Superfund Program
Proposed Plan
Lightman Drum Superfund Site
May 2009
U.S. Environmental Protection Agency,
Region 2
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EPA ANNOUNCES PROPOSED PLAN
This Proposed Plan identifies the Preferred Alternative
to address ground-water contamination at the Lightman
Drum Superfund Site (Site) in Winslow Township,
Camden County, New Jersey, and provides the rationale
for this preference. Alternatives have been developed to
address groundwater contaminated primarily with
Volatile Organic Compounds (VOCs), including
chlorinated hydrocarbons such as trichloroethene (TCE)
and tetrachloroethene (PCE) as well as nonchlorinated
hydrocarbons such as benzene and xylene.
The U.S. Environmental Protection Agency's (EPA)
Preferred Alternative to address groundwater
contamination is Alternative 4A, Air Sparging/Soil
Vapor Extraction near the source areas with Pump
and Treat for the downgradient portion of the
groundwater contamination. This remedy will also
include Institutional Controls and Monitored Natural
Attenuation. Soil contamination will be addressed
through a new Operable Unit (OU2).
This Proposed Plan includes summaries of all the
cleanup alternatives evaluated for the Site groundwater.
This document is issued by EPA, the lead agency for
Site activities, and the New Jersey Department of
Environmental Protection (NJDEP), the support agency.
EPA, in consultation with NJDEP, will select the final
remedy for the groundwater after reviewing and
considering all information submitted during a 30-day
public comment period. EPA, in consultation with
NJDEP, may modify the preferred alternative or select
another response action presented in this Proposed Plan
based on new information or public comments.
Therefore, the public is encouraged to review and
comment on all the alternatives presented in this
document.
EPA is issuing this Proposed Plan as part of its
community relations program under Section 117(a) of
the Comprehensive Environmental Response,
Compensation and Liability Act (CERCLA, commonly
known as Superfund). This Proposed Plan summarizes
information that can be found in greater detail in the
Remedial Investigation and Feasibility Study (RI/FS)
reports and other documents contained in the
Administrative Record for the Site.
MARK YOUR CALENDAR
PUBLIC COMMENT PERIOD:
June 16, 2009 - July 16, 2009
EPA will accept written comments on the Proposed Plan
during the public comment period.
PUBLIC MEETING: June 25, 2009
EPA will hold a public meeting to explain the Proposed
Plan and all of the alternatives presented in the Feasibility
Study. Oral and written comments will also be accepted at
the meeting. The meeting will be held in the Municipal
Building, 125 South Route 73, Braddock, NJ from 7 to 9
PM.
For more information, see the Administrative Record
at the following locations:
U.S. EPA Records Center, Region 2
290 Broadway, 18th Floor.
New York, New York 10007-1866
(212)637-4308
Hours: Monday-Friday - 9 am to 5 p.m., by appointment.
Camden County Library, South County Branch
35 Coopers Folly Road
Atco, NJ 08004
Hours M-F 10am - 9pm, Sat 10am - 6pm
SITE DESCRIPTION
The Site covers approximately 15 acres in Winslow
Township, Camden County, New Jersey (Block 4404, Lot
6) and falls within the New Jersey Pinelands Protection
Area. The Site is approximately 300 feet wide and is
bordered by Route 73 to the east and the railroad formerly
owned by Pennsylvania Railroad to the west (Figure 1).
Currently, the portion of the Site nearest to Route 73 is
operated by United Cooperage, a drum brokerage
business, which stores drums and tractor trailers at the
Site. There is a small septic system on the Site as well as
a well for nonpotable uses.
SITE HISTORY
Prior to 1974, the Site was used for agriculture.
Beginning in 1974, the Lightman Drum Company
operated an industrial waste hauling and drum
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reclamation business there. In 1978, NJDEP issued a
one-year Temporary Operating Authorization that
allowed for the storage of various wastes including
chemical powders, pesticides, waste oil, oil sludges,
paints, pigment, thinner, ink residues, ketones, alcohols,
and mixed solvents. The permit was not renewed.
In 1987, NJDEP collected soil samples which revealed
the presence of various organic and inorganic
compounds at the Site. A more extensive investigation
of the soil and groundwater took place under an NJDEP
Administrative Order from 1989 to 1990. During this
investigation, about 80 soil samples were collected and
12 deep and shallow monitoring wells were installed.
These samples were concentrated in known storage
areas. These known areas are as follows.
Underground Diesel Fuel Tanks
Two fiberglass underground tanks (750 and 1,500
gallons) were installed in 1976 in the south-central
portion of the Site. They were used for diesel fuels until
the early 1980s and were removed in 1990. Soil
samples collected by NJDEP in the vicinity of the tanks
showed low levels of petroleum hydrocarbons and one
detection of TCE.
Unlined Waste Disposal Pit
An Unlined Waste Disposal Pit was located in a small
depression in a wooded area in the west-central portion
of the Site. This pit was accessed by a dirt road leading
from Lightman Drum Company's main operations area.
As part of the NJDEP investigation of the Site, it was
reported that the pit was used for the disposal of a single
tank trailer of wastes including waste paint and possibly
oil in 1976. The Lightman Drum Company reportedly
removed the waste from this area shortly after it was
deposited. There are no other records.
Former Waste Storage Tanks
Two 5,000-gallon underground storage tanks were
formerly located in the north-central area of the Site.
The tanks were reportedly used to store waste paint
pigments, ink sludges, and thinners. The tanks operated
under the NJDEP Temporary Operating Authorization.
NJDEP observed the removal of the tanks in 1984.
Warehouse
Drums were stored in a warehouse located in the eastern
part of the Site until a fire destroyed the warehouse in
1985. Only the concrete foundation slab remains.
Drum Storage Areas
There were various drum storage areas throughout the
active portion of the Site. The investigated areas
included the main storage areas along the southern
property boundary, west of the former diesel tanks, and
along the northern tree line east of the former waste
storage tanks.
The NJDEP studies showed the presence of elevated
levels of VOCs and Semi-Volatile Organic Compounds
(SVOCs) in the groundwater and VOCs, SVOCs
pesticides, and inorganic compounds in the soil.
In May 1999, NJDEP requested that EPA perform a
Hazard Ranking System Evaluation. As a result of the
evaluation, EPA placed the Site on the National Priorities
List on October 22, 1999. At that time, EPA became the
lead agency for Superfund remediation activities at the
Site.
In November 2000, EPA issued an Administrative Order
requiring a group of Potentially Responsible Parties
(PRPs) to conduct a Remedial Investigation and
Feasibility Study. The Remedial Investigation work plan
was approved in 2002. Following review of the initial
results, installation of additional wells and piezometers
(groundwater sampling sites) was approved in September
2003. The work plan was updated and the investigations
have been expanded as necessary from 2003 to the
present. Additional soil samples were collected in May
200, and additional groundwater transect and monitoring
well data were collected in 2007.
A second Administrative Order (Removal Order) was
issued by EPA in 2007, under which the PRPs removed
over 480 cubic yards of contaminated soil from the
unsaturated and saturated zones in the vicinity of the
former Underground Waste Storage Tanks. During the
course of the soil removal, areas of unnaturally colored
soils and an area of VOC-contaminated soils were
identified. Removal of the unnaturally colored soils is
ongoing and soil data have recently been collected.
A more complete explanation of these investigations and a
summary of their results are discussed in the Site
Characteristics section, below.
SITE CHARACTERISTICS
The entire Site is located within the New Jersey Pinelands
area. In general, the topography of the area is flat. The
majority of the Site is wooded with a 0.8-acre area of
wetlands at the westernmost portion of the property.
There is farm and woodlands to the north and a wooded
area as well as commercial development to the south.
There are a few residences and small businesses along
Route 73.
