United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R02-91/141
June 1991
SEPA Superfund
Record of Decision
Warwick Landfill, NY
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50272-101
REPORT DOCUMENTATION 1. REPORT NO. 2.
PAGE EPA/ROD/R02-91/141
4. TWo and SubtWe
SUPERFUND RECORD OF DECISION
Warwick Landfill, NY
First Remedial Action
7. Authors)
». Performing Organization Name and Addrea*
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
3. Recipient's Accession No.
5. Report Date
06/27/91
6.
8. Performing Organization Rept No.
10. ProjecVTssk/WorkUnitNo.
11. Contnct(C) or Grant(G) No.
(C)
(G)
13. Type of Report & Period Covered
800/000
14.
15. Supplemental Note*
16. Abstract (Limit: 200 words)
The 13-acre Warwick Landfill is an inactive municipal and industrial waste disposal
site in the Town of Warwick, Orange County, New York. Land use in the area is
predominantly residential, and the site is surrounded by woodlands and wetlands. The
estimated 3,000 people who reside approximately 1.5 miles northeast of the site use
residential wells as a source of drinking water. From 1898 until its closure in
1978, the Warwick Landfill accepted municipal and industrial wastes and sludge.
Landfill contamination is attributed to the unpermitted and illegal disposal
practices conducted by waste haulers and trespassers. As a result of reports of
illegal onsite dumping in 1979, and an inspection after a property transfer in 1984,
State investigations were conducted, and revealed soil, sediment, ground water, and
surface water contamination throughout the site. This Record of Decision (ROD)
addresses the contaminant source, the onsite landfill, and provides an interim ground
water remedy for the first operable unit (OU1). The final remedy for ground water
(OU2) will be addressed in a subsequent ROD. The primary contaminants of concern
affecting the soil, and ground water are VOCs including benzene, TCE, toluene, and
(See Attached Page)
NY
17. Document Analysis a. Descriptora
Record of Decision - Warwick Landfill,
First Remedial Action
Contaminated Media: soil, gw
Key Contaminants: VOCs (benzene, TCE, toluene, xylenes), other organics
(PAHs, phenols), metals (arsenic, chromium, lead)
b. kfenthters/Open-Ended Terms
c. COSATI Reid/Group
18. Availabifty Statement
19. Security daw (This Report)
None
20. Security Class (This Psge)
None
21. No. of Pages
98
22. Price
(SeeANSt.Z39.18)
See Inatmctionf on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-3S)
Department of Commerce
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EPA/ROD/R02-91/141
Warwick Landfill, NY
First Remedial Action
Abstract (Continued)
xylenes; other organics including PAHs and phenols; and metals including arsenic,
chromium, and lead.
The selected remedial action for this site includes regrading the landfill mound,
capping the landfill with a 22-acre multi-layer cover, and installing with a gas
venting system; installing and maintaining point-of-use treatment systems consisting of
granular activated carbon units at contaminated residential wells until a final ground
water remedy can be evaluated; sampling residential wells; monitoring ground water a-nd
air; evaluating wetlands adjacent to the property in an effort to mitigate potential
threats from the site; and implementing institutional controls including deed
restrictions, and site access restrictions such as fencing. The estimated present
worth cost for this remedial action is $14,279,600, which includes an annual O&M cost
of $526,300 for years 0-3 and $422,900 for years 4-30.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific ground water cleanup goals will be
addressed in the final remedial action but water at the point of use must meet Federal
MCLs.
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ROD FACT SHEET
SITE
Name:
Location/State:
EPA Region:
HRS Score (date)
NPL Rank (date):
ROD
Date Signed:
Selected Remedv
Capital Cost:
O & M:
Present Worth:
LEAD
Warwick Landfill
Warwick, Orange County, New York
II
29.41 (March 1989)
1022 (February 1991)
June 27, 1991
*Capping of landfill in accordance with 6
NYCRR Part 360 closure requirements;
*Residential well sampling program;
*Provision of point-of-use treatment systems
to select residential wells;
*Groundwater monitoring program;
*Landfill gas venting;
*Fencing around perimeter of Site;
^Recommendations that ordinances be
established or restrictions imposed on deed
to ensure integrity of cap; and,
*Measures to mitigate potential disturbance
of adjacent wetlands.
$ 7,442,000
$ 526,000(yrs 1-3)
422,900(yrs 4-30)
$ 14,279,600
Remedial, EPA
Primary Contact (phone): Julia E. Allen (212-264-8476)
Secondary Contact (phone): Douglas Garbarini (212-264-0109)
WASTE
Type and media:
Origin:
Soil-
*VOCs- benzene, ethylbenzene, xylenes,
chlorobenzene,
*Inorganics- arsenic, barium, lead, chromium.
Groundwater-
*VOCs- trichloroethane, chloromethane,
benzene, xylenes, ethylbenzene, isopropyl
benzene, 1,4-dichlorobenzene,
*Inorganics- antimony, barium, lead,
chromium, arsenic.
Pollution originated as a result of illegal
disposal of hazardous wastes at this
location. ~~
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RECORD OP DECISION
WARWICK LANDFILL SITE
TOWN OF WARWICK
ORANGE COUNTY, NEW YORK
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION II
NEW YORK
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DECLARATION FOR THE RECORD OF DECISION
Site Name and Location
Warwick Landfill, Town of Warwick, Orange County, New York
Statement of Basis and Purpose
This decision document presents the selected remedial action for
the first operable unit ("OU1") for the Warwick Landfill site
("the Site"), located in the Town of Warwick, Orange County, New
York, which was chosen in accordance with the requirements of the
Comprehensive Environmental Response, Compensation and Liability
Act, 42 U.S.C. §§ 9601-9675, as amended, and to the extent
practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan, 40 CFR Part 300. This decision document
explains the factual and legal basis for selecting the remedy for
the Site. The information supporting this remedial action
decision is contained in the administrative record for the Site.
The administrative record index is attached (Appendix III).
The New York State Department of Environmental Conservation
("NYSDEC") concurs with the selected remedy (Appendix IV).
Assessment of the Site
Actual or threatened releases of hazardous substances from the
Site, if not addressed by implementing the response action
selected in this Record of Decision ("ROD"), may present an
imminent and substantial endangerment to public health, welfare,
or the environment.
Description of the Selected Remedy
This operable unit represents the first of two operable units
planned for the Site. It addresses the principal threats posed
by the Site through controlling the source of contamination and
provides an interim measure to ensure that area residents have a
potable water supply. The second operable unit (OU2) will
further characterize the fate and transport of the contaminants
emanating from the Site and will serve as the basis for the
decision on a final groundwater remedy.
The major components of the selected remedy include:
* Capping of the landfill in accordance with 6 NYCRR Part
360 closure requirements for New York State solid waste
landfills;
* Development and monitoring of landfill ga-s vents
throughout the landfill mound;
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* Development and implementation of a residential well
sampling program;
* Provision of point-of-use treatment systems to local
residental wells, as needed;
* Development and implementation of a groundwater
monitoring program using existing monitoring wells as
well as additional groundwater monitoring wells
installed within the landfill mound;
* Construction of fencing around the perimeter of the 25-
acre leasehold;
* Recommendations that ordinances be established or
restrictions imposed on the deed to ensure that future
use of the Site property will maintain the integrity of
the cap; and
* Measures to mitigate potential disturbance of adjacent
wetlands.
Declaration
The selected remedy is protective, of human health and the
environment, complies with federal and state requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost effective. However, because
treatment of the principal threats of the Site was not found to
be practicable under OU1, this remedy does not satisfy the
statutory preference for treatment as a principal element of the
remedy. The size of the landfill, and the fact that the remedial
investigation did not identify on-site hot spots that represent
the major sources of contamination, preclude a remedy in which
contaminants could be excavated and treated effectively.
Because this action does not constitute the final remedy for the
groundwater portion of the Site, the statutory preference for
remedies that employ treatment that reduce toxicity, mobility, or
volume as a principal element will be addressed at the time of
the final response action. Subsequent actions are planned to
address fully the threats posed by groundwater contamination.
This remedy will result in hazardous substances remaining on-site
above health-based levels, thus a review will be conducted no
later than five years after commencement of the remedial action
to ensure that the remedy continues to provide adequate
protection of human health and the environment.
bnstantine Sidamon-Eristoff / / Date
Regional Administrator •'
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DECISION SUMMARY
WARWICK LANDFILL SITE
TOWN OF WARWICK
ORANGE COUNTY, NEW YORK
United States Environmental Protection Agency
Region II, New York
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TABLE OF CONTENTS
SITE NAME, LOCATION AND DESCRIPTION 1
SITE HISTORY AND ENFORCEMENT ACTIVITIES 2
HIGHLIGHTS OF COMMUNITY PARTICIPATION . . 4
SCOPE AND ROLE OF OPERABLE UNIT 5
SUMMARY OF SITE CHARACTERISTICS 5
SUMMARY OF SITE RISKS 9
DESCRIPTION OF ALTERNATIVES 13
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 18
SELECTED REMEDY 25
STATUTORY DETERMINATIONS 27
DOCUMENTATION OF SIGNIFICANT CHANGES .... 29
ATTACHMENTS
APPENDIX I. FIGURES
APPENDIX II. TABLES
APPENDIX III. ADMINISTRATIVE RECORD INDEX
APPENDIX IV. NYSDEC LETTER OF CONCURRENCE
APPENDIX V. RESPONSIVENESS SUMMARY
11
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SITE NAME, LOCATION AND DESCRIPTION
The Warwick Landfill site (the "Site") is located approximately
one and one-half miles northeast of the Village of Greenwood Lake
in the Town of Warwick, Orange County, New York. The Site is
approximately three-fourths of a mile north of State Route 17A
and fronts Penaluna Road on its western boundary between Old
Tuxedo Road and Old Dutch Hollow Road (see Figure l). No
buildings exist on the landfill property except for a
substantially demolished brick structure. The landfill mound
transects a small valley and occupies approximately 13 acres of a
former 25 acre leasehold area. This leasehold is a portion
of a 64 acre parcel of property.
The Village of Greenwood Lake is a semi-rural residential
community located approximately forty miles northwest of New York
City. Total population of the Village of Greenwood Lake is
estimated to be 3,000. The Town of Warwick has a population of
approximately 25,000.
Elevations within one mile of the Site range from 700 feet to a
little more than 1300 feet MSL; relief is moderate. Broad upland
areas are generally underlain by massive rocks. Valleys
represent zones of less resistant bedrock and shearing along
faults. The dominant features comprising the Site consist of a
north-south trending wetlands valley spanned by the northeast
trending landfill mound. Maximum relief throughout the Site is
approximately 60 feet.
The area surrounding the Site is generally wooded with clusters
of residential homes, all of which utilize private wells as their
source of drinking water. The two homes closest to the Site are
approximately 250 feet southwest of the landfill boundary and 300
feet northeast of the landfill boundary, respectively.
The landfill mound is sparsely vegetated with grasses and small
shrubs supporting small mammals (rats, cottontail rabbits and
opossum) and some avifauna (bluebirds, robins). Contiguous to.
the landfill mound are two wetland areas: an emergent
marsh/scrub-shrub wetland, approximately nine acres in size, in
the southeast; and a smaller, palustrine, forested scrub-shrub,
deciduous wetland, approximately three to four acres in size, to
the northwest. Upland habitats surround both wetlands.
An unnamed intermittent stream drains the small wetlands area on
the northwest side of the Site and flows north into a creek that
flows westward and then southward into Greenwood Lake. Another
stream, located on the landfill's southeast side, flows southward
into the larger wetlands area which is drained by an unnamed
perennial stream that flows south and west into Greenwood Lake.
Greenwood Lake is designated a Class "A" waterbody by the New
York State Department of Environmental Conservation ("NYSDEC").
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The wetlands and streams draining the site area do not support
fishing or other recreational activities. However, it is a
suitable habitat for small aquatic wildlife, such as frogs and
turtles.
Two aquifers exist beneath the Site. The overburden aquifer is
an unstratified drift deposit consisting of a mixture of clay,
silt, sand, gravel, and boulders which widely range in size,
shape, and permeability. The bedrock aquifer generally consists
of moderately fractured quartz-plagioclase gneiss, hornblende-
feldspar gneiss, and amphibolite.
A review of existing flood insurance maps indicated that no
portions of the Site are located in either the 100- or 500- year
flood zone.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
The Site was owned and farmed by the-Penaluna family from 1898 to
the mid-1950s, when the Town of Warwick leased the property from
the Penaluna family and utilized it as a refuse disposal area.
The facility accepted waste from the Town of Warwick, which
includes the Villages of Florida, Warwick and Greenwood Lake, and
other surrounding towns in Orange County. Evidence indicates
that there was some industrial waste disposed of at the landfill
during this time. The Town of Warwick operated the landfill
until 1977.
In April 1977, the Site was leased from the property owner, Mrs.
Millie Mae Penaluna, by Grace Disposal and Leasing, Ltd. ("Grace
Disposal"), Harriman, New York. On July 15, 1977, Grace Disposal
was granted a permit to operate the refuse disposal area by the
Orange County Department of Health ("OCDOH"). Under Grace
Disposal's operation, municipal wastes and industrial
wastes/sludges were disposed of in the landfill.
In 1978, the State of New York took over the regulation of
landfills from the counties. In February, 1978, Grace Disposal
submitted an application to NYSDEC to operate the Warwick
Landfill. A Draft Environmental Impact Statement ("DEIS") was
compiled for a NYSDEC Solid Waste Management Facility operation
permit at the Site by P. Joseph Corless, Consulting Engineers,
Inc. on December 27, 1978. The DEIS findings indicated that
approximately 300,000 cubic yards of refuse per year were handled
at the landfill for an unspecified duration. It also concluded
that leachate and surface run-off generated at the Site did not
measurably affect surface water and groundwater in the area, and
also, that the water quality of the stream which drains the
wetland area south of the Site was in compliance with New York
State Surface Water Standards. However, the NYSDEC requested
additional information from the applicant which included the
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drilling and water sampling of on-site monitoring wells and
boring and analyses of on-site soils.
In 1979, in response to concerns of local citizens who had
reported observations of suspicious dumping activities at the
landfill, the NYSDEC and the EPA collected and analyzed two
leachate samples at the Site. The results indicated the presence
of heavy metals, phenols, and various volatile organic compounds,
some of which exceeded the New York State Drinking Water
Standards and the USEPA National Primary Drinking Water
Regulations.
Based on the results of these samples and that Grace Disposal did
not perform the additional tasks necessary for the submittal of
an adequate DEIS within a reasonable time period, the application
to operate the landfill was denied by NYSDEC on September 4,
1979, and the landfill was ordered to be closed.
Pursuant to a New York State court order, the Site was covered,
graded, and closed by Grace Disposal. On June 11, 1980, NYSDEC
was notified that a Certificate of Dissolution had been filed by
Grace Disposal.
In 1984, ownership of the property was transferred to Orange
County for non-payment of back taxes. It was conveyed from
Orange County to Newburgh N.Y. Developers in November 1986. In
1987, the property was transferred to the current owners, L and B
Developers, Inc.. On March 22, 1991 a federal lien was filed at
the Orange County Courthouse, Goshen, New York which secures
payment to the United States of all costs and damages for which L
and B Developers, Inc. is liable to the United States pursuant to
Section 107(a) of CERCLA, 42 U.S.C. §9607(a).
In March 1985, a field investigation program was performed by
Woodward-Clyde Consultants, Inc. for the NYSDEC. The information
generated was utilized to prepare a Hazard Ranking System ("HRS")
assessment of the site. Based upon the HRS score, the Site was
proposed for inclusion on EPA's National Priorities List ("NPL")
of uncontrolled hazardous waste sites in 1985 and was added to
the NPL in March 1989.
On December 28, 1988, special notice letters were sent to
fourteen entities who were determined at that time to be
potentially responsible parties ("PRPs") at the Site. These
entities were: All County Environmental Services Corporation;
All County Resource Management Corporation; Ford Motor Company;
Grace Disposal & Leasing, Ltd.; Instrument Systems
Corporation/Lightron Corporation; International Paper; I.S.A. of
New Jersey, Inc.; L & B Developers; Jones Chemicals; Nepera,
Inc.; New York University Medical Center; Reichold Chemicals,
Inc.; Round Lake Sanitation Corporation; and Union Carbide
Corporation. The special notice letters informed these parties
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of their potential liability at the Site and offered them the
opportunity to undertake the RI/FS for the Site. The PRPs were
given sixty days from receipt of notice to submit a good faith
offer. .
Since EPA did not receive any good faith proposals from the PRPs
to undertake or finance the Remedial Investigation/Feasibility
Study ("RI/FS"), EPA contracted Ebasco Services, Incorporated to
perform the RI/FS using monies from the Superfund ("the Fund").
Field work for the RI/FS began in August 1989 and was completed
in February 1991.
Based upon information received through responses to information
request letters, EPA sent general notice letters on February 27,
1991 to Georgia Pacific Corporation and the Town of Warwick,
informing them of their status as PRPs.
HIGHLIGHTS OF COMMUNITY PARTICIPATION
The RI/FS reports and the Proposed Plan ("PP") for the Site were
released for public comment on February 25, 1991. These
documents were made available to the public in the administrative
record file at the EPA Docket Room in Region II, New York and the
information repositories at the New York State Department of
Environmental Conservation, Albany, New York, the Warwick Town
Hall, Warwick, New York and Greenwood Lake Village Hall,
Greenwood Lake, New York. A press release announcing the
availability of these documents was issued on February 25, 1991.
The public comment period was set by EPA to end on March 26,
1991.
Two extensions to the public comment period were requested by the
Dutch Hollow Homeowners' Association ("DHHA"), the Technical
Assistance Grant ("TAG") recipient, at the Site. First, a thirty
day extension to the public comment period was granted. Second,
a two week extension was granted. These extensions were granted
to afford the DHHA's technical advisor sufficient opportunity to
review and comment on the RI/FS and PP. The public comment period
closed on May 9, 1991.
During the public comment period EPA held a public meeting to
present the RI/FS reports and the Proposed Plan, answer
questions, and accept both oral and written comments. The public
meeting was held in the cafeteria of the Greenwood Lake Middle
School, Greenwood Lake, New York on April 22, 1991. At this
meeting, representatives from the EPA, the NYSDEC and the New
York State Department of Health ("NYSDOH") answered questions
about problems at the Site and the remedial alternatives under
consideration and received comments from the local citizens and
the Technical Advisor Grant ("TAG") consultants. Responses to
the comments received during the public comment period are
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included in the Responsiveness Summary (see Appendix V).
SCOPE AND ROLE OF OPERABLE UNIT
EPA has divided the remedial work necessary to mitigate both off-
site and on-site contamination stemming from the Site into two
operable units. The first operable unit addresses the control of
the source of contamination at the Site and is the focus of this
document.
The purpose of the response action under OU1 is to: 1) minimize
the infiltration of rainfall and snow melt into the landfill,
which will reduce the quantity of water percolating through the
landfill materials and leaching out contaminants; 2) eliminate
the risk to area residents associated with contaminated
groundwater ingestion and exposure; 3) minimize any further
contamination of the wetlands and drainage channels which feed
into Greenwood Lake; and 4) reduce the movement and toxicity of
the contaminated landfill leachate, thereby reducing downgradient
migration of contaminants.
Although the results of the RI/FS indicate the possible need for
on-site groundwater remediation, the extent and direction of the
groundwater plume could not be delineated. The second operable
unit ("OU2") will allow for further characterization of the fate
and transport of the contaminants emanating from the Site and
will serve as the basis for the decision on a final groundwater
remedy. In addition, the impacts of site contamination on the
adjacent wetlands will be monitored and a detailed environmental
assessment will be performed under OU2. .
This response action will utilize permanent solutions and
alternative treatment technologies to the maximum extent
practicable. However, because the treatment of the principal
threats of the Site is not practicable, this response action does
not satisfy the statutory preference for treatment as a principal
element of the remedy. The size of the landfill, and the fact
that the RI did not identify on-site hot spots in the soil that
represent the major sources of contamination, preclude a remedy
in which contaminants could be excavated and treated effectively.
SUMMARY OF SITE CHARACTERISTICS
The Warwick Landfill was used for the disposal of municipal solid
waste (MSW) from the late 1950s until its closure in 1980.
During the late 1970s, according to observations of surrounding
landowners, suspicious dumping activities, including disposal of
hazardous wastes, took place at the Site. Information available
to EPA indicates that hazardous wastes were disposed of at the
Site.
