United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R02-91/131
December 1990
oEPA
Superfund
Record of Decision:
General Motors/Central
Foundry Division, NY
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R02-91/131
3. Recipient1* Accession No.
4. Ira* and Subtitle
SUPERFUND RECORD OF-DECISION
General Motors/Central Foundry Division, NY
First Remedial Action
S. Report Dale
12/17/90
7. Author)*)
8. Performing Organization Rept No.
». Performing Organization Name end Addreu
10. Pro|ect/Ta*k/Work Unit No.
11. Contnct(C) or Grant(G) No.
(C)
(G)
12. Sponsoring Organization Name and Addreu
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Typo of Report ft Period Covered
800/000
14.
15. Supplementary Note*
16. Abstract (Limit: 200 words)
The 270-acre General Motors/Central Foundry Division site is an active aluminum casting
plant in Massena, St. Lawrence County, New York. The site is bordered by the St.
Lawrence River to the north, the St. Regis River Mohawk Indian Reservation (which
includes Turtle Creek) to the east, the Raquette River to the south, and a
manufacturing facility to the west. Surrounding land use is mixed residential and
industrial. The site overlies a surficial alluvial aquifer and is adjacent to
wetlands, .both of which, have been contaminated. Additional onsite features of concern
include the unlined North and East Disposal Areas and the Industrial Landfill, which
contain contaminated soil, debris, sludge; four unlined Industrial Lagoons, which
contain contaminated liquids, sludge, and soil; the rivers and creek which contains
contaminated sediment; contaminated soil on the St. Regis Mohawk Reservation and on
General Motors property; and contaminated associated wetlands. From 1959 to 1980,
hydraulic fluids containing PCBs were used in the onsite aluminum casting operations.
During the 1960's, PCS oil-laden wastewater was routinely discharged to one of the four
industrial lagoons resulting in sludge buildup. Wastewaters were discharged to the St.
Lawrence River. During the mid-1970's, the migration of water and sludge through a
(See Attached Page)
17. Document AnalyaJa a. Descriptors
Record of Decision - General Motors/Central Foundry Division, NY
First Remedial Action
Contaminated Media: soil, sediment, sludge, debris, gw, sw
Key Contaminants: VOCs (TCE), other organics (PAHs, PCBs, phenols)
b. Identifiers/Open-Ended Terms
c. COSATI Bold/Group
18. AvailabUty Statement
18. Security das* (This Report)
None
20. Security da** (This Page)
None
21. No. olPagea
207
22. Price
(See ANSI-Z39.18)
See Instruction* on Revene
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R02-91/131
General Motors/Central Foundry Division, NY
First Remedial Action
Abstract (Continued)
breached berm surrounding the East Disposal Area resulted in PCB contamination on the
St. Regis Reservation and in Turtle Creek. Further contamination stemmed from the
placement of PCB-contaminated soil on the bank of the Raquette River, as well as from
discharge of surface water runoff from the site to the Raquette River. In 1976, a
wastewater treatment system, which included a lagoon for solids settling was installed
resulting in which created PCB-laden sludge buildup in the onsite lagoon. PCB-laden
sludge from the lagoon was periodically removed to the East and North Disposal Areas and
the Industrial Landfill. Solid industrial wastes were disposed of in the Industrial
Landfill as well. Investigations by General Motors from 1985 to 1989 confirmed and
characterized onsite and offsite contamination in soil, sediment, sludge, and ground
water. As a result, in 1988 an interim cap was placed over the Industrial Landfill.
This Record of Decision (ROD) provides a final remedy for all site areas and media
except the East Disposal Area and the Industrial Landfill, which will be addressed in a
subsequent ROD. The primary contaminants of concern affecting the soil, sediment,
sludge, debris, ground water, and surface water are PCBs, and to a much lesser degree,
VOCs including TCE; and other organics including PAHs, and phenols.
The selected remedial action for this site includes dredging and excavating
approximately 62,000 cubic yards of contaminated soil and sediment from PCB "hot spots"
in the St. Lawrence and Raquette rivers, Turtle Creek, and associated wetlands and
riverbanks; excavating approximately 142,000 cubic yards of sludge, soil, and debris
from the North Disposal Area and the four Industrial Lagoons (two of the four of the
lagoons are inactive and will be remediated currently, the two active lagoons will be
remediated after they are taken out of service); excavating approximately 49,000 cubic
yards of soil from the Reservation and General Motors property; dewatering and treating
dredged and excavated material using bioremediation, another equivalent treatment, or
incineration based on treatability test results; disposing of residuals and material
with low-level contamination onsite, placing a vegetated cap over the residuals; pumping
and onsite treatment of contaminated ground water; discharging the treated water onsite
to surface water; implementing interim surface runoff controls at the East Disposal
Area; and monitoring sediment, ground water, and surface water. The estimated present
worth cost for this remedial action is $78,000,000, which includes an annual O&M cost of
$464,000 for years 0-8, $197,000 for years 9-10, $464,000 for years 11-13, and $197,000
for years 14-30.
PERFORMANCE STANDARDS OR GOALS: Excavation levels for PCB-contaminated materials are
based on TSCA requirements and St. Regis Mohawk PCB clean-up requirements, and include
1 mg/kg (TSCA) for sediment in the St. Lawrence and Raquette Rivers, 1 mg/kg (St. Regis)
for soil on the St. Regis Reservation, 0.1 mg/kg (St. Regis) for sediment in Turtle
Creek, and 10 mg/kg (TSCA) for onsite soil and sludge on the General Motors facility.
PCB-contaminated material will be treated to a level of 10 mg/kg or less. Phenols in
onsite solids will be remediated to a level of 50 mg/kg. Ground water cleanup standards
are based on State standards, and include TCE 5 ug/1, PCBs 0.1 ug/1, and phenols 1 ug/1.
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SITE
Name:
Location:
HRS Score:
NPL Rank:
ROD
Date Signed;
Remedy:
Capital Cost:
0 & M/Year:
Present Worth;
ROD FACT SHEET
General Motors - Central Foundry Division (first
operable unit)
Massena, St. Lawrence County, New York
Group 5
350
December 17, 1990
Dredging/excavation of sediments and soils in the
St. Lawrence and Raquette Rivers and in Turtle
Creek; excavation of sludges, soil and debris in
the North Disposal area, in the four Industrial
Lagoons, and in other areas on G.M. property;
excavation of soil on St. Regis Mohawk Reservation
land; treatment of dredged/excavated material by
either biological treatment (or another innovative
treatment technology which has been demonstrated
to achieve site treatment goals) or thermal
destruction to be determined following
treatability testing; and downgradient groundwater
recovery and treatment.
$ 84.8 million
$ 197,000 - $ 464,000 per year
$ 78 million
Potentially Responsible Party
Lisa Carson, (212) 264-6357
General Motors Corporation
PCBs, phenols, PAHs
Sediments, soil, sludges, and groundwater
On-site disposal of PCBs used in hydraulic fluids
Est. Quantity: Approximately 253,000 cubic yards of PCB
contaminated material addressed in this ROD
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DECLARATION FOR THE RECORD OF DECISION
SITE NAME AND LOCATION
General Motors Corporation - Central Foundry Division Site
Massena, St. Lawrence County, New York
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for
the General Motors - Central Foundry Division Superfund Site, in
Massena, New York, which was chosen in accordance with the
requirements of the Comprehensive Environmental Response,
Compensation and Liability Act of 1980 (CERCLA), as amended by
the Superfund Amendment and Reauthorization Act of 1986 (SARA),
and the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). This decision document explains the
factual and legal basis for selecting the first operable unit
remedy for this Site.
The New York State Department of Environmental Conservation
(NYSDEC) and the St. Regis Mohawk Tribe concur on the selected
remedy. Letters of concurrence from NYSDEC and the St. Regis
Mohawk Tribe are appended to this document.
The information supporting this remedial action decision is
contained in the Administrative Record for this Site.
ASSESSMENT OF THE SITE
Certain actual or threatened releases of hazardous substances at
or from this Site, if not addressed by implementing the response
action selected in this Record of Decision (ROD) , may present a.-.
imminent and substantial endangerment to public health, welfare,
or the environment.
DESCRIPTION OF THE REMEDY
This action or "operable unit" is the first of two operable units
that are planned for the Site. This operable unit addresses
several of the principal threats at the Site by treating
contaminated river system sediments and sludges, soil, and
groundwater at the Site. The second operable unit will address
the threats resulting from the East Disposal Area and the
Industrial Landfill at the Site.
The major components of the selected remedy include:
Dredging and excavation of sediments and soils fror,
polychlorinated biphenyl (PCB) contaminated areas in
the St. Lawrence and Raguette Rivers, Turtle Creek, a.-. !
associated riverbanks and wetlands;
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Interim surface runoff control to prevent migration of
contamination from the East Disposal Area;
Excavation of PCB contaminated sludges, soil, and
debris in the North Disposal Area, in and around the
four Industrial Lagoons, and in other areas on General
Motors (G.M.) property (two of the four lagoons, which
are currently in use by G.M., will be remediated when
they are taken out of service);
Excavation of PCB contaminated soil on St. Regis Mohawk
Reservation land adjacent to the G.M. facility;
Recovery and treatment of groundwater downgradient from
the Site with discharge of treated groundwater to the
St. Lawrence River; and
Treatment of dredged/excavated material by either
biological treatment (or another innovative treatment
technology which has been demonstrated to achieve site
treatment goals) or thermal destruction to be
determined by the U. S. Environmental Protection Agency
(EPA) following treatability testing. Treatment
residuals will be disposed on-site. Other innovative
PCB treatment technologies will be tested concurrently
with biological treatment so that EPA will have
additional information in the event that biological
treatment proves to be unsatisfactory for treatment of
any Site material. EPA will select the treatment
technologies to be employed, in consultation with
NYSDEC and the St. Regis Mohawk Tribe.
DECLARATION
The selected remedy is protective of human health and the
environment, complies with Federal, State and Tribal requirements
that are legally applicable or relevant and appropriate to the
remedial action (or provides grounds for invoking a waiver of
these requirements), and is cost-effective. This remedy utilizes
permanent solutions and alternative treatment technologies to the
maximum extent practicable and satisfies the statutory preference
for remedies which employ treatment that reduces toxicity,
mobility, or volume as a principal element.
Because this remedy will result in hazardous substances remaining
on-site above health-based levels in the active Industrial
Lagoons until they are taken out of service, a review will be
conducted within at least five years after commencement of
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DECISION SUMMARY
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION SITE
MASSENA, 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 3
SCOPE AND ROLE OF OPERABLE UNIT 4
SUMMARY OF SITE CHARACTERISTICS 5
SUMMARY OF SITE RISKS 8
DESCRIPTION OF ALTERNATIVES 11
SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES 26
DESCRIPTION OF THE SELECTED REMEDY 33
STATUTORY DETERMINATIONS 38
DOCUMENTATION OF SIGNIFICANT CHANGES 41
ATTACHMENTS
APPENDIX 1 - FIGURES
APPENDIX 2 - TABLES
APPENDIX 3 - NYSDEC AND TRIBAL LETTERS OF CONCURRENCE
APPENDIX 4 - RESPONSIVENESS SUMMARY
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SITE NAME. LOCATION. AND DESCRIPTION
The General Motors - Central Foundry Division (G.M.) Site is
located on Rooseveltown Road in St. Lawrence County in Massena,
New York. The Site consists of several waste areas at an active
G.M. manufacturing facility along with contaminated soils on
G.M.'s property and on the St. Regis Mohawk Reservation,
contaminated sediments in the St. Lawrence and Raquette Rivers
and in Turtle Creek, associated riverbanks and wetlands, and
contaminated groundwater. Because the Mohawk people have a
cultural and spiritual link to the St. Lawrence region, which
they call Akwesasne. special consideration must be given to
Native American concerns in evaluating and remediating the Site.
The G.M. facility is bordered on the north by the St. Lawrence
River, on the east by the St. Regis Mohawk Indian Reservation, on
the south by the Raquette River and on the west by the Reynolds
Metals Company and property owned by Conrail (see Figure 1).
Land use in the area surrounding the Site consists of mixed
residential and industrial uses. The Reynolds Metals Company
facility and another facility west of the Site owned by the
Aluminum Company of America are presently under investigation by
the U. S. Environmental Protection Agency (EPA) and the New York
State Department of Environmental Conservation (NYSDEC). The
nearest residence is located on the St. Regis Mohawk Indian
Reservation approximately 300 feet from the G.M. facility
boundary. St. Lawrence River flows are partially controlled by
the Moses-Saunders Power Dam, located approximately four miles
upstream from the Site.
The G.M. facility consists of approximately 270 acres of
industrial and undeveloped land. Wetlands lie east of the
facility in the area surrounding Turtle Creek. There are no
federally listed endangered or threatened species known to
inhabit the St. Lawrence River. However, the River does support
a number of New York State listed endangered, threatened and
special concern fish species. The River and adjacent habitats
also provide nesting for a variety of water birds and shorebirds.
Federally listed endangered falcons and bald eagles have been
reported in the Massena area.
The Site, as defined by EPA, consists of several major areas
which are depicted schematically in Figure 2. The North and East
Disposal Areas and the Industrial Landfill contain soil, debris,
and sludge. The four unlined Industrial Lagoons contain liquids,
sludges, and solids and are referred to as the 350,000 gallon,
500,000 gallon, 1.5 million gallon and 10 million gallon lagoons.
The Site also includes contaminated sediments, riverbanks, and
associated wetlands of the St. Lawrence River, the Raquette River
and Turtle Creek (formerly called the unnamed tributary on the
St. Regis Mohawk Reservation), contaminated soil on the St. Regis
Mohawk Indian Reservation, contaminated soil on G.M. property no.
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associated with the specific disposal areas already mentioned,
and contaminated groundwater.
Groundwater flow generally reflects surface topography and flows
north toward the St. Lawrence River and northeast to Turtle
Creek. Turtle Creek and the adjacent wetlands serve as discharge
areas for shallow groundwater flow. There is also some limited
shallow groundwater flow south toward the Raquette River. A few,
residents on Raquette Point rely on groundwater as a drinking
water supply. The remainder of the Raguette Point residents
obtain water from a public water supply system which has its
intake in the St. Lawrence River at the mouth of the Raguette
River, approximately 1.5 miles downriver from the G.M. facility.
SITE HISTORY AND ENFORCEMENT ACTIVITIES
G.M. has operated an aluminum casting plant at the Site since
1959. Until 1980, polychlorinated biphenyls (PCBs) were a
component of hydraulic fluids used in diecasting machines at the
G.M. facility. PCBs provided protection against fire and thermal
degradation in the high temperature environment of the diecasting
machines. G.M. no longer uses the diecasting process at the
facility.
In the early 1960's, wastewater containing PCB-laden oil passed
through the 1.5 million gallon lagoon and then to the St.
Lawrence River. In 1968-1969, a lined interceptor lagoon was
added adjacent to the 1.5 million gallon lagoon. This lined
lagoon was subseguently buried and is considered by EPA to be a
part of the North Disposal Area. In 1976, a wastewater treatment
system was installed at the plant. In that system, wastewater
was sent to the 350,000 gallon lagoon for solids settling.
Treated water was pumped to the 500,000 gallon and 10 million
gallon lagoons for reuse as plant process water. Periodically,
water was discharged to the St. Lawrence River from the 1.5
million gallon lagoon. The 1.5 million gallon lagoon was not
used for settling after 1976; however, water passed through the
1.5 million gallon lagoon, which contained PCB sludges, prior to
discharge to the St. Lawrence River after 1976. After further
modifications to G.M.'s wastewater treatment process, the 350,000
gallon lagoon was taken out of service in 1980. All four lagoons
are subject to regulation under the Toxic Substances Control Act
(TSCA) because they were part of G.M.'s wastewater process after
February 17, 1978, the date the TSCA PCB regulations became
effective.
During operations, PCB laden sludge from the 1.5 million gallon
lagoon and from the wastewater treatment plant was periodically
removed to the North and East Disposal areas and to the
Industrial Landfill. The Industrial Landfill has also received
foundry sand, soil and concrete excavated during plant
construction, diecasting machines, and solid industrial waste.
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The Landfill was covered with an interim cap in 1988. The North
Disposal Area also received construction debris, soil and tree
stumps. The East Disposal Area contains soil and sludge along
with construction debris. The North and East Disposal Areas and
the Industrial Landfill were not lined.
In 1975, a berm surrounding the East Disposal Area was breached.
Water and sludge flowed east to the St. Regis Mohawk Reservation
and to Turtle Creek. Visible spill material was removed from the
Reservation to G.M. property. In 1970, PCB contaminated soil
excavated during plant expansion was placed on the north bank of
the Raguette River. In addition, G.M. discharged surface water
runoff to the Raquette River until 1989 under a State Pollution
Discharge Elimination System (SPDES) permit.
The G.M. Site was placed on the Superfund National Priorities
List ("NPL") in September 1983 as a result of G.M.'s past waste
disposal practices. G.M. indicated a willingness to perform the
Remedial Investigation and Feasibility Study (RI/FS) for the
Site. On April 16, 1985, EPA and G.M. entered into an
Administrative Order on Consent (Index No. II CERCLA-50201) for
G.M.'s performance of the RI/FS. Draft and Phase II RI reports
were submitted to EPA in May 1986 and May 1988, respectively.
G.M. performed additional river sampling in February 1989, and
submitted a report on the additional sampling to EPA in May 1989.
On June 9, 1989, EPA approved the RI report, which consists of
the draft RI report, the Phase II RI report and the sediment
sampling report, for the Site. The RI report delineated those
areas in need of remediation throughout the Site. G.M. submitt-::
the draft FS report to EPA in November 1989.
G.M. also entered into a 1985 Consent Order with EPA under the
authority of TSCA. In addition to payment of penalties for
failure to comply with certain TSCA regulations, G.M. agreed tc
close an abandoned pump house on-site.
HIGHLIGHTS OF COMMUNITY PARTICIPATION
The FS and Proposed Plan for the G.M. Site were released to the
public in March 1990. These documents, along with the RI, were
made available to the public in information repositories
maintained at EPA Region II offices in New York city, at the
Massena Public Library, and at the St. Regis Mohawk Tribal
Building. The notice of availability of these documents was
published in the Massena Daily Courier-Observer on March 21,
1990. A public comment period was held from March 21, 1990
through June 18, 1990. The public comment period was extended
once upon the request of the St. Regis Mohawk Tribe.
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A public meeting was held on April 25, 1990. At this meeting,
representatives from EPA answered questions and received comments
on EPA's Proposed Plan and the other remedial alternatives under
consideration. In addition, a public availability session was
held in Massena on April 26, 1990. The public availability
session was an additional informal opportunity for the public to
ask questions or comment on EPA's Proposed Plan. On May 9, 1990,
EPA met with representatives of the Public Advisory Committee
(PAC) in Cornwall, Ontario, Canada to receive the PAC's comments
on EPA's Proposed Plan.
A response to comments received during the public comment period
is included in the Responsiveness Summary which is part of this
Record of Decision (ROD). The Responsiveness Summary and ROD,
along with the Administrative Record for the Site are available
at the information repositories referenced above.
SCOPE AND ROLE OF RESPONSE ACTION
EPA has organized the work at the Site into two operable units.
This ROD for operable unit one presents the selected remedy for
the contaminated sediments, contaminated groundwater, soils on
the G.M. facility and on the Reservation, and material in the
Industrial Lagoons and the North Disposal Area at the Site.
Operable unit two, which will be the subject of a separate ROD,
will address the East Disposal Area and Industrial Landfill.
Initially, a second operable unit was required so that EPA could
reevaluate Industrial Landfill data and better factor community
concerns into its decision-making process for the Industrial
Landfill.
EPA has deferred its remedial decision for the East Disposal Ar~-:
to the second operable unit in order to evaluate the impact and
applicability of new EPA guidance on Superfund sites which are
contaminated with PCBs ("Guidance on Remedial Actions for
Superfund Sites with PCB Contamination," OSWER Directive 9355.4-
01, August 1990). This guidance was issued following the publ:;-
comment period for the G.M. Site and, while it does not affect
the remedy selected in this ROD for other Site areas, it may
affect EPA's remedy selection for the East Disposal Area and the
Industrial Landfill. Specifically, this guidance recommends
that, when considering cleanup of areas which contain large
volumes of PCB contaminated material (like the East Disposal Ar& :
and the Industrial Landfill), a cleanup alternative which
combines treatment of highly contaminated material with
containment of less contaminated material be evaluated. EPA wil.
evaluate such an alternative in the coming months and plans to
issue a second operable ROD which addresses remediation of the
East Disposal Area and the Industrial Landfill in early 1991. ::-.
order to expedite site cleanup, the second operable unit remedy
for the East Disposal Area and the Industrial Landfill will be'
consistent with the remedy selected in this document.
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The remediation of the entire G.M. Site will be complete only
after EPA has selected and implemented remedial actions for both
operable units. The final remediation of the Site is intended to
address the entire Site with regard to the principal threats to
human health and the environment posed by the Site. The findings
of the Risk Assessment are summarized in a later section of this
document.
SUMMARY OF SITE CHARACTERISTICS
Contaminant Characteristics
Based on sampling and analyses conducted during the RI/FS, there .
are four major contaminants at the G.M. Site - PCBs, polyaromatic
hydrocarbons (PAHs), phenols and volatile organic compounds
(VOCs). At the G.M. Site, PAHs, phenols, and VOCs were found at
much lower concentrations and in fewer samples than PCBs.
Therefore, the primary contaminant of concern at the Site is
PCBs. In addition, any method of treatment selected for the Site
will also treat PAHs, phenols, and VOCs. For these reasons, PCBs
have, in most cases, driven the remedy selection at this Site,
although EPA intends to address all contaminants during the
cleanup of the Site.
PCBs tend to bioaccumulate in human and animal fatty tissue and
are classified by EPA as probable human carcinogens. The major
target organs of PCB exposure are the liver and skin.
Occupational exposure to relatively high concentrations of PCBs
have resulted in changes in blood levels of liver enzymes and
skin effects such as chloracne. PCBs have produced liver tumors
in laboratory studies of rats. In addition, PCBs cause adverse
reproductive effects in laboratory animals at low levels and may
cause similar results in humans.
Affected Media
This section summarizes the quantities and types of contaminaticr.
found in each area of the Site under consideration for this
operable unit. Table 1 summarizes the volume of contaminated
soil, sludge, and sediments associated with various cleanup
levels for the Site. Table 2 summarizes the types of
contaminants and their concentrations in several areas of the
Site.
Contaminated River and Creek Sediments
Over 62,000 cubic yards of contaminated river sediments and soil
with PCB concentrations above 1 part per million (ppm) are
located in and along the St. Lawrence River, Raguette River and
Turtle Creek ("the river system"). The majority of the
contaminated sediments are within the St. Lawrence River
(currently estimated at 56,000 cubic yards). The area of the
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Raguette River impacted by the Site includes a currently
estimated 6,000 cubic yards of soil and sediments located on the
northern bank of the River and in the river near the former G.M.
outfall. There are additional soils and sediments in and around
Turtle Creek which are contaminated with PCBs at levels above 0.1
ppm. Ttfese soils are not included in the estimated volume of
sediments and soils given above and may significantly increase
this estimate.
The highest PCB concentration detected in St. Lawrence River
sediments is 5,700 ppm. The highest PCB concentrations detected
in the Raquette River area and in Turtle Creek are 390 ppm and 48
ppm, respectively. PAHs were also detected in St. Lawrence River
sediments adjacent to the G.M. facility at levels up to 8 ppm.
In addition, NYSDEC has detected total PCB concentrations as high
as 36 ppm in the Raquette River with at least four additional
samples above 5 ppm PCBs.
North Disposal Area, Contaminated Soil On the St. Regis Mohawk
Reservation. Contaminated Soil On G.M. Property
The North Disposal Area consists of approximately 51,000 cubic
yards of soil, debris and sludge with PCB concentrations greater
than 10 ppm. This area includes a buried interceptor lagoon
located adjacent to the 1.5 million gallon lagoon. The highest
PCB concentration detected in the North Disposal Area is 31,000
ppm. Phenols were detected in three North Disposal Area samples
with a maximum phenol concentration of 5,000 ppm. Fifteen
different VOCs were detected sporadically in North Disposal Area
subsurface soil with maximum concentrations of perchloroethylene
(PCE) at 800 parts per billion (ppb) and of vinyl chloride at 15S
ppb.
There are approximately 15,000 cubic yards of soil on the St.
Regis Mohawk Indian Reservation contaminated with PCBs at
concentrations above 1 ppm. The highest PCB concentration
detected on the Reservation during the RI/FS is 48 ppm. In
addition, NYSDEC has detected total PCB concentrations as high as
3,101 ppm in Turtle Creek with at least four additional samples
above 100 ppm PCBs. There are also approximately 34,000 cubic
yards of soil in various areas on the G.M. property which are
contaminated with PCBs at concentrations greater than 10 ppm.
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Industrial Lagoons
The status of the lagoons and the volumes of lagoon material with
PCB concentrations greater than 10 ppm are as follows:
Lagoon Volume Status
350,000 gallon 4,000 yd3 Inactive
500,000 gallon 2,000 yd3 Active
1.5 million gallon 16,000 yd3 Inactive
10 million gallon 69.000 vd3 Active
TOTAL 91,000 yd3
The highest PCB concentration detected in the lagoon sediments
was 750 ppm (detected in the 1.5 million gallon lagoon). The
highest PCB level detected in the 350,000 gallon lagoon was 700
ppm, while the highest PCB level detected in the 500,000 gallon
lagoon was 383 ppm. The highest PCB level detected in the 10
million gallon lagoon was 300 ppm. The highest phenol
concentration (detected in the 350,000 gallon lagoon) was 26,200
ppm. VOCs and metals were also detected at levels above
background, with the highest levels generally detected in the
350,000 gallon lagoon.
The two inactive lagoons, the 350,000 gallon lagoon and the 1.5
million gallon lagoon, contain precipitation and process water
from past plant operations. The two active lagoons, the 500,000
gallon lagoon and the 10 million gallon lagoon, contain treated
process water which is reused daily in the G.M. process.
Groundvater
PCBs were detected at concentrations up to 1.3 ppm in groundwater
associated with the Site. VOCs were also detected in some
groundwater samples with maximum vinyl chloride,
dichloroethylene, and trichloroethylene concentrations of 50 ppb,
686 ppb and 50 ppb, respectively. The highest levels of PCB and
VOC contamination were detected in samples of groundwater
downgradient of the Industrial Landfill.
Potential Routes of Migration and Exposure
Contamination may migrate from surface areas into groundwater,
surface water, and off. the G.M. facility. The volatilization of
PCBs is also a potential route of exposure. PCBs carried in
surface water runoff may migrate to the Reservation. In
addition, PCBs in the river system may be ingested by aquatic
organisms and begin to bioaccumulate within the food chain.
Therefore, one potential pathway of human exposure is human
consumption of PCBs in the fatty tissue of fish and wildlife.
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SUMMARY OF SITE RISKS
The qualitative and quantitative information on risks to human
health presented in this section is based on EPA's baseline risk
assessment for the G.M. Site which, in turn, was based on the
Superfund Public Health Evaluation Manual. Qualitative
information on environmental risks is based on a recent study of
contaminants in fish performed by NYSDEC and the St. Regis Mohawk
Tribe and preliminary natural resource surveys performed by
NYSDEC, the St. Regis Mohawk Tribe, the U.S. Department of the
Interior, and the National Oceanic and Atmospheric
Administration.
Contaminant Identification and Exposure Assessment
Because PCBs are the primary contaminant of concern at the G.M.
Site, EPA's baseline risk assessment for the Site reviewed the
human health risks resulting from exposure to PCBs in soils,
sediments, and groundwater. The potential routes of human
exposure to Site contamination are the ingestion of fish and
wildlife containing PCBs, ingestion of drinking water (potential
future exposure route), ingestion of and dermal contact with PCB
contaminated soil, infant ingestion of breast milk, inhalation of
dust, and dermal contact while swimming. Two potential exposure
routes, inhalation of dust and dermal contact while swimming,
were not evaluated quantitatively in EPA's risk assessment
because these routes were expected to be relatively minor
compared to the other routes of exposure considered for the Site.
Exposed populations include the residents of the St. Regis Mohawk
Indian Reservation, Canadians who are downriver of the Site, and
G.M. workers.
A major assumption of the EPA risk assessment was that the Site
would not be developed for residential uses. In addition,
because the St. Regis Mohawk Indian Reservation contains the
closest residential population to the Site, the St. Regis Mohawk
Tribe was considered the exposed population for the purposes of
calculating exposure assumptions in EPA's risk assessment. Table
3 presents the exposure assumptions and the exposures used by EPA
in its baseline risk assessment.
Toxicity Assessment
Cancer potency factors (CPFs) have been developed by EPA's
Carcinogenic Assessment Group for estimating excess lifetime
cancer risks associated with exposure to potentially carcinogenic
chemicals. CPFs, which are expressed in units of (mg/kg-day) ',
are multiplied by the estimated intake of a potential carcinogen,
in mg/kg-day, to provide an upper-bound estimate of the excess
lifetime cancer risk associated with exposure at that intake
level. The term "upper bound" reflects the conservative estimate
of the risks calculated from the CPF. Use of this approach makes
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underestimation of the actual cancer risks unlikely. CPFs are
derived from the results of human epidemiological studies or
chronic bioassays to which animal-to-human extrapolation and
uncertainty factors have been applied. The CPF value for PCBs is
7.7 (mg/kg-day)'. This value was calculated for the oral route
of exposure but was used in EPA's risk assessment for all routes
due to a lack of other CPF values.
Reference doses (RfDs) have been developed by EPA for indicating
the potential for adverse health effects from exposure to
chemicals exhibiting noncarcinogenic effects. RfDs, which are
expressed in units of mg/kg-day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals.
Estimated intakes of chemicals from environmental media (e.g.,
the amount of a chemical ingested from contaminated drinking
water) can be compared to the RfD. RfDs are derived from human
epidemiological studies or animal studies to which uncertainty
factors have been applied (e.g., to account for the use of animal
data to predict effects on humans). These uncertainty factors
help ensure that the RfDs will not underestimate the potential
for adverse noncarcinogenic effects to occur. The current RfD
value for PCBs is 0.0001 mg/kg-day. EPA is in the process of
reviewing the RfD for PCBs.
Human Health Risk Characterization
Excess lifetime cancer risks for the Site were determined by
multiplying the intake levels (given in Table 3) with the CPF for
PCBs, 7.7 (mg/kg-day) '. These risks are probabilities that are
expressed in scientific notation (e.g., 1 x 10'6) . An excess
lifetime cancer risk of 1 x 106 indicates that as a plausible
upper bound, an individual has an additional one in one million
chance of developing cancer as a result of site-related exposure
to PCBs over a 70-year lifetime under the specific exposure
conditions presented at the Site.
Table 4 presents a summary of the total carcinogenic risks and
the carcinogenic risks posed by each exposure pathway for
residents of the St. Regis Mohawk Tribe. It should be noted that
the risks from ingestion of fish and wildlife are much greater
than the risks associated with the other exposure pathways
evaluated.
The potential risk of noncarcinogenic effects of PCBs in a single
medium is expressed as the hazard index (HI) (or the ratio of the
intake level for a given medium, given in Table 3, to the RfD fcr
PCBs, 0.0001 mg/kg-day). The total HI was generated by adding
the His across all media. The HI provides a useful reference
point for gauging the potential significance of PCB exposures
across all media.
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Table 5 presents a summary of the total HI and the His posed by
each exposure pathway for residents of the St.Regis Mohawk Tribe.
Again, the noncarcinogenic effects associated with ingestion of
fish and wildlife are much greater than the effects associated
with the other pathways evaluated.
There were several uncertainties in EPA's risk assessment, which
are primarily a result of assumptions made as part of the
exposure assessment described above. For instance, data on the
eating, hunting, and fishing habits of the Reservation population
were based on a case study using an unstructured interview
questionnaire of key informants rather than on a large-scale
random sample statistical survey of the entire Reservation
population. Data on fish and wildlife PCB concentrations were
limited and were restricted to fish from waters near the
Reservation. Historical data showing surface water contamination
in the St. Lawrence River were used despite the fact that more
recent data from the Reservation did not indicate PCB
contamination. Standard uncertainties exist with respect to
adult soil ingestion rates.
The estimation of health risks involves many uncertainties.
Given these uncertainties, EPA used conservative assumptions
(i.e.. assumptions that protect human health) throughout its risk
assessment. As a result, EPA's risk assessment provides an
estimate of the risks to the Mohawk population from exposures
that are reasonably expected to occur under current conditions
and during and after remediation of the Site.
Environmental Risks
EPA, NYSDEC, the St. Regis Mohawk Tribe and Natural Resource
Trustees are continuing to assess the risks posed to the
environment by the Site. Ongoing studies by NYSDEC and the St.
Regis Mohawk Tribe will assess the risks to wildlife posed by tr.e
Site.
NYSDEC and the St. Regis Mohawk Tribe, in a recent study of PCB
concentrations in area fish reached the following conclusions:
the river area adjacent to the G.M. Site is one
principal PCB source area as reflected by
concentrations in fish;
relatively high concentrations of polychlorinated
dibenzofurans (PCDFs) were present in fish from the
mouth of Turtle Creek; and
PCB, dioxin, and mercury exceeded the criteria for
fish-eating wildlife in the study area.
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Based on the currently available information, there are presently
unquantified risks to the environment from the Site. This ROD
may only partially address these risks. Given the presence of
PCBs in the river system, New York State listed endangered,
threatened and special concern fish species may be impacted by
the Site. PCBs have been detected in area wildlife and in
wetlands which provide habitat for water birds and other
wildlife.
New York State, the St. Regis Mohawk Tribe, the U.S. Department
of Commerce, and the U.S. Department of the Interior are each
natural resource trustees pursuant to the Comprehensive
Environmental Response, Compensation and Liability Act of 1980
(CERCLA) with trustee interests in the river system and environs
as a result of the impacts noted in this ROD as well as other
impacts to natural resources which have been observed. The
trustees are currently in the preliminary stages of the natural
resource damage assessment process.
Risk Summary
Certain actual or threatened releases of hazardous substances at
or from the Site, if not addressed by implementing the response
action selected in this ROD, may present an imminent and
substantial endangerment to public health, welfare, or the
environment.
DESCRIPTION OF ALTERNATIVES
Remedial alternatives are presented in this section for each area
of the Site. Because many of the alternatives include PCB
treatment, a discussion of PCB treatment technologies is
presented as an introduction. This is followed by a discussion
of cleanup levels selected by EPA for this Site.
Treatment Technologies
Six methods of treatment for Site soil, sludges and sediments
were examined: biological destruction, chemical destruction,
chemical extraction, thermal destruction (incineration), thermal
extraction and solidification. Each of these treatment
technologies has been tested at other hazardous waste sites.
Although some have been found to be effective in treating PCBs,
each technology, with the exception of thermal destruction, would
require a pilot or field testing program before full-scale use at
this Site. Thermal destruction would require trial incinerator
burns to establish operating conditions.
Biological Treatment
Biological destruction of PCBs using naturally occurring or
scientifically engineered bacteria was determined to be a
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feasible alternative for the remediation of contaminated soils,
sediments, and sludges at the Site. For this Site, biological
treatment would involve processing excavated soils and sludges or
dredged sediment in slurry form in above-ground batch reactors.
Preprocessing would be necessary to remove bulky items. Bacteria
and nutrients would be.added to the tanks and the tanks would be
mechanically aerated and agitated. The bacteria would degrade
PCBs to nonhazardous products. Preliminary bench-scale tests of
Site soil by G.M. have demonstrated up to 63% reduction of PCBs,
from 291 ppm to 108 ppm, after three days of biological
treatment.
Because biological treatment would be performed on material in
slurry form, a large quantity of water will be produced during
treatment and during subsequent dewatering operations. This
water would be discharged to the St. Lawrence River in compliance
with SPDES requirements which currently require that PCB
concentrations in the discharge be non-detectable, down to the
method detection level, using EPA Laboratory Method Number 608.
Because PCB volatilization is a concern, if necessary, the
reactors would be covered or fitted with emissions control
equipment. Major applicable or relevant and appropriate
requirements for biological treatment are federal Clean Air Act
(CAA) and New York State air quality standards along with
Resource Conservation and Recovery Act (RCRA) hazardous waste
treatment regulations and TSCA disposal requirements.
Biological treatment is an innovative technology. Approximately
one year would be required for preliminary testing and technology
development. In addition, biological treatment may not
sufficiently reduce PCB concentrations in those materials with
initially high PCB concentrations.
Chemical Destruction
This technology employs a chemical dechlorination process to
treat contaminated soils, sludges, and sediments. In the
proprietary KPEG process, PCB-contaminated materials are reacted
with a reagent, potassium polyethylene glycol or a similar
chemical to remove the chlorine atoms from PCBs. If successful,
this process converts PCBs to a glycol-like compound which is
less toxic than PCBs. Full-scale process equipment is currently
available.
For this Site, chemical dechlorination would be performed in a
batch mixed reactor at approximately 300°F with an excess of
reagent. The vendor of this process indicates that residual PCB
concentrations as low as 2 ppm are achievable. Preprocessing is
necessary to remove bulky items. Water, used to wash treated
solids, would be discharged to the St. Lawrence River in
compliance with SPDES requirements. Because PCB volatilization
is a concern, if necessary, the reactors would be covered or
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fitted with emissions control equipment. Major applicable or
relevant and appropriate .requirements for chemical destruction
are federal CAA and New York State air quality standards along
with RCRA hazardous waste treatment regulations and TSCA disposal
requirements.
Chemical Extraction
Chemical extraction is based on the proprietary B.E.S.T. (Basic
Extractive Sludge Treatment) process. Other similar processes
are also available. This technology involves concentrating PCBs
found in large volumes of solids and sludges into smaller volumes
of an oily extract through the use of triethylamine, a solvent.
The PCS rich extract must then be disposed. Preprocessing is
necessary to remove bulky items. Full-scale process equipment is
currently available.
The vendor reports that solids residual concentrations less than
0.1 ppm PCB are possible. Tests on sludge showed PCB
concentrations of 130 ppm in treated sludge with an initial PCB
concentration of 5800 ppm.
Process water would be treated and discharged to the St. Lawrence
River in compliance with SPDES requirements. Major applicable cr
relevant and appropriate requirements for chemical extraction are
TSCA disposal requirements and RCRA hazardous waste treatment
regulations. The PCB extract would be treated and disposed on-
site or transported off-site for disposal, if necessary.
Thermal Destruction
Thermal destruction technology involves the incineration of sol;J
material. After material processing, sorting and, if necessary,
dewatering, solids and sludges are fed to the incinerator. A
rotary kiln incinerator was used to develop cost estimates,
however, the particular type of incinerator to be used would be
determined during design. Incinerators are commercially
available and have achieved the 99.9999% destruction removal
efficiency required by TSCA.
Scrubber water would be treated and discharged to the St.
Lawrence River in compliance with SPDES requirements. Major
applicable or relevant and appropriate requirements for thermal
destruction are TSCA and RCRA incineration and disposal
requirements, and CAA requirements. Incinerator ash would be
tested and, if found to be non-hazardous, backfilled on-site.
Thermal Extraction
Thermal extraction involves the removal of organics from a solid
or sludge waste stream under lower temperature conditions than
those of incineration. The organic contaminants are not
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destroyed during this extraction process; rather another
treatment process would be necessary to permanently destroy the
liquid PCB extract. Full-scale experimental and pilot-scale
thermal extraction units are available. Vendor pilot studies
have reduced PCBs from an initial concentration of 18,000 ppm to
less than 0.1 ppm.
Scrubber water would be treated and discharged to the St.
Lawrence River in compliance with SPDES requirements. Major
applicable or relevant and appropriate requirements for thermal
extraction are TSCA disposal requirements, RCRA treatment
requirements, and CAA requirements. The PCB extract would be
treated and disposed on-site or transported off-site for
disposal, if necessary.
Solidification
Solidification of the excavated material involves the physical
encapsulation, chemical reaction, or both, of the excavated
material. A commercially available additive is mixed with the
waste to create a slurry which is allowed to harden to a solid
material. This solid material can then be disposed.
Solidification is used to limit the leachability, or "leaking",
of the PCBs into the environment. There is no data on
destruction of PCBs during the solidification process.
Because PCB volatilization during solidification is a concern, if
necessary, emissions control equipment would be required. Majcr
applicable or relevant and appropriate requirements for
solidification are CAA and New York State air quality standards
along with TSCA and RCRA disposal requirements. Solidified
material would require cover and long-term maintenance since PCI-s
would not be permanently destroyed.
The treatment options discussed above can be used separately or
in combination with each other to treat soils, sludges and
sediments at the Site. For example, because biological treatr.er.:
may not be effective on highly concentrated wastes, EPA has
evaluated a mixed treatment alternative which involves
incineration of material contaminated with PCBs over 500 ppm ar.j
biological treatment of material with PCB concentrations below
500 ppm.
Cleanup Levels for the Site
EPA has chosen cleanup levels and treatment levels for PCBs ani
other chemicals at this Site. Cleanup levels are those levels
which must be met in the river system and in soil and groundwat-:.-
at the Site once remediation is completed. Treatment levels ar-~
those levels which must be met in the residual of any treatment
process which is employed to remediate the Site. Site cleanup
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levels and treatment levels for all contaminants of concern are
specified in Table 6.
EPA has selected a soil PCB cleanup level of 1 ppm on the St.
Regis Mohawk Indian Reservation. This level is based on
applicable St. Regis Mohawk regulations which specify a soil
cleanup level of 1 ppm PCBs and on the EPA recommended PCB soil
action level of 1 ppm for residential areas as given in the
August 1990 PCB guidance referred to earlier. EPA estimates that
there are 15,000 cubic yards of soil with PCB concentrations
above 1 ppm on the St. Regis Mohawk Reservation. Reservation
soil which is excavated, treated, and disposed on G.M. property
must have PCB concentrations less than or equal to 10 ppm prior
to disposal. This treatment level is based on the cleanup and
treatment levels selected by EPA for soil/sludge on the G.M.
facility, as described below. This is appropriate because
contaminated soil from the Reservation would be deposited on the
G.M. facility after treatment. Because the cleanup levels and
treatment levels for Reservation soils are not identical,
Reservation soil with PCB concentrations above 1 ppm and below 10
ppm would not require treatment prior to disposal on the G.M.
facility.
EPA has selected a soil/sludge PCB cleanup level of 10 ppm on the
G.M. facility. This level is based, in part, on EPA's risk
assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Mohawk population and,
in part, on the August 1990 PCB guidance which recommends soil
PCB cleanup levels between 10 ppm and 25 ppm in industrial areas.
EPA has selected a cleanup level on the lower end of this range
because access to remediated areas will be unlimited to G.M.
personnel and because contaminants in on-site soils impact
groundwater and surface water quality. EPA has selected a
soil/sludge total phenols cleanup level of 50 ppm based on
federal RCRA guidance for closure of surface impoundments. EPA
estimates that there are 176,000 cubic yards of soils and sludges
in the Industrial Lagoons, in the North Disposal Area, and in
other areas on the G.M. facility contaminated with PCBs above 1C
ppm which are being addressed in this operable unit. In general,
the treatment levels for soil/sludge on the G.M.. facility (see
Table 6) are consistent with the cleanup levels for the G.M.
facility. This is appropriate because treated soil would be
deposited on the G.M. facility after treatment.
The groundwater PCB cleanup goal selected by EPA is 0.1 ppb, as.
measured at the boundary of the Industrial Landfill and
Industrial Lagoons, based on New York State requirements. This
level is lower than the proposed federal maximum contaminant
level of 0.5 ppb. Because PCBs sorb to soil, the effectiveness
of PCB removal from the groundwater aquifer may be limited. The
phenol groundwater cleanup level is 1 ppb based on New York Stat-t
requirements. The EPA cleanup levels for VOCs shown in Table £
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are based on federal and State requirements which are either
applicable or relevant and appropriate for the Site. Groundwater
would be treated to comply with SPDES requirements before it
would be discharged to the St. Lawrence River. The treatment
levels for groundwater are given in Table 6. These levels are
based on New York State SPDES requirements which regulate the
levels of contaminants which may be discharged to the waters of
New York State. This is appropriate since groundwater will be
discharged to the St. Lawrence River following treatment.
EPA's selected remedy for river sediments requires the
delineation of areas in the river system which are severely
contaminated, called PCB hotspots. Hotspot areas as defined in
this ROD are then subject to sediment remediation as described
below. At this Site, EPA has defined PCB hotspots to be areas
with concentrations above 1 ppm in St. Lawrence River and
Raquette River sediments and associated soils and above 0.1 ppm
in Turtle Creek and Raquette River sediments within the
boundaries of the Reservation.
The 1 ppm PCB cleanup in the St. Lawrence and Raquette Rivers was
based on interim federal and State sediment quality criteria
guidance as well as on EPA's risk assessment. Application of
interim federal sediment quality criteria guidance indicates that
a PCB cleanup level in sediments should be between 0.08 and 2
ppm. State sediment quality criteria guidance indicates that PCB
cleanup levels well below 1 ppm are required to achieve
protection of the environment. EPA's risk assessment for the
Site demonstrates that a 1 ppm PCB cleanup level in sediment
corresponds to a 4 x 10s excess cancer risk.
