Superfund Proposed Plan
U.S. Environmental Protection
Agency, Region II
Nepera Chemical Company, Inc. Superfund Site
Hamptonburgh, Orange County, New York
May 2011
EPA ANNOUNCES PROPOSED PLAN
This Proposed Plan describes the proposed change to
the September 28, 2007 Record of Decision (ROD)
issued by the U.S. Environmental Protection Agency
(EPA) in consultation with the New York State
Department of Environmental Conservation
(NYSDEC) for the Nepera Chemical Company
Superfund Site (Site) located in Hamptonburgh, New
York. The proposed change applies to the soil
remedy component of the ROD.
The remedy described in the 2007 ROD required:
• excavation of the soil in the source area
(former lagoon area),
• the design and construction of an on-site
biocell to contain the excavated soil,
• the installation of a soil vapor extraction
(SVE) system within the biocell, and
• operation of the SVE and the biocell systems
to remediate contaminated soil.
In addition, the ROD included a groundwater remedy
whereby groundwater in the overburden would be
treated with oxygenating compounds (e.g., Oxygen
Releasing Compounds), which will flow radially
outward from the former lagoon area and also
downward to create an aerobic environment and,
thereby, stimulate biodegradation within the area of
elevated groundwater contamination. As the
excavated soils would remain on-Site, the ROD also
included a requirement for institutional controls,
namely, that an environmental easement/restrictive
covenant would be filed in the property records of
Orange County noting restrictions on the use of the
property.
Based on new data collected during the
implementation of the 2007 remedy, EPA is proposing
that the contaminated soils in the source area (former
lagoon area) be excavated and transported to an off-
site facility for treatment and/or disposal. All of the
other components of the 2007 remedy, including the
treatment of groundwater with oxygenating
MARK YOUR CALENDAR
May 20, 2011 - June 20, 2011: Public comment period
related to this Proposed Plan.
June 15, 2011 at 7:00 P.M.: Public meeting at the Town
of Hamptonburgh Town Hall in Campbell Hall, New York.
compounds, remain unchanged. This Proposed Plan
was developed by EPA in consultation with the
NYSDEC.
EPA is issuing this 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) and
300.435(c) of the National Oil and Hazardous
Substances Pollution Contingency Plan (NCP). The
nature and extent of the contamination at the Site and
the alternatives summarized in this Proposed Plan are
further described in the September 28, 2007 Record
of Decision (ROD), June 16, 2006 Remedial
Investigation (Rl) Report, the June 26, 2007 Feasibility
Study (FS) Report, and the 2011 Final Remedial
Design Report. EPA and NYSDEC encourage the
public to review these documents to gain a more
comprehensive understanding of the Site and
Superfund activities that have been conducted at the
Site.
This Proposed Plan is being provided to inform the
public of EPA's preferred amendment to the soil
remedy and to solicit public comments pertaining to
the remedial alternatives evaluated, including the
preferred alternatives. EPA's preferred amendment to
the soil remedy consists of the excavation of the soil in
the source area (former lagoon area) and
transportation of the contaminated soils to an off-site
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INFORMATION REPOSITORIES
Copies of the Proposed Plan and supporting
documentation are available at the following
Information repositories:
Town of Hamptonburgh Town Hall
18 Bull Road
Campbell Hall, New York 10916
Telephone: (845) 427-2424
Hours: Monday - Friday: 9:00 AM to 3:30 PM
USEPA-Region II
Superfund Records Center
290 Broadway, 18th Floor
New York, New York 10007-1866
(212)637-4308
Hours: Monday - Friday: 9:00 AM to 5:00 PM
The Proposed Plan can also be found under
"Additional Documents" on EPA's Nepera Chemical
Company website:
www.epa.gov/region02/superfund/npl/nepera
facility for treatment and/or disposal. This soil
remedial alternative is referred to in this Proposed
Plan as Soil Alternative 2. The groundwater remedy
was previously selected by EPA in a Record of
Decision issued on September 28, 2007. The
groundwater remedy remains unchanged and,
therefore, is not discussed at length in this Proposed
Plan. The groundwater remedy will be followed by a
long-term groundwater monitoring program where
groundwater samples would be collected and
analyzed regularly to verify that the concentrations
and extent of groundwater contaminants are
diminishing.
The amendment to the soil remedy described in this
Proposed Plan is the preferred soil remedy for the
Site. 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
selection of the amended soil 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 Proposed Plan
COMMUNITY ROLE IN SELECTION PROCESS
EPA and NYSDEC rely on public input to ensure that
the concerns of the community are considered in
selecting an effective remedy for each Superfund site.
To this end, the Rl and FS reports and this Proposed
Plan continue to be available to the public for a public
comment period which begins on May 20, 2011.