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Upwards to 60 feet of landfill material exists in some areas of
the Site. Under the Town of Warwick's operation, it is estimated
that 300,000 cubic yards of refuse per year were disposed of at
the Site. Aerial photographs show that the landfill increased
significantly in size under Grace Disposal's operation of the
landfill in the late 1970s.
The study area for the RI/FS of OU1 was divided into
environmental areas presenting on-site, background, upgradient,
and downgradient locations, with background conditions not
considered to be within the groundwater flow path as related to
the Site. The locations of these sampling stations are
graphically displayed in Figure 2.
Groundwater
As part of the groundwater investigation, a total of fifteen
monitoring wells were installed. Eight wells were installed in
the overburden aquifer and seven in the bedrock aquifer. Three
rounds of groundwater sampling were conducted. The groundwater
samples were analyzed for volatile organics, semi-volatile
organics, pesticides and PCBs, inorganics and standard water
quality parameters. Contaminants in the groundwater exceeding
federal and/or State maximum contaminant levels are summarized in
Table 1.
Because of the complex nature of the geology at the Site, which
includes both fractured and weathered bedrock, the direction of
groundwater flow was not fully ascertained under OU1. Groundwater
in both the overburden and bedrock aquifers appears to discharge
into the southeastern wetlands which lies adjacent to the
landfill.
Overburden Aquifer
Eight volatile compounds were detected in the overburden
aquifer. Well depths in the overburden aquifer ranged from
six feet (WL-7Sa) to 72 feet (WL-7Sb). The maximum
concentrations were detected at monitoring well WL-2S (well
depth 10 feet) which is located immediately adjacent to the
northwest boundary of the landfill. At this location the
highest levels were detected for chloromethane and
trichloroethene, both exceeding State maximum contaminant
levels ("MCLs"), No pesticide/PCB compounds were detected
in any of the overburden wells. Semi-volatile contamination
was limited to the phthalate compounds and did not exceed
MCLs.
Ten of the twenty-two metals detected in the overburden
wells exceeded State MCLs. Additionally, two metals
(antimony and beryllium) exceeded Federal proposed maximum
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contaminant level goals ("MCLGs") and nickel exceeded the
Federal Proposed MCL. The maximum concentrations of 15 of
the 22 metals detected were observed in the third round
sample collected at monitoring well WL-7Sa (well depth six
feet) which is located northwest of the landfill.
Concentration levels similar to those at WL-7Sa third round
data were also observed in the third round sample collected
at WL-8S (well depth 47 feet) which is located west of the
landfill. Additional sampling will be conducted in these
wells as part of the OU2 investigation.
Bedrock Aquifer
Thirty volatile compounds were detected in the on-site and
downgradient bedrock groundwater. Well depths in the
bedrock aquifer ranged from 33 feet (WL-3D) to 120 feet
(WL-8D). Benzene, chloromethane, 1,4-dichlorobenzene,
ethylbenzene, isopropylbenzene and total xylenes exceeded
MCLs. No pesticide/PCB compounds were detected. Three
semi-volatile contaminants were detected; two in the on-site
downgradient groundwater (BEHP and 2-methylnaphthalene) and
one in the background groundwater (di-n-butylphthalate).
None were at levels above MCLs. Six metals: barium,
chromium, iron, lead, manganese and mercury exceeded State
MCLs; antimony exceeded the federal MCLG of 3.0 ug/1 and
nickel exceeded the federal proposed MCL of 100 ug/1.
Residential wells
A total of forty-two area residential wells were sampled by EPA
and NYSDOH. The results identified contamination above state
and/or federal MCLs in three residential wells located
geographically northeast of the Site. All wells are believed to
be bedrock wells drilled to significant depths ( >200 feet). RW-
04, which is within 300 feet of the northeastern edge of the
Site, showed the highest level of residential well contamination
and exceeded state MCLs for 1,1,1-trichloroethane and 1,1-
dichloroethane, and both the state and federal MCL for 1,1-
dichloroethene. Although it has not been determined whether the
residential well contamination is site-related, the pumping of
residential wells may induce the flow of contaminants from the
landfill towards these wells through bedrock fractures.
Surface Water
The highest levels of organic compound contamination in the Site
surface water were observed at sampling locations in the vicinity
of the landfill which included on-site leachate samples L-l, L-2,
L-3, and surface water sample SW-1. Eighteen volatile organic
compounds were detected, of which 16 were detected in the on-site
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samples and 6 in the downgradient samples. Chlorobenzene, in
particular, was detected at a concentration greater than the 5.0
ug/1 NY Class "A" Standard for surface waters at every location
except leachate sample location L-3. Phenol and 4-methyl phenol,
ranging in concentration from 4.0 ug/1 to 65 ug/1, were also
detected above the 5.0 ug/1 NY Class "A" Standard at leachate
sample location L-3.
Of the pesticide/PCB compounds analyzed, only a single detection
of aldrin was observed at on-site leachate sample location L-3,
exceeding the 0.001 ug/1 NY Class "C" Standard. Nine metals
exceeded NY Class "A" or "C" Standards in the on-site surface
water, including aluminum, barium, cobalt, iron, lead, magnesium,
manganese, vanadium and zinc. A summary of contaminants
exceeding legally applicable or relevant and appropriate
requirements ("ARARs") is found in Table 2.
Sediments
Sediment sampling, as for surface water, focused in the area
surrounding the Site in order to evaluate horizontal migration of
contamination off-site. Sediment contamination was limited to
phthalate and PAH compounds. A total of 18 PAH compounds were
detected, of which 9 are considered carcinogenic and 9 are non-
carcinogenic. Concentrations were observed to be highest in the
downgradient sediments. This observation is suspected to be the
result of road re-surfacing operations in the vicinity of the
sample locations. Background concentrations of PAHs, when
totalled, exceeded on-site sediment concentration. All on-site
wetland metal results exceeded site background concentrations.
Table 3 presents a summary of the analytical results.
Soils
Soil sampling data is divided into the unsaturated and saturated
zone soils to evaluate the vertical migration of contamination
emanating from the Site into the groundwater. Three of the soil
borings were drilled into the landfill mound. Table 4 presents a
summary of the contaminants of concern detected in the landfill
soils.
Several volatile compounds were detected in landfill soil samples
in both the saturated and unsaturated zones. Landfill soil
boring SB-14, located in the north-central area of the landfill
mound, was observed to have the highest concentration of these
compounds. Three polychlorinated dibenzo-p-dioxins (PCDDs) and 3
poly-chlorinated dibenzofurans (PCDFs) compounds were detected in
the landfill unsaturated zone samples at below health based risk
levels. The congener exhibiting the highest human health risk
(2,3,7,8-TCDD) was not detected. Metals in the landfill soils
8
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generally exceeded off-site background concentrations. Antimony
and lead were seen in highest concentrations in SB-14 (antimony:
15.6 mg/kg and lead: 176 mg/kg).
GEOPHYSICAL INVESTIGATION
A geophysical investigation, which included a magnetic
gradiometer survey and terrain conductivity screening, was
conducted at the Site to identify areas within the landfill where
buried drums might be present. Based on the results of this
investigation, three test pits were excavated to observe the
landfill material. Nothing other than debris typical of
municipal landfills was observed in the fill material excavated.
No buried drums were located.
The potential for direct human exposure as well as the potential
for further contaminant migration to groundwater and surface
water exists at the Site. There are no permanent controls in
place to prevent contaminant migration.
SUMMARY OF SITE RISKS
EPA conducted a baseline Risk Assessment to evaluate the
potential risks to human health and the environment associated
with the Warwick Landfill Site in its current state. The Risk
Assessment focused on contaminants in the groundwater, surface
water, sediment and soil which are likely to pose significant
risks to human health and the environment. The summary of the
contaminants of concern (COC) in sampled matrices is listed in
Table 5.
EPA's Risk Assessment identified several potential exposure
pathways by which the public may be exposed to contaminant
releases at the Site under current and future land-use
conditions. Groundwater, surface water and sediment exposure
were assessed for both potential present and future land use
scenarios. These exposure pathways were evaluated separately for
adults and children. In addition, exposure to soils for on-site
residents and workers, in the future event of residential
development and/or construction activities on the landfill, was
evaluated. A total of nine exposure pathways were evaluated
under possible on-site future land use conditions. The exposure
pathways considered under future uses are listed in Table 6. Two
estimates were developed, corresponding to reasonable maximum and
reasonable average exposures.
Under current EPA guidelines, the likelihood of carcinogenic
(cancer causing) and non-carcinogenic effects due to exposure to
site chemicals are considered separately. It was assumed that
the toxic effects of the site-related chemicals would be
additive. Thus, carcinogenic and non-carcinogenic risks
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associated with exposures to individual compounds of concern
were summed to indicate the potential risks associated with
mixtures of potential carcinogens and non-carcinogens,
respectively.
Non-carcinogenic risks were assessed using a hazard index ("HI")
approach, based on a comparison of expected contaminant intakes
and safe levels of intake (Reference Doses). Reference doses
("RfDs") have been developed by EPA for indicating the potential
for adverse health effects. RfDs, which are expressed in units
of mg/kg-day, are estimates of daily exposure levels for humans
which are thought to be safe over a lifetime (including sensitive
individuals). Estimated intakes of chemicals from environmental
media (e.g.. the amount of a chemical ingested from contaminated
drinking water) are compared with the RfD to derive the hazard
quotient for the contaminant in the particular medium. The
hazard index is obtained by adding the hazard quotients for all
compounds across all media.
A hazard index greater than 1 indicates that the potential exists
for non-carcinogenic health effects to occur as a result of site-
related exposures. The HI provides a useful reference point for
gauging the potential significance of multiple contaminant
exposures within a single medium or across media. The reference
doses for the compounds of concern at the Warwick Landfill site
are presented in Table 7. A summary of the non-carcinogenic
risks associated with these chemicals across various exposure
pathways is found in Table 8.
It can be seen from Table 8 that the HI for non-carcinogenic
effects from ingestion of the groundwater (reasonable maximum
exposure for children) is 31, therefore, non-carcinogenic effects
may occur from the exposure routes evaluated in the Risk
Assessment. The non-carcinogenic risk was attributable to
several compounds including arsenic, manganese and antimony
detected in the overburden aquifer in the on-site monitoring
wells and not the residential wells.
Potential carcinogenic risks were evaluated using the cancer
potency factors developed by EPA for the compounds of concern.
Cancer slope factors (SFs) have been developed by EPA's
Carcinogenic Risk Assessment Verification Endeavor for estimating
excess lifetime cancer risks associated with exposure to
potentially carcinogenic chemicals. SFs, which are expressed in
units of (mg/kg-day)"1, are multiplied by the estimated intake of
a potential carcinogen, in mg/kg-day, to generate an upper-bound
estimate of the excess lifetime cancer risk associated with
exposure to the compound at that intake level. The term "upper
bound" reflects the conservative estimate of the risks calculated
from the SF. Use of this approach makes the underestimation of
the risk highly unlikely. The SF for the compounds of concern
are presented in Table 9.
10 f
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For known or suspected carcinogens/ EPA considers excess upper
bound individual lifetime cancer risks of between ID"4 to 10* to
be acceptable. This level indicates that an individual has not
greater than a one in ten thousand to one in a million chance of
developing cancer as a result of site-related exposure to a
carcinogen over a 70-year period under specific exposure
conditions at the Site. At present, New York State is supplying
three residences with bottled water and has attached carbon
filtration units to their wells because of the elevated levels of
volatile organics detected in their wells. The maximum potential
total excess lifetime cancer risk for a child using the highest
levels of contaminants detected in the contaminated residential
wells is 1.99 x 10"*? the HI for this pathway is 3.91, which is
unacceptable.
The cumulative upper bound cancer risk at the Warwick Landfill
site is 4.98 x 10"*. Hence, the risks for carcinogens at the Site
are at the high end of the acceptable risk range of 10"* to 10"6
(see Table 10). The estimated total risks are primarily due to
ingestion of unfiltered groundwater, which contributed 3.94 x 10"1
to the carcinogenic risk calculations and was attributable to
beryllium and 1,1-dichloroethene. The calculations were based on
the contaminants detected in on-site monitoring wells, and not
the residential wells. It was assumed that in the future, these
wells would be used for residential purposes. Exposure of
residents to groundwater volatiles while showering, utilizing
reasonable maximum exposure conditions, contributed 9.79 x 10"5 to
the total cancer risk. Reasonable maximum adsorption conditions
due to wading in the surface water contributed 3.60 x 10"6 and
ingestion of the landfill soils by children playing on the Site
contributed 5.06 x 10'7 to the total cancer risk. These estimates
were developed by taking into account various conservative
assumptions about the likelihood of a person being exposed to
these media. For example, it was assumed that the Site
contaminant plume will migrate downgradient to residential wells.
Uncertainties
The procedures and inputs used to assess risks in this
evaluation, as in all such assessments, are subject to a wide
variety of uncertainties. In general, the main sources of
uncertainty include:
- environmental chemistry sampling and analysis
- environmental parameter measurement
- fate and transport modeling
- exposure parameter estimation
- toxicological data
Uncertainty in environmental sampling arises in part from the
potentially uneven distribution of chemicals in the media
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sampled. Consequently, there is significant uncertainty as to
the actual levels present. Based on a detailed review of the
Warwick Site groundwater data for representativeness, precision,
completeness, comparability and accuracy as per EPA's Guidance
document Data Usability in Risk Assessment (October 1990), one
sample, the third round inorganic analysis of well WL-7Sa was
eliminated from this risk assessment because it did not
accurately reflect the site characteristics based on the two
previous sampling efforts. Environmental chemistry analysis
error can stem from several sources including the errors inherent
in the analytical methods and characteristics of the matrix being
sampled.
Uncertainties in the exposure assessment are related to estimates
of how often an individual would actually come in contact with
the chemicals of concern, the period of time over which such
exposure would occur, and in the models used to estimate the
concentrations of the chemicals of concern at the point of
exposure.
Uncertainties in toxicological data occur in extrapolating both
from animals to humans and from high to low doses of exposure, as
well as from the difficulties in assessing the toxicity of a
mixture of chemicals. These uncertainties are addressed by
making conservative assumptions concerning risk and exposure
parameters throughout the assessment. As a result, the Risk
Assessment provides upper bound estimates of the risks to
populations near the Landfill, and is highly unlikely to
underestimate actual risks related to the Site.
More specific information concerning public health risks,
including a quantitative evaluation of the degree of risk
associated with various exposure pathways, is presented in the Rl
Report.
Actual or threatened releases of hazardous substances from this
site, if not addressed by the selected alternative or one of the
other remedial measures considered, may present an imminent and
substantial endangerment to the public health, welfare, and the
environment through the continued leaching of contaminants from
the landfill.
ENVIRONMENTAL ASSESSMENT
The environmental assessment evaluated potential exposure routes
of the Site contamination to terrestrial wildlife and aquatic
life. However, because of the low concentrations of contaminants
detected, lack of potential bioaccumulation, absence of fishing
and other recreational activity, the environmental assessment was
not quantified. The wetlands in the vicinity of the Site were
delineated. The need to minimize the disturbance of these
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wetlands habitats via migration of contaminants from the
landfill, as well as via any future remediation activities, was
identified as an important factor to be considered in both the
selection and design of the Site remedy. Further environmental
efforts, including studies of the emergent vegetation portion of
the southeastern wetlands and a full delineation of the
northwestern wetlands, will be performed under OU2 for the Site
and before the commencement of remediation activities at the
Site.
DESCRIPTION OF ALTERNATIVES
Following a screening of remedial technologies in accordance with
the NCP, the following remedial alternatives were developed for
the Site. The alternatives were further screened based on
technical considerations such as effectiveness, implementability,
and cost. The time to implement reflects only the actual
construction or implementation time. It does not include the
time required to negotiate with PRPs, procure design and
construction contracts and design the selected remedy, all of
which may take from 18 to 30 months.
These alternatives are:
Alternative 1: No Action
Capital Cost: $6,800
0 & M Cost: $55,500/yr
Present Worth Cost: $887,800
Time to Implement: 1 month
The Superfund program requires that the no-action alternative be
considered as a baseline for comparison with the other
alternatives;; The no-action alternative does not include any
physical remedial measures that address the contamination at the
Site.
»
This alternative would consist of a long-term groundwater
monitoring program that would provide data for the assessment of
the impact of leaving contaminated materials on-site on the
underlying groundwater. This program would utilize existing
wells which were installed during the remedial investigation at
the Site. Groundwater samples would be taken on a quarterly
basis.
In addition, the no-action alternative would include the
development and implementation of a public awareness and
education program to enhance the community's knowledge of the
conditions existing at the Site. This alternative would require
the involvement of the local government, various health
departments and environmental agencies.
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Under this alternative, the Site would be reviewed no less often
than each five years pursuant to CERCLA requirements. Using data
from the groundwater sampling program, these five year reviews
would include the reassessment of health and environmental risks
due to the contaminated material left on-site. If justified by
the review, remedial actions may be implemented to remove or
treat the wastes.
Alternative 2: Limited Action/Point of Use Treatment
Capital Cost: $223,300
0 & M Cost: $176,100/yr (yrs 1-3),
$ 62,700/yr (yrs 4-30)
Present Worth Cost: $1,523,800
Time to Implement: 4-6 months
As with Alternative 1, the limited-action alternative would
include a groundwater monitoring program and a public awareness
program. However, this alternative would also provide for
restricted site access and controlled point-of-groundwater-use
treatment.
A chain link fence would surround the perimeter of the Site,
thereby restricting access. Warning signs would be placed that
would caution the public as to the Superfund status of the Site.
We would recommend that institutional controls in the form of
local ordinances be developed to restrict future use of the land
because of the threat of contamination.
A residential well survey and sampling plan would be undertaken
in the immediate site area. Point-of-use treatment systems would
be installed on to residential wells where contaminants detected
above allowable drinking water standards are found in the well
water. Based on the previous results of the residential well
samples collected by EPA and the New York State Department of
Health ("NYSDOH") during the RI, small, low flow granular
activated carbon treatment units would be used. This would allow
for the removal of organics and would be installed in the well
pump discharge piping before the water enters into domestic use.
For the purposes of developing a conservative cost estimate, it
has been assumed that 42 residential wells would receive carbon
filtration units and be sampled on a semi-annual basis for three
years. The actual monitoring plan would be coordinated with the
OU2 groundwater investigation. As noted above, the OU2
investigation would serve as the basis for the final remedy for
the treatment of contaminated groundwater and provision of a
potable drinking water supply, if necessary.
As with Alternative 1, a review of the Site's status would be
conducted no less often than each five years.
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Alternative 3: Capping/Point of Use Treatment
Capital Cost: $7,442,000
O & M Cost: $526,300/yr (yrs 1-3),
$422,900/yr (yrs 4-30)
Present Worth Cost: $14,279,600
Time to Implement: 18-24 months
The major feature of Alternative 3 would be the construction of a
multi-layer closure cap over the landfill mound. This would
minimize the infiltration of rainfall or snow melt into the
landfill and reduce the movement of the contaminated leachate to
the groundwater.
The landfill mound surface area, including the side slopes, is
estimated to be 22 acres. It is currently covered with less than
6 inches of soil. This layer is beginning to show the effects of
erosion and previously buried materials are starting to become
exposed. Prior to construction of the cap, the landfill mound
would have to be regraded and compacted to provide a stable
foundation for placement of the various layers of the cap.
The design of the cap would comply with the standards of Title 6,
New York State Compilation of Rules and Regulations (NYCRR), Part
360, which addresses New York State Solid Waste Management
Facilities and landfill closure requirements. The main feature
of landfill closure is the placement of a highly impermeable cap
over the landfill to reduce the infiltration of water into the
fill. The cap would include allowances for the installation of
gas vents necessary for the escape of methane generated by the
decomposition of landfill materials. The use of an active or
passive landfill venting system would be determined during the
remedial design. The cap would also provide for groundwater
monitoring wells within the landfill mound. These wells would be
utilized to provide groundwater samples for analyses to clearly
show the effect of groundwater flow through the saturated portion
of the landfill materials on the surrounding aquifers.
The surface of the constructed cap would be graded to allow for
precipitation and snow melt runoff to be directed to the existing
drainage channels around the perimeter of the landfill mound.
These natural channels should have adequate capacity to handle
the extra flow. These intermittent streams follow differing
routes, but eventually feed into the Greenwood Lake drainage
basin.