*
Therefore, in an attempt to minimize residual risks, EPA has
selected 1 ppm as a cleanup goal in the St. Lawrence and Raquette
Rivers. In selecting the 1 ppm cleanup goal in the St. Lawrence
and Raquette Rivers, EPA has also balanced its desire for a very
low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in tr.e
St. Lawrence and Raquette Rivers is achievable and provides an
acceptable measure of protection to human health.
The 0.1 ppm hotspot definition for Turtle Creek selected by EFA
is based on Tribal regulations and applies to the entire area c:
Turtle Creek, including the adjacent cove (see Figure 3). While
EPA acknowledges the applicability of the Tribal regulations ir.
Turtle Creek, technical limitations of dredging, which is the
only means of removing sediment, may prevent compliance with tr. i£
requirement.
EPA estimates that there are 62,000 cubic yards of sediments ar.j
soils in the river system with PCB concentrations above 1 ppr. :r
the St. Lawrence and Raquette Rivers and in Turtle Creek. The.--:-
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are additional soils and sediments in and around Turtle Creek
which are contaminated with PCBs at levels below 1 ppm. These
soils are not included in the estimated volume of sediments and
soils given above.
River system sediments which are treated must have PCB
concentrations less than or equal to 10 ppm prior to disposal.
This treatment level is based on the cleanup and treatment levels
selected by EPA for soil/sludge on the G.M. facility, as
described above. This is appropriate because contaminated
sediments would be deposited on the G.M. facility after
treatment. Because the cleanup levels and treatment levels for
sediments are not identical, Reservation sediments with PCB
concentrations above 0.1 ppm and below 10 ppm and other sediments
with PCB concentrations above 1 ppm and below 10 ppm would not
require treatment to remove contaminants prior to disposal on the
G.M. facility.
Contaminated River and Tributary Sediments
The remedial alternatives evaluated for the river system include:
no action, in-place containment of river sediments, and dredging
of sediments with on-site treatment (using one of the six PCB
treatment technologies outlined above).
No Action for the River Sediments
The Comprehensive Environmental Response, Compensation and
Liability Act of 1980 (CERCLA) requires that the "no action"
alternative be considered at Superfund sites. This alternative
consists of allowing the contaminated river sediments,
riverbanks, and associated wetlands to remain in their present
state in the river system.
No actions would be taken to remove or contain contaminated
sediments or soil which currently pose a threat to human health
and the environment in these areas. There are no costs or
implementation times associated with the no action alternative
for river sediments.
In-Place Containment of River Sediments
This alternative (also called in-situ containment) consists of
the placement of a graded aggregate cover over the contaminated
river sediments (see Figure 4). This alternative is designed to
limit the transport of river sediments and is based on methods
used to reduce shoreline erosion.
In this alternative, a silt curtain would be installed around the
hotspots to minimize downstream transport of sediments disturbed
during placement of the cover. The hotspots of PCB contamination
in the river system would then be backfilled with a graded
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filter. The thickness of the layers and the type of aggregate to
be used in the cover would be determined during design of the
cover and would depend on river bottom slope, flow, and current
velocity.
Following completion of backfilling activities, the silt curtain
would be removed and any accumulated sediment would be moved to
the shore for on-site or off-site disposal. The ultimate method
of disposal of the accumulated sediment, would be determined
following completion of the containment system and would depend
on the PCB concentration and water content of the sediments.
Annual inspections to determine the cover's effectiveness in
containing PCBs and preventing the movement of these hazardous
substances into the water column would be performed. Long-term
maintenance of the cover, including repair and replacement, would
be performed as required.
EPA estimates that the total present worth cost of this
alternative is $ 3.6 million. This alternative would require
approximately 6 months to construct following completion of
design. Because containment of contaminated sediments would be
used to mitigate one of the principal threats from this Site,
sediment containment would be performed at the earliest
opportunity.
Sediment Dredging and On-Site Treatment
This alternative consists of dredging approximately 62,000 cubic
yards of PCB contaminated hotspots in the river system and
wetlands and on the riverbanks with subsequent on-site treatment
with one or a combination of the six treatment methods described
earlier. Prior to remediation, a silt curtain or other sediment
control device would be installed to control sediment that might
be suspended during dredging activities. In addition, a sheet
pile wall would be installed on the river side of the dredging
area to provide a stilling basin for dredging operations. Prior
to remediation of the Raquette River sediments and riverbank
soils, the sludges contained in the storm sewer line leading to
the existing G.M. outfall to the Raquette River would be removed
and the outfall would be monitored and secured to ensure that it
could not serve as a source of future contamination to the River.
During design, a decision would be made on the most appropriate
type of dredging method .to minimize sediment resuspension.
During dredging, contaminated sediments within the previously
defined PCB hotspots in the river system would be removed.
Sediments which are suspended during dredging and which are
deposited downstream may be redredged, if necessary. From an
engineering perspective, removal of virtually all sediments in
fairly shallow areas will be the simplest way to ensure
compliance with EPA's cleanup goals and will provide an extra
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measure of protection in areas where even low levels of PCBs in
sediments pose a risk to wildlife.
If necessary for treatment, a temporary sediment dewatering basin
and a sediment storage area would be constructed on the shore in
the vicinity of sediment remediation. Leachate and decant water
from these areas would then be pumped to a wastewater treatment
plant and subsequently discharged to the river in compliance with
SPDES requirements.
After dredging, the material would be treated on-site using one
or a combination of the six treatment methods described above.
Treatment residuals would be required to have PCS concentrations
below the G.M. facility soil cleanup level of 10 ppm PCBs. Bulk
river debris which could not be treated would be disposed in a
facility which meets all TSCA requirements, as necessary. The
treated sediments would be dewatered and disposed in areas
located on G.M. property and covered with a vegetated soil cap
which complies with New York State and TSCA chemical waste
landfill requirements, provided they were non-hazardous,
adequately dewatered, and met EPA's treatment goals for the Site.
The silt curtain and sheet pile wall would be removed and
decontaminated or disposed after completion of the dredging
operation. Dredged areas would be covered and restored to their
original grade with clean fill and the riverbed, riverbanks, and
wetlands restored as closely as possible to their pre-dredging
condition.
Major applicable or relevant and appropriate requirements (ARARs,.
for this alternative are relevant and appropriate RCRA treatment
regulations, applicable TSCA disposal requirements, Tribal PCB
requirements (see Table 7) which are applicable on the
Reservation, relevant and appropriate RCRA closure requirements,
applicable New York State solid waste disposal requirements,
relevant and appropriate New York State hazardous waste disposal
requirements, and applicable SPDES requirements.
The costs of this alternative depend on the type of treatment
used and are presented in Table 8. As shown, present worth costs
range from $ 7.7 million to $ 32 million. Implementation times
for this alternative range from a few months (for solidificaticr..
to two years (for chemical extraction or thermal destruction).
These times do not include time required to construct treatment
units. Design and construction of treatment units, including
performance of required treatability studies, could be perforned
in approximately two years. Because removal of contaminated
sediments would be used to mitigate one of the principal threats
from this Site, sediment dredging would be performed at the
earliest opportunity. Sediment storage would be used, as
necessary, to expedite sediment dredging while treatability test--
were conducted and treatment facilities were built.
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North Disposal Area, Contaminated Soil on the St. Regis Mohawk
Reservation, Contaminated Soil on 6.M. Property
The following alternatives were evaluated for the contaminated
material in these areas: no action, capping, solids excavation
and on-site treatment (using one of the methods outlined above),
and excavation of the material with on-site disposal.
No Action for the North Disposal Area. Reservation Soil and Soil
on G.M. Property
This alternative consists of allowing the 100,000 cubic yards of
contaminated soils, sludges and solids in these areas to remain
in their present state. No actions would be taken to remove or
contain contaminated materials which currently pose a potential
threat to human health and the environment in these areas. There
are no costs or implementation times associated with the no
action alternative for these areas.
Capping of the North Disposal Area. Reservation Soil, and Soil on
G.M. Property
This alternative includes containing wastes in the North Disposal
Area on-site to minimize infiltration. As part of this
alternative, shallow soil on the St. Regis Mohawk Reservation and
soils from areas on G.M. property not associated with past
disposal practices would be excavated and consolidated on G.M.
property, possibly in the North Disposal Area.
The North Disposal Area (including the buried interceptor lagoon}
and other soils would then be graded to enhance surface drainage.
Surface water would be rerouted and discharged to the river
system, in accordance with SPDES requirements.
Two specific capping methods were considered by EPA: a soil
cover and a synthetic composite cover. In the soil cover method,
after grading, the North Disposal Area and other soils would be
compacted and covered with one layer of a synthetic material
known as geotextile, two feet of clay and six inches of topsoil.
Revegetation of the cover, regular cover inspection and
maintenance, and groundwater monitoring would complete the
remediation. Dust suppression measures would be implemented
during cover construction.
The composite cover alternative also includes compaction of the
North Disposal Area and other soils. The North Disposal Area and
other soils would then be capped using the following materials:
three feet of clay, one layer of flexible membrane liner, one
layer of drainage material, one layer of geotextile, eighteen
inches of rooting zone soil and six inches of topsoil.
Revegetation of the covers, regular cover inspection and
maintenance, and groundwater monitoring would complete the
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remediation. Dust suppression measures would be implemented
during cover construction. Excavated areas on the Reservation
would be restored to their original condition with clean fill and
revegetated. Excavated areas on G.M. property would be covered
to reduce erosion and prevent migration.
Major ARARs for this alternative are applicable TSCA disposal
requirements, Tribal PCS requirements which are applicable on the
Reservation, applicable New York State solid waste disposal
requirements, and relevant and appropriate RCRA and New York
State hazardous waste disposal and closure requirements. The
present worth costs of this alternative are $ 4.2 million for a
soil cover and $ 4.8 million for a composite cover. This
alternative would require approximately two years to complete.
Excavation and On-Site Treatment of Solids in the North Disposal
Area. Reservation Soil, and Soil on G.M. Property
This alternative consists of excavating 51,000 cubic yards of
contaminated soil, debris and sludge in the North Disposal Area
(including the buried interceptor lagoon) with concentrations
above 10 ppm PCBs, 15,000 cubic yards of contaminated soil on the
Reservation with concentrations above 1 ppm PCBs, and
approximately 34,000 cubic yards of soil on the G.M. property
with PCB concentrations above 10 ppm and treating them with one
or a combination of the six treatment methods discussed above.
Following excavation, material from the Reservation would be
temporarily stockpiled near the location of the on-site treatment
facility.
Solids would be preprocessed to reduce particle size. Large
contaminated objects which could not be treated would be disposed
in a facility which meets all TSCA requirements, as necessary.
Non-hazardous treated material with concentrations less than
EPA's cleanup levels (see Table 6) would be disposed in areas on
G.M. property and covered with a vegetated soil cap which
complies with New York State and TSCA chemical waste landfill
requirements. Treatment residuals would be required to have PCB
concentrations below the G.M. facility soil cleanup level of 10
ppm PCBs. The excavated areas on the Reservation would be
restored with clean fill to their original grade. Excavated
areas on G.M. property would be covered to reduce erosion and
prevent migration. These areas would be graded to prevent any
surface water runoff from G.M. property and restored to support
vegetation. A long-term groundwater monitoring program would
also be implemented.
Major ARARs associated with this alternative are applicable TSCA
disposal requirements, relevant and appropriate RCRA treatment
regulations, Tribal PCB requirements which are applicable on the
Reservation, applicable New York State solid waste disposal
requirements, relevant and appropriate RCRA and New York State
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hazardous waste disposal and closure requirements, and CAA and
New York State air quality standards. The costs of this
alternative are given in Table 9. Present worth costs range from
$ 25 million to $ 56 million. Implementation times for this
alternative range from a few months (for solidification) to four
years (for chemical extraction or thermal destruction). These
times do not include time required to design or construct any
required treatment units.
Excavation and On-Site Disposal of Solids in the North Disposal
Area. Reservation Soil, and Soil on the G.M. Property
This alternative consists of excavation of 100,000 cubic yards of
contaminated soils, debris and sludges in the North Disposal Area
(including the buried interceptor lagoon), on the Reservation,
and on G.M. property followed by placement of these materials in
an on-site double-lined landfill located on G.M. property.
A landfill would be constructed on the Site in compliance with
federal and state regulations governing landfill construction.
The landfill would be bermed and would be designed so that the
base of the landfill was above the groundwater table.
Contaminated material would then be excavated and transported to
the on-site landfill for disposal. Following disposal, the
landfill would be covered and closed according to federal and
state regulations.
The excavated areas on the Reservation would be restored with
clean fill to their original grade and revegetated. Excavated
areas on G.M. property would be covered to reduce erosion and
prevent migration. Maintenance of the landfill would include
upkeep of the landfill cover and an access road, leachate
treatment, and semi-annual groundwater monitoring. Treated
leachate and groundwater would be discharged to the St. Lawrence
River in compliance with SPDES requirements.
Major ARARs for this alternative are RCRA closure requirements
which are relevant and appropriate for the wastes at the Site,
applicable New York State solid waste disposal requirements,
relevant and appropriate New York State hazardous waste disposal
and closure requirements, Tribal PCS requirements which are
applicable on the Reservation, and TSCA disposal requirements
which are applicable at this Site. The present worth cost of
this alternative is $ 24 million. Implementation time is
approximately three years.
Industrial Lagoons
The following alternatives were evaluated for the sludges
contained in the four lagoons (350,000 gallon, 500,000 gallon,
1.5 million gallon and 10 million gallon): no action, solids ar.d
sludge excavation and on-site treatment (using one of the
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treatment alternatives outlined above) and solids and sludge
excavation with disposal in an on-site disposal area.
No Action for the Laaoons
Under this alternative, the 91,000 cubic yards of sludge and
underlying soil in the four Industrial Lagoons would not be
remediated. The 500,000 gallon and 10 million gallon lagoons
would continue to function as part of G.M.'s wastewater treatment
system. The 1,500,000 gallon and 350,000 gallon lagoons would
remain inactive and would not receive additional waste materials.
Lagoon Solids Excavation and On-Site Treatment
This alternative consists of excavating 91,000 cubic yards of
contaminated sludges and underlying soils to a level of 10 ppm
PCBs in the Industrial Lagoons and treating them with one or a
combination of the six treatment methods discussed above. Prior
to excavation, water in the lagoons would be removed, treated and
discharged to the St. Lawrence River in compliance with SPDES
requirements. During excavation, all sludges would be removed.
Sludges would be delineated during remedial action either
visually or through the use of physical tests, such as the EPA
Paint Filter Test. Underlying soil contaminated above 10 ppm
PCBs would also be removed. Following excavation, material might
be temporarily stockpiled near the location of the on-site
treatment facility. Solids would be preprocessed to reduce
particle size. Treated material with concentrations less than
EPA's cleanup levels (see Table 6) would be disposed in areas cr.
G.M. property and covered with a vegetated soil cap which
complies with New York State and TSCA chemical waste landfill
requirements for a cover. Treatment residuals would be require::
to have PCB concentrations below the Site soil cleanup level of
10 ppm PCBs. In compliance with TSCA and as explained in
subsequent sections of this-ROD, sludge with initial
concentrations above 500 ppm would be required to have PCB
concentrations below 2 ppm after treatment. The excavated side2
and bottoms of the lagoons would be covered to reduce erosion ar. :
prevent migration. A long-term groundwater monitoring prograr.
would also be implemented.
Major ARARs for this alternative are RCRA treatment requirementr
which are relevant and appropriate for the wastes at the Site,
applicable New York State solid waste disposal requirements,
relevant and appropriate RCRA and New York State hazardous wast-.
disposal and closure requirements, and TSCA disposal requirement.:
which are applicable at this Site. The present worth costs of
this alternative range from $ 24 million to $ 48 million and arc-
shown in Table 10. Implementation times for this alternative
range from a few months (for solidification) to four years (fcr
chemical extraction or thermal destruction). These times do n:r
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include time required to design and construct any required
treatment units.
Lagoon Solids Excavation with On-Site Disposal
This alternative consists of excavation of contaminated sludges
and underlying soils in the Industrial Lagoons followed by
placement of these materials in an on-site double-lined landfill
located on G.M. property.
A landfill would be constructed on the Site as described
previously for the on-site disposal of North Disposal Area soils,
Water in the lagoons would be removed, treated and discharged to
the St. Lawrence River in compliance with SPDES requirements.
Contaminated sludge and soil would then be excavated and
transported to the on-site landfill for disposal. Following
disposal, the landfill would be covered and closed according to
federal and state regulations. The sides and bottoms of the
lagoon areas would be covered to reduce erosion and prevent
migration.
Maintenance of the landfill would include upkeep of the landfill
cover and an access road, leachate treatment, and semi-annual
groundwater monitoring. Treated leachate and groundwater would
be discharged to the St. Lawrence River in compliance with SPDES
requirements.
Major ARARs for this alternative are applicable New York State
solid waste disposal requirements, relevant and appropriate RCRA
and New York State hazardous waste disposal and closure
requirements, and TSCA disposal requirements which are applied::!':
at this Site. The present worth cost of this alternative is S :.
million. Implementation time is approximately four years.
Groundwater /-
Groundwater may be remediated by one of the following remedial
alternatives: no action, containment of the groundwater and
extraction and treatment of contaminated groundwater.
No Action for Groundwater
Under the no action alternative for groundwater, no groundwater
remediation would occur. However, groundwater monitoring would
be performed for a 30-year period.
The present worth of the groundwater monitoring costs associated
with the no action alternative is $ 1.2 million. This
alternative could be implemented immediately.
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Groundwater Containment
This alternative provides for installation of a slurry wall
downgradient of the Site to a depth sufficient to achieve a
hydraulic barrier. The slurry wall would be keyed into the
lowermost till deposit at the Site. In this way, the hydraulic
pathway provided by the higher permeability sand layer would be
eliminated. Pumping wells would also be installed on the G.M.
side of the slurry wall as a hydraulic control measure. The
water from the pumping wells would be treated in a wastewater
treatment system which could include a combination of aeration,
clarification, filtration, air stripping and carbon adsorption to
remove VOCs and PCBs from the groundwater. After treatment, the
water would be discharged to the St. Lawrence River in compliance
with SPDES requirements.
Monitoring wells and piezometers would be placed inside and
outside of the slurry wall's perimeter to detect possible
infiltration and assure the integrity of the slurry wall.
The major ARARs associated with this alternative are RCRA and New
York State groundwater monitoring requirements. The present
worth cost associated with this alternative is $ 7.6 million.
Implementation time for this alternative is two years.
Groundwater Recovery and Treatment
This alternative consists of the installation of recovery wells
or trenches hydraulically downgradient of the Site for the
removal and treatment of groundwater. Pumping wells or trenches
could be located along the downgradient sides of the Industrial
Landfill, the Industrial Lagoons, and the East Disposal Area.
Extracted groundwater would be pumped to a wastewater treatment
plant for treatment which could include a combination of
aeration, clarification, filtration, air stripping and carbon
adsorption to remove VOCs and PCBs from the groundwater. After
treatment, the water would be discharged to the St. Lawrence
River in compliance with SPDES requirements. Treated groundwater
would be required to have PCB concentrations consistent with the
SPDES requirements. Groundwater treatment residuals (e.g. . sper.t
carbon) would be tested and disposed as hazardous waste, if
necessary.
The major ARARs associated with this alternative are relevant ar.i
appropriate Safe Drinking Water Act Maximum Contaminant Levels
(MCLs), New York State groundwater quality standards, Tribal PCE
requirements, RCRA treatment and land disposal requirements whicr.
are applicable if the groundwater treatment residuals are RCRA
hazardous wastes, and federal and State groundwater monitoring
regulations. The present worth cost associated with this
alternative is $ 4 million. Implementation time for this
alternative is two years.
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SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
In accordance with the National Contingency Plan (NCP), a
detailed analysis of each alternative was performed. The purpose
of the detailed analysis was to objectively assess the
alternatives with respect to nine evaluation criteria that
encompass statutory requirements and include other gauges of the
overall feasibility and acceptability of remedial alternatives.
The analysis was comprised of an individual assessment of the
alternatives against each criterion and a comparative analysis
designed to determine the relative performance of the
alternatives and identify major trade-offs, that is, relative
advantages and disadvantages, among them.
The nine evaluation criteria against which the alternatives were
evaluated are as follows:
Threshold Criteria - The first two criteria must be satisfied in
order for an alternative to be eligible for selection.
1. Overall Protection of Human Health and the Environment
addresses whether a remedy provides adequate protection
and describes how risks posed through each pathway are
eliminated, reduced, or controlled through treatment,
engineering controls, or institutional controls'.
2. Compliance with Applicable/ or Relevant and Appropriate
Requirements (ARARs) is used to determine whether each
alternative will meet all of its federal and state
ARARs. When an ARAR is not met, the detailed analysis
should discuss whether one of the six statutory waivers
is appropriate.
Primary Balancing Criteria - The next five "primary balancing
criteria" are to be used to weigh major trade-offs among the
different hazardous waste management strategies.
3. Long-term Effectiveness and Permanence focuses on any
residual risk remaining at the Site after the
completion of the remedial action. This analysis
includes consideration of the degree of threat posed cy
the hazardous substances remaining at the Site and the
adequacy of any controls (for example, engineering and
institutional) used to manage the hazardous substances
remaining at the Site.
4. Reduction of Toxicity, Mobility, or Volume Through
Treatment is the anticipated performance of the
treatment technologies a particular remedy may employ.
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5. Short-term Effectiveness addresses the effects of the
alternative during the construction and implementation
phase until the remedial response objectives are met.
6. Implementability addresses the technical and
administrative feasibility of implementing an
alternative and the availability of various services
and materials required during its implementation.
7. Cost includes estimated capital, and operation and
maintenance costs, both translated to a present-worth
basis. The detailed analysis evaluates and compares
the cost of the respective alternatives, but draws no
conclusions as to the cost-effectiveness of the
alternatives. Cost-effectiveness is determined in the
remedy selection phase, when cost is considered along
with the other balancing criteria.
Modifying Criteria - The final two criteria are regarded as
"modifying criteria," and are to be taken into account after the
above criteria have been evaluated. They are generally to be
focused upon after public comment is received.
8. State and Tribe Acceptance reflects the statutory
requirement to provide for substantial and meaningful
State and Tribal involvement.
9. Community Acceptance refers to the community's comments
on the remedial alternatives under consideration, along
with the Proposed Plan. Comments received during the
public comment period, and the EPA's responses to those
comments, are summarized in the Responsiveness Summary
which is attached to this ROD.
The following is a summary of the comparison of each
alternative's strengths and weaknesses with respect to the nine
evaluation criteria.
Overall Protection of Human Health and the Environment
With the exception of the no action alternatives, each of the
alternatives for the various contaminated areas, if properly
implemented, operated, and maintained, protects human health and
the environment. Although the alternatives differ in the degree
of protection they afford, all provide human health risks within
the acceptable EPA range of 10'" to 10"6.
The current risks to the adult Mohawk population associated with
the no action alternatives for river sediments and Reservation
soil are not within the EPA risk range. EPA estimates that the
current risks to the adult Mohawk population associated with the
no. action alternatives for the North Disposal Area and for the
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Industrial Lagoons are within the EPA risk range. However, based
on information supplied by G.M. and on its experience at other
sites, EPA believes that the current risks to G.M. workers from
these areas is unacceptable. Since the no action alternatives
are not protective, they will not be considered in the remainder
of this analysis.
Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs)
All alternatives comply with ARARs or provide the grounds for
invoking an ARAR waiver as noted below.
Sediment Dredging and On-Site Treatment
During dredging, EPA's goal is removal of all contaminated
sediments within PCB hotspots. Within Turtle Creek, this goal is
in compliance with the Tribal PCB ARAR of 0.1 ppro PCBs. Based on
limited previous experience at other Superfund sites and federal
projects, it is possible that dredging to 0.1 ppm PCBs will be
technically impracticable. Therefore, this alternative requires
that EPA waive the Tribal sediment standard due to technical
impracticability, as discussed in CERCLA, section 121(d)(4)(C).
EPA would consult with the St. Regis Mohawk Tribe and NYSDEC
before making a final determination as to the technical
impracticability of meeting the Tribal sediment PCB ARAR.
Excavation and On-Site Treatment of Solids in the North Disposal
Area, Reservation Soil, and Soil on G.M. Property and Lagoons
Solids Excavation and On-Site Treatment
According to TSCA disposal regulations and policy, all treatment
residuals with PCB concentrations above 2 ppm must be disposed in
a TSCA chemical waste landfill. However, these alternatives
specify that treatment residuals with PCB concentrations less
than 10 ppm will be disposed on G.M. property in a disposal
facility which will include, at a minimum, a vegetated soil cap.
Therefore, depending on the type of disposal facility ultimately
selected during design, these alternatives require that, in
accordance with TSCA regulations (40 CFR 761.75(c) (4)), EPA waive
certain TSCA chemical waste landfill requirements for treatment
residuals with PCB concentrations above 2 ppm. These TSCA
chemical landfill requirements would be waived because treatment
residuals which meet Site cleanup standards do not present an
unreasonable risk of injury to health or the environment from
PCBs. EPA bases this finding on its risk assessment and the EPA
August 1990 PCB guidance which indicate that 10 ppm is protective
of human health at the Site.
In addition, TSCA regulations require that sludges with PCB
concentrations above 500 ppm be incinerated in a TSCA compliant
incinerator or be treated by a method equivalent to incineration.
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In compliance with TSCA, any sludges with initial PCB
concentrations above 500 ppm which cannot be treated by an
innovative technology to achieve PCB residuals below 2 ppm must
be incinerated.
Groundwater Recovery and Treatment
During recovery and treatment, EPA's cleanup goal is the New York
State PCB ARAR of 0.1 ppb PCBs. Based on EPA studies of other
sites, EPA has found that the final groundwater cleanup level
will depend on technical considerations such as the propensity of
PCBs to sorb to soil.
Long-Term Effectiveness and Permanence
In general, remedies which include excavation and treatment
perform best with respect to long-term effectiveness and
permanence. Containment and capping remedies provide a lower
degree of permanence in remediating contamination at the Site.
Although sediment containment with a graded cover would reduce
the erosive force of the flowing river water and would limit
movement of contaminants into the environment, its long-term
effectiveness is dependent upon the adequacy and reliability of
the sediment cover. Long-term monitoring and maintenance of
contained sediments which would be required would be difficult to
achieve because the cover is located underwater. Little
information is available on the frequency of maintenance or on
the probability of cover failure. If the sediment cover fails,
risks on the order of 102 would be present immediately. Sediment
dredging permanently removes the risks from contaminated
sediments.
Similarly, capping of solids in the North Disposal Area and other
areas is less permanent than solids excavation. Long-term
monitoring and maintenance of covered areas would be required
these areas would not be usable once capped. On-site disposal
without treatment would not implement any permanent treatment
technologies and is less effective in the long-term than
treatment and disposal.
With respect to the treatment alternatives, thermal destruction
is a permanent and effective technology since it results in
destruction of PCBs. Of all the technologies considered, it is
likely that incineration will meet required treatment levels.
Chemical extraction, biological treatment, chemical destruction
and thermal extraction technologies have the potential to
permanently remediate the Site; however, uncertainties exist
because these technologies have not been proven in the past.
Treatability studies would be necessary during the design phase
to ensure long-term effectiveness of these alternatives.
Solidification is less permanent than other treatment
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technologies considered and solidified material would require
long-term management.
The long-term effectiveness of groundwater containment depends on
the stability of the slurry wall. The long-term effectiveness of
groundwater recovery and treatment depends on the reliability of
the recovery system. Both groundwater containment or recovery
and treatment would reduce the risk from direct exposure to
contaminated groundwater.
Reduction of Toxicity, Mobility or Volume
Biological treatment, chemical destruction, and thermal
destruction perform best with respect to this measure.
Containment alternatives do not employ treatment although they do
reduce contaminant mobility. Treatment alternatives address
principal threats through treatment of contaminated materials.
Biological treatment, chemical destruction, and thermal
destruction reduce the toxicity, mobility and volume of toxic
contaminants. Chemical and thermal extraction reduce the volume
of toxic contaminants. Solidification reduces the mobility of
toxic contaminants.
Groundwater alternatives would reduce the mobility of the
contaminated groundwater; groundwater treatment would also reduce
the toxicity and volume of the contaminants in the treated
groundwater.
Short-Term Effectiveness
Containment alternatives which can be implemented quickly with
moderate amounts of dust generation perform best with respect tc
short-term effectiveness. Any alternatives which incorporate
Site excavation would be accompanied by an increase in dust
generation during excavation. Although mitigative measures would
be used, the emission of contaminated dust during excavation is
much greater than during containment activities where the
contaminated soils would remain relatively undisturbed.
Implementation of sediment dredging would result in resuspensicr.
of sediments. Minimization of sediment resuspension would be
accomplished through the use of engineering controls such as
sheet piles, silt curtains, and coffer dams and through select ic.-.
of appropriate dredging equipment and production rates. These
controls have been proven to control sediment resuspension.
Biological treatment, thermal destruction, chemical destruction,
thermal extraction, and solidification result in air emissions
which will have a short-term effect on the community and Site
workers. The.short-term excess cancer risks to the adult Mohawk
population and remediation workers during implementation of th~
remedial alternatives are presented in Table 11. Risks to
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remediation workers can be mitigated through the use of
protective equipment. Risks to G.M. workers would be lower than
those for remediation workers.
The area on the St. Regis Reservation will be impacted by
excavation of the North Disposal Area and emissions from
treatment equipment; precautions to minimize potential impacts
will be included in the design phase for the remediation of the
Site. If necessary, these precautions may include temporary
relocation of Raquette Point residents. Any impacted wetlands or
habitats will be restored after excavation, if necessary.
Residual impacts to the wetlands may remain after excavation.
Groundwater alternatives do not pose significant short-term risks
to the community or workers.
Sediment dredging would require approximately one year to
complete. Completion of pilot treatability studies (if
necessary), remedial design and construction for all alternatives
will take up to two years. The time to complete a biological
treatment process for all areas addressed in this operable unit
is estimated to be three years from completion of construction of
the treatment units. Chemical destruction of all of the
contaminated material addressed in this ROD would take
approximately four years from construction completion, assuming a
treatment rate of 175 cubic yards per day.
Utilizing three treatment units after construction completion,
the chemical extraction alternative would require five years for
treatment of all areas addressed in this ROD assuming each unit
processed 49 cubic yards per day. Using the thermal destruction
alternative for all of the contaminated material addressed in
this ROD, the remedial action would take seven years to complete
following construction, assuming a processing rate of 4.2 cubic
yards per hour. The thermal extraction alternative would require
approximately four years for completion of the remedial action
following construction, assuming a processing rate of seven cubic
yards per hour. The solidification alternative, at a process
rate of 200 tons per hour, would require approximately one-half
year to complete following construction.
Implementability
All of the alternatives are implementable from an engineering
standpoint. However, there are some inherent difficulties which
may be encountered during implementation of some alternatives.
Engineering controls will be employed to minimize sediment
resuspension during the dredging process. Although adequate
sediment dredging services are currently available, dredging will
require coordination with the governments of the St. Regis Mohawk
Tribe, New York State, and Canada.
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The construction of a sediment cover system will involve some
sediment resuspension. In the event that the sediment cover
fails and dredging is required, the multi-layer sediment cover
material would be an impediment. Monitoring of the sediment
cover system will be severely hampered by ice cover during the
winter months.
Solids excavation in the North Disposal Area, on the Reservation
and on G.M. property is easily implementable. Treatment
alternatives will require treatability studies to optimize the
design and operating parameters for the treatment system. These
treatability studies will determine the implementability of
innovative technologies including biological treatment, chemical
destruction, and chemical and thermal extraction. If innovative
technologies are not found to be implementable, other more proven
technologies, such as incineration, would be used to treat soils,
sludges and sediments. Full-scale equipment and vendors are
available for chemical destruction, chemical extraction, thermal
destruction, and solidification.
Cost
The costs associated with the alternatives for each disposal area
are presented in Tables 8-10. These costs are estimates and
may change as a result of design and construction modifications.
Capital costs include fixed costs (costs associated with
equipment mobilization and site preparation) and non-fixed costs
(costs associated with treatment of a specific disposal area).
Capital costs are only incurred once for each treatment
technology. Thus, significant savings (in fixed costs) from
those costs displayed in the Tables 8 -10 will result whenever
the same treatment technology is used for two different disposal
areas.
State and Tribe Acceptance
New York State has expressed a preference for permanent remedies
which include excavation and treatment of most contaminated
soils, sediments, and sludges from the Site. The St. Regis
Mohawk Tribe has indicated that its primary concern is protection
of the Mohawk people's health and environment through expeditious
cleanup of the Site. To this end, they support the removal of
contamination from the Reservation and comprehensive controls
which ensure that there will be no further migration of
contamination from the G.M. Site onto the Reservation, or into
waters utilized by the Mohawk people. Consequently, the Tribe
advocated inclusion of the East Disposal Area in this ROD.
NYSDEC and the Tribe have concurred on this ROD (see Appendix 3).
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Community Acceptance
Comments from the community submitted during the public comment
period indicate that the community has varying opinions regarding
remediation of the Site. Many citizens expressed a desire for
complete removal and treatment of all contamination at the Site.
Other citizens, many of them residents of Massena, supported a
G.M. plan for Site remediation which included sediment
containment, excavation of Reservation soil and soil in the North
Disposal Area, excavation and treatment of the inactive lagoons,
and groundwater recovery and treatment. Community comments are
responded to in detail in the Responsiveness Summary which is an
appendix to this document.
DESCRIPTION OF THE SELECTED REMEDY
The major components of the selected remedy for the first
operable unit include:
Dredging/excavation and on-site treatment of sediments and
soils in PCS hotspots in the St. Lawrence and Racruette
Rivers and in Turtle Creek, in associated wetlands, and on
St. Lawrence and Raquette River banks
Hotspots in the St. Lawrence and Raquette Rivers and Turtle
Creek will be dredged and excavated to remove PCBs. All PC5
contaminated sediments in the hotspots will be removed giver.
the technological limitations associated with dredging. E?A
anticipates that residual PCB levels in dredged hotspot
areas will be no greater than 1 ppm in the St. Lawrence and
Raquette Rivers. In selecting the 1 ppm cleanup goal in the
St. Lawrence and Raquette Rivers, EPA has balanced its
desire for a very low cleanup level which will minimize
residual risk with the constraints posed by the limitations
of dredging as a means of removing sediment. EPA believes
that a 1 ppm cleanup goal in the St. Lawrence and Raquette
Rivers is achievable and provides an acceptable measure of
protection to human health.
EPA intends to comply with the Tribal PCB ARAR by removing
sediments with PCB concentrations greater than 0.1 ppm PCEs
in Turtle Creek. However, technical limitations may
preclude removal of sediments to 0.1 ppm PCBs. If this is
the case, EPA will remove all contaminated sediments to the
extent practicable due to the limitations of dredging
technology. Sediment resuspension will be minimized throur.-.
the use of engineering controls. However, if, as a result
of dredging, resuspended sediments settle on Tribal land,
they will be subject to the Tribal sediment ARAR.
Based on a 1 ppm PCB cleanup level, the PCB hotspot in the
St. Lawrence River extends from approximately 1200 feet
above the G.M. outfall to 700 feet below the mouth of Turf.
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Creek and approximately 300 feet from the shore. The PCB
hotspot in the Raquette River, based on a 1 ppm PCB cleanup
level, extends to the soils on the riverbank and to the
sediments in the river which are along the shore
approximately 250 feet upriver and 250 feet downriver from
the G.M. outfall. The approximate limits of the PCB hotspot
in Turtle Creek extend from the cove at the mouth of Turtle
Creek to a point 2500 feet upstream from the mouth of Turtle
Creek.
Prior to remediation, a wetlands assessment, floodplains
assessment, cultural resources survey, and a statement of
consistency with the New York Coastal Management Program
will be required. Excavated sediments will be dewatered, as
necessary. Decanted water would be treated, as necessary by
methods which could'include a combination of aeration,
clarification, filtration, air stripping and carbon
adsorption to remove VOCs and PCBs and discharged to the St.
Lawrence River. Bulk items which are not amenable to
treatment will be separated from the sediments and disposed
in a facility which meets all TSCA requirements, as
necessary.
During remediation, additional sediment analyses may be
required to better delineate PCB hotspots. In addition,
silt curtains or other sediment control devices will be
installed to control sediment that might be disturbed durir.c
dredging activities. Sheet pile walls will be installed cr.
the river side of the dredging areas to provide a stilling
basin for dredging operations. Prior to remediation of the
Raquette River sediments, the sludges from the existing G.x.
outfall to the Raquette River will be removed and the
outfall will be plugged and secured to ensure that it will
not serve as a source of future contamination to the River.
Sediments will be treated to levels below 10 ppm PCBs. Tr.-:
type of treatment to be used will be determined on the basi-
of treatability tests during design. If any sediments
cannot be treated to levels below 10 ppm PCBs using
biological treatment alone, incineration or one of the otw.e.-
innovative technologies tested during design which has beer-
demonstrated to achieve site treatment goals will be used t
treat them.
Treated sediments and sediments with initial PCB
concentrations below 10 ppm will be disposed on G.M.
property and covered with a vegetated soil cap which
complies with New York State and TSCA chemical waste
landfill requirements for a cover. The disposal area will
be maintained. Dredged areas, riverbanks, and wetlands :.-.
the river system and on the St. Regis Mohawk Reservation
will be restored, as closely as possible, to their origir-:.
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35
grade and pre-dredging conditions. Post-remediation
monitoring of the St. Lawrence River, Raquette River, and
Turtle Creek and associated wetlands and riverbanks will be
conducted to ensure that PCBs and other contaminants at
unacceptable levels are no longer found in or migrating to
these areas. Monitoring program plans will be finalized by
EPA, in consultation with NYSDEC and the St. Regis Mohawk
Tribe.
Because sediments present a principal threat at this Site,
sediment excavation will proceed as soon as possible. If
necessary to expedite sediment dredging, sediment will be
stored in an upland protected area while treatability
testing is conducted.
Interim surface runoff control in the East Disposal Area
The East Disposal Area will be contoured and revegetated as
necessary to prevent surface runoff to the St. Regis Mohawk
Reservation and to minimize movement of contaminated surface
soil from the G.M. facility. Where possible, recontouring
will be accomplished through the addition of fill so as not
to disturb PCBs buried in the East Disposal Area. In
addition, any contaminated surface water which is diverted
from the East Disposal Area during and after recontouring
will be treated to comply with SPDES requirements and
discharged to the St. Lawrence River. A remedy for the East
Disposal Area and Industrial Landfill will be the subject of
a second operable unit ROD. Because contaminated surface
soil in the East Disposal Area is a principal threat at this
Site, runoff prevention will proceed as soon as possible.
Excavation and on-site treatment of PCS contaminated sludges
and soils in the North Disposal Area, in the four Industrial
Lagoons, and in other areas on G.M. property (active
lagoons, while being addressed in this operable unit ROD.
will be remediated when they are taken out of service)
Soil and sludge in the North Disposal Area (including the
buried interceptor lagoon) and in miscellaneous areas on
G.M. property with concentrations above the cleanup levels
given in Table 6 will be excavated and treated to levels
below 10 ppm PCBs. The type of treatment to be used will be
determined on the basis of treatability tests during design.
If any material cannot be treated to levels below 10 ppm
PCBs using biological treatment alone, incineration or one
of the other innovative technologies tested during design
which has been demonstrated to achieve site treatment goals
will be used to treat it. Bulk items which are not amenatie
to treatment will be separated and disposed in a facility
which meets all TSCA requirements, as necessary. Treated
-------
36
soils will be backfilled in areas on G.M. property and
covered with a vegetated soil cap which complies with New
York State and TSCA chemical waste landfill requirements for
a cover. The disposal area will be maintained. The
excavated areas in the North Disposal Area will be covered
to reduce erosion and prevent migration.
Standing water in the inactive lagoons will be drained,
treated as necessary to remove PCBs and discharged to the
St. Lawrence River. All sludge in the lagoons will be
excavated. Underlying soil with contaminant concentrations
above the levels given in Table 6 will also be excavated and
treated to levels below 10 ppm PCBs. The type of treatment
to be used will be determined on the basis of treatability
tests during design. If any lagoon material cannot be
treated to levels below 10 ppm PCBs using biological
treatment alone, incineration or one of the other innovative
technologies tested during design which has been
demonstrated to achieve site treatment goals will be used to
treat it. Treated materials will be disposed in areas on
G.M. property and covered with a vegetated soil cap which
complies with New York State and TSCA chemical waste
landfill requirements for a cover. The excavated areas in
and around the lagoons will be covered to reduce erosion and
prevent migration. The active lagoons will be remediated in
exactly the same manner when they are taken out of service
by G.M. In the interim, any contamination from the active
lagoons which migrates to groundwater will be recovered as
described below. For purposes of cost estimation, EPA has
assumed that the active lagoons will be taken out of service
in ten years.
Excavation and on-site treatment of PCS contaminated soil cr.
St. Regis Mohawk Reservation land adjacent to the G.M.
facility
Soil on the Reservation with PCB concentrations above 1 ppr
PCBs will be excavated. Soil with PCB concentrations above
10 ppm will be treated to levels below 10 ppm. Bulk iter.s
which are not amenable to treatment will be separated and
disposed in a facility which meets all TSCA requirements, as
necessary. The type of treatment to be used will be
determined on the basis of treatability tests during design.
If any soil cannot be treated to levels below 10 ppm PCBs
using biological treatment alone, incineration or one of the
other innovative technologies tested during design which has
been demonstrated to achieve site treatment goals will be
used to treat it.
Treated soils and soils with initial PCB concentrations
below 10 ppm will be disposed in areas on G.M. property ar.u
covered with a vegetated soil cap which complies with New
-------
37
York State and TSCA chemical waste landfill requirements for
a cover. The disposal area will be maintained. Excavated
areas on the St. Regis Mohawk Reservation will be restored,
as closely as possible, to their original grade and
condition. Post-remediation monitoring on the Reservation
will be conducted to ensure that PCBs are no longer
migrating to areas from the G.M. facility. During
remediation, necessary measures will be taken to protect
Mohawk cultural resources. To protect the Tribe's spiritual
values, a Mohawk cultural representative may need to be
present during much of the remediation work on Mohawk lands.
Downgradient groundwater recovery and treatment with
discharge of treated aroundwater to the St. Lawrence River
Groundwater will be recovered downgradient of the Industrial
Landfill, the Industrial Lagoons, and the East Disposal
Area. Extracted groundwater will be pumped to a wastewater
treatment plant for treatment which could include a
combination of aeration, clarification, filtration, air
stripping and carbon adsorption to remove VOCs and PCBs from
the groundwater. After treatment, the water will be
discharged to the St. Lawrence River. Groundwater will be
treated to comply with SPDES requirements. Groundwater will
be extracted and treated until groundwater PCB
concentrations, as measured at the boundary of the
Industrial Landfill, the Industrial Lagoons, and the East
Disposal Area are below 0.1 ppb. During and after
remediation, groundwater and surface water will be
monitored. If necessary, additional groundwater and/or
surface water recovery and treatment will be used to ensure
that no contamination is migrating from the Site.
Testing of other PCB treatment technologies
Other innovative PCB treatment technologies will be tested
concurrently with biological destruction so that EPA will
have additional information in the event that biological
destruction proves to be unsatisfactory for treatment of any
Site material. Biological treatment will be used wherever
EPA determines it to be viable. In the event that
biological treatment is ineffective for a certain area of
the Site or for certain Site materials, other innovative PCB
treatment technologies (which have been demonstrated to
achieve site treatment goals) or incineration may be
employed. The criteria used to judge the treatment
technologies during treatability testing include
effectiveness and cost. EPA will select the treatment
technologies to be employed, in consultation with NYSDEC and
the St. Regis Mohawk Tribe.
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38
The total present worth cost of the first operable unit selected
remedy is $ 78 million. A breakdown of estimated costs
associated with the selected remedy is presented in Table 12.
STATUTORY DETERMINATIONS
Protection of Human Health and the Environment
The selected remedy protects human health and the environment
through the permanent treatment of contaminated sediments, soils,
and sludges and through groundwater treatment. Treatment
residuals will be covered. Bulk items which are not amenable to
treatment will be separated and disposed in a facility which
meets all TSCA requirements, as necessary. Following
implementation of the selected remedy, the excess cancer risk to
the adult Mohawk population will be on the order of 10s to 106,
depending on the residual sediment level attained after dredging.
Compliance with ARARs
A list of ARARs for the selected remedy is presented in Table 13.
The selected remedy complies with these ARARs or provides the
grounds for invoking a waiver as described below.
During dredging, EPA will attempt to meet the Tribal PCB ARAR of
0.1 ppm PCBs in Turtle Creek. However, based on limited previous
experience at other Superfund sites and federal projects,
dredging to 0.1 ppm PCBs may be technically impracticable.
Therefore, EPA is waiving the Tribal sediment standard where it
proves to be technically impracticable to achieve during
dredging, as discussed in CERCLA, section 121(d)(4)(C). EPA will
consult with the St. Regis Mohawk Tribe and NYSDEC before making
a final determination as to the technical impracticability of
meeting the tribal sediment PCB ARAR. EPA will base its
determination on the results of dredging conducted in Turtle
Creek.