A public meeting will be held during the public
comment period at Town of Hamptonburgh Town Hall
on June 15, 2011 at 7:00 P.M. to present the history
and facts pertaining to the Site, to elaborate further on
the reasons for recommending the preferred remedy
and to receive public comments.
Comments received at the public meeting, as well as
written comments, will be documented in the
Responsiveness Summary section of an Amended
Record of Decision, the document which will formalize
the selection of any change to the remedy.
Written comments on this Proposed Plan should be
addressed to:
Mark Dannenberg
Remedial Project Manager
U.S. Environmental Protection Agency
290 Broadway, 20th Floor
New York, New York 10007-1866
Telephone: (212)637-4251
Fax:(212)637-3966
Email: Dannenberg.mark@epa.gov
SCOPE AND ROLE OF ACTION
This primary objective of this Proposed Plan is to
present an Amendment to the ROD for the Nepera
Chemical Company Superfund Site. This Proposed
Plan presents a remedial action focusing on the
cleanup of contaminated soils at the Site. The
proposed remedy would excavate and remove
contaminated soil from the Site for off-site treatment
and/or disposal, which would eliminate the potential
for direct contact with contaminated soils, minimize
the migration of contaminants from the soils to the
groundwater, restore groundwater quality, and
minimize any potential future health and
environmental impacts.
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SITE BACKGROUND
Site Description
The property is located on the south side of Orange
County Highway 4 in Hamptonburgh, Orange County,
New York, approximately 1.5 miles southwest of the
Village of Maybrook (see Figure 1). The Site is owned
by Nepera Chemical Company, Inc. (Nepera). The
Site property is 29.3 acres in area; approximately 5
acres of the Site were used for the operation of
industrial wastewater disposal lagoons (see Figure 2).
The Site is located in a rural residential/agricultural
area, bounded by Orange County Highway 4 to the
north, Beaverdam Brook to the west, the Otter Kill to
the south, and an undeveloped tract of land to the
east. Three residences exist in the immediate vicinity
of the Site, one to the southwest, one to the north and
one to the northeast (on the other side of Orange
County Highway 4).
Approximately 7,000 people live within three miles of
the Site, with the closest residences located
approximately 250 feet to the west-southwest and 175
feet to the northeast. Public water supply wells for the
Village of Maybrook are located approximately 800
feet to the northeast of the Site property. All
residences in the immediate vicinity of the Site rely on
private wells for the potable water supply. Based on
annual monitoring conducted for the private wells
nearest the Site, the private wells continue to meet
drinking water quality standards for public water
supplies.
Site Geology/Hydrogeology
The Site is in an area of rolling hill topography and is
located within a 4.5 square mile watershed consisting
of Beaverdam Brook and its tributaries, which
discharge to the Otter Kill, located approximately 500
feet to the south of the property. The geologic units at
the Site are divided into two primary units, the
overburden (comprised of topsoil, fill, and gravel) and
the bedrock (comprised of shale). Ground surface
topography is generally bedrock controlled, meaning
that the ground surface generally follows the bedrock
surface topography. The overburden thickness at the
Site is also related to bedrock topography in that it is
generally thinner (or absent) over bedrock ridges,
while greater overburden thicknesses have been
deposited in bedrock depressions and valleys. The
overburden ranges in thickness from 0 to 20 feet.
Most of the Site is forested. The former lagoon area,
which was stripped of vegetation while in use, is now
covered with grasses, wild flowers, and mixed brush.
There are two aquifers that exist beneath the Site, the
overburden aquifer and the bedrock aquifer. The
overburden aquifer is the surficial unit which overlies
the bedrock aquifer. The deeper bedrock aquifer is
the primary source for public water in the area. No
significant layers of impeding clays were observed
between the two aquifers within the study area. An
east to west trending groundwater divide is present in
the bedrock aquifer underlying (and transecting) the
lagoon area. As such, groundwater flow has a
northerly and a southerly component radiating from
this divide.
Three public water supply wells in Maybrook are
located in the bedrock aquifer at depths of over 200
feet below ground surface (bgs).
Site History
The Site was used for the disposal of industrial
wastewater generated at the Nepera Chemical
Company facility in Harriman, New York, located
approximately 25 miles from the Site. Wastewater
was trucked to the Site and disposed of in six
constructed lagoons from 1953 through December
1967. Approximately 5 acres of the Site were used for
these lagoon operations. No wastewater disposal has
occurred at the Site since December 1967. Three of
the lagoons were backfilled with clean soil in 1968: the
remaining three lagoons were backfilled with clean soil
in 1974.
Beginning in 1967, numerous investigations were
conducted by various consultants for Nepera to
determine the extent of contamination at the Site.
