PB94-963713
EPA/ROD/R01-94/087
September 1994
EPA Superfund
Record of Decision:
Somersworth Sanitary Landfill Site,
Somersworth, NH,
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DECLARATION FOR THE RECORD OF DECISION
Somersworth sanitary Landfill Superfund Site
Somersworth, New Hampshire
STATEMENT OF PURPOSE
This Decision Document presents the selected remedial action for
the Somersworth Sanitary Landfill Superfund site in Somersworth,
New Hampshire, developed in accordance with the Comprehensive
Environmental Response, Compensation and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), the National Oil and
Hazardous substances Contingency Plan (NCP), and 40 CFR Part 300
et.sea., as amended. The Region I Administrator has been
delegated the authority to approve this Record of Decision (ROD).
The State of New Hampshire concurs with the selected remedy,
including both the preferred alternative and the contingency
alternative.
STATEMENT OF BASIS
This decision is based on the Administrative Record which has
been developed in accordance with section 113(k) of CERCLA and
which is available for public review at the Somersworth Public
Library in Somersworth, New Hampshire, and at the Region I Waste
Management Division Records Center at 90 Canal Street, Boston,
Massachusetts. The Administrative Record Index (Appendix E to
the ROD) identifies the items which comprise the Administrative
Record upon which the selection of the remedial action is based.
ASSESSMENT OF THE SITE
Actual or threatened releases of ha~ardous substances from this
Site, if not addressed by implementing the response actions
selected in this ROD, may present an imminent and substantial
endangerment to the public health or welfare or to the
environment.
DESCRIPTIO..O~ THB SELECTED REMEDY
The selected remedy for the Somersworth sanitary Landfill
Superfund site includes both source control and management of
migration components to obtain a comprehensive remedy.
The source control remedial measures for the creferred
alternative include: .
.
installation of a treatment wall composed of impermeable
barrier sections and innovative, permeable, chemical
treatment sections to provide in-situ (in-place), flow-
through treatment of contaminated ground water at the
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barrier sections, sheet piling or slurry walls, will direct
contaminated ground water through the treatment sections
where detoxification of the VOCs will occur; and
.
placement of a permeable cover over the landfill allowing
precipitation to flush contamination from the waste area.
This cover will remain as long as contaminants continue to
leach from the landfill waste and the chemical treatment
"wall" is functioning. After cleanup levels have been
achieved and can be maintained without use of the treatment
"wall," EPA will evaluate an appropriate landfill cover to
be installed to close the landfill.
If it is determined that preferred alternative will not meet
performance standards, the contingency alternative will be
implemented. The source control remedial measures for the
continaency alternative include:
.
construction of a diversion trench on the upgradient side of
the landfill to intercept and divert groundwater around the
la~dfill. To the extent practicable, this diverted
groundwater will be used to recharge the downgradient
wetlands. A perimeter slurry wall would be completed around
the landfill waste. Permeable treatment sections of
chemical treatment wall would be removed and replaced by
slurry wall material. The final component would be a
landfill cover which complies with RCRA C requirements. The
purpose of these components is to lower the ground water to
below the waste in an attempt to meet interim ground water
cleanup levels in the overburden aquifer at the compliance
boundary. The ground water levels would be monitored to
determine if the water table would be lowered below the
waste and ground water quality would be monitored to ensure
that overburden ground water will meet interim ground water
cleanup levels at the compliance boundary. If either of
these conditions cannot be met, then extraction and
treatment of overburden ground. water from within the slurry
wall will be implemented. The remedial design will
determine the number, location and pumping rates of each
well, as well as, the most appropriate treatment technology
and discharge location. On-site treatment and disposal
methods and pretreatment and discharq. at the Somersworth
wastewater treatment facility are the two options which will
be evaluated. .
The management of migration remedial measures for both the
preferred and contingency remedies include:
.
installation of a pump in bedrock monitoring well B-l2R to
extract contaminated ground water. The contaminated ground
water will be either discharged onto the landfill. to enhance
flushing or injected just upgradient of the chemical
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treatment wall to receive treatment for the preferred
alternative or treated with the extracted over~urden ground
water for the contingency alternative. The need for bedrock
ground water extraction wells down gradient of the chemical
treatment wall or perimeter slurry wall will be investigated
during the design. This investigation will focus on the
number, location, and flow rate of the wells; the timing of
their installation; and the impacts on the overall ground
water cleanup; and
natural attenuation of contaminated groundwater beyond the
compliance boundary to lower contaminant concentrations
through physical, chemical and biological processes until
groundwater cleanup levels are met. After completion of
source remediation, no further contamination will be added
to the groundwater at levels which would prevent attainment
of the groundwater cleanup levels. It has been estimated
that overburden groundwater which has been affected by the
landfill will clean itself to the groundwater cleanup levels
within approximately fifty-five years after completion of
chemical treatment wall or perimeter slurry wall.
Additional measures include:
.
institutional controls to ensure that the affected ground
water will not be used until ground water cleanup levels
have been met. These controls should place further
restrictions on development and ground water use in and
around the wetland areas, as well as, along Blackwater Road
south of the landfill to ensure that new wells are not
installed or existing wells are not put back into service.
Examples of acceptable institutional controls include use
restrictions imposed on deeds, zoning ordinances, and the
state of New Hampshire's ground water management zone, among
others. As part of this portion of the remedy, a fence will
be installed around the landfill to restrict access. The
area requiring fencing will be determined during design; and
a detailed ground water monitoring program to be developed
during remedial design. The program will address long-term
monitoring of the aquifer and performance monitoring of the
chemical treatment wall. At a minimum, the sampling event
frequency for the aquifer monitoring will be quarterly for
the first three years for at least VQCs. Biannual sampling
for other organics and inorganic compounds for that period
should be conducted. Inorganic compounds will be sampled
using a low flow sampling technique to ensure that the data
is representative of theinorganics moving with the ground
water.
.
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DECLARATION
The selected remedy, including the preferred and th'e contingency
alternatives, is protective of the human health and the
environment, attain federal and state requirements that are
applicable or relevant and appropriate for each remedial action,
and are cost-effective. This remedy satisfies the statutory
preference for remedies that utilize treatment as a principal
element to reduce the toxicity, mobility, or volume of hazardous
substances. In addition, this remedy utilizes permanent
solutions and alternative treatment technologies to the maximum
extent practicable.
tC'-l (~f-
~L\~
....
Date
John P. DeVillars
Regional Administrator
u.s. EPA, Region I
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RECORD OF DECISION SUMMARY
SOMERSWORTH SANITARY LANDFILL SUPERFUND SITE
TABLE OF CONTENTS
contents
Paqe Number
I.
SITE NAME, LOCATION AND DESCRIPTION
. . . . . . .
II.
SITE HISTORY AND ENFORCEMENT ACTIVITIES. . . . . . . .
A. Land Use and Response History. . . . . . . . . . .
B. Enforcement History. . . . . . . . . . . . .
III. COMMUNITY PARTICIPATION
. . . . .
. . . . . .
. . . . .
IV.
SCOPE AND ROLE OF OPERABLE UNIT OR RESPONSE ACTION. . .
V~
SUMMARY OF SITE CHARACTERISTICS. . . .
A.' 80i1 .... . . . . . . . . . . . . . . . . . . .
B. . Ground Water. . . . . . . .
C. Surface Water and Sediments. . . . . . . . . . . .
D . Ai r . . . . . . . . . . . .
. . . . .
. . . . .
.........
VI.
SUMMARY OF SITE RISKS
. . . . .
. . . .
. . . . .
VII. DEVELOPMENT AND SCREENING OF ALTERNATIVES. . . . . . .
A. Statutory Requirements/Response Objectives. . . . .
B. Technology and Alternative Development and
screeDinq . . . . . . . . . . . . . . . . . .
VIII.
DESCRIPTION OF ALTERNATIVES
. . . . .
. . .0 . .
IX.
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
X.
THE SELECTED REMEDY. . . . . . . . . . . . . . . . . . .
A. Interim Ground Water Cleanup Levels. . . . . . . .
B. Description of Remedial components. . . . . . . . .
XI.
STATUTORY DETERMINATIONS ......
A. .The Selected Remedy is Protective of Human Health
and the Environment. . . . . . . . . . . . . . . .
The Selected Remedy Attains ARARs . . . . . . . . .
The Selected Remedial Action is cost-Ettective
The Selected Remedy utilizes Permanent Solutions
and Alternative Treatment or Resource Recovery
TechDoloqies to the Maximum Extent Practicable
The Selected Remedy satistie. the Preterence tor
Treatment Which Permanently and Siqniticantly
reduces the Toxicity, Mobility or Volume ot the
Hazardous Substances as a principal Element. . . .
B.
c.
D.
E.
XII. DOCUMENTATION OF SIGNIFICANT CHANGES.
. . . . . .
XIII. STATE ROLE
............
. . . . . .
. . . .
1
1
1
2
J
3
4
4
4
5
5
6
12
12
13
14
2G
28
28
31
34
34
35
38
39
40
40
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FIGURES
site Map
Areas ot Ground Water Contamination
Risk Assessment Exposure Areas
Chemical Treatment Wall
Landtill Cover Schematic
Fiqure 1
Fiqure 2
Fiqure 3
Fiqure 4
Fiqure 5
APPENDICES
Supplemental Risk Assessment
Responsiveness Summary
AltAR Tables.
State Declaration ot Concurrence
Administrative Record Index
Appendix A
Appendix B
Appendix C
Appendix D
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ROD DECISION SUMMARY
SOMERSWORTH SANITARY LANDFILL SUPERFUND SITE
1.
SITE NAME, LOCATION AND DESCRIPTION
The Somersworth Sanitary Landfill Superfund Site (the "Site") is
located on the north side of Blackwater Road approximately 300 to
400 feet west of the intersection of Blackwater Road and High
Street (State Route 9) and one mile southwest of the center of
the city of Somersworth in Strafford County, New hampshire
(Figure 1).
The site includes the approximately twenty-six acre waste
disposal area and adjacent wetlands northwest of the former
landfill. The City owns the entire landfill area and much of the
wetlands. The landfill was operated by the city from the mid-
1930's until 1981 when the City began taking wastes to a regional
incinerator. From 1981 to the present, in the southwest portion
of the landfill, those wastes which can not be incinerated are
stockpiled and hauled away. Approximately ten acres of the
eastern portion of the landfill have been reclaimed by the City
for recreational facilities; tennis and basketball courts, ball
fields, and a playground.
Numerous residential properties exist to the n~rth, south and
east of the Site, including an apartment building located
adjacent to the Site at the northeast corner. A fire station and
a National Guard Armory are located just east of the Site.
The landfill is entirely within the Peter's Marsh Brook surface
drainage basin. The brook is a tributary to Tate's Brook which
flows into the Salmon Falls River, the water supply for both
Somersworth and Berwick, Maine. Ground water flows northwesterly'
towards the brook and discharges to the brook and adjacent
wetlands. A decommissioned municipal water supply well (well no.
3) is located approximately 2300 feet north-northwest of the
site.
A more complete description of the Site can be found in the
Remedial Investigation Report at pages 1-2 through 2-4 and pages
5-1 through 5-20. .
II.
SITS HISTORY AND EHPORCBMENT ACTIVITIES
A.
Lan4 Us. an4 R..pons. History
The Somersworth Sanitary Landfill accepted municipal and
industrial wastes from the mid-1930's to 1981. The landfill
began as a burning dump in the northeast corner of the Site.
In 1958 burning was stopped and landfilling began. Natural
50ils were excavated beyond the working area, the excavation
filled with refuse, and covered at the end of each day with
Record of Decl.Ian, SCII8nworth S8nltary Landfill Sl4J8rf\l'ld Site, .Iww 21, 1991.
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the excavated natural, sandy soils. The landfill expanded
in a generally westerly direction. The eastern portion of
the landfill was not used for disposal after 1975. At that
time preparations commenced for a recreational park on that
portion of the landfill. The park was completed in late
1978.
In 1981 the City ceased waste disposal operations at the
landfill and joined the Lamprey Regional Solid Waste
Disposal Cooperative. Waste was thenceforth disposed of at
the Cooperative's incinerator in Durham, New Hampshire.
With the cessation of landfilling operations, the City
installed four ground water monitoring wells near the Site's
northern and western boundaries. Samples taken from these
wells indicated the presence of volatile organic compound
(VOC) contamination. As a result of this and subsequent
investigations, the landfill was placed on the National
Priority List (NPL) on September 8, 1983.
A more detailed description of the site history can be found
ih the Remedial Investigation Report at pages 1-4 to 1-6.
B.
Enforcement History
In 1989, the Somersworth Landfill Trust (SLT) was formed by
the City of Somersworth and approximately' thirty businesses
and industries which had an interest in the Site. The SLT
voluntarily signed an Administrative Order by Consent with
EPA and the State of New Hampshire. By this order, which
took effect on April 28, 1989, the SLT agreed to complete
limited aspects of the Remedial Investigation and to prepare
the Feasibility Study for the Site.
On December 8, 1993, EPA notified thirty-one parties who
either owned or operated the facility, generated wastes that
were shipped to the facility, arranged for the disposal of
wastes at the facility, or transported wastes to the
facility of their potential liability with respect to the
Site. Many of the parties notified were members of the SLT.
A meeting was held with these potentially responsible
parties (PRPs) on January 13, 1994, regarding the settlement
of the PRPs' liability at the Site.
The PRP. have been active in the remedy selection process
for this Site. In addition to having performed the
Feasibility Study, technical comments presented by PRPs
during the public comment period at a meeting were
summarized in writing, and the summary and written comments
were included in the Administrative Record.
lecord of Dietston, Sa88raworth sanitary Landfill SUperfund Site, June 21, 1~
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III. COMMUNITY PARTICIPATION
Throughout the Site's history, community concern and involvement
have been increasing as costs of the remedy have become clearer.
EPA has kept the community and other interested parties apprised
of the site activities through informational meetings, fact
sheets, press releases and public meetings.
The lead agency for the performance of the Remedial Investigation
was the New Hampshire Water Supply and Pollution Control
commission (NHWSPCC), the predecessor to the Department of
Environmental Services, Waste Management Bureau. During the
Remedial Investigation, NHWSPCC addressed community concerns and
kept citizens informed about and involved in activities. On
December 10, 1984, NHWSPCC held an informational meeting in the
Wood School, Somersworth to describe the plans for the Remedial
Investigation. On June 21, 1989, NHWSPCC held an informational
meeting in the Wood School, Somersworth to discuss the results of
the Remedial Investigation and to describe plans for the
Feasibility Study.
On. December 8, 1993, EPA issued the Proposed Plan and on December
9, 1993, made the administrative record available for public
review at EPA's offices in Boston and at the Somersworth Public
Library. On December 14, 1993, EPA held an informational meeting
to discuss the. results of the Remedial Investigation and the
cleanup alternatives presented in the Feasibility Study and to
present the Agency's Proposed Plan. Also during this meeting,
the Agency answered questions from the public. From December 15,
1993, through February 14, 1994, the Agency held a public comment
period to accept comments on the alternatives presented in the
Feasibility Study and the Proposed Plan and on any other
documents previously released to the public. EPA published a
notice and brief analysis of the Proposed Plan in Foster's Daily
Democrat on December 29, 1993, and announced the time and
location of the public hearing. On February 8, 1994, the Agency
held an informal public hearing at the Somersworth Vocational
Education Center to discuss the Proposed Plan and to accept any
oral comments. A transcript of this hearing and the comments, as
well as, the Agency's response to comments are included in the
attached responsiveness summary.
IV.
SCOP. UID ROLE 01' OPERABLB UNIT OR RESPONSE ACTION
The selected remedy was developed by combining components of
different source control and management of migration alternatives
to obtain a comprehensive approach for Site remediation. In
summary, the remedy provides treatment of contaminated overburden
and bedrock ground water with flushing of contamination from the
source area. This remedial action will address the principal
threat to human health and the environment posed by the site: the.
potential future ingestion of contaminated ground water.
Record of Deciaian, SGllerswrth SlIIitary LendfiU ~f\JId Sit., Jww 21, 1994
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v.
SUMMARY OF SITE CHARACTERISTICS
Pages 9 through 24 of the Feasibility Study contain an overview
of the Remedial Investigation. The significant findings of the
Remedial Investigation are summarized below.
A.
Soil
Low levels of VOCs and SVOCs were detected in soil
samples collected from within and around the landfill.
Inorganic compounds in the soil samples collected from
the Site were at or below background levels.
B.
Ground Water
Fifty ground water monitoring wells have been installed
in geologic test borings to characterize ground water
flow and quality. Water level measurements and water
quality samples have been taken several times between
1985 and 1992. Data from 1985 through 1987 were
presented in the Remedial Investigation. Data from
1989 through 1992 were presented in the Remedial
Investigation Data Gathering Report. In addition, a
ground water extraction pump test was conducted to
further define the hydrology of the Site.
Results of the investigations indicate that
approximately fifteen to seventy-five feet of glacial
till, sand, and gravel overlie a moderately to highly
fractured bedrock. Total ground-water flows across the
Site are approximately 200 to 300 gallons per minute.
(gpm) with about five percent of the flow (ten to
fifteen gpm) occurring in the bedrock. The general
direction of flow is towards the north-northwest in
both the overburden and bedrock aquifers. The bedrock
aquifer discharges upward into the overburden aquifer
along Peter's Marsh Brook and the wetlands. Landfill
waste was found to be below the water table in several
borings and test pits.
While no PCB's or pesticides were detected in any
sampling rounds, VOCs and inorganic compounds were
detected in a ground water plume beneath and down
gradient of the landfill, as well as in ground water in
an area along Blackwater Road (see Figure 2).
Principal contaminants detected during the 1985 through
1987 sampling rounds included: l,l-dichloroethylan.;
cis and trans 1,2-dichloroethylene; l,l-dichloroethane;
trichloroethylene; tetrachloroethylene; arsenic; and
chromium. Principal contaminants detected during the
1989 through 1992 sampling rounds included: benzene;
l,l-dichloroethylene; cis and trans 1,2-
lecord of Decision, Sa8trsworth Sanit.ry Landfill SUperfund Site, June 21, 1994
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dichloroethylene: 1,2-dichloroethane:
trichloroethylene, tetrachloroethylene, vinyl chloride,
arsenic; and chromium. statistical analysis of the
data for arsenic and chromium, as well as for several
other metals, has determined that concentrations of
metals found in the ground water affected by the
landfill are similar to concentrations found outside
the affected ground water. Therefore, it appears that
the presence of these metals is not related to disposal
of hazardous substances at the Site.
The contaminated plume appears to have reached a steady
state condition with its furthest extent approximately
1700 feet northwest of the northwest edge of the
landfill waste disposal area. However, detections of
increased levels of contaminants have occurred in
individual monitoring wells occasionally.
c.
Surface Water and Sediments
Sediment samples were taken in 1985 and 1986 at several
locations in Peter's Marsh Brook upstream and
downstream of the landfill. xylenes (maximum
concentration - 130 ppb) were detected at three
locations downstream of the landfill. At only one of
these stations were other VOCs detected
(methylcyclohexane - 200 ppb, toluene - 70 ppb,
ethybezene - 20 ppb, and carbon disulfide - 20 ppb) .
No semi-volatile organic compounds (SVOCs) were
detected in any sediment sample. Inorganic analyses
showed levels upstream and downstream of the landfill
to be at similarly low levels.
Surface water samples taken at the same locations as
the sediment samples showed the presence of several
VOCs at ~he same downstream locations as the sediment
samples which showed VOCs. The most prevalently
detected compound and the compound detected at the
highest level was 1,2-dichloroethylene (cis and trans)
with a maximum concentration of 25.2 ppb. Other VOCs
detected included trichloroethylene, 1,1-
dichloroethane, 1,2-dichloroethane, benzene, toluene,
tetrahydrofuran, and diethyl ether. All were typically
detected at less than 5 to 10 ppb. Subsequent sampling
done in 1992 in standing water in the wetlands did not
result in any VOCs being detected. Inorganic compounds
were detected at low levels.
I).
Air
Ambient air samples were collected from the four
corners of the Site and the center of the Site.
lecord of Declaion, Sc88r8worth Sanitary LandfiU ~ Site, Jww 21, 199ft
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Analysis of these samples indicated that VQCs were
present at acceptable levels as specified by the State
of New Hampshire.
A complete discussion of site characteristics can be found in the
Remedial Investigation Report at pages 7-1 through 7-30 and in
the Remedial Investigation Data Gathering Report at pages 10
through 47.
VI.
SUMMARY OF SITE RISKS
A Risk Assessment (RA) was performed to estimate the probability
and magnitude of potential adverse human health and environmental
effects from exposure to contaminants associated with the Site.
The public health risk assessment followed a four step process:
1) contaminant identification, which identified those hazardous
substances which, given the specifics of the site were of
significant concern; 2) exposure assessment, which identified
actual or potential exposure pathways, characterized the
potentially exposed populations, and determined the extent of
possible exposure; 3) toxicity assessment, which considered the
types ~nd magnitude of adverse health effects associated with
exposure to hazardous substances, and 4) risk characterization,
. which integrated the three earlier steps to summarize the
potential and actual risks posed by hazardous substances at the
site, including carcinogenic and non-carcinogenic risks. The
first human.health risk assessment was based on" data that were
collected several years ago (1985 through 1987). Since the
nature of the ground water contamination has changed over the
years, potential future exposure and risks from ground water were
reevaluated utilizing more recent data which were collected
between 1989 and 1992 and presented in the Remedial Investigation
Data Gathering Report. This risk assessment addressed only the
two exposure points identified in the original risk assessment
which posed a potential public health risk, consumption of ground
water from the area down-gradient from the landfill and from the
area along Blackwater Road across from the landfill. The results
of this supplementary public health risk assessment for the
Somersworth Sanitary Landtill Site are discussed below followed
by the conclusions ot the environmental risk assessment.
Record of DtcI,IGn, So8rswrth S8nitary Landfill ~f&nf Site, J... 21, '*
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TABLE lA: SUMMARY OF CONTAMINANTS.
OF CONCERN IN GROUND WATER IN AREA 4
contaminants
of Concern
Average
concentration
(J.La/l)
Antimony
Arsenic
Benzene
Beryllium
Carbon Disulfide
Chlorobenzene
1,2-Dichloroethylene
1,1-Dichloroethylene
Lead
Manganese
Methylene Chloride
Tetrachloroethylene
Trichloroethylene
vinyl Chloride
(tot. )
19
24
6
l'
6
5'
177
4'
3
560
14
13.8
54
107
Maximum
Concentration
(J.La/l)
Frequency
of Detection
41
203
10
1
38
5
1200
4
29
4610
76
140
370
1900
3/15
18/22
14/33
4/15
7/33
13/33
20/33
3/33
11/15
21/22
15/33
13/33
26/33
26/33
Maximum concentration detected used to represent "average"
rather than convention of using one-half the detection to
calculate
TABLE lB: SUMMARY 01' CONTAMINANTS
OF CONCERN IN GROUND WATER IN AREA 5
contaminants
of concern
Average
Concentration
(J.La/l)
l'
39
2
350
3.5
1430
11
. Benzene
1,2-Dichloroethylene
1,1-Dichloroethylene
Manqanese
Tetrachloroethylene
Trichloroethylene
vinyl Chlozoi48
( tot. )
Maximum
Concentration
(J.La/l)
1
130
2
848
4
6200
25
Frequency
of Detection
1/8
7/8
2/8
6/6
3/8
. 4/8
5/8
Maximum concentration detected used to represent "average--
rather than convention of using one-half the detection to
calculate
Fourteen contaminants of concern, listed in tables found in
Appendix A of this Record of Decision and Tables lA and 18,
above, were selected for evaluation in the supplementary risk
assessment. These contaminants constitute a representative
. subset of the more than 60 contaminants identified at the Site
during the Remedial Investigation and subsequent Remedial
Investigation Data Gathering. The fourteen contaminants of
Record of Deciaion, SC8Irnorth S8nitary landfill ~ Sft., J... 21, ,~
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concern were selected to represent potential site related hazards
based on toxicity, concentration, frequency of detection, and
mobility and persistence in the environment. A summary of the
health effects of each of the contaminants of concern can be
found in Appendix A to this Record of Decision.
Potential human health effects associated with exposure to the
contaminants of concern were estimated quantitatively or
qualitatively through the development of several hypothetical
exposure pathways. These pathways were developed to reflect the
potential for exposure to hazardous substances based on the
present uses, potential future uses, and location of the Site.
currently, land use northeast and east of the Site and along
Blackwater Road south of the Site is residential with pUblic
water provided by the City of Somersworth. Open land exists
north and west of the Site, much of which contains wetlands.
Approximately 2300 feet north and west of the Site is an
abandoned municipal water supply well. The potential exists for
contaminated ground water to be consumed if either existing or
new residences along Blackwater Road south of the Site install
wells or if public demand results in a need for use of the
aquifer formerly tapped by the abandoned municipal well. The
following is a brief summary of the exposure pathways evaluated.
A more thorough description can be found in the Remedial
Investigation, Section 8, pages 3 through 6.
Five exposure areas were delineated based upon the nature and
extent of contamination, geographic location, and land use and
exposed populations (Figure 3). Pathways quantitatively
evaluated included: ingestion of ground water, two liters per day
for seventy years; ingestion and dermal contact with soil by
persons ranging in age from two to thirty for fifty to 100
exposures per year: direct contact with surface water for
children aged six to fifteen for twenty-four to forty~eight
exposures per year; and ingestion of 0.3 kilograms of fish per
meal for twelve to twenty four meals per year for sixty-five
years. In addition, inhalation of vapors and particulates was
qualitatively assessed. For each pathway evaluated, an average
and a reasonable maximum exposure estimate was generated
corresponding to exposure to the average and the maximum .
concentration detected in that particular medium. For the
supplementary risk assessment, the pathway for ingestion of
ground water was evaluated using an exposure frequency of thirty
years and an ingestion rate of two liters per day.
Excess lifetime cancer risks were determined for each exposure
pathway by mUltiplying the exposure level with the chemical
specific cancer factor. Cancer potency factors have been
developed by EPA from epidemiological or animal studies to
reflect a conservative "upper bound" of the risk posed by
potentially carcinogenic compounds. That is, the true risk is
Record of Decf.fan. Sa88r8wartll 58nitary Landffll ~f1nt Site. oIwwe 21. 19M
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unlikely to be greater than the risk predicted. The resulting
risk estimates are expressed in scientific notation as a
probability (e.g. 1 x 10-6 for 1/1,000,000) and indicate (using
this example), that an average individual is not likely to have
greater that a one in a million chance of developing cancer over
70 years as a result of the defined site-related exposure to the
compound at the stated concentration. Current EPA practice
considers carcinogenic risks to be additive when assessing
exposure to a mixture of hazardous substances.
The hazard index was also calculated for each pathway as EPA's
measure of the potential for non-carcinogenic health effects. A
hazard quotient is calculated by dividing the exposure level by
the ~eference dose (RfD) or other suitable benchmark for non-
carcinogenic health effects for an individual compound.
Reference doses have been developed by EPA to protect sensitive
individuals over the course of a lifetime and they reflect a
daily exposure level that. is likely to be without an appreciable
risk of an adverse health effect. RfDs are derived from
epidemiological or animal studies and incorporate uncertainty
factors to help ensure that adverse health effects will not
occur. The hazard quotient is often expressed as a single value
(e.g. 0.3) indicating the ratio of the stated exposure as defined
to the reference dose value (in this example, the exposure as
characterized is approximately one third of an acceptable
exposure level for the given compound). The hazard quotient is
only considered additive for compounds that have the same or
similar toxic endpoint and the sum is referred to as the hazard
index (HI). (For example: the hazard quotient for a compound
known to produce liver damage should not be added to a second
whose toxic endpoint is kidney damage).
The tables below depict the carcinogenic and non-carcinogenic
risk summary for the contaminants of concern in ground water
evaluated in the supplementary risk assessment to reflect
potential future risks from ingestion corresponding to the
average and the reasonable maximum exposure (RME) scenarios for
the two exposure points, Area 4 (downgradient wetlands) and
Area 5 (Blackwater Road).
Record of Del.ion, sc.eraMOrth S8nit.ry l81dfill ~W1d Site, Jww 21, 1996
-------
Concentration Cancer Potency
contaminant of (/J.q/l) Factor Risk Estimate
Concern (Class) avq Max (mq/kq/day) -', avq RME
Arsenic (A) 24 203 1. 75 4. 8xlO" 4.2X10'3
Benzene (A) 6 10 2. 9X10'z 2.1xlO-6 3. 4X10-6
Beryllium (B2) l' 1 4.3 7. lxl0'S 7. lxlO'S
l,l-Dichloroethene (C) 4' 4 6xl0" 2 . 8xlO'S 2. 8xlO's
Methylene Chloride 14 76 7. 5xlO'3 1. 2xlO-6 6. 7X10-6
(B2)
Tetrachloroethylene 13.8 140 5.2Xl0-Z 8. 4Xl0-6 a. 5X10's
(B2)
Trichloroethylene (B2) 54 370 1.lXl0-Z 7. Oxl0-6 4. aX10's
Vinyl Chloride (A) 107 1900 1.9 2. 4X10-3 4. 2X10-Z
CARCINO(:;Li't'IC RISKS i'Ol<. '.:..ii.; POSSIBLE FUTURE INGESTION-
OF GROUNDWATER FROM AREA 4
ami
3.0xl0-3
4.7xlO-Z
, .
Ingestion based on exposure factor of 2.9xlO.z l/kg/day
Maximum concentration detected used to represent "average" rather than
convention of using one-half the detection to calculate
NON-CARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION-
OF GROUNDWATER PROM AREA ..
contaminant of Concentration Reference Target Hazard
Concern (/.&g/l) Dose Endpoint of Quotient
(Class) avq Max (mq/kq/cSay) Toxicity avq RME
Antimony (D) 19.2 41.3 0.0004 Blood, 1.3 2.8
Heart
Carbon Disulfide 6 38 0.1 Development .0017 .014
Chlorobenzene (D) 5' 5 0.Q2 Liver .0068 .0068
1,2- 177 1200 0.009 Liver, .54 3.7
Dichloroethylene Kidney
(total) (D)
Lead (B2) J 29 na 1.4t> cutoff
Manqanese 560 4610 0.005 CNS 3.1 25
-
,
Ingestion based on exposure factor of 2.9xlO.z l/kg/day
Maximum concentration detected used to represent '''average'' rather than
convention of using one-halt the detection to calculate
Recard of Decf8fan, So8I,awv.th S81itary L8RHiU Superfu'ld Sit., .June 21, 1~
-------
CARCINOGENIC RISKS FOR THE POSSIBLE FUTURE INGESTION-
OF GROUNDWATER FROM AREA 5
Concentration Cancer potency
contaminant of (I/oq/l) Factor Risk Estimate
concern (Class) avq max (mq/kq/day) -, avq RME
Benzene (A) l' 1 2. 9X10.Z 3. 4xlO.7 3. 4xlO.7
l,l-Dichloroethene (C) 2 2 6xlO.' 1. 4xlO.S 1.4X10-s
Tetrachloroethylene 3.5 4 5.2x10.z 2. 4x10.6 2. 4x10'6
(B2)
Trichloroethylene (B2) 1430 6200 1.1X10-z 1. axlO-1. 8. OxlO-1.
Vinyl Chloride (A) 11 25 1.9 2. 4xlO.1. 5. 6x10.1.
~
4.4xlO-1.
1.4xlO.3
-
Inqestion based on exposure factor of 2.9X10.Z l/kq/day
Maximum concentration detected used to represent "averaqe" rather than
convention of usinq one-half the detection to calculate
NON-CARCINOGENIC RISKS FOR THE POSSIBLE FUTURE 'INGESTION-
" OF GROUNDWATER FROM AREA 5
contaminant of concentration Reference Tarqet Hazard
Concern (l/og/1) Dose Endpoint of Quotient
(Class) avq max (mq/kg/day) Toxicity ave; RME
1,2-Dichloroethylene 39 130 0.009 .12 ..4
(total) (D)
Manganese 350 848 0.005 CNS 1.9 4.6
Ingestion based on exposure factor of 2.9xlO.z l/kg/day
For Area 4 ground water located down-gradient from the landfill,
carcinogenic risks fall outside the acceptable risk range of 10'" to 10-6
for both the average and reasonable maximum exposure scenarios. Most of
this risk is due to arsenic and vinyl chloride. For non-carcinogenic
risks, the hazard index slightly exceeded one. The major contributors to
the non-carcinogenic effects are antimony, manganese and 1,2-
dichloroethylene. For Area 5 ground water located across Blackwater Road
from the landfill, carcinogenic risks also fall outside the acceptable risk
range of 10-4 to 10-6 for both the average and reasonable maximum exposure
scenarios. Most of this risk is due to trichloroethylene, and vinyl
chloride. For non-carcinogenic risk, the hazard index of one was exceeded
"due to manganese.
-
In addition, concentrations of several of the compounds exceeded their
ARARs, MCLGs or.MCLs, in various samples. These compounds and associated
lecord of Decf.fan. Sc88rsMOf'th S8nit.ry Landfill ~fW1d Site, ..... 2', '994
-------
MCLG or MCL include: antimony (6 ~g/l), arsenic (50 ~g/l),
benzene (5 ~g/l), 1,2-dichloroethylene (ciS-70 ~g/l and trans-IOO
lead (action level of 15 ~g/l), methylene chloride (5~g/1),
tetrachloroethylene (5~g/1), trichloroethylene (5~g/1), and
vinyl chloride (2~g/1).
J,Lg/l) ,
A qualitative environmental risk assessment was performed during the
Remedial Investigation and a Wetlands Assessment was conducted during the
Feasibility Study. No sensitive plant or animal species were identified in
the vicinity of the Site. The conclusion of the environmental risk
assessment was that the Site was not likely to pose a risk to aquatic
organisms. The wetlands assessment indicated that there have been no
apparent adverse impacts to the wetlands.
Actual or threatened releases of hazardous substances from this site, if
not addressed by implementing the response action selected in this ROD, may
present an imminent and substantial endangerment to public health and
welfare. Therefore, contaminated ground water must be remediated through
implementation of the selected remedy.
VII. DEVELOPMENT AND SCREENING OF ALTERNATIVES
A. statutory Requirements/Response Objectives
Under its legal authorities, EPA's primary responsibility at Superfund
sites is to undertake remedial actions that are protective of human health
and the environment. In addition, Section 121 of CERCLA establishes
several other statutory requirements and preferences, including: a
requirement that EPA's remedial action, when complete, must comply with all
federal and more stringent state environmental standards, requirements,
criteria or limitations, unless a waiver is invoked; a requirement thatEPA
select a remedial action that is cost-effective and that utilizes permanent
solutions and alternative treatment technologies or resource recovery.
technologies to the maximum extent practicable; and a preference for
remedies in which treatment which permanently and significantly reduces the
volume, toxicity or mobility of the hazardous substances is a principal
element over remedies not involving such treatment. Response alternatives
were developed to be consistent with these Congressional mandates.
Based on preliminary information relating to types ot contaminants,
environmental media ot concern, and potential exposure pathways,. remedial.
action objective. were developed to aid in the development and screening of
alternative.. The.e remedial action objectives were developed to mitigate
existing and fu~ure potential threats to public health and the environment.
These response objectives were:
.
Prevent ingestion of contaminated ground water by local
residents; .
.
Prevent the public from coming into direct contact with
contaminated solid wastes, surface soils, surtac~ water, and.
sediments;
Record of D~f.fan, Sc8IrsllOl'tll s.nftlry Llndffll ~rf"" Sfte, J.... 21. 19M
-------
Reduce or eliminate migration of contaminants from the solid
wastes or soils into ground or surface water;
Reduce or eliminate off-site migration of contaminants in excess
of regulated allowable limits; and
Ensure that the ground water and surface water have residual
contaminant levels that are protective of human health and the
environment.
B. Technoloqy and Alternative Development and screening
CERCLA a~d the NCP set forth the process by which remedial actions are
evaluated and selected. In accordance with these requirements, a range of
alternatives were developed for the site.
with respect to source control, the RI/FS developed a range of alternatives
in which treatment that reduces the toxicity, mobility, or volume of the
hazardous substances is a principal element. This range included an
alternative that removes or destroys hazardous substances to the maximum
extent feasible, eliminating or minimizing to the degree possible the need
for long-term management. This range also included alternatives that treat
the principal threats posed by the site but vary in the degree of treatment
employed and the quantities and characteristics of the treatment residuals
and untreated waste that must be managed; alternatives that involve little
or no treatment but provide protection through engineering or institutional
controls; and a no action alternative.
with respect to ground water response action, the RI/FS developed a limited
number of remedial alternatives that attain site specific remediation.
levels within different timeframes using different technologies; and a no
action alternative.
As discussed in Chapter 3 of the Feasibility study, the RI/FS identified,
assessed and screened technologies based on implementability,
effectiveness, and cost. These technologies were combined into ten
comprehensive alternatives. Chapter 4 of the Feasibility Study and the
Feasibility study Addendum presented the remedial alternatives developed by
combining the technologies identified in the previous screening process in
the categories identified in Section 300.430(e) (3) of the NCP. The purpose
of the initial screeninq was to narrow the number of potential remedial
actions for further detailed analysis while preserving a range of options.
Each alternative was then evaluated in Chapter 5 of the Feasibility Study.
Table 11 identities the ten alternatives that were evaluated.
Record of Decision, Sc8M"s_th S."it8ry Landfill ~rf\l1d Site, Jw. 21, 1994
-------
VIII.
DESCRIPTION OF ALTERNATIVES
This Section provides a narrative summary of each alternative evaluated. A
detailed tabular assessment of each alternative can be found in Table 14 of
the Feasibility Study (March 1993) with modifications presented in the
Feasibility Study Addendum.
Alternative 1: No Action. This alternative was evaluated in the.FS
to serve as a baseline for all remedial alternatives under
consideration. Under this alternative, no action would be taken
except for long-term monitoring of ground water near the site on a
semi-annual basis. The results of the ground water sampling from
ground water monitoring wells would be reviewed to evaluate any
changes that occur and to reassess further remedial actions that may
be required.
This alternative is primarily a data collection activity; no treatment
or containment of the landfill wastes or contaminated ground water
would occur, and no effort would be made to reduce the risk of
potential human exposure to contamination. It is possible that a
reduction in the level of contaminants in the ground water may occur
over an extremely long time period due to natural attenuation;
however, the length of time needed to attain cleanup levels in ground
water cannot be predicted.
Estimated
Estimated
Estimated
Time for Design and Construction: None
Capital Cost (1993 DOllars): $0
Operation and Maintenance Costs (1993 DOllars):
$775,500
$775,500
Estimated Total Cost (1993 Dollars):
Alternative 2: Limited Action.This alternative is similar to
Alternative 1, except in addition to semi-annual ground water.
monitoring, it would include institutional controls to minimize the
potential of exposure to contamination. Institutional controls would
include restricting access to the Site by installing a fence around
the site, providing an alternate water supply to area residents (if
necessary), and placing ground water use restrictions on land
surrounding the Site.
This alternative would not include treatment or containment of
contamlnat~on in the disposal area. Although the Limited Action
alternative would reduce the potential risk of human exposure to on-
site contaminants, some health risk from uncontained contamination
would remain. Contaminated ground water would continue to migrate
into the wetland area. As mentioned in Alternative 1, the natural
processes of dilution and degradation may decrease the level of
contamination over time. However, without treatment or containment,
neither the mobility of the contaminants nor the volume of
contamination would be reduced.
Record of Deci.fan. SC88rIworth Sanit8ry L8ndfiU ~fn Sft., .IWIe 21, 1994
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Estimated
Estimated
Estimated
Estimated Total Cost (1993 Dollars):
Time for Design and Construotion: None
capital Cost (1993 Dollars): $100,500.