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The Site and adjacent properties are zoned for industrial
use, though a portion of the corridor along Route 73
southeast of the Site is zoned as minor commercial. The
Windsor Township administrative code requires that all
properties within 200 feet of the municipal water main
be connected to the public water supply system and use
of private wells for drinking water is prohibited. Pre-
existing wells may be used for nonpotable purposes if
they do not contain contaminants. The nearest municipal
well, well #8 is located about 7,500 feet southwest
(downgradient) of the Site. The well draws water from
about 140 feet below the ground surface and pumps at
1,000 gallons per minute. This well has been used
sporadically since August 2007.
According to the Delaware Valley Regional Planning
Commission, over 34,000 people live in Winslow
Township as of 2007, and approximately 8,000 people
live within a 3-mile radius of the Site.
The results of investigations conducted at the Site
indicate that the area is underlain by well-drained sandy
soils with poor filtering capacity. Active areas of the
Site have a thin layer of relatively impermeable fill.
Under the soil is the Cohansey-Kirkwood aquifer system
which is used extensively as the water supply in the area
of the Site.
The Cohansey-Kirkwood aquifer system, which dips
eastward toward the Atlantic Ocean is a relatively
uniform unconfmed aquifer consisting of yellowish
brown coarse to fine-grained sand. Groundwater within
the aquifer flows primarily to the south in the vicinity of
the Site. The base of the Cohansey-Kirkwood formation
is defined as the top of a clay bed lying at the base of the
Kirkwood at 100 feet below the ground surface.
Sediment and Surface Water Investigations
A total of eight sediment samples were taken from four
sample locations. One location is from the wetlands at
the western edge of the Site, one from a background
sample upgradient of the Site, and two locations in
Pump Branch Creek. Based on historical aerial
photographs and the present Site configuration, the
nearest Site operation activity to the sediments was the
unlined Waste Disposal Pit which is about 750 feet
away.
The sediment samples were screened against the NJDEP
Sediment Screening Criteria (Lowest Effect Level) and
the Site Background levels. The surface water samples
were screened against the NJDEP Surface Water Quality
Criteria and Site Background levels. Analyses of the
sediment samples showed that no VOCs or semi-VOCs
exceeded the NJ standards. Two pesticides and some
metals were found at levels above the NJ standards.
However, the area of and surrounding the Site has been
historically used for farming and, therefore, it likely that
the presence of pesticides do not stem from operations at
Site. Lead, copper, arsenic, and mercury levels exceeded
the NJ criteria. These concentration levels are unlikely to
be Site related because the highest levels are found either
upgradient or in the farthest downgradient areas.
Four surface water samples were taken, one from each of
the sediment sampling locations. Analysis of the samples
showed that VOCs, pesticides, and Polychlorinated
Biphenyls (PCBs) were not detected in any of the
samples. There was one detection of an SVOC in the
background sample location. Some sample concentrations
exceeded NJ Standards for lead and arsenic. It is likely
that the metals in the surface water reflect the metal
content in the sediments. Since the sediment metal levels
are not likely to be from the Site, it is also unlikely that
the metals in the surface water are from the Site.
Soil Investigations
Unsaturated Soils
During the Remedial Investigation, 40 subsurface
unsaturated zone soil borings were installed throughout
the operational areas of the Site to locate areas of
contamination. An additional nine borings were installed
in the wooded area of the Site to determine background
levels of contaminants. The unsaturated zone soil borings
were installed to the water table but in cases where field
screening did not show contamination, the deepest sample
was collected at five to six feet below the ground surface.
The soils were tested for VOCs, SVOCs, pesticides,
metals, and PCBs. The soil sampling results were
compared to the 1999 NJDEP Non-Residential Direct
Contact Soil Cleanup Criteria and the NJDEP Impact to
Groundwater Criteria for screening purposes, since those
criteria were in effect when the samples were collected.
There were detections of all the classes of contaminants
except for PCBs. Although other contaminants were
detected, none of the levels exceed the NJDEP standards.
The NJDEP standards used for screening were either the
Non-residential Direct Contact Soil Cleanup Criteria or
Impact to Groundwater Criteria, which ever was more
stringent for that contaminant. Almost all contaminant
levels were also below the NJDEP Residential Direct
Contact standards. The exceptions are lead and hexavalent
chromium which are found in the areas of unnaturally
colored soils. These unnaturally colored soils are being
removed under the 2007 Removal Order.
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In May 2009, the PRPs submitted data collected in the
unsaturated and saturated soils from an area of elevated
VOC levels. This area of elevated VOCs was identified
during the Removal Action (2008-2009) and is located
just east of the soil excavation area and in the vicinity of
the Former Waste Storage Tank Area. These data
indicate that some unsaturated soil samples contained
elevated levels of volatile contaminants, including PCE
and TCE. Potential risks posed by this contamination
have not yet been fully evaluated. EPA will establish a
second Operable Unit (OU2) to evaluate soil
contamination at the site further and, if necessary,
develop a remedy for the soil contamination.
The details of the investigation and the analyses can be
found in the Remedial Investigation Report which is part
of the Administrative Record.
Saturated Soils
In April and May of 2006, 18 additional soil borings
were installed to evaluate the presence of contaminants
in the saturated zone. The saturated zone starts at about
12 to 14 feet below the ground surface and samples were
taken starting at three feet above the water table (nine to
11 feet below the ground surface) and continuing as
deep as 34 to 36 feet below the ground surface. Ten of
these borings were installed in the area of the Former
Waste Storage Tanks, three borings were installed in the
area of the former Unlined Waste Disposal Pit, and two
borings were installed in the area of the former
Southwest Drum Storage Area.
Analyses of samples from borings showed that the only
contaminants which exceeded the NJDEP Impact to
Groundwater criteria were VOCs such as ethylbenzene,
tetrachloroethene (PCE) and total xylenes. These
elevated values: 150 mg/1 (milligrams per liter) for
ethylbenzene, 39 mg/1 for PCE, and 1,700 mg/1 for total
xylenes were all found in the vicinity of the former
Waste Tank Storage Area. Most of the contamination in
this area was found in a localized zone close to the water
table.
Since contamination of the saturated soils was confined
to the relatively small area of the former Waste Tank
Storage Area, in September 2007, EPA issued a
Removal Order to address the removal of saturated soils
in the area of the former Waste Storage Tank Area. The
PRPs removed a volume of soils 33 feet by 16 feet by 25
feet deep (over 480 cubic yards). Removal of the soils
was completed in 2008.
During the removal of the contaminated saturated soils
in the former Waste Storage Tank Area, unnaturally
colored soils were observed in the unsaturated soils at or a
few inches below the surface throughout the Site.
Analyses of these soils found that most colors contained
heavy metals, especially lead, in excess of NJ Standards.
All the un-naturally colored (i.e., red, green, yellow) soils
are currently being removed under the 2007 Removal
Order.
Also during removal of the soils, a new area of VOC
contamination has been located in the unsaturated soils
just east of the Former Waste Storage Tank Area. This
area appears to be limited in size, but has been shown to
contain elevated levels of VOCs. The data collected
during the Removal Action will be further evaluated as
part of a separate operable unit for soils. The results of the
soil sampling conducted during the Remedial
Investigation did not identify any "principal threat
wastes" at the Site.
WHAT IS A "PRINCIPAL THREAT"?
The NCP establishes an expectation that EPA will use treatment to
address the principal threats posed by a site wherever practicable (NCP
Section 300.430(a)(l)(iii)(A)). The "principal threat" concept is
applied to the characterization of "source materials" at a Superfund site.
