Superfund Record of Decision Dupage County Landfill/Blackwell Forest Preserve, Warrenville, IL


                                   EPA/ROD/R05-98/092
                                   1998
EPA Superfund
     Record of Decision:
     DUPAGE COUNTY LANDFILL/BLACKWELL FOREST
     PRESERVE
     EPA ID: ILD980606305
     OU01
     WARRENVILLE, IL
     09/30/1998

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EPA 541-R98-092

                                                     SEP 30 1998




                                    Prepared by:

                        U.S. ENVIRONMENTAL PROTECTION AGENCY

                                      Region V

                                 Chicago,  Illinois

                                   September 1998

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                                    Declaration
                           Selected Remedial Alternative
                                      for the
                  DuPage County Landfill/Blackwell Forest Preserve
                              DuPage County, Illinois

Site Name and Location

DuPage County Landfill/Blackwell Forest Preserve
DuPage County, Illinois

Statement of Basis and Purpose

This decision document presents the rationale for selecting the final site-wide remedy for the DuPage County
Landfill/Blackwell Forest Preserve Site ("DuPage County Landfill" or "the Site") located in DuPage County,
Illinois. This Record of Decision was completed in accordance with the reguirements of the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980  ("CERCLA"), as amended by the Superfund
Amendments and Reauthorization Act of 1986  ("SARA")  and, to the extent practicable, the National Oil and
Hazardous Substances Pollution Contingency Plan ("NCP"). This decision document explains the factual and
legal basis for selecting the final remedy for the Site. The information supporting this remedial action
decision is contained in the Administrative Record for the Site. The State of Illinois has expressed a
willingness to concur with the selected remedy. This letter of concurrence will be added to the
Administrative Record for this Site.

Assessment of the Site

Actual or threatened releases of hazardous substances from this Site, if not addressed by implementing the
response action selected in this Record of Decision ("ROD"), may present an imminent and substantial
endangerment to public health, welfare, or the environment.

Description of the Selected Remedy

The remedial action contained in this ROD will be a final Site-wide remedy. The selected remedial action
addresses the major threat posed by this Site by off-site treatment and disposal of leachate and addresses
the low level sources of contamination by containment of the landfill and contaminated soils, management of
landfill gas and Monitored Natural Attenuation for ground water. The final remedy builds upon previously
implemented response actions which include: cap improvements, installation and operation of a leachate
collection system, off-site leachate treatment, and installation of a landfill gas management system. The
final remedy selected for the Site incorporates both long-term operation and maintenance of these components
and other response actions. Specifically,  the United States Environmental Protection Agency  ("U.S. EPA") has
determined that the following measures should be implemented as the long-term remedy in order to fully
address all threats to human health and the environment posed by contamination at the Site:

       •      Institutional controls in the form of  future land-use and ground water use restrictions;

       •      Long-term cap inspection and maintenance including storm water and erosion control,

       •      Long-term operation and maintenance  of the landfill leachate collection system with
              possible augmentation;

       •      Continued off-site treatment and disposal of landfill leachate;

       •      Long-term operation and maintenance  of the passive landfill gas  venting system with
              possible augmentation to active gas  collection and on-site thermal treatment;

Monitored Natural Attenuation for ground water, and

       •      Long-term ground water,  landfill gas,  and leachate monitoring.

The selected remedial action, incorporating previous response actions, will address all threats posed by the
Site.

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Declaration of Statutory Determinations

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. The remedy utilizes permanent solutions and alternative treatment (or resource recovery)
technologies to the maximum extent practicable, and satisfies the statutory preference for remedies that
employ treatment that reduces toxicity, mobility, or volume as a principal element.

Because this remedy will result in hazardous substances remaining on-site above health-based levels, a review
will be conducted every five years after commencement of remedial action to ensure that the remedy continues
to provide adequate protection of human health and the environment.

U.S. EPA has determined that its future response at this Site does not require any further physical
construction. Therefore, the Site now qualifies for inclusion on the Construction Completion List.

Data Certification

The following information was used in determining the selected remedy and is included in the ROD:

       •       A description of the Contaminants of Potential Concern and their  respective
              concentrations;

       •       Baseline risk represented by the Contaminants of Potential Concern;

       •       Cleanup levels established for Contaminants of Potential Concern  and the basis
              for the levels,

       •       Current and future land use assumptions  from the Baseline Risk Assessment;

       •       Land use that will be available at the Site as a result of the selected remedy;

       •       Estimated capital,  operation and maintenance (O&M),  and total present worth
              costs; discount rate; and the number of years over which the remedy cost estimate
              is projected; and

       •       Decisive factors(s)  that led to selecting the remedy.

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                                 TABLE OF CONTENTS

                     SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
                  DUPAGE COUNTY LANDFILL/BLACKWELL FOREST PRESERVE

I.      SITE NAME, LOCATION AND DESCRIPTION  	1

II.     SITE HISTORY AND ENFORCEMENT ACTIVITIES  	4

III.    HIGHLIGHTS OF COMMUNITY PARTICIPATION  	8

IV.     SCOPE AND ROLE OF RESPONSE ACTION WITHIN SITE STRATEGY 	8

V.      SUMMARY OF SITE CHARACTERISTICS 	9

VI.     SUMMARY OF SITE RISKS 	21

VII.    DESCRIPTION OF ALTERNATIVES  	32

VIII.   SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES  	39

IX.     THE SELECTED REMEDY 	59

X.      STATUTORY DETERMINATIONS 	62

XI.     RESPONSIVENESS SUMMARY 	68

XII.    ADMINISTRATIVE RECORD	69

                                 DESCRIPTION OF TABLES

                  DUPAGE COUNTY LANDFILL/BLACKWELL FOREST PRESERVE
                              DuPage County, Illinois

Table 1  -    Select VOCs and Semi-VOCs in  Leachate	13
Table 2  -    Select Metals in Leachate 	14
Table 3  -    Select Landfill Gas Results 	14
Table 4  -    Select Inorganics in Soils 	15
Table 5 -     Select VOCs in On-Site Ground Water 	16
Table 6  -    Select Metals in On-Site Ground Water  	18
Table 7  -    Contaminants of Potential Concern by Medium	22
Table 8  -    Health Risk Estimates 	29
Table 9  -    Summary of Potential Chemical-Specific ARARs	41
Table 10 -    Summary of Potential Location-Specific ARARs	43
Table 11 -    Summary of Potential Action-Specific ARARs	45

                               DESCRIPTION  OF FIGURES

               DUPAGE COUNTY LANDFILL/BLACKWELL FOREST PRESERVE SITE
                              DuPage County, Illinois

FIGURE 1  -  SITE LOCATION MAP	  2
FIGURE 2  -  SITE FEATURES MAP	  3
FIGURE 3  -  PLUME MAP	  17

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DECISION SUMMARY FOR THE FINAL REMEDIAL ACTION

DUPAGE COUNTY LANDFILL/BLACKWELL FOREST PRESERVE SITE
DuPage County, Illinois
CERCLIS ID # - ILD980606305

I. SITE NAME, LOCATION AND DESCRIPTION

The DuPage County Landfill/Blackwell Forest Preserve Site ("the Site") is located approximately 6 miles
southwest of downtown Wheaton, near Warrenville, in DuPage County, Illinois (see Figure 1). The Site is
located in Section 226, Township 39 North, Range 9 East, DuPage County. Illinois. The Site is part of the Roy
C. Blackwell Forest Preserve and is owned by the Forest Preserve District of DuPage County.

The Site is an approximately 40-acre landfill centrally located within the approximately 1200-acre Blackwell
Forest Preserve. The Forest Preserve is owned and managed by the DuPage County Forest Preserve District
("FPD") and is open space containing woodlands, grasslands wetlands and lakes used by the public for
recreational uses such as hiking, camping, boating, fishing and horseback riding. The boundaries that define
the Site (within the greater Forest Preserve) are: on the north and east, the landfill is west of the "C"
shaped Silver Lake from Spring Brook on the north to Butterfield Road on the south. The southern boundary
extends along Butterfield Road to the intersection of Butterfield Road and the West Branch of the
DuPage River, and then north to the intersection of the West Branch of the DuPage River and Spring Brook. The
western boundary of the Site is formed by Spring Brook.

The surface topography generally slopes from northwest to southeast across the county. The maximum elevation
of the Site is the 150-foot tall landfill itself (also known as Mt. Hoy). The top of the landfill is
approximately 840 feet mean sea level (M.S.L.). The landfill slopes sharply south toward Sand Pond which has
an elevation of 690 M.S.L. and more gently northeast toward Silver Lake at 708 M.S.L. Figure 2 is a Site
Features Map.

The landfill is located within the Spring Brook watershed of the West Branch of the DuPage River drainage
basin. From Spring Brook, surface water drains to the West Branch of the DuPage River and, ultimaltely, to
the Des Plaines River.

The hydrogeologic setting varies in an east to west direction (upgradient to downgradient). East or
upgradient of the landfill the following units are present, in ascending order: the bedrock aguifer, the
Malden/Tiskilwa Till aguitard, and the Yorkville Till aguitard. West or downgradient of the landfill, the
bedrock aguifer and the Malden/Tiskilwa Till aguitard are present along with the shallower outwash aguifer.
The location of the landfill is such that it lies across the contact between the outwash aguifer and the
Yorkville Till aguitard. Therefore, the outwash aguifer is not present upgradient or east of the landfill.
The dolomite bedrock aguifer and the outwash aguifer are the only aguifers present and are interconnected
downgradient of the Site. Ground water flows in the bedrock (or deep aguifer) are consistently in a
southwesterly direction. Surface water exerts considerable control on the shallow outwash aguifer ground
water flow. The flow path for the outwash aguifer is initially southwesterly from the landfill. As ground
water approaches Spring Brook the flows bend more southerly. At the south end of
the landfill, near Spring Brook, ground water flow is actually southeasterly toward Sand Pond and Pine Lake.

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hundred feet east of Spring Brook). The VOCs found in private wells are inconsistent with the shallow ground
water contaminant mixture. One possible explanation for the trace VOCs in the deeper aguifer may be the prior
use of cleaners that were washed down drains and leached out of septic systems.

II. SITE HISTORY AND ENFORCEMENT ACTIVITIES

A. Site History

The 40-acre tract of land that is now the landfill was originally purchased by the FPD in 1960. The
surrounding 1,100 acres were purchased during the next five years, with the intent of developing recreational
uses after construction of the landfill. Initially, the FPD planned to use a nearby inactive gravel pit for
solid waste disposal. However, in 1963 gravel excavations were ongoing at the pit and continued through July
1969. Concurrent with the gravel mining operation, the nearby lakes were enlarged and deepened. The gravel
from the pit was sold to offset the cost of lake construction, recreational projects, and flood control
projects. With the mining operation generating revenues, and the large amount of clay removed during the lake
improvements that could be used for construction of a landfill elsewhere, the FPD abandoned the idea of
placing waste in the gravel pit and began development of the landfill in its present location.

The landfill was originally designed with a three-to-one clay to refuse ratio, with the fill area to be
constructed as a honeycomb of one-acre cells. Each cell would have a 1.5 foot thick clay base and a perimeter
clay berm eight to nine feet in height. Each cell would be filled with two, three-foot lifts of refuse,
separated by 6 inches of clay, and the cell would then be covered by 1.5 feet of clay. The cells were to be
offset to maximize stability of the landfill. The landfill was then to be capped with 12 feet of compacted
clay, covered by soil and vegetation.

Although daily records were not kept to detail how the construction proceeded, generally cells were developed
across several acres by building side berms, and then filling the cells with refuse and daily cover. At the
completion of each cell, the clay cover was installed and side berms were constructed for the next layer of
refuse. As the landfill construction proceeded upward, the clay covers served as the liners for overlying
cells. Approximately 1.5 million cubic yards of waste were deposited in the landfill between 1965 and 1973,
creating Mt. Hoy which is approximately 150 feet above the original ground surface.

The following is a chronology of activities at the Site:

1965 Construction of the landfill.

1969 The first leachate well was installed to monitor the amount and types of liguids contained in the
landfill.

1970's Ten (10) monitoring/piezometer wells were installed surrounding the landfill and
measurement of ground water levels and samples for pH and chloride were taken.

1973 The last load of public refuse was accepted at the landfill.

1976 The picnic and camping areas, hiking trails, swim lake and Mt. Hoy opened at the preserve.

1980-82 In 1980, leachate was observed seeping from the north slope of the landfill. For this reason, 23
wells were installed to monitor ground water and two geologic studies were completed.

1982 Due to concerns about the accumulation of landfill gases, ten (10) shallow gas
vents and six (6) deep gas vents were installed in the landfill.

1983 Ground water/surface water sampling program was implemented (continued until 1989).

Leachate is a liguid (usually rainwater) that has percolated through contaminated soil and
landfill waste and accumulates and transports contaminants.

1984-96 Twenty (20) additional monitoring wells were installed and added to the routine
sampling program, two (2) shallow and eight (8) deep gas vents were installed
and fourteen (14) borings were completed in the landfill.

1986 The Site was evaluated by the U.S. EPA for inclusion on the National Priorities
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List (NPL). The NPL is a list of sites throughout the country that are eligible for
study and cleanup, if necessary, under the Superfund program.

1989 The FPD agreed to conduct a Remedial Investigation (RI) and a Feasibility Study
(FS) at the Site. The purpose of the RI was to determine the extent of
contamination associated with the Site and evaluate risks to human health and the
environment. The FS evaluates alternatives for cleaning up the Site.

1990 The Site was formally listed on the NPL.

1994 The Remedial Investigation to determine the nature and extent of contamination
is approved by U.S. EPA.

1995 The Feasibility Study analyzing cleanup alternatives is submitted to U.S. EPA by the FPD.

1996 The FPD entered into an Administrative Order on Consent (AOC) to complete
several components of the reguired design and cleanup of the Site under removal authority.

1996 The FPD installs nine leachate extraction/landfill gas collection wells.

1997 A cap integrity investigation is completed and cap repairs are initiated.

The leachate system extraction/containment is completed and off-Site treatment begins.

The landfill gas collection system construction is completed and implemented.

Five additional compliance/detection monitoring wells were installed.

1998 The final cap improvements are completed.

B. Response Actions

The Forest Preserve District, as both owner and operator of the Site, assumed full responsibility for
investigation and cleanup. As indicated in the above chronology. EPA and FPD) entered into an Administrative
Order on Consent (AOC) in 1996. The purpose of the AOC was to expedite several response actions at the Site.
The AOC Statement of Work identified a number of activities the FPD would conduct immediately, including:

• Soil borings to determine if any areas of the landfill did not have a minimum of
two feet of low permeability cover material;

• Make any necessary repairs to the cap to ensure two feet of low permeability
material is present above the waste;

• Enhance the surface drainage from the landfill to guard against the pooling of
surface water and to prevent erosion;

• Install nine leachate extraction wells to remove liguids from within the landfill
to protect underlying ground water;

• Install a subsurface pipe-work system to transport extracted leachate to a central
collection tank for storage; this leachate is then transported to a permitted off-Site,
facility for treatment and disposal,

• Install a passive landfill gas collection system to augment the 25 existing gas vents,

• Provide evidence that trees on the landfill were not in areas where root
penetration could allow percolation of precipitation through refuse within the landfill,

• Evaluate the existing monitoring wells and implement monitoring to ensure that
contaminant levels were not increasing or moving in a way that they could
jeopardize either human health or the environment.

• Provide as-built plans of storm water drainage from the top of the landfill and
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make any necessary modifications to ensure that contaminants from within the
landfill were not inadvertently being drained from the landfill to nearby areas of
the forest preserve; and

• Maintain all components to ensure the continued operation of the systems in the
short-term to prevent contamination of ground water from exceeding Maximum
Contaminant Levels.

To date, all of these activities have been completed.

III. HIGHLIGHTS OF COMMUNITY PARTICIPATION

The U.S. EPA released a Proposed Plan for the final remedy for the Site for public review and comment on July
8, 1998. The Proposed Plan and supporting documents were placed in the information repositories at the U.S.
EPA Region V Office, the Warrenville Public Library and the Nichols Library. A Proposed Plan Fact Sheet was
mailed to everyone on U.S. EPA's mailing list and press releases were sent to local media. Notice of the
availability of the Proposed Plan was also included in advertisements in the Warrenville Daily Herald and
Warrenville Free Press. U.S. EPA held a public meeting on July 22, 1998, at the Warrenville Community
Building. At this meeting, representatives of U.S. EPA provided background information on the Site, explained
the Proposed Remedy, answered guestions and accepted formal comments from the public on the Proposed Plan.
U.S. EPA also accepted written comments during the comment period, which ran from July 10, 1998 to August 10,
1998. A response to all comments received during the public comment period is contained in the Responsiveness
Summary, which is attached to this ROD.

IV. SCOPE AND ROLE OF RESPONSE ACTION WITHIN SITE STRATEGY

The overall strategy for cleaning up this Site includes a combination of early removal actions conducted
under the 1996 AOC, along with contingent and long-term actions described in this final ROD. Removal
authority is typically used when emergency situations arise or, as in the case of this Site, when discreet
response actions can occur that are: 1) not technically complex. 2) do not reguire a lengthy planning period,
3) can result in an immediate risk reduction, and 4) the response action is fully consistent with the
long-term remedial approach. The reguired response actions for this Site were not technically complex, a
willing Responsible Party was present, and the reguired response actions could be efficiently and effectively
addressed from both a cost and scheduling perspective. For these reasons, U.S. EPA, Illinois EPA and the FPD
agreed to conduct early response actions as an integral part of the overall Site strategy for final remedy.

The most significant threat for this Site is leachate, which will continue to be collected, treated and sent
off-Site for disposal. The rationale for treatment of leachate is that it has high concentrations of
contaminants and presents a large threat for migration to ground water. The leachate has been initially
addressed through early actions, however, the long-term component has not yet been addressed. This ROD will
address the threat posed by leachate by adding long-term operation and maintenance reguirements.

The lower level threats posed by this Site are landfill wastes, landfill gas, and contaminated ground water.
These are considered low level threats due to the lower potential for direct exposure, lower toxicity and/or
lower mobility. This ROD will address the low level threats of landfill waste and landfill gas through
containment. Like the leachate, the landfill waste and landfill gas threats were initially addressed in early
actions through cap improvements and the installation and interim operation of a passive landfill gas venting
system. These low level threats will be addressed in the ROD through long-term operation and maintenance of
the cap and the operation and maintenance of the passive landfill gas system. This ROD will address the low
level threat posed by ground water by reguiring additional response actions. Finally, this ROD will reguire
contingencies for augmentation of the leachate and landfill gas systems, in the event the early action
components, as currently designed, are incapable of meeting the long-term remedial goals of this ROD). This
ROD will also include long-term monitoring and periodic remedy review reguirements. The overall intent of
this ROD is to incorporate all of the previous early response actions and, through the addition of the
reguirements of this ROD, address all remaining actual, potential, present and future risks associated with
this Site.

V. SUMMARY OF SITE CHARACTERISTICS

As stated previously, the Site is an approximately 40-acre landfill. Due to the physical nature of the
landfill, disposal has resulted in the contamination of ground water, soil, air, sediments and surface water.
The following is a more detailed description of Site features, followed by a summary of the nature and extent
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of contamination from the sampling results of the RI and finally a discussion of the estimated risks posed by
the contaminated media.