As mentioned, groundwater monitoring wells would be installed
within the landfill mound. Groundwater samples would be
collected for analyses to evaluate the effect of the cap on the
groundwater flow through the saturated portion of the landfill
materials on the surrounding aquifer. Emissions from landfill
gas vents would also be monitored. --
15 +
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This alternative would also include the supply of point-of-use
treatment systems, the installation of a security fence
surrounding the perimeter of the Site, institutional controls
restricting future use of the Site, and the implementation of a
groundwater monitoring program (see Alternative 2) . In addition,
a review of the Site's status would be conducted no less often
than each five years.
Alternative 4: Capping/Groundvater Pumping and Treatment/Chemical
Precipitation/Carbon Adsorption/Point of Use Treatment
Capital Cost: $8,779,900
0 & M Cost: $759,000/yr (yrs 1-3),
$645,600/yr (yrs 4-30)
Present Worth Cost: $19,013,100
Time to Implement: 2-2 1/2 Years
This alternative is identical to Alternative 3, with the addition
of an extensive groundwater pumping system within the landfill
mound to control leachate migration.
The groundwater extraction system would consist of a series of
pumping wells installed around the inside of the landfill
perimeter. The groundwater pumping wells would extend through
the landfill material and end at bedrock. They would be screened
through the entire saturated length. It is estimated that
approximately 21 extraction wells would be required to provide
optimum capture of the contaminated groundwater beneath the
landfill. These wells would produce an estimated total removal
rate of 20 gallons per minute or 28,800 gallons per day. These
estimates, presented in detail in the FS report, would be field
verified via performance of an aquifer pumping test during the
remedial design.
The groundwater collected would be treated in an on-site
treatment system. This treatment system would use chemical
precipitation and flocculation followed by sedimentation to
remove metals and suspended solids. A carbon adsorption system
would be utilized to remove organic compounds.
The organic compounds and metals present in the extracted
groundwater would be treated to concentrations which are below
the site-specific surface water discharge standards which would
be determined in accordance with the New York State Pollutant
Discharge Elimination System ("SPDES"). It is expected that the
effluent groundwater would be discharged to the adjacent wetlands
unless detrimental impacts would result from such an action.
Other discharge options, such as reinjection, would be evaluated
during the design of the remedy.
Under Alternative 4, solids are expected to accumulate at a rate
of approximately 500-510 pounds per day, wet weight, for a total
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annual accumulation of 92 tons. Treatment residues generated
would be disposed of in accordance with Resource Conservation and
Recovery Act ("RCRA") Land Disposal Restriction requirements.
This alternative would also include the supply of point-of-use
treatment systems, the installation of a security fence
surrounding the perimeter of the Site, institutional controls
restricting future use of the Site, and the implementation of a
groundwater monitoring program (see Alternative 2). In addition,
a review of the Site's status would be conducted no less often
than each five years.
Alternative 5: Capping/Subsurface Barrier/Groundwater Pumping
and Treatment/Chemical Precipitation/Carbon Adsorption/Point of
Use Treatment
Capital Cost: $15,811,300
O & M Cost: $l,032,000/yr (yrs 1-3),
$ 918,600/yr (yrs 4-30)
Present Worth Cost: $30,241,300
Time to Implement: 2-2 1/2 years
This alternative is similar to Alternative 4, with the addition
of a subsurface barrier.
The subsurface barrier would consist of a grout curtain along the
northeast section of the landfill and a slurry wall used in
combination with a grout curtain to enclose the remainder of the
landfill. The grout curtain northeast of the landfill would
extend approximately 100 feet into bedrock. The remainder of the
grout curtain would extend approximately" twenty feet into the
rock; fifteen feet into weathered bedrock and five feet into
competent rock.
The slurry wall would be placed above the shallow (approximately
twenty feet deep) grout curtain within the overburden material
adjacent to the landfill mound. The slurry wall would be
constructed as a vertical trench, typically a mixture of soil-
bentonite or cement-bentonite backfill.
Groundwater pumping would be conducted inside the slurry wall
perimeter to create an upward hydraulic gradient to prevent
dissolved contaminants from migrating downward into deeper
aquifer zones. The groundwater would then be treated for removal
of heavy metals through a chemical precipitation process prior to
treatment with activated carbon and discharge to the adjacent
wetlands, in accordance with SPDES requirements. Treatment
residuals would be handled in the same manner as those generated
under Alternative 4.
This alternative would also include the supply of point-of-use
treatment systems, the installation of a security fence
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surrounding the perimeter of the Site, institutional controls
restricting future use of the Site, and the implementation of a
groundwater monitoring program (see Alternative 2). In addition,
a review of the Site's status would be conducted no less often
than each five years.
SUMMARY 07 COMPARATIVE ANALYSIS OF ALTERNATIVES
All remedial alternatives were evaluated in detail utilizing nine
criteria as set forth in the NCP and OSWER Directive 9355.3-01.
These criteria were developed to address the requirements of
Section 121 of CERCLA to ensure all important considerations are
factored into remedy selection decisions.
The following "threshold" criteria are the most important and
must be satisfied by any alternative in order to be eligible for
selection:
Threshold Criteria o Overall protection of human health and
the environment; and
o Compliance with applicable or relevant
and appropriate requirements.
The following "primary balancing" criteria are used to make
comparisons and to identify the major trade-offs between
alternatives:
Primary Balancing o Long-term effectiveness and permanence;
Criteria o Reduction in toxicity, mobility, or
volume through treatment;
o Short-term effectiveness;
o Implementability; and
o Cost.
The following;"modifying" criteria are considered fully after the
formal public comment period on the Proposed Plan is complete:
Modifying Criteria o State/support agency acceptance; and
o Community acceptance.
The nine criteria are summarized below:
1. 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.
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2. Compliance with ARARs addresses whether or not a remedy
would meet all of the applicable or relevant and appropriate
requirements of federal and state environmental statutes and
requirements or provide grounds for invoking a waiver.
3. 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.
4. Reduction of toxicity, mobility, or volume through treatment
is the anticipated performance of a remedial technology,
with respect to these parameters, that a remedy may employ.
5. 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 periods until cleanup goals
are achieved.
6. Implementability is the technical and administrative
feasibility of a remedy, including the availability of
materials and services needed.
7. Cost includes estimated capital and operation and
maintenance costs, and the present worth costs.
8. State acceptance indicates whether, based on its review of
the RI/FS and the Proposed Plan, the State supports,
opposes, and/or has any identified reservations with the
preferred alternative.
9. Community acceptance refers to the public's general response
to the alternatives described in the Proposed Plan and the
RI/FS reports. Factors of community acceptance to be
discussed include support, reservation, and opposition by
the community.
A comparative analysis of these alternatives based upon the
evaluation criteria noted above, are as follows:
Overall Protection of Human Health and the Environment
Alternatives 1 and 2 do not favorably address the remedial action
objectives developed for the Site and do not contain any measures
for mitigation of groundwater or surface water contamination. In
addition, Alternative 1 does not provide any protection for human
health and the environment. Alternative 2, as well as
Alternatives 3, 4 and 5, would reduce groundwater exposure risk
to local residents via private water supply treatment units, and
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would be protective of human health for the current water users.
The closure cap system of Alternatives 3, 4 and 5 provides a
partial solution to the problems at the Site because the cap
would eliminate infiltration of rainfall or snow melt into the
landfill, thus reducing the quantity of water percolating through
the landfill materials and leaching out contaminants. The cap
would also eliminate existing leachate seeps and prevent the
formation of contaminated surface leachate seeps emanating from
within the landfill mound, flowing into the natural drainage
channels and contaminating nearby surface water. Alternative 3
does not include any direct groundwater control or remediation
measures; therefore, the contaminated groundwater would remain
unaffected. However, the private treatment units proposed in
Alternatives 2-5 would eliminate current risks associated with
contaminated groundwater ingestion and exposure. The monitoring
of these units would be coordinated with the OU2 groundwater
investigation.
The extensive extraction and treatment system of Alternatives 4
and 5 would provide a reduction in the quantity of contaminated
groundwater generated, via the cap, and would control the
movement and toxicity of the contaminated landfill leachate
groundwater by pumping out and treating this water and preventing
its downgradient migration.
The impermeable subsurface barrier recommended in Alternative 5
would divert overburden groundwater flow around the contaminated
material, thereby reducing the volume of groundwater coming into
contact with the contaminant source while minimizing migration of
contaminants into the overburden and bedrock aquifers.
Compliance with ARARs
Alternative 1 would not meet any of the chemical-specific ARARs,
because it does not include any contaminant mitigation or control
measures. Alternatives 2 and 3 include treatment only for
private potable water supplies, thereby providing potable water
in compliance with drinking water standards. Alternatives 3, 4,
and 5 will comply with New York State Part 360 closure
requirements.
The groundwater pumping, treatment and discharge system of
Alternatives 4 and 5 would meet the action-specific ARARs for
discharge of the treated groundwater. These alternatives would
not address chemical specific ARARs, such as MCL/MCLGs, in the
groundwater; these will be addressed under the OU2 groundwater
investigation. All location-specific ARARs would be complied
with during implementation of any of the alternatives. Disposal
of residuals under Alternatives 4 and 5 would comply with all
ARARs related to off-site transport, handling and disposal.
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Lona-Tenn Effectiveness and Permanence
Alternatives 4 and 5 would reduce the continued migration of
contaminants into the groundwater. Although the groundwater
treatment facility could be designed for continuous long-term
use, there are concerns regarding the effectiveness of the
pumping and treatment of the groundwater due to the fractured
bedrock and complex hydrogeological conditions existing beneath
the Site.
The monitoring and replacement of the point-of-use treatment
units in Alternatives 2-5 would ensure that residents would
have a potable water supply until a decision on a final
groundwater remedy is made under OU2. The OU2 investigation will
evaluate the need for and methods of restoring the aquifers to
their best beneficial use.
The closure cap proposed in Alternatives 3, 4 and 5 is a
permanent technology that would be maintained at regular
intervals to ensure its structural integrity and impermeability.
In addition, the cap would provide for long-term elimination of
stormwater and snow melt infiltration into the landfill.
Alternative 2 would provide for private potable water supply well
treatment, but includes no further measures to control or
remediate site contamination. Alternative 1 does not include any
measures for containing, controlling or eliminating any of the
on-site contamination, or reducing the potential of exposure to
the contaminated landfill materials.
Reduction in Toxicity. Mobility, or Volume
Alternatives 1 and 2, the no-action and limited-action
alternatives, do not contain any remedial measures which would
reduce the toxicity, mobility or volume of the groundwater
contamination. However, the limited-action alternative addresses
measures for reduction of risk to residents related to exposure
to contaminants in the groundwater via filtration units.
Alternatives 3, 4, and 5 provide measures to reduce the mobility
of contaminants by reducing the amount of water infiltrating into
the landfill. The formation of contaminated surface leachate
seeps, which have caused nearby surface water contamination,
would be eliminated.
Implementation of Alternatives 4 and 5 would have the greatest
impact on the toxicity, mobility and volume of the contaminated
groundwater by preventing precipitation infiltration and
extracting the groundwater beneath the landfill mound and
subjecting it to treatment. These alternatives would remove the
contaminated groundwater from within the vicinity of the
landfill, thereby reducing the volume of the hazardous compounds.
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The subsurface barrier proposed in Alternative 5 would provide
additional reduction of the mobility of the contaminants into the
overburden aquifer by installation of the slurry wall surrounding
the perimeter of the landfill. The grout curtain would limit the
transport of the contaminants into the bedrock aquifer.
Short-Term Effectiveness
Alternative 1 would not include any physical construction
measures and therefore would not present a risk to the community
as a result of its implementation. Alternative 2 would require a
minimal amount of site activity during installation of the fence.
Risks to the community and site workers would also be
insignificant.
The remaining alternatives involve major construction activities
at the Site and the use of heavy earthmoving equipment.
Potential hazards to the surrounding community and environment
will include adverse traffic conditions, airborne dust and
particulate emissions, an increase in noise levels, and adverse
impacts to the wetlands area. All of these impacts, due to
implementation of either Alternative 3, 4 or 5, could be
mitigated in part through the employment of proper construction
techniques and operational procedures. In addition to risks to
the public, the potential for worker exposure to contaminated
media is greater as a result of the amount of construction
activity taking place. These risks would be minimized by proper
health and safety training and the use of personal protective
equipment.
The treatment system of Alternatives 4 and 5 would require
storage and handling of hazardous materials. These activities
may be accomplished with minimal health risk to workers by the
development and implementation of safe operating and maintenance
practices and precautions. Compliance with applicable
regulations will ensure proper hazardous waste transportation
procedures and disposal of drummed process sludge at an approved
off-site RCRA facility.
The construction of the subsurface barrier under Alternative 5
could cause adverse environmental impacts to the adjacent
wetlands. Excavation would be necessary in the vicinity of the
wetlands and would cause sedimentation and disruption of the
ecosystem. Restoration or replacement of the wetlands would be
necessary if these areas were impacted due to implementation of
Alternative 5.
Implementability
Technical Feasibility
Alternatives 1 and 2 would involve minimal on-site activity;
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fence installation and groundwater monitoring are easily
implemented and supply of individual filtration units to nearby
residents is also readily available. The construction
procedures, materials and earthworking equipment required for the
implementation of Alternatives 3, 4 and 5 are conventional and
are used extensively in standard commercial and industrial
applications.
The treatment system for Alternatives 4 and 5 would utilize
standard unit operations and water treatment equipment that will
be well-suited for this application and are technically reliable
under typical site conditions. However, based on information
obtained during the remedial investigation of OU1, the direction
of the groundwater plume was not fully characterized due to the
complex hydrogeological conditions existing at the Site.
Therefore, it would be difficult to determine the technical
feasibility of designing a pumping and treatment system for
groundwater remediation under this operable unit.
The transportation and disposal of the de-watered process sludge
generated under Alternatives 4 and 5 involves easily
implementable practices and the use of commercially available
facilities. Excavation activities necessary for the subsurface
barrier of Alternative 5 would require specialized operations.
The slurry wall proposed under Alternative 5 would ensure against
lateral migration of contamination in the overburden aquifer.
However, the effectiveness of this alternative may be limited due
to the heavily fractured nature of the bedrock.
Administrative Feasibility
All of these alternatives would involve some degree of
institutional management. Alternative 1 would require
administrative coordination of the groundwater monitoring program
and the five year site status reviews, along with the development
of the public education program. Alternative 2 would require a
similar level of control for those activities, and also for
maintenance of the security fence and distribution/installation
of filtration units to residents.
The administrative requirements for Alternatives 3, 4 and 5
include the groundwater monitoring program, filtration unit
supply, and the security fence inspection. In addition to these
activities, the structural integrity and impermeability of the
closure cap and subsurface barrier must be maintained through a
program of periodic surveillance and necessary repairs. Because
of the large land area of the landfill, this item would be fairly
substantial.
In addition, Alternatives 4 and 5 require an extensive monitoring
program, as well as the operation and maintenance of the
23
-------
groundwater treatment facility. The administrative elements of
this are extensive because they include equipment maintenance
schedules, system effluent monitoring to comply with the SPDES
permit and to adjust operating parameters, and transportation and
disposal of hazardous process residuals in compliance with
regulations.
Availability of Services and Materials
Host services and materials required for implementation of any of
these potential remedial alternatives are readily available.
Standard construction equipment and practices can be employed for
the fence installation of Alternatives 2-5 and the extensive
site work activities of Alternatives 3, 4 and 5. Most of the
materials and equipment required for these alternatives may be
obtained local to the Site. However/ excavations necessary for
the installation of the subsurface barrier (Alternative 5) may
require that specialized operations and equipment be obtained
from non-local sources.
Because the work would be taking place on a Superfund site, all
on-site personnel must have approved health and safety training.
Many companies are available to provide this training to
contractors. The engineering and design services required for
implementation of Alternatives 3, 4 and 5 may be obtained from
many vendors. Hazardous waste transportation and disposal is
also commercially available.
Cost
Cost estimates were calculated for each of the five alternatives.
Present worth cost estimates consider a 5% discount rate and a
30-year operational period. The costs are as follows:
Capital O&M Present
Alternative Cost ($) Cost (Sl/vr Worth fS)
1 6,800 55,500 887,800
2 223,300 176,100(yrs 1-3) 1,523,800
62,700(yrs 4-30)
3 7,442,000 526,300(yrs 1-3) 14,279,600
422,900(yrs 4-30)
4 8,779,900 759,000(yrs 1-3) 19,013,100
645,600(yrs 4-30)
5 15,811,300 l,032,000(yrs 1-3) 30,241,300
918,600(yrs 4-30)
24
-------
State Acceptance
The State of New York, through the NYSDEC, concurs with EPA's
selected remedy. See Appendix IV.
Community Acceptance
EPA believes that the selected remedy has the support of the
affected community, with the exception that the community would
prefer that a permanent source of alternative water be supplied
under OU1. As noted above, the need for a permanent alternate
water supply will be evaluated in the second operable unit.
Community comments can be reviewed in the public meeting
transcript which is included in the administrative record. A
Responsiveness Summary which summarizes all comments received
during the public comment period and answers the questions and
concerns raised at the public meeting on April 22, 1991 is
attached as Appendix V to this document.
SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the
detailed analysis of the alternatives, public comments, and
NYSDEC*s comments, EPA has determined that Alternative 3, Capping
and Point-of-Use Treatment Systems, is the appropriate remedy for
Operable Unit One of the Warwick Landfill site.
The selected alternative for OU1 will achieve substantial risk
reduction through source control and an interim groundwater
remedy. A further characterization of the fate and transport of
the contamination emanating from the Site will be studied under
OU2 and will serve as the basis for the decision on a final
groundwater remedy.
The major components of the selected remedy are as follows:
* Construction of an approximately 22 acre multi-layer
cap consistent with New York State Part 360 solid waste
landfill closure requirements;
* Regrading and compaction of landfill mound to provide a
stable foundation for the placement of the cap prior to
its construction;
* Construction of a gas venting system following the
testing and characterization of landfill gas emissions;
* Performance of air monitoring prior to, during, and
following construction at the Site, to ensure that air
emissions resulting from the cap construction meet the
applicable or relevant and appropriate requirements;
25 t:
-------
* installation of groundwater monitoring wells within the
landfill mound to observe the effect of groundwater
flow patterns through the saturated portion of the
landfill and to monitor the movement of contaminants
beneath the landfill;
* Quarterly groundwater monitoring program using existing
groundwater monitoring wells and newly installed wells
within the mound;
* Construction of fencing around the perimeter of the 25-
acre leasehold;
* Recommendations that ordinances be established or
restrictions imposed on the deed to ensure that future
use of the Site property will maintain the integrity of
the cap;
* Implementation of a residential well sampling program
of area residential wells;
* As an interim measure, fitting and maintenance of
granular activated carbon units on residential wells
where contaminant levels found exceed either federal or
state maximum contaminant levels ("MCLs") or on those
residential wells which are threatened by potential
contamination in exceedance of MCLs based on the
results of the residential well sampling program and
the OU2 investigation. The units will be maintained
until the decision on a final groundwater remedy is
evaluated under OU2; and
* Evaluation and delineation of the northwestern and
southeastern wetlands and the drainage channels flowing
through these wetlands adjacent to the landfill.
REMEDIATION GOALS
The purpose of this response action is to reduce the present risk
to human health and the environment due to contaminants leaching
from the landfill mound. The capping of the landfill will
prevent the infiltration of rainfall and snowmelt into the
landfill, thereby reducing the potential for contaminants
leaching from the landfill and negatively impacting the wetlands
habitat and groundwater quality.
This response action will also ensure that, until a decision on a
final groundwater remedy is made in OU2, the area residents are
protected from drinking contaminated groundwater by the
installation of point-of-use treatment systems on residential
26
-------
wells. In addition, a full evaluation of the two adjacent
wetlands will be performed prior to remediation activities to
determine any measures which may be necessary to mitigate
potential negative impacts to the wetlands. No residual
management is needed.
STATUTORY DETERMINATIONS
Under its legal authorities, EPA's primary responsibilities at
Superfund sites is to undertake remedial actions that achieve
protection of human health and the environment. In addition,
Section 121 of CERCLA establishes several other statutory
requirements and preferences. These specify that when complete,
the selected remedial action for this site must comply with
applicable or relevant and appropriate environmental standards
established under federal and state environmental laws unless a
statutory waiver is justified. The selected remedy also must be
cost-effective and utilize permanent solutions and alternative
treatment technologies or resource recovery technologies to the
maximum extent practicable. Finally, the statute includes a
preference for remedies that employ treatment that permanently
and significantly reduce the volume, toxicity, or mobility of
hazardous wastes, as available. The following sections discuss
how the selected remedy meets these statutory requirements.