Based on the results of these investigations, NYSDEC
placed the Site on the New York Registry of Inactive
Hazardous Waste Disposal Sites. On August 17,
1984, the State of New York entered into a Consent
Decree with Nepera to conduct a remedial
investigation to determine the nature and extent of
contamination at the Site.
On June 1, 1986, the EPA placed the Site on the
National Priorities List (NPL) of sites under the
Comprehensive Environmental Response
Compensation and Liability Act 1980 (CERCLA), as
amended. NYSDEC continued as the lead regulatory
agency overseeing the implementation of the RI/FS.
Under an Administrative Order with NYSDEC, signed
on March 21, 1988, Nepera hired a contractor to
conduct a RI/FS of the Site in 1988. The first draft Rl
was submitted in March 1996. NYSDEC and EPA
determined that further work was necessary to define
the type and extent of soil contamination at the Site
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and to determine the downgradient extent of
groundwater contamination at the Site. The finding of
this additional investigation were documented in the
June 2006 Final Rl Report.
In 2007, at the conclusion of the RI/FS, the lead
agency for the Site was re-designated from NYSDEC
to EPA. A ROD was issued by EPA on September
28, 2007. Under a Consent Agreement entered on
October 8, 2008, and signed by EPA and Nepera,
Nepera hired a contractor to perform the Remedial
Design (RD). The Final Remedial Design Report was
approved by EPA in February 2011.
RESULTS OF THE REMEDIAL INVESTIGATION
Major field activities performed during the Rl included:
on-Site soil borings, soil sampling, monitoring well
drilling and installation, groundwater sampling, and
residential well sampling. Since EPA is proposing to
amend only the Soils Remedy Alternative, and not the
other components of the remedy selected in the 2007
ROD, this section will only focus on the nature and
extent of soil contamination. The results of the Rl are
summarized below. For further information on the
groundwater remedy at the Site, as well as additional
information pertaining to other aspects of the Site, see
the 2007 ROD (which is still on file at both public
repositories).
Soil
Nepera performed the Rl in several phases. Soil
sampling activities were conducted in 1991 and 1996.
Focused soil sampling identified contamination in the
lagoon area and determined the lagoon area to be the
primary source of the contaminants in the
groundwater plume. The primary contaminants
identified during soil sampling activities include
benzene (maximum concentration of 13 milligrams per
kilogram (mg/kg)), chlorobenzene (maximum
concentration of 12 mg/kg), ethylbenzene (maximum
concentration of 22 mg/kg), toluene (maximum
concentration of 52 mg/kg), xylenes (maximum
concentration of 300 mg/kg) and pyridine-related
compounds (maximum concentration of 74 mg/kg of
2-amino pyridine). Each of these contaminants are
considered as Contaminants of Concern (COCs) for
the Site. An additional 120 soil samples were
collected from the lagoon area in 2003 to evaluate
concentration levels of metals. Soil samples were
also collected from locations not impacted by the Site
to determine Site-specific background levels for
metals. Analytical data from the 2003 sampling
activities indicated that the metals in the lagoon area
were consistent with background concentrations and,
as such, metals are not considered to be COCs.
RESULTS OF THE REMEDIAL DESIGN
Major RD activities included: on-Site soil borings, soil
sampling, surveying activities, and recalculation of the
volume estimates of the contaminated soil within the
former source area. The results of the RD are
summarized below.
Additional sampling was conducted in late 2010 to
identify pyridine-related compounds that, in previous
analytical studies, were tentatively identified. One
pyridine-related tentatively identified compound (TIC)
was positively identified, namely 2,4-bipyridine. This
compound was added to the list of Contaminants of
COCs for the Site, and a remediation goal was
established for 2,4-bipyridine (see Table 1, below).
Surveying activities along with a thorough analysis of
test pitting and boring information was performed.
This work led to a better defined contamination source
area. The projected volume of contaminated soils at
the Site was recalculated. In addition, a waste
characterization of the contaminated soils was
conducted. Much of the soil is now expected to be
classified as non-hazardous. As such, the capital cost
for disposal will be significantly less than projected in
the FS. In addition, Nepera identified three
Treatment, Storage, and Disposal (TSD) facilities
within close proximity of the Site willing to accept the
waste. These facilities are much closer than projected
in the FS. The calculation of the volume estimates for
the contaminated soils is presented below.
The former lagoons are within an area approximately
five acres in size, but the total area of the actual six
lagoons is smaller. The total area of contaminated
soils (i.e., the six lagoons) is estimated to be 128,850
square feet (approximately three acres). The volume
calculations for contaminated soil are based on the
actual surface area of each lagoon, the average depth
of the overburden within each lagoon (down to
bedrock), the thickness of a distinct black-stained
layer observed during the completion of test pits, and
the clean fill that was put into the lagoons when they
were closed (in 1968 and 1974).
