Southeast Rockford Ground Water Contamination EPA OU 03 Rockford, Il


                                    EPA/ROD/R05-02/077
                                    2002
EPA Superfund
     Record of Decision:
     SOUTHEAST ROCKFORD GROUND WATER
     CONTAMINATION
     EPA ID:  ILD981000417
     OU03
     ROCKFORD, IL
     06/11/2002

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SOUTHEAST ROCKFORD GROUNDWATER
CONTAMINATION SUPERFUND SITE, ROCKFORD, ILLINOIS

DECLARATION FOR THE RECORD OF DECISION

SITE LOCATION AND HISTORY

The Southeast Rockford Groundwater Contamination Superfund Site (CERCLIS ID No.
ILD981000417) is located in Rockford, Illinois and consists of three Operable Units.
Operable Unit One (Drinking Water Operable Unit) provided some residents with a safe
source of drinking water by connecting 283 homes to the city water supply. Operable Unit
Two (Groundwater Operable Unit) addressed the area-wide groundwater contamination. An
additional 264 homes were first connected to the city water supply system. A remedial
investigation was then conducted to characterize the nature and extent of the groundwater
contamination and to provide information on source areas responsible for contamination.
This operable unit identified four areas that were the primary sources of groundwater
contamination. These areas were identified as Source Areas 4, 7, 9/10 and 11.

Operable Unit Three (Source Control Operable Unit or SCOU) began as a State- lead action
in May 1996 to select remedies for each of the Source Areas. Field investigations included
soil borings and soil gas samples at all four areas, surface water and sediment sampling
at Area 7 and groundwater monitoring well installation and sampling at area 9/10. Based on
the results of these investigations, the Illinois Environmental Protection Agency
(Illinois EPA) identified a series of cleanup alternatives and preferred options for the
final remedies at the four areas. These alternatives and preferred options were published
in a Proposed Plan that was presented to the public in July 2001. This Record of Decision
(ROD) contains the actions, alternatives and preferred options of Operable Unit Three that
will address contamination in the soil and leachate at Source Areas 4, 7, 9/10 and 11.

STATEMENT OF PURPOSE

This decision document contains the selected remedial actions for the Southeast Rockford
Superfund Site, developed in accordance with the Comprehensive Environmental Response,
Compensation and Liability Act of 1980 (CERCLA) , as amended by the Superfund Amendments
and Reauthorization Act of 1986 (SARA) and to the extent practicable, the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP). This decision is based upon the
contents of the administrative record for the Southeast Rockford Superfund Site. The
United States Environmental Protection Agency (U.S. EPA), Region V supports the selected
remedy on the Southeast Rockford Site.

ASSESSMENT OF THE SITE

The response action selected in the ROD is necessary to protect the public health, public
welfare and the environment from actual releases of hazardous substances. Contaminated
soils, nonagueous phase liguid (NAPL), and leachate from Source Areas 4, 7, 9/10, and 11
constitute principal threats of continued contamination to the groundwater, unless
remediated. Therefore, technologies in this ROD are designed to remediate the Source Areas
and remove these principal threats. The remaining area-wide contamination will be
remediated by the natural attenuation of groundwater.

DESCRIPTION OF THE SELECTED REMEDY

The selected remedy is comprised of treatment options for the four Source Areas.
Definition of the entire site is the extent of groundwater contamination encompassing an
area approximately three miles by two and a half miles that includes residential, light
industrial, industrial and municipal properties. Remedy selection was based upon the
nature and extent of contamination, as well as consideration of the types of and uses of
the properties in each area. The remedies used in this ROD will accomplish the following

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results: (1) stop on-going contamination of the groundwater, thus protecting the water
resources for future generations;  (2) ensure that volatile organic compounds (VOCs) in
soil gas do not move into the basements of nearby residences; (3) protect people from
ingestion of contaminated groundwater; (4)  reduce the risk of direct contact with
contaminated soil or free product beneath the ground surface; and (5) assure the project
is in compliance with the Operable Unit Two ROD provisions that reguired the controlling
of groundwater-contamination sources.

Operable Unit Three will fulfill the reguirements to reduce and control potential
groundwater risks to the environment and bring all of the site's previously selected
remedial actions into compliance with State groundwater protection laws. Operable Unit
Three will also address contaminated soils, NAPL  (non-agueous phase liguid) and leachate
that are principal threats and the primary causes of groundwater contamination at the four
Source Areas.

Source Control Alternatives developed within the Operable Unit Three feasibility study
(FS) and discussed within this ROD are separated into soil and leachate alternatives. In
some cases, technologies designed to remediate soil, NAPL and leachate contamination are
either not sufficient to protect human health and the environment, or they are not
practical solutions. In these cases, technologies are considered to contain, rather than
treat the resulting groundwater contamination. In order to simplify the ROD, technologies
intended to contain contaminated groundwater in the immediate vicinity of the four primary
source areas are considered leachate alternatives.

STATUTORY DETERMINATIONS

It is considered the opinion of the Illinois EPA  (in consultation with U. S. EPA Region V)
that the selected remedy is protective of human health and the environment, attains
federal and state reguirements that are applicable or relevant and appropriate for this
remedial action (or invokes an appropriate waiver),  is cost-effective and utilizes
permanent solutions and alternative treatment technologies  (or resource recovery) to the
maximum extent practicable and satisfies the site at levels that will allow for limited
use and restricted exposure, a statutory review will be conducted within five years after
initiation of remedial action to ensure that the remedy is, or will be protective of human
health and the environment.

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ROD  DATA  CERTIFICATION  CHECKLIST

The following information is included in the Decision Summary section of this ROD
(additional information can be found in the Administrative Record for the site):

•       Chemicals of concern and their respective concentrations.
•       Baseline risk represented by the chemicals of concern.
•       Cleanup levels established for chemicals of concern and the basis for these levels.
•       How source materials constituting principal threats are addressed.
•       Anticipated land uses and current and potential future  uses of groundwater addressed
       in the baseline risk assessment and ROD.
•       Potential land and groundwater uses that will be available at the site as  a result
       of the selected remedy.
•       Estimated capital,  annual operation and maintenance (O&M)  and total present worth
       costs,  discount rate and the number of years over which the remedy cost estimates
       are projected.
•       Key factor(s)  that led to selecting the remedy (how the selected remedy provides the
       best balance of tradeoffs with respect to the balancing,  modifying, criteria key to
       the decision).
       WtlliamE. Muiw.Di:
       Superfund Division
       U.S. EPA- Region V
tor
                                               Dale
       Renee Cipriano, Director
       Illinois EPA
                                             Date

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DECISION SUMMARY
SOUTHEAST ROCKFORD GROUNDWATER CONTAMINATION
SUPERFUND SITE, ROCKFORD, ILLINOIS

SITE NAME, LOCATION AND DESCRIPTION

The Southeast Rockford Groundwater Contamination Site is located in the southeast portion
of Rockford, Illinois and covers an area approximately three miles long by two and one
half miles wide. The contaminant plume in the groundwater with concentrations above 10
parts per billion (ppb) defines the boundaries of the Southeast Rockford Superfund Site,
as defined by the Operable Unit Two ROD. The extent of the Southeast Rockford Groundwater
Contamination Site is shown in Figure 1.

The area is a predominantly suburban residential area, with scattered industrial, retail
and commercial operations throughout. Most of the building structures at this site are
one- or two-story residential dwellings, but several industrial areas also exist along
Harrison Avenue. There are also a substantial number of commercial and retail operations
along Alpine Road, Eleventh Street and Kishwaukee Street. The topography of the site is
essentially flat lying, with gradual sloping towards the Rock River. The four major
identified source areas of groundwater contamination at the site are identified in the
Operable Unit 2 ROD. Figure 1 also illustrates the general locations of the four major
source areas. Other groundwater plumes in the area were investigated, but were not
determined to be sources of the chlorinated VOCs found in residential wells.

Because of a relative abundance of groundwater resources, the City of Rockford's (the
City's) primary source of potable water is groundwater. Geology of the Southeast Rockford
Groundwater Contamination Site consists of unconsolidated glacial deposits deposited upon
Ordovician Age dolomite and sandstone. A buried bedrock valley over 200 feet in depth cut
into the Ordovician bedrock units lies within the site boundaries and contains large
unconsolidated sand and gravel deposits. The buried bedrock valley connects with the
current position of the Rock River to the west of the site. Together, the unconsolidated
glacial deposits and the bedrock units make up two different but hydraulically connected
aguifers, both of which are used for potable water supplies. Unconsolidated sands and
gravels, as well as the bedrock units contained within the Southeast Rockford Groundwater
Contamination Superfund Site meet the reguirements pursuant to Title 35 Illinois
Administration Code Part 620.210 for Class I Potable Resource Groundwater. The site was
proposed for inclusion on the National Priorities List (NPL) on June 24, 1988, and was
formally added to the NPL on March 31, 1989 as a state-lead, federally funded Superfund
site.