Protection of Human Health and the Environment
Alternative 3 is considered to be fully responsive to this
criterion and to the identified remedial response objectives.
Capping the landfill protects human health and the environment by
reducing the mobility of contaminated materials off-site. The
leaching of contaminants into the wetlands and aquifers will be
significantly reduced. The carcinogenic and non-carcinogenic
risks associated with groundwater ingestion and inhalation will
be eliminated for current groundwater users with the provision of
point-of-use treatment systems on residential wells.
Compliance with ARARs
Attainment of chemical-specific ARARs for groundwater will be
hastened due to reduced leaching following construction of the
cap. Final groundwater remediation, however, will be addressed
in the second operable unit. Point-of-use treatment systems will
allow attainment of chemical-specific ARARs at residential wells.
The source of surface water contamination (leachate seeps) will
be eliminated. Action- and location-specific ARARs will be
complied with during implementation.
Action-specific ARARs:
* New York State Solid Waste Management Facilities 6
27
-------
NYCRR Part 360
* National Emissions Standards for Hazardous Air
Pollutants (NESHAP)
* 6 NYCRR Part 257 Air Quality Standards
Chemical-specific ARARs:
The selected remedy will enable drinking water MCLs to be met at
the groundwater point of use by installation of domestic granular
activated carbon units on residential wells.
* SDWA Maximum Contaminant Levels (MCLs)
* 6 NYCRR Part 703.5 Groundwater Quality Regulations
* 6 NYCRR Part 702 Surface Water Standards
* 10 NYCRR Part 5 State Sanitary Code
Location-specific ARARs:
* Clean Water Act Section. 404, 33 USC 1344
* Fish and Wildlife Coordination Act 16 USC 661
* Wetland Executive Order 11990
* National Historic Preservation Act 16 USC 470
* New York State Freshwater Wetlands Law ECL Article 24,
71 in Title 23
* . Newj York State Freshwater Wetlands Permit Requirements
and Classification 6 NYCRR 663 and 664
* New York State Endangered and Threatened Species of
Fish and Wildlife Requirements 6 NYCRR 182
Other Criteria, Advisories, or Guidance To Be Considered:
* SDWA MCL Goals (40 CFR Parts 141.50 - 141.51) provide
goals for toxic compounds for public drinking systems
* New York Guidelines for Soil Erosion and Sediment
Control
* New York State Sediment Criteria December 1989
* New York State Air Cleanup Criteria January 1990
28
-------
Cost-Effectiveness
The selected remedy provides overall effectiveness proportional
to its cost. The total capital and present worth costs for the
remedy are estimated to be $7,442,000 and $14,279,600,
respectively. A detailed breakdown of the estimated costs of
this remedy is provided in Table 11.
Utilization of Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent Practicable
The selected remedy utilizes permanent solutions and alternative
treatment technologies to the maximum extent practicable. The
selected remedy represents the best balance of trade-offs among
the alternatives with respect to the evaluation criteria. The
State and the community also support the selected remedy, with
the exception that the community requests a permanent water
supply under OU1.
With the construction of the landfill cap, the direct contact
risk to the soils will be eliminated. Point-of-use treatment
systems installed on residential wells where contamination
exceeds federal and/or state MCLs will eliminate exposure to well
water contamination.
No short-term adverse impacts and threats to human health and the
environment are foreseen as the result of implementing the
selected remedy. However, to minimize and/or prevent potential
worker exposure to contaminants during construction of the
landfill cap, personal protection equipment will be utilized.
The selected remedy will require construction of a landfill cap.
No technological problems should arise since the technologies are
readily available.
Preference for Treatment as a Principal Element
The statutory preference for remedies that employ treatment as a
principal element cannot be satisfied, because treatment of the
principal threats of the Site is not practicable under this
operable unit. The size of the landfill and the fact that there
are no identified on-site hot spots that represent the major
sources of contamination preclude a remedy in which contaminants
could be excavated and treated effectively.
DOCUMENTATION OF SIGNIFICANT CHANGES
There are no significant changes from the preferred alternative
presented in the Proposed Plan.
29
-------
APPENDIX
FIGURES
-------
. ir.rr.u-W STATIONS
Figure 1 - SITE LOCATION
rf/ft', f
i.
POOR QUALITV
ORIGINAL .
r
i 1 1
-------
SYVSS*- IEC-£ND
»--j sa. »»«•>=
Figure 2 - SAMPLIKG LOCATIONS
S5-"
s»-s
POOR QU
ORIGINAL
ill
_TI s^T SS-»
1 -
= I
-------
APPENDIX
TABLES
-------
Tnblo 1- Contominnnts Exceeding ARARS in Ovorburdon Groundwater
Chemical Name
Frequency
Arithmetic
Mean(ug/l)
Range of
Concentrations(ug/l)
Most Stringent ARAR
(ug/l)
ORGANICS Volatlles: (ug/l)
Chloromethane
Trichloroethane
2/21
2/21
6.5
1.7
6.0 - 27.0
1,6 - 18.0
5.0 (10 NYCRR Part 5)
5.0(10NYCRRPart5).
INORGANICS Total Metals: (ug/l)
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
Copper
Iron
Lead
Manganese
Mercury
Nickel
Zinc
9/20
15/20
20/20
9/20
6/20
19/20
19/20
14/14
12/13
19/19
5/20
18/20
16/16
27.5
14.7
609.0
3.6
1.9
191.9
165.3
19,900
82.2
8,849.6
0.28
214.2
251.9
18.0 - 210.0
1.1 -200.0
10.0 - 7,370.0
1.2-99.0
2.0 - 482.0
11.1 -2,270.0
4.0- 1,970.0
199.0-1,170.000.0
5.1 - 450.0
4.3 - 89,100.0
0.2 - 33.8
22.2 - 3,700.0
5.7 - 6,290
3.0 (Fed. Prop. MCLG)
25.0 ( NY Class GA)
1,000 (10 NYCRR Part 5)
1.0 (Fed. Prop. MCLG)
10.0 (10 NYCRR Part 5)
50.0* (10 NYCRR Part 5)
1,000.0 (10 NYCRR Part 5)
300.0 (10 NYCRR Part 5)
25.0 (NY Class GA)
300.0 (10 NYCRR Part 5)
2.0 (10 NYCRR Part 5)
100.0 (Fed. Prop. MCL)
5,000.0 (10 NYCRR Part 5)
* ARAR value for hexavalent Chromium (CR VI)
-------
Tnblo 1 (Continued) - Contaminants Exceeding ARARS in Dodrock Groundwator
Chemical Name
Frequency
Arithmetic
Mean(ug/l)
Range of
Concentrations(ug/l)
Most Stringent ARAR
(ug/0
ORGANICS Volatlles: (ug/l)
Chloromethane
Benzene
Ethylbon7ono
M & P Xylonoo
O-Xylonos
Isopropyl benzene
1 ,4-Dichlorobenzene
2/22
2/22
?/22
3/22
3/22
2/22
4/22
10.6
1.2
1.1
P.I
1.4
X
1.0
1.9-65.0
7.6 - 10.0
1.0-5.5
0.0 - P0.1
2.2- 12.0
0.1 -.6.0
1.6-6.0
5.0 (10 NYCRR Part 5)
5.0 (10 NYCRR Part 5)
5.0 (10 NYCRR Part 5)
5.0 (10 NYCRR Part 5)
5.0 (10 NYCRR Port 5)
5.0 (10 NYCRR Part 5)
5.0 (10 NYCRR Part 5)
INORGANICS Tctal Metals: (ug/l)
Antimony
Barium
Chromium
Iron
Leab
Manganese
Mercury
Nickel
4/20
20/23
18/23
16/16
9/17
20/23
1/23
19/23
11.6
185.5
40.5
7975.6
9.9
2372.6
0.2
33.8
20.4 - 25.0
2.3 - 1500.0
4.1 - 223.0
43.1 - 43,600.0
3.1 - 48.8
23.0 - 17,300.0
2.9
5.0 - 102.0
3.0 (Fed. Prop. MCLG)
1,000 (10 NYCRR Part 5)
50.0* (10 NYCRR Part 5)
300.0 (10 NYCRR Part 5)
25.0 (NY Class GA)
300.0 (10 NYCRR Part 5)
2.0 (10 NYCRR Part 5)
100.0 (Fed. Prop. MCL)
* ARAR value for hexavalent Chromium (CR VI)
-------
Table 1 (Continued) - Contaminants Exceeding ARARS In Northeast Residential Wells
Chemical Name
Frequency
Arithmetic
Mean(ug/l)
Range of
Concentrations(ug/l)
Most Stringent ARAR
(ug/i)
ORGANICS Volatlles: (ug/l)
1,1 - Dlchloroethene
1,1 - Dlchloroethane
1,1,1 - Trichloroethane
M & P Xylenes
1/5
2/5
3/5
3/5
2.20
3.72
17.26
3.08
9.0
0.1 - 17.0
0.1 - 85.0
1.4-9.7
5.0 (10 NYCRR Part 5)
5.0 (10 NYCRR Part 5)
5.0 (10 NYCRR Part 5)
5.0 (10 NYCRR Part 5)
INORGANICS Total Metals: (ug/l)
Iron
Manganese
5/5
4/5
4253.8
379.18
106.0 - 16,600.0
8.4 - 867.0
300.0 (10 NYCRR Part 5)
300.0 (10 NYCRR Part 5)
-------
Table 2- Contaminants Exceeding ARARS in On-Site Surface Water
Chemical Name
Frequency
Arithmetic
Mean(ug/l)
Range of
Concentratlons(ug/l)
Most Stringent ARAR (ug/l)
ORGANICS
Volatlles (ug/l)
Chlorobenzene
1 ,3-Dlchlorobenzene
1 ,4-Dichlorobenzene
5/7
1/1
1/2
11.8
5.7
2.9
0.7 - 20.0
5.7
5.2
5.0 (NY Class "A" Standard)
5.0 (NY Class "A" Standard)
5.0 (NY Class "A" Standard)
Semlvolatlles (ug/l)
oBNA
Hexachlorobutadiene
Phenol
4-Methyl phenol
Bis(2-ethylhexyl)pthalate
1/7
2/9
3/9
2/9
X
12.6
11.2
4.3
3.0
33.0 - 44.0
4.0 - 65.0
6.0 - 14.0
1.0 (NY Class "A" Standard)
5.0 (NY Class "A" Standard)
5.0 (NY Class "A" Standard)
0.6 (NY Class "A" Standard)
o Pestlcldes/PCBs
Aldrin
1/9
0.028
0.043
0.001 (NY Class "A" Standard)
i
INORGANICS: Total Metals (ug/l)
Aluminum
Arsenic
Barium
6/6
2/6
8/8
13,966.0
3.4
539.0
348.0 - 72,100.0
4.9-9.6
116.0-2,660.0
100 (NY Class "A" Standard)
190 (NY Class "A" Standard)
1,000 (NY Class "A" Standard)
-------
Table 2 (continued) - Contaminants Exceeding Al \P •-, in On-Slto Surface Water
Cadmium
•
Chromium
Cobalt
Coppor
Iron
Lead
Magnesium
Manganese
Nickel
Vanadium
Zinc
2/6
V7
5/0
4/8
8/0
0/0
8/0
6/6
7/0
5/8
4/4
2.6
31.1
19.4
23.2
296,704.0
116.5
50,688.0
2,234.2
35.4
36.0
1,470.3
1.3-0.4
7.3 - 1.50.0
0.9 - 76.0
10.0 - 97.2
5,430.0-1,940,000.0
4.5 - 655.0
22,200.0 - 99,700.0
420.0 - 7,080.0
12.5-103.0
3.6 - 200.0
53.0-4,960.0
0.3-9.4 (Calc. - NY Class "A"
Standard)
47.0-1, 075 (Cole. -NY CI033
"A" Standard)
5.0 (NY Class "A" Standard)
2.5-1 18.0 (Calc. NY Class "A"
Standard)
300.0 (NY Class "A" Standard)
0.3-97.0 (Calc. NY Class "A"
Standard)
35,000 (NY Class "A"
Standard)
300 (NY Class "A" Standard)
24-739 (Calc. NY Class "A"
Standard)
14.0 (NY Class "A" Standard)
30.0 (NY Class "A" Standard
* On-silp surface water includes surtace water and leacnate sampling stations: bwin, L-i, L-2, (and its duplicate L-4)
and L-3).
-------
TJ
08
TAIH.K 'I - CoinpnH.Non of Su(Mmi»ono
4-Chloro-3-motltylplionol
4-Hotliylphonol
Oonxolc Acid
01 i(2-othyllioxyl )phthalato
Ot-n-Oiitylpliihalatn
(PAIIi)
NnncarclnoooniI
Nsphthalono
2-Motylnaphtha!ono
Aconaphthylono
Aconaphthono
0(boniofur«n
Fluorono
Anthracono
Pluoranthrono
Pyrono
Carctnoooni: ,
Phonanlhrono
non«o(»)«;nthracono
Chrysono
RANGE OF ON-S1TI! WETLAND^
CONCCNTIIAT.IONS
420.0
2.0
3,0-370,0
7.0-lfi.O
3.0-11.0
NO
NO
900.0
nn.0-230.0
2>io.o-nr.o.o
NO
150.0
60,0
NO
75.o-ino.o
230.0
170.0-350.0
120.0-4-10.0
190.fl-S,700.0
130.0-3,700.0
noniol
Uoniol
Homo
hifluoranthono
k)fluorsntliono
a)pyrono
I ndonoU , 2 , 3-COlpyrono
nih8nio[A,ll]8ntl\racono
Uonio[G,ll,nporyluno
ino.o-
200.0-
230.2-
ino.o-
230.0-
220.0-
320.0-
1SO.O-
130.0-
2,noo,o
2,100.0
2,100.0
1,000.0
•1,900.0
•2,100.0
• 1,000.0
•410.0
•1,000.0
RANCE OF
-.CONCENTMT.WH5
HO
NO
r..o
f..O
NO
r.7.o
lllll.O
NO
n2.o
1DO.0-410.0
S4.0
73.0-120.0
ino.o .
70.0
62.0-370.0
lf.0.0-700.0
74.0-1,000.0
urn. 0-3, lion, o
1,700.0-2fi,000.0
2,000.0-24,000.0
ft),0-1 n, ooo.o
700.0-11,600.0
1100.0-9,200.0
5110.0-6,000.0
2,500.0-4,nno.o
710.0-0,4.10.0
• 330.0-3,500.0
100.0-1,400.0
:HO.0-3,400.0
RANGE OF (lACKGROUNO
_WNC.ENT.I
-------
TABU? 3 (Continued)
MGAMICS
o Total Hotalil (mg/ku)
"D
Aluminum
Antimony
Artenlc
Barium
Oorylllum
Cadml urn
Calcium
Chromium
Cobalt
Coppar
Iron
Load
Haanoilum
Hanganoio
Mercury
Nlckol
Potaiilum
Sodium
Vanadium
Zinc
3030
OQ
g>
i— 1 —
1 SH^B
3
Radioactive Icotopoc
Radlocarlion 14C (ud/o lodlmont)
Tritium Jll (uCI/ml water)
RANGE OF ON-SITE WETLANUl/ RANGE OFDoWNGRAOIENTl/
CONCtNIBAUflfc'" «™"«,T,,AYin»K
fi, 510.0-30,1100.0
9.2-24.3
0,9-6.6
42.3-257.0
0.6-3.9
0.411-1.2
1,720.0-23,900.0
7.7-29.3
5.9-17.1
0.9-33.6
12,200.0-215,000.0
16.7-90.4
2,100.0-7,550.0
104.0-1,320.0
0.14-0.97
9.2-39,3
475.0-2,490.0
123.0-3,410,0
16,1-33.1)
60.7-220.0
NO
NO
RANGE OF OACKGROUND
.CONCENTRATIONS
VALUES,
7,950.0-17,000,0
5.7
2,1-5.6
26.2-217.0
1.1-2.7
0.20-0.71
004.0-10,500.0
10.7-14.1
6.0-24.6
1
7.4-15.0
17,000.0-36,300.0
13.0-25.3
2,940.0-9,200.0
22(1.0-6,370.0
0.29
14.5-21.8
461.0-044.0
44.9-666,0
15.1-25.5
57.2-125.0
9,000.0-11,400.0
6.3-0.9
1.0-4.7
27.5-42.1
0.6-1.4
0.16-0.48
710.0-14,200.0
10. 4-15. 0
6.0-9.1
1. (5-14.1
20,200.0-29,500.0
11.6-17.6
2,570.0-9,700.0
133.0-1140.0
NO
13.3-21.9
423.0-1,050.0
34,0-524.0
12.3-21.9
54.7-110.0
10,000 - 300,000 (Oragun, 3, JJOjl
0,6 - 10 Draoun, 3, 900
10 - 40 (Oraoun, 3. 1900
100 - 3,500 Oragun, 3, 1900
1 - 2 (Glacial Till}
Kabata-Pcndlot
1904)
0.01 - 7 (Oraoun, 3. 1908)
100 - 400,000 Oragun, 3, 1900)
10 - 00 (Oragun. 3, 1900)
3 . 15 (Glacial Till;
Kabata-Pondloi
1904)
2 - 100 (Draoun, 3. 1908)
7,000 - 550,000 Oragun, 3, 1900)
3 -/ 30 (Oragun, 3. 1900)
6 - f.,000 (Draoun, J. 1900)
100 - 4,000 (Oragun, 3. 1900)
0 02 - 0.36 (Glacial Till;
°'° Kabata-Nndlot
1904)
10 - 30 (Glacial Till;
Kabata-Pondlot
1904)
400 - 30,000 (Oragun, 3. 1900)
750 - 7,500 Oraoun, 3. 900)
20 - 500 (Oragun, 3. 1900)
10 - 300 (Draoun, 3. 1900)
NO
NO
I/ Ploato rofor to Tablo 4.0-3 for tamplo 0rou,)1n0J.
NO Non dotoct.
1!A S°.S.in.?HldvS!;« rejected a. a roiult of data validation.
NA
NA
Nono
None
-------
TABLE A
WARWICK LANDFILL SITE
CONTAMINANTS OF CONCERN EXISTING IN SOILS (ug/kg)i/
Chemical Name Unsaturatefl Zone^/ £ajLU_r_a££3.
Zone2-^
Benzene 2.0 4.0
Chlorobenzsne — 28.0
Ethylbenzene 79.0 220.0
Xylenes 25.0 49.0
Arsenic 4.6 4.6
Barium 111.0 66.5
Beryllium • 0.91 1.0
Chromium 18.0 24.6
Cobalt 12.5 12.5
Iron 23,900 25,700
Lead 176.0 136.0
Manganese 661.0 646.0
Kercury 0.5 0.44
Nickel 21.5 ' 22.7
Vanadium - 16.8 19.5
Zinc 127.0 314.0
I/ MexiEum detected concentrations.
— Not detected.
-------
ob
riiriucAi
IIAIII;
Volitllin
Action!
lltnirni
2-llnltniin*
Culiim IMnilMil*
Clilorohinitiit
Cltlornlllilni
Clilorofoim
fill 01 o«ii Hunt
I, l-niclilorottlnni
l.l-lllclilornillitni*
Clt-l.i-nlclttoroitliint*
Clliylliinun*
7-llMinont*
lioiiropylbtnitn*
MilliyUn* Clilorld*
ll-propyllmirtin*
n-linpropylloluin**
Slyrtti*
TilridiUrodlitnt
lolucnf
IrlcMorotthin*
1,1,1-lrlcltlnrotlhin*
l,3,S-lrlnilhylbiniint*
I, J,4-lrlinlliyllunl»il«*
H t n iyll lotd
o-iyl«ii«i
Jiml:YolitlliH
UiiiiTviilou 's«Tur»i«il
SOIL
WAIIWII.K lAIIIHII.I. SI
SUHIMHY OF StUCHIl CMIIIUAI.S or • ML CONCtflM
IK SAHi'iin mmirc
iisen ton f|UAiimMivi; IVAI .unii
filillllNlMAUn
. — ,rv!!!'ii'
Uni»lur»l("l
..
