United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R03-91/138
June 1991
&EPA Superfund
Record of Decision:
Modern Sanitation Landfill, PA
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REPORT DOCUMENTATION 1. REPORT NO. 2.
PAGE EPA/ROD/R03-91/138
4. IMemdSubWe
SUPERFUND RECORD OF DECISION
Modern Sanitation Landfill, PA
First Remedial Action - Final
7. Authors)
12. Sponsoring Or0miz>lion Nuns end Atfcfrscs
U.S. Environmental Protection Agency
401 M Street-, S.W.
Washington, D.C. 20460
3. Redpfenrs Accession No.
S. Report D«te
06/28/91
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IX Type of Report & Period Covered
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16. Abstract (Umte 200 words)
The 83-acre Modern Sanitation Landfill site is an active landfill in the Townships of
Windsor and Lower Windsor, York County, Pennsylvania. Land use in the area is
predominantly agricultural and residential, with nearby woodland areas. The site
includes an old, inactive, unlined 66-acre landfill area, which is the subject of
this Record of Decision (ROD), and an adjacent active 17-acre double-lined landfill
area to the north. Other site features include borrow areas for landfill soil cover
material; ground water extraction systems to the east, west, and south of the
landfill; a wastewater treatment plant; a landfill gas-extraction system; and a
low-permeability final cover system. Since the early 1940's, Modern Trash Removal
has used the site for municipal, and non-hazardous and hazardous industrial waste
stream disposal activities. Industrial waste disposed of onsite includes inorganic
production residues, pesticide waste sludge, PCB wastes, and oil and paint waste. In
1977, a ground water interceptor trench was constructed to collect leachate from the
west side of the site. The collected water currently is pumped to the onsite
treatment facility. In 1981, the State detected onsite ground water contamination by
VOCs on the western site border, and in 1983, determined that the western interceptor
(See Attached Page)
17. Document Analysis s. Descriptors
Record of Decision - Modern Sanitation Landfill, PA
First Remedial Action - Final
Contaminated Media: soil, debris, gw
Key Contaminants: VOCs (benzene, PCE, TCE, toluene, xylenes) metals (lead)
b. McntlOera/Open-EndBd Terms
c. COSATI Fiekl/Group
18. Avsilabifty Statement
19. Security Class (This Report)
None
20. Secuitjr Ctasa (This P*ge)
None
21. No. of Pages
54
22. Price
(See AHSM39.18)
See Instructions on Reverse
OPTIONAL rUHM 272 (4-77)
(Formerly NT1S-35)
Department of Commerce
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EPA/ROD/R03-91/138
Modern Sanitation Landfill, PA
First Remedial Action - Final
Abstract (Continued)
trench should be upgraded and modified, and that quarterly sampling of monitoring wells
should be implemented to detect the leachate seeps and the presence of leachate
constituents in ground water. As a result, extraction wells to augment the western
interceptor trench were installed. Leachate studies in 1985 also identified organic
contamination in the eastern site area; and, as a result, 13 extraction wells were
installed along the eastern perimeter. Four surface impoundments were operated onsite
to treat ground water and leachate collected by the interceptor and extraction wells.
In 1987, the surface impoundments were clean closed, and a replacement treatment
facility, which included metal precipitation, filtration, and air stripping, was
constructed. In addition, as of 1990, 64 of the 66-acre unlined landfill had been
covered with a low permeability cap. This ROD provides a final remedy for the source
of leachate seeps and ground water constituents. The primary contaminants of concern
affecting the soil, debris, and ground water are VOCs including benzene, PCE, TCE,
toluene, and xylenes; and metals including lead.
The selected remedial action for this site includes completing the low permeability cap
and final cover system over the 66-acre unlined landfill; expanding the existing ground
water extraction system on both the eastern and western sides of the site; maintaining
the onsite wastewater treatment facility that treats extracted ground water with
physical/chemical and biological treatment, followed by filtration and air stripping
prior to discharge of the treated wastewater onsite; managing the landfill gas
collection system; and continuing ground and surface water monitoring. The present
worth cost for this remedial action is $18,078,000, which includes an annual O&M cost
of $1,175,000.
PERFORMANCE STANDARDS OR GOALS: Ground water clean-up goals are based on State and
Federal standards and background contaminant levels, whichever are lower.
Chemical-specific ground water goals include benzene 5 ug/1 (MCL), PCE 5 ug/1 (MCL),
and TCE 5 ug/1 (PMCL).
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RECORD OY DECISION
MODERN LANDFILL
DECLARATION
SITE NAME AND LOCATION
Modern Landfill Site
Windsor and Lover Windsor Townships
York County, Pennsylvania
STATEMENT OF BASIS AND PURPOSE
*
This decision document presents the selected remedial action
for the Modern Landfill Site, also known as the CERCLA Site in
the Remedial Investigation, in York County, Pennsylvania. The
selected remedial action was chosen in accordance with the
Comprehensive Environmental Response, Compensation and Liability
Act of 1980, as amended by the Superfund Amendments and
Reauthorization Act of 1986 (CERCLA); and, to the extent
practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). This decision is based on the
Administrative Record for this site.
The Pennsylvania Department of Environmental Resources (PADER),
acting on behalf of the Commonwealth of Pennsylvania, has
verbally concurred with the selected remedy.
ASSESSMENT OY THE SITE
Pursuant to duly delegated authority, 1 hereby determine,
pursuant to Section 106 of CERCLA, 42 U. S. C. Section 9606, that
actual or threatened releases of hazardous substances from this
site, as discussed in "Summary of Site Risks", if not addressed
by implementing the response action selected in this Record of
Decision (ROD), may present an imminent and substantial
endangerment to the'public health, welfare, or the environment.
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DESCRIPTION OY THE REMEDY ^
Modern Landfill is located in the Townships of Windsor and
Lower Windsor, in York County, PA, and is adjacent to Prospect
Road approximately one-half mile south of Route 124. The
Landfill has been used continually for waste disposal since the
early 1940's, and it has principally accepted municipal/residual
wastes throughout its history of operation. Evidence exists,
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however, that some disposal of hazardous substances has occurred
at this site, though the exact quantities, the nature of these
substances, and the particular locations of their disposal are
currently unknown to EPA. According to existing records, some of
these wastes have been removed from the site.
In response to public health concerns, Modern Trash Removal
of York, Inc., under a 1987 Administrative Consent Order and
Agreement with the Pennsylvania Department of Environmental
Resources (PADER), conducted a Remedial Investigation/Feasibility
Study (RI/FS) for this site. Early in the Rl process, it was
determined that groundwater contamination emanates from the old,
unlined portion of the landfill. This unlined portion, which is
currently inactive, is part of what is referred to as the CERCLA
site, because it is the subject of EPA's and PADER's remedial
efforts under CERCLA.
The selected remedy for this site addresses the long-term
threats present at the Modern Landfill site. The principal
components of the selected remedy are as follows:
• Continued operation and maintenance of all previous
remedial actions conducted onsite, including the landfill
cap, groundwater extraction system, onsite wastewater
treatment facility, gas extraction system (for removal and
destruction of landfill generated methane gas) and
groundwater and surface water monitoring.
• Completion of the landfill cap system and final cover for
the unlined 66-acre landfill.
• Maintenance of site fencing and all access restrictions.
• The addition of extraction wells to the eastern and
western extraction systems to prevent contaminated
groundwater from bypassing those systems.
• The completion of additional monitoring and/or extraction
wells as needed to ensure protectiveness and to control
groundwater flow, respectively.
• As a goal, restore contaminated groundwater to background
quality.
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STATUTORY DBTBRMZXXTZOV8
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective.
This remedy utilizes permanent solutions and alternative
treatment technologies, to the maximum extent practicable, and
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satisfies .the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a
principal element.
Because the selected remedy will result in hazardous
substances remaining onsite above health-based levels, a review
under Section 121(c) of CERCLA, 42 U. S. C. 9621(c) will be
conducted within five years after the commencement of remedial
action to ensure that the remedy continues to provide adequate
protection of human health and the environment.
Edwin B. Erlckson Date
Regional Administrator
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RECORD OF DECISION
MODERN LANDFILL SITE
DECISION SUMMARY
A. 8ZTB NAME, LOCATION, AND DESCRIPTION
General
Modern Landfill is located in the Townships of Windsor and
Lover Windsor, in York County, PA. It is approximately adjacent
to Prospect Road, one-half mile south of Route 124. The Modern
Landfill Site, also referred to as the CERCLA Site in the
Remedial Investigation/Feasibility Study (RI/FS), consists of the
original 66-acre unlined landfill together with all other
property that as a whole is bounded on the east and west by the
respective groundwater extraction and monitoring systems, on the
north by the 17-acre, double-lined landfill expansion, and on the
north by the Southern extension of both monitorin and extraction
systems. The Modern Landfill Site is only a portion of what is
referred to in the RI/FS as Modern Landfill. The landfill has
been used continuously for waste disposal since the early 1940's,
and it has principally accepted municipal/residual wastes
throughout its history of operation. The Site is shown on maps
in Figures 1 and 2.
Modern Landfill is an active landfill permitted by the
Pennsylvania Department of Environmental Resources (PADER) to
accept municipal waste and a number of non-hazardous industrial
waste streams. It includes an inactive, unlined 66-acre area and
an active, synthetic HDPE double-lined area. The original 66-
acre unlined landfill is located on land owned by Horace Heindel
and is operated by Modern Trash Removal of York, Inc., (Modern)
under terms of a lease agreement. Modern owns additional
property contiguous to the leasehold.
Modern Landfill contains several components including:
The original 66-acre unlined landfill;
An existing, PADER-approved, contiguous 17-acre double-
ined landfill area;
Borrow areas for daily, intermediate, and final cover;
A proposed, contiguous northern horizontal expansion area;
A proposed, noncontiguous southwest expansion area;
Eastern and western perimeter groundwater extraction
ystems and western groundwater interceptor trench;
A wastewater treatment plant;
A landfill gas-extraction system;
Erosion and sedimentation control systems; and
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feiu A« SHOWN
SITE LOCATION PLA
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AflY \ ^..H?--51^'
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REGIONAL LOCATION M/
M006RN
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• A low-permeability final cover system.
To ensure consistency with the Remedial
Investigation/Feasibility Study (RI/FS), throughout this Record
of Decision the following definitions will be used to describe
the various areas of the Modern Landfill Site:
• The CERCLA Site: This area includes the unlined 66-acre
landfill and all Modern Landfill property (leased by Modern
from Horace Heindel) up to and including the monitoring
wells just within the eastern and western edges of the
extraction system, as well as land owned by Modern. The
boundaries of the CERCLA Site are shown in Figure 3. •
• The property: This area includes all Modern Landfill
property (owned and leased) exclusive of the CERCLA Site.
• Off the property! This area includes local areas beyond
the CERCLA Site and the property.
The facility is located within the Conestoga Valley Section
of the Piedmont Physiographic Province. Topographically, this
province is characterized by well-developed northeast-southwest
trending valleys and drainage patterns. The Landfill is located
on a hill bounded on the north, east, and west by streams
(unnamed tributaries to Kreutz Creek).
Approximately 800 people live within a one-mile radius of
Modern Landfill, while about 3,100 people live within a three-
mile radius of the Site. Land usage in the area is primarily
farming and residential. Away from the immediate vicinity of the
Modern Landfill the land is used predominately for arable farming
with some pasture land existing. Several woodland areas and
small apple orchards are also located in the area.
The nearest city to the Modern Landfill is York,
Pennsylvania, located about 8 miles to the west, with other
communities located within a distance of 4 to 6 miles from the
Site.
Climate
The climate of the area is relatively mild and humid. The
average precipitation observed at the York, Pennsylvania,
meteorological station is 41 inches per year. Average snowfall
is about 30 inches per year, which is equivalent to about 2.5
inches of rainfall. Mean winter temperature is 34 degrees F and
the mean summer temperature is 76 degrees F, with temperature
extremes above 95 degrees F and below 0 degrees P not uncommon.