A. Geology and Hydrogeology

Geology

The geology of DuPage County consists of recent alluvial and Pleistocene glacial deposits overlying Silurian
dolomite bedrock. The surficial deposits are predominantly the result of Wisconsin-age glaciation, with minor
modifications by recent alluvial processes. Till Members of the Wedron Formation, and sand and gravels of the
Henry Formation, are present in the area of the Site. The following unconsolidated stratigraphic units have
been identified at the Site in ascending order: The Tiskilwa, Till Member, the Maldern Till Member, the
Yorkville Till Member, and the Batavia Member of the Henry Formation.

The unconsolidated stratigraphic seguence is variable across the Site in an east to west direction. This is
due to the Site's location on the western edge of the West Chicago Moraine. The uppermost till unit present
at the Site, the Yorkville Till Member, forms this moraine. Meltwater from the glacier that deposited the
till appears to have formed a river which flowed north to south along the front of the moraine. Previously
deposited glacial sediments were subseguently eroded and re-deposited as the Batavia Member outwash sands and
gravels.

Hydrogeology

The hydrostratigraphic setting at the Site varies in an upgradient to downgradient (east to west) direction.
Upgradient of the landfill, the following hydrostratigraphic units are present in ascending order: the
bedrock aguifer, the Malden/Tiskilwa Till aguitard, and the Yorkville Till aguitard. Downgradient ofthe
landfill, the following units are found, in ascending order: the bedrock aguifer, the Malder/Tiskilwa Till
aguitard, and the outwash aguifer. The landfill lies across the contact between the outwash aguifer and the
Yorkville Till aguitard. Therefore, the outwash aguifer is not present upgradient of the landfill.

Two aguifers are present at the Site: the outwash aguifer, that has its eastern-most limit beneath the
landfill, and the dolomite bedrock aguifer, which is present beneath the entire Site. These two aguifers are
hydraulically connected downgradient of the landfill via the Malden/Tiskilwa Till aguitard.

The glacial outwash aguifer is a valley train deposit, consisting of coarse-grained sand and gravel,
deposited by meltwater along the front of the West Chicago Moraine. In boring logs prepared for the Site, the
aguifer is described as a brown to gray fine to coarse sand, gravelly sand, or sand with gravel. The range of
hydraulic conductivity values determined during the RI for this aguifer was 1.4 x 10 -2 cm/sec to 6.4 x 10 -2
cm/sec.

The surface water bodies present downgradient of the landfill exert considerable control on the ground water
flow system within the outwash aguifer. The West Branch of the DuPage River, exhibits a generally consistent
surface water elevation. Sand Pond and Pine Lake are hydraulically connected to the River via the outwash
aguifer. The net effect of this hydraulic connection is a flattening of the horizontal gradient in the
vicinity of the lakes, as the river's influence is propagated eastward. Spring Brook, located downgradient of
the landfill, consistently loses water to the aguifer. This causes development of a zone of stagnation in
groundwater between the Spring Brook and Sand Pond. The flattening of the horizontal gradient within the
outwash aguifer downgradient of the landfill serves to strengthen the vertical gradient between the outwash
aguifer and bedrock aguifer. The flow path for the outwash aguifer is initially southwesterly from the
landfill. As ground water approaches Spring Brook the flows bend more southerly. At the south end of the
landfill near Spring Brook ground water flow is actually, southeasterly toward Sand Pond and Pine Lake.

Characteristics of the dolomite aguifer were observed in rock cores obtained during the RI. The dolomite was
light brown to light gray in color and hard. Fracture orientations noted in the cores were predominantly
horizontal. Hydraulic conductivity values determined for the dolomite aguifer during the RI ranged from 7.1 x
10 -6 cm/sec to 3.0 x 10 -2 cm/sec.

Horizontal gradients within the bedrock aguifer are consistently in a southwesterly direction, toward the
West Branch of the DuPage River.

B. Nature and Extent of Contamination

Source Areas
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During the RI, samples were taken from the potential source areas and the potential migration pathways at the
Site. The source areas included the landfill, leachate, landfill gas, and the media included ground water,
surface water, soil, leachate, gas/air and sediment. Additionally, ground water from 51 private supply wells
located off-site were sampled to assess potential impacts from Site related wastes.

The major source of this Site is the 40-acre landfill itself. The contents are the source of contaminated
soil, migrating leachate, and landfill gas. Approximately 1.5 million cubic yards of refuse were disposed of
at the Site between 1965 and 1973. The waste materials have been classified as general household refuse and
light industrial waste. Historical records indicated that the users of the landfill were generally municipal
waste haulers and scavenger companies from the area. An estimated three, to four tong of waste was disposed
of at the landfill per day. Therefuse volume calculated including the interstratified daily cover is 1.9
million cubic yards.

Leachate volumes were estimated at 53 to 74 million gallons prior to the installation of the leachate
extraction system. This estimate was based on leachate elevations measured at the vents at the time of the
RI, with an assumed refuse porosity of 25 to 35 percent which may overestimate the leachate volume. Modeled
leakage from the landfill was estimated between 3.5 million to 5.2 million gallons per year prior to cap
improvement and implementation of leachate, and landfill gas extraction systems.

The total amount of landfill gas contained in the landfill is difficult to measure. However, measurements of
gas flow at the landfill vents indicated a range in flow volume from a low of "no flow" to 15ft 3/min.

Ground water contamination as a source is described as a plume in the shallow aguifer. Ground water
contamination at the Site at the time of the RI was mostly limited to the shallow outwash aguifer. The
shallow aguifeir plume began directly beneath the west half of the landfill (where the outwash aguifer
begins) and continued west and southwest of the landfill until the shallow aguifer met surface water. The
shallow aguifer is not present upgradient of the landfill. There were lower concentrations of contaminants
found in the deeper ground water below and slightly southwest of the landfill footprint at the time of the
RI.

Types of Analyses Conducted in the RI

From within the sources and potentially impacted media, a number of different types of analyses were
conducted during the RI. The following is a summary of the type of analyses conducted.

Volatile Organic Compounds

• Chlorinated alkenes - Compounds within this group are common industrial solvents
which represent a potential degradation seguence.

• Chlorinated alkenes - These compounds are also common industrial solvents which
represent a potential degradation seguence.

• Aromatics - This group includes water soluble products from gasoline and other
hydrocarbon products. Aromatic compounds are used as solvents and reagents for a
variety of manufacturing processes.

• Ketones - Compounds within this group are common solvents, used in paints, cement
adhesives, resins, and cleaning fluids.

Semivolatile Organic Compounds

• Phenols - These compounds are used in adhesives, epoxies, plastics and a variety of
synthetic fibers and dyes.

• Polynuclear Aromatic Hydrocarbons (PAHs) - This group of compounds is associated
with and derived from coal and oil, and the incomplete combustion of carbonaceous
materials. Asphalt or blacktop are other common sources for PAHs.

• Phthalates - These compounds are associated with plastics and plastic making processes.
and are common laboratory contaminants associated with sample containers.
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• PCBs - Compounds within this group are mixtures of polychlorinated biphenyl-S
identified and sold under the trade name Aroclors. Aroclors were formerly used
extensively in industrial applications as non-flammable oils for high temperature
applications. 0

Metals - Metals are discussed based on toxicity. Metals analyzed included:

• Non-regulated nutrients or low-toxicity metals

RCRA-toxic metals

• Metals regulated by U.S. EPA Maximum Contaminant Levels (MCLs) or Illinois Ground
Water Quality Standards.

The revised RI was completed in 1994, the following subsections summarize the results of this sampling by
media.

A. Landfill Leachate

Organics - The organic chemicals detected in the 4 leachate samples included chlorinated alkanes and alkenes,
aromatics and ketones. Ketones were found at the highest concentration (17,000 ug/L of 2-butanone).
Significant concentrations of acetone (10,000 ug/L). and toluene (3,200 ug/L) were also found. Also,
trichloroethene was found as high as 720 ug/1, which exceeds the RCRA Toxicity Characteristic Leaching
Procedure limit. No Ketones were detected in any other media than the leachate.

Semivolatiles detected in leachate include phenols, phthalates and PAHs, the highest being 4-methylphenol
found at 17,000 ug/L.

Select VOCs/SemiVOC's in leachate from the RI are presented in Table 1.

Table 1. Select VOCs and SemiVOCs in Leachate

Well Volatile Organic Concentration EPA
Location Compounds in (ug/L) TCLP

SV5 vinyl chloride 22 200
SV8 acetone 10,000
SV5 chlorobenzene 28 100,000
DV5 ethylbenzene 130
DV8 1,1-dichloroethane 180
SV9 1,2 dichloroethene 480
SV9 trichloroethene 720 500
SV9 tetrachloroethene 220 700
SV8 benzene 160 500
SV8 4-methyl-2-pentanone 1,100
SV9 toluene 3,200
SV9 xylenes 470
SV8 2-butanone 17,000
SV8 4-methylphenol 17,000

Exceeds RCRA TCLP Waste Designation

Inorganics - Metals were detected in all of the leachate samples, at concentrations generally higher than
found in ground water or surface water. Antimony and selenium were the only two metals that were tested for
but were not detected in the leachate. The more significant regulated inorganics such as arsenic, barium,
cadmium, chromium, lead, mercury and silver were all detected in the leachate samples. Maximum concentrations
of 4.7 ug/L for mercury and 482 ug/L for lead were detected in the leachate. The other inorganics were
detected, but were either at much lower levels, and/or were not regulatorily or environmentally significant.
RCRA Toxicity Characteristic Leaching Procedure (TCLP) were not exceeded for any of the inorganics detected
in leachate.

Table 2. Select Inorganics in Leachate
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Location Metal Concentration (ug/L)TCLP(ug/L)
SV9 iron 2,410,000
DV5 arsenic 45.7 5000
SV9 sodium 1,200,000
SV9 manganese 59,800
SV9 lead 482 5000
SV9 cadmium 150 1000
DV5 chromium 144 5000
SV9 mercury 4.7 200
SV9 cyanide 13.0
No pesticides or PCBs were detected in any of the leachate samples.

B. Landfill Gas

Landfill Gas- Similar contaminants were found in the landfill gas to those found in leachate. Compounds found
in the landfill gas included BETX compounds (benzene ethylbenzene, toluene and xylene) and chlorinated
solvents (trichloroethene, tetrachloroethene, trans-1,2-dichloroethene, cis-1,2-dichloroethene, and vinyl
chloride). Other volatile compounds detected in landfill gases included freon compounds, acetone, methylene
chloride. 4-methyl-2-pentanone, and 2-butanone. Toluene was detected at the highest concentration (92,000
ppbv).

There are no direct regulatory comparisons for landfill gas. However, although similar compounds were
detected in the landfill gas and the leachate, the concentrations in the gas were generally higher than those
in leachate. For example, the maximum vinyl chloride concentration was 22 ug/L in the leachate at SV5 and
21,000 ppbv in the gas at SV04 (note: all gas concentrations are expressed as ppb in air on a volumetric
basis). Similar trends were observed in other compounds such as toluene in leachate at 3,200 ug/L and 92,000
ppbv in gas and tetrachloroethene at 220 ug/L in leachate and 17,000 ppbv in gas. Of the organic compounds
detected, eight were found in landfill gas samples and not leachate. Table 3 is a select group of RI landfill
gas results.

Table 3. Select Landfill Gas Results

Location Compound Concentration (ppbv)
SV04 vinyl chloride 21,000
SV08 methylene chloride 17,000
SV09 trichloroethene 28,000
DVIO tetrachloroethene 17,000
DV05 1,4-dichlorobenzene 7,300
SV02 benzene 2,700
SV08 toluene 92,000
SV04 cis- 1,2-dichloroethene 44,000

C. On-Site Soils

Soils -Thirteen soil sample were collected at ten locations during the Remedial Investigation (RI). Two
samples were taken at three locations and one sample each at seven locations. Five of these samples were in
background locations. The on-Site surface soil sampling included potential run-off areas, seep areas and
landfill cover soil.

Organics - No volatile organic compounds were detected in soils except for low levels of 1,1,1-
trichloroethane in two background samples. One sample from a leachate seep area indicated semivolatiles
including benzo(b)fluroanthene and benzo(k)fluroanthene both at 580 ug/kg and one background sample detected
semivolatiles. Also, one sample and its duplicate indicated 56 and 47 ug/kg PCBs at a depth less than 6
inches. No PCBs were detected at the next deeper interval.

Inorganics - In general, the highest metal concentrations were from soils thought to be in the drainage way
west of the Swim Lake parking lot. However, with the exception of silver, all metals analyzed did not exceed
3-times background.

Table 4. Select Inorganics in Soils

Location Metal Concentration (mg/L) Background
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SS06 iron 24,300 21,140
SS03 arsenic 6.5 6.46
SS01 lead 36.7 24
SS01 chromium 70.8 28
SS01 mercury 0.19 0.08

No pesticides were detected in any of the surface soil samples obtained at the Site.

D. On-Site Ground Water

Ground Water Organics - Periodic ground water sampling began for this Site in the 1980's. Nineteen of the 23
downgradient wells sampled contained organic compounds, including chlorinated alkenes such as
tetrachloroethene, trichloroethene, 1,2-dichloroethene and vinyl chloride and alkanes such as
1,1,1-trichloroethane, 1,1-dichloroethane, and chloroethane. In addition, the aromatic Compound benzene was
identified in 4 wells. The highest VOC concentrations were detected in shallow monitoring wells close to the
landfill.

Of the 32 VOCs detected in leachate, only 9 were present in ground water. Select VOCs and SVOCs in ground
water are presented in Table 5.

VOC concentrations in ground water have improved significantly over time, but there is one on-Site shallow
well that still exceeds the regulatory standards. The highest concentrations were detected in monitoring
wells directly downgradient of the landfill in the shallower outwash aguifer. Concentrations of total VOCs
detected in the deeper bedrock aguifer have historically been much lower (10 ppb or less). Column 4 of Table
5 summarizes some of the results of the November 1997/July 1998 guarterly ground water sampling for
comparison to the 1991/92 RI data. Figure 3 shows the estimated VOC plume (based on November 1997 data).

Inorganics in Ground Water - Although metals were detected in the shallow outwash aguifer, with the exception
of iron and manganese, EPA Maximum Contaminant Levels (MCLs) were not exceeded. Iron and manganese
concentrations in the shallow aguifer exceeded expected background levels, exceeded the EPA MCL secondary
standard (the secondary standard is for drinking water aesthetics and not health) and the IEPA Class I
Drinking Water Standards. Table 6 summarizes select on-Site metal samples. As illustrated in column 4 of
Table 6, sampling in 1997 continues to show significant improvement but there are still exceedences of IEPA
Class I Drinking Water Standards for iron and manganese in the shallow aguifer. Manganese and iron were also
detected above background in five and three bedrock aguifer wells respectively. Current bedrock aguifer
sampling indicated no exceedences of iron above the IEPA Class I
Drinking Water Standards, but the U.S. EPA secondary standard was exceeded (secondary standards relate to the
aesthetics of drinking water, i.e., taste and smell) for iron and the IEPA standards were exceeded for
manganese.

E. Private Wells

Organics - In addition to the wells sampled on-Site, 51 private ground water wells located both downgradient
and upgradient of the Site were sampled. No semivolatiles or PCBs were detected. The VOCs 1,1-dichloroethane
and cis-1,2-dichloroethene were detected in 15 private wells, however the concentrations were very low (0.6
to 2 ppb). There is no regulatory standard foe 1,1-DCA and the standard for 1,2-DCE is 70 ppb, indicating
that these concentrations are well below the regulatory standard. It is speculated that the low level VOCs
may be a result of cleaners disposed of in nearby septic systems.

Inorganics - As anticipated, some levels of background inorganics were detected in all private wells.
Arsenic, lead, zinc manganese, iron and calcium concentrations were the significant inorganics. Arsenic was
detected in 14 of the 51 downgradient wells but at levels below the MCL. Arsenic concentrations downgradient
of the Site were not significantly different than upgradient concentrations.

Lead and zinc were detected in several private wells, but at levels higher than Site monitoring wells. This
suggests that these metals may have been a result of the private water systems.

Manganese was detected in 24 of the 51 downgradient private wells and 5 upgradient wells. The SMCL was
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exceeded in eight downgradient wells for manganese. This indicates a potentially high background
concentration of manganese.

Iron concentrations were present in 44 of the 51 downgradient wells and all 5 upgradient wells exceeded the
State Drinking Water Standard. This indicates high background concentrations of iron.

Several trace pesticides were detected in samples that were not detected in any Site media. These pesticides
may have been a result of laboratory contamination.

F. Surface Water

Surface water samples were taken from Silver Lake, Pine Lake, Sand Pond, Spring Brook and at off-Site
background locations.

Organics - No organic compounds were found in any of the surface water samples.

Inorganics - Samples from Silver Lake contained concentrations of arsenic, mercury, copper, calcium,
magnesium, potassium and sodium. However, the concentrations were less than two times other background
samples. Aluminum, lead and manganese were found in Silver Lake, but not in the background samples. Barium
and iron were detected at concentrations greater than two times background concentrations.

Surface water samples from Pine Lake indicated the presence of inorganics, but only manganese was present at
concentrations greater than background.

Analysis of surface water samples from Sand Pond included barium, manganese, calcium, iron, magnesium and
sodium. The concentrations were present at greater than two-times other background samples.

The highest concentrations of inorganic constituents detected in surface water were found in Spring Brook.
However, these concentrations are not believed to be related to the landfill, since Spring Brook receives
wastewater effluent upstream of the landfill, is subject to upgradient surface water run-off, and is a losing
stream to ground water.

G. Sediment

No pesticides or PCBs were detected in any of the sediment samples.

Organics - The only VOCs detected in sediment samples were from Sand Pond. The VOCs detected were vinyl
chloride (5 ug/kg) and 1,1-dichloroethane (3 ug/kg). SVOCs were detected in both background sediment samples
and samples potentially impacted by Site run-off. Site samples generally contained higher concentrations of
SVOCs than were found in background samples.

Inorganics - Sediment samples from the Site lakes generally contained metals at concentrations less than two
times other background samples. While metals were detected in the downstream sample from Spring Brook at
greater than two times the concentrations detected in the upstream sample, these elevated concentrations are
not attributed to the landfill. Spring Brook discharges to the water table downgradient of the landfill and
receives wastewater influent and surface water run-off upstream of the landfill.

C. Current and Potential Future Site and Resource Uses

Present and Future On-Site Land Use - The current on-Site land use is now and, for the past 20 plus years,
has been recreational. Future land use changes are prohibited by the Forest Preserve District Charter across
the entire Forest Preserve and specifically in the area of the landfill by EPA-reguired deed restrictions
from the AOC. The FPD will continue to manage the entire Forest Preserve surrounding the landfill
recreationally and prohibit any other use, in perpetuity. Therefore, potential future land use changes
on-Site are not considered reasonable.

Present and Future Off-Site Land Use - Because the landfill is part of an approximately 1200-acre Forest
Preserve, the only adjacent land use of significance is west of Spring Brook due to its proximity to the
landfill. This area is now, and for the purpose of future use considerations, will be assumed to be
residential. There is no real likelihood of future use changes on-Site that would increase exposure to
adjacent property to Site soils, sediments, leachate, landfill gas, or surface water. Therefore, off-Site
future use will be discussed only to the extent ground water threatens to migrate.
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Present and Future On-Site Ground Water Use - Similar to the present and future land use, the ground water
use is restricted on-Site. The Forest Preserve Charter restricts residential development which indirectly
restricts residential ground water use on-Site. Further, deed restrictions specifically prevent installation
of wells in the area of the landfill. It is reasonable to assume that these restrictions will last in
perpetuity. Although ground water use is restricted, by definition, the State of Illinois considers this
ground water to be Class I Drinking Water and EPA requires restoration of ground water to its beneficial use.
Ground water on-Site directly down gradient from the landfill exceeds both the EPA MCLS and the IEPA Class I
Drinking Water Standards. For this reason, the ground water remedy will be required to meet these standards
in a reasonable time-frame.