• The volume of the clean backfill in the lagoon
area is conservatively estimated to be 11,000
cubic yards. This is based on a total surface
area of the actual lagoons of 75,000 square
feet and a depth of four feet. Sampling will be
performed to validate this assumption during
remedy implementation.
• The volume of the soil extending from the top
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of the stained soils, which have typically been
contaminated, down to the top of competent
bedrock is conservatively estimated to be
24,000 cubic yards. Furthermore, it is
conservatively estimated that approximately
50% of the soil below the 4-foot backfill
material is stained. As such, approximately
12,000 cubic yards of the 24,000 cubic yards
is assumed to be stained and 12,000 cubic
yards is assumed to be non-stained. For a
conservative estimate, one-third of this "non-
stained" material (4,000 cubic yards) is
assumed to exceed the soil cleanup
objectives.
• Therefore, the total volume of contaminated
material is estimated to be 16,000 cubic
yards. The projected volume for offsite
disposal is 16,000 cubic yards (which is
approximately 21,600 tons).
• The estimate for the total volume of
contaminated soil used in the September 28,
2007 ROD was 24,086 cubic yards.
Based on the updated information, the revised
calculation for the projected volume of contaminated
soils that will be transported from the Site for
treatment and/or disposal is approximately 33% less
than the previous calculation used in the September
28, 2007 ROD.
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 Rl. A baseline ecological risk assessment was
also conducted to assess the risk posed to ecological
receptors because of Site-related contamination. As
the findings of the human health and ecological risk
assessments have not changed since September 28,
2007, only a summary of the risk assessments is
provided below. For further information on the human
health risk assessment and the ecological risk
assessment, see the September 28, 2007 ROD
(which is still on file at both public repositories).
Human Health Risks
In the Human Health Risk Assessment, chemical data
were used to calculate cancer risks and noncancer
health hazards expressed as individual Hazard
Quotients (HQ). These cancer and noncancer risks,
for the most conservative scenario (namely, future
residential use of the Site) are expressed below.
EPA's statistical analysis of the groundwater sampling
data indicates that the probable exposure
concentrations of benzene (330 micrograms per liter
(ug/l)), xylenes (270 ug/l), 2-aminopyridine (189 ug/l),
and aniline (16 ug/l), when evaluated under future
residential exposure scenarios, are associated with
noncancer hazard quotients of 21, 4, 570, and 23,
respectively. In addition, the concentration of
benzene is associated with an excess lifetime cancer
risk of 1 in 1,000 (1 x 10'3). All of these values
exceed EPA's acceptable levels of noncancer hazard
or excess lifetime cancer risk.
Similarly, EPA's evaluation of the soils indicates that
direct exposure to the probable exposure
concentrations of benzene (4,440 ug/kg), toluene
(10,000 ug/kg), chlorobenzene (1,000 ug/kg), xylenes
(69,000 ug/kg), and 2-aminopyridine (23,400 ug/kg)
are associated with hazard quotients of 42, 7, 5, 61,
and 2, respectively. All of these values exceed EPA's
acceptable levels of noncancer hazard. In addition,
the concentration of benzene is associated with an
excess lifetime cancer risk of 1 x 10"^.
These risk and hazard levels indicate that there is
significant potential risk to receptors from direct
exposure to contaminated soil and groundwater.
These calculated risks to human health indicate that
action is necessary by EPA to undertake remedial
measures to reduce the risks associated with the
observed contamination in soil and groundwater and
restore the groundwater to beneficial use.
Ecological Risk Assessment
A baseline ecological risk assessment (BERA) was
prepared to identify the potential environmental risks
associated with surface water, groundwater, sediment,
and soil. The results of the BERA suggested that
there are contaminants in groundwater, soils, and
sediment, but they are not present at levels posing
significant risks to ecological receptors. The potential
for risk to ecological receptors exposed to Site-related
contaminants was limited to isolated locations,
primarily in Lagoon 6, and the risk associated with this
area used the conservative assumption that the
ecological receptors (e.g., soil invertebrates,
mammalian insectivores, and carnivores) spend 100%
of their lives in the area of Lagoon 6. The
contaminants that were identified in the BERA
(outside of Lagoon 6) were determined not to pose a
potential for adverse ecological effects because they
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were common elements of soil that were not related to
Site operations, the detected concentrations were
lower than background levels, the frequency of
detections was low, or the HQs were only slightly
above 1 with no adverse impacts to populations
expected. A detailed presentation of these data can
be found in the Rl Report.