A source material is material that includes or contains hazardous
substances, pollutants or contaminants that act as a reservoir for
migration of contamination to ground water, surface water or air, or
acts as a source for direct exposure. Contaminated ground water
generally is not considered to be a source material; however, Non-
Aqueous Phase Liquids (NAPLs) in ground water may be viewed as
source material. Principal threat wastes are those source materials
considered to be highly toxic or highly mobile that generally cannot be
reliably contained, or would present a significant risk to human health
or the environment should exposure occur. The decision to treat these
wastes is made on a site-specific basis through a detailed analysis of the
alternatives using the nine remedy selection criteria This analysis
provides a basis for making a statutory finding that the remedy employs
treatment as a principal element.
Groundwater Investigations
Overview
The Site in located within the New Jersey Pinelands area;
and, therefore the groundwater underlying the Site is
classified as Class I-PL. As such, the screening criteria
for the groundwater is the higher of either background
(contaminants levels found in the groundwater near and
upgradient of the site but not affected by the site) or the
NJDEP Practical Quantitation Limit (see glossary).
Based on the soil investigations, two sources of
groundwater contamination were identified. One
groundwater plume emanates from the former Waste
Storage Tanks Area and is referred to as the eastern plume
and another plume emanates from the Unlined Pit Area
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and is referred to as the western plume (Figurel).
Both plumes contain both chlorinated and non-
chlorinated hydrocarbons and are relatively long and
narrow. They also increase in depth with distance from
the source where they are overlain by nonimpacted
(clean) groundwater. The eastern plume is defined
primarily by its elevated levels of TCE and PCE and
extends about 4,500 feet downgradient of the Site
property boundary, at which point it is about 85 feet
below ground surface with about 65 feet of non-
impacted water above it. The western plume is also
defined by TCE and PCE and extends 1,500 feet
downgradient of the Site property boundary, at which
point it is about 55 feet below ground surface with about
45 feet of non-impacted water above it.
As described in the remedy alternatives section, the
groundwater contamination at the Site can be further
evaluated as two areas. One area is the groundwater
contamination found immediately under the Site and
under the first property to the south. This is referred to
as the near-site groundwater contamination. The other
area is farther to the south and is referred to as the
downgradient groundwater contamination (Figure 1).
Results of the Groundwater Investigations
From August 2002 to December 2004, 243 groundwater
samples were collected using a Geoprobe™ (temporary
well point) system to characterize the groundwater at,
and in the vicinity of, the Site. The results were used to
determine where to place permanent groundwater
monitoring wells and were compared to the I-PL
screening levels (PQLs) to delineate areas of concern.
There were detections of 22 different VOCs in the 243
transect samples taken. The PQLs for the most common
contaminants are 1 ug/1 (micrograms per liter) for TCE,
1 ug/1 for PCE, 1 ug/1 for benzene and 2 ug/1 for total
xylenes.
One set of VOCs in the groundwater at this Site are non-
chlorinated hydrocarbons such as benzene and xylenes.
These are components of fuels and are also used in
industrial processes. They were found mostly closer to
the Site than the PCE and TCE plumes and in both the
eastern and western plumes. The highest level in the
eastern plume was 63,600 ug/1 for total BTEX (benzene,
toluene, ethyl benzene, and xylene) found in a
Geoprobe™ sample close to the Former Waste Tank
Storage area and the plume still had over 100 ug/1 under
about 1500 feet to the south (eastern plume). The
highest western plume was smaller with a high value of
32 ug/1. just to the south of the Site boundary.
Another set of VOCs are the chlorinated hydrocarbons, of
which TCE and PCE are the ones most commonly found
in the groundwater at the Site. These chemicals are
chlorinated hydrocarbons commonly used to clean
machinery, among other uses. They were both detected at
elevated levels in the near-site and downgradient
groundwater and define both the eastern and western
plumes. During Geoprobe™ sampling from 2002 to 2004,
the highest levels found was 470 ug/1 for PCE which was
found in the near-site groundwater and 310 ug/1 for TCE
in the downgradient groundwater. Both of these samples
are in what is now the eastern plume. Degradation of
chlorinated ethenes in groundwater may be occurring as
evidenced by the presence of the daughter product cis-1,2-
DCE. The presence of cis- 1,2-DCE may be the result of
partial biodegradation of chlorinated ethenes, although the
geochemical environment at the Site does not appear to be
supportive of complete degradation.
Also seen in a downgradient area in the eastern plume
were a few "hot spots" or specific, well defined areas of
relatively high PCE and TCE concentration. These hot
spots contained over 100 ug/1 of each of these
contaminants.
Based on the results of the Geoprobe™ investigation, 23
monitoring wells were installed from 2005 to 2007.
These new wells, as well as the on-site office supply well,
were sampled. The results from the wells helped to define
the distribution of contaminants in and downgradient of
the Site. High levels of nonchlorinated hydrocarbons
were found near the former Waste Storage Tank Area and
immediately downgradient.
The highest levels of on-site contamination were found in
a monitoring well near the former Waste Storage Tank
Area. Those values were 4,200 ug/1 for PCE and 2,100
ug/1 for TCE measured in March 2006. Downgradient,
the highest value was 250 ug/1 for TCE measured in
February 2005 in the eastern plume. The maximum
detected concentration of total xylenes on the Site was
90,000 ug/1 in 2006 and the maximum detected
concentration immediately downgradient from the Site
was 370 ug/1 measured in February 2005.
During sampling of the groundwater monitoring wells in
2006 and 2007, concentrations of TCE and PCE in the
downgradient wells decreased compared to the earlier
sampling events and the hot spots identified earlier
appeared smaller. Based on this observation, additional
Geoprobe groundwater samples were taken along two
transects in July 2007 in order to determine if the hot
spots had migrated or attenuated. Results from that
sampling event indicated that the hot spots may have
migrated to the west.
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SCOPE AND ROLE OF THE ACTION
EPA is addressing the cleanup of this Site through
immediate actions to address an imminent threat to
human health, and two phases of long-term cleanup.
Immediate actions, known as removal actions, are
ongoing. In 2007, EPA issued a Removal Order to
require excavation of source area soils in the saturated
zone near the Former Waste Storage Tanks Area. The
excavation was approximately 33 feet by 16 feet by 25
feet deep (over 480 cubic yards). During the removal
action, unnaturally colored soils were observed, and
after investigation, these soils are being removed. In
early 2009, another nearby area of VOC-contaminated
soils was also identified and characterized.
The first phase of long-term cleanup of the Site, which
is the subject of this Proposed Plan, will provide for
implementation of a remedy to address groundwater
contaminants in both the eastern and western plumes
near their on-site sources and in the downgradient areas.
The second phase of long-term cleanup will address
contaminated soil through a second Operable Unit
(OU2) which will be used to evaluate and address
contamination of these soils further.
SUMMARY OF SITE RISKS
RISK SUMMARY
The purpose of the risk assessment is to identify
potential cancer risks and noncancer health hazards at
the Site assuming that no further remedial action is
taken. A baseline human health risk assessment was
performed to evaluate current and future cancer risks
and noncancer health hazards based on the results of the
Remedial Investigation.
A screening-level ecological risk assessment was also
conducted to assess the risk posed to ecological
receptors due to site-related contamination.
As part of the RI/FS, EPA conducted a baseline risk
assessment to estimate the current and future effects of
contaminants on human health and the environment. A
baseline risk assessment is an analysis of the potential
adverse human health and ecological effects of releases
of hazardous substances from a site in the absence of
any actions or controls to mitigate such releases, under
current and future land, groundwater and surface
water/sediment uses. The baseline risk assessment
includes a human health risk assessment (HHRA) and an
ecological risk assessment.
The cancer risk and noncancer health hazard estimates in
the HHRA are based on current reasonable maximum
exposure scenarios and were developed by taking into
account various health protective estimates about the
frequency and duration of an individual's exposure to
chemicals selected as chemicals of potential concern
(COPCs), as well as the toxicity of these contaminants.
Cancer risks and noncancer health hazard indexes (His)
are summarized below.