Present and Future Off-Site Ground Water Use - There are private wells currently in use both cast and west of
Spring Brook. On-Site ground water is classified by the State of Illinois for use as Class I drinking water.
This is the most conservative classification has the most stringent standards, and represents the most
reasonable future use protection. As with the on-Site ground water, EPA MCLs also apply to off-Site ground
water. Currently, contamination in the shallow aquifer near the landfill foot print has exceedences in both
VOCs and metals. There is a 300-600 foot buffer of shallow ground water between the landfill and Spring Brook
where there are exceedences of the EPA Secondary MCL for iron and manganese but below any EPA primary MCL.
However, the shallow aquifer does not flow off-Site due to the Spring Brook hydrologic boundary. Finally, in
addition to the buffer zone and hydrologic boundary, the deeper aquifer supplies water to the vast majority
of private wells.

Deep ground water does flow toward the adjacent private wells, but does not contain Site related VOC
contamination. Metals present in on-Site deep ground water exceed the State Class I Drinking Water standards,
but are not significantly greater than upgradient samples. Some manganese and/or iron concentrations exceed
the EPA secondary standards in the deep aquifer at the Site boundary. However, secondary standards are for
drinking water aesthetics (i.e., taste and smell) and do not present health risks. The deeper aquifer exceeds
the EPA secondary standard for total dissolved solids, which is not thought to be related to the Site. At the
present time, both manganese and iron at the Site boundary are currently not significantly higher than
upgradient concentrations.

VI. SUMMARY OF SITE RISKS

A. Human Health Risks

CERCLA requires that U.S. EPA protect human health and the environment from current and potential exposure to
releases of hazardous substances at or from the Site. As part of the RI, a Baseline Risk Assessment was
required to assess the current and potential future risks posed by the Site. The Baseline Risk Assessment
determines whether contamination at the Site could pose an unacceptable health risk or environmental risk, in
the absence of any remedial action. Potential threats to public health are estimated by making assumptions
about the manner, frequency, and length of time a person could be exposed to Site-related contaminants.

All chemicals identified in Site media were evaluated: soil, ground water, surface water, sediments, gas and
leachate. Each sample was assessed by evaluating data qualifiers and blank sample concentrations. The RI data
from each media was evaluated to select Contaminants of Potential Concern (CPCs). CPCs are those chemicals
present at the Site most likely to be of concern to human health and the environment. CPCs were selected
based on a comparison of contaminants found in each media to background and blank sample data for each media.
Table 7 summarizes the CPCs selected for each media from the RI. Based on the results of the RI, U.S. EPA
directed the PRPs in calculating the risks that the Site would pose to human health and the
environment if no remedial actions were taken.
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The risk assessment process involves assessing the toxicity, or degree of hazard, posed by the substances
found at the Site, and the routes by which humans and the environment could come into contact with these
substances. There are some uncertainties inherent in the assessment. Theprimary sources of uncertainty in the
preparation of a risk assessment are:

• Problems with environmental sampling and analysis, and selection of chemicals;

• Exposure parameter estimation;

• Toxicity values may over or under-estimate risk (especially animal studies extrapolated
to humans);

• Behavioral patterns cannot be predicted with certainty, and

• Models used to predict environmental fate and transport may over or underestimate risk.
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Table 7
Contaminants of Potential Concern by Medium
Blackwell Landfill Site
DuPage County, Illinois
Analytes
LF
Gas
Private
Wells
Silver Sand
Lake Pond
Pine
Lake
Silver
Lake
Sand
Pond
Pine
Lake
Land-
fill
Ditch
VOLATILES
Chi or ome thane
Vinyl chloride
Chloroethane
Methylene chloride
Acetone
Carbon disulfide
1,1-Dichloroethene
1,1-Dichlorcethane
1,2-Dichloroethene
(cis)
1,2-Dichloroethene
(trans)
2-Butanone
1,2-
Di chloropropane
Trichloroethene
Benzene
4-methyl-2-
pentanone
Tetra-chloroethene
Toluene
Chlorobenzene
Ethylbenzene
X
X
X
X

X
X
X
X
X

X
X
X

X
X
X
X
X
X
X

X
Xylenes (mixed)
Dichlorodifluromet
hane
Dichlorotetra
fluorine thane
Trichlorofluro
methane
Trichlorotri
fluroethane
4-Ethyltoluene
1,3,5,-Tri
methylbenzene
1,2,4-Tri
methylbenzene
X
X

X
X
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SEMI VOLATILES

1,4-Dichloro X
benzene
Acenaphthene X
Fluorene X
Phenanthrene X X
Anthracene X
Fluoranthene X X
Pyrene X X
Butyl X
benzylphthaiate
Benzo(a) X X
anthracene
Chrysene X X
Benzo(b) X X
fluoranthene
Benzo(k) X X
fluoranthene
Benz-o(a)pyrene X X
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Analytes LF Private
Gas Wells

Silver Sand Pine Silver Sand Pine Land- Ditch
Lake Pond Lake Lake Pond Lake fill

Indeno(l,2,3- X X
cd)pyrene
Dibenz(a,h) X
anthracene
Benzo(g,h,i) X X
perylene
PESTICIDES/
PCBs
Dieldrin X
4,4'-DDE X
Endrin X
4,4'-ODD X
PCB X X
Endrin Aldehvde X

METALS
Aluminum X
Antimony X X
Arsenic X
Barium XXX XX
Calcium
Copper X
Iron
Lead X X
Magnesium
Manganese XXX
Nickel X
Potassium X
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Analytes LF Private
Gas Wells

Silver Sand Pine Silver Sand Pine Land- Ditch
Lake Pond Lake Lake Pond Lake fill

Selenium X
Silver X X
Sodium X X
Zinc X X

TIC GROUP

Acids cyclic
Acids, non-cyclic X
Alcohols cyclic
Alcohols,
oxygenated
Ethers, cyclic X

Amines
Benzenes, ethyl
methyl
Benzenes,
halogenated
Benzenes, X X
oxygenated
Benzenes, propyl
Benzenes,
trimethyl
Hydrocarbons, X
branched
Hydrocarbons, X
cyclic
Ketones, cyclic
Pyridines,
substituted
Phenols,
substituted
PAHs, non-TCL X
Furans
Sulfides X

Notes.
Refer to Section 8.2 of the RI report for a description of the method used to select chemicals of
potential concern. It should be noted that a chemical does not necessarily pose a health concern just
because it was selected as a Contaminant of Potential Concern. Rather, based on the chemical
concentration, it was considered to be elevated above normal levels for the area (i.e , background),
and therefore was considered a chemical of potential concern to be evaluated within the risk
assessment. Essential nutrients (calcium, magnesium, iron, potassium), even if elevated above
background concentrations, were not considered chemicals of potential concern because of their low
toxicity.

Legend
LF - Landfill
TIC - Tentatively Identified Compound
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The Baseline Risk Assessment evaluated current and future potential human health or environmental risks
associated with the Site. The qualitative risk assessment examined contaminants detected in ground water and
soils during the field investigation phase of the RI. These contaminants were evaluated with respect to their
carcinogenicity, toxicity, and possible exposure pathways from and at the Site.

In order to conduct a conservative evaluation of the risks posed by the Site, a number of critical
assumptions were made, including the following:

• No corrective action will take place;

• There are no ground water restrictions;

• There is no potential for future development of the Site;

• The area around the surrounding the Site will be residential;

• The contaminant concentrations in the various media will not to change over time;

• The Site is adequately characterized;

• The Contaminants of Potential Concern are associated with the majority of Site health
risk; and

• Risk/dose within an exposure route are additive.

With knowledge of the risk assessment uncertainties and assumptions, the first step in the risk assessment
process is to determine which chemicals are of concern to human health. To determine this, a comparison of
the concentrations of the chemicals detected in each media and in areas potentially impacted by the landfill,
is made to concentrations of chemicals in the same media collected in areas not impacted by the landfill
(commonly called "background"). This comparison was made to determine which chemical concentrations in each
media were significantly elevated above background. The chemicals detected above background are considered to
be the Contaminants of Potential Concern. Health risks are calculated for each Contaminants of Potential
Concern. Based on this analysis, it was determined that there were Contaminants of Potential Concern in
sediment and surface water samples from Silver Lake and Sand Pond and in soil samples collected on the
landfill. There were also Contaminants of Potential Concern in the air, (based on modeling of landfill gas
emissions), and in private well samples. While no tissue samples were analyzed from fish in the Site lakes,
it was conservatively assumed that fish may contain certain Contaminants of Potential Concern detected in the
Silver Lake sediment samples.

The second step was to determine pathways of exposure, based on current land use conditions, and the
characteristics of contamination at the Site. Activity assessments were conducted of Blackwell Forest
Preserve recreational users and employees. These surveys were performed to determine how frequently, and for
what duration, each of these populations were likely to be in an area where it was likely that they would be
exposed to any Contaminants of Potential Concern in all medias (i.e., sediment, surface water, soil, ambient
air and fish). In addition, demographic information was collected on residents living near the landfill.
Information on the duration of time residents normally live at a residence was determined from national
statistics. Residents living near the landfill, in the downgradient direction of ground water flow, were
conservatively considered to be exposed to Contaminants of Potential Concern in the air and in private well
water. Based on the activity assessments and national statistics, and the concentration of Contaminants of
Potential Concern in media, estimates of chemical exposure were calculated for each population.

Risks were quantitated for those potentially exposed subpopulations to represent a Reasonable Maximally
Exposed population (RME population), rather than each exposed subpopulation. The reasonable maximally exposed
subpopulation represents the subpopulation that, for reasons of their sensitivity, and/or lifestyle, have the
greatest potential for exposure proportional to the level of human exposure. This RME population is
considered to be the most likely group potentially affected by contamination at the Site. The current and
future land use health risks association with exposure to contaminated media were evaluated for:

• Recreational users;

• Trespassers;

• Employees; and
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• Off-Site residents.

Toxicity information was compiled for each Contaminants of Potential Concern. Individual chemicals were
separated into two categories of chemical toxicity, based on whether they exhibited principally
noncarcinogenic or carcinogenic effects. Next, the health effects of both categories of chemicals were
evaluated. Known or suspected carcinogens and non-carcinogens were addressed independently.

The risk characterization integrates the exposure and toxicity assessments into a measurable expression of
risk for each exposure scenario. The cancer risk is expressed as a probability of a person developing cancer
over the course of his or her lifetime. Cancer risks from various exposure pathways are assumed to be
additive. Excess lifetime cancer risks less than 1x10- 6 (one-in-one million) are considered acceptable by
U.S. EPA. Excess lifetime cancer risks between 1x10 -4(one-in-ten thousand) to 1x10 -6 reguire U.S. EPA and
Illinois EPA (the Agencies) to decide if remediation is necessary to reduce risks and to what levels cleanup
will occur. Excess lifetime cancer risks greater that 1x10 -4 generally reguire remediation.

For noncarcinogens, potential risks are expressed as a hazard index. A hazard index represents the sum of all
ratios of the level of exposure of the contaminants found at the Site to that of contaminants' various
reference doses. In general, hazard indices which are less than one are not likely to be associated with any
health risks. A hazard index greater than one indicates that there may be a concern for potential health
effects resulting from exposure to noncarcinogens. Table 8 summarizes the total risk for all projected users
and a theoretical Maximally Exposed Individual (MEI).

Table 8. Health Risk estimates

User Noncancer
RME Ave. RME Ave.
Recreational 3x10 -2 4x10 -4 1x10 -6 1x10 -8
Trespasser 2x10 -2 3x10 -4 1x10 -10 5x10 -13
Employee 4x10 -2 1X10 -3 1x10 -6 2x10 -8
Off-Site Resident 9x10 -1 5x10 -1 3x10 -6 4x10 -7
MEI 9x10 -1 5x10 -1 4x10 -6 4x10 -7

MEI - Maximally Exposed Individual

A shown in Table 8, under the current and reasonable future use conditions, the excess lifetime cancer risks
were estimated at or below the 10 -6 cancer range and several orders of magnitude below the 10 -4 cancer
risk. The Maximally Exposed Individual (MEI) was well below the acceptable risk range of 10 -4 to 10 -6.

The excess cancer risk for the Reasonable Maximum Exposure (RME) to the Maximally Exposed Individual (MEI) is
3x10 -6 to 4x10 -6 for the most at risk off-Site resident. However, the 3x10 -6 in off-Site resident total
cancer risk is largely due to traces of pesticides found in 5 of 51 off-Site residential wells. Pesticides
were not found in leachate samples or monitoring wells around the landfill and the pesticides are believed to
be from past agricultural land use or laboratory artifacts.

The non-cancer hazard index for the RME to the MEI is 0.9. While this is very close to 1,93% of the noncancer
health risk is associated with antimony exposure from one off-Site residential well. The antimony (and lead)
in this well is believed to be from the home's water distribution system, not from the landfill.

B. Ecological Risks

An ecological assessment was conducted to evaluate the potential risks to non-human receptors associated with
the Site. Potential receptors and exposure pathways were evaluated, including the presence of endangered or
threatened species in the area. The objectives of the ecological assessment was to:

• Characterize the natural habitats and populations on and in the vicinity of the Site
(ecological communities);

• Identify those habitats and populations that may be influenced by the Site; and

• Evaluate actual or potential adverse effects that chemicals from the Site may have on these
habitats and populations.
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Ecological inventory information was reviewed and the Site was inspected for signs of adverse ecological
effects. Environmental media were sampled and analyzed to determine if chemicals which could adversely affect
ecological communities at the Site were present. To derive an indication of what compounds or chemicals would
be most likely to represent a risk to the environment, conservative values for chemical toxicity and biotic
uptake were used to indicate potential biotic effects from detected Contaminants of Potential Concern. The
results of these analyses are:

• There appears to be little risk to ecological communities and or populations in those,
communities at the Site from organic chemicals in environmental media, since the organic
species were either not detected (pesticides), detected at few locations and at very low
concentrations (VOCs), were not Site related (SVOCs), or were determined to be present
at concentrations below which adverse ecological effects are associated (SVOCs and PCBs
in the terrestrial environment);

• Metals are Contaminants of Potential Ecological Concern in some sediment samples.
However, metals concentrations of potential concern are limited to isolated areas;

• Metals of potential ecological concern in Site surface soils appear to be present in
concentrations lower than those sufficient to affect small terrestrial mammal populations;

• Contaminants of Potential Ecological Concern at concentrations detected in surface water
do not appear to pose and ecological hazard to aguatic species in Silver Lake and Sand Pond;

• Possible risk from SVOCs in sediment exist in sediment at one isolated location in Silver
Lake. This location is near an asphalt parking lot. It is possible that the SVOCs are from
the parking lot, not the Site; and

• Sampling, analytical, and statistical uncertainties affect the Ecological Assessment.
Application of limited reference data, assumptions on the size, range and feeding rates of
species, and influences at the Site, other than influences from Contaminants of Potential
Concern, also introduce uncertainties into the Ecological Assessment.

C. Remedial Objectives

As stated previously, there have been a number of early actions completed under CERCLA removal authority that
addressed contamination on an interim basis. The following is a description of the final remedial objectives
for this Site in light of the previously completed response actions.

Landfill Cap - The long-term remedial objective for the cap is to minimize infiltration into the landfill,
and eliminate potential direct exposure to leachate, landfill gas, and contaminated soil/waste material
within the landfill. As stated previously, a study was completed to determine the extent of refuse, determine
the extent of a minimum of 2 feet of low permeability materials above that refuse, and make any reguired
improvements to the cap. The study was completed and the cap improvements have been completed. Compliance
with long-term Post Closure Care reguirements of Illinois Administrative Code under IAC 35 807 and 811 for
the cap are the critical ARARs for this objective.

Leachate System - The critical objective is to manage the threat of the leachate migration and exposure
through a reguirement for active collection and off-Site treatment and disposal. As described previously,
nine extraction wells were placed into the landfill. The intent of the leachate collection system was to
install a sufficient number of extraction wells to capture leachate throughout the landfill. The leachate
system was designed to minimize leachate seeps out of the landfill, eliminating any potential for direct
exposure, and to protect against leachate migrating to ground water that results in an exceedence of
regulatory standards. The leachate system is designed so that if in the future it is determined to be
insufficient in meeting these objectives, it can be readily upgraded. Long-term operation of the leachate
collection, storage system with off-Site disposal will reguire compliance with Illinois Administrative Code
for Post-Closure reguirements (35 IAC) and the National Pollutant Discharge Elimination System (NPDES) permit
(40 CFR 122 and 125) for leachate disposal. Augmentation of the system will reguire compliance with Illinois
Administrative Code (35 IAC) and OSHA construction reguirements.

Landfill Gas System - The objective of the landfill gas system is to appropriately manage landfill gas to
minimize migration into ground water or through the cap. By reducing gas buildup beneath the cap, it is
anticipated that full recreational use of the hill can be maintained. A landfill gas system was installed
concurrently with the leachate extraction system and is up and running. The landfill gas system is also
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flexible so that if in the future it is determined to be insufficient in meeting these objectives, it can be
augmented. Long-term operation will reguire compliance with Illinois Administrative Code (35 IAC)
Post-Closure reguirements for Landfill Gas Management and the Clean Air Act. Augmentation of the system will
reguire compliance with Illinois Administrative Code (35 IAC) and OSHA construction reguirements.

Ground Water - The remedial objective for ground water is to restore all ground water beyond the landfill
boundaries to its maximum beneficial use in a reasonable amount of time. This objective will be measured
against the Safe Drinking Water Act EPA MCLs and IEPA Class I Drinking Water Standards.

Long-term Monitoring - The objective of the long-term monitoring is to ensure no unacceptable exposure
through long-term remedy performance. Long-term monitoring will be subject to Illinois Administrative Code
(35 IAC) Post-Closure Reguirements.

Institutional Controls - Another important remedial objective for long-term Site management is to restrict
any activities that would interfere with the remedy.

VII. DESCRIPTION OF ALTERNATIVES

The following is a discussion of remedial alternatives developed and evaluated for the Site. One of the four
remedial alternatives is the "no action" alternative and the other three reguire further response actions.
The NCP reguires that a no-action alternative be considered at every Site. The no-action alternative serves
primarily as a point of comparison for other alternatives. These alternatives were developed from applicable
remedial technology process options and are, evaluated for effectiveness, implementability and cost. The
alternatives meeting these criteria were evaluated and compared to the nine criteria reguired by the NCP.
Treatability studies were not performed in support of this remedy decision and are not anticipated to be a
necessary part of implementation of any of the alternatives for this Site.

SOURCE CONTROL ALTERNATIVES

Common Components

Due to fact that a number interim actions have occurred at the Site, all alternatives include the
following components completed in the early action.

1. Institutional Controls

Institutional controls include fencing, deed restrictions, and warning signs. Site access is controlled by a
fence and warning signs to discourage unauthorized entry onto the Site. Deed restrictions have been
instituted to prohibit disturbance of the Site and preclude future development of the Site.

2. Flood Protection

Erosion control measures were completed during early action construction to ensure tile reduction of flood
water velocity during future flooding.

3. Storm Water Controls

Storm water control measures were completed during the early action to control storm water (i.e., runoff
control berms, engineered slope, discharge ditches).