Surface Water Hvdroloerv
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FIGURE 3
Final Cover—Plan View
WMttwatar
TrMITTMflt
Facility
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The drainage patterns evident in this area of York County
vary between trellis and dendritic with a tendency towards north-
south and northeast-southwest trending valleys. These drainage
patterns are considered to reflect the underlying geologic
structure. The landfill Site is bounded on the east, north, and
vest by two tributaries which are referred to as the eastern and
western tributaries. The tributaries are fed by springs and
runoff/ and flow effectively northward and discharge into Kreutz
Creek, which then flows northwards and then eastward, 11 miles,
into the Susquehanna River. Kreutz Creek does not supply water
to any downstream inhabitants or municipalities.
Regional Geology
Modern Landfill is located in the Conestoga Valley section
in the northern part of the Piedmont Province. The Piedmont
Province is a broad plateau sloping gently eastward from the Blue
Ridge Province to the Coastal Plains. It is underlain by
metamorphic or plutonic rocks, and cut by sediment filled basins
of Jurassic age. The Piedmont Province is the eastern extreme of
the five tectonic provinces which compose the Appalachian
Mountain Chain. The main regional structure in the area is a
pre-metamorphic thrust fault which forms the boundary between
Precambrian metavolcanics and schists and Cambrian meta-
sediments. This fault, known as the Martic Line, is locally a
well defined pre-metamorphic thrust fault with Precambrian
Wissahickon Schist overlying Ordovician Conestoga Limestone. In
the area to the south of Modern Landfill, the Martic line is
poorly defined as it divides the Cambrian phyllite from the
Precambrian/Cambrian schists, two very similar rock types. This
information suggests that much of the classic work done in
Lancaster County may not be an analog for the geologic setting in
the vicinity of Modern Landfill.
B. Site HISTORY AID BBTORCEMBYT ACTIVITIES
History
Prior to the commencement of the Remedial
Investigation/Feasibility Study, Modern Landfill and the area
around the Modern Landfill had already been the subject of
several geologic studies. The first study relating to remedial
activities at Modern Landfill was conducted in 1975. At that
time, the investigations centered on the feasibility of utilizing
shallow pumping wells as a primary leachate recovery system for
Modern Landfill and concluded that leachate from the 66-acre
unlined landfill could be effectively collected in this manner.
Between January and May, 1981, PADER collected groundwater
samples from wells and springs in the vicinity of Modern Landfill
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and detected volatile organic chemicals in some of these samples.
The EPA Region III Field Inspection Team (PIT) contractor then
conducted a Preliminary Assessment and Site Investigation (PA/SI)
in 1982. The PA/SI report recommended the following actions be
taken:
• Periodic sampling of nearby residential wells;
• Sampling of groundwater and surface water being used by
area farms for livestock and irrigation;
• Determining the effectiveness of the leachate collection
system;
* • Investigating reactivation of the onsite wastewater
treatment facility; and,
• Investigating possible actions to mitigate the groundwater
problem.
Additional studies were conducted based on these recommendations.
A hydrogeologic study of the landfill was conducted in 1982
and involved "the installation of tvo monitoring wells and the
extension of two existing monitoring wells. Surface water,
monitoring wells, and residential drinking wells were sampled.
In 1983 the effectiveness of the western interceptor trench
was evaluated and it was determined that the interceptor trench
should be modified and upgraded. Quarterly sampling of
monitoring wells began in August 1983.
An investigation of leachate collection alternatives in the
western perimeter region was conducted in 1984. Geologic data
was reviewed, wells were installed and sampled, and the need for
additional work was determined. A series of borings were
completed, existing perimeter wells were sampled, and 11
interceptor wells were installed. An existing water supply well
was activated as an extraction well.
In June, 1984, the 66-acre unlined landfill was scored in
accordance with the Hazard Ranking System for possible inclusion
on the National Priorities List (NPL) under CZRCLA. The unlined
landfill received a score of 36, based on potential for exposure
to contaminated groundwater. The Modern Landfill Site was
proposed for inclusion on the NPL in October 1984.
A follow-up study in 1985 was conducted to investigate
leachate interception alternatives in the northern and eastern
perimeters of the CZRCLA Site. Organic contaminants were found
at the eastern, but not the northern, border of the CZRCLA Site.
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As a result of this investigation, 13 extraction wells were
installed along the eastern perimeter.
The Modern Landfill Site was officially listed on the NPL in
June, 1986.
Previous Actions
The original 66-acre landfill had no active method of
leachate control. The area is now equipped with groundwater
interceptor and collection systems to control the migration of
leachate constituents from the unlined landfill.
As of December, 1990, approximately 64 acres of the 66-acre
unlined landfill are presently covered with a PAPER approved,
low-permeability cap. The entire 66-acre unlined landfill is
scheduled to receive a FADER approved low-permeability final
cover system. Thirty-six acres are already at final elevations
and are currently being capped. When final elevations are*
reached, the 66-acre landfill will have a 20-acre plateau area
and a 46-acre side slope area. The synthetic geomembrane final
cover system proposed for the 20-acre plateau area and the 46-
acre clay side slope cap area are designed to reduce infiltration
of precipitation and thereby reduce the quantity of leachate
generated by the landfill.
Leachate seeps and the presence of leachate constituents in
the groundwater were noticed in the past on the west side of the
CERCLA Site and, as a result, a groundwater interceptor trench
and lagoon treatment system were constructed in 1977. The
groundwater interceptor trench is between 6 and 15 feet below
ground and is approximately 2,200 feet long. Seepage water
collected by this trench is pumped to an onsite treatment
facility.
In January 1985, a network of 12 groundwater extraction
wells, designed to augment the western groundwater interceptor
trench, became operational. In 1987 two additional wells were
added to the system and a 14th well became operational in January
1990. Water pumped from these wells is treated at the onsite
treatment facility.
A groundwater extraction system similar to that installed on
the western side of the landfill was constructed on the eastern
perimeter and became operational in November 1986. Water pumped
from this extraction system is also treated at the onsite
treatment facility.
Modern operated four surface impoundments to treat
groundwater and leachate collected by the interceptor and
extraction wells along the western perimeter of the CERCLA Site.
Treatment consisted of metals precipitation, aeration, and
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clarification. These surface impoundments were lined with 6 to
12 inches of soil cement and an asphalt coating. These
impoundments were clean-closed in May 1987 under a PAOER-approved
closure plan.
In April, 1987, a replacement treatment facility for the
surface impoundments became operational. The replacement
facility accepts flow from the eastern and western groundwater
extraction well systems, the western interceptor trench, and
leachate from the existing double-lined landfill and slope cap
area. This facility has a design capacity of 500,000 gallons per
day and includes physical/chemical and biological treatment
systems. The physical/chemical portion includes metals
precipitation, filtration, and air-stripping. The biological
treatment portion was added to enable treatment of leachate
collected in the recently constructed double-lined landfill
cells.
Permits and PAPER Consent Orders
Modern Landfill and the associated extraction and treatment
systems operate in accordance with several permits and Consent
Orders issued by PADER. Each of these is briefly described
below.
Modern Landfill is permitted by PADER under Solid Waste
Permit No. 100113 issued on August 17, 1978, to accept municipal
waste and a number of non-hazardous industrial (residual) waste
streams. The original 66-acre unlined landfill does not accept
waste and is being capped. The active double-lined landfill and
vertical expansion area are operated pursuant to a permit
modification issued by PADER on December 12, 1986. The gas
extraction system is also covered by this solid waste permit.
Modern operated four surface impoundments from September
1976 to April 1987 to treat leachate seepage collected by an
interceptor trench and extraction wells along the western
perimeter of the landfill under a PADER Hater Quality Management
Permit Mo. 6786201 issued on September 24, 1976.
On November 20, 1986, PADER issued NPDES Permit No.
PA0046680 that permitted construction of a temporary treatment
plant to treat groundwater from the eastern groundwater
extraction wells; continued operation of the impoundment *
treatment system for the western extraction wells and interceptor
trench; and construction of a new treatment plant consisting of
physical/chemical and biological treatment. The temporary
treatment plant and four surface impoundments were decommissioned
by June 1987 in accordance with a May 27, 1987 agreement with
PADER.
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The physical/chemical portion of the new treatment plant
includes an air stripper, permitted under PADER Air Quality
Control Permit Mo. 67-330-004, to remove volatile compounds from
the extracted groundwatcr and leachate.
CERCLA Enforcement Activities
Modern entered into a September 20, 1984 Consent Order and
agreement with PADER to correct conditions at Modern Landfill,
most notably, leachate from the 66-acre unlined landfill
contaminating the groundvater and surface water. This Consent
Order and Agreement was superseded by a Consent Agreement and
Order dated December 3, 1986. In accordance with these Orders
and Agreements, Modern undertook several remedial actions,
including construction of groundwater extraction systems and a
wastewater treatment plant.
The RI/FS for the Modern Landfill Site was conducted
pursuant to a Consent Order and Agreement entered into by Modern
and PADER on November 4, 1987.
Potentially Responsible Party (PRP) Searches for the Modern
Landfill Site have been conducted in the past and are continuing
at the present time. Two PRPs have been identified and have been
issued General Notice Letters. Several other parties have been
issued requests for information under Section 104(e) of CERCLA.
C. HIGHLIGHTS OF COMMUNITY PARTICIPATION
There has been moderate community interest in the Modern
Landfill Site due to its proximity to and its impact on the
groundwater of nearby residences.
In accordance with Sections 113 and 117 of CERCLA, 42 U.S.C.
Sections 9613 and 9617, EPA held a public comment period from
April 16, 1991 through June 15, 1991 for the proposed remedy at
the Modern Landfill site. A public meeting on the proposed remedy
for this Site was held on May 7, 1991 at the Eastern High School,
York County , PA. With respect to the remedy proposed by EPA for
this Site, however, little community interest exists.
Some concern was expressed by those in attendance at the
meeting that not all citizens interested in the Site may have
been aware of the meeting, and both an extension to the comment
period and a second public meeting were requested. In lieu of
the public meeting, EPA prepared a fact sheet on the proposed
action at the Site and directly mailed the fact sheet to several
hundred potentially interested residences. EPA also offered to
meet informally with local officials and/or representatives of
any citizens groups if requested. No such meeting requests were
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received. In response to requests made at the May 7, 1991
meeting, however, the public comment period was extended to June
15, 1991.
O. SCOP1 AMD ROLE OF TH1 RESPONSE ACTIOM
The only concern presenting significant risk to necessitate
remediation at the CERCLA Site is the presence of volatile
organic contaminants in the leachate from the 66-acre unlined
landfill. There is no principal threat at Modern Landfill.
Previous Site investigations have detected volatile organic
compounds and some inorganic constituents in the groundwater and
surface water on the CERCLA Site as well as in some on-property
residential drinking water wells; however, these residences are
no longer in existence.
Groundwater beneath the CERCLA Site exceeded Federal and
State drinking water standards for the following chemicals:
benzene, carbon tetrachloride, 1,2-dichloroethene, 1,1-
dichloroethene, trichloroethene, and vinyl chloride. The
presence of these chemicals indicates that an Excess Lifetime
Cancer Risk (ELCR) for the potential ingestion of water from
beneath the CERCLA Site is greater than the acceptable EPA risk
limits. The current response action will reduce or eliminate the
low level threat posed by the contaminated groundwater beneath
the CERCLA Site.
1. SUMMARY 0V Site CHARACTERISTICS
Disposal History
The disposal history of Modern Landfill is based on a review
of correspondence between regulatory agencies and Modern and its
industrial customers. Also investigated were complaints,
permits, Site inspections, and other documents related to the
Site. Modern Landfill users were identified from gate receipts,
but those receipts did not provide information as to waste type
or composition. Data currently available provide only partial
information on the Modern disposal history and in most cases
waste quantities and locations in the 66-acre unlined landfill
are not currently known to EPA.