Human Health Risk Assessment
The site and surrounding properties are currently zoned
industrial. Future land use is expected to remain the
same, though there may be residential development
downgradient. The baseline risk assessment began by
selecting COPCs in the various media that would be
representative of site risks. The chemicals of concern
(COCs) for the site are TCE and PCE.
The baseline risk assessment evaluated health effects that
could result from exposure to surface soil, subsurface soil,
groundwater, surface water and sediment. Based on the
current zoning and anticipated future use, the risk
assessment focused on a variety of possible receptors,
including current and future commercial/industrial
workers, current and future adolescent and pre-adolescent
trespassers, future residents (child and adult) and future
construction worker. Among all receptors evaluated at
the site, future site workers and residents had potential
adverse health impacts due to exposure to site
contaminants released from the Lightman Drum site.
Groundwater contamination contributed to the cumulative
risk, but, based on soil data available at the time, soil
contamination did not.
Since the risk assessment for the Remedial Investigation
and Feasibility Study was performed, additional soil data
were collected during the ongoing removal actions.
These data indicate that there is some elevated VOC
contamination in soils. It is not clear how these new data
may affect risks calculated for the Site. Based on this
information, EPA will create a separate Operable Unit
(OU2) for soils to evaluate the nature and extent of soil
contamination and risk posed by this soil contamination.
The findings of the risk assessment for soils are presented
below, but will be modified using new data, as
appropriate, during the OU2 investigations. This
Proposed Plan addresses only groundwater risks. Soils
risks based on the new data will be addressed in a
subsequent remedy.
Although residents and businesses downgradient are not
currently impacted, groundwater is designated by the
State as a potable water supply, meaning it could be used
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for drinking in the future. Therefore, potential exposure
to groundwater was evaluated. A complete discussion
of the exposure pathways and estimates of risk can be
found in the Human Health Risk Assessment for the site
in the information repository.
Summary of Risks to Future Site Workers: Cancer
risks and noncancer health hazards were evaluated for
exposure to soil and groundwater. Cancer and non-
cancer risks for exposure to soil were within EPA's
acceptable risk range. With respect to groundwater, the
excess lifetime cancer risk estimate is 6.9 x 10~2, which
exceeds EPA's acceptable levels of risk. The calculated
HI is 556, which exceeds EPA's threshold value of 1.
The risks are primarily attributed to TCE and PCE in the
groundwater.
Summary of Risks to Residents: Cancer risks and
noncancer health hazards were evaluated for exposure to
groundwater for the adult and child residents. The
excess lifetime cancer risk estimate for the adult resident
and child resident are 2.6 x 10~2 and 4.6 x 10~2,
respectively. These risks exceed EPA's acceptable
levels of risk. The calculated HI for the adult resident
and child resident are 1243 and 183, respectively. The
Hazard Index values for these receptors exceed EPA's
threshold value of 1. The risks are primarily attributed
to TCE and PCE.
Summary of Risks to Future Construction Workers:
Cancer risks and noncancer health hazards were
evaluated for exposure to soil. The excess lifetime
cancer risk estimate is 6.9 x 10~5, which is within the
acceptable risk range. The calculated HI is 50.1, which
exceeds EPA's threshold value of 1. The elevated HI is
primarily attributed to hexavalent chromium in the
unnaturally colored soils. The risk was calculated under
the assumption that the all measured chromium was
present as hexavalent chromium. Upon further
investigation, it was determined that the hexavalent
chromium was found to range between nondetectable
and a maximum of 11.1% of the total chromium in each
sample. As stated previously, the area of unnaturally
colored soils is limited in size and is currently being
addressed under a removal action.
Summary of Risks to Future Trespassers: Cancer
risks and noncancer health hazards were evaluated for
exposure to soil, surface water and sediment for the
adolescent and pre-adolescent trespasser. The excess
lifetime cancer risk estimates for the adolescent and pre-
adolescent trespasser are 3.3 x 10~6 and 3.2 x 10~6, which
is within EPA's acceptable risk range. The calculated
His for the adolescent and pre-adolescent trespasser are
0.16 and 0.18, which do not exceed EPA's threshold
value of 1. The risks are primarily attributed to arsenic.
Upon review of the data, it has been determined that the
concentrations of arsenic are representative of
background.
EPA evaluated the potential for vapor intrusion into
structures within the area that could be potentially
affected by the groundwater contamination plume. The
groundwater data collected during this investigation
suggest that the groundwater plumes increases in depth as
they migrate in a southerly direction. This resulted in a
barrier of clean water above the plume which would
prevent the generation of vapors that could impact any
structures above the contaminated plume in downgradient
areas. Currently, there are not any structures above the
plume. This will be verified during the groundwater
monitoring program following remedy selection.
The results of the human health risk assessment indicated
that there is significant potential risk to potentially
exposed populations from direct exposure to groundwater.
For these receptors, exposure to groundwater results in an
excess lifetime cancer risk that exceeds EPA's target risk
range of 10"4 to 10"6, as well as NJDEP's acceptable
cancer risk level of 10"6 The HI is above the acceptable
level of 1. These risk estimates are based on the
reasonable maximum exposure scenarios and were
developed by taking into account various conservative
assumptions about the frequency and duration of an
individual's exposure to groundwater, as well as the
toxicity of the chemicals of concern. The chemicals in
groundwater that contribute most significantly to the
cancer risk and noncancer hazard are TCE and PCE. In
the risk assessment, risks posed by Site soils were not
determined to pose an unacceptable risk to receptors.
However, new data show that an area of the Site near the
Former Waste Storage Tanks contains elevated levels of
VOCs. To address this new area of soil contamination,
EPA will create a second Operable Unit to evaluate risks
posed by site Soils further. No soil remedy is proposed at
this time.
Screening Level Ecological Risk Assessment
A Screening Level Ecological Risk Assessment was
conducted to evaluate ecological receptors using the site.
Potential risks were assessed by comparing contaminant
concentrations with benchmark toxicity values. Hazard
quotients were calculated for each individual contaminant
of potential ecological concern for certain receptors
included in the assessment endpoints. Additionally, food-
chain modeling was conducted to determine exposure
concentrations in upper-trophic level receptors.
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Although potential risks were indicated for aquatic
receptors, the hydrologic conditions do not support an
aquatic community. Consequently, the sediment
contaminant concentrations were incorporated into the
terrestrial assessment. The most significant risk
associated with amphibians was from aluminum.
Potential risk to terrestrial invertebrates was found to be
from chromium, copper, and mercury. Mammals and
birds were found to be at risk to aluminum, chromium,
lead, mercury, selenium, and pesticides. The
contaminants which were found to have the greatest
hazard quotient were aluminum and chromium. The
sample with the maximum aluminum concentration was
from an upgradient location and the areas of elevated
chromium contamination were remediated. All of the
other site- related contaminants, based on an average
exposure basis, would not exceed a hazard quotient of 1.
Therefore, the risks calculated are negligible and do not
warrant additional evaluation.
Summary
It is EPA's current judgment that the Preferred
Alternative identified in this Proposed Plan, or one of
the other active measures considered in the Proposed
Plan, is necessary to protect public health or welfare or
the environment from actual or threatened releases of
hazardous substances into the environment.
WHAT IS RISK AND HOW IS IT
CALCULATED?
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 contaminants of
concern 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 identified in the previous step are evaluated.
Examples of exposure pathways include incidental ingestion
of and dermal contact with contaminated soil. Factors
relating to the exposure assessment include, but are not
limited to, the concentrations that people might be exposed
to and the potential frequency and duration of 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 (dose) and
severity of adverse effects (response) are determined.
Potential health effects are chemical-specific and may
include the risk of developing cancer over a lifetime or other
non-cancer health effects, 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
effects.