Operation and Maintenanoe Costs (1993 DOllars):
$775,500
$876,000
Alternative 3: Limited Aotion, Landfill Cover, Extraction of Bedrook
Ground Water with Treatment, Ground Water Monitoring. This
alternative combines the Limited Aotion alternative (identified above)
with an engineered landfill cover and extraction of ground water from
the bedrock at monitoring well B-12R and from a series of wells in the
bedrock downgradient of the landfill. The cover would extend across
the .26-acre landfill and would consist of a multi-layer design
consistent with the requirements of RCRA Subtitle C. The cover would
prevent direct contact with contaminated soil and solid wastes and
prevent rain water and snow melt from draining through the landfill.
Control points to collect and discharge landfill-generated gas would
also .be installed, if necessary. The surface would be graded to
promote surface water runoff which would, in turn, decrease
percolation through the landfill and slow the rate of contaminant
entry into ground water beneath the landfill. This would subsequently
reduce the quantity of contaminants entering the ground water and
. surface water, but since wastes currently lie below the ground water
table, the migration of contaminants would not be stopped completely,
thus allowing contamination to continue to enter the wetland areas.
The ground water to be pumped from the bedrock would be treated at the
POTW as in Alte~native ad.
Estimated Time for Design and Construction: 2 years
Estimated capital Cost (1993 DOllars): $9,520,700
Estimated Operation and Maintenance Costs (1993 DOllars):
$1,297,100
$10,817,800
Estimated Total Cost (1993 DOllars):
Alternative 4: Limited Action, Landfill Cover, Enhanced In-Situ
Biological Treatment, Natural Attenuation, Bedrock Ground Water
Extraction with In~situ Treatment, and Ground Water Monitoring. This
alternative uses enhancement of natural biological processes to treat
the contamination flowing through the landfill. Additional, necessary
nutrients would be applied to the landfill to hasten the biological
degradation. processes and naturally detoxify the contaminated ground
water entering the wetlands area. In order to accelerate "flushing"
of the landfill, ground water extracted from bedrock will be reapplied
to the landfill. Also, to maximize "flushing" by precipitation, an
impermeable cover will not be placed on the landfill as long as the
enhanced biological treatment is functioning.
Estimated Time for Design and Construction: 2 years
Bstimated capital Cost (1993 Dollars): '10,287,700
Bstimated operation and Maintenance Costs (1993 DOllars):
'2,535,100
'12,822,800
Estimated Total Cost (1993 DOllars):
Record of Deci.ion. ~worth S8nit.ry Landfill ~fV1d Site. .1&1'18 21. 1~
-------
Alternative s: Limited Action, Landfill Cover, In-Situ Chemical
Treatment Wall and Ground Water Diversion, Ground Water Extraction
from Bedrock, and Ground Water Monitoring. The key element of this
alternative is the construction of the permeable treatment wall
composed of impermeable barrier sections and innovative, permeable,
chemical treatment sections to provide in-situ (in-place), flow-
through treatment of contaminated ground water at the landfill waste
boundary (the compliance boundary). The barrier sections, sheet
piling or slurry walls, will divert ground water through the treatment
sections where detoxification of VOCs occurs. End products are non-
toxic ethenes and ethanes, carbon dioxide, water and chlorides. No
residuals are created which require disposal.
The contaminated ground water to be extracted from the bedrock
downgradient of the landfill will be pumped at approximately the rate
of flow of the bedrock ground water beneath the landfill. An
extraction well at monitoring well B-l2R will further reduce the
amount of contamination in the bedrock ground water. The purpose of
collecting this ground water is: 1) to prevent additional contaminants
.from discharging from the bedrock to the ground water in the vicinity
of the wetlands to enable that ground water to naturally clean itself;
and 2) to enable achievement of standards at the compliance boundary,
the edqe of the landfill, in the shortest time practicable,
approximately fiftY-five years.
In order to accelerate "flushing" of the landfill, ground water
extracted from bedrock will be reapplied to the' landfill. Also, to
maximize "tiushing" by precipitation, an impermeable cover will not be
placed on the landfill as long as the chemical treatment "wall" is
functioning and contaminants are leaching from the landfill waste.
After cleanup levels have been achieved and can be maintained without
use of the treatment "wall," EPA will evaluate an appropriate
landfill cover to be installed to close the landfill. The extraction
of the bedrock ground water and the use of the in-situ chemical
treatment "wall" will prevent additional contaminants from entering
the wetlands area, thus allowing the ground water to clean itself in
the shortest time feasible.
Estimated
Estimated
Estimated
Time for Design and Constructions 3 years
Capital Co.t (1"3 DOllar.)s $12,744,700
Operations and XaiDteDaDce Cost. (1"3 Dollars):
$2,240,100
$14,'84,800
Estimated Total Cost (1"3 DOllars):
Alternative. la and Ib: Limited Action, Landfill Cover, Slurry Wall
(Partial Cia) or Perimeter rib]), Natural Attenuation, Bedrock Ground
Water 8xtraction with Treatment, and Ground Water Monitoring. These
alternatives would add a partial or a perimeter slurry wall to
Alternative 3 in order to more effectively contain the waste by
lowering the ground water below the waste thus, minimizing migration
of contaminants to the wetlands area ground water. .Upq~adient ground
water diversion would be required to prevent the artificial raisinq of
I8COrd of Decf.fan. Sc8u--th Sanitary landfill $uperfU1d Sft_, .Iww 21, 19M
-------
the ground water when it encounters the slurry wall'. This diverted
ground water would be recharged into the wetlands to lessen the
impacts caused by the interruption of flow.
Estimated
Estimated
Time for Design and Construction: 2 years
Capital Cost (1993 Dollars): 6a - $11,610,200
6b - $12,434,200
operation and Maintenance Costs (1993 DOllars):
6a or 6b - $li296,600
Total Cost (1993 Dollars): 6a - $12,906,800
6b - $13,730,800
Estimated
Estimated
Alternatives 7a and 7b: Limited Action, Landfill Cover, Bedrock and
Overburden Ground Water Extraction with On-site (7a) or Off-Site (7~)
Ground Water Treatment, and Ground Water Monitoring. These
alternatives provide the remedial action in Alternative 3 with the
addition of extraction of contaminated ground water from the
overburden aquifer underlying the landfill. For Alternative 7a, the
treated ground water would be discharged on site. Ground water
extraction would minimize the migration of landfill-generated
contaminants. The on-site treatment system would likely consist of
some combina~ion of a metals removal unit, biological waste water
treatment unit, or activated carbon adsorption unit. The ground water
would be treated at a rate up to 2000 gallons per minute, generating
up to 9,600 pounds of waste sludge per day. Actual flows and sludge
generation rates would be determined during pre-design studies. The
sludge would be properly disposed of at an off-site landfill in
accordance with all applicable laws.
The extraction process would dewater between 40 and 190 acres of the
downqradient wetlands. To limit this environmental impact for the on-
site treatment system, treated water would be discharged downgradient
from the extraction location, providing clean ground water to the
wetlands. However, significant dewatering would still result. On-
site discharge of treated water would also produce a hydraulic barrier
that reduces the potential for off-site migration of contaminants.
For the off-site treatment option at the POTW, Alternative 7b,
pretreatment might be needed as described in Alternative 8d, below.
However, for flows in e~cess of 485 qpm, major expansion of the POTW
would be necessary. In addition, to attempt to lessen the wetland
impacts, potable municipal water would have to be recharged to the
wetlands since treated ground water would be discharged off-site at
the POTW. As with option 7a, significant adverse wetland impacts
would still result.
RICard of DlCi.ion. Sc88rsworth Sanitary Landfill 5'4»rflld Site. JW18 21. 19M
-------
Estimated
Estimated
Time for Desiqn and construction: 2 years
Capital Cost (1993 Dollars): 7a - $35,495,700
7b - $21,62'4,700
operation and Maintenance Costs (1993 DOllars):
7a - $25,053,100
7b - $40,753,100
7a - $60,548,800
7b - $62,377,800
Estimated
Estimated Total Cost (1993 Dollars):
Alternatives 8a and 8b: Limited Action, Landfill Cover, Bedrock and
Overburden Ground Water Extraction with on-site (8a) or Off-site
Ground Water Treatment (8b) and Partial Slurry Wall, and Ground Water
Monitoring. These alternatives include the same components as
Alternatives 7a and 7b (Limited Action, Landfill Cover, On-Site and
Off~Site Ground Water Extraction/Treatment/Discharge) with the
addition of a partial slurry wall upgradient from the landfill (Sa for
on-site treatment and Sb for off-site treatment).
The presence of the partial slurry wall would cause an artificial rise
in the groundwater table upqradient of the landfill. A drainage
system would be installed to prevent this artificial rise in the water,
table, and to divert water around the buried wastes. The discharge of
this diverted water to the wetlands downgradient of the landfill would
minimize the impact to the wetlands. However, some impact to the
wetlands would remain as a result of the ground water extraction.
Estimated Total COlt (1"3 Dollars) I
The upgradient slurry wall would reduce the amount of ground water
entering the 'landfill area, thereby reducing the amount of water which
comes into contact with the wastes. As a result, the ground water
extraction rate could be reduced to about 900 gallons per minute and
the amount of sludge produced during treatment would be reduced to
about 2,900 pounds per day. The sludge would be disposed of at an
off-site landfill in accordance with all applicable laws.
Estimated Time for Design and Construction: 2 years
Estimated capital Cost (1993 Dollars): 8a - $26,016,700
8b - $18,354,700
Estimated Operations and Maintenance Costs (1993 Dollars):
8a - $10,332,100
8b - $16,245,100
8a - $3',348,800
8b - $34,599,800
Alternative. 8e and 8d: Limited Action, Landfill Cover, Perimeter
Slurry .al1 witb Ground Water Diveraion, OVerburden Ground Water
Extraction witbin Slurry .all, Bedrock Ground Water Bxtraction, On-
Site (8c) or Off-Site (8d) Ground Water Treatment and Discharge, and
Ground Water Monitoring. These alternatives include the same
components as Alternatives 7a and 7b (Limited Action, Landfill Cover,
On-Site and Off-Site Ground Water Extraction/Treatment/Discharge) with
the addition of a perimeter slurry wall upgradient from the landfill
(8e for on-site treatment and Sdfor off-site treatment).
Record of Decfsfan. Sc8Iraworth s.nitary L8ndfiU ~fW1d Sfte, .lww 21, 1~
-------
For Alternative ac, the extracted ground water would be conveyed to an
on-site wastewater treatment system. This treatment system would
include some combination of a metals removal unit, biological waste
water treatment unit or activated carbon adsorption unit. Waste
sludge generated by the treatment unit, approximately 400 pounds per
day, would be properly disposed of at an off-site landfill operating
in compliance with all applicable laws. After the extracted ground
water is treated on-site, it would be used to recharge the wetlands,
as needed. For Alternative ad, the extracted ground water would be
conveyed to the Somersworth POTW through sanitary sewer lines. The
integrity of the existing sanitary sewer lines would require
verification prior to discharging the extracted ground water. If the
extracted ground water does not neet the pretreatment requirements of
the Somersworth POTW, a pretreatment system would be required on site.
That system would focus primarily on reducing suspended metals and
solids. The extracted ground water would then be treated at the
Somersworth POTW. It is estimated that the POTW can handle up to
about 485 gallons per minute (gpm) of extracted ground water before
needing expansion. The estimated bedrock and ground water extracted
by implem~ntation of this alternative would be approximately 140 gpm.
The actual flow could be lower depending on the ability of the cover
and slurry wall to hydraulically isolate the overburden aquifer
beneath the landfill. Therefore, it is unlikely that the capacity of
the POTW would have to be increased. The POTW-treated ground water
would be discharged to the Salmon Falls River.
Estimated Time tor Design and Construction: 2 years
Estimated capital Cost (1993 Dollars): 8c - $16,507,850
8d - $18,393,871
Estimated operations and Maintenance Costs (1993 Dollars:
8c - $ 3,264,962
8d - $ 2,823,722
8c - $19,772,812
8d - $21,217,593
Estimated Total Cost (1993 Dollars):
Alternative 9: Complete Excavation, Removal, and oft-site Disposal of
Landtilled Waste, Natural Attenuation, Bedrock Ground Water Extraction
with Treatment, and Ground Water Monitoring: Alternative 9 involves
the excavation and off-site disposal of solid wastes and surface soils
present at the site. Extraction and treatment of bedrock ground water
would be conducted as in Alternative 3.
This alternative would provide a permanent, low-maintenance measure
tor'source control. However, there are high costs associated with the
excavation and oft-site disposal due to the long distance to be
travelled to reach a RCRA-approved disposal facility and the number of
trips that would be required to the landfill. The closest RCRA-
approved landtill is 250 miles away, and the estimated number of truck
t~ips is 22,500. '
Record of Decision, ~MOrt" Sanitary Landfill ~rfW1d Site, Jw.e 21, 1994
-------
Estimated
Estimated
Estimated
Time for Design and Construction: 1 year
capital Cost (1993 Dollars): $259,705,200
operations and Maintenance Costs (1993 Dollars):
$630,600
Total Cost (1993 DOllars): $260,335,800
Estimated
Alternative 10: Limited Action, Landfill Cover, Excavation and On-
site Reconsolidation of Landfilled Waste, Bedrock Ground Water.
Extraction with Treatment, and Ground Water Monitoring. This
alternative would differ from Alternative 10 in that wastes would be
completely removed from below the water table, reconsolidated on-site
and placed entirely above the water table, then capped with an
impermeable cover which meets RCRA subtitle C requirements for final
closure of hazardous waste sites.
Estimated
Estimated
Estimated
Time for Design and Construction: 1 year
capital Cost (1993 DOllars): $16,338,700
Operations and Maintenance Costs (1993 Dollars):
$1,297,100
$17,635,800
Estimated Total Cost (1993 Dollars):
. IX.
SUMMARY OP THE COMPARATIVE ANALYSIS OF ALTERNATIVES
Section l2l(b) (1) of CERCLA presents several factors that at a minimum EPA
is required to consider in its assessment of alternatives. Building upon
these specific statutory mandates, the National contingency Plan
articulates nine evaluation criteria to be used in assessing the individual
remedial alternatives.
A detailed
evaluation
summary of
respect to
follows:
analysis was performed on the alternatives using the nine
criteria in order to select a site remedy. The following is a
the comparison of each alternative's strength and weakness with
the nine evaluation criteria. These criteria are summarized as
Threshold criteria
The two threshold criteria described below must be met in order for
the alternatives to be eligible tor selection in accordance with the
NCP.
1.
OYerall protection of human health and the environment
addresses whether or not a remedy provides adequate
protection and describes how risks posed throuqh each
pathway are eliminated, reduced or controlled through
treatment, engineering controls, or institutional controls.
2.
compliance with applicable or relevant and appropriate
requirements (ARARS) addresses whether or not a remedy will
meet all of the ARARs of other Federal and state
environmental laws and/or provide grounds for invokinq a
waiver.
R8COrd fit Decf.fan. SC88l'hD1'th S8nita,.y LandfHl ~fn Site. ..... 21. 1M
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primarv Balancinq criteria
The following five criteria are utilized to compare and evaluate the
elements of one alternative to another that meet the threshold
criteria.
3.
Long-term effectiveness and permanence addresses the
criteria that are utilized to assess alternatives for the
long-term effectiveness and permanence they afford, along
with the degree of certainty that they will prove
successful.
4.
Reduction of toxicity, mo~ility, or volume through treatment
addresses the degree to which alternatives employ recycling
o~ treatment that reduces toxicity, mobility, or volume,
including how treatment is used to address the principal
threats posed by the site.
5.
Short-term effectiveness addresses the period of time needed
to achieve protection and any adverse impacts on human
health and the environment that may be posed during the
construction and implementation period, until cleanup goals
are achieved.
6.
Implementa~ility addresses the technical and administrative
feasibility of a remedy, including the availability of
materials and services needed to implement a particular
option.
Cost includes estimated capital and operation Maintenance
(O&M) costs, as well as present worth costs.
7.
Modifvina criteria
The mOdifying criteria are used in the final evaluation of remedial
alternatives generally after EPA has received public comment on the
RIfFS and Proposed Plan.
8.
state acceptance addresses the State's position and key
concerns related to the preferred alternative and other
alternatives, and the State's comments on ARARs or the
proposed use of waivers.
Community acceptance addresses the pUblic's general response
to the alternatives described in the Proposed Plan and RIfFS
report.
9.
A detailed tabular assessment of each alternative according to the two
threshold and five primary balancing criteria can be found in Table 14
of the Feasibility Study.
Record of Deciaiori, SQ88I"swortll S.,itary Landfill ~hrd Site, Jww 21, 199ft
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FOllowing the detailed analysis of each individual alternative a
comparative analysis, focusing on the relative perfor~ance of ~ach
alternative against those criteria, was conducted. This comparative
analysis can be found in the Feasibility Study Addendum.
The section below presents the nine criteria and a brief narrative
summary of the alternatives and the strengths and weaknesses according
to the detailed and comparative analyses.
1.
Overall Protection of Human Health and the Environment
With the exception of Alternative 1 (the no-action alternative),
Alternatives 7a and 7b (overburden ground water extraction with on-
site or off-site treatment), and Alternatives Sa and Sb (partial
slurry walls and overburden ground water extraction with on-site or
off-site treatment), each of the alternatives is protective.
Alternative 1 is not protective because it would leave contamination
above acceptable levels in the groundwater and the wetlands for an
indefinite period of time, without any other measures to prevent
exposure. Because Alternatives 7a, 7b, Sa, and Sb would not employ
perimeter slurry walls, overburden ground water extraction would
result in significant environmental damage to the wetlands due to
extensive dewatering which could not be mitigated through recharge of
treated effluent or of municipal water. Furthermore, because the pump
and treat technology would not remediate the wetland area ground water
faster or more effectively than Alternative 1,' protective levels of
ground water contamination would not be achieved in the foreseeable
future. Although otherwise similar to alternative 1, Alternative 2
would achieve protectiveness through promulgation of institutional
controls to limit exposures to contaminated media. (The reliability
of such controls over the long period of time required under that
alternative is, however, a consideration in the evaluation of this
alternative under other criteria.) Alternative 3 combines the
institutional controls of Alternative 2 with a RCRA Subtitle C Cover
and pumping and treating of bedrock ground water. The Cover
Positively prevents contact with wastes and minimizes leachate
generation to shorten the time until ground water achieves protective
levels. The pumping and treating of the bedrock ground water will,
also, shorten the time to achieve protective levels so that the length
of time that institutional controls must be in place will be
shortened, thus their likelihood ot being effective is enhanced. In
contrast to alternative 7, the low pumping rates anticipated should
have no negative impact. on the wetland environment. Alternatives 4
and 5 provide protectiveness from the in-situ treatment methods
employed which will provide shorter time. to achieve protective levels
in ground water by enhancing the rate of remediation through
enhancement of biodegradation (Alternative 4) or by effectively
eliminating contaminant migration continuing into the wetland area by
employing the chemical treatment "wall" (Alternative 5). As with the
previous alternatives, institutional controls would prevent exposures
until cleanup levels are achieved. Alternative 6 achieves protective
levels in a manner similar to Alternative 3 and would provide some
Record of Deci.ian.. ~"'worth S8nitary L8ndffU ~ Sfte. ..... 21. 1994
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isolation of the waste through the use of slurry walls and cover
(thereby somewhat shortening the time to achieve protective levels of
contamination in the ground water). Alternatives 8c and 8d employ
pump and treat technologies and perimeter slurry walls to remediate
the ground water both in bedrock and overburden aquifers. With
appropriate recharge techniques, the impact on wetlands should be
minimal. Therefore, Alternatives 8c and 8d (on-site or off-site
treatment with a full slurry wall) are protective. Alterr.ative 9
achieves protectiveness by completely removing waste from the Site and
relying on institutional controls to prevent ingestion of contaminated
ground water. Alternative 10 achieves protectiveness by
reconsolidating wastes above the ground water table, under a RCRA
subtitle C cover.
2.
Compliance with ARARs
Most alternatives will meet all ARARs, but there are several
exceptions. Alternative 2 cannot meet the RCRA Subtitle C closure
requirements due to the lack of the required cover and an inability to
meet the chemical-specific ARARs (SDWA MCLs) at the compliance
boundary (the edge of the landfill) within an acceptable timeframe.
Since Alternative 2 provides no active measures to reduce
, contamination, contaminants will remain in the ground water
indefinitely. Alternatives 3 and 6a, which include the requisite
cover, would not meet the chemical-specific ARARs at the compliance
boundary since 'contaminants would continue to emanate from the waste
located in the ground water. While the cover would reduce leachate
production, wastes and associated contamination would remain in the
ground water indefinitely. Alternative 6acould not meet the chemical-
specific ARARs at the compliance boundary because of the presence of
landfill waste in the ground water which would continue to contribute
contamination above cleanup levels to the ground water
Alternatives must pass the two threshold criteria to be evaluated
using the remaining criteria. Based on the discussion above, the
alternatives that may be analyzed under the balancing and mOdifying
criteria are: 4, 5, 6b, 8c, 8d, 9 and 10.
3.
Long-Term Effectiveness and Permanence
Alternatives 4 and 5 would maintain protection over the long term
since the technologies treat the source of contamination and allow for
faster natural attenuation in the wetlands area. Long-term management
should be minimal. After the treatment process has ,been completed,
residual risks and the need for further maintenance or exposure
control would be minimal. Alternative 6b would require long-term
maintenance ot the cover, as well as, the upgradient ground water
diversion and perimeter slurry wall. Some contaminated ground water
would be released to the wetlands since the wastes would be left in
place and might not be completely isolated. Alternatives 8c and ad
prevent dewatering of the wetlands by isolating the wetlands through
the use of a perimeter slurry wall to allow natural attenuation to
Record of Decision, Sc8ersworth S8nft8ry LendfiU ~fU1d Site, .I18'Ie 21, 199(.
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occur in the wetland areas. Extraction and treatment within the
slurry wall will result in a magnitude of residual risk nearly as low
as Alternatives 4 and 5, both of which should more directly address
the source of contamination in the landfill and not produce treatment
residuals requiring management. Long-term management is more complex
than for other alternatives which do not employ the added flows from
extraction of overburden ground water. Alternative 9 results in the
lowest magnitude of residual risk since all waste is to be removed
from the Site. Alternative 10 would lower remaining risk somewhat by
removing wastes from the ground water.
4.
Reduction of Toxicity, MObility, or Volume through Treatment
Alternatives 4, 5, 6b, 8c, 8d, 9 and 10 all employ identical
extraction systems for bedrock ground water and provide treatment as
Well. Therefore, all are identical with respect to the degree of
reduction of toxicity, mobility, and volume of contaminants in the
bedrock ground water. Alternatives 4, 5, 8c and 8d all employ
treatment methods to reduce toxicity, mobility, and volume of
contamination in the overburden aquifer. The principal difference
among these alternatives is that Alternatives 4 and 5 would result in
total destruction of the contamination. Alternatives 8c and 8d
generate significant amounts of sludge which would require ultimate
disposal.
5.
Short-Term Effectiveness
This factor involves several considerations, including (a) short term
risks to the community during implementation, (b) potential dangers to
workers during implementation, (c) potential environmental effects of
the remedial action itself during implementation, and (d) the length
ot time required to achieve cleanup levels.
All alternatives present comparable risks of exposure to contaminated
groundwater during the period required to complete the restoration of
the groundwater. As noted below, those time frames vary; the
alternatives with the shortest time frames thus present the least
short-term risk. (The time trame associated with each alternative is
indicated below.) The risk is greatest under alternatives 1 and 2
since no capping of the landfill or cleanup of ground water/leachate
will take place under these alternatives, and cleanup levels would not
be attained' in the toreseeable future.
Time trame. tor achievement of protective levels under the
alternative. are projected to be as follows: Alternatives 6b, 8c, and
ad would require about one year to implement and approximately titty-
tive years to achieve cleanup goals in the overburden aquifer down-
gradient ot the edge of the landfill. Alternative.S would require up
to three years to implement and approximately fitty-tive years to
achieve cleanup goals in the overburden aquifer down-gradient of the
'edge of the landtill. Alternative 4 would require up to four years to
implement and approximately tifty-five years to achieve cleanup goals
Record of Decf.fan, Sc88rallDrth Sanit.ry L8ndffll ~fl.l'd Sfte, Juw Z1, 19M
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in the overburden aquifer down-gradient of the edge of the landfill.
Alternatives 9 and 10 would require one year to implement and
approximately eighty-three years to achieve cleanup goals in the
overburden aquifer down-gradient of the edge of the landfill. As a
result of the bedrock ground water extraction and treat~ent systems,
it is expected that the bedrock ground water would achieve cleanup
goals at least as quickly as the overburden ground water.
with respect to environmental risks, or risks to workers, during
implementation,. Significant risks to human health and the
environment could result from an inadvertent release of contamination
during the waste excavation and removal or reconsolidation process
which would be utilized in Alternatives 9 or 10. Alternative 9 poses
the greatest risk due to the complete excavation and off-site disposal
of. the landfill wastes. Alternative 10 would be an improvement since
wastes will not be disposed of off-site but still would be excavated.
Stringent health and safety measures would be required during the
implementation of these alternatives to protect construction crews and
nearby residents. Minor releases of VOCs and/or particulates may
occur during the regrading of the solid wastes and soils prior to the
installation of the cover which is utilized in Alternatives 4, 5, 6b,
Be, and 8d, and 10. Dust control measures, the use of interim covers,
air monitoring (if necessary), and proper health and safety training
would minimize. exposures to construction crews and nearby residents.
Minimal incidental exposures to workers would be expected for the
construction of any of the ground water extraction and treatment
systems. Reme~ial activities are not expected to adversely i~pact the
community during or after implementation. Minimal risks to workers
are associated with the construction of the perimeter slurry wall and
collection drain utilized in Alternatives 6b, 8c and 8d.
Alternatives 8c and Bd would create minimal impacts on wetlands, since
mitigation ~easures should prove to be effective. Alternative 6b is
less harmful since wetland impacts could be nearly completely
mitigated. Alternative 10 would have the next highest level of risk
to the environment because of the continued migration of contaminated
ground water into the wetlands. Alternatives 4, 5, and 9 would have
the lowest level of risk to the environment.
6.
Impl...Dtability
All of the alternatives can be implemented using standard construction
methods. The principal difference among alternatives concerns the
reliability of the technology. Neither Alternative. 4 nor Alternative
5 has been implemented at the scale proposed. The likelihood that
technical problems will occur with the delivery system used to provide
nutrients to the landfill in Alternative 4 is high. The potential for
preferred pathways developing so that portions of the waste do not
receive nutrient$ is likely. For Alternative 5, the mechanisms which
occur that detoxify the contamination within the i~-situ chemical.
treatment wall are not well documented or understood. . There is also
an unknown potential for fouling, plugging and exhaustion of capacity
Record of Decf.fon, S08IrsMOrth S~it.ry Landfill SUperfund Sft., June Z1, 1~
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or effectiveness. However, additional remedial actions could easily
be undertaken if required. Implementation of Alternative 9 would be
difficult from an administrative basis. The ability of a RCRA-
approved landfill to handle the large volumes of waste (approximately
450,000 tons) is unknown. In addition, the large number of truck
trips necessary to transport the wastes over long distances may create
substantial fugitive dust and fuel emissions. Finally, with the large
number of trips, the potential exists for a truck traffic accident
which could release contaminated material. All other aAlternatives
(6b, Bc, ad, and 10) are roughly equivalent in their implementability.
7.
Cost
The capital, operation and maintenance, and total cost for each
alternative is provided as part of the site description in Section
VIII., Description of Alternatives. For comparative purposes, all
costs are based upon thirty years of operation of each alternative.
The actual costs would differ somewhat based upon the length of time
necessary to achieve cleanup levels.
8.
State Acceptance
The State has reviewed the FS, the Proposed Plan, and this Record of
Decision and concurs with the remedy.
9.
Community Acceptance
Community acceptance of this Proposed Plan has been evaluated based on
comments received at the public meetings and during the public comment
period. In general, most of the community members who expressed views
supported Alternative 5, the innovative technology chosen as the
preferred alternative, but did not support the contingency remedy of
pump-and-treat. Some community members questioned the innovative
technology because of the uncertainties about its effectiveness or
implementability. However, overall sentiment in the community is that
the No Action or Limited Action alternatives would be more appropriate
remedies based upon the pUblic's perception of risk and cost-
effectiveness. The Somersworth Landfill Trust, which includes the
City of Somersworth stated in its comments that it did not feel that
any response action was necessarily warranted, but that if remedial
action were to be taken, Alternative 5 should be selected. .A further
discussion ot community concerns is found in the Responsiveness
Summary, Appendix B.
Overall comoarison of alternatives under above criteri~
The NCP requires EPA to select the alternative that meets the threshold
criteria of. protectiveness and ~ compliance, and best balances the
remaining seven criteria. EPA has concluded that Alternative 5 represents
the best balance of the criteria, subject to concerns stemming from its.
innovative nature. Because of those concerns, EPA has identIfied a
RICOI'd of Deci.fan, Scaerawortla SMit.ry Landfill S&.tperfWId Sit., .111'18 21, 1M
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=~ntingent remedy, Alternatives 8c and 8d (to be constructed in stages),
~hich best meet the NCP criteria if Alternative 5 does not prove to be
successful.
7he basis for selecting these alternatives is as follows. First, EPA may
not consider any alternative that fails to achieve one or both of the
~hreshold criteria. Alternatives 1, 7, 8a and 8b were found not to be
protective, and Alternatives 2, 3 and 6a were found not to comply with
ARARs. Therefore, those alternatives could not be considered further.
In choosing among the remaining alternatives, major concerns included the
time frame required to complete the remedial action (which affected both
long-term effectiveness and short-term effectiveness), and cost, although
other factors affected the selection as well. Alternative 9 was inferior
on all relevant considerations: it involved the longest time frame of any
alternative (other than alternatives 1 and 2 which were not under
consideration), presented significant short term risks, and was vastly more
expens,ive than any other alternative. Alternative 10 was less costly than
several other options, while more costly than others, but also had a longer
remedial time frame and presented significant short-term risks.
This' left Alternatives 4, 5, 6b, ac and ad. Among these, Alternatives 6b,
8c and ad had the ,shorter time frame and advantages over the others in
terms of implementability. However, the time frame is only slightly
shorter than under the other options, and Alternatives Bc and Bd are
considerably more costly. Alternative 6b is questionable in terms of long-
term effectiveness' of the slurry wall to maintain hydraulic control to
isolate the wastes. Alternatives ac and 8d rely on pumping the overburden
ground water to maintain that control, but at additional cost. Due to cost
considerations, EPA looked closely at Alternatives 4 and 5. These two
alternatives were similar in terms of time frame, use of treatment, and
short-term effectiveness. Alternative 4 was somewhat less expensive;
however, significant concerns exist about its implementability. The
likelihood that technical problems will occur with the delivery system used
to provide nutrients to the landfill in Alternative 4 is high. The
potential for preferred pathways developing so that portions of the waste
do not receive nutrients is likely. Finally as between these alternatives,
community support was much stronger for Alternative 5. Therefore,
Alternative 5 was preferable to Alternative 4.
Alternative 5 is significantly cheaper than Alternatives 8c and 8d;
however, concerns about its implementability still exist. Therefore, in
the overall balancing of alternatives the two approaches are similar.
Since there are no current exposures to contaminated groundwater, and
exposure is generally unlikely in the very near term, EPA has chosen to
proceed'with alternative 5 and to proceed with it pending a final decision
on its implementability which will be based on the information and
experience gained in carrying it out. It it is found not to be
implementable, either alternative 8c or 8d will be implemented.
Record of Decision, Sc8erhorth Sanitary LandfHl ~f1.IId Sit., Jww 21, 1~
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x.
THE SELECTED REMEDY
The selected remedy is Alternative 5 with Alternatives Be or Bd as the
contingency remedy if Alternative 5 is determined to be ineffective. Each
of these alternatives are comprehensive, including technologies for both
source control and management of migration. The remedial components of the
selected remedy are described in detail, below.
A.
Interim Ground Water Cleanup Levels
Interim cleanup levels have been established in ground water for all
contaminants of concern identified in the Baseline Risk Assessment
found to pose an unacceptable risk to either public health or the
environment. Interim cleanup levels have been set based on the ARARs
(e.g., Drinking Water Maximum Contaminant Level Goals (MCLGs] and
MCLs) as available, or other suitable criteria described below.
Periodic assessments of the protection afforded by remedial actions
will be made as the remedy is being implemented and at the completion
of the remedial action. At the time that Interim Ground Water Cleanup
Levels identified in the ROD and newly promulgated ARARs and modified
ARARs which call into question the protectiveness of the remedy have
been achieved and have not been exceeded for a period of three
consecutive years, a risk assessment shall be performed on the
residual ground water contamination to determine whether the remedial
action is protective. This risk assessment of the residual ground.
water contamination shall follow EPA procedures and will assess the
cumulative carcinogenic and non-carcinogenic risks posed by ingestion
of ground water and inhalation of VOCs from domestic water usage. If,
after review of the risk assessment, the remedial action is not
determined to be protective by EPA, the remedial action shall continue
until either protective levels are achieved, and are not exceeded for
a period of three consecutive years, or until the remedy is otherwise
deemed protective. These protective residual levels shall constitute
the final cleanup levels for this Record of Decision and shall be
considered performance standards for any remedial action.
Because the aquifer at and beyond the compliance boundary for the
l~ndfill is a Class IIB aquifer (a potential source of drinking
water), MCLs and non-zero MCLGs established under the Safe Drinking
Water Act are ARARs.
Interim cleanup levels tor known, probable, and possible carcinogenic
compound. (CIa.... A, B, and C) have been established to protect
against pot.ntial carcinogenic effects and to conform with ARARs.
Becau.. the MCLGs for Class A & B compounds are set at zero and are
thus not suitable for use as interim cleanup levels, MCLs and proposed
MCLs have been selected as the interim cleanup levels for these
Classes of compounds. Because the HCLGs for the Class C compounds are
greater than zero, and can readily be confirmed, MCLGs and proposed
MCLGs have been selected as the interim cleanup lev~ls for Class.C
compounds.
R8COt'd of Decision. Sc88r8Morth S8nit.ry Landfill S&4*"fl.l1d Site. JI.8I8 21. 199'.
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Interim cleanup levels for Class D and E compounds (not classified
and no evidence of carcinogenicity) have been established to prote~t
against potential non-carcinogenic effects and to conform with ARARs.
Because the MCLGs for these Classes are greater that zero and can
readily be confirmed, MCLGs and proposed MCLGs have been selected as
the interim cleanup levels for these classes of compounds.
In situations where a promulgated State standard is more stringent
than values established under the Safe Drinking Water Act, the State
standard was used as the interim cleanup level. In the absence of an
MCLG, an MCL, a proposed MCLG, proposed MCL, State standard, or other
suitable criteria to be considered (i.e., health advisory, state
guideline) an interim cleanup level was derived for each compound
having carcinogenic potential (Classes A, a, and C compounds) based on
a 10.6 excess cancer risk level per compound considering the ingestion
of ground water and inhalation of VOCs from domestic water usage. In
the absence of the above standards and criteria, interim cleanup
levels for all other compounds (Classes D and E) were established
based on a level that represents an acceptable exposure level to which
the,human population including sensitive subgroups may be exposed
without adverse affect during a lifetime or part of a lifetime,
incorporating an adequate margin of safety (hazard quotient equals
one) con~idering the ingestion of groundwater and inhalation of VOCs
from domestic water usage. If a value described by any of the above
methods was not capable of being detected with good precision and
accuracy or was below what was deemed to be the background value, then
the practical quantification limit or background value was used as
appropriate for the Interim Ground Water Cleanup. Level. '
Table I below summarizes the Interim Cleanup Levels for carcinogenic
and non-carcinogenic contaminants of concern identified in ground
water.
TABLE I: INTERIM GROUND WATER CLEANUP LEVELS
carcinogenic
contaminants of
Concern (class)
Benzene (A)
1,1-Dichloroethylene (C)
Methylene Chloride (B2)
Tetrachloroethylene (B2)
Trichloroethylene (B2)
vinyl Chloride '(A)
Interim
Cleanup
Level (ua/l)
5
7
5
5
5
2
Basis
SUK
Level of
Risk
1.7xlO-6
...9X10'5
4.4X10-7
3.1X10-6
I.5xlO-7
...5Xl0.5
1.0X10-4
MCL
MCLG
MCL
MCL
MCL
MCL
Non-carcinoqenic
Contaminat.
of Concern (Class)
Dichloroethylene (D)
CiS-1,2-
'1'rans-l,2-
Interim
Cleaup
Level (ua/l)
Basis
Tarqet
Endpoint
of Toxicitv
Liver, Kidney
Liver, Kidney
Hazard
Quotient
70
100
MCLG
MCLG
0.19
0.14
HI
Liver, KidDey
0.33
lecord of D8Cfaian, Sa8enwortll SMitary Llndfttl ~rfU'td Site, Jww 21, 1*
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These interim cleanup levels are consistent with ARARs or SUitable TBC
criteria for ground water, attain EPA's risk management gOal for remedial
actions and are dete~ined by EPA to be protective. However, the true te
of protection cannot be made until residual levels are known.
Consequently, at the time that Interim Groundwater Cleanup Levels
identified in the ROD and newly promulgated ARARs and mOdified ARARs whici
call into question the protectiveness of the remedy have been achieved ane
have not been exceeded for a period of three consecutive years, a risk
assessment shall be perfo~ed on the residual ground water contamination t
dete~ine whether the remedial action is protective. This risk assessment
of the residual grOund water Contamination shall follow EPA procedures and
will assess the Cumulative carcinogenic and non-carcinogenic risks POsed b
ingestion of ground water and inhalation of VOCs from domestic water USage
If, after review of the risk assessment the remedial action is not
determined to be protective by EPA, the remedial action shall Continue
until either protective levels are achieved and are not exceeded for a
period of three consecutive years, or until the remedy is otherwise deemed
protective. These protective residual levels shall constitute the final
cleanup levels for this Record of Decision and shall be considered
performance standards for any remedial action.
Several metals have been detected sporadically in ground water samples from
the Site at ~oncentrations which exceed ARARs and/or which would caUse
pUblic health risks to be outside of EPA's acceptable risk range of 10" to
.10'. for carcinogenic risks or to exceed a hazard index of one for non-
carcinogenic effects. These metals include: antimony, arsenic, beryllium,
and manganese. However, statistical analyses have been done on each of
these metals and no statistical difference could be seen between the metals
data uP-gradient and down-gradient of the landfill. This would indicate
that the metals are naturally ocCurring or backgroUnd and as sUch no
cleanup level will be set. In addition, the samples for metals were
obtained USing standard techniques which may result in an overestimation of
the concentrations of metals in the aquifer. During the long-term ground
water monitoring required as an element of the remedy, low-flow sampling
techniques will be employed to accUrately represent the metals actually
moving with the ground water. Based on EPA's eXPerience with these
sampling teChniques, concentrations are expected to be lower than those
presented in the Remedial Investigation and sUbsequent Remedial
Investigation Data Gathering Report. These are the data Which will be Used
in the risk assessment to be conducted on the residual contamination tc
ensure that the remedy is protective. .
All Interim Groundwater Cleanup Levels identified in the ROD and newly
promulgated ARAR. and modified ARARs which call into question the
protectiveness of the remedy and the protective levels determined as a
consequence Of the risk assessment of residual Contamination, must be met
at the Completion Of the remedial action at the points of compliance, the
aquifer at and beyond the edge of the landfill (down-qradient Of the
chemical treatment wall). EPA has estimated that these levels will be
obtained within approximately fifty-tive years after completion of the
source Control component.