Uv«il>ui.don IJoOi.ock
llulyllitniyl phlliiUl*
llltlhvl pfilli«l»lt
Ill-n-liuty) |.MI..I«t«
nl-n-nclyt
CirclnooinU TAIIi*
Noncti clnootnlc I'Alll
lltiiiolo Ac dl
n«niyl ilcoliot
1,1-IMclilorolicniini*
l,4-Ulclilorob«nitnt
4-Htlliyl plitnol
Plunol
AUrln
x
x (-)
X
X
X
X (-)
X
X
X
x'(-)
Table 5
On:5U«
Dloiln/.bitini
Dleiln
Furtn
JotiUlitiln
Antimony
Ariinlo
X(-)
X
Btrylllim
Cidolum
Coin 1 1*
Copptr
Iron*
I..J'
Htngtntit
Htrcury
Siltnlun
SM.tr
llulllum
Vintdlum
. ^bS
X(-)
X(-)
X
X(-)
X
X(-)
X(-)
X
X(-)
X(-)
Net Itltcltd
Jtltcttd
X
x (-)
-------
Tnblc G
or
WAHUICK lAtiiirm. SMI:
r. ANO cunncNT ANI» rtitiinr. I.ANII tisr.
-o
DO
2 3*
OQ
^§::
>>
CKOoiurt.MciHun
o Air
.ImmuraJlilliw.
.Cyiluillon.
o Soli
o Grounilwaltr
o Surfac* Walir.
o S«dl*i»nl
n Inhalation of viilal.llnt
n Infill »t Inn 11 f rinjlllvo Out I;
lit i ma I Cmtlacl; anil
I iiijit 11 Ion
o Inlitlillnn of vnlatllrf
thnworlng; llentul cnnttct
will l« (lioworliiij; tnil
o Dirntl conttrt wlilln
w»illng; tint
lnu«it linn
o nermd contact wlillo
Air mnnltorlnij (ilmlolnnl i»l-
IIID «n»lyiriiiinil It rnvnrml with
voil . In I ho
H-'J ft »nnn. llmrnfnrn
t»liir*lnil »iul HIM Alum I oil
ml It *i«i «v* lua tint only
• t polnntlal tourr.nt to
w«l«ir contamination anil If
Hunt t rurt Ion l«lifll pl*ct
In tint fulur*.
Ground** I rr It mcil at
potaliln walor
o Surf»r« water Imdlot do
nut tiipfiort (liltlni) or
olhnr riicruallon
acllvltlot
o Surfarn waUr liodlnt do
not tii|i|i|i(H I f I filing or
othor racr«atlon actlvltlct
Po I on U.f 1.1 v.C i! PO m/_P.on v.li lion
n M/\
Urildnnlt
Site Woiktri
o nntldonlt
o Ratldontt
0 dpjldenlt
-------
Tatle 7
CHTMICAl K
2-Eutanon*
Carbon Dlsulftd*
CMorcitnzeni
Chi oro fora
1.1-DlcSlcro«thtnt
VASVTrX lANDFIll SITE
TOX1CITY DATA ITS aOCAAClM*;! NIC EFFECTS
or OCHJCALS or TQIIHIIM.
cost Risrwic rvALtiAitnt -IRIS''
- Oral KFO
Inhalation BIT)
10
l.COC-CI
2.00E-C2
1.COE-C2
S.EOC-G3
1.1.1-Tr!cJ»loro«lh«n«
1.1-DlchIorotth«n*
Iricnloroethen*
Tetr»ch1oro«thent
Slyren*
6.00E-C2
9.onr.-r.?
2.COE-7!
NO
KH
9.00E-02
5.DOE-02
KO
KO
9.3Gr-03
3.1>ac«00
3.onr.no
2.0i3E«00
1.0CE-01(H«Jst) 1.DGE-C1 (H«»tt)
2.TOE-CO 3.C3E-01
1.CE-JJ2
2.0E-01
tcsr ?.zs
1910
TS. iss:
Acid
B«t (
p-'n.LI.
7.COC-C2
5.00C-C3
5.00E-:-*
l.OOE-53
3.70E-C2
l.COE-?!
3.COE-04
l.OOE-W
1.00E-C2
3.COE-33
3.0CE-03
e.ooE-cs
9.00C-03
2.COE-01
-?2 (l!eas'.J
r:L-:r: '." ?rre=e. 7fte s^ctrcs-- c?
-*.=it!:*-e:e is osei 5=r the cs —«—-«:~ Tl'l.f
tesa-.-se it js =;( ci^er-rit^I T " '" ''
POOR QUALITY
ORIGINAL
Syst*. oU»rvi» Fsurth Quarter HEAST 7990 ^er. noted..
-------
Table 8
Ea?csure Pathway
VAJTWXX LANDFILL STFE
i-i-ATION OF K~AN HEALTH RISK Em.uA7ICNS
ACTSS PATHWAYS FCR RESIDENTS
UNDEX PRESENT/FUTURE LAND USE
Hazard Inefer for Ken=ar=4r.oe-fiTe Effects
Atiults
Average Kaxisiua
Case Reasonable Cats
* 1} g»=-es--Tg ts ErsL-r.cvater
Insertion cf Chesicals ir. Ercir-.cwater
Dersal Adsorpticr. of Qiesicals in
Erxisufwater
Inhalation cf Grcur.dvcter Volatile*
Total
2) Re=reztionaLl Use of Surface Water Bodies
Incic'e-ital Ir.cesticn cf Che=icals in
Surface Water"
Cer=a1 Acsorpticn cf Cheaicals in
Surftcs Water
Cer=**: Afssrpticr. cf Cher.ica*s in
Seci=e.-.ts
Total
21*
21-0
I.nrasticn of Chesicals ir. Scils
Denal Afsorpticn t= C-.e=ica1s in Ssils
Ir-ha'aiicn of Checica's in Scils
7 cUl
Te ''* Eiscsu
fTetal 1. 2 ar.e •'
E.9HE-C4
2.23E-C=
6.20E-04
21.0
Diile'ren
hixi=u=i
Averace Reasonable
21
2.77E-04
1.2SE-C3
21.0
3.9=3-3* l.EcZ-2*
S.41E-03 0.13
6.47--Q7 ^.C=E-;3
1.24E-02 0>1 =
6.0=E-Vi
3.2CE-34
1.13E-05
3.21E-04
21.15
Cas
21*
Case
31*
1.E5--04 3.25E-04 f
T.4cr_;.3 2.73--03
21-0
31.0
3.75E-04 O.S5
2.S5E-Q4
3.00E-02 0.73
2.EOE-:3 2.?3i-:=
£.51--:= 3.12E-04
2.23E-C7 2.?S;-?6
2.E=E-:3 3.14E-C4
21.0 . 31.763
Espcsare Pathway
Ha;ard Tr.e'e* fer Kongarcineeer.ie Effects
Averace
2.£=£-04
9.51E-25
i.2;r-os
3.£2E-04
Reasonable
Kaxir.ira
Case
1) Er^csarg to Soi's
Exr=s*_TB to Ciesicals ir. Sc-."is
Cersil Acsorpticn of Ciesicals in Soils
Ir.hala.ii en of Chesicals in Soils
Total
T — -=jrires crea.-tss^ rislcs cf £^.1 acui-fers a=ses=ed
E.57E-D4
4.SCE-C4
POOR QUALITY
ORIGINAL
e^-ial future land-use risks czly.
-------
•D
08
loMicifv iiAtA rnn run NH AMY rAnnnor,rN.c crrr.ns
Or UHMM.AI.S (ir I'lMtNIIAI. liwCMIN
oosf RtsroMsr. i.vAi.i>ArinM -.ins'', Aimiisr wo
Table 9
lirMICAI. MAMT £=
OQ
Unl.|M of
llrni«nt
Ctrl.nn III nil ridt
I'lilnrnlirnitnt
f Itlnrnfoim
I, l-IHcliloro«tluni
I Iliyllirnitn*
Itnitroiiyl Imnmn*
MtlliyUni CMorlilft 7.10r-n.1
1,1. l-lrlclilnro«lli(rif
Inliion*
rMni fyiil dint
I, l-IHcliloriitHunt
Nfl
fi.inr.ni
r.. mil-01
i.:
I.mi:-n7 (iimti)
is.inr-n?
j.miixi/
Xylfimi, mliril
Irl rirMoronllitnt
Slyrrn*
St"llv01»l!.lll
0 HNA
nnninlc Acid
Ditniil Ml)
'4-Mtlliylplifnol Nil
lUiiclilnrnliiiltdltn* 7'.HOT-117
phiii«i*i« • i. (17 - Prplitlil* MiHn»n C»r( I ntiunil, SiifrtcUnt wvlilnni* (if r »r r I noi|nnl 1:11 y In tnlmtll. ln»iUl|H*l* «vltltnr» flf CltC 1 nogtniC' ty In mMlnl
(irniip C - Ponllil* Ilixnm r»'r Inoonii. l.lnllml
-------
lAM/rlLL SITE
SUKfATlCS Or KuKAH K£AL7H RISX ESTIKATICNS
ACOS5 PATHWAYS FOR RESIDENTS
RESENT/FUTURE LAND USE
Table 10
Exposure Pathway
Average
1) Erpcsure to Ersoncwattr
Incestien cf Oiesicals in Grounc'water 1.1SE—04
Excess Lifetiex Cancer Risfc
e'ults
Kazir.ua
. Reasonable Case
C-iileren
Average
Reasonable
7.E7E-05 .l.lSE-24
Cereal Absorption cf Clericals in
Inhalation cf erssnsrwaier Volatiles
Total
2) Recreational Use of Surface Water Eixfiei
Incicental Incestica cf Oieaicals in
Surface Vater 3
2.32E-07 1.33E-06
1.61E-C5 9.7CE-05
1.3-4E-04 4.53E-04
D err, si Absorption c-f Cnesicals in
Surface Vater
C=r=sl Acssrpticn cf Cieaicals in
6.S1E-OS
3.60E-25
1.79E-07 3.13E-C-7
2.3Qg-:-5 4.21E-:-S
1.02E-04 1.60E-C4
1.6EE-07 £.6'.E-D7
l.?£E-07 3.25E-C:
3) Fx:.-^r= t
Ineesiicn cf
De.-nal Acscrp
Inhalatica cf
4) Vcr-jt Case
Sc=-!£r^:s
Tc^-il
Chesica's is Soils
ticn tc desicals in Soils
Chesica's in Soils
Tetal
Exscsvrs To All Exsesurs
rictE"; 1. 2 ar.d 3)
E.2?E-12
l.O'E-07
l.eiE-jo'
6.05E-11
2.15E-11
1.62E-08
1 .34E-24
1.10E-09
4 Ocr-C5
5.4-.E-C7
2.SOE-C-9
7.77E-10
5.45E-07
4.S£E-04
1.51E-07
-3.53E-D7
£.=CE-Oe
1.G7E-10
3.07E-T1
6.51£-:S
1 .C2E— C-4
O.C;;_-.C
, c.r_,-
5.0£E-:~
7.1XE-1C
2.11E-10
£.07E-37
1.S-4E-C4
pos-jre Fachwzy
WASWICC U-S'DFiLL SITE
SUXyATION Or KiVMi KEAi.rri RISX ETriKATICXS
AGIGS5 PAr-WAYS FOR CDHSTRUCTICfi VC?JCE=S
USDS FJTURr LAND L'SE
Kesscncbl e
Kaxisa
Case
V i)
Ex
De:
Execjare ts Soi's
osura ts Cjcaicals in Soils
.-=il Asscrpticn cf Casicals in Soils
cn of Ciesicals io Soils
' Total
7.71E-09
2.e;E-n
7.77E-39
8.12E-08
4.34E-10
8.2SE-OS
POOR QUAL
ORIGINAL
r—es cr-ea-tas^ r-isks cf ail £.—,^ifers assessed.
•2^i--use risks cnlv.
-------
u_j uJi L»
"LTLi I Li U 'LI
"D
08
TARI.E n-3
ALTERNATIVE 35 CAPPING/POINT OF USE TREATMENT
CAPlTALCOST_ESUMATn3JJ99LDOLLARS).
ii
LITY/CONSTRUCT.10M
:, SUPPORT FACILITIES
1, Office Trailers
2, Decontamination Trailers
3, Parking anil Equipment Area
[. GROUNOWATER MONITORING WELLS
I, SECURITY FENCING/SIGHS
\l. GRADE AND COMPACT LANDFILL SURFACE
V. MULTI-LAYER CAP
1. Clay Layer
2, Sand/Soli Layer
3, Topsoll Cover
4. Seeding
I, GRADE CAP SURFACE
I, PASSIVE-LANDFILL GAS CONTROL SYSTEM
ft *
I. PRIVATE WATER SUPPLY TREATMENT UNITS
C ES.T.IHATED.OUANUT.IES
MATERIAL_(.U
UNtUIUCt COST.
INST.AUATJOMJ.1).
UNLLIllUCli CUS.T.
All numbon arc rnundoil to nearest hunilrnil.
Total Construction Cost
DIRECT CONSTRUCTON
2
2
5,000 sy
fi
4,750 ft
21.6 acres
21,6 acres
52,270 cu yd
69,760 ctiyil
17,440 c« yd
21.6 acros
21 .fi acros
10
42
I
/
9,400
10,000
9.20
2,000
(From
INCL
31,23
30.75
31.35
3,900
INCL
3,700
(From
. 10,000
36,000
46,000
12,000
Tahlo n-2s Item III)
1,633,430
2,703,200
550,232
04,240
60,040
Table n-2; Horn IV.)
Total Olrijct Construction
Contingency 0 20% of TOCC
Plnnnlnij/rnnlnoorlng (J 101
Lagnt anil Ailmtiil jlrntlvo t
INCL
INCL
2.65 13,250
2,200 13,200
3,015 65,124
INCL 1
10,000
36,000
59,300
25,200
113,000
65,100
H
cu
0*
,633,400 **
IMCL 2,703,200 *"*
INCL
INCL
1,500 32,400
4,520 01,360
Cost (TDCO !
<
of TDCC :
or. of rncc
550,200
04,200
32,400
149,400
41,600
» 5,512,600
1,102,500
551,300
275,600
$ 7,442,000
-------
tan)
\xJ* u-h LJi L-h L-h L-h
i—r. LJl LJI
TAtlLE n-0
ALTERNATIVE 35 CAPPINO/POINT OP USE TREATMENT
O,O AMNUAL_OPEnAT.IOHJ\HD_HAIHT.nNAHCn,COST_i:S.TlH/\T.i:SJ.U19.LDOLUaS.).
~; Oas.l.s.oLEsUmattt
08
SITE MONITORING PROGRAM
1, Water Sampling
2, Water Laboratory Analysis
(15 samples quarterly)
3. Gas Laboratory Analysis
4. Report
4, Residential Well Sampling
(2 samples semi-annual)
3, Residential Well Sampling
(42 wells by semi-annual)
MAINTEMANCE
1, Wells, Gas Vents, Cap,
Fencing
2. Residential Water Filters
ANNUAL OiM COST
CONTINGENCY
TOTAL ANNUAL OHM COST
tit
SITE STATUS REVIEWS AND
PUBLIC AWARENESS PROGRAMS
Present Worth 'of Reviews
Present Worth Annual Costs
2 Persons
-------
APPENDIX III
ADMINISTRATIVE RECORD INDEX
-------
05/16/91 Index Chronological Order Page: 1
WARWICK LANDFILL Documents
Document Nunber: WAR- 001 -0578 To 0580 Date: 06/03/83
Title: (Letter forwarding the results of the Preliminary Investigation)
Type: CORRESPONDENCE
Author: Ganser. Donald R.: Woodward- Clyde Consultants
Recipient: Nosenchuck, Norman H.: NY Dept of Environmental Conservation
Attached: WAR-001-0581
Document Number: WAR-001-0581 To 0950 Parent: WAR-001-0578 Date: 09/30/83
Title: Engineering Investigations at Inactive Hazardous Waste Sites in the State of New York - Phase
I - Preliminary Investigation, Warwick Landfill
Type: PLAN
Author: none: Woodward- Clyde Consultants
Recipient: none: NY Dept of Environmental Conservation
Document Nunber: WAR -00 1-0024 To 0577 Date: 03/01/85
Title: Engineering Investigations at Inactive Hazardous Waste Sites in the State of New York - Phase
II Investigations - Warwick Landfill Site, Town of Warwick, Orange County, New York
Type: PLAN
Author: none: Woodward- Clyde Consultants
Recipient: none: NY Dept of Environmental Conservation
Document Number: WAR-001-0001 To 0023 Date: 08/01/88
Title: Aerial Photographic Analysis of the Warwick Landfill Site - Greenwood Lake, New York
Type: GRAPHIC
Author: none: US EPA
Recipient: none: US EPA
Document Number: WAR -00 1-0954 To 1186 Parent: WAR-001-0951 Date: 01/01/89
Title: Final Field Operations Plan, Remedial Investigation and Feasibility Study, Warwick Landfill
Site, Warwick, New York
Type: PLAN
Author: none: Ebasco Services
Recipient: none: US EPA
-------
05/16/91 Index Chronological Order Page: 2
WARWICK LANDFILL Documents
Document Number: UAR-002-0210 To 0234 Parent: WAR-002-0208 Date: 01/01/89
Title: Final Community Relations Plan, Warwick Landfill Site, Town of Warwick, Orange County, New
York
Type: PLAN
Author: Marshall, Sydne B.: Ebasco Services
Recipient: none: US EPA
Document Number: UAR-001-0951 To 0953 Date: 01/31/89
Title: (Letter submitting the Final Field Operations Plan (FOP) for the Warwick Landfill site)
Type: CORRESPONDENCE
Author: Sachdev, Dev R.: Ebasco Services
Recipient: Alvi, M. Shaheer: US EPA
Attached: WAR-001-0954
Document Number: WAR-002-0208 To 0209 Date: 01/31/89
Title: (Letter forwarding the Community Relations Plan for the Warwick Landfill site)
Type: CORRESPONDENCE
Author: Sachdev, Dev R.: Ebasco Services
Recipient: Wing, Robert: US EPA
Attached: UAR-002-0210
Document Number: WAR-001-1205 To 1381 Date: 05/01/89
Title: Final Work Plan, Remedial Investigation and Feasibility Study, Warwick Landfill Site, Warwick,
New York
Type: PLAN
Author: none: Ebasco Services
Recipient: none: US EPA
Document Number: WAR-002-0200 To 0207 Parent: WAR-002-0199 Date: 06/01/89
Title: Preliminary Health Assessment - Warwick Landfill - Orange County, Warwick, New York
Type: PLAN
Author: none: NY Dept of Health
Recipient: none: US EPA
-------
Index Chronological Order
WARWICK LANDFILL Documents
05/16/91
Document Number: UAR-002-0199 To 0199 Date: 07/12/89
Title: (Letter forwarding a copy of the Preliminary Health Assessment for the Warwick Landfill)
Type: CORRESPONDENCE
Author: Nelson, William: Agency for Toxic Substances & Disease Registry (ATSDR) -
Recipient: Wing, Bob: US EPA
Attached: WAR-002-0200
Document Number: WAR-002-0405 To 0448 Date: 08/01/89
Title: Superfund Update - Warwick Landfill Site, Town of Warwick, Orange County, New York - Fact
Sheet #1
Type: PLAN
Author: none: US EPA
Recipient: none: none
Document Number: WAR-002-0388 To 0396 Parent: WAR-002-0587 Date: 08/07/89
Title: Summary of Issues Raised - EPA Public Availability Session, August 7, 1989 - Warwick Town
Hall, Warwick, New York
Type: PLAN
Author: none: Ebasco Services
Recipient: none: none
Page: 3
Document Number: WAR-002-0387 To 0387
Date: 08/15/89
Title: (Memo forwarding a summary of issues raised during the EPA Public Availability Session held
in Warwick, New York, on August 7, 1989)
Type: CORRESPONDENCE
Author: Marshall, Sydne B.: Ebasco Services
Recipient: Lozada, J.: Ebasco Services
Attached: WAR-002-0388
-------
05/16/91 Index Chronological Order
WARWICK LANDFILL Documents
Document Number: WAR-001-2331 To 2349 Date: 01/01/90
Title: Results of Stage 1A Cultural Resources Survey, Warwick Landfill Site, Town of Warwick, Orange
County, New York
Type: PLAN
Author: Fiedel, S.: Ebasco Services
Recipient: none: US EPA
Document Number: WAR -002 -0385 To 0386 Date: 04/27/90
Title: (Memo regarding) Meeting with Dutch Hollow Homeowner's Association
Type: CORRESPONDENCE
Author: Rychlenski, Ann: US EPA
Recipient: Garbanni, Doug: US EPA
Document Number: WAR-001-1187 To 1204 Date: 05/31/90
Title: (Letter forwarding the attached revised Field Change Request Form, SAS request, and parameter
table for three additional leachate samples to be scanned for full dioxin)
Type: CORRESPONDENCE
Author: Sielski, Mark: Ebasco Services
Recipient: Gupta, Rahul: US EPA
Docunent Number: WAR -002 -0397 To 0404 Date: 10/01/90
Title: Fact Sheet - Warwick Landfill: Private Well Water Sampling Results
Type: PLAN
Author: none: NY Dept of Health
Recipient: none: none
Document Number: WAR -00 1-2354 To 2357 Date: 10/01/90
Title: Superfund Update - Warwick Landfill Site, Town of Warwick, Orange County, New York
Type: CORRESPONDENCE
Author: none: US EPA
Recipient: none: none
-------
05/16/91 Index Chronological Order Page: 5
WARWICK LANDFILL Documents
Document Number: WAR -002-0198 To 0198 Date: 12/19/90
Title: (Letter requesting a written statement indicating whether any endangered or threatened species
are present in the project area)
Type: CORRESPONDENCE
Condition: MISSING ATTACHMENT
Author: Hargrove, Robert W. : US EPA
Recipient: Corin, Leonard P.: (IS Fish & Wildlife Service
Document Number: WAR-002-0197 To 0197 Date: 01/17/91
Title: (Letter responding to a December 19, 1991 letter requesting information on the presence of
federally listed or proposed endangered or threatened species in the vicinity of the site)
Type: CORRESPONDENCE
Author: Corin, Leonard P.: US Fish & Wildlife Service
Recipient: Hargrove, Robert W. : US EPA
Document Number: WAR-001-1384 To 1737 Parent: WAR-001-1382 Date: 02/01/91
Title: Final Remedial Investigation Report, Warwick Landfill Site, Warwick, New York, Volume I of
III
Type: REPORT
Author: none: Ebasco Services
Recipient: none: US EPA
Document Number: WAR-001-1738 To 2316 Date: 02/01/91
Title: Final Remedial Investigation Report, Warwick Landfill Site, Warwick, New York, Volume II of
III
Type: REPORT
Author: none: Ebasco Services
Recipient: none: US EPA
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05/16/91
Index Chronological Order
WARWICK LANDFILL Documents
Page: 6
Document Number: WAR-001-2317 To 2330
Date: 02/01/91
Title: Final Remedial Investigation Report, Warwick Landfill Site, Warwick, New York, Volume III
of III
Type: REPORT
Author: none: Ebasco Services
Recipient: none: US EPA
Document Number: WAR-001-2352 To 2353
Date: 02/01/91
Title: (Letter outlining the NYSOEC's preferred alternative and stating objections to EPA's Alternative
No. 5)
• Type: CORRESPONDENCE
Author: Chen, Marsden A.: NY Dept of Environmental Conservation
Recipient: Pavlou, George: US EPA
Document Number: WAR-002-0002 To 0185 Parent: WAR-002-0001
Title: Final Feasibility Study Report, Warwick Landfill Site, Warwick, New York
Type: REPORT
Author: none: Ebasco Services
Recipient: none: US EPA
Date: 02/01/91
Document Number: WAR-002-0186 To 0196 Date: 02/01/91
Title: Superfund Proposed Plan - Warwick Landfill Site, Town of Warwick, Orange County, New York
Type: PLAN
Author: none: US EPA
Recipient: none: none
Document Number: WAR-001-1382 To 1383 . Date: 02/11/91
Title: (Letter submitting the Final Remedial Investigation (RI) Report for the Warwick Landfill site)
Type: CORRESPONDENCE
Author: Verdibello, Mario: Ebasco Services
Recipient: Allen, Julia: US EPA
Attached: WAR-001-1384
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05/16/91 Index Chronological Order Page: 7
WARWICK LANDFILL Documents
Document Number: WAR-002-0001 To 0001 Date: 02/11/91
Title: (Letter submitting the Final Feasibility Study (FS) Report for the Warwick Landfill site)
Type: CORRESPONDENCE
Author: Verdibello, Mario: Ebesco Services
Recipient: Allen, Julia: US EPA
Attached: WAR-002-0002
Document Number: WAR-001-2350 To 2351 Date: 02/22/91
Title: (Letter forwarding attached table containing amendments to risk assessment spreadsheets. Chromium
III vs. Chromium VI)
Type: CORRESPONDENCE
Author: Sielski, Mark: Ebasco Services
Recipient: Allen, Julia: US EPA
Document Number: WAR-002-0235 To 0384 Date: 04/25/91
Title: (Transcript of) Public Meeting for the Warwick Landfill Superfund Site, Town of Warwick, Orange
County, New York
Type: LEGAL DOCUMENT
Author: Guardiano, Ellen L.: Meister Reporting Services
Recipient: none: US EPA
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APPENDIX IV
NYSDEC LETTER OF CONCURRENCE
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New York State Department of Environmental Conservation
50 Wolf Road, Albany, New York 12233 -7010
Thomas C. Joriing
Commissioner
HAY 2 0 199V
Ms. Kathleen C. Callahan
Director
Emergency & Remedial Response Division
U.S. Environmental Protection Agency
Region II
26 Federal Plaza
New York, NY 10278
Dear Ms. Callahan:
Re: Record of Decision
Warwick Landfill ID No. 336014
The New York State Department of Environmental Conservation
has reviewed your Record of Decision, received May 9, 1991, for the
Warwick Landfill Site and finds it to be acceptable.