4. Improved Landfill Cap

An improved landfill cap was constructed over parts of the landfill where insufficient low permeability
materials were present, in accordance with the applicable Illinois EPA's Solid Waste Management Regulations.
The landfill improvements prevent direct contact with the waste, prevent migration of contaminated soils into
surface water, reduce infiltration of precipitation into the landfill thereby reducing generation of leachate
and also aid in reducing the percolation of leachate from the landfill into ground water. There will be no
additional cap construction under the proposed final Site-wide remedy.

5. Ground Water Monitoring

A ground water monitoring network was established on the Site using existing monitoring wells and the
construction of 5 new monitoring wells to monitor upgradient and downgradient ground water conditions.
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6. Gas Collection

Landfill gases are being collected with passive gas extraction wells. Landfill gases are collected from the
extraction welt locations and vented at the top of Mt. Hoy.

7. Leachate Extraction

Leachate is currently being extracted from the landfill. A series of 9 vertical extraction wells were
installed in the landfilil and screened in the permeable water-bearing zones. Leachate is collected by a
system of piping buried under the landfill cap and is temporarily stored in a 10,000 gallon holding tank.

8. Leachate Treatment

The leachate treatment system includes off-Site transport to a permitted treatment system capable of treating
the appropriate contaminants (i.e., volatile organic compounds, sernivolatile organic compounds, and metals).

The following is a list of the technologies evaluated and a discussion of the alternatives to be added to the
activities previously completed and described above.

Alternative 1 - No Action

Description: No Action

Estimated Capital Cost: $0
Estimated Annual O&M Costs: $0
Estimated Present-Worth Costs: $0
Estimated Implementation Time frame: None

The inclusion of the No-Action Alternative is reguired by law to give U.S. EPA a basis for comparison. This
Alternative does not take any action to remediate the Site and does not consist of any treatment components,
engineering controls, monitoring, or institutional controls. This Alternative involves no remedial measures
and would not effectively (1) prevent migration of leachate to ground water (possibly resulting in
exceedences of regulatory standards), (2) reduce the volume of leachate, (3) control landfill gas emissions,
or (4) eliminate the potential for direct exposure. The majority of Remedial Action Objectives would not be
met with this Alternative.

Alternative 2 -- Long-Term Leachate Extraction and Off-Site Disposal; Contingent Augmentation of the Leachate
and Landfill Gas Systems; Long-term O&M for all Existing Components, and Long-term Monitoring

Estimated Costs:

Capital Costs:
Contingent Leachate System $270,000
Contingent Gas $ 20,000
CONTINGENT CAPITAL COSTS $290,000

Operation and Maintenance Costs:
Leachate O&M $94,000
Cap O&M $ 2,400
Landfill Gas O&M S 3,600
Monitoring $299,000
ANNUAL O&M $399,000

NET PRESENT WORTH (29 years at 7%) $5,739,000
(29 years at 3%) $8,497,000

Estimated Time-frame: Extraction and off-site disposal of leachate, landfill gas management, O&M and
monitoring would be ongoing responsibilities.

This Alternative includes long-term operation and maintenance of all of the early action components,
including: leachate extraction and off Site disposal, landfill gas management, cap/institutional controls
maintenance and long term monitoring of leachate, landfill gas and ground water, as appropriate. In addition,
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this Alternative also includes contingencies for the augmentation of the leachate extraction system with up
to 9 additional leachate/landfill gas extraction wells and transition from passive to active landfill gas
collection with thermal treatment.

Ground water under the Site would not be addressed under Alternative 2 as required by 35 IAC 620.250. Gas
venting would be in compliance with 35 IAC 218.

Contingent augmentation of the leachate and landfill gas systems, if necessary, would be in compliance with
OSHA construction requirements, 35 IAC 811.309 requirements for leachate treatment and disposal systems, and
35 IAC 811.311 for landfill gas management systems. If a thermal flare is constructed on -Site, monitoring
under 35 IAC 212-218 would be required.

Monitoring of leachate, landfill gas and ground water would all be in accordance with an approved Operation
and Maintenance (O&M) Plan and 35 IAC Post-Closure Care Requirements.

Alternative 3 - Long-term Leachate Extraction and Off-Site Disposal, Contingent Augmentation of the Leachate
System and Landfill Gas Systems; Long-term O&M for all Existing Components; Long-term Monitoring, and
Monitored Natural Attenuation for Ground Water

Estimated Costs:

Capital Costs:
Contingent Leachate System $270,000
Contingent Gas $ 20,000
CONTINGENT CAPITAL COSTS $290,000

Operation and Maintenance Costs:
Leachate O&M $94,000
Cap O&M $ 2,400
Landfill Gas O&M $ 3,600
Monitoring $299,000
ANNUAL O&M $399,000

Monitored Natural Attenuation Costs:
Baseline Study $55,000
Additional Monitoring $25,000
TOTAL MNA COST $80,000

NET PRESENT WORTH (29 years at 7%) $5,819,000
(29 years at 3%) $8,577,000

Estimated Time-frame: Extraction and off-site disposal of leachate, landfill gas management, O&M and
monitoring would be ongoing responsibilities. MNA would be shorter-term requirements with the bulk of the
work being conducted in the first five years.

Contingent augmentation requirements of the leachate and landfill gas systems in alternative 3 are the same
as in Alternative 2. In fact, alternative 3 includes all the components of Alternative 2 with the addition of
Monitored Natural Attenuation for ground water. Monitored Natural Attenuation includes an initial
comprehensive baseline investigation and periodic sampling to compare projected contaminant concentrations
and actual analytical data to measure clean up progress. The Monitored Natural Attenuation of ground water
may include varying combinations of biodegradation, abiotic transformation, intrinsic bioremediation,
dilution, dispersion and adsorption of ground water contaminants. Preliminary analytical data strongly
support the projected success of MNA to meet cleanup goals in a reasonable amount of time.
Order of magnitude decreases in ground water contaminants have been documented from 1992 sampling compared to
the results of the 1997/98 data. It is reasonably expected that once the other components of the remedy have
been in place for a while, significant additional improvements in ground water quality will be realized. To
document this anticipated, improvement in ground water quality, significant additional monitoring and
modeling will be required. This type of monitoring is more comprehensive than monitoring intended to ensure
the effectiveness of the remedy. Ground water under the Site would be managed as a ground water management
zone in accordance with 35 IAC 620.250 until Class I potable resource ground water standards listed in 35 IAC
620.410 are met.
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Alternative 4 - Long-term Leachate Extraction and Off-Site Disposal; Contingent Augmentation of the Leachate
System and Landfill Gas Systems; Long-term O&M for all Existing Components; Long-term Monitoring, and Ground
Water Extraction and Treatment Construction/Operation.

Estimated Costs:

Capital Costs:
Contingent Leachate System $270,000
Contingent Gas $ 20,000
CONTINGENT CAPITAL COSTS $290,000

Ground Water Pump and Treat $726,000
TOTAL CAPITAL COST $1,016,000

Operation and Maintenance Costs:
Leachate O&M $94,000
Cap O&M $ 2,400
Landfill Gas O&M $ 3,600
Monitoring $299,000
Ground Water $ 83,000
ANNUAL O&M $482,000

NET PRESENT WORTH (29 years at 7%) $7,553,813
(29 years at 3%) $10,923,813

Estimated Time frame: Extraction and off-site disposal of leachate, landfill gas management, O&M and
monitoring would be ongoing responsibilities. The actual design/construction of the ground water
pump-and-treat system would be complete in about 3.5 years.

Contingent augmentation of the leachate and landfill gas systems are the same as in Alternatives 2 and 3.
Alternative 4 includes all of the components of Alternative 3, with the exception of the Monitored Natural
Attenuation. This Alternative replaces the Monitored Natural Attenuation with ground water extraction and
treatment. This would involve installing 20 ground water extraction wells in the upper aguifer downgradient
of the landfill to capture contaminants which have the potential to migrate off Site. The extracted ground
water would be conveyed through underground piping to a treatment system. Following treatment to remove
volatile organic compounds, the treated ground water would be discharged in compliance with a Illinois
Administrative Code and NPDES permit (40 CFR 122 and 125) reguirements. A pre-design
investigation may be necessary to develop the appropriate configuration of ground water extraction wells.

PERIODIC REVIEWS/CONTINGENCIES FOR CLEANUP ALTERNATIVES

Alternatives 2, 3 and 4 will reguire a critical review after the completion of one year of operation (at a
minimum) of the early action. The purpose of the critical review is to determine whether the leachate system
and/or landfill gas system augmentation will be reguired. If data demonstrates that the leachate system is
not effective in managing leachate such that it poses a direct exposure threat, or ground water would not be
remediated in a reasonable amount of time, up to 9 additional extraction wells would be added. If the data
indicate that the landfill gas system is not effective at managing gas, it may be transitioned to active gas
collection and reguire on-Site thermal treatment. Prior to, or at the time of, these critical reviews it may
be determined that additional reviews may be reguired. These periodic reviews are in addition to the CERCLA
Five-Year Review process for sites where wastes are left on-Site. If the data available at the first such
review is insufficient for a reliable trend analysis, evaluation of remedy performance will be completed in
the subseguent review or at some earlier time to be established during the first review.

An evaluation of ground water information gathered for each Five-Year Review will be used to determine
whether or not there is a need for additional action to reduce cleanup times. This may be a part of, or in
addition to, any reguired Monitored Natural Attenuation studies reguired under Alternative 3.

The ground water cleanup goals that must be achieved within a reasonable period of time are EPA MCLs and IEPA
Class I Drinking Water Standards. The determination of whether additional measures will be reguired for
ground water will be based on compliance/projected compliance with the cleanup levels within a reasonable
period of time. For this type of situation, a reasonable period of time for meeting the MCLs can be defined
as less than 30 years.
At each Five-Year Review or earlier, as necessary, U.S. EPA, in consultation with Illinois EPA, will evaluate
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the following criteria in order to determine the need for additional remedial measures:

1. Existing contaminant levels;

2. Trends in contaminant concentrations, if any,

3. Effectiveness of the source control measures,

4. Potential reduction in restoration time frames to less than 30 years;

5. Potential for the contaminants in the ground water to reach regulatory standards
and/or asymptotic levels throughout the plume; and

6. Alternative remedial measures available to meet ground water standards and the
cost thereof,

Additional measures will be necessary if an evaluation of the above criteria indicates: (1) concentrations
within the plume have not decreased; (2) concentrations within the plume do not show the potential to
decrease below regulatory levels in less than 30 years; or (3) source control measures do not meet their
remedial objectives of preventing off-Site contaminant migration.

Long term ground water monitoring would be conducted to monitor and ensure the effectiveness of Alternatives
2, 3 and 4. Ground water monitoring results will be evaluated annually to aid in predicting contaminant
trends. The ground water monitoring program developed during the design phase will be used. The plan includes
development of a continuous monitoring record; identification of select wells throughout the plume to monitor
changes in both the horizontal and vertical extent of the plume; a specific sampling freguency; and
identification and monitoring of areas containing higher contaminant concentrations,
if any.

If additional measures are determined to be necessary based on Five-Year Reviews, they are likely to involve
augmentation of the existing system for components other than ground water. If additional measures are
reguired for ground water, they may include pump-and-treat design or other remedial measures, including any
applicable new technology. The applicability of new technologies will be evaluated in terms of technical and
economic feasibility. The design of additional measures (should they be necessary) will include: locating
extraction wells (or other remedies) to maximize hydraulic capture of the plume and considering areas of
greater contaminant concentrations, if any.

VIII. SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES

The following nine criteria, outlined in the NCP at 40 CFR 300.430 (e) (9) (iii), were used to compare the
alternatives listed above and to determine the alternative for remediation of the soils, leachate, landfill
gas, and ground water contamination that: (1) is protective of human health and the environment; (2) attains
ARARs; (3) is cost effective; and (4) represents the best balance among the evaluating criteria. The
alternative that meets the two "threshold" reguirements of protectiveness and ARAR-compliance, and provides
the "best balance" of trade-offs, with respect to the remaining criteria, is determined from this evaluation.

A. THRESHOLD CRITERIA

1. OVERALL PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT

Overall protection of the public health and the environment addresses whether a remedy provides adeguate
protection of human health and the environment and describes how risks posed by each exposure pathway are
eliminated, reduced, or controlled through treatment, engineering controls, or institutional controls.

Alternative 1 does not meet this criteria because it does not take any action to protect human health and the
environment. Therefore, Alternative 1 does not eliminate, reduce, or control risks.

Alternative 2 addresses the threat of leachate through long-term active collection and off-Site treatment and
disposal. Leachate collection will reduce leachate migration to receptors, further reducing the potential
future exposure of human health and the environment. The long-term cap inspection and repair reguirements
provide protection against future direct exposure to leachate, waste material and contaminated soils for
current and future use. The operation and maintenance of the existing landfill gas systems provides
protection against exposure to landfill gas emissions under static conditions. Alternative 2 meets the
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contingency requirements for augmentation of the leachate and landfill gas system. However, Alternative 2
does not have a ground water remedy component for future protection of human health and the environment. For
this reason, Alternative 2 does not fully meet this criteria.

Alternative 3 contains all of the protections in Alternative 2, with the addition a Monitored Natural
Attenuation remedy component for future protection of ground water. The Monitored Natural Attenuation remedy
component would provide future protection of human health and the environment. Alternative 3 fully meets this
criteria.

Alternative 4 includes all of the protections of Alternative 3 but replaces MNA with a ground water
pump-and-treat component. The ground water pump-and-treat system would provide future protection of human
health and the environment. Alternative 4 fully meets this criteria.

2. COMPLIANCE WITH APPLICABLE OR RELEVANT AND APPROPRIATE REQUIREMENTS addresses whether a remedy will meet
federal and state environmental statutes and regulations and/or provide grounds for invoking a waiver.

A. Compliance with Chemical-Specific ARARs - Table 9 is a summary of Federal and State of Illinois
chemical-specific ARARS. Chemical-specific ARARs address air emission standards and ground water quality.

Ground Water Quality - Class I Potable Resource Ground Water Quality Standards listed in 35 IAC 620.410 apply
to ground water. For Alternatives 3 and 4, until compliance with the standards of IAC 620.410 is achieved,
ground water would be managed as a ground water management zone under IAC 620.250. U.S. EPA MCLs under 40 CFR
141 are relevant and appropriate for ground water outside the boundary of the landfill. Alternatives 3 and 4
contain a ground water component designed to meet Illinois Ground Water Quality Standards and MCLs outside
the landfill boundary in a reasonable amount of time. Alternatives 1 and 2 do not contain a ground water
component and would not meet either of these chemical-specific standards.

Air Emissions - Air emissions from the passive landfill venting system would be required to meet the
requirements of 35 IAC 243 and the Clean Air Act 40 CFR Part 50. The IAC chemical-specific air requirements
limits emissions of photochemically reactive organic material (e.g., VOCs) to less than 8 pounds per hour.
The system is currently operating below that amount. Should augmentation be required in Alternatives 2, 3 and
4 that result in greater than 8 pounds per hour, controls to reduce emissions may be required.

B. Compliance with Location-Specific ARARs - Table 10 includes a list of potential Federal and State of
Illinois location-specific ARARs. Potential location-specific ARARs; relate to flood plains, wetlands and
open waters. All alternatives meet the Federal and State of Illinois location-specific ARARs.

C. Compliance with Action-Specific ARARs - Finally, Table 11 contains a list of potential Federal and State
of Illinois action-specific ARARS. Action-specifie ARARs relate to construction safety standards, cap repair,
Post-Closure leachate and landfill gas emissions, water quality, and discharge requirements.

Landfill Cap - Alternatives 2, 3 and 4 require long-term management of the existing landfill cap in
compliance with 35 IAC Post Closure Care requirements (35 IAC 807.503-503, 523 and 524 and 811.111). Because
there is no cap construction proposed in this remedy, there are no cap construction requirements (35 IAC 811
construction requirements do not apply). Alternatives 2, 3 and 4 would all meet the ARAR requirements for the
landfill cap.
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Table 9: Potential Chemical-Specific ARARs
DuPage County Landfill/Blackwell Forest Preserve Superfund Site - Warenville, Illinois
MEDIA

Surface Water
REQUIREMENT

Protect State water for aquatic life, agricultural use.
primary and secondary contact use, most industrial use,
and to ensure aesthetic quality of aquatic environment.

Pretreatment Standards of State and local POTW
Effluent Guidelines and Standards
CITATION

Water Quality Standards 35 IAC 302.202-
302.212
35 IAC 310.201-220
35 IAC 304.102-126
Prohibition of discharge of oil on hazardous substances
into or upon navigable waters
Federal Water Pollution Control Act
Section 311(b) (3)

40 CFR 110.6,117.21
Comply with all applicable Federal and State water
quality criteria.
Groundwater Meet State Groundwater Quality Standards using a
Groundwater Management Zone
Enforceable numeric standards for public water supplies.
CWA Section 304(a) and information
published in the Federal Register pursuant
to this section; 35 IAC 302.612-669

35 IAC 620.410 unless modified in
accordance with the substantive
requirements in 35 IAC 620.250 to 350

Safe Drinking Water Act MCLs, 40 CFR
141.11-141.16, MCLGs - 40 CFR 141.50-
141.51 and Secondary MCLs - 40 CFR
143.3
Air
Air Quality Standards.
35 IAC 243.120-126, Clean Air Act 40
CFR Part 50
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MEDIA

Floodplains
Table 10: Potential Location-Specific ARARs
DuPage County Landfill/Blackwell Forest Preserve Superfund Site -

REQUIREMENT

Action to avoid adverse effects, minimize potential harm,
and restore and preserve natural and beneficial values (in
relation to implementation of the RA).

Facility shall not restrict the flow of a 100-year flood,
result in washout of solid waste from a 100-year flood, or
reduce the temporary water storage capacity of the 100-
year floodplain

Facility located in a 100-year floodplain must be
designed, constructed, operated, and maintained to
prevent washout of any hazardous waste by a 100-year
flood
Warenville, Illinois

CITATION

Executive Order 11988, Floodplain
Management, 40 CFR 6, Appendix A,
Section 6(a)(5)

35 IAC 811.102(b)
35 IAC 724.118(b)
Wetlands
Governs construction and filling in the regulatory
floodway of rivers, lakes, and streams of Cook, DuPage,
Kane, Lake, McHenry, and Will Counties, excluding the
City of Chicago

Action to minimize the destruction, loss, or degradation
of wetlands
92 IAC Part 708
Executive Order 11990, Protection of
Wetlands, 40 CFR 6, Appendix A,
Section 6(a)(5)
Action to minimize adverse effects of dredged or fill
materials
CWA 40 CFR 230.70-230.77
Stream
Requires Federal agencies involved in actions that will
result in the control or structural modification of any
stream or body of water for any purpose, to take action to
protect the fish and wildlife resources which may be
affected by the action
Fish and Wildlife Coordination Act,
40 CFR 6.302(g)
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Table 11: Potential Action-Specific ARARs
DuPage County Landfill/Blackwell Forest Preserve Superfund Site - Warenville, Illinois
MEDIA
Construction
REQUIREMENT

Establishes health and safety standards to be used in
construction.
CITATION

OSHA 29 CFR 1910
Post-Closure Care
Landfill
General provisions governing post-closure reguirements
including the development and implementation of post-
closure performance standards, inspection and repair,
monitoring reguirements and implementation of post-
closure activities.
35 IAC 807.501, 502, 503, 523 and 524
Specific provisions governing post-closure reguirements
inspections and maintenance periods. Also, specific
provisions regarding cap and drainage repairs and future
use considerations.
35 IAC 811.111
Post-Closure Care -
Leachate
Establishes minimum reguirements for leachate
sampling.