I8COrd 0# Decf.fan. Sc8Iras....-u. s.nftary L8ndfitl ~ Site. "... 21. '"'
30
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B.
Description of Remedial Components
EPA has selected an innovative, emerging technology involving a
permeable, chemical treatment "wall" because of the potential benefits
which would be achieved by its use over other alternatives. These
benefits include: complete detoxification of VOCs, no residuals
requiring treatment or disposal, simple operation, low maintenance,
and relatively low costs. .
.
1.
In-situ chemical treatment "wall" (Fiaure 4) and around
water diversion
This is the key element of the remedy, the construction of a
treatment wall composed of impermeable barrier sections and
innovative, permeable, chemical treatment sections to provide in-
situ (in-place), flow-through treatment of contaminated ground
water at the landfill waste boundary (the compliance boundary).
The barrier sections, sheet piling or slurry walls, will direct
contaminated ground water through the treatment sections where
detoxification of the VOCs will occur.
Because of the emerging, innovative nature of this technology,
the following activities must be accomplished in order to ensure
that the remedy is effective:
collection of additional, necessary hydrogeologic data,
.
.
bench-scale studies to determine the degradation rate of
VOCs in site ground water under simulated in-situ
conditions, if evaluation of the bench-scale studies.
indicate the applicability of the technology to the Site,
installation of an in-situ, pilot-scale chemical treatment
wall,
.
.
development of a ground water flow model for evaluation of
pilot-scale field results: and if this evaluation continues
to demonstrate the applicability of the technology,
design, installation, and evaluation of the full-scale
chemical treatment wall.
EPA will require that all activities up to and including final
design be completed within two years. The final design documents
will include a detailed monitoring program to assess the
effectiveness of the chemical treatment wall.
If, at any time after the construction of the remedy, EPA
determines, based upon a review of the data developed during the
monitoring program, that the remedy is likely not to be
protective or that the remedy's anticipated performance no longer
warrants its selection, then the design for the contingency
lecord of Decl.lon, Sc8rsworth Sanitary Landfill 5'4'8rf\nt Site, .11818 21, 1~
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remedy will begin. Upon determining that the selected remedy
will not meet performance standards, the contingency remedy will
be constructed in two stages with the first stage being evaluated
to determine if the next stage of the contingency remedy is
needed. As a component of the first stage, a diversion trench
will be constructed on the upgradient side of the landfill to
intercept and divert groundwater around the landfill. To the
extent practicable, this diverted groundwater will be used to
recharge the downgradient wetlands. A second component of the
first stage would be the completion of a perimeter slurry wall
around the landfill waste. Permeable treatment sections of
chemical treatment wall would be removed and replaced by slurry
wall material. The final component of the first stage would be a
landfill cover which complies with RCRA C requirements. The
purpose of the components of this stage is to lower the ground
water to below the wastes in an attempt to meet interim ground
water cleanup levels in the overburden aquifer at the compliance
boundary. This stage of the contingency remedy is essentially
Alternative 6b, as set forth in the Feasibility Study. The
ground water levels would be monitored to determine if the water
table would be lowered below the waste and ground water quality
would be monitored to ensure that overburden ground water will
meet interim ground water cleanup levels at the compliance
boundary. If either of these conditions cannot be met, then
stage two of the contingency remedy would be implemented. This
would consist of the extraction and treatment of overburden
ground water from within the slurry wall. The remedial design
will determine the number, location and pumping rates of each
well, as 'well as, the most appropriate treatment technology and
discharge location. On-site treatment and disposal methods and
pretreatment and discharge at the Somersworth wastewater
treatment facility are the two options which will be evaluated.
Completion of stage two of the contingency remedy would complete
all components ot Alternative 8c or 8d.
2.
Landfill cover
To maximize "flushing" ot contaminants from the landfill waste
and subsequently through the chemical wall for treatment, a
permeable cover allowing precipitation to infiltrate the waste
area will be placed on the landfill as long as contaminants
continue to leach from the landfill waste and the chemical
treatment "wall" is functioning. After cleanup levels have been
achieved and can be maintained without use of the treatment
"wall,. EPA will evaluate an appropriate landfill cover to be
installed to close the landfill. The evaluation will be based on
the data collected as part of the monitoring program.
If the contingency remedy is implemented, a mUlti-layer,
impermeable cover which meets the requirements of RCRA C will be
designed, installed, and maintained over the landfill (Figure. 5).
18COI"d of De:ciafan, Sc8Iraworth s.nit8ry L8ndffll ~f\n:I Site, June 21, 19M
-------
3 .
Bedrock qround water extraction and treatment
Extraction of bedrock ground water will be done at monitoring
well B-12R and down gradient of the chemical treatment wall. A
pump will be installed in monitoring well B-12R and the effluent
will be piped to the landfill for treatment through the chemical
treatment wall. The contaminated ground water will be either
discharged onto the landfill to enhance flushing or injected just
upgradient of the chemical treatment wall to receive treatment.
After installation and operation of this well has begun, its
effectiveness in remediating the down-gradient bedrock ground
water so that the extent of the bedrock ground water extraction
system down gradient of the chemical treatment wall can be
determined. The studies required will focus on the number,
location, and flow rate of the wells; the timing of their
installation; and the impacts on the overall ground water
cleanup.
If the contingency remedy is implemented, the extracted bedrock
ground water will be treated at the Somersworth Wastewater
Treatment Facility or, if the second phase of the contingency is
implemented, the bedrock ground water will be treated along with
the overburden ground water.
4.
Natural attenuation for the wet~s around water clume
The use of the chemical treatment wall and bedrock ground water
extraction will prevent contaminants from continuing to discharge
to the wetlands ground water. This will allow the ground water
to naturally attenuate in as short a time as practicable, .
estimated at. fifty-five years.
5.
Institutional controls to crevent use of contaminated qround
water
Potential demands for water during the fiftY-five year period
prior to achieving ground water cleanup levels make the
implementation of institutional controls an important element of
the remedy. Therefore, institutional controls will be used to
ensure that the affected ground water will not be used until
ground water cleanup levels have been met. These controls should
place further restrictions on development and ground water use in
and around the wetland areas, as well as, along Blackwater Road
south of the landfill to ensure that new wells, are not installed
or existing wells are not put back into service. As part of this
portion of the remedy, a fence will be installed around the
landfill to restrict access. The area requiring fencing will be
determined during design.
lecord of Decf8tan. SC8eMIwrth Swlitary Landfill Sl4I8I'fW1d Site. oIW18 21. 19M
-------
6.
Ground water monitorinq
A detailed ground water monitoring program will be developed
during remedial design. The program will address long-term
monitoring of the aquifer and performance monitoring of the
chemical treatment wall. At a minimum, the sampling event
frequency for the aquifer monitoring will be quarterly for the
first three years for at least VOCs. Biannual sampling for other
organics and inorganic compounds for that period should be
conducted. Inorganic compounds will be sampled using a low flow
sampling technique to ensure that the data is representative of
the inorganics moving with the ground water.
To the extent required by law, if any hazardous substances,
pollutants or contaminants remain at the Site, EPA will review
the Site at least once every five years after the initiation of
remedial action to assure that the remedial action continues to
protect human health and the environment.
XI.
STATUTORY DETERMINATIONS
,The remedial action selected for implementation at the Somersworth Sanitary
Landfill Site is consistent with CERCLA and the NCP. The selected remedy
, is protective of human health and the environment, attains ARARs and is
cost effective. The selected remedy also satisfies the statutory
preference for treatment which permanently and significantly reduces the
mObility, toxicity or volume of hazardous substances as a principal
element. Additionally, the selected remedy utilizes alternate treatment
technologies to the maximum extent practicable.
A.
The Selected Remedy is Protective of Human Health and the
Environment
The remedy at this Site will permanently reduce the risks posed to
human health and the environment by eliminating, reducing or
controlling exposures to human and environmental receptors through
treatment, engineering controls, and institutional controls: more
specifically, for the selected remedy, through the use ot an in-situ
chemical treatment wall to treat contaminated ground water emanating
trom the landtill, bedrock ground water extraction and treatment
through the chemical treatment wall, and institutional controls to
restrict u.. of contaminated ground water: for the contingency remedy,
through i.olation ot the wastes by an impermeable landtill cover and a
perimeter slurry wall, by bedrock ground water extraction and
treatment at the Somersworth Wastewater Treatment Facility or on-site,
by extraction and treatment ot overburden ground water if necessary,
and by institutional controls to restrict use ot contaminated ground
water. '
lecord 0' D8cl8ion, 5a8Ir8worth S8nit.ry L8ndfill Superfund Site, June 21, 1994
-------
Moreover, the selected remedy and contingency remedy will achieve
potential human health risk levels that attain the .10-4 to 10"6
incremental cancer risk range and a level protective of
noncarcinogenic endpoints, and will comply with ARARs and to-be-
considered criteria. At the time that the Interim Ground Water
Cleanup Levels identified in the ROD and newly promulgated ARARs and
modified ARARs which call into question the protectiveness of the
remedy have been achieved and have not been exceeded for a period of
three consecutive years, a risk assessment shall be performed on the
residual ground water contamination to determine whether the remedial
action is protective. This risk assessment of the residual ground
water contamination shall follow EPA procedures and will assess the
cumulative carcinogenic and non-carcinogenic risks posed by ingestion
of ground water and inhalation of VOCs from domestic water usage. If,
after review of the risk assessment, the remedial action is not
determined to be protective by EPA, the remedial action shall continue
until protective levels are achieved and have not been exceeded for a
period of. three consecutive years, or until the remedy is otherwise
deemed protective. These protective residual levels shall constitute
the final cleanup levels for this Record of Decision and shall be
considered performance standards for any remedial action.
. B.
The Selected Remedy Attains ARARs
This remedy will attain all applicable or relevant and appropriate
federal and state requirements that pertain to the site.
Environmental laws from which ARARs for the selected remedial action
are derived, and the specific ARARs include:
Chemical-Soecific
Safe Drinking Water Act (SDWA), 40 CFR 141.50 - 141.62, Maximum
contaminant .Level Goals (MCLGs), where greater than zero
Safe Drinking Water Act (SDWA), 40 CFR 141.11-141.16, Maximum
Contaminant Levels (MCLs) .
Clean Water Act (CWA) , Federal Water Quality Criteria (FWQC) for
protection of human health
CWA, Federal Water Quality Criteria (FWQC) for protection of aquatic
life
New Hampshire Primary Drinking Water criteria (MCLs and MCLGs) under
RSA Ch. 485, promulgated at Env-Ws 316 and 317 (to the extent they are
more stringent than MCLs and non-zero MCLGs)
Env-WS 410.05, Ambient Ground Water Quality Standards (to the extent
they are more stringent than MCLs and non-zero MCLGs)
Env-wS Part 432, Water Quality Criteria for Protection of Human Health
and Protection of Aquatic Life
Record of Decisfan, s..rsworth S..itary Landfill ~f\nI Sft., Jww 2', '99(.
-------
Location-Specific
CWA section 404~ 40 CFR Part 230~ 33 CFR Parts 320-330
RSA 217A NH Native Plant Protection Act
RSA 485-A-17, Dredging and Control of Run-Off~ Env-Ws Part 415,
Dredging Rules
RSA Ch. 482-A, Fill and Dredge in Wetlands; and Env-Wm 300-400, and
600, Criteria and Conditions for Fill and Dredge in Wetlands
Env-Ws 410.26, Ground Water Management Zone
Action-Soecitic - Alternative 5
Env-ws 4l0.24(a) and (b), Criteria for Remedial Action.
NOTE: other criteria in 410.24, which do not impose distinct
requirements but rather are weighed more generally in selecting
remedial action plans would not be ARARs.
Env-Ws 410.27, Groundwater Management Permit Compliance Criteria.
NOTE: This provision requires a revised remedial action plan
where implementation of an approved plan fails to meet
performance standards. At this site, the revised remedial plan
will be as specified in the phased contingency remedy described
elsewhere in this ROD. .
~:re~:~~s~~r~h=a:~~~~~:t~~:~ei~~~~~~;O~~'P;~t~~ui:~:as thev are
Env-Wm 353.09 and 353.10, Siting requirements for hazardous waste
facilities and variances
Env-Wm 702.08 Environmental and Health Requirements
Env-Wm 702.09 General Design Requirements
Env-Wm 702.11 Ground Water Monitorinq
Env-Wm 702.12 Other Monitorinq
Env-Wm 708.02 Operation Requirements
Env-Wm 708.03 Technical Requirements
Fuqitive Dust Emission Control, NH Admin. Rules, Env-A 1002
Env-Wm403 Industrial and Municipal Wastewater Discharqe Permits
We 604 Abandonment of Wells
18Card of Decf8fon, Sc8Inworth Sanit.ry LrdfiU ~f"" Sft., .lww 21, 1~
-------
~ction-SDecific - ~lternative 8c
clean water Act, Discharge of Treatment System Effluent, 40 CFR 122
. '
40 CFR 125, 40 CFR 131, and 40 CFR 136, Nat~onal Pollutant Discharge
Elimination System
Fugitive Dust Emission Control, NH Admin. Rules, Env-A 1002
RSA 485-A:8 Surface Water Classifications
RSA 485-A:12 Enforcement of Classification
Env-Ws 410.24(a) and (b), Criteria for Remedial Action.
NOTE: Other criteria in 410.24, which do not impose distinct
requirements but rather are weighed more generally in selecting
remedial action plans would not be ARARs.
Env-Ws 410.27, Groundwater Management Permit Compliance Criteria.
Env-Ws 4.10.07, 410.09, 410.10 Prohibited Discharge, Groundwater
Discharge Zone, Groundwater Discharge Permit Compliance Criteria
Env-Wm 403 Industrial and Municipal Wastewater Discharge Permits
We 604 Abandonment of Wells
New HamDshire Hazardous Waste Reaulations. in so far as they are
relevant to this alternative. includina in Darticular:
Env-Wm 353.09 and 353.10 Siting requirements for hazardous waste
facilities and variances
Env-Wm 702.08 Environmental and Health Requirements
Env-Wm 702.09 General Design Requirements
Env-Wm 702.11 Ground Water Monitoring
Env-Wm 702.12 Other Monitoring
Env-Wm 708.02 operation Requirements
Env-Wm 708.03 Technical Requirements
Record of Dei.ian, Sc88r8l1D1'th Sanitary Landfill S&4*'fW1d Site, .1&.18 21, '*
-------
Action-Specific - Alternative 8d
Clean Water Act, Discharge of Treatment System Effluent, 40 CFR 122,
40 eFR 125, 40 CFR 131, and 40 CFR 136, National Pollutant Discharge
Elimination System
Fugitive Dust Emission Control, NH Admin. Rules, Env-A 1002
Env-Ws 410.07, 410.09, 410.10 Prohibited Discharge, Groundwater
Discharge Zone, Groundwater Discharge Permit compliance Criteria
We 604 Abandonment of Wells
Env-ws 410.24(a) and (b), Criteria for Remedial Action.
NOTE: Other criteria in 410.24, which do not impose distinct
requirements but rather are weighed more generally in selecting
remedial action plans would not be ARARs.
Env-Ws 410.27, Groundwater Management Permit Compliance Criteria.
New Hampshire Hazardous Waste Reaulations. in so far as they are
relevant to this alternative. includina in particular:
Env-Wm 353.09 and 353.10 Siting requirements for hazardous waste
facilities and variances
Env-Wm 702.08 Environmental and Health Requirements
Env-Wm 702.09 General Design Requirements
Env-Wm 702.11 Ground Water Monitoring
Env-Wm 702.12 Other Monitoring
Env-Wm 708.02 Operation Requirements
Env-Wm 708.03 Technical Requirements
The ARAR Tables, Appendix C, present a more detailed explanation of
eachARAR and whether it is applicable or relevant and appropriate as
well a8 other environmental criteria considered.
c.
The .elected Ramedial Action i. Co.t-Bttective
In the Agency's judgment, the selected remedy is cost-etfective, i.e.,
the remedy affords overall effectiveness proportional to its costs.
In selecting this remedy, once EPA identified alternatives that are
protective of human health and the environment and that attain, or, as
appropriate, waive ARARs, EPA evaluated the overall effectiveness of
each alternative by assessing the relevant three'criteria--long term
effectiveness and permanence; reduction in toxicity, mobility, and
lecard of Decfafan, SC8Ir8wortll S8nftary L8I'Idffll ~fW1d Sfte, Jw.e 21. 1994
-------
volume through treatment; and short term effectiveness, in
combination. The relationship of the overall eff,ectiveness of this
remedial alternative was determined to be proportional to its costs.
The costs of the selected remedy, Alternative 5, in 1993 dollars are:
Estimated capital Cost: $12,744,700
Estimated 0 & M Costs: $ 2,240,100
Estimated Total Cost: $14,984,800
Approximately $9,000,000 of the total costs of the selected remedy
reflect costs for the design, construction, and maintenance of a RCRA
C landfill cover. However, as stated in Section X.B.2., after cleanup
levels have been achieved and can be maintained without use of the
chemical treatment "wall," EPA will evaluate an appropriate cover to
be installed to close the landfill. A significant cost reduction
could be realized.
Should the preferred alternative fail to be protective, the
contingency remedy will be implemented, the overall effectiveness of
which is proportional to its costs. The costs of the contingency
remedies- (Alternatives 8c and 8d)are presented below:
8c
8d
$18,393,871
. $ 2,823,722
$21,217,593
Estimated Capital Cost: $16,507,350
Estimated 0 & M Costs: $ 3,264,962
Estimated Total Cost: $19,772,812
If it is determined that the first stage of the contingency remedy is
effective, then the costs would be similar to the costs of
Alternative 6b, as presented below:
Estimated capital Cost: $12,434,200
Estimated 0 & M Costs: $ 1,296,600
Estimated Total Cost: $13,730,800
D.
The Selected Remedy Utilizes Permanent Solutions and Alternative
Treatment or Resource Recovery Technologies to the Maximum Extent
Practicable
Once the Agency identified those alternatives that attain ARARs and
that are protective of human health and the environment, EPA
identified which alternative utilizes permanent solutions and
alternative treatment technologies or resource recovery technologies
to the maximum extent practicable. This determination was made by
deciding which one of the identified alternatives provides the best
balance of trade-offs among alternatives in terms of: 1) long-term
effectiveness and permanence; ,2) reduction of toxicity, mObility or
volume through treatment; 3) short-term effectiveness:
4)implementability; and 5) cost. The balancing test emDhasized 10n9-
. t~rm effectiveness and permanence and the reduction of toxicity,
mobility and volume through treatment; and considered the preterence
for treatment as a principal element, the bias against off-site land
lecord of Decf.fan, ~rswortll Sanitary Landfill Sl4l8rfWld Sft., Jww 21, 1~
-------
disposal of untreated waste, and community and state acceptance. The
selected remedy provides the best balance of trade-offs among the
alternatives.
The selected remedy, Alternative 5, provides the best balance among
the alternatives that complied with ARARs and were protective. As
described in Section IX., Summary of the Comparative Analysis of
Alternatives, Alternative 5 and Alternative 4, rank highest among the
alternatives for both long-term effectiveness and permanence and.
reduction of toxicity, mobility or volume through treatment. For
short-term effectiveness Alternative 5 ranks among the top four
alternatives which met the threshold criteria. It ranks somewhat
lower than the top four alternatives (Alternative 6b, ac, ad, and 10)
on implementability because of its use of an emerging, innovative
technology. However, it ranks significantly higher than Alternative 4
which relies on enhanced biological mechanisms to be effective.
Alternative 5 ranks in the top two, along with Alternative 4, for
lowest costs. The State has supported the selected remedy, including
the. contingency remedy. . Based upon comments received at the public
hearing and written comments, the community conditionally supports the
selected remedy over all others which meet ARARs and are protective.
The primary concern of the community is the cost of any remedial
action. Furthermore, Alternative 5 is the remedial action alternative
which was most strongly favored by the Somersworth Landfill Trust
throughout the development of the Feasibility Study.
E.
The Selected Remedy Satisfies the Preference for Treatment Which
Permanently and Significantly reduce. the Toxicity, Mo~ility or
Volume of the Hazardous Substances as a principal Element
The principal element of the seleoted remedy is the in-situ treatment
of ground water by a chemical treatment wall. This element addresses
the primary threat at the Site, contamination of ground water. The
selected remedy satisfies the statutory preference for treatment as a
principal element by permanently reducing the toxicity of contaminants
in the groundwater.
XII. DOCUMENTATION OP SIGNIFICANT CHANGES.
EPA presented a proposed plan (preferred alternative) for
remediation of the Site on December 14, 1993. The source control portion
of the preferred alternative included an in-situ chemical treatment wall
and landfill cover. The management of migration portion of the preferred
alternative included natural attenuation and limited bedrock ground water
extraction and treatment. A contingency alternative was p~esented should
the preferred alternative prove not to be protective. The contingency
alternative included a landfill cover meeting the requirements of RCRA C, a
perimeter slurry wall with upgradient ground water diversion and wetland
recharge, and overburden and bedrock ground wa~er extraction and treatment.
Based upon comments received during the public comment period, EPA, in
consultation with the New Hampshire Department of Environmental Services,
has determined that the contingency alternative, if implemented, would be
constructed in two stages. The first stage would include all components of
lecord of D.cf.fon. SC88ra.o.-th S8'1itary Landfill ~fWld Sft.. J... Z1. 1994
-------
the original contingency alternative except the overburden ground water
extraction and treatment. The goal of this stage would be to lower the
ground water below the waste, thereby minimizing or eliminating the
production of leachate and the migration of contaminants beyond the
compliance boundary above cleanup levels. The need for the second stage
extraction and treatment of overburden ground water within the slurry wail
would be determined based upon an evaluation of the effectiveness of the'
first stage to minimize leachate production and contaminant migration.
Water levels would be monitored to determine if the water table falls below
the waste and water quality will be evaluated to determine if ARARs can be
attained at the compliance boundary. This change to the contingency
alternative could result in potential cost savings that would be realized
if pumping and treating the overburden ground water within the slurry wall
is not necessary to meet ARARs and to be protective.
XIII. STATE ROLE
The New Hampshire Department of Environmental Services has reviewed the
various alternatives and has indicated its support for the selected remedy,
,including the contingency remedy. The State has also reviewed the Remedial
Investigation, Risk Assessment, Feasibility study, and Feasibility Study
Addendum to determine if the selected remedy is in compliance with
applicable or relevant and appropriate state environmental laws and
regulations. The State of New Hampshire concurs with the selected remedy
for the Somersworth sanitary Landfill site. A copy of the declaration of
concurrence is attache~ as Appendix D.
R8COf"d of Decision. Sc88ra.....th Sanitary Landfill S",*,nnd Sit., .1&818 21, 1994
-------
-------
Figure 1
SOMERSWORTH SANITARY LANDFILL SITE LOCATION MAP
BERWICK, MAINE
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. MUNICIPAL LANDFILL SITE
-------
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-------
FIGURE 5
Typical Multi-layer Cap Cross Section
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APPENDIX A
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Addendum to the Risk Assessment for Somersvorth MuniciDal
Landfill
Somersworth. Hew BamDshire
June 21. 1994
prepared by Mary Ballew, Environmental Scientist,
-------
I.
II.
III.
IV.
V.
VI.
VII.
Table of Contents
Introduction to human health risk assessment...3
A.
components of the risk assessment...3
B.
summary of site description,
investigations...5
history,
earlier
and
Hazard identification...6
A.
data sources, evaluation and statistical analysis...6
B.
selection of contaminants of concern...S
Exposure assessment...ll
A.
characterization of exposure setting...ll
B.
identification of exposure pathways...13
c.
quantification of exposure...15
Toxicity and dose-response assessment...16
A.
carcinogenic responses...16
B.
noncarcinogenic responses...17
Risk characterization...19
A.
methodology...19
B.
risk summary...20
c.
discussion of uncertainties...23
Summary and conclusions...23
Appendix A
concern. . .25
toxicity
profiles
contaminants
of
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risk addendum for Somersworth June 21, 1994 ---
I. INTRODUCTION
As part of the Remedial Investigation/Feasibility study (RI/FS)
at Superfund hazardous waste sites, the National Oil and
Hazardous Substances Pollution Contingency Plan' requires the
performance of baseline human health and ecological risk
assessments. The purpose of the baseline risk assessment is to
determine, in the absence of remediation, whether contaminants
identified at the site pose a current or potential risk to human
health or the environment. The analysis assists in evaluating
whether remediation is necessary.
. The purpose of this addendum is to supplement the human health
section of an earlier risk assessment based on exposure
measur~~ents from 1986. This study examines the risk for two
populations near the Somersworth landfill: future residents
along Blackwater Road (area 5) and in area 4 (wetlands). The
only scenario evaluated herein is the risk to a future resident
whom will inqest groundwater from wells in areas 4 and 5. This
analysis only uses samples collected from tes~ wells between
November 1989 and January 1992. .
A. Components of the risk assessment
The risk assessment for human health consists of four components:
hazard identification, exposure assessment, toxicity evaluation,
and risk characterization. Hazard identification examines the
contamination at the site and selects the contaminants of concern
(COCs), which are those contaminants likely to pose the greatest
risk to human health. The exposure assessment estimates
exposures to receptor populations from site-specific data on
releases of chemicals. The toxicity evaluation describes the
toxicological effects from exposure to each COC and summarizes
relevant toxicity criteria. The risk characterization estimates
carcinogenic and noncarcinogenic risks by using information from
the toxicity evaluation and the exposure assessment. uncertainty
is also evaluated within the risk characterization.
'National Oil and Hazardous Substances Pollution Contingency
Plan, Final Rule. 40 CFR part 300, Federal Register,
55(46):8666, 1990.
2Wehran Engineers and Scientists and GOldberg-Zoino &
.. Associates, Inc., Remedial Investigation for Somersworth
Municipal. Landfill, Somersworth, New Hampshire, May 1989.
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risk addendum for Somersworth June 21, 1994 ---
This addendum to the risk assessment was conducted in accordance
with the following EPA guidance:
US EPA Reqion I Waste Manaqement Division Risk Ucdates:
December, 1992
Risk Assessment Guidance for SUDerfund (RAGS). Volume I:
Human Health Evaluation Manual
(Part A) interim final, EPA 540/1/-89, December
1989.
Development of Risk-Based preliminarv Remediation
Goals (Part B) publication 9285.7-01B,
December 1991, PB92-963333.
Risk Evaluation of Remedial Alternatives (Part C).
pUblication 9285.7-01C, December 1991, PB92-
963334.
Human Health Evaluation Manual. SUDDlemental Guidance:
"standard Default EXDosure Factors" OSWER Directive
9285.6-03 (EPA, March 25, 1991).
SUDDlemental Guidance to RAGS:Calculatinq the Concentration
Term, (Publication 9285.7-08I, June 22, 1992)
EPA Reqion I SUDDlemental Risk Assessment Guidance for the
SUDerfund Proqram (EPA 901/5-89-001, June 1989).
Final Guidance Data Useabilitv in Risk Assessment (Part A)
(publication 9285.7-09A, April 1992, PB92-963356)
Guidance for Data Useabilitv in Risk Assessment (Part B).
(publication 9285.7-09B, Ma~ 1992, PB92-963362)
Dermal EXDosure Assessment: Pr~Dles and ADDl~
(EPA 600/8-91/0118, January, 1992)
Air/Superfund National Technical Guidance study Series.
Volumes I, II, III, and IV (EPA 450/1-89-001,002,003,004,
July 1989).
Guidelines for:
a. Carcinogen Risk Assessment (51 FR 33992, September
24, 1986);
. . b.
Exposure Assessment Guidelines (57 FR 22887,
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risk addendum for Sornersworth June 21, 1994
B.
Summary of site description, history and earlier
investigations
This section summarizes information available in the report of
the remedial investigation: please see this report for further
details. The Somersworth Municipal Landfill is located in the
central portion of Somersworth, New Hampshire, approximately one
mile southwest of the City proper. The approximately 26 acre
site is situated entirely on land owned by the City of
Somersworth. The City has owned and operated the landfill since
1945. There is little information about the composition of the
waste generated and no records from the landfill operation. One
industry acknowledged disposing of eighty 35-gallon drums of
chemical waste per week3. Other industrial wastes included
paper, plastic, wood, rags, and leather. Given the contamination
at the site, the few records of industrial usage probably
underestimate what was disposed at the site. Although the
landfill was still active in 1989, the last year reported in the
RI, at that time it accepted only those materials that cannot be
incinerated. In 1989, these materials were disposed of in the
western portions of the landfill (the "stump dump"). The eastern
part of the landfill contains a recreational complex with a
playground, playing fields, and tennis and basketball courts. To
the east and adjacent to the landfill is an apartment complex,
National Guard Armory and firehouse. To the south lie several
residences and an auto repair shop. ,To the west about 200 to 300
feet from the landfill lies Peter's Marsh Brook. An associated
wetland lies along the western and northern edges of the
landfill.
Two water supply wells were located near the landfill; well
Number 3 about 2300 ft north-northwest and Number 4 about 800 ft.
southwest. Both have been dismantled and sealed because of high
metals, inadequate yields, and the risk of contamination from the
landfill. Another groundwater production well, residential well
RW-2 located immediately south of the landfill, was
decommissioned by 1989 (Wehran risk assessment). Groundwater
from the landfill is moving in a west-northwesterly direction.
There is direct hydraulic communication between the overburden
and the heavily fractured bedrock underlying it, so for risk
assessment purposes this is a single unconfined aquifer. All
surface runoff from the active and inactive portions of the
landfill eventually reaches Peter's Marsh Brook. This is a
tributary of Tate's Brook which is a tributary of the Salmon
Falls River. Both Somersworth, New Hampshire and. Berwick, Maine
take their drinking water from this river. The intakes on the
3The RI did not specify the number of weeks during which
this disposal occurred.
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risk addendum for Somersworth June 21, 1994
river are about 1.5 miles north-northeast of the landfill and
about 7.5 miles downstream. The Wehran risk assessment estimated
that less than 3% of the concentrations that reach Peter's Marsh
Brook would subsequently reach the intakes on the Salmon Falls
River.
The Somersworth municipal landfill accepted municipal and
industrial refuse for on-site disposal between the mid 1930's and
1981. Local industries include tanneries, bleacheries, shoe
manufacturers, and metal finishing operations. Since there is a
lack of records at the site, it is not clear which of these
industries disposed of waste therein. Groundwater quality
studies (initiated in 1980) indicated that the volatile organic
compounds (VOC's) leaching from the landfill were contaminating
the groundwater under the site. Subsequent investigations
documented both inorganic and organic contamination of
groundwater and surface water in the area.
The site was listed on EPA's National Priority List (NPL) in
accordance with the National contingency Plan (NCP) and the
Comprehensive Environmental Response, Compensation, and Liability
Act (CERCLA, commonly referred to as the "Superfund"
legislation). The NPL listing triggered remedial investigative
activities under the direction of EPA, the first of which was a
Remedial ActiQn Master Plan (RAMP) in September 1983. Work on
the Remedial Investigation (RI) was initiated by November 1984
by Wehran Engineers and Scientists and the final RI report was
submitted by May 1989.
II.HAZARD IDENTIFICATION
A.
Data sources, evaluation and statistical analysis
This section describes the data sources and the methods used to
statistically analyze, describe, and summarize the data.
Canonie Environmental sent EPA-New England a list of wells and
contaminants sampled at Somersworth. The State of New Hampshire,
which in this case superceeds the EPA Contract Laboratory
Program, reviewed the data. This analysis uses samples collected
from test wells between November 1989 and January 1992.
Following the terminology of the RI and the earlier risk
assessment (see below) we divided the site into two areas of
interest. Area 4 is a wetland bordering the landfill and Roger
Duwart identified 19 sampling locations in the plume in this
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risk addendum for Somersworth June 21, 1994 ---
area: B-6L", B-6Rs, B-8L, B-8R, B-9L, B-9R, OB-2, OB-3, OB-4U6,
OB-4R, OB-SU, OB-SR, OB-6U, OB-6R, OB-16U, OB-16R, OB-17U, OB-
17R, OB-18U. Area 4 is downgradient of the landfill according to
the EPA-New England hydrologist. Area S contains S sampling
locations: B-12R, B-12L, B-13R, B-13L, B-13WT. Area 5 is not
downgradient of the assumed borders of the landfill but according
to the EPA-New England hydrologist it is downgradient of one
highly contaminated well. It is possible that the landfill
extends further than assumed and that this contaminated well is
within the real boundaries of the landfill or that there is a
second, highly contaminated source of solvents within the
landfill. The upper and lower aquifers communicate significantly
at Somersworth so I did not separately analyze their risks.
I contacted steve Stodola at the EPA lab in Lexington and he
advised me on how to analyze and interpret the raw data. The
data qualifiers are slightly different from those used by EPA-New
England. Rejected results did not appear in the data. Data was
marked as "not evaluated" (NE), "not reported" (NR), or "not
detected" (ND) . The State of New Hampshire distinguished between
two types of estimated data: (1) an estimate for which the
detected concentration of the analyte was higher than the
calibration ~ange (E); and (2) an estimate for. which the detected
concentration of the analyte was below the quantitation limit
(J). Following EPA-New England policy7, estimated data and data
without qualifiers was used in the risk assessment. Samples
marked with a B meant that the chemical was also found in the
laboratory blank. Following EPA policy8, I used the Sx,lOx rule
to distinguish true readings of the chemical from false positives
caused by contamination. For common laboratory contaminants 9
10, the sample must have ten times more chemical than the blank
to be valid. For all other chemicals, the concentration in the
""L" refers to a sample taken from the lower part of the
upper aquifer
s"R" refers to a sample taken from a bedrock well
6"U" refers to the upper part of the upper aquifer.
7Region 1 Supplement to RAGS, op cit.
8RAGS 1989, op cit.
9 ie., acetone, methyl ethyl ketone, methylene chloride,
toluene, and phthalate esters
10p.5-16 in Risk Assessment Guidance for Superfund, vol 1,
Human Health Evaluation Manual (Part A) EPA/540/1-89/002 Dec.
1989.
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risk addendum for Somersworth June 21, 1994
sample must be five times greater than in
The blank for this comparison was the one
time to the sample. If the sample failed
the sample was a nondetect.
the blank to be valid.
collected closest in
the 5x,10x rule, then
All nondetects were set to one half of the detection level and
different chemicals had different limits of detection. The
nondetects entered into the calculation of an "average case"
scenario. In accordance with EPA-New England guidance, this
scenario is based on the arithmetic mean of the concentration of
contaminants in the plume. Only wells located over or
downgradient of the plume entered into this calculation. This
approach is currently under review by an EPA workgroup. The
"reasonable worst case" exposure scenario is based on the maximum
concentration of a chemical measured in a sample. The results of
duplicate samples were averaged; however, samples from the same
well at different time periods were not averaged.
The UptakejBiokinetic (UBK) model, version 0.99d, was employed to
calculate risks from lead exposures. This model examines
exposures for the most sensitive members of the population which
the model assumes to be children between the ages of 6 months and
6 years. Lead concentrations in ground water (average' only as .
recommended by EPA) were entered into the model and default
parameters were used for the remaining variables.
B.
Selection of contaminants of concern
After assembling the data, I used the risk screening table from
Region III" to exclude from further consideration chemicals
with either.low toxicity or low concentrations. This narrowed
down to 15 contaminants of concern for area four and seven for
area five. Table 1 shows the contaminants of concern in each
area of the site and the wells with the highest hits at each
site. It also shows the number of samples with exceedances of
MCLs out of those in which a COC was detected. In area four, the
wetlands, contamination appears widespread. Vinyl chloride,
manganese, arsenic, benzene, and 1,2-DCE are highest at the edge
of the 1and~ill. Antimony, ch1orobenzene, cobalt, beryllium, and
methylene chloride are highest just outside the landfill. TCE,
PCE, 1,1-DCE, lead, and carbon disulfide are highest about 1,000
feet downstream of the landfill in the wetlands. Most of the.
metals were highest in the bedrock wells and the wells in the
lower part of the upper aquifer. Although the contamination
extends quite far into the area four wetlands, the largest part
"Memorandum from Roy L. Smith, PhD., Senior Toxicologist,
Region III EPA to the RBC Table mailing list concerning the risk-
based concentration table, third quarter 1993; memo dated July 9,
1993.
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risk addendum for Somersworth June 21, 1994 ---
of the toxic contamination is less than 1,000 feet away from the
landfill. The MCLs or action levels were exceeded for eight
contaminants of concern in area 4. The evidence for a true
exceedance of MCLs or action levels is weakest for antimony12,
arsenic13, benzene1'-, and lead1s and strongest for 1,2-
dichloroethene, tetrachloroethene, trichloroethene, and vinyl
chloride. The.evidence for exceedance of MCLs is particularly
strong for vinyl chloride (23 samples exceeded the MCL out of 27
samples with detects of vinyl chloride) which chemical also
presents the greatest risk at the site. In area five, which is
near the residences along Blackwater Road, all but one of the
COCs were highest in a bedrock well, B-12, on the edge of the
landfill. Most of the few samples collected for 1,2-
dichloroethene,trichloroethene, and vinyl chloride exceeded
their MCLs (table 1). These are the same chemicals that are
major contaminants in area four. The small number of samples
collected in this location mean that any analysis based on these
numbers is very uncertain; the true concentrations of
contaminants could be higher than those represented herein.
1ZBased on the small number of total detects and the small
number ot exceedances of MCLs.
13Based on the small number of exceedances of MCLs given the
large number of samples with detects.
14Based on the small number of exceedances of MCLs given the
large number of samples where benzene was detected. .
15Based on the small number of detects of lead and the small
number. of detects that exceed the action level.
-------
Table 1.
Contaminants of concern at Somersworth
contaminant
of concern,
MCL
(ppb)
area 4,
wetlands
highest
well
area 5,
Blackwater Rd
highest
well
antimony, 6 >MCL16, 2/417 B9R18 not COC19
arsenic, 50 >MCL, 3/22 OB17U20 not COC
benzene, 5 > MCL, 4/19 OB17U, x21. B12R
OB17R
beryllium, 4 x B6R not COC
B8Li2
carbon disulfide x OBSR not COC
chlorobenzene x B6L not COC
1,1- x OB6U x B12R
dichloroethene, 7
1,2-dichloro- >MCL, 12/31 OB17U >MCL, 5/7 B12R
ethene, 70
lead, AL=15 >AL, 2/7 B8L not COC
manganese x OB16R x B12L
methylene >MCL, 4/7 OBSR not COC
chloride, 5
tetrachloro- >MCL, 6/13 OB6U x B12R
ethene, 5
trichloro- >MCL, 18/27 OB6U >MCL, 4/4 B12R
ethene, 5
vinyl chloride, 2 >MCL, 23/27 OB17U >MCL, 4/5 I B12R
16>MCL or AL ~ highest level exceeds MCL or action level.
17(1 ot samples >MCL)/(# of samples with detects).
18R = the bedrock aquifer.
19not COC = not a contaminant of concern in area 5 because
it fails to pass the region III risk screening test.
20U= the upper part of the upper aquifer.
21X = contaminant present.
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III.