Please contact Mr. Jonathan Greco, of my staff, at (518) 457-3976
if you have any questions regarding this matter.
Sincerely,
Edward 0. Sullivan
Deputy Commissioner
cc: J. Allen, USEPA, Region II
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APPENDIX V
RESPONSIVENESS SUMMARY
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RESPONSIVENESS SUMMARY
WARWICK LANDFILL SUPERFUND SITE
WARWICK, NEW YORK
The U.S. Environmental Protection Agency ("EPA") held a public comment period from
February 25, 1991 to May 9, 1991 to receive comments from interested parties on the
Remedial Investigation and Feasibility Study ("RI/FS") reports and Proposed Plan for the
Warwick Landfill Superfund site ("Site").
A public participation meeting was conducted by EPA on April 22,1991 at the Greenwood
Lake Middle School, Greenwood Lake, New York to discuss remedial alternatives, to
present EPA's preferred remedial alternative, and to provide an opportunity for the
interested parties to present oral comments and questions to EPA.
This responsiveness summary provides a synopsis of citizens' comments and concerns
about the Site as raised during the public comment period, and EPA's responses to those
comments. All comments summarized in this document were considered in EPA's final
decision for selection of the remedial activities for remediation of the Warwick Landfill
Superfund site.
This responsiveness summary is divided into the following sections:
I. Responsiveness Summary Overview - This section briefly describes the
background of the Warwick Landfill Superfund site and summarizes the proposed
and selected alternatives.
II. Background on Community Involvement and Concerns - This section provides a
brief history of community interests and concerns regarding the Warwick Landfill
Superfund site.
III. Summary gj Public Comments and EPA's Responses - This section summarizes
comments expressed verbally at the public meeting, and also, those received
through written correspondence, and provides EPA's responses to these
comments.
IV. Appendices - This section includes a copy of the agenda for the public meeting
(Appendix A) and the public meeting sign-in sheets (Appendix B).
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I. RESPONSIVENESS SUMMARY OVERVIEW
Site Background
The Site is located approximately one and one-half miles northeast of the Village of
Greenwood Lake in the Town of Warwick, Orange County, New York. The Site is
approximately three-fourths of a mile north of State Route 17A and fronts Penaluna Road
on its western boundary between Old Tuxedo Road and Old Dutch Hollow Road. No
buildings exist on the landfill property except for a substantially demolished brick
structure. The landfill mound transects a small valley and occupies approximately 13
acres of a 25 acre leasehold area of land.
The area surrounding the Site is generally wooded with clusters of residential homes, all
of which utilize private wells as their source of drinking water. The two homes closest to
the Site are approximately 250 feet southwest of the landfill boundary and 300 feet
northeast of the landfill boundary, respectively.
The Site was owned and farmed by the Penaluna family from 1898 to the mid-1950s,
when the Town of Warwick leased the property from the Penaluna family and utilized it
as a refuse disposal area. The facility accepted municipal wastes from the Town of
Warwick, which includes the Villages of Florida, Warwick and Greenwood Lake, and other
surrounding towns in Orange County. The Town of Warwick operated the landfill until
1977.
In April 1977, the Site was leased from the property owner, Mrs. Millie Mae Penaluna, by
Grace Disposal and Leasing, Ltd. ("Grace Disposal"), Harriman, New York. On July 15,
1977, Grace Disposal was granted a permit to operate the refuse disposal area by the
Orange County Department of Health.
In the spring of 1979, in response to concerns of local citizens who had reported
observations of suspicious dumping activities at the landfill, New York State Department
of Environmental Conservation ("NYSDEC") and EPA collected and analyzed two leachate
samples at the Site. The results indicated the presence of heavy metals, phenols, and
various volatile organic compounds, some of which exceeded the New York State
Drinking Water Standards and the USEPA National Primary Drinking Water Regulations.
Based on the results of these samples and that Grace Disposal did not perform the
additional tasks necessary for the submittal of an adequate draft environmental impact
statement, the application to operate the landfill was denied by NYSDEC on
September 4, 1979 and the landfill was ordered closed.
Pursuant to a New York State court order, the Site was covered, graded, and closed by
Grace Disposal. On June 11,1980, NYSDEC was notified that a Certificate of Dissolution
had been filed by Grace Disposal. In 1984, ownership of the property was transferred to
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Orange County for non-payment of back taxes. It was conveyed from Orange County
to Newburgh. N.Y. Developers in November 1986. In 1987, the property was transferred
to the current owners, L and B Developers.
In March 1985, a field investigation, based on the findings of a September 1983 site
investigation, was performed by Woodward-Clyde Consultants, Inc. for the NYSDEC. The
information generated was utilized to prepare a Hazard Ranking System ("HRS")
assessment of the Site. Based upon the HRS, the Site was proposed for inclusion on
EPA's National Priorities List ("NPL") of uncontrolled hazardous waste sites in 1985 and
was added to the NPL in March 1989.
On December 28, 1988, Special Notice letters were sent to fourteen entities who were
determined at that time to be potentially responsible parties ("PRPs") at the Site. The
Special Notice letters informed these parties of their potential liability at the Site and
offered them the opportunity to undertake the RI/FS for the Site. The PRPs were given
sixty days from receipt of notice to submit a good faith offer.
Since EPA did not receive any good faith proposals from the PRPs to undertake or
finance the RI/FS, EPA contracted with Ebasco Services, Incorporated to perform the
RI/FS pursuant to monies from the Superfund ("the Fund").
Field work for the RI/FS began in August 1989 and was completed in February 1991.
On February 27,1991, EPA sent general notice letters to Georgia Pacific Corporation and
the Town of Warwick, informing them of their status as PRPs. These entities were
designated PRPs following a response received from Georgia Pacific to a 104(e)
information request letter.
Summary of Proposed and Selected Remedial Alternative
The remedial alternatives considered for the Site are described in the RI/FS and Proposed
Plan for this first operable unit ("OU1"). All alternatives considered are listed below:
o Alternative 1 - No Action
o Alternative 2 - Limited Action/ Point of Use Treatment
o Alternative 3 - Capping/ Point of Use Treatment
o Alternative 4 - Capping/ Groundwater Pumping/ Chemical Precipitation/
Carbon Adsorption/ Point of Use Treatment
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o Alternative 5 - Capping/ Subsurface Barrier/ Groundwater Pumping/
Chemical Precipitation/ Carbon Adsorption/ Point of Use
Treatment
EPA, with the concurrence of NYSDEC, chose a remedy which addresses the principal
threats posed by the Site through capping of the landfill and supplying point of use
treatment systems to area residents, as needed.
II. BACKGROUND OF COMMUNITY INVOLVEMENT
Community interest in the Site has been high throughout the RI/FS process. The
community has been kept aware of activities at the Site through local newspaper articles,
fact sheets, press releases, public notices and public information meetings.
The Dutch Hollow Homeowners' Association ("DHHA") was awarded a Technical
Assistance Grant ('TAG") in February 1991. Two extensions to the public comment
period were requested by DHHA to afford the DHHA's technical advisor sufficient
opportunity to review and comment on the RI/FS reports and the Proposed Plan.
III. SUMMARY OF PUBLIC COMMENTS AND EPA'S RESPONSES
The comments detailed below include those expressed at the public meeting on April 22,
1991 and those received in writing during the public comment period. The major concern
expressed by the community is the potential migration of contaminants from the landfill
into their private residential wells. A residential well sampling program conducted by EPA
and New York State Department of Health ("NYSDOH") identified volatile organic
contamination in exceedance of New York State and/or Federal drinking water standards
in three residential wells northeast of the Site.
All comments received have been summarized and organized into five main categories:
the Proposed Plan, the Remedial Investigation/Feasibility Study Reports, Other Concerns,
the Superfund Process, and Operable Unit Two.
THE PROPOSED PLAN
COMMENT: The technical advisor to the DHHA commented that because the fate and
transport of contaminants from the landfill has not been determined with certainty,
conservative assumptions are needed on which to base measures to protect area
residents.
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RESPONSE: EPA agrees with this comment and developed the Risk Assessment for the
Site using conservative assumptions. The Risk Assessment identified the cumulative
upper bound cancer risk at the Site, using reasonable maximum exposure conditions for
adults, at 4.98 x 10"*, which is at the high end of the acceptable cancer risk range of 10"4
to 10"6. The major contributor to this number is from the ingestion of groundwater from
on-site monitoring wells, assuming the wells were used in the future for drinking water
purposes. The selected remedy includes point-of-use treatment systems, namely granular
activated carbon ("GAG") units, to minimize the risk of contaminated groundwater
ingestion for the homeowners in the vicinity of the Site. To date, sampling conducted by
EPA and NYSDOH has identified three residences that require point-of-use treatment
systems. These residences have already been provided with point-of-use treatment
systems by NYSDEC. The residential wells receiving point-of-use treatment systems will
be determined following an extensive and ongoing residential well sampling program.
Because the fate and transport of contaminants from the landfill was not fully
characterized under OU1, EPA has determined that a second operable unit ("OU2") is
necessary to determine a final groundwater remedy.
*Carbon Filtration Units
COMMENT: The technical advisor to the DHHA commented that EPA's interim measure
of only providing carbon filtration units for residential drinking water supplies is not
enough to protect residential well users until a final groundwater remedy is determined
under OU2.
RESPONSE: A total of forty-two residential wells were sampled by EPA and NYSDOH
during the remedial investigation. The results identified contamination in exceedance of
New York State and/or Federal maximum contaminant levels ("MCLs") in three residential
wells located geographically northeast of the Site. The contaminants detected above
MCLs are volatile organics which can be removed through the use of carbon filtration
units attached to the homeowners' wells. Based on the levels of contamination detected,
these units are capable of reducing the concentrations of contaminants in the drinking
water to below drinking water standards, thus ensuring protection of human health for the
current water users. In addition, the levels of contaminants detected in residential wells,
although above New York State drinking water standards, present risks which are within
EPA's acceptable risk range.
COMMENT: The technical advisor to the DHHA commented that carbon filtration units
have a number of disadvantages includinp: 1) they require continuous monitoring and
maintenance; and 2) the carbon canisters have a limited life and must be replaced.
RESPONSE: The carbon filtration units are designed to provide an interim measure of
protection to the current users of residential wells where contaminants in exceedance of
New York State and/or Federal drinking water standards have been detected. Provisions
have been included in the ROD for operation and maintenance of these filters, in
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conjunction with a semi-annual residential well sampling program. As part of the
operation and maintenance program, the carbon filters will be replaced, as necessary.
The carbon units are well-suited for the types and concentrations of contaminants
identified in the residential wells.
COMMENT: A number of residents inquired about which homes will be getting carbon
filtration units and the maintenance program associated with the units. In addition,
questions were raised as to how long EPA believes that carbon filtration units would be
used until a permanent remedy is finalized under OU2.
RESPONSE: A residential well sampling program of the homes in the vicinity of the Site
will be enacted during the remedial design phase of OU1, Based on the results of this
sampling program, homes with contamination above Federal and/or New York State
MCLs will receive granular activated carbon units. For cost estimating purposes, it was
assumed that 42 residences will require filters. A semi-annual monitoring program will be
performed for at least three years. The results will aid in the development of an
equipment maintenance and/or replacement program.
In the event that the potentially responsible parties do not undertake the Remedial Design
and Remedial Action ("RD/RA") for OU1, EPA will initially pay for the installation and
operation and maintenance of the filters using monies from the Fund until a final remedy
for alternate water is selected, if necessary, and implemented. EPA will ultimately seek
to recover its costs from the PRPs in a cost recovery action.
The RI/FS for OU2 should be completed and another Record of Decision ("ROD") will be
signed within the three year period in which the residential well sampling program is
taking place. Should the final remedy selected in the second operable unit call for the use
of carbon filters rather than an alternate water supply, New York State would be
responsible for long term operation and maintenance of these filters.
COMMENT: The technical advisor to the DHHA stated that the proposed semi-annual
sampling for only three years and the review of the Site's status every five years is
inadequate. Selection of Alternative 3, which calls for attachment of GAC units on
contaminated residential wells is not a permanent measure to remediate the Site and the
potential exists for future spread of contamination.
RESPONSE: The use of GAC units on selected residential wells, based on the findings
of the residential well sampling program, is an interim remedial measure to minimize the
risk to current users of contaminated residential wells. EPA will conduct an extensive
groundwater investigation on the hydraulic forces in the landfill area which will include the
study of contaminant transport conditions at the Site. This will provide the necessary data
to select a final groundwater remedy under OU2 within a three year period.
COMMENT: A resident asked if wells that have no contamination would receive carbon
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filters.
RESPONSE: No, residential wells with no contamination and those that are not in the
potential pathway of a contaminant plume emanating from the landfill will not receive
carbon filters.
COMMENT: A resident inquired as to whether carbon filters have already been installed
on contaminated wells.
RESPONSE: Under a recommendation made by NYSDOH, NYSDEC has installed
carbon filtration units on the three residential wells where contaminants were detected in
exceedance of New York State and/or Federal drinking water standards.
*Alternative Water Supply
COMMENT: The technical advisor commenting on behalf of the DHHA urged that a
permanent source of alternative water be found as soon as possible and this requirement
be specified in the Record of Decision. EPA should consider the economic and
psychological (stress) burdens placed on the area residents by an extended period of
uncertainty. The main justification for delaying a provision of alternate water to residents
near the landfill must be cost.
RESPONSE: At this time, the source of contamination in the residential wells located
northeast of the Site has not been positively linked to the contamination emanating from
the landfill. Additional hydrogeological studies, including the investigation of groundwater
flow patterns beneath the Site, is necessary under OU2 to determine a final groundwater
remedy. At that time, the need for a permanent alternate water supply will be determined.
Community acceptance will be factored into the remedy selection.
COMMENT: A resident expressed concern that the flow of water in the vicinity of the Site
might not ever be known due to the fractured bedrock in the area and complex
hydrogeological conditions. Because of this, he believes that an alternative water supply
should be provided at the earliest date possible. Another resident questioned the
efficiency of remediation solutions when so many unknowns exist.
RESPONSE: EPA has chosen a two operable unit approach to the Site. EPA's strategy
is conservative, yet moves ahead using a time table which does not jeopardize public
health and the environment. Under the first operable unit, the landfill cap will reduce the
quantity of water percolating through the landfill and leaching out contaminants. The
installation of point-of-use treatment systems, although not a permanent remedy, will
protect the current users from the risk of contaminated groundwater ingestion. OU2 will
satisfy the need for additional site investigations to determine a final groundwater remedy
and evaluate the need for and feasibility of an alternate water supply. Therefore, EPA's
prudent course of action, that is, performing a second operable unit isJn_the best interest
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of the overall protection of human health and the environment.
*Bottled Water
COMMENT: The technical advisor to the DHHA questioned whether a more protective
interim measure should consist of both carbon filtration units and bottled water because
carbon filtration is not an effective treatment for all classes of contaminants detected in
the monitoring wells around the landfill.
RESPONSE: EPA agrees that carbon filtration units are not an effective treatment for all
classes of contaminants detected in groundwater monitoring wells. However, EPA is most
concerned with protecting the current users of residential wells where contaminants are
in exceedance of New York State and/or Federal drinking water standards. The
proposed semi-annual residential well sampling program is designed to identify
contaminated residential wells. In the event that contaminants which cannot be removed
through carbon filtration are detected above MCLs in residential wells, then EPA will
provide an alternative means to protect these well users. •
COMMENT: A resident inquired whether bottled water should be provided for shower
users since skin cells may absorb contaminated water.