SITE HISTORY

Early groundwater investigations by the State indicated that many private and municipal
wells were impacted by chlorinated solvent contamination at levels exceeding federal
health standards. Further investigations determined that the solvents were used by
industries and were released directly into the environment from units such as storage
tanks or from improper disposal practices. These investigations formed the basis of the
NPL listing. During 1990, an emergency action by U. S. EPA resulted in 293 homes being
connected to the City's municipal water supply system. This action was eligible for U. S.
EPA emergency funding, because several residential wells had contaminant levels above
removal action levels (RALs). The U. S. EPA determined the extent of the water well
hook-ups with support from Illinois EPA.

The next course of action was to address residential wells whose contaminant levels were
below RALs, but above federal health standards (Maximum Contaminant Levels or MCLs). Camp
Dresser & McKee (COM), under the direction of Illinois EPA, conducted a residential
wellsampling investigation. This investigation became the first of three Operable Units to
address site-related contamination. Pursuant to this study and its recommendations, a ROD

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was signed in June 1991. This ROD required an additional 264 homes to be connected to the
City's municipal water supply and for the construction of a granular activated carbon
(GAG) treatment system on one municipal well. The GAG unit was installed as a temporary
measure that would be finalized in the second Operable Unit.

Between 1991 and 1994, an inclusive, two-phased remedial investigation  (RI) was performed
to define the nature and extent of groundwater contamination and to gather preliminary
information on the source areas responsible for residential well contamination. These
actions culminated in a second ROD signed in September 1995, that essentially required
additional hookups to the City's water supply, groundwater monitoring, continued operation
of the GAG unit installed in the first ROD and future source control measures at four
major source areas of site-related groundwater contamination. Pursuant to a consent decree
between the federal government, the state government and the City of Rockford signed in
early 1998, the City of Rockford agreed to implement all provisions of the Operable Unit 2
ROD.
                    Figure  1. Map of  Southeast Rockford Groundwater Contamination

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SITE ENFORCEMENT ACTIVITIES

Since the development of the 1995 ROD, there have been two major enforcement agreements
developed between the U. S. EPA, Illinois EPA and parties associated with the Southeast
Rockford site. The first of these was a consent decree entered by the federal district
court in Rockford in April 1998. This decree required the City of Rockford to install
water mains and services within the public right-of-way, provide needed connections to
homes and businesses, supplement the previously existing groundwater well-monitoring
network with new wells, and commence a long- term well- network sampling and analytical
program. This work has entered the monitoring phase. Over 9200 feet of new water mains
have been installed, and an additional 262 individual water service connections have been
made. A total of nine new groundwater monitoring wells were installed, with several of
these located near the Rock River. The consent decree also required the payment of up to
$200,000 by the City of Rockford to the State of Illinois and federal government, for
future oversight costs.

The court entered the second consent decree in January 1999; This decree provided for the
reimbursement of approximately $9.1 million dollars for past expenditures by the federal
and state agencies that responded to the Southeast Rockford site, as well as a payment of
approximately $5 million for a portion of future cleanup costs for Area 7. This innovative
feature of the decree anticipates the need to perform remediation at Area 7, because
unlike the other soil source areas of concern, it appears that waste materials were
brought to Area 7 from other locations. The second consent decree was amended in September
2001 that resulted in the collection of an additional $140,000.

COMMUNITY PARTICIPATION OVERVIEW

In accordance with Section 117, 42 U.S.C. § 9617, of CERCLA, the Illinois EPA and the U.S.
EPA held a public comment period from June 11 through August 20, 2001 to allow interested
parties to comment on the Feasibility Study and Proposed Plan for the Source Control
Operable Unit of the Southeast Rockford Groundwater Contamination Superfund site in
Rockford, Illinois. The Illinois EPA presented the Feasibility Study and Proposed Plan at
six informational meetings (two per day) on June 26, June 27 and June 28, 2001 and at a
formal hearing held in two sessions on July 19, 2001. The informational meetings were held
at the Villa Di Roma restaurant at llth and Harrison Streets in Rockford and the public
hearing was held at the Brooke Road United Methodist Church at 1404 Brooke Road in
Rockford.

A Responsiveness Summary is attached to the ROD to document the Illinois EPA's responses
to comments received during the public comment period. These comments were considered
prior to selection of the final remedy for the four major sources of contamination at the
Southeast Rockford Superfund site. The remedy is detailed in Illinois EPA's ROD, with
which the U.S. EPA concurs.

BACKGROUND OF COMMUNITY INVOLVEMENT AND CONCERNS

Illinois EPA has been responsible for conducting community relations activities during the
investigation for the Drinking Water Operable Unit (Operable Unit One) , Phase I and Phase
II of the Remedial Investigation and Groundwater Feasibility Study (Operable Unit Two) and
the Source Control Remedial Investigation and Feasibility Study (Operable Unit Three).

The site was first brought to the attention of the Illinois EPA by a citizen's complaint
that plating waste had been dumped in an abandoned well. Subsequent tests of nearby
private wells did not detect plating wastes but did find chlorinated solvents ( commonly
used in industry for degreasing purposes). A meeting held in 1984 by the Illinois
Department of Public Health (IDPH) and the Illinois EPA drew a crowd of approximately 200.
Continuing concerns by citizens, however, did not surface until the site was placed on the
National Priorities List in 1989 and financial institutions began refusing home mortgages
and improvement loans in the area.

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During the first operable unit, many citizens resisted the idea of connections to the
public water supply, because, in order to receive the hookup,  they had to sign an
agreement to be annexed into the City of Rockford (if their property became contiguous to
city property).  That issue is no longer a major concern,  since nearly all of the area has
now been annexed by the City of Rockford.

The City of Rockford has entered into two consent decrees with the State of Illinois and
the United States of America regarding the Southeast Rockford Groundwater Contamination
Superfund Site.  The original consent decree was entered in federal court in April 1998.
That consent decree reguired the City of Rockford to perform the remedial work reguired by
the September 29, 1995 Groundwater ROD. The ROD included water main extensions and
approximately 400 hookups to the City of Rockford's water supply system, groundwater
monitoring and continued use of carbon treatment at one of the municipal water supply
wells.

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SCOPE AND ROLE OF THE RESPONSE ACTION AND OPERABLE UNITS

INTRODUCTION

The Southeast Rockford Groundwater Contamination Site encompasses an area approximately
three miles by two and a half miles. The site is primarily defined by the extent of
groundwater contamination over 10 ppb of total chlorinated VOCs, as shown in Figure 1.
Property within the site boundaries is used for residential, light industrial, industrial
and municipal purposes. Remedial actions conducted under Operable Units One and Two
addressed the area-wide groundwater contamination, but reguired additional work at the
four source areas. The site characteristics for the four source areas are described in the
Section titled, DESCRIPTION OF SOURCE AREAS.

OPERABLE UNIT ONE

Because of the size and complexity of the groundwater contamination in the area, the
Illinois EPA and U.S. EPA (the Agencies) organized activities at the site into smaller,
more manageable groups of activities called Operable Units. The Illinois EPA and its
consulting/engineering firm, Camp Dresser & McKee (CDM), began work under Operable Unit
One with a remedial investigation. The primary focus of Operable Unit One was to address
contamination in residential wells. An additional 117 private wells were sampled as a part
of the Operable Unit One Remedial Investigation. The objective of this sampling event was
to determine how many homes had wells with levels of VOCs below the time critical removal
action cutoff, but above maximum contaminant levels (MCLs) . Illinois EPA's sampling
revealed that additional residences needed to be connected to the City's water supply
system. A proposed plan for Operable Unit One was made public in March 1991. A ROD for
Operable Unit One was signed on June 14, 1991. The ROD called for more residences to be
connected to the municipal water supply system and for a temporary granular activated
carbon (GAG) water treatment unit to be installed at one of Rockford's municipal wells.
The municipal well had been closed in 1985 due to unsafe levels of VOCs (CDM, 1990). The
GAG unit was installed to assure sufficient potable water capacity for residents added to
the City's water distribution system. By November 1991, an additional 264 homes were
connected to city water. Between the U. S. EPA's time-critical removal action and Illinois
EPA's Operable Unit One, a total of 547 homes received service connections to the City's
water supply system. A Remedial Action Report, signed by U. S. EPA on December 21, 1992,
certified that the selected remedy for Operable Unit One was operational and functional
(Illinois EPA Operable Unit Two ROD).

OPERABLE UNIT TWO

Remedial Investigations for Operable Unit Two began in May 1991 under the direction of the
Illinois EPA (CDM, 1992). The objective of the Operable Unit Two remedial investigation
was to characterize the nature and extent of groundwater contamination throughout the site
and to provide information on "source areas" that were responsible for the contamination
(CDM, 1992).

Because of the size and complexity of the site, the remedial investigation was conducted
in two phases. Phase I activities expanded the original NPL boundaries into a larger study
area within Southeast Rockford, encompassing approximately five sguare miles (CDM, 1993
1-2). Operable Unit Two, Phase I field activities included the following: 1) a 225-point
soil gas survey; 2) the installation and sampling of 33 monitoring wells at 11 locations;
and 3) the sampling of 19 Illinois State Water Survey Wells and 16 industrial wells (CDM,
1993 1-2). Fieldwork for Phase I was completed in October of 1991. Based on preliminary
data, eight potential sources of groundwater contamination were identified (CDM, 1992).