In addition to commercial and residential refuse, Modern
Landfill was permitted to accept and did accept several
industrial waste streams during the operating history of the 66-
acre unlined landfill. Information on these wastes, to the
extent known is given below.
•odium Kolybdate Waste. Approximately 15 to 20 tons per
year of an inorganic residue from sodium molybdate
production were disposed of at Modern Landfill for an
8
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undetermined number of years starting prior to 1972. The
waste was reported to have been composed of the following:
Molybdenum Trioxide, Sulfur, Cupric Oxide, Ferric Oxide,
Silicon Dioxide, and Water.
Pesticide Waste. Pesticide wastes from an unspecified
source were disposed of at Modern Landfill in the summer of
1972.
Rare Earth Chlorides. In 1973, PADER approved in principle
the encapsulation of rare earth wastes in crushed limestone
in the 66-acre unlined landfill. About 1,000 cubic yards of
rare earth chlorides containing thorium and uranium and 500
cubic yards of cerium fluoride were disposed of at Modern
Landfill between 1975 and 1979. The exact composition of
the wastes is unknown. Although some traces of these
elemental species were found in groundwater and soils during
the Remedial Investigation (and their analysis subsequently
carried through the Risk Assessment), no evidence of risk
from these wastes has been determined at the Site.
Paper Manufacturing Sludge. A sludge from paper
manufacturing was disposed of at Modern Landfill during 1975
through ..1981. The waste was reported to contain 60 percent
inorganic material and 40 percent organic material. The
waste apparently had a low pH and contained heavy metals.
Modern was eventually ordered to cease acceptance of this
waste by PADER.
Polyehlorinated Biphenyls (PCBs). An estimated 20 to 70
drums of PCS wastes were disposed of at Modern Landfill in
the mid-1970's. In September and October 1985, these drums
and 400 cubic yards of contaminated soil were excavated and
transported offSite for disposal.
Btaylene Diamine. On December 13, 1980, a rolloff container
was unloaded at Modern Landfill. A liquid leaking from the
container was analyzed and determined to contain ethylene
diamine. There is no clear evidence that this waste was
ultimately disposed of at Modern Landfill.
Oily Wastes. During a PADER inspection of Modern Landfill
on March 10, 1982, about 40 cubic yards of mixed residual
and municipal wastes were unloaded at the facility. About
one fourth of the waste mixture was saturated with a
petroleum liquid. The exact nature of the waste was
apparently never determined.
Paint Waste. Paint waste was disposed of at Modern Landfill
according to a PADER inspection in April, 1984. PADER
ordered the generator to cease sending this waste to
facilities not permitted to accept such wastes. The
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characteristics and composition of the waste and the
quantity disposed are not known.
A set of chemicals of potential concern at the Site has been
selected for detailed evaluation in the risk assessment and are
shown in Table 1, summarized by environmental media.
Geologic and Hvdroqeoloqic Conditions
The surface and subsurface investigation determined that a
synform underlies Modern Landfill and that the presence of a
synform structure under Modern Landfill is consistent with the
regional geology mapped in the RI/FS report.
The hydraulic conductivity of the geologic formations at
Modern Landfill decrease with depth and can be related to the
presence or absence of lineations, which are interpreted to be
main fracture sets, within the rock materials, the phyllite
exhibits a strong anisotropy, while the hydraulic conductivity of
the meta-sandstone appears to be relatively isotropic. The
dolostone zone exhibits a heterogeneous distribution of hydraulic
conductivity values, which are probably related to fracture
systems trending east-west through the zone. Most geologic
contacts show higher hydraulic conductivity values than the
adjacent rock mass.
Groundwater flows towards the eastern and western extraction
systems with the possible exception of the groundwater flowing
from beneath the north-central area of the 66-acre unlined
landfill, which may be bypassing the western extraction system.
This flow possibly bypassing the extraction system passes through
Vintage dolostone, which has characteristic east-west zones of
high hydraulic conductivity alternating with zones of low
hydraulic conductivity.
It is conservatively estimated that the travel time of
leachate percolating from the central section of the 66-acre
unlined landfill and moving to the western extraction system is 2
years, while the travel time to the eastern extraction system is
3.5 years under non-pumping conditions.
The) groundwater extraction systems at Modern Landfill have
lowered the groundwater surface elevation along both the eastern
and western extraction systems. These drawdown troughs cause
groundwater to flow toward the extraction wells, effectively
capturing the majority of contaminated groundwater. This
drawdown has also substantially reduced stream flows in both the
eastern and western tributaries of Kreutz Creek.
Organic contaminant concentrations in wells at or inside the
extraction system* have generally followed a bell-shaped curve
since startup of the groundwater extraction systems.
10
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Concentrations rose after startup of the extraction system as
contaminated groundvater was pulled to the veils, then fell,
usually below their initial levels. This trend is consistent
among veils in all areas of Modern Landfill, indicating that the
changes are due to the extraction system, rather than to changes
in the contaminant source.
Wells outside the extraction system generally have either
continued to shov no contamination or contaminant concentrations
have decreased since startup of the extraction system.
Sediment. Surface Water, and Air Quality
Modern Landfill is located in the drainage catchment area
for Kreutz Creek and is bounded on the east and vest by tvo
unnamed tributaries vhich are fed by springs and runoff.
Background data vere unavailable for comparison vith the Modern
Landfill sediment data because the eastern and vestern
tributaries originate on Modern Landfill property; hovever, as
discussed later, risks from lov levels of compounds in sediments
vere vithin ranges generally considered acceptable by EPA.
During the Remedial Investigation, surface vater samples
vere collected from the eastern and vestern tributaries, the
sedimentation ponds, and the vastevater treatment plant outfall.
No organic chemicals and 15 inorganic chemicals vere detected in
the surface vater. Because the tributaries originate on the
Modern Landfill property, no background surface vater data are
available and samples could not be compared to background levels.
Air samples vere analyzed for total volatile organic
compounds. Volatilization of organic compounds and fugitive dust
generations are the main release mechanisms into air at Modern
Landfill. The operating methane gas monitoring, extraction, and
flare system, vhich consists of gas extraction veils and gas
collection trenches around the southern, eastern, and vestern
perimeters of Modern Landfill, minimizes the potential for air
releases to the ambient air form the CZRCLA Site. The vastevater
treatment plant includes an air stripper to remove volatile
compounds during treatment of vater from the interceptor trench
and extracted groundvater from the extraction systems.
During air monitoring of the Site, only trace levels of
organic vapors and no radiation above Site specific background
vere detected in the ambient air. The 66-acre unlined landfill
has been covered vith soil or synthetic caps and therefore no
potential for fugitive dust emission exists from this area.
11
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F. SUMMARY OF Site RISKS
Hunan Health Riskg
The 66-acre unlined landfill has received a PADER-approved
closure cover which is being upgraded with a low permeability
cap. In some portions above the 66-acre unlined landfill, a
synthetic liner has also been installed. As a result of these
conditions, there is no potential for fugitive dust emissions
from potential contaminant source areas in the 66-acre unlined
landfill.
. The 66-acre-unlined landfill, covered and capped, is not a
source of direct contact exposure. Based on this consideration,
combined with the lack of information on the exact locations of
potential contaminant source areas and the fact that capping the
66-acre unlined landfill has reduced the accessibility to such
source areas, it was determined that subsurface solids sampling
within the 66-acre unlined landfill itself would not be feasible
or necessary. Continued operation of the extraction system will
steadily deplete concentrations from potential source areas
within the 66-acre unlined landfill. For the reasons summarized
above, evaluation of potential exposure pathways related to
ambient air and to possible source areas in the CERCLA Site was
not necessary for this assessment.
Based on sampling results and a review of the summarized
data, chemicals identified as potentially.Site-related were
selected for further evaluation in the risX assessment. The
criteria for selection included presence in environmental media
at concentrations above background and/or blank concentrations
and their relationship to past disposal practices at the Site.
Sample concentrations of inorganic chemicals were compared
with those levels considered to be naturally occurring in the
Site region; if the detected levels were elevated above
background, the chemical was considered for further evaluation in
the assessment. Site-specific background sediment or surface
water samples could not be collected during the RI since the
eastern and western tributaries originate on the property. A
comparison of Modern Landfill site sediment results with
available regional soil background values was made. Sediment
concentrations which were within these background ranges were
considered to be- present at naturally occurring levels and Were
not further evaluated. Available regional background data of
inorganic chemicals in soil throughout the state and from three
locations within 50 miles of the Modern Landfill were used in the
evaluation.
As a final screen to select chemicals of potential concern,
organic chemicals which were detected infrequently in the samples
12
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collected from a specific medium, and were detected at
consistently low concentrations in a sampled environmental
medium, and are not known to be associated with past disposal
practices, were not considered to be chemicals of potential
concern. Prior to removing chemicals from further evaluation
based on these considerations, except for those chemicals that
are present at or below naturally occurring background levels,
their applicable or relevant and appropriate requirements or
toxicity criteria were checked to ensure that chemicals that may
be toxic even at very low doses were not removed.
Based on a review of the Modern Landfill RI/FS data, a set
of chemicals of potential concern has been selected for detailed
evaluation in the risk assessment. These chemicals are
summarized by environmental media in Table l.
For risk assessment purposes, individual pollutants were
separated into two categories of chemical toxicity depending on
whether they exhibit noncarcinogenic or carcinogenic effects.
This distinction relates to the currently held scientific opinion
that the mechanism of action for each category is different. EPA
has adopted, for the purpose of assessing risks associated with
potential carcinogens, the scientific position that a small
number of molecular events can cause changes in a single cell or
a small number of cells that can lead to tumor formation. This
is described as a no-threshold mechanism, since there is
essentially no level of exposure to a carcinogen which will not
result in some finite possibility of causing the disease. In the
case of chemicals exhibiting noncarcinogenic effects, however, it
is believed that organisms have protective mechanisms that must
be overcome before the toxic endpoint is manifested. This
threshold view holds that a range of exposures from just above
zero to some finite value can be tolerated by the organism
without appreciable risk of causing cancer. Some chemicals can
exhibit both carcinogenic and noncarcinogenic effects.
Health criteria for chemicals exhibiting noncarcinogenic
effects are generally developed using reference doses (RfDs).
The Rfl>, expressed in units of mg/kg/day, is an estimate of the
daily exposure to the human population that is likely to be
without an appreciable risk of deleterious effects during a
lifetime. TIM RfD provides a benchmark to which chemical intakes
by other routes may be compared. Potential concern for
noncarcinogenic effects of a single contaminant in a single
medium is expressed as the Hazard Quotient (HQ) [or, the ratio of
estimated intake derived from the contaminant concentration in a
given medium to the contaminant's reference dose]. The HQ is
also referred to as the Dose/RfD ratio. By adding the HQs for
all contaminants within a medium or across all media to which a
given population may reasonably be exposed, the Hazard Index (HI)
can be generated. The HI provides a useful reference point for
13
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TIble 1
CHEMICAlS CF POTENHAl ZZUCVUl FCR THg -CCMN LANCFiii.
Chwical GrcundwMr Surface Mttr Saduwit
Oraanica:
1 . 1 . 1 - tr 1 eft Jof8»tfta««
1.1*41 eft lorectftaM
I.l-dlch1ore«tm««
1 . 2*dicft lora>tnan>
l!2-dienlorc«thon« (total)
1 . 4-dich loraotfutn*
'•ovtfty iphcno 1
4CVtOfl4
bflMtM
bti(2*4tfiy1hviy1)pht)ia1at>
carton tttraeftlorldc
cftlorwtJian*
ehlorofora
d left lorof luoroHthaiw
•tftylbvucn*
nmftylcnc eft lor 1 do
noneareinoooflte PAMs
o^o**Jty Itfws
totracft loroctiWM
to 1 VMM __^__
trtiw-l . 2-dleft lorocthoM
trieiilorMthoM
tr left lorof luoroMthaM
vinyl ehlorioo)
>y1«M« (total)
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X X
X
cab* It v X
cynl* X
irw X
'•Otf XX
X
maul x
x
fUdlotettv*
22t X X
*2L 5 x
I 230 X X
I X X-
• t
I
-------
gauging the potential significance of multiple contaminant
exposures within a single medium or across media.