Risk Summary Conclusion
Exposure to contaminated soil poses risks to human
health. Furthermore, the contaminated soil continues
to be a source of groundwater contamination. In
addition, exposure to contaminated groundwater
poses risks to human health. In the 2007 ROD, a
determination was made that a remedial action should
be taken to reduce contamination in the soil to levels
below cleanup objectives and to restore the
contaminated groundwater for future use. This
determination has not changed since the 2007 ROD.
The amended remedy proposed in this Proposed Plan
still requires contamination in the soil to be reduced to
levels below cleanup objectives.
REMEDIAL ACTION OBJECTIVES
Remedial action objectives (RAOs) are media-specific
goals to protect human health and the environment.
These objectives are based on available information
and standards such as applicable or relevant and
appropriate requirements (ARARs), to-be-considered
(TBC) guidance, and risk-based levels established in
the risk assessment.
The overall remedial action objective is to ensure the
protection of human health and the environment. The
general remedial action objectives identified for the
Site are to:
1. prevent exposure of human and
ecological receptors to contaminated
soils and contaminated groundwater;
2. minimize migration of contaminants
from soils to groundwater;
3. restore the aquifer(s) to beneficial
use;
4. ensure that hazardous constituents
within the soil meet acceptable levels
consistent with reasonably anticipated
future use; and
5. minimize potential human contact with
waste constituents.
Preliminary Remediation Goals
Preliminary Remediation Goals (PRGs) were selected
based on federal and state promulgated ARARs, risk-
based levels, background concentrations, and
guidance values. These PRGs were 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 FS Report. The PRGs for soil are shown in
Table 1 below.
Table 1: Preliminary Remediation Goals
Contaminant
Benzene
Chlorobenzene
Ethylbenzene
Toluene
Xylenes
2-amino pyridine
Pyridine
Alpha picoline
Acetone
Aniline
2,4-bipyridine 3
PRG for Soils
(ug/kg)
60 1
1.1001
1,0001
700 1
260 1
400 2
400 2
575 2
50 1
1,5102
400 2
1 The values shown are from NYSDEC Subpart 375:
Remedial Program Soil Cleanup Objectives.
2 The values shown were derived by NYSDEC based
on the Division Technical and Administrative
Guidance Memorandum: Determination of Soil
Cleanup Objectives and Cleanup Levels, Division of
Hazardous Waste Remediation, January 24, 1994.
3 The parameter was determined to be present in Site
soils as a result of a soil sampling survey performed in
2010.
SUMMARY OF REMEDIAL ALTERNATIVES
CERCLA Section 121(b)(1), 42 U.S.C. Section
9621 (b)(1), mandates that remedial actions must be
protective of human health and the environment, cost-
effective, 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. CERCLA Section 121(d), 42
U.S.C. Section 9621 (d) further specifies that a
remedial action must attain a level or standard of
control of the hazardous substances, pollutants, and
contaminants that at least attains ARARs under
federal and state laws, unless a waiver can be justified
pursuant to CERCLA Section 121(d)(4), 42 U.S.C.
Section 9621 (d)(4).
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The objective of the feasibility study (FS) as it pertains
to soil contamination was to identify and evaluate
cost-effective remedial action alternatives which would
minimize the risk to public health and the environment
resulting from soil contamination at the Site.
Detailed descriptions of the remedial alternatives for
addressing the contamination associated with the Site
can be found in the FS report and in the September
28, 2007 Record of Decision. During the RD, waste
characterization, volume estimates, and cost
information were refined; these refinements are
reflected in the alternatives described below.
This Proposed Plan presents a summary of three soil
remediation alternatives (including a "No-Action"
alternative). The groundwater remedy remains
unchanged and is, therefore, not addressed in this
Proposed Plan.
SOIL REMEDIAL ALTERNATIVES
The two active soil remedies presented below would
include institutional controls. Specifically, an
environmental easement/restrictive covenant would be
filed in the property records of Orange County. The
easement/covenant would, at a minimum, require: (a)
restricting new construction at the Site unless an
evaluation of the potential for vapor intrusion is
conducted and mitigation, if necessary, is performed
in compliance with an EPA approved site
management plan; (b) restricting the use of
groundwater on the site property as a source of
potable or process water unless groundwater quality
standards are met; and (c) the owner/operator to
complete and submit periodic certifications that the
institutional and engineering controls are in place.
A Site Management Plan (SMP) would be developed
to address groundwater at the site. The SMP would
provide for the proper management of all Site remedy
components post-construction, such as institutional
controls, and shall also include: (a) monitoring of Site
groundwater to ensure that, following the soil
excavation, the groundwater quality continues to
improve and contaminant levels are reduced to levels
below Federal and State standards; (b) identification
of any use restrictions on the Site; (c) necessary
provisions for implementation of the requirements of
the above easement/covenant; and (d) provision for
any operation and maintenance required of the
components of the remedy.