According to TSCA disposal regulations and policy, soil treatment
residuals with PCB concentrations above 2 ppm must be disposed in
a TSCA chemical waste landfill. However, in accordance with TSCA
regulations, EPA is waiving certain TSCA chemical waste landfill
requirements for soil treatment residuals with PCB concentrations
above 2 ppm and below 10 ppm. Specifically, provided the
residuals are soils with a low water content and PCB
concentrations below 10 ppm, EPA is waiving the TSCA requirements
on landfill location and the TSCA requirement for a leachate
collection system. These TSCA chemical landfill requirements are
being waived under TSCA (40 CFR 761.75(c)(4)) because soil
treatment residuals which meet Site cleanup standards do not
present an unreasonable risk of injury to health or the
environment from PCBs.
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39
According to New York State hazardous waste disposal regulations
at 6 NYCRR Part 370, all treatment residuals which satisfy the
New York State definition of hazardous waste must be disposed in
a landfill which meets New York State requirements. EPA does not
anticipate that treatment residuals will be hazardous (e.g.. have
PCB concentrations above 10 ppm). However, all treatment
residuals will be considered solid waste under New York state
regulations at 6 NYCRR Part 360. New York State solid waste
regulations, while mandating several requirements, including the
use of a liner and leachate collection system, allow for less
stringent requirements based on the potential pollution of the
waste (6 NYCRR Part 360-2.14 (a)).
During design, EPA, NYSDEC and the Tribe will finalize plans for
the disposal of residuals. These plans will include certain
provisions to ensure proper residuals disposal. For instance,
the location of the residuals placement area will be selected
such that the groundwater beneath the area flows towards the
groundwater recovery and treatment system. Further, the
residuals will be placed in a manner to ensure that they are not
in contact with the shallow groundwater aquifer. The design of
the cap will specify that soil with a very low permeability will
be used. The cap will be constructed and maintained to prevent
erosion and graded to direct runoff from the capped area. Should
certain treatment residuals be hazardous or require greater
protection than discussed above, EPA in consultation with New
York State and the St. Regis Mohawk Tribe, will impose
appropriate requirements in the finalized residuals treatment and
disposal design plans.
In addition, TSCA regulations require that sludges with PCB
concentrations above 500 ppm be incinerated in a TSCA compliant
incinerator or be treated by a method equivalent to incineration.
In compliance with TSCA, any sludges with initial PCB
concentrations above 500 ppm which cannot be treated by an
innovative technology to^ achieve PCB residuals below 2 ppm must
be incinerated.
During groundwater recovery and treatment, EPA's cleanup goal is
the New York State PCB ARAR of 0.1 ppb PCBs. Based on EPA
studies of other sites, EPA has found that the final groundwater
cleanup level will depend on technical considerations such as the
propensity of PCBs to sorb to soil.
Cost-Effectiveness
The selected remedy is cost-effective because it has been
demonstrated to provide overall effectiveness proportional to its
costs. The present worth of the selected alternative is $ 78
million. EPA has selected an alternative which includes the us-
of biological treatment and incineration. This is a cost-
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40
effective remedy since biological treatment was the least
expensive of the treatment remedies evaluated for the Site.
Sediment dredging and treatment, although approximately seven
times more expensive than containment, is cost-effective because
it is a highly permanent and effective remedy for the principal
threat at the Site and because it reduces contaminant toxicity.
Similarly, the additional costs associated with lagoon sludge
excavation and treatment and excavation and treatment of solids
in the North Disposal Area, on the Reservation, and on G.M.
property are proportional to the long-term effectiveness and
reductions in toxicity afforded by these alternatives. The
higher degree of effectiveness and the reduction in contaminant
mobility associated with groundwater recovery and treatment
justifies the additional costs associated with this alternative.
Utilization of Permanent Solutions and Alternative Treatment
Technologies to the Maximum Extent Practicable
EPA has determined that the selected remedy represents the
maximum extent to which permanent solutions and treatment
technologies can be used in a cost-effective manner for the first
operable unit at the G.M. Site. Of those alternatives that are
protective of human health and the environment and meet ARARs,
the selected remedy provides the best balance of tradeoffs in
terms of long-term effectiveness and permanence, reduction in
toxicity, mobility, and volume through treatment, short-term
effectiveness, implementability, and cost while also considering
the statutory preference for treatment as a principal element and
considering State, Tribe and community acceptance.
The selected remedy offers a higher degree of permanence than
containment alternatives. Because PCBs are highly persistent ir.
the environment, removal and treatment provide the most effective
way of assuring long-term protection. In addition, the use of
biological treatment (or another innovative treatment
technology), incineration, and groundwater treatment results in
the reduction of toxicity and mobility of PCBs. Extraction
technologies only reduce the volume of PCB contaminated
materials. Although there are short-term impacts associated wit.-.
the selected remedy, these can be mitigated and will not pose an
unacceptable risk to the surrounding community, G.M. workers, cr
remediation workers.
Biological treatment presents some difficulties in implementation
since it must be tested during design. However, incineration is
a proven technology for the destruction of PCBs which can be used
if necessary to ensure destruction of contaminated materials.
Biological treatment is the least costly of all treatment
alternatives evaluated. Therefore, use of biological treatment
minimizes the cost of the selected alternative provided
treatability tests show that it performs in a manner comparable
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41
to the other technologies considered. In addition, EPA favors
the development of biological treatment since it is an innovative
technology.
The selection of treatment is consistent with Superfund program
expectations that indicate that highly toxic, persistent wastes
are a priority for treatment which ensures long-term
effectiveness. Among the treatment alternatives considered for
the various areas of the Site, the major tradeoffs that provided
the basis for EPA's remedy selection were proven effectiveness of
incineration and the cost of biological treatment.
Preference for Treatment as a Principal Element
By treating the contaminated sediments and solids in the river
system, in the North Disposal Area, on the Reservation and on
G.M. property and by treating contaminated groundwater, the
selected remedy satisfies the statutory preference for remedies
that employ treatment as a principal element for several of the
principal threats posed by the Site.
DOCUMENTATION OF SIGNIFICANT CHANGES
The Proposed Plan for the G.M. Site was released on March 21,
1990. The Proposed Plan identified the following preferred
alternative:
sediment dredging;
excavation of lagoon sludges in all four Industrial
Lagoons;,
excavation of solids and sludges in the North and East
Disposal Areas, on the Reservation, and on G.M.
property;
groundwater recovery and treatment
incineration of all excavated/dredged material with PCB
concentrations greater than 500 ppm and biological
treatment of all excavated/dredged material with PCB
concentrations less than 500 ppm.
After reviewing all written and verbal comments received during
the public comment period, EPA has made five significant changes
from this proposed alternative. These changes were made based on
new information received during the public comment period from
EPA, the public, G.M., the St. Regis Mohawk Tribe and NYSDEC.
EPA has determined that its remedial decision for the East
Disposal Area should be deferred. This determination was based
on the fact that new EPA policy on Superfund sites with PCB
contamination which may affect EPA's decision for the East
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42
Disposal Area was released during the public comment period. EPA
will select a remedy for the East Disposal Area and the
Industrial Landfill in a second operable unit ROD.
EPA has determined that G.M. plant operations could be impacted
during remediation of the active wastewater lagoons. This
determination is based on comments received from G.M. which
stated that the lagoons are an integral part of current plant
operations. In addition, any groundwater releases from the
active lagoons which would be a source of contamination to the
environment will be dealt with through the groundwater recovery
and treatment remedy specified in this ROD. As a result, EPA has
delayed remediation of active lagoons. The method of remediation
for the lagoons is exactly the same as for inactive lagoons,
however, EPA will delay remediation of the active lagoons as long
as they remain in service.
EPA has determined that the use of on-site incineration should be
minimized in the selected remedy. This determination was based
on comments from the public and the Tribe which stated that
incineration was the least preferred treatment method for the
Site. As a result, EPA will rely on the results of treatability
tests to determine whether biological treatment will be used to
treat the various areas at the Site. In the event that
biological treatment is ineffective for a certain area of the
Site, other treatment technologies which will be tested
concurrently with biological treatment may be employed. In the
event that these other technologies are ineffective, incineration
will be used at the Site.
EPA has determined that a lower PCB cleanup goal is warranted in
St. Lawrence River sediments and soils. This determination was
based on comments from the public, NYSDEC, the Tribe, and the
Natural Resource Trustees which called for lower cleanup levels
in the river system. Based on these comments and on a review of
the data used to determine the initial sediment cleanup level,
EPA has revised the PCB cleanup level in the St. Lawrence River
to 1 ppm. The 1 ppm level roughly corresponds to a 10'5 excess
cancer risk to adult Mohawks.
Finally, EPA has determined that a higher PCB cleanup goal is
warranted in Raguette River sediments. This determination was
based on a review of PCB data which shows that all contamination
detected in the Raguette River is located on the riverbank and in
the sediment near the former G.M. outfall. Since this area is
not located on the Reservation, EPA has revised the PCB cleanup
level in the Raguette River to 1 ppm.
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APPENDIX 1
FIGURES
-------
LAKE ST. UVMENCC
CANADA
CORNWAUL
ISLAND
(CANADA)
WOODWARD-CLYDE CONSULTANTS
LOCATION OF STUDY ART A
ST. IMWINCC MVCft SYSTEMS
net
ncuui
-------
AKWESASNE MOHAWK NATION
DISPOSAL AREA
INDUSTRIAL
LANDFILL
AREA
NORTH
DISPOSAL
AREA
FIGURE 2
SITE LAYOUT
I
i
i
i
i
h
//
/1
it
//
/
w
RAQU^TTE RIVER
SOURCE: G.M. REMEDIAL INVESTIGATION, MAY 1986
-------
t
N
RESIDENCES
*<
Turtle Creek
i
r^
X
VV
GENERAL MOTORS
FACILITY
AKWESASNE
MOHAWK
NATION
HC
K
'\\
SCALE
1 : 2400
II
FIGURES
DELINEATION OF TURTLE CREEK
-------
BUSTIM) OROUND
ILT CURTAIN
QRADED
FILTER
(SEE DETAIL!
CONTAMINATE O
SEDIMENT
GRADED FILTER DETAIL,
(NOT TO SCALE)
APPROXIMATE THICKNESS S-1S MET
FIGURE 4
DESIGN CONCEPTS: IN-PLACE CONTAINMENT OF SEDIMENTS
SMALL OIA.
ORAVEL
SOURCE: C.M. DRAFT FEASIBIUTY STUDY. NOVEMBER 1989
-------
APPENDIX 2
TABLES
-------
Site Area
TABU7. 1
VOLUMES Ol- PCB C:ONTAMINATF,D MATERIAL
AT THE C.M. SITE
Volume of Material Volume of Material Volume of Material Volume of Material Volume of Material
River Sediments
Lagoons
North and East
Disposal Areas
Industrial Landfill
Reservation Soils*
Other Areas
TOTAL
where: ppm
with PCDs
> 1 nnm fvd1)
62,000
103,000
311,000
442,000
15,000
60,000
993,000
= parts per million
with PCBs
> 10 nnm fvd')
34,000
91 ,000
225,000
424,000
15,000
34,000
823,000
with PCBs
> 25 ppm fvd')
29,000
84,000
195,000
420,000
15,000
4,000
747,000
with PCBs
> 50 ppm fvd3)
24,000
83,000
126,000
316,000
15,000
1,000
565,000
with PCBs
> 500 ppm fvd3)
16,000
42,000
76,000
305,000
15,000
0
454,000
yd3 = cubic yards
Calculation of Reservation soil volumes is based on a 1 ppm action level.
Mi.ili I'c.isiln'liiv Sliulv I'M (I.M. Site, November 1989
-------
AIM CUD ABfA
1. NORIH DISPOSAL ARFA
n. SoiIs/S1urige
riMMIIINMIS
PCIK (lotnl )
SIMWRT in *i nran is
IMT IIO MASS! HA
(ARRRIVIAIIIWS DMIMin Al I MD Of IAHI f )
nMCIMIBAIKM
llBl Mil NO)
VOCs
S: 0.77 - 17,000 prm (7B/7B)
Modinn = 6.1 |H«n
S/S: O.H .11.ram mm (S6/61)
Median = JO ftfVt
S: No detects
S/S: VC 0.158 ppm (1/9)
PCE 0.8 ppm (?/9)
Brniene 0.01 ppm O/°>
WK 0.1 ppm (1/9)
DCE 0.3 ppm (1/9)
Phenol/Substituted Phenol
S: No detect
S/S: Up to 5000 ppm
(3/9)
PNAs
S: BMDl
S/S: 2 MethyInaphthalene
2.0 ppm
(1/9)
S = Surface
S/S = Subsurface
BNOl = Below Method Detection limit
(1/9) - Nuniier of Snmples Detected/Nunt>er of Samples Analyzed
OCF = 1,2-Trans-dichloroethyleoe
PCF - letrnrhlorrx'thylene
l(f - 1 r irhlnrorlhylpnr
Hit - Mrlhyl flhyl ItPKmr
VIMS - Volntil^ Oiqnnif ( i«n|)«Mjrw1<;
VI - Vinyl ( hi in lilf
I'IB's - Piilyihlni innl>^1 Ri|^>poyls
f'NA's = PolytMKrlpnr Ai(«nntic Hyttr ocnrtxms
OIMNIS
Two patterns of PCB
concentrations with 25 ppm at a 20-foot depth.
fifteen different VOCs detected
in soil samples. All VOC
concentration values in soil
borings were less than 0.3 ppm.
with the exception of PCE and
DCE in two samples.
Two borings accounted for the
only quantifiable observations
of substituted phenols (?.*-
dimethyl-phenol, 2-methylphenol,
and 4-methyl phenol). The
highest concentrations of
phenols were associated with
areas of past waste disposal or
treatment.
eleven PNM were detected in
surficial soils and boring
samples. All PNAs. with the
exception of 2-methyl-
naphthalene, were detected below
the HOI.
)«0:BTE:ms0101t.rev
Revlslon:November
-------
9MWRV Of HI Bl SIH IS
««: no MASSINA
AIMrun ARIA
RANIJ!__(,! Rl «R N(;Y J_
OVMNIS
Phthnlntrs
S: Up to ?.0 HOT (?/4)
S/S: tl|> to U HOT (W)
Metals
S: See comwnt
b. Ground Water
2. EAST DISPOSAL AREA
B. Soils
PCBs (1248) (MU ?4B, HUKA.
MW14B)
PCBs (Total)
VOCs
S = Surface
S/S = Subsurface
BMOl - Below Method Detection Limit
(1/9) = Nintier of Samples Detected/Nurfier of Samples Analyzed
OCf = 1,?-Irans-dichloroethylene
PCF = letrachloroethylene
ICF = f r iirhl oroplhylene
HI It - Holhyl Fthyl Kotooe
V(HX - Vnlntilr Orqnnic CnnfVHjnrls
VI - Vitiyl (til or i(lr
PCR'i = Pol yf hi c»i in«t rfl Ri^rnyls
PMA's = Polynnclpnr Aromntic Hydrocarbons
Not Detected to 0.0041 ppm
S: Up to 41.000 ppm (60/68)
Median = 1? ppm
S/S: Up to 30.000 ppm (87/89)
Median = 2.5 ppm
S: MEK up to 0.01 ppm (1/8)
S/S: Xylene up to 0.008 ppm
(4/18)
Toluene up to 0.01 ppm
(4/18)
four phthalatp compounds were
detected in surficial soil and
boring samples. Quantifiable
concentrations of phthalate
compounds ranged from 0.891 to
17.8 ppm in five of thirteen
samples.
Only manganese and magnesium
were observed at concentrations
above those in background
samples. Neither constituent
warrants consideration for
remedial action.
Results indicate lower
concentrations in Phase II Rl in
comparison to Phase I Rl.
Most of the PCBs were found
within the boundaries of
previous sludge disposal areas.
Three additional areas adjacent
to the sludge disposal areas
were also defined.
Phase I and Phase II HI results
indicated the presence of eleven
VOCs. These concentrations are
low and do not warrant further
assessment.
?
-------
IMIF ?
StMMART or Bl Rl Sill IS
nc-cio MASSIMA
AIIICIID ARIA
Phenols/Suhst itutr<< I'hriwils
rTMCf NIRAIKM
_ RANI4_ (I Rl UN MCTi_
S: Up to 11.000 |H«n
S/S: Up to fl.OOO pim
(S/lfl)
PNAs
S: BMDL to 0.6 ppm
-------
I ABIE 2 (CONIINUTD)
SUMMIT Of HI BISUIIS
CMC CIO MASS! MA
AfttCUO AHEA
3. INDUSTRIAL LANDFILL
a. Soils/Uaste
CONSIIIUENIS
PCBs (Total)
tAHCE (IBIOUNCT
S: Up to 45 ppn <27/27)
Median = 1.7 ppn
S/S: Up to 4)00 ppm (00/90)
Median = 1.7 ppn
COHHEinS
VOCs
S: BMDL
S/S: TCE up to 1.1 ppn (2/12)
Phenols/Substituted Phenols
PNAs
Phthalates
S Surface
S/S Subsurface
BMDl « Below Method Detection limit
(1/9) Nutter of Samples Detected/Number of Samples Analyzed
DCF. 1,2-Irans-dichloroethylene
PI F lelrachloroelhylene
1(1 Ir ichlor oethylene
m I ftrihyl I Ihyl imnr
VTJ< vulclllr Oiysxn (<«|Ni
-------
lAHIf ? (ITMIIMID)
9MWMV O» tl BIS1H IS
IMT fll» NASMMA
AIHCIID ARIA
CdHSMMNMIS
Mi-lnls
_RANU (i RI a* w.»j_
Soo T
Ground Water
Pr.Bs (1?4fl) (MW-16A1B)
lip lo 1.1 ppm
S
s/s
BH01
nil
ri I
ii f
i i
V" N \
VI
P( B's
PNO'S
VOCs (MU 168)
Phenols/Substituted Phenols
PKAs (MU 268)
Phthalates (several wells)
Metals
Surface
Subsurface
Below Method Detection limit
Nintwr of Samples Detectrd/Nun*>er of Samples Analyied
1.? Ir mis rtii hloroelhylnw
Iptrnihlof f »* 1 h y I ef >e
ll I I h I IU Iff t hy I ft If
Mrlhrl flhrl let. ***
V..lA1llr llli|,»ltli I .«*^MH»HI-.
V i.ixl I III ..c ulr
Pill y< hi or irtat M| Rl|tflpnyl<;
Pnl yivir leaf Aiimntu Hyili IK Bibons
1.? OCF up to 0.6A6 ppm
(0/6)
ICC up to O.OSO ppm
VC O.OSO ppm (4/6)
Up to 0.074 ppm
Up to 0.188 ppm
Up to 0.082 ppm
See Comments
five sample?; out of 70 showed
levels nlxive hnrkground (Al, »..
Co. Cu, Cr. Ic. Mi, /n). the
occurrence of trnre metals is
probably cfcir lo the prpsrnce nf
foumlry sands and mil lo the
disposal of PCS waste oils.
Only samples from well 16A and
16B showed a consistent
occurrence (PCBs). The Phase II
data indicate the extent of
harardous substance migration in
ground water in the vicinity of
the landfill is more limited
than shown by the Phase I RI
data.
Only samples from well MU 168
showed a consistent pattern of
VOC occurrence. Phase II RI
data showed lower
coneentrat ions.
Concentrations decreased from
Phase I RI results to Phase II
RI results.
four PHAs delected in NU-268 in
Phase I and not Phase 11.
Phthalates were seen in the
Phase I III but not in Phase II
III sampling of wells.
All were within background
concentrations.
7A9 tl Ufl-Bir
Revision:»0'
-------
IARII ?
SIRMARV IH 81 RlVinlS
u«: no NASSI HA
Af if ciio
4 . IAf.OOMS
A. Sltiilges
((MSI i im MIS
I'l II-; ( 1,''.n)
r(«n Ml (A I K
RANIJ
Up
CIBMHIS
All I ngoom wrre fmvirl In hnve
PCRs in and/of iMmralh slmlfjo
.within thp I oqoons nivl *;i>il
imravli oti»l y Rfljarpnl lo I ;if)n In A p|«i> (S/K)
liiliwric i^> In /fl |n«n (U/H)
ICE n> In 1 M«n (S/K)
VC to 2 ri"> ('/")
Xylrrws tf> to IS n*» (4/U)
Phenols/Substituted
PNAs
Phthalates
S = Surface
S/S * Subsurface
BHDl = Below Method Detection limit
(1/°) « Nintier of Sample* Oetected/Nuntoer of Siwfiles Anatyied
OCF = 1,7 trans dit hloroethylene
III li ic him iM-ltiylrnp
Mil Mplhyl I lhrl lrl«w
VIM s Vulnlilr lli'l.inii I i«^>m>(-;
VI Vl»yl I III in nlr
PCfl's = I'itt yi hi or mnl Ml Rf|4>rnyl<;
PNA's = f'olyTNMlear AMmntic Hyifr rn at IMHIS '
Up to ?6,000 pp"
Up to 30 pfm (3/U>
Up to 37 ppn (3/U)
Ihirtepn VOCs were detected in
soil and/or sltidqe!1; fiom the
laqoon area. VOCs showed up
most often and were general I y at
the highest conrentrat ions in
sludges fron the ISO.000 gal loo
lagoon. tight different VOCs
were detected from sludges from
the SOO.000 gallon lagoon, five
different VOCs were detected in
the 1.5 Hi-gallon lagoon.
Constituents included phenol,
2.4-methylphenol. and 4 methyl-
phenol.
Nine PMAs were detected in
sludges from one or more of the
lagoons. Sixteen of 37 reported
occurrences of PNAs were of
concentrations below the MDI .
Only one phthalate was detected
In the 350,000 gal Ion lagoon.
Ihree phtdeletes were detected
in the 1.5 M gal lagoon. Iwo
phthalates were detected in the
500,000-gal I on lagoon.
7iS9 31 3*0:»!f :«a<:03nit .rev
Revliion:Nove«ber 1°fl9
-------
Afire no MIA
b. SoiIs
? (OMIIMMO)
SIMMRf Of ! »ISin IS
(M: clo NASHUA
CIMSIIIIftNIS
Ni If nsmliphrnyliiminr
Mi-l.ils
I'l'Hs (total )
VOCs
Phenols/Substiluted Phenols
PNAs
Phthalates
Metals
S > Surface
S/S * Subsurface
BMDl = Below Method Detection limit
11/9) « Number of Sanities Delected/number of Samples Analyied
DCf * 1,?-lrans-dichloroethylene
PCE c Tetrachloroethylene
ICE * Irirhlofnethylene
HI I = Mrthyl llhyl frl«nr
VIK n Vnlntilr Oiqnnir (innpnovls
VI - Vinyl (him utr
P( R ' ^ : Till yf hi of ui.tt rflO pp« (11/11)
HiNfinn = /.ft |ifn
S/S: ll|) In 41 ppn ((R/43)
Mftlinn - II |if»n
S: Mo detects
S/S: NIK up to 0.1 ppii (4/6)
S: No detects
S/S: Up to 4 ppn
S: BMDIs
S/S: BHOIs
S: BMDl
S/S: Up to
(I/O)
<6/6)
See C
its
Oetcrtrd in the ISO.noO gal loo
I aqonn .
Fleven of ?} metal-; r
background, notably C. Pb, Hg.
PCB concentrations ranged from
BMDl to ?tm p»ra.
rive VOCs Mere detected in soil
samples. With the eiireption of
NfK, all values of VOCs were
less than 0.01 ppm.
All concentrations of compounds
in this group were observed
below the MDl, with the
except ion of phenol in one
sanple.
Sin PMAs were detected (below
the MDl) in the surface soil
samples.
The surface soil sample
contained only di-n-
butylphthalate at below MDl.
Bis(Z ethyl he«yl ) phlhalate and
di-n-butylphthalate were
detected below the MDl in all
boring samples.
Hi. Ce, Mg were found above
background.
340:m:mas(MOIt.rev
-------
TAME 2 (CmilMVD)
SIRWART or RI ni ran is
IIMC-CID MASSINA
AMI CUD ARM
CIMSIIIIIIHIS
_RAIIIJ (IRIUMNrVJ
COM MIS
Ground Water
PCIK (J24B) (??H)
UP to n.nn/
Ihe Rl I data from MU2J8
suggested migrnt ion ol PCBs frnm
the 10 M-gallon laqonn. Both
Phase II samples from MU-21B
Mere free of detectable PCBs.
Ihis makes it uncertain if PCBs
nre migrating by a ground uater
pathway. Three of four rounds
from MW KB and MU-24B produced
reportable PCB levels indicating
the probable existence of PCBs
in ground water.
VOCs
See comments
A few constituents were noted at
low concentrations.
Phenols/Substituted Phenols
Up to 2.7 ppm
(at 228)
S
s/s
BHOl
(1/9)
DCE
PCE
ICE
NFK
VOCs
VC
PCB's
PNA's
PNAs
Phthalates
Metals
Surface
Subsurface
Below Method Detection limit
Number of Samples Detected/Number of Samples Analyzed
1.2-lrans-dichloroethylene
Tetrachloroethylene
Irirhloroethylene
Methyl Ethyl Ketone
Volatile Organic Compounds
Vinyl Chlni irtc
Polyrhloc inntMl Hifjhpnyls
Pol yrnic I enr Aronwitic Hydrocarl>ons
No detects
Up to 0.029 ppm (at 22B)
See conmen19
Phenols were detected
rounds from MU 228.
in all
Detected above BMDl in MU 22B
and MW24B in one of four rounds.
All were within background
concentrations. Mercury was
reported at 2.6 ug/l (over the
MCI) Iron MU-22B. Ihis was not
confirmed by other HI sampling
rounds or NYDEC split samples.
269.31 340:RIE:ma
-------
I ABIE ?
StMMRY OF Bl CON IS
IMC CIO NASSINA
CfWrTHIRATirw
. JMLl*
S. SI. IAURFNCE RIVER SFDIHFNI
pr.Bs
no - s.fiin
Mnli.m = /.<
VOCs
Phenols/Substituted Phenols
Phthalates
PNAs
MtK Up to 0.0321 ppm
BMDL
Up to 3.2? ppm (8.8)
Benio(a)anthracene 8MOI to 8
ppm.
Metals
S - Surface
S/S = Subsurface
BMOl - Below Method Detection ll«lt
(1/9) > Mirfcer of Sanples Detected/Hmfcer of Samples Analyicd
OCE > 1.2-trans-dichloroethylene
PCE * Tetrachtoroethylene
TCE ° Trichloroethylene
MEK ' Methyl Ethyl Ketone
VOCs « Volatile Organic Conpounth
VC » Vinyl Chloride
PCB's = Polychlorinated Biphenyls
PMA's = PolytmclfBr Arnmntic Hydrocnrbnos
See Comments
CtjMMMIS
Snnples generally contained from
? to 4 times as murh Aroclor
1?V as 1^8. This is the o.tly
location where other thnn
Aroclor 1248 was detected. No
measurable concentrations of the
2. 3. 7, 8-isomers of dionin or
furan were observed in any
samples.
Significant concentrations of
VOCs were not observed.
Significant concentrations of
acid extractables were not
observed.
Sixteen of PNAs Mere detected in
the eight sediment samples
collected adjacent to the site.
Ho measurable concentrations of
the 2, 3, 7, 8,-isomers of
dioxln or furan Mere observed in
any samples.
Mercury and selenium were above
local background concentrations
but within those reported for
soils in Hew York.
40:RIE:mas03011. rev
Revltlon:November 1
-------
2 (trail imro)
9MMBT (tr Rl HI Silt IS
CM: n n MASSI NA
AIM run ARIA
tonsil UN NIS
mNCTNIRAIKM
RANM _(l Rl_« «:!
6. RAQUFITF: RIVFR
rriK
n. Sediments
b. Soils on River Bank
S: O.W ?.?
MCI I inn = l.J p|«i
S: 0.22 - J? (in/It)
Median = 1.7 p(»i»
In addition. a "Highly
I oca) i led" It detect of 240 pfim
at outfall uas found.
7. Off SHE SOUS (UNNAMED
TRIBUTARY)
PCBs (Total)
S: NO - 4B (49/B?)
Median =0.59
The spatial distribution of PCBs
indicates that runoff over a
limited area in the southeast
corner of the GMC-CFD facility
uas the primary route by which
PCBs migrated from the facility.
VOCs
Phenols
PNAs
Phthalates
Metals
S: MEK upto 0.9 npm (J/15)
S: BMDl (1/15)
S: BMDL (15/15)
S: BMDL - 7.99 ppm (1/15)
See Comments
Ho Metals were identified above
background levels.
S = Surface
S/S = Subsurface
BMDl - Below Method Detection Limit
(1/9) = Number of Smrfiles Detected/Nuitwr of Samples Analy/ed
DCF = 1.?-Trans-dichloroethytene
PCF = lelrarhloroethylene
U.'f = I r i chl oroethyl POP
Ml > - Methyl f thyl Kptonp
V»M ; - Volnlilp Oi qnnt ( f infVHirwts
vC - V myl I M cir n(p
PI H ' s - Co I yt h I <»r mul p<1 R if^tPny I <;
CNA's - Polymjclpnr Arinwlii Hyilr o< nrlxms
340:RTE:mas0501t.rev
RevIHion:November 19R9
-------
TABLE 3
Summary of Exposure Assumptions and Exposures
via All Pathways for the G.M. Site
Pathway
Fish Ingestion
Consumption
Fish Concentration
Exposure
Wildlife Consumption
Consumption
Wildlife Concentration
Exposure
Soil Ingestion
Soil Ingestion
Soil Concentration
Exposure
Water Ingestion
Ingestion
Water Concentration
Exposure
Most Probable
130 g/day
1.7 mg/kg
0.003 mg/kg-day
6.6 g/day
23 mg/kg
0.002 mg/kg-day
39 mg/day (child)
10 mg/day (adult)
0.065 mg/kg
1.1 x 107 mg/kg-day
1.4 I/day
1.0/zg/l
2 x 10s mg/kg-day
Worst Case
130 g/day
6.9 mg/kg
0.013 mg/kg-day
6.6 g/day
33 mg/kg
0.003 mg/kg-day
200 mg/day (child)
100 mg/day (aduh',
3.3 mg/kg
3.5 x 106 mg/kg-da;,
2.0 I/day
7.5 Mg/1
2.1 x 104 mg/kg-d-.
-------
TABLE 3 (com.)
Summary of Exposure Assumptions and Exposures
via All Pathways for the G.M. Site
Pathway Most Probable Worst Case
Breast Milk
Ingestion 800 ml/day 800 ml/day
Milk Concentration 0.07 mg/1 0.22 mg/1
Exposure 8.9 x 10s mg/kg-day 2.8 x 10'" mg/kg-day
where: g = grams
mg = milligrams
kg = kilograms
1 = liters
Atg = micrograms
ml = milliliter
Source: "Baseline Risk Assessment for GM/Massena Site," prepared by Gradient
Corporation for the U. S. Environmental Protection Agency, September
15, 1989.
-------
TABLE 4
Summary of Carcinogenic Risks to Mohawks
Pathway Most Probable Worst Case
Fish Ingestion 2.4 x 102 1.0 x 10'
Wildlife Consumption 1.7 x 102 2.4 x 102
Soil Ingestion 8.5 x 107 2.7 x 10s
Water Ingestion 1.5 x 10' 1.7 x 103
Breast Milk 6.8 x 10" 2.2 x 103
TOTAL 4.2 x 102 1.3 x 10!
Source: "Baseline Risk Assessment for GM/Massena Site," prepared by Gradient
Corporation for the U. S. Environmental Protection Agency, September
15, 1989.
-------
TABLE 5
Summary of Noncarcinogenic Effects on Mohawks
Pathway Most Probable Worst Case
Fish Ingestion 31.6 128.
Wildlife Consumption 21.7 31.1
Soil Ingestion 1.1 x 103 3.5 x 102
Water Ingestion 0.2 2.1
Breast Milk ' 8.9 x 10' 2.8
TOTAL 54.4 164.0
Source: "Baseline Risk Assessment for GM/Massena Site," prepared by Gradier.:
Corporation for the U. S. Environmental Protection Agency, September
15, 1989.
-------
TABLE 6
G.M. SITE CLEANUP LEVELS
Medium
Sediment in the
St. Lawrence and
Raquette Rivers*
Contaminant
PCBs
Cleanup Level
1 ppm
Treatment Level
<10 ppm
Sediment in
Turtle Creek*
PCBs
0,1 ppm
<10 ppm
Soil/Sludge on
G.M. Property
PCBs
Total Phenols
10 ppm
50 ppm
<10 ppm
50 ppm
Soil on the
Reservation
PCBs
1 ppm
<10 ppm
Groundwater
PCBs
Total Phenols
1,2 DCE
TCE
Vinyl Chloride
0.1 ppb
1 ppb
100 ppb
5 ppb
2 ppb
=65 ppt *
1 ppb
50 ppb
3 ppb
300 pp:
where: ppm = pans per million
ppt = parts per trillion
1,2 DCE = 1,2-(trans)-dichloroethylene
TCE = trichloroethylene
VC = vinyl chloride
* Cleanup levels given for sediments were used to define PCB hotspo;
** In compliance with TSCA regulations, sludge with initial PCB
concentrations above 500 ppm is subject to a 2 ppm treatment lev-;-!
*** Water would be treated to comply with SPDES which currently req.
that PCB concentrations in the discharge be non-detectable, down :
method detection level, using EPA Laboratory Method Number 60s
-------
TABLE 7
ST. REGIS MOHAWK PCB CLEANUP REQUIREMENTS
Medium Cleanup Standard
Sediments 0.1 ppm
Soil 1 ppm
Groundwater 10 ppt
Air 5 ng/m3
Surface Water 1 ppt
where: ppm = pans per million
ng = nanograms
m3 = cubic meter
ppt = pans per trillion
-------
TABLE 8
COSTS ASSOCIATED WITH SEDIMENT DREDGING AND ON-SITE TREATMENT
Alternative Construction Cost Annual O&M Cost Present Worth Costs
($M) fSK/vear) f$M)
Dredging and 7.7 30 7.7
Biological Treatment
Dredging and 29 12 29
. Chemical Destruction
Dredging and 22 12 22
Chemical Extraction
Dredging and 32 12 32
Thermal Destruction
Dredging and 29 12 29
Thermal Extraction
Dredging and 17 12 17
Solidification
Dredging and a Combination 21.5 24 21.5
of Biological Treatment and
Thermal Destruction*
where: O&M = operation and maintenance
$M = millions of dollars
$K = thousands of dollars
Costs are based on an assumption of biological treatment of sedimer.rs
with PCB concentrations between 1 ppm and 500 ppm and thermal
destruction of sediments with PCB concentrations greater than 500 ppr
Source: Draft Feasibility Study for G.M. Site, November 1989
-------
TABLE 9
COSTS ASSOCIATED WITH EXCAVATION AND ON-SITE TREATMENT OF
SOLIDS IN THE NORTH DISPOSAL AREAS,
RESERVATION SOILS. SOILS ON G.M. PROPERTY
Alternative Construction Cost Annual O&M Cost Present Worth Costs
(SK/vear) fSM)
Excavation and -25 102 25
Biological Treatment
Excavation and 49 165 49
Chemical Destruction
Excavation and 36 165 36
Chemical Extraction
Excavation and 56 165 56
Thermal Destruction
Excavation and 49 165 49
Thermal Extraction
Excavation and 27 165 27
Solidification
Excavation and a Combination 38 267 38
of Biological Treatment and
Thermal Destruction*
where: O&M = operation and maintenance
$M = millions of dollars
$K = thousands of dollars
Costs are based on an assumption of biological treatment of sediments
with PCB concentrations between 1 ppm and 500 ppm and thermal
destruction of sediments with PCB concentrations greater than 500 ppm.
Source: Draft Feasibility Study for G.M. Site, November 1989
-------
TABLE 10
COSTS ASSOCIATED WITH LAGOON SOLIDS EXCAVATION
AND ON-SITE TREATMENT
Alternative
Construction Cost
Excavation and
Biological Treatment
Excavation and
Chemical Destruction
Excavation and
Chemical Extraction
Excavation and
Thermal Destruction
Excavation and
Thermal Extraction
Excavation and
Solidification
Excavation and a Combination
of Biological Treatment and
Thermal Destruction*
24
42
31
47
42
22
47
Annual O&M Cost
(SK/vearl
102
165
165
165
165
165
267
Present Worth Costs
($M1
24
42
31
47
42
22
48
where: O&M = operation and maintenance
$M = millions of dollars
$K = thousands of dollars
Costs are based on an assumption of biological treatment of sediments
with PCB concentrations between 1 ppm and 500 ppm and thermal
destruction of sediments with PCB concentrations greater than 500 ppm.
Source:
Draft Feasibility Study for G.M. Site, November 1989
-------
TABLE 11
ESTIMATED WORST CASE TRANSIENT CANCER RISKS AND NONCARCINOGENIC EFFECTS FOR
ADULT INDIANS AND REMEDIATION WORKERS DURING IMPLEMENTATION OF REMEDIAL ACTIONS
Alternative
Transient Cancer
Risks to
Adult Indians
Capping of the North Disposal 4.0 x 107
Area
Sediment Dredging with Treatment 2.1 x 10s
by a Combination
of Biological Treatment
and Thermal Destruction
Excavation of the North Disposal 3.3 x 10"
Area with Treatment by a
Combination of Biological
Treatment and Thermal Destruction
Transient Noncarcinogenic Transient Cancer Transient Noncarcinogenic
Effects on Risks to Effects on
Adult Indians Remediation Workers Remediation Workers
(Hazard Index) (Hazard Index)
5.2 x 10"1
2.7 x 10'
2.1 x 10:
1.6 x 10s*
1.6 x
3.7 x 103**
2.1 x 102*
2.0 x 10'
4.7'
Source:
Risks or hazard indices estimated for North and East Disposal collectively.
Risks or hazard indices estimated for North and East Disposal Areas and Industrial Lagoons collectively.
"Risk Assessment for Five Remedial Alternatives at the G.M. Site," prepared by Gradient Corporation for
the U. S. Knvironmenial Protection Agency, April 2, 1990.
-------
TABLE 11 (cont.)
ESTIMATED WORST CASE TRANSIENT CANCER RISKS AND NONCARCINOGENIC EFFECTS FOR
ADULT INDIANS AND REMEDIATION WORKERS DURING IMPLEMENTATION OF REMEDIAL ACTIONS
Alternative
Transient Cancer
Risks to
Adult Indians
Excavation of the Industrial
Lagoons with Treatment by a
Combination of Biological Treatment
and Thermal Destruction
7.0 x 10;
Transient Noncarcinogenic
Effects on
Adult Indians
(Hazard Index)
7.7 x 10<
Transient Cancer
Risks to
Remediation Workers
3.7 x 10
3**
Transient Noncarcinogenic
Effects on
Remediation Workers
(Hazard Index)
4.7**
Source:
Risks or hazard indices estimated for North and East Disposal Areas and Industrial Lagoons collectively.
"Risk Assessment for Five Remedial Alternatives at the G.M. Site," prepared by Gradient Corporation for
the U. S. Environmental Protection Agency, April 2, 1990.
-------
TABLE 12
SUMMARY OF COSTS OF SELECTED REMEDY
Component of
Selected Remedy
Sediment Dredging with
a Combination of
Biological Treatment and
Thermal Destruction***
North Disposal Area,
Reservation Soil,
and G.M. Property Soil
Excavation with a
Combination of
Biological Treatment and
Thermal Destruction***
Active Industrial Lagoon
Excavation with a
Combination of
Biological Treatment and
Thermal Destruction***
Inactive Industrial Lagoon
Excavation with a
Combination of
Biological Treatment and
Thermal Destruction***
Groundwater Recovery
and Treatment
TOTAL*****
Construction Cost
f$M)
21.5
38
39.6
25.8
84.8
O&M Costs
CSK/vear*")
24 (3 years)
267 (5 years)
267 (3 years)
267 (3 years)
197 (30 years)
464 (years 1 - 8)
197 (years 9 - 10)
464 (years 11 - 13)
197 (years 14-30)
O&M begins after completion of construction.
Based on an assumed discount rate of five percent
Present Worth Cost
f$M)**
21.5
38
24.6'
26
78*
-------
TABLE 12 (cont.)
SUMMARY OF COSTS OF SELECTED REMEDY
*** Costs are based on an assumption of biological treatment of sediments with
PCB concentrations between 1 ppm and 500 ppm and thermal destruction of
sediments with PCB concentrations greater than 500 ppm.
**** Present worth costs reflect the assumption that active lagoons will be
remediated in ten years.
***** Reflects the savings (in fixed incineration and biological treatment costs)
realized by utilizing the same treatment technologies for all areas of the Site.
-------
TABLE 13
MAJOR APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS,. AMONG OTHERS..
ASSOCIATED WITH THE SELECTED REMEDY
Chemical-Specific ARARs
Safe Drinking Water Act
Maximum Contaminant Level (MCL) for trichloroethylene and vinyl chloride
St. Regis Mohawk Tribe Requirements
PCB cleanup levels in soil, sediment, air, water, and groundwater
Clean Air Act
National Ambient Air Quality Standards at 40 CFR Part 50
New York State Requirements
Groundwater regulations at 6 NYCRR Part 703
Surface water regulations at 6 NYCRR Part 701, including Appendix 31
Air quality standards at 6 NYCRR Part 257
Action-Specific ARARs
Toxic Substances Control Act
40 CFR 761.60-79 PCB disposal requirements
Resource Conservation and Recovery Act
Closure requirements at 40 CFR 264 Subparts G, K, L, and N
Groundwater monitoring requirements at 40 CFR 264 Subpart F
Incineration requirements in 40 CFR 264 Subpart 0
Design and operating requirements for a new unit at 40 CFR Subpart N
Design and operating requirements for tank at 40 CFR Subpart J
Generator requirements at 40 CFR 262
Transporter requirements at 40 CFR 263
Land Dispsosal Restrictions (for hazardous treatment residuals only) at 40 CFR 268
-------
TABLE 13 (com.)
MAJOR APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS, AMONG OTHERS.
ASSOCIATED WITH THE SELECTED REMEDY
Clean Water Act
Best Available technology and monitoring requirements at 40 CFR 122.44(a, e, i)
Best Management Practices program requirements at 40 CFR 125.100
Rivers and Harbors Act
Dredging requirements at 33 CFR 320-330
New York State Requirements
Solid Waste Management Facility regulations at 6 NYCRR Part 360
Final status standards for hazardous waste facilities at 6 NYCRR Pan 3.73-2
Implementation of National Permit Discharge Elimination System at 6 NYCRR 750-757
Location-Specific ARARs
Executive Orders 11988 and 11990
Floodplains management and protection of wetlands at 40 CFR 6.302 and 40 CFR 6.
Appendix A
Fish and Wildlife Coordination Act
Protection of endangered species and wildlife at 33 CFR Parts 320-330 and 40 CFR
6.302
National Wildlife Historical Preservation Act
Preservation of historic properties at 36 CFR 65 and 36 CFR 800
Endangered Species Act
Protection of endangered species at 50 CFR 200, 50 CFR 402
Clean Water Act
Section 404 requirements for dredge spoil discharge at 40 CFR 230 and 33 CFR Pars
320-330
Wild and Scenic Act
Protection of recreational river at 40 CFR 6.302(e)
-------
TABLE 13 (cont.)
MAJOR APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS, AMONG OTHERS,
ASSOCIATED WITH THE SELECTED REMEDY
Coastal Zone Management Act
Conduct activities in manner consistent with State program
New York State Requirements
Wetlands land use regulations at 6 NYCRR Part 661
Freshwater wetlands requirements at 6 NYCRR 662-665
Endangered species requirements at 6 NYCRR 182
Coastal zone management policies at 1 NYCRR Part 600
To Be Considered" Requirements
Toxic Substances Control Act
40 CFR 761.120-135 PCB Spill Policy
Safe Drinking Water Act
40 CFR 141.61 and 54 FR, May 22, 1989, 22062: Proposed MCLs for PCB and 1,2
trans-dichloroethylene
Clean Water Act interim sediment criteria for PCBs, EPA, April 1988
New York State sediment criteria for PCBs
Resource Conservation and Recovery Act clean closure level for phenol, EPA, October, 1987
-------
APPENDIX 3
NYSDEC AND TRIBAL LETTERS OF CONCURRENCE
-------
New York State Department of Environmental Conservation
50 Wolf Road, Albany, New York 12233 - 7010
Thom»s C. Jortlnp
CommlsslcrMf
Mr. Richard L. Caspe, P.E.
Director
Emergency and Remedial Response Division
U.S. Environmental Protection Agency HPP 1 '
Region II U_L 1 *
26 Federal Plaza
Hew York, NY 10278
Dear Mr. Caspe:
Re: General Motors - Central Foundry Division Site
Draft Record of Decision (ROD)
NYS Site #6-45-007
New York State Department of Environmental Conservation supports the selected
remedies as presented in the revised draft ROD of December 4, 199C for
remediation of the contaminated areas associated with the General Motors (GM)
site that are the subject of this operable unit. The Department's position
regarding the cleanup levels, as stated in our previous letter datea
September 27, 1990, is still pertinent to this revised version.
If you have any questions concerning this matter, please contact Michael J.
O'Toole, Jr., P.E., at (5X8) 457-5861.