Human carcinogenic risk is evaluated by determining the
excess lifetime cancer risks (ELCRs) for actual or potential
exposures. ELCRs are determined by multiplying a contaminant's
exposure dose by the cancer potency factor (CPF). CPFs are
expressed in units of (mg/kg/day) and describe an upper bound
estimate of the relative carcinogenic potency of a toxicant.
These calculated risks are probabilities that are generally
expressed in scientific notation. An ELCR of i x 10~* indicates
that, as a reasonable upper bound, an individual has a one-in-
one million chance of developing cancer as a result of Site-
related exposure to a carcinogen over a 70 year lifetime under
the specific exposure conditions at a Site.
Data shoving Health Effects Criteria and other important
risk related information used in determining the risks associated
with this Site are contained in the Tables in Appendix A to this
Record of Decision.
The following risk summary is presented for this Record of
Decision:
In the risk assessment, a set of chemicals of potential
concern were selected for detailed evaluation based on the RI
sampling results. Chemicals were selected separately for three
environmental media: groundwater, surface water, and sediments.
A total of 26 organic chemicals, 11 inorganic chemicals, and four
radionuclides were selected for the risk assessment. The risk
assessment then evaluated the potential human health risks
associated with exposure to those chemicals of concern.
To evaluate potential human health risks, several exposure
pathways were selected for detailed evaluation under both current
and possible future Site use conditions. An exposure pathway,
defined as a source and mechanism of chemical release, an
environmental transport medium, a point of potential exposure,
and a route of exposure, is considered "complete* is all of these
elements are present. If an exposure pathway was considered
complete, then the potential risk was quantitatively calculated.
In addition to the above conditions, two scenarios were
considered during the risk assessment: a no-action and a no-
further-action alternative. The no-action alternative reflects
the Site as it would be without the current groundwater
extraction and treatment system operating. The no-further-
action alternative corresponds to the current condition of the
Modern Landfill CERCIA Site with the extraction and treatment
systems operating. The assessment of these two alternatives
14
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enables a determination to be made of whether further remedial
action is required for Modern Landfill.
For the no-action and no-further-action alternatives under
both future and current Site use conditions, the pathways for
direct contact with surface waters and sediments on the CERCLA
Site was not complete because no sediments or surface waters
exist on the CERCLA Site. No quantitative evaluation was
conducted for these pathways.
The pathways for direct contact with surface waters and
sediments, for the no-action and no-further-action alternatives
off the property under current Site use conditions is complete;
however, because off property RI data for sediments and surface
water are not available, no quantitative evaluation was
conducted.
For both future and current Site use conditions under the
no-further-action alternative, surface water flows on the
property are intermittent, and surface water contact is minimal.
For this reason, no quantitative evaluation of this pathway was
conducted.
For current Site use under the no-further-action
alternative, no groundwater pathway was found to exist because no
receptors are currently located on the CERCLA Site, on the
property, or off the property. Mo current groundwater receptors
exist as no residences currently exist on the CERCLA Site. The
eastern and western tributaries form a discharge for the aquifers
and therefore on-property and off-property residential wells,
which are located beyond the tributaries would not be expected to
contain Site-related leachate constituents. Residents north,
northeast, and northwest of the CERCLA Site have been hooked up
to the municipal water system.
For future Site use under the no-action alternative, the
groundwater pathway was found to be complete for receptors on the
property. Available- data, however, were insufficient to
quantitatively evaluate this pathway.
For each complete exposure pathway, potential risles to human
health were quantitatively estimated. The results of the risk
assessment are summarized in Table 2 and are discussed below.
• Current Lead Use Conditions-Potential for Voncareinogenio
Bffects. vo-aetioa and Bo-Further lotion Alternatives. The
hazard index values associated with incidental and
infrequent direct contact with sediments in the eastern and
western tributaries were less than one for both the average
and maximum reasonable cases. The hazard index values
associated with incidental and infrequent direct contact
with surface water in the eastern and western tributaries
15
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Table 2
SUMMIT 0* POTMmi XUMN NfjUfH IISK eSTtHATK fCI "COflN
()KJ-»CTIOI MO NO-njITHfl-ACTlCa AlTWHATlVH)
Eioosurt »§tfi»«y
Currtnt Land usa Condi tiono
wo- Action Aitarnativa (d)
Oirtet Sodimant Contact
utstarn Tributary
Eaatarn Tributary
Oirtet Surface uatar Contact
wtatarn Tributary
Eaatarn Tributary
€xcai
Avoraoe
CatO
Zt-99
NC
NC
tt tifttina C*near «i»» (a)
Pl*us>Bta PrMoainanr
C«so Choatcais
1C-OI NA
21-01 NA
NC NC
NC NC
tfonearcinoeanic EH»ctj o
MMIKI^I
Avtriqo 'ttusiolt '-ssomi.-arr
C4SO C*§« C.^tmicjts C)
<1 <1 NA
<1 <1 NA
' <1 <1 MA
lard Ut« Conditfans
tnfMtion of SrouidMttr (•>
On tn« CXtCU Sit*
•o-Mtfon Attomativ*
Action
a-os
a-os
81-03
vc. i.t-oa.
1,1-OCA, ecu
vc. i.i-oa.
1,1-OCA. ecu
On tM
«• Action
tnaufflcitnt aata av»Uatol« to tvalvatt.
1.2-eci. cctt,
tram*i,2-oei.
1.2-OCI. CCU.
trans-i,2-8Ct,
Action Altcmotiv*
Off ti
(•••Action Altarrwtlv*
Action
1f-fl»
2I-OT
(•)
U-0*
(•) TH« uBBJtr bovnd Individual MCOM lifotia* cancor risk roaroocnts tfM additional profioeility tftat an individuals may
doMiop cancar ovw a 78-yoor lifctla* ao o rosuit of upoaura conditions avaluatad. Tho) tarfot eancar riu rar^a us.
by VA to •voluato Jusarfvnd «1tM la from lt>0ft to 1t-0*.
(b) Tho ftourd indom indicatao MHotftor or not aipoauroo to •icturo* of nonearcinooonic cnaBieala oay rawlt in aowrso
• hooltn affocu. A ftoaartf inote IOM tlion ona indicatao tftot advon* Huaan itooltt offacu aro unlikaly to occur.
(c) Uatad enooicala ar» thooo nitk aMOM llfotia* cancor riaU of 11-0* or motor for carctnaaana and tiMao -itn C8l:if
ratio* of om or orootor for avorooo COM condltiono.
-------
were less than one for the no-action alternative. Direct
surface water contact for the no-further-action alternative
was not quantitatively evaluated. Adverse noncarcinogenic
effects would not occur under the exposure scenarios
evaluated.
• Future Land Use Conditions: Excess Lifetime Cancer Risks.
Sediment and surface water contact pathways were not
evaluated separately under future land use conditions
because the present Site use scenarios addressing these
pathways of exposure are considered to be representative of
possible future Site use exposure conditions.
Several groundwater ingestion pathways were, however,
evaluated under potential future CERCLA Site and surrounding
land use conditions. These included ingestion of
groundwater on the CERCLA Site, on the Modern Landfill
property, and off the Modern Landfill property, with the
exception of on the property risks for the no-action
alternative, each pathway was evaluated for both the no-
action and no-further-action alternatives.
He-Action Alteraative. The potential excess lifetime cancer
risks for groundwater ingestion on the CERCLA Site are 3 x
10 for the average case and 8 x 10"* for the maximum
reasonable case. The chemicals with estimated cancer risks
greater than 10"* for the average case included vinyl
chloride, 1,1-dichloroethane, 1,1-dichloroethene, and carbon
tetrachloride.
The concentrations measured in wells on the CERCLA Site
assumed to be unaffected by the extraction system were also
used to provide a very conservative indication of potential
on property concentrations under the no-action alternative.
Thus the risks presented for ingestion of groundwater on the
CERCLA Site provide an upper bound indication of potential
future risks on the property under the no-action
alternative.
For potential groundwater ingestion off the property, the
estimated excess lifetime cancer risks for the no-action
alternative were 2 x 10 for the average case and l x 10
for the) maximum reasonable case, which are at or below the
low end of EPA's target cancer risk range. v
Ho-rurther-Aotioa Alternative. The potential excess
lifetime cancer risks for groundwater ingestion on the
CERCLA Site under the no-further-action alternative were the
same as the risks for groundwater ingestion on the CERCLA
Site under the no-action alternative because the same set of
groundwater data were used for both alternatives.
16
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For groundwater ingestion on the property for the no-
further-action alternative, the total cancer risk estimates
were 2 x 10'6 for the average case and 2 x 10*' for the
maximum reasonable case. No individual chemical exceeded
the 10*6 excess cancer risk for the average case. The risks
estimated for future groundwater ingestion on the property
are likely to be overestimated since reductions in chemical
concentrations due to continued operation of the extraction
system and natural processes were not assumed to occur.
For potential groundwater ingestion off the property under
the no-further-action alternative, the estimated cancer
risks were 2 x 10 for the average case and 1 x 10"* for the
maximum reasonable case.
• Future Land Use Conditions: Potential for Noncarcinogenic
Effects. Ho-Action Alternative. Adverse noncarcinogenic
effects would not be expected to occur under the average
case but could occur under the maximum reasonable case
scenario as a result of daily ingestion of groundwater on
the CERCLA Site in the future under the no-action
alternative. This would result from daily exposures for 70
years to the currently measured maximum detected
concentrations of 1,2-dichloroethene, trans-1,2-
dichloroethene, carbon tetrachloride, and trichloroethene in
groundwater. It is likely that the hazard index values are
overestimates since this scenario assumes that current
groundwater concentrations will persist for at least 30 to
100 years in the future even though concentrations will
likely decrease over time.
The data from the CERCLA Site also provide an upper-bound
estimate of the potential for noncarcinogenic effects to
occur due to the daily ingestion of groundwater on the
property for future Site use conditions under the no-action
alternative.
Potential use of groundwater off the property in the future,
under the no-action alternative, is not expected to result
in adverse noncarcinogenic effects as the hazard index
values are less than the threshold level of one.
Vo-rurther-Aotion Alternative. Since the data from the
CZRCLA Site were used to evaluate both no-action and no-
further actions alternatives, the potential for v
noncarcinogenic effects to occur due to the ingestion of
groundwater on the CZRCLA Site in the future under the no-
further-action alternative is the same as the potential for
noncarcinogenic effects to occur under the no-action
alternative.
17
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Potential use of groundwater on the property and off the
property in the future, under the no-further-action
alternative, is not expected to result in adverse
noncarcinogenic effects as the hazard index values are less
than the threshold level of one.
Based on the Excess Lifetime Cancer RisJc from the potential
ingestion of groundwater on the CERCLA Site, 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,welfare, or the environment.
Environmental Evaluation
An ecological assessment was not conducted as part of this
risk assessment. This was based on several reasons, including
the results of an aquatic biological investigation conducted from
the summer of 1981 to the spring of 1982 in the western tributary
by FADER. FADER concluded that "leachate from Modern Landfill
has not resulted in any degradation to the unnamed [western}
tributary to Kreutz Creek. The greatest single factor
contributing to poor conditions in the creek was siltation causes
by grazing cattle on the Heindel farm.* This study was conducted
prior to the operation of the western extraction system, when
groundwater recharge to the tributary was still a potentially
important migration pathway for volatile organic chemicals from
the 66-acre unlined landfill. Since it began operating, the
extraction system has significantly reduced the surface water
flow in both the western and eastern tributaries and thus also
minimized the potential for Site-related chemicals to have an
adverse impact on the tributaries. Additionally, there is
currently no potential for chemicals of potential concern
associated with the CERCLA Site to migrate via surface runoff
into the tributaries.