Operable Unit Two, Phase II field activities were conducted from January 1993 to January
1994. The following activities were conducted during the Phase II investigation: (1) 212
soil gas points were sampled; (2) 44 monitoring wells were installed and 165 groundwater
samples were obtained; (3) 55 soil borings were conducted and 126 soil samples were

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obtained; (4) 24 groundwater samples were obtained from residential wells; (5)  20
residential air samples were taken; and  (6)  two test pits were excavated in the study area
(CDM, 1995 RI 1-1).  Although several other groundwater plumes of contamination were
identified,  the Phase II investigation concluded that there were four primary source areas
that were impacting the major plume that constitutes the site. The four primary source
areas (Area 4, Area 7, Area 9/10, and Area 11)  are identified in Figure 1.

Phase II activities included groundwater modeling that helped to determine future
contaminant concentrations within the plume and projected general plume migration
directions.  The modeling indicated that contaminant levels for 1,1,1-TCA in the plume will
remain at levels above its MCL of 200 ppb for 205 years, assuming that the four source
areas are remediated. However, if the four source areas are not remediated modeling
predicts that over 300 years will be necessary for remediation of the groundwater  (CDM,
1995 FS 5-3).

Based on the results of the Remedial Investigation and Feasibility Study  (RI/FS)  conducted
under Operable Unit Two, Illinois EPA issued a Proposed Plan on Operable Unit Two in July
of 1995. The ROD for Operable Unit Two was signed on September 29, 1995. The major
components of the selected remedy included:  municipal water hook-ups for homes and
businesses projected to have combined concentrations of 1,1,1-TCA and 1,1-Dichloroethane
(1,1-DCA) at levels of 5 ppb or greater; groundwater monitoring for 205 years and future
source control measures at the four primary source areas. Although source control was a
component of the selected remedy within the Operable Unit Two ROD, the ROD stated that the
actual technology to be used for source control measures would be addressed within
Operable Unit Three.

OPERABLE  UNIT  THREE

Field work for the Operable Unit Three remedial investigation began under the direction of
Illinois EPA on May 20, 1996. The investigation included: soil gas samples and soil
borings at all four areas; surface water and sediment sampling at Area 7 and monitoring
well installation and groundwater sampling at Area 9/10. In total, the Operable Unit Three
investigation included:

•       68 soil gas  samples;
•       13 soil borings with one soil sample  per boring in Areas 4, 7,  and 11 and two
       samples per  boring in Area 9/10;
•       Dye shaker testing for the presence of NAPL;
•       14 surface soil samples;
•       Geoprobe groundwater screening at three locations;
•       Installation of three monitoring wells;  and
       Five groundwater samples (CDM,  2000 RI).

The results of the Operable Unit Three investigations, along with information obtained
from previous investigations were used to characterize the four source areas as described
within the section of this ROD entitled, DESCRIPTION OF SOURCE AREAS.  Information obtained
during previous investigations was used to generate the Operable Unit Three feasibility
study, which in turn, provides the basis for this ROD.

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SITE CHARACTERISTICS

INTRODUCTION

This ROD addresses the overall site remedy for the four major source areas that are
contributing to the overall groundwater contamination within the Southeast Rockford
Superfund Site. The four source areas encompass an area of three miles by two and a half
miles, as shown in Figure 1. Groundwater contamination within this area has occurred in
the sand and gravel aguifer that is contained within a buried bedrock valley. Generally
the contamination follows the bedrock valley and the direction of groundwater flow is east
to west, towards the Rock River. The problems within the Southeast Rockford Groundwater
Contamination Superfund Site are complex and interrelated. As a result, The Illinois EPA
has divided the remediation efforts into four source areas. Each Source Area is described
in the following paragraphs.

AREA 4

Source Area 4 is situated in a mixed industrial, commercial and residential area located
east of Marshall Street and south of Harrison Avenue. Area 4 is comprised of the former
machine shop (Swebco Manufacturing, Inc.) located at 2630 Marshall Street and a
residential trailer park (Barrett's) located on the northeast portion of Area 4. According
to previous site investigation results, elevated concentrations of dichloroethane (TCA)
were detected in soil at a depth of eight feet below ground surface (bgs) in the former
machine shop loading dock and parking lot areas. Also, elevated concentrations of
chlorinated VOCs were detected in several down-gradient groundwater monitoring wells.
These groundwater results indicate that Area 4 is impacting the site-wide groundwater. No
elevated concentrations of chlorinated VOCs were detected in the trailer park area.

AREA 7

Source Area 7's primarily an open grassy area located at the east terminus of Balsam Lane.
Area 7 encompasses a city park (Ekberg Park) and an open area containing wooded areas.
Ekberg Park consists of a basketball court, tennis court, and a playground. The open field
and wooded areas exist south of the park on a hillside that slopes to the north. Two small
valleys merge at the base of the hill, allowing surface water to drain northward into an
unnamed creek. Private residences border Area 7 on the east and southeast.

Part of Area 7's past history includes a gravel pit as shown on the Rockford South
Quadrangle map (USGS 1976) . Examination of aerial photographs since the 1950s indicates
that various activities have occurred at this location. In particular, a 1970 aerial photo
shows areas of excavation and disturbed ground in two large areas centered at about 600
and 1,300 feet east of the east end of Balsam Lane. A third suspect area is located along
the small tributary valleys passing from southeast to northeast of Balsam Lane. In these
valleys, debris and areas void of vegetation are visible on 1958, 1964 and 1970 aerial
photos. In addition, the Illinois EPA and the U. S. EPA have received several past reports
of illegal dumping in Area 7.

Based on previous site investigation results, elevated concentrations of ethylbenzene,
toluene, xylene (ETX) and chlorinated VOCs were detected in soil in the northern portion
of Area 7. The vertical extent of soil contamination extends to a depth of 27 to 29 feet.
Chlorinated VOCs were also detected in shallow groundwater and surface water in the
unnamed creek. The groundwater results indicate that Source Area 7 is impacting the
site-wide groundwater.

AREA 11

Area 11 is located north of Harrison Avenue and east of llth street. Historically,
manufacturing activities in Area 11 included the production of paint and various varnish
products for the furniture industry, as well as gears and rollers for newspaper presses.

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Presently, a restaurant, a machinery painting facility and a wood products supplier are
active in Area 11.

The Area 11 groundwater contaminant plume consists primarily of aromatics (xylene, toluene
and ethylbenzene), although elevated concentrations (up to 2,900 ppb) of several
chlorinated VOCs are also present. Results from the Phase II remedial investigation (CDM
1995) indicate the presence of a NAPL within Area 11. A NAPL is a liquid usually comprised
of hydrocarbons such as fuels or solvents that do not mix with groundwater in the aguifer.
The NAPL within Area 11 is a light NAPL, as indicated by its presence near the top of the
water table. The thickness of the NAPL in Area 11 is generally five to ten feet, but at
some points, may approach 25 feet.

AREA 9/10

Area 9/10 is an industrial area that is bounded by llth Street on the east, 23rd Avenue on
the north, Harrison Avenue on the south and 6th Street on the west. This part of the study
area has a long history of industrial activity that extends as far back as 1926. At that
time, the Rockford Milling Machine and Rockford Tool companies merged to become the
Sundstrand Machine Tool Company which is located at the northwest corner of llth Street
and Harrison Avenue (Lundin 1989). Industries in the area include Sundstrand Corporation's
Plant #1, the former Mid-States Industrial facility, Nylint Corporation warehouse
(formerly occupied by General Electric) , Paoli Manufacturing, Rockford Products
Corporation, Rohrbacher Manufacturing, and J. L. Clark.

According to previous investigations, an outdoor drum storage area associated with the
former Sundstrand Plant # 2 was located at the southwest corner of the Sundstrand parking
lot (9th Street and 23rd Avenue). From 1962 to 1985, various 55-gallon drums of
VOC-bearing materials including tetrachloroethene (PCE) , TCA, toluene, acetone and
methylene chloride were stored in this area. In addition, from 1962 through 1987, the dock
area at Sundstrand Plant # 1 housed approximately 14 underground storage tanks (USTs).
These USTs were constructed of steel and contained solvents, cutting oils, fuel oil and
jet fuel (JP4). The solvents included PCE, TCA and solvents that were used for parts
cleaning.