Sincerely,
Edward 0. Sullivan
Deputy Commissioner
cc: G. Pavlou, USEPA
L. Carson, USEPA
R. Tramontane, NYSDOH
J. Privitera/D. Sommer, NYSDOL
TDTHL r . C-l-
-------
New Yoric State Department of Environmental Conservation
60 Wolf Road, Albany, New Yortc 12233 .7010
Mr. Richard L. Cospe, P.E.
Director
Emergency and Remedial Response Division
U. S. Environmental Protection Agency
Region II
26 Federal Plaza
New York, New York 10278
fc£LS>.
Thomit C, Jorflng
SEP 2 7 199Q
Dear Mr. Caspe;
Re:
General Motors - Central Foundry Division Site
Draft Record of Decision (ROD)
NYS Site 16-45-007
York State Department of Environmental Conservation supports the
selected remedies as presented in the draft ROD of September 26, 1990 for
remediation of the contaminated areas associated with the G«ft»ral Motors
site that are the subject of this operable unit.
The Remedy selected by USEPA is appropriate, and it is e significant step in
the direction of remediating high levels of contamination in the Massena
area. The Department acknowledges UsEPA's progressive view in selecting
cleanup levels of 1 ppm for sediment and 10 ppm for soil which will go a
lone way in r.inirr.izing the risk presently presented, by the contamination.
H?w«ver, as the ROD acknowledges, this cleanup standard will result in
residual risk to the environment. Potential injuries related to residual
risk after remediation has been implemented will be quantified and evaluated
froB a natural resource damage perspective. The quantification of this
residual risk will form the basis for the State's pursuit of monetary
daragee against CM and others for natural resource damages. Obviously, the
greater the residual risk from lingering contamination, the more the State
will seek in monetary damages from OM. Therefore, while the Department
accects USEPA's proposed cleanup levels, we strongly encourage CM to
eliminate as much of the contamination a* possible, while it is in the
process of remediating th* environs of this site and to pursue the lowest
possible cleanup level that is feasible under conditions existing.
If you have any questions concerning this matter, please contact
Mr. Michael J. O'Tocle, Jr., P.E. at (518) 457-5861.
Sincerely,
EdwarB 0. Sullivan
Deputy Commissioner
cc: G. Pavlou, USEPA
L. Carson, USEPA
R. Tramor.tano, NYSDOH
J. Privitera/D. Sommer, NYSDOL
22'= e=£s
0££1
= 01
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SAINT REGIS MOHAWK TRIBE
TRIBAL COUNCIL CHIEFS TRIBAL CLERK
L.DAVID JACOBS COMMUNITY BUILDING CAROL HERNE
LINCOLN C. WHITE HOCANSBURG, NEW YORK 13655 TRIBAL ADMINISTRATOR
NORMAN J. TARBELL 518-358-2272 SAKAKOHE PEMBLETON
FAX #518-358-3203
December 7,1990
Mr. Constantine Sidamon-Eristoff
Regional Administrator
U.S. Environmental Protection Agency
Region II
26 Federal Plaza
New York, New York 10278
Re: Draft Record of Decision for General Motors Central Foundary
Division Site, Massena, New York
Dear Mr. Sidamon-Eristoff:
The Saint Regis Mohawk Tribe generally supports and concurs with the draft
Record of Decision (ROD) provided to us on December 5, 1990, which selects
remedies for contaminated areas on and adjacent to the General Motors site that are
part of this first operable unit.
The Saint Regis Mohawk Tribe has indicated that its primary concern is
protection of the Mohawk people's health and environment through the
expeditious and permanent cleanup of the site. To this end, the Tribe supports the
removal of contamination from the Reservation and comprehensive controls
which ensure that there will be no further migration of contamination from the
General Motors site 'onto the Reservation or into the environment utilized by the
Mohawk people. Consequently, the Tribe advocated inclusion of the East Disposal
Area in this ROD and voiced its concerns about incineration.
Although EPA decided to include the East Disposal Area in a second ROD
which will also address the so-called Industrial Landfill, the Saint Regis Mohawk
Tribe is pleased that EPA will proceed expeditiously to issue this second ROD
AKWESASNE "LAND WHERE THE PARTRIDGE DRUMS'
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Mr. Constantine Sidamon-Eristoff
December 4,1990
Page 2
covering these areas in early 1991. We look forward to working with you to bring
about a comprehensive remedy addressing the remaining portion of the site on
such an accelerated schedule.
Very truly yours
cc Thomas C. Jorling, NYSDEC
Hea
'avid Jacobs
^ C,
Chief Lincoln C. White
Chief Norman J. Tarbell
AKWESASNE "LAND WHERE THE PARTRIDGE DRUMS"
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APPENDIX 4
RESPONSIVENESS SUMMARY
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RESPONSIVENESS SUMMARY
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION SITE
MASSENA, NEW YORK
As part of its public participation responsibilities, the U.S.
Environmental Protection Agency (EPA) held a public comment period
from March 21, 1990 through June 18, 1990 for interested parties
to comment on EPA's draft Feasibility Study (FS) and Proposed Plan
for the General Motors - Central Foundry Division Superfund Site
(G.M. Site). Both documents presented the alternatives considered
for cleaning up the G.M. Site. The Proposed Plan also described
EPA's proposed remedy for Site cleanup and solicited public comment
on all alternatives under consideration.
EPA held a public meeting on April 25, 1990 at the Massena Township
Municipal Building in Massena, New York. At this meeting,
representatives from EPA answered questions and received oral and
written comments on EPA's Proposed Plan and the other remedial
alternatives under consideration. In addition, a public
availability session was held in Massena on April 26, 1990. The
public availability session was an additional informal opportunity
for the public to ask questions about EPA's Proposed Plan. No
comments were submitted at the public availability session. On May
9, 1990, EPA met with representatives of the Remedial Action Plan
Public Advisory Committee (PAC) in Cornwall, Ontario, Canada to
receive the PAC's oral and written comments on EPA's Proposed Plan.
In addition to comments received at the public meeting, EPA
received written comments and two petitions regarding its Proposed
Plan. Responses to significant comments, both oral and written,
received during the public comment period are included in this
Responsiveness Summary which is part of the Record of Decision
(ROD) for the G.M. Site. It also summarizes comments received
during the public comment period from G.M., from New York State
agencies, from the St. Regis Mohawks, from Canadian citizens and
agencies, as well as from the two federal natural resource trustees
at the Site, the National Oceanographic and Atmospheric
Administration (NOAA) and the Department of Interior (DOI). New
York State and the St. Regis Mohawk Tribe have concurred with the
first operable unit ROD for the Site.
The Responsiveness Summary provides EPA and the public with a
summary of citizens' comments and concerns about the Site as raised
during the public comment period, and EPA's responses to those
concerns. All comments summarized in this document were factored
into EPA's final decision for selection of the remedial
alternatives for cleanup of the Site. EPA's selected remedy for
the first operable unit at this Site is described in the Decision
Summary of the ROD.
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This Responsiveness Summary is organized into the following five
sections.
I. RESPONSIVENESS SUMMARY OVERVIEW. This section briefly
describes the Site and activities conducted to date by EPA and G.M.
relative to the Superfund process, and outlines the preferred
remedial alternative.
II. BACKGROUND ON COMMUNITY INVOLVEMENT AND CONCERNS. This
section provides a brief history of community interest and concerns
regarding the Site.
III. SUMMARY OF MAJOR QUESTIONS AND COMMENTS RECEIVED FROM THE
LOCAL COMMUNITY AND EPA'S RESPONSES TO THESE COMMENTS. This
section summarizes both oral and written comments submitted to EPA
by the local community during the public comment period and EPA's
responses to these comments. "Local community" means those
individuals who have identified themselves as living in the
immediate vicinity of the Site and are threatened from a health or
environmental standpoint.
IV. COMPREHENSIVE SUMMARY OF SIGNIFICANT LEGAL AND TECHNICAL
COMMENTS AND EPA'S RESPONSES TO THESE COMMENTS. This section
summarizes other oral and written comments submitted to EPA during
the public comment period and EPA's responses to these comments.
It is comprised of specific legal and technical questions and,
where necessary, elaborates with technical detail on answers
covered in Part III.
V. REMAINING CONCERNS. This section discusses community concerns
that EPA will be aware of as it prepares to undertake the remedial
designs and remedial actions at the Site.
APPENDICES
There are four appendices attached to this document. They are as
follows:
APPENDIX A: Proposed Plan
APPENDIX B: Public Notice that was printed in the Massena,
New York newspaper on March 21, 1990 to
announce the public meeting and public comment
period
APPENDIX C: Sign-in sheets of attendees at the April 25,
1990 public meeting and the April 26, 1990
public availability session
APPENDIX D: Written comments received by EPA during the
public comment period and summarized in Secticr.
IV of this Responsiveness Summary. EPA's
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responses to the written comments are also
included in Section IV of this Responsiveness
Summary.
I. RESPONSIVENESS SUMMARY OVERVIEW
A. SITE DESCRIPTION
The Site, which includes an active G.M. manufacturing plant, is
located in Massena, New York, in St. Lawrence County. G.M. has
operated an aluminum casting plant at the Site since 1959. From
1968 to 1980, polychlorinated biphenyls (PCBs) were a component of
the hydraulic fluids used in the plant's diecasting machines. PCBs
provided protection against fire and thermal degradation in the
high temperature environment of the diecasting machines. G.M.
periodically landfilled sludges containing PCBs and other hazardous
substances in on-site disposal pits.
The Site, as defined by EPA, consists of several major waste areas.
The North and East Disposal Areas and the Industrial Landfill
contain PCS contaminated soil, debris, and sludge. The four
Industrial Lagoons with nominal sizes of 350,000 gallons, 500,000
gallons, 1.5 million gallons and 10 million gallons contain PCB
contaminated liquids, sludges, and solids. The Site also includes
PCB-contaminated sediments and associated wetlands of the St.
Lawrence and Raquette Rivers and Turtle Creek (formerly called the
unnamed tributary on the St. Regis Mohawk Reservation); PCB
contaminated soil on the St. Regis Mohawk Indian Reservation and
on the banks of the St. Lawrence and Raquette Rivers; PCB-
contaminated soil on G.M. property not associated with the specific
disposal areas already mentioned; and contaminated groundwater.
Approximately 253,000 cubic yards of PCB contaminated material are
being addressed in the first operable unit ROD for the Site.
B. SITE ACTIVITIES
The G.M. Site was placed on the Superfund National Priorities List
(NPL) in September 1983 as a result of G.M.'s past waste disposal
practices. G.M. indicated a willingness to perform the Remedial
Investigation and Feasibility Study (RI/FS) for the Site. On April
16, 1985, EPA and G.M. entered into an Administrative Order c:-.
Consent (Index No. II CERCLA-50201) for G.M.'s performance of the
RI/FS. Draft and Phase II RI reports were submitted to EPA in May
1986 and May 1988, respectively.
G.M. performed additional river sampling in February 1989, ar.i
submitted a report on the additional sampling to EPA in May 1989.
On June 9, 1989, EPA approved the RI report, which consists of the-
draft RI report, the Phase II RI report and the sediment sampling
report, for the Site. The RI report delineated those areas in nee.:
of remediation throughout the Site. G.M. submitted the draft F."
report to EPA in November 1989.
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C. SUMMARY OF PREFERRED REMEDIAL ALTERNATIVES PRESENTED IN THE
EPA PROPOSED PLAN
The following is a summary of the remedial alternatives evaluated
within the Draft FS and the Proposed Plan. Alternatives which were
identified as EPA's preferred alternative in the March 1990
Proposed Plan are highlighted.
Area 1: Contaminated River and Tributary Sediments
No Action for the River Sediments
In-Place Containment of River Sediments
Sediment Dredging and On-Site Treatment
Area 2: North and East Disposal Areas, Contaminated Soils on the
St. Regis Mohawk Reservation, Contaminated Soils on G.M.
Property
No Action for the North and East Disposal Areas,
Reservation Soils and Soils on G.M. Property
Capping of the North and East Disposal Areas, Reservation
Soils, and Soils on G.M. Property
Excavation and On-Site Treatment of Solids in the North
and East Disposal Areas, Reservation Soilsf and Soils on
G,M. Property
Excavation'""and On-Site Disposal of Solids in the North
and East Disposal Areas, Reservation Soils, and Soils on
the G.M. Property
Area 3: Industrial Landfill (EPA did not specify a preferred
alternative for the Industrial Landfill but instead
solicited comment on the public's preference regarding
its remediation).
No Action for the Industrial Landfill
Capping of the Industrial Landfill
Industrial Landfill Excavation and On-Site Treatment
Industrial Landfill Solids Excavation with On-Site
Disposal
Area 4: Industrial Lagoons
No Action for the Lagoons
Lagoon Solids Excavation and On-Site Treatment
Lagoon Solids Excavation with On-Site Disposal
Area 5: Ground Water
No Action for Ground Water
Ground Water Containment
Ground Water Recovery and Treatment
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D. SUMMARY OF EPA'S SELECTED REMEDIAL ALTERNATIVE
This action, or "operable unit," is the first of two operable units
that are planned for the Site. The second operable unit will
address the threats resulting from the East Disposal Area and the
Industrial Landfill at the Site.
The major components of the selected remedy include:
Dredging and excavation of sediments and soils from PCB
contaminated areas in the St. Lawrence and Raquette
Rivers, Turtle Creek, and associated riverbanks and
wetlands;
Interim surface runoff control to prevent migration of
contamination from the East Disposal Area;
Excavation of PCB-contaminated sludges, soil, and debris
in the North Disposal Area, in and around the four
Industrial Lagoons, and in other areas on G.M. property
(two of the four lagoons, which are currently in use by
G.M. , will be remediated when they are taken out of
service);
Excavation of PCB-contaminated soil on St. Regis Mohawk
Reservation land adjacent to the G.M. facility;
Recovery and treatment of groundwater downgradient from
the Site with discharge of treated groundwater to the St.
Lawrence River; and
Treatment of dredged/excavated material by either
biological treatment (or another innovative technology
which has been demonstrated to achieve site treatment
goals) or thermal destruction to be determined by EPA
following treatability testing. Treatment residuals will
be disposed on-site. Other PCB treatment technologies
will be tested concurrently with biological treatment so
that EPA will have additional information in the event
that biological treatment proves to be unsatisfactory for
treatment of any Site material. EPA will select the
treatment technologies to be employed, in consultation
with NYSDEC and the St. Regis Mohawk Tribe.
II. BACKGROUND ON COMMUNITY INVOLVEMENT AND CONCERN
Because of the high level of interest in the Site, EPA has
implemented a community relations program throughout the RI/FS
activities at the Site. This has included both formal and informal
meetings with local officials, members of the St. Regis Mohawk
Tribe, New York State representatives, Canadian officials art:
citizens, community and environmental groups, and other interested
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citizens. EPA has also provided a Technical Assistance Grant (TAG)
to the Akwesasne Task Force on the Environment (members of the St.
Regis Mohawk Tribe) to assist them in their efforts to fully
participate in the Superfund decision-making process for the site.
In November 1988, EPA conducted a workshop on the various
technologies available to remediate PCB-contaminated soils,
sludges, and ground water. EPA also prepared and distributed
eleven fact sheets to update the public about on-site activities
and to describe the various alternatives that could be considered
to remediate the PCB-contaminated media at the Site.
It should be noted that the St. Regis Mohawk Tribe has had a change
in leadership since the close of the EPA public comment period.
Consequently, the Tribe, in a letter to EPA dated October 31, 1990,
provided additional comments to those which were submitted during
the public comment period. EPA has, in this Responsiveness
Summary, presented and responded to those comments submitted by the
Tribe during the public comment period. However, EPA considered
the Tribe's October 31, 1990 comments in finalizing the first
operable unit ROD. The St. Regis Mohawk Tribe has concurred with
the first operable unit ROD which reflects EPA's consideration of
the October 31, 1990 comments. A copy of the Tribe's October 31,
1990 letter to EPA is contained in the Administrative Record for
this Site.
III. SUMMARY OF MAJOR QUESTIONS AND COMMENTS RECEIVED DURING THE
PUBLIC COMMENT PERIOD AND EPA'8 RESPONSES TO THESE COMMENTS
Comments raised by the local community during the public comment
period for the Site and EPA's responses to them are summarized
below. Comments submitted during the public comment period are
organized into the following eight general categories:
Preference for EPA's or G.M.'s Proposed Cleanup Plan
International Impact of G.M. Site Contamination
Selection of Industrial Landfill Remedial Alternatives
River Sediment Remedial Alternatives
Effectiveness of Remediation Techniques
Timeframe for Remediation
Liabilities and Responsibilities
Other Concerns
Although EPA sought public comment on remediation of the East
Disposal Area and the Industrial Landfill, EPA has opted to defer
selection of remedial alternatives for these areas to reevaluatc-
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the-
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs.
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A. PREFERENCE FOR EPA'8 OR G.M.'S PROPOSED CLEANUP PLAN
During the public comment period, G.M. put forth its own plan for
Site remediation which included in-place containment of river
sediments with investigation of natural biodegradation in these
areas, excavation and treatment of Reservation soil and soil in the
North Disposal Area, excavation and treatment of material in the
350,000 gallon and 1.5 million gallon inactive lagoons, in-place
containment of material in the East Disposal Area and Industrial
Landfill with investigation of natural biodegradation of material
in these areas, and groundwater recovery and treatment.
Comment: The Mayor of Massena, New York, several other local
officials, representatives from G.M., and G.M. plant employees
expressed support for G.M.'s alternative cleanup plan instead of
the EPA Proposed Plan. Generally, these commentors referenced the
higher cost of the EPA Proposed Plan, the short-term risks
associated with dredging and excavation, and concerns about the
potential impacts associated with incineration of PCB-contaminated
soils and sediments. These commentors also stated their belief
that the G.M. plan was sufficiently protective of public health and
the environment.
Response: EPA recognizes that several of the remedial alternatives
put forth by G.M. may pose fewer short-term risks than those
remedial alternatives proposed by EPA. However, EPA's "Risk
Assessment for Five Remedial Alternatives" indicates that none of
the remedial alternatives considered in the FS pose unacceptable
short-term risks to human health. (EPA defines unacceptable excess
cancer risks as those outside the EPA risk range of 10"4 to 10"6.)
Short-term risks (e.g.f during excavation or incineration) to
residents of the Reservation can be mitigated through temporary
relocation, if necessary. In addition, risks to remediation
workers can be mitigated through the use of protective equipment.
EPA also recognizes that there may be impacts associated with
incineration and that the public is very concerned about the use
of on-site incineration. For this reason, EPA has chosen to
minimize the use of on-site incineration in its selected remedy as
detailed in the ROD. EPA will rely on the results of treatability
tests to determine whether biological treatment (or another
innovative technology) or incineration will be used to treat the
various areas at the Site. In the event that biological treatment
is ineffective for a certain area of the Site, other treatment
technologies which will be tested concurrently with biological
treatment may be employed. In the event that other technologies
are ineffective, incineration will be used at the Site.
After carefully balancing the specific characteristics of the Site
against the nine criteria as outlined in the National Oil and
Hazardous Substances Contingency Plan (NCP), EPA has determined
that the long-term effectiveness and permanence afforded by the
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8
selected alternative offset any short-term risks posed by the
selected alternative and the higher costs of the selected remedy.
The NCP is the regulation promulgated by EPA for implementation of
the Superfund statute.
Comment: Representatives of the St. Regis Mohawk Tribe,
representatives of Students for Environmental Awareness from the
State University of New York at Potsdam, and several interested
citizens expressed general support for EPA's Proposed Plan.
Permanence of the cleanup remedy and long-term protection of public
health and the environment were stressed as more important criteria
than cost and short-term risks associated with excavation and
treatment.
Response: EPA has determined that the selected remedy as outlined
in the ROD represents the maximum extent to which permanent
solutions and treatment technologies can be used in a cost-
effective manner for the first operable unit at the G.M. Site. Of
those alternatives that are protective of human health and the
environment and meet the requirements of other environmental laws
and regulations, the selected remedy provides the best balance of
tradeoffs in terms of long-term effectiveness and permanence,
reduction in toxicity, mobility, and volume through treatment,
short-term effectiveness, implementability, and cost while also
considering the statutory preference for treatment as a principal
element and considering State, Tribe and community acceptance.
Among the treatment alternatives considered for the various areas
of the Site, the major tradeoffs that provided the basis for EPA's
remedy selection were proven effectiveness of incineration and the
cost of biological treatment.
B. INTERNATIONAL IMPACT OF G.M. SITE CONTAMINATION
Comment: A citizen from Cornwall, Ontario expressed appreciation
to EPA for encouraging Canadian participation and comment in the
decision-making process for selecting a remedial alternative for
the Site. The citizen referenced Article 4 of the Boundary Waters
Treaty of 1909 in which the United States and Canada agreed "not
to pollute the Boundary Waters and not to pollute waters crossing
the Boundary." This citizen requested that EPA formalize a
relationship with the Canadian Government to deal with the Site,
and ultimately to deal with two other neighboring sites impacting
Canadian waters.
Response: EPA recognizes the potential impacts of the Site en
Canadian citizens and has, within the constraints of the Superfund
regulations, endeavored to involve all interested Canadian citizens
and local officials, as well as their U.S. counterparts and members
of the Mohawk Nation, in its decision-making process.
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C. SELECTION OF INDUSTRIAL LANDFILL REMEDIAL ALTERNATIVES
Comment: An interested citizen stated that the Industrial Landfill
should be excavated and treated. He further noted that by
modifying some of the design assumptions, EPA could significantly
reduce the short-term health risks associated with the excavation
that are identified in the Risk Assessment.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
Comment: An interested citizen questioned whether the Industrial
Landfill was secure.
Response: The Industrial Landfill cannot be considered secure
since recent sampling results from groundwater monitoring wells
surrounding the Industrial Landfill indicate that PCBs are leaching
from the Landfill. Although the Industrial Landfill has an interim
cap which was designed to reduce leachate production, the
Industrial Landfill was designed prior to the passage of the
Resource Conservation and Recovery Act (RCRA) and the Toxic
Substances Control Act (TSCA) and does not meet the requirements
of these laws.
The interim cap has eliminated the release of air-borne
contaminants. However, the Landfill was not constructed with any
mechanism for capture of contaminated leachate. Therefore, as part
of the selected remedy for this operable unit, EPA will recover and
treat contaminated groundwater. This will reduce the continued
off-site migration of contaminated groundwater. The Industrial
Landfill, itself, will be addressed in the second operable unit
ROD.
Comment: Representatives of the St. Regis Mohawk Tribe,
representatives of Students for Environmental Awareness from the
State University of New York at Potsdam, and several interested
citizens stated that the Industrial Landfill should be excavated
and treated in the same manner as the other disposal areas. These
commentors stated the need for permanence in the remedy selected.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. E?A
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10
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
D. RIVER SEDIMENTS REMEDIAL ALTERNATIVES
Comment: Representatives of the St. Regis Mohawk Tribe,
representatives of Students for Environmental Awareness from the
State University of New York at Potsdam, and several interested
citizens stated that the river sediments cleanup level should be
0.1 parts per million ("ppm") PCBs as proposed by EPA for Tribal
properties. These commentors stated that the lowest technically
achievable cleanup levels should be implemented for all of the
contaminated Site areas.
Response: As required by the Superfund legislation, EPA has
recommended a cleanup level on the Reservation that is consistent
with promulgated applicable regulations of the St. Regis Mohawk
Tribe. EPA believes that the 0.1 ppm level may not be achievable
in all areas due to the technical limitations of dredging as a
means of removing sediment.
EPA has selected a 1 ppm cleanup goal in the St. Lawrence and
Raquette Rivers. In selecting a 1 ppm cleanup goal in the St.
Lawrence and Raquette Rivers, EPA has balanced its desire for a
very low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in the
St. Lawrence and Raquette Rivers is achievable and provides an
acceptable measure of protection to human health.
Comment: The New York State Department of Environmental
Conservation (NYSDEC) suggested that during the remedial design
phase EPA should strive to achieve the lowest feasible cleanup
levels for PCB-contaminated soils and sediments.
Response: EPA is required to select a cleanup level that is
protective of human health and the environment. EPA believes that
the selected cleanup levels are protective of human health and the
environment. New York State has concurred with the first operable
unit ROD.
EPA has selected a soil/sludge PCS cleanup level of 10 ppm on the
G.M. facility. This level is based, in part, on EPA's risk
assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population as
well as on EPA recommended PCB soil action levels for industrial
areas which were based, in part, on risk to Site workers. In
general, EPA recommends soil PCB cleanup levels between 10 ppm and
25 ppm in industrial areas. EPA has selected a cleanup level on
the lower end of this range because access to remediated areas will
be unlimited and because on-site soils impact ground water and
surface water quality. The 10 ppm cleanup level is consistent with
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11
PCB cleanup levels selected for industrial areas at other Superfund
sites.
Comment: Several interested parties stated that the contamination
emanating from the Site and migrating into the St. Lawrence River
should be treated in conjunction with contamination emanating from
the nearby ALCOA and Reynolds facilities.
Response: EPA concurs and notes that both the cleanups of the
ALCOA and Reynolds facilities are currently proceeding under the
authority of federal Unilateral Administrative Orders and State
Consent Orders. Currently, investigation of the river system and
adjacent wetlands surrounding the ALCOA and Reynolds facilities are
being conducted to determine the nature and extent of contamination
from their facilities and to determine appropriate remediation
plans for those facilities. It is EPA's objective to coordinate the
cleanup efforts at the G.M. Site with the cleanup of the other
facilities to the extent possible.
E. EFFECTIVENESS OF REMEDIATION TECHNIQUES
Comment: Several interested citizens, representatives of the St.
Regis Mohawk Tribe, and NYSDEC suggested that EPA conduct
concurrent treatability studies on several technologies in addition
to bioremediation and incineration to ensure that the most
effective treatment method can be quickly implemented.
Response: EPA agrees with this suggestion and has incorporated it
in to the selected remedy for the G.M. Site.
Comment: Several interested citizens and local officials
questioned the safety of incineration as a remedial alternative.
These representatives noted the problems with dioxin experienced
by some incinerators and inquired about the safeguards EPA would
employ to prevent similar problems.
Response: EPA has reduced the use of incineration in its selected
remedy for the Site. EPA notes that while incineration, is a
costly technology, it has been proven to be very effective in
permanently destroying many types of hazardous wastes. In fact,
incineration is currently considered the most effective technology
for destroying PCB-contaminated wastes. EPA notes that federal and
state regulations require 99.9999% of the PCBs in the waste that
is fed into the incinerator must be removed (as measured in the
incinerator ash). Although minute amounts of dioxin may be
generated during incineration, EPA is committed to working with the
community as well as incineration experts to ensure that what
incineration must be used at the Site is safe. In this way, EPA
will design a system of safeguards as well as a monitoring systen
to ensure that the incinerator is operating correctly and at
optimal conditions.
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12
F. TIME FRAME FOR REMEDIATION
Comment: NYSDEC's Wildlife Pathologist, students from the State
University of New York at Potsdam, and several interested citizens
stated that the length of time from initially identifying the
contamination problems to proposing a cleanup plan at the Site has
been too lengthy and stressed the need for more rapid cleanup
action.
Response: EPA acknowledges that the cleanup process for the G.M.
Site has been lengthy. EPA notes that the size and complexity of
the contamination at the Site has contributed to the length of
EPA's efforts to date. EPA also notes that some of the "delay" has
occurred as a result of its attempt to respond to the enormous
amount of comment received during the investigation process.
6. LIABILITIES AND RESPONSIBILITIES
Comment: Several interested citizens and local officials queried
EPA as to who would make the final cleanup decision and how the
decision would be implemented.
Response: After consideration of all public comments received
during the public comment period, EPA selects the remedial
alternatives to be implemented at the Site. This decision is
documented in the ROD for the Site. Following the signing of the
ROD, EPA will begin negotiating with G.M. for implementation of the
remedy described in the ROD. G.M. will have 60 days to present a
good faith offer to EPA to implement the ROD. If G.M. makes a good
faith offer within the 60 days, the Superfund law allows another
60 days for EPA and G.M. to finalize an agreement. If G.M. and EPA
finalize an agreement, then G.M., under EPA's supervision and
direction, will begin the remedial design phase of the cleanup.
If EPA and G.M. cannot come to agreement, then EPA may initiate
enforcement action against G.M. or may perform the cleanup using
its own contractors and seek to recover its costs from G.M. at a
later date.
Comment: An interested citizen questioned who was responsible for
any long-term problems that might result from the residual
contamination remaining on-site.
Response: When residual contamination is left on-site, EPA is
obligated to evaluate the Site at least once every five years.
Furthermore, EPA's Proposed Plan includes ongoing monitoring of
Site groundwater. Where possible, EPA seeks to have responsible
parties, the responsible party in this case, G.M., assume the
financial responsibility for the ongoing monitoring under EPA's
direction.
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H. OTHER CONCERNS
Comment: One citizen asked whether G.M. continues to use PCBs at
the G.M. Central Foundry facility.
Response: G.M. discontinued the use of PCBs in 1980, however,
underground pipes and drains continue to contain residual PCBs from
the years when G.M. used PCBs as a component of the hydraulic
fluids used in the diecasting machines.
IV. COMPREHENSIVE SUMMARY OF MAJOR LEGAL AND TECHNICAL COMMENTS
AND EPA18 RESPONSES TO THESE COMMENTS
GENERAL MOTORS CORPORATION
Cleanup Level
Comment: EPA has taken the unwarranted step in its Proposed Plan
of establishing a single numerical concentration threshold for all
soils and sediments 500 ppm PCBs as the dividing line for use
of incineration rather than bioremediation. All materials with
less than 500 ppm PCBs would receive biological treatment (or some
other treatment such as chemical extraction or thermal destruction
if biological treatment is ineffective) . All material over 500 ppr,
would be incinerated on-site.
Response: EPA's original decision to establish a numerical
threshold for use of incineration was not unprecedented and was
based on the fact that data in the FS indicated that biological
treatment would not be effective for material with PCB
concentrations above 500 ppm and on Superfund and TSCA policy.
However, where permitted by law and by newly issued guidance, ir.
an effort to reduce the use of incineration at the Site, EPA, ir.
its selected remedy, has not specified a threshold concentration
which will mandate the use of incineration.
EPA will rely on the results of treatability tests to determine
whether biological treatment (or another innovative technology) or
incineration will be used to treat the various areas at the Site.
In the event that biological treatment is ineffective for a certain
area of the Site, other treatment technologies, which will be
tested concurrently with biological treatment, may be employed.
In the event that other technologies are ineffective, incineration
will be used at the Site.
Comment: The effectiveness of biotreatment is continually be in-;
improved. In light of this continuing progress, it is arbitrary
to forbid biotreatment from being tested and used on material r.
containing more than 500 ppm PCBs.
Response: EPA's original decision to establish a numeric:*:
threshold for use of incineration was not unprecedented and w?.;-.
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based on the fact that initial data in the FS indicated biological
treatment would not be effective for material with PCB.
concentrations above 500 ppm and on Superfund and TSCA policy.
However, in an effort to reduce the use of incineration at the
Site, EPA, in its selected remedy, has not specified a threshold
concentration which will mandate the use of incineration.
EPA will rely on the results of treatability tests to determine
whether biological treatment (or another innovative technology) or
incineration will be used to treat the various areas at the Site.
In the event that biological treatment is ineffective for a certain
area of the Site, other treatment technologies which will be tested
concurrently with biological treatment may be employed. In the
event that other technologies are ineffective, incineration will
be used at the Site.
Comment: EPA's Proposed Plan imposes too stringent dredging/
excavation and treatment requirements.
Response: The cleanup levels and treatment levels specified in the
ROD were selected by EPA to ensure protection of human health and
the environment. EPA has indicated in the ROD those areas where
specified cleanup levels or treatment levels may not be attainable.
EPA has based its judgement of attainability on its limited
experience at other sites. Actual data on the attainability of any
of the cleanup or treatment levels specified in the ROD will only
be obtained during implementation of the remedial action. Thus,
any judgement of the severity or attainability of EPA's cleanup
levels is premature and arbitrary.
Comment: G.M. believes that the cleanup criteria proposed in EPA's
Proposed Plan are inappropriate, since the PCBs in soils at the
Site do not present a significant current or future threat to human
health or the environment. G.M. believes the health risk of the
PCBs at the Site has been overstated, since the opportunities for
exposure to the PCBs at the Site are extremely limited.
Response: Based on the results of the RI and its risk assessment,
EPA has determined that the Site poses a current unacceptable risk
to human health and the environment. PCBs which reside in river
system sediments have begun to accumulate in the food chain and
have been found in wildlife at the Site. Further, a large volume
of soil is contaminated with PCBs at levels up to three orders of
magnitude above EPA recommended action levels for industrial areas
and four orders of magnitude above EPA recommended levels for
residential areas. G.M.'s own risk assessment shows that current
excess cancer risks to G.M. workers are outside the EPA acceptable
risk range. Finally, although some opportunities for exposure to
PCBs at the Site are currently limited, EPA is required to evaluate
the reasonable maximum exposure to PCBs presented by the Site. In
so doing, EPA has found that there are considerable opportunities
for exposure to Site PCBs.
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Public Participation
Comment: G.M. requests that all their comments, including
attachments, appendices, and other accompanying documents, be fully
considered and placed in the Administrative Record for the Site.
Response: By law, EPA must comply with this request. All comments,
attachments, appendices, and other accompanying documents received
during the public comment period will be placed in the
Administrative Record subsequent to the signing of the ROD.
Comment: Strong local opposition to incineration has developed
within communities near the Site and in Canada.
Response: Comments received during the public comment period
indicate that the community has varying opinions regarding the
proposed remediation of the Site. Many citizens expressed a desire
for the complete removal and treatment of contamination at the
Site. Other citizens expressed concern that adequate health and
safety precautions be implemented, particularly in relationship to
the incineration component of the remedy. EPA did receive comments
which expressed complete opposition to incineration.
EPA has reduced the use of incineration in its selected remedy. EPA
will rely on the results of treatability tests to determine whether
biological treatment (or another innovative technology) or
incineration will be used to treat the various areas at the site.
In the event that biological treatment is ineffective for a certain
area of the Site, other treatment technologies which will be tested
concurrently with biological treatment may be employed. In the
event that other technologies are ineffective, incineration will
be used at the Site.
Comment: Local opposition to incineration may result in additional
delays in the implementation of this remedy.
Response: Although EPA has received comments from some U.S.
citizens, Canadian citizens, and environmental groups expressing
concern and requesting assurances that appropriate safeguards be
utilized in implementing the incineration component of the remedy,
EPA has received only limited opposition to incineration as a
component of the selected remedy. To the contrary, numerous
commentors have expressed a preference for the permanence of
incineration as a component of the selected remedy as long as
stringent controls are implemented.
EPA has reduced the use of incineration in its selected remedy. EPA
will rely on the results of treatability tests to determine whether
biological treatment (or another innovative technology) or
incineration will be used to treat the various areas at the Site.
In the event that biological treatment is ineffective for a certair.
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area of the Site, other treatment technologies which will be tested
concurrently with biological treatment may be employed. In the
event that other technologies are ineffective, incineration will
be used at the Site.
Remedial Investigation/Feasibility Study
Comment: Mercury, lead, nickel, cadmium and magnesium have been
observed above background levels in some lagoon soils and sludges
on the Site. Limited samples taken from the Industrial Landfill
showed elevated (above background) levels of aluminum, arsenic,
cobalt, copper, chromium, iron, nickel and zinc. Furthermore,
limited samples of St. Lawrence River sediments displayed levels
of some heavy metals above background for New York State soils.
Emissions of heavy metals during incineration of these materials
would also be a concern.
Response: EPA agrees that heavy metals will be a concern if
incineration of Industrial Lagoons sludges is required. However,
at this time, EPA has no reason to believe that incineration of
lagoon sludges would be prohibited due to the presence of heavy
metals.
Heavy metals emissions can be controlled through proper incinerator
design and control. In addition, if concentration of metals in
incinerator ash causes incinerator ash to be hazardous, the ash
will be further treated before being disposed in a hazardous waste
facility.
Comment: Site-specific characteristics, which largely determine
environmental and health risks, have not been adequately
identified.
Response: EPA disagrees with this comment. EPA believes the areas
of the Site that are being addressed in the Operable Unit I ROD
have been adequately characterized in the RI/FS and the risk
assessment that was conducted by Gradient Corporation. While EFA
has grouped various areas of the Site together in the Proposed Plan
and ROD for ease of explanation, EPA thoroughly evaluated each area
of the Site to determine environmental and health risks and tc
develop an appropriate remediation plan.
Comment: The FS findings determined that based on substantial
differences between Site areas, different remedial approaches
should be employed. EPA's plan does not distinguish between areas.
Response: As indicated in the FS, EPA fully recognizes the
substantial differences between Site areas. EPA has further
factored these site-specific characteristics into the remedy
selection process as required by the NCP.
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Proposed Plan
Comment: EPA must consider the sheer size of the Site, the
restricted access of the Site, its impermeable soils, and the
demonstrated characteristics of PCBs, in determining the
appropriate remedy for the Site. The Comprehensive Environmental
Response, Compensation and Liability Act (CERCLA) also requires EPA
to consider costs. Both the proposed 10 ppm cleanup standard for
PCBs in soils and the associated treatment requirements do not have
any basis in science or policy.
Response: EPA has considered the size of the Site, its current
restricted access, its fairly impermeable soils, and the
characteristics of PCBs in developing its selected remedy. After
careful consideration of the site-specific characteristics, EPA
evaluated and balanced each of the proposed remedial alternatives
according to the nine criteria defined in the NCP. EPA then
balanced the nine criteria to determine the appropriate remedies
for cleaning up contaminated soils and sludges.
EPA has selected a soil/sludge PCB cleanup level of 10 ppm on the
G.M. facility. This level is based, in part, on EPA's risk
assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population and,
in part, on EPA guidance which recommends soil PCB cleanup levels
between 10 ppm and 25 ppm in industrial areas. EPA has selected
a cleanup level on the lower end of this range because access to
remediated areas will be unlimited to G.M. personnel and because
contaminants in on-site soils may impact groundwater and surface
water quality. EPA has selected a soil/sludge total phenols
cleanup level of 50 ppm based on federal RCRA guidance for closure
of surface impoundments. EPA estimates that there are 176,000
cubic yards of soils and sludges in the Industrial Lagoons, in the
North Disposal Area, and in other areas on the G.M. facility
contaminated with PCBs above 10 ppm which are being addressed in
this operable unit.
EPA has also decided to contour the East Disposal Area to prevent
surface runoff to the St. Regis Mohawk Reservation and to minimize
movement of contaminated surface soils. A final remedy for the
East Disposal Area will be addressed with the Industrial Landfill
in the second operable unit ROD.
Comment: EPA's Proposed Plan does not discuss the fact that no
other Superfund site has involved such large volumes of soil
containing PCBs at low concentrations. This indicates that site-
specific balancing of the remedy selection criteria has not
occurred.
Response: EPA's Proposed Plan is not meant to be a comprehensive
document which describes every aspect of EPA's decision-making with
regard to the Site. Rather, the Proposed Plan is intended to be
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a summary of EPA's proposal for Site remediation written to solicit
community input into the Superfund decision-making process.
EPA has balanced site-specific factors into its decision-making for
the G.M. Site as documented in the ROD. Further, the draft FS for
the Site indicates that there are approximately 565,000 cubic yards
of material on the Site with PCB concentrations above 50 ppm. This
is evidence of a large volume of soil with substantial PCB
concentrations at the Site.
Comment: The NCP requires that the decision-maker compare the
incremental cost differences of the alternatives being considered
to their incremental differences in effectiveness. Cost must be
proportional to overall effectiveness. EPA's proposed remedy for
the Site reflects a failure to adequately balance these criteria.
Response: EPA has complied with the NCP's requirements for cost-
effectiveness as explained in the "Statutory Determinations"
section of the ROD. The NCP does not require an incremental
demonstration of cost-effectiveness. The only reference in the NCP
which remotely resembles the position of the commentor is located
at 55 Fed. Reg. 8729 (March 8, 1990), wherein EPA agrees with a
commentor's statement that "a cost-effective remedy is one with
cost proportional to the remedy's overall effectiveness.
Comment: The FS analysis for the Site supports the selection of
a remedy that is more protective and significantly less costly than
the one proposed by EPA. G.M.'s recommendation, based on the FS,
would tailor the use of treatment and containment methods to the
specific characteristics of the areas on the Site where soil,
debris and sediments containing PCBs have been found. G.M.
believes that EPA did not properly balance the CERCLA remedy
selection criteria when it proposed incineration and biotreatment
to extremely low levels as the remedial measures for the entire
Site.
Response: G.M.'s interpretation of the FS analysis and the remedy
put forth by G.M discount the CERCLA preference for treatment
expressed at Section 121(b)(1). EPA's selected remedy was derived
through a site-specific balancing of the nine evaluation criteria
described in the NCP. EPA has met the CERCLA preference for
treatment at the Site where possible, and has tailored its remedy
and cleanup goals to the various areas of the Site, as necessary.
Comment: EPA's proposed use of incineration also presents
substantial uncertainties, costs, and implementation issues net
presented by other technologies. Key areas of concern with the use
of incinerators in general include air emissions and other
environmental hazards and operational difficulties. Given the
restricted access of the Site, the relative immobility of PCBs, the
lack of evidence that Aroclor 1248 or 1232 is harmful, and the ease
of effectively isolating PCBs at most of the Site areas from hunar.
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i
and wildlife exposure through less hazardous and more cost-
effective measures, there is no reason to incur the costs and
uncertainties of incineration on the scale mandated by EPA.
Response: EPA disagrees with several of the premises of this
comment. First, of the six technologies evaluated in detail in the
draft FS, only incineration is a technology which has been in use
commercially for many years. In fact, of the six technologies
presented, all but incineration are characterized by EPA as
innovative technologies. Biological treatment is the most
innovative technology considered since it has not been proven at
full-scale. In addition, while the other five technologies require
some degree of treatability testing to determine effectiveness in
treating PCBs, data on the effectiveness, cost, and implementation
of incineration are readily available from vendors and other
Superfund sites. Several of the technologies considered present
air emissions concerns and greater operational difficulties than
incineration.
Second, the RI/FS does not support the theory that the Site is
inaccessible. Since the Site is an operating facility and areas
of the Site, including those areas on the St. Regis Mohawk
Reservation are not fenced, access continues to be a concern.
Third, although the literature indicates differences of opinion on
the potential impact of various Aroclors, EPA has used existing
guidance (which is supported by much of the current literature) to
characterize risks from PCBs at the Site.
Finally, although containment of contamination is less difficult
than excavation or dredging and treatment of contamination, EPA is
bound by CERCLA to prefer technologies in which treatment that
permanently and significantly reduces the volume, toxicity or
mobility of the PCBs is a principal element.
Comment: Unburned hydrocarbons, PICs, and heavy metals may also
ultimately end up in the fly ash and bottom ash resulting fro:?.
incineration. Heavy metals in the ash will likely exhibit greater
leachability than in the original soil feed, thereby potentially
requiring additional treatment such as solidification or
stabilization. EPA has not evaluated the costs for additional
management of hazardous ash in the Proposed Plan.
Response: EPA agrees with this comment. The draft FS, as submitted
by G.M. , assumes that fly and bottom ash from the incineration
process is non-hazardous. If incineration is required at the Site
and all or part of the incinerator ash is tested and found to be
hazardous, EPA will either treat the ash further to render it non-
hazardous or dispose of the ash in compliance with hazardous waste
requirements.
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Comment: Incineration poses additional environmental hazards
including fires, explosions, fuel spills and other catastrophic
events.
Response: Each remedial alternative evaluated in the FS has unique
advantages, disadvantages, and potential impacts. Each remedial
alternative also exhibits unique degrees of effectiveness to
remediate specific wastes. While EPA recognizes the disadvantages
associated with incineration, the Agency has concluded, based on
the current commercial use of incineration, that this potential is
negligible. Incineration has been demonstrated to be an effective
alternative for remediating PCBs in soils and sludges. This
technology has been effectively used at numerous Superfund sites
and federal projects.
Comment: The characteristics of the materials on particular areas
of the Site will make incineration of many of those materials
exceptionally difficult and potentially impossible to implement.
Response: EPA recognizes that bulk materials present in the North
Disposal Area or in sediment may not be amenable to incineration
or any other type of treatment. EPA, as part of the remedy
selected in the ROD, will remove bulk items which cannot be treated
and dispose of them in a TSCA compliant landfill on-site.
EPA has reduced the use of incineration in its selected remedy. EPA
will rely on the results of treatability tests to determine whether
biological treatment (or another innovative technology) or
incineration will be used to treat the various areas at the Site.
In the event that biological treatment is ineffective for a certain
area of the Site, other treatment technologies which will be tested
concurrently with biological treatment may be employed. In the
event that other technologies are ineffective, incineration will
be used at the Site.
However, EPA believes that PCB-contaminated soils can be
effectively remediated through a combination of biological
treatment and incineration. At other Superfund sites with PCB-
contaminated soil and sludges, incineration has been demonstrated
to be a very effective remedial alternative.
Comment: The types of materials present in the East Disposal Area
and the Industrial Landfill make excavation and incineration of the
contents of those areas practically and technically not achievable.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
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will consider this comment when developing a Proposed Plan for the
East Disposal Area and Industrial Landfill.