EXPOSURE ASSESSMENT
This section evaluates the likelihood, magnitude, and frequency
of exposure to the contaminants of concern at the Somersworth
site. It identifies the pathways and routes by which receptors
may contact contaminants. Exposure assessment includes: (1)
characterization of exposure setting which describes the physical
setting and identifies potentially exposed populations; (2)
identification of exposure pathways which identifies the media of
concern and the actual and potential exposure routes; (3)
development of exposure scenarios which describes both the
present and future scenarios and the exposure parameters; and (4)
quantification of exposure which estimates exposure point
concentrations and doses. Based on the description of the site
in the RI, the physical characteristics of the site were used to
ass~ss the pathways by which human receptors may become exposed
to site contaminants. Exposure scenarios were developed based on
this information and consideration of land use and human behavior
patterns. Given that this document is an addendum to an earlier
risk assessment23 and that there is new data only for
groundwater, only the groundwater pathway will be evaluated
herein. Additional pathways were evaluated in the Wehran risk
assessment and. the situation at the site has not changed
sUbstantially since that analysis. Estimates of exposure doses
were calculated for the groundwater exposure pathway considering
the future use. of the site. In accordance with current EPA-New
England guidance, the average-case and reasonable worst-case
exposures (maximum contaminant concentrations) were assessed.
Values for intake variables (such as consumption rates) were
chosen so that the combined effect of all of the values will
result in conservative but reasonable estimates. Therefore not
all intake variables will represent maximum values.
A.
Characterization of exposure setting
The physical characteristics of the site and characteristics of
the human population on and near the site were evaluated to
determine which parameters might influence exposure to site
contaminants and to help identify exposure pathways. The
physical setting of the Somersworth site is described in Section
I. This section focuses on the actual and potential receptors at
the site. Land use as described in the RI was evaluated in
assessing the present and potential populations which live, work,
or otherwise spend time at or in the area of the Somersworth
site. This analysis assesses the likelihood that. various groups,
23Wehran Engineers and Scientists, Methuen, MA., and
GOldberg-Zoino and Associates, Inc., Manchester,NH., Volume I,
Remedial investigation, Somersworth Municipal Landfill,
Somersworth, New Hampshire. Prepared for New Hampshire
Department of Environmental Services, Waste Management Division,
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risk addendum for Somersworth June 21, 1994 ---
including sensitive subpopulations, will be exposed to site
contaminants.
1.
Receptors under present land use
The Somersworth Municipal Landfill is a 26-acre landfill that
received liquid and solid wastes from local industries and
residences from the mid-1930's to about 1981. After 1981,
landfill operations ceased and the western part of the landfill
was used as a "stump dump" for tree stumps, brush, and household
appliances. The Somersworth Municipal Landfill is located in a
generally urban setting on the outskirts of the city of
Somersworth. The site is about one mile southwest of the city
center. In 1985 the population of Somersworth was about 11,400.
The. population of Berwick, Maine on the other side of the Salmon
Falls River was about 4,200.
There are residences near the landfill along Blackwater Rd.
There are employees at several businesses and a National Guard
Armory nearby. The workers, because they spend less time near
the landfill, should receive lower exposures to the toxicants
than the residents, so this analysis considers the most exposed
and sensitive population to be residents. Pedestrian access to
the site and the contaminated wetlands is unrestricted. Fishing
takes place in Peter's Marsh Brook, however access to the brook
and movement through the adjoining the wetlands is difficult.
There is heavy seasonal hunting of woodcock and partridge in the
wetlands. Vehicular access to the site is possible. Trespassing
is likely and there is a possibility of motorcycle access.
Trespassers, primarily youths, are the most probable receptors af
contaminants present in sediments and surface water from the
contaminated wetlands. At present, the western part of the
landfill is covered with the "stump dump" and clean fill and the
eastern part of landfill is covered with clean fill about 0.5 to
3 feet deep (in the Forest Glades Park): therefore the present
hazard to trespassers from the surface soils on the landfill is
small. Wehran in 1989 found ponded areas on the playground and
the landfill. Water in the ponds or the leaching of contaminants
through the fill material to the surface soil in these locations
could be a source of exposure to trespassers. Landfill workers
are potential receptors of site contaminants but their exposure
is less than that of a youth trespasser for all contaminated
media but ambient air. It is assumed that the workers will avoid
the sediments and surface waters in the wetlands because ot their
knowledge of contamination there and because they will be busy
working. Groundwater in the vicinity is contaminated with the
metals manganese and iron. Because of tha poor water quality,
two public water wells near the landfill and a private well along.
Blackwater Road are closed. At present no one drinks' the .
groundwater from wells near the landfill.
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risk addendum for Somersworth June 21, 1994 ---
2.
Receptors under future land use
Land immediately south of the Somersworth landfill is currently
occupied by residences. There is the possibility of further
development in this area along Blackwater Road. At present the
houses in the area use town water and the well water, if they
tried to use it, is unpleasant because it is contaminated with
metals that affect the taste and appearance of the water. At
present it is not economical to remove the metals from the water
but in the future treating water for metals may become cheaper so
that future residents, industries, or even the municipal water
plant may decide to use groundwater in the vicinity of the
landfill.
.There is a possibility of a future risk to trespassers if the
soil cover on the site erodes, especially in areas of high human
contact such as the playground, playing fields, or motorcycle
trails~. Also leaching of chemicals through seasonal ponding
areas on the playground or landfill may eventually lead to
contamination of surface soils in small "hot spots".
B.
Identification of exposure pathways
The purpose o~ this step is to identify complete exposure
pathways to be evaluated in the risk assessment. To be complete,
a pathway must consist of the following four elements:
. a source and mechanism of chemical release into the
environment;
. a transport medium by which the released chemical may reach a
receptor (such as groundwater) ;
. a point of potential contact of the human receptor with the
contaminated medium:
. an exposure route (such as ingestion or inhalation)
The sources and mechanisms of chemicals at the site are discussed
in section I of this report. Transport media, points of .
potential contact, and exposure routes are discussed in the
Wehran RI report in the chapter on risk assessment. Discussion
of the exposure pathways (above) shows that the situation at the
site has not changed substantially since the 1989 .risk assessment
was performed. Although EPA currently uses different guidances
and standards for risk assessment, the 1989 risk assessment used
the appropriate guidances available at that time. EPA does not
require the re-calculation of risks for the site unless there is
new information or a change in site conditions since the last
assessment.
Since the. only media for which there is new information is
groundwater and the current risks from groundwater should not
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risk addendum for Somersworth June 21, 1994 ---
change substantially since the last risk assessment24, this
analysis will concentrate only on the risks of ingestion of
groundwater by future residents at the site. Also, if there
been any change in risk since 1989, ingestion of groundwater
likely to show the greatest change.
have
is
Based on anticipated future use of vicinity ground water,
ingestion of groundwater is a potential route of exposure.
Future ingestion of groundwater from wells at the boundary of the
landfill (especially along Blackwater Road) is considered a
viable exposure option. Also, the no-action alternative and some
of the proposed treatments for the site do not exclude the
possibility of drilling a groundwater well through the landfill
or the contaminated wetland in the future. Because the aquifers
, in the overburden and the highly fractured bedrock are
substantially hydraulically connected, exposure to groundwater
will be evaluated for both water bearing units together.
Exposure to residents via dermal contact with contaminated
groundwater was not evaluated quantitatively in the risk
assessment because the magnitude of such exposure should be
insignificant compared to other groundwater sources. This is due
to the short duration of exposure and the low permeability of the
skin to contaminants in tap water.25 The inhalation exposures
from the domestic use of groundwater contaminated with VOCs can
only be evaluated qualitatively. Quantitatively estimating this
exposure source is difficult because the inhalation models of
volatilized contaminants during bathing, showering, or cooking or
from seepage into basements are highly uncertain and depend on
site conditions. It is even more difficult to estimate the
exposure of future residents.26 The residential receptor for
future scenarios involving ground water was assumed to be a 70 kg
adult. Future residents adjacent to the landfill were assumed to
be exposed to groundwater for a period of 30 years which is the
90th percentile for time at a single residence.u They were
assumed to ingest contaminated waster on a daily basis, except
for two weeks spent away from home, which results in 350 days per
year of exposure.
Z4This is because currently groundwater is not being
consumed at the site.
z5Supplemental Risk Assessment Guidance for the Superfund
Program, EPA 901/5-89/001, June 1989.
UIbid
z7Human Health Evaluation Manual, Supplemental Guidance,
Standard' default exposure factors, interim final, Office of Solid
Waste and' Emergency Response, March 1991.
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risk addendum for Somersworth June 21, 1994 ---
The Wehran RI details information about the exposure pathways,
exposure points, and receptor populations at the Somersworth
Municipal Landfill. This RI considered all of the reasonable
pathways, including ingestion of ground water (based on 1986
samples), ingestion of surface soils or dry exposed sediments,
dermal contact with surface soils or dry exposed sediments,
ingestion of submerged sediments, dermal contact with submerged
sediments, dermal contact with surface water from perennial water
bodies, and inhalation of air emissions. The additional exposure
pathways are adequately covered in the textU and tables~ of
this report so they will not be discussed further herein.
c.
Quantification of exposure
This section describes the methodology and approach for
determining exposure point concentrations of COCs and chemical
specific intakes (dose) for the receptors and pathways selected
for quantitative analysis. The exposure point concentration is
the measured or estimated amount of a chemical in the
environmental medium of concern at the point of human contact.
Exposure point concentrations were developed for the groundwater
pathway based only on recent site sampling data (Chapter II).
conservatively, concentrations at exposure points for future
scenarios were assumed to be those measured during field
sampling. No dilution or degradation was assumed. The exposure
point concentrations for water are expressed in mass per unit
volume (milligrams per liter, mgjl). To represent the reasonable'
maximum exposures, the maximum concentration was used as the
exposure point concentration. The average exposure was evaluated
using the arithmetic mean concentration. The method ,of
calculating the average was explained in Chapter II. The
following equation was used to estimate the exposure dose to
humans that would result from the concentration of the
contaminant in the sampled groundwater:
28chapter 8, risk assessment in Volume I, Remedial
investigation, Somersworth Municipal Landfill, Somersworth, New
Hampshire, Wehran Engineers and Scientists, and GOldberg-Zoino &
Associates, Inc, May 1989. '
, 29See Table 15 and note Tables 16-21, risk assessment tables
in Volume II, Tables, Remedial investigation, Somersworth
Municipal Landfill, Somersworth, New Hampshire, Wehran Engineers
and Scientists, and Goldberg-Zoino & Associates, Inc, May 1989.
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risk addendum for Somersworth June 21,
1994 ---
Figure 1. Ingestion of chemicals in drinking water, future
residential exposure scenario~
exposure dose (mg/kgday) =
C x IR x EF x UC
BW x AVG x 365 days/yr
where:
C = groundwater concentration (~g/l)
IR = water ingestion rate (2 l/day)
EF = exposure frequency (350 days/yr)
UC = units conversion (1 x 10.3mg/~g)
BW = body weight (70 kg for an adult)
AVG = number of years over which the exposure is averaged
(70 years for carcinogenic and 30 years for non-carcinogenic
effects)
IV.
TOXICITY AND DOSE-RESPONSE ASSESSMENT
This section presents scientific evidence of toxicity and reviews
the relationship between dose and health effects for each
contaminant of concern. Section V., Risk Characterization, uses
this information to estimate the carcinogenic and non-
carcinogenic risks to a population exposed to the COC's on site.
Sources of toxicity information are EPA's Integrated Risk
Information System (IRIS) on-line database and the scientific
literature. Toxicity values came from the following sources, in
descending order of use: .
. IRIS
. Health Effects Assessment Tables (HEAST) and Supplements
. EPA's Environmental Criteria and Assessment Office
Appendix A contains summaries of toxicity information for all of
the contaminants of concern. These summaries also include the
standards and criteria in effect now for each COCo The
inhalation and oral slope factors were used to calculate the
carcinogenic risks of the COCs and the RfDs were used to
calculate the noncarcinogenic risks (hazard index).
A.
Carcinogenic responses
Evaluation of the effects of COCs known or suspected to be
carcinogens (EPA classes A, B1, B2) conforms to the most recent
EPA policy. Slope factors (also known as cancer potency factors)
estimate the risks from cancer. The slope factor is the upper
95% confidence limit of the slope of the dose-response curve and
30From Risk assessment guidance for superfund (RAGS), Volume
I- Hum~n Health Evaluation Manual (Part A). December 1989.
-------
risk addendum for Somersworth June 21, 1994 ---
is extrapolated to low doses. When a slope factor was not
available for a cae, the cancer risk was not evaluated
quantitatively.
Table 2. The EPA classification for the weight of evidence of
carcinogenicity.
cancer class
description of evidence
group A sufficient evidence exists from
human carcinogen epidemiological studies to support a
causal association between exposure to a
given agent and cancer
group B
probable human
carcinogen
B1 limited human evidence and sufficient
animal evidence
B2 sufficient animal evidence and no or
inadequate human evidence
group C limited animal evidence and no or
possible human inadequate human evidence
carcinogen
group D inadequate animal and human data
not classifiable as
to human
carcinogenicity
group E evidence of noncarcinogenicity in humans
probable
noncarcinogen
B. Noncarcinogenic responses
Although lead is a carcinogen (EPA class B2) the calculations for
the health risks of lead are based upon noncarcinogenic
endpoints. For estimation of the risks from lead in residential
areas, EPA requires use of the UptakejBiokinetic model (UBK
model) for lead and EPA-NewEngland uses version O.99d (May 1994)
of the model. The average concentrations of lead in groundwater
enters into the model as the concentration of lead in drinking
water and the rest of the model uses the default parameters. EPA
requires calculation of the risk from lead for the most sensitive
population which is assumed to be children between the ages of 6
-------
months and 6 years.
risk addendum for Somersworth June 21, 1994 ---
Noncarcinogenic risks other than lead are estimated by analyzing
chronic exposures to COCs in relation to chronic reference doses
(RfDs). A chronic RfD is an estimate of a daily concentration of
a chemical to which the human population can be exposed without
experiencing adverse health effects during a lifetime of
exposure. The RfD takes into account the presence of sensitive
subpopulations in the human population.
Chronic RfDs are derived from the following equation:
. eq.1
where:
NOAEL =
LOAEL =
UF =
MF =
RfD (mgjkgday) or (mgjmJ) = NOAEL or LOAEL
UF*MF
the "no observable adverse effects level", the chemical
dose at which there is no statistically or biologically
significant difference in frequency of an adverse
effect between exposed and control populations.
the "lowest observable adverse effects level", the
lowest dose at which a statistically significant
difference in the frequency of an adverse effect
exists.
the uncertainty factor, which is included to account
for differences among species, variation in human
sensitivity, and extrapolations from subchronic to the
chronic NOAEL or from the LOAEL to the NOAEL.
the modifying factor, an additional uncertainty factor
that accounts for uncertainties in the overall validity
of the study and database.
If the oral RfD was not available for a given cae, then the oral
exposure pathway was not assessed quantitatively for that coco
Available d~ta on all COCs at Somersworth for chronic and
subchronic noncarcinogenic effects is listed in Appendix A. The
chronic oral RfDs listed include the appropriate uncertainty and
mOdifr,inq factors. For more information, see the EPA database
IRIS. 1
31Inteqrated Risk Information System (IRIS) on-line
database, National Library of Medicine, updated monthly (1994).
-------
risk addendum for Somersworth June 21, 1994 ---
v.
RISK CHARACTERIZATION
The goal of the risk characterization is to quantify the
increased probability of developing cancer or suffering an
adverse noncarcinogenic effect as a result of exposure to site
contaminants. The future human health risks attributable to the
site COC's are discussed in this section. The risk
characterization integrates data developed from the exposure
assessment and the toxicity and dose-response assessment to
derive numerical estimates of carcinogenic and noncarcinogenic
risk. Risk from Somersworth site contaminants is assessed for
groundwater under "average" and "reasonable maximum exposure"
(RME) (maximum detected concentrations) conditions.
A.
Methodology
Risk is a function of chemical toxicity and the route and
duration of exposure. EPA's cancer slope factors and RfDs,
discussed in section D, were used as indicators of toxicity in
the risk characterization. The chemical and pathway (water)
specific doses calculated in accordance with the method outlined
in Figure 1 is used to represent exposure. Summary risk tables
are presented within the text of this section. Risks associated
with lead exposure were evaluated using the lead Uptake
Biokinetic model (UBK), version 0.99d.
Incremental carcinogenic (CA) risk associated with exposure to
contaminants is typically calculated according to the following
equation: .
eq. 2
incremental CA risk = slope factor x dose
where the incremental CA risk represents the probability of
developing cancer over a 70-year lifetime from exposure to the
toxicants on site.
Cancer risk is unitless and usually expressed in the units of
scientific notation. For example, a risk of 1 x 10-6 (or lE-06)
indicates that an individual has one chance in a million
(1,000,000) of developing cancer as a result of a lifetime of
exposure to toxicants on site. Incremental cancer risk was
calculated for each COC for which EPA provides a slope factor
using the pathway of the risks to future adult residents from
ingesting groundwater. In accordance with EPA policy, the risks
from all carcinogenic contaminants were summed within each area
to provide total cancer risks for area 4 .and area 5. EPA has not
identified a single value that represents a significant
incremental cancer risk. However, the NCP target risk range for.
Superfund sites has been set at approximately 10-4 to 10-6 per
-------
risk addendum for Somersworth June 21, 1994 ---
environmental medium.32
Potential noncarcinogenic effects were evaluated based on a
comparison of chemical-specific chronic exposure doses with
corresponding protective doses derived from health criteria.
result of this comparison is expressed as the Hazard Quotient
(HQ) :
The
eq. 3
Hazard Quotient = Exposure dose/protective dose
A HQ that exceeds unity (one) suggests a greater likelihood of
deveioping an adverse subchronic or chronic toxic effect.
However, the uncertainty factors built into the protective dose
usually result in overly protective (conservative) dose values.
Therefore, the protective dose is likely well below that for
which adverse effects will be seen. HQs were calculated for each
contaminant for which health criteria are currently available
(Tables 3 and 5). The HQs for every contaminant were summed to
produce a rough estimate of the risk specific to a given pathway,
the Hazard Index (HI). In estimating the HI, potential responses
were conserv~tively assumed to be additive. This procedure gives
the best estimate of true risk when the HQs are summed for the
same toxic endpoint or target organ; combining .across toxic
endpoints gives only a crude index or estimate of hazard from the
chemical. '
B.
Risk Summary
An overall summary of the Somersworth site carcinogenic and.
noncarcinogenic risk from groundwater is presented in Tables 3 to
6. It does not include current risks of ingestion of groundwater
because no one is drinking the water at present (see Chapter I).
Risks from the site other than those from groundwater are
detailed in the Wehran 1989 RI referenced earlier. Risks are
calculated separately for area 4 (wetlands) and area 5
(Blackwater Rd) because of differing contaminant exposures to
receptor populations that might live in these areas in the
future. These tables include cumulative cancer risk values and
HIs for the pathway of ingestion of groundwater for adults. They
receive exposure in a scenario of future land use of drinking
water from wells adjacent to the landfill. Risks specific to a
medium, for which the NCP target risk range of 10-4 to 10-6
applies, can be calculated by summing all pathways for a given
medium and receptor. Chemical specific risk values (RfDs and
cancer slope factors) are presented in Appendix A.
3240 CFR Part 300, National Oil and Hazardous Substances
Pollution Contingency Plan, Final Rule, Federal Register, 55(46)
8666, '1990
-------
area 4 non-carcinogenic risk
Table J. Non-carcinogenic risks from ingestion of groulIllwillcr hy fUlurc ildult rcsidcnls ;tdJilccnllo Ihc' SlItncr!>worth silc. arcil .. wdl;lIIds
IIV
compound
antimony
carbon disulfide
chlorobenl.ene
dichloroethene( 1,2- )(tolal)
lead
manjl,anesc.
foot -
note s
MCt.
(mg/l )
RID highc!.t
oral COliC
mg/kgda y (mg/l or ppm)
ave.
conc
(mgll or ppm)
ill avcragc
COliC
ii.hc~J-h- -0.-006-- --0:0014 .-
lIa 0.1
lIa 0.02
0.07 0.001}
o'-04i . -- -2~8T(+OO
O.0.3S l.OE-02
0.005 6.HE-0.3
1.200 3.7E+OO
0.029 not applicablc
",~!5} -~ .2.SE:+OI
"--~---=-'O.M9-----' 1.31[.+Olf
0.006 1.7E-0.'
0.005 6.HE-0.3
0.177 5.4E-OI
o.om 1.4% > cutoff
-- O~!L,~_llE-t2Q
EPA
---. -- - -- -. - ---. - - - . .- - - -
arSenic-- ---0.050--- - A 1.75 0.203 4.~E-03
benzene 0.005 A 0.029 0.010 3.4E-06
beryllium k 0.004 B2 4.3 0.001 7.1E-05
dichloroethene(1.1-) I 0.007 C 0.6 0.004 2.8E -05
methylene chloride 0.005 B2 0.0075 0.076 6.7E-06
tetrachloroethene m 0.005 B2,C 0.052 0.14 8.5E-05
trichloroethene m 0.005 B2,C 0.011 0.370 4.8E -05
vinyl chloride g,n 0.002 A 1.9 1.900 4.2E-02
1I()
ilt highc!.t
COliC
c
f,g
h,i
na 1101
lIa- ~. J19£1S
--~.. - - - .
---------
Table 4. Carcinogenic risks from ingestion of groundwater by luture adult residents adjacent to the Somersworth site; area 4 wetlands
cancer cancer
potency highest risk at
MCL cancer lactor cone highest
footnotes (mg/l) class 1/(mg/kgday) (mg/l) cone
area 4 carcinogenic risk
,compound
-. -.. - - - -...
-- ------... .-
.-- .-".- - .----
-----...- ---- --
.. . --- - - ... .
....----_.--- -.-----.
.--.
SUMMARY OF AREA 4 RISKS
(1) Total cancer ri$k:
(2) lotal hazard index:
(a) blood or circulatory:
(b) liver or kIdney:
(c) CNS:
(3) children with blood lead above 10ug/dl:
risk at
maximum
exposure
4.7E-02
31.8
2.8
3.7
25
not applicable
risk at
average
exposure
3.0E -03
4.9
1.3
0.5
3.1
1.40%
ave
cone
(mg/l)
CY024
0.006
0.001
0.004
0.014
0.0138
0.054
0.107
...... .. -
Gllln:r
das.'i
lIa
lIa
D
D
B2
D
cancer
risk at
aye
cone
4.8E -04
21 E -06
71 E -05
2BE -05
12E -06
8.4E -06
7.0E -06
2.4E -03
sysll:lIl~
anct:lt:d
hy
t:u III P' IUlld
hluud. h";lrl
devduplllt:1I1
liver
liver. kidlley
-------
Footnotes 'or tables three and four:
a. na=not available
b. HQ is hazard quotient. .
c. method 'or calculating hazard quotient:
«cone mgJI * 2 Vday * 350 dlyr * 30 yr)/(30yr * 365d/yr * 70kg BW))IA'D mg/kglday
d. Risks above 1 E -4 or hazard quotients above 1.0 are in bold.
e. The Risk Assessment Guidance for Superfund (RAGS, 1989) recommends against presenting an average concentration
that is higher than the maximum sa"1'led at the site; we 'ollow RAGS herein.
When the maximum is close to the detection limit, as in this case, it sometimes occurs that the average,
as calculated according to EPA-New England guidance, is greater than the maximum.
Here the average calculated according to guidance is 0.006 mg/l and the risk at this concentration is 7.5E -03.
,. 'MCL based on the cis isomer which is the most hazardous.
g. RfD 'or 1,2-dichloroethene and cancer potency 'actor 'or vinyl chloride based on heast.
h. Lead has an action level for water d O.015mg/l.
i. At the average concentration of lead, 1.4% of children in the age group Six months
to 6 years (which is the most sensitive population) will have blood leads above 10ug/dl.
This is the concentration that the EPA proposes as a screening level for blood lead in children
EPA's goal is to keep the average blood lead for 95% 0' children below 10 ug/dl.
j. method 'or calculating cancer risk:
«cone mgJI * 2 Vday * 350d/yr * 3Oyr)/(70yr * 365d/yr * 70kg BW))* CPF 1/(mg/kg/day)
k. Here the average calculated according to guidance (see above) is 0.002 mg/I and the risk at this concentration is 8E -05.
I. Here the average calculated according to guidance (see above) is 0.006 mg/l and the risk is 4.2E -05.
m. From EPA ECAO.
n. The average concentration was calculated from all 0' the wells in the vicinity 0' the plume.
One ha" the concentration of the non-detects was substituted wherever there were non-detects.
-------
area 5 non-carcinogenic risk
Table 5. Non-carcinogcnic risks from ingestion of groundwater hy future adult residents ildJiln:ntto the Sonlnsworth site. area :\ BI.u:kwah:r Rd.
compound
- - ---
dichloroclhene( 1.2- )(lolal)
manganese
fool -
nole.: s
a:h.~:(J.cT-- - .0.07
g na
_. --- -- _u
MC!.
IUD highc~
oral conc
mg/kgday (mg/l or IIllm)
110
al highe~
COliC
ave.:.
cone
(mg/l or pplll)
Ill)
alavcragc
COliC
4.0E-':Of" --
4.6E+OO
----0.039' - .- - - -LtE-UI
0.:\50 1.9E+OO
c.llln:r
class
-n-- -
I)
--"-------
area 5 carcinogenic risk
Carcinogenic risks from ingestion of groundwater by future adult residents adjacent to the Somersworth site; area 5, Blackwater Rd.
cancer cancer
potency highest risk at
MCL cancer factor conc highest
footnotes (mg/I) class 1/(mg/kgday) (mg/I) conc
cancer
risk at
ave
conc
Table 6.
compound
- .. -
benzene --. - - u -- --- - --
dichloroethene(1.1-)
tetrachloroethene
trichloroethene
vinyl chloride
---=.:..=:==-- - - -=---==--~'-~h-,-i -.
J
k
k
f
-- --- -- -
- ---------
_. "-- ---
risk at
maximum
exposure
1.4E -03
4.6
SUMMARY OF AREA 5 RISKS
(1) Total cancer risk:
(2) total haZard index (CNS):
0.005
0.007
0.005
0.005
0.002
-. O:O(J') .- - -- -- O. i ~
U.005 O.MM
EPA
- ---.
--- - - -- ------
- - - - -- --
-------- ~
ave
conc
(mg/I)
A
e
B2,e
B2.e
A
0.029 0.001 - 3~4E .:ot 0.001
0.6 0.002 1.4E -05 0.002
0.052 0.004 2.4E-06 0.0035
0.011 6.200 8.0E -04 1.430
1.9 0025 5.6E-04 0.011
u --------
risk at
average
exposure
4.4E -04
1.9
3~4E :"'07
1.4E -05
2.1E-06
1.8E-04
2.4E -04
la rgl'l
or~al1
-------
Footnotes for tables five and six:
a. HQ is hazard qliotient.
b. method for calculating hazard quotient:
«cone mgJl * 21/day * 350 d/yr * 30 yr)/(30yr . 365d/yr * 70kg BW)/RfD mg/kg/day
c. The average concentration was calculated from all of the wells in the vicinity of the plume
One half the concentration of the non-detects was substituted wherever there were non-detects
This procedure is currenUy under review by EPA
d. Risks above 1E-4 or hazard quotients above 1.0 are in bold.
e. MCl ba~d'on the cis isomer which is the most hazardous.
f. RfD for 1,2-dichloroethene and cancer potency factor for vinyl chloride based on heast.
g. !\8=not available
h. method for calculating caneer risk:
«cone mgJl * 2 Vday * 35Od/yr * 3Oyr)/(70yr * 365d/yr. 70kg BW)* CPF 1/(rng/kg/day)
i. RAGS recommends against presenting an average concentration that is higher than the maximum sampled at the site;
we follow RAGS herein. When the maximum is close to the detection limit, as in this case, it sometimes occurs that the average,
as calculated according to EPA-New England guidance. is greater than the maximum
The average calculated according to guidarx:e is 0.006 mg/I and the risk is 1. 9E - 06.
j. The average calculated according to guidarce is 0.003 mg/I and the risk is 2.4E -05
-------
risk addendum for Somersworth June 21, 1994 ---
1.
Qualitative assessment of risk
Most of the contaminants at the site had either RfOs or cancer
potency factors from IRIS, HEAST, or the EPA ECAO. The only
contaminants that did not are potassium, magnesium, iron, and
sodium. EPA does not have standards for potassium or magnesium.
Both are essential nutrients for human health, constituents of
the human body, and have very low toxicity to humans. Magnesium
forms a body burden of about 20 grams in the bone and muscle and
the body has mechanisms to maintain a balance of magnesium
concentrations in the tissues. At the given concentrations in
groundwater, it is unlikely that either potassium or magnesium
will represent a risk to future residents near the landfill.
Although sodium is also an essential nutrient, chronic exposure
to high doses of sodium in drinking water has been linked to
increased blood pressure in humans. High blood pressure that
goes untreated for years is associated with circulatory and
kidney problems. EPA does not have an RFO or MCL for sodium but
has established a drinking water equivalent level (OWEL) for
sodium. The OWEL is a lifetime exposure concentration protective
of adverse, non-cancer health effects, that assumes all of the
exposure to a contaminant is from a drinking water source. The
DWEL for sodium is 20 mgjl. About 20 samples from areas four and
five exceed the OWEL. One well had 123 mg/l and another had 94
mg/l. This means that the groundwater is too salty to drink
safely over the course of a lifetime. It is unclear whether this
salt is site related, mobilized by the site, related to snow
removal activities, or naturally occurring.
Iron is also an essential nutrient but excess dietary iron can
cause chronic iron toxicity.33 In chronic iron toxicity, iron
in the human body increases from a normal level of three to five
grams (g) to an abnormal level of 20 to 40 g. It concentrates in
the liver, pancreas, spleen, endocrine organs, and heart.
Clinical effects from chronic iron toxicity include disturbances
in liver function, diabetes mellitus, endocrine disturbances, and
cardiovascular effects. EPA has a secondary maximum contaminant
level for .iron of 0.3 mg/l. The secondary MCL is a
recommendation for public water supplies and is based on
preventing stains on laundry and odor or taste problems in
drinking water. Many samples (22) from areas 4 and 5 exceeded
this concentration; the maximum concentration was 74.6 mg/l and
several wells exceeded 20 mg/l. The US Public Health Service in
1969 recommended that public water supplies be kept below 0.3
~
33casarett and Ooull's Toxicology, 3rd edition, Klassen CD,
Amdur MO, Doull J, ed. Macmillan 1986, pp 613-14.
-------
risk addendum for Somersworth June 21, 1994 ---
mg/l and they did base this recommendation on human health.34
The exact iron concentration in groundwater that would produce
chronic iron toxicity in humans is unclear, but it is probably
good to keep the iron levels below 0.3 mg/l. Most of the wells
near the landfill exceed this recommended level now so there will
be some risk of chronic iron toxicity if future residents ingest
the groundwater. If a person was safe from chronic iron toxicity
at levels below 0.3 mg/liter, then for a 70 kg man consuming 2
liters of water per day, the person would be safe consuming below
0.00857 mg/kgday. If this were the case, the hazard quotient for
iron in the groundwater at Somersworth would be at or below 240.
This HQ would make iron the largest noncarcinogenic risk at the
site. EPA does not yet have a national policy on the level of
iron that is safe for consumption in drinking water; however,
some iron ingestion is necessary to prevent anemia in humans.
2.
Quantitative assessment of risk
Tables three and four outline the noncarcinogenic and
carcinogenic risks for the wetlands in area 4 at the Somersworth
municipal landfill. The concentrations of 8 chemicals exceed the
maximum contaminant level (MCL): antimony, arsenic, benzene,
1,2-dichloroethene, lead, methylene chloride, tetrachloroethene,
trichloroethene, and vinyl chloride. Also, the maximum
concentration of lead in the groundwater exceeds the action level
for lead in drinking water. Noncarcinogenic hazard indices
exceeded unity by more than an order of magnitude for groundwater
ingestion by future residents. Manganese represents the greatest
hazard with a HQ of thirty one; the total hazard index is about'
32. Antimony and l,2-dichloroethene, that pose the other
noncarcinogenic risks, exceed one yet are less than ten. The
hazard from ingesting this water is greatest for effects to the
central nervous system. The UBK lead model predicts that, at the
average concentration of lead, about 1.4% of children ingesting
the lead in groundwater in area 4 will develop a blood lead above
10 micrograms per deciliter. The cancer risks in this area are
high;. the lifetime risk from vinyl chloride alone is 4 X '10.2 or
400 per 10,000 population. This is 100 to 10,000 times the 10-4
to 10-6 risk level. For each of arsenic, beryllium, and 1,1-
dichloroethene, lifetime cancer risk also exceeds 10-4. The
risks at the highest concentrations are about an order of
magnitude greater than those at the average concentrations;
however, even the average risk for arsenic and vinyl chloride
34From the US PUblic Health Service, Community Water Supply
study: Analysis of National Survey Findings, US .Department of
Health, Education, and Welfare, Washington, D.C. 1970, as cited
in pp.409-411 Casarett and Doull's Toxicology, 2nd ed., Doull J,
Klaassen' CD, Amdur MO, eds., Macmillan 1980.
-------
risk addendum for Somersworth June 21, 1994 ---
exceeds 10-4.
The total cancer risk at area 4 is about 5 x 10-2.
In area 5, where there are residences along Blackwater Road,
there are seven contaminants of concern and only three of those
exceed the MCL: 1,2-dichloroethene, trichloroethene, and vinyl.
chloride (Tables 5 and 6). In this area the hazard index, based
only on manganese, is five. Lead concentrations measured here
are too low to constitute a health risk. For each of
trichloroethene and vinyl chloride, lifetime cancer risk exceeds
1 x 10-4. The total cancer risk is about 2 x 10-2 at Blackwater
Road.
C.
Discussion of uncertainties
The carcinogenic and noncarcingenic risk estimates presented in
this .report are not intended to be calculations of absolute risk
to individuals who reside adjacent to the Somersworth Municipal
Landfill. Uncertainties in underlying data prevent exact
determination of risk to receptor populations. The goal of the
risk assessment is to provide reasonable, conservative risk
estimates to guide decision making. By using standardized
methodology guidelines (Chapter I) and standardized EPA default
exposure factors, risk assessments for Superfund sites provide a
basis for determining whether remediation needs to be considered.
Risk is broadly a function of exposure and toxicity. Therefore,
uncertainties in characterizing either of these lead to
inaccuracy in risk estimates. Also, future land uses and future
concentrations of contaminants in an area are uncertain. Given
the proximity of the site to the center of the City of
Somersworth, this land may be used for residential or industrial
purposes in the future. One large uncertainty in exposure at
this site results from the small number of wells (5) in area 5.
Only one of the wells was highly contaminated and it was
uncertain if the contamination in the other wells was from the
contaminated one or directly from the landfill. This is also the
area which is most likely to receive future development. If
exposure is underestimated here, the risks to future adult
residents ingesting groundwater from wells in area 5 may be
higher than. those shown herein.
VI.
SUMMARY AND CONCLUSIONS
Thus for both the wetlands in area 4 and Blackwater Road in area
5, the future cancer risks from ingestion of groundwater are
hundreds of times higher than the target risk range of the NCP.
In area four the lifetime cancer risk is about 5 x. 10-2 and in
area five about 2 x 10-2. The hazard indices show toxicity an
order of magnitude higher than unity in area 4 and about 5 times
unity in area 5. The total hazard index for area four is 32 and
for area. five is five. The risk from lead exposure is low at
area 5 and higher in area 4, where exposure exceeds the action
-------
risk addendum for Somersworth June 21, 1994 ---
level for lead. Therefore, it seems that the hazard from lead is
of concern in area 4 and minimal in area 5. The risk estimates
in area 5 are highly uncertain because of the small number (5) of
wells in this location and the future risks from ingestion of
groundwater in this location could be higher. The qualitative'
risk assessment shows that future residents that ingest the
groundwater may have considerable health risks from salt (sodium
chloride) and iron.
-------
risk addendum for Somersworth June 21, 1994 ---
VII.
Appendix A.
TOXICITY SUMMARIES FOR CONTAMINANTS OF CONCERN
This is a summary of toxicity information provided for the
benefit of the reader. All of these summaries (except where
noted) are based upon information provided to EPA in a work
assignment (COllSl) by TRC Environmental corporation for
Bennington landfill (4/4/94).
Antimony
Antimony is used: (1) as an alloy constituent in pewter and
white metal, (2) in the manufacture of storage battery plates,
solder and ammunition; (3) as a fire-retardant in textiles; (4)
to dye steel, aluminum, pewter and zinc; (4) as antimony
potassium tartrate, used as a medicinal and as a fixative in
dyeing. Antimony is naturally present in water bodies as
antimony oxide. It sorbs to clays and minerals and should be
stable in soils. Antimony primarily affects the lungs upon
inhalation and may lead to kidney and liver damage upon
ingestion.
Reports from humans and animals suggest that inhalation of about
4 mg/m3 antimony may lead to ca~diac dysfunction, injury to heart
muscle, and elevated blood pressure. Antimony may cause an
increase in spontaneous abortions in pregnant women and reduced
weight gain in infants whose mothers were exposed. Antimony is
mutagenic. Antimony increased the risk of lung cancer via
inhalation for exposed workers and rats but the number of studies
is insufficient to characterize it as a carcinogen. The LCso
values for Dachnia maqna and the fathead minnow range between
9,000 and 22,000 mg/l.
Standards for Antimony
Unclassified by EPA as to carcinogenicity
.oral slope factor
.chronic oral RfD
'MCL
. AWQC
NA
4 x 10-4 mg/kgday
0.006 mg/l
0.088 mg/l, acute (proposed)
0.030 mg/l, chronic (proposed)
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risk addendum for Somersworth June 21,
1994 ---
Arsenic
Industrial compounds of arsenic include arsenic disulfide,
arsenic pentoxide, arsenic trichloride, arsenic trisulfide, and
lead arsenate; the primary form is arsenic trioxide. The last is
used in the production of pigments, the manufacture of glass, the
printing of textiles, tanning, and the productio~ of anti-fouling
paints. Arsenic is quite mobile in the environment but the
number of valence states (4) makes it hard to characterize.
Arsenic readily bioaccumulates but often biotransforms to
methylated arsenicals which are volatile compounds that evaporate
from surface waters. It sorbs to clays, iron oxides, and
particulate matter. In the absence of sorptive materials arsenic
usually leaches into groundwater where it moves easily. Removal
of atmospheric arsenic occurs primarily through wet and dry
precipitation.
Arsenic absorbs easily into the human body through the
gastrointestinal lining. Absorbed arsenic distributes in the
nails, hair, .bone and skin in humans and metabolizes to
methylated arsenicals. Arsenic is acutely toxic to humans and
the subacute lethal dose for humans is about 0..6 mg/kgday.
Ingestion can cause nausea, vomiting, diarrhea and other
gastrointestinal disorders. Chronic exposure may cause tingling
or burning sensations in the skin, weakness, loss of body weight,
bronchitis, or skin disorders. Children who drank water
containing 0.8 mg/l arsenic developed myocardial infarctions and
arterial thickenings. Concentrations of arsenic in drinking
water of 0.5 mg/l may have caused gangrene in the feet and toes
in 0.9% of the exposed population in Taiwan. Arsenic increases
the frequency of fetal malformations, is teratogenic, and affects
DNA. Arsenic in drinking water increases the risk of skin
cancer. Inhalation of arsenicals increases the risk of lung
cancer. Rates of bladder, lung, kidney, and colon cancer may
also be elevated in a Taiwanese population exposed to arsenic in
drinking water. It is difficult to induce cancers in laboratory
animals exposed to arsenic. Arsenic is acutely toxic to .
freshwater and saltwater species and juveniles are the most
susceptible (toxicity can occur as low as 40 ~g/l.