Risk Characterization: This step summarizes and combines
exposure information and toxicity assessments to provide a
quantitative assessment of site risks. Exposures are
evaluated based on the potential risk of developing cancer
and the potential for noncancer health hazards. The
likelihood of an individual developing cancer is expressed as
a probability. For example, a 10" 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
explained in the Exposure Assessment. Current Superfund
guidelines for acceptable exposures are an individual
lifetime excess cancer risk in the range of 10"4 to 10"6
(corresponding to a one-in-ten-thousand to a one-in-a-million
excess cancer risk). For noncancer health effects, a "hazard
index" (HI) is calculated. An HI represents the sum of the
individual exposure levels compared to their corresponding
reference doses. The key concept for a noncancer HI is that
a "threshold level" (measured as an HI of less than 1) exists
below which noncancer health effects are not expected to
occur.
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REMEDIAL ACTION OBJECTIVES
Remedial action objectives (RAOs) were developed for
groundwater to address the human health risks and
environmental concerns posed by Site-related
contamination.
Groundwater Remedial Action Objectives
Prevent or minimize potential current and future
human exposures including ingestion of and
dermal contact with groundwater that presents a
significant risk to public health and the
environment;
Minimize the potential for migration of the
contaminants of concern in groundwater; and
Restore the aquifer to Class I-PL standards
within a reasonable time frame.
To achieve these RAOs, cleanup goals for groundwater
at the Site were identified. The site lies within the New
Jersey Pinelands Protection Area and the groundwater is
classified as Class I-PL. The applicable groundwater
quality standards correspond to background values or
the practical quantification limit (limit of the accuracy
of the testing method) whichever is higher for each
contaminant. These standards are more stringent or
equivalent to federal MCLs.
SUMMARY OF REMEDIAL ALTERNATIVES
Potential remedial technologies and process options
were identified and screened using effectiveness,
implementability and cost as the criteria, with the most
emphasis on the effectiveness of the remedial
technology. Those technologies that passed this initial
screening were then assembled into five remedial
alternatives for groundwater contamination. Two of the
alternatives have two subalternatives each. The
subalternatives reflect the differences in treating the
groundwater contamination near the site boundary and
the more diffuse contamination downgradient from the
site.
All of the groundwater remedial alternatives, with the
exception of the No Further Action Alternative
(Alternative 1) would include institutional controls such
as a Classification Exception Area (CEA) with well
drilling restrictions, to minimize the public's potential
exposure to contaminated groundwater until the
groundwater meets the remediation goals. However,
consistent with expectations set out in Superfund
regulations, none of the alternatives rely exclusively on
institutional controls to achieve protectiveness.
The time frames presented below for construction do not
include the time for pre-design investigations, remedial
design, or contract procurements. Each of the
groundwater alternatives will take longer than five years
to achieve remediation goals. Therefore, a review will be
conducted every five years (Five-Year Review) after the
initiation of the remedial action, until remediation goals
are achieved.
More information on each of the technologies included in
the remedial alternatives discussion can be found at the
following EPA sponsored web sites.
For Air Sparging and Soil Vapor Extraction:
http: //www. cluin.org/download/citizens/citsve .pdf
For Monitored Natural Attenuation:
http: //www. cluin.org/download/citizens/mna.pdf
For In-Situ Chemical Oxidation:
http: //www. clu-in.org/download/citizens/oxidation .pdf
For Pump and Treat Systems:
http://www.cluin.org/download/citizens/pump and treat.
rjdf
Institutional Controls are legal and administrative controls
such as zoning decisions, deed notices, or the
establishment of Classification Exception Areas. They
protect the public by prohibiting certain actions in areas
of contamination. More information about Institutional
Controls can be found at:
http: //www. epa. gov/fedfac/pdf/ic ctzns guide .pdf
Alternatives
Alternative 1 - No Further Action
The No Further Action Alternative was retained, as
required by the National Contingency Plan (NCP), and
provides a baseline for comparison with other
alternatives. No remedial actions would be implemented
as part of the No Further Action Alternative.
Furthermore, this alternative would not involve any
monitoring of groundwater or institutional controls.
Groundwater would continue to migrate and the
contamination would continue to attenuate through
natural attenuation processes.
Total Capital Cost $0
Operation and Maintenance $0
Total Present Net Worth $0
Time frame 0 years
-------
Alternative 2 -Air Sparging/Soil Vapor Extraction +
Institutional Controls + Monitored Natural
Attenuation
This alternative addresses contaminated groundwater by
constructing an Air Sparging/Soil Vapor Extraction
system operating near the source areas for both the east
and west plumes. The downgradient portions of the
plumes would be monitored as the contaminants
attenuate.
Air Sparging is an in-situ technology for the removal of
volatile and some semi-volatile compounds from
groundwater. Air is injected into the groundwater
through wells which causes the contaminants to
evaporate (become a gas). This gas moves upward
through the groundwater and into the soils above the
groundwater. These contaminated gases then will be
removed by a Soil Vapor Extraction system.
In a Soil Vapor Extraction system, extraction wells are
drilled into the soils above the groundwater. Then, a
vacuum is applied to the wells which pulls the gases out.
The gases are then passed through a material such as
activated carbon which traps the contaminants. The
activated carbon will be regenerated or disposed of
properly.
Air Sparging and Soil Vapor Extraction are appropriate
for this site because the contaminants in the
groundwater will easily become vapors when air is
added. In addition, the soils in and above the
groundwater are sandy and vapors can move through the
soils easily.
To be protective of human health, Institutional Controls
which include a groundwater Classification Exception
Area would be established in conjunction with well
drilling restrictions to minimize exposure to
contaminated groundwater until the groundwater in the
aquifer meets the remediation goals. Concurrently,
long-term groundwater monitoring would be
implemented to provide an understanding of changes in
contaminant concentrations and spatial distributions
overtime.
The implementation of Monitored Natural Attenuation
requires long-term monitoring for VOCs, and BTEX
and additional groundwater quality parameters to
monitor the contaminants as they attenuate. Sentinel
wells will be placed between the end of the
contaminated groundwater plume and public water
supply well #8. This would ensure EPA's ability to take
any necessary action in the unlikely event that
contaminated groundwater moves toward a water supply
well.
Air Sparging /Soil Vapor Extraction $5,450,000
Monitored Natural Attenuation $1,880,000
Total Present Net Worth $7,330,000
Time frame
Air Sparging/Soil Vapor Extraction 5 years
Monitored Natural Attenuation >30 years
Alternative 3 - In-Situ Chemical Oxidation +
Institutional Controls + Monitored Natural
Attenuation
In this alternative, contamination near the source areas
will be treated through the injection of chemicals to help
the contaminated materials decompose. The downgradient
portions of the plumes will be monitored as the
contaminants attenuate.
When In-Situ Chemical Oxidation is used, an oxidant or
oxygen releasing compound is injected into wells placed
in the contaminated groundwater. The oxidant mixes with
the contaminants causing them to decompose. When the
process is complete, only water and other harmless
breakdown products are left.
For the eastern plume, near its source area, two different
process options would be used: permanganate and
hydrogen peroxide plus iron (Fenton's reagent). Fenton's
Reagent would be used first due to the presence of
benzene. After the benzene has been removed,
permanganate would be injected. Since permanganate is
less reactive, it would be effective for a longer time. Since
there is no benzene in the western plume, only the
permanganate will be used.
As described in Alternative 2, Institutional Controls
which would include a groundwater CEA would be
established and the groundwater would be sampled
regularly as part of the Monitored Natural Attenuation
portion of the remedy.
In-Situ Chemical Oxidation $8,150,000
Monitored Natural Attenuation $1,880,000
Total Present Net Worth $10,030,000
Time frame
In-Situ Chemical Oxidation 1 Year
Monitored Natural Attenuation >30 Years
Alternative 4A - Air Sparging/Soil Vapor Extraction +
Downgradient Pump and Treat + Institutional
Controls + Monitored Natural Attenuation
In this variation of Alternative 4, Air Sparging and Soil
Vapor extraction would take place near the source areas
10
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as in Alternative 2. In addition, any hot spots identified
in the downgradient area in the plumes would be
remediated by a Pump and Treat System.