Comment: At several Superfund sites involving PCBs, EPA has
selected remedial alternatives other than incineration as a remedy
because of one or mpre of the above problems. Such sites include
the Sullivan's Ledge site in Massachusetts, the Wide Beach
Development and York Oil sites in New York, the Kane & Lombard site
in Maryland, the Chemical Control site in New Jersey, the Pepper's
Steel and Alloy site in Florida, the Envirochem/Northside Sanitary
Landfill, Sheridan Disposal Services and Midco sites in Indiana,
the Sol Lynn and French Limited sites in Texas, the Commencement
Bay Nearshore Tidal Flats, Western Processing, and Queens City
Farms sites in Washington, the Pacific Hide and Fur site in Idaho,
and the M.G.M. Brakes site in California.
Response: The cleanup technologies selected by EPA in the ROD are
consistent with those selected for other Superfund sites with
similar characteristics. EPA has reduced the use of incineration
in its selected remedy. EPA will rely on the results of
treatability tests to determine whether biological treatment (or
another innovative technology) or incineration will be used to
treat the various areas at the Site. In the event that biological
treatment is ineffective for a certain area of the Site, other
treatment technologies which will be tested concurrently with
biological treatment may be employed. In the event that other
technologies are ineffective, incineration will be used at the
Site. During treatability testing, EPA will evaluate several of
the technologies selected for the sites referenced by G.M.
Comment: EPA's approach to remediation of the Site appears to be
the desire to achieve "permanence." Under CERCLA and existing EPA
policy, however, the desire for "permanence" does not alone justify
selection of an extreme and costly treatment remedy.
The NCP requires that the Agency compare the cost differences of
alternatives being considered, to the differences in effectiveness
of the alternatives (Fed. Reg. 8728-29, March, 1990). EPA's
Proposed Plan for the Site provides for an extremely costly and
impracticable remedy.
Response: EPA has balanced all of the remedial alternatives
evaluated according to the nine criteria defined in the NCP
(300.430 {e){a}{iii};300.430{f}{i}{i}), including balancing the
incremental cost differences with the differences in effectiveness
prior to selecting the remedies outlined in the ROD. The selected
remedy is cost-effective because it has been demonstrated to
provide overall effectiveness proportional to its costs.
Comment: Both EPA and NYSDEC have recognized that, in some
instances (i.e., large landfills) "permanent" remedies are not
appropriate. If permanence was the sole criterion for remedy
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selection, the FS could be limited to a survey of destruction
technologies and a treatability analysis. No significant balancing
of alternatives under EPA's "balancing criteria" would be needed.
CERCLA, the NCP, and a variety of EPA guidance documents relevant
to the preparation of FSs, however, explicitly call for multiple
alternatives involving various degrees of treatment to be arrayed
and analyzed. Under the specific circumstances of the Site, a
remedy can be selected that incorporates a variety of different
technologies to provide protectiveness and long-term effectiveness
at a cost which is proportional to the risks being addressed. When
the potential problems with incineration are put in the context of
the Superfund remedy selection criteria, they show that EPA's
proposed incineration remedy scores poorly with respect to short-
term effectiveness, implementability, and cost.
Response: While G.M.'s description of EPA's regulations and policy
regarding analysis of a range of alternatives is essentially
correct, it's conclusions regarding the use of incineration are not
warranted. The draft FS for the Site does indeed incorporate
containment alternatives, in accordance with the NCP. However,
when the long-term effectiveness and permanence of incineration of
other, less expensive treatment technologies are weighed against
that of containment, treatment of the highly persistent PCBs at the
Site is warranted. EPA does not agree that implementation of
incineration poses great difficulty. In fact, as stated in the
draft G.M. FS, incineration can be implemented using proven
equipment and technologies.
Comment: The individual characteristics of the areas on the Site
are not reflected in EPA's Proposed Plan. National EPA policy
provides that the use of treatment should account realistically for
the character of the waste materials, the size of the Site, and
similar considerations.
Response: After careful consideration of G.M.'s site-specific
characteristics, EPA evaluated and balanced each of the proposed
remedial alternatives according to the nine criteria defined in
the NCP. EPA balanced the nine criteria to determine the
appropriate remedies for cleaning up the Site.
EPA's Proposed Plan is not meant to be a comprehensive document
which describes every aspect of EPA's decision-making with regard
to the Site. Rather, the Proposed Plan is intended to be a summary
of EPA's proposal for site remediation written to solicit community
input into the Superfund decision-making process.
Comment: In OSWER Directive No. 9355.0-26, "Advancing the Use of
Treatment Technologies for Superfund Remedies" (Feb. 21, 1989), and
in the NCP, EPA specifically stated that treatment technologies are
most appropriate for wastes that cannot be reliably controlled
through containment, such as liquids, highly mobile materials such
as solvents, and high concentrations of toxic compounds. PCBs in
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soil are not mobile, nor are they highly toxic. EPA's proposal to
incinerate all soils containing PCBs over 500 ppm and to
bioremediate all soils containing less than 500 ppm is unwarranted
and arbitrary.
Response: Based on the results of the RI and the Risk Assessment,
EPA has determined that a large volume of soil is contaminated with
PCBs at levels significantly above EPA recommended action levels.
EPA has selected a soil/sludge PCB cleanup level of 10 ppm on the
G.M. facility. This level is based, in part, on EPA's risk
assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population and,
in part, on EPA guidance which recommends soil PCB cleanup levels
between 10 ppm and 25 ppm in industrial areas. EPA has selected
a cleanup level on the lower end of this range because access to
remediated areas will be unlimited to G.M. personnel and because
contaminants in on-site soils may impact groundwater and surface
water quality. EPA has selected a soil/sludge total phenols
cleanup level of 50 ppm based on federal RCRA guidance for closure
of surface impoundments. EPA estimates that there are 176,000
cubic yards of soils and sludges in the Industrial Lagoons, in the
North Disposal Area, and in other areas on the G.M. facility
contaminated with PCBs above 10 ppm which are being addressed in
this operable unit.
EPA has reduced the use of incineration in its selected remedy. EPA
will rely on the results of treatability tests to determine whether
biological treatment (or another innovative technology) or
incineration will be used to treat the various areas at the Site.
In the event that biological treatment is ineffective for a certain
area of the Site, other treatment technologies, which will be
tested concurrently with biological treatment, may be employed.
In the event that other technologies are ineffective, incineration
will be used at the Site.
Comment: G.M. agrees with EPA's Proposed Plan to excavate soils
and treat them on the Site. However, G.M. strongly disagrees with
the cleanup level of 10 ppm PCBs proposed for this area in EPA's
plan because these materials pose minimal risk to human health and
the environment, and treatment of such materials to that level
results in very high costs.
Response: Based on the results of the RI and the Risk Assessment,
EPA has determined that a large volume of soil is contaminated with
PCBs at levels significantly above EPA recommended action levels.
EPA has selected a soil/sludge PCB cleanup level of 10 ppm on the
G.M. facility. This level is based, in part, on EPA's risk
assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population and,
in part, on EPA guidance which recommends soil PCB cleanup levels
between 10 ppm and 25 ppm in industrial areas. EPA has selected
a cleanup level on the lower end of this range because access tc
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remediated areas will be unlimited to G.M. personnel and because
contaminants in on-site soils may impact groundwater and surface
water quality. EPA has selected a soil/sludge total phenols
cleanup level of 50 ppm based on federal RCRA guidance for closure
of surface impoundments. EPA estimates that there are 176,000
cubic yards of soils and sludges in the Industrial Lagoons, in the
North Disposal Area, and in other areas on the G.M. facility
contaminated with PCBs above 10 ppm which are being addressed in
this operable unit.
Comment: EPA should allow for the use of innovative technologies
including bioremediation for soils and debris above 500 ppm PCBs.
Consistent with the Draft PCB Guidance, no treatment should be
mandated for soils and sediments containing less than 500 ppm,
although treatment should be allowed.
Response: EPA has reduced the use of incineration in its selected
remedy. EPA will rely on the results of treatability tests to
determine whether biological treatment (or another innovative
technology) or incineration will be used to treat the various areas
at the Site. In the event that biological treatment is ineffective
for a certain area of the Site, other treatment technologies, which
will be tested concurrently with biological treatment, may be
employed. In the event that other technologies are ineffective,
incineration will be used at the Site.
The final Guidance on Remedial Actions for Superfund Sites with PCB
Contamination, OSWER Directive 9355.4-01, does recommend treatment
of soil in industrial areas with PCB concentrations above 500 ppm.
However, EPA has evaluated the nature of soil contamination in the
North Disposal Area and has determined that segregation of material
with PCB concentrations above 500 ppm would be difficult and would
result in small volumes of soil to be contained. For this reason,
EPA has opted to treat, as a whole, contaminated soil in the North
Disposal Area.
Comment: EPA should allow for the simultaneous evaluation of
several innovative technologies to determine what methods provide
cost-effective and efficient remediation for soils both above and
below 500 ppm. Biological treatment and incineration should not
be mandated as the only treatment technologies to be used without
an evaluation of alternatives.
Response: EPA has reduced the use of incineration in its selected
remedy. EPA will rely on the results of treatability tests to
determine whether biological treatment (or another innovative
technology) or incineration will be used to treat the various areas
at the Site. In the event that biological treatment is ineffective
for a certain area of the Site, other treatment technologies which
will be tested concurrently with biological treatment may be
employed. In the event that other technologies are ineffective,
incineration will be used at the Site.
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Comment: EPA's proposed remedy for the East Disposal Area presents
significant health risks and a high likelihood of failure due to
practical problems with implementation of the incineration remedy.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
Comment: EPA failed to consider the off-site disposal of
incineration residues which, if hazardous, would push the
approximately $54 million of this alternative even higher.
Response: The ROD explains EPA's consideration of the disposal of
incineration residues. The draft FS, as submitted by G.M., assumes
that fly and bottom ash from the incineration process is non-
hazardous. If incineration is required at the Site and all or part
of the incinerator ash is tested and found to be hazardous, EPA
will either treat the ash further to render it non-hazardous or
dispose of the ash in compliance with hazardous waste requirements.
Comment: EPA's plan does not distinguish between active and
inactive waste water treatment lagoons on the Site. Any remedial
actions regarding the active lagoons must recognize the fundamental
importance of these units to the ongoing operations of the plant.
The company agrees with EPA's plan regarding the inactive lagoons,
subject to the general objections concerning cleanup levels and
limitations on applicable technologies.
The active lagoons are part of the recirculating water system at
the G.M. plant. This system is vital to the plant's continued
operation. The active lagoons provide cooling water to the plant
and process water required in the lost foam casting process. The
active lagoons at the G.M. facility contain PCBs at relatively low
concentrations which migrate slowly. EPA should reconsider the
proposed remediation alternative for the active lagoons.
Response: In response to this comment, EPA's selected remedy delays
cleanup of the active lagoons until they are taken out of service
by G.M. The active lagoons will be remediated in the same manner
as the inactive lagoons when they are taken out of service. In the
interim, any groundwater releases from the active lagoons will be
treated subsequent to recovery, as specified in the first operable
unit ROD.
Comment: EPA's Proposed Plan to require the dredging and treatment
of sediments from the St. Lawrence River is unlikely to be
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effective. EPA's proposal is likely to result in unnecessary
public health and environmental risk resulting from the
resuspension of sediments containing PCBs in the river's water
column. Sediments containing PCBs suspended during dredging which
are not captured by silt control devices will simply be redeposited
downstream.
Response: EPA recognizes that there may be some difficulties
associated with resuspension of contaminants during dredging.
However, dredging has been used effectively at another Superfund
site in New Harbor, Massachusetts to remove PCB-contaminated
sediments from an estuary.
There are several factors which EPA believes will contribute to the
effectiveness of dredging as a means of removing sediment from the
St. Lawrence River. First, the area to be dredged is fairly
shallow and is located adjacent to the shore of the St. Lawrence
River. Second, the use of engineering controls such as sheet pile
walls has been shown to substantially reduce sediment resuspension.
Third, the selection of the dredging technique can be made with the
goal of minimizing sediment resuspension. Fourth, the public
health and environmental impacts resulting from sediment dredging
(which is of relatively short duration) are likely to be lower than
the current risks posed by the contaminated sediment. Finally, in
the event that monitoring indicates that there are any downstream
depositional areas which collect resuspended sediments, they can
be dredged to remove those resuspended sediments. The iterative
process of sampling, excavating and re-sampling is contemplated as
an integral part the remedial action.
Comment: EPA's plan to require dredging and treatment of river
sediments to a cleanup level of 2.0 ppm is not likely to be
achievable using available dredging technology. Such technology
has a limited effective removal rate, even with multiple passes
with dredging equipment. Sediments resuspended in the water colur.n
during dredging which are ' not transported downstream will
eventually settle back down onto underlying sediments. Because cf
dredging inefficiency and inevitable resuspension problems, EPA's
cleanup level of 2.0 ppm is likely to be not achievable.
Response: In response to comments, EPA has modified its cleanup
level for the St. Lawrence and Raquette River to 1 ppm PCBs. The
1 ppm PCB cleanup in the St. Lawrence and Raquette Rivers was base::
on interim federal and State sediment quality criteria guidance as
well as on EPA's risk assessment. Application of interim federal
sediment quality criteria guidance indicates that a PCB cleanup
level in sediments should be between 0.08 and 2 ppm. State-
sediment quality .criteria guidance indicates that PCB cleanup
levels well below 1 ppm are required to achieve protection of the
environment. EPA's risk assessment for the Site demonstrates th?.-;
a 1 ppm PCB cleanup level in sediment corresponds to a 4 x 10 '
excess cancer risk.
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Therefore, in an attempt to minimize residual risks, EPA has
selected I ppm as a cleanup goal in the St. Lawrence and Raquette
Rivers. In selecting the 1 ppm cleanup goal in the St. Lawrence
and Raquette Rivers, EPA has also balanced its desire for a very
low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in the
St. Lawrence and Raquette Rivers is achievable and provides an
acceptable measure of protection to human health. The 0.1 ppm
cleanup goal for Turtle Creek selected by EPA is based on Tribal
requirements. This level may not be achievable in all areas due
to the technical limitations of dredging as a means of removing
sediment.
Comment: G.M. believes that EPA should come to a prompt
determination that the Industrial Landfill should be closed in
place, with enhancement of the existing cap and implementation of
additional ground water recovery and treatment systems.
Excavation of the landfill is estimated to result in substantially
increased potential risk to human health and the environment.
Since the landfill exhibits lower overall PCB concentrations in
much greater volumes of soil than other areas on the Site, the cost
of excavation is grossly disproportionate to the protection to be
achieved..
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
Comment: The landfill is filled with large bulk debris that would
render treatment of much of the material technically infeasible.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
Comment: EPA's Proposed Plan makes no attempt to analyze and
balance the CERCLA criteria in light of the site-specific
circumstances detailed in the FS. Because EPA's proposed plan for
the Site is essentially generic it could be applied to virtually
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any PCB site in the nation the plan does not adequately satisfy
CERCLA or the NCP.
Response: EPA disagrees with this comment. EPA, based on site-
specific characteristics, has evaluated each remedial alternative
against the nine criteria set forth in the NCP and in full accord
with the guidance for selection of cleanup remedies for PCB-
contaroinated sites.
Comment: The cutoff for regulation of PCBs under TSCA is 50 ppm.
Under Superfund guidance concerning the applicability of RCRA land
disposal restrictions to soil and debris, the threshold
concentration for treatment of materials containing PCBs is 100
ppm. (Superfund LDR Guide #6A, OSWER Directive No. 9347.306FS,
July 1989). Proper management of soils and debris containing more
than 50 ppm PCBs would be fully protective of human health and the
environment. No remediation of on-site soil PCB concentrations
under 50 ppm is necessary.
Response: EPA's selected remedy is consistent with applicable or
relevant and appropriate requirements (ARARs) and other policies
which warranted consideration at the Site. The RCRA land disposal
restrictions are not ARARs for this operable unit ROD due to the
fact that RCRA wastes were not found in any of the areas of the
Site addressed in this operable unit. EPA's cleanup levels are
selected after considering its risk assessment, policies, and
ARARs.
EPA has selected the 10 ppm cleanup level for PCB-contaminated
soils at the G.M. facility based in part on EPA's risk assessment
for the alternatives considered for the Site. The risk assessment,
which was conducted according to all appropriate EPA methods and
protocols, indicated that 10 ppm is protective of the Indian
population. In addition, this level meets EPA recommended PCB soil
action levels for industrial facilities, which were based, in part,
on risk to site workers. In general, EPA recommends soil PCB
cleanup levels between 10 ppm and 25 ppm in industrial areas. EPA
has selected a cleanup level on the lower end of this range because
access to the remediated areas will be unlimited and because on-
site soils impact surface and ground water quality. The 10 ppm PCB
cleanup level is consistent with PCB cleanup levels selected for
industrial areas at other Superfund sites.
Comment: EPA's cleanup criteria for river sediments are also too
stringent, in light of the characteristics of PCBs and the
limitations of current dredging technologies.
Response: It is impossible to determine, with any accuracy, the
efficiency of dredging in removing contaminated sediments. EPA's
selected remedy acknowledges that the 1 ppm cleanup level selected
for St. Lawrence and Raquette River sediments is an attempt to
minimize residual risks. In selecting the 1 ppm cleanup goal in
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the St. Lawrence and Raquette Rivers, EPA has also balanced its
desire for a very low cleanup level which will minimize residual
risk with the constraints posed by the limitations of dredging as
a means of removing sediment. EPA believes that a 1 ppm cleanup
goal in the St. Lawrence and Raquette Rivers is achievable and
provides an acceptable measure of protection to human health.
The 0.1 ppm PCB cleanup goal for Turtle Creek selected by EPA is
based on Tribal regulations. This level may not be achievable in
all areas due to the technical limitations of dredging as a means
of removing sediment.
Comment: G.M. questions EPA's rationale and technical support for
recommending dredging, rather than simply capping the St. Lawrence
River sediments, if capping will still be required after dredging
is completed.
Response: EPA has determined that dredging is an effective way of
removing the volume of contaminated sediments in the river system
based on limited previous experience at other Superfund sites and
federal projects. In addition, dredging of sediments is a
permanent remedy which allows treatment to reduce toxicity,
mobility, and volume of PCBs.
In addition, although sediment containment with a graded cover
would reduce the erosive force of the flowing river water and would
limit movement of contaminants into the environment, its long-term
effectiveness is dependent upon the adequacy and reliability of the
sediment cover. Long-term monitoring and maintenance of contained
sediments which would be required would be difficult to achieve
because the cover is located, underwater. Little information is
available on the frequency of maintenance or on the probability of
cover failure. If the sediment cover fails, risks on the order of
10" would be present immediately. Sediment dredging permanently
removes the risks from contaminated sediments.
Comment: EPA's ground water cleanup criterion of 0.1 ppb is
unwarranted and infeasible, given the nature of ground water
underneath the Site and the adsorptive characteristics of PCBs.
Even if soils on the Site are treated to 10 ppm PCBs as proposed
by EPA, it is improbable that an 0.1 ppb aquifer cleanup criterion
could be achieved in the foreseeable future.
Response: During recovery and treatment, EPA's cleanup goal is the
New York State PCB ARAR of 0.1 ppb PCBs. Based on EPA studies of
other sites, EPA has found that the final groundwater cleanup level
will depend on technical considerations such as the propensity of
PCBs to sorb to soil. If during implementation of the remedy the
groundwater cleanup goal of 0.1 ppb PCBs proves impossible to
achieve, EPA will consider modifying the groundwater recovery and
treatment portion of the selected remedy.
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Risk Assessment
Comment: Several recent surveys of the scientific literature have
shown that no reasonable medical or scientific basis exists for
concluding that acute or chronic exposure to PCBs found at the Site
could cause cancer, liver disease, or any one of a number of other
alleged human health effects rumored to result from PCB exposure.
Response: While congener specific analyses might be the best
approach for determining the risks from the types of PCBs found at
the G.M. Site, it is expensive and difficult to obtain such
analyses at this time. There is also a great deal of uncertainty
surrounding the toxicology of all the possible congeners from the
mixtures of concern at this Site. In view of all these
difficulties, EPA is compelled to use a protective approach in
assessing risk to PCBs.
Comment: The risk assessment inappropriately assumes that all PCBs
are potentially carcinogenic and have similar potency factors,
based on studies of Aroclor 1260.
Response: This is the customary practice based on the uncertainties
in the toxicological literature and uncertainties involved in using
an Aroclor rather than a congener specific approach.
Comment: As described in the Gradient risk assessments, any
treatment technologies that cannot be used in-situ will result in
the release of PCBs into the air from excavation, soil handling and
dust emissions prior to treatment. EPA's Proposed Plan completely
fails to consider the risk associated with the excavation and
treatment of these materials.
The Gradient risk assessment utilized several problematic
assumptions in connection with its estimate of potential excess
lifetime cancer risk resulting from excavating this area that
tended to bias the result in favor of EPA's proposal. For example,
Gradient assumed that the exposed area during excavation of the
East Disposal Area would correspond to the daily volume needed for
incineration and biotreatment assuming an excavation depth of one
meter. This does not take into account the practical difficulties
with implementing excavation (the need for space to stage and move
equipment, separate debris, move trucks, etc.), all of which tend
to increase the amount of soils containing PCBs that are exposed
to the air during implementation. As the amount of exposed soil
increases, PCB volatilization rate and potential exposures
increase.
Response: Gradient did not fail to consider risk associated with
excavation and treatment. In particular, Gradient used a
conservative approach in estimating risks from dioxin and furans
generated during incineration. It is not unreasonable to assume
that the exposed area during excavation of the East Disposal Area
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would correspond to the daily volume needed for incineration and
biotreatment. The need for space to stage and move equipment,
separate debris and move trucks will necessarily increase the
amount of soils containing PCBs which are exposed to air.
Volatilization from exposed soils can be limited by implementing
engineering controls during construction if this transport
mechanism appears to be of concern.
EPA's Proposed Plan is not meant to be a comprehensive document
which describes every aspect of EPA's decision-making with regard
to the Site. Rather, the Proposed Plan is intended to be a summary
of EPA's proposal for Site remediation written to solicit community
input into the Superfund decision-making process.
Comment: Because of the large percentage of bulk debris present
in the East Disposal Area, EPA's proposed excavation and treatment
remedy presents a high likelihood of failure due to practical
problems with implementation of the remedy.
EPA did not consider in its Proposed Plan the increased health
risks and costs attendant to excavation, transportation and
disposal of these untreatable materials.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
Comment: Gradient's approach to modeling releases during dredging
operations contains a number of optimistic assumptions which
demonstrate that Gradient's risk assessment underestimates the
potential releases and risks associated with dredging. Gradient's
approach assumes an idealized efficiency for suspended sediment
control, lower releases of suspended sediments to the river, and
a shorter dredging time than are supportable. These assumptions
combine to underestimate the potential lifetime cancer risks
associated with dredging.
Response: Gradient made many conservative (protective) assumptions
however, to compensate for uncertainty. They assumed, for example,
a dredging period of 172 days even though the actual dredging is
likely to be shorter. Additionally, the intrinsic conservatism of
toxicological parameters ensures that the action will be protective
of human health and environment.
Comment: According to the Gradient risk assessment, a cap over the
remaining sediments is likely to be required even after dredging
because of the inefficiency of dredging as a remedial technology.
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The risk assessment completely failed to evaluate the levels of
risk reduction and residual risk that would be provided by a
sediment capping alternative which did not involve dredging.
Response: The Gradient risk assessment evaluated three possible
dredging scenarios - the use of dredging alone (with no release of
resuspended sediments), the use of dredging followed by sediment
resuspension, and the use of dredging to remove sediments followed
by capping of resuspended residuals. These options were evaluated
to estimate the bounds of the risk posed by dredging. The true
risk from dredging may lie somewhere between these extremes. The
level of residual risk associated with sediment capping is likely
to be similar to the level associated with dredging followed by
sediment capping. However, dredging would permanently address the
area of Site contamination which poses a principal threat to human
health and the environment.
Comment: EPA's proposal fails to adequately consider the risk
created by the resuspension of sediments containing PCBs resulting
from dredging, and the possibility that such sediments will be
redeposited downstream.
This is likely to result in increased short-term and possibly long-
term exposure of fish, wildlife, and consumers of fish to PCBs.
Response: The Gradient risk assessment evaluated three possible
dredging scenarios - the use of dredging alone (with no release of
resuspended sediments), the use of dredging followed by sediment
resuspension, and the use of dredging to remove sediments followed
by capping of resuspended residuals. These options were evaluated
to estimate the bounds of the risk posed by dredging.
Comment: EPA's risk assessment of Site sediments inflated
estimated risks because of erroneous assumptions concerning the
levels of human exposure to PCBs in water and fish. The assessment
also failed to account for background levels of PCBs from upstrear,
sources. Consequently, a stringent sediment cleanup level would
have no discernible effect on ambient levels of PCBs in the St.
Lawrence River.
Response: There were several uncertainties in EPA's risk
assessment. Due to time and financial constraints, data on the
eating, hunting, and fishing habits of the Reservation population
was based on a case study using an unstructured interview
questionnaire of key informants rather than on a large-scale randor.
sample statistical survey of the entire Reservation population.
Data on fish and wildlife PCB concentrations were limited and were
restricted to fish from waters near the Reservation. Historical
data on surface water contamination in the St. Lawrence River were
used despite the fact that more recent data from the Reservation
did not indicate PCB contamination.
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Despite these uncertainties, however, based on the RI and the Risk
Assessment, EPA has determined that as a result of past operating
practices, G.M. has released PCBs to the St. Lawrence river system.
RI data show that PCB levels in sediment are higher in the area
adjacent to the G.M. outfall. Therefore, EPA believes that cleanup
of the area of sediment contamination adjacent to the G.M. outfall
will mitigate effects of PCBs on wildlife and reduce the
bioaccumulation of PCBs in the food chain near the Site.
EPA also recognizes that PCBs are likely entering the St. Lawrence
River from non-site sources contributing to PCB levels in sediments
and surface water. In order to maximize the effectiveness of the
remediation, EPA will attempt to coordinate the cleanup effort in
the St. Lawrence River with the cleanup of other potential source
areas associated with ALCOA and Reynolds facilities.
Comment: Because of the characteristics of PCBs and the specific
characteristics of the Site, the potential risks posed by the Site
do not warrant the excessively low cleanup criteria proposed in
EPA's Proposed Plan. Access to the Site is restricted and it will
remain so in the future. PCBs in soil and debris are relatively
immobile and the Aroclors present at the Site pose much less risk
than EPA has presumed.
Response: EPA has selected the 10 ppm cleanup level for PCB
contaminated soils at the G.M. facility based in part on EPA's risk
assessment for the alternatives considered for the Site. The risk
assessment, which was conducted according to all appropriate EPA
methods and protocols, indicated that 10 ppm is protective of the
Indian population. In addition, this level meets EPA recommended
PCB soil action levels for industrial facilities, which were based,
in part, on risk to Site workers. In general, EPA recommends soil
PCB cleanup levels between 10 ppm and 25 ppm in industrial areas.
EPA has selected a cleanup level on the lower end of this range
because access to the remediated areas will be unlimited and
because on-site soils impact surface and ground water quality. The
10 ppm PCB cleanup level is consistent with PCB cleanup levels
selected for industrial areas at other Superfund sites.
Comment: The health risks of PCBs are overstated in EPA's
analysis. Substantial evidence supports distinguishing between
Aroclor 1260, on which EPA bases its risk assessment protocol, and
Aroclor 1248 (found on the G.M. Site) and Aroclor 1232 (found in
small concentrations in the St. Lawrence River adjacent to the
Site).
Response: Although the assessment of risk using congener specific
analyses would be the best approach for PCBs, it is expensive and
difficult to obtain such analyses at this time. There is also a
great deal of uncertainty surrounding the toxicology of all the
possible congeners from the mixtures of concern at this Site. In
view of all these difficulties, EPA is compelled to use a
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protective approach in assessing risk to PCBs which assumes that
the risk from all aroclors is equivalent to that of Aroclor 1260.
Comment: There is considerable scientific evidence indicating that
significant differences in toxicity and tumorigenicity exist
between PCB congeners. A comparison of the recommended cancer
potency factor developed by Chase et al. for Aroclor 1248 (0.4
mg/kg/day"1), with EPA's cancer potency factor based on Aroclor 1260
(7.70 mg/kg/day"1), shows that the Aroclor 1248 potency factor,
which remains a conservative figure, is 19 times lower than the
Aroclor 1260 value. The difference between the cancer potency
factor should be incorporated into EPA's cleanup level.
Response: The Chase et. al. 1989 study was extensively reviewed on
behalf of the Pennsylvania Department of Environmental Resources.
Although Chase et al. made some valid points concerning body weight
vs. surface area extrapolations and uncertainties associated with
using data from the Aroclor 1260 bioassay, many more uncertainties
were introduced by Chase et al. than were resolved. These pertain
specifically to completeness of the toxicological data base and the
impact of mechanistic assumptions on risk assessment. Finally, it
was noted that the basis of toxicological surrogacy advocated by
Chase et al. is not supported by chemical analytical data and
appears to be based on obsolete evidence. EPA guidelines on risk
assessment are based on the principle that conservative assumptions
should be used to circumvent potential public health problems
associated with uncertainty in risk assessment. This is the
approach which was taken in the G.M. Site risk assessment.
Comment: The chances of significant current or future human
exposure to PCBs located on-site at the G.M. facility are remote.
With the exception of the Raquette River bank, the G.M. plant
property is a restricted access area. The Site is fenced and
monitored by cameras, and plant security officers are on duty 24
hours per day. The restricted nature of the Site supports a
cleanup level of 50 ppm PCBs for on-site soils.
Response: EPA has selected a soil/sludge PCB cleanup level of 10
ppm on the G.M. facility. This level is based, in part, on EPA's
risk assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population and,
in part, on EPA guidance which recommends soil PCB cleanup levels
between 10 ppm and 25 ppm in industrial areas. EPA has selected
a cleanup level on the lower end of this range because access to
remediated areas will be unlimited to G.M. personnel and because
contaminants in on-site soils may impact groundwater and surface
water quality.
Comment: The Agency states that a 10 ppm level for PCBs in soils
documented in the Proposed Plan is based on EPA's TSCA PCB spill
cleanup policy and on requirements submitted by New York State.
TSCA spill policy clearly shows that it provides for a cleanup
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level of no less than 25 ppm PCBs at restricted access sites such
as Massena. Further, to our knowledge, New York State has not
promulgated a state standard for the cleanup of PCBs in soils.
Response: As explained in the ROD, EPA has selected a soil/sludge
PCB cleanup level of 10 ppm on the G.M. facility. This level is
based, in part, on EPA's risk assessment for the alternatives
considered for the Site which indicates that 10 ppm is protective
of the Indian population and, in part, on EPA guidance which
recommends soil PCB cleanup levels between 10 ppm and 25 ppm in
industrial areas. EPA has selected a cleanup level on the lower
end of this range because access to remediated areas will be
unlimited to G.M. personnel and because contaminants in on-site
soils may impact groundwater and surface water quality.
Comment: In addition to conflicting with existing EPA guidance,
a cleanup level of 10 ppm PCBs is inconsistent with other RODs for
sites containing PCBs and is likely to be considered arbitrary by
the courts.
Response: The 10 ppm cleanup level is consistent with PCB cleanup
levels selected for industrial areas at other Superfund sites.
Comment: EPA proposed a cleanup goal of 0.1 ppm PCBs for the
sediments in the Raquette River and the unnamed tributary, "based
on Tribal requirements." EPA's recognition in its Proposed Plan
that such a standard "may be technically impracticable" in light
of "previous experience at other Superfund sites and federal
projects" makes it inappropriate for use as an ARAR or as a
criterion "to be considered."
Response: G.M. has incorrectly interpreted CERCLA's mandates
regarding ARARs, as well as EPA policy. Technical impracticability
is cited as one of only six reasons which may be used to justify
waiving of an ARAR (CERCLA 121(d)(4)). EPA's determination that
the Tribal requirements are ARARs is based on the procedures by
which the Tribal standards were developed, and their applicability
to the Site as described in CERCLA 121(d)(2)(C)(iii).
Comment: There is no evidence that the standard for cleanup of
sediments created by the St. Regis Mohawk Tribe is of general
applicability or that it has any demonstrated basis from a human,
health or environmental perspective. The language of the Tribal
resolution enacting the 0.1 ppm "clean-up standard for PCBs"
clearly refers to the Site. It is unlikely that the 0.1 pp-
standard applies to any other PCB remedial action, or has any
intended application, other than to the Site. Moreover, this ARAR
may effectively preclude certain remedial actions on Tribal lands,
and certainly precludes land disposal of sediments from the unnamed
tributary and the Raquette River on Tribal lands. Consequently,
the Tribal criterion is not an "ARAR" under the language of CERCLA
and the NCP.
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Response: EPA has previously addressed a similar issue to that
raised by the above-quoted comment. In the preamble to the NCP,
EPA stated:
Indian commentors contended that ARARs should not be defined
as promulgated laws, regulations or requirements, because some
Indian tribe laws, which could apply to a Superfund cleanup,
may not be promulgated in the same fashion as state or federal
laws.
NCP Preamble, 55 Fed. Rea. 8742 (March 8, 1990). EPA responded to
the NCP commentors as follows:
EPA realizes that tribal methods for promulgating laws may
vary, so any evaluation of Tribal ARARs will have to be made
on a case-by-case basis.
55 Fed. Reg. 8742. In the case of the St. Regis Mohawks, EPA has
determined that the PCB criteria established by the Tribe are
"promulgated", that is, they fit within that class of criteria
which "are of general applicability and are legally enforceable."
55 Fed. Reg. 8841. In addition, EPA disagrees that the criterion
was promulgated solely so as to apply to the G.M. Site and notes
that the ALCOA and Reynolds facilities are immediately upriver, and
the York Oil Superfund Site is next door to the Reservation.
The commentor states that the Tribal criterion cannot be an ARAR
since it "may effectively preclude certain remedial actions on
Tribal lands, and certainly precludes land disposal of sediments
from the unnamed tributary and the Raquette River on Tribal lands."
It seems that the commentor is referring to the provision of CERCLA
which states:
Except as provided in clause (ii) . . . , a state standard,
requirement, criteria, or limitation . . . which could
effectively result in the state-wide prohibition of land
disposal of hazardous substances, pollutants or contaminants
shall apply.
Section 121(d)(2)(B)(ii) of CERCLA.
Under clause (iii), the Tribal standard would not be an ARAR if it
could be demonstrated that the "requirement . . . was adopted for
the purpose of precluding remedial actions or other land disposal
for reasons unrelated to protection of human health and the
environment." CERCLA § 121(d) (2)(B)(iii)(II).
EPA has no reason to believe that the Tribe promulgated its PCB
sediment criterion in order to preclude remedial actions on
reservation land, or for reasons unrelated to protection of human
health and the environment, and has therefore determined that the
criterion is applicable. Further, it cannot be said with any
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degree of certainty that the Tribe's promulgation of protective
criteria will effectively preclude land disposal on Reservation
land. As would be the case if EPA were examining New York State
criteria, states promulgate protective cleanup standards, but
permit land disposal, so long as such disposal is done in a manner
that is protective of human health and the environment and in
accordance with applicable environmental laws.
Comment: Section 300.515 of the NCP also confirms that the lead
and support agencies must identify their respective potential ARARs
during the scoping of the RI/FS.
G.M. has no specific information showing that final Tribal Council
standards were identified to EPA in a timely manner in compliance
with the requirements of the NCP or CERCLA. G.M. received notice
of the proposed standards only in January, 1989. Therefore, a
cleanup level of 0.1 ppm PCBs based on Tribal "requirements" as
stated in EPA's plan is not an ARAR under CERCLA.
Response: G.M. received notice of the proposed Tribal ARARs on
January 1989. The FS was released in November 1989. EPA considers
this timely notice of potential ARARs by the Tribe.
Comment: Since 0.1 ppm PCBs in sediments may be technically
impracticable even if the Tribal standards comply with the
procedural requirements of CERCLA and the NCP, the 0.1 ppm standard
should be waived by EPA.
Response: During dredging, EPA will attempt to meet the Tribal PCB
ARAR of 0.1 ppm PCBs in Turtle Creek. However, based on limited
previous experience at other Superfund sites and federal projects,
dredging to 0.1 ppm PCBs may be technically impracticable.
Therefore, EPA is waiving the Tribal sediment standard where it
proves to be technically impracticable to achieve during dredging.
Comment: EPA stated in its plan that the cleanup standard for
ground water at the Site will be 0.1 ppb PCBs "based on New York
State requirements." EPA cites New York State requirements
concerning limits for Class GA ground water as the authority for
treatment of ground water to 0.1 ppb. A maximum level of 0.1 ppb
PCBs in ground water, however, is not a requirement that was
developed by New York State to define necessary levels of aquifer
remediation. These regulations were developed for the purpose of
prospectively protecting potable ground water. Because this
criterion was not meant to establish levels of aquifer remediation,
it is not applicable to this remedial action. The criterion is
also not relevant and appropriate to this Site.
Response: New York State has the authority and responsibility for
developing classification standards for ground water aquifers.
EPA's authority under CERCLA includes appropriately implementing
state ARARs when they exist. EPA concurs with New York State that
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their ground water classification system is an appropriate ARAR for
the Site.
Comment: The natural characteristics of the aquifer do not favor
the use of ground water in the vicinity for drinking water wells
and does not support classification of the ground water as GA
water.
Response: New York State has the authority and responsibility for
developing classification standards for ground water aquifers.
EPA's authority under CERCLA is limited to appropriately
implementing state ARARs when they exist. EPA concurs with New
York State that their ground water classification system is an
appropriate ARAR for the Site.
Comment: New York State standards are not relevant and appropriate
for the Site because there are currently no drinking water wells
on the Site, and ground water is very unlikely to be used in this
location as a future drinking water source. The local aquifers
exhibit natural impurities, are of relatively low productivity, and
surface water is available for use as a treatable drinking water
source.
Response: EPA disagrees and points out that downgradient wells
exist on the St. Regis Mohawk Reservation that could become
contaminated in the future. Additionally, under CERCLA authority,
the State of New York has the authority to establish ARARs and
their own methods for classifying ground water quality.
Comment: A cleanup level for PCBs in ground water of 0.1 ppb is
impossible to achieve given the adsorptive characteristics of PCBs.
For this reason, the criterion is inappropriate and should be
changed.
Response: During recovery and treatment, EPA's cleanup goal is the
New York State PCB ARAR of 0.1 ppb PCBs. Based on EPA studies of
other sites, EPA has found that the final groundwater cleanup level
will depend on technical considerations such as the propensity of
PCBs to sorb to soil. If during implementation of the remedy the
groundwater cleanup goal of 0.1 ppb PCBs proves impossible to
achieve, EPA will consider modifying the groundwater recovery and
treatment portion of the selected remedy.
Comment: EPA's ROD should indicate the uncertainty associated with
achieving cleanup goals in ground water, and should discuss the
possibility (1) that information gathered during the implementation
of the remedy may reveal that it is technically impractical to
achieve health-based concentrations throughout the area of
attainment, and (2) that another remedy or a contingent remedy may
be needed.
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Response: The first operable unit ROD explains that the final
groundwater cleanup level will depend on technical considerations
such as the propensity of PCBs to sorb to soil. If during
implementation of the remedy, the groundwater cleanup goal of 0.1
ppb PCBs proves impossible to achieve, EPA, in conjunction with New
York State and the St. Regis Mohawk Tribe, will consider modifying
the groundwater recovery and treatment portion of the selected
remedy.
Comment: It is technically infeasible to monitor PCBs in ground
water or discharge water reliably at a level of 0.1 ppb. A Method
Detection Limit (MDL) of 0.065 ppb PCBs (Method 608, developed
under the Clean Water Act) for Aroclor 1242, using pure PCBs and
reagent water is the basis for EPA's 0.1 ppb ground water cleanup
level for PCBs at the Site. The Method 608 MDL, however, does not
define detection limits for other Aroclors or for environmental
water samples. Past analyses of water samples from the Site
indicate that minimum detection levels of Aroclor 1248 have had to
be adjusted regularly to account for matrix-related chemical
interference with the analyses. Data from the Site indicate that
when using Contract Laboratory Program (CLP) methods for
quantifying Aroclor 1248, the quantification limit is 0.5 ppb.
Because of this limit, compliance with EPA's proposed 0.1 ppb
standard cannot be demonstrated, regardless of the level of
treatment.
Response: EPA notes that G.M.'s current monitoring of its PCB
discharges to the St. Lawrence River achieves a detection limit of
65 ppt PCBs. Non-CLP methods may be required to achieve the
analytical detection limits required in surface water.
Comment: A cleanup standard of 0.1 ppb is five times higher than
the 0.5 ppb maximum contaminant level (MCL) recently proposed by
EPA for potential drinking water sources (54 Fed. Reg. 22062, May
22, 1989). According to Superfund guidance concerning removal
action levels at contaminated drinking water sites, MCLs, if
available, are generally considered to be the appropriate cleanup
standard. (OSWER Directive No. 9360.1-10, October 6, 1987.)
Response: CERCLA and the final NCP are appropriate references for
information on how EPA sets site cleanup goals. The groundwater
PCB cleanup goal selected by EPA of 0.1 ppb, as measured at the
boundary if the Industrial Landfill and Industrial Lagoons, is
based on New York State requirements. The NCP states (40 CFR Part
300.400(g)(4)) that state standards which are more stringent than
federal requirements may be ARARs.
ST. REGIS MOHAWK TRIBE
NOTE: The St. Regis Mohawk Tribe has had a change in leadership
since the close of the EPA public comment period. Consequently,
the Tribe, in a letter to EPA dated October 31, 1990, provided
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additional comments to those which were submitted during the public
comment period. EPA has, in this Responsiveness Summary, presented
and responded to those comments submitted by the Tribe during the
public comment period. However, EPA considered the Tribe's October
31, 1990 comments in finalizing the first operable unit ROD. The
St. Regis Mohawk Tribe has concurred with the first operable unit
ROD which reflects EPA's consideration of the October 31, 1990
comments. A copy of the Tribe's October 31, 1990 letter to EPA is
contained in the Administrative Record for this Site.
Proposed Plan
Comment: The Tribe supports EPA's preferred remedial alternative
for the Industrial Lagoons, but expressed concern that biological
treatment may not be viable given that the lagoons contain
significantly higher levels of phenols than PCBs.
Response: While EPA believes that biological treatment holds
promise to significantly reduce the volume and toxicity of
contaminants, it recognizes that biological treatment is an
innovative technology. Therefore, other PCB treatment technologies
will be tested concurrently with biological destruction so that EPA
will have additional information in the event that biological
destruction proves to be unsatisfactory for treatment of any Site
material. Biological treatment will be used wherever EPA
determines it to be viable. In the event that biological treatment
is ineffective for a certain area of the Site or for certain Site
materials, other PCB treatment technologies may be employed.
Comment: The Tribe supports EPA's preferred remedial alternative
for groundwater.
Response: No response necessary.
Comment: There is no data to support the biological treatment
alternative considering the nature and extent of contamination
present at the Site. EPA should conduct parallel field-testing of
other suitable, innovative, permanent treatment technologies listed
in the Proposed Plan in the event that biological treatment proves
unsuitable.
Response: In response to comments from the Tribe and others, other
PCB treatment technologies will be tested concurrently with
biological destruction so that EPA will have additional information
in the event that biological destruction proves to be
unsatisfactory for treatment of any Site material. Biological
treatment will be used wherever EPA determines it to be viable.
In the event that biological treatment is ineffective for a certain
area of the Site or for certain Site materials, other PCB treatment
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technologies may be employed. The criteria used to judge the
treatment technologies during treatability testing include
effectiveness and cost.
Comment: The Tribe supports EPA's preferred cleanup alternative
for the North and East Disposal Areas, contaminated soils on the
St. Regis Reservation, and contaminated soils on G.M. property but
is concerned about the possibility of residual on-site soils,
sludge and debris (10 ppm) leaving the property and recontaminating
Reservation property. The Tribe requests that specific run-off
control measures be included in the remedial design. Also, it
requested that clean fill be used to replace excavated soils from
the Reservation, and the Reservation property be returned to normal
conditions.
Response: EPA has incorporated run-off control measures and
restoration of Reservation soil into its ROD.
Cleanup Levels
Comment: The Tribe supports EPA's preferred cleanup alternative
for Area 1 of the Site, but objects to EPA's selection of a 2 ppm
PCB cleanup level in the St. Lawrence River.
Response: EPA has selected a 1 ppm cleanup level in the St.
Lawrence and Raquette Rivers. The 1 ppm PCB cleanup in the St.
Lawrence and Raguette Rivers was based on interim federal and State
sediment quality criteria guidance as well as on EPA's risk
assessment. Application of interim federal sediment quality
criteria guidance indicates that a PCB cleanup level in sediments
should be between 0.08 and 2 ppm. State sediment quality criteria
guidance indicates that PCB cleanup levels well below 1 ppm are
required to achieve protection of the environment. EPA's risk
assessment for the Site demonstrates that a 1 ppm PCB cleanup level
in sediment corresponds to a 4 x 10"5 excess cancer risk.