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DESCRIPTION OF SOURCE AREAS
SOURCE AREA 4
Source Area 4 is bounded by Harrison Avenue to the north, Alton Avenue to the south, and
Marshall Street to the west (see Figure 2). Barrett's Mobile Home Park is located just
east of the area. The source of contamination is believed to be leaking underground
storage tanks beneath the parking lot of Swebco Manufacturing, Inc., located at 2630
Marshall Street (CDM, 1993 2-14) . Swebco was a precision machining shop that produced
metal parts. The property is approximately one acre in size and is currently zoned light
industrial. The properties surrounding Area 4 are currently zoned either residential or
light industrial and include small businesses and single-family homes. Officials with the
City of Rockford Planning Division indicate the future plans for Area 4 and surrounding
properties are consistent with current uses (Dust).
Source Area 4
Proposed Plan
Excavation, On-ijtf Low Temperature Thermal
Dasorptwr (LITD). andLeaehate Containment
"* LTFD brealmenl unit
™ Ground water fGW) tre afcn snl building
•"• Grotind*ai6r manassmiTil zone
* iOnrtiOnngwetl
0 OrQUTHjwater eMratlion wells carawctn 6y
underground pipmg ia GWireMment Builflmg
I I tnsling buildings .
I Subsurface sail n
(ncrt la srsle)
Figure 2. Source Area 4 Map

Illinois EPA Bureau of Land files indicate that Swebco Manufacturing, Inc. used three
underground storage tanks. The underground storage tanks are located beneath the parking
lot at the facility and available information indicates they are likely to be empty (CDM,
2000 RI 1-5). The contents of the tanks have been reported to be fuel oil and waste oil
(CDM, 2000 RI 1-5). It is suspected that the waste oil may have contained 1,1,1-TCA, which
is a noncarcinogen.

Soil borings performed within Area 4 to depths of approximately 30 feet bgs indicate the
subsurface is largely comprised of medium grain sand (CDM, 1995 Appendix A). The borings
also indicate that the sand is overlain with approximately five feet of silty topsoil in
most areas. Groundwater is encountered at approximately 29 feet bgs (CDM, 2000 RI 3-1).
Groundwater in the unconsolidated sediments beneath Area 4 flows in a west-northwest
direction (CDM, 1995 RI 4-41).

During Phase II of the Operable Unit Two remedial investigation (December 1992), high
concentrations of 1,1,1-TCA were found in soils beneath a parking lot at the Swebco
facility (CDM, 1995 RI 4- 37,4- 41). Further investigation identified soil contamination
at concentrations up to 510 parts per million ( ppm) and appears to extend to a depth of
35 feet (CDM, 2000 RI 3-1). The extent of contaminated soils is an area approximately 50
by 75 feet, with the long axis oriented east-west (CDM, 2000 RI 3-1). Assuming a thickness

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of eight feet and an average 1,1,1-TCA soil concentration of 275 ppm, the volume of highly
contaminated soil was estimated at 1,100 cubic yards, with a weight of 1,1,1-TCA at 977
pounds (CDM, 2000 RI 4-41). As 1,1,1-TCA from the contaminated soils are water soluble,
contaminants from Area 4 are highly mobile in groundwater, as evidenced by high levels of
1,1,1-TCA (1 ppm) in down-gradient wells (CDM, 1995 RI 4-99). The cause of contamination
is believed to be a single source which consists mostly of 1,1,1 TCA (CDM, 2000 RI 3-1).
Table 1 shows the maximum concentrations of the contaminants of concern at Area 4.

Soil Gas and Indoor Air
Soil gas (air in the void spaces within soil) concentrations of 1,1,1-TCA at Area 4 range
from below detection limits to 7.2 ppm (CDM, 2000 RI 3-3). Residential air sampling
identified 1,1,1-TCA, TCE, PCE, 1,1-DCA, and 1,1-Dichloroethylene (1,1-DCE) in the indoor
air of homes within the area (CDM, 1995 RI 4-83). The 1995 RI Report concluded that the
results could not be directly correlated with groundwater contamination. The report also
concluded that concentrations for all compounds were below health- based air guidelines
available in 1995 (CDM, 1995 RI 4-85, 90). Because the majority of the indoor air samples
with significant detections were those taken from sump pits in basements of homes in Area
4, IDPH recommended that the pits be filled to limit potential exposure. Contact with the
owners of homes with sump pits indicated that many had taken the advice of IDPH and filled
the pits.

U.S. EPA has recently begun to consider new air screening values. After reevaluating the
indoor air data from homes near Area 4, U.S. EPA and Illinois EPA have decided to conduct
additional air sampling in the homes to ensure that concentrations are below levels of
concern. Illinois EPA plans to conduct the sampling and analysis during the remedial
design phase, but actual fieldwork may not begin until sometime in 2002.

As part of the Five Year Review obligation to ensure that a remedy remains protective of
health and the environment, Illinois EPA and U. S. EPA will continue to evaluate new
developments in this field. When conducting future indoor air sampling, the Agencies will
determine if homeowner activities or hobbies might have influenced sampling results. After
accounting for such factors, the Agencies would consider a variety of possible responses
such as checking soil gas pathways between the site and residence; determining whether
additional measures should be taken to increase the capture zone of the area soil remedy
and whether it may be appropriate to install air purifying canisters in the homes.

Surface Soils
Surface soil samples from Area 4 identified several VOCs including 1,1,1-TCA at
concentrations up to 0.1 ppm (CDM, 1995 RI 4-34). Polynuclear Aromatic Hydrocarbons
(PNAs) , and compounds associated with pesticides and polychlorinated biphenyls (PCBs) were
also identified in Area 4 soils. Concentrations of PCBs and pesticides found in Area 4
surface soils do not pose a threat to human health. Concentrations of individual PNAs
ranged from non-detection (ND) to 16 ppm (CDM, 2000 RI Table 3-1). Concentrations of PCBs
and pesticides ranged from ND to 0.100 ppm (CDM, 1995 RI 4-34) and ND to 0.026 ppm (CDM,
2000 RI Table 3-1).

Sub-Surface Soils
Sub-surface soil samples from approximately three to ten feet bgs surface at Area 4 showed
higher concentrations of VOCs, PNAs and pesticides. Elevated concentrations of VOCs and
PNAs were found primarily in two soil borings (SB4-1 and SB4-5) taken beneath the parking
lot at the facility. Elevated concentrations in both borings were found around 30 feet bgs
with individual VOCs (1,1,1-TCA) up to 510 ppm (CDM, 2000 RI 3-14) and PNAs, such as
naphthalene, up to 3 ppm (CDM, 1995 RI 4- 40). The highest concentration of an individual
pesticide compound in the subsurface was 0.005 ppm (CDM, 1995 RI 4-40). Inorganic
compounds were detected in Area 4 at levels below background.

Groundwater
Significant groundwater contamination exists beneath and down gradient of Area 4. Elevated
levels of 1,1,1-TCA and TCE were identified in wells down gradient of the facility at
concentrations of 1.0 ppm and 0.02 ppm, respectively. The potential pathways of

-------
                   Table 1. Contaminants of Concern at Source Area 4
Contaminant1
Volatile Organics
1,1-Dichloroethene
1 ,1 ,1 -Trichloroethane
Trichloroethene
Semi volatile
Benzo(a)anthracene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(a)pyrene
Dibenzo(a,h)anthracene
Metals
Beryllium
SOIL (ppm)
Concentration Range in Soil
Above 1 0 feet

BDL
BDL-0.11
BDL-0.025

BDL-5.6
0.06-11
0.07-11
BDL-1.1
BDL-0.43

0.2-0.7
Below 10
feet

BDL
BDL-510.0
BDL

BDL
BDL
BDL
BDL
BDL

NA
Remediation
Goal


0.06 2
9.1183
0.06 2

0.9 2
1.386
1.856
0.23 6
0.09 2

1.517
GROUNDWATER
(ppb)
Concentration


BDL-10J
BDL-1,000
BDL-28

NA
NA
NA
NA
NA

NA
MCL


7
200
5

NA
NA
NA
NA
NA

NA
Notes:
ppm -   Parts per million or milligrams per kilogram
ppb -    Parts per billion or micrograms per liter
MCL-    Maximum Contaminant Level developed pursuant to Safe Drinking Water Act
BDL-    Below detection limit of laboratory instruments or methods
NA -    Compound was not analyzed or measured in laboratory
J -      Value is estimated based on laboratory results
1       Only compounds that exceed Tier 1 screening level in soil or an MCL in groundwater are included
        in Table. Compounds in bold text are contaminants of concern for soil, and associated
        remediation objectives shall be attained through remediation. Remediation objectives shown for
        all other compounds are only for informational purposes. See section entitled "Remedial Action
        Objectives" for details.
2       Remediation Goal is the Tier 1 residential screening level for soil for direct contact.
3       Remediation Goal Calculated using equation R15 of TACO that takes attenuation into account.
4       Only Tier 1 residential screening levels for soil for direct contact are considered for semivolatiles
        because semivolatiles are not currently groundwater contaminants and are not expected to
        become groundwater contaminants.
5       Compound will be evaluated further through sampling during remedial design. Although
        compound exceeds Tier 1 residential screening level for soil for direct contact, it is not
        considered a chemical of concern at this time because semivolatiles' are prevalent in
        environment and not found in groundwater.
6       95% Upper Confidence Limit on background concentrations
7       Upper Tolerance Limit on site-specific beryllium background concentrations.
                                              15

-------
contaminant migration include groundwater and void spaces in soils (e.g. soil gas). Soil
gas concentrations of 1,1,1-TCA in the immediate vicinity of Area 4 range from below
detection limits to 7.2 ppm (CDM, 2000 RI 3-3). Surface migration of contaminants is not
likely, given that most of Area 4 is paved.

