives would comply with the applicable
action- and location-specific ARARs, where such
exist.
Long-Term Effectiveness and Permanence
Source controls implemented earlier at the JIS
Landfill site as part of the 1995 remedy have been
effective in minimizing the landfill as a source of
groundwater COCs. Therefore, since the primary
plume's natural attenuation processes would
eventually be effective in the reduction of COC
concentrations in groundwater, all the remedial
alternatives evaluated should eventually provide
similar measures of long-term effectiveness and
permanence.
However, the biosparge pilot project's (GWS's) long-
term effectiveness is the most predictable of the
alternatives, since it was constructed in 2005 and
has been monitored since that time. Biosparging
under GW3 is expected to aggressively continue
reducing COC concentrations through treatment,
i.e., in-situ biodegradation of organic COCs and
and oxidation/precipitation of inorganic COCs, and
thereby accelerate the restoration of groundwater
quality.
The extent of natural attenuation at the Site has
been documented, and it should continue to
effectively and permanently reduce COC
concentrations in the downgradient areas of the
primary plume beyond the influence of either the
biosparge (GW3) or the groundwater extraction
(GW4) system. The existing alternate water supply
and the implementation and enforcement of
institutional controls would protect residents until
such time as the restoration of groundwater quality
to meet its intended use is complete.
Alternative GW4 manifests more uncertainty as to
long-term effectiveness, as it may be difficult to
establish and maintain complete hydraulic
containment under this alternative. GW4 may also
be subject to operational uncertainty due to the
inorganics content of the groundwater, which
creates the potential for fouling well screens,
pumps, treatment equipment, and reinjection
trenches.
GW2 provides greater long-term effectiveness than
GW1 through the monitoring of groundwater and
enforcement of institutional controls for protection
of residents and workers while restoration of the
groundwater quality is underway. However, the
long-term effectiveness and permanence of GW1
and GW2 are the least of the remedial alternatives
evaluated.
Reduction in Toxicity, Mobility or Volume through
Treatment
Only GW3 and GW4 reduce the toxicity, mobility, or
volume of the COCs through treatment. Both
alternatives reduce the ability of the COCs to
continue migrating beyond the point of injections /
extractions. As a result, the perform a nee of these
alternatives under this criterion could be
comparable through proper engineering and
operation e.g., selection of optimum pumping
locations, operational adjustments to groundwater
volumes extracted/ air volumes injected, etc.
However, neither alternative has an impact on the
area upgradient of the extraction/injection system,
as the COCs present in this area are subject to the
rate at which the source, i.e., the landfill itself,
naturally attenuates. In GW4, extracting
groundwater from the aquifer would accelerate
groundwater flow in the vicinity of the pumping
wells and therefore draw the COCs to the
extraction point faster than GW3. However, this
would not have an impact on source attenuation;
therefore, the length of time that both alternatives
EPA Region 2 - August 2009
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needed to achieve cleanup criteria would be similar.
Downgradientofthe extraction/injection points, GW3
would perform slightly better, since it has been
observed that oxygen-enriched groundwater has
been expanding further into the downgradient area
during the biosparge pilot project, thereby providing
in-situ treatment over a larger area of the primary
plume. Consequently, GW3 is somewhat more
effective in the reduction of toxicity, mobility and
volume of COCs.
Short-Term Effectiveness
The differences in short-term effectiveness
associated with the four alternatives are typically
associated with the risks posed by system
construction, maintenance, and monitoring activities,
as well as the potential for spills or leaks of treatment
chemicals, sludges, or contaminated groundwater.
GW1, GW2, and GW3 do not involve construction
(GW3 has already been constructed) and therefore
pose less short-term construction risk than GW4.
Because GW3 is already constructed and
operational, no delays for design and construction
would be encountered and the time period to begin to
achieve protection would be eliminated.
There would be relatively minor risks associated with
the monitoring programs included with Alternatives
GW2, GW3, and GW4. There would also be some
worker risks associated with both GW3 and GW4
involving treatment system operation and
maintenance, including the storage and handling of
chemicals and oxygen/compressed air. All these
risks can be minimized through the implementation of
proper health and safety procedures and operating
plans.
Implementability
GW1 by definition is easily implementable since there
would be no work involved, no required access to
off-site properties, etc. GW2 should also be relatively
easy to implement, as some engineering controls are
already in place and minimal access to off-site
properties would be necessary.
Implementation of GW3 is similar to that of GW2
since GW3 has already been implemented. There is
some additional system monitoring involved with the
implementation of GW3.
GW4 would need to be constructed and would be the
most difficult to implement. It would also require
more monitoring than any of the other alternatives.
Alternatives GW2, GW3 and GW4 all require access
to off-site areas, but GW4 requires considerably more
land and access as this alternative includes the need
to install, operate, and maintain a set of reinjection
trenches off-site to return the treated groundwater
back to the aquifer.
Cost
The estimated capital, annual operation and
maintenance (O&M, which includes monitoring),
and present-worth costs for each of the alternatives
are presented in TABLE 2:
TABLE 2: Cost Comparison for Groundwater
Remediation Alternatives
Remedial
Alternative
GW1
GW2
GW3
GW4
Capital Cost
0
$10,000
$0*
$4,743,450
Annual Cost
0
$37,200
$301 ,000
$1,150,500
Present
Worth
0
$391 ,000
$4,560,000
$13,301,000
Duration of
Alternative
N/A
30 years
30 years
30 years
'Capital costs in the amount of $1,969,219 were expended in 2005 to
construct the biosparge pilot project.