Therefore, in an attempt to minimize residual risks, EPA has
selected 1 ppm as a cleanup goal in the St. Lawrence and Raquette
Rivers. In selecting the 1 ppm cleanup qoal in the St. Lawrence
and Raquette Rivers, EPA has also balanced its desire for a very
low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in the
St. Lawrence and Raquette Rivers is achievable and provides an
acceptable measure of protection to human health.
Remediation
Comment: The length of remediation can be shortened by utilizing
different technologies. The current estimate of 10 years is based
on a thermal destruction facility capacity of 4.2 tons per hour.
Facilities exist today that can treat 20 tons per hour in 3 years
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time assuming an on-line efficiency of 80% and waste estimate of
421,000 cubic yards. The use of two systems could shorten the
treatment period to 1.5 years. A shortened treatment period is
warranted because it would greatly reduce the risks associated with
exposure time.
Response: During the Remedial Design phase of the project, EPA
will optimize operating parameters for any treatment technologies
employed at the Site.
Comment: The Industrial Landfill appears to be a continuing and
active source of PCB releases to the St. Lawrence River. Immediate
ground water control measures should be implemented to prevent the
flow of PCBs from the Industrial Landfill into the St. Lawrence
River. If dredging of the St. Lawrence River is to be effective,
the source of PCBs should be eliminated. In addition, the Tribe
will consider the possibility of an "interim" cap while in-place,
permanent treatment technologies are investigated. However,
additional sampling should be conducted at the Industrial Landfill
to further delineate the nature and extent of contamination, since
the contents of the landfill remain largely unknown. In addition,
because there will be a potential risk to the Mohawk community from
contaminants leaching from the Industrial Landfill, the Tribe
requests a central role in the ongoing monitoring of the landfill.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
The design of any monitoring systems will be performed or overseen
by EPA, in conjunction with the St. Regis Mohawk Tribe, NYSDEC, and
the Canadian Government. With respect to the Superfund program,
EPA treats the St. Regis Mohawk Tribe in essentially the same
manner as a State.
Cost
Comment: The cost of the incineration alternative ($476 to $640
per ton) is overestimated. A more accurate estimate would be $200
per ton based on similar projects conducted by Cross/Tessitore
Associates.
Response: The costs noted in the FS are an estimate for purposes
of comparison only. A variety of site-specific criteria will
determine actual incineration costs.
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MOHAWK COUNCIL OF AKWE8ASNE
Remedial Investigation/Feasibility Study
Comment: Data collected by NYSDEC indicate heavy PCB contamination
of sediment in Contaminant Cove on Mohawk territory, an area of
roughly 4 acres. Contaminant Cove is located at the mouth of
Turtle Creek and adjacent to the Industrial Landfill. Contaminant
Cove was not included in the Proposed Plan. Approximately 20 acres
of sediment upstream from Contaminant Cove is also potentially
contaminated, extrapolating from available data.
Response: The so-called "Contaminant Cove" was included in EPA's
Proposed Plan and was considered part of Turtle Creek. EPA
approximates that the limits of the PCB hotspot in Turtle Creek
extend from the cove at the mouth of Turtle Creek to a point 2500
feet upstream from the mouth of Turtle Creek.
Comment: Less than 20% of the material in the lagoons and none of
the soil located beneath the lagoons has been characterized. An
overwhelming lack of information about the nature and extent of
contamination precludes rational selection of a treatment
alternative for the lagoon area. In particular, the selection of
biodegradation may be ill-advised if concentration of phenols are
as high as preliminary results in the RI have suggested.
Response: EPA has sufficiently characterized the Site to select
a remedial alternative for the Industrial Lagoons. During the
remedial design phase, EPA will further delineate the design and
operating parameters of the selected alternatives. While EPA
believes that biological treatment holds promise to significantly
reduce the volume and toxicity of contaminants, it recognizes that
biological treatment is an innovative technology and subsequently
has included limited additional treatability studi.es in the ROD in
case biological treatment proves ineffective.
Comment: The volume of material in the Industrial Landfill that
is contaminated with over 500 ppm of PCBs is greatly overstated in
the FS and Proposed Plan. The results of the RI indicate that the
volume of landfill material containing over 500 ppm approximates
71,000 cubic yards, whereas a volume of 305,000 cubic yards is
given in the FS and Proposed Plan. Overstatement of the volume of
contaminated soil results in a significant overestimate of cleanup
costs. EPA needs to explain why the volume of contaminated
material in the Industrial Landfill increased significantly between
what was stated in the RI versus what was stated in the FS.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
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guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
Proposed Plan
Comment: The Industrial Landfill should be permanently remediated
by destroying PCBs and other hazardous materials rather than
remediating by containment, which is not a permanent option.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
Comment: EPA should reject biodegradation as a treatment
alternative unless or until it has been shown to be effective on
the basis of treatability studies, pilot studies and field testing
at the Site. Of the available treatment alternatives reviewed in
the FS and Proposed Plan, biodegradation is the most flawed
scientifically; it is also technically the most difficult to
implement. Therefore, it can be predicted with a high degree of
confidence that biodegradation will not succeed in remediating the
G.M. Site.
Response: EPA does not believe that biological treatment is
scientifically flawed; rather, EPA believes that it holds promise
to significantly reduce the volume and toxicity of Site PCBs.
Other PCB treatment technologies will be tested concurrently with
biological destruction so that EPA will have additional information
in the event that biological destruction proves to be
unsatisfactory for treatment of any Site material. Biological
treatment will be used wherever EPA determines it to be viable.
In the event that biological treatment is ineffective for a certain
area of the Site or for certain Site materials, other PCB treatment
technologies may be employed.
Comment: The effectiveness of biodegradation as a treatment remedy
for all hazardous chemicals in all areas of the Site should be
demonstrated.
Response: Biological treatment will be tested to demonstrate its
effectiveness in treating Site contamination.
Comment: EPA should conduct pilot studies and field tests of
alternative treatment technologies, such as chemical extraction,
thermal extraction, and chemical dechlorination, prior to the ROD.
These technologies are likely to be significantly more effective
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and cost-effective than biodegradation because they are capable of
remediating a number of hazardous organic chemicals that are
present at the Site.
Response: Other PCB treatment technologies will be tested
concurrently with biological destruction so that EPA will have
additional information in the event that biological destruction
proves to be unsatisfactory for treatment of any Site material.
Comment: EPA should characterize the more than 80% of liquid,
sludge and underlying soil in the lagoon area prior to final remedy
selection and signing of the ROD. In addition, biodegradation is
not an effective remedial treatment for the lagoons because the
major lagoon contaminants are phenol, substituted phenols and
polycyclic aromatic hydrocarbons (PAHs), not PCBs.
Response: EPA believes that the lagoons have been adequately
characterized to select a remedy. Treatability studies will be
conducted during the remedial design on biological treatment and
other treatment technologies.
Cleanup Levels
Comment: The Mohawk Tribal PCB standards should be applied as
ARARs for the entire Site like the NYSDEC standards are applied to
the entire Site. Territory belonging to the St. Regis Mohawk Tribe
and bordering G.M. property to the east and north constitutes an
integral part of the Site. The inseparability of Mohawk territory
and G.M. property on the Site results in the relevance and
applicability of Tribal PCB standards for the entire Site.
Response: The St. Regis Mohawk Tribe's ARARs are applicable on the
Reservation. EPA has the statutory obligation to implement ARARs
identified to it. The remedy reflects this process.
Comment: The TSCA regulations are not appropriate for the G.M.
Site. However, the granting of a waiver of TSCA regulations, as
recommended in the Proposed Plan, could conceivably result in the
removal of all legal requirements to successfully treat material
contaminated with 500 ppm or less of PCBs if biological treatment
fails. Once the TSCA waiver is granted, it could conceivably be
legal to leave at the Site any material containing 500 ppm or less
of PCBs that cannot be treated successfully by the biodegradation
process. The proposed TSCA waiver urgently requires clarification
in order to ensure that health-based cleanup standards are not
replaced by biodegradation performance standards.
Response: EPA believes that TSCA regulations are applicable for
this Site. EPA has clarified the meaning of its limited waiver of
certain TSCA requirements.
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According to TSCA disposal regulations and policy, soil treatment
residuals with PCB concentrations above 2 ppm must be disposed in
a TSCA chemical waste landfill. However, in accordance with TSCA
regulations (40 CFR 761.75(c)(4)), EPA is waiving certain TSCA
chemical waste landfill requirements for treatment residuals with
PCB concentrations above 2 ppm and below 10 ppm. Specifically, EPA
is waiving the TSCA requirements on landfill location, the TSCA
requirement specifying the locations of groundwater monitoring
wells, and the TSCA requirement for a leachate collection system.
These TSCA chemical landfill requirements are being waived because
soil treatment residuals which meet Site cleanup standards do not
present an unreasonable risk of injury to health or the environment
from PCBs.
Remediation
Comment: Monitoring of excavated material and treatment residues
should be an integral part of the Proposed Plan.
Response: Groundwater monitoring is part of the selected remedy.
However, residuals which are disposed as specified in the ROD and
are at or below health based levels will not require monitoring.
Comment: Only 15,000 cubic yards of Mohawk territory, roughly
corresponding to 6 acres of Turtle Creek sediment to a depth of 2
feet, are included in the FS/Proposed Plan recommendations. Based
on the results of the RI, there are approximately 6 acres of
contaminated sediment and 14 acres of contaminated soil on Mohawk
territory east of the G.M. property line.
Response: The volumes given in the FS are estimates only and will
be refined during remedial action implementation. EPA believes
that the volumes presented in the comment may be overestimated.
Cost
Comment: The cost of biodegradation is the same as or greater thar.
the cost of other treatment alternatives. From the standpoint of
environmental protection, biodegradation is the least cost-
effective of the treatment alternatives considered for material
contaminated with 500 ppm or less of PCBs.
Response: EPA disagrees with this comment. Biodegradation is the
least expensive of the treatment alternatives which permanently
destroy PCBs.
Comment: The average unit incineration costs projected in the
Proposed Plan are $687 per cubic yard. This unit cost exceeds the-
high end of the market range ($100-$500 per cubic yard, assuming
a cubic yard weighs a ton) . The cost of incineration can te
reduced by a factor of 3 to 5 by selecting a technology vendor at
the lower end of the market range for incineration.
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Response: Incineration unit costs as given in the FS are $350 per
cubic yard. The $687 per cubic yard figure includes costs
associated with materials handling and residuals disposal.
Other
Comment: The ROD must include a public education program;
treatability study to determine the effectiveness of the proposed
remedial technologies; procedures and protocols for public and
government control of the proposed remedial actions, as well as
oversight capabilities; and additional contaminant sampling and
analysis in the lagoon.
Response: Monitoring of the remedial action will be performed or
overseen by EPA, NYSDEC, the Canadian government and the St. Regis
Mohawk Tribe. With respect to the Superfund program, EPA treats
the St. Regis Mohawk Tribe in essentially the same manner as a
State. In addition, as part of the Superfund process, EPA actively
solicits public involvement in all activities. The Superfund
statute also provides mechanisms for financing public participation
in the remedial process, such as provision of technical assistance
grants for hiring of consultants.
ST. LAWRENCE ENVIRONMENT TRUSTEE COUNCIL
(includes representatives from the St. Regis Mohawk Tribe, New York
State, National Oceanic and Atmospheric Administration and the
Department of the Interior)
Comment: The St. Lawrence Environment Trustee Council supports
EPA's preferred cleanup alternative for Area 1 of the Site, but
objects to EPA's selection of a 2 ppm PCB cleanup level in the St.
Lawrence River. The 2 ppm cleanup level will not be adequately
protective of living resources in the St. . Lawrence River
environment. Several studies which looked to the relationship of
sediment PCBs to PCB body burdens in aquatic organisms,
particularly fish, have found that PCB sediment concentrations of
0.1 ppm or less are reasonably protective of aquatic organisms, and
concentrations any higher could have chronic toxic effects.
Therefore, the cleanup level in the St. Lawrence River should be
0.1 ppm.
Response: EPA's selected 1 ppm PCB cleanup in the St. Lawrence and
Raquette Rivers was based on interim federal and State sediment
quality criteria guidance as well as on EPA's risk assessment.
Application of interim federal sediment quality criteria guidance
indicates that a PCB cleanup level in sediments should be between
0.08 and 2 ppm. State sediment quality criteria guidance indicates
that PCB cleanup levels well below 1 ppm are required to achieve
protection of the environment. EPA's risk assessment for the Site
demonstrates that a 1 ppm PCB cleanup level in sediment corresponds
to a 4 x 10 excess cancer risk.
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Therefore, in an attempt to minimize residual risks, EPA has
selected 1 ppm as a cleanup goal in the St. Lawrence and Raquette
Rivers. In selecting the 1 ppm cleanup goal in the St. Lawrence
and Raquette Rivers, EPA has also balanced its desire for a very
low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in the
St. Lawrence and Raquette Rivers is achievable and provides an
acceptable measure of protection to human health.
Comment: The Industrial Landfill appears to be a continuing and
active source of PCB releases to the St. Lawrence River. Immediate
ground water control measures should be implemented to prevent the
flow of PCBs from the Industrial Landfill into the St. Lawrence
River. If dredging of the St. Lawrence River is to be effective,
the source of PCBs should be eliminated.
Response: EPA's selected remedy includes groundwater recovery and
treatment to mitigate the flow of Site leachate to the river
system.
CORNELL UNIVERSITY
Public Participation
Comment: EPA should give the utmost consideration to the comments
and recommendations of the St. Regis Mohawk Tribe and their elected
representatives in revising the Proposed Plan and before issuing
a ROD.
Response: Tribal acceptance is one of nine criteria used by EPA
in selecting remedial actions. Tribal acceptance of EPA's remedy
is viewed as a modifying criteria which may alter EPA's selected
remedy.
Comment: The St. Regis Mohawk Tribe, because of its geographical
location in relation to the Site, among other reasons, should be
given a great deal of oversight over any remediation technologies
used to clean up the G.M. Site.
Response: EPA agrees.
Risk Assessment
Comment: The risk assessment should be reformulated for a 175 year
population exposure period to take into account the Mohawk view of
the full Circle of Life. The ARARs submitted by the St. Regis
Mohawk Tribe are in line with that philosophy, and failure to
achieve them will reflect a continued impact on the people and the
ecosystem.
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Response: Although the NCP directs EPA to account for Indian
Tribal Laws in formulating ARARs, there is no provision for taking
customs, mores, or religious views into account. An exposure of
175 years is well beyond the range of scientifically documented
life spans.
Comment: Many particulars needed for the risk assessment are
either missing or were disregarded by EPA's risk assessment
consultant. Additionally, there was not a full consideration of
uncertainty analysis. Therefore, the estimates of risk may be
inappropriate, and to the extent that the risk assessment is
inaccurate, it could negatively affect the St. Regis Mohawk Tribe
for many decades.
Response: The risk assessment was conducted in accordance with
current EPA guidance, regulation, and policies for risk
assessments. The discussion of uncertainty presented in the
baseline risk assessment is consistent with standard risk
assessment practice for characterizing uncertainties in addition
to complying with guidance.
Comment: The ROD should address ecotoxicologic (non-human health)
impacts of the G.M. Site and the attendant actions and policies.
Response: EPA, along with NOAA and NYSDEC, are continuing to assess
potential environmental impacts of the G.M. Site and will address
these impacts in subsequent decisions. There are no standard
quantitative methods for estimating environmental risks which are
analogous to the methods EPA uses to evaluate human health risks.
Comment: The amount of PCB-contaminated material at the Site is
unknown. Since estimates have ranged considerably, this primary
uncertainty should be factored into all calculations.
Response: The volumes and costs presented in the RI, FS and risk
assessment are estimates for purposes of developing and comparing
alternatives.
Cleanup Levels
Comment: EPA should consider other remediation technologies
besides biodegradation and incineration, and should field test
remediation technologies concurrently, especially in light of the
fact that biodegradation is not a proven technology and has no data
to support its effectiveness.
Response: Other PCB treatment technologies will be tested
concurrently with biological destruction so that EPA will have
additional information in the event that biological destruction
proves to be unsatisfactory for treatment of any Site material.
Biological treatment will be used wherever EPA determines it to be
viable. In the event that biological treatment is ineffective for
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a certain area of the Site or for certain Site materials, other PCB
treatment technologies may be employed. The criteria used to judge
the treatment technologies during treatability testing include
effectiveness and cost.
Comment: The St. Regis Mohawk Tribe's cleanup standards for
sediment, water and soil should be used throughout the cleanup area
because they are stricter and will better protect the health of the
river ecosystem.
Response: The St. Regis Mohawk Tribe's ARARs are applicable on the
Reservation. EPA has the statutory obligation to implement ARARs
identified to it. The remedy reflects this process.
Remediation
Comment: The 12-month St. Lawrence Seaway revitalization project
may be impacted, or impact, remediation at the G.M. Site. The
Seaway revitalization project could result in Seaway traffic,
resuspension or release of deeper residue, or loading of the G.M.
Site from upstream sources.
Response: EPA appreciates this comment and will take it into
consideration during the Remedial Design phase of the project.
Cost
Comment: The cost of the incineration alternative is overestimated
and should be recalculated. Cost is important to the many people
in the Massena area who are legitimately concerned about the future
of industry there. If EPA's estimations were recalculated
according to realistically lower figures, many people may not feel
obligated to support G.M.'s plans, and G.M. would perhaps be more
willing to cooperate with EPA's plans.
Response: A number of factors must be considered when determining
relative costs for remedial alternatives. The costs outlined in
the Proposed Plan are within industry norms for similar remediation
efforts. During the remedial design, EPA will further delineate
the operating parameters and refine the cost estimates.
ST. LAWRENCE UNIVERSITY
Proposed Plan
Comment: The St. Lawrence University representative supports EPA's
preferred remedial alternative for the contaminated river and
tributary sediments. The risk of resuspension of contaminated
sediments with subsequent transport downstream can be minimized by
use of techniques, such as coffer dams and silt curtains with
monitoring, to isolate the area dredged. The in-situ containment
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alternative is not acceptable because it cannot guarantee permanent
stabilization of PCB-contaminated sediments.
Response: No response necessary.
Comment: Several treatment technologies, not just in situ
biological treatment, should be evaluated so that a suitable,
innovative and permanent treatment technology can be implemented
as rapidly as possible.
Response: Other' PCB treatment technologies will be tested
concurrently with biological destruction so that EPA will have
additional information in the event that biological destruction
proves to be unsatisfactory for treatment of any Site material.
Biological treatment will be used wherever EPA determines it to be
viable. In the event that biological treatment is ineffective for
a certain area of the Site or for certain Site materials, other PCB
treatment technologies may be employed.
Cleanup Levels
Comment: The Tribal requirement of .1 ppm for PCBs in sediments
should remain the cleanup goal for all PCB-contaminated sediments,
both in the St. Lawrence River as well as in the tributaries.
Since the major route of exposure to human populations near the
Site is ingestion of fish and wildlife, and the St. Regis Mohawk
Tribe traditionally fishes in the St. Lawrence River and hunts
along its shores, there is a risk to the Tribe and other local
citizens from continuing contamination of fish and wildlife by even
relatively low levels of PCBs remaining in the treated sediments.
Response: The St. Regis Mohawk Tribe's ARARs are applicable on the
Reservation. However, they were considered and found to be
inappropriate for non-Reservation lands because they could not be
consistently applied. EPA does not agree that Mohawk territory is
inseparable from the rest of the Site since Reservation boundaries
are clearly denoted.
The 1 ppm PCB cleanup in the St. Lawrence and Raquette Rivers was
based on interim federal and State sediment quality criteria
guidance as well as on EPA's risk assessment. Application of
interim federal sediment quality criteria guidance indicates that
a PCB cleanup level in sediments should be between 0.08 and 2 ppm.
State sediment quality criteria guidance indicates that PCB cleanup
levels well below 1 ppm are required to achieve protection of the
environment. EPA's risk assessment for the Site demonstrates that
a 1 ppm PCB cleanup level in sediment corresponds to a 4 x 10"5
excess cancer risk.
Therefore, in an attempt to minimize residual risks, EPA has
selected 1 ppm as a cleanup goal in the St. Lawrence and Raquette
Rivers. In selecting the 1 ppm cleanup goal in the St. Lawrence
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and Raquette Rivers, EPA has also balanced its desire for a very
low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in the
St. Lawrence and Raquette Rivers is achievable and provides an
acceptable measure of protection to human health.
Other
Comment: A permanent remedy should be selected for the Industrial
Landfill because of the large number of PCB-contaminated materials
(424,000 cubic yards), the high concentrations of PCBs in the
materials, and the landfill's proximity to the St. Lawrence River.
A "permanent" cap would not be adequate to prevent further ground
water contamination and migration.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
PUBLIC ADVISORY COMMITTEE (PAC) for
ST. LAWRENCE REMEDIAL ACTION PLAN
Public Participation
Comment: Canadians were given no consultative status until March
1990. Other affected groups, such as the St. Regis Mohawk Indians
and New York State, were consulted prior to March 1990. The
Canadians clearly are a largely affected group when one considers
that this population is downstream and downwind of the Site. Why
were they not included in the public participation process before?
Response: Canadians are not afforded the same rights as States in
the Superfund process. However, EPA has sought Canadian government
input in the Superfund process for this Site in the past and is
committed to seeking Canadian input on monitoring of remedial
actions in the future.
Comment: The Canadian people should have the right to participate
in the determination of all remedial options, monitor all remedial
actions, and cause the cessation of remedial actions if they are
deemed to adversely affect Canadian health and welfare. PAC
particularly expects this right as it pertains to three issues:
- the processes used in dredging contaminated sediments
from the riverbeds and the potential re-suspension cf
contaminants;
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the processes used in excavation at the Site and the
potential dangers of airborne dust carried into Canadian
lands and waters; and,
the selection of a permanent solution for the destruction
of PCB-contaminated materials present in the soils and
waters at, and around, the Site.
Response: Canadians are not afforded the same rights as States in
the Superfund process. However, EPA has sought Canadian government
input in the Superfund process for this Site in the past and is
committed to seeking Canadian input on monitoring of remedial
actions in the future.
Cleanup Levels
Comment: One cleanup level should be utilized at the lowest ARAR
for each media. Using the argument of accessibility in justifying
varying cleanup levels in different areas is not viable since
future uses of the property may change this accessibility.
Response: ARARs are defined by CERCLA and the NCP to be the
requirements of other environmental laws which apply to the Site
or are relevant and appropriate to the circumstances of the Site.
The lowest ARAR has been considered in selecting Site cleanup
levels. However, it should be noted that St. Regis Mohawk Tribal
regulations are not ARARs for non-Reservation lands.
Comment: Canadian ARARs are as follows:
50 ppb (ug/kg) for sediments
1000 ppb (ug/kg) for soils
0.1 ppb (ug/L) for ground water
65 ppt (ng/L) for surface water discharge.
These ARARs agree with select ARARs of New York State, the St.
Regis Mohawk Indians and the Ontario Ministry of the Environment
guideline for Open Water Disposal of Dredged Sediment. PAC expects
that the ARARs as defined above will be applied to any area that
has been contaminated by PCBs from the G.M. facility.
Response: EPA is restricted by the CERCLA and SARA legislation and
the implementing guidance outlined in the NCP and other documents
to specific criteria to be considered when determining an ARAR.
The cleanup levels recognized by the Canadian government do net
meet this criteria. However, EPA has endeavored to select cleanup
levels and technologies that will be effective in remediating the
PCB contamination present on-site. The ROD presents a full
discussion of the cleanup levels selected for the Site.
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Remedial Alternatives
Comment: All dredged sediments should be deposited on the Site and
appropriately landfilled if under 1 ppm or appropriately treated
if over 1 ppm. PAC believes that contaminated sediments should be
removed to the fullest extent possible. Limitations on sediment
removal techniques, not concentrations, should be the guiding
factor in sediment removal. The only acceptable concentrations in
sediments is at which there will be no significant uptake in
predatory fish.
Response: EPA has selected to dredge hot spot areas in the St.
Lawrence River to a cleanup level of 1 ppm. EPA has defined PCB
hot spot areas to be areas in the St. Lawrence River with
concentrations above 1 ppm. These areas are within the vicinity
of the G.M. outfall in the St. Lawrence River. The St. Lawrence
River hot spot definition is based on federal and state sediment
quality criteria guidance as well as on EPA's risk assessment. EPA
has carefully balanced all site-specific characteristics against
the nine criteria outlined in the NCP. Further, EPA believes that
these cleanup levels will be protective of public health and the
environment.
Comment: Treatment efficiency is enhanced when homogeneous
materials are fed to a treatment operation. In situ sampling
should be used to evaluate the concentrations of contaminants in
various materials at various depths or locales so that a management
plan can be developed that effectively utilizes all treatment modes
for the reduction or elimination of amount, volume, and toxicity
of contaminated media.
Response: EPA recognizes that treatment efficiency is enhanced when
homogenous materials are treated. As a result, EPA will rely on
the results of treatability tests to determine whether biological
treatment (or another innovative technology) or incineration will
be used to treat the various areas at the Site. In the event that
biological treatment is ineffective for a certain area of the Site,
other treatment technologies which will be tested concurrently with
biological treatment may be employed. In the event that other
technologies are ineffective, incineration will be used at the
Site.
Comment: The consolidation and storage of contaminated materials,
without reduction of toxicity, in areas of restricted access is an
unacceptable remediation technique. Stewardship of such an area
by G.M. is an invitation to them to close the plant and walk away.
Any excavated, consolidated and/or stored materials should be
treated to minimum cleanup levels.
Response: For the first operable unit, EPA has not selected the
consolidation and storage of any contaminated materials without
prior treatment to reduce toxicity. EPA's ROD calls for biological
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treatment (r another innovative technology) or incineration of all
contaminated materials. To ensure that backup treatment
technologies are available in case biological treatment does not
prove effective enough in reducing toxicity, EPA has also included
limited additional treatability studies in the ROD.
High Temperature Destruction
Comment: Reformed chemical products, products of incomplete
combustion, undestroyed PCBs and residual organic toxins found in
incinerator ash should all be evaluated to establish the
destruction and removal efficiency of any high temperature
incineration system utilized.
Response: Incineration has been demonstrated to be an effective
technology for remediating PCBs in soils and sludges. As part of
the remedial action, EPA will determine the operating parameters
of the selected remediation and will .evaluate the appropriate
method to handle the fly ash residue.
Comment: If high temperature destruction is adopted, a performance
standard for contamination in the ash should be one of the criteria
used to determine effectiveness of the incineration technology.
PAC will not support any destruction technology that has detectable
concentrations of dioxin and furan.
Response: If incineration is required at the Site and all or part
of the incinerator ash is tested and found to be hazardous, EPA
will either treat the ash further to render it non-hazardous or
dispose of the ash in compliance with hazardous waste requirements.
Comment: Reduction of both toxicity and quantity of contaminated
materials should be an objective of the remediation. PAC is not
convinced that high temperature incineration systems can attain a
significant reduction of toxic materials.
Response: Incineration has been demonstrated as the most effective
technology to treat PCB-contaminated soils and sludges. Current
federal regulations for air emissions require a 99.9999% removal
efficiency ensuring the effective reduction of contaminants.
Comment: Any high temperature destruction facility used should
have, at a minimum, the following:
monitoring systems that measure destruction efficiency
continuously during combustion;
an automatic cut-off system that immediately shuts down
the incinerator if destruction efficiency falls; and,
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a facility that has a zero-discharge capacity, i.e., a
closed loop system with no emissions (a stackless
incinerator).
Response: EPA employs stringent environmental controls when
implementing remediation at Superfund sites. At the Site, EPA will
design the incinerator in full compliance with federal and state
regulations.
Comment: High temperature incineration should not be permitted
unless there is a full scale environmental monitoring program.
This should include high volume air sampling and monitoring of
land-based species that bioaccumulate PCBs quickly.
Response: The design of any incinerator monitoring systems used
at the Site will be a joint effort between EPA, New York State, and
the St. Regis Mohawk Tribe. The public will be consulted
throughout.
Comment: High temperature incineration should be the technology
of last resort because of the impact that it may have on the
environment and populations in the area. PAC is particularly
concerned that downwind populations will be adversely affected by-
emissions.
Response: EPA has determined that the use of on-site incineration
should be minimized in the selected remedy. This determination was
based on comments from the public and the Tribe which stated that
incineration was the least preferred treatment method for the Site.
As a result, EPA will rely on the results of treatability tests tc
determine whether 'biological treatment (or another innovative
technology) or incineration will be used to treat the various areas
at the Site. In the event that biological treatment is ineffective
for a certain area of the Site, other treatment technologies which
will be tested concurrently with biological treatment may he
employed. In the event that other technologies are ineffective,
incineration will be used at the Site.
Comment: PCBs and toxic materials should be extracted from soils
and sediments. Then, only the extracted contaminated material
should be destroyed using high temperature destruction. This would
make destruction easier and more controllable because of the less
heterogenous nature of the waste being destroyed.
Response: EPA will test chemical and thermal extraction of Site
media during treatability testing.
Risk Assessment
Comment: The Canadians have been excluded in the definition cf
exposed populations. Since Canadians drink the water downstrear
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of the Site and catch and eat fish from these waters, clearly they
are a part of the exposed population.
Response: EPA fully recognizes that areas in Canada include some
of the potentially exposed populations. The St. Regis Mohawk Tribe
was selected as the exposed population for evaluation in the risk
assessment to ensure that the most conservative analysis of impacts
was utilized, since they are directly adjacent to the Site and thus
have the most direct exposure. EPA has selected cleanup levels and
remedial technologies for both the on-site contamination and that
of hot spot areas within the St. Lawrence, Raquette Rivers and
Turtle Creek, that will be protective of both public health and the
environment.
Other
Comment: Although G.M. maintains that PCBs, shown to be present
in the St. Lawrence River alongside the G.M. facility, do not move
because they are in a sheltered bay, PAC firmly believes that G.M.
is partly responsible for the PCBs proven to exist downstream in
the St. Lawrence River and Lake St. Francois.
Response: EPA and NYSDEC are in close coordination in evaluating
the overall PCB contamination problem within the St. Lawrence
River.
Comment: TSCA chemical waste and landfill requirements should not
be waived for the residuals from the innovative biological
treatment process or deposits of incinerator ash.
Response: Only certain TSCA chemical waste landfill requirements
are being waived in the selected remedy. According to TSCA
disposal regulations and policy, soil treatment residuals with PCB
concentrations above 2 ppm must be disposed in a TSCA chemical
waste landfill. However, in accordance with TSCA regulations (40
CFR 761.75(c)(4)), EPA is waiving certain TSCA chemical waste
landfill requirements for treatment residuals with PCB
concentrations above 2 ppm and below 10 ppm. Specifically, EPA is
waiving the TSCA requirements on landfill location, the TSCA
requirement specifying the locations of groundwater monitoring
wells, and the TSCA requirement for a leachate collection system.
These TSCA chemical landfill requirements are being waived because
soil treatment residuals which meet Site cleanup standards do not
present an unreasonable risk of injury to health or the environment
from PCBs.
Comment: After reviewing all available materials, PAC has
determined that there are discrepancies in the PCBs used and
discharged on the Site and PCB loadings measured at the Site. PAC
therefore requests an audit of G.M.'s records in order to establish
the number of PCBs dumped on the Site.
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Response: EPA believes it has adequate information to determine an
appropriate remediation plan for the first operable unit at the
Site and at this point, does not believe an audit is warranted.
Industrial Landfill
Comment: The Landfill Disposal Area should be remediated in the
same manner as other contaminated areas at the Site.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
ONTARIO MINISTRY OF THE ENVIRONMENT (MOE)
Comment: In the interest of ensuring timely remediation, remedial
treatments other than bioremediation should be considered and
tested.
Response: The selected remedy specifies that EPA will rely on the
results of treatability tests to determine whether biological
treatment (or another innovative technology) or incineration will
be used to treat the various areas at the Site. In the event that
biological treatment is ineffective for a certain area of the Site,
other treatment technologies, which will be tested concurrently
with biological treatment, may be employed. In the event that
other technologies are ineffective, incineration will be used at
the Site.
Comment: Remediation of the St. Lawrence River sediments should
include measures to reduce the resuspension of sediments during
dredging, and should also consider the provision of a sediment cap
to the dredged area and area of redeposition. Short-term onshore
storage of contaminated sediments should also be explored to
expedite the dredging, dewatering and secure storage of the
sediments.
Response: EPA concurs with this comment.
Comment: The Ontario MOE would prefer a more stringent (than 2
ppm) cleanup criterion applied to the St. Lawrence River sediments
and would settle for a less stringent (perhaps 25 ppm) criterion
applied to all existing material on the G.M. property.
Response: EPA's selected remedy specifies a 1 ppm cleanup level in
the St. Lawrence River. The cleanup level on the G.M. Site remains
10 ppm based, in part, on EPA's risk assessment for the
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alternatives considered for the Site which indicates that 10 ppm
is protective of the Indian population and, in part, on EPA
guidance which recommends soil PCS cleanup levels between 10 ppm
and 25 ppm in industrial areas. EPA has selected a cleanup level
on the lower end of this range because access to remediated areas
will be unlimited to G.M. personnel and because contaminants in on-
site soils may impact groundwater and surface water quality. ,
Comment: It is premature to conclude that there is no off-site
migration of PCBs via ground water without first conducting further
characterization of subsurface soils and ground water.
Response: EPA's selected remedy includes groundwater recovery and
treatment to mitigate off-site migration of contaminants.
Comment: The Ontario MOE is concerned that, even though the Site
is in close proximity to the Ontario border and the Site impacts
Canadian portions of the St. Lawrence River, EPA and G.M. reports
do not mention Canadian interests or the effects of the Site upon
the Canadian environment.
Response: EPA fully recognizes that areas in Canada include some
of the potentially exposed populations. The St. Regis Mohawk Tribe
was selected as the exposed population for evaluation in the risk
assessment to ensure that the most conservative analysis of impacts
was utilized, since they are directly adjacent to the Site and thus
have the most direct exposure. EPA has selected cleanup levels and
remedial technologies for both the on-site contamination and that
of hot spot areas within the St. Lawrence, Raquette Rivers and
Turtle Creek, that will be protective of both public health and the
environment.
ENVIRONMENT CANADA, FISHERIES AND OCEANS CANADA/ HEALTH AND WELFARE
CANADA, AND MINISTERS de 1'ENVIRONMENT du QUEBEC
Comment: The Canadian Review Panel believes that additional
sampling and analysis is required to fully characterize the extent
of the contamination at the Site. Specifically, the panel believes
the sampling has been deficient with regard to sediment sampling
to define the total extent of the zone of contamination,
particularly in depositional areas downstream of the Site in the
St. Lawrence River and Lake St. Francis.
Response: EPA believes that it has sufficient data to choose
remedial alternatives for the Site.
Comment: The panel also believes that the sampling has been
deficient with regard to clearly identifying the sources and
accurately characterizing the toxicities of the various Aroclors
found in St. Lawrence River sediments adjacent to the Site; and
resolving the apparent contradiction between the IT results which
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identified only Aroclor 1242 in St. Lawrence River sediments and
the Phase I RI findings which identified Aroclors 1232 and 1248.
Response: EPA, in coordination with NYSDEC, is evaluating
potential PCB source areas of facilities adjacent to or in
proximity to the Site. EPA also recognizes differences in the
Aroclors present and believes they may be do natural dechlorination
of the PCBs.
Comment: In addition, the panel believes the sampling has been
deficient with regard to the depth and spatial density of on-site
ground water monitoring wells which are not sufficient to.identify
the occurrence of dense non-aqueous phase liquids (DNAPL).
Response: EPA believes it has sufficient data to select a remedy
to control migration.
Comment: The panel believes that the sampling has been deficient
with regard to the calculation of sediment resuspension and
downstream migration using proposed mechanical dredging/silt
curtain methodology to assess risk which was based entirely on
assumptions with no real data representing actual conditions (river
velocity, cross-sectional profile, curtain efficiency, downstream
current patterns, etc.).
Response: The FS utilized standard EPA methodology to calculate
sediment suspension and downstream migration. Actual performance
parameters will be developed during the remedial design and
remedial action phases of Site remediation.
Comment: The panel believes that the sampling has been deficient
with regard to quantification of sources and sediment contamination
upstream of the Site, particularly to determine the potential for
sediment recontamination following remediation.
Response: EPA recognizes that there are likely other source areas
upgradient of the Site. EPA is coordinating the cleanup level for
the river systems surrounding the Reynolds and ALCOA facilities.
Comment: In addition, the panel believes that the sampling has
been deficient with regard to quality assurance and quality control
protocols which need to be clearly described and improved for
future analyses.
Response: All standard protocols for quality assurance/quality
control were incorporated in the RI/FS for the Site.
Comment: The panel also believes that the sampling has been
deficient with regard to collection of aquatic data from biota
because the bioaccumulative characteristics of PCBs through the
food chain present a significant risk to human health.
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Response: EPA disagrees and believes adequate data has been
collected to select a remedial alternative.
Comment: The panel believes that the sampling has been deficient
with regard to projections of the trajectory and maximum dimensions
of the incinerator stack plume.
Response: The evaluation of risks associated with a feasibility
study does not require a risk assessment of the same depth as a
baseline risk assessment. The assessment conducted for the
incineration option is adequate to meet the requirement in this
regard. In addition, numerous full scale risk assessments which
have been conducted for hazardous waste incinerators show that the
risks from normal operation are far greater than the risks from
upset conditions. Therefore, the risks predicted by EPA for normal
operations can be used as a benchmark. Published literature which
evaluates indirect exposures to incinerator emissions (Chrostowski
and Foster 1989) from incineration of dioxin in soils reveals risks
below EPA's levels of concern for Superfund sites. These results
appear to be applicable to the G.M. Site. Emission control devices
on the incinerator are likely to limit metal emissions to
negligible levels. Increased volatilization for PCBs will only be
a small factor higher than baseline volatilization.
Comment: The Panel is concerned that the 10 ppm PCS cleanup level
for soils is not stringent enough because the treated soils may
continue as a potential source of contamination for the river
sediments. The Panel also believes that the methodology used to
determine the cleanup level for the St. Lawrence River is
incorrect.
Response: EPA has selected a soil/sludge PCS cleanup level of 10
ppm on the G.M. facility. This level is based, in part, on EPA's
risk assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population and,
in part, on EPA guidance which recommends soil PCB cleanup levels
between 10 ppm and 25 ppm in industrial areas. EPA has selected
a cleanup level on the lower end of this range because access to
remediated areas will be unlimited to G.M. personnel and because
contaminants in on-site soils may impact groundwater and surface
water quality.
The 1 ppm PCB cleanup goal in the St. Lawrence and Raquette Rivers
was based on interim federal and state sediment quality criteria
guidance as well as on EPA's risk assessment. Application of
interim federal sediment quality criteria guidance indicates that
a PCB cleanup level in sediments should be between 0.08 and 2 ppm.
State sediment quality criteria guidance indicates that PCB cleanup
levels well below 1 ppm are required to achieve protection of the
environment. EPA's risk assessment for the Site demonstrates that
a 1 ppm PCB cleanup level in sediment corresponds to a 4 x 10'5
excess cancer risk.
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Therefore, in an attempt to minimize residual risks, EPA has
selected 1 ppm as a cleanup goal in the St. Lawrence and Raquette
Rivers. In selecting the 1 ppm cleanup goal in the St. Lawrence
and Raquette Rivers, EPA has also balanced its desire for a very
low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in the
St. Lawrence and Raquette Rivers . is achievable and provides an
acceptable measure of protection to human health.
Comment: The Panel suggests that hydraulic dredging should be
used in lieu of mechanical dredging for sediment removal.
Response: EPA has selected dredging as a component of the remedial
alternative selected for PCB-contaminated sediments at the Site.
During the design phase, EPA will determine the most appropriate
type of dredging method to minimize sediment resuspension.
Comment: The Panel believes that sufficient data exist to indicate
the presence of PCB DNAPL in the fill and glacial sediments
adjacent to the lagoon and disposal areas. The Panel suggests that
additional investigations should be implemented to define the
presence and migration potential of the DNAPL. The Panel notes
that this investigation should be completed prior to the initiation
of on-site excavation and ground water pumping activities due to
the potential for these activities to spread the DNAPL.
Response: Based on the information in the RI/FS and risk
assessment, EPA does not believe sufficient data exists to indicate
DNAPL is present in the fill and glacial sediments adjacent to the
lagoon.
Comment: The Panel has concerns regarding the remediation
techniques proposed for the Site. The Panel is unconvinced that
bioremediation is feasible for such a large scale operation and
suggests that alternative technologies should be identified in case
the bioremediation is found not to be suitable. The Panel would
also like assurances that appropriate pretreatment of waste
materials would be performed prior to incineration activities.
Response: Other PCB treatment technologies will be tested
concurrently with biological destruction so that EPA will have
additional information in the event that biological destruction
proves to be unsatisfactory for treatment of any Site material.
Biological treatment will be used wherever EPA determines it to be
viable. In the event that biological treatment is ineffective for
a certain area of the Site or for certain Site materials, other PCB
treatment technologies may be employed. The criteria used to judge
the treatment technologies during treatability testing include
effectiveness and cost.
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Comment: In order to ensure that sediment dredging is conducted
in as short a time-frame as possible, the Panel requests that more
specific information be made available on dredging operations and
vastewater treatment capacities and techniques.
Response: The ROD includes a detailed discussion of the dredging
component of the remedial alternative to treat sediments in the St.
Lawrence River, Raquette River, and Turtle Creek. Specific
information on how the dredging operations are to be implemented,
wastewater treatment capacities, and techniques to be utilized,
will be developed in the design phase, subsequent to the signing
of the ROD. EPA intends to continue its ongoing public involvement
activities to solicit suggestions and comments throughout the
remedial design and implementation. EPA looks forward to continued
input from the Panel throughout the remaining remedial activities
at the Site.
Comment: The Panel believes that the risk assessment should
include residual and transient risks for human consumption of
waterfowl and other biota such as turtles, and that the transient
risk for workers and Mohawks should be re-evaluated based on more
realistic time periods for the treatment of soils, wastes and river
sediments.
Response: The risk assessment was conducted in accordance with EPA
guidance, regulations, and policies for risk assessments. It is
impossible to determine with any accuracy actual dredging times,
and potential releases of suspended sediment. Gradient made many
conservative (protective) assumptions however, to compensate for
uncertainty. They assumed, for example, a dredging period of 172
days even though the actual dredging is likely to be much shorter.
Additionally, the intrinsic conservatism of toxicological
parameters ensures that the action will be protective of human
health and the environment.
Comment: The Panel is concerned that even though there is
extensive documentation of soil and sediment PCB concentrations,
there are insufficient data regarding the specific PCB sources at
the Site. The Panel believes that a great deal of effort and cost
could be expended, particularly in the removal of river sediment,
without being certain the major source to the river has been shut
off. The Panel suggests that the overall remedial strategy must
include the specific identification of loadings of PCBs and other
chemicals from the various source areas on and adjacent to the-
Site.
Response: EPA believes that it has adequate information about the
Site to select and implement an appropriate remedy. The majority
of the PCBs currently in the St. Lawrence River were deposited ir.
G.M.'s outfall prior to 1980. This source of contamination to t he-
River has been mitigated through the New York State Polluticr
Discharge Elimination System.
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Comment: The Panel suggests that a monitoring plan for the
remedial actions should be developed which is acceptable to all
affected parties, and requests that the Canadian authorities
participate in the development of the plan.
Response: The design of any monitoring systems used at the Site
will be a joint effort between EPA, New York State, the St. Regis
Mohawk Tribe, and the Canadian government.
GREAT LAKES UNITED on behalf of:
Atlantic Chapter of the Sierra Club
Atlantic States Legal Foundation
Canadian Auto Workers Local 444
Canadian Environmental Law Association
Canadian Institute for Environmental Policy
Clean Water Alliance
Clearwater
Lake Michigan Federation
National Wildlife Federation, Great Lakes Natural Resource Center
Pollution Probe
Ontario Toxic Waste Research Coalition
Public Participation
Comment: EPA should work with a citizen oversight committee to
assess, review, select, and monitor the remediation of all
contaminants on the Site.
Response: As part of the Superfund process, EPA actively solicits
public involvement in the assessment, review, and monitoring of EPA
activities. EPA also encourages public input into the decision-
making process. CERCLA and SARA are very clear, however, that the
final remedial alternative decision-making authority rests with the
EPA Regional Administrator. Throughout the RI/FS at the Site, EPA
has strived to keep the public informed through public meetings,
fact sheets, seminars and press releases. EPA looks forward to a
continued close working relationship with interested U.S. and
Canadian citizens, as well as the St. Regis Mohawk Tribe during the
remedial design.
Remedial Alternatives
Comment: EPA and G.M. should assess other permanent treatment
technologies in addition to incineration and biological treatment
for all contaminants on the Site.
Response: Other PCB treatment technologies will be tested
concurrently with biological destruction so that EPA will have
additional information in the event that biological destruction
proves to be unsatisfactory for treatment of any Site material.
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Biological treatment will be used wherever EPA determines it to be
viable. In the event that biological treatment is ineffective for
a certain area of the Site or for certain Site materials, other PCB
treatment technologies may be employed. The criteria used to judge
the treatment technologies during treatability testing include
effectiveness and cost.
Comment: If incineration remains the treatment technology chosen
for materials contaminated above 500 ppm, EPA must select a thermal
destruction technology and require pollution control equipment that
will minimize, to the greatest degree, the release of any air
pollutants.