Non-Aqueous Phase Liquid (NAPL)
Soil boring SB4-202 taken in the northern part of Swebco's parking lot tested positive for
the presence of a light non-agueous phase liguid (LNAPL) directly above and within the top
portion of the saturated zone. SB4-204 is believed to be right at the source of the area's
contamination and contained 510 ppm of 1,1,1-TCA. LNAPL was found present at the source
from 27 to 35 feet bgs and was not found in deeper portions of SB4-202 (CDM, 2000 RI
3-14). Soil boring SB4-202 encountered a low permeability clay layer from approximately 62
feet bgs through 65 feet bgs, where the boring was terminated. In most cases, compounds
found at Area 4 are considered to be Dense Non-Agueous Phase Liguids (DNAPLs). The
physical and chemical properties of DNAPL compounds cause them to sink through the
groundwater until geologic material with a low permeability (such as clay) is encountered.
However, DNAPLs do not always present themselves as a phase separate from water and the
presence of other less dense solvents may change the DNAPL compound's behavior in the
subsurface (U. S. EPA, Groundwater). Visual examination and headspace analysis on soil
samples obtained directly above the clay layer did not exhibit DNAPL presence (CDM, 2000
RI App. B).

SOURCE AREA 7
Raldaaa
Soure* Area 7
Prooosed Ran
Scfl wmfmr «nra«i
-------
Source Area 7 is located in the most southeastern portion of the Southeast Rockford
Superfund Site, northwest of the intersection of Alpine and Sandy Hollow Road.
Specifically, Area 7 is located at the eastern end of Balsam Lane (see Figure 3). The area
contains Ekberg Park, a municipal park owned and maintained by the Rockford Park District.
The park consists of open grassland, paved tennis and basketball courts, a children's
playground, and a parking area. The park is zoned residential and the City's future plans
are consistent with current use (Dust). Area 7 also includes privately owned agricultural
land and wooded areas to the south and north of the park (Dust). Surface water drainage at
Area 7 follows the area's topography that slopes downward from south to north. Two small
valleys merge at the base of the hillside on the south of the area and feed into an
unnamed creek that borders the north side of the site. Residential areas border the area
to the east and west.

Elevated concentrations of VOCs in monitoring well number 106 (MW106) and aerial
photographs showing ground surface excavations helped to identify Area 7 as an area of
concern (COM, 1995 RI 4-12) . Part of Area 7 was once a gravel pit, as shown on historical
maps compiled by the United States Geological Survey. Examination of aerial photographs
since the 1950s identifies areas of excavation and disturbed ground east of the end of
Balsam Lane. In addition, U.S. EPA has received reports of illegal dumping in the area in
the past (COM, 2000 RI 1-5) .

The geology at Area 7 consists of a heterogeneous combination of sands, silts, and clays
that overlay dolomite bedrock. The heterogeneous nature of the geology at Area 7
correlates well with reports of past activities such as guarrying and land filling.
Groundwater in both the upper unconsolidated and bedrock aguifer travels in a northwest
direction. Depth to groundwater ranges from 36 feet at MW135 located south of the park, to
13 feet in MW134 within the park, to less than two feet in MW105 near the creek (COM, 1995
RI Table 3-3).

Soil Gas and Indoor Air
Soil gas surveys completed in May 1992 and February 1993 identified 1,1,1-TCA, PCE and TCE
at levels ranging up to 3.8 ppm, 1.1 ppm and 0.690 ppm respectively (COM, 1995 RI 4-14,
and 17). The highest concentration for the sum of 1,1,1-TCA, PCE and TCE concentrations in
soil gas was 5.59 ppm obtained south of the basketball courts ( COM, 1995 RI 4-15). Soil
gas data obtained in 1996 identified concentrations for the sum of 1,1,1-TCA, PCE and TCE
ranging up to 460 ppm in areas north of the children's playground; however, the 1996 data
were generated using different procedures than those used in 1992 and 1993.

Residential air sampling in the vicinity of Area 7 identified levels of 1,1,1-TCA, TCE and
PCE, at levels less than those found in homes near Area 4. As with Area 4, results could
not be directly correlated with groundwater contamination. Concentrations for most
compounds were below that of indoor air studies conducted in other cities and all were
below health- based air guidelines in place in 1995 (CDM, 1995 RI 4-85, 90).

Test Pits
Three test pits were excavated in Area 7 in June 1993. The test pits revealed metal cans,
other metal objects, glass bottles and miscellaneous trash. Soil samples taken from the
test pits identified PCE ranging up to 22 ppm, 1,1,1-TCA up to 4 ppm, and TCE up to 3 ppm
(CDM, 1995 RI 4-25). Table 2 identifies concentrations of contaminants of concern found in
Area 7 soils and groundwater. Soil samples from each test pit were also analyzed for
Toxicity Characteristic Leaching Procedure (TCLP) contaminants. Concentrations in the TCLP
soil sample from test pit 2 exceeded the TCLP regulatory level for TCE and PCE at
concentrations of 1.1 ppm and 0.7 ppm, respectively (CDM, 1995 RI 4-26).
-------
Rallroacf
Tracks
DSurface Wstar S»mpJ»
Sample
Not to Scale
Figure 4. Source Area 7 Hot Spots

Surface Soils
Surface soil samples identified the presence of VOCs, PNAs, metals, and pesticides in
surface soils. Surface soil concentrations of VOCs, which are the contaminants of primary
concern, ranged up to 0.22 ppm of 1,2-Dichloroethylene (1,2-DCE), 0.04 ppm of 1,1,1-TCA,
0.14 ppm of TCE, and 0.4 ppm of PCE (CDM, 1995 RI 4-32). One SVOC, bis(2-ethylhexyl)
phthalate was detected in all surface samples and could be either due to laboratory
contamination or plastics disposed of at the site (CDM, 1995 RI 4-32). With the exception
of bis(2-ethylhexyl) phthalate, only two surface soil samples contained concentrations of
PNAs, most notably benzo(a) pyrene at levels up to 0.17 ppm. All semi-volatile
concentrations were below site-background. Metals concentrations in surface soils at Area
7 were compared to site-specific background concentrations for beryllium and thallium.
Pesticide concentrations in surface soils are likely due to the agricultural activities in
the area (CDM, 1995 RI 4-32) .

Sub-Surface Soils
Twenty-four soil borings were conducted at Area 7 in order to characterize the nature and
extent of contamination bgs in areas that were identified by soil gas and surface soil
analysis (CDM, 1995 RI 4-43). The VOCs most often identified were TCA, PCE and xylene. The
VOC 1,1,1-TCA was found at concentrations of 360 ppm from depths of 4 to 6 feet in sample
SB7-24A, and 380 ppm from depths of 15 to 17 feet in sample SB7-8D (CDM, 1995 RI 4-43).
PCE was identified at levels ranging up to 260 ppm in sample SB7-8D. Xylene was identified
at concentrations ranging up to 210 ppm in SB7-10A (CDM, 1995 RI 4-43).

Subsurface sampling results from past investigations identify three primary VOC source
areas (hot spots) at Area 7. Figure 4 identifies the three hot spots located at Area 7.
Notable concentrations of total VOCs in the hot spot located at the southern portion of
Area 7 (the southern hot spot) at the confluence of the surface water drainage ditches,
extends from approximately 4 to 28 feet bgs. Significant concentrations of total VOCs in
this area include: 441 ppm in SB7-14 at 4 feet bgs; 1,019 ppm in SB7-8 at 15 feet bgs; and
357 ppm in SB7-9 at 20 feet bgs (CDM, 1992 RI Figure 4-19). Notable concentrations of
total VOCs in the hot spot located just west of the tennis courts (the central hot spot)
extend from approximately 19 to 23 feet bgs. Concentrations of total VOCs in the central
hot spot include 35 ppm in SB7-4 at 20 feet bgs (CDM, 1995 RI Figure 4-19). Lastly,
significant concentrations of total VOCs were identified in the northern portion of Area
-------
7, north and west of the playground area (the northern hot spot). Total VOC
concentrations in the northern hot spot include: 627 ppm in SB-24 at 4 feet bgs; 17
ppm in SB7-202 at 11 feet bgs; and 875 ppm in SB7-201 at 25 feet bgs (CDM, 1995 RI Figure
4-19). Significant contamination in the northern hot spot ranges from 3 to at least 28
feet bgs. The depth to which contamination extends in this area was not determined (the
soil boring was terminated upon encountering a clay layer rather than risk spreading
contamination deeper) (CDM, 1995 RI 3- 20).