Standards for Arsenic
EPA class A carcinogen
.oral slope factor:
.chronic oral RfD:
.MCL:
.AWQC:
1. 75 (mg/kgday) 0.1
3.0 X 1004 mq/kgday
0.05 mg/l
acute:
360 ~g/l
chronic:
190 ~g/l
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risk addendum for Somersworth June 21, 1994 ---
Benzene
Benzene is a clear, colorless, aromatic hydrocarbon that has a
sweet odor; its odor threshold is 2 ppm. It is extremely.
flammable and volatile. Benzene is widely used in the production
of industrial chemicals, such as styrene and phenols, and in the
manufacture of rubber, plastic, and inks. Benzene is photo-
oxidized rapidly (half-life less than one day) in the atmosphere.
Benzene is retained in moist soils and slowly transports into
groundwater where it is stable. Benzene is highly lipid soluble
and is absorbed via inhalation, ingestion, and dermal contact.
It is sequestered in fatty tissue and is detoxified in the liver.
Target organs include the bone marrow, CNS, and the respiratory
system. Acute exposure to benzene via inhalation can be fatal
within minutes. Chronic exposure can cause aplastic anemia,
leukop~nia, and thrombocytopenia in humans. In rodents, benzene
causes an increase in the incidence of tumors, carcinomas,
leukemias, and lymphomas that is directly proportional to dose.
Benzene causes statistically significant increases in the
incidence of leukemia in workers exposed via inhalation. It may
also cause lymphatic and hematopoietic cancers in humans.
Benzene causes leukemia in dogs and rats.
Standards for Benzene
EPA class A carcinogen
oral slope factor:
inhalation slope factor:
provisional RfC:
provisional RfD:
1 to 2 day AIC:
30 day AIC:
MCL:
2.9 X 10-2 (mg/kgday)-'
2.9 X 10-2 (m~/kgday)-'
6 x 10-3 mg/m (ECAO 3/25/94)
3 x 10-4 mg/k~day (ECAO 1/24/94)
3 x 10-2 mg/m (ECAO 4/14/94)
6 x 10-2 mg/m3 (ECAO 4/14/94)
5.0 /Jog/l
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riSk addendum for Somersworth June,21, 1994 ---
Beryllium
Beryllium is a gray metal that is used as an alloy in numerous
industries because of its light weight and high tensile strength.
As an alloy it is used in machinery parts, in springs, in non-
sparking tools, on airplanes, in drill bits, in watches, and in
switch parts. Exposure to beryllium is generally associated with
the processes of milling and alloying. Coal combustion and
milling releases particulate beryllium into the atmosphere.
Atmospheric beryllium deposits in the soil where it sorbs to
particulate matter in the relatively insoluble form of beryllium
oxide. In surface waters, most beryllium compounds hydrolyze to
beryllium hydroxide which sorbs to particulate matter in the
water. Beryllium is taken up by the lungs during inhalation and
the GI tract during ingestion of water. It accumulates primarily
in the skeleton although some collects in the liver and kidneys.
Acute exposures to inhaled beryllium in humans resulted in death
from interstitial pneumonitis. Chronic exposure in humans can
cause death by inflammation of cells within the alveoli;
enlargement of the heart, liver and spleen; cyanosis; and the
development of kidney stones. Beryllium increases mutagenicity
in hamster and human lymphocyte cells. It is carcinogenic in
animals but carcinogenicity has not yet been demonstrated in
humans. In rats only 5 ppm beryllium sulfate in drinking water
caused an increase in cancerous growths. Intravenous injection
caused bone cancer in rabbits and intratracheal injection caused
various cancers in the lungs of rats. Beryllium is toxic to
freshwater species and may be mildly toxic to saltwater species,
The presence of calcium carbonate in the water appears to
decrease the toxicity of beryllium. Addition of beryllium salts
to the diet of poultry and livestock caused changes in skeletal
growth and failure of long bones to develop properly.
Standards for Beryllium
EPA Class,B2 carcinogen
oral slope factor:
chronic oral RfD:
MCL:
AWQC:
4.3 (m?(kgday)-'
5 x 10. mg/kgday
4 x 10.3 mq/l .
acute: 130 ~g/l (LOEL)
chronic: 5.3 ~g/l (LOEL)
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risk addendum for Somersworth June 21, 1994 ---
Carbon Disulfide
Carbon disulfide is a clear, colorless, very flammable and highly
volatile liquid that has an ether-like odor when pure and a
sulfurous odor when impure. It is used in the manufacture of a
variety of products (e.g. rayon, cellophane, carbon
tetrachloride, rubber chemicals, flotation devices, ammonium
thiocyanate, sodium thiocyanate, xanthogenates, and insecticide)
and as a solvent. Carbon disulfide evaporates rapidly (with a
half life of 11 minutes) from surface water. Volatilization may
be the major escape route from soils as well, although this has
not been proven. The gas does not bind to soil particles.
Carbon disulfide is rapidly absorbed into the lungs of humans.
Carbon disulfide and its metabolites distribute rapidly to body
fat and highly perfused tissues in rats but does not appear to
bioaccumulate. Carbon disulfide is rapidly excreted via the
lungs and urine and its metabolites are excreted more slowly via
the urine. Occupational exposure to carbon disulfide is
associated with cardiovascular, neurologic, psychologic,
immunologic and ocular effects. . Rats exposed to high
concentrations showed alterations in blood cells; disorientation;
hair loss; and destruction of central and peripheral nervous
tissue. other studies in animals showed cardiovascular, hepatic,
renal, and gastrointestinal effects. Carbon disulfide may cause
resorption o( the developing fetus or reduce fetal body weights.
It causes testicular damage in male rats. There was an excess of
lymphocytic leukemia deaths in rubber workers exposed to multiple
solvents, one of which was carbon disulfide. There is evidence
of an association between exposure and disease, but because of
the number of other confounding exposures to solvents, it is
difficult to isolate an effect due to carbon disulfide alone.
Standards for Carbon Disulfide
Unclassified by EPA as to carcinogenicity
.oral slope factor:
.chronic oral RfD:
.MCL:
NA
1 x 10.' mg/kgday
NA
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risk addendum for Somersworth June 21,
1994 ---
Chlorobenzene
Chlorobenzene is a colorless liquid with a mild aromatic odor.
It is an intermediate in the production of dyes and pesticides"
and used to manufacture aniline, phenol, and chloronitrobenzene.
Chlorobenzene in air degrades slowly by free radical oxidation.
since it is both insoluble and volatile, its release in water
results in rapid transfer to air. It binds to soil where it
resists biodegradation and migrates slowly to water.
Chlorobenzene bioaccumulates in fish, aquatic invertebrates, and
algae and metabolizes to other compounds in higher organisms. In
rats that had acute inhalation exposures, chlorobenzene collected
in fat tissue, liver, and kidney. It is excreted via exhalation
and urination. Ingestion of chlorobenzene in beagles showed an
"increasing response with increasing dose: (1) cellular changes in
the liver "and bile duct at a moderate dose (55 mg/kgday), and (2)
death,. loss of body weight, gross liver pathology, kidney damage,
GI changes, and effects on the blood and urine at high dose
(about 270 mg/kgday). In mice and rats administered
chlorobenzene by gavage, low doses (60 or 125 mg/kg) produced
liver damage and decreased liver weight: moderate doses (250
mg/kg) caused decreased body weight gain and lesions: and high
doses (500 or 750 mg/kg) caused death, lesions in many organs,
decreased body weight gain, or altered serum biochemistry.
Inhalation studies in animals found little or no effect from
chlorobenzene. Chlorobenzene is acutely toxic to fish at levels
greater than 25 mg/1 and to aquatic invertebrates at levels
greater than 10 mg/l.
standards for Chlorobenzene
EPA class D carcinogen
.oral slope factor:
.chronic oral RfD:
.MCL:
NA
2 x 10-2 mg/kgday
NA
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risk addendum for Somersworth June 21, 1994 ---
1,1 Dichloroethene
1,1 Dichloroethene (1,1 DCE) is a clear liquid with a sweet
smell. It is used in the manufacture of paint, varnish, lacquer,
soap, and finish removers; as a solvent; and as a cleaning agent
in the dry cleaning industry. 1,1 DCE volatilizes from surface
waters and is photo-oxidized in the air. 1,1 DCE will probably
absorb to organic materials in surface soil and will volatilize
from surface soils with low organic content. It may readily
leach from soil and migrate into groundwater. In rats, 1,1 DCE
readily absorbs via digestion or inhalation and excretes through
exhalation and urination. Oral or inhalation exposure leads to
liver or kidney damage in rats, guinea pigs, rabbits, dogs, and
monkeys. Mice and rats showed increased DNA alkylation and
repair in both liver and kidney; this is a sign of mutagenicity
which indicates a potential for carcinogenicity in these organs.
Inhalation of 1,1 DCE caused kidney cancer in male mice and
mammary tumors in rats. 1,1 DCE is not extremely toxic to
freshwater or saltwater organisms; LC50 values (the concentration
lethal to 50% of the organisms) range between 80 and 200 mgjl.
Standards for 1,1 Dichloroethene
EPA class C carcinogen
'oral slope factor:
'chronic oral RfD:
'MCL:
6 X 10'1 (mgjkgday)-1
9 x 10'3 mgjkgday
7 J,l.gjl
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risk addendum for Somersworth June 21, 1994 ---
1,2-Dichloroethene
1,2-Dichloroethene(DCE) usually consists of a mixture of 60% cis-
DCE and 40% trans-DCE. Each isomer shows different toxic
properties. At room temperature, 1,2-dichloroethene is a liquid
with a slight acrid, ethereal odor. It is used as a solvent for
acetylcellulose, resins, and waxes; to extract rubber, oils, and
fats; as a refrigerant; and in the manufacture of pharmaceuticals
and artificial pearls.
The half-life of the vapor form of the trans isomer is about one
to six days and the cis isomer is even shorter. Volatilization
is probably the main means of dispersion from surface soils.
Some may be carried back to earth in rainwater. Biodegradation
of 1,2-DCE in subsurface soil is probably a slow process so that
it probably leaches from these soils into groundwater. One
author reported that about half the groundwater in New Jersey was
contaminated with the trans form.
Virtually 100% of ingested DCE and 35-50% of inhaled DCE may be
absorbed systemically. Ingestion of cis-DCE by rats caused liver
toxicity and inhalation of trans-DCE by rats caused damage to the
lung and liver. DCE exposure in rats reduced the ability of the
animals to detoxify contaminants (inhibits the MFO system) and
the cis isomer appeared to produce a stronger effect than the
trans. In animals, cis-DCE increased mutations and caused
chromosomal mutations in bone marrow. Acute toxicity occurs at
11.6 mg/l in freshwater and 224 mg/l in saltwater aquatic life.
Toxicity may occur at lower concentrations with more sensitive
species than those tested.
Standards for 1,2-dichloroethene
EPA Class D carcinogen for the cis isomer and no classification
for mixed isomers.
chronic oral RfD:
cis:
1 x 10-2
2 x 10-2
9 x 10-3
70 ~g/l
100 ~g/l
mg/kgday
mg/kgday
mgjkgday
MCL:
trans:
mixed:
cis:
trans:
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risk addendum for Somersworth June 21, 1994 ---
Lead
Lead and its compounds may enter and contaminate the global
environment by natural occurrence or during mining, smelting, .
processing, and use. Lead consumption increased by 3% for every
year between 1962 and 1971 which was largely due to demands for
batteries and gasoline additives. Residents may be exposed to
lead via paints and plasters, crayons from China, glazes in
pottery, lead fumes or ashes from the burning of battery casings,
car. exhaust in areas where gasoline contains lead, and the use of
solder or paint in hobbies. Particulate lead is removed from the
atmosphere by wet or dry deposition. Its transport in ground or
surface waters depends on its oxidation state. In polluted
waters and soils, lead strongly binds to organic materials.
However,it is not easily absorbed by living plants.
. .
Adults absorb about 8% of ingested lead and children absorb 50-
60%. This rate can be influenced by nutritional status and the
presence of or type of food in the stomach. About 35 to 40% of
inhaled lead is absorbed by adults and the amount absorbed
depends on particle size. In humans hemopoiesis is the most
sensitive system affected by lead; as little as 0.4 ~g Pb/ml
blood in adults decreases the amount of hemogLobin and heme
proteins produced. Chronic exposure of rats to 5 mg Pb/l water
produced slight effects on the conduction velocity of nerves,
blood pressure, and the source of energy in heart muscle (cardiac
ATP). Lead exposure during childhood has been linked to deficits
in higher mental functions (as measured by IQ and other tests).
occupational exposure to lead during pregnancy increases
miscarriages, premature delivery, and early membrane rupture.
Lead also produces developmental and mutagenic effects in
animals. There is a correlation between sister-chromatid
exchange and lead exposure in workers. Lead that composes as
little as 1% of the diet (or 3 to 4 mg/day or 500 to 2000
mg/kgday) can yet increase the incidence of renal tumors in rats.
Lead nitrate produces chronic toxicity in freshwater crustaceans
at as little as 12 ~g/l.
standards for Lead
EPA class 82 carcinogen
There is no RfD or slope factor; EPA requires the use of the UBK
model to determine the noncarcinogenic risks of lead; there is no
policy on the carcinogenic risks.
Action level:
AWQC:
0.015 mg/l
acute: 0.083 mg/l
chronic: 0.0032 mq/l
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risk addendum for Somersworth June 21, 1994 ---
Manganese
Manganese (Mn) is used as an allqy in steel and iron
manufacturing. Manganese compounds are used in the manufacture,
of batteries, paints, varnishes, dyes, inks, fireworks,
fertilizers, and disinfectants. Organic Mn is used as an anti-
knock agent in unleaded gasoline in the US and Canada. In the
atmosphere, Mn is present as a particulate form and breaks down
by photochemical and thermal reactions. It is removed from the
atmosphere by wet and dry deposition. The environmental fate of
Mn in water is affected by the amount of dissolved oxygen and the
a9idity of the water. In the presence of dissolved oxygen, Mn
forms oxide compounds which either remain suspended or deposit in
the sediments. The residence times of these compounds can be as
much as 300 years. In soils, the solubility of Mn is increased
with'low.pH and with high concentrations of chlorides, nitrates,
or sulfates. Under these conditions, Mn is transported readily
and is absorbed rapidly by plants., Also, these conditions often
prevail in the leachate from landfills; although the Mn at a site
may be naturally occurring, the presence of leachate may increase
the solubility of Mn and facilitate its transport or uptake.
Absorption of Mn occurs primarily in the gastrointestinal tract
and is controlled homeostatically by the amount of Mn already
present in the body. Under normal conditions approximately three
percent of ingested Mn is absorbed. Small Mn particles deposit
in the alveoli and are excreted within four days. About 40 to 70
percent of absorbed Mn is excreted in the feces. Mn appears to
be absorbed differently from food than from drinking water, so
EPA developed two separate oral RfDs (IRIS 4/9435). Mn is an
essential nutrient in the human diet. Standard diets from the
US, England; and Holland reveal average daily intakes of 2.3 to
8.8 mg Mn/day. Normal intake may be well over 10 mg per day,
especially in vegetarian diets. The National Research Council
declared that an "adequate and saf~" level of intake was 2-5
mg/day for adults. Mn exposed adults in Greece showed a
increased frequency of neurobehavioral symptoms that showed a
dose-response relationship. Such symptoms included weakness,
fatigue, gait disturbances, tremors, and problems with muscle
tone. Well. water in the high exposure area had 1600 to 2300 ~g/l
Mn versus 3.6 to 14.6 ~g/l in the low exposure area; symptoms
appear at a dose of about 0.06 mg/kgday. Their dietary exposure
might have been somewhere between 5 and 15 mg/day; the exact
number is unsubstantiated. In Japan, residents consuming large
amounts ot Mn from water contaminated with battery wastes
experienced severe neurobehavioral symptoms of lethargy,
35Since much of the information about the toxicity of
manganese involves recent research that was not reflected in the
TRC toxicity profiles, much of the information that follows is
referenced in IRIS.
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risk addendum for Somersworth June 21, 1994 ---
increased muscle tonus, tremor, and mental disturbances. The
most severe symptoms were seen in the elderly and children
appeared unaffected. By retrospective estimation, the water may
have contained 28 mg/l of Mn which is an intake of about 0.8
mg/kgday in a 70 kg adult. Studies in rats and Rhesus monkeys
support these findings although rats are far less sensitive than
humans to the effects of Mn. Neonatal rats show a much greater
rate of GI absorption of Mn than rats even a few days older (days
1 to 14 vs day 18). Also, neonates show a greater rate of
transfer of Mn from the blood to the brain than do adults.
Dieter et al (1992) (see IRIS) says that, because of the greater
sensitivity of the young, "if there were a toxicological limit to
Mn according to the principles of preventive health care, then it
would have to be set at 0.2 mg/l of Mn for infants as a group at
risk." The EPA RfD of 0.005 mg/kgday is roughly equivalent to a
drinking water standard of 0.2 mg/l. However, at this point
there is no MCL for Mn and even 0.2 mg/l may not be sufficient to
protect the infant population since the RfD is based on a lack of
response in adults at this concentration. Mn appears naturally
in several different valence states and many different compounds
which may have different absorption rates and toxicities.
Manganese depresses reproductive functions in male and female lab
animals, and causes impotence, still births and spontaneous
abortions in humans. It has mutagenic effects in bacterial and
mammalian cells. Manganese compounds, such as Mn chloride, Mn
acetylacetonate, and Mn dioxide, increase the incidence of tumors
near the site of injection. EPA does not, however, conclude that
the same is true for elemental Mn. Inhalation of Mn or Mn
compounds by workers at levels typically found in Mn production
facilities leads to significant increases in the frequency of .
neurobehavioral symptoms such as: fatigue; memory, attention and'
concentration difficulties; nightmares; sweating; sexual
dysfunction; lower back pain; joint pain; and noises in the ears.
In advanced Mn poisoning at the higher levels found in some
workplaces, the symptoms are even more severe (hand tremor,
changes in handwriting, loss of balance when turning, difficulty
in reaching a fixed point).
Standards for Manganese
EPA Class D Carcinogen
chronic oral RfD:
water:
food:
10-3 mg/kgday
x 10-"
10-5 mg/m3
5 x
1.4
5 x
NA
water and fish consumption: 0.1 mg/l
fish consumption only: ~one
A criterion for domestic water supplies of 0.05 mg/l should
minimize the objectionable qualities of Mn, such' as staining of
laundry and undesirable taste (Quality Criteria for Water, July
1976, PB-263943).
chronic inhalation RfC:
MCL:
AWQC:
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risk addendum for Somersworth June 21, 1994 ---
Methylene Chloride
Methylene chloride is a widely used industrial degreaser and
paint remover. It is a low temperature extractant; a solvent for
oil, fats, waxes, and cellulose acetate; a flammability
depressant in aerosols; and a caffeine extractant for coffee and
tea. It leaves surface soils and water primarily through
volatilization. In the atmosphere it photo-oxidizes to carbon
dioxide, carbon monoxide, and phosgene, or returns to earth via
wet and dry deposition. It does not sorb well to soils and does
not bioaccumulate. It readily leaches to groundwater.
It is readily inhaled and concentrates in adipose tissue
primarily, and in brain, blood, and liver secondarily. In rats
doses of 50 mg/kgday resulted in histologic alterations of the
liver. Subchronic exposure (to> 100 ppm methylene chloride) of
rats produced narcosis and lethargy. In humans, methylene
chloride produces irritation of mucus membranes and side effects
such as lassitude, loss of appetite, numbness, and light
headedness. Acute exposure causes heart arrhythmia and death in
humans and liver and kidney damage in lab animals. It is
mutagenic in' bacterial cells and causes mitotic recombination in
yeast cells.
Rats and mice exposed to up to 4000 ppm methylene chloride
developed mammary adenomas, fibroadenomas, hepatocellular
adenomas, and carcinomas. Female rats exposed to 5 and 250
mg/kgday showed a slight increase in the incidence of
hepatocellular carcinomas and neoplastic nodules. Acute toxicity
for freshwater species range between 193,000 and 224,000 mg/l and
for saltwater species between 256,000 and 331,000 mg/l.
Standards for Methylene Chloride
EPA Class 82 Carcinogen
oral slope factor:
chronic oral RfD:
MCL:
7.5 X 10'3 (mg/kqday)'1
6 X 10.2 mq/kqday
5 /J.9/ 1
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risk addendum for Somersworth June .21, 1994 ---
Tetrachloroethene
Tetrachloroethene, often called perchloroethylene (PCE) , is a
clear liquid with an odor similar to that of ether. It is used.
as a dry-cleaning solvent: a degreaser: a fumigant: a chemical
intermediate: and medically as a anthelmintic. It volatilizes
rapidly when released to surface waters and soils. In the
atmosphere it interacts with hydroxyl radicals to produce carbon
monoxide, carbon dioxide, and hydrogen chloride. It adsorbs to
the organic material in soil, however in soils with low organic
content tetrachloroethene leaches into and transports readily in
groundwater. It degrades slowly in groundwater where it can
remain for months or years. In water in degrades to vinyl
chloride and dichloroethene.
Tetrachloroethene distributes mainly to fatty tissues and at much
lower concentrations in the blood and liver of humans. Only four
percent of the tetrachloroethene absorbed by humans is
metabolized. Absorbed tetrachloroethene is excreted via the
lungs and its metabolites are excreted via the urine at a half
life of 144 hours. When taken orally it is absorbed via the GI
lining and this transport is facilitated by fats and oils.
Chronic exposure in humans effects the CNS, mucous membranes,
eyes, and skin. Acute exposure can cause unconsciousness,
dizziness, or vertigo and can be fatal at massive doses. In rats
and mice, it causes toxicity to kidney and liver tissue. It
causes fetal resorption and skeletal abnormalities in rats and
mice. Tetrachloroethene causes cancer, often liver cancer, in
rats and mice. Dry cleaning workers exposed to PCE, carbon
tetrachloride, and trichloroethene had an excess of lung,
cervical, and skin cancers and leukemia. Tetrachloroethene is
moderately toxic to aquatic organisms. It is toxic to trout at
an LC of 4.8 mg/1.'
Standards for Tetrachloroethene
EPA class falls on a continuum of 82 to C
oral slope factor:
chronic oral RfD:
subchronic oral RfD:
MCL:
5.2 X 10-2 (mg/kgday)-1
1 X 10-2 mg/kgday
1 x 10-1 mg/kgday
0.005 mg/l
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risk addendum for Somersworth June 21, 1994 ---
Trichloroethene
Trichloroethene (TCE) is a synthetic chlorinated hydrocarbon that
is colorless, nonflammable, and noncorrosive. It is used as a
metal degreaser, to decaffeinate coffee, as a dry cleaning agent,
and as an intermediate in the production of pesticides, paints,
and varnishes. TCE is moderately volatile and used nationwide so
it appears in many hazardous waste sites. About 3 percent of
drinking water supplies came from well water containing TCE above
0.5 .~g/l. Much of the TCE released comes from the metal
degreasing industry in the form of volatilization and accidental
spills. Large amounts of spent TCE is now reclaimed. TCE
volatilizes from surface waters and soils and is rapidly degraded
in .air. In moist soil and groundwater, TCE is stable and can
remain there for months or years. TCE usually degrades to 1,2
dichloroethene or vinyl chloride. The major avenue of TCE
contamination to humans is via groundwater. It does not
bioaccumulate in animals or food chains. TCE ingested by rats
concentrated in the fat, kidney, lung, male reproductive system,
brain, and liver. TCE and its metabolites excrete via urine,
exhalation, sweat, feces, and saliva.
Oral exposure of humans to 15 to 25 ml TCE caused vomiting and
abdominal pain followed by transient unconsciousness; it damages
the liver. In rats and mice it caused kidney damage. There is a
high rate of miscarriages among women exposed to TCE in the
workplace. In animals, exposure caused reduced fetal body
weight, delay in development of the skeleton, male reproductive
problems, and hydrocephalus. It is mutagenic in bacteria.
TCE is produces liver cancer in different strains of mice via
inhalation or oral exposure. A study in the dry cleaning
industry (see tetrachloroethene) showed cancer in the workers.
It took very high concentrations of TCE to kill freshwater
aquatic organisms (about 39 to 100 mg/l) so that at most
concentrations found in water, TCE is practically nontoxic for
freshwater aquatic organisms.
Standards for Trichloroethene
EPA class on a continuum from B2 to C
oral slope factor:
chronic oral RfD:
MCL: .
1.1 x 10-2 (mq/kqday)-l
6 x 10-3 mg/kgday
0.005 mq/l
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risk addendum for Somersworth June 21, 1994 ---
Vinyl Chloride
Vinyl chloride is used in the manufacture of polyvinyl chloride
(PVC) , rubber, glass, electrical wire, and automotive parts.
When released to surface waters, vinyl chloride volatilizes to
the atmosphere within a few hours where it chemically degrades.
In the atmosphere it degrades within a day or two of its release.
When released to the ground, it does not absorb to soils and
leaches readily to groundwater. In groundwater it may degrade to
carbon dioxide and the chloride ion. Groundwater is the major
source of human exposure to vinyl chloride. In groundwater vinyl
chloride forms as a byproduct of the degradation of some
chlorinated hydrocarbon solvents such as trichloroethene and
tetrachloroethene. vinyl chloride is absorbed rapidly in rats
'exposed via inhalation and ingestion. It concentrates in the
liver, kidneys, muscle, lungs, spleen, brain, and fat of rats.
Vinyl chloride produces acutely and chronically toxic,
developmental, and carcinogenic effects in humans and animals.
Vinyl chloride and its metabolites are excreted in the urine.
Vinyl chloride is toxic to the liver in workers exposed during
the manufacture of PVC. Chronic exposure to high concentrations
of vinyl chloride causes bronchitis, headache,' irritability, and
severe systemic disorders such as sclerotic syndrome36, bone
alterations, a decrease in blood platelets, and liver damage.
Vinyl chloride causes skeletal abnormalities and increase in
fetal death rates in animals exposed via inhalation. A
significant increase in fetal deaths was noted in women whose
husbands were occupationally exposed. Vinyl chloride also
produced abundant chromosomal aberrations in exposed workers. It
appears to be mutagenic in bacteria and fruit flies. Vinyl
chloride is a known human and animal carcinogen. Chronic
occupational exposure increases the number of carcinogenic tumors
in the liver, brain, lung, hemopoietic system, and the
lymphopoietic system.
standards for Vinyl Chloride
EPA Class A-Carcinogen
Oral slope factor:
chronic oral RfD:
AIC:
1. 9 (mg/kgday)-'
NA
2 x 10-2 mg/mJ
cancer)
0.002 mg/l
(not protective against
MCL: ,
36Hardening of the skin
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APPENDIX B
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PREFACE
The U.S. Environmental Protection Agency (EPA) held a pUblic
comment period, from December 15, 1993, to February 14, 1994, to
provide an opportunity for interested parties to comment on the
March 1993 Feasibility Study (FS), the Feasibility StUdy Addendum
and the December 1993 Proposed Plan prepared for the Somersworth
Sanitary Landfill Superfund Site (the "Site") in Somersworth, New
Hampshire. The FS examines and evaluates various options, called
remedial alternatives, for addressing contamination of
groundwater, soil and sediment at the Site. EPA identified its
preferred alternative for the cleanup of the Site in the Proposed
Plan before the start of the pUblic comment period.
The purpose of this responsiveness summary is to identify major
comments raised during the pUblic comment period and to provide
EPA response to the comments. EPA has considered all of the
comments summarized in this document before selecting a final
remedial alternative for the contamination at the Site.
This responsiveness summary is divided into the following
sections:
I.
ov:~~~w.o~ Remedia~ A~te~[aI~~e~ ~O~~~d~~e~ ~~ ~h~ '
F;:S~~:~1;~ Studv a d ea b 1t t d n m nclud1nq
the Preferred Alter~ative - This section briefly outlines
the remedial alternatives evaluated in the draft FS and the
Proposed" Plan, including EPA's preferred alternative.
II.
Backaround on Communitv Involvement and Concerns - This
section provides a brief history of community interest and.
concerns regarding the Site, as well as, EPA initiatives in
keeping the community informed of Site activities.
III. S~~~~~ of Comments Received Durina the Public Comment
Period and EPA R~;-"'" ..- ''''5 - '":'~is section summarizes and
provides EPA resp:.;.:.:>.;:=> to the oral and written comments
received from the pUblic during the public comment period.
In Part I, the comments received from citizens and EPA's
responses are organized by subject. In Part II, the'"
comments received from Potentially Responsible Parties
(PRPs) are presented, followed by EPA's response.
Exhibit A - This exhibit is a copy of the transcript " from the
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I. OVERVIEW OF REMEDIAL ALTERNATIVES CONSIDERED IN THE DRAFT
FEASIBILITY STUDY AND FEASIBILITY STUDY ADDENDUM, INCLUDING THE
PREFERRED ALTERNATIVE
Alternative 1: No Action. This alternative was evaluated
in the FS to serve as a baseline for all remedial
alternatives under consideration. Under this alternative,'
no action would be taken except for long-term monitoring of
ground water near the site on a semi-annual basis.
Alternative 2: Limited Action. This alternative is
similar to Alternative 1, except in addition to semi-annual
ground water monitoring, it would include institutional
controls to minimize the potential of exposure to
contamination.
Alternative 3: Limited Action, Landfill Cover, Extraction
of Bedrock Ground Water with Treatment, Ground Water
Monitoring. This alternative combines the Limited Action
alternative (identified above) with an engineered landfill
c9ver and extraction of ground water from the bedrock at
monitoring well B-12R and from a series of wells in the
bedrock downgradient of the landfill.
Alternative 4: Limited Action, Landfill Cover, Enhanced In-
situ Bioloqical Treatment, Natural Attenuation, Bedrock
Ground Water Extraction with In-situ Treatment, and Ground
Water Monitoring. This alternative uses enhancement of
natural biological processes to treat the contamination
flowing through the landfill. Additional, necessary
nutrients would be applied to the landfill to hasten the
biological degradation processes and naturally detoxify the
contaminated ground water entering the wetlands area.
EPA's selected remedy is Alternative 5.
Alternative 5, Limited Action,Landfill Cover, In-Situ
Chemical Treatment and Ground Water Diversion, Ground Water
Extraction from Bedrock, and Ground Water Monitoring. The
key element of this alternative is the construction of a
permeable treatment wall composed of impermeable barrier
sections and innovative, permeable, chemical treatment
sections to provide in-situ (in-place), flow-through
treatment of contaminated ground water at the landfill waste
boundary.
Alternative. 'a and 'hi Limited Aotion, Landfill Cover,
Slurry .all (Partial ['a] or Perimeter ['h]), Batural
~ttenuation, Bedrock Ground .ater B&traction with Treatment,
and Ground .ater Monitorinq. These alternatives would add a
partial or a perimeter slurry wall to Alternative 3 in order
to more effectively contain the waste by lowering the ground
water below the waste thus, minimizing migration of
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3
ground water diversion would be required to 'prevent the
artificial raising of the ground water when it encounters
the slurry wall. This diverted ground water would be
recharged into the wetlands to lessen the impacts caused by
the interruption of flow.
Alternatives 7a and 7b: Limited Action, Landfill Cover,
Bedrock and Overburden Ground Water Extraction With On-Site
C7a) or Off-site C7b) Ground Water Treatment, and Ground
Water Honitoring. These alternatives provide for a landfill
cover with the addition of extraction of contaminated ground
water from the overburden aquifer underlying the landfill.
For Alternative 7a, the groundwater would be treated and
discharged on site. For the off-site treatment option,
Alternative 7b, treatment would be done at the Somersworth
wastewater' treatment facility. Pretreatment might be
needed.
Alternatives 8a and 8b: Limited Action, Landfill Cover,
Bedrock and Overburden Ground Water Bxtraction with On-site'
C8a) or Off-Site Ground Water Treatment C8b) and Partial
Slurry Wall, and Ground Water Honitoring. These
alternatives include the same components as Alternatives 7a
and 7b (Limited Action, Landfill Cover, On-Site and Off-Site
Ground'Water Extraction/Treatment/Discharge) with the
addition of a partial slurry wall upgradient from the
landfill (Sa for on-site treatment and Sb for off-site
treatment).
EPA's contingency remedy would be Alternative Sc or Sd.
Alternative 8c or 8d: Limited Action, Landfill Cover,
Perimeter Slurry Wall with Ground Water Diversion,
OVerburden Ground Water Bxtraction within Slurry Wall,
Bedrock Ground Water Extraction, on-Site (8c) or Off-Site
(8d) Ground Water Treatment and Discharge,and Ground Water
Honitoring. These alternatives differ from Alternatives Sa
and Sb by the addition of a perimeter slurry wall which
would result in lower pumpinq rates and minimization of
wetlan~ dewatering effects.
A1ter.Da~ive" Complete Ixcavation, Removal, and Off-Site
Di.po.al of Landfilled Waste, .atural Attenuation, Bedrock
Ground Water Extraotion with Treatment, and Ground Water
Monitoring. Alternative 9 involves the excavation and oft-
site disposal of solid wastes and sUrface soiis present at
the site. Extraction and treatment ot bedrock ground water
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4
Alternative 10: Limited Action, Landtill Cover, Complete
Excavation and on-site Reconsolidation ot Landtilled Waste,
Bedrock Ground Water Extraction with Treatment, and Ground
water Monitoring. This alternative would differ from
Alternative 9 in that wastes would be completely removed
from below the water table, reconsolidated on-site and
placed entirely above the water table, then capped with an
impermeable cover.
Background on community Involvement
II.
Throughout the Site's history, community concern and involvement
have been increasing as costs of the remedy have become clearer.
EPA has kept the community and other interested parties apprised
of the Site activities through informational meetings, fact
sheets, press releases and public meetings.
Since the lead agency for the performance of the Remedial
Investigation was the New Hampshire Water Supply and Pollution
Control Commission (NHWSPCC), the predecessor to the Department
of Environmental Services, Waste Management Bureau, NHWSPCC
addressed community concerns and kept citizens informed about and
involved in activities during the Remedial Investigation. On
December 10, 1984, NHWSPCC held an informational meeting in the
Wood School, Somersworth to describe the plans for the Remedial
Investigation'. On June 21, 1989, NHWSPCC held an informational
meeting in the Wood School, Somersworth to discuss the results of
the Remedial Investigation and to describe plans for the
Feasibility Study.,
On December 9, 1993, EPA made the administrative record available
for public review at EPA's offices in Boston and at the
Somersworth Public Library. EPA published a notice and brief
analysis of the Proposed Plan in Foster's Daily Democrat on
December 29, 1993, and made the plan available to the public at
the Somersworth Public Library.
On December 14, 1993, EPA held an informational meeting to ,
discuss the results of the Remedial Investigation and the cleanup
alternatives presented in the Feasibility Study and to present
the Agency's Proposed Plan. Also during this meeting, the Agency
, answered questions from the public. From December, 15, 1993,
through February 14, 1994, the Agency held a public comment
period to accept comments on the alternatives presented in the
Feasibility Study and the Proposed Plan and on any other
documents previously released to the public. On February 8,
1994, ,the Agency held an informal public hearing to discuss the
Proposed Plan and to accept any oral comments. A transcript ot
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5
III. Summary of Comments Received During the Public Comment
Period and EPA Responses
A.
citizen and Interested Party Comments
Comment A-l: One resident of Somersworth expressed concern over
the appearance of the landfill and the odor on a hot summer day.
He felt that complete excavation and incineration was the only
way to solve the problem.
EPA Response: Excavation and off-site disposal was evaluated in
the teasibility study and Proposed Plan. This alternative was
not chosen because: it would not address ground water
contamination as effectively as the preferred alternative and its
costs were much higher than the preferred alternative. The
incineration technology option was screened out during the
Feasibility study on the basis of technical inapplicability.
Also, the cost of this option would be much higher than the
preferred alternative.
Comment A-2:, Several commenters expressed concerns about the
costs associated with both the preferred alternative and the
contingency alternatives and the impacts upon ~he taxpayers of
Somersworth.
SPA Response: EPA is sensitive to the cost impacts that
Superfund remedies have on municipalities. One reason that EPA
chose the innovative technology alternative and would allow the
contingency alternative to be staged is the potential cost
savings which could be realized. In addition, while EPA believes
that the City is a Potentially Responsible Party for .
contributions to the cost of the cleanup, EPA has also named
other parties as being responsible for cleanup costs.
Comment A-3: Several commenters stated that the Superfund Law
should not require PRPs to pay for activities done before the law
was enacted. These commenters suggested that the federal
government should pay for remedial actions rather than placing
the burden on municipalities.
BPA ...poD..1 The Superfund Law does not affix blame for actions
taken prior to its enactment, but rather it requires parties that
took actions that caused or may cause public health or
environmental problems to be reSDonsible for funding the remedies
to those problems. If no such parties are found, Superfund
monies are then able to be expended on the cleanup. To use the
limited Superfund monies to pay for cleanups at all Superfund
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6
Comment A-4z One commenter provided business literature from a
firm specializing in bioremediation techniques to assist in EPA's
evaluation of alternatives.
EPA Response: Bioremediation was an integral element in
Alternative 4. This option was not selected, principally due to
concerns about the ability of the distribution system to deliver
the appropriate nutrients without setting up preferred pathways
and causing short-circuiting around the contamination. A more
detailed discussion of bioremediation can be found in the
Feasibility Study and the Proposed Plan.
Comment A-5: One commenter wrote that the preferred alternative
with the contingency alternative did not meet the first threshold
evaluation criteria of "Overall Protection of Human health and
the Environment" since there was a "lack of consideration of the
detriment to human health and represented by the expenditure of
public resources." A similar sentiment had been expressed in the
pUblic meeting held December 14, 1993. This resident amplified
on his comment by comparing the calculated excess cancer cases
associated with ingestion of ground water at the Site (based on
recent Site data this ranges from a maximum of 47 per 1000 to an
average of 0.6 per 1000) to the cancer risk which the general
population faces (about 250 per 1000). He furtber stated that
EPA's alternative is 150 to 500 times greater than "the
societally defined value of pUblic health protection."
EPA Responsez EPA's evaluation criteria are defined in the
National Oil and Hazardous Substances POllution Contingency Plan
(NCP) which regulates implementation of the Superfund law. The
source of remedy funding is not and cannot be addressed by these
criteria. In the case of the Somersworth Sanitary Landfill
Superfund Site, there is currently no way of knowing how costs
will be apportioned between pUblic and private responsible
parties nor how those parties may choose to finance those costs.
With respect to the comments concerning the risks associated with
the Site, EPA's cleanup is consistent with the NCP's regulatory
requirement which sets the upper bound of the acceptable cancer
related risk of not more than 0.1 excess cancer cases in 1000
(one in 10,000) which, also, means that any exposed individual
should not have an additional risk greater that one in 10,000.
EPA is required to select a remedial action to achieve that goal
in a cost-effective manner.
Comment &-.. A resident wrote that since there is not a current
risk to either human health or the environment and there are
initiatives currently in progress to improve the Superfund law
(especially in the areas of risk assessment and cost
.considerations), EPA should choose Alternative 2 (limited action
and monitoring) until the law is changed and the need for a
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7
the December 14, 1993, public meeting and in a letter from the
Somersworth City Council.
EPA Response: Regarding potential amendments to the Superfund
law, it is undoubtedly possible that legislation could be adopted
that changes the Superfund law. The Clinton administration has,
in fact, proposed a comprehensive Superfund reform proposal to
Congress. However, there is no certainty that amendments will be
adopted in the current congressional session, or as to what they
might contain if adopted; nor, would any revised statute
necessarily result in a change to the remedy for this Site.
Under these circumstances, postponing action could result in an
indefinite delay in Site cleanup. Moreover, if the Agency were
to postpone all remedial decision making until a new law is
enacted, the entire national cleanup program would be stalled.