Response:EPA agrees with the comment and EPA intends to meet all
appropriate federal and state air quality regulations as part of
the implementation of the selected remedy.
Cleanup Levels
Comment: Great Lakes United supports EPA's proposal to excavate
and treat contaminated sediments in the St. Lawrence and Raquette
Rivers and Turtle Creek. However, the cleanup levels for PCBs in
sediments are not protective enough. The U.S. Fish and Wildlife
Service has recommended a cleanup level of .05 ppm for other
Superfund sites and the Kalamazoo River. This number is based upon
bioaccumulation of PCBs in wildlife, [references attached]
Response: EPA's selected remedy for river sediments requires the
delineation of PCB hot spots in the river system. At this Site,
EPA has defined PCB hot spots to be areas with concentrations above
1 ppm in St. Lawrence and Raquette River sediments and above 0.1
ppm in Turtle Creek. The St. Lawrence River hot spot definition
is based on federal and state sediment quality criteria guidance
as well as on EPA's risk assessment. The 0.1 ppm hot spot
definition for the Turtle Creek is based on Tribal regulations.
Other
Comment: A PCB audit should be conducted for the Site. The burden
of proof should be on G.M. to document the destination of any PCBs
that are unaccounted for in the audit.
Response: EPA believes it has adequate information to determine an
appropriate remediation plan for the first operable unit at the
Site, and at this point, does not believe that an audit is
warranted.
Industrial Landfill
Comment: EPA should identify a preferred option for the Industrial
Landfill. This option should be a specific, permanent treatment
strategy which will address all contaminants.
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Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
CORNWALL AGAINST POLLUTION
Remedial Alternatives
Comment: The incineration of PCBs does not eliminate the
pollution. It merely changes the form. The products of incomplete
combustion may include highly toxic dioxin or dibenzofuran.
Additionally, elevated levels of heavy metals could be expected in
the incinerator ash which would then require disposal. Cornwall
Against Pollution is not prepared to contribute to the profits of
G.M. with its health.
Response: EPA has selected a combination of biological treatment
(or another innovative treatment technology) and incineration as
the remedial alternatives to be implemented at the Site, to ensure
the protection of public health and the environment. While
biological treatment is a relatively new and innovative technology,
EPA believes it holds promise to significantly reduce the volurr.e
and toxicity of contaminants. Additionally, as a backup, EPA has
included limited additional treatability studies in the ROD in case
biological treatment proves to be ineffective. Incineration has
been demonstrated to be the most effective permanent remedy for the
destruction of PCBs and has been successfully implemented at other
Superfund sites. EPA intends to implement stringent controls or.
all aspects of the selected remedy and intends to meet all
appropriate federal and state air quality regulations as part cf
the implementation of the selected remedy. EPA will also handle
any residue materials, including the fly ash, in compliance with
all applicable requirements.
Comment: By proposing incineration which would result in harmful
air emissions to Canada, EPA has chosen to export a portion of its
pollution problem. This position is unforgivable, given that the
affected population has not agreed to accept the potential risks.
Response: Incineration has been demonstrated to be the most
effective permanent remedy for the destruction of PCBs and has beer.
successfully implemented at other Superfund sites. As part of the
design of the incineration component of the selected remedy, EPA
will incorporate stringent controls to ensure compliance with all
appropriate federal and state requirements.
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Risk Assessment
Comment: The risk assessment does not consider potential risks to
Canadian citizens. Substantial risk to Canadians will result if
incineration, excavation and dredging are implemented.
Response: While the St. Regis Mohawk Tribe was selected as the
exposed population for evaluation in the risk assessment, this was
done to ensure the most conservative analysis of potential impacts
since they are directly adjacent to the Site and have the most
direct exposure to Site contamination. EPA however, fully
recognizes that Canadian citizens are potentially exposed
populations and are concerned about EPA's selected remedial
alternative.
EPA has successfully implemented excavation, incineration and
dredging at other Superfund sites. These technologies have been
demonstrated to be effective in permanently reducing the volume of
contaminated material. EPA intends to implement stringent
environmental controls to ensure compliance with all appropriate
federal and state requirements.
Comment: The risk assessment assumes optimal operation conditions
for the incineration facility. The Draft FS states that optimal
conditions could not be expected at the Site given the periodic
severity of the climate and likelihood of variable feed
characteristics.
Response: The evaluation of risks associated with a feasibility
study does not require a risk assessment of the same depth as a
baseline risk assessment. The assessment conducted for the
incineration option is adequate to meet the requirement in this
regard. We also point out that numerous full scale risk
assessments which have been conducted for hazardous waste
incinerators show that the risks from normal operation are far
greater than the risks from upset conditions. Therefore, the risks
predicted by EPA for normal operations can be used as a benchmark.
Published literature which evaluates indirect exposures to
incinerator emissions (Chrostowski and Foster 1989) from
incineration of dioxin in soils reveals risks below EPA's levels
of concern for Superfund sites. These results appear to be
applicable to the G.M. Site. Emission control devices on the
incinerator are likely to limit metal emissions to negligible
levels. Increased volatilization for PCBs will only be a small
factor higher than baseline volatilization.
Comment: The risk assessment ignores interactions among
carcinogens. Yet, the study admits that the assumption that
carcinogens act independently may not be true.
Response: EPA guidance is that carcinogens should be treated in an
additive fashion. This is due to the fact that carcinogenic risks
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are probabilities. Since the risks from individual chemicals are
independent, addition of probabilities is warranted. Additionally,
most toxicologists subscribe to the fact that interactions at the
extremely low doses potentially experienced by environmental
receptors will be biochemically prohibited from interaction.
Comment: The risk assessment did not quantify a number of
significant risks referenced in the Draft FS, including:
anticipated incinerator and/or emission control upsets
which may result in emissions of dioxin, furan,
hydrochloric acid, sulfuric acid, particulates and
others;
potential downwind deposition of these emissions and the
resulting impact to soil, water, cropland, animal grazing
and human contact;
potential emissions of metal from soil materials and fuel
combustion; and
increased volatilization due to sorting/crushing and
mixing feed material.
Response: The evaluation of risks associated with a feasibility
study does not require a risk assessment of the same depth as a
baseline risk assessment. The assessment conducted for the
incineration option is adequate to meet the requirement in this
regard. We also point out that numerous full scale risk
assessments which have been conducted for hazardous waste
incinerators show that the risks from normal operation are far
greater than the risks from upset conditions. Therefore, the risks
predicted by EPA for normal operations can be used as a benchmark.
Published literature which evaluates indirect exposures to
incinerator emissions (Chrostowski and Foster 1989) from
incineration of dioxin in soils reveals risks below EPA's levels
of concern for Superfund sites. These results appear to be
applicable to the G.M. Site. Emission control devices on the
incinerator are likely to limit metal emissions to negligible
levels. Increased volatilization for PCBs will only be a small
factor higher than baseline volatilization.
PARTI QUEBECOIS BEAUHARNOIS - HUNTINGDON COUNTY
Comment: The officials of Beauharnois-Huntingdon County are
concerned that their citizens' health may be impacted by the
remedial actions at the Site. They are especially concerned with
the following proposed actions: dredging of the St. Lawrence River
may threaten the quality of their drinking water; excavation
activities may release contaminated dust which would be carried
towards the County by prevailing winds; and emissions fror
incinerators and improperly combusted wastes would also be carried
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by prevailing winds into agricultural areas. The Parti Quebecois
Beauharnois-Huntingdon County believes that its concerns have not
been adequately addressed, and requests active involvement in all
future remedial planning, including monitoring of all remedial
operations.
Response: EPA has considered the short-term risks associated with
Site remediation. The design of any monitoring systems used at the
Site will be a joint effort between EPA, New York State, the St.
Regis Mohawk Tribe and the Canadian government.
NY STATE DEPARTMENT OF ENVIRONMENTAL CONSERVATION (NYSDEC)
Comment: NYSDEC believes that the proposed cleanup level of 2 ppm
PCB for the St. Lawrence River sediments will not be protective of
human health and the environment and that different remedial
options for the sediments should be explored in order to evaluate
the technical feasibility of a more stringent cleanup level.
Response: EPA has selected to remediate hot spot areas within the
St. Lawrence River to the lowest level that is technically
feasible. Hot spot areas have been defined as those with
concentrations of PCBs over 1 ppm in the St. Lawrence and Raquette
River sediments and 0.1 ppm in Turtle Creek. The St. Lawrence
River hot spot definition is based on federal and state sediment
quality criteria guidance as well as EPA's risk assessment. The
0.1 ppm hot spot definition for Turtle Creek is based on Tribal
regulations. The effectiveness of currently available technology
may limit the cleanup level that is practically achievable.
Comment: NYSDEC supports the 10 ppm PCB cleanup level for portions
of the G.M. property that have controlled/secured access, but
believes that a lower cleanup level could be attained in unsecured
areas, especially in areas susceptible to runoff.
Response: EPA has selected a soil/sludge PCB cleanup level of 10
ppm on the G.M. facility. This level is based, in part, on EPA's
risk assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population and,
in part, on EPA guidance which recommends soil PCB cleanup levels
between 10 ppm and 25 ppm in industrial areas. EPA has selected
a cleanup level on the lower end of this range because access to
remediated areas will be unlimited to G.M. personnel and because
contaminants in on-site soils may impact groundwater and surface
water quality. EPA has selected a soil/sludge total phenols
cleanup level of 50 ppm based on federal RCRA guidance for closure
of surface impoundments. EPA estimates that there are 176,000
cubic yards of soils and sludges in the Industrial Lagoons, in the
North Disposal Area, and in other areas on the G.M. facility
contaminated with PCBs above 10 ppm which are being addressed ir.
this operable unit.
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Comment: NYSDEC believes that the cleanup level for sludge in the
industrial lagoons should be at a minimum 10 ppm PCBs and that any
lagoons remaining in use should have PCB levels that would not
cause contravention of ground water standards should the PCBs leach
from the lagoons.
Response: EPA has selected a cleanup level of 10 ppm for the
Industrial Lagoons. Inactive lagoons will be remediated when they
are taken out of service.
Comment: NYSDEC suggests that a tiered approach, based on
concentrations of PCBs, be applied to the methodology for treatment
and management of waste materials and residuals. This is in an
effort to balance the desire to remove pollutants, apply treatment
technologies where feasible and to develop remedial programs which
are economically viable. Additionally, NYSDEC believes this
approach would allow G.M.'s resources to be used to remove more
pollutants from the environment.
Response: EPA has selected a combination of biological treatment
(or another innovative treatment technology) and incineration as
the selected remedial alternative. Incineration has been
demonstrated to be an effective technology for remediating PCB-
contaminated soils and sludges. Biological treatment is in
innovative technology that shows promise that it can effectively
reduce the volume and toxicity of PCB-contaminated materials. To
ensure the availability of effective treatment as a component of
the remedy, EPA in the ROD stipulates that limited additional
treatability studies will be conducted.
Comment: NYSDEC is skeptical as to the viability of bioremediation
and believes that other appropriate technologies could be tested
concurrently with bioremediation.
Response: Other PCB treatment technologies will be tested
concurrently with biological destruction so that EPA will have
additional information in the event that biological destruction
proves to be unsatisfactory for treatment of any Site material.
Biological treatment will be used wherever EPA determines it to be
viable. In the event that biological treatment is ineffective for
a certain area of the Site or for certain Site materials, other PCB
treatment technologies may be employed. The criteria used to judge
the treatment technologies during treatability testing include
effectiveness and cost.
Industrial Landfill
Comment: NYSDEC believes that sufficient information is available
regarding the Industrial Landfill to implement the beginnings of
a remedial action plan. NYSDEC suggests the following actions be
taken: ground water/leachate collection, containment and
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treatment; remediation of the waste pile or portions thereof; and
a proper closure of the landfill for any remaining wastes.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill. Groundwater recovery and treatment are
included in the first operable unit ROD.
U.S. DEPARTMENT OF COMMERCE, NATIONAL OCEANIC AND ATMOSPHERIC
ADMINISTRATION (NOAA)
Comment: EPA's cleanup goal of 2 ppm in the St. Lawrence River may
not be fully protective of natural resources. This is especially
true in the case of the white whale population which has a tendency
to bioaccumulate PCBs. NOAA believes that the 0.1 ppm cleanup goal
in the sediments of the Raquette River and Turtle Creek appears to
be a more appropriate cleanup goal for the protection of natural
resources.
Response: EPA's selected remedy for river sediments requires the
delineation of PCS hotspots in the river system. Hotspot areas as
defined are then subject to sediment remediation as described
below. At this Site, EPA has defined PCS hotspots to be areas with
concentrations above 1 ppm in St. Lawrence River and Raquette River
sediments and soils and above 0.1 ppm in Turtle Creek sediments and
soils.
The 1 ppm PCS cleanup goal in the St. Lawrence and Raquette Rivers
was based on interim federal and State sediment quality criteria
guidance as well as on EPA's risk assessment. Application of
interim federal sediment quality criteria guidance indicates that
a PCB cleanup level in sediments should be between O."08 and 2 ppm.
State sediment quality criteria guidance indicates that PCB cleanup
levels well below 1 ppm are required to achieve protection of the
environment. EPA's risk assessment for the Site demonstrates that
a 1 ppm PCB cleanup level in sediment corresponds to a 4 x 10"5
excess cancer risk.
Therefore, in an attempt to minimize residual risks, EPA has
selected 1 ppm as a cleanup goal in the St. Lawrence and Raquette
Rivers. In selecting the 1 ppm cleanup goal in the St. Lawrence
and Raquette Rivers, EPA has also balanced its desire for a very
low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in the
St. Lawrence and Raquette Rivers is achievable and provides an
acceptable measure of protection to human health.
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The 0.1 ppm hotspot definition for Turtle Creek selected by EPA is
based on Tribal regulations. This level may not be achievable in
all areas due to the technical limitations of dredging as a means
of removing sediment.
U.S. DEPARTMENT OF THE INTERIOR (DOI)
Comment: An adequate environmental risk assessment has not been
performed to demonstrate that EPA's cleanup level of 2 ppm proposed
for the St. Lawrence River sediments will be protective of fish and
wildlife. Based on the published data available, the U.S. DOI
concludes that a residual sediment level of 2 ppm PCB will pose a
threat to fish species that forage significantly in the area of
contamination, and also to fish-eating waterfowl, waterbirds and
raptors.
Response: In an attempt to minimize residual risks, EPA has
selected 1 ppm as a cleanup goal in the St. Lawrence and Raquette
Rivers. In selecting the 1 ppm cleanup goal in the St. Lawrence
and Raguette Rivers, EPA has also balanced its desire for a very
low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in the
St. Lawrence and Raguette Rivers is achievable and provides an
acceptable measure of protection to human health.
Comment: The U.S. DOI would like to see information regarding the
expected residual levels of PAHs in the St. Lawrence River
sediments, and believes that an environmental risk assessment
should be performed to determine the potential adverse impacts of
any residual PH contamination on the fish and wildlife.
Response: EPA expects that remediation of PCBs.in sediments will
remove PH contamination in St. Lawrence River sediments.
Comment: The U.S. DOI believes that further characterization of
the lower glaciofluvial unit at the Site is needed to determine if
the unit is a potential pathway for migration of hazardous
substances from the Industrial Landfill.
Response: EPA believes it has sufficient data to select a remedy
for Site groundwater. The selected remedy includes groundwater
recovery and treatment to prevent off-site migration of
contamination.
Comment: The U.S. DOI believes that previous data collected at the
Site indicates that PCB contamination may be present in the cove
area at the mouth of Turtle Creek, yet the Phase I and Phase II
investigations did not sample in this area. Additional sampling
should be conducted in and around the cove area to characterize the
contamination.
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Response: EPA has included the cove area at the mouth of Turtle
Creek in the ROD. Hot spots of contaminated sediments in this area
will be remediated by dredging and treatment. Based on an ARAR
established by the St. Regis Mohawk Tribe, EPA has established a
cleanup goal of 0.1 ppm. EPA recognizes that the currently
available technologies may preclude remediation to this level. EPA
will strive to meet this cleanup goal if technically feasible.
REYNOLDS METALS COMPANY (REYNOLDS)
Cleanup Levels
Comment: Reynolds Metals Company requested additional information
on how EPA determined the selected cleanup levels. Additionally,
it noted that the cleanup levels across the media are inconsistent
and disparate. Further explanation of the cleanup levels followed
by a reopening of the public comment period is requested. This
should include:
a discussion of how EPA arrived at the sediment cleanup
level of 2 ppm;
a discussion of how EPA arrived at the 10 ppm cleanup
level for PCBs in soils and sludges; and,
a discussion of how EPA arrived at the 2 ppm cleanup
.level for Industrial Lagoon sludges.
Response: A complete description of EPA's sediment cleanup levels
is given in the ROD decision summary. Reopening of the public
comment period is not required for this Site.
Comment: The proposed cleanup level of 10 ppm for PCBs in on-site
soils, sludges, and sediments is overly stringent, inconsistent
with the EPA PCB Spill Cleanup Policy and inconsistent with cleanup
standards used at other similar sites. A cleanup level of 25 ppr.
is warranted by the EPA PCB Spill Cleanup Policy.
Response: EPA has selected a soil/sludge PCB cleanup level of 10
ppm on the G.M. facility. This level is based, in part, on EPA's
risk assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population and,
in part, on EPA guidance which recommends soil PCB cleanup levels
between 10 ppm and 25 ppm in industrial areas. EPA has selected
a cleanup level on the lower end of this range because access tc
remediated areas will be unlimited to G.M. personnel and because
contaminants in on-site soils may impact groundwater and surface-
water quality. EPA has selected a soil/sludge total phenols
cleanup level of 50 ppm based on federal RCRA guidance for closure
of surface impoundments. EPA estimates that there are 176,00.
cubic yards of soils and sludges in the Industrial Lagoons, in the-
North Disposal Area, and in other areas on the G.M. facility
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contaminated with PCBs above 10 ppm which are being addressed in
this operable unit.
Comment: The proposed cleanup level of 2 ppm for sediment in the
St. Lawrence River is overly stringent and inconsistent with
cleanup standards used at other similar sites and it also may be
technically impossible to achieve. In-place capping would allow
for natural biodegradation of the PCB-contaminated sediment at less
potential risk than dredging.
Response: The 1 ppm PCB cleanup goal in the St. Lawrence and
Raquette Rivers was based on interim federal and state sediment
quality criteria guidance as well as on EPA's risk assessment.
Application of interim federal sediment quality criteria guidance
indicates that a PCB cleanup level in sediments should be between
0.08 and 2 ppm. State sediment quality criteria guidance indicates
that PCB cleanup levels well below 1 ppm are required to achieve
protection of the environment. EPA's risk assessment for the Site
demonstrates that a 1 ppm PCB cleanup level in sediment corresponds
to a 4 x 10"5 excess cancer risk.
Therefore, in an attempt to minimize residual risks, EPA has
selected 1 ppm as a cleanup goal in the St. Lawrence and Raquette
Rivers. In selecting the 1 ppm cleanup goal in the St. Lawrence
and Raquette Rivers, EPA has also balanced its desire for a very
low cleanup level which will minimize residual risk with the
constraints posed by the limitations of dredging as a means of
removing sediment. EPA believes that a 1 ppm cleanup goal in the
St. Lawrence and Raquette Rivers is achievable and provides an
acceptable measure of protection to human health.
EPA has selected a soil/sludge PCB cleanup level of 10 ppm on the
G.M. facility. This level is based, in part, on EPA's risk
assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population and,
in part, on EPA guidance which recommends soil PCB cleanup levels
between 10 ppm and 25 ppm in industrial areas. EPA has selected
a cleanup level on the lower end of this range because access to
remediated areas will be unlimited to G.M. personnel and because
contaminants in on-site soils may impact groundwater and surface
water quality.
Comment: The cleanup level for PCBs in all soils and sludge at the
Site should be no lower than 25 ppm.
Response: EPA has selected a soil/sludge PCB cleanup level of 10
ppm on the G.M. facility. This level is based, in part, on EPA's
risk assessment for the alternatives considered for the Site which
indicates that 10 ppm is protective of the Indian population and,
in part, on EPA guidance which recommends soil PCB cleanup levels
between 10 ppm and 25 ppm in industrial areas. EPA has selected
a cleanup level on the lower end of this range because access to
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remediated areas will be unlimited to G.M. personnel and because
contaminants in on-site soils may impact groundwater and surface
water quality.
Comment: The cleanup level of .1 ppb for discharges and ground
water is technically infeasible and inconsistent with CERCLA. The
method detection limit (MDL) for the waters around the Site is
certainly higher than .1 ppb due to the complex nature of those
waters. Moreover, EPA has stated on several occasions (e.g., 54
Fed. Reg. at 22100 (May 22, 1989)) that a discharge limit should
be set at between 5 and 10 times the applicable MDL.
Response: EPA has selected a cleanup goal of 0.1 ppb for PCBs based
on New York State requirements for Class GA aquifers. EPA has also
selected cleanup goals for VOCs in compliance with federal and
state ARARs. EPA notes that the 0.1 ppb level for PCBs is below
the .5 ppb federal MCL. However, under the NCP, EPA is required
to remediate to the state requirement if it is more stringent then
the federal requirement. Further, EPA recognizes that because PCBs
sorb to soil, the effectiveness of PCB removal from ground water
may be limited.
Comment: The potential health risks associated with PCB
contamination in subsurface soils is lower than those for surface
soils because of the greatly reduced likelihood of direct contact
and migration through runoff. Thus it may be appropriate to
propose lower cleanup standards for subsurface soils. This is
consistent with EPA policy.
Response: Recent ground water sampling indicate that low levels of
PCBs are present. Based on existing information, EPA believes that
the levels of PCB contamination present in soils is contributing,
through leaching, to the ground water contamination on the Site.
EPA's proposed cleanup level is designed to reduce the amount of
PCBs available to leach into the ground water. The proposed
cleanup level is clearly within the defined parameters established
for industrial sites as outlined in the latest available EPA
guidance.
Remedial Alternatives
Comment: The risks posed by several remedial alternatives
consistent with CERCLA, other than those preferred by EPA are
significantly less than the risks posed by those alternatives
preferred by EPA. For example, the risks related to the capping
of sediments and allowing for natural biodegradation in the
Raquette and St. Lawrence Rivers is significantly less than the
risks associated with dredging these sediments. The Proposed Plan
does not adequately address these issues.
Response: EPA recognizes that several of the remedial alternatives
evaluated pose fewer short-term risks than those remedial
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alternatives selected by EPA. After carefully balancing the
specific characteristics of the Site against the nine criteria as
outlined in the NCP, EPA has determined that the long-term
effectiveness, permanence, and protectiveness of public health and
the environment afforded by the selected alternatives offset any
short-term risks posed by the selected alternative.
Comment: There are logistical and technical difficulties with the
incineration of large quantities of soil and debris. EPA should
consider other available treatment alternatives like capping and
in situ bioremediation. This treatment would be expected to
achieve the percentage reduction of PCBs specified in Superfund LDR
Guide #6A, "Obtaining a Soil and Debris Treatability Variance for
Remedial Actions." This document recognizes biological treatment
as a preferred remedial alternative for PCBs and does not require
combining alternate treatment technologies when application of one
treatment technology will achieve the concentration levels
specified from the percentage reduction range.
Response: The Land Disposal Restrictions are not ARARs for this
operable unit ROD. In addition, other PCB treatment technologies
will be tested concurrently with biological destruction so that EPA
will have additional information in the event that biological
destruction proves to be unsatisfactory for treatment of any Site
material. Biological treatment will be used wherever EPA
determines it to be viable. In the event that biological treatment
is ineffective for a certain area of the Site or for certain Site
materials, other PCB treatment technologies may be employed.
Comment: The potential health risks associated with incineration
are unlikely to be acceptable to the neighboring community,
including Site neighbors in Canada.
Response: Although EPA has received comment from some U.S.
citizens, Canadian citizens, and environmental groups expressing
concern and requesting assurances that appropriate safeguards be
utilized in implementing the incineration component of the remedy,
EPA has received only limited opposition to incineration as a
component of the selected remedy. To the contrary, numerous
commentors have expressed a preference for the permanence of
incineration as a component of the selected remedy as long as
stringent controls are implemented. Nevertheless, EPA has reduced
the use of incineration in its selected remedy for the Site.
Comment: The contents of the lagoons include PCBs which tend not
to migrate in this media. Why has EPA not considered the generally
accepted remedy of solidification and closure for the on-site
lagoons?
Response: EPA did evaluate solidification and closure of the on-
site lagoons in the FS. After careful consideration of the Site's
unique characteristics in accordance with the nine criteria as
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outlined in the NCP (300.430{e{a}{iii};300.430 {f}{i}{i}), EPA has
selected excavation and treatment of the lagoon sludges in the ROD.
The combination of these technologies is considered the best
balance for the Site.
Other
Comment: An examination of the methods utilized in estimating
costs for the alternatives reveals that the actual costs of the
alternatives could be dramatically higher than indicated.
Response: As part of the FS, EPA evaluates the relative cost of the
various remedial alternatives that are being considered. During
the design phase, EPA will further refine and delineate the
remediation costs based on the actual parameters of the remedial
alternatives selected.
Risk Assessment
Environ, Reynolds Metals Company's consultant, comments on the
Gradient Corporation report of April 2, 1990, "Risk Assessment for
Five Remedial Alternatives at 6.M. Site Massena, New York"
Comment: The remedies preferred by EPA are not those that present
the lowest risk. According to Tables 6-1 and 6-2 in the Gradient
Corporation report of April 2, 1990, "Risk Assessment for Five
Remedial Alternatives at G.M. Site Massena, New York," the greatest
estimated increases in risk are associated with the process of
excavation and the greatest estimated reductions in risk are
associated with the installation of a cap.
Response: EPA recognizes that several of the remedial alternatives
put forth by G.M. may pose fewer short-term risks than those
remedial alternatives proposed by EPA. However, EPA's "Risk
Assessment for Five Remedial Alternatives" indicates that none of
the remedial alternatives considered in the FS pose unacceptable
short-term risks to human health. (EPA defines unacceptable excess
cancer risks as those outside the EPA risk range of 10"4 to 10'6.
EPA defines unacceptable non-cancer effects as those with a hazard
index greater than 1.) Risks to residents of the Reservation can
be mitigated through temporary relocation, if necessary. In
addition, risks to remediation workers can be mitigated through the
use of protective equipment.
EPA also recognizes that there may be impacts associated with
incineration and that the public is very concerned about the use
of on-site incineration. For this reason, EPA has chosen to
minimize the use of on-site incineration in its selected remedy as
detailed in the ROD. EPA will rely on the results of treatability
tests to determine whether biological treatment (or another
innovative technology) or incineration will be used to treat the
various areas at the Site. In the event that biological treatment
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is ineffective for a certain area of the Site, other treatment
technologies which will be tested concurrently with biological
treatment may be employed. In the event that other technologies
are ineffective, incineration will be used at the Site.
After carefully balancing the specific characteristics of the Site
against the nine criteria as outlined in the NCP, EPA has
determined that the long-term effectiveness and permanence afforded
by the selected alternative offset any short-term risks posed by
the selected alternative and the higher costs of the selected
remedy.
Comment: The vast amount of experience with PCBs and other
hydrophobic chemicals at other sites indicates that a cap often
substantially reduces exposure to (and hence risk from) PCB-
contaminated soils without a substantial increase in risk during
remediation. Capping alone should have been considered for PCB-
contaminated sediments.
Response: Capping was considered by EPA. However, after carefully
balancing the specific characteristics of the Site against the nine
criteria as outlined in the NCP, EPA has determined that the long-
term effectiveness and permanence afforded by the selected
alternative offset any short-term risks posed by the selected
alternative and the higher costs of the selected remedy.
Comment: The worst case scenarios used in the risk assessment
combine many worst-case assumptions and may generate "risk" that
is so extreme that it is unrealistic and not applicable to any one
individual. While the worst case estimate appears to be properly
characterized, the "roost probable case scenario" was only adjusted
for average concentrations in media but not average exposures.
Response: This document was conducted in accordance with EPA Risk
Assessment Guidance for Superfund and the NCP using the concept of
a reasonable maximum exposure (RME). The RME is defined as the
highest exposure that is reasonably expected to occur at a site.
The intent of the RME is to estimate a conservative exposure case
(i.e. well above the average case) that is still within the range
of possible exposures.
Comment: The soil parameters assumed in the risk assessment for
purposes of modeling PCB volatilization are inconsistent and
unrealistically conservative.
Response: The PCB volatilization model is consistent with EPA's
Development of Advisory Levels for Polychlorinated Biphenyls (PCBs)
Cleanup.
Comment: The estimates of volatilization rates do not reflect
recent scientific literature regarding physical/chemical parameters
-------
79
for PCBs and, thus, provide estimates of volatilization that are
likely to overestimate actual volatilization.
Response: The PCB volatilization model is consistent with EPA's
Development of Advisory Levels for Polychlorinated Biphenyls (PCBs)
Cleanup.
Comment: Some of the data and assumptions used to estimate
systemic dose are more conservative than usually used by EPA and
are not warranted based on available data.
Response: The factors used to estimate dose in the risk assessment
are consistent with EPA guidance(Superfund Exposure Assessment
Manual, Exposure Factors Handbook) and general practice at
Superfund sites elsewhere.
Comment: Although the risk assessment assumes that congeners of
PCDDs and PCDFs have different carcinogenic potencies, the same
carcinogenic potency was assumed for all PCBs. The possibility for
a threshold for the carcinogenic effects of all PCDDs, PCDFs, and
PCBs should be discussed, as should the effect of such an
assumption on the estimated risks.
Response: EPA's cancer policy is based on linear low-dose response
in the absence of a scientifically demonstrated threshold. This
is the cause for chemicals of concern in this assessment.
Industrial Landfill
Comment: EPA should strongly consider capping the landfill. This
is consistent with the most recent revisions to the NCP which
recognizes that treatment of large landfills is not a feasible
alternative.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
ALUMINUM COMPANY OF AMERICA (ALCOA)
Remedial Alternatives
Comment: EPA's "Draft Guidance on Selecting Remedies for Superfund
sites with PCB Contamination" asserts that there are three primary
options for non-liquid PCBs at concentrations of 50 ppm or greater:
incineration, treatment equivalent to incineration, and disposal
in a chemical waste landfill. There is no separate consideration
-------
80
given to PCBs at concentrations greater than 500 ppm. Why, then,
were other innovative alternatives like bioremediation not
considered? This would be consistent with EPA's policy of
utilizing innovative techniques.
Response: Other PCB treatment technologies will be tested
concurrently with biological destruction so that EPA will have
additional information in the event that biological destruction
proves to be unsatisfactory for treatment of any Site material.
Biological treatment will be used wherever EPA determines it to be
viable. In the event that biological treatment is ineffective for
a certain area of the Site or for certain Site materials, other PCB
treatment technologies may be employed.
Cleanup Levels
Comment: The St. Regis Mohawk Tribe ARARs are admirable goals, but
may not be technically achievable and place an unwarranted burden
on General Motors.
Response: The St. Regis Mohawk Tribe has the authority under
CERCLA to establish ARARs for tribal properties. EPA recognizes
and supports these ARARs at the Site. However, based on limited
previous experience at other Superfund sites and federal projects,
sediment dredging to 0.1 ppm PCBs may be technically impracticable.
Therefore, during sediment dredging in Turtle Creek, EPA will
attempt to meet the Tribal ARAR of 0.1 ppm PCBs. Where it is
technically impracticable to achieve the Tribal sediment standard,
EPA will need to waive this ARAR.
Industrial Landfill
Comment: The proposed excavation of the Industrial Landfill is
inappropriate. Excavation of the landfill will increase estimated
cancer risks in both the long and short terms because of
difficulties in implementing this alternative. A synthetic
composite cap represents a better remedial alternative.
Considering this, the expenditure of nearly $200,000,000 for
excavation seems unwarranted.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
-------
81 .
Comment: A waiver of ARARs for the Industrial Landfill is
appropriate when one considers that the current risks posed by the
landfill are within accepted EPA guidelines.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
Comment: ALCOA recommends that a synthetic composite cap and
ground water collection and treatment be utilized for the
Industrial Landfill. EPA's baseline risk assessment reveals a
plausible upper bound estimated cancer risk for this Site that is
well within EPA's acceptable criteria. Additionally, EPA's "Draft
Guidance on Selecting Remedies for Superfund Sites with PCB
Contamination" allows landfill closure as an acceptable alternative
to excavation and treatment. This approach takes into account the
anticipated use of the Site once the alternative is implemented.
Response: EPA has deferred selection of a remedial alternative for
the Industrial Landfill and the East Disposal Area to reevaluate
Industrial Landfill and East Disposal Area data, better factor
community concerns into its decision-making process for the
Industrial Landfill, and evaluate the impact of new federal
guidance on Superfund sites which are contaminated with PCBs. EPA
will consider this comment when developing a Proposed Plan for the
Industrial Landfill.
V. REMAINING CONCERNS
Concerns raised by the community regarding remedial action and
design activities at the Site will continue to be important
community issues throughout the remedial design phase.
Interest by the St. Regis Mohawk Reservation which abuts the Site,
Canadian citizens and local U.S. residents, especially G.M.
workers, is likely to continue at the already high level and may
increase even further once remedial design activities begin. Area
residents should be kept fully informed of the status of remedial
activities throughout this phase in order to dispel public concern.
Suggestions by several interested citizens about EPA coordinating
with a Citizens Advisory Group should be considered during the
remedial design and second operable unit RI/FS.
-------
APPENDIX A
EPA'S PROPOSED PLAN
-------
Snperfond Proposed PL
\
SZEPA
Region 2-
General Motors Corporation
Central Foundry Division
St Lawrence County, Massena, New York
-March 1990
ANNOUNCEMENT
OF THE PROPOSED PLAN
This Proposed Plan identifies the U.S.
Environmental Protection Agency's (EPA's)
preferred option for cleaning up the contaminated
soils, lagoon sludges, river sediments, wetlands,
and groundwater associated with the General
Motors Corporation Central Foundry Division
f G.M/) Superfund Site (the 'Site') located in St.
Lawrence County, Massena, New York. In
addition, the Plan includes summaries of other
alternatives which could be used to remediate the
Industrial Landfill at the Site.
COMMUNITY ROLE
IN THE SELECTION PROCESS
The Proposed Plan is being distributed to solicit
public comment regarding EPA's preferred option
as well as the other alternatives which could be
used to clean up the Site. In addition, EPA is
soliciting comment on alternatives presented for
cleaning up the Industrial Landfill at the Site. At
this time, EPA has not specified a preferred
alternative for the Industrial Landfill. The public
comment period will begin on March 21,1990 and
continues until May 21,1990.
EPA, in consultation with the New York State
Department of Environmental Conservation
(-NYSDEC7) and the St. Regis Mohawk Tribe.
will select a remedy for the Site only after the
public comment period has ended and the
information submitted during this time has been
reviewed and considered.
EPA is issuing this Proposed Plan as pan of its
public participation responsibilities under section
117(a) of the Comprehensive Environmental
Response, Compensation and Liability An
(CERCLA). Detailed information on all of the
material discussed here may be found in the
November 1989 Feasibility Study (FS) report and
other documents contained in the administrative
record file for this Site. These documents,
including the Remedial Investigations (RIs) and
the Baseline Risk Assessments, are available at the
following locations:
US. Environmental Protection Agency
Region II Office
26 Federal Plaza, Room 747
New York, New York 10278
SL Regis Mohawk Indian Reservation
Community Building
vHogansburg, New York 13655
Massena Public Library
14 Glenn Street
Massena, New York 13662
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EPA, in consultation with the NYSDEC tad the
St Regis Mohawk Tribe, may modify the preferred
Alternative or select another response action
presented in this Plan and the PS report based on
new information or public comments. Therefore,
the public is encouraged to review and comment
on fji the alternatives identified here.
i
Written comments can be sent to:
SITE LOCATION MAP
'Lisa
Project 'Manajef;:;f |:||
U.S. Environmetrtal'::f:|ll
.Protection'Agency ff&il
26 Federal Plaza, Room 747
Hew York, New York 10278
EPA wfll hold a public meeting at 7:30 pjn. on
April 25,1990 at the St. Regis Mohawk School in
Hogansburg, New York, EPA will present the
findings of the PS and the preferred remedy for
the Site. All interested persons are encouraged
to attend to ask questions and provide comments.
SITE
HISTORY
The Site which includes an active General Motors
manufacturing plant is located in Massena, New
York, in St. Lawrence County. The G.M, facility
is bordered on the north by the SL Lawrence
River, on the east by the St. Regis Mohawk
Indian Reservation, on the south by the Raquette
River and on the west by the Reynolds Metals
Company and property owned by Conrail. CM.
has operated an aluminum casting plant at the
Site since 1959.
From 1968 to 1980, polychJorinated biphenyls
(*PCBs*) were a component of the hydraulic fluids
used in the diecasting machines. PCBs provided
protection against fire and thermal degradation in
the high temperature environment of the
diecasting machines. G.M. periodically landfilled
sludges containing PCBs and other hazardous
substances in on-site disposal pits. The Sue
consists of several areas.
The North and East Disposal Areas and the
Industrial Landfill contain soil, debris, and sludge
The Four Industrial Lagoons contain 350,001
gallons, 500,000 gallons, 1.5 million gallons and 10
million gallons of liquids, sludges, and solids. The
-------
Site abo includes contaminated Mdimeats and
associated wetlands of the SL Lawreone River, the
Raquene River and Turtle Greek (formerly called
tie unnamed tributary on the St Regis Mohawk
Reservation), contaminated aoO on the St. Regis
Mohawk Indian Reservation and on the banks of
the St. Lawrence and Raqnette Rivers,
contaminated soil on CM. property not associated
with the specific disposal areas already mentioned,
and contaminated groundwater associated with the
Site. As a gross estimate, the Site contains
approximately 823,000 cubic yards (approximately
equal to 823,000 tons) of material contaminated
with PCBs at concentrations above ten parts per
million (ppm).
The Site was placed on the Superfund National
Priorities List (*NPL*) in September 1983 as a
result of GM.'t past waste disposal practices.
G.M. indicated a willingness to perform the
Remedial Investigation and Feasibility Study
(RITS) for the Site. On April 16,1985, EPA and
G.M. entered into an Administrative Order on
Consent (Index No. IICERCLA-50201) for G-M/s
performance of the RI/FS. Phase I and Phase II
RI reports were submitted to EPA in May 1986
and May 1988, respectively.
G.M. performed additional river campling in
February 1989, and submitted a report on the
additional sampling to EPA in May 1989. On
June 9,1989, EPA approved the RI report, which
consists of the draft RI report, the Phase D RI
report and the sediment sampling report, for the
Site. The RI report delineated those areas in
need of remediation throughout the Site. G.M.
submitted the FS report to EPA in November
1989.
SCOPE OF THE RESPONSE
ACTION
The FS for the Site focuses on reviewing and
evaluating alternative methods for remediating all
of the contaminated areas at the Site. The overall
objective of the cleanup is to reduce the PCB and
other contaminant concentrations to levels
protective of human health and the environment.
SUMMARY OF SITE RISKS
EPA and G-M.'s consultant conducted
independent analyses to estimate the health
problems that could result if the contamination at
the G.M. Massena Site were not cleaned up. This
analysis fc referred to as a baseline risk
assessment
The RI reports show that there are four major
contaminants at the Site PCBs, poryaromatic
hydrocarbons (PAHs), phenols and volatile organic
compounds (VOCs). At the G.M. Site, PAHs,
phenols, and VOCs were found at much lower
concentrations and in fewer samples than PCBs.
Therefore, the primary contaminant of concern at
the Site is PCBs and PCBs were used by EPA in
developing its baseline risk assessment. Although
this Proposed Plan focuses on PCBs, the other
major contaminants at the Site wfl] also be
addressed during the cleanup of the Site.
In conducting the risk assessment, the focus was
on the health effects that could result from
ingestion of fish and wildlife containing PCBs,
direct ingestion of and contact with PCB
contaminated soils, and ingestion of surface water.
The exposed populations include the residents of
the Su Regis Mohawk Indian Reservation and
workers at the Site.
PCBs tend to accumulate in human and animal
tissue and are classified by EPA as probable
human cancer causers. The major organs affected
by PCBs are the liver and the skin. PCBs have
produced liver tumors in laboratory studies of rats.
In addition, PCBs cause harmful reproductive
effects in certain animals at low levels and may
cause similar results in humans.
EPA's baseline endangerment assessment for the
Site indicates that the most significant public
health risk is from ingestion of fish and wildlife
which have been exposed to PCB contaminated
sediments and soils. These risks are on the order
of 2 z IV3, which indicates that, as a plausible
upper bound, an individual has a two in one
hundred chance of developing cancer as a result
of fish or wildlife-related exposure to PCBs. Risks
-------
from contact with tod mgestion of PCB
contaminated sofl were on the order of 1 z 10 "*,
which is a one in one million chance of
developing cancer. EPA considers risks in the
range ICTto 10"* to be generally acceptable; risks
from fish and wildlife ingesu'on are not within this
range. Ingestion of fish and wildlife also posed
much higher risks for Don-cancer effects than did
other exposure pathways.
Stated another way, PCB contaminated sediments
and soils which are eaten by fish and wildlife pose
the greatest threat to human health at the Site,
while direct human contact with PCB
contaminated soils poses a much lower risk to
health. Thus, actual or threatened releases of
hazardous substances from this Site, if not
addressed by the preferred alternative or one of
the other active measures considered, may present
a current or potential threat to public health,
welfare, or the environment.
CLEANUP LEVELS
FOR THE SITE
EPA has chosen cleanup levels for PCBs and
other chemicals at this Site based on a number of
factors. They include requirements of federal and
State laws and regulations and requirements of the
St. Regis Mohawk Tribe for Reservation lands.
The levels are chosen to be protective of human
health and the environment, and vary according to
where the contamination occurs.
The cleanup level chosen for PCBs in St.
Lawrence river sediments is 2 ppm, based on
federal guidance. The cleanup goal chosen for
sediments in the Raquette River and Tunic Creek
is 0.1 ppm PCBs, based on Tribal requirements.
The cleanup level for son and sludges on G.M.
property is 10 ppm PCBs, based on federal and
State policies. The cleanup level for soils on the
Reservation is 1 ppm PCBs, based on Tribal
requirements. Groundwater will be treated to 0.1
pans per billion (ppb) PCBs, based on State
requirements. Other contaminants in gronndwaier
wflJ be treated to levels which comply with federal
and State requirements.
SOIL, SLUDGE,
SEDIMENT TREATMENT
TECHNOLOGIES EVALUATED FOR
THE G.M. SITE
The FS identified several technologies which could
be used to treat PCBs and other contaminants in
soils, sludges and sediments in the various areas
at the Site.
Six methods of treatment for soils, sludges and
sediments were examined: biological destruction,
chemical destruction, chemical extraction, thermal
destruction (incineration), thermal extraction and
solidification. Each of these treatment
technologies has been tested at other hazardous
waste sites. Although some have been found to
be effective in treating PCBs, each technology,
with the exception of thermal destruction, would
require a pilot or field testing program before
full-scale use at this Site. Thermal destruction
would require trial incinerator burns to assure
correct operating conditions.
Biological destruction of PCBs using scientifically
engineered bacteria was examined and found to be
a feasible alternative for the remediation of
contaminated soils, sediments, and sludges. The
most likely biological treatment would involve
processing in above-ground tanks. Bacteria and
nutrients are added to the tanks along with waste.
If successful, biological treatment changes PCBs
to less toxic materials, including carbon dioxide
and water. Biological treatment is not thought to
be an effective treatment method for materials
with PCB concentrations greater than 500 ppm.
Chemical destruction uses the KPEG chemical
dechlorination process. In this process, PCB-
contaminated materials are reacted with potassium
polyethylene grycol, or KPEG, to alter the
molecular structure of the PCBs.
Chemical extraction using the B.E.S.T. (Basic
Extractive Sludge Treatment) process was also
evaluated. This technology involves concentrating
large volumes of PCBs into smaller volumes of an
-------
ofly extract Hie extraa mast then be disposed.
Hie B.ES.T. process utilizes triethylamine,
solvent, ID extraa PCBs from the solids.
Hie thermal destruction alternative involves the
incineration of excavated and dredged material
One type of incinerator that has been used at
other hazardous waste sites fc the rotary kilo
incinerator.
Thermal extraction of the excavated solids is
another treatment technology applicable to the
Site. This technology involves the removal of
organic from a solid waste stream under lower
temperature conditions than those of incineration.
The organic contaminants are not destroyed
during this extraction process; rather mother
treatment process would be necessary to
permanently destroy the organic material
SoUdlfksflon, or chemical fixation, of the
excavated material involves the physical
encapsulation, chemical reaction, or both, of the
excavated material A commercially available
additive is mixed with the waste to create a solid
material This solid material can then be
disposed. Solidification would serve to limit the
teachability, or leaking*, of the PCBs into the
environment.
The treatment options discussed above can be
used separately or in combination with each other
to treat soils, sludges and sediments at the Site.
For example, EPA has evaluated a mixed
treatment alterative which involves incineration
of only those scuds contaminated with PCBs over
500 ppm and biological treatment of solids below
500 ppm.