RESPONSE: Based on the risk analysis performed during the remedial investigation,
exposure of those residents currently utilizing the northeast residential wells to
groundwater volatiles while showering, under reasonable maximum exposure conditions,
contributed 9.79 x 10~5 to the total cancer risk and 0.005 to the total noncarcinogenic risk.
These northeast residential wells are those wells where contaminants were found in
exceedance of MCLs. Because these risk calculation numbers falls within the acceptable
risk range as set forward in the National Contigency Plan ("NCP"), EPA does not have
reason to believe that bottled water is necessary to minimize exposure to volatile organics
while showering. Furthermore, the installation of carbon filters on the residential wells will
effectively remove any volatile organic contaminants present in the well water.
*Residential Well Sampling Program
COMMENT: A consultant to one PRP commented that the analytical parameters and the
frequency for the proposed residential well sampling program should be reviewed at the
end of the first year. Because residential well sampling is potentially one of the most
sensitive aspects of the remedial investigation process, the responsibilities and responses
associated with the sampling program should be defined and understood prior to initiating
sampling activities.
RESPONSE: The residential well sampling program will be developed to determine which
area residential wells require point-of-use treatment systems. EPA believes that sampling
selected area residential wells for the full Target Compound List (TCL")"parameters on
•
f-
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a semi-annual basis until a final groundwater remedy is determined under OU2 is
necessary to ensure the effectiveness of the treatment systems and the protection of the
residential well users. EPA will evaluate the need to design a one-year review of the
residential well sampling program during the remedial design.
*Groundwater Monitoring
COMMENT: A consultant to one PRP stated that the long-term groundwater monitoring
program should be reviewed after the first year of quarterly monitoring. This would allow
for the deletion of analytical parameters, as appropriate, and reduce unnecessary costs.
The proposed long-term monitoring program should initially be designed for years one
through five. Continued sampling should be conducted only as necessary based on the
review at the end of five years.
RESPONSE: The results of the monitoring program will be evaluated periodically and
could potentially result in modification to the plan. However, EPA believes that any
reduction in sampling frequencies or parameters tested for is not in the best interest of
the local community at this time. Additionally, modifying the proposed long-term
monitoring program from thirty years to five years is unwarranted. Furthermore, the 6
NYCRR Part 360 closure rules require that a post-closure monitoring and maintenance
operations manual be developed and followed for a minimum of thirty years after the
landfill cap is constructed.
*Landfill Gas
COMMENT: The technical advisor to the DHHA stated that the composition of the landfill
gases should be characterized before designing the venting system for the landfill cap.
RESPONSE: The testing and characterization of landfill gas emissions will be further
defined during design of the remedial action under OU1. A gas venting system, either
passive or active, will be designed and constructed following the characterization of landfill
gas emissions.
*Landfill Cap
COMMENT: A resident inquired as to what the normal life of a cap is.
RESPONSE: The normal life of a landfill closure cap is approximately thirty years. The
selected remedy, as stated in the Record of Decision, requires an annual operation and
maintenance program to evaluate the integrity of the cap in conformance with 6 NYCRR
Part 360 standards for a minimum of thirty years following closure. In addition,
effectiveness of the containment remedy in protecting human health and the environment
will be evaluated every five years.
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COMMENT: A resident asked what the difference was between the existing cap on the
landfill and the proposed cap which will be developed in accordance with 6 NYCRR Part
360 rules. Another resident questioned whether the proposed cap would include a
synthetic membrane component.
RESPONSE: The existing cap is a mixture of sand and gravel. At the time of
construction, it was upwards to two feet in thickness. At present, garbarge is exposed
at the surface in some areas of the landfill. At other locations, only a few inches of sand
and gravel still remain. The design of the proposed cap would comply with the standards
of 6 NYCRR Part 360. At a minimum the cap must consist of: 1) a bottom layer allowing
for a gas venting system; 2) a low permeability barrier layer and a barrier protection layer;
and, 3) a topsoil layer. The inclusion of a synthetic membrane component is allowable
under 6 NYCRR Part 360 and will be decided upon during the remedial design.
COMMENT: A resident asked whether any portion of the landfill is below the
groundwater level. If this is the case, capping the landfill would not eliminate the
hydrologic forces causing lateral migration.
RESPONSE: Hydrologic data gathered during the Rl indicate that a portion of the landfill
does lie in the saturated zone beneath the groundwater table. EPA agrees that capping
the landfill might not eliminate all hydrologic forces causing lateral migration. This issue
will be investigated further under OU2.
COMMENT: A consultant to one PRP commented that the proposed landfill cap design
described in Alternative 3 of the Proposed Plan and Feasibility Study report can be
constructed in a more cost-effective manner in accordance with the requirements of 6
NYCRR Part 360. The recommended design variations for Alternative 3 could result in
an estimated cost savings of up to $1.9 million.
RESPONSE: The Feasibility Study report, Proposed Plan and ROD provide conceptual
plans for the landfill cap design. EPA will evaluate variations for construction of the landfill
cap during the remedial design. The remedial design report will outline the thickness and
composition of all layers of the cap, and the drainage and gas collection specifications,
as necessary to comply with 6 NYCRR Part 360 closure rules. The costs outlined in the
Feasibility Study are estimates and will be refined during the remedial design.
COMMENT: A resident asked whether it would be cheaper to remove the landfill material
from the landfill and haul it away rather than monitor the landfill for many years.
RESPONSE: The removal of materials from the Warwick Landfill would entail the
involvement of enormous and unmanageable quantities of material, approximately 800,000
-1,000,000 cubic yards and 1,000,000-1,500,000 tons of waste. This amount of material
would require extensive treatment, such as incineration, stabilization, or a combination of
both, for disposal at a RCRA landfill at substantial costs. In addition, the logistical and
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regulatory parameters associated with this undertaking would be extensive and cost-
prohibitive.
COMMENT: A resident commented that a study should be performed on the effect of
the increased run-off from the landfill following cap construction into nearby drainage
channels. The cap will likely encroach on existing wetlands resulting in the loss of
wetlands. A consultant to one PRP commented that costs associated with the wetlands
were not considered in the cost evaluation and should be estimated as part of the
evaluation of remedial alternatives.
RESPONSE: The disposition of the stream flow and resultant run-off from construction
of the cap will be determined during the remedial design. The two wetlands, northwest
and southeast of the Site, will be fully delineated and the impacts of the cap construction
on these wetlands will be analyzed. Engineering designs will attempt to maintain current
steady state conditions. Included in the capital costs for the landfill cap construction, as
outlined in the FS report, are funds available for environmental monitoring and impact
evaluations.
COMMENT: A resident questioned whether the cap will have an effect on flow to area
residential wells and whether there were any known examples of other landfill areas where
neighboring residential wells were affected by landfill cap construction.
RESPONSE: Although the construction of the landfill cap could affect the local
hydrological conditions in the area, the current domestic water supplies draw water from
a more regional area and are not dependent on infiltration through the present landfill to
recharge the aquifers. In addition, the majority of groundwater from the Site appears to
be discharging into the overburden and/or wetlands area. Downward hydraulic gradients
indicating flow into the bedrock from the landfill were not observed in any of the adjacent
cluster monitoring wells. The EPA is not aware of a change in area residential well flow
rates in the vicinity of a landfill following the placement of a closure cap over the landfill.
THE REMEDIAL INVESTIGATION/FEASIBILITY STUDY REPORTS
*Remedial Investigation
COMMENT: A resident inquired whether stream samples were collected under passive
or active conditions during field activities, that is, whether they were collected during quiet
flow conditions and after a heavy rainfall.
RESPONSE: The two rounds of stream samples taken during the Rl were collected
several weeks apart to provide data regarding the contaminant load in the stream during
high flow and low flow conditions. However, samples were not collected immediately after
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a heavy rainfall. In general, contaminants detected in streams are typically lower under
high flow conditions due to dilution from rainfall as opposed to low flow condition during
which groundwater is entering the stream. Results of stream samples over two rounds
indicated non-detectable levels of contaminants at downstream locations (near
Greenwood Lake).
COMMENT: A reporter asked whether other radioactive materials other than tritium-3H
and radiocarbon-14 were tested for in groundwater monitoring wells and any residential
wells because Union Carbide, a designated PRP for the Site, ran a nuclear reactor facility
in Sterling Forest for many years.
RESPONSE: The former Union Carbide facility in Sterling Forest, known as Union
Carbide's Corporate Research Laboratory or Medical Products Division, is presently
owned by Cintichem, Inc.. The facility produces radio-pharmaceuticals for the diagnosis
of human illnesses. Only trrtium-3H and radiocarbon-14 were analyzed for in the
groundwater monitoring wells because they are the longest lived radioactive isotopes
typically found in hospital wastes.
COMMENT: A consultant for one of the PRPs stated that the constituents detected in
leachate samples from the Warwick Landfill are consistent with those detected in other
municipal landfill leachate samples and that the concentrations found at the Site are
generally less than those reported for other municipal landfills.
RESPONSE: The above comment was based on a paper written by G.J. Farquhar in the
Canadian Journal of Engineering, Vol. 16, No. 3, (1989) on the study of nine Wisconsin
landfills. While it may be true that the results of the limited leachate sampling at the
Warwick Landfill site (two rounds at three locations) showed contamination no greater
than other municipal landfills, contamination in the groundwater monitoring wells above
MCLs indicate that hazardous substances are present at the Site which warrant
remediation under the Superfund program.
COMMENT: A resident asked what was the farthest distance from the landfill where
contamination was detected. Another resident asked at what rate does groundwater flow
in the area surrounding the landfill.
RESPONSE: Based on the results of the remedial investigation, the furthest distance
from the landfill where volatile organic contamination was detected was in monitoring well
WL-6D approximately 800 feet southwest of the landfill mound.
In general, movement of contamination is calculated using two variables: 1) the rate at
which contamination leaches into the groundwater system, and 2) the rate of groundwater
flow. Based on the groundwater investigation under OU1, groundwater is assumed to
flow at a rate of approximately 41 ft/yr south and 70 ft/yr north of the landfill in the
overburden and 59 ft/yr south and 3,139 ft/yr north of the landfill..in..the bedrock.
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Additional groundwater flow studies will be a major focus of OU2 and will involve the
development of a hydrogeochemical model which calculates the extent of contamination
emanating from the Warwick Landfill.
COMMENT: A resident asked whether residential well 1 ("RW-1") is contaminated.
RESPONSE: Volatile organic contamination did not exceed New York State and/or
Federal drinking water standards in RW-1. However, based on the September 1989
sampling by EPA, 56 ppb lead was detected. NYSDOH took two samples from the
outside faucet in in February 1991. The first draw sample contained copper at 2010 ppb,
iron at 6150 ppb, both above New York State secondary drinking water standards and
lead at 319 ppb, above New York State and Federal primary drinking water standards.
The second sample, taken after running the tap, contained only iron in excess of New
York State secondary drinking water standards. The secondary drinking water standard
for iron has been established at 300 ppb for aesthetic (taste, odor, cleaning quality)
purposes only. There are no health concerns associated with elevated levels of iron.
NYSDOH concluded that the sampling results are evidence that the source of metals in
the tap water is the household plumbing.
COMMENT: A resident questioned whether another well further downstream from WL-
6D, the farthest well location from the landfill where contaminants have been detected,
should have been installed to monitor groundwater.
RESPONSE: EPA plans on installing additional monitoring wells to determine the extent
of contamination as part of the second operable unit.
COMMENT: A resident questioned why the owners of property on which a monitoring
well is installed were not notified if contaminants were detected in the sampling results
from that monitoring well.
RESPONSE: As a courtesy, EPA should have notified the owners of the property on
which a monitoring well is installed of test results and is in the process of doing so.
COMMENT: A resident inquired about the extent of wetland studies and bioaccumulation
studies performed under the first operable unit.
RESPONSE: The EPA conducted an environmental risk assessment to evaluate the
potential ecological impacts associated with the contamination identified at the Warwick
Landfill. However, because of the low concentrations of contaminants detected, lack of
potential bioaccumulation, absence of fishing and other recreational activity, the
environmental assessment was not quantified. However, a functional analysis using the
Army Corps of Engineer's Wetland Evaluation Technique was performed on the
southeastern wetland.
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The two wetland areas are contiguous to the landfill mound and consist of emergent
marsh/scrub-shrub wetland to the southeast, approximately nine acres in size, and a
smaller, palustrine, forrested/scrub-shrub, deciduous wetland, approximately three and
one-half acres, to the northwest. EPA delineated these wetlands using the Federal
multi-parameter methodology. The slow waters of the scrub/shrub area allow time for
settling of particulates, and subsequent biological and chemical degradation. The
wetlands act as filters and long-term storage compartments that improve water quality.
This is particularly important for the downstream communities.
The need to minimize the disturbance of these wetland habitats via migration of
contaminants from the landfill, as well as via any future remediation activities, will be
considered in the design of the Site remedy.
*Glycol Ethers and Antimony Contamination in Groundwater
COMMENT: The technical advisor to the DHHA expressed concern that two classes of
contaminants, antimony and glycol ethers, have been found in the landfill monitoring
wells. These contaminants are not effectively treated by carbon filtration. There is
presently no reliable residential well data for antimony and glycol ethers in the remedial
investigation. All analyses for antimony were rejected in residential well samples and
EPA's method for detecting glycol ethers is not very sensitive and can severely
underestimate their true concentrations.
RESPONSE: Upon review of the appropriate data validation report, the cause of the
antimony rejection was found to be poor Contract Required Detection Limit (CRDL)
standard recovery. To verify the linearity of the calibration curve near the CRDL for
inorganic contaminant analysis, a two times the CRDL standard concentration is analyzed
at the beginning and end of each analysis run. USEPA Region II data validation criteria
states that if the CRDL standard recovery is less than 50% recovery, all data within the
nondetect to 240 ug/l range should be rejected. The recoveries for the antimony CRDL
standard for residential well samples were 73.0% for the initial standard and 38.5% for the
final standard. This poor recovery of antimony is inherent in the method as antimony is
easily lost by volatilization from the hydrochloric acid media in the digestion procedure.
In considering the validation report, it can be discerned that any concentration of
antimony above 240 ug/l would not be affected. Because the recovery for one of the
standards was less than 50%, all values were rejected and this indicates that all
concentrations were below 240 ug/l. The Federal proposed MCLG is 3 ug/l. Future
residential well sampling by EPA will include analysis for antimony. If antimony is present,
EPA will consider appropriate action to ensure the protection of human health and the
environment.
Unless specific information is available which indicates that a particular compound (or
class of compounds) is present at a site that warrants the use of a particular analytical
14
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method, the methods selected for use at sites are based upon types of compounds which
are commonly found in environmental samples. The analytical methods utilized by EPA
for organic contaminants at the Warwick Landfill examine a set of target compounds
commonly found in environmental samples (the TCL), which if present could be positively
identified.
If compounds other than those on the TCL are present, and if the analytical equipment
utilized is sensitive to these compounds, the method will also search through a library of
greater than 50,000 organic compounds in an attempt to match "fingerprints" for these
non-TCL compounds. This is done for up to 20 compounds which the instrument records
as being present in the greatest amounts. The method does not include internal
standards for the "library" search compounds which could be utilized to positively identify
their presence. Therefore, these compounds are called "tentatively identified compounds"
(TICs"), although under appropriate circumstances, one could make a strong argument
that particular TICs are indeed present. It should also be noted that it would be virtually
impossible to develop a method which could be specific enough to clearly identify the
50,000 plus chemicals formerly or presently in use, while simultaneously being sensitive
enough to detect the low level concentrations which are of concern for many chemicals.
It is true that glycol ethers were tentatively identified in samples collected at four of the
fifteen monitoring wells and these compounds may not be effectively removed by carbon
treatment units. However, these compounds were not even tentatively identified in the
residential well sampling performed by EPA. Furthermore, the contamination found at the
residential wells has not been positively linked to the Site itself and might be the result of
a localized release of contaminant (e.g. via a septic system). Even if the contamination
present in some of the residential wells can eventually be attributed to the Site, EPA
presently has no reason to believe that these glycol ether compounds, although water
soluble and thus mobile, will ever migrate to the residential wells. Therefore, EPA believes
that the use of carbon treatment units is an appropriate and effective interim means of
providing potable water to affected residents. In addition EPA will also perform some
sampling and analysis to specifically investigate glycol ether contamination. The objective
of this effort would be to provide positive identification of glycol ethers if they should be
present in the groundwater at or around the Site, and the extent of their presence.
*Risk Assessment
COMMENT: The technical advisor to the DHHA commented that the effect of capping
on air emissions was not addressed in the health risk assessment.
RESPONSE: EPA plans to evaluate health-based risk levels as a result of air emissions
from the landfill during the remedial design.
COMMENT: The technical advisor to the DHHA stated that it is inappropriate to assume
that current contaminant concentrations in the groundwater provide a conservative
15
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estimate of potential future contaminant concentrations. The existence of additional
sources of groundwater contaminants within the landfill cannot be ruled out with any
degree of confidence. In addition, because areas of high and lower contaminant
concentrations may be hydrologically connected, the concentrations reaching domestic
water wells could exceed those predicted from current on-site and off-site measurements.
RESPONSE: EPA believes that the Risk Assessment contained in the Rl does use
appropriately conservative procedures for estimating contaminant concentrations to which
persons might be exposed under current and future use conditions at the Site. In
addition, it must be realized that contaminant concentrations may decrease overtime due
to chemical and biological degradation of some contaminants.
COMMENT: The technical advisor to the DHHA questioned whether using showering as
the only scenario under which a resident would be likely to inhale volatile contaminants
in the domestic water supply is appropriate.
RESPONSE: While EPA realizes that showering is not the only route through which a
resident is exposed to volatile contaminants, EPA believes that the approach taken was
conservative. For the Site, the reasonable maximum exposure scenario for shower
exposure estimated that a person is exposed for 19.8 minutes per day to volatile
contaminants not the 12 minutes suggested by the Exposure Factors Handbook. As
previously mentioned, the exposure of those using the northeast residential wells to
groundwater volatiles while showering, under reasonable maximum exposure conditions,
contributed 9.79 x 10~5 to the total cancer risk and 0.005 to the total noncarcinogenic risk.
These calculation is within the acceptable ranges as set forward in the NCP.
COMMENT: The technical advisor to the DHHA stated that the Risk Assessment
incorrectly identifies lead as a compound for which toxicity data are not adequate to
support quantitative risk assessment. The problem posed in assessing risks of lead is
that the procedures employed by EPA for non-cancer risk assessment are invalid for lead.
RESPONSE: The actual choice of words concerning lead may have misled the reviewer.
The statement from Chapter 6 of the Rl report, Toxicity Data are not adequate to support
a quantitative Risk Assessment" was based on EPA's Risk Assessment Guidance (RAGS
1989) and EPA Region II protocol. A contaminant at a site, such as lead, that does not
have an accepted EPA slope factor or reference dose, cannot be quantitatively assessed
in the Risk Assessment for a Superfund site. However, the contaminants potential risk
must be addressed qualitatively in the Risk Assessment as to its potential health
concerns. It is then left to EPA to decide whether a potential health impact may occur
from that contaminant.
COMMENT: The technical advisor to the DHHA believes that, in general, the discussion
of the concept of "threshold" present in the Risk Assessment is somewhat misleading.
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RESPONSE: EPA believes that the discussion of "threshold" in the Risk Assessment
follows the general consensus within the scientific community.
COMMENT: The technical advisor to the DHHA commented that for some toxicants, the
total dose received over an extended period is a better indicator of toxicrty than average
daily dose (chronic daily intake in the terminology of the current assessment).
RESPONSE: EPA Risk Assessment protocols and accepted models examine exposure
based on average daily dose not total dose.
COMMENT: The technical advisor to the DHHA pointed out that the toxicity of chromium
is discussed only in the trivalent form, while measurements on-srte appear to represent
total chromium.
RESPONSE: The discussion of chromium has been amended in the Risk Assessment
of the Rl to include hexavalent chromium. The health-based risk numbers have been re-
calculated for chromium and incorporated into the ROD.
COMMENT: The technical advisor to the DHHA commented that actual grouping of
chemicals by target organs in the Risk Assessment is too narrow, and does not fully
represent the degree of overlap in the pattern of toxicity exhibited by each chemical.
RESPONSE: EPA agrees with this comment. However, we do not believe that it affects
the conclusions reached in the Risk Assessment.