Therefore, EPA believes an appropriate remedy should be selected
under the current law. People will continue to live around this
site and therefore, can potentially be exposed to contaminated
ground water. This potential will exist even if public water is
available, as people do not always behave as prescribed by
governmental institutions. Therefore, it is incumbent on EPA to
implement a remedial action which will remove that potential risk
as soon as practicable. .
Comment A-7: Several commenters at the public hearing expressed
the opinion that only monitoring and institutional controls
should be required since the landfill is at a steady-state
condition and appears to be cleaning itself up.
EPA Response: Monitoring and institutional controls were
evaluated as Alternative 2. There were several problems cited {n
the Proposed Plan and Feasibility Study Addendum with. how this
alternative complies with the NCP evaluation criteria: a failure
to achieve protectiveness over the long period of time that
contamination would remain in the ground water; failure to comply
with applicable or relevant and appropriate requirements; failure
to.provide a permanent remedy; no reduction in toxicity, mobility
or volume through treatment: and, no short-term effectiven~ss
since the time to reach cleanup goals could not be predicted
(but, much more than eighty-three years, the longest projected
cleanup time tor the remedial alternatives evaluated). In
addition, ground water that is a potential drinking water source
is required by the statute and regulations to be cleaned up to
regulatory standards. However, a remedy relying on institutional
controls would not achieve those levels for the indefinite
future. The length of time required for. the contaminants to
attenuate is so long that even for an aqu~fer that is not
currently used it exceeds a time frame that EPA would consider
reasonable to allow the contamination to remain; that. approach
would not comply with the regulatory expectation that cleanup
goals will be achieved within a reasonable timeframe. See 40 CFR
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8
groundwater needs for as long as 80 to 100 years. Furthermore
over that span of time the reliability of controls on well'
drilling or other exposure is very difficult to predict. There
is also evidence that contamination from the landfill may not
decline steadily. For example, the oldest portion of the
landfill lies under the tennis courts. Given the amount of
subsidence (settling due to decomposition of organic material)
that has occurred in this area just in the last few years, as
evidenced by the cracks and unevenness of the tennis courts'
surface, steady-state within the landfill waste may not have been
achieved. In addition, the fact that vinyl chloride was detected
at very high levels in a well at the edge of the landfill could
suggest that mechanisms are occurring within the landfill that
make it prudent to implement a treatment-based remedy at least
for source control. Finally, the NCP clearly indicates [40 eFR
.300.430a(l} (iii) (D)] that sole reliance on institutional controls
is the least desirable option to provide protection of public
health, since such controls can be changed or ignored over time.
B.
Comments from the Somersworth Landfill Trust (SLT) and
PRP Representative.
Comment B-1: TheSLT maintains that the source of all
contamination. in the bedrock ground water is located in the
vicinity of monitoring well B-l2R. Therefore, the SLT disagrees
with the need. for down-gradient bedrock extraction wells unless
an extraction well at B-l2R is shown to be ineffective through
performance monitoring. Furthermore, the SLT has concerns that
the operation of down-gradient bedrock extraction wells will draw
ground water beneath the chemical treatment wall, thus adversely
affecting its performance.
EPA Re.pon..: The Record of Decision allows for the opportunity
to demonstrate the effectiveness of an extraction well at B-12R
before downgradientextraction wells. are required. EPA continues
to believe that this area could not be the source of all bedrock
ground water contamination, however, early implementation of
extraction at B-l2R could determine that. With respect to the
adverse impacts of the downgradient bedrock extraction wells on
the performance of the chemical treatment wall, if they are
required, EPA believes that given the low total expected
extraction rates (approximately equal to the bedrock. ground water
flow under the landfill) and a predicted discharge of bedrock
ground water to the overburden on the upgradient side of the
treatment wall, proper design should eliminate any such impacts.
comment B-21 The SLT has provided a schedule for implementation
of the chemical treatment wall which indicates that the design
could be complete within two years and the installation could be
complete. within two and a half years. However, they indicate
only two one month review periods and a desire for flexibility in
the three year time frame for implementation which was specified
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9
EPA Respon.e: The Record of Decision modifies the proposed plan
so as not to establish a deadline for full implementation and
evaluation of the remedy. Instead, it establishes a two-year
schedule for design completion. As specified in the Record of
Decision, activities to be performed during this time period.
include: collection of additional, necessary hydrogeologic data;
bench-scale studies to determine the degradation rate of VOCs in
site ground water under simulated in-situ conditions, if
evaluation of the bench-scale studies indicate the apPlicability
of the technology to the Site; installation of an in-situ, pilot-
scale chemical treatment wall; development of a ground water flow
model for evaluation of pilot-scale field results; and if this
evaluation continues to demonstrate the applicability of the
technology, completion of final design of the fUll-scale chemical
treatment wall. The time frame for full implementation will be
determined later, although EPA still hopes that a three-year
. period will be sufficient. Should the responsible parties agree
to conduct the remedial design and remedial action, EPA intends
to require few deliverables during the design in order to
expedite the process. The only review with approval will be
required on the fUll-scale design. The bidding and construction
should begin immediately after the design is approved. However,
the evaluation of the viability of the fUll-scale treatment wall
will begin as soon as it is installed. Data w111 be carefully
reviewed so that interpretations can be made to determine if the
system is functioning effectively and whether it appears that the
cleanup levels will be attained. Therefore, depending on data
interpretation, a decision on the effectiveness of the remedy,
and on the potential need for implementation of the contingency
remedy could be made anytime after construction. This will
provide flexibility and incentive for both parties to work
closely and cooperatively in the data gathering and
interpretation process so that appropriate actions can be taken.
Comment B-3: The SLT believes that after the treatment wall has
operated for fiftY-five years that there will be no need for any
cover since the landfill will have been flushed clean.
SPA R.spons., First, neither the Proposed Plan nor the Record of
Decision state that the treatment wall will be in operation for
fiftY-five year. (or for any other specific period of time).
FiftY-five y.ars is the length of time over which EPA estimates
the wetland ground water will naturally attenuate. EPA agrees
that if a point is reached at which ground water leaching from
the landfill is below the cleanup levels even before treatment,
it will no longer be necessary to maintain the chemical treatment
wall and the landfill can be closed: how long this would take is
unknown. (However, before that decision could be made EPA would
require a high degree of confidence that contamination levels
. . have been permanently reduced.) What the appropriate landfill
cover may. be at that time will depend on the circumstances as
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10
scientific knowledge and technology could have changed
significantly, EPA believes it would be premature to determine
now what the appropriate closure would consist of. EPA wishes to
preserve the flexibility of making those decisions after having
reviewed actual monitoring data which will have spanned several
years. EPA notes that the New Hampshire Hazardous Waste laws
have been identified as relevant and appropriate to the site, and
for that reason a RCRA Subtitle C type cap has been assumed for
purposes of evaluating the cost and other aspects of the remedy;
however, the appropriateness of the closure requirements can only
be assessed in light of the circumstances as they are exist at
the time closure is conducted. In addition, the State of New
Hampshire will playa role in determining how the landfill will
ultimately be closed.
The'SLT contends that the contingency remedy is not appropriate
for this Site and inconsistent with applicable law. Each comment
and response relative to this contention is listed individually
below as 8-4 through 8-9.
Comm.n~ B-4' The SLT states that there is no current public
health risk because (1) there are no receptors to groundwater at
the site (i.e., no drinking water wells in the area); (2) the
highest level of contamination of surface waters associated with
the landfill ever detected was 118 ppb of total VOCs in 1988, and
more recent samples have been much lower: (3) the Salmon Falls
River is not impacted: (4) there is no documentation of any
recreational use .of the wetlands. The fishing derby is
downstream and there is no evidence of fish contamination, and ~
state health assessment concluded that exposure to water in the
wetlands is not expected to result in adverse health effects.
However, the Proposed Plan states, without supporting
documentation in the RI or Risk Assessment, that a carcinogenic
health risk could exist through contact with contaminated
sediments or surface water in Peter's Marsh Brook.
The SLT also states that there is no current risk to the
environment because (1) water quality criteria for aquatic life
are being met in Peters Marsh Brook: (2) there is no evidence of
any harm to biota in the wetlands: (3) the RI says the Site does
not appear to present a threat to organisms in the brook; (4) the
Proposed Plan acknowledges the Site is "not likely" to pose a
risk to the environment. .
SPA Re.pon.e. As indica~ed in the Record of Decision, EPA agrees
that there is little current risk to the public or the
environment from exposure to contaminated media at this Site.
The Ba.8line Risk Assessment did, however, present a "worst case"
carclnoqenic risk slightly greater than EPA's goal of not more
than one excess cancer risk in ten thousand, principally as a
result ot exposure to arsenic in Peter's Marsh Brook (Remedial
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11
Comment B-5: The SLT believes that there is no "real" future
risk because (1) the plume has stabilized and has been at a
steady state for 10-30 years and is unlikely to migrate further,
and so does not pose a threat to any location where drinking
water wells are located; (2) any use of groundwater by residents.
of Blackwater Road is highly unlikely as city water is available
and the groundwater has a high natural metals content; (3) the
installation of other drinking water wells is highly unlikely
because of poor experience with the prior well which was shut
down for reasons unrelated to the site; (4) the City has recently
constructed a new water treatment facility using the Salmon Falls
River as a source which will meet city's need for the foreseeable
future; (5) residential development in wetlands is virtually
inconceivable due to inhospitable terrain and various federal,
state and local laws. The SLT cites statements in the preamble
to the National Contingency Plan to the effect that residential
development should not be assumed where its likelihood is small,
and similar agency risk assessment guidance. The SLT contends
that the mere length of time does not demonstrate that there is a
great likelihood of development. The SLT also contends that an
exceedance of MCLs is not enough to show risk unless there is
also evidence of potential exposure.
EPA RespoDse: For the purposes of a baseline risk assessment,
EPA has used the exposure scenario of human consumption of ground
water to represent a realistic, potential future exposure
pathway. EPA, as stated in the Feasibility Study Addendum,
believes this to .be appropriate for several reasons. First, the
ability of the aquifer affected by the Site to produce useable
quantities of ground water has been demonstrated in the past by
the installation of two municipal water supply wells. The
principal reason that neither is currently being used is purely
economic: a water supply source is available which can be made
potable more cheaply. EPA believes that it is realistic and
appropriately conservative to assume that over fifty-five or more
years, changes in economics and water resource availability could
make this aquifer attractive once again. Therefore, given the
very long period over which the aquifer would remain contaminated
in the absence of any response action, it is reasonable to take
the possible future demand for this water as a municipal drinking
water source into account. The existence of the new water
treatment plant makes such usage unlikely for the near future,
but by no means for the full length of time that contamination
would remain present in the absence of remediation. Furthermore,
with respect to potential use by residents, portions of the
contaminated aquifer are currently overlain by residential land.
In spite of the availability of an alternate water supply, there
.is always a potential that the ground water will be used. Again,
economics is often the reason, i.e. it may be cheaper to use a .
private well than to pay for municipal water. Finally, while a
great deal of the contaminated plume is overlain by wetlands,
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12
upon and wells installed which could draw contaminated ground
water to them. Also, institutional controls to prevent
construction in wetlands are not fool proof. As time passes, the
pressure to develop wetlands will continue. All of these factors
imply that the assumption of potential consumption of .
contaminated ground water is realistic.
With respect to the appropriateness of the original risk
assessment procedures, EPA has provided a Supplemental Risk
Assessment for potential future ground water consumption down-
gradient of the landfill and along Blackwater Road (Record of
Declsion, Appendix A). This has reconfirmed the magnitude of
potential risk even with updated exposure scenarios.
Commen~ B-': The SLT maintains that since there is an absence of
risk, no remedy may be implemented.
EPA Response: As stated in the response to Comment 8-5, a
potential risk has been established and confirmed.
Commen~ B-7: The SLT in its written and oral comments, as well
as, other representatives at the pUblic hearing, expressed
concern over mandating a contingency remedy at this time rather
than reevaluating the options available at the. time a contingency
is needed.
EPA Response: EPA's past experience has shown that time and
money can be saved by having chosen a contingency remedy during
the remedy selection process. Furthermore, in this case there is
enough uncertainty about the effectiveness of the innovative
remedy that the agency wishes to be in a position to immediately'
begin implementing a contingency remedy in the case of failure.
If a contingency remedy is not chosen at this time, more delay
would occur while the replacement remedy was selected, after an
intervening delay of several years or more. If, during design of
the contingency remedy, new, site-specific information is
discovered which could have an impact on the previously selected
contingency, EPA would evaluate that information and proceed
accordingly.
Comment B-8. The SLT believes that if the innovative technology
is ineffective, the contingent remedy should not include an
overburden pump-and-treat system nor a cover consistent with RCRA
Subtitle C. The SLT maintains that MCLs are not ARARs because no
one will ever consume the water due to poor quality (iron and
manganese) and the availability of public water. This, according
to the SLT, obviates the need for pump-and-treat. Also, the SLT
cites the Feasibility Study as indicating the negative affects ot
the pump-and-treat system on wetlands, which the SLT believes are
. so. severe that it MCLs were ARARs they could be waived since the
pump-and-~reat option would "result in greater risk to human
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13
maintains that an impermeable RCRA C cover is not necessary for
two reasons: there is no dermal exposure risk and a permeable
cover would prevent exposure to contaminated wastes, and waste is
already in the ground water so that prevention of infiltration
through the waste to prevent leachate generation would not be .
effective.
EPA Response: The NCP requires ARARs to be attained in potential
drinking water sources; 40 CFR 300.430. This applies to both the
preferred and contingency alternatives. In applying this
requirement, it is EPA's policy to treat all aquifers as
potential drinking water sources unless they are contaminated
naturally or from other, non-site related sources to such a
degree as to be unusable. See 55 FR 8732-33 (March 8, 1990).
Previous responses concerning the potential of this aquifer as a
drinking water source indicate that MCLGs and/or MCLs are ARARs.
The 'pres~nce of iron and manganese does not result in this
aquifer being considered to be unusable as a drinking water
source, since standard water treatment technology (coagulation,
sedimentation and rapid sand filtration) is routinely employed to
remove iron and manganese, as well as other metals. Furthermore,
it should be noted that the State of New Hampshire has not
classified this aquifer as not suitable as a drinking water
supply. As discussed above, the fact that the ground water is
not currently used does not show that it will not be used in the
future over the long period that contaminants would remain in the
wetland in the absence of remediation. In order to attain the
ARARs, a pump-and-treat system provides the best balance of the
remedy selection criteria among the alternatives considered, for
reasons stated in the Feasibility Study Addendum, the Proposed
Plan, and the Record of Decision.
EPA has provided a clear rationale for the contingency remedy in
the Feasibility StUdy Addendum. The contingency remedy is
intended to function as a system and its individual components
cannot be evaluated unrelated to each other. Alternatives 8c and
Sd employ landfill covers in conjunction with Derimeter slurry
walls and ground water extraction wells with on-site ana off-site
aisposal options. The FS preparea by the SLT's contractor
estimated a'.pumping rate of 600 gpm with additional study
recommended to determine the impact on wetlands. EPA believes
that the pumping rate is unnecessarily high and that effective
mitigation ot wetland impacts can b. made when using a lower,
more appropriate pumping rate. Thi. conclusion is based upon the
evaluation ot Alternative 6b in the Feasibility StUdy which
indicate. that without overburden ground water extraction only
ten gallons per minute would move through the landfill by flowing
through the slurry wall. If overburden extraction is necessary,
it is likely to be only enough to lower the water table within
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To meet ARARs (wastes similar to RCRA hazardous wastes were
disposed of at the landfill), the landfill cover must comply with
the RCRA C landfill cover requirements. Meeting these
requirements will minimize infiltration of precipitation and
leachate generation and thus, lower pumping rates. The pumping
rate should be set to depress the ground water to belo~ the
bottom of the waste and maintain it there if the first stage of
the contingency alternative (RCRA C cover, perimeter slurry wall
and upgradient diversion drain) cannot accomplish this. Since
flow in the bedrock under the landfill is only about 5% of the
flow through the landfill, EPA does not expect a significant
amount of bedrock ground water to be captured by overburden
pumping within the slurry wall. In addition, the series of down
gradient bedrock wells intended to be used outside the slurry
wall will tend to counteract any effects on the bedrock ground
water by the overburden pumping, i.e. the existing gradient in
the bedrock should be maintained. Pumping at 600 gpm, however,
would tend to induce gradients which would result in forcing
upgradient overburden ground water to flow beneath the slurry
wall, severely impacting the wetlands. Therefore, total pumping
rates expected for this alternative should be significantly less
than 600 gpm recommended by the SLT in the Feasibility StUdy. A
flow of 125 gpm, treatment costs for which are presented in
Appendix F of the FS, is a more appropriate pumping rate for this
alternative. Furthermore, the pumping rate necessary to maintain
the ground water below the landfill waste will probably be
significantly less than 125 gpm. Ground water diverted by the
trench upgradient of the slurry wall would tend to lower the
water table outside the slurry wall which will further reduce the
tendency for flow beneath the slurry wall. This ground water
collected by the upgradient trench would be reintroduced to the'
wetlands in such a manner as to prevent dewatering. Thus, the
implementation of the contingency remedy would not result in
greater risk to human health and the environment.
Comment B-9: The SLT argues that the landfill closure
requirements of RCRA Subtitle C are neither applicable nor
relevant and appropriate for the contingency remedy because there
is no evidence that RCRA wastes were accepted at the landfiil
after the date that the RCRA regulations went into effect and the
low contaminant concentrations in ground water.
SPA Re.pon... EPA agrees that RCRA Subtitle C is not
applicable. However, it is relevant and appropriate because
hazardous materials sufficiently similar to RCRA hazardous wastes.
were disposed of in the landfill. Furthermore, the evidence
indicates that such wastes were disposed ot over an extended
period of time, and while precise volumes are unknown the
evidence is that such volumes were significant. The'
concentration of contaminants in the ground water generally does
not determine whether RCRA is relevant and appropriate; EPA
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contamination does not impact ground water at all, or where
leachate meets health-based levels. (CERCLA Compliance With
Other Laws Manual, Interim Final (Aug. 8, 1988) at 2-20.)
Neither condition is true at the Somersworth landfill.
Comment B-10: The SLT maintains that the cost estimates for the
contingency remedies are too low because the appropriate pumping
rate is 600 gallons per minute.
EPA Response: The pumping rate used by EPA (140 gpm) was
estimated and, as indicated in the Record of Decision, will need
to be verified during design. As previously noted, EPA believes
that the 600 gpm pumping rate is excessive. However, as
mentioned in the Feasibility Study Addendum, the costs for the
pumping rate for the overburden aquifer (125 gpm) were obtained
from the Feasibility Study prepared by the SLT's contractor.
Comment B-11: Neither the chemicals listed in the Proposed Plan
as representing health risks nor those listed as requiring
cleanup levels match the VOCs presented in the Feasibility Study
that were detected at concentrations in excess of their MCLGs or
MCLs.
EPA Response: The list of chemicals representing unacceptable
Site risks was taken from the original risk assessment to which
vinyl chloride was added since it was subsequently detected
several orders of magnitude above its MCL. Those chemicals and
several others which exceeded MCLs or MCLGs in subsequent
sampling rounds were listed in the Proposed Plan to have cleanup
levels set. Even though a compound may not present a risk
exceeding the goal, once risks from any site-related chemicals
are identified, all Site-related compounds must achieve ARARs.
The Feasibility Study correctly includes benzene and 1,2-
dichloroethane as being detected above MCLs and thus are included
on the list of compounds having a cleanup level set. Vinyl
chloride should have been included in that list of compounds in
t~e Feasibility Study, however. For a complete discussion of
Site risks and cleanup levels, see Sections VI. and X.A. of the
Record of Decision. .
Comment 8-12. An SLT contractor questioned how extraction of
down gradient bedrock ground water could speed up the time
required to achieve MCLs at the compliance boundary as stated in
the Proposed Plan.
BPA ae.pons., The bedrock ground water discharge to the
overburden just down gradient of the treatment wall is
contaminated above MCLs. Since that is the point ot compliance, ,
by capturing and treating that ground water, MCLS at'the
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Comment B-13: The SLT contractor supports the theory of
biodegradation as it was described in the Feasibility Study and
questions EPA's rationale for not being convinced that the
biodegradation mechanisms are operating at the Somersworth
Landfill as described in the Feasibility Study.
EPA Response: EPA's position in this regard is stated in detail
in the FS addendum. In brief, however, there are two bases for
EPA's rationale that we are not convinced that the biodegradation
mechanisms are operating as described in the Feasibility Study.
First, biodegradation is described as ~ mechanism responsible
for observed contaminant reductions. Much of the apparent
reduction in concentration of contaminants and the apparent
steady-state condition is as likely to have occurred at this Site
from dilution, advection, dispersion, volatilization, chemical
reduction, and adsorption as from biodegradation mechanisms.
Secondly, as this commenter points out, "there is no one case
study that demonstrates the interrelationship of these organisms
in a landfill/wetland environment" and yet that undemonstrable
interrelationship forms the cornerstone of the biodegradation
discussion in the FS. EPA acknowledges that biodegradation is
occurring, but its importance to the cleanup at this Site has no~
and can not be documented without major expenditures of time and
money. Eve~ then, it may not be the most important factor. In
the absence of more substantial evidence than the FS presents,
EPA is unwilling to design a remedy based on mere assumptions
about what may be occurring at the Site.
Comment B-14: The contractor believes that EPA is inconsistent
in the Feasibility Study Addendum because it states that an
impermeable cover won't adversely affect natural attenuation
mechanisms yet previously stated that biodegradation mechanisms
were not necessarily operating as described in the Feasibility
Study.
EPA Response: As stated previously, EPA acknowledges the
existence of the biodegradation mechanisms but is not convinced
as to their degree of importance. Other natural attenuation
mechanisms are also at work. By installing an impermeable cover,
these physical/chemical mechanisms are not appreciably affected,
especially in the down gradient wetlands where an impermeable
cover may result in a much lower influx of contaminants thus
allowing the other mechanisms to continue to be effective on a
lesser mass of contamination.
Comment B-15: The contractor disagrees with what it
characterizes as EPA's assertion that an impermeable cover will
not affect methane production.
"BPA Response: EPA's position on the impact of an impermeable
cover is more accurately reflected by this sentence in the
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severely limit aerobic microbial activity, given the limited
amount of oxygen which is no doubt presently available, the
effect when weighed against source reduction is minimal. II
Comment B-l&: The contractor believes that an effective nutrient
delivery system could be designed for the Somersworth Landfill,
contrary to the evaluation of Alternative 4 in the Proposed Plan
which expresses concern over preferred pathways being developed
so that portions of the wastes would not receive nutrients.
EPA Response: The effectiveness of in situ bioremediation is
dependent on the efficiency of the nutrient delivery system.
Since water is often used as a carrier for these nutrients, the
permeability of the soil to water is a critical parameter. Soils
with a low permeability to water (such as the extensive amount of
peat in the wetland areas needing to be remediated) may not be
suitable for in-situ bioremediation since the nutrients will tend
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EXHIBIT A
PUBLIC HEARING TRANSCRIPT
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U.S. ENVIRONMENTAL PROTECTION AGENCY
EPA REGION I PROPOSED PLAN
SUPERFUND PROGRAM
SOMERSWORTH SANITARY LANDFILL SITE
SOMERSWORTH, NEW HAMPSHIRE
In the Matter of:
)
)
PUBLIC HEARING ON )
EPA REMEDIAL INVESTIGATION/FEASIBILITY STUDY)
AND PROPOSED PLAN FOR THE CLEANUP OF THE )
SOMERSWORTH SANITARY LANDFILL SUPERFUND SITE)
CC(Q)fJ~tf
---------------------------------------------
Somersworth Vocational High School
Cemetery Road
Somersworth, New Hampshire 03878
Tuesday, February 8, 1994
7:03 p.m.
PANEL:
Daniel J. Coughlin
Chief, NH, Superfund Section
Waste Management Division
U.S. Environmental Protection
J.F.K. Federal Building
Boston, MA 02203
Agency
Roger Duwart
Remedial Project Manager
U.S. Environmental Protection Agency,
Waste Management Division (HSN-CANS)
J.F.K. Federal Building
Boston, MA 02203
Region I
Paul Lincoln
Project Manager
New Hampshire Department
6 Hazen Drive
Concord, NH 03301
of Environmental Services
.
. -
UR ASSOCIADS
P.O. 80% 8'3
EXBTZR, RH 03833
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2
1
INDEX
2
3
SPEAKERS
PAGE
4
5
Daniel J. Coughlin 3
Roger Duwart 5
Douglas Elliott 9
Richard Goupil 14
Bill Boulanger 15
William Farrell 16
Michael Micucci 17
Roger. Berube 18
Rich Rouleau 20
6
7
8
9
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1
PROCEEDINGS
2
MR. COUGHLIN:
I want to thank yqU
Good evening.
3
for coming tonight.
I
Can everyone hear me all right?
4
understood last time we had a little problem.
So we have a
05
mike here, and hopefully you can -- If you can't hear me,
6
say so.
7
My name is Dan Coughlin, I'm the Chief of the New
8
Hampshire Superfund Section at EPA in Boston.
My staff and
9 . I are responsible for the implementation of the Superfund
10
Program in New Hampshire.
11
With me tonight are, on my right, direct right, is
12
RogerODuwart, he's the Remedial Project Manager for the
13
Somersworth Superfund Site, and Paul Lincoln, who is the
Project Manager for the New Hampshire Department of
14
15
Environmental Services.
16
We are here tonight to conduct a public bearing to
get public 0 coomments on EPA' s Remedial
17
18
Investigation/Feasibility Study and the proposed plan for
the cleanup of the Somersworth Sanitary Landfill Superfund
Sit..
A8 you probably are awar., we held a public
meeting on December 14th, 1993 to discuss the Remedial
Investigation/Feasibility Study and the proposed cleanup
with you.
A 30-day public comment period was announced at
that meeting.
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4
1
the public, extended that to a 60-day comment period, so the
comment period will now end on February 14th, 1994.
2
3
Before we start the hearing, let me describe the
4
5
format for tonight.
First Roger will give you a very brief
6
overview of the proposed plan and how we are recommending
that the landfill be cleaned up.
7
Following his presentation, we will accept any
8
oral comments that you may wish to make.
And those comments
9
will be for the record.
As you can see, we have the entire
10
meeting being transcribed, and everything that you wish to
say will be transcribed in its entirety.
11
12
Those of you who wish to make a comment should
have signed in up front, signed in on a blue index card.
I
13
14
have them up here.
If you haven't signed in and wish to
15
make a comment, would you please fill out ODe of the index
cards, either now or sometime during the presentation and
16
17
get the card to me, or Norm probably will get the card to
me.
plaa.
Also available up front are copies of the proposed
If you don't have one with you, I would recommend
that you get it.
I'. going to call on you general~y in order of
. .
when yousiqned up tonight, unle.. .there'. so.ebody who
wishes to make a statement, or indicated they wi.hed to make
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1
commitments or other commitments this evening.
2
As I said, all comments will be transcribed.
3
After everybody has made their comments, we will close the
4
public hearing.
Just so there is no misunderstanding, we
,5
will be only taking comments, we will not answer any
6
questions or respond to the comments tonight.
That will be
7
done in the Responsiveness Summary, which is made part of
our decision document when we render a decision on the
8
9
cleanup of the Superfund Site.
That decision document is
10
kno~n as the Record of Decision.
So that is when your
11
comments and questions will be responded to as a result of
12
this'hearing.
We will stay around after the formal hearing and
13
talk to whoever would like to talk with us, answer any
15
16
questions you'd like, whatever, if you just w,ant to come up
and speak to any of us.
17
And with that, that pretty much describes how we
will run the hearing.
Does everybody understand?, Are there
any questions before we start?
(No response.)
MR. COUGHLIN:
okay, with that, I'm going to ask
Roger to do his brief summary.
MR. DUWART:
As Dan said,' this will be very brief,
it's just to set the tone for this ev.nin9~ r8ll1Dd us why'
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As you all are by this time aware, the Somersworth
2
Sanitary Landfill began in operation in the early to mid
3
1930s, continued until 1981.
At that time the city began
4
closure proceedings, and as part of that, four wells were
5
installed and sampled.
The samples came back with levels of
6
volatile organic compounds which are called VOCs, theY're
industrial solvents and degreasers.
7
8
As a result of these compounds, the landfill was
placed on the national priority list, making it eligible for
9
10
federal funding.
The final listing was in 1984, September
11
8th to be exact, and money was presented. to the state in
12
1984 to conduct a remedial investigation.
They hired a
13
14
contractor in order to assess the nature and extent of the
contamination at the site.
This was completed in 1989 and
15
published.
16
The findings, basically, very quickly, were that
there was contaminated groundwater found beneath and
downgradient from the landfill, extending into the. wetlands,
and ~ended across Blackwater Road to the south of
Blackwater Road.
At about the sam. tiae tha~ ~he.e finding. wer.
published, the Somersworth Landfill Trust was formed by the
city, and several interested industri.. and bu.ines.e. cam.
~o EPA and requested the responsibility and requested the
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Somersworth Sanitary Landfill Superfund Site.
A Feasibility Study is the basis of our proposed
2
3
plan, it's what we built, our proposed plan, the
4
alternatives that were developed by the consultants to the
5
Somersworth Landfill Trust beginning back in 1989.
6
Very briefly, our proposed plan consists of a
7
8
couple of different alternatives.
Our preferred
alternative, which was indicated the proposed plan as
9
Alternative NO.5, is an emerging, innovative alternative of
10
an In-Situ chemical treatment wall which is designed to
11
completely detoxify the groundwater as it flows through it.
12
It would have a permeable cover during implementation and an
appropriate cover at closure, and that to be determined at
13
14
the time of closure.
15
Bedrock groundwater that is contaminated around.
the si~e would be collected through wells and treated
16
17
through the chemical treatment wall, either by a
reapplication to the landfill to help it flush or injected
jus~ behind ~he chemical ~rea~men~ wall if we can'~ get it
OD~ ~he landfill, if i~ can'~ be designed that way.
Three other aspects of this alternative, the
preferred alternative, are also common to the contingency
alternative that we proposed.
The.e are institutional
controls to prevent. people from drinking the groundwater,
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1
groundwater to clean itself as the clean water flows through
the chemical treatment wall and helps to flush it, and
2
3
finally groundwater monitoring, to make sure that this
alternative is, in fact, doing what it was advertised to do.
4
5
Total costs without a cap is approximately $6
Depending on the type of cap that is put on, it
6
million.
7
could be as much as $9 million more, unlikely that it would
8
9
be that expensive.
As I said earlier, this is an emerging, innovative
'10
technology, and as a
result, we have also proposed a
11
contingency remedy, which is a more traditional impermeable
12
13
cap with pump-and-treat technology for the groundwater.
would be a mUlti-layer impermeable cap, the $9 million
It
14
impermeable cap, a perimeter slurry wall around the site to
isolate the waste from the groundwater, both bedrock pumping
15
16
as well as overburdened groundwater pumping, the groundwater
that is in beneath the landfill, with treatment either on
17
site at a treatment plant to be constructed at the landfill
or. off site at the Somersworth Municipal Treatment Facility.
Groundwater would be recharged to the wetlands,
becauae W8 would be taking some groundwater out of the
recharge area.
We would recharge the wetlands, 80 that we
would try not to dry those up and not cause problema there.
Again, the three tinal aspects are the same as
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9
1
controls, natural attenuation, and groundwater monitoring.
These contingency alternatives would run in the order of 20
2
3
to $22 million, which is why we have proposed the innovative
4
technology.
We believe the innovative technology offers
5
some siqnificant advantages, and this is why we believe it
6
is worth trying and why we also expect it to work.
It gives
7
complete degradation of the contamination.
There are no
8
contaminated residuals that we have to worry about disposing
.of, there are no moving parts, it's low in maintenance, low
9
10
in operation, and, relatively speaking, lower in cost.
11
Now to get to the part of the eveninq that we're
12
here for, I'll turn it back to Dan and we'll take your
13
comments.
14
MR. COUGHLIN:
Okay, we will go into the public
15
hearing now.
If you would stand up and try to speak clearly
16
and loudly so that our transcriber can hear it and we can
have exactly what you have to say on record, we would
appreciate it.
ADd I will start with Doug Elliott, the Manager of
the City of Somersworth.
MR. ELLIO'rl':
Thank you, Dan.
Good evening, my name i8 Dougla8 Elliott, and I'm
City Manager for the City of Somernorth.
As set forth in
Resolution 2594, adopted by the Somersworth.City Council on
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Alternative 5 as the final cleanup plan for the Somersworth
2
Landfill.
3
I've been authorized and directed by the City
4
Council to comment on the EPA proposed plan.
Tonight I will
.5
present a brief statement in support of the city's position
and will submit detailed written comment on or before
6
7
February 14th, 1994.
The City of Somersworth, by resolution of the City
8
9
.Council adopted on February 6th, 1989, signed an
Administrative Order with the United States and State of New
10
11
Hampshire to participate in the completion of the remedial
investigation and preparation of the Feasibility Study for
12
13
the Somersworth Landfill.
Joining the city in the
14
Administrative Order were some 36 area businesses.
During
15
the past five years the city and these businesses,
functioning together as the Somersworth Landfill Trust, have
16
worked diligently to complete their obligations under the
Administrative Order.
The trust has spent approzimately $2.2 million,
and the city has contributed in exc... of $1 million towards
thi. amount, for various environmental studies at the
landfill and the surrounding area.
Through the expenditure
of this very significant SUID of JDOney, the city haa
concluded that the landfill pre..nt. no real pr..ent or
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institutional controls and monitoring is necessary at this
2
time.
3
Like the Federal and State Governments, the city,
too, is concerned first and foremost about the health and
4
.5
6
welfare of its citizens and the environment with which it
has been entrusted to manage.
As a result, the city would
7
not support a course of action that it believes would put
the public's health at risk.
8
9
Both the city and the EPA appear to agree that the
contaminated groundwater at the site does not present a
10
11
current risk as the city water supply is available to all
12
potentially-affected residents.
However, we believe that
13
the potential future threat to public health that has been
14
identified by the EPA is based on highly unrealistic
15
assumptions about future groundwater usage and should not 'be
the driving force behind any closure plan or other remedy
16
17
for the landfill.
18
During this five-year process, the city has
rec~gnized the limitations of the Federal Superfund Loan,
and ~ha~'s probably an understatement, and has encouraged
both the federal and state environmental agencies to make
use of the flexibilities that currently exist within the law
and to also look at new and innovative ways to address old
problema.
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knowing what remedies have been selected at other sites here
in New Hampshire, the city and other trust members have
looked at and presented to the EPA certain new technologies
that present viable alternatives to the standard cap, pump
and treat approach for municipal landfills.
In light of the
existing federal law and EPA's interpretation of the law,
the Somersworth City Council has endorsed and supports
Alternative 5 as the final cleanup plan for the landfill,
finding that it is in the best interest of the city.
Despite our differences with EPA about whether any
significant remedy is required for landfill, we applaud the
agency for having the courage to look at new solutions that
satisfy the law and are more cost-effective than traditional
approaches.
While the city supports the selection of
Alternative 5, it cannot support Alternatives 8-C or 8-D as
a contingent remedy, as the city believes they represent a
grossly wasteful response that is neither justified by any
pre.en~ or future risk or appropriate under existinqfederal
lave
The cost of such a remedy would be ruinous to the city
and other members of the trust.
In addition to being a wasteful response to a site
where there's no significant risk pre.ented, a cap, pump or
treat remedy is likely to have adverse environmental
consequences at this site.
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1
of the adjacent wetlands which serves as a nutrient for
2
bacteria, there would be great contaminants.
Should the treatment wall and Alternative 5 fail
3
4
to produce satisfactory results, the EPA has the authority
5
to consider an alternative remedy.
We believe any future
6
remedy should be based on the conditions present at this
7
site at that time.
8
Contaminant levels in the groundwater have been
declining over time, and we believe there is substantial
9
10
evidence that the groundwater is being cleaned through
11
natural attenuation.
12
In addition, during the public debate of the
13
Superfund statute during the past two years, there has been
14
substantial criticism of both the remedy selection process
15
and the EPA's method of assessing risk.
While we
16
acknowledge that the EPA can only enforce and implement the
Superfund statute as it is currently written, the city
17
cannot support a contingent remedy that it believes is not
currently justifiable and will clearly not be justifiable
under Superfund after it is amended.
Of course the city will submit written detailed
comments on the proposed plan that will be consistent with
my remarks tonight before the end of the public comment
period.
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that both the u.s. EPA and the New Hampshire Department of
2
Environmental Services have made on behalf of this project,
and we look forward to working with you to bring this matter
3
4
to a successful final close.
5
Thank you.
6
MR. COUGHLIN:
Thank you.
7
Richard -- you're going to have to help me on
8'
this, Richard --
9
MR. GOUPIL:
Goupil.
10
MR. COUGHLIN:
Goupil?
Could you spell that for
11
me, sir,
just so I get the spelling right in the transcript.
12
13
MR. GOUPIL:
G-o-u-p-i-l.
MR. COUGHLIN:
G-o-u-p-i-l.
Thank you very much.
14
MR. GOUPIL:
I just have a couple of questions to
15
ask.
I've been a resident of Somersworth for the last
22 years, and I have struggled for the last 22 years to pay
my taze. to this toWD.
And what the City Manaqer has just
.ai~ and what I've been understandinq, that the Somersworth
LaDdfill ia non-hazardous, that it is cleaning itself up.
The SPA haa also, if I'm misunderstood, has a180 said that
it is cleaning itself up, that it's not hazardous.
So why
are we taking a chance of puttinq a burden on this city,
forcing people out of their homes when they cannot afford a
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As it stands now, we're fighting against this one
2
here.
Last week we had a meeting, they want to build mo're
3
schools.
We can't handle it.
We can't handle new schools,
4
we can't handle another project like this as taxpayers.
5
What happened to freedom?
If we fight you people,
6
you people are going to take us to court, drag us through
7
the courts, and you've all said, it's not hazardous.
can't understand that.
I just
8'
9
Twenty-five years ago I went Viet Ham because my
country told me, my government, all these agencies told me
10
11
it was my duty, that I had to go for freedom.
Right now,
12
what I can see, the EPA is taking our freedom away from us.
13
They're telling us, you will do it, we will make you do it,
14
we will force you out of your homes.
do it, we don't care.
If you can't afford to
15
16
That's all I have to say.
17
MR. COOGHLIN:
Thank you very much, well stated.
Bill Boulanger.
MR. BOULANGER:
Did I pronounce that right?
Boulanger, B-o-u-I-a-n-g-e-r.
My name is Bill Boulanger, I'm a Ward 4 Councilor
for the City of Somersworth, and I do agree, just to echo
some of the City Manager's comments on that we are not in
total agreement of what the EPA haa stuck us with on the
remedy, but in the best interest of the public, we had to
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17
18
19
20
21
22
23
24
25
16
1
However, I'm here to fight on your contingency
that you proposed on the city, that you're not leaving any
2
3
leeway on that at all.
I mean if this doesn't work three
4
years down the road, that we're getting stuck with pump and
5
treat, regardless if pump and treat works or not.
Pump and
6
treat, from what I can understand, is not a proven formula
7
either, that the contingency plan should be left open, that
if this doesn't work, that the city and the trust and the
8
9
EPA can come back and look at the landfill again, not just
strap us with this pump and treat method, because that may
10
11
not work three or four years down the road.
As far as the cap, if we flush out the dump and
12
13
14
the dump is clean, I can't see why we have to put a cap on
it.
I mean if it's clean to the EPA's regulations, why
15
should we have to do any more work on it?
I'd just like to echo the City Manager's comments,
16
and I support his comments as well.
Thank you.
MR. COUGHLIN:
Thank you very much.
William Farrell.