According to the Pennsylvania Fish and Game Commission, none
of the fish, amphibians, or reptiles on the state's endangered or
threatened species lists are known to occur in the vicinity of
the Modern Landfill. According to the U.S. Fish and wildlife
Service, except for occasional transient species, no federally
listed or proposed threatened or endangered species under their
jurisdiction are known to exist in the general vicinity of Modern
Landfill. Finally, according to FADER"s Bureau of Forestry,
there are no "significant natural features of concern* (such as
plant and animal species of special concern, exemplary natural
communities and unique geologic features) in the general vicinity
of Modern Landfill. A 1988 wetlands field study also concluded
that wetlands of the kind and size observed at Modern Landfill is
not a uniquely important ecological habitat. Based on this
information, it was concluded that an ecological assessment need
not be conducted as part of the risk assessment.
18
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Q. DB8CBX7TXOM OF ALTERNATIVES
Based on data collected and the risk assessment results of
the Remedial Investigation/Feasibility Study, EPA has established
remedial action objectives for the Modern Landfill Site.
Remediation is generally focused on exposure pathways shoving
excess lifetime cancer risks greater that l x 10'6 or, for
noncarcinogens, a hazard index greater than the threshold level
of one. These points of departure were exceeded for the
groundvater ingestion exposure pathway only. Remedial action
objectives have therefore been developed for groundvater only.
The general remedial action objectives for the Modern
Landfill Site are:
• Reduce leachate production and migration to groundvater.
• Reduce the amount of groundwater degradation on the CERCLA
Site.
• Decrease the potential for migration of degraded groundwater
from the Modern Landfill property.
• Minimize migration of leachate constituents into surface water.
• Prevent exposure to contaminated groundvater.
• Restore contaminated groundwater to beneficial uses where
practicable.
• As a goal, restore contaminated groundwater to background
quality.
The baseline risk assessment concluded that under the no-
further-action alternative, risks from ingestion of groundwater
on the property and off the property were veil within EPA's
target risk range of 10"* to 10 . Even for the no-action
alternative, risks off the property were calculated to be well
within this range. Thus, remediation is needed only on the
CERCLA Site, not on the property and/or off the property.
The following substances have been evaluated for groundwater
ingestion risks on the Modern Landfill CERCLA Site with an
estimated upper bound excess lifetime cancer rusk of 1 x 10 or
greater, or with a GDI to RfD ratio of 1.0 or greater. These
substances will be removed to their background levels as
described later in this Record of Decision.
benzene carbon tetrachloride
chloroform 1,4-dichlorobenzene
total dichlorobenzenes 1,1-dichloroethane
19
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1 , 2-dichloroethane 1 , 1-dichloroethene
trans-l,2-dichloroethene 1,2-dichloroethenes (total)
methyl chloride tetrachloroethene
trichloroethene vinyl chloride
Area of Attainment
The National Contingency Plan, in discussing documentation
of the remedy selection in the ROD states that "Performance shall
be measured at appropriate locations in the groundvater, surface
water, soils, air, and other affected environmental media.1*
Under current Site conditions, groundvater flov from the CERCLA
Site is effectively contained by the existing groundvater •
extraction system. To monitor the effectiveness of the
remediation and protection provided to users of the groundvater
in the vicinity, groundvater monitoring points outside the
extraction system are appropriate (and some are already
installed) .
The attainment area for Modern Landfill is located between
the CERCLA Site and the existing groundvater compliance
monitoring and assessment points. All of these compliance
monitoring and assessment points are located veil within the
property boundaries so that if vater quality is determined to be
unacceptable^ steps can be taken to prevent further migration and
to protect human health and the environment. Additional
compliance and monitoring points may be constructed if deemed
necessary by the PADER and/or EPA.
Alternatives
EPA studied a variety of technologies to determine which
vere applicable for use at the Modern Landfill Site. After a
preliminary screening of technologies vas completed, those most
applicable to the Site vere developed into remedial alternatives.
The alternatives vhich vere developed to treat the relatively lov
level threat from the Modern Landfill Site are as follovs:
• Alternative l — No-Action
• Alternativ«< 2A — Mo Further Action (Continued Operation of
Groundvater and Vapor Extraction Systems)
• Alternative 2B — • Groundvater and Vapor Extraction Systems and
Final cover v
• Alternative 2C — Augmented Extraction Systems plus Final Cover
A more detailed description of each of these alternatives
follovs.
20
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Alternative 1 — Mo Action
Capital Cost: $0
Operation and
Maintenance Costs: $218,500
Present Worth Cost: $3,398,000
The National Contingency Plan requires that a no action
alternative be evaluated in detail. This provides a baseline for
comparison to other alternatives. At the Modern Landfill Site,
however, a true no-action alternative is not possible. The best
approximation to a no-action alternative is ceasing current
actions, that is, shutting off the extraction system and ceasing
maintenance of the cap and other components of the existing
remedial action . The no-action alternative would include
groundwater monitoring consisting of sampling and analysis in
accordance with PAOER Solid Waste Permit No. 100113.
This alternative provides more protection to human health
and the environment than a true no-action alternative as some
leachate constituents have already been removed from the
landfill, the cap already in place will continue to reduce
infiltration and the concentration of leachate constituents in
the groundwater, and the Site fence will continue to restrict
access to the Site.
In general, this alternative would not meet the Applicable
or Relevant and Appropriate Requirements (ARARs) for this Site,
particularly the groundwater remediation goals of background
water quality.
Alternative 2A — • No Fu,rth.**T Action (Continued Operation of the
Existing Groundwater and Vapor Extraction Systems)
Capital Cost: $47,000
Operation and
Maintenance Costa: $1,107,500
Present Worth: $16,963,500
This alternative involves the continued operation and
maintenance of all existing remedial actions, including the
landfill cap, groundwater extraction system, onsite wastewater
treatment facility, vapor extraction system, and groundwater
monitoring.
A landfill cap and final cover are currently under
construction. This alternative does not include completion of
the landfill caps currently under construction but does allow for
21
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maintenance of completed caps. The purpose of the cap system is
to reduce infiltration of precipitation which will ultimately
result in the reduction of the amount of leachate produced from
the Site area, thereby reducing the concentration of leachate
constituents in the groundwater.
A network of 12 groundwater extraction wells which was
designed and installed in 1985 augments the western groundwater
interceptor trench. An additional two extraction wells were
added in 1987, bringing the total number of extraction wells on
the western perimeter to 14. Along the eastern perimeter a
similar extraction system, consisting of 13 wells, became
operational in 1986.
The purpose of the extraction system is to create a
hydraulic barrier to groundwater flow from the CERCLA Site and to
remove groundwater containing leachate constituents. All
extracted water is diverted to and processed through the onsite
wastewater treatment facility. The treatment facility, permitted
under PAOER Water Quality Management Permit No. PAD00678201, is
designed to accept flow from both the eastern and western
groundwater extraction systems and the groundwater interceptor
trench. The wastewater treatment facility is comprised of a
physical/chemical plant and a biological plant to treat extracted
groundwater.' Wastewater received from the physical/chemical
treatment plant is processed in the biological treatment plant
and returned to the physical/chemical plant prior to sand
filtering. Wastewater is then processed through the air strippe-
before discharge.
Site fencing is included in this alternative to restrict
Site access. The section of the CERCLA Site west of Prospect
Road is surrounded by existing Site fencing and sections of the
CERCLA Site east of Prospect Road are enclosed by Site fencing.
The risk assessment shoved that risk* associated with direct
surface water and sediment contact for the no further action
alternative to be below the regulatory levels of concern. The
existing Site fence is therefore protective of human health and
the environment by restricting Site access.
The purpose- of the landfill gas management system at Modern
Landfill is to prevent landfill gas migration off the property.
The operation of the landfill gas management system subjects the
entire refuse, volume to a pressure equal to or slightly less than
that of atmospheric pressure, reducing landfill gas migration.
In addition to the above, groundwater monitoring in
accordance with the PAOER Solid Waste Permit NO. 100113 would
continue with this alternative, both upgradient and downgradient
of the Site to detect changes in groundwater quality. The
groundwater monitoring program currently includes three quarterly
sampling and analysis periods during the months of March, June,
22
-------
and December, and one annual sampling and analysis period during
September.
The current water quality monitoring system consists of 19
groundvater monitoring wells, 14 groundwater constituent
assessment wells, the 27 eastern and western extraction wells,
and 17 surface water sampling points.
New groundwater monitoring and assessment wells may be
needed on the property to evaluate progress toward meeting the
remediation goals in the attainment area. The exact location and
number of these wells will be determined in the Remedial Design
phase.
This alternative would be expected to meet all ARARs,
except the groundwater remediation goals under future conditions.
Alternative 2B — Groundwater and Vapor Extraction Systems and
Final Cover
Capital Cost: $3,486,500
Operation and
Maintenance Costs: $1,166,500
Present Worth Cost: $17,947,000
This alternative consists of the some remedial actions as
Alternative 2A plus additional remedial actions that are
currently planned and permitted to enhance the effectiveness of
the overall remedy. These additional actions include completion
of the cap and final cover over the 66-acre unlined landfill.
In additional to the completion of the landfill caps, the
entire 66-acre unlined landfill will receive a PADER approved
low-permeability final cover system. The final cover over the
landfill vill include a 20-acre plateau cap and a 46-acre side
slope cap.
This alternative is also expected to comply with ARARs.
Under future use conditions, however, the Pennsylvania background
requirement for background quality may not be met either on
and/or off the site should groundwater bypass the extraction
system.
Alternative 2C —Augmented Extraction Systems Plus Final Cover
Capital Cost: $3,509,000
Operation and
Maintenance Costs: $1,175,000
23
-------
Present Worth Cost: $18,078,000
This alternative includes all of the actions undertaken and
planned for in Alternatives 2A and 2B above, in addition, this
alternative includes further expansion of the existing
groundvater extraction system. The objective of this alternative
is to minimize the flow of degraded groundvater that could
potentially escape the extraction well system to the northwest.
In this alternative, two additional wells are proposed at
the northwest end of the western extraction system. These
proposed wells are strategically located to capture groundwater
that might bypass the current the north end of the western*.
extraction system.
This alternative, like Alternative 2A and 2B, is expected to
meet ARARs.
R. SUMMARY Of THE COMPARATIVE ANALYSIS OF ALTERNATIVES
The four remedial action alternatives described above were
evaluated under the nine criteria in the NCP, 40 CFR
300.430(e) (9) . These nine criteria can be further categorized
into three groups: threshold criteria, primary balancing
criteria, and modifying criteria, as follows:
Threshold Criteria.
• Overall protection of human health and the environment
• Compliance with applicable or relevant and appropriate
requirements (ARARs)
Primary Balancing Criteria
• Long-term effectiveness
• Reduction of toxicity, mobility, or volume through
treatment
• Short-term effectiveness
• Implementability
• Cost
Modifi
• Community Acceptance v
• State Acceptance
These evaluation criteria, which measure the overall
feasibility and acceptability of the remedy, relate directly to
requirements in Section 121 of CERCLA, 42 U.S.C. Section 9621.
Threshold criteria must be satisfied in order for a remedy to be
eligible for selection. Primary balancing criteria are used to
24
-------
weigh major trade-offs between alternatives, state and community
acceptance are modifying criteria formally taken into account
after public comment is received on the Proposed Plan.
The comparative evaluation of alternatives follows.
overall Protection of Human Health and the Environment.
Alternative 1 would not be protective of human health and
the environment as the Site would return to its previous
uncontrolled state and leachate constituents could migrate in
both the groundwater and surface water. As this Alternative is
not protective of human health and the environment, it will not
be considered further in this Record of Decision. Alternatives
2A, 2B, and 2C would be protective of human health and the
environment by decreasing the potential for direct contact with
surface water and sediments, and by decreasing the potential for
ingestion of groundwater containing leachate constituents.