Establishes minimum reguirements for leachate
collection.
35 IAC 811.206
35 IAC 811.308
Leachate Treatment
Storage and Disposal
Post-Closure Care -
Landfill Gas
Leachate Treatment and Disposal System: Establishes
standards for leachate storage systems and standards for
discharge to an off-site treatment works.

Landfill Gas Monitoring Program: Establishes minimum
reguirements for gas collection at the site.
35 IAC 811.309(d)(e)
35 IAC 807,811.310
Establishes minimum reguirements landfill gas sampling.
35 IAC 811.130
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Landfill Gas Landfill Gas Management System: Establishes minimum
Management requirements for gas venting and collection systems

Visible and particulate matter emission standards and
limitations (particulate)

Sulfur air emissions standards and limitations

Organic material emissions standards and limitations

Carbon monoxide emissions standards and limitations

Nitrogen oxide emissions standards

Volatile Organic Material emission standards

Verify that there is no "excessive release" of hydrogen
sulfide emissions during landfill gas management.

Verify that emissions of hazardous pollutants do not
exceed levels expected from sources in compliance with
hazardous air pollution regulations.

Estimate emission rates for each pollutant expected.

Develop a modeled impact analysis of source emissions.

Use Reasonably Available Control Technology (RACT).

Landfill Gas Processing Landfill Gas Processing and Disposal System:
and Disposal
Post-Closure Care -
Ground Water

Discharge to POTW
Establishes minimum requirements for landfill gas
processing and disposal

Groundwater Monitoring Program: Establishes minimum
requirements for groundwater monitoring at the site

Prevent introduction of pollutants into POTW which will
interfere with POTW operation.

Establishes standards for discharges to POTWs.
35 IAC 811.311

35 IAC 212.123 (visible) and 212.321

35 IAC 214.162

35 IAC 215.143

35 IAC 216.121. 216.141

35 IAC 217,121

35 IAC 218.143

35 IAC 211.2090, 35 IAC 214.101
415 ILCS 5/9. l(b), CAA Section 112,
40 CFR 61.12-14
35 IAC 291.202

35 IAC 291.206

35 IAC 211.5370, 35 IAC Part 215,
Appendix E

35 IAC 811.312
35 IAC 811.319(a) and Part 811.318
35 IAC 310.201(a)(c) and 310.202, and
local POTW regulations

CWA 40 CFR 403, 40 CFR 122 and 125,
and 40 CFR 131
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Leachate - Extracted leachate associated with Alternatives 2, 3 and 4 would continue to extracted, collected
and transported off-Site to a POTW and treated under an existing permit. This would be in accordance with
Illinois Administrative Code 35 Post-Closure Care (35 IAC 807 and 35 IAC 811.206) and for Leachate Treatment,
Storage and Disposal (35 IAC 811.309 and NPDES/CWA 40 CFR 403). If augmentation was reguired to the leachate
system, it would be completed in compliance OSHA reguirements (29 CFR 1910) and Illinois Administrative Code
35 for leachate collection (35 IAC 308) and leachate system construction and off-site discharge reguirements
(35 IAC 811.309). Alternatives 2, 3 and 4 would meet these reguirements.

Air Emissions - Air emissions from the landfill gas system (Alternatives 2 through 4) would be subject to the
relevant Post-Closure reguirements of 35 Illinois Administrative Code (35 IAC 807, 811.130, 310 and
monitoring under 218.143) and the Clean Air Act (CAA Section 112, 40 CFR 61.12-14). Alternatives 2, 3 and 4
would meet these reguirements. If augmentation including on-Site construction of a thermal treatment devise
is completed, it would be done so that it is in compliance with OSHA construction standards and Illinois
Administrative Code for construction of landfill gas systems (35 IAC 811.310 and 311). The augmentation would
also trigger sampling under 35 IAC 221-218 and compliance with the Clean Air Act, Section 112, 40 CFR
61.12-14. Alternatives 2, 3 and 4 would meet these reguirements.

Ground Water - Alternative 4 includes ground water extraction, treatment and disposal. That disposal would be
regulated by National Pollution Discharge Elimination System Permit Regulations (40 CFR 122 and 125), the
Water Quality Effluent Limitations section of the Clean Water Act (40 CFR 131), and 35 IAC Parts 304 and 309.
Sampling and analysis associated with discharge to a surface water body are found in 40 CFR 136.

Monitoring - All monitoring of leachate, landfill gas and ground water would be completed under Illinois
Administrative Code 35 for Post-Closure Regulations (35 IAC 807 and 811). Alternatives 2, 3 and 4 would meet
these ARARs.

Alternatives 3 and 4 are the only Alternatives to successfully meet all of the threshold criteria. Therefore,
Alternatives 1 and 2 will not be subjected to the following primary balancing criteria.

B. PRIMARY BALANCING CRITERIA

3. LONG-TERM EFFECTIVENESS AND PERMANENCE

Long-term effectiveness and permanence refers to expected residual risk and the ability of a remedial action
to maintain reliable protection of human health and the environment over time, once cleanup levels have been
met. The effectiveness of the remedy would also be tracked by long-term monitoring. Pursuant to the NCP,
Five-Year Reviews would be conducted to determine if the remedy is effectively reducing contaminant
concentrations, if the effective limit of the remedy has been reached, or if additional actions are needed.

A. Magnitude of Residual Risk

Alternative 3

Residual risks left by Alternative 3 would be reduced lower than those calculated in the Baseline Risk
Assessment and Ecological Assessment. The continued operation of the leachate extraction system would reduce
the potential risks associated with high leachate volume and elevations in proportion to the resultant
decrease in leachate volume, elevations and chemical concentrations. The magnitude of these reductions will
be dependent on the recoverability of the leachate from the landfill interior.

The existing passive landfill gas venting system would continue to relieve buildup of gas within the
landfill. The volume of gas would decrease as the refuse in the landfill stabilizes, reducing the risk
associated with fracturing of the existing cap and generation of future leachate.

The entire remedy would be subject to a Five-Year Review. Additionally, a one year (or more often) critical
review of the leachate extraction system would be completed. This review would consist of evaluating the
effectiveness of leachate extraction to lower the leachate heads in existing leachate wells and reduce the
volume of leachate contained in the landfill. Ground water monitoring data would document whether leachate
extraction results in a corresponding decrease in ground water contaminant concentrations. Depending upon the
results of this analysis and the number of wells that go dry, an additional 9 leachate extraction wells may
be installed and operated.

Landfill gas and volume and discharge calculations will be completed to determine if the system should be
upgraded from passive to active gas removal. Contaminant concentrations will also be gathered to determine
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whether on-Site thermal treatment is required.

A baseline Monitored Natural Attenuation Study will be completed, including projected cleanup times. Actual
data would be periodically evaluated against projected data to determine if ground water will be restored to
its beneficial use in a reasonable amount of time. The accumulated database from ground water monitoring
would be evaluated to assess the on-going ground water quality downgradient of the landfill. The Monitored
Natural Attenuation of ground water may include varying combinations of biodegradation, abiotic
transformations, intrinsic bioremediation, dilution, dispersion and adsorption of ground water contaminants.
Preliminary analytical data strongly support the projected success of MNA to meet cleanup goals in a
reasonable amount of time. Order of magnitude decreases in ground water contaminants have been documented
from 1992 sampling compared to the results of the 1997/98 data. It is reasonably expected that once the other
components of the remedy have been in place for a while, significant additional improvements in ground water
quality will be realized. The concentrations of contaminants in ground water concentration will continue to
decrease by natural attenuation/dilution processes and also because contaminant loading will be decreased as
leachate volume and pressure head are reduced by the leachate collection system. Since most of the ground
water contaminants that exist at the Site are already at low concentrations, it is likely that only minimal
reduction of actual contaminant mass would occur initially in ground water.

Alternative 4

Residual risks left by Alternative 4 would also be reduced lower than those calculated in the Baseline Risk
Assessment and Ecological Assessment.

Alternative 4 is identical to Alternative 3 but replaces the Monitored Natural Attenuation ground water
component with a ground water extraction, treatment, and discharge system. All other components are the same
and result in a similar residual risk. If treated ground water is discharged to surface water or the sewer
and regulatory levels would be met. Again because of the low ground water contaminant concentrations, even
very large volume removals of ground water for treatment would only result in a minimal removal of the mass
of contaminants.

B. Adequacy and Reliability of Controls

FPD ownership of the property is an adequate and reliable control for the Site. The landfill is maintained by
FPD personnel. The possibility of residential or commercial development is eliminated by FPD ownership, since
the FPD lacks the authority to sell any portion of the Forest Preserve to a private party.

Leachate extraction and treatment is a well developed remedial technology. The volume and sustainable yield
of leachate at the landfill would be identified through extended pumping of the landfill extraction wells.
Both Alternatives 3 and 4 include critical analyses and contingencies in the event agumentation is required.
The FPD would manage the system and would utilize local contractors, suppliers, and FPD personnel for system
monitoring, operation, and maintenance. The Wheaton Sanitary District POTW is currently being utilized to
treat the collected leachate under an existing pretreatment permit. It is not anticipated that major elements
of the system would require replacement. Submersible pumps placed in the leachate wells may require periodic
maintenance to ensure adequate performance.

Passive landfill gas venting exists at the Site. Passive landfill gas venting is widely used and has proven
to be an adequate and reliable means to limit landfill gas build-up and problems associated with landfill gas
accumulation. The venting system is mechanically simple to operate and maintain. Both Alternatives 3 and 4
have a contingency for transition from passive to active treatment and the addition of gas vents. These are
activities that have been successfully completed at numerous sites, and there are a number of proven
technologies for active gas collection and on-Site treatment.

Alternative 3 includes ground water Monitored Natural Attenuation. The science behind this technology is
rapidly expanding and becoming more well defined. Monitored Natural Attenuation has been successfully applied
to a wide range of contaminants in a ever-expanding universe of Site-specific conditions. For Monitored
Natural Attenuation, there are no specialized field engineered systems that require maintenance or operation.

Alternative 4 includes ground water extraction and treatment, which is a well developed and widely utilized
remedial technology. Because of the number of wells and the high pumping rate that would be required to
achieve hydraulic control in the permeable outwash deposits, long-term management and maintenance of the
system would be required. However, this is a technology with proven reliability.

4. Reduction of Toxicity, Mobility, or Volume Through Treatment
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This criterion considers factors such as: the treatment process used and the material treated; the amount of
hazardous material destroyed or treated; the reduction in toxicity, mobility, or volume through treatment;
the irreversibility of the treatment; the type and quantity of treatment residuals; and the reduction of
inherent hazards. These factors are considered where appropriate.

A. Treatment Process Used and Materials Treated

Leachate - Both Alternatives 3 and 4 include extraction ard collection of leachate at the landfill, followed
by off-Site treatment of the extracted leachate to remove inorganics and destroy organics. Treatment of the
extracted leachate would be off-Site at the Wheaton Sanitary District POTW. The metals in the leachate are
treated through precipitation; semivolatiles and volatiles are biologically treated.

Landfill Gas - Both Alternatives 3 and 4 include possible augmentation from passive venting of landfill gas
to active collection and on-Site treatment of landfill gas. Thermal treatment is a destructive technology
that would be used on-Site. This technology uses flame to thermally treat the gases and has an efficiency of
85% or greater.

Ground Water - Alternatives 3 and 4 both provide treatment components for ground water. Alternative 3 relies
on natural physical, chemical, and biological processes such as aerobic and anaerobic degradation, dilution,
adsorption, and advection to remediate ground water. Alternative 4 uses engineered systems to chemically
precipitate and physically strip contaminants from ground water. Both Alternatives are designed to meet
regulatory standards in a reasonable amount of time.

B. Amount of Contaminated Materials Destroyed or Treated

The volume of leachate in the landfill may be as high as 50-70 million gallons, and as much as 9,500 gallons
per day of leachate may be generated by infiltrating precipitation. Although there are a number of
uncertainties associated with these conservative estimates, the leachate extraction program under both
Alternative 3 and Alterative 4 will reduce the volume of contaminated leachate at the Site. Depending on the
accuracy of the volume estimates and sustainable yield of leachate, some portion or a majority of this
material may be collected at the Site and treated at the POTW.

C. Degree of Expected Reductions in Toxicity, Mobility, or Volume

Extraction, collection, and treatment of leachate from the landfill would result in reduction of leachate
toxicity for both Alternatives 3 and 4. The actual effect of a leachate extraction system on the reduction of
toxicity, mobility, and volume would be determined by measuring sustainable leachate yields during pumping,
and monitoring leachate heads in the landfill to develop reliable estimates of leachate volume.

Removal of leachate from the landfill would decrease the mobility of the landfill leachate by reducing the
hydraulic head potentially present at the landfill base. Use of submersible pumps in the leachate extraction
wells would provide hydraulic control of leachate migration and mobilize leachate contaminants towards the
collection wells. The volume of leachate present in the landfill would be reduced by extraction, provided the
extraction system could produce an effluent flow rate greater than the rate of infiltration through the
landfill cap. Both Alternatives utilize technologies that have been proven to effectively reduce contaminant
toxicity, mobility and volume.

Alternatives 3 and 4 include the existing passive landfill gas venting system to continue to relieve buildup
of gas within the landfill. The volume of gas within the landfill would decrease as the refuse in the
landfill stabilizes, reducing the risk associated with fracturing of the existing cap and generation of
future leachate. Alternatives 3 and 4 also contain contingent transition from passive to active landfill gas
extraction and on-Site destructive thermal treatment. These contingencies would result in larger volumes of
gas being removed and a destructive technology being applied. Both Alternatives utilize technologies that
have been proven to effectively reduce contaminant toxicity, mobility and volume.

Alternatives 3 and 4 also both have a ground water component with a remedial goal of meeting regulatory
standards in a reasonable amount of time. Alternative 3 relies on natural processes where Alternative 4
requires engineered systems such as on-Site pumping, active treatment and discharge. Both Alternatives are
based on technologies that have been proven to effectively reduce contaminant toxicity, mobility and volume.

D. Degree to Which Treatment is Irreversible
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Leachate extraction and off-Site disposal and treatment would irreversibly reduce the volume of leachate
present in the landfill. The concentrations would be reduced by removal of concentrated leachate that
accumulated in the landfill during construction and operation of the landfill. Leachate generated by recent
infiltration of rain water could have a lower contaminant concentration, thereby reducing the overall
toxicity of the leachate. Contaminants present in the extracted leachate would be irreversibly destroyed or
removed from the water by off-Site treatment at the Wheaton Sanitary District POTW.

Landfill gas would be irreversibly treated under the contingencies of Alternatives 3 and 4. Thermal treatment
is destructive to efficiencies greater than 85%.

The ground water components for Alternatives 3 and 4 would irreversibly reduce the volume of contaminants
present in ground water at the Site. Alternative 3 utilizes natural processes while Alternative 4 relies on
engineered practices. Both Alternatives provide irreversible treatment.

E. Type and Quantity of Residuals Remaining After Treatment

Any residuals associated with leachate treatment at the Wheaton Sanitary District POTW would be mixed with
non-Site related residuals associated with routine operation of the treatment plant. These residuals would be
disposed of according to the POTW permitting reguirements.

The landfill gas thermal treatment would result in residual air emissions. The technology is largely
destructive, but there would be residual gas emissions. These residual emission must be below regulatory
levels.

Alternative 3 has no ground water residuals after treatment. Ground water treatment under Alternative 4 may
result in off-Site disposal of metal residuals from a precipitate and discharge of treated water either to
on-Site surface water or the POTW.

F. Reduction of Inherent Hazards

Alternatives 3 and 4 would egually reduce inherent hazards posed by high leachate volumes and heads in the
landfill by leachate extraction and treatment. Alternatives 3 and 4 further reduce the mobility and volume of
leachate and landfill gas by maintaining the integrity of the cap. A correctly functioning cap will
significantly reduce the amount of infiltration that moves contaminants into leachate and ultimately migrates
to ground water. A reduction in infiltration will also directly result in a reduction in the volume of
leachate to be extracted and treated.

Alternatives 3 and 4 would egually reduce inherent hazards posed by landfill gas through passive gas
management. Depending upon the volumes and concentrations of gas, further reductions of inherent hazards may
occur through active collection and thermal treatment.

Alternatives 3 and 4 would egually reduce inherent hazards posed by ground water.

5. SHORT-TERM EFFECTIVENESS

Short-term effectiveness addresses the potential adverse effects that implementation of a remedial action may
cause, considers the length of time needed to implement an alternative and the risks the alternative poses to
workers, residents and the environment during implementation.

A. Risks to Community During Remedial Actions

Alternatives 3 and 4 pose only minor risks to the community from truck traffic reguired for transport of the
leachate for treatment.

B. Risks to Workers During Remedial Actions

There is a minor risk for workers during the transfer of leachate from the containment tank to the trucks for
transport to the treatment system under both Alternatives 3 and 4. These risks can be minimized by following
the Site Safety Plan, using the proper safety gear, proper maintenance, and the use of standard operating
procedures.

Workers performing sampling activities as part of implementing monitoring would incur potential risk through
exposure to chemicals in the ground water, leachate, and landfill gas. This risk would be minimized through
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the use of safety procedures and personal protective equipment.

Alternative 4 may present minor risk for workers during the construction, operation and monitoring of the
pump-and-treat system. This risk would be minimized through the use of safety procedures and personal
protective equipment.

C. Environmental Impacts

Implementation of either Alternative 3 or 4 is not anticipated to pose additional risk to the environment.

D. Time Until Remedial Action Objectives are Achieved

The Remedial Action Objective for leachate is reducing the volume of leachate which could have the potential
to release to ground water. The time needed to achieve the Remedial Action Objective to reduce leachate
volume would be dependent on the actual volume present in the landfill and the sustainable yield of leachate
recovery. It is anticipated that leachate will be required to be removed in the long-term (longer than 30
years).

Landfill gas management will also be required in the long-term (greater than 30 years) due to the potential
for damage to the cap.

Ground water Remedial Action Objectives are currently not being met on only a relatively small portion of the
Site. The exact time to meet regulatory standards would be estimated through completion of a Monitored
Natural Attenuation Study (Alternative 3) or in a ground water pump-and treat system design (Alternative 4).
A reasonable time frame for ground water clean up may be 30 years. Off-Site migration of ground water
contaminants is not occurring at the Site.

6. IMPIiEMENTABILITY

Implementability addresses the technical and administrative feasibility of a remedial action, including the
availability of services and materials and services needed to implement a particular option.

All Alternatives are expected to be technically feasible and administratively implementable.

A. Technical Feasibility

Leachate extraction, transport, and off-Site disposal is the same for both Alternatives 3 and 4. Operation of
the leachate extraction technology is well developed and an extraction system has been operational. The
degree of success of such a recovery system varies because of the changes in the total volume of leachate and
the availability of that leachate for extraction. The feasibility of recovering significant portions of
leachate from this Site would be evaluated through the first critical evaluation and continued operation of
the extraction system. Contingent augmentation is equivalently feasible.

The passive landfill gas venting system is in place and functioning. Implementing additional venting through
new leachate extraction wells would be technically feasible. Contingent augmentation for either Alternative 3
or 4 would use standard equipment and procedures and is also technically feasible.

Procedures for conducting Monitored Natural Attenuation of Ground Water under Alternative 3 are readily
implementable, well developed, and have proven reliability. Ground water extraction technologies are well
developed for Alternative 4, and construction of the treatment system is technically feasible. The
technologies of metal precipitation and air stripping would need to be sized accordingly, but there is
standard equipment and procedures for designing systems.