MR. FARRELL:
I'm 8ill Farrell for General Linen
Service.
The information to date indicates that the
landfill presents no risk to the human element.
General
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20
21
22
23
24
25
17
1
be a sufficient remedy.
However, in case a more substantial
2
3
cleanup is required, General Linen would support
Alternative, preferred Alternative No.5, and at the same
4
time would oppose Alternative, contingency Alternative
5
No.8.
6
Thank you.
7
MR. COUGHLIN:
Thank you.
8
Is it Michael Micucci?
9
Michael Micucci, Ward 3
MR. MICUCCI:
Yes.
10
Councilor from Somersworth.
11
I was a big opponent of Alternative 5, but in a
show.of unity with the City Council, I will back Alternative
12
13
5, although I feel that the experimental nature of this
project leaves a big risk for the contingency to be in place
14
15
in later years.
I feel that it should be a renegotiated thing if
16
17
this does not work, where the City of Somersworth is
18
reluctantly looking at this Alternative 5.
And I just feel
the ,experimental nature of this whole thing could leave the
cit.y paying a lot more money than what it should.
I also know the EPA's position in that the EPA is
just doing what the law require., but the Congre8. i. what
has to change the law a. it i. writt.en.
You have to under.tand, too, that t believe that
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. 10
18
19
20
21
22
23
. 24
25
18
1
Number one, they are the ones who years ago said, bury your
trash, burn your trash, do what you have to do to get rid of
2
3
it.
They're the ones who gave the permission to go ahead
4
with this.
So I don't feel that the state or the Federal
.5
Government are without fault.
6
And I would also like you to consider not giving
us the contingent alternatives that you have come up with,
7
8
and hopefully this Alternative 5 will work.
Thank you.
9
MR. COUGHLIN:
Thank you, sir.
11
Roger Berube.
12
13
MR. BERUBE:
Yes, Roger Berube, Councilor Member
at Large.
14
It's been a long time cOming, this decision.
I am
15
supporting Alternative No.5 because I believe it is the
16
most cost-effective way to go.
The problem that I have, like I have stated in the
17
past, is that if the Federal Government is to mandate laws
the way they do to the cities and state, then they should be
paying the cost, I have a problem with the cost.
I think
the people in Washington are getting the message, because I
understand there's probably three bills in the Congress
right now at this time reviewing what has happened with
EPA's man -- well, it's not really EPA's mandated fiz, it is
the Congress.
And I think theY're looking at that, because
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19
20
21
22
23
24
2S
19
1
it's going to be very costly and it's going to bankrupt some
cities, I believe, because we're having hard times right
2
3
We're looking, especially in the northeast, you're
now.
4
looking at the State of New Hampshire where there's a lot of
5
jobs that's been lost, we don't have the growth.
We're
6
looking at the shipyard, a problem with the shipyard,
looking at Pratt Whitney.
7
8
Again, you know, if there is no life-threatening
situation at that dump at this time, I can't understand how,
9
10
you know, they want us to spend the kind of money that we're
11
talking about.
12
Like I said, I do support Alternative No.5
13
because we really don't have any choice.
And I think it is
14
the most cost-effective.
Because we have to do something,
15
according to the law.
But I would hope that the people in the Congress
16
17
that are always coming back to the state and telling us,
well, if anything is mandated, then, you know, we're going
18
to .chang- the law and it should be paid by whoever is
mandating those laws.
And it's not happening.
And I'm sure
w.'ll bav. people running around for office 4gain very
shortly througbout tbe country making these type of
statements, but they don't deliver, that's the wbole idea.
Who delivers is the small towns.
And I qu~ant:~e you, when"
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18
19
20
21
22
23
24
2S
20
1
they're going to have the power, the law will be changed,
2
and we're going to pay again.
Because we're not only going
3
to pay once, we're going to be paying two times, and we all
4
know that.
A small state like New Hampshire, they get away
.S
with it, we don't have much representative in Washington.
6
Thank you.
7
MR. COUGHLIN:
Thank you, sir.
8
Rich Rouleau.
9
MR. ROULEAU:
Rich Rouleau representing R.M.
10
Rouleau Incorporated.
R.M. Rouleau has been selected as one
11
of the 31 potentially-responsible parties.
I've got,
12
basically, four points.
Three of them are basically
13
recapping what everyone else has already indicated.
R.M. Rouleau feels that there is enough evidence
14
15
which indicates that:
16
A:
The site does not pose a threat to the health
or lives of people.
B:
The site does not pose a significant threat to
the environment.
And, c:
The sit. is at a steady state and
po88ibly even cleaning itself up, to justify the
implementation of institutional controls and future
monitoring only, rather than the remedial action being
sUggested by EPA.
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19
20
21
22
23
.24
25
21
1
remedial action which will destroy the financial status of
the city as well as that of many PRPs if it isn't really
2
3
necessary or justifiable.
4
Point 2:
If EPA does require remedial action
5
beyond institutional controls and monitoring, we suggest
that Alternate 5 be implemented.
6
7
Point 3:
We disagree with the inclusion of the
8
contingency plan which will require the conventional cap,
pump and treat remedial action in the event that Alternate 5
9
10
is not successful.
We suggest that if Alternate 5 is not
11
effective after a few years, then the condition of the site
and the available technology at the time should be
12
13
reassessed and further action should then be determined.
14
Mandating a contingency plan at this time which may not be
the most feasible and practical contingency at the time of
15
16
possible implementation seems ludicrous.
17
And Point 4:
With regard to the selection of the
31 potentially-responsible parties, we question EPA's method
of'.election of the said parties.
We ask why R.M. Rouleau
Incorporated is the only contractor selected.
Certainly
there are other general contractors, possibly painting
contractor., maybe roofing contractors, and a variety of
other type. of contractors who use the dump as much or more
than R.M. Rouleau Incorporated.
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18
19
20
21
22
23
24
2S
22
1
repair shops in town who are not on the list.
Why are they
2
not on it when others are?
They all do the same types of.
3
oil changes, for instance.
4
It appears that the selection process may not be
fair, and we do not appreciate having been selected as one
5
6
of the 31 potentially-responsible parties.
As one of only 31 selected parties, we will be
7
8
saddled with a cleanup contribution which will be far in
9
excess of what we would feel would be our fair share.
We
10
suggest that the selection of PRPs be looked at again with
the possibility of adding more low contributors to the list,
11
12
thus ,.spreading out the expense of remedial action.
13
Thank you.
MR. COUGHLIN:
Thank you.
14
15
16
That completes all the cards that I have here.
there anybody else who would like to make a statement?
Is
17
(No response.)
MR. COtJGBLIN:
Last chance.
(No response.)
MR. COtJGBLIN:
If not, I would encourage you, if
you would like to say something or make a comment, to submit
written comments to the agency.
You can submit coma.nts as
long as theY're postmarked before"Valentin.'s Day, February
14th, and we will consider them and include responses to
them in the responsiveness smmllary, which, as I said, is
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13
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15
16
17
18
19
20
21
22
23
24
25
-.
23
1
part of the Record of Decision.
So with that I will declare the meeting closed. .
2
3
And we will stay around up front here, if anybody has any
questions or would like to talk to us.
4
5
Thank you for coming.
(Whereupon, at 7:30 p.m., the hearing was concluded.)
6
7
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9
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'. .
24
CERTIFICATE
STATE OF NEW HAMPSHIRE
Rockingham, ss.
I, Victor C. Rasmussen, Court Reporter and Notary
Public in and for the State of New Hampshire, do hereby
certify that the foregoing Pages 1 through 23 to be a true,
complete and accurate transcript of the hearing In the
Matter of the Public Hearing on EPA Remedial
Investigation/Feasibility Study and Proposed Plan for the
cleanup of the Somersworth Sanitary Landfill Superfund Site,
held at the time and place hereinbefore set forth, to the
best of my knowledge, skill and ability.
{~.~
V ctor c.. Rasmussen
-------
APPENDIX C
-------
Somersworth Sanitary Landf~1I Superfund Site
CHEMICAL-SPECIFIC
APPUCABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARs)
Medium
Requirement
FEDERAL REQUIREMENTS:
Synopsis of Requirement
Applicable or
Relevant and Appropriate
I
,
Ground Waler 40 CFR 141.11-141.16 Safe Drinking Water Act Standards for public drinking water systems. Used as cleanup Relevant and appropriate where no nOt~
and Surface (SDWA) Maximtm Contaminant Levels (MCLs) standards for aquifers and surface water bodies that are potential zero MCLG is available
Water drinking water sources. i
Ground Water 40 CFR 141.50 - 141.62 SDWA Maximum Nonenforceable goals for public drinking water systems. Where Non-zero MCLGs are potentially relev
-------
Somersworth Sanitary Landfill Superfund Site
GENERAL ACTION-SPECIFIC
APPUCABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARs)
Synopsis of Requirement
Action to be Taken to
Attain Requirement
..
Medium
Potential Requirement
FEDERAL REQUIREMENTS:
Applicable or
Relevant and Appropriate
. ..
-
Hazardous Hazardous Waste AegLJations,
Waste ACAA Subtitle C, 40 CFA Part 264
ACAA Subtitle C establishes standards Management of hazardous wastes as Applicable to some alternatives,
applicable to treatment, storage, transport, and part of the CERCLA response must relevant and appropriate to others
disposal of hazardous waste and the closure of comply with substantive requirements Has effect through state hazardou
hazardous waste facilities. of Subtitle C regulations. waste requirements, which operal.
in lieu of direct federal regulatir..
See discussion of tho..
roqlliromonts bulow.
Discharge of treated ground water Applicable.
and treated leachate to surface water
must comply with these requirements.
G r 0 u n d Discharge 0' Treatment System Effluent, 40 Imposes limitations on discharge to surface water.
Water CFR 122,40 CFR 125, 40 CFR 131, and 40
CFR 136, National Pollutant Discharge
Elimination System.
STATE REQUIREMENTS:
Hazardous RSA 01. 147-A, New Hampshire Hazardous Standards for management of hazardous waste Management of hazardous waste as See following
Waste Waste Management Act and Hazardous and closure of hazardous waste facilities: part of the CERCLA response must analysis.
Waste RLJes, Env-Wm Chapters 100-1000. Operates in lieu of Federal RCRA Subtitle C comply with the substantive standards
Specific requirements detailed below. requirements. of these rules.
Hazardous Env-Wm 353.09 and 353.10 Siting Restrictions on siting of hazardous waste fac~ities. Any new hazardous waste facility Applicable.
Waste requirements fer hazardous waste faclities must comply with the siting
and variances requirements or with criteria for a
variance.
section by section
Hazardous Env-Wm 702.08 Environmental and
Waste Requirements
Hazardous Env-Wm 702.09
Waste Requirements
General
Design All hazardous waste and transfer facilities are
to meet specified design requirements.
Health Requires operator of a hazardous waste fac~ity to Operation of hazardous waste facility Applicable or relevant
meet certain standards for surface water, ground must meet relevant standards and appropriate, . depending
water, air. criteria. NOTE: worker protection altemative.
requirements are not ARAR, but
OSHA and state law approved under
OSHA must be complied with per
~. 300.1 5O(e) of NCP
Construct any hazardous waste Applicable or relevant
treatment facility in accordance with appropriate, depending
design requirements. altemative. .
Specified types of hazardous waste treatment Implement a ground water monitoring Relevant and appropriate.
facilities must monitor migration of . hazardous program per requirements.
waste as specified.
a~~r
and!
on'
Hazardous Env-Wm 702.11 Ground Water Monitoring
-------
GENERAL ACTION-SPECIFIC
APPUCABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARs)
G r 0 u n d We 604 Abandonment of Wells
Water
Potentia' Requirement
FEDERAL REQUIREMENTS:
G r 0 u n d Env-Ws 410.07, 410.09, 410.10 Prohibited Prohibits discharges to ground water without use Remedial measures involving Applicable.
Water Discharge, Groundwater Discharge Zone, of BAT; requires controls on use of groundwater discharges to ground water
Groundwater Discharge Pennit Compliance within discharg zone; sets limits on discharges to must comply with this regulation.
Criteria groundwater
G r 0 u n d Env-Wm 403 Industrial and Municipal This regulation requires a permit for discharge of Discharge of treated ground water Relevant and appropriate.
Water Wastewater Discharge Pennits wastewater. and disposal of treated leachate must
comply with these requirements.
If ground water wells are abandoned, Applicable.
requirements for closure must be
followed.
Requires existing beneficial uses and the water Discharge to surface water must Applicable.
quality to sustain existing beneficial uses to be comply with this requirement.
01<, "rained and protected. Limited degradation as
a . ,>ult of insignificant discharges may be
al .,~.
Synopsis of Requirement
Action to be Taken to
Attain Requirement
-
Medium
Applicable or
Relevant and Appropriate
- - - '- -- - . ,
Imposes requirements for closure of wells.
Sur fa c e Env-Ws Part 437 Antidegradation Policy
Water
--
- -
. ..
.,
-------
Medium
Wetlands
WeUands
WeUands
Floodplains
Floodplains
Groundwater
Endangered
species
WeUands
Somersworth Sanitary Landfill Superfund Site
LOCATION-SPECIFIC
APPUCABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARs)
Requirement
FEDERAL REQUIREMENTS:
CWA Section 404; 40 CFR Part 230; 33 CFA These requirements control the discharge of dredged or fill
Parts 320-330 material into wetlands and require mitigation for any such
discharge.
Federal agencies are required to preserve and enhance natural
and beneficial values of wetlands and to minimize the
destruction, loss, and degradation of wetlands.
Contains the EPA policy for carrying out the provisions of EO
11990.
Federal agencies are required to reduce the risk of flood loss,
to minimize impact of floods, and to restore and preserve the
natural and beneficial value of floodplains.
Contains the EPA policy for carrying out the provisions of EO
11988.
Synopsis 01 Requirement
Executive Order 11990 -- Wetlands
40 CFA Part 6, Appendix A
Executive Order 11988 -- Floodplains
40 CFA Part 6, Appendix A
STATE REQUIREMENTS:
Env-Ws 410.26 Groundwater
Zone
Management At contaminated sites, requires groundwater management zone
to be designated and use restricted. Where wells are currently
in service, altemative drinking water must be provided.
Groundwater extraction from well within in the zone must be
.restricted by easement or ownership if required to complete
the remedy."
plant ASA 217A NH Native Plant
Protection Act
Prohibits damaging plant species listed as endangered within
the state.
ASA 485-A-17, Dredging and Control of Run- These requirements establish criteria for conducting any
Off; Env-Ws Part 415, Dredging Rules activity in or near state surface waters which significantly alters
terrain or may otherwise adversely affect water quality, impede
natural runoff, or create unnatural runoff. This includes
excavation, dredging, and grading of topsoil in or near
wetlands areas.
........................................... """""""""""""''''''''''''''''''''''''''''''''''''.,.,.......,..........,....,....... ...................
"'''''',..-...
[[["""'''''''''''''''' [[[
Applicable or
-------
LOCATION-SPECIFIC
APPUCABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS (ARARs)
Applicable or
Medium Requirement Synopsis of Requirement Relevant and Appropriate
FEDERAL REQUREUENTS:
Wedands RSA Ch. 482.A, AI and Dredge in Wedands; These requirements regulate filling and other activities in or Applicable.
and Env-Wm 300-400, 81d 600, Criteria and adjacent to wetlands. They establish criteria for the protection
Conditions tor Fill 81d Dredge in Wedands of wetlands from adverse impacts on fish, wildlife, commerce,
-------
Somerswortb Sanita~ Landfill S~perfund Site
ACTION-SPECIFIC ARARS
Alternative 5: Umited action, landfill cover, enbanced in-situ cbemical restoration, natural attenuation, bedrock ground water extraction with in-situ
treatment, and ground water monitoring
Medium
Potential Requirement
FEDERAL REQUIREMENTS:
Synopsis of Requirement
Hazardous Hazardous Waste Regulations,
Waste RCRA Subtitle C, 40 CFR Part 264
RCRA Subtitle C establishes standards
applicable to treatment, storage, transport, and
disposal of hazardous waste and the closure of
hazardous waste facilities.
STATE REQUIREMENTS:
Action to be Taken to
Attain Requirement
t
Applicable or
Relevant and Appropriate
-
Management of hazardous wastes as Relevant and appropnate.
part of the CERCLA response must Has effect through stall?
comply with substantive requirements hazardous waste requirements, I'
of Subtitle C regulations. which operate in lieu of direct
federal regulation. See discussion
01 those requirements below.
Hazardous RSA Ch. 147-A, New Hampshire Hazardous Standards for management of hazardous waste Management of hazardous waste as See following
Waste Waste Management Act and Hazardous and closure of hazardous waste facilities. part of the CERCLA response must analysis.
Waste RlAes, Env-Wm Chapters 100-1000, Operates in lieu of Federal RCRA Subtitle C comply with the substantive standards
in so far as they are relevant to this requirements. of these rules.
altemative, including in particular those
listed below.
Hazardous Env-Wm 353.09 and 353.10 Siting Restrictions on siting of hazardous
Waste requirements 'for hazardous waste fac~ities facilities.
and variances
waste Any new hazardous waste facility Applicable.
must comply with the siting
requirements or with criteria for a
variance.
Health Requires operator of a hazardous waste facility to Operation of hazardous waste facility Applicable.
meet certain standards for surface water, ground must meet relevant standards and
water, air. criteria. NOTE: worker protection
requirements are not ARAR, but
OSHA and state law approved under
OSHA must be complied with per
S. 300.150(e) of NCP
Construct any hazardous waste Applicable.
treatment facility in accordance with
design requirements.
Specified types 01 hazardous waste treatment Implement a ground water monitoring Relevant and appropnate.
facilities must monitor migration of hazardous program per requirements.
waste as specified.
Hazardous Env-Wm 702.08 Environmental and
Waste Requirern:ents
Hazardous Env-Wm 702.09
Waste Requirements
General
Design All hazardous waste and transfer facilities are
. to meet specified design requirements.
Hazardous Env-Wm 702.11 Ground Water Monitoring
Waste
--------
------------------------------------
----------------------------------------- ------------------------------
----------------------------
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Somersworth Sanitllry Landfill Superfund Site
ACTION-SPECIFIC ARARS
Alternative 5: Umlted adion, landfill cover, enhanced in-situ chemical restoration, natural attenuation, bedrock ground water extraction with in-situ
treatment, and ground water monitoring .
Action to be Taken to Applicable or
SynopsIs of Requirement Attain Requirement Relevant and Appropriate
Requires groundwater monitoring by certain Implement ground water monitoring Relevant and Appropriate.
facilities. as specified, if necessary.
Variety of requirements relating to operation and Comply with substantive specified Applicable to operation of a 'I
closure of hazardous waste treatment facility. requirements, not with procedural hazardous waste facility; relevant i
requirements. and appropriate as to closure. .
Imposes various requirements for operation of a Comply with specified requirements. Applicable to operation of a
hazardous waste treatment facility hazardous waste treatment facih\',
RSA Ch. 125-C, Air Pollution Control; NH Air pollution controls, as specified below. See below. See below.
Admin. Rules, Env-A 100-1300, as specified
below.
Fugitive Dust Emission Control, NH Admin. Activities such as construction and excavation Maintain dust control during site Applicable.
Rules, Env-A 1002 must include precautions to prevent, abate, and remediation.
control fugitive dust emissions.
G r 0 u n d Env-Ws 410.24(a) and (b), Criteria for Requires remedial action for groundwater to The remedy must achieve these Applicable.
Water Remedial Action ensure protection of human health and the specified goals.
environment and attain the groundwater quality
criteria of Env-Ws 410.03.
G r 0 u n d Env-Ws 410.27, Groundwater Management Where an approved remedial action plan fails to If the preferred remedy fails to meet Applicable.
Water Pennit Compliance Criteria meet performance standards, a revised plan must performance standards, a revised
be developed. Additional investigation or remedial plan consisting of the contingent
action may be required. Groundwater must be rem e d y will be a d opt e d .
monitored and managed in accordance with the Groundwater must be monitored and
plan until contamination sources are removed or managed as prescribed.
treated and compliance witl) groundwater quality
criteria are achieved.
Municipal This regulation requires a permit for discharge 01 Discharge of treated ground water Relevant and appropllate.
wastewater. and disposal of treated leachate must
comply with these requirements.
If ground water wells are abandoned, Applicable.
requirements for closure must be
followed.
Medium Potential Requirement
Hazardous Env-Wm 702.12 Other Monitomg
Waste
Hazardous Env-Wm 708.02 Operation Requirements
Waste
Hazardous Env-Wm 708.03 Technical Requirements.
Waste
Air
Air
G r 0 u n d Env-Wm 403 Industrial and
Water Wastewater Discharge Penn its
G r 0 u n d We 604 Abandonment of Wells
Water
!!
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Somersworth Sanitary Landfill Superfund Site
ACTION-SPECIFIC ARARS
Alternative 8: Umited action, landfill cover, perimeter slurry wall, groundwater extraction (with on-site or off-site treatment), natural
attenuation, overburden and bedrock ground water extraction with treatment, and ground water monitoring
Medium
Potential Requirement
FEDERAL REQUIREMENTS:
Synopsis of Requirement
Action to be Taken to
Attain Requirement
Applicable or
Relevant and Appropriate
\;
Hazardous Hazardous Waste Regulations,
Waste RCRA Subtitle C, 40 CFR Part 264
RCRA Subtitle C establishes standards Management of hazardous wastes as Relevant and appropriate.
applicable to treatment, storage, transport, and part of the CERCLA response must Has effect through state hazardous;
disposal of hazardous waste and the closure 01 comply with substantive requirements waste requirements, which operal\-'
hazardous waste facilities. of Subtitle C regulations. in lieu of direct federal regulatior'.
See discussion of tho~.
requirements below.
Discharge of treated ground water Applicable if treated ground wate
and treated leachate to surface water discharged to surface water.
must comply with these requirements.
G r 0 u n d Discharge of Treatment System Effluent, 40 Imposes limitations on discharge to surface water.
Water CFR 122,40 CFR 125, 40 CFR 131, and 40
CFR 136, NatiOnal Pollutant Discharge
Elimination System.
STATE REQUIREMENTS:
'.
,.
Hazardous Env-Wm 702.09
Waste Requirements
waste Any new hazardous waste facility Applicable.
must comply with the siting
requirements or with criteria for a
variance.
Hazardous Env-Wm 702.08 Environmental and Health Requires operator 01 a hazardous waste fac~ity to Operation of hazardous waste facility Applicable.
Waste Requirements meet certain standards for surface water, ground must meet relevant standards and
water, air. criteria. NOTE: worker protection
requirements are not ARAR, but
OSHA and state law approved under
OSHA must be complied with per
~. 3OO.150(e) of NCP
Construct any hazardous waste Applicable.
treatment facility in accordance with
design requirements.
Hazardous RSA Ch. 147-A, New Hampshire Hazardous Standards for management of hazardous waste Management of hazardous waste as See following
Waste Waste Management Act and Hazardous and closure of hazardous waste facilities. part of the CERCLA response must analysis.
Waste Rules, Env-Wm Chapters 100-1000, Operates in lieu of Federal RCRA Subtitle C comply with the substantive standards
in so far 8S they are relevant to this requirements. of these rules.
alternative, including in particular those
listed below.
Hazardous Env-Wm 353.09 and 353.10 Siting Restrictions on siting of hazardous
Waste requirements for hazardous waste fac~ities facilities.
and variances
section by
I'
section i
I
I
I
I
I
General
Design All hazardous waste and transfer facilities are
to meet specified design requirements.
.................... [[[""'"''''''''''''''''''
'"''''''''
...................
.......
.......
......................
.......
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----
Somersworth Sanitary Landfill Superfund Site
ACTION-SPECIFIC ARARS
Alternative 8: Umited action. landfill cover. perimeter slurry wall. groundwater extraction (with on-site or off-site treatment), natural
. attenuation. overburden and bedrock ground water extraction with treatment, and ground water monitoring
Action to be Taken to Applicable or
Synopsis of Requirement Attain RequIrement Relevant and Appropriate
Specified types of hazardous waste treatment Implement a ground water monitoring Relevant and appropriate.
facilities must monitor migration of hazardous program per requirements.
waste as specified.
Requires groundwater monitoring by certain Implement ground water monitoring Relevant and Appropriate.
facilities as specified, if necessary.
Variety of requirements relating to operation and Comply with substantive specified Applicable to operation of
closure of hazardous waste treatment facility. reqUirements, not with procedural hazardous waste facility; relevan.
requirements. and appropriate as to closure.
Comply with specified requirements. Applicable to the operation of F
hazardous waste treatment facility
See be/ow.
I
!'
MedIum Potential Requirement
Hazardous Env-Wm 702.11 Ground Water Monitori'lg
Waste
Hazardous Env-Wm 702.12 Other Monitori'lg
Waste
Hazardous Env-Wm 708.02 Operation Requirements
Waste
Hazardous Env-Wm 708.03 Technical Requirements.
Waste
Air
Air
Air
Air
Air
Imposes various requirements for operation of a
hazardous waste treatment facility
RSA Ch. 125-C, Air Pollution Control; NH Air pollution controls, as specified be/ow.
Admin. Rules, Env-A 100-1300, as specified
below.
Env-A 505.02(e) Emergency Procedures
See below.
Imposes obligations on sources of air pollution in Comply with directions of state in Applicable.
cases of pollution emergency. case of "waming" status.
Env-A 902 Malfunctions of Air Pollution Provides limited relief from other requirements in No action required. Provides relief Relevant and appropriate.
Control Equipment case of malfunction. Notification requirements are from other ARARs.
not ARARs.
Fugitive Dust Emission Control, NH Admi'l. Activities such as construction and excavation Maintain dust control during site Applicable.
Rules, Env-A 1002 must include precautions to prevent, abate, and remediation.
control fugitive dust emissions.
Env-A 1305 Impact Analysis and Permit Requires air quality impact analysis
Requirements emitting regulated substances.
./
I!
I
of devices Discharge from any new or modified Applicable.
facility must comply with requirements
of section.
Prohibits disposal to Class B waters unless Surface water discharge from any Applicable.
treated to prevent lowering below classification response action must comply with
these requirements
Any discharge to ground water or surface water Remedial altematives involving Applicable.
that lowers the quality of the water below the discharge to ground water or
its classification is prohibited. surface water must comply with these
standards.
Sur f ace RSA 485-A:8 Surface Water Classifications
Water
G r 0 u n d RSA 485-A: 12 Enforcement of Oassification
Waterl
Su rface
Water
"""""""""'"'' [[[
""'0"'"''''''''''''''''''''''''''''''''''
'... .........................
-------
Somersworth Sanitary Landfill Superfund Site
ACTION-SPECIFIC ARARS
Alternative 8: Umlted action, landfill cover, perimeter slurry wall, groundwater extraction (with on-site or off-site treatment), natural
attenuation, overburden and bedrock ground water extraction with treatment, and ground water monitoring
Medium Potentia' Requirement
G r 0 U n d RSA 485-A:13 Permit for discharge
Waterl
Surface
Water
Action 10 be Taken to Applicable or
Synopsis 0' Requirement Attain Requirement Relevant and Appropriate
Discharge or disposal must comply. with effluent Remedial measures involving Applicable.
limitations. . discharges to ground or surface water
must comply with these standards.
On-site discharges do not require
permit.
G r 0 u n d Env-Ws 410.24(a) and (b), Criteria for Requires remedial action for groundwaler to The remedy must achieve these Applicable.
Water Remedial Action ensure prolection of human health and the specified goals.
environment and attain the groundwater quality
criteria of Env-Ws 410.03.
G r 0 u n d Env-Ws 410.07, 410.09, 410.10 Prohibited Prohibits discharges 10 ground water without use Remedial measures involving Applicable if Ireatment e/nuenl
Waler Discharge, Groundwater Discharge Zone, of BAT; requires controls on use of groundwater discharges to ground water discharged to ground water.
Groundwater Discharge Permit Compliance within discharg zone; sets limits on discharges to must comply with this regulation.
Criteria groundwater
G r 0 u n d Env-Ws 410.27, Groundwater Management Where an approved remedial action plan fails to If the preferred remedy fails to meet Applicable.
Water Permit Compliance Criteria meet performance standards, a revised plan must performance standards, a revised
be developed. Additional investigation or remedial plan will be adopted. Groundwater
action may be required. Groundwater must be must be monitored and managed as
monitored and managed in accordance with the prescribed.
plan until contamination sources are removed or
treated and compliance with groundwater quality
criteria are achieved.
G r 0 u n d Env-Wm 403 Industrial and Municipal This regulation requires a permit for discharge of Discharge of treated ground water Relevant and appropriate.
Water Wastewater Discharge Permits wastewater. and disposal of treated leachate must
comply with these requirements.
If ground water wells are abandoned, Applicable.
requirements for closure must be
followed.
Requires existing beneficial uses and the water Discharge to surface water must Applicable.
quality to sustain existing beneficial uses to be comply with this requirement.
maintained and protected. limited degradation as
a result of insignificant discharges may be
allowed.
j:
!
G r 0 u n d We 604 Abandonment of Wells
Water
Imposes requirements for closure of wells.
Sur f ace Env-Ws Part 437 Antidegradation Policy
-------
APPENDIX D
state Declaration of Concurrence
-------
"'.---,
....-:-~
... - -
... '- -J' '
<1 "1- t:NHDES
. ~-- ._---.. ..--
. - - - -- - - - - - - .
.------- ---
State of ~ew Hampshire
DEPARTMENT OF ENVIRONMENTAL SERVICES
6 Hazen Drive. P.O. Box 95. Cnncord. NH 03302-0095
603-271-3503
FAX 603-271-2807
TDD An:c,,: Relay NH I-XIX)-7.15-~~0-I
June 21, 1994
John P. DeVillars
Regional Administrator
USEPA-Region I
JFK Federal Building (RAA)
Boston, MA 02203
RE:
Record of Decision
Somersworth Municipal Landftll
. Somersworth, New Hampshire
Dear Mr. DeVilhitrs:
The New Hampshire Department of Environmental Services has reviewed the
. Record of Decision (ROD) for the Somersworth Municipal Landfill Superfund Site located
in Somersworth, NH. The ROD was drafted by the United States Environmental
Protection Agency and selects a preferred remedy having the following components: .
AIR RESOURCES DIV.
64 No. Main Sueer
Caller 8o~ 2033
Concord. N.H. 03302-2033
Tel. 603-271-1370
Fax 603-271-1381
(1 )
an innovative, in-situ chemical treatment wall with groundwater diversion.
The wall will be composed of permeable treatment sections and
impermeable barrier sections and will be located to intercept contaminated
groundwater flowing from the landfill. The barrier sections will divert
contaminated groundwater through chemical treatment sections where
detoxification of volatile organic compounds will occur.
(2)
a permeable landfill cover. The permeable cover will promote leaching of
soluble contaminants from the landfill waste by allowing infiltration of
precipitation. After specified groundwater clean-up levels are achieved and
maintained without use of the treatment wall, an appropriate landfill cover
will be designed and constructed.
(3)
a bedrock groundwater extraction well. Initially, one extraction well will be
constructed (outside the landfill footprint) to remove contaminated
groundwater from bedrock. Effluent from the well will be either discharged
to the landfill (where it will percolate into the waste mass and enhance
flushing of landfill contaminants) or will be injected just upgradient of the
treatment wall. In both cases, the effluent will pass through the treatment
wall for detoxification. The need for additional bedrock groundwater
extraction wells will be evaluated during the remedial .design of the.
preferred remedy.
WASTE MANAGEMENT DIV.
6 Hazen Drive
Concord. N.H. 03301
Tel. 603-21\-2900
Fax 603-21\-2456
WATER RESOURCES DIV.
64 No. Main Sue",
P.O. 80.2008
Concord. N,H. 03302-2008
Tel. 603-271-3406
Fax 603-271-6588
WATER SUPPLY & POLLUTION CONTROL DIV.
P.O. 8o~ 95 .
Concord. N.H. 03302-0095
Tel. 603-21\-3503
-------
~N(""""'''''''
~~'.mte~t~
~ Services
John P. OIVIJI8rs, RIg. Adm".
USEPA.WMO
RE: Rlcord of Olel8lon
Some-r1h L8nd111, Some_rth. NH
June 21, 1 aa..
Plge 2
Contingency Remedy
The ROD also specifies a contingency remedy if the preferred remedy proves to
be ineffective and does not meet specified performance standards. The contingency
remedy will be constructed in two stages, with the first stage being evaluated to
determine if the next stage is required. The first stage of the contingency remedy has the
following components:
(3)
(4)
(1)
a perimeter slurry wall. A slurry wall (extending to bedrock) will encompass
the existing landfill waste mass in an effort to minimize overburden
groundwater/waste contact and thus reduce formation of leachate and
migration of contaminants. Existing impermeable barrier sections will be
incorporated into the perimeter slurry wall.
(2)
a groundwater diversion trench. A groundwater diversion trench will be
constructed on the upgradient side of the landfill to prevent an artificial rise
of the groundwater surface when it encounters the slurry wall. Overburden
groundwater will be intercepted and diverted to wetlands located
downgradient of the landfill.
a landfiU cap. A multi-layer, impermeable cap will be constructed over the
entire landfill in accordance with RCRA Subtitle C requirements.
bedrock groundwater extraction. Item (3) of the preferred remedy, bedrock
groundwater extraction, will be included with this stage of the contingency
remedy. Extracted bedrock groundwater will likely be treated at the
Somersworth Wastewater Treatment Facility.
The design objective of Stage One of the contingency remedy is to eliminate the
source of groundwater contamination and to meet interim groundwater cleanup levels in
the overburden aquifer at the compliance boundary. Groundwater levels and quality in
the vicinity of the landfill will be monitored to verify that the Stage One design objective
has been achieved. If construction of Stage One does not result in both elimination of
waste/groundwater contact and attainment of specified interim groundwater cleanup
-------
John P. DeVlllllra, Reg. Admh.
USEPA-WMD
RE: Record of Dee.1on
Somerawarth L8ndt11, Somerawarth, NH
June 21, 1884
Page 3
~-.I" N""""",..."..
Enviro'nme~t~
-~~ Services
The second stage of the contingency remedy has the following component:
(5)
extraction and treatment of overburden groundwater located within the slurry
wall. The remedial design will determine the location, number and pumping
rates of each well, along with the most appropriate treatment technology
and discharge location of contaminated groundwater. On-site treatment and
disposal methods and pretreatment and discharge at the Somersworth
Wastewater Treatment Facility are the two options which will be evaluated.
Extracted bedrock groundwater (see Item (4) of the Contingency Remedy)
will be treated and disposed along with the extracted overburden
groundwater.
State of New Hampshire Remediation Policy
The New Hampshire Code of Administrative Rules, Env-Ws 410 establish
standards, criteria and procedures to remediate sites with contaminated groundwater.
Generally, the rules require that remediation of such sites include source removal,
containment, or treatment, containment of groundwater contamination within the limits of
a specified groundwater management zone, and reduction of groundwater contaminant
levels within that zone.
Both the preferred and contingency remedies described in the ROD are consistent
with the approach that would be required under Env-Ws 410 and State policy, although
the proposed remedial techniques differ from those typically required by the State. The
preferred remedy is designed to treat the source of groundwater contamination via an in-
situ chemical treatment wall. The contingency remedy is designed to minimize
groundwater/waste contact, thus eliminating the source of groundwater contamination, by
constructing a perimeter slurry wall and a landfill cap (constructed in accordance with
RCRA Subtitle C specifications). Both remedies will include periodically monitoring
groundwater to verify effectiveness.
ARARs
The preferred remedy and the contingency remedy will comply with applicable or
-------
John P. DeV".... Reg. Admin.
USEPA-WMD
RE: Record of Decillion
Somel'lWOrth L8ndt11, Somel'lWOrth, NH
June 21, 1884
Page 4
~ NEW HAM...."..
~~';me~tai
~ -",,--,- Services
State Concurrence
The New Hampshire Department of Environmental Services, acting on behalf of
the State of New Hampshire, concurs with the preferred and contingency remedies
described in the ROD. The State assures that if the Superfund Trust Fund is used, the
State will contribute its statutorily required cost share, if State funds are available.
Sincerely,
~\-J,~-
Robert W. Varney
Commissioner
?)'
PJOfTGH/amklsmlfrod.1Ir
cc: Daniel Coughln. P.E.. USEPA
RogerDuwart.USEPA
Phip J. O'Brien. Ph.D.. Director, NHDES-WMD
Harry Stewart. P.E., NHDES-GPB
Carl W. Buter, P.E., NHDES-WMEB
Maureen Smith, E8q., NHDOJ-AGO
Paul Lincoln, P.E.. NHDES-WMEB
-------
APPENDIX E
-------
--_...
VOLUME I
VOLUME II
VOLt1MB III
VOLUHE IV
VOLUHE V
3.0
4.0
SOMERS WORTH SANITARY LANDFILL
NPL SITE ADMINISTRATIVE RECORD
Table of Contents
1.0
Pre-Remedial
1.2 Preliminary Assessment
1.3 Site Inspection
1.18 FIT Technical Direction
Associated Records
Documents (TDDs) and
3.0
Remedial Investigation (RI)
3.1
3.2
3.3
3.4
Correspondence
Sampling and Analysis Data
Scope of Work
Interim Deliverables
3.0
Remedial Investigation (RI) (continued)
3.4
3.6
Interim De1iverables (continued)
Remedial Investigation (RI) Reports
3.0
Remedial Investigation (RI) (continued)
3.6
Remedial
(continued)
Investigation
(RI)
Remedial Investigation (RI) (continued)
3.6 Remedial
(continued)
3.7 Work Plans and Progress
3.9 Health Assessments
3.12 Action Memoranda
Investigation
(RI)
Reports
Feasibility Study (FS)
4.1
4.2
4.4
4.5
Correspondence
Sampling and Analysis Data
Interim Deliverables
Applicable or Relevant
Requirements (ARARS)
and
Appropriate
Reports
-------
SOMERSWORTH SANITARY LANDFILL
NPL SITE ADMINISTRATIVE RECORD
Table ot Contents (continued)
VOLUHE VI
4.0 Feasibility Study (FS) (continued)
4.6 Feasibility Study
VOLUME VII
4.0 Feasibility Study (FS) (continued)
4.6 Feasibility Study (continued)
VOLtJKB VIII
4.0 Feasibility Study (FS) (continued)
4.6 Feasibility Study (continued)
VOLUME IX
4.0 Feasibility Study (FS) (continued)
4.6 Feasibility Study (continued)
VOLUME X
4.0 Feasibility Study (FS) (continued)
4.6 Feasibility Study (continued)
VOLUME XI
4.0 Feasibility Study (FS) (continued)
4.6
Feasibility Study (continued)
VOLUMB XII.
4.0
Feasibility study (FS) (continued)
4.6
Feasibility Study (continued)
VOLma: XIII
4.0
Feasibility Study (FS) (continued)
4.6
-------
VOLUME XIV
VOLUME XV
SOMERSWORTH SANITARY LANDFILL
NPL SITE ADMINISTRATIVE RECORD
Table of Contents
4.0 Feasibility Study (FS) (continued)
4.6
Feasibility Study (continued)
4.0
Feasibility Study (FS) (continued)
4.7
4.9
Work Plans and Progress Reports
Proposed Plans for Selected Remedial Action
5.0
Record of Decision (ROD)
5.1
5.3
5.4
Correspondence
Responsiveness Summaries
Record of Decision (ROD)
10!0 Enforcement
10.7 Administrative Orders
11.0 Potentially Responsible Party (PRP)
11.5 Site Level - General Correspondence
11.7 PRP Steering Committee Documents
11.9 PRP-Specific Correspondence
13.0 Community Relations
13.3 News Clippings/Press Releases
13.4 Public Meetings
13.5 Fact Sheets
14.0 Congressional Relations
14.1 Correspondence
16.0 Natural Resources Trustee
16.1 Correspondence
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SOMERSWORTH SANITARY LANDFILL
NPL SITE ADMINISTRATIVE RECORD
Table of Contents
VOLUME XV (continued)
17.0 Site Management Records
17.4 Site Photographs/Maps
17.7 Reference Documents
17.8 State and Local Technical Reports
-------
Introduction
This document is the Index to the Administrative Record for
the Somersworth sanitary Landfill National Priorities List
(NPL) site. Section I of the Index cites site-specifi'c
documents, and Section II cites guidance documents used by EPA
staff in selecting a response action at the site.