Alternative 2B would be more protective than 2A as the completion
of the cap would further reduce the potential of leachate
generation, while Alternative 2C, in addition to the above
benefits, would ensure the removal of contaminants that may be
bypassing the extraction system to the north.
Compliance with Applicable or Relevant and Appropriate
Requirements
Alternative 2C would comply with all ARARs. Groundwater
extraction will continue until the Pennsylvania ARAR for
background water quality is reached. Under Alternatives 2A and
2B, however, requirements may not be met on and/or off the
property in the future should groundwater bypass the current
extraction system. Alternative 2C will ensure that such
bypassing does not occur.
Long Term Effectiveness
The magnitude of residual risk will be substantially reduced
by implementation of any of the Alternatives. The use of
groundwater extraction and landfill gas extraction serves as a
method of leachate constituent removal. This, in combination
with reduced mobility of leachate constituents from the existing
low-permeability landfill cap, will mitigate a substantial amount
of potential risk. v
The risks associated with direct contact with sediment and
surface water have been shown to be well below the regulatory
levels of concern. These risks will be further minimized by the
existing Site fencing and the reduction of constituent migration
to the surface water. The risks associated with ingestion of
groundwater are being reduced by the installation of landfill
caps, the connection of an additional well under Alternative 2B,
25
-------
and the completion of final cover and another extraction well
under alternative 2C.
Reduction of Toxicity, Mobility/ or Volume Through Treatment.
All three alternatives, 2A, 2B, and 2C reduce the inherent
hazards associated with ingestion of degrades groundvater by
operation of the groundvater extraction system. Degraded
groundwater removed by the extraction system typically contains
chlorinated hydrocarbons and some inorganic compounds. Leachate
constituents are physically and chemically separated from the
groundwater by the onsite wastewater treatment plant.
Some reduction in the volume of leachate constituents
present in the landfill has and will be accomplished by the
groundwater and vapor extraction systems. The mobility of
leachate constituents will be reduced by the existing low-
permeability landfill cap. The reduced infiltration of
precipitation results in reduced migration of leachate
constituents into the groundwater.
Alternatives 2B and 2C will each remove incrementally
greater amounts of contaminants from the groundwater, and
Alternative 2C will further reduce the mobility of contaminants
with the completion of the final landfill cover system.
Short Term Effectiveness
With all three Alternatives, implementation of the full
remedies would commence almost immediately. As the groundwater
extraction and vapor extraction systems have been in operation
for some time, the short term effectiveness of each remedy has
already been demonstrated.
Alternatives 2B and 2C would require some additional time
from selection of remedy to implementation; however, this
timeframe would be expected to be less than one year.
Additionally, the. final cover system to be implemented with
Alternative 2C would further reduce the mobility of the
contaminants in an extremely short timeframe.
The community, workers, or the environment are not expected
to be adversely affected by any of the Alternatives.
zaplemeatability v
All phases of Alternative 2A have been implemented except
the installation of additional monitoring wells. Implementation
of this Alternative poses no technical difficulties. This
alternative is relatively simple to operate and is reliable.
26
-------
All components of Alternative 2B have been implemented with
the exception of the installation of additional monitoring veils,
and completion of landfill capping and final cover. Again, the
implementation of these actions pose minimal difficulty.
All components of Alternative 2C have been implemented
except the installation of additional monitoring wells,
completion of landfill capping and final cover, and the design
and installation of two additional extraction wells. The
completion of these actions pose minimal difficulty. The
alternative is relatively simple to operate and is reliable.
All materials and services required by this alternative are
common construction items and procedures, and involve routine
sampling and analytical procedures.
Cost
The capital cost for Alternative 2A is relatively low at
$47,000 as most of the components of this remedy have already
been implemented. The Operation and Maintenance Costs of all of
the Alternatives are, for all practical purposes, about equal at
just over $1 million, and the Present Worth Costs of all of the
Alternatives,are just about equal, ranging from $16,963,500 for
Alternative 2A to $18,078,000 for Alternative 2C.
Community Acceptance
A public meeting on the proposed plan for Modern Landfill
was held on May 7, 1991. Comments received from the public
during the public comment period are referenced in the
Responsiveness Summary attached to the Record of Decision. No
major public objection to the proposed remedy for Modern Landfill
exists.
State Acceptance
PAOER, on behalf of the Commonwealth of Pennsylvania, has
verbally concurred in the selection of Alternative 2C.
Z. THB BWLKTtD RHCBDY
Based upon consideration of information available for the
Modern Landfill Site, including the documents available in the
Administrative Record, an evaluation of the risks currently posed
by the Site, the requirements of CERCLA, the detailed evaluation
of alternatives, and community input, EPA has selected
Alternative 2C as the remedy to be implemented at Modern
Landfill.
27
-------
This Alternative involves the continued operation and
maintenance of all existing remedial actions, including the
completion and maintenance of the landfill cap and final cover
system, groundwater extraction system, installation of additional
extraction wells to ensure the capture of contaminated
groundwater flowing to the north, onsite wastewater treatment
facility, vapor extraction system, and groundwater monitoring.
The 66-acre unlined landfill will have a 20-acre plateau area and
a 46-acre side slope area. A total of 27 groundwater extraction
wells will continue in operation. The groundwater extraction
system will continue to operate until the remediation goal of
background levels of contaminants is reached. The clean up level
for the aquifer contaminants are, for each contaminant, the lower
of- (l) the standards listed in Table 3 and (2) the background
level of that contaminant. Background concentrations for each of
the contaminants listed in Table 3 shall be the method detection
limit for the method of analysis utilized with respect to that
contaminant. As of the date of this Record of Decision, the
appropriate methods of analysis are 40 C.P.R. Part 136 (Series
601 and 602), and 40 C.F.R. Part 141 (Series 524.2). The
attainment area for this remediation is located between the
CERCLA Site and the groundwater compliance monitoring and
assessment points, all of which are located within the property
boundaries. If implementation of the selected remedy
demonstrates, in corroboration with hydrogeological and chemical
evidence, that it will be technical impracticable to achieve and
maintain the remediation goals throughout the area of attainment,
the EPA, in consultation with the Commonwealth of Pennsylvania,
intends to amend the ROD or issue an Explanation of Significant
Differences to inform the public of alternative groundwater
goals.
Groundwater form both the eastern and western extraction
systems and the groundwater interceptor trench will be treated at
the onsite wastewater treatment facility and discharged to the
unnamed tributary to Kreutz Creek in accordance with the
requirements of PADER permit PAD00678201. The treatment process
consists of both biological and physical/chemical treatment
trains,, sand filtering, and air stripping.
Continued groundwater and surface water monitoring is also a
part of the selected remedy as is the installation of additional
monitoring and extraction wells if needed. Site fencing is
included in this alternative to restrict Site access and minimize
any direct contact threat.
Remediation of these lev level threats at the Modern
Landfill Site will effectively eliminate the risks associated
with potential ingestion of groundwater on the CERCLA Site.
28
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Table 3
Remediation Goals for Groundvater
COMPOUND (a)
TARGET CONCENTRATION (ucr/1)
BASIS
BENZENE
CARBON TETRACHLORIDE
CHLOROFORM
1 , 4-DICHLOROBENZENE
TOTAL OICHLOROBENZENE
1 , 1-DICHLOROETHANE
1 , 2-DXCHLOROETHANE
1 , 1-DICHLOROETHENE
TRANS-1 , 2 -DICHLOROETHENB
1,2-DICHLOROETHENES (TOTAL)
METHYLENE CHLORIDE
TETRACHLOROETHENB
TRICHLOROETHENE
VINYL CHLORIDE
ftBFm TO PAOB 2C oip TBI FBC1?
5
5
13
75
75
5
5
7
100
70
11
5
5
2
RD OF DBCXfiXOV TO
MEDIATION OOALB F
MCL
MCL
RISK BASED
(b,c)
MCL
MCL (d)
QUANTITATION
LIMIT (e)
MCL
MCL
PMCL
PMCL (f)
RISK BASED (b)
PMCL
MCL
MCL
R A COMPLBTB
OR THIB 8IT1.
-------
TABLE 3 (con't.)
REMEDIATION GOALS FOR CROUNOUATER
(CONTINUED)
ND Not detected at level* at or above the quantitatlon limit.
(a) Includes all chea)lcal* evaluated for groundwater ingestion risks on the Modern Landfill CERCLA sice
with an estimated upper bound excess lifetime cancer risk of 1 x 10'* or greater, or with a GDI to RfD
ratio of 1.0 or greater (aee Table 6-31 of the rlak assessment, Chapter 6 of the RI Report).
(b) Risk-baaed levela are calculated assuming ingestion of 2 liters/day. 36S days/year, for 30 years by a
70 kg Individual.
(c) The MCL for total trihaloaethanes la 100 ig/1.
(d) Value for 1,4-dlchlorobenzene.
(e) Baaed on the EPA Contract Laboratories Program contract-required quantltation Unit. This is
conalatant with the MCL for 1,2-dlchloroathane, which haa approximately the same cancer potency as
1,1-dichloroethane. The risk-based concentration for 1,1-dichloroethane would be 0.9 /«g/l (1 x 10 *
exceaa lifetime cancer rlak.
(f) Value for cls-l,2-dlchloroethene.
-------
The Capital Cost of this Alternative is $3,509,000, the
annual Operation and Maintenance Costs are $1,175,000, and the
Present Worth Cost is $18,078,000.
J. STATUTORY DETERMINATIONS
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 established several other statutory
requirements and preferences. These specify that when complete,
the selected remedial action for a Site must comply with
applicable or relevant and appropriate environmental standards
established under Federal and State environmental laws unless a
statutory waiver is granted. The selected remedy must also be
cost-effective and utilize treatment technologies or resource
recovery technologies to the maximum extent practicable. Finally
the statute includes a preference for remedies that permanently
and significantly reduce the volume, toxicity, or mobility of
hazardous wastes.
Protection of B[uj{tn Health and the Envircyn.nien.tt
The selected remedy will be protective of human health and
the environment by eliminating the threat posed by the hazardous
substances within the Modern Landfill. These hazardous
substances currently provide a threat to human health due to
potential ingestion of groundwater on the CERCLA Site. The
selected remedy will eliminate that potential risfc by extracting
the contaminated groundwater beneath the Site and treating the
contaminated groundwater before discharge.
Any potential for direct contact with Site contaminants will
be eliminated by completion of the cap and final cover systems
over the unlined 66-acre landfill. These cap and cover systems
will also reduce the production of leachate and contaminated
groundwater which originates under the CERCLA Site. In addition,
Site fencing will restrict access to the Site to further reduce
the direct contact risk.
TIM selected remedy will not pose any unacceptable short-
term risks or cross-media impacts to the Site, the workers, or
the community. The; selected remedy will be readily
implementable.
Compliance with ARARs
The selected remedy will attain all applicable or relevant
and appropriate requirements for the Site. These requirements
are shown in Appendix B. Most specifically, the Pennsylvania
action-specific requirement to remediate groundwater to
29
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background concentrations (25 PA Code,chapter 75, Part 264.97)
will be mat through implementation of this remedy, if
implementation of the selected remedy demonstrates, in
corroboration with hydrogeological and chemical evidence, that it
will be technically impracticable to achieve and maintain the
remediation goals throughout the area of attainment, the EPA, in
consultation with the Commonwealth of Pennsylvania, intends to
amend the ROD or issue an Explanation of Significant Differences
to inform the Public of alternative groundwater goals.
Cost Effectiveness
The estimated present worth cost of the selected remedy is
$18,078,000. EPA and the Commonwealth of Pennsylvania believe
the selected remedy is cost-effective in mitigating the risks
posed by the Modern Landfill Site. Although the no-action
alternative can be implemented at a much lower cost, that
alternative is not protective of human health and the environment
and does not meet ARARs. Alternatives 2A and 2B are only
slightly less expensive than the selected remedy and do not
provide the same amount of protection as the selected remedy.