According to the capital cost, O&M cost and present worth
cost estimates, Alternative GW1 has the lowest cost and
GW4 has the highest cost when comparing all alternatives.
• State Acceptance
This Post-Decision Proposed Plan is currently
under review by the NJDEP.
Community Acceptance
Community acceptance of the preferred alternative
will be assessed in the ROD following review of the
public comments received on this Post-Decision
Proposed Plan.
PREFERRED ALTERNATIVE
Based upon the evaluation of the various alternatives
summarized above, EPA recommends employing
Alternative GW3, which includes biosparging with monitored
natural attenuation and institutional controls to remediate
contaminated groundwater in the primary plume. The
biosparging pilot system installed in 2005 has proven to be
an effective method of addressing the primary plume. This
system would continue to operate as the permanent full-
scale remedy for groundwater in the near-field primary
plume.
Implementation of this alternative would have the following
additional benefits:
• The treatment is performed in-situ and
there is no potential human contact with the
COCs;
• The progression of oxygen into the area
downgradient of the injection system provides
active treatment of groundwater in this area;
and
• The biosparge pilot system, already
operating as a full-scale project, would not be
subject to construction delays, or construction
health and safety issues.
EPA Region 2 - August 2009
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In accordance with EPA Region 2's Clean and Green policy,
EPA will evaluate the use of sustainable technologies and
practices during the design, construction and operation of any
remedial alternative selected for the Site. However, the
biosparging alternative would make the most effective use of
energy and land resources i.e., it is "greener" and less
resource-intensive compared to conventional
extraction/treatment technology.
The treatment zone established through biosparging the
aquifer along the landfill's eastern boundary presently extends
approximately 1,400 feet downgradient of the landfill into the
primary plume. This zone is expected to increase overtime
and further supplement the natural attenuation that is
documented to be occurring in the remaining portion of the
primary plume. A CEA would also be established by the
NJDEP to regulate new potable well installations in plume
areas until remediation is completed. The primary plume
area is no longer expanding, according to previous monitoring
results.
This preferred alternative for the primary plume would
complement the other previously implemented remedial
actions for the JIS Site, i.e., upgrade of the landfill cap to a
modified NJDEP hazardous waste cap, installation of security
fencing around the landfill, provision of water main extension
and connections to residents with contaminated wells
downgradient of the landfill, and performance of a program to
monitor natural attenuation of COC concentrations in the
groundwater. Details of a long-term monitoring plan would be
reviewed and approved by EPA and NJDEP.
Additionally, the PRPs, under the direction of NJDEP and
EPA, are presently assessing the potential for soil vapor from
the volatile organics in the primary plume to infiltrate
structures constructed over the plume. As part of the
amended remedy, EPA will include an approach for ensuring
that both existing and new structures in the plume area will not
be adversely impacted by soil vapor intrusion. This approach
may include testing and mitigation services, as well as
institutional controls on new construction to include soil vapor
design features, if necessary.
EPA Region 2 - August 2009 Page 11
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TABLE 1 -
Parameter
Volatile Organic Compounds
1,3-DICHLOROBENZENE
1,1-DICHLOROETHANE
1,2-DICHLOROBENZENE
1,1,1-TRICHLOROETHANE
4-METHYL-2-PENTANONE
1,1-DICHLOROETHENE
ETHYLBENZENE
ACETONE
1,4-DICHLOROBENZENE
VINYL CHLORIDE
TRANS-1,2-DICHLOROETHENE
CHLOROFORM
1,2-DICHLOROETHANE
XYLENE(TOTAL)
1,1,2,2-TETRACHLOROETHANE
CIS-1,2-DICHLOROETHENE
1,2-DICHLOROPROPANE
TETRACHLOROETHENE
METHYLENE CHLORIDE
TOLUENE
CHLOROBENZENE
TRICHLOROETHENE
BENZENE
Semi-Volatile Organic Compounds
NITROBENZENE
1,2,4-TRICHLOROBENZENE
Metals
GROUNDWATER CLEANUP CRITERIA
JIS LANDFILL
Groundwater
Units Criteria1
600
50
600
30
100
1
700
6000
75
1
100
70
2
1000
1
70
1
1
3
600
50
1
1
BARIUM
BARIUM, DISSOLVED
CHROMIUM, DISSOLVED
COPPER
COPPER, DISSOLVED
NICKEL
NICKEL, DISSOLVED
ZINC
ZINC, DISSOLVED
ANTIMONY, DISSOLVED
CHROMIUM (TOTAL)
LEAD, DISSOLVED
ANTIMONY
CADMIUM, DISSOLVED
CADMIUM
LEAD
ARSENIC, DISSOLVED
ARSENIC
MANGANESE, DISSOLVED
MANGANESE
2000
2000
70
1300
1300
100
100
2000
2000
6
70
5
6
4
4
5
3
3
50
50
1 Groundwater Cleanup Criteria for the JIS Landfill Site is the lower value of the NJGWQS or USEPA MCL.
NJGWQS- New Jersey Groundwater Quality Standards (N.J.A.C 7:9-6) October 2005
(http://www.state.nj.us/dep/wnis/bwqsa/docs/njac79C.pdf)
USEPA MCL - National Primary Drinking Water Regulations, EPA 816-F-09-004, May 2009.
(http:/ / www.epa.gov/ saf ewater/ contaminants/ index.html)
EPA Region 2 - August 2009
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y? vv-, . . • .
JIS SITE
PRIMARY PLUME AREA
figure 1
JIS SITE PLUME AREA LOCATIONS
South Brunswick, New Jersey
F-00(054)GN-WA003 MAY 19/2009
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