NAPL
Subsurface sampling results for VOCs that were obtained during the Operable Unit Two
remedial investigation suggest the presence of NAPL in the northern and southern hot spots
in Area 7. Specific tests designed to positively identify NAPL were not performed on soils
in the southern hot spot. The investigation of this hot spot was conducted largely during
the Operable Unit Two remedial investigation and work plans did not provide for specific
tests for NAPL presence. However, PCE concentrations found in soil sample SB7-8D taken
from soil boring SB7-8 suggest the presence of a NAPL (CDM, 1995 RI 4-48) . The boring log
also indicates an elevated headspace and a strong solvent odor for sample SB7-8D (CDM,
1995 RI Appendix A). Based on density, PCE detected within this sample would be expected
to be present as a DNAPL. DNAPLs are also known as sinkers because if they are present at
high concentrations they will sink in groundwater rather than float on top of the water
table. However, VOCs that are less dense than PCE, such as xylene, naphthalene and 2-
methyl naphthalene were also identified within soil boring SB7-8 at concentrations high
enough to exist as NAPL (CDM, 1995 RI 4-48). At higher concentrations, these compounds
would usually present themselves as an LNAPL and would float on or near the top of the
water table, rather than sink. Headspace analyses noted in the boring log for SB7-8 shows
the highest readings (130 ppm) at 15 feet bgs, just below the approximate depth at which
the water table was encountered (CDM, 1995 RI Appendix A). Headspace analysis drops to 60
ppm at 25 feet bgs, and 11 ppm at 45 feet bgs where the boring was terminated. The
decrease in headspace analysis, with depth away from the water table indicates that if a
NAPL were present in this hot spot, it would likely present itself as an LNAPL. The
decrease in headspace analysis with depth also helps to discount the presence of a DNAPL
at this area, although it cannot be ruled out.
-------
Table 2. Area 7 Contaminant Concentration Ranges and Preliminary Remediation Goals
Contaminant1
Volatile Organics
Benzene 3
Chloroform 3
Chlorobenzene 3
1,1-Dichloroethene
1,2-Dichloroethane
1 ,2-Dichloroethene(total)
Ethylbenzene
Methylene Chloride
Tetrachloroethene
Toluene
1 ,1 ,1 -Trichloroethane
1,1,2-Trichloroethane
Trichloroethene
Vinyl Chloride
Xylenes (total)
Semivolatile Organics
2,4-Dinitrotoluene 8
Metals
Beryllium
Pesticides
Dieldrin 8
SOIL (ppm)
Concentration Range in
Soil
Above 10
feet

BDL
BDL
BDL
BDL-0.003
BDL-0.008
BDL-49.0
BDL-26.0
BDL-0.03
BDL-110.0
BDL-23.0
BDL-360.0
BDL-0.004
BDL-24.0
BDL
BDL-210.0

BDL- 1.50

0.13-0.66

BDL-0.036
Below 10
feet

BDL-0.22
BDL-0.57
BDL-1.6
BDL-1.3
BDL-0.18
BDL-47.0
BDL-31.0
BDL-0.01
BDL-260.0
BDL-23.0
BDL-460.0
BDL-0.46
BDL-130.0
BDL
BDL-190.0

BDL

BDL-0.002
Remediation Goals2
Proximal

0.03 4
0.0006 4
1.04
0.06 4
0.02 4
0.941 5'6
57.347 5
16957
1.4655
255 7
180.033 5
0.619 5
0.3105
0.01 4
1197

0.162 5

NC
Distal

0.03 4
0.0006 4
1.04
0.06 4
0.02 4
11.5825'6
144 7
1695 7
94 7
255 7
499 7
56.315 5
7.220 5
0.01 4
1197

80.9 5

NC
Area-
wide

0.8
0.3
130
700
0.4
1200
400
13
11
650
1200
1800
5
0.03
410

0.9

1.51 9

NC
NC
0.004 4
GROUNDWATER
(ppb)
Concentration

BDL-23

BDL-180J
BDL-13
BDL-5,900
BDL-31,000

BDL-1,200
BDL-170
BDL-8,000
BDL
BDL-650
BDL-75
BDL-1,100

NA
MCL

7
5
170 6
700

5
1,000
200
5
5
2
10,000

NA
Notes:
ppm - Parts per million or milligrams per kilogram
ppb - Parts per billion or micrograms per liter
MCL- Maximum Contaminant Level developed pursuant to Safe Drinking Water Act
J - Value is estimated based on laboratory results
BDL- Below detection limit of laboratory instruments or methods
NA- Compound was not analyzed or measured in laboratory
NC- Remediation objective not calculated
1 Only compounds that exceed Tier 1 screening level in soil or an MCL in groundwater are included in Table.
Compounds in bold text are contaminants of concern for soil and associated remediation goals shall be
attained through remediation. Remediation objectives shown for all other compounds are only for
informational purposes.
2 Remediation goal split into three goals. Two are for protection of groundwater for two different "hot spots":
Proximal is the hot spot closest to the Groundwater Management Zone boundary while distal is the hot spot
farthest away. The third remediation goal is for direct contact with soil and applies to all of Area 7.
21
-------
3 Benzene, chloroform and chlorobenzene are not considered chemicals of concern because they were
only detected in a small percentage of soil samples (less than 2%).
4 Remediation goal is the Tier 1 residential screening level for soil for protection of
groundwater.
5 Remediation goal calculated using equation R15 of TACO that takes attenuation into account.
6 No MCL is available for 1,2-Dichloroethene (total). Therefore, MCL for cis-1,2- Dichloroethene
is used to calculate soil remediation objectives as well as to evaluate groundwater
contamination.
7 Soil Saturation Limit used. TACO stipulates that remediation goals cannot exceed the soil
saturation limit. Therefore, when equation R15 of TACO generated a remediation objective
greater than the saturation limit, the saturation limit is used instead.
8 2,4-Dinitrotoluene and Dieldrin not included as a chemical of concern because they were not
found in the groundwater. 2,4-Dinitrotoluene was detected in one out of three soil samples at
concentrations above its Tier 1 residential screening level for ingestion. However,
2,4-Dinitrotoluene was not included as a chemical of concern for the following reasons: the
concentration for 2,4-Dinitrotoluene was estimated; it was only detected at five feet below the
ground surface; and, it was only detected in 1 out of 3 samples. The sample containing
2,4-Dinitrotoluene is within a hot spot to be addressed by proposed alternatives.
9 Site specific background value. For beryllium, the value is the Upper Tolerance Limit on
background data.

The northern hot spot was investigated during Operable Unit Three and the work plan
provided for testing designed to identify NAPL. Analysis performed on soil samples
obtained in the northern hot spot within Area 7 positively identified NAPL. A total VOC
concentration of 875 ppm was identified in the soil sample taken from SB7-201 at 25 feet
bgs. NAPL in soils from 25 to 27 feet bgs from SB7-201 was identified visually. In
addition, a shaker dye test was performed that confirmed the presence of NAPL from 25 to
27 feet bgs. SB7-201 was terminated at 27 feet, after the boring encountered a clay layer
(CDM, 1995 RI 4-48) . Many of the compounds detected in the sample obtained from 25 to
27 feet bgs are commonly associated with DNAPLS ( U. S. EPA, Groundwater). Additionally,
the presence of free product approximately 13 feet below the water table and directly
above an impermeable clay layer are indicative of DNAPL.

Concentrations of total VOCs in the central hot spot located just west of the tennis
courts are not indicative of NAPL, as evidenced by soil boring SB7-4. Concentrations of
total VOCs in the central hot spot include 35 ppm in SB7-4 at 20 feet bgs (CDM, 1995 RI
Figure 4-19). Concentrations greater than 1% of a contaminant's solubility are strongly
indicative of the presence of NAPL. These concentrations were shown by the shaker dye
tests performed in the area ( CDM, 1995 RI Appendix A). Headspace analysis results
indicate that the most highly contaminated zone within SB7- 4 is 20 feet bgs
(approximately 10 feet below the water table), and headspace analysis results decrease
down to zero at 37 feet bgs helping to rule out the possibility for DNAPL (CDM, 1995 RI
Appendix A).

Groundwater
Groundwater samples taken from monitoring wells MW135 and MW106A (located down gradient
from Area 7) had concentrations of 1,1,1-TCA at 8 ppm and 7.9 ppm, respectively. Other
VOCs detected in the groundwater ( down gradient of Area 7) include PCE, TCE, 1,2-DCE
(total), vinyl chloride and ethyl benzene. Table 2 identifies concentrations of primary
contaminants of concern identified within the groundwater near Area 7.

Surface Water and Sediment
In June 1996, samples were taken from surface water and sediments in the unnamed creek
at the north end of Area 7. This was necessary to determine if past activities had
affected the creek. Figure 4 illustrates Area 7 surface water and sediment sampling
locations. Four creek sediment samples were obtained during the Operable Unit Three
remedial investigation. Only one VOC, 1,2-dichloropropane (1,2-DCP) was identified within
the sediment. Concentrations of 1,2-DCP ranged up to 0.007 ppm (CDM, 2000 RI 3-22). The
PNAs fluoranthene, pyrene, benzo (a) anthracene and chrysene were detected in every
sediment sample (CDM, 2000 RI 3-26) . Pesticides and PCBs were also detected in the
-------
creek sediment.