B. Administrative Feasibility

The ongoing leachate extraction and disposal component of both Alternatives are administratively feasible.
The existing pretreatment permit with the Wheaton Sanitary District POTW may need to be maintained for
on-going off-Site disposal of leachate for both Alternatives 3 and 4.

C. Availability of Services and Materials

The materials, services, and equipment required to implement both Alternatives 3 and 4 are readily available.
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7. Cost

Cost includes estimated capital and operation and maintenance costs for a remedial action.

Alternative 1

No Cost

Estimated Costs:

Capital Costs:
Contingent Leachate System $270,000
Contingent Gas $ 20,000
CONTINGENT CAPITAL COSTS $290,000

Operation and Maintenance Costs:
Leachate O&M $ 94,000
Cap O&M $ 2,400
Landfill Gas O&M $ 3,600
Monitoring $299,000
ANNUAL O&M $399,000

NET PRESENT WORTH (29 years at 7%) $5,739,000
(29 years at 3%) $8,497,000

Capital Costs The capital costs for the contingencies are estimated to be $290,000. This includes $270,000
for additional leachate and $20,000 for contingent gas collection and treatment.

Operation and Maintenance - Operation and maintenance costs would be those incurred from operating the
leachate recovery system, including power, mechanical systems upkeep, and periodic replacement (e.g.,
lubrication, repair, etc.), heating, and preheating (if appropriate). Operation and maintenance costs would
also be incurred for ground water guality monitoring, leachate head monitoring and characterization. The
annual O&M cost for Alternative 2 is estimated to be $399,000, with the largest cost going to monitoring. It
is assumed that the leachate extraction system would be operated for greater than 30 years.

Alternative 3 - Long-term Leachate Extraction and Off-Site Disposal; Contingent Augmentation of the Leachate
System and Landfill Gas Systems, Long-term O&M for all Existing Components; Long-term Monitoring, and
Monitored Natural Attenuation for Ground Water

Estimated Costs:

Capital Costs:
Contingent Leachate System $270,000
Contingent Gas $ 20,000
CONTINGENT CAPITAL COSTS $290,000

Operation and Maintenance Costs:
Leachate O&M $ 94,000
Cap O&M $ 2,400
Landfill Gas O&M $ 3,600
Monitoring $299,000
ANNUAL O&M $399,000

Monitored Natural Attenuation Costs:
Baseline Study $ 55,000
Additional Monitoring $ 25,000
TOTAL MNA COST $ 80,000

NET PRESENT WORTH (29 years at 7%) $5,819,000
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(29 years at 3%) $8,577,000

Capital Costs The capital costs for the contingencies are estimated to be $290,000. This includes $270,000
for additional the leachate system and $20,000 for contingent gas collection and treatment.

Operation and Maintenance - Operation and maintenance costs would be the same as Alternative 2 and include
costs incurred from operating the leachate recovery system, including power, mechanical systems upkeep, and
periodic replacement (e.g., lubrication, repair etc.), heating, and preheating (if appropriate). Operation
and maintenance costs would also be incurred for ground water guality monitoring, leachate head monitoring
and characterization. The annual O&M cost for Alternative 3 is the same as Alternative 2 and is estimated to
be $399,000, with the largest cost going to monitoring. It is assumed that the leachate extraction system
would be operated for greater than 30 years.

Ground Water - The ground water component in Alternative 3 includes Monitored Natural Attenuation. The
baseline study includes sampling for multiple parameters that are not included in routine monitoring and
complex fate and transport modeling. The baseline study is estimated to cost $55,000. Monitored Natural
Attenuation also may include additional rounds of sampling to illustrate progress toward restoring ground
water to its beneficial use in a reasonable amount of time. These additional sample reguirements are
estimated to cost $25,000.

Alternative 4 - Long-term Leachate Extraction and Off-Site Disposal; Contingent Augmentation of the Leachate
System and Landfill Gas Systems; Long-term O&M for all Existing Components; Long-term Monitoring, and Ground
Water Extraction and Treatment Construction/Operation.

Estimated Costs:

Capital Costs:
Contingent Leachate System $270,000
Contingent Gas $ 20,000
CONTINGENT CAPITAL COSTS $290,000

Ground Water Pump and Treat $726,000
Construction Cost

TOTAL CAPITAL COST $1,016,000

Operation and Maintenance Costs:
Leachate O&M $ 94,000
Cap O&M $ 2,400
Landfill Gas O&M $ 3,600
Monitoring $299,000
Ground Water $ 83,000
ANNUAL O&M $482,000

NET PRESENT WORTH (29 years at 7%) $7,553,813
(29 years at 3%) $10,923,813

Capital Costs The capital costs for the contingencies are estimated to be $290,000. This includes $270,000
for additional leachate and $20,000 for contingent gas collection and treatment, similar to Alternatives 2
and 3.

Ground Water - The ground water component in Alternative 4 includes installation of ground water
pump-and-treat system. The capital costs for this system are estimated at $726,000.

Operation and Maintenance - O&M costs would be similar to Alternatives 2 and 3. However, there would be
additional costs for O&M of the ground water system. The additional annual O&M for ground water treatment is
$83,000.

C. MODIFYING CRITERIA

8. STATE ACCEPTANCE

State acceptance indicates whether, based on its review of the RI/FS and Proposed Plan, the State of Illinois
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concurs, opposes, or has no comment on the selected remedial action.

The State of Illinois has expressed a willingness to concur with the selected remedy. The letter of
concurrence will be added to the Administrative Record for this Site.

9. COMMUNITY ACCEPTANCE

Community acceptance addresses the community's acceptance of the preferred Alternative presented in the
Proposed Plan based on comments received during the public comment period. The Responsiveness Summary,
attached to this ROD, contains the significant comments received during the public comment period and the
U.S. EPA's responses to those comments.

IX. THE SEIiECTED REMEDY

The U.S. EPA has selected Alternative 3 for the final remediation of the DuPage County Landfill Superfund
Site.

Alternative 3 includes:

• long-term institutional controls;
• long-term operation and maintenance of the improved landfill cap;
• long-term leachate extraction with possible augmentation of 9 additional wells;
• long-term off-Site leachate treatment and disposal;
• long-term passive landfill gas collection with possible augmentation to active with a
flare;
• Monitored Natural Attenuation for ground water ; and
• long-term ground water, leachate, landfill gas monitoring.

Estimated Costs:

Capital Costs:
Contingent Leachate System $270,000
Contingent Gas $ 20,000
CONTINGENT CAPITAL COSTS $290,000

Operation and Maintenance Costs:
Leachate O&M $ 94,000
Cap O&M $ 2,400
Landfill Gas O&M $ 3,600
Monitoring $299,000
ANNUAL O&M $399,000

Monitored Natural Attenuation Costs:
Baseline Study $ 55,000
Additional Monitoring $ 25,000
TOTAL MNA COST $ 80,000

NET PRESENT WORTH (29 years at 7%) $5,819,000
(29 years at 3%) $8,577,000

The long-term institutional controls (deed restrictions, erosion/flood control) and operation and maintenance
of the cap (inspections, improvements, etc.) will begin immediately and extend for the long-term (greater
than 30 years). These components of the remedy will ensure that land use changes or on-site construction is
not completed in a way that may present an exposure risk or would negatively impact the remedy. Specifically,
the deed restrictions bars future development of the Site and bars ground water use. The cap will eliminate
possible direct exposure to leachate, landfill gas, or other waste material. Also, the cap will result in a
significant reduction in the long-term generation of leachate.

The selected remedy will address the main source of mobile contamination by the extraction and off-Site
treatment of leachate from the landfill for the long-term (greater than 30 years). Extraction of leachate and
maintenance of the cap will be ongoing responsibilities. Treatment and disposal of the leachate will be
conducted off-Site in the long-term.
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Landfill gas will also be addressed in the long-term (greater than 30 years) due to the ongoing threat of gas
build-up damaging the cap. Landfill gas will be addressed to minimize exposure and the threat of migration to
ground water. Landfill gases will be managed to allow future recreational use of Mt. Hoy for the long-term.

The recommended Alternative may or may not reguire additional design and construction of the contingent
components. The first critical evaluation will be completed after one year of operation. If augmentation is
reguired, it would be completed in about 3.5 years.

Ground water contamination should continue to decrease dramatically and result in achieving cleanup levels in
less than the estimated 30 years. A detailed analysis of the ground water projections will be completed
during the first phase of the Monitored Natural Attenuation Remedy Study. The Monitored Natural Attenuation
of ground water may include varying combinations of biodegradation, abiotic transformations, intrinsic
bioremediation, dilution, dispersion and adsorption of ground water contaminants. Preliminary analytical data
strongly support the projected success of MNA to meet cleanup goals in a reasonable amount of time. Order of
magnitude decreases in ground water contaminants have been documented from 1992 sampling compared to the
results of the 1997/98 data. It is reasonably expected that once the other components of the remedy have been
in place for a while, significant additional improvements in ground water guality will be realized. Based on
existing data, it appears that ground water guality has made significant improvement, such that regulatory
standards may be met well in advance of 30 Years. Additionally, contamination significantly above background
levels is not migrating off-Site.

Monitoring is an essential part of this remedy. A monitoring network will be established on the Site that
includes leachate, landfill gas, and ground water. Monitoring will serve two purposes: 1) evaluate the
effectiveness of the treatment/containment components or the remedy to reduce risks, and 2) monitor for
changes in potential migration of contaminated media from the Site. If monitoring identifies that
contamination is not decreasing or being managed appropriately and/or cleanup levels are not being achieved,
the remedy will be re-evaluated.

Cleanup levels to be achieved by the selected remedial action will be chemical-specific ARARs. If multiple
contaminants are present in the media (i.e. ground water), and cleanup of individual contaminants to ARARs
result in a cumulative risk in excess of 10 -6 across a media, cleanup levels of contaminants will be
risk-based and cumulative across a media to 10 -6 or less. If chemical-specific ARARs (to not exist for
contaminants, cleanup levels of contaminants will be risk-based and cumulative across a media to 10 -6 or
less.

The point of compliance for ground water cleanup levels will be the landfill boundary. Ground water will meet
the U.S. EPA primary MCLs and EPA 620 Standards outside of the landfill footprint. All on-Site ground water
that does not currently meet these standards will be placed in a ground water management zone and remediated
using Monitored Natural Attenuation. On-Site ground water will be managed as a IAC 620 Groundwater Management
Zone until the standards or background concentrations are met.

The point of compliance for cleanup levels of landfill gas emissions shall be sampling at the top of the Mt.
Hoy and the landfill boundary. These are areas of potential landfill gas emissions and areas of recreational
use. The air standards for recreational users is 10 -6 and a hazard index less than 1.

The selected remedial action is expected to be the final response for the Site. Because this remedial action
will result in hazardous substances remaining on-Site, a review will be conducted within five years after
commencement of remedial action to ensure that the remedial action continues to provide adeguate protection
of human health and the environment.

X. STATUTORY DETERMINATIONS

U.S. EPA's primary responsibility at Superfund sites is to select and implement remedial actions that achieve
adeguate protection of human health and the environment. Section 121 of CERCLA establishes several statutory
reguirements and preferences. When complete, a remedy selected by U.S. EPA must comply with ARARs under
federal and state environmental laws (unless a statutory waiver is justified). The selected remedy must also
be cost effective and utilize permanent solutions and alternative treatment or resource recovery to the
maximum extent practicable. Finally, the statute includes a preference for remedies that employ treatment
processes that permanently and significantly reduce the toxicity, mobility, or volume of
hazardous substances, pollutants, and contaminants. The U.S. EPA believes that Alternative 3 meets the
threshold criteria and provides the best protection with respect to the criteria used to evaluate the
alternatives (National Contingency Plan 40 CFR Part 300.430(f)(5)(ii)(A-F). The implementation of the
selected remedy at the Site satisfies these reguirements and preferences as follows:
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A. Protection of Human Health and the Environment

The selected remedy will protect human health and the environment by utilizing institutional controls to
reduce risks. Specific actions include fencing portions of the Site and posting warning signs and imposing
deed restrictions on the landfill property. The risks posed by inhalation of landfill gases are reduced by
collecting and treating landfill gases, if necessary. The potential for direct exposure to leachate will be
addressed through the cap and leachate extraction and off-Site treatment.

The ground water will be actively addressed through Monitored Natural Attenuation. In addition to Monitored
Natural Attenuation, the interaction of several components of Alternative 3 will assist in decreasing ground
water contamination and achieve cleanup levels. The repaired landfill cap will reduce infiltration of
precipitation into the landfill, thereby reducing generation of leachate, and will also reduce the
percolation of leachate from the landfill into ground water. Extraction and treatment of leachate from the
landfill will address the primary source of ground water contamination. Management of landfill gas will also
minimize the threat of gas migrating to ground water.

Cleanup levels to be achieved by the selected remedial action will be chemical-specific ARARs. If multiple
contaminants are present in the media (i.e. ground water), and cleanup of individual contaminants to ARARs
result in a cumulative risk in excess of 10 -6 across a media, cleanup levels of contaminants will be
risk-based and cumulative across a media to 10 -6 or less. If chemical-specific ARARs do not exist for
contaminants, cleanup levels of contaminants will be risk-based and cumulative across a media to 10 -6 or
less.

Long-term monitoring will be conducted to ensure the effectiveness of the remedy.

B. Attainment of ARARs

Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)

Applicable reguirements are those cleanup standards, standards of control, and other substantive
reguirements, criteria, or limitations promulgated under Federal or State environmental or facility siting
law that specifically address a hazardous substance, pollutant, contaminant, remedial action, location, or
other circumstance at a CERCLA site. Relevant and Appropriate reguirements are those cleanup standards,
standards of control, and other substantive reguirements, criteria, or limitations promulgated under Federal
or State environmental or facility citing law that, while not "applicable" to a hazardous substance,
pollutant, contaminant, remedial action, location, or other circumstance at a CERCLA site, address problems
or situations sufficiently similar to those encountered at the CERCLA site that their use is well suited to
this particular Site.

Compliance with ARARs addresses whether a remedial action will meet all reguirements of federal and state
environmental laws and regulations and/or provide a basis for a waiver from any of these laws. Federal and
State ARARs are divided into three categories: chemical-specific, action-specific, and location-specific.
Alternative 3 will meet or attain all Federal or State ARARs and will be implemented in a manner consistent
with those laws. It is important to note that on-Site actions are reguired to comply with ARARs, but must
comply only with the substantive parts of the ARAR. Off-Site actions must comply only with applicable
reguirements, but must comply fully with both substantive and administrative reguirements. The selected
remedy will meet all ARARs under federal and more stringent state environmental laws. A list
of ARARs for the Site is contained in Tables 9, 10 and 11. The primary ARARs that will be achieved by the
selected remedy are:

1. Chemical-Specific ARARs

Chemical specific ARARs regulate the release to the environment of specific substances having chemical
characteristics. Chemical-specific ARARs typically determine the extent of clean-up at a Site. For this Site,
these are:

a. Federal Chemical-Specific ARARs

Chemical-specific ARARs include those laws and reguirements that regulate the release of contaminants to the
environment. These include:

Safe Drinking Water Act, 40 CFR 141.61 (organic) and 141.62 (inorganic) Maximum Contaminant Levels (MCLs)
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and, to a certain extent, 40 CFR 141.50 (organic) and 141.51 (inorganic) non-zero Maximum Contaminant Level
Goals (MCLGs). The Federal Drinking Water Standards promulgated under the Safe Drinking Water Act (SDWA) are
applicable to municipal drinking water supplies servicing 25 or more people. MCLGs are relevant and
appropriate when the standard is set at a level greater than zero (for non-carcinogens), otherwise,
MCLs are relevant and appropriate. At the Site, MCLs and MCLGs are relevant and appropriate. The point of
compliance for the Federal drinking water standards is at the boundary of the landfill.

Clean Air Act (40 CFR Part 50) - The Clean Air Act reguirements include the TSP standard for air discharges.
This reguirement is applicable to the Site because the gas extraction and treatment, leachate treatment, and
various other treatment methods which are part of this remedy are potential sources of fugitive dust,
particulates, and/or VOCs.

b. State Chemical-Specific ARARs

Illinois Administrative Code Class I Potable Resource Ground Water Quality Standards listed in 35 IAC 620.410
apply to ground water. For Alternative 3, until compliance with the standards of IAC 620.410 are achieved,
ground water would be managed as a Groundwater Management Zone under IAC 620.450.

Illinois Administrative Code for landfills. The chemical-specific air reguirements are contained in 35 IAC
Section 243 limits emissions of photochemically reactive organic material (e.g., VOCs) to less than 8 pounds
per hour. The system is currently operating below that amount. Should augmentation be reguired in Alternative
3 that result in greater than 8 pounds per hour, controls to reduce emissions may be reguired.

2. Location -Specific ARARs

Location-specific ARARs are those reguirements that relate to the geographic position (if the Site. For the
Site, these are:

a. Federal Location-Specific ARARs

Floodplain Management Executive Order 11988, 40 CFR 6, Appendix A, Section 6(a)(5) - This order reguires
minimization of potential harm to or within flood plains and the avoidance of long- and short-term adverse
impacts associated with the occupancy and modification of flood plains. This order is applicable to the Site
since it is located within a flood plain and additional work may be reguired. Alternative 3 would meet this
ARAR.

Wetland Management Executive Order 11990 - This order reguires federal agencies to avoid, to the extent
possible, the long- and short-term adverse impacts associated with the destruction or modification of
wetlands. This reguirement is applicable to the Site since there are wetlands located on the Site and
additional contingent work may be reguired. Alternative 3 would meet this ARAR.

Clean Water Act 40 CFR 230.70-230.77 - Reguires actions to minimize adverse effects of dredged or fill
materials. Alternative 3 would meet this ARAR.

Fish and Wildlife Coordination Act - Reguires Federal agencies to take action to protect fish and wildlife
resources that may be affected by stream or body of water modifications. Alternative 3 would meet this ARAR.

b. State Location-Specific ARARs

Location-specific ARARs are those reguirements that relate to the geographical location of a Site. State
location-specific ARARs identified for this action are:

35 IAC 811 and 35 IAC 724 100-Year Floodplain reguirements - A facility shall not restrict the flow of a
100-year flood, result in washout of solid waste from a 100-year flood, or reduce the temporary water storage
capacity of the 100-year floodplain. A facility located in a 100-year floodplain must be designed,
constructed, operated, and maintained to prevent washout of any hazardous waste by a 100-year flood.
Alternative 3 meets this ARAR.

92 IAC Part 708 Construction and Filling Reguirements - Governs construction and filling in the regulatory
floodway of rivers, lakes, and streams of Cook, DuPage, Kane, Lake, McHenry, and Will Counties, excluding the
City of Chicago. Alternative 3 meets this ARAR.

3. Action-Specific ARARs
-------
a. Federal Action-Specific ARARS

OSHA 29 CFR Safety Standards - Construction activities included in Alternative 3 would be subject to
standards found in 29 CFR 1910 and 29 CFR 1926. Threshold limit values would be monitored in the breathing
zone during construction activities. Alternative 3 would meet this ARAR.

Clean Air Act and Emission Limitations, CAA Section 112, 40 CFR 61.12-14. Requires that emissions of
hazardous pollutants do not exceed levels expected from sources in compliance with hazardous air pollution
regulations These requirements relate to air quality and emission limitations for landfill gas. Alternative 3
would meet this ARAR.