Finally, there is a requirement that those private wells
(in the vicinity of the Site) and the Town of Maybrook
Public Water Supply wells, all currently being
monitored in relation to this Site, will continue to be
monitored on an ongoing basis. The frequency of the
residential well sampling will be periodically
reevaluated.
Soil Remedial Alternatives
Alternative 1 - No Action
Capital Cost:
Annual Cost:
Present-Worth Cost:
Construction Time:
$0
$0
$0
Not Applicable
The "No Action" alternative is considered in
accordance with NCP requirements and provides a
baseline for comparison with other alternatives. If this
alternative were implemented, the current status of the
Site would remain unchanged. Institutional controls
would not be implemented to restrict future Site
development or use. Engineering controls would not
be implemented to prevent Site access or exposure to
Site contaminants. Although existing security fencing
at the Site would remain, it would not be monitored or
maintained under this alternative.
Alternative 2 - Excavation and Off-Site Disposal
Capital Cost: $3,000,000
Annual Cost: $25,000
Present-Worth Cost: $3,026,900
Construction Time:
1 year
Alternative 2 involves the excavation of soils within the
former lagoons containing COCs at concentrations
exceeding NYSDEC Soil Cleanup Objectives for
unrestricted land use. The excavated soils would be
disposed of off-Site at a permitted TSD facility. Prior to
off-Site land disposal, contaminated soils would be
required to comply with federal Resource
Conservation and Recovery Act (RCRA) land disposal
requirements to the extent applicable.
The Capital Cost associated with Alternative 2 has
been revised/updated since the FS Report. Sampling
performed during the RA will define how much of the
contaminated soil would be classified as hazardous
waste, which may alter, somewhat, the cost to handle
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and dispose of that material.
Alternative 2 would include the following major
components:
• excavation of on-Site soils;
• disposal of excavated soils exceeding soil
cleanup objectives for unrestricted use for the
COCs at appropriate off-Site facility (or
facilities);
• post excavation sampling to verify
achievement of soil cleanup objectives;
• backfilling of excavated areas with clean soil
meeting the requirements of 6NYCRR
Subpart 375-6.
Alternative 3 - Excavation and On-Site SVE and
Biocell
Capital Cost:
Annual Cost:
Present-Worth Cost:
Construction Time:
$2,388,000
$406,000
$3,232,200
2 years
This alternative would involve the excavation of the
soils within the former lagoons and treatment of the
soils with concentrations of COCs exceeding the
NYSDEC Soil Cleanup Objectives (SCOs) for
unrestricted land use utilizing soil vapor extraction
(SVE) and biological degradation within an on-Site
engineered below-grade biocell. Excavated soils
would be treated to reach unrestricted land use SCOs.
The soils would be treated within the biocell by
installing perforated pipes within multiple layers of the
biocell. The perforated pipes would be connected to a
blower unit to draw air through the piles; contaminants
would be volatilized into this air. The air would be
treated, if necessary, using carbon adsorption, prior to
being recirculated or exhausted to the atmosphere.
Nutrients would be added to the treatment layers as
required to enhance biological degradation.
In general, the biocell would be operated in two
primary modes: SVE mode (high air flow rate); and
bioremediation mode (low airflow rate).
During the SVE mode, the system would be operated
at higher air flow rates which would be selected to
optimize the removal of the volatile organic
compounds (VOCs) constituents using SVE. After the
removal rate of the VOCs decreases to an asymptotic
or nominal rate, the system would be switched over to
the bioremediation mode. During the bioremediation
mode, the system would be operated at an optimized
air flow rate selected to sustain the aerobic
biodegradation of the remaining VOCs and semi-
volatile organic compounds.
In addition, physical controls, such as regular
maintenance of the perimeter fence, would be
implemented to restrict Site access and thereby
prevent the potential exposure to chemicals present in
the soils in the vicinity of the former lagoons.
COMPARATIVE ANALYSIS OF ALTERNATIVES
During the detailed evaluation of remedial alternatives,
each alternative is assessed against the following nine
evaluation criteria: overall protection of human health
and the environment, compliance with ARARs, long-
term effectiveness and permanence, reduction of
toxicity, mobility or volume through treatment, short-
term effectiveness, implementability, cost, and state
and community acceptance. The evaluation criteria
are described below.
• 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 ARARs 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 requirements or
provide grounds for invoking a waiver.
• Long-term effectiveness and permanence refers to
the ability of a remedy to maintain reliable protection
of human health and the environment over time, 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, that 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.
• Implementabilitv is the technical and administrative
feasibility of a remedy, including the availability of
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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 if, based on its review
of the RI/FS and Proposed Plan, the State concurs
with the preferred remedy.