Utilization of Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery Technologies to the Maximum
Extent Practicable
EPA has determined that the selected remedial action
represents the maximum extent to which permanent solutions and
treatment technologies can be utilized while providing the best
balance among the other evaluation criteria. Of the alternatives
that are protective of human health and the environment and meet
ARARs, EPA has determined that the selected remedy provides the
best balance of trade-offs in terms of long-term effectiveness
and permanence; implementability; short-term effectiveness;
reduction in toxicity, mobility, or volume through treatment;
state and community acceptance; and the CERCLA preference for
treatment.
The selected remedy addresses the long-term, low-level
threats posed by the Site contaminants at Modern Landfill. The
remedy is protective of human health and the environment, meets
ARARs, and is cost-effective. Treatment as a principal element
is provided for in the onsite treatment of extracted groundwater
and leachate prior to discharge.
As this alternative would result in hazardous substances
remaining onsite, 5-year reviews, pursuant to Section 121(c) of
CERCLA, will be required to monitor the effectiveness of this
alternative.
30
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x. DocmmrrATioir OT SIGHIFICAHT CHANGES
No significant changes froa the Proposed Plan have been
made.
31
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Appendix A
Page 1 of 3
HCJM.TH EFFECTS CRITERIA FOR INHALATION EXPOSURE TO CiCMCAlS CF POTENTIAL CC.SCs?
C*a»ieal
Aeatena
Atuitnufl
Senzone
Caremeatnie PAH*
(at 9enzo{a]pyreno)
3 i s( 2-tthy Inuy t Jpntna late
CaOfcttJB
Carton tatraehloride
Chloreathane
Chloroform
Cobalt
Cyanide
Olcnlorobenzenes:
(as 1.2-Otehlorobenzane)
(as 1.4-Olenlorobenzane)
1.1-0 left lorootftane
1.2-0 left loroetnane
1.1-Otenloroetftene
1.2-0 left loroetftene (total):
en-
trant-
Olchloroflueraaethane
Etftylbonxene
lee*
Mercury:
Inoroaulc and ATkyl
ftmurltl
Nttftylene chloride
4-Netnylphenel
Noncarcinaeenlc MHe
Nickel: **
Soluble salt*
Refinery dust
Subwlfld*
Rad1u» 221
Tatracnloraethene .
Thortia 230
Toluene
Trlehlofeethene
rrlehlereflyoreMthana)
Urentifli
vanedlui
vinyl cntorld*
Xyleme (total):
Nlad
1 • 1 • l-Tr lchlereette»*
Dafartneo Oosa
(RfO)
(mj/ke/day)
0.0001
—
—
-•
—
•-
—
0.04
oil
—
~
—
-•
••
—
_
0.0001
t —
_
_
3 e*/ed*
~»
•~
—
-
^,
»
••
1
ol
mm
"m
0.4*
0.1
Safaty
P*ctor (a)
1. 000
»-
—
-•
—
—
••
1.000
100
1.000
••
— •
-~
••
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—
^.
100
^
««•
100
«•
—
—
-
.„
_•
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101
1.001
_
•"
1.001
1.001
Sourea (b)
HEA
--
—
—
—
—
—
HCA
HU
HU
-•
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—
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—
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HCA
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HCft
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Canetr ^otincy
—
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•• •
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--
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FootaetM «r« «• T«*1> HOC.
-------
Appendix A
Page 2 of 3
T* £?P£CTS
ro c:i£.».':.:-.s OP ?OT£.lT.'.JI. ::.NCi?t
4<
:.w«inc4i
*Ctt9"t
AljBtnufll
3«nuffl
3anr«na ,
C*reinessflic PAHs (fj
(-• 3«k«M f *1 f%M*MK.l
4s aenxoiijpyrwnwj
8ij(2-ttnylheayl)p*«tha1at«
C40B1US
Carbon tatraelilorlds
Ch lorsatnane
Ch lorof on*
Cabal t
Cyanidt
Ofcnlorebaiutftts (1)
Us l.4-01chlor«fc«n«nt)
1.1-OlehlorecttiaM
1.2-OtcMoraatlww
l.l'OicMoraatMM
l.2-01eiitorMtlww (total) (1):
ets-
trans-
0 left lorof luoroM than*
EUiylbsrnsi*
Iron
Ltad
Manganese
Ntreury:
Inorganic
Inorganic and Alkyl
Neiwial
NstfiylefW ehlorid*
4-MstnylpMnel
Nonearctnoaanlc fit* (1)
(as ttapftttialm)
Nidul:
Soltftl* salts
Raf tiwry Huat
Submlfidi
Radius 220
Radii* 220
Tctracft lerMttwn*
TherUai 230
TollWW
iricnioror luorositJwM
Uraaitai
vanadl«
vinyl chlorldt
Xy1«Ms (taut):
Mind
t.l.l-Trld»1grostha«d
sftrtnet Oott
!3fO)
.•ng/na/day)
O.t
- (D
O.OS
—
• —
0.02
0.001 (food) *
O.OOOS (•atar)
0.0007
- (1)
0.01
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0.02
0.1
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0.000
0.01
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0.1
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ol
0.0003 (f) ^
0.0003*
0.00
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0.4«
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mm
mm
o.ot
OJ
0.0073* *
0.3
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Jf-«2
- - . tincsr Pottncy •*•:"
:4ftty Fietor '"
:te-.9r («) Souret (b) (n^/kj/tfay)-! Source (b) i. -.e--.i
'..COO IBIS
• •
100 IBIS 11 - -1
2.9C-02 rais A
U.S ' -*A (a) zl
i-aw '"is i.4£-o2 :ats »2
10 lit A .. («)
\ w*
1-OM !»»$ 1.3C-01 IRIS =Z
1-000 IHIS 8.1E-03 IRIS =2
500 IHIS 11 11 —
l-22 ** 2. 41-02 H£A 32
1. 000 HIA 9.1E-02 «6A 32
. .I! .I* 9.1C-02 IRIS 32
1.000 IBIS 6.01-01 IRIS C
1.000 HA
1.000 IRIS
** *" »m •« -•
1.000 Il|$ _ _ • „
•— •- ^0 ^^ ..
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IN ICA « ::
10 MCA ~ 1! 11
1.000 HCA - -
, i22 !!'* 7-a-« I8IJ »
I.OOO HIS —
100 ICA -
300 111$ m. -
1.. --
^
—
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t.™ »IS O.OU- «A 32
IN ills HI! 11
1.000 HA. . 1.1I-4B HCA 32
1 AIM • Iff f »•*•"*• >^* °*
i • WWf r^A | •• •— • —
— — -. s.oi-oi (i) —
100 HCA »•»"» '« _
- - 2.3 Htt A
100 IIP. — ~
1.000 III*. —
Footnote* ar« « Takta 0-lC.
-------
Appendix A Page 3 of 3
FOOTNOTES ?OH HEALTH £r?ECTS C8ITERIA
d) Safety fietors iff tfte products of uncertainty factors and .iwdifying factors, Uncertainty 'actors .sec :
-evelca -eference soies generally eonsm of itultiaies of 10. «itn eacn factor representing a jptc:r-: i-
af uncertainty in tre oata available. !>• standard uncertainty factors include tre following:
. a 13-fold factor to account for the variation in sensitivity among the noiwers of
:ne numan sopu'ation:
. a 10-fold factor to account for the uncertainty in ntrapoUting animal data
:o :'• cast of "unans:
. a 13-fold factor to account for uncertainty in extrapolating from less-than-
c.iromc NOAELs to cnronic .tOACLs; and
. a 10-fold factor to account for tne uncertainty in tstraoolating fro* IQAEUs
to NOACLl.
Modifying factor* art aooHtd at the) discretion of the rtvletwr to cover other uncertainties in tne data.
(b) CRIS • tne cnevtcal files of EH's Integrated Risk Information Systea (as of 08/01/89): *CA --.Health
Effects Assessnent Stamary Tables (04/01/89): HA • Health Advisory (Office of Or inning water).
(c) EM weight of evidence classification scheme for carcinogens: A—Hasan Carcinogen, sufficient
evidence froe htanan epidamiologlcal studies: 81—Preaaole Husaui Carcinogen, limited evidence frae
epidemiologtcal studies and adequate evidence frqa antwl studies: 82—Probable Huean Carcinogen.
inadequate, evidence fro* epiaeanological studies and adequate evidence from antnal studes:
C—Possible Huean Carcinogen. Halted evidence in antoals m the absence of hiaMn data:
0—«ot Classified as to husen carcinogentcity: and E—Evidence of Noncarclnegenlelty.
(d) Health Effects Assessnnt far 8e«o(a)pyrene. Environmental Criteria and Assessnnt Office.
Cincinnati. Ohio. ETA 540/1-M-04I.
(e) There Is inadequate evidence for carcinogenicIty of this ceapound by the oral route.
(f) Based on Aft) for eatnyl eereury.
(8) 8e1Ues. I. 19M. Personal cenwilcatlen «tth Or. letart Bellies. Carelncgen Assessnent Sroup.
EPA. Ale* In tht EPA 1994 Health Effects Assessment for Trlenloroethylene. Enviromenta)
Criteria and Assessment Office. Cincinnati. Ohio. EM/S4Q/1-C9-049.
(h) Based on metabolized date.
(t) For these chemical mixtures, talcity dttt for one) of the most toxic compounds in th* mixture
is used to represent the entire mixture. 0.9.. benm(a)pyrene for carcinogenic *ANs. naphthalene
for noncarcinogentc •AMs. 1.4-dlchlorobenzene for dlchlerobmnienea. cts-l.2-d1ch1oroothene
for 1.2-dlchtoraethenes.
(j) The cancer potency factor, derived using Information In PA (19M). Is in units of
(k) AN interim IfO -as calculated for use In this isseisment from the orel LOU (RTECS 1917)
ting to the approach described to Layto* et el. (1997).
(1) A"l"terlm RID could not b* calculated because) oral 109* velum* -ere not available
(RTftt 1997).
• • Pending/under review. » /
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APPENDIX B
APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS
MODERN LANDFILL
REQUIREMENT DESCRIPTION
Federal Standards for several toxic
RCRA Maximum chemicals are set forth to protect
Concentration Limits groundwater. Standards will be used
(40 CFR 264.94) when setting goals for acceptable levels
of the listed chemicals.
Safe Drinking Water Federal Standards for several chemicals
Act Maximum including the RCRA MCLs, adopted to
Contaminant Levels protect public drinking water systems.
(40 CFR Part 141) Standards will be considered and used in
characterizing human health risks
associated with possible contaminated
groundvater used for public consumption.
PA Hazardous Waste Requires cleanup of groundwater to
Regulations background levels.
(25 PA Code 264.97)
PA Safe Drinking State act which established drinking
Water Act of 1984 water standards at least as stringent as
(25 PA Code 109 i£j. Federal Standards.
SfiSU)
PA Municipal Waste State Requirements on monitoring
Landfill Regulations groundwater for potential leachate
(Title 25, Chapter constituents.
273.281-288)
PA Water Quality PADER water Quality Standards include
Standards (PA Cods requirements for dissolved oxygen,
Title 25, Chapter temperature increase, pH, total
93) coliform, and chemical-specific effluent
limits. Limits set on a case by case
basis.
PA NPDES System (PA State requirements on limitation of
Code Title 25, discharge from treatment facilities.
Chapter 92)
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PA Wastevater
Treatment
Requirements (PA
Code Title 25,
Chapter 95 et. seq.)
PA Clean Streams Lav
(35 P.P. Section
691.1)
Clean Air Act-
National Ambient Air
Quality Standards
(40 CFR 50)
PA Air Pollution
Control Regulations
(PA Code Title 25,
Chps 121-143)
Construction,
Modification,,
Reactivation, and
Operation (Air
Stripping)
(PA Cod* Title 25,
Chapter 127)
PA Municipal Waste
Landfill Regulations
(PA Code Title 25,
Chapter 273.234-
273.236, and
273.292,293)
PA Water Resources
Regulations and
NPDES (25 PA Code
92.1 efc. sea.l
PA Municipal Waste
Landfill Regulations
(PA Coda Titla 25,
Chapter 273.271-
273.277)
State Requirements that set levels for
surface water releases from treatment
facilities.