40 CFR 122 and 125, the National Pollution Discharge Elimination System Permit Regulations and 40 CFR 131 the
Water Quality Effluent Limitations sections applies to the off-Site treatment and disposal of leachate.
Alternative 3 would meet these ARARs.

b. State Action-Specific ARARs

35 IAC 807 and 811 Post-Closure Care - Establishes minimum requirements for maintenance and inspection of
final cover and vegetation and establishes minimum requirements for ground water and landfill gas monitoring.
Alternative 3 would meet these ARARs.

35 IAC 811 206, 308 and 309 Post-Closure Care for Leachate Treatment, Storage and Disposal - These
regulations deal with the leachate sampling, leachate collection, leachate storage and the extracted leachate
that would be treated off-Site by a POTW under an existing permit. Alternative 3 would meet these ARARs.
Augmentation of the leachate system would also meet 35 IAC 811.309 system design requirements.

35 IAC 807 and 811 Post-Closure Care for Landfill Gas - These regulations deal with monitoring landfill gas.
35 IAC 218 deals with ongoing landfill gas emissions. Alternative 3 would meet these ARARs. If augmentation
including on-Site construction of a thermal treatment device is completed, it would be done so that it is in
compliance with Illinois Administrative Code for construction of Landfill Gas Systems (35 IAC 811.310 and
311). The augmentation would also trigger sampling under 35 IAC 221-218 and compliance with the Clean Air
Act, Section 112, 40 CFR 61.12-14. If augmentation is required, the system would be designed to meet these
requirements.

4. To Be Considered

No To Be Considered criteria were found.

C. Cost Effectiveness

The U.S. EPA believes that the selected remedial action is cost-effective in mitigating the risks posed by
the Site contaminants within a reasonable period of time. Section 300.430(f)(ii)(D) of the NCP requires that
EPA evaluate cost-effectiveness by comparing all the alternatives which meet the threshold criteria of
protection of human health and the environment against three additional balancing criteria: long-term
effectiveness and permanence; reduction of toxicity, mobility, or volume through treatment; and short-term
effectiveness. The selected remedial action meets these three criteria and provides overall effectiveness in
proportion to its cost. The estimated cost for the selected remedial action is $290,000 in contingent capital
cost, $399.000 in annual O&M and $80,000 in ground water Monitored Natural Attenuation cost, which is a
reasonable value for the results expected to be achieved by the selected remedial action. The Net
Present Value for Alternative 3 for 29 years at the 7% discount rate is $5,819,000. The U.S. EPA believes the
selected remedy is the most cost-effective remedy that also achieves ARARs and satisfies the other criteria
of the NCP and Section 121 of CERCLA.

D. Utilization of Permanent Solutions and Alternative Treatment Technologies to the Maximum Extent
Practicable

U.S. EPA has determined that the selected remedy represents the maximum extent to which permanent solutions
can be utilized in the most cost-effective manner to eliminate exposure to contaminated soil at the Site and
prevent the continued migration of contaminants into the ground water. Of the alternatives that are
protective of human health and the environment and comply with ARARs, U.S. EPA has determined that the
selected Alternative provides the best balance in terms of long-term effectiveness and permanence, reduction
in toxicity, mobility or volume through treatment, short-term effectiveness, implementability, cost and
-------
consideration of state and community acceptance.

The criterion of overall protection of human health and the environment and long-term effectiveness and
permanence were crucial in the decision to select Alternative 3. Overall protection of human health and the
environment was best achieved by the selected remedial action because it provides protection of human health
from risks through institutional controls and cap maintenance to eliminate the direct exposure pathway,
collection and off-Site treatment and disposal of leachate. The threat of exposure to landfill gas and damage
to the cap is managed by the landfill gas system, and ground water is addressed through Monitored Natural
Attenuation. By treating leachate, collecting landfill gas, and minimizing infiltration, ground water
contamination will decrease, cleanup levels will be achieved, and the continued migration
of leachate and contaminated ground water is reduced.

Long-term effectiveness and permanence was best achieved by the selected remedial action due to leachate and
ground water treatment components. Leachate in the landfill will be extracted and treated to reduce residual
risks in ground water. The ground water in the shallow aguifer beneath and adjacent to the landfill will be
cleaned up through Monitored Natural Attenuation. U.S. EPA believes that Monitored Natural Attenuation can
achieve cleanup standards in a time that is comparable to pump-and-treat, is egually as protective as
pump-and-treat, is far less costly ($5,819,000 Net Present Worth for Alternative 3 versus $7,553,813 for
Alternative 4), and is more easily implemented.

The State of Illinois has expressed a willingness to concur with the selected remedy. The letter of
concurrence will be added to the Administrative Record for this Site. The community's comments received
during the public comment period are summarized in the Responsiveness Summary, attached to this ROD, along
with the U.S. EPA's response to comments.

The selected remedial action meets the statutory reguirement to utilize permanent solutions and treatment
technologies, to the maximum extent practicable.

E. Preference for Treatment

The selected remedial action satisfies the statutory preference for treatment as a principal element.
Landfill leachate will be collected/extracted and treated off-Site. Depending upon landfill gas
concentrations, landfill gas may also be thermally treated on-Site. Ground water will be treated on-Site
using natural attenuation processes. The DuPage County Landfill, the low level waste source of contamination,
will not be treated, but will be contained by a landfill cap.

XI. RESPONSIVENESS SUMMARY

This Responsiveness Summary has been prepared to meet the reguirements of Sections 113(k)(2)(B)(iv) and
117(b) of CERCLA, as amended by SARA, which reguires U.S. EPA to respond "to each of the written or oral
presentations" on a Proposed Plan for remedial action. On July 8, 1998, U.S. EPA made available to the public
for review and comment the FS and Proposed Plan for the final remedy at the Site. U.S. EPA received comments
at the public meeting on July 12, 1998. Additional written comments were also submitted to U.S. EPA during
the comment period. This Responsiveness Summary summarizes those comments and concerns expressed by the
public and other interested parties in written and oral form on the recommended remedy.

Summary of Comments Received During the Public Comment Period

Comments received during the public comment period are summarized in this section. Some of the comments have
been paraphrased in order to effectively summarize them in this document. For the sake of consistency and
privacy, U.S. EPA has referred to all individual commenters as "he." The reader is referred to the public
meeting transcript and copies of written comments submitted, all of which are contained in the Administrative
Record for the Site. The Administrative Record is available for review at the information repositories.

Comment

I would want to ensure that monitoring extend beyond the limits of the current plume as long as
possible, that it not be restricted just to the areas that are currently seen as troublesome but that
it look at the broader picture, particularly in that southeast guadrant where the drainage down
towards Spring Brook and river occurs.

Response
-------
The U.S. EPA concurs with the comment on the necessity to sample not only in the area of known
contamination but downgradient from that area. For this reason the FPD is required to submit
a long-term plan to sample wells within the plume (called detection wells) and downgradient of
the plume (called compliance wells). The approved monitoring plan calls for sampling thirteen
(13) wells within the area of contamination (detection wells) and ten (10) wells downgradient
(compliance wells) of the contamination. Four (4) of the ten (10) compliance wells were recently
installed to be used in combination with the previously installed wells. These wells are placed
in the very guadrant between the landfill and Spring Brook and the river identified in this
comment. These wells will be sampled for the long-term.

Comment

Are there any plans to retest the wells in the vicinity when you think you have got the problem
solved?

Response

There are several areas and wells to which this comment could apply so the following will
respond to each. The first area of note is the detection wells located within the plume (the area
where there is currently contamination). Sampling in this area will continue in the long-term,
well past the time when contamination is no longer present. The FPD will be required to
initially demonstrate through sampling that the contamination is being reduced within the plum.
In the longer-term the FPD will be required to demonstrate through sampling that the other
remedy components are working (cap, landfill gas, leachate removal). For this reason, the
detection wells will be sampled, most likely, inperpetuity. The second area is the compliance
wells located downgradient of the detection wells. These compliance wells will be sampled as
long as contamination is detected in the detection wells, and for some period after contamination
is no longer present. So for these areas, the wells will also be retested. There are also a number
of additional wells on-Site that are not designated as compliance or detection wells and there
are private wells on the other side of Spring Brook. It is anticipated that none of these wells
will be retested unless specific information identified at a later time indicates this need.
Sampling of these wells is currently considered either unnecessary to monitor the extent of
contamination and/or unnecessary to demonstrate the remedy's effectiveness.

XII. ADMINISTRATIVE RECORD

The Superfund Administrative Record Index for this Site is attached.

-------
U.S. EPA ADMINISTRATIVE RECORD
REMEDIAL ACTION
DUPAGE COUNTY LANDFILL/BLACKWELL FOREST PRESERVE
DUPAGE COUNTY, ILLINOIS
UPDATE #1
05/24/95
TITLE/DESCRIPTION
AR
DOC#
1
2
3
4
5
6
DATE
12/00/94
12/00/94
12/00/94
12/00/94
12/00/94
12/00/94
AUTHOR
Warzyn Inc.
Warzyn Inc.
Warzyn Inc.
Warzyn Inc.
Warzyn Inc.
Warzyn Inc.
RECIPIENT
U.S.
U.S.
U.S.
U.S.
U.S.
U.S.
EPA
EPA
EPA
EPA
EPA
EPA
Final Remedial Investigation Report: Volume 1
of 3 (Text, Tables, and Figures)

Final Remedial Investigation Report: Volume 2
of 3 (Appendices A-F)

Final Remedial Investigation Report: Volume 3
of 3 (Appendices G-Y)

Final Remedial Investigation Report: Volume 3
of 3 (Addendum 1 of 3: Attachment E)

Final Remedial Investigation Report: Volume 3
of 3 (Addendum 2 of 3: Attachment E)

Final Remedial Investigation Report: Volume 3
of 3 (Addendum 3 of 3: Attachments F-0)
PAGES

424

628

469

766

734

744
-------
U.S. EPA ADMINISTRATIVE RECORD AR
REMEDIAL ACTION
DUPAGE COUNTY LANDFILL/BLACKWELL FOREST PRESERVE
DUPAGE COUNTY, ILLINOIS
UPDATE #2
10/01/96

DOC# DATE AUTHOR RECIPIENT TITLE/DESCRIPTION PAGES

1 03/01/96 U.S. EPA Forest Preserve Administrative Order by Consent w/Attached 62
District of DuPage Cover Letter
County
-------
NO.
U.S. ENVIRONMENTAL PROTECTION AGENCY
REMEDIAL ACTION
ADMINISTRATIVE RECORD
FOR
DUPAGE COUNTY LANDFILL/BLACKWELL FOREST PRESERVE LANDFILL SITE
DUPAGE COUNTY, ILLINOIS
UPDATE #3
JULY 9, 1998
DATE AUTHOR RECIPIENT TITLE/DESCRIPTION
PAGES
1 12/28/92 Hoffman, D., Lance, R.,
Warzyn, Inc. U.S. EPA
Cover Letter Forwarding
the Draft Feasibility
Study for the Blackwell
Forest Preserve Landfill
Site
2 01/22/93 McLane, G.,
PRC
Environmental
Management,
Inc.
Lance, R.,
U.S. EPA
Letter re: PRC's Comments
on the December 1992
Draft Feasibility Study
for the Blackwell Forest
Preserve Landfill Site
13
3 01/25/93 Tuggle, B.,
U.S. DOI/
Fish &
Wildlife
Service
Lance, R.,
U.S. EPA
Letter re: FWS 's Comments
on the Draft Feasibility
Study for the Blackwell
Forest Preserve Landfill
Site
4 01/28/93 Marrero, J. ,
U.S. EPA/
Air Toxics
& Radiation
Branch
Lance, R.,
U.S. EPA
Memorandum re: ATRB's
Review of the Draft
Feasibility Study Report
for the Blackwell Forest
Preserve Site
5 01/29/93 Kleiman, J. , Lance, R.,
U.S. EPA U.S. EPA
Memorandum re: RCRA's
Review of the Draft
Feasibility Study for
ARARs for the Blackwell
Forest Preserve Site
6 07/28/94 Warzyn
Engineering
U.S. EPA
Drawing: Water Table
Map for Upper Aquifer
at the Backwell Forest
Preserve Landfill Site
7 02/21/95 Kleman, J.,
U.S. EPA
Heaton, D.,
U.S. EPA
Memorandum re: RCRA's
Review of the Alternative
Array Document for the
Blackwell Forest Preserve
Landfill Site for ARARs
04/04/95 Marrero, J.,
U.S. EPA/
Air Toxics
& Radiation
Branch
Heaton, D.,
U.S. EPA
Memorandum re: ARARs
for the Blackwell Forest
Preserve Landfill Site
9 04/07/95 Lanham, R., Heaton, D.,
IEPA U.S. EPA
Letter re: lEPA's
Response to U.S. EPA's
Request for Additional
ARARs Information for
the Blackwell Forest
Preserve Landfill Site
-------
NO. DATE
AUTHOR
RECIPIENT
DuPage County/Blackwell Forest AR
Update #3 Page 2
TITLE/DESCRIPTION PAGES
10 07/24/95 Marrero, J. ,
U.S. EPA/
Air Toxics
& Radiation
Branch
Heaton, D.,
U.S. EPA
Memorandum re: ATRB's
Review of the Draft
Feasibility Study for
the Blackwell Forest
Preserve Landfill Site
11 08/08/95 Kleiman, J. , Heaton, D.,
U.S. EPA U.S. EPA
Memorandum re: RCRA's
Review of the Feasibility
Study for the Blackwell
Forest Preserve Landfill
Site for ARARs
12 03/01/96 Muno, W.,
U.S. EPA
Utt, R.,
Forest
Preserve
District
of DuPage
County
Letter Forwarding
Attached Administrative
Order by Consent for
the DuPage County Land-
fill/Blackwell Forest
Preserve Site
60
13
1997
Montgomery
Watson
Addressees
Construction Progress
Meeting Notes for the
Period August 26 -
December 3, 1997 for the
Blackwell Forest Preserve
Landfill Site
29
14 1997-1998 Montgomery
Watson
U.S. EPA
Monthly Progress Reports
for the Period October
1997 - May 1998 for the
Blackwell Forest Preserve
Landfill Site
53
15 01/00/97 Montgomery
Watson
U.S. EPA
Technical Memorandum:
Predesign Investigation
for the Blackwell Forest
Preserve Landfill Site
299
16 02/00/97 Montgomery
Watson
U.S. EPA
Leachate Collection
System Expedited Final
Design: Volume 1 of 2
(Text, Tables, Figures
and Appendices A-D)
[Final] for the Blackwell
Forest Preserve Landfill
Site
201
17 02/00/97 Montgomery
Watson
U.S. EPA
Leachate collection
System Expedited Final
Design: Volume 2 of 2
(Appendices E-G) [Final]
for the Blackwell Forest
Preserve Landfill Site
188
18 03/04/97 Bellot, M.,
U.S. EPA
Benedict, J.
Forest
Preserve
District
of DuPage
County
Letter re: U.S. EPA's
Comments on the Predesign
Investigation Technical
Memorandum for the Black-
well Forest Preserve
Landfill Site
-------
NO. DATE
AUTHOR
19 04/10/97 Montgomery
Watson
RECIPIENT

U.S. EPA
DuPage County/Blackwell Forest AR
Update #3 Page 3
TITLE/DESCRIPTION PAGES
Predesign Report for
the Blackwell Forest
Preserve Landfill Site
w/ Cover Letter
335
20 04/04/97 Bellot, M.,
U.S. EPA
Benedict, J.
Forest
Preserve
District
of DuPage,
County
Letter re: U.S. EPA/
lEPA's Comments on the
February 1997 Leachate
Collection System Ex-
pedited Final Design
Report for the Blackwell
Forest Preserve Landfill
Site
21 04/10/97 Montgomery
Watson
U.S. EPA
MW's Responses to U.S.
EPA's March 4, 1997
Comments on the January
1997 Predesign Investiga-
tion Technical Memorandum
for the Blackwell Forest
Preserve Landfill Site
22 04/21/97 Buettner, W. Bellot, M.,
& P. Vagt; U.S. EPA;
Montgomery et al.
Watson
FAX Transmission re:
Preliminary Agenda for
the April 23, 1997
Meeting Concerning the
Blackwell Forest Preserve
Landfill Site
23 04/23/97 Montgomery
Watson
U.S. EPA
Tables: (1) SOW Com-
pliance Project schedule,
(2) Expedited Project
Schedule and Drawings:
(3) Preliminary Grading
Plan and (4) Typical
Cover Details for the
Blackwell Forest Preserve
Landfill Site
24 05/00/97 Montgomery
Watson
U.S. EPA
Revised Leachate Collec-
tion System Expedited
Final Design: Volume 1 of
2 (Text, Tables, Figures
and Appendices A-D)
[Final] for the Blackwell
Forest Preserve Landfill
Site
217
25 05/00/97 Montgomery
Watson
U.S. EPA
Revised Leachate Collec-
tion System Expedited
Final Design: Volume 2 of
2 (Appendices E-G) [Final]
for the Blackwell Forest
Preserve Landfill Site
184
-------
NO. DATE
AUTHOR
RECIPIENT
DuPage County/Blackwell Forest AR
Update #3 Page 4
TITLE/DESCRIPTION PAGES
26 05/02/97
Vagt, P. &
W. Buettner;
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter re: MW's Response
to U.S. EPA/IEPA' s
Comments on the February
1997 Leachate Collection
System Expedited Design
Report for the Blackwell
Forest Preserve Landfill
Site
13
27 05/13/97
Bellot, M., Benedict, J. , Letter re: U.S. EPA's
U.S. EPA Forest Partial Approval of the
Preserve Leachate Collection Sys-
District terns Expedited Final
of DuPage Design Report for the
County Blackwell Forest Preserve
Landfill Site
28 05/15/97
Buettner, W.,
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter Forwarding
Attached Photographs of
the North and West
Stormwater Collection
systems at the Blackwell
Forest Preserve Landfill
Site
29
05/20/97
Dovantzis, K. ,
PRC
Environmental
Management,
Inc.
Bellot, M.,
U.S. EPA
Letter re: PRC's Tech-
Review of the May 1997
Leachate collection
System Expedited Final
Design Report for the
30 06/02/97
Montgomery
Watson
U.S. EPA
Cap Repair 100% Design
Report for the Blackwell
Forest Preserve Landfill
Site w/ Cover Letter
156
31 06/09/97
Buettner, W.,
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter re: Boring Logs
Omitted from the April
1997 Predesign Report
for the Blackwell Forest
Preserve Landfill Site
32 06/09/97 Buettner, W., Bellot, M.,
Montgomery U.S. EPA
Watson
Letter re: Manhole MH-3
Groundwater Sample Results
at the Blackwell Forest
Preserve Landfill Site
76
33 06/16/97 Bellot, M.,
U.S. EPA
Benedict, J. ,
Forest
Preserve
District
of DuPage
County
Letter re: U.S. EPA/
lEPA's Comments on the
May 1997 Final Leachate
Collection System Ex-
pedited Final Design
Report for the Blackwell
Forest Preserve Landfill
Site
-------
NO. DATE
AUTHOR
RECIPIENT
DuPage County/Blackwell Forest AR
Update #3 Page 5
TITLE/DESCRIPTION PAGES
34 06/17/97 Bellot, M.,
U.S. EPA
Benedict, J.
Forest
Preserve
District
Letter re: U.S. EPA's
Conditional Approval of
the June 1997 Cap Repair
100% Design Report for
the Blackwell Forest
Preserve Landfill Site
35 06/23/97
Dovantzis, K. ,
PRC
Environmental
Management,
Inc.
Bellot, M.,
U.S. EPA
Letter re: PRC's Tech-
nical Review of the June
1997 Cap Repair 100
Percent Design Report
for the Blackwell Forest
Preserve Landfill Site
36 07/00/97 Montgomery
Watson
U.S. EPA
Revised Predesign Report
for the Blackwell Forest
43
Preserve Landfill Site
37 07/03/97 Vagt, P.,
Montgomery
Watson
Addressees
Memorandum re: the July
15, 1997 Pre-Construction
Meeting for the Blackwell
Forest Preserve Landfill
Site
38 07/10/97 Buettner, W., Bellot, M.,
Montgomery U.S. EPA
Watson
Letter re: MW's Response
to U.S. EPA/IEPA' s
June 16, 1997 Comments on
the Final Leachate Collec-
tion System Expedited
Final Design Report for
the Blackwell Forest
Preserve Landfill Site
20
39 07/14/97 Van Matre, L., Public
Chicago
Tribune
Newspaper Article: Waste
Cleanup to be Done at
Blackwell
40 07/25/97 Dovantzis, K. , Bellot, M.,
PRC U.S. EPA
Environmental
Management,
Inc.
Letter re: PRC's Tech-
nical Review of MW's
July 10, 1997 Response
to U.S. EPA's Comments
on the Leachate Collection
System Expedited Final
Design Report for the
Blackwell Forest Preserve
Landfill Site
41
07/28/97
Buettner, W.,
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter Forwarding
Attached Draft Deed
Restriction for the DuPage
county Landfill/Blackwell
Forest Preserve Site
-------
NO. DATE
AUTHOR
RECIPIENT
DuPage County/Blackwell Forest AR
Update #3 Page 6
TITLE/DESCRIPTION PAGES
42
08/07/97
McDonough, J.
& W. Buettner;
Montgomery
Watson
Maki, B.,
DuPage
County
Letter Forwarding
Attached July 28, 1997
Stormwater Runoff/Erosion
Control Plan for Leachate
Collection System and
Landfill Cap Repair for
the Blackwell Forest
Preserve Landfill Site
43
08/12/97
Buettner, W.,
Montgomery
Watson
Bellot, M.,
U.S. EPA;
FAX Transmission re:
Cancellation of August
13, 1997 Construction
Progress Meeting for
the Blackwell Forest
Preserve Landfill Site
44
08/14/97
Blair, T.
W. Buettner;
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter: Pre-Construction
Investigation Addendum
for the Blackwell Forest
Preserve Landfill Site
10
45
08/19/97
Lindland, K.,
U.S. EPA
Mack, K.,
Office of
Dupage County
State's
Attorney
Letter re: U.S. EPA's
Reguest for Confirmation
that Permits will not be
Reguired for Work Performed
at the Blackwell Forest
Preserve Site
46 08/21/97 Bellot, M. ,
U.S. EPA
Benedict, J.,
Forest
Preserve
District
of DuPage
County
Letter re: U.S. EPA/
lEPA's Review of the
July 10, 1997 Response
to Comments for the
Final Leachate Collection
System Expedited Final
Design for the Blackwell
Forest Preserve Landfill Site
47 08/21/97 Bellot, M.,
U.S. EPA
48 08/28/97 Buettner, W.
Montgomery
Watson
Benedict, J.
Forest
Preserve
District
of DuPage
County