• 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.
Overall Protection of Human Health and the
Environment
If no action were to be implemented, Alternative 1
would not provide any control of exposure to
contaminated soils, offer no reduction in risk to human
health posed by contaminated soils, and provide no
groundwater protection. Alternative 2 would be
protective of human health and the environment since
all contaminated soils would be removed from the
Site. Alternative 3 would also be protective of human
health and the environment since all contaminated
soils would be excavated and treated within a closed
treatment system. Direct contact risks for both
Alternatives 2 and 3 would be reduced by removing
contaminated soils. In addition, Alternatives 2 and 3
would reduce or eliminate potential impacts to
groundwater.
Compliance with ARARs and TBCs
If no action were to be implemented, Alternative 1
would not achieve ARARs and TBCs.
Alternatives 2 and 3 would both meet unrestricted use
NYS Part 375 SCOs. However, Alternative 2 would
meet the SCOs within 3 or 4 months, whereas
Alternative 3 would most likely not meet these SCOs
for 3 or more years.
Since Alternatives 2 and 3 would involve the
excavation of contaminated soils, they would require
compliance with fugitive dust and VOC emission
requirements. In addition, Alternative 2 and Alternative
3, to a lesser extent, would be subject to Federal and
state regulations related to the transportation and off-
site treatment/disposal of wastes.
Long-Term Effectiveness and Permanence
Alternatives 1 would not reduce risk in the long term,
since the contaminants would not be controlled,
treated or removed. Alternative 2 provides the highest
degree of long-term effectiveness and permanence,
because the impacted soils are permanently removed
from the Site. Alternatives 2 and 3 both involve long-
term groundwater monitoring requirements.
Reduction of Toxicity, Mobility, or Volume of
Contamination through Treatment
Alternatives 1 and 2 do not use any treatment
technologies on-Site to reduce the toxicity, mobility or
volume of contaminants through treatment. However,
under Alternative 2, contaminated soils may undergo
thermal treatment off-site at the TSD facility (if
necessary based on compliance with RCRA land
disposal requirements), which would reduce the
toxicity, mobility or volume of contaminants through
treatment. Alternative 3 involves treatment that would
effectively reduce the toxicity, mobility, or volume of
contaminants on-Site.
Short-Term Impacts and Effectiveness
There are no short-term impacts for the No Action
alternative (Alternative 1). Under Alternatives 2 and 3,
some particulate emissions may result during soil
handling, excavation and/or removal. Dust control
and soil erosion and sedimentation controls would
reduce the short-term impacts. Safety techniques
including alarmed perimeter air monitoring equipment
and fencing would be used to minimize exposure
risks. Alternative 2 requires the transportation of the
contaminated soils to an off-site location, which would
result in more truck traffic entering and leaving the
Site. It is estimated that there would be no more than
20 truck trips per day. This impact would be
minimized as it is subject to New York State and
federal regulations related to the transportation and
off-site treatment/disposal of wastes; trucks would be
instructed to stay on roads designated as truck routes
and the transportation plan will be shared with the
Town of Hamptonburgh.
Implementability
Except for Alternative 1 which requires no action
whatsoever, Alternative 2 would be the simplest to
implement as no construction is necessary and there
are no on-going operation and maintenance issues
pertaining to treatment of the soils on Site. Long-term
groundwater monitoring would be required under both
Alternatives 2 and 3 to assess the effectiveness of the
soils remedy in reducing the affect on the groundwater
contamination. Each of the remedial technologies are
well established and proven. However, it is not
precisely known how long the on-Site biocell
associated with Alternative 3 would need to be
operated; specifically, the biocell may need to be
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operated additional years to achieve the remediation
goals for the pyridine compounds.
Cost
Alternative 1 (No-Action) has no cost because no
activities are implemented. Alternative 3 has the lower
capital cost ($2,388,000) of the two active soil
alternatives followed by Alternative 2 ($3,000,000).
However, Alternative 2 has lower annual costs
($25,000) than Alternative 3 ($405,000). As a result,
Alternative 2 has the lower overall present value cost
($3,026,900) than Alternative 3 ($3,232,200). These
present value costs for Alternatives 2 and 3 are
virtually the same, but Alternative 2 would be
completed, with certainty, in a much shorter time span
then Alternative 3. If Alternative 3 takes longer than
the projected two years, the cost associated with
Alternative 3 will increase over $400,000 per year.
State Acceptance
NYSDEC concurs with the preferred remedy.
Community Acceptance
Community acceptance of the preferred alternative will
be assessed in the ROD following review of the public
comments received on the various reports and this
Proposed Plan.