State Requirements set forth to protect
and ensure the integrity of streams.
Standards for particulate matter.
Standards regulate emissions from air
pollution control devices.
Requirements include BAT (Best Available
Technology), plan approval, and special
requirements in non-attainment areas.
Design and performance standards for
final cover. Closure with waste in
placa. Requirements for landfill gas
management practices at municipal waste
landfills.
Authorizes NPDES discharges and
treatment facility construction.
Laachata Management and Treatment
Standards.
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40 CFR 122.44, 125
40 CFR 125.100,
125.104
PA Municipal Waste
Landfill Regulations
(Operation and
Maintenance)
(PA Code Title 25,
Chapter 273.321-322)
PA Code Title 25
Ch. 102
PA Code Title 25,
Chapter 273.242
29 CFR 1926
PA Hazardous Sites
Cleanup Act
(PA Code Title 35,
Chs. 1-13)
Best Available Technology to control
toxic and non-conventional pollutants
from treataent of vastevater.
Best Management Practices and objectives
for control of toxic constituents to
surface waters.
A closure and post-closure plan must be
submitted to and approved by PADER.
Development of an Erosion and
Sedimentation Control Plan.
Requires erosion and sedimentation
control for municipal waste landfills.
Safety and health regulations for
construction worlc.
Outlines hazardous sites cleanup in the
state of Pennsylvania.
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RESPONSIVENESS SUMMARY
MODERN LANDFILL RECORD OF DECISION
YORK COUNTY, PENNSYLVANIA
From April 16, 1991 through June 15, 1991, the U. S.
Environmental Protection Agency (EPA) held a public comment
period on the Proposed Plan and the Remedial
Investigation/Feasibility study (RI/FS) for the Modern Landfill
site in York County, Pennsylvania. A public meeting on the
Proposed Plan was held on May 7, 1991, a transcript of which is
part of the Administrative Record for this site. This
responsiveness summary summarizes comments on the Proposed Plan
and RI/FS pertinent to the Record of Decision that were expressed
by interested parties and provides EPA's responses to the
comments.
This responsiveness summary is divided into the following
sections:
• Overview
• Background on Community Involvement
• Summary of Comments Received during Public Comment
Period and Agency Responses
• Remaining Concerns
A. OVERVIEW
At the time of the public comment period, EPA had already
endorsed a preferred alternative for the Modern Landfill site.
EPA's recommended alternative addressed contaminated groundwater
at the site. The preferred alternative specified in the Record
of Decision (ROD) consists of the following:
• Continued operation and maintenance of all previous
remedial actions conducted onsite, including the landfill
cap, groundwater extraction system, onsite wastewater
treatment facility, gas extraction system (for removal and
destruction of landfill generated methane gas) and *
groundwater and surface water monitoring.
• Completion of the landfill cap system and final cover for
the unlined 66-acre landfill.
• Maintenance of site fencing and all access restrictions.
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• The addition of extraction wells to the eastern and
western extraction systems to prevent contaminated
groundwater from bypassing those systems.
• The completion of additional monitoring and/or extraction
wells as needed to ensure protectiveness and to control
groundwater flow, respectively.
If implementation of the selected remedy demonstrates, in
corroboration with hydrogeological and chemical evidence, that it
will be technically impracticable to achieve and maintain the
remediation goals throughout the area of attainment, the EPA, in
consultation with the Commonwealth of Pennsylvania, intends to
amend the ROD or issue an Explanation of Significant differences
to inform the public of alternative groundwater goals.
B. BACKGROUND OH COMMUNITY INVOLVEMENT
There has been moderate community interest in the Modern
Landfill site due to its proximity to and its impact on the
groundwater of nearby residences. With respect to the remedy
proposed by EPA for this site, there has been little community
interest. A fact sheet on EPA's proposed action at the site was
sent to representatives of Windsor and Lower Windsor Townships
and to several hundred residents in the area who EPA believed may
have been interested in EPA's proposed action.
C. SUMMARY 07 COMMENTS RECEIVED DURINO TBB PUBLIC COMMENT PERIOD
AND AGENCY RESPONSES
Comments raised during the public comment period for the
Modern Landfill Sit* are summarized below. EPA responses to the
comments are provided.
Comments received fro* Modern Sanitation of York, Ine.
Modern Sanitation of York Inc., the current operator of the site,
provided several comments to EPA. These are addressed below.
1. Modern Landfill commented that the Pennsylvania ARAR for
remediation of groundwater to background levels is neither
applicable nor relevant and appropriate.
EPA Reaponaai EPA disagrees. EPA has accepted the
Pennsylvania requirement for remediation of groundwater to
background levels as an ARAR.
2. Modern Landfill commented that if a state or federal ARAR is
not met, it may be waived. In particular, ARAR waivers are
appropriate when compliance with the requirement is
technically impracticable froa an engineering perspective.
Modern has therefore requested that the Pennsylvania ARAR
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requiring treatment of groundvater to background levels be
waived.
EPA Response: EPA disagrees that the Pennsylvania ARAR
requiring treatment of groundvater to background levels
should be waived. Modern Landfill has submitted two
reports, one entitled "Review of Remediation Goals at Modern
Landfill," Golder Associates Inc., June 1991, and the second
a letter report by IGF Kaiser Engineers, dated June 14,
1991, to support this waiver request. Based on site geology
and using data from the existing extraction systems, Modern
has demonstrated that remediation of groundwater to
background quality, using Method Detection Limits as the
background standard, would take in excess of 100 years and,
for some of the contaminants of concern, up to 200 years.
EPA Guidance on Remedial Actions for contaminated
Groundwater (OSWER Directive 9283.1-2) contains provisions
for ARAR waivers based on the technical impracticability of
an ARAR. Specifically, for groundwater remedies, those
remedies which generally would exceed 100 years for
implementation may be waived using the technical
impracticability standard.
EPA does not fully agree with the contents of the reports
submitted by Modern Landfill. In particular, EPA takes
exception to the development of the linear regression
constants using total priority pollutant concentrations and
applying those constants to individual components. This
method does not reflect a true representation of the value
of those constants. EPA also cannot support, based on the
information contained in the reports, the assumptions made
about contaminant dilution due to groundwater flow. Without
verification of these assumptions, the conclusions of the
reports are not acceptable. EPA believes that with the
collection of additional data from the continued operation
of the extraction systems, a re-evaluation of this situation
can be made. If implementation of the selected remedy
demonstrates, in corroboration with hydrogeological and
chemical evidence, that it will be technically impractiable
to achieve and maintain the remediation goals throughout the
area of attainment, the EPA, in consultation with the
Commonwealth of Pennsylvania, intends to amend the ROD or
issue an Explanation of Significant Differences (ESD) to
inform the public of alternative groundwater goals, v
3. Modern commented that a waiver of the background water
quality ARAR is appropriate based on inconsistent
application of a State requirement.
EPA-Response; EPA disagrees. While it is correct that an
ARAR may be waived when it has been inconsistently applied,
the background ARAR has historicaly be applied in a
consistent manner.
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4. Modern commented on some inaccuracies in the Proposed Plan.
a. Modern commented that the Proposed Plan states that 362
acres of Modern Landfill is permitted and currently active;
however, 362 acres are permitted, 17 acres are lined,
another 17 acres are under construction and 66 acres, which
are included in the CERCLA site, are unlined.
EPA Response; EPA agrees to this clarification.
b. Modern commented that the record should reflect that the
landfill principally accepted non-hazardous
municipal/residual waste.
EPA Response; EPA does not believe that sufficient data on
past disposal practices exists to state this definitively.
EPA believes that the majority of the wastes appear to have
been municipal wastes but the extent of their composition is
not currently known to EPA.
c. Modern commented that the record should state that drums
of PCBs were not disposed at the site but rather, the drums
were removed from the Site for disposal elsewhere.
EPA Response; EPA agrees. The Record of Decision reflects
this fact.
d. Modern commented that the proposed plan states as one of
the goals of the remedial action the restoration of
contaminated groundwater to beneficial uses. Modern further
states that this was not a goal set forth in the Feasibility
Study and is not appropriate for the Site.
EPA Response; EPA disagrees. EPA's policy is to restore
groundwater to beneficial uses wherever practicable. This
goal, though not stated in the PS, is appropriate for the
Modern Landfill Site.
e.~ Modern commented that the proposed plan discusses
closure of the unlined landfill and installation of a cap in
accordance with PAOER regulation. Modern states that this
should be clarified to state that closure and installation
are in accordance with applicable PADER municipal solid
waste regulations to avoid possible misinterpretations.
EPA RMPonaa; EPA agrees with this clarification.
f . Modern commented that the approximately $15 million in
pre-1990 capital and operation and maintenance costs spent
by Modern Landfill for remedial actions to date should be
included in the cost of the alternative remedies discussed
in the plan.
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EPA Response! EPA disagrees. The pre-1990 costs are not
part of the proposed remedial action. Furthermore, since
these costs are common to all alternatives, the evaluation
of alternatives is not considered to be inaccurate.
g. Modern commented that the proposed plan inaccurately
describes the extent of the area to be covered upon
completion of the low permeability cap and placement of the
final cover over the site. The plan states that these
actions will cover the entire CERCLA site which, for the
purpose of this record of decision, has been defined as the
unlined 66-acre landfill and all Modern property up to and
including the monitoring wells. The actual remedy provides
for a cap and final cover over the unlined landfill only.
EPA Response! EPA agrees with this description of the
proposed remedy.
h. Modern states that in the section on Evaluation of
Alternatives, the proposed plan should state that the
potential risk from ingestion of groundwater is
hypothetical.
EPA Response! EPA disagrees. The risk from ingestion of
groundwater on the CERCLA Site is a potential one being
addressed by this Record of Decision. The fact that a risk
is potential does not make it hypothetical.
5. Comments were received from Mr. James Smith, a resident near
Modern Landfill.
a. Mr. Smith states that in 1988 Modern was drilling wells
which were affecting the water level in Mr. Smith's well.
EPA Response; As a result of the Remedial Investigation
for this site, it has been shown that groundwater flow is
not in the direction of the Smith property. Mr. Smith
presented no evidence to determine that a causal
relationship exists between the well pumping at Modern
Landfill and the levels in his wells. These facts
notwithstanding, the proposed remedy will continue to
monitor groundwater and surface water at the site to ensure
the effectiveness of the remedy and the protection of ^human
health and the environment.
b. Mr. Smith presented data to show that contaminants from
beneath the CERCLA Site are not being contained.
EPA Response; There is no indication of the source of the
data submitted nor the sampling and analysis methods used in
the data gathering process. No inference can be made from
this data, based on the Remedial Investigation, that
contaminants from Modern Landfill are affecting offsite
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walls. Th« proposed remedy will, however, provide for
continual monitoring and evaluation of the effectiveness of
the extraction systems and allows for their augmentation if
deemed necessary by EPA or PAOER.
c. Mr. Smith commented that a major fault exist directly
beneath the unlined landfill.
EPA Response; Mr. Smith's conclusion that the fault line
lies directly beneath the landfill is based on preliminary
reports done before the commencement of the Remedial
Investigation at the Site. The information in those reports
was updated and refined through subsequent investigations to
show that the fault line in question is south of the Modern
Landfill and not beneath it.
d. Mr. Smith commented that the public notice advertising
the public meeting for the site was done improperly as the
notice was placed with commercial advertising and not the
legal notices and, as a result, fewer people than expected
attended the public meeting.
EPA Response: EPA disagrees. EPA followed its normal
procedures for advertising public meetings. In addition,
EPA mailed several hundred fact sheets after the public
meeting to potentially interested parties and offered to
meet with representatives from each township and interested
citizens to discuss their concerns. EPA believes that the
public was adequately notified and had ample time to provide
comments on the proposed plan.
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