Bellot, M.,
U.S. EPA
Letter re: U.S. EPA/
lEPA's Comments on the
the July 25, 1997 Revised
Predesign Report for
the Blackwell Forest
Preserve Landfill Site

Letter Forwarding
Attached Addendum No. 4:
Field Sampling Plan for
the North Stormwater Pipe
Subsurface Soil Investi-
gation and Surface Water
Sampling of Sand Pond
for the Blackwell Forest
Preserve Landfill Site
90
49
09/09/97
Buettner, W.,
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter re: Backfill of
Leachate Collection Sys-
tem Trenches at the
Blackwell Forest Preserve
Landfill Site
20
-------
NO. DATE
AUTHOR
RECIPIENT
DuPage County/Bleckwell Forest AR
Update #3 Page 7
TITLE/DESCRIPTION
PAGES
50 09/15/97 Labunski, S., Bellot, M. ,
Tetra Tech U.S. EPA
EM, Inc.
Letter re: Tetra Tech's
Technical Review of the
August 28, 1997 Field
Sampling Plan and Quality
Assurance Project Plan
for the Predesign
Activities at the Black-
well Forest Preserve
Landfill Site
51 09/19/97
Dovantzis, K.
Tetra Tech
EM, Inc.
Bellot, M.,
U.S. EPA
Letter re: Field over-
sight Summary No. 1 for
Final Remedial Design
Activities at the Black-
well Forest Preserve
Landfill Site
25
52 09/22/97
Buettner, W.,
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter re: Use of the
Low Flow Sampling Method
for Quarterly Groundwater
Monitoring Activities
at the Blackwell Forest
Preserve Landfill Site
w/ Attached April 1996
U.S. EPA Publication
Ground Water Issue: Low
Flow (Minimal Drawdown)
Groundwater Sampling
Procedures (EPA/540/
S-95/504)
14
53
09/24/97
Buettner, W.,
Montgomery
Watson
Bellot, M.,
U.S. EPA
Addendum No. 3 to the
Final Leachate Collection
System Expedited Design
Report for the Blackwell
Forest Preserve Landfill
Site
24
54 10/08/97 Bellot, M.,
U.S. EPA
Benedict, J., Letter re: U.S. EPA/
Forest IEPA' s Comments on the
Preserve August 28, 1997 Addenda
District to Sampling Plans for
of DuPage the Proposed Investigation
County of the North Stormwater
Pipe and Surface Water
Sampling of Sand Pond
for the Blackwell Forest
Preserve Landfill Site
55 11/20/97
Dovantzis, K. ,
Tetra Tech
EM, Inc.
Bellot, M.,
U.S. EPA
Field Oversight Summary
No. 2 for Final Remedial
Design Activities at the
Blackwell Forest Preserve
Landfill Site
87
-------
NO. DATE
56 12/04/97
AUTHOR
Buettner, W.,
Montgomery
Watson
DuPage County/Blackwell Forest AR
Update #3 Page 8
RECIPIENT TITLE/DESCRIPTION PAGES
Bellot, M. , Revised Addenda to 96
U.S. EPA Sampling Plans for the
Proposed investigation
of North Stormwater Pipe
and Surface Water Sampling
of Sand Pond at the
Blackwell Forest Preserve
Landfill Site
57 12/05/97
Buettner, W.,
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter re: Water Sample 59
Results from Manhole MH-
20 for the installation
of the Leachate Control
System at the Blackwell
Forest Preserve Landfill Site
58 12/22/97
Dovantzis, K. ,
Tetra Tech
EM, Inc.
Bellot, H.,
U.S. EPA
Letter re: Tetra Tech's
Technical Review of the
Revised Addendum to the
Sampling Plan for the
North Stormwater Pipe
at the Blackwell Forest
Preserve Landfill Site
59 12/24/97 Bellot, M.,
U.S. EPA
Benedict, J.
Forest
Preserve of
Dupage
County
Letter re: Revised
Addenda to Sampling
Plans for the Proposed
Investigation of the
North Discharge Pipe
at the Blackwell Forest
Preserve Landfill Sit
60 12/31/97 Dovantzis, K., Bellot, M.,
Tetra Tech U.S. EPA
EM, Inc.
Letter re: Field over-
sight Summary No.3 for
Final Remedial Design
Activities at the Black-
well Forest Preserve
Landfill Site
19
61 01/07/98 Buettner, W., Bellot, M.,
Montgomery U.S. EPA
Watson
Letter re: outstanding
Construction Items
Identified During the
Pre-Final Inspection
for the Blackwell Forest
Preserve Landfill Site
62 01/22/98 Tetra Tech
EM, Inc.
U.S. EPA
Draft Site-Specific 522
Plans for the Blackwell
Forest Preserve Landfill Site
63 02/00/98 Montgomery
Watson
U.S. EPA
Monitoring Well Assess-
ment Report for the
Blackwell Forest Preserve
Landfill Site
123
64 02/18/98 Vagt, P., Bellot, M. ,
Montgomery U.S. EPA
Watson
Letter re: Natural
Attenuation Study at the
Blackwell Forest Preserve
Landfill Site
-------
NO. DATE
65 02/26/98
66 03/11/98
AUTHOR
Finkelberg,
L., U.S. EPA/
Field
Services
Section
Finkelberg,
L., U.S. EPA/
Field
Services
Section
DuPage County/Blackwell Forest AR
Update #3 Page 9
RECIPIENT TITLE/DESCRIPTION PAGES
Bellot, M., Memorandum re: FSS' 4
U.S. EPA Review of the Draft
Quality Assurance Project
Plan for Natural Attenu-
ation Evaluation and
Split Sample Collection
at the Blackwell Forest
Preserve Landfill Site
(Incorrectly Dated
February 26, 1997)

Bellot, M., Memorandum re: FSS' 5
U.S. EPA Review of Addendum #5
to the Quality Assurance
Project Plan for the
Blackwell Forest Preserve
Landfill Site
67 03/23/98 Bellot, M.,
U.S. EPA
Benedict, J.,
Forest
Preserve
District
of DuPage
County
Letter re: U.S. EPA/
lEPA's Approval, with
Modification, of the
February 18, 1998
Proposed Natural Atten-
uation Study for the
Blackwell Forest Preserve
Landfill Site
04/00/98 Montgomery
Watson
U.S. EPA
Quality Assurance
Project Plan: Addendum
#5 (Quarterly Groundwater
Monitoring) for the
Blackwell Forest Preserve
Landfill Site
19
69 04/00/98 Montgomery
Watson
U.S. EPA
Quality Assurance Pro-
ject Plan: Addendum #6
(Selected Revisions) for
the Black-well Forest
Preserve Landfill Site
55
70 04/13/98 Montgomery
Watson
U.S. EPA
Review and Planning
Meeting Notes for 1998
Activities at the Black-
well Forest Preserve
Landfill Site
16
71 04/21/98 Buettner, W., Bellot, M.,
Montgomery U.S. EPA
Watson
Quarterly Groundwater
Report: First Round
(November 1997) for the
Blackwell Forest Preserve
Landfill Site
44
72 04/21/98 Buettner, W.
& 1). Vagt;
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter re: Anomalous
Phenol and Phthalate
Concentrations in the
First Round of Quarterly
Groundwater Sampling at
the Blackwell Forest
Preserve Landfill Site
w/ Attachments
362
-------
NO.
73
DATE
04/24/98
AUTHOR
Buettner, W. ,
Montgomery
Watson
RECIPIENT
Bellot, M.,
U.S. EPA
DuPage County/Blackwell Forest AR
Update #3 Page 10
TITLE/DESCRIPTION PAGES
Cover Letter Forwarding
Revisions and Addenda
for the Quality Assurance
Project Plan for the
Blackwell Forest Preserve
Landfill Site
1
74 05/12/98 Finkelberg, L., Bellot, M.,
U.S. EPA/ U.S. EPA
Field
Services
Section
Memorandum re: FSS'
Review of Addendums #5
and #7 to the QAPP for
the Blackwell Forest
Preserve Landfill Site
75 05/19/98 Mishra, M., Bellot, M.,
Tetra Tech U. S. EPA
KM, Inc.
Letter re: Tetra Tech's
Technical Review Comments
on the April 21, 1998
(1) First Round of Ground-
water Monitoring Report
and (2) Anomalous Phenol
and Phthalate Concentra-
tions Report for the
Blackwell Forest Preserve
Landfill Site
76 06/00/98 Montgomery
Watson
U.S. EPA
Field Sampling Plan: 17
Addendum #4 (Natural Atten-
uation Study) for the
Blackwell Forest Preserve
Landfill Site
77 06/00/98 Montgomery
Watson
U.S. EPA
Quality Assurance Pro-
ject Plan: Addendum #7
(Natural Attenuation
Study) for the Blackwell
Forest Preserve Landfill
Site
131
78 06/11/98 Tetra Tech
EM, Inc.
U.S. EPA
Field oversight Summary
No. 1 for Remedial
Activities oversight for
the DuPage County Landfill
Site
10
79 06/15/98 Buettner, W.
& P. Vagt;
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter re: Revised
Natural Attenuation Study
for the Blackwell Forest
Preserve Landfill Site
13
80 06/30/98 Mishra, M., Bellot, M.,
Tetra Tech U.S. EPA
EM, Inc.
81 07/00/98 U.S. EPA Public
Letter re: Tetra Tech's
Technical Review Comments
on the Revised Draft
Operations and Mainten-
ance Plan for the DuPage
County Landfill Site

Proposed Plan for the
DuPage County Landfill
Site
17
-------
NO. DATE
AUTHOR
RECIPIENT
DuPage County/Blackwell Forest AR
Update #3 Page 11
TITLE/DESCRIPTION
PAGES
82 07/01/98 Bellot, M.,
U.S. EPA
83 07/07/98 Bellot, M.,
U.S. EPA
Benedict, J.
Forest
Preserve
District
of DuPage
County

Benedict, J.
Forest
Preserve
District
of DuPage
County
Letter re: U.S. EPA/
lEPA's Approval of the
Revised Natural Attenu-
ation Study for the
Blackwell Forest Preserve
Landfill Site

Letter re: U.S. EPA's
Approval of the June 1998
Quality Assurance Project
Plan Addenda #4, #6 and #7
for the Dupage County
Landfill Site
-------
U.S. ENVIRONMENTAL PROTECTION AGENCY
REMEDIAL ACTION

ADMINISTRATIVE RECORD
FOR
DUPAGE COUNTY LANDFILL/BLACKWELL FOREST PRESERVE LANDFILL SITE
DUPAGE COUNTY, ILLINOIS

UPDATE #4
SEPTMBER 24, 1998
NO. DATE
AUTHOR
1 06/00/95 Montgomery
Watson
RECIPIENT

U.S. EPA
TITLE/DESCRIPTION PAGES

Draft Feasibility Study 326
Report for the Blackwell
Landfill NPL Site
2 11/24/97 First
Environmental
Laboratories,
Inc.
Montgomery
Watson
Analytical Reports for
the DuPage County Land-
fill/Blackwell Forest
Preserve Landfill Site
182
3 01/22/98 Tetra Tech
EM, Inc.
U.S. EPA
Draft Site Specific
Plans for the Blackwell
Forest Preserve Landfill
Site
532
4 02/00/98 Montgomery
Watson
U.S. EPA
Quality Assurance
Project Plan: Addendum
No. 5 (Quarterly Ground-
water monitoring) for
the Blackwell Landfill
Site
275
5 04/00/98 Montgomery
Watson
U.S. EPA
Quality Assurance
Project Plan: Addendum
#6 (Selected Revisions)
for the Blackwell Land-
fill Site
56
6 04/16/98 Johnson, S.,
Prairie
Analytical
Systems,
Inc.
Mottashed, W. ,
First
Environmental
Laboratories,
Inc.
Letter re: Modifications
to the standard operating
Procedure for Method
525.2 w/ Attachments
19
7 05/12/98 Finkelberg, L., Bellot, M.,
U.S. EPA/ U.S. EPA
Field
Services
Section
Section
Memorandum re: FSS'
Review of Addendums (#6
and #7) to the Quality
Assurance Project Plan for
Additional Activities at
the Blackwell Landfill
Site
06/00/98 Montgomery
Watson
U.S. EPA
Quality Assurance
Project Plan: Addendum
No. 4 (Field Sampling
Plan—Natural Attenuation
Study) for the Blackwell
Landfill Site
17
-------
NO. DATE
AUTHOR
9 06/00/98 Montgomery
Watson
RECIPIENT

U.S. EPA
DuPage County/Blackwell Forest AR
Update #4
Page 2
TITLE/DESCRIPTION

Quality Assurance
Project Plan: Revised
Addendum No. 7 (Natural
Attenuation Study) for
the Blackwell Landfill
Site
PAGES
133
10 06/15/98 Buettner, W.
& P. Vagt;
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter re: the Proposed
Natural Attenuation
Study at the Blackwell
Forest Preserve Landfill
Site
13
11 06/15/98 Buettner, W.
& P. Vagt;
Montgomery
Watson
Bellot, M.,
U.S. EPA
Letter re: MW's Response
to U.S. EPA Comments on
the Proposed Natural
Attenuation Study at the
Blackwell Forest Preserve
Landfill Site
12 06/16/98 Beard, G. ,
U.S. EPA
13 06/24/98 Mishra, M.,
Tetra Tech
EM, Inc.
Benedict, J.
Forest
Preserve
District of
DuPage
County

Bellot, M.,
U.S. EPA
Letter re: Recovery of
Costs for oversight
Activity Performed at
the DuPage County Land-
fill Site
Letter re: Field Over-
sight Summary No. 1 for
Remedial Activities at
the DuPage County Land-
fill Site
14 07/00/98 U.S. EPA
15 07/07/98 Bellot, M.,
U.S. EPA
Public
Benedict, J.
Forest
Preserve
District of
DuPage
County
Fact Sheet: "U.S. EPA
Recommends Cleanup Plan
for the DuPage County
Landfill Superfund Site"

Letter re: U.S. EPA's
Approval of the June
1998 Quality Assurance
Project Plan Addendums
Nos.4,6 and 7 for the
DuPage County Landfill/
Blackwell Forest Preserve
Landfill Site
12
16 07/15/98
Vagt, P.
W. Buettner;
Montgomery
Watson
Bellot, M.,
U.S. EPA
Monthly Status Report
for June 1998 for the
Blackwell Landfill Site
17
17 07/15/98
Van Matre, L.,
Chicago
Tribune
Public
Newspaper Article:
"Forest Preserve Waste
Cleanup Set to End Soon:
Blackwell Work May End
in Month"
-------
NO. DATE
18
07/27/98
AUTHOR

Griesemer, B.
& W. Buettner;
Montgomery
Watson
DuPage County/Blackwell Forest AR
Update #4
Page 3

RECIPIENT TITLE/DESCRIPTION PAGES

Addressees Meeting Notes re: the 2
July 16, 1998 Pre-
Construction Kick-Off
Meeting for the Blackwell
Landfill Site
19 07/29/98 Puishes, R., Public
Warrenville
Post

20 08/10/98 Efficiency U.S. EPA
Reporting
21 08/17/98 Vagt, P., Bellot, M.,
Montgomery U.S. EPA
Watson
Newspaper Article: "EPA
Reports on Landfill
Cleanup"

Transcript of July 22,
1998 Public Meeting re:
the DuPage County (Black-
well) Landfill Site

Monthly Status Report
for July 1998 for the
Blackwell Landfill Site
22
08/24/98
Griesemer, B.
& W. Buettner;
Montgomery
Watson
Addressees
Meeting Notes re: the
August 19, 1998 Second
Construction Progress
Meeting Concerning Cap
Repair Construction at
the Blackwell Landfill
Site
23 08/28/98 Bellot, M.,
U.S. EPA
Distribution
List
Memorandum: Distribution
of the Draft ROD for the
DuPage County Landfill
Site
24
09/10/98
25
09/14/98
Benedict, J.,
Forest
Preserve
District of
DuPage
County

Buettner, W.,
Montgomery
Watson
Bellot, M.,
U.S. EPA
Bellot, M.,
U.S. EPA
Fax Transmission: Written
Records Concerning the
Leachate Collection System
at the Blackwell Forest
Preserve Landfill Site
Letter re: Response
Action Cost Estimates
for the Blackwell Land-
fill Site
26 09/16/98 Bellot, M.,
U.S. EPA
File
Memorandum re: Placement
of the Draft Feasibility
Study for the DuPage
County Landfill into the
Administrative Record
-------