In a Pump and Treat System, wells are placed in the
contaminated groundwater. The contaminated
groundwater is pumped out and placed in a treatment
system where it is cleaned. The removed contaminants
are either destroyed or disposed of properly. The clean
water can be put back into the ground or discharged to a
surface source.
For this site, the first step would be to delineate hot
spots. Hot spots are areas within the larger groundwater
plume which are significantly higher in contaminant
concentration than the rest of the plume. The method to
locate any hot spots will be defined during the Remedial
Design portion of the remediation.
Once the hot spots are defined, an appropriate number
(estimated to be one or two) of extraction wells would
be installed into the contaminated groundwater and the
contaminated groundwater would be extracted and
treated. EPA is also considering the use of an ART
(Advanced Remediation Technology) system in which
the contaminated groundwater is extracted, treated and
reinjected within specially designed wells. In this case,
the water would not need to be treated and reinjected
separately. If a traditional Pump and Treat System is
used, the contaminated groundwater would be filtered
through an activated carbon system. The clean water
would be re-injected and the carbon would be
regenerated or disposed of properly.
The rest of the plume will be monitored as it would be
allowed to attenuate through natural processes.
As described in Alternative 2, Institutional Controls
which would include a groundwater CEA would be
established and the groundwater would be sampled
regularly as part of the Monitored Natural Attenuation
portion of the remedy.
Air Sparging/Soil Vapor Extraction $5,540,000
Downgradient Pump & Treat $2,810,000
Monitored Natural Attenuation $1,880,000
Total Present Net Worth $10,140,000
Time frame
Air Sparging/Soil Vapor Extraction 5 Years
Downgradient Pump and Treat and
Monitored Natural Attenuation <30 Years
Alternative 4B - In-Situ Chemical Oxidation +
Downgradient Pump and Treat + Institutional
Controls + Monitored Natural Attenuation
In this alternative, In-Situ Chemical Oxidation would be
used to treat contamination in the near source areas as in
Alternative 3, and a Pump and Treat System would be
used in the downgradient areas as in Alternative 4A.
As described in Alternative 2, Institutional Controls
which would include a groundwater CEA would be
established and the groundwater would be sampled
regularly as part of the Monitored Natural Attenuation
portion of the remedy.
In-Situ Chemical Oxidation $8,150,000
Downgradient Pump & Treat $2,180,000
Monitored Natural Attenuation $1,880,000
Total Present Net Worth $ 12,840,000
Time frame
In-Situ Chemical Oxidation 1 Year
Downgradient Pump and Treat and
Monitored Natural Attenuation <30 Years
Alternative 5A - Air Sparging/Soil Vapor Extraction +
Downgradient In-Situ Chemical Oxidation +
Institutional Controls + Monitored Natural
Attenuation
In this Alternative, Air Sparging and Soil Vapor
Extraction would be used as in Alternative 2. In the
downgradient area of the groundwater plume, In-Situ
Chemical Oxidation would be used after hot spots have
been defined and characterized. Potassium permanganate
alone would be used in the downgradient area because
benzene is not present.
As described in Alternative 2, Institutional Controls
which would include a groundwater CEA would be
established and the groundwater would be sampled
regularly as part of the Monitored Natural Attenuation
portion of the remedy.
Air Sparging/Soil Vapor Extraction $5,450,000
Downgradient In-Situ
Chemical Oxidation $4,190,000
Monitored Natural Attenuation $1,880,000
Total Present Net Worth $11,520,000
Time frame
Air Sparging/Soil Vapor Extraction 5 Years
Downgradient In-Situ
Chemical Oxidation and
Monitored Natural Attenuation <30 Years
11
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Alternative SB - In-Situ Chemical Oxidation +
Downgradient In-Situ Chemical Oxidation +
Institutional Controls + Monitored Natural
Attenuation
In this alternative, In-Situ Chemical Oxidation would be
used near the source areas as in Alternative 3 and would
also be used in the downgradient contaminated
groundwater as in Alterative 5A.
As described in Alternative 2, Institutional Controls
which would include a groundwater CEA would be
established and the groundwater would be sampled
periodically as part of the Monitored Natural
Attenuation portion of the remedy.
Near Site In-Situ Chemical Oxidation $8,150,000
Downgradient In-Situ
Chemical Oxidation $4,190,000
Monitored Natural Attenuation $1,880,000
Total Present Net Worth $ 14,220,000
Timeframe
Near Site In-Situ Chemical Oxidation 1 Year
Downgradient In-Situ Chemical
Oxidation and
Monitored Natural Attenuation <30 Years
EVALUATION OF REMEDIAL ALTERNATIVES
Nine criteria are used to evaluate the different remedial
alternatives individually and against each other in order
to select the best alternative. This section of the
Proposed Plan profiles the relative performance of each
alternative against the nine criteria, noting how it
compares to the other options under consideration. The
nine evaluation criteria are discussed below. A more
detailed analysis of the presented alternatives can be
found in the Feasibility Study report.
THE NINE SUPERFUND EVALUATION
CRITERIA
1. Overall Protectiveness of Human Health and the
Environment evaluates whether and how an alternative
eliminates, reduces, or controls threats to public health and
the environment through institutional controls, engineering
controls, or treatment.
2. Compliance with Applicable or Relevant and
Appropriate Requirements (ARARs) evaluates whether the
alternative meets federal and state environmental statutes,
regulations, and other requirements that pertain to the site,
or whether a waiver is justified.
3. Long-term Effectiveness and Permanence considers
the ability of an alternative to maintain protection of human
health and the environment overtime.
4. Reduction of Toxicity, Mobility, or Volume (TMV) of
Contaminants through Treatment evaluates an
alternative's use of treatment to reduce the harmful effects of
principal contaminants, their ability to move in the
environment, and the amount of contamination present.
5. Short-term Effectiveness considers the length of time
needed to implement an alternative and the risks the
alternative poses to workers, the community, and the
environment during implementation.
6. Implementability considers the technical and
administrative feasibility of implementing the alternative,
including factors such as the relative availability of goods and
services.
7. Cost includes estimated capital and annual operations
and maintenance costs, as well as present worth cost.
Present worth cost is the total cost of an alternative over time
in terms of today's dollar value. Cost estimates are expected
to be accurate within a range of +50 to -30 percent.
8. State/Support Agency Acceptance considers whether
the State agrees with the EPA's analyses and
recommendations, as described in the RI/FS and Proposed
Plan.
9. Community Acceptance considers whether the local
community agrees with EPA's analyses and preferred
alternative. Comments received on the Proposed Plan are
an important indicator of community acceptance.
12
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Overall Protection of Human Health and the
Environment
The No Action Alternative (Alternative 1) is not
considered protective of human health and the
environment, because it does not prevent the current and
future use of contaminated groundwater which could
present an unacceptable human health risk. Because the
No Action Alternative is not protective of human health
and the environment, it was eliminated from
consideration under the remaining eight criteria.
The remaining alternatives are considered protective.
They all provide for active treatment near the source
areas and include institutional controls to minimize
potential exposure to contaminated groundwater until
remediation goals have been achieved.
Alternatives 2 and 3 do not provide for active treatment
of hot spots in the downgradient portion of the
groundwater plumes as they rely instead on unenhanced
natural attenuation processes, which would require a
long time
(> 30 years) to achieve the remediation goals.
Alternatives 4A, 4B, 5A and 5B involve active treatment
of downgradient hot spots which would reduce the time
to achieve remediation goals at the Site.