Three surface water samples were obtained from the creek. Six VOCs were detected,
1,1,1-TCA, TCE, 1,1-DCA, 1,1-DCE, 1,2-DCE and chloroethane. There was no discernable
pattern in the distribution of contaminants detected in surface water samples. Total VOCs
were identified at 0.09 ppm upstream, as compared to 0.065 ppm downstream. Total VOCs in
surface water at the confluence of the surface water drainage ditch and the unnamed creek
were 0.111 ppm (CDM, 2000 RI 3-26).

On December 16, 1998, Illinois EPA obtained additional samples of the surface water and
sediments within the creek. The objective of the sampling event was to provide more
information regarding the type and source of contaminants. A total of six samples were
taken from the creek - two sediment samples and four surface water samples. Sampling
locations for this event are also identified within Figure 4. The December 1998 sampling
event identified several compounds that were not detected during the 1996 investigation
(Takas). In addition, higher concentrations of several compounds that had been previously
detected were identified (Takas). Table 3 summarizes the concentrations of contaminants
identified in the sediment during both the 1996 and 1998 investigations. Table 4
summarizes the concentrations of contaminants identified in the surface water during both
the 1996 and 1998 investigations. Construction activities on the property south of the
creek have resulted in an altering of the creeks natural drainage. Additional sampling may
be reguired because of these activities.

SOURCE AREA 9/10
ARE A 9/10
Soil Vapor Extraction and Enhanced
Mr Sparging. Contingent R*m*tfy
Pump and Trail
Treatment Building
Soil Vapor Extraction System
Sparging
Figure 5. Source Area 9/10 Map
-------
Table 3. Area 7 Creek Sediment Concentrations and Ecological Benchmarks (mg/kg)
Analyte
Naphthalene (A)
Acenaphthene (A)
Dibenzofuran (A)
Fluorene (A)
Anthracene (A)
Carbazole (A)
Fluoranthene (B)
Pyrene (B)
Benzo(a)anthracene (B)
Chrysene (B)
Benzo(b) fluoranthene (B)
Benzo(a)pyrene (B)
lndeno(1,2,3-cd) pyrene
(A)
Dibenzo(a,h)anthracene
(A)
Benzo(g,h,i)perylene (A)
Di-n-butylphthalate (A)
Chloromethane (A)
Vinyl chloride (A)
Chloroethane (A)
Acetone (A)
1,1-Dichloroethane (A)
1,2-Dichloroethane (total)
(A)
1,1,1-Trichloroethane (A)
Heptachlor epoxide (A)
Barium (A)
Calcium (A)
Cobalt (A)
Iron (A)
Potassium (A)
Magnesium (A)
Sodium (A)
Lead (A)
Vanadium (A)
Sample Locations
X102
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
0.110
ND
0.028
0.014
0.029
0.110
0.190
0.062
ND
101.00
8530
5.10
13400.0
0
1320.00
5210
551.00
88.90
31.20
A7CS-4
ND
ND
ND
ND
ND
ND
0.590
0.140 J
0.230 J
0.270 J
0.510
0.054 J
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND

-
-
-
—
-
-
-
-
-
A7CS-1
ND
ND
ND
ND
ND
ND
0.240 J
0.086 J
0.120 J
0.130 J
0.250J
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND

-
-
-
—
-
-
-
-
-
A7CS-2
ND
ND
ND
ND
ND
ND
0.092 J
0.042 J
0.038 J
0.044 J
0.094 J
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND

-
-
-
—
-
-
-
-
-
X101
0.063(1)
0.170
0.091
0.180
0.240
0.310
1.600
1.300
0.690
0.740
0.870
0.590
0.440
0.110
0.390
ND
.013
ND
ND
.014
ND
ND
ND
0.0026
16
29100
ND
6690
ND
14400
247
ND
12.1
A7CS-3
ND
ND
ND
ND
ND
ND
0.120 J
0.100J
0.054J
0.069 J
0.1 20J
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND

-
-
-
—
-
-
-
-
-
Benchmark
0.0346 (2,3)
0.00671 (2,3)
-
0.010(4)
0.03162(5)
-
0.03146(4)
0.04427 (4)
0.0317(2)
0.02683 (4)
-
0.0319(2)
0.01732(4)
0.00622 (2,3)
0.170(6)
-

-
-
-
-
-
-
0.00060 (2)
-
-
-
-
-
-
-
30.20 (3)
-
24
-------
Notes:
A Compound not evaluated in March 1999 Ecological Risk Assessment and exceeds existing screening
benchmark or no benchmark exists
B Compound detected at concentration higher than that which was evaluated in March 1999 Ecological Risk
Assessment
J Value is estimated based on laboratory results
1 Concentrations shown in bold exceed ecological screening benchmark
2 Canada interim = Canadian Sediment Quality Guidelines for the Protection of Aquatic Life - Interim Freshwater
Sediment Quality Guidelines (ISQGs) http://www.ec.gc.ca/ceqg-rcqe/sediment.htm
3 Florida threshold = Florida Department of Environmental Protection, Office of Water Policy - Sediment Quality
Assessment Guidelines (SQAGs) Threshold Effect Levels
http://www.dep.state.fl.us/dwm/documents/sediment/default.htm (Table 5, p.77)
4 NOAA lowest threshold = National Oceanic and Atmospheric Administration Screening Quick Reference Tables
(SQUIRTs) - Freshwater Sediment Lowest ARCS H. azteca Threshold Effect Level (TEL)
http://response.restoration.noaa.gov/living/SQuiRT/SQuiRT.html
5 ARCS probable = Assessment and Remediation of Contaminated Sediments (ARCS) Program of National
Biological Service for U.S. EPA Great Lakes National Program Office - Probable Effect Concentration (PEC)
http://www.hsrd.ornl.gov/ecorisk/reports.html (sediment report, Table 4, p.17)
6 Ontario low = Ontario Ministry of the Environment - Lowest Effect Level
http://www.hsrd.ornl.gov/ecorisk/reports.html (sediment report, Table 4, p.17)
25
-------
Table 4. Surface Water Contaminant Concentrations and Ecological Screening
Benchmarks (ug/L)

Analyte
bis(2-Ethylhexyl)
phthalate (A)
Vinyl chloride (A)
Chloroethane (B)
Acetone (A)
1,1-Dichloroethene (B)
1,1-Dichloroethane (B)
1,2-Dichloroethene (B)
Chloroform (A)
Trichloroethene (B)
Xylene (total) (A)
Aluminum (A)
Chromium (A)
Copper (A)
Iron (A)
Lead (A)
Antimony (A)
Zinc (A)
Sample Locations
S202
ND
48 J
87 J
ND
88
1300.00
2200.00
10.00
22.00
21.00
6310
7.4
9.6
9946
11.5
ND
49
S204
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
27900.00
46.90 (7)
84.90
527000
108
7
340
A7SW-3
ND
ND
10
ND
ND
30
42
ND
U
ND
-
-
-
-
-
-
-
S203
13.00
ND
ND
ND
ND
ND
ND
ND
ND
ND
7770
14.0
43.2
251000
54.4
3.7
193
A7SW-1
ND
ND
ND
ND
1 J
19
54
ND
U
ND
-
-
-
-
-
-
-
A7SW-2
ND
ND
ND
ND
ND
13
31
ND
ND
ND
-
-
-
-
-
-
-
S201
ND
ND
ND
17.00
ND
ND
ND
ND
ND
ND
42.8
ND
ND
6650
ND
ND
7.6
Benchmark
-
-
-
-
-
-
-
-
-
-
5-100.00(3)
11, 74(5)
9.00 (5)
1000.00(5)
2.50 (5)
3.0(6)
120.00(5)
S

7
Notes:
A Compound not evaluated In March 1999 Ecctograei RteX Assessment and exceeds existing screening
oeft&nrri£fk or no pench^iBflc exists
8 Compound delected at concentrator higher then that wrticN was evaluated in March 1999 Ecological Risk
Assessment
J Value it estimated tidfted on laboratory result?
1 ConcerUrgUDni In fcmld exceed acokogkcal screenirtg benchmark
2 IMroit EPA Water Quality Criteria
3 Canada = Canadian Water Quality Guidelines Far Vie Protection of Aquatic Life - Freshwater Water Quality
Guidelines

4 NQAA • National Oceanic and Atmospheric AdnMnislration Screening Quick Reference TafcM* (SQUIRTs)
- Freshwater Acute
AWQC = U-S. EPA - Ambient Water Quality Criteria Freshwater GHer ion Continuous ConcanlraHon
(CCC) NMkMiel RecommerKfed Water Quality Criteria - Careclton EPA S22-Z -99-00 1 Aprt 1 999, For
ctwomium, 1 1 ygfl- and 74ug/L art tfw critwri* for Chrorrtiivn *3, and Chrocnrum +fj, respactwely.
NQAA = NaQonal Oceanic and Atmospheric Adnnnalraton Screerrino Oulck Reference Tabtes (SQUIRts)
Chronic htto "-•JSF>or-:
Concentration is for Crinprnlwn
26
-------
Source Areas Nine and Ten have been combined and evaluated together as Area 9/10. Area
9/10 is an industrial area that is bounded by Eleventh Street on the east, Twenty-third
Avenue on the north, Harrison Avenue on the south and sixth street on the west. The
properties to the immediate north of Area 9/10, across Twenty-third Avenue, are
residential and are zoned as such. South of Area 9/10, across Harrison Avenue, properties
are used for both commercial and residential purposes. Area 9/10 is zoned as light
industrial, while the properties to the south are zoned mixed residential and commercial
(Dust). Future uses for Area 9/10 and adjacent properties planned by the City of Rockford
are consistent with current uses (Dust). Figure 5 provides graphical information for Area
9/10. Problems regarding site access and concern over underground utilities at Area 9/10
have limited past investigations and their ability to provide complete and accurate
information about the sources located in this area.