PROPOSED REMEDY
Based upon an evaluation of the various alternatives,
EPA, in conjunction with NYSDEC, recommends
Alternative 2 - Excavation and Offsite
Treatment/Disposal of Contaminated Soils.
The preferred remedy consists of an amendment to
the 2007 ROD as follows: 1) excavation of
contaminated soils throughout the former lagoon area
where contaminants in the soils exceed NYSDEC Soil
Cleanup Objectives for unrestricted use, 2) transport
of contaminated soils that exceed the SCOs to a
permitted Treatment, Storage, and Disposal facility,
and 3) backfilling the excavated areas with clean fill.
The groundwater remedy previously selected in the
September 28, 2007 ROD remains unchanged and
includes the component of long-term groundwater
monitoring. Specifically, the groundwater remedy
includes the initial application of oxygenating
compounds and, if necessary, additional applications
to groundwater in the future.
Alternative 2 effectively removes the sources of
contamination in the soils, thereby eliminating further
impacts to groundwater. Post-excavation sampling
shall be performed to verify achievement of SCOs.
Clean fill would be used to backfill all excavated
areas. Prior to backfilling, the excavated area will be
treated with oxygenating or oxygen-releasing
compounds to create an aerobic environment and,
thereby, stimulate biodegradation within the area of
elevated groundwater contamination. After the initial
treatment, additional applications of the oxygenating
compounds may be necessary. During the initial
phase, additional overburden and bedrock
groundwater monitoring wells will be installed and
incorporated into a Site-wide management plan which
will include a groundwater monitoring program which
is part of this preferred alternative. This program will
be developed to determine and monitor the effects of
the soils and groundwater remedies on both the
overburden and bedrock aquifers to reduce
contaminant levels to below Federal and State
standards. Institutional controls, i.e., groundwater well
restrictions, will be put in place at the Site.
Institutional controls would be enacted at the Site
which would include the development of an
environmental easement/restrictive covenant to be
filed in the property records of Orange County that
would include groundwater use restrictions on the
Site. Furthermore, new construction at the Site will be
restricted unless an evaluation of the potential for
vapor intrusion is conducted and mitigation, if
necessary, is performed
This alternative involves the removal of contaminated
soils from the Site, which are above health-based
levels. If justified by post-excavation sampling or from
future reviews, additional remedial actions may be
implemented at the Site.
Basis for the Remedy Preference
EPA believes that Alternative 2 is the most cost-
effective option for the contaminated soils given the
evaluation criteria and reasonably anticipated future
land use. Alternative 2 is protective of human health
and the environment, would provide a permanent
solution, and would achieve soil cleanup objectives for
the Site-related COCs in the shortest amount of time
and in the most cost-effective manner. Therefore,
EPA and NYSDEC believe that Alternative 2 would
effectuate the soil cleanup while providing the best
balance of tradeoffs with respect to the evaluating
criteria.
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Alternative 1 was not identified as the preferred
alternative because it calls for no action and would not
be protective of human health and the environment.
Similarly, Alternative 3 is not proposed because it is
more expensive than Alternative 2 and will take
several years longer to realize cleanup objectives.
Alternative 2 will result in the removal of the source of
groundwater contamination which will work, in
conjunction with the groundwater action at the Site, to
attain the performance standards for groundwater.
The preferred remedy would be protective of human
health and the environment, provide long-term
effectiveness, achieve ARARs in a reasonable time
frame and be cost-effective among alternatives with
respect to the evaluation criteria.
Therefore, EPA and NYSDEC believe that the
combination of Alternative 2 and the current
groundwater remedy would successfully remediate the
contaminated soils and expedite the remediation of
contaminated groundwater at the Site, while providing
the best balance of tradeoffs among the alternatives
with respect to the evaluation criteria. Furthermore,
the preferred remedy relating to soils would utilize
permanent solutions and treatment technologies to the
maximum extent practicable.
In accordance with EPA Region 2's Clean and Green
policy and in order to maximize the net environmental
benefits, EPA will evaluate the use of sustainable
technologies and practices when performing the
remedial activities associated with the selected
remedy. Furthermore, pursuant to Section 121(c) of
CERCLA, EPA will review site remedies no less often
than every five years. As long as hazardous
substances remain at this Site above levels that would
not allow for unlimited use and unrestricted exposure,
EPA will continue to review the Site remedy no less
often than every five years.
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SOURCE: USGS MAYBRGQK NEW YORK AND
GOSHEM NEW YORK QUADRANGLE MAP
SOURCE: RAND McNALLY ROAD ATLAS
NEW YORK
03698-00{032)GN-WA014 JUN £3/2006"
figure 1
SITE LOCATION
FORMER LAGOON SITE
Hamptonburgh, New York
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