Compliance with Applicable or Relevant and
Appropriate Requirements (ARARs)
The alternatives that include active downgradient
remediation; 4A, 4B, 5A, and 5B are expected to comply
with chemical-specific ARARs by achieving
remediation goals in less than 30 years. The other
alternatives, 2 and 3 will also achieve the chemical-
specific ARARs but it is expected to take more than 30
years because they do not include active downgradient
remediation. All of the alternatives will comply with
location- and action-specific ARARs.
Long-Term Effectiveness and Permanence
Alternatives 2 and 3 would be effective for removal of
groundwater contamination near the source areas but
will not actively remove hot spots in the downgradient
portion of the plumes. Some of the downgradient
contaminants will degrade over time and the rest will
dissipate. Although detailed modeling was not
performed to predict the estimated timeframe for
downgradient portion of the plumes to be restored
through monitored natural attenuation alone, it is
estimated that remediation will take more than 30 years.
Alternatives 4A, 4B, 5A and 5B would all be effective
and permanent in the long term. All of these alternatives
would ultimately result in groundwater contaminant levels
being reduced to meet the remediation goals though active
remediation of both near the source areas and
downgradient areas. Because there would be active
remediation of any down gradient hot spots, it is estimated
that the remediation goals will be met in less than 30
years.
Reduction of Toxicity, Mobility, or Volume Through
Treatment
Alternatives 2 and 3 are expected to reduce the toxicity
and volume of contaminants in the groundwater near the
source areas through active treatment. In the
downgradient area, the alternatives could result in some
reduction in toxicity or volume due to unenhanced natural
processes. There would be no reduction in mobility in the
downgradient area. Therefore, Alternatives 2 and 3 are
the least effective in meeting this criteria.
Alternatives 4A, 4B, 5A, and 5B would be expected to
reduce the toxicity and volume of contaminants both near
the source areas and in the downgradient portions of the
plume.
Alternatives 4A and 4B will also reduce the mobility of
downgradient contaminants to a greater extent than
Alternatives 2 and 3 through pumping of any hot spots.
The In-Situ Chemical Oxidation technology included in
Alternatives 5A and 5B would destroy contaminants,
thereby reducing their toxicity and volume.
Short-Term Effectiveness
Each alternative has some short term impacts because it
would be necessary to construct parts of the remedies on
the property of nearby land owners and possibly near
railroad tracks and wetlands. For the remedial options in
the near source areas, the remedial options; air sparging
and soil vapor extraction, or in-situ chemical oxidation;
will likely only involve the landowner on the southern
side of the site.
For the air sparging and soil vapor extraction options in
Alternatives 2, 4A and 5A, the impact is expected to be
minimal once the wells, pipes, and vacuum system are
constructed because only air will be injected into the
ground and any mobilized vapors will be extracted under
nearby vacuum. This air sparging and soil vapor
extraction option is estimated to operate for
approximately 5 years.
The in-situ chemical oxidation system used in
Alternatives 3, 4B, and 5B in the near source areas is
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expected to have more of a short-term impact compared
to the air sparging and soil vapor extraction technologies
used in Alternatives 2, 4A and 5A. This is because of
the number of injection points and the injection of
oxidants. Injection of oxidants may increase the mobility
of some metals (e.g. chromium) and other compounds,
and the oxidants themselves require special handling
and storage. The oxidation of the organic compounds
found in the groundwater is an exothermic (heat
generating) reaction. Special precautions would be
needed to protect workers on-site. It is estimated that a
near-site In-Situ Chemical Oxidation system will run for
one year.
The potential for impact for treating downgradient
groundwater hot spots depends on the specific
remediation technology. The potential impacts from In-
Situ Chemical Oxidation are discussed above. The full
extent of any impacts would depend on the number and
location of the injection wells.
The impact of a groundwater pump and treat would also
depend on the size and extent of hot spots. Mobile units
may be used and may be effective and would have a
minimal impact. Use of an ART system would also
have a minimal impact. However, a larger system may
involve installing pipes over many properties and may
have a bigger impact.
Implementability
Alternatives 2 and 3 would be the second easiest to
implement. Alternative 2 (Air Sparging/Soil Vapor
Extraction) uses standard services and equipment. There
are no special safety precautions necessary because only
surface air is injected. Alternative 3 (In-Situ Chemical
Oxidation) also uses standard services and equipment.
However, chemical oxidants can be dangerous and
would require special handing. In both cases, an access
agreement would likely be necessary with only one
property on the southern boundary.
The other alternatives 4A, 4B, 5A, and 5B would be
more difficult to implement. Further defining hot spots
will entail access agreements with multiple nearby
property owners and may also require access near
railroad tracks and in wetlands. Alternatives 4A and 4B
(downgradient pump and treat) may include the
construction of pipelines, wells, and a treatment system
on one or more properties. This may be minimized if an
ART or mobile system is used. In the downgradient
area, In-Situ Chemical Oxidation in Alternatives 5A and
5B may be difficult to implement depending on the areal
extent of the hot spots, the number of injection wells
necessary, and the volume of oxidant needed.
Cost
The present worth cost for Alternatives 2 and 3 are the
next lowest but those alternatives do not actively
remediate downgradient hot spots. Alternative 4A is the
alternative with the lowest cost that will meet the
remediation goals and remediate downgradient hot spots.
State/Support Agency Acceptance
The State of New Jersey agrees with the preferred
alternative in this Proposed Plan.
Community Acceptance
Community acceptance of the preferred alternative will be
evaluated after the public comment period ends and will
be described in the Responsiveness Summary of the
Record of Decision for this Site. The Record of Decision
is the document that formalizes the selection of the
remedy fora site.
SUMMARY OF THE PREFERRED ALTERNATIVE
Alternative 4A, Air Sparging and Soil Vapor Extraction
near the source areas; Pump and Treat for downgradient
groundwater hot spots with Institutional Controls and
Monitored Natural Attenuation for the downgradient
portions of the plume, is the preferred remedial alternative
for groundwater contamination at this Site.
This alternative consists of the installation of injection
wells for the air sparging system and removal wells for
the Soil Vapor Extraction system near the Former Waste
Storage Tank Areas (east plume), the Former Unlined Pit
Areas (west plume), and the immediate downgradient
areas. Air will be pumped into the groundwater which
will promote the transition of contaminants into vapors.
It is estimated that the system would consist of over 60 air
injection wells located on the Lightman property and the
adjacent property to the south.
The vapors will migrate out of the groundwater and into
the overlying soils. Then, the vapors will be removed by
the soil vapor extraction system and captured on activated
carbon. It is estimated that the soil vapor extraction
system would consist of about 40 wells located on the
Lightman property and the adjacent property to the south.
In the areas of contaminated groundwater further
downgradient from the site, remediation will occur in
phases. In the first phase, the plume will be examined to
fully characterize hot spots. Then, a pump and treat
system will be constructed to collect the contaminated
14
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groundwater, remove the contaminants, and return the
clean water to the groundwater. Any residual
contamination would be monitored as it attenuates
through natural processes.
Institutional Controls such as a groundwater CEA would
be established in conjunction with well drilling
restriction to minimize exposure to contaminated
groundwater until the groundwater meets the
remediation goals. Concurrently, long-term groundwater
monitoring would be implemented to provide an
understanding of changes in contaminant concentrations
and spatial distributions over time. Sentinel wells will
be placed between the end of the contaminated
groundwater plume and public water supply well #8.
This would ensure EPA's ability to take any necessary
action in the unlikely event that contaminated
groundwater moves toward a water supply well.
Consistent with EPA Region 2's Clean and Green
policy, EPA will evaluate the use of sustainable
technologies and practices with respect to any remedial
alternative selected for the Site.
As is EPA's policy, Five-Year Reviews will be
conducted until remediation goals are achieved.