COMMENT: The technical advisor to the DHHA believes that the report should be more
explicit and forceful in reminding the reader that the lack of a toxic hazard value
(Reference Dose = RfD or Slope Factor = SF) for a substance does not in any way imply
a lack of hazard. While the Risk Assessment presents only oral RfDs for styrene,
ethylbenzene, and perchloroethylene, these chemicals are toxic by inhalation as well.
RESPONSE: Inhalation slope factors are presented for styrene and perchloroethylene
while ethylbenzene has no EPA approved inhalation toxicity indices. The lack of inhalation
RfDs for styrene and perchloroethylene point towards the fact that these contaminants
either do not elicit a non-carcinogenic response or there is not enough data available in
the literature to derive an appropriate toxicity index via this exposure pathway. However,
since inhalation slope factors exist they will show a potential carcinogenic response
through this exposure pathway.
For ethylbenzene no carcinogenic response has been shown and ft does not appear to
elicit a noncarcinogenic response through inhalation based on the current toxicological
literature.
COMMENT: The technical advisor to the DHHA stated that there is a significant
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misstatement regarding the nature of the risk estimates provided by the Superfund risk
assessment process. While slope factors derived from animal studies are upper-bound
estimates of the slope of the dose-response function, the corresponding risk estimates
are not upper-bound estimates, because the exposure (dose) estimates are not upper-
bound estimates. In fact, for cases where slope factors are estimated from human rather
than animal data, the slope factors themselves are "best estimates", rather than upper
bound estimates.
RESPONSE: EPA disagrees with this comment. Page 8-6 of RAGS 1989 states,
"Because the slope factor is often an upper 95th percentile confidence limit of the
probability of response based on experimental animal data used in the multistage model,
the carcinogenic risk estimate will generally be an upper bound estimate. This means that
EPA is reasonably confident that the True Risk' will not exceed the risk estimate derived
through use of this mode and is likely to be less than that predicted".
COMMENT: The technical advisor to the DHHA noted that the author of the Risk
Assessment has chosen not to add non-cancer risks for childhood exposure to those for
adult exposure. This ignores the reasonable maximum exposure case of 17 years of
childhood residence followed by 13 years of residence in adulthood (i.e. 30 years total
residence).
RESPONSE: EPA calculates noncarcinogenic exposures (intakes) by averaging over the
shortest exposure period for acute toxicants (e.g. exposure event or a day) and averaging
intakes over the period of exposure for longer term exposure. EPA only considers
carcinogenic exposures cumulative since RfDs are estimates of the daily exposure to the
human population of a chemical which is likely to be without appreciable risk of
deleterious effects during a lifetime or portion thereof. The exposure scenarios used in
this Risk Assessment for noncarcinogenic exposures are based on a daily exposure for
17 years for children and 70 years for an adult.
COMMENT: The technical advisor to the DHHA commented that in the toxic hazards
descriptions the terminology employed changes from chemical to chemical. In addition,
much of the material appears to be old "boilerplate" that might benefit from review.
RESPONSE: The toxicity profiles used are those found in the latest EPA Integrated Risk
Information System ("IRIS") database.
COMMENT; The technical advisor to the DHHA noted that the term "Chronic Daily
Intake" (GDI) is applied to the results of two distinct calculations. "Average Daily Dose"
(ADD) is appropriate for calculating non-cancer risks (Hazard Quotients and Hazard
Indices), while "Lifetime Average Daily Dose" (LADD) is used to calculate cancer risks.
RESPONSE: The terminology suggested by the commentor is part of the Exposure
Factors Handbook and not part of RAGS (1989). The Warwick- Landfill site Risk
•
f-
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Assessment follows Superfund convention.
COMMENT: The technical advisor to the DHHA believes that the presentation of risk
values with three significant digits (e.g. 1.18 x 10"4) is misleading.
RESPONSE: EPA does not believe that the use of three significant digits is misleading
because it provides the reader more information regarding the potential risk level at a site
than reporting risks as 1 x 10"*, 1 x 10"5 or 1 x 10"6. In addition, if one were to convert
1.18 x 1CT4 to one significant figure (e.g. 1 x 10"*) the rounding error encountered in risk
assessments would be enormous and could seriously misinterpret the potential site risks
when examining cumulative risks across pathways.
*Feasibilitv Study
COMMENT: The technical advisor to the DHHA stated that the most serious problem
with this RI/FS is that the FS did not sufficiently reflect the data gaps and uncertainties
in the Rl report or address all of the risks identified in the baseline risk assessment.
RESPONSE: EPA believes that the FS does identify the data limitations as outlined in
Chapter 7 of the Rl report and addresses the risks identified in the baseline risk
assessment. Because of the recognized data limitations under OU1, which include: 1)
identifying the contaminant source of the three residential wells; 2) defining the vertical
and horizontal extent of the groundwater plume; and 3) evaluating landfill air emissions,
a second operable unit is necessary.
COMMENT: The technical advisor to the DHHA commented that the key deficiency of
the FS report is that it fails to address the fact that there are significant risks associated
with inorganic contaminants and strongly hydrophilic contaminants in groundwater at and
near the Site. The carbon filters only address organic chemical contamination and might
be ineffective in removing inorganic contaminants that the Rl identifies as presenting a
significant risk.
RESPONSE: Inorganic contamination in exceedance of New York State and/or Federal
drinking water standards was detected in on-s'rte groundwater monitoring wells. Inorganic
contamination (lead) was detected in one residential well which was attributed to the
household plumbing system rather than the landfill. This was the only residential well
which exhibited inorganic contamination above drinking water standards. The strongly
hydrophilic contaminants referred to in the above comment are the tentatively identified
compounds ('TICs") known as the glycol ether compounds in a few of the groundwater
monitoring wells and leachate samples. These glycol ethers were not identified as TICs
in residential wells.
At this time, the assessment of TIC compounds must be qualitative because of the
tentative identification, uncertainties about precise concentrations, and limited information
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about the toxic effects of these compounds. EPA plans to conduct sampling specific to
the identification of glycol ether compounds in OU2. In addition, the residential well
samples will be analyzed for the full Target Compound List. Should contaminants be
identified, which cannot be effectively removed by carbon filters, in exceedance of MCLs
in residential wells, EPA will consider alternative measures to protect the health of the
current well users.
COMMENT: A consultant to one of the PRPs commented that certain major cost items
have not been included in the total capital cost items of Alternative 3. These items not
costed under Alternative 3 include: mobilization costs; temporary erosion control
measures; health and safety planning and implementation; wetland assessment and
mitigation; and surface runoff control measures. The additional items could add
approximately $1,000,000 to the capital costs listed in the referenced tables of the FS
report.
RESPONSE: It is true that the above mentioned comments are not specifically outlined
in the cost estimates for Alternative 3. The cost of many of these items, such as
mobilization costs, temporary erosion control measures, health and safety planning and
implementation and surface runoff control measures are incorporated into the landfill cap
construction cost estimates. A detailed cost breakdown will be provided during remedial
design.
OTHER CONCERNS
COMMENT: A resident asked whether Greenwood Lake would ever be monitored under
the Superfund program.
RESPONSE: Based on results of samples taken near the lake during the Rl for the first
operable unit, EPA sees no reason to sample the waters of Greenwood Lake under the
Superfund program. Additional environmental monitoring during OU2 in the wetlands
adjacent to the landfill will determine whether there is a need for further testing
downstream.
COMMENT: A resident inquired whether there would be any consideration of seeing
methane used to recoup some of the money spent during remediation of the Site.
RESPONSE: The results of the air monitoring using portable HNu and OVA meters
during the summer months of the field investigation indicated methane levels of less than
40 ppm. In addition, excessive methane levels were not encountered when digging the
three landfill soil borings. These results, combined with the size and age of the landfill,
are reasons to believe that there is not sufficient methane generated to warrant methane
collection from an economic perspective.
20 *•
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COMMENT: A reporter asked why a health survey had not been performed on the
residents in the vicinity of the Site.
RESPONSE: In July 1989, NYSDOH under a cooperative agreement with the Agency for
Toxic Substances and Disease Registry prepared a preliminary health assessment for the
Site which can be found in the Administrative Record for the Site. The assessment
concluded that the Site does represent a potential public health threat and recommended
continued monitoring of private residential wells. To date, 42 area residential wells have
been sampled. A comprehensive residential well sampling program will be established
during remedial design of this first operable unit. This information as well as information
provided in the RI/FS indicates that a health survey is not warranted.
COMMENT: A resident asked whether it could be determined the quantity and
classification of hazardous substances produced by companies in the Warwick Landfill
area to deduce what materials might be disposed of at the Site.
RESPONSE: The manifest system under the Resource Conservation and Recovery Act
allows for the tracking of chemicals from generation to ultimate disposal. However,
because disposal practices at this Site took place from 10 to 35 years ago at a time when
documentation of waste disposal was less regulated, it is difficult to quantify the wastes
generated by area companies and disposed of at the Warwick Landfill. To date, EPA has
identified 16 PRPs which include: generators of hazardous substances transported to the
Site; transporters disposing of waste at the Site; the landfill operators; and the current
owner of the Site.
COMMENT: A resident asked which government agency he should contact if he would
like his residential well sampled.
RESPONSE: If the resident would like his well sampled at the earliest date possible, he
should contact the NYSDOH which has been conducting the residential well sampling
program in the vicinity of the Site. In addition, he should send a letter to EPA requesting
that his well, provided it is among the 42 residential wells in the vicinity of the Site, be
included in the residential well sampling program during the remedial design.
COMMENT: An area resident inquired if EPA has any provisions for purchasing his
property. He states that he has not been able to sell it because those outside of the
regulatory authorities have deemed his water supply unsatisfactory, yet contamination has
not been detected in exceedance of New York State and/or Federal drinking water
standards. -
RESPONSE: Under the law, the EPA can only reimburse property owners for property
it acquires to implement a Federal project. However, the Agency's actions should not
stop individuals from exploring whether they have a cause of action against those
responsible parties for diminution of their property values.
21 *;
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* Future Qontaminant Releases
COMMENT: A resident expressed concern that contaminants might continue to leach
out of the landfill for twenty years and EPA may no longer be in existence to protect the
public's health and the environment.
RESPONSE: The Superfund is funded primarily by taxes on crude oil and petroleum
products and on certain chemicals and is therefore atypical of other EPA programs which
rely on tax revenues. Barring no reauthorization of the CERCLA statute, the Fund is
expected to have sufficient monies and provisions necessary to ensure that remedies
which involve containment of waste continue to be protective of human health and the
environment. In fact, because hazardous substances will remain on-site as outlined in the
ROD, the Site will be reviewed every five years to ensure that this is the case, pursuant
to CERCLA requirements. The State of New York, or possibly the PRPs with State and
Federal oversight, will be responsible for operating the landfill to maintain the effectiveness
of the closure system.
COMMENT: A resident expressed concern that there could be drums in the landfill which
will not break down for another 20 years.
RESPONSE: Drums constructed of plastics or metal (that is not exposed to water) may
not degrade within a twenty year time period. However, buried drum materials, if present
at the Site, have been exposed to infiltrating rainwater, perched water, and perhaps
groundwater within the landfill for over ten years and such exposure could cause the
rusting and disintegration of metal containers. It is possible that there are buried
hazardous wastes in the landfill that have not leached into the groundwater and have yet
to form a contaminant plume. For this reason, the Superfund program requires that the
Site be reviewed every five years for at least thirty years. In addition, the groundwater
monitoring program, as specified in the selected remedy, will enable changes in
contaminant levels to be detected. In the event of a significant increase in contamination
stemming from the Site posing a threat to human health and the environment, the EPA
would develop plans to remediate the situation in a timely manner. In addition, the
second operable unit will evaluate the need to implement a final remedy for the
groundwater at the Site. If the remedy calls for treatment of the groundwater, then the
likelihood that significant contamination would leave the landfill would be further reduced.
In February 1991, a geophysical investigation, which included a magnetic gradiometer
survey and terrain conductivity screening, was conducted at the Site to identify areas
within the landfill where buried drums might be present. Based on the results of this
investigation, three test pits were excavated to observe landfill material. No buried drums
were located.
22
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THE SUPERFUND PROCESS
COMMENT: The technical advisor to the DHHA questioned the delay of the decision on
a residential water supply. The advisor stated that it should be given top priority, in
accordance with Section 118 of CERCLA, as amended. The issues-that are of most
concern to the members of DHHA, the extent of contamination and the safety of
residential water supplies, have been delayed until a future date.
RESPONSE: At present, contaminants have been detected in three residential wells in
exceedance of New York State and/or Federal drinking water standards. Because of the
complex hydrogeological conditions at the Site and the limited field investigation under
OU1, EPA believes that a second operable unit is necessary to characterize Site
hydrogeological conditions and the fate and transport of contaminants emanating from
the landfill. The Warwick Landfill site is listed on the National Priorities List ("NPL") and
is accordingly a top priority site for the EPA Superfund Program.
COMMENT: A resident inquired about the date when EPA will finalize the Record of
Decision and when remedial action at the Site will begin.
RESPONSE: EPA plans on finalizing the ROD in June 1991. Following the signing of the
Record of Decision, EPA will send a General Notice letter with an attached Consent
Decree to the PRPs informing them of their responsibilities. The negotiation process will
be expected to conclude in early September 1991. If negotiations prove successful, EPA
will enter into a Consent Decree with the PRPs which must undergo public comment prior
to entry by the Court. This process could take several months. In the alternative, EPA
could elect to issue a unilateral order to the PRPs to do the RD/RA. It is roughly
estimated that, either by Consent Decree or unilateral order, the PRPs would not be
expected to commence RD/RA until the beginning of 1992. Whether or not the PRPs or
the Superfund finances the RD/RA, the remedial action will begin approximately 18
months after the start of the remedial design.
COMMENT: A reporter inquired about the cost of the Ringwood alternate water supply
system developed for the community surrounding the Ringwood Mines Superfund site in
New Jersey and whether it is the same situation at the Warwick site.
RESPONSE: An alternate water supply system was not developed under the Superfund
program for the Ringwood Mines Superfund site. The potable wells surrounding the Site
did not show levels of contamination exceeding MCLs. At present, EPA is overseeing the
operation and maintenance program conducted by the PRP for the Ringwood Mines site.
COMMENT: A resident inquired about how much importance the EPA places on the
community's input during the public comment period before the Record of Decision is
signed. ~ -••
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RESPONSE: The selected remedy in the ROD is not finalized until the public comment
period is closed and EPA has had the opportunity to review and address the community's
concerns. Community acceptance is one of the nine evaluation criteria developed by EPA
to address the technical and policy considerations that are important for selecting among
potential remedial alternatives. The other eight criteria are: overall protection of human
health and the environment; compliance with legally applicable or relevant and appropriate
requirements; long term effectiveness; reduction of toxicrty, mobility or volume; short term
effectiveness; implementability; cost; and state acceptance. The preferred alternative
provides the best balance among all nine criteria based on available information. Barring
substantial opposition during the public comment period or the addition of new and
relevant information calling for a change in remediation alternatives, the preferred
alternative becomes the selected remedy in the ROD.
OPERABLE UNIT TWO
COMMENT: The technical advisor to the DHHA recommended that future site
investigations include analyses of capture zones resulting from residential well use.
RESPONSE: EPA plans to address the dynamic aspects of groundwater hydraulics at
the Site. The work will be performed under OU2 and will include pumping test(s) and
analyses of capture zones from residential wells, more extensive groundwater monitoring
using additional well installations and existing wells, and the development of a site
hydrogeochemical model. The OU2 work plan will outline the investigation for the second
operable unit.
COMMENT: A resident inquired about the cost of OU2 and development of a final
groundwater remedy.
RESPONSE: At this time, EPA estimates that the costs for the OU2 remedial
investigation and feasibility study will be approximately $500,000. The cost of a final
groundwater remedy cannot be determined until a remedy is chosen after the RI/FS is
complete.
COMMENT: A resident asked what water supply system would take the place of the
residential wells.
RESPONSE: Pending the outcome of the additional hydrogeological investigation, EPA
anticipates investigating several alternative water supply remedies under OU2. Remedies
investigated would include but not be limited to: 1) installing another residential well at
another location and depth elsewhere on each homeowner's property; 2) a community
well system servicing the residents surrounding the Site; and, 3) connecting residential
water lines to the Village of Greenwood Lake's municipal water supply. The FS for OU2
is also expected to evaluate alternatives for containing/treating site groundwater.
24
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APPENDIX A
PUBLIC MEETING AGENDA
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION II
JACOB !C JAVITS FEDERAL BUILDING
NEW YORK. NEW YORK 1O276
PUBLIC KEETING FOR THE WARWICK LANDFILL
SUPERFUND SITE/ TOWN O? WARWICK, ORANGE COUNTY/ NEW YORK
MONDAY/ APRIL 22, 1991
7:00 P.M.
GREENWOOD LAKE MIDDLE SCHOOL
GREENWOOD LAKE, NEW YORK
AGENDA .
Welcome & Introduction Ann Rychlenski
Corj~ur.:.ty Relations
Coordinator, U.S. EPA,
Region 2
Overview of the Superfund Doug Garbarini, Chief
Process Eastern NY/Caribbean Superfunc
Section 1
U.S. EPA, Region 2
Presentation of the Renedial Julia Allen, Project Manager
Investigation/Feasibility U.S. EPA, Region 2
Study Report
Presentation of the Proposed Julia Allen, Project Manager
Plan U.S. EPA, Region 2
Question & Answer Period
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APPENDIX B
PUBLIC MEETING SIGN-IN SHEETS
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.UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION II
JACOE K. JAVITS FEDERAL BUILDING
NEW YORK. NEW YORK 1O276
SIGN IK SSSET
WARWICK LANDFILL SUPZRPUND SITE PUBLIC KEETING
MONDAY, APRIL 22, 1991
GREENWOOD LAKE KIDDLE SCHOOL, GREENWOOD LAKE/ KEW YORK
PLEASE PRINT YOUR NAKE AND ADDRESS CLEARLY SO THAT WE CAN
KAiNTAiN ACCURATE MAILING LISTS. THANKS.
KA
ADDRESS
C7
^ 1 - gc-x
'
re. fJ\f.
V G
lOtt f
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I UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION II
JACOB K. JAVITS FEDERAL BUILDING
NEW YORK. NEW YORK 1O278.
. SIGN IN SHEET
WARWICK LANDFILL SUPERFUND SITE PUBLIC MEETING
MONDAY/ APRIL 22, 1991
GREENWOOD LAKE KIDDLE SCHOOL/ GREENWOOD LAKE, NEW YORK
PLIASS PRINT YOUR KAME AND ADDRESS CLEARLY SO THAT WE CAN
MAINTAIN ACCURATE MAILING LISTS. THANKS.
NAHE ADDRESS
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION 11
JACOB K. JAVr7S FEDERAL BUILDING
NEiV YORK. NEW YORK 1O27S
SIGN XV SHEET
WARWICK LANDFILL SUTSRJUND BITE PUBLIC KEETING
XONDAY, APRIL 22, 1991
GREENWOOD LAX3 KIDDLE SCHOOL/ GREENWOOD LAKE/ NEW YORK
PLEASE PRINT YOUR NAME AND ADDRESS CLEARLY SO THAT WE CAN
MAINTAIN ACCURATE HAILING LISTS. THANKS.
NAME
ADDRESS
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION!!
JACO3K.JAVITS FEDERAL BUILDING
NEWYORK. NEW YORK 1O278
SIGN IN EZEET
WARWICK LANDFILL SUPERPUND SITE PUBLIC HEETING
XONDAY, APRIL 22, 1991
GREENWOOD LAKE KIDDLE SCHOOL, GREENWOOD LAKE, HEW YORK
PLEASE PRINT YOUR NAME AND ADDRESS CLEARLY SO THAT WE CAN
KAINTAIN ACCURATE HAILING LISTS. THANKS.
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UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION II
**>•*
JACOB K- JAVITS FEDERAL BUILDING
NEW YORK. NEW YORK 1O278
SIGN IN SHEET
WARWICK LANDFILL SUPERTUKD SITE PUBLIC KEETIKG
MONDAY, APRIL 22, 1991
GREENWOOD LAKE KIDDLE SCHOOL, GREENWOOD LAKE, NEW YORK
PLEASE PRINT YOUR NAME AND ADDRESS CLEARLY SO TEAT WS CAN
MAINTAIN ACCURATE HAILING LISTS. THANKS.
NAME ADDRESS
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