The Administrative Record is available fo~ public review at
EPA Region I's Office in Boston, Massachusetts, 90 Canal
Street (617-573-5729) and the Somersworth Public Library, 27
Main Street,Somersworth, New Hampshire 03878. Questions'
concerning the Administrative Record should be addressed to
the EPA Region I site manager.
The Administrative Record is required by the Comprehensive
Environmental Response, Compensation, and Liability Act
(CERCLA), as amended by the Superfund Amendments and
-------
Section I
-------
3.0
ADMINISTRATIVE RECORD INDEX
for the
Somersworth Sanitary Landfill
1.0
Pre-Remedial
1.2
Preliminary Assessment
1.
"Potential Hazardous Waste Site: Identification and
Preliminary Assessmentll Form, EPA Region I (April
29, 1982).
1.3
Site Inspection
IIpotential Hazardous Waste site: Site Inspection
Report,lI EPA Region I (July 26, 1982).
1.18 FIT Technical Direction Documents (TDDs) and Associated
Records
1.
1.
NUS Corporation, Superfund Division, Document
Transmittal addressed to Peter McGlew, EPA Region I
(May 24, 1983). With attached memo from John M.
Panaro, NUS Corporation to Peter McGlew, EPA Region
. I (May 24, 1983). Concerning Dover and Somersworth
Landfill Sampling Project. .
NUS Corporation, Superfund Division, Document
Transmittal from Rich DiNitto to Peter McGlew, EPA
Region I (September 21, 1983) with attached me~o
from John Panaro, NUS Corporation to Peter McGlew,
EPA Region I (September 1, 1983). Concerning
summary of laboratory data for Dover and
Somersworth, New Hampshire.
2.
*
Additional FIT Technical Direction Documents (TDDs)
and Associated Records may be reviewed, by
appointment only, at EPA Region I, Boston,
Massachusetts.
Remedial Investigation (RI)
3.1
Correspondence
1.
Telephone Record of phone call from Norm Leclerc,
Project Coordinator, to Diana King, EPA Region I
(November 25, 1991). Concerning deadline for PRP
response to SOW and possibility .that plume has
moved further than thought and the obligation to
-------
3.4
3.2
Sampling and Analysis Data
*
Sampling and Analysis Data from the Rem~dial
Investigation may be reviewed, by appointment only,
at EPA Region I, Boston, Massachusetts.
1.
Sampling results for the new wells at Somersworth
Municipal Landfill collected November 7 and 8,
1990.
EPA 624 sample results from samples collected
January 24 through January 27, 1992.
Resul ts from NHDES Sampling on March 12, 1992.
Tables which summarize results from
field activities for the Somersworth Landfill Site
prior to March 26, 1992.
2.
3.
4.
3.3
Scope of Work
1.
Letter from Mark E. Beliveau, Sanders & McDermott
(attorney for Blackwater Road Landfill PRP Group)
to Sila Gonzalez, EPA Region I (October 25, 1991).
Concerning EPA October 11, 1991 Supplemental
Addi tional Remedial Investigation Data Gathering
Activities Scope of Work. .
Interim Deliverables
1.
"Preliminary Draft Remedial Action Master Plan for
Somersworth Landfill, Somersworth, New Hampshire,
(January 5, 1983)" prepared by Camp Dresser &
McKee, Inc., and subconsultants.
"Site Safety Plan Remedial Investigation
Somersworth Municipal Landfill, Somersworth, New
Hampshire," Wehran Engineering Corporation (January
1985). (Note: Original is missing page 13.)
"Quality Assurance Project Plan Remedial
Investigation, Somersworth Municipal Landfill,
Somersworth, New Hampshire," Wehran Engineering
Corporation (July 1985).
"Appendices - Quality Assurance Project Plan -
Remedial Investigation, Dover Municipal Landfill,
Dover, New Hampshire, Somersworth Municipal
Landfill, Somersworth, New Hampshire," Wehran
Engineering Corporation (April 1985).
"Ground Water Extraction, Somersworth Landfill,
Somersworth, New Hampshire," Canonie Environmental
(October 1988). .
2.
3.
.4.
5.
-------
..__.~---- .
3.7
. .
3.9
3.6
Remedial Investigation (RI) Reports
1.
"Remedial Investigation, Somersworth Municipal
Landfill, Somersworth, New Hampshire," Volume I
(text), Volume II (Tables and Figures, Appendices
A-F), and Volume III (Appendices G-L), Wehran
Engineers and Scientists (May 1989).
"RI Data Gathering Report, Somersworth Landfill,
Somersworth, New Hampshire," Canonie Environmental
(May 1990).
"RI Data Gathering Report, Somersworth Landfill,
Somersworth, New Hampshire," Canonie Environmental
(May 1992).
2.
3.
Work Plans and Progress Reports
1.
"Investigation Plan Remedial Investigation,
Somersworth Municipal Landfill, Somersworth, New
Hampshire," Wehran Engineering Corporation
(March 1985).
Letter from Diana King, EPA Region I, to Norman
Leclerc, Project Coordinator, City of Somersworth
(December 27, 1991). Concerning the Review and
Acceptance of Work Plan Addendum for Additional
Remedial Investigation Activities Somersworth
Landfill, Somersworth, New Hampshire, prepared by
Canonie Environmental (December 17, 1991).
2.
Health Assessments
1.
"Health Assessment for Somersworth Municipal
Landfill Site," New Hampshire Department of Health
and Human Services and the Agency for Toxic
Substances and Disease Registry U.S., Public Health
Service (March 1989).
"Addendum to Public Health Assessment, Somersworth
Sanitary Landfill, Somersworth, Strafford County,
New Hampshire". Cerc1is No. NHD980520225. New
Hampshire Department of Health and Human Services
and the Agency for Toxic Substances and Disease
Registry U.S., Public Health Service.
2.
3.12 Action Memoranda
1.
Memorandum from Merrill S. Hohman, EPA Region I to
Michael R. Deland, EPA Region I. Concerning
authorization to conduct a remedial investigation
and feasibility study (February 8, 1984).
-------
- .-----.---....
4.1
Feasibility Study (FS)
Correspondence
4.0
7.
8.
1.
Letter from Norman Leclerc, Project Coordinator, to
Diana King, EPA Region I (April 16, 1991).
Concerning Ms. King's comments relative to the
Somersworth Landfill Feasibility Study not being
received as promised, and the subsequent
rescheduling of the meeting originally scheduled
for May 10, 1991.
Letter from Diana King, EPA Region I, to Norman
Leclerc, Project Coordinator (April 23, 1991).
Concerning the transmittal of attached set of
partial comments made on the Draft Feasibility
Study (FS) for Somersworth Landfill (February
1991) .
Letter from Norman Leclerc, Project Coordinator, to
Diana King, EPA Region I (April 30, 1991) .
Concerning the receipt of "partial set of comments"
from Ms. King, the need to reschedule the meeting
scheduled for May 10, 1991, and the date when final
comments will be received.
Letter from Douglas R. Elliott,' Jr., City Manager,
to Merrill S. Hohman, Director Waste Management
Division, EPA Region I (May 20, 1991). Concerning
the distress of the Trustees of the Somersworth
Landfill Trust with the Agency's decision not to
allow the proposed additional work.
Letter from Diana King, EPA Region I, to Norman
Leclerc, Project Coordinator (May 20, 1991) .
Concerning transmittal of attached supplemental
comments made on the Draft Feasibility Study (FS)
for Somersworth Landfill (February 1991).
Letter from Diana King, EPA Region I, to Norman
Leclerc, Project Coordinator (May 27, 1991).
Concerning transmittal of attached Final Review
Comments on Draft Feasibility study (FS) for
Somersworth Landfill (February 1991).
Letter from Sherilyn Burnett Young, Rath, Young,
Pignatelli & Oyer (attorney for PRP Steering
committee) to Sila Gonzalez, EPA Region I
(June 18, 1991). Concerning Somersworth Municipal
Landfill Feasibility Study. .
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(June 19 , 1991). Concerning the Settling parties
being unable to submit the FS until July 5, 1991.
2.
3.
4.
5.
6.
-------
4.1
14.
15.
16.
17.
Correspondence (continued)
9.
Letter from Diana King, EPA Region I, to Norman
Leclerc, Project Coordinator (June 21, 1991).
Concerning revision of Somersworth Sanitary
Landfill Feasibility Study submittal extension to
June 28, 1991.
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(June 26, 1991). Concerning the Settling Parties
continued need for the July 5, 1991 date for FS
submittal and disagreements with Diana King's
letter dated June 21, 1991.
Memo from John W. Billiard, Canonie Environmental
to Diana King, EPA Region I (July 2, 1991).
Concerning the expected delivery of 6 copies of the
Somersworth Landfill Feasibility study on or before
July 5, 1991.
Letter from John W. Billiard,
Environmental, to Diana King, EPA Region I
(July 3, 1991). Concerning transmittal of six
copies of the "Feasibility Study, Somersworth
Landfill, Somersworth, New Hampshire".
Telephone Record of phone call from Norman Leclerc,
Project Coordinator, to Diana King, EPA Region I
(March 19, 1992). Concerning mailing of sampling
results on March 27, 1992, wetlands evaluation, and
the possibility of non-attainment zone for ground
water.
Telephone Record for phone call from Diana King,
EPA Region I, to Norman G. Leclerc, Project
Coordinator (March 25, 1992). Concerning request
for final sampling data to be sent today, and
Norman Leclerc's notification that he will request
an extension for the Technical Memorandum
submittal.
Letter from Diana King, EPA Region I, to Norman G.
Leclerc, Project Coordinator (March 25, 1992).
Concerning Somersworth Sanitary Landfill Superfund
Site Supplemental Additional Remedial Investigation
Data Gathering (RIDG) Activities.
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(March 25, 1992). Concerning
for an extension to April 10,
required by the approved
Addendum.
Letter from Diana King, EPA Region I, to Norman G.
Leclerc, Project Coordinator (~arch 26, 1992) ~
Concerning the April 1, 1992 deadl~ne'to submit the.
Technical Memorandum to EPA. .
10.
11.
12.
Canonie
13..
the official request
1992 of the schedule
Revised Work Plan
-------
4.1
21.
22.
23.
24.
Correspondence (continued)
18.
Letter from Douglas R. Elliott, Jr., City Manager,
to Julie Belaga, EPA Region I (April 13, 1992).
Concerning the Somersworth Landfill PRP Group's
disagreements with EPA's refusal to allow an
extension to grant an additional investigation. '
Letter from Douglas R. Elliott, Jr., Chairman,
Somersworth Landfill Trust, to Phillip J. O'Brien
Ph. D, New Hampshire Department of Environmental
Services (April 13,1992). with attached letter to
Julie Belaga (April 13, 1992). Concerning the
request for support on the matter of an additional
investigation at the Somersworth Municipal Landfill
Site.
Letter from Merrill S. Hohman, EPA Region I, to
Douglas R. Elliott, Jr., City Manager
(May 15, 1992). Concerning response to
April 13, 1992 letter to Julie Belaga, and EPA
refusal to grant a further extension of time to do
the work proposed in the sow.
Letter from Douglas R. Elliot, Jr., City Manager,
to Merrill S. Hohman, EPA Region I (May 20, 1991).
Concerning Doug Elliott's request to meet with
Merrill Hohman to discuss the latest proposal for
innovative ground water treatment.
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(June 5, 1992). Concerning the request for
permission to obtain a 100 liter sample of water
from monitoring well No. OB-17U to be used for a
laboratory bench scale test to evaluate the
effectiveness of the EnviroMetal process on the
ground water from the site containing high
concentrations of vinyl chloride.
Letter from Douglas R. Elliott, Jr., City Manager,
to Merrill S. Hohman, EPA Region I (May 29, 1992).
Concerning meeting date following submittal of FS,
and disappointment with "statement that a meeting
to allow us to present and explain the
"EnviroMetal" process would be of no value".
Letter from Merrill S. Hohman, EPA Region I, to
Douglas R. Elliot, Jr., City Manager
(June 10, 1992). Concerning response to
May 20, 1992 letter regarding the decision by EPA
not to allow a schedule delay to study
bioremediation at the Somersworth Sanitary Landfill
Superfund Site.
19.
20.
-------
4.1
28.
29.
30.
31.
32.
Correspondence (continued)
25.
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(June 12, 1992). Concerning the request to see
R.S. Kerr Environmental Research Laboratory's
comments on the FS, and to express the
disappointment of the Somersworth Landfill Trust to
Merrill Hohman's letter of May 15, 1992 rejecting
the Trust Proposal to perform a short study.
Letter from John W. Billiard, Canonie
Environmental, to Diana King, EPA Region I
(June 15, 1992). Concerning transmittal of eleven
copies of the Feasibility study Report for review
and approval.
Letter from Douglas R. Elliott, Jr., City Manager,
to Merrill S. Hohman, EPA Region I
(July 15, 1992). Concerning response to
July 14, 1992 meeting, and the renewal of the
request for a six month suspension to allow the
Trust to conduct a treatability study for both the
biorestoration and the EnviroMetal alternatives.
Letter from Merrill S. Hohman, EPA Region I, to
Douglas R. Elliott, Jr., City Manager
(August 5, 1992). Concerning response to
July 15, 1992 letter and agenda for
August 10, 1992 meeting.
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I .
(October 14, 1992). Concerning transmittal
October 14, 1992 "Risk Assessment for
Somersworth Municipal Landfill, Somersworth,
Hampshire", by Cambridge Environmental, Inc.
Letter from Diana King, EPA Region I, to Norman
Leclerc, Project Coordinator (December 3, 1992).
Concerning the transmittal of attached comments on
the Draft Feasibility Study for the Somersworth
Landfill (June 1992).
Letter from Diana King, EPA Region I, to Norr.\an
Leclerc, Project Coordinator (December 16, 1992).
Concerning transmittal of additional comments on
the Draft Feasibility Study for the Somersworth
Landfill (June 1992). .
Letter from John W. Billiard,
Environmental, to Diana King, EPA Region I
(March 5, 1993). Concerning transmittal of 13
copies of the Final Feasibility Study Report.
26.
27.
of
the
New
Canonie
-------
4.2
4.4
4.1
Letter from John W. Billiard, Canonie
Environmental, to Mr. Norman G. Leclerc, Project
Coordinator (July 20, 1993). Concerning Canonie
Environmental's response to EPA comments in rega~d
to the Somersworth Landfill Feasibility Study.
Wi th attached letter to Mr. Roger Duwart, EPA
concerning transmittal of same.
Letter from David Major, Beak Consultants Limited,
to Mr Roger Duwart, EPA Region I (July 21, 1993).
Concerning transmittal of attached "Technical
Memorandum: Recent Developments of the Envirometal
Process", prepared by Enviromental Technologies,
Inc., for Beak Consultants Limited (July 1993).
Letter from Mr. David Major, Beak Consultants
Limited, to Mr. Roger Duwart, EPA Region I
(August 10, 1993). Concerning documentation of
telephone conversation from August 3, 1993
regarding the solubility of dechlorinated end-
products by the EnviroMetal process.
Letter from John H. Guswa, GeoTrans, Inc., to Mr.
Roger Duwart, EPA Reg ion I (September 8, 1993).
Concerning summary of GeoTrans technical approach
for remediation of VOC contaminated groundwater in
bedrock beneath and adj acent to the Somersworth
Landfill site.
Correspondence (continued)
33.
34.
35.
36.
1.
Sampling and Analysis Data
Memorandum from Paul Lincoln, New Hampshire
Department of Environmental Services, to Diana
King, EPA Region I (February 12,1993). Concerning
transmittal of map and list of residences that were
previously sampled at Somersworth, NH.
1.
Interim Deliverables
2.
3.
"Draft Initial Screening
Environmental (February 1991).
"Draft Technical Memorandum, Remedial
Objectives and Response Actions",
Environmental (February 1991).
"Risk Assessment for the Somersworth
Landfill, Somersworth, New Hampshire
(October 14, 1992)". Prepared by
Environmental Inc., with attached
letter from Norman G. Leclerc, Project
to Diana King, EPA Region I
(October 14, 1992).
Report" ,
8
Canonie
Response
Canonie
Municipal
Cambridge
transmittal
-------
4.7
4.5
Applicable
(ARARS)
Relevant
and
or
Appropriate
Requirements
1.
4.6
Draft ARAR tables, U. S. Environmental
Agency, Region I (December 8, 1993).
Feasibility Study
Protection
1.
"Draft Feasibility Study for Somersworth Municipal
Landfill, Volume I ( Text, Tables, and Figures,
Appendices A-E), Somersworth, New HampShire,"
Canonie Environmental (February 1991).
"Feasibility Study (June 1991), Somersworth
Landfill Site, Somersworth, New Hampshire", Volume
I ( Text, Tables, and Figures), Volume II
(Appendices A-G), and Volume III (Appendix F:
Supporting calculations), prepared by Canonie
Environmental.
"Feasibili ty Study (June 1992) , Somersworth
Landfill Site, Somersworth, New Hampshire", Volume
I ( Text, Tables, and Figures, Appendices A-B),
Volume II ( Appendices C-H), prepared by Canonie
Environmental.
"Feasibility Study (March .1993), Somersworth
Landfill Site, Somersworth, New. Hampshire", volume
I (Text, Tables, and Figures), Volume II
(Appendices A-G), and Volume III (Appendices H-J) ,
prepared by Canonie Environmental.
"Addendum to the Feasibility Study
(December 1993), Somersworth sanitary Landfill
Superfund Site, Somersworth, New Hampshire",
prepared by U.S. Environmental Protection Agency.
2 .
3.
4.
5.
Work Plans and Progress Reports
1.
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(April 10,1991).. Project Progress Report (No. 22)
concerning additional remedial investigation (RI)
and data collection and feasibility study (FS).
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(May 8, 1991). Project Progress Report (No. 23)
concerning additional remedial investigation (RI)
and data collection and feasibility study (FS).
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(June 11, 1991). Project Progress Report (No. 24)
concerning additional remedial investigation (RI)
and data collection and feasibility study.
2.
3.
-------
..- . -.-.-.... .-
4.9
5.0
4.7
Work Plans and Progress Reports (continued)
4.
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(July 8, 1991). Project Progress Report (No. 25)
concerning additional remedial investigation (RI)
and data collection and feasibility study (FS).
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(August 8, 1991). Project Progress Report (No. 26)
concerning additional remedial investigation eRI)
and data collection and feasibility study (FS).
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(October 10, 1991). Project Progress Report (No.
28) concerning additional remedial investigation
eRI) and data collection and feasibility study
( FS) .
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(March 11, 1992). Project Progress Report (No, 33)
concerning additional remedial investigation (RI)
and data collection and feasibility study (FS).
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(April 13, 1992). Project Progress Report (No. 34)
concerning additional remedial investigation (RI)
. and data collection and feasibility study (FS).
Letter from Norman G. Leclerc, Project Coordinator,
to Diana King, EPA Region I
(May 8, 1992). Project Progress Report (No. 35)
concerning additional remedial investigation (RI)
and data collection and feasibility study (FS).
5.
6.
7.
8.
9.
1.
Proposed Plans for Selected Remedial Action
"Proposed Plan for Cleanup at the Somersworth
Sanitary Landfill," U.S. Enviornmental Protection
Agency (December 1993).
5.1
Record ot Decision (ROD)
1.
Correspondence
Letter from Roger Duwart, EPA Region I to the City
Council, City of Somersworth (April 8, 1994).
Concerning EPA response to letter dated February
28, 1994, requesting a delay in a decision on site
remedial action. .
-------
5.3
Responsiveness Summaries
1.
Cross-Reference: Responsiveness. Summary is
Appendix C of the Record of Decision [Filed and
cited as entry number 1 in 5.4 Record of Decision
(ROD)].
The following citations indicate documents received by
EPA Region I during the formal public comment period.
2.
Comments dated December 16, 1993 from Shirley J.
White on the December 1993 "Proposed Plan for
Cleanup at the Somersworth Sanitary Landfill," EPA
Region I.
Comments dated January 5, 1994 from Keith H. Dinger
on the December 1993 "Proposed Plan for Cleanup at
the Somersworth Sanitary Landfill," EPA Region I.
Comments dated January 18, 1994 from Robert M. Tarr
on the December 1993 "Proposed Plan for Cleanup at
the Somersworth Sanitary Landfill," EPA Region I.
Comments dated February 11, 1994 from Francis
Garofano on the December 1993 "Proposed Plan for
Cleanup at the Somersworth Sanitary Landfill," EPA
Region I.
Comments dated February 14, 1994 from Douglas R.
Elliott, City Manager, City of Somersworth on the
December 1993 "Proposed Plan for Cleanup at the
Somersworth Sanitary Landfill," EPA Region I.
Letter from the City of Somersworth City Councilors
to Roger Duwart, EPA Region I (February 28, 1994).
Concerning a request to delay a Record of Decision
on the Somersworth Landfill Site.
Comments (no date given) from John Young on the
December 1993 "Proposed Plan for Cleanup at the
Somersworth Sanitary Landfill," EPA Region I.
3.
4.
5.
6.
7.
8.
5.4
Record of Decision (ROD)
1.
"Record of Decision Summary, Somersworth Sanitary
Landfill Superfund Site," EPA, Region I,
June 21, 1994.
10.0 Enforcement
10.7 Administrative Orders
1.
Administrative Order, In the Matter of Somersworth
Sanitary Landfill, Somersworth, New Hampshire,
Docket No. I-89-1020 (April 28, 1989).
-------
11.0 Potentially Responsible Party (PRP)
11.5 Site Level - General Correspondence
1.
Letter from Philip L. Munck, City of Somersworth to
Daniel Coughlin, EPA Region I and Michael Sills,
New Hampshire Department of Environmental Services
(July 31, 1987). Concerning PRP take-over of
Feasibility Study.
Letter from Philip L. Munck, City of Somersworth
and William E. McDonogh, General Electric Co.
Community Relations to Richard Pease, New Hampshire
Department of Environmental Services and Roger
Duwart, EPA Region I (September 22, 1987).
Concerning reaffirmation of desire to assume
responsibility for completion of Remedial
Investigation/Feasibility Study for Somersworth
Site and designation of co-chairs for the PRP
Group.
2.
1~.7 PRP Steering Committee Documents
1.
Letter from Sherilyn Burnett Young, Rath, Young,
Pignatelli & Oyer (attorney for PRP Steering
Committee) to Daniel Coughlin, EPA Region I
(April 6, 1988). With the attached, "Shift Toward
Enforcement" article and letter. from Oliver P.
Wesley, Canonie Environmental to Norman Leclerc,
Somersworth PRP Technical Committee.
(March 30,1988). Concerning request for expedited
~emedy as solution to the municipal owned and
operated landfill. (Note: Second letter from
Canonie Environmental is missing).
1.
11.9 PRP-Specific Correspondence
Letter from Seth D. Jaffe, Foley, Hoag, & Eliot,
(Attorney for New England Telephone), to Norman G.
Leclerc, Project. Coordinator (May 5, 1992).
Concerning transmittal of signature pages to the
Administrative Order and Trust Agreement for the
Somersworth Municipal Landfill Site. With attached
signature pages.
13.0 Community Relations
13.3 News Clippings/Press Releases
1.
"What's really in Somersworth
Daily Democrat, April 7, 1983.
dump?" ,
Foster's
-------
13.3 News Clippings/Press Releases (continued)
2.
Informational Notice - Results of groundwater and
surface water monitoring for Somersworth Landfill,
New Hampshire Water Supply and Pollution Control
Commission (October 6, 1983). .
Informational Notice - Results of ground water and
surface water monitoring for Dover Landfill, New
Hampshire Water Supply and Pollution Control
Commission (October 6, 1983).
Notice of Public Meeting - December 10, 1984, New
Hampshire Water Supply and Pollution Control
Commission.
"State Pollution Control Commission Updates
Progress at Somersworth Municipal Landfill, II New
Hampshire Water Supply and Pollution Control
Commission (May 1985). .
"State Pollution Control Commission Updates at
Somersworth Municipal Landfill," New Hampshire
Water Supply and Pollution Control Commission
(September 1985).
"Environmental News - EPA Reaches Settlement With
32 Parties For Past Costs at Somersworth Superfund
Site," EPA Region I (December 20, 1989).
3.
4.
5.
6.
7.
13.4 Public Meetings
1.
New Hampshire Water Supply and Pollution Control
Commission Agenda, Public Informational Meeting
(June 21, 1989) for the Somersworth Municipal
Landfill Superfund Site, with attached flow chart
of site responsibilities.
Transcript of Public Hearing on EPA Remedial
Investigation/Feasibility Study and Proposed Plan
for the Cleanup of the Somersworth Sanitary
Landfill Superfund Site (February 8, 1994).
2~
13.5 Fact Sheets
1.
"Remedial Investigation Somersworth
Landfill" Agenda, New Hampshire Water
Pollution Control Commission (December
With attached fact sheet. .
Municipal
Supply and
10, 1984).
-------
--....-.-'----.--.-- ...---
14.0 congressional Relations
14.1 Correspondence
1.
Letter from James M. McLin, Mayor of Somersworth,
NH, to the Honorable Bill Zeliff, Member of
Congress (May 6, 1991). concerning Somersworth.
Municipal Landfill history, current status, and
city concerns.
Letter from the Honorable William H. Zeliff, Jr.,
Member of Congress, to James M. McLin and
Somersworth City Council, City of Somersworth
(May 31, 1991). Concerning response to
May 6, 1991 letter.
Letter from the Honorable William H. Zeliff, Jr.,
Member of Congress, to Julie Belaga, EPA Region I
(June 3, 1991). Concerning request for removal of
the Somersworth Landfill site from the National
Priorities List. .
Letter from Jul ie Belaga, EPA Reg ion I, to the
Honorable William H. Zeliff, Jr., Member of
Congress (July 10, 1991). concerning response to
June 3, 1991 letter, and notification that the
Somersworth Landfill Site cannot be considered for
deletion from the NPL at this time.
Letter from William K. Reilly, EPA, to the
Honorable Robert Smith, Member of Congress
(March 13, 1992). Concerning response to meeting
with New Hampshire Congressional delegation, with
attached newspaper clipping concerning "NH
Superfund sites part of pilot program".
Letter from Julie Belaga, EPA Region I, to the
Honorable William H. Zeliff, Jr., Member of
Congress (May 18, 1992). Concerning response to
April 14, 1992 letter forwarded on behalf of the
City of Somersworth, New Hampshire.
Letter from Julie Belaga, EPA Region I, to the
Honorable Robert Smith, Member of Congress
(May 18, 1992). Concerning response to
April 14, 1992 letter forwarded on behalf of the
City of Somersworth, New Hampshire.
Letter from Julie Belaga, EPA Region I, to the
Honorable Warren B. Rudman, Member of Congress (May
18, 1992). Concerning response to
April 14, 1992 letter forwarded on behalf of the
City of Somersworth, New Hampshire.
2.
3.
4.
5.
6.
7.
8.
-------
14.1 Correspondence (continued)
9.
Letter from the Honorable Robert Smith, Member of
Congress, to Merrill S. Hohman, EPA Region I
(June 1, 1992), with attached letter from Douglas
Elliott, City Manager to Merrill S. Hohman, EPA
Region I (May 20, 1991). Concerning lack o(
response to April 14, 1992 request, and the request
of a review of the matter and an explanation of the
outcome. . .
Letter from the Honorable William H. Zeliff, Jr.,
Member of Congress to Julie Belaga, EPA Region I
(July 17, 1992). Concerning response to Public
Meeting cosponsored with the City of Somersworth
Tuesday, July 14, 1992.
10.
16.0 Natural Resource Trustee
16.1 Correspondence
1.
Letter from Jonathan P. Deason, Office of
Environmental Affairs, to Merrill S. Hohman, EPA
Region I (October 7, 1991). Concerning the
Preliminary Natural Resources Survey (PNRS) and
report of the Somersworth Municipal Landfill Site,
Somersworth, New Hampshire.
Letter from Cyndi Perry, u.s. Fish and Wildlife
Service, to Diana King, EPA Region I
(February 6, 1992). Concerning EPA's inquiry about
Department of the Interior's position regarding a
covenant not to sue for natural resource damages at
the Somersworth Municipal Landfill Site.
2. .
1.
16.4 Trustee Notification Form and Selection Guide
2.
Letter from Merrill S. Hohman, EPA Region I to
William Patterson, u.S. Department of the Interior
(May 27, 1987) with attached Trustee Notification
Form and Selection Guide. Concerning notification
of potential damages to natural resources under the
jurisdiction of the Department of the Interior.
Letter from Merrill S. Hohman, EPA Region I to
Sharon Christopherson, National Oceanographic and
Atmospheric Administration Coastal Resource
Coordinator (May 27, 1987). Concerning
notification of potential damages to natural
resources under the jurisdiction of National
Oceanographic and Atmospheric Administration.
-------
16.4 Trustee Notification Form and Selection Guide (continued)
3.
Letter from Gordon Beckett, U.S. Department of the
Interior to Paul Marchessault, EPA Region I
(July 21, 1987). Concerning the receipt of the
Trustee Notification and interest in further
coordination with the EPA.
Letter from Daniel Coughlin, EPA Region I to
Kenneth Finkelstein, National Oceanographic and
Atmospheric Administration Coastal Resource
Coordinator (November 21, 1988). Concerning
notification of EPA's concluding negotiations with
a self - appointed "PRP Group."
Letter from Daniel Coughlin, EPA Region I to
William Patterson, U.s. Department of the Interior
(November 21, 1988). Concerning notification of
EPA's concluding negotiations with a self-appointed
"PRP Group."
4.
5.
17.0 site Management Records
17.4 Site Photographs/Maps
2."
*
The photographs referenced below may be reviewed,
by appointment only, at EPA Region I, Boston,
Massachusetts.
1.
Letter from Thomas R. Osberg, EPA Region I to Tim
Porter, EPA Region I (April 4, 1985). Concerning
transmittal of Report, "Site Analysis Somersworth
Landfill NPL Site;Somersworth, New Hampshire (~IC
#85009)," a series of five photographic coverages
(April 1985). .
Memorandum from David E. Strzempko, Roy F. Weston,
Inc. Technical. istance Team, to Ruth Leabman,
Enviropod Aeria- ~otography Site File Spring 1992
(August 20, 1992). Concerning transmittal of
explanation of the Enviropod aerial photography
deliverables for the Somersworth Landfill Site,
Somersworth, NH (TOO #01-9204-07A, PCS # 1933), an
oblique photograph (May 7, 1992).
1.
17.7 Reference Documents
United States Department of the Interior Geological
Survey, "High levels of arsenic in the groundwaters
of southeastern New Hampshire: a geochemical
reconnaissance". Preliminary report.
-------
17.8 State and Local Technical Records
1.
"Solid Waste Management Alternatives for Dover and
Somersworth, New Hampshire -Summary, II The MITRE
Corporation, Metrek Division (December 1978).
"Solid Waste Management Alternatives for Dover and
Somersworth, New Hampshire -Detailed Report," The
MITRE corporation, Metrek Division
(December 1978).
Letter Report from Michael P. Donahue, New
Hampshire Water Supply and Pollution Control
Commission to Richard Hughto, Camp, Dresser & McKee
(December 21, 1982). Concerning transmittal of
attached analytical data.
Letter Report from Michael P. Donahue, New
Hampshire Water Supply and Pollution Control
commission to Norman LeClerc, Project Coordinator,
Somersworth, New Hampshire (May 2, 1983).
Concerning installation of monitoring wells.
Letter from Jam~s R. Dalton, General Electric
Company to Thomas Sweeny, Bureau of Solid Waste
Management (February 9, 1977).
Letter from Thomas E. Roy, Bureau of Sol id Waste
Management, to Coleen Fuerst, General Electric
company (March 22, 1979). Concerning guidance on'
metal sludges.
Letter from Norman Leclerc, Project Coordinator, to
Paul Sanborn, Bureau of Sol id Waste Management
(June 18, 1981). concerning landfill closure by
the city of Somersworth.
Letter from Norman Leclerc, Project Coordinator, to
Paul Sanborn, Bureau of Solid Waste Management
(July 13, 1981). Concerning more information
regarding the landfill closure and environmental
sampling.
Letter from Chris Hagger, Ecology and Environment,
Inc., to Bob Young, Ecology and Environment, Inc.
(August 3, 1982). Concerning site inspection of
the Somersworth Municipal Landfill.
Letter from Dawn Channing, Bureau of Hazardous
Waste Management, to Brenda Short, Somersworth Wood
Heel (September 22, 1982). Concerning the
Hazardous Waste Generator notification form to be
completed.
Letter from Michael P. Donahue, PE, state of New
Hampshire Water Supply and Pollution Control
Commission, to Mr. Norman Leclerc, Project
Coordinator (May 2, 1983) . ' Concerning the
installation of monitoring wells. with attached
site plan.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
-------
12.
17.8 state and Local Technical Records (continued)
13.
14.
15.
"site Inspection, GE Site,
Hampshire 0-583-3-4-20 Rev.
Corporation of US EPA.
Letter from Patrick Gillespie, Wehran Engineering,
to Donald Onusseit, New Hampshire Water Supply and
Polution Control Commission (January 8, 1985).
concerning a drum with a General Electric label
found in the landfill.
Letter from Kenneth W. Marschner, New Hampshire
Office of Waste Management, to Colleen Fuerst,
General Electric (February 1, 1985). Concerning
the Notice of violation and order of abatement.
Letter from Sharon A. Yergeau, New Hampshire Bureau
of Hazardous Waste Compliance and Enforcement, to
Susan Hanamoto, US EPA Region I (May 12, 1986).
Concerning attached supporting documentation for
the declassification of Miller Shoes.
Somersworth,
2.0" by
New
NUS
-------
Section II
Guidance Documents
-------
9.
10.
GUIDANCE DOCUMENTS
EPA guidance documents may be reviewed at EPA Region I, Boston,
Massachusetts.
General EPA Guidance Documents
1.
U.S. Environmental Protection Agency. Office .of Research and
Development. Municipal Environmental Research Laboratory.
Handbook for Evaluatinq Remedial Action Technoloqy Plans (EPA-
600/2-83-076), August 1983. (2307]
u.s. Environmental Protection Agency. Office of Emergency and
Remedial Response. Community Relations in SUDerfund: A
Handbook (Interim Version) (EPA/hw-6), September 1983.
2.
3.
u.S. Environmental Protection Agency. Office of Ground-Water
Protection. Ground-Water Protection Strateqy, August 1984.
(2403)
4.
"Guidelines Establishing Test Procedures for the Analysis of
Pollutants Under the Clean Water Act; Final Rule and Interim
Final Rule and Proposed Rule" (40 CFR Part 136), Federal.
Reqister, October 26, 1984. (c036]
U. S. Environmental Protection Agency. Office of Emergency and
Remedial Response. Hazardous Response Support Division.
Standard Operating Safety Guides, November 1984. [c082)
5.
6.
"National Oil and Hazardous Substances Pollution contingency
Plan," Code of Federal Reaulations (Title 40, Part 300), 1985.
U.S. Environmental Protection Agency. Office of Solid Waste
and Emergency Response. Guidance on Feasibil i ty Studies under
CERCLA (ComDrehensive Environmental ResDonse. ComDensation.
and Liability Act) (EPA/540/G-85/003), June 1985.. [c034]
7.
8.
u.S. Environmental Protection Agency. Office of Soli4 Waste
and Emergency Response. Guidance of Remedial Investiaations
under CERCLA (ComDrehensive Environmental ReSDonse.
ComDensation. and Liability Act) (EPA/540/G-85/002), June
1985. [c035]
Memorandum from Gene Lucero to the U.S. Environmental
Protection Agency, August 28, 1985 (discussing community
relations at Superfund Enforcement ~ites). tC053]
U.S. Department of Health and Human Services. National
Institute for Occupational Safety and Health, and occupational.
Safety and Health Administration. OccuDational Safety and
Health Guidance Manual for Hazardous Waste Site Activities,
-------
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
21.
22.
u.s. Environmental Protection Agency. Office of Research and
Development. Hazardous Waste Engineering Research Laboratory.
Handbook: Remedial Action at Waste Disposal Sites (Revised)
(EPA/625/6-85/006), October 1985. (2309]
u.s. Environmental Protection Agency. Office of Emergency and
Remedial Response. Communitv Relations in Superfund: A
Handbook (Interim Version) (EPA/HW-6, OSWER Directive 9230.0-
3A) March 1986.
u.S. Environmental Protection Agency. Office of Solid Waste
and Emergency Response. Mobil Treatment Tecnnoloaies for
Superfund Wastes (EPA/540/2-86/003 (f», September 1986.
[2311]
u.s. Environmental Protection Agency. Office of Emergency and
Remedial Response. Draft Guidance on Remedial Actions for
contaminated Groundwater at Superfund Sites (OSWER Directive
9283.1-2), September 20, 1986. [c022]
u. S. Environmental Protection Agency. Office of Emergency and
Remedial Response. Superfund Public Health Evaluation Manual
(OSWER Directive 9285.4-1), October 1986. [5014]
Comprehensive Environmental Response. Compensation.
Liabilitv Act of 1980, amended October 17, 1986. (c018]
and
"Hazardous Waste Management Systems Land Disposal Restrictions
Final Rule," (November 1986), 40 CFR Part 260 Et AI. [cl031
u.S. Environmental Protection Agency. Office of Emergency and
Remedial Response. Superfund Federal-Lead Remedial proiect
Manaaement Handbook (EPA/540/G-87/001, OSWER Directive 9355.1-
1), December 1986. (2010]
u.S. Environmental Protection Agency. Office of Solid Waste
and Emergency Response. Interim Guidance on Superfund
Selection of Remedy (OSWER Directive 9355.0-19), December 24,
1986. [9000]
u.S. Environmental Protection Agency. Office of Research and
Development. Hazardous Waste Engineering Research Laboratory.
Technoloqy Briefs: Data Reauirements for Selectina Remedial
Action Technoloay (EPA/600/2-87/001), January 1987. (c088]
U.S. Environmental Protection Agency. Office of Solid Waste
and Emergency Response. Data Ouality Obiectives for Remedial
Response Activities: Development Process (EPA/540/G-87/003),
March 1987. [2001]
Letter from Lee M. Thomas to James J. Florio, Chairman,
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Committee on Energy and Commerce, u.S. House of
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27.
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29.
3.0.
. 31.
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[c044]
23.
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Director, Waste Management Division, Regions I, IV, V, VII,
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Region II; Director, Hazardous Waste Management Division,
Regions III and VI; Director, Toxics and Waste Management
Division, Region IX; Director, Hazardous Waste Division,
Region X; Environmental Services Division Directors, Region I,
VI, and VII"), July 9, 1987 (discussing interim guidance on
compliance with applicable or relevant and appropriate
requirements). [c055]
U. s. Environmental Protection Agency. Office of Emergency and
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26.
u. S. Environmental Protection Agency. Office of Emergency and
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035) (June 1988). [7000] .
"Catalog of Superfund Program Directives," (July 1988), OSWER
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32.
u.s. Environmental Protection Agency. Office of Solid Waste
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