COMMUNITY PARTICIPATION
EPA provided information regarding the cleanup of the
Lightman Drum Superfund Site to the public through
public meetings, the Administrative Record file for the
Site and announcements published in the Courier-Post
newspaper. EPA encourages the public to gain a more
comprehensive understanding of the Site and the
Superfund activities that have been conducted there.
For further information on EPA's preferred alternative
for the Lightman Drum Superfund Site:
Renee Gelblat Natalie Loney
Remedial Project Manager Community Relations
(212)637-4414 (212)637-3639
U.S. EPA
290 Broadway, 19th Floor
New York, New York 10007-1866
The dates for the public comment period; the date, the
location and time of the public meeting; and the
locations of the Administrative Record files are
provided on the front page of this Proposed Plan.
15
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GLOSSARY
ARARs: Applicable or Relevant and Appropriate
Requirements. These are Federal or State environmental rules
and regulations that may pertain to the Site or a particular
alternative.
Carcinogenic Risk: Cancer risks are expressed as a number
reflecting the increased chance that a person will develop
cancer if exposed to chemicals or substances. For example,
EPA's acceptable risk range for Superfund hazardous waste
sites is 1 x 10~4 to 1 x 10~6, meaning there is 1 additional
chance in 10,000 (1 x 10"4) to 1 additional chance in 1 million
(1 x 10"6) that a person will develop cancer if exposed to a Site
contaminant that is not remediated.
CERCLA: Comprehensive Environmental Response,
Compensation and Liability Act. A Federal law, commonly
referred to as the "Superfund" Program, passed in 1980 that
provides for response actions at sites found to be contaminated
with hazardous substances, pollutants or contaminants that
endanger public health and safety or the environment.
COPC: Chemicals of Potential Concern.
SLERA: Screening Level Ecological Risk Assessment. An
evaluation of the potential risk posed to the environment if
remedial activities are not performed at the Site.
FS: Feasibility Study. Analysis of the practicability of multiple
remedial action options for the Site.
Groundwater: Subsurface water that occurs in soils and
geologic formations that are fully saturated.
HHRA: Human Health Risk Assessment. An evaluation of the
risk posed to human health should remedial activities not be
implemented.
HI: Hazard Index. A number indicative of noncarcinogenic
health effects that is the ratio of the existing level of exposure
to an acceptable level of exposure. A value equal to or less
than one indicates that the human population is not likely to
experience adverse effects.
HQ: Hazard Quotient. HQs are used to evaluate
noncarcinogenic health effects and ecological risks. A value
equal to or less than one indicates that the human or ecological
population are not likely to experience adverse effects.
ICs: Institutional Controls. Administrative methods to prevent
human exposure to contaminants, such as by restricting the use
of groundwater for drinking water purposes.
Nine Evaluation Criteria: See text box on Page 7.
Noncarcinogenic Risk: Noncancer Hazards (or risk) are
expressed as a quotient that compares the existing level of
exposure to the acceptable level of exposure. There is a level
of exposure (the reference dose) below which it is unlikely for
even a sensitive population to experience adverse health
effects. USEPA's threshold level for noncarcinogenic risk at
Superfund sites is 1, meaning that if the exposure exceeds the
threshold; there may be a concern for potential noncancer
effects.
NPL: National Priorities List. A list developed by USEPA of
uncontrolled hazardous substance release sites in the United
States that are considered priorities for long-term remedial
evaluation and response.
Operable Unit (OU): a discrete action that comprises an
incremental step toward comprehensively addressing site
problems. This discrete portion of a remedial response
manages migration, or eliminates or mitigates a release, threat
of a release, or pathway of exposure. The cleanup of a site can
be divided into a number of operable units, depending on the
complexity of the problems associated with the site.
Practical Quantitation Level (PQL): means the lowest
concentration of a constituent that can be reliably achieved
among laboratories within specified limits of precision and
accuracy during routine laboratory operating conditions.
Present-Worth Cost: Total cost, in current dollars, of the
remedial action. The present-worth cost includes capital costs
required to implement the remedial action, as well as the cost
of long-term operations, maintenance, and monitoring.
Proposed Plan: A document that presents the preferred
remedial alternative and requests public input regarding the
proposed cleanup alternative.
Public Comment Period: The time allowed for the members
of a potentially affected community to express views and
concerns regarding USEPA's preferred remedial alternative.
RAOs: Remedial Action Objectives. Objectives of remedial
actions that are developed based on contaminated media,
contaminants of concern, potential receptors and exposure
scenarios, human health and ecological risk assessment, and
attainment of regulatory cleanup levels.
Record of Decision (ROD): A legal document that describes
the cleanup action or remedy selected for a site, the basis for
choosing that remedy, and public comments on the selected
remedy.
Remedial Action: A cleanup to address hazardous substances
at a site.
RI: Remedial Investigation. A study of a facility that supports
the selection of a remedy where hazardous substances have
been disposed or released. The RI identifies the nature and
extent of contamination at the facility and analyzes risk
associated with COPCs.
Saturated Soils: Soils that are found below the Water Table.
These soils stay wet.
TBCs: "To-be-considereds," consists of non-promulgated
advisories and/or guidance that were developed by EPA, other
federal agencies, or states that may be useful in developing
CERCLA remedies.
Unsaturated Soils: Soils that are found above the Water
Table. Rain or surface water passes through these soils.
These soils remain dry:
USEPA: United States Environmental Protection Agency. The
Federal agency responsible for administration and enforcement
of CERCLA (and other environmental statutes and
regulations), and final approval authority for the selected
ROD.
VOC: Volatile Organic Compound. Type of chemical that
readily vaporizes, often producing a distinguishable odor.
Water Table: The water table is an imaginary line marking
the top of the water-saturated area within a rock column.
16
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LEGEND
NOTE
APPROXIMATE PROPERTY LINE - LIGHTMAN DRUM SITE
GENERAL OLmjNE OF GROUNDWATER PLUME (SEE NOTE 2)
ONSITE WATER SUPPLY WELL (LOCATION APPROXIMATE)
MONITORING WELL
GEOPROBE AQUIFER PROFILE BORINGS
(LOCATION APPROXIMATE)
STAFF GAUGE
SURFACE WATER SAMPLE (LOCATION APPROXIMATE)
SEDIMENT SAMPLE (LOCATION APPROXIMATE)
PUMP BRANCH CREEK (SEE NOTE 3)
1.) ND = NOT DETECTED
2.) ISOCONCENTRATION CONTOURS BASED ON GEOPROBE AND MONITORING WELL PCE DATA
COLLECTED 2006-2007. DATA FROM MW-2B AND MW-8B WERE NOT CONTOURED AS
THEY ARE SCREENED BELOW THE PLUME. WHERE MONITORING WELL DATA FROM 2006 AND
2007 WERE AVAILABLE, 2007 DATA WAS USED.
3.) APPROXIMATE CREEK LOCATION ESTIMATED FROM 1995 AERIAL PHOTO. EPHEMERAL IN
VICINITY OF LIGHTMAN PROPERTY.
REFERENCES
1.) AERIAL PHOTOGRAPH TAKEN FROM USDA GEOSPATIAL DATA GATEWAY, DATED 2006.
2.) MONITORING WELLS, STAFF GAUGE AND PIEZOMETERS SHOWN WERE BASED ON
SURVEY INFORMATION SUPPLIED BY JAMES M. STEWART, INC.
3.) GEOPROBE PROFILE BORINGS AND SURFACE WATER/SEDIMENT SAMPLING LOCATIONS
WERE LOCATED IN THE FIELD BY COLDER ASSOCIATES, INC. PERSONNEL USING A
HANDHELD GPS UNfT AND ARE APPROXIMATE ONLY.
4.) PARCEL BOUNDARIES FROM CIS DATABASE OF NEW JERSEY.
300
H
FEET
LIGHTMAN DRUM SITE
WINSLOW TOWNSHIP, NEW JERSEY
SITE CONDITIONS
FIGURE 1
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