After treatment by any of the above methods, the
treated material (including soils, sediments, and
sludges) would be backfilled into the excavated
areas located on the G.M. property. Those soils
excavated from the St. Regis Reservation and river
sediments would also be backfilled on the G.M.
property following treatment. The excavated areas
on the SL Regis Reservation would be restored to
their original condition using clean fill, if
necessary.
SUMMARY
OF
ALTERNATIVES
The remedial alternatives are presented by area
of the Site which they address. In addition to
treatment technologies, the FS also addressed a
"no action' alternative, containment technologies,
and groundwater alternatives which are discussed
below.
AREA It CONTAMINATED RTVER AND
TRIBUTARY SEDIMENTS
Approximately 50,000 cubic yards of contaminated
river sediments with PCB concentrations above 2
ppm are located in the St. Lawrence River,
Raquette River and Turtle Creek, The three
surface water bodies are collectively referred to as
the river system. Some of these sediments lie in
wetland areas along the river system. The highest
PCB concentration detected in the river sediments
is 5,700 ppm.
The possible remedial alternatives for the river
system include: no action, in-place containment
of the river sediments, and dredging of sediments
with on-site treatment (using one of the
technologies outlined above).
No Action for the River Sediments
CERCLA requires that the *no action* alternative
be considered at Superfund sites. This alternative
consists of allowing the contaminated river
sediments and wetlands to remain in their present
state in the river system.
In-Piace Containment of River Sediments
This alternative (also called in-situ containment)
consists of the placement of a graded aggregate
cover over the contaminated river sediments (see
figure). Annual inspections to determine the
cover's effectiveness in containing the PCBs and
other hazardous substances and preventing the
-------
movement of these hazardous substances into the
water column would be performed. This
alternative also provides for the necessary
maintenance of the cover.
filter Loyer Rock Riprop
Woter Level
niter Fobric
In-Situ Containment
of River Sediments
Sediment Dredpng and On-Site Treatment
This alternative involves dredging the
contaminated sediments in the river system and
wetlands. Prior to remediation, a silt curtain
would be installed to minimize rcsuspension of
sediment during dredging activities. In addition,
a sheet pile wall would be installed on the river
side of the dredging area to serve as the primary
sediment control device.
After dredging, the material would be treated on-
cite using one or a combination of the six
treatment methods described above. Any water
resulting from the dredging process would be
treated in an appropriate wasiewater treatment
system. The treated sediments would be backfilled
into areas located on the G.M. property. The silt
curtain and sheet pile wall would be removed
after completion of the dredging operation and
the riverbed, riverbanks, and wetlands restored.
COST ANALYSIS OF REMEDIAL ALTERNATIVES-
AREA 1: CONTAMINATED RIVER AND TRIBUTARY SEDIMENTS
No Action
Containment
Construction*
Cost fSM)
60(JK)
33
Dredging and Treatment
Biological Treatment 7.7
Chemical Destruction 29
Chemical Extraction 22
Thermal Destruction 32
Annual Operation**
& Maintenance (SKAr)
127
30
12
12
12
12
Total
Present Worth
1.2
3.6
7.7
29
22
32
Biological Treatment of Sediments with PCBs Concentrations Between 2 ppm and 500 ppm and
Thermal Destruction of Sediments with PCB Concentrations Greater than 500 ppm
2L5 24 21.5
Thermal Extraction 29
Solidification 17
12
12
29
17
Capital costs include fixed costs (costs associated with equipment mobilization and site
preparation) and non-fixed costs (costs associated with treatment of a specific disposal area).
Power costs for treatment alternatives have been included as capital costs.
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AREA 2; NORTH AND EAST DISPOSAL
AREAS. CONTAMINATED SOILS ON THE ST.
REGIS MOHAWK RESERVATION.
CONTAMINATED SOILS ON G.M. PROPERTY
The North and East Disposal Areas consist of
approximately 225,000 cubic yards of soils, debris
and sludges with PCB concentrations greater than
10 ppnx The highest PCB concentrations detected
in the North and East areas are 31,000 ppm and
41,000 ppm, respectively. The maximum phenol
concentration detected in the East area is 11,000
ppm. There are approximately 15,000 cubic yards
of tofl on the Mohawk Indian Reservation
contaminated with PCBs at concentrations above
1 ppm. The highest PCB concentration delected
on the Reservation is 48 ppm. There are also
approximately 40,000 cubic yards of soil in various
areas on the G.M. property which are
contaminated with PCBs at concentrations greater
than 10 ppm. This includes soils in the area
adjacent to the Raqoette River as well as other
areas on the G.M. property.
The following alternatives apply to the
contaminated material in these areas: no action,
capping, solids excavation and on-site treatment
(using one of the alternatives outlined above), and
excavation of the material with on-site disposal
No Action for the North and East Disposal Areas.
Reservation Soils and Soils on G.M. Property
CERCLA requires that the *no action* alternative
be considered at Superfund Sites. The North and
East Disposal Areas would not receive additional
waste materials; however, no remediation would
occur at any of these areas under this alternative.
Capping of the North and East Disposal Areas.
Reservation Soils, and Soils on G.M. Property
This alternative has been subdivided into two
potential capping methods: a soil cover and a
synthetic composite cover. The soil cover
alternative involves excavating the contaminated
soils on the St. Regis Mohawk Reservation and
the contaminated soils adjacent to the Raquette
River and in other areas on the CM. property
and consolidating these excavated materials within
the East Disposal Area. The North and East
Disposal Areas would then be graded to provide
surface drainage, compacted and covered with one
layer of a synthetic material known as geotextile,
two feet of day and six inches of topsoil.
Revegetation of the area and groundwater
monitoring would complete the remediation.
The composite cover alternative also consists of
excavating the contaminated soils on the St. Regis
Mohawk Reservation and the contaminated soils
adjacent to the Raquette River and in other areas
on the CM. property and consolidating these
excavated materials within the East Disposal Area.
Grading and compaction of the North and East
Disposal Areas would then be performed. The
North and East Disposal Areas would then be
capped using the following materials: three feet
of clay, one layer of flexible membrane liner, one
layer of drainage material, one layer of geotextile,
eighteen inches of rooting zone soil and six inches
of topsofl. Revegetation of the North and East
Disposal Areas and groundwater monitoring would
complete the remediation.
Excavation and On-Site Treatment of Solids in
the North and East Disposal Areas. Reservation
Soils, and Soils on G.M. Property
This alternative consists of excavating the
contaminated soils, debris and sludges in the
North and East Disposal Areas, on the
Reservation, and on the G.M. property and
treating them with one or a combination of the
six treatment methods discussed above. The
treated material would then be backfilled into
excavated areas located on the G.M. property.
The excavated areas on the Reservation would be
restored with dean fill.
Excavation and On-Site Disposal of Solids in the
North and East Disposal Areas. Reservation Soils.
and Soils on the C.M. Property
This alternative consists of excavation of
contaminated soils, debris and sludges in the
North and East Disposal Areas, on the
Reservation, and on the G.M. property followed
by placement of these materials in an on-site
landfill located on G.M-'s property. The excavated
areas on the Reservation would be restored with
dean fill. Long-term monitoring of the disposal
area would be performed.
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COST ANALYSIS OF REMEDIAL ALTERNATIVES
AREA 2; NORTH AND EAST DISPOSAL ARIAS. CONTAMINATED SOILS ON THE ST. REGIS
MOHAWK RESERVATION. CONTAMINATED SOILS ON G.M^PROPERTY
Capping
Soil Cover
Composite Cover
Cost fSM)
4.4
Solids Excavation ud Treatment
Biological Treatment 45
ChemicaJ Destruction 118
Chemical Extraction 85
Thermal Destruction 136
Annual Operation"
A Maintenance (SKfrr)
185
185
102
165
165
165
Total
Present Worth f5Nf>
6.1
8J
45
118
85
-136
Biological Treatment of Solids with PCB Concentrations Below 500 ppm and Thermal Destruction of
Solids with PCB Concentrations Greater than 500 ppm
86 267 87
Thermal Extraction 118 165 118
Solidification 60 165 60
On-SIt* Disposal
29
192
31
Capital costs include fixed costs (costs associated with equipment mobilization and site
preparation) and non-fixed costs (costs associated with treatment of a specific disposal area).
Power costs for treatment alternatives have been included as capital costs.
AREA 3: INDUSTRIAL IANDFTLL
Approximately 424,000 cubic yards of soil, debris
and sludges contaminated with PCBs it
concentrations above 10 ppm are located in this
area. The highest PCB concentration detected in
the Industrial Landfill is 4300 ppm. No action,
capping, solids excavation and on-site treatment
(using one of the alternatives outlined above), and
excavation of the 'landfill with subsequent
redisposal in an on-site disposal area are potential
remedial alternatives for this area.
No Action for the Industrial Landfill
CERCLA requires that the 'no action* alternative
be considered at Superfund sites. The interim
cover already installed on the Industrial Landfill
by G.M., at EPA's and New York State's request,
would remain in place, with no upgrading
performed.
Capping of the Industrial Landfill
This alternative has been subdivided into two
potential methods of containment: a soil cover
and a synthetic composite cover. Under the soil
cover option, the Industrial Landfill would be
graded, compacted and covered with one layer of
a synthetic material known as geotextile, two feet
of clay and six inches of topsoiL Revegetation of
the area would complete the remediation.
The composite cover alternative also includes
grading and compaction of the Industrial Landfill.
The Industrial Landfill would then be capped
using the following materials: three feet of clay,
one layer of flexible membrane liner, one layer
drainage material, one layer geotextile, eighteen
inches of rooting zone soil and six inches of
topsoil. Revegetation of the Industrial Landfill
and groundwater monitoring would complete the
remediation.
-------
Industrial T-"Klfill Solids Excavation and On-Site Industrial L
Treatment Disposal
This alternative consists of excavating the
contaminated soils, debris and sludges in the
Industrial Landfill and treating them with one of
the six treatment methods discussed above. The
treated material would then be backfilled into
excavated areas located on the CM. property.
Solids Excavation with On-Site
This alternative consists of excavation of
contaminated sofl, debris and sludges in the
Industrial 1*nAKU followed by placement of these
materials in an on-site engineered landfill located
on G.M/s property. Long-term monitoring would
be performed.
COST ANALYSIS OF REMEDIAL ALTERNATIVES-
AREA 3: INDUSTRIAL LANDFILL
Capping
Sofl cover
Composite cover
Construction*
Cost
13
3.5
Solids Excavation and Treatment
Biological Treatment 61
Chemical Destruction 176
Chemical Extraction 125
Thermal Destruction 202
Annual Operation*'
& Maintenance (SK/rr)
185
185
102
165
165
165
Total
Present Worth fSNf>
3
52
61
177
126
203
Biological Treatment of Solids with PCB Concentrations Between 10 ppm and 500 ppm and Thermal
Destruction of Solids with PCB Concentrations Greater than 500 ppm
179 267 180
Thermal Extraction 176
Solidification 87
On-Site Disposal 32
165
165
192
177
Capital costs include fixed costs (costs associated with equipment mobilization and site
preparation) and non-fixed costs (costs associated with treatment of a specific disposal area).
Power costs for treatment alternatives have been included as capital costs.
-------
AREA 4: INDUSTRIAL LAGOONS
The sludges contained in the four lagoons
(350,000 gallon, 500,000 gallon, LS million gallon
and 10 million gallon) may be remediated by one
of the following remedial alternatives: DO action,
solids and sludge excavation and on-site treatment
(using one of the treatment alternatives outlined
above) and solids and sludge excavation with
disposal in an on-site disposal area. The lagoons
contain approximately 91,000 cubic yards of
sludges and soils contaminated with PCBs at
concentrations above 10 ppra, primarily in the
350,000 gallon lagoon. The highest PCB
concentration detected in the lagoons is 750 ppm,
while the highest phenol concentration detected
B 26,000 ppm. VOCs and metals were also
detected at levels above background, primarily in
the 350,000 gallon lagoon.
No Action for the Lagoons
CERCLA requires that the *no action* alternative
be considered at Superfund sites. The 500,000
gallon and 10 million gallon lagoons would
continue to function as part of G.M's wastewater
treatment system, but no remediation would occur.
The 1,500,000 gallon and 350,000 gallon lagoons
would remain inactive and would not receive
additional waste materials; however, DO
remediation would occur at the lagoons.
Lagoon Solids Excavation and On-Site Treatment
This alternative consists of excavating the
contaminated solids, including underlying soil, and
sludges in the lagoons and treating them with one
of the six treatment methods discussed above.
Prior to excavation, liquids in the lagoons would
be removed, treated and discharged. The treated
material would then be backfilled into excavated
areas located on the GM. property.
La poo n Solids Excavation with On-Site Disposal
This alternative consists of excavation of
contaminated solids, including underlying soils
and sludges in the four lagoons, followed by
placement of these materials in an on-site landfiU
located on C.M's property. Prior to excavation,
liquids in the lagoons would be removed, treated
and discharged. The excavated areas would be
backfilled if needed. Long-term monitoring of the
groundwater would be performed.
COST ANALYSIS OF REMEDIAL ALTERNATIVES
AREA 4: INDUSTRIAL "LAGOONS
Construction*
Cost
Solids and Sludge Excavation and Treatment
Biological Treatment
Chemical Destruction
Chemical Extraction
Thermal Destruction
24
42
31
47...
Annual Operation**
& Maintenance (SK/vr)
102
165
165
165
Total
Present Worth fSM)
24
42
31
47
Biological Treatment of Solids and Sludges with PCB Concentrations Between 10 ppm and.500 ppm and
Thermal Destruction of Solids and Sludges with PCB Concentrations Greater than 500 ppm
47*** 267 48
Thermal Extraction 42 165 42
Solidification 22 165 22
On-SIte Disposal 21 192 23
Capital costs include fixed costs (costs associated with equipment mobilization and site
preparation) and non-fixed costs (costs associated with treatment of a specific disposal area).
' Power costs for treatment alternatives have been included as capital costs.
See cost discussion on page 19 for further explaination of these costs.
10
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AREAS; GROUNDWATER
PCBs were detected it concentrations up to 13
ppm in groundwater associated with the Site.
VOCs were also detected in tome froondwater
samples. The highest levels of PCB contamination
were detected in samples of groondwater
associated with the Industrial Landfill.
Groundwater from the Site discharges to the St.
Lawrence River. Groundwater may be remediated
by one of the following remedial alternatives: BO
action, containment of the groundwater and
extraction and treatment of contaminated
groundwater.
No Action for Groundwater
CERCLA requires that the 'no action* alternative
be considered at Superfund sites. No groundwater
remediation would occur, however, groundwater
monitoring for a 30-year period would be
performed. Groundwater monitoring costs are
included in the cost estimates for the no action
alternative.
Croundwater Containment
A subsurface slurry wall consisting of either a
soil/'bemonite mixture or a cement/bentonite
mixture would be constructed to a depth sufficient
to achieve a hydrologic barrier. The slurry wall
would be located hydrologicalry downgradient of
the Site to prevent the flow of groundwater from
the Site to the St. Lawrence River and the SL
Regis Mohawk Indian Reservation. Observation
wells would be placed inside and outside of the
slurry wall's perimeter to detect possible
infiltration and determine the integrity of the
slurry wall Pumping wells would also be installed
on the G.M. side of the slurry wall to control the
flow of groundwater. The water from the
pumping wells would be treated in a wasiewater
treatment system, with discharge to the SL
Lawrence River.
Groundwater Recovery and Treatment
This alternative involves the construction of
extraction wells or trenches located hydrologicalty
downgradient of the Site on G.M. property. The
contaminated groundwater would be extracted
from the aquifer and pumped to a wastewater
treatment plant for treatment by a combination of
air stripping to remove the volatile organic
compounds and carbon adsorption to remove
PCBs from the groundwater. After treatment, the
water would be discharged to the St. Lawrence
River.
COST ANALYSIS OF REMEDIAL ALTERNATIVES
AREAS: CROUNDWATER
Construction*
Cost fSMl
Groundwater
Containment
Groundwater Recovery
and Treatment 2
Annual Operation**
& Maintenance fSK/rrt
167
197
Total
Present Worth (SM)
7.6
' Capita! costs include fixed costs (costs associated with equipment mobilization and site
preparation) and non-fixed costs (costs associated with treatment of a specific disposal area).
Power costs for treatment alternatives have been included as capital costs.
11
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EVALUATION OF
ALTERNATIVES
Nine criteria were used to evaluate the remedial
alternatives. The criteria are described below.
The first two criteria, protection af human health
and the environment and compliance with
applicable or relevant and appropriate
requirements are considered by EPA to be
threshold criteria which most be met by each
alternative.
Overall protection of bnmin health and the
environment addresses whether or not a remedy
provides adequate protection and describes bow
risks posed through each pathway are »Htnmat«*i
reduced, or controlled through treatment,
engineering controls, or institutional controls.
Compliance with ARARs addresses whether or
not a remedy will meet all of the applicable or
relevant and appropriate requirements (ARARs)
of federal. Tribal and State environmental statutes
and/or provides a basis for an ARAR waiver.
Long-term effectiveness refers to the abfliry of a
remedy to maintain reliable protection of human
health and the environment over time once
cleanup goals have been met.
Reduction oTtoridry. mobility or volume addresses
the performance of the remedy in terms of using
treatment to reduce the toricity, mobility, or
volume of the contaminants of concern in the
environment.
Short-term effectiveness addresses the period of
time needed to achieve protection, and any
adverse impacts on human health that may be
posed during the construction and implementation
period untO cleanup goals are achieved.
Implementabiliry refers to the technical and
administrative feasibility of implementing a
remedy, including the availability of materials and
services required to implement a particular option.
Cost includes estimated capital and operation and
maintenance costs of the remedy, and the net
present worth cost of the alternatives.
State and Tribe acceptance indicates whether,
based on their review of the R1TS and Proposed
Plan, the State and Tribe concur with, oppose, or
have no comment on the preferred alternative at
the present time.
Community acceptance will be assessed in the
Record of Decision following a review of the
public comments received on the RI/FS report and
the Proposed Plan.
EPA'S PREFERRED
ALTERNATIVES
EPA's preferred alternative includes a combination
of treatment methods for the various areas of the
She.
AREA 1; CONTAMINATED RIVER AND
TRIBUTARY SEDIMENTS
The preferred remedial alternative for the river
system is dredging of the sediments with on-site
treatment The cleanup level for PCBs in
sediments in the St. Lawrence River will be 2
ppm. This cleanup level is based on EPA's draft
sediment quality criteria document, as well as on
an estimation of residual risks from sediments at
2 ppm. The cleanup goal for sediments in the
Raquette River and in Turtle Creek is 0.1 ppm.
However, the technical limitations associated with
the dredging process may make it impossible to
achieve 0.1 ppm in these sediments.
Sediments with PCB concentrations above 500
ppm will be incinerated. Sediments contaminated
with PCBs below 500 ppm will be biologically
treated to destroy PCBs.
Monitoring wfll be conducted during dredging to
determine the efficiency of the process as well as
to monitor potential impacts of dredging. This
will include monitoring of the St. Regis Mohawk
Reservation public water supply since the water
intake for this system is downstream of the
sediment dredging area at the Site.
12
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AREA fc NORTH AND EAST DISPOSAL
AREAS. RTSERVATION SOILS. AND SOIi" ON
C.M. PROPERTY
The preferred remedial alternative for these areas
b solids excavation and on-cite treatment. The
cleanup level for all soils, stodge, and debris in
the Nona and East Disposal Areas and on the
CM. property is 10 ppm PCBs. This level is
based, in pan, on the Toxic Substances Control
Act (TSCA) PCS spOJ cleanup policy and on
requirements submitted by New York State. The
cleanup level for soils on the Reservation is 1
ppm PCBs. This level is based on requirements
submitted by the St. Reps Mohawk Tribe.
AH sons, sludge, and debris with PCS
concentrations above 500 ppm will be incinerated.
Material contaminated with PCBs below 500 ppm
will be biologically treated to destroy PCBs.
AREA 3; INDUSTRIAL LANDFILL
As pan of its decision-making process, EPA is
soliciting comment on the alternatives presented
for cleaning up the Industrial Landfill EPA will
propose an alternative after evaluating public
comment on the alternatives presented in this
Plan.
Costs (presented on previous pages in tabular
form) for capping or excavating and treating the
landfill range from $3,000,000 to $202,000,000.
At present, the Industrial Landfill poses an
estimated 19 z 10** cancer risk to the adult Indian
population. After installation of a composite
cover, it is estimated that the led us trial Landfill
would pose a 19 z 10"* cancer risk to the adult
Indian population. After excavation and
incineration of the Industrial Landfill, cancer risks
to the adult Indian population would be
approximately 3.7 x 10". This risk could be
lowered through relocation of nearby residents
during incineration. Risks to Indian children are
lower than risks to Indian adults.
AREA 4: INDUSTRIAL LAGOONS
The preferred remedial alternative for the lagoons
is solids and sludge excavation with on-site
treatment The cleanup level for the lagoons is
10 ppm PCBs. This level is based, in part, on the
TSCA PCS apQ] cleanup policy and on
requirements submitted by New York State.
Excavated material wfll be pre-treated, as
necessary, to remove metals. Material
contaminated with PCB concentrations above 500
ppm will be incinerated. Material contaminated
with PCBs above 10 ppm and below 500 ppm will
be biologically treated to destroy PCBs. If
biological treatment does not result in PCB
concentrations below 2 ppm, the lagoon material
wfll be further treated to achieve 2 ppm by other
methods such as chemical extraction or thermal
destruction.
AREA ft CROUNDWATER
The preferred remedial action for groundwater is
groundwater recovery and treatment.
Groundwater will be treated to PCB levels of 0.1
ppb, based on State requirements. Other
contaminants will be treated to levels which
comply with federal requirements and State
requirements which are more stringent than
federal requirements.
COSTS ASSOCIATED WITH THE PREFERRED
ALTERNATIVE
The estimated total capital cost of EPA's
preferred alternative is $135,000,000. Annual
operation and maintenance costs are $464,000 for
the first six years and $197,000 for the following
24 years. The total present worth of the
preferred alternative is $138,000,000. This is
based on a 10% annual interest rate, a 30 year
period of performance for groundwater recovery
and treatment and a 6 year period of performance
for solids treatment. These costs do not include
costs associated with remediation of the Industrial
Landfill
TESTING OF BIOLOGICAL TREATMENT
The contaminated soils, sludges, debris and
sediments at the Site will be excavated and
dredged, with treatment by a combination of
thermal and biological destruction. Those
materials at levels over 500 ppm PCBs will be
incinerated, while those materials at
concentrations of less than 500 ppm PCBs wiU
be treated by a biological degradation process.
13
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In order to determine the effectiveness of the
innovative biological degradation process at the
G.M. Site, pilot trea?abiliry studies wfl] be
performed. At the conclusion of the treatability
studies, EPA will evaluate the effectiveness of
biological treatment for the materials at
concentrations below 500 ppm PCBs. For all
areas, except the Industrial Lagoons, biological
treatment must result in a PCB concentration of
less than 10 ppm for the treatment to be
considered successful. For Industrial Lagoon
material, biological treatment must result in a
PCB concentration of less than 2 ppm for the
treatment to be considered successful. If
biological treatment cannot achieve these goals,
PCB contaminated material may be treated with
an alternative treatment technology such as
chemical extraction or thermal destruction.
COST ANALYSIS OF PREFERRED ALTERNATIVE-
Construction*
Cost fS\f>
Annual Operation**
tt Maintenance (SK/yrl
Total
Present Worth ftM)
AREA 1: CONTAMINATED RIVER AND TRIBUTARY SEDIMENTS
Sediment Dredging with Biological Treatment of Sediments with PCBs Concentrations Below 500 ppm
and Thermal Destruction of Sediments with PCB Concentrations Greater than 500 ppm
21.5
24
21.5
AREA 2: NORTH AND EAST DISPOSAL AREAS, RESERVATION SOILS, AND SOILS ON G.M.
PROPERTY
Soils, Sludge, and Debris Excavation with Biological Treatment of Solids with PCB Concentrations
Below 500 ppm and Thermal Destruction of Solids with PCB Concentrations Greater than 500 ppm
86
AREA 4: INDUSTRIAL LAGOONS
267
87
Solids and Sludge Excavation with Biological Treatment of Solids and Sludges with PCB Concentrations
Between 10 ppm and 500 ppm and Thermal Destruction of Solids and Sludges with PCB Concentrations
Greater than 500 ppm
47
AREAS: GROUNDWATER
Groundwater Recovery and Treatment
2
TOTAL* 135
267
48
197
464 (6 years)
197 (following 24 years)
4
138
These total costs reflect the cost savings which result from treating areas 1, 2, and 4 at the same
time. See cost discussion on page 19 for further explanation of these costs.
14
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REMEDIATION PROCESS DIAGRAM
BRIEF DESCRIPTION OE PREFERRED ALTERNATIVES FOR SOLIDS
SOLIDS EXCAVATION
E*covolion involves (he rernovol
of contominoted moteriol using
eilher slondord construction
equipment or speciol equipment
adapted to reducing disturbance
of waste.
SEDIMENT DREDGING
Dredging is a special type of
Cfccavolion performed through
water requiring equipment that
may be mounted on a barge if
the water depth exceeds the
reach of construction equipment
ON-SITE TREATMENT
- Thermal eidraclion
solidification.
and destruction
- Biological destruction
- Chemical extraction
and destruction
-------
RATIONALE FOR
RECOMMENDATION
This section briefly describes bow cadi of the
alternatives were evaluated against the Nine
Criteria.
Overall Protection of Hainan Health and (be
Environment
Except for the no action alternative, each of the
alternatives for the various contaminated areas, if
properly operated and maintained, protects human
health and the environment.
Compliance with Applicable, Relevant, and
Appropriate Requirements (ARARs)
Actions taken at any Superfund site must meet all
applicable or relevant and appropriate
requirements of federal, State, and Tribal laws or
provide grounds for waiving these requirements.
The No-Action alternative does not comply with
ARARs.
Major Federal ARARs
The Toxic Substances Control Act (TSCA) is a
federal law which regulates the disposal of PCBs.
In general, depending on the nature of the PCB
containing material and the PCB concentration in
the material, TSCA may require incineration or
disposal in a chemical waste landfill approved for
PCB disposal. PCBs that are required to be
incinerated may also be disposed of by an
approved alternate method that provides PCB
destruction equivalent to incineration. The TSCA
regulations are applicable to the disposal of the
soU, sludges, debris and river sediments once they
have been excavated and dredged during cleanup.
Treatment alternatives for the sludges, soils, and
sediments involve the use of innovative
technologies, such as biological treatment, to treat
those materials with PCB concentrations below
500 ppm. It appears that TSCA regulations would
require that innovative treatment of the Industrial
Lagoon sludges must be equivalent to incineration
and must therefore reduce PCBs to concentrations
no greater than 2 ppm after treatment.
According to EPA's treatment goals for the Site,
any innovative treatment (including biological
treatment) of areas, other than the Industrial
Lagoons, must remove PCBs to concentrations
below 10 ppm. Unless innovative treatment (e,g.,
biological treatment) of PCB contaminated
materials reduces PCB concentrations to levels
below 2 ppm, the residuals from the innovative
treatment process wfll be disposed of in an on-
site TSCA chemical waste landfill However,
under TSCA, EPA is proposing to waive certain
TSCA chemical waste landfill requirements if the
residuals from the innovative treatment process do
oot present an unreasonable risk of injury to
health or the environment from PCBs.
Portions of the Resource Conservation and
Recovery Act (RCRA) which are relevant and
appropriate to the proposed remedy for the Site
will be met by all alternatives. These
requirements include RCRA groundwater
monitoring requirements, RCRA closure
requirements, RCRA storage requirements, and
RCRA incinerator requirements. All alternatives,
with the exception of No-Action and Capping of
Solids with a Soil Cover, would comply with
RCRA requirements.
Alternatives which involve groundwater treatment
will comply with relevant and appropriate cleanup
levels established under the Safe Drinking Water
Act Alternatives which involve actions in
wetlands will comply with relevant and appropriate
requirements of the Clean Water Act
Major State ARARs
Major New York State ARARs which are relevant
and appropriate to the alternatives being
considered for this Site include State groundwater
quality standards which will be met by the
groundwater recovery and treatment alternative.
Other State regulations governing wetlands,
coastal management, and hazardous waste
treatment, storage, and disposal requirements are
relevant and appropriate to this action and will be
met by all alternatives evaluated.
16
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Maior Tribal ARARs
The St. Regis Mohawk Tribe has submitted the
following ARARs which are applicable to actions
oa the Reservation:
Sofl IJD pans per million
Sediment 0.1 pans per million
Groundwater 10.0 pans per trillion
Surface Water 1.0 pans per trillion
Air 5.0 nanograms per cubic meter
For the remedial actions which wfll be conducted
on the Si. Regis Reservation, the Tribal ambient
standard for sofl wfll be achieved. As a cleanup
goal, EPA wfll attempt to achieve the Tribal
sediment standard of 0.1 ppm in sediments in the
Raquette River and Turtle Creek, However, it
may prove technically impracticable to achieve 0.1
ppm in these sediments due to limitations of
dredging technology.
According to CERCLA Section 121(d)(4)(c), EPA
may select a remedial action that does not attain
an ARAR if compliance with the ARAR is
technically impracticable from an engineering
perspective. Based on previous experience at
other Superfund sites and federal projects,
dredging to 0.1 ppm may be technically
impracticable. Therefore, EPA is proposing to
waive the Tribal sediment standard where it is
technically impracticable to achieve. The ability
to achieve 0.1 ppm PCBs in sediments wfll be
evaluated during the dredging process, taking into
account the demonstrated technical limitations of
the dredging equipment.
Long-Tern Effectiveness and Permanence
The No-Action Alternative would not provide
long-term effectiveness in protecting human health
and the environment In general, containment
and capping remedies provide a lesser degree of
permanence in remediating contamination at the
Site. Sediment containment with a graded cover
would reduce the erosive force of the flowing river
water and would limit movement of contaminants
into the environment; however, it is less
permanent than sediment removal through
dredging. The long-term effectiveness of
groundwater containment or recovery and
treatment would be reduced if the slurry wall or
the recovery well system fails. Oroun^water
containment or recovery and treatment would
reduce the risk from direct ingesikm of the
contaminated surface water.
With respect to the treatment alternatives, thermal
destruction is a permanent and effective
technology since it results in destruction of PCBs.
Chemical extraction, biological treatment, chemical
destruction and thermal extraction technologies
have the potential to permanently remediate the
Site; however, some uncertainties exist A pilot
study would be necessary during the design phase
to ensure long-term effectiveness of these
alternatives.
On-site disposal without treatment would not
implement any permanent treatment technologies
and is less effective in the long-term than
treatment and disposal Regardless of which
remedial alternative is implemented, some
monitoring would be essential to ensure long-term
effectiveness.
Reduction of ToxJdty, Mobility or Volume
The No-Action Alternative would not reduce
toxicity, mobility or volume of the contaminated
material.
Although capping and containment alternatives
would reduce the mobility of contaminated
material, no treatment would be performed.
Croundwater alternatives would reduce the
mobility of the contaminated groundwaier,
groundwater treatment may also reduce the
toxicity and volume of the contaminants in the
treated groundwater.
Solids and sludge treatment alternatives involve
excavation and subsequent treatment of the
excavated materials. Biologies! treatment,
chemical destruction, chemical extraction, thermal
destruction or thermal extraction would reduce the
mobility, toxicity and volume of the contaminated
material. A combination of thermal treatment
(materials over 500 ppm) and biological treatment
(materials below 500 ppm) would reduce the
mobility, toxicity and volume of the contaminated
material.
17
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Sediment dredging and treatment of the dredged
material with one of the treatment methods
outlined above, would reduce the mobility, tontity
and volume of the contaminated river sediments.
On-site disposal without treatment would reduce
only the mobility of the contaminated material.
Short-Term Effectiveness
The No-Action Alternative does not provide
short-term effectiveness, as the contaminated
groundwater and solids remain at the Site. Site
capping, would involve an increase in dust during
construction; however, the contaminated soils
would remain relatively undisturbed.
The area on the St. Regis Reservation may be
impacted by excavation; precautions to minimize
potential impacts will be included in the design
phase for the remediation for the Site.
Groundwater alternatives do not pose significant
implementation problems.
Sofl and sludge treatment alternatives will
immediately reduce the potential for direct contact
with hazardous materials upon initiation of the
remedial action. Community and worker exposure
would be minimized by the use of construction
methods that minimize air emissions and surface
water runoff, also, protective equipment that
minimizes workers' contact with the contaminated
materials would be utilized. Air quality will be
monitored during remediation.
Completion of pilot treatability studies, remedial
design and construction will take up to two years.
The time to complete a biological treatment
process for all areas except the Industrial Landfill
is estimated to be five years from completion of
construction of the treatment units. Chemical
destruction of all of the contaminated material
would take approximately six years from
construction completion, assuming a treatment
rate of 175 cubic yards per day.
Utilizing five treatment units after construction
completion, the chemical extraction alternative
would require five years for treatment of all areas
assuming each unit processed 49 cubic yards per
day. Using the thermal destruction alternative for
all of the contaminated material at the Site, the
remedial action would take ten years to complete
following construction, assuming a processing rate
of 42 cubic yards per hour. The thermal
extraction alternative would require approximately
seven years for completion of the remedial action
following construction, assuming a processing rate
of seven cubic yards per hour. The solidification
alternative, at a process rate of 200 tons per hour,
would require approximately one year to complete
following construction.
A combination of incineration for solids with PCS
concentrations greater than 500 ppm and
biological treatment for solids with PCB
concentrations below 500 ppm would require five
yean to complete after construction, assuming
biological treatment and incineration were
implemented at the same time.
Sediment dredging would require approximately
one year to complete. Implementation of
sediment dredging would require extensive controls
to minimi^ sediment redeposition in the river.
On-site disposal without treatment would require
use of construction and protective methods to
minimize community and worker exposure and
would also necessitate the use of controls to
minimize sediment redeposition.
Implementabilitv
All of the alternatives are implementable from an
engineering standpoint. However, there are some
inherent difficulties which may be encountered
during implementation of some alternatives.
Technological limitations may affect the efficiency
of dredging as a means of removing contaminated
sediments since some sediments will be
resuspended during the dredging process. As
mentioned in the discussion on short-term
effectiveness, each of the alternatives would
require the development of a health and safety
plan to minimize worker and community exposure
during implementation.
Treatment alternatives wfll require treatabiLiry
studies to optimize the design and operating
parameters for the treatment system. These
treatability studies will determine the
implementability of innovative technologies such
as biological treatment. If innovative technologies
18
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are not found to be implemestable, other more
proven technologies, such as incineration, would
be nsed to treat soils, sludges and sediments.
Cost
The costs associated with the alternatives for each
disposal area are presented in tables on previous
pages. These costs are estimates and may change
as a result of design and construction
modifications.
Capital costs include fixed costs (costs associated
with equipment mobilization and site preparation)
and non-fixed costs (costs associated with
treatment of a specific disposal area). Capital
costs are only incurred once for each treatment
technology. Thus, significant savings (in fixed
costs) from those costs displayed in the tables wfll
result whenever the same treatment technology is
used for two different disposal areas.
For example, the capital costs associated with
thermal destruction of Area 4, the Industrial
Lagoons, are $47,000,000. The capital costs
associated with a combination of biological and
thermal destruction of Area 4 are $46,000,000.
However, the preferred remedy provides for a
combination of biological treatment and thermal
destruction for several disposal areas at the Site,
thereby saving fixed costs. The one-time fixed
costs for biological treatment are approximately
$14,100,000. The one-time fixed costs for
incineration are approximately $6,400,000. The
non-fixed costs for incineration of lagoon materials
are approximately $15,000,000 greater than the
non-fixed costs for a combination of incineration
and biological treatment of lagoon materials.
State, Tribe and Community Acceptance
These criteria will be addressed at the dose of the
public comment period by considering comments
from the State of New York, the St. Regis
Mohawk Tribe and the public.
SUMMARY OF
RATIONALE FOR RECOMMENDED
ALTERNATIVE
The proposed remedy for the Site is protective of
human health and the environment and affords a
high degree of long-term effectiveness and
permanence while utilizing treatment as a
principal element The treatment process
provided for in this proposed plan would be
designed to meet ARARs, where possible. The
preferred alternative provides the best balance
among the alternatives with respect to the criteria
used to evaluate the alternatives. Moreover, thisj
combination of alternatives would satisfy the
statutory preference for remedies which utilize
treatment as a principal element and for
permanent remedies. Selection of this
combination also allows for implementation of an
innovative treatment technology (biological
treatment). This combination of alternatives is
also the lowest cost combination of alternatives
which is protective of human health and the
environment and utilizes highly permanent
treatment technologies as a principal element
Biological treatment alone is less expensive than
the proposed remedy but biological treatment is
not considered effective for material with PCB
concentrations above 500 ppm. Chemical and
thermal extraction technologies are less expensive
than the selected remedy for some areas of the
Site. However, extraction technologies result in
an extract with a very high PCB concentration
which must be further treated before it can be
disposed. Solidification is less expensive than the
selected remedy, however, solidification offers a
much lower degree of permanence than the
proposed remedy since PCBs are still bound
within the solidified material
19
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Glossary,
Aquifer
AT underground rock or toB foundation that is capable of supplying water to wells and springs.
Feasibility Stady (FS)
The second pan of a two-part study Remedial Investigation/Feasibility Study (RI/FS). Hie
1%asjb0iry Study involves identifying and evaluating the most appropriate technical approaches
for addressing contamination problems at a Superfund cite.
Ground Water
Water that fills spaces between sand, soil rock and gravel particles beneath surface of the earth.
Rain water that does not evaporate or drain to surface water such as streams, rivers, ponds, or
lakes, but slowly seeps into the ground, forming a ground water reserwir. Ground-water flows
considerably more slowly than surface water, often along routes that lead to streams, rivers
ponds, lakes and springs.
Hydrogeologk
A word in reference 16 the science of hydrology, which studies the interactions among surface
water, ground water, and the earth's rocks and soils.
National Priorities list (NFL)
A roster of uncontrolled hazardous waste sites nationwide Chat pose an actual or potential
threat to human health or the environment, and are eligible for investigation and cleanup under
the federal Superfund program.
« Plume ':/..:,..
A defined area of ground water contamination believed to have originated from a known source.
Proposed Plan
A document that describes all the remedial
alternatives considered by U.S. EPA for addressing contamination at a Superfund site, including
the preferred VS. EPA alternative.
Remedial Action
A series of steps taken to monitor, control, reduce or eliminate risks to human health or the
environment. These risks were caused by the release or threatened release of contaminants
form a Superfund Site. - j,;:,,..- - .. . . .-.,.-. ..,;. /".;:, .;:..,;,.-,,c.;; v^::...:.:".. :::;.
Remedial Alternative
A combination of technical and administrative methods, developed and evaluated in the
Feasibility Study, that can be used to address contamination at a Superfund site. :
Remedial Investigation (RI) .:.-.. :,'..:-'- ..."'...; : ,..:..-:;r;::::s'':",".;'/..".'.
The first part of a two-pan study Remedial Investigation/Feasibility Study. The Remedial
Investigation involves collecting and analyzing technical and background information regarding a
Soperfund site to determine the nature and extent of contamination that may be present. The
investigation also determines bow conditions at the site may affect human health the
environment .
Hespoasrveness Summary
A Section within the Record of Decision that presents VS. EPA's responses to public
comments on the Proposed Plan and RI/FS.
Sediment
Mod, Sand, gravel, and decomposing animals and plants that settle to the bottom of surface
water. .--
Superfund
The common name for the federal program established by the Comprehensive Environmental
Response and, Liability Act (CERCLA) of 1980, as amended on 1986. The Snperfund law
authorizes US. EPA to investigate and cleanup the nations most serious hazardous waste sites.
20
v>EPA
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APPENDIX B
PUBLIC NOTICE PUBLISHED IN THE
MASSENA DAILY COURIER-OBSERVER NEWSPAPER
ON MARCH 21, 1990
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THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
ANNOUNCES
PROPOSED REMEDIAL ALTERNATIVES FOR THE
GENERAL MOTORS CORPORATION-CENTRAL FOUNDRY DIVISION SITE
St Lawrence County, Massena, New York
The U.S. Environmental Agency (EPA) recently evaluated alternatives for cleaning up the contaminated
soils, lagoon sludges, river sediments, wetlands and groundwater associated with the General Motors
Corporation-Central Foundry Division Superfund Site. As pan of its public participation responsibilities
under section 117(a) of the Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA), EPA is issuing a Proposed Plan for public comment which summarizes EPA's proposed plan
for cleaning up the Site as well as the other alternatives considered for Site cleanup.
The public comment period for this Site is from March 21,1990 to May 21,1990. EPA will hold a public
meeting on its proposed plan on April 25, 1990 at the St. Regis Mohawk School in Hogansburg, New
York. Comments received during the public comment period and at the public meeting will be considered
in selecting the final cleanup plan for the Site. EPA has evaluated a variety of alternatives to cleanup the
Site. The alternatives for the Site areas are listed below:
AREA 1: Contaminated River and Tributary Sediments: No action; In-place containment of river
sediments; Sediment dredging and on-site treatment
AREA 2: North and East Disposal Areas, contaminated soils on the St Regis Mohawk Reservation.
contaminated soils on G.M. Property; No action; Capping of North and East Disposal Areas;
Excavation and on-site treatment of solids; Excavation and on-site disposal of solids.
AREA 3: Industrial Landfill; No action; Capping of Industrial Landfill; Excavation and on-site
treatment of solids; Excavation and on-site disposal of solids.
AREA 4 On-slte Lagoons; No action; Lagoon solids excavation and on-site treatment; Lagoon solids
excavation with on-site disposal.
AREA 5: Groundwaten No action; Groundwater containment; Groundwater recovery and treatment.
EPA's preferred alternative for Areas 1,2 and 4 is sediment dredging and solids excavation followed by a
combination of biological treatment and thermal destruction. EPA's preferred alternative for Area 5 is
groundwater recovery and treatment EPA has not specified a preferred alternative for the Industrial
Landfill; rather EPA will be soliciting comment on the Area 3 alternatives. Information regarding the
preferred alternative as well as the other alternatives will be discussed at the public meeting. Also, detailed
information on these alternatives is available for review in the Proposed Plan and Remedial Investigation
and Feasibility Study Reports (RI/FS) which are located at the following repositories:
United States Environmental St. Regis Mohawk Indian Massena Public Library
Protection Agency Reservation 14 Glen Street
26 Federal Plaza, Room 747 Community Building Massena, N.Y. 13662
N.Y, N.Y. 10278 Hogansburg, N.Y. 13655
Written comments on the proposed alternatives should be sent to:
Lisa Carson, Project Manager
U.S. Environmental Protection Agency
26 Federal Plaza, Room 747
New York, New York 10278
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APPENDIX C
SIGN-IN SHEETS FROM THE APRIL 25, 1990 PUBLIC MEETING
AND THE APRIL 26, 1990 AVAILABILITY SESSION
HELD IN MASSENA, NEW YORK
-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
MAILING
NAME STREET CITY ZIP PHONE REPRESENTING LIST
265 -Q620
/V/o-
tes
*
ts
-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
NAME
STREET
CITY
ZIP
PHONE
REPRESENTING
MAILING
LIST
-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
MAILING
NAME STREET CITY ZIP PHONE REPRESENTING LIST
-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
NAME
'N
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3x>T1\
STREET
3OQ /^
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^
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MAILING
CITY ZIP PHONE REPRESENTING LIST
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-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
NAME
STREET
lii E.CJlwhrt
ZIP
i*tit
PHONE
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MAILING
REPRESENTING LIST
-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
MAILING
LIST
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-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
NAME
IL4l
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STREET CITY
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ZIP
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-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
MAILING
STREET CITY ZIP PHONE REPRESENTING LIST
.... ; ' ' } < '
-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
NAME
UnU II
(V LJLn*l^iTj(Lj:+*(
STREET
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CITY
ZIP PHONE REPRESENTING
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MAILING
LIST
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£/
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-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
NAME
E\ JL
A -
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TJ &LLVI I . ^
iCU
A-
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STREET
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CITY
ZIP
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REPRESENTING
MAILING
LIST
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-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
NAME
STREET
CITY
ZIP
PHONE
REPRESENTING
MAILING
LIST
-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC MEETING
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 25, 1990
ATTENDEES
(Please Print)
MAILING
NAME STREET CITY ZIP PHONE REPRESENTING LIST
?
-------
UNITED STATES PROTECTION AGENCY
REGION II
PUBLIC AVAILABILITY SESSION
FOR
GENERAL MOTORS - CENTRAL FOUNDRY DIVISION
MESSENA, NEW YORK
APRIL 26, 1990
ATTENDEES
(Please Print)
NAME
STREET
CITY
ZIP
PHONE
REPRESENTING
MAILING
LIST
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APPENDIX D
WRITTEN COMMENTS RECEIVED BY EPA DURING THE PUBLIC COMMENT PERIOD
AND SUMMARIZED IN SECTION III OF THIS RESPONSIVENESS SUMMARY.
EPA'S RESPONSES TO THE FOLLOWING COMMENTS ARE ALSO INCLUDED
IN SECTION IV OF THIS RESPONSIVENESS SUMMARY.
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DUE TO ITS SIZE,
THIS APPENDIX WAS NOT INCLUDED
WITH THIS COPY.
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