Area 9/10 has a history of industrial activity that extends back as far as 1926, when the
Rockford Milling Machine and Rockford Tool companies merged to become the Sundstrand
Machine Tool Company, located at the northwest corner of Eleventh Street and Harrison
Avenue (Lunden). Current industries that operate in the area include Sundstrand
Corporation's Plant #1, Paoli Manufacturing, Rockford Products Corporation, and J.L.
Clark. Mid-States Industrial Company (also known as Rockford Power Machinery) Nylint
Corporation, and Rohrbacher Manufacturing were also primary facilities in the area, but
are no longer in operation (COM, 2000 RI 1-7, 3-55). The geology at Area 9/10 is
unconsolidated sand and gravel to a depth of at least 101 feet bgs, as determined by
SB9/10-201. No clay or silt units were encountered (with the exception of some fill
material within eight feet of the ground surface) in the borings conducted by CDM for the
Operable Unit Three investigation. Information from boring logs for two borings conducted
near the intersection of Ninth and Harrison Avenue indicate that the unconsolidated sand
and gravel in Area 9/10 continues to approximately 235 feet bgs, where bedrock is
encountered. One of the boring logs from Illinois State Geological Survey well records
identifies a till unit from 120 to 130 feet bgs. Borehole drilling just west of Area 9/10
at the intersection of Twenty-third Avenue and Fourth Street indicated that the
unconsolidated sediments are at least 169 feet thick, with a 12-foot-thick clay unit from
132 to 144 feet bgs. The water table at Area 9/10 is generally encountered between 30 and
35 feet bgs (CDM, 2000 RI 3-55, 57).

Investigation results, summarized below, indicate that significant sources of VOC
contamination exist within Area 9/10. Four primary potential source locations within Area
9/10 were investigated and are discussed below.

Sundstrand Plant #1
Available information regarding Sundstrand Plant #1 (Illinois EPA 104e Reguests; Harding
Lawson Associates 1992) documents the existence of three major potential source areas at
the facility: (1) the Outdoor Storage Area; (2) the loading dock; and (3) the Waste
Recycling Area. Additional sources of contamination include underground storage tanks
(USTs) located throughout the facility and other historical solid waste management units
(SWMUs). Some of the other SWMUs contained within the facility include a wastewater
treatment plant, an old plating area, a sodium dichromate line, an old dichromate line and
an old drum wash area. The Outdoor Storage Area, formerly located at the southwest corner
of Ninth Street and Twenty-third Avenue, was used to store VOCs. Soils located below this
area had elevated concentrations of VOCs. Additionally, an underground storage tank (UST)
adjacent to the Outdoor Storage Area was used to store VOCs.

During its history, Plant 1 has contained numerous USTs related to different activities at
the facility. These USTs ranged in capacity from 500 gallons to 10,000 gallons, and
numbered up to 40 USTs at any one time. Records indicate that many old USTs have been
removed or abandoned in place for a variety of reasons, including leaking tanks.
Construction of some of the USTs and their associated piping systems include many that
were made of steel. The loading dock at Plant #1 has contained approximately 14 USTs at
various times between 1962 and 1987. USTs at Plant 1 contained a variety of materials
including: chlorinated solvents, stoddard solvent; cutting oils; fuel oils; lapping oil;
1318 oil; rust oil; DTE 25 oil; mineral spirits (7024 or Naphthol spirits); petroleum
-------
naphtha; gasoline; and jet fuel (JP4, JP5, and JP8). Some of the tanks within the facility
were used to contain waste materials such as: used JP4; used 7024; waste oil; and
solvents (PCE, TCE, 1,1,1-TCA, Stoddard). The Waste Recycling Area is the third potential
source at Sundstrand's Plant # 1. The Waste Recycling Area is located inside the facility,
and is up gradient of the west end of the Nylint building (CDM, 2000 RI 3-75,76).

Mid-States Industrial
A drum storage area at the Mid-States Industrial facility (formerly Rockford Power
machinery) is another potential source at Area 9/10. Trichloroethene was identified in the
shallow soils in this vicinity up to 67 ppm (Fehr-Graham Associates, 1989).

Nvlint
Investigations were conducted at the property leased by Nylint during the Operable Unit
Three remedial investigation. High concentrations of 1,1,1-TCA were found in soil gas at
the west end of the building, suggesting a potential nearby source. Soils samples from the
area did not detect elevated VOCs, indicating that soil gas is either migrating from an
adjacent area (where soil samples were not collected), or that volatilization from the
groundwater is responsible for observed soil gas concentrations (CDM, 2000 RI 3-76).

Rockford Products
Elevated concentrations of VOCs in soil gas (greater than 1,000 ppb) at the Rockford
Products facility on Ninth Street indicate this is a potential source. As with Nylint,
soil samples from the area did not detect elevated VOCs, indicating that soil gas is
either migrating from an adjacent area (possibly beneath the building) or volatilizing
from the groundwater. It should be noted that the location of elevated soil gas
concentrations is down gradient from Sundstrand Plant #1's Outdoor Storage Area. Migration
of VOCs from the Outdoor Storage Area and volatilization from the groundwater could be the
cause of elevated soil gas concentrations. Information currently available does not allow
for a determination of all sources of contamination in Source Area 9/10.

Soil Gas
The soil gas investigation conducted as a part of the Operable Unit Three investigation
identified several portions of Area 9/10 with distinctly high soil gas concentrations. The
areas are: 1) west and northwest of the Sundstrand plant (the southeast corner of Twenty-
third Avenue and Ninth street); 2) immediately south of the Sundstrand Plant and in the
Rockford Product parking lot; 3) immediately north of the Rockford Products building on
Ninth Street; 4) the west end of the Nylint building; 5) the Mid-States Industrial
facility and 6) the intersection of Ninth Street and Harrison Avenue. Elevated
concentrations of chlorinated compounds detected in soil gas include: PCE; TCE; 1,1,1-TCA;
1,2-DCE; 1-1-DCA; and vinyl chloride. Non-chlorinated VOCs detected include BTEX (benzene,
toluene, ethylbenzene, and xylene) compounds that were ubiguitous, in small-to-moderate
amounts. Table 5 includes total VOCs detected within the soil gas of Area 9/10. (CDM
Operable Unit Three RI 3-57).

The soil gas distribution for PCE indicates the presence of significant concentrations
(0.100 ppm) on the northwest, west and southwest sides of the Sundstrand Plant on Ninth
Street, and in the area just north of Rockford Products, at the intersection of Ninth
Street and Harrison Avenue. Trichloroethene concentrations in soil gas greater than 0.100
ppm were found at the southwest corner of the Mid-States building and at the west end of
the Nylint building. Concentrations of 1,1,1-TCA were the most significant and pervasive
of any soil gas compound in Area 9/10. The largest area of elevated TCA (greater than
0.100 ppm) occurs just south of the west part of Sundstrand Plant #1 and extends south-
southwest across Rockford Products parking lot. The distribution of 1,1,1-TCA closely
resembles that of total VOCs shown on Figure 7, Table 7 of CDM Operable Unit Three RI
3-57.

No indoor air analysis was performed in Area 9/10, because the area is mostly industrial
and the homes in the area appear to be outside significant areas of groundwater
contamination. Also, soil gas concentrations near the homes are low.
-------
Surface Soils
A total of four surface soil samples were obtained in Area 9/10. The only VOC detected was
methylene chloride (a common laboratory contaminant). A total of 20 PNAs were detected,
including phenanthrene, fluoranthene, pyrene and chrysene. Dieldrin and gamma-Chlordane
were the pesticides most often detected. Concentrations of detected metals were not
remarkable. Table 5 summarizes the results of Area 9/10 investigations.

File searches revealed records of soil contamination from chlorinated solvents including
tetrachloroethylene ( PCE) , trichloroethene (TCE) , 1,1,1-tichloroethane, 1,1
dichloroethene, 1,2 dichloroethane and 1,1,2 tichloroethane. Additional contamination
exists in the soil from the release of petroleum fuels such as JP4, JP7, mineral spirits,
fuel oil and BTEX compounds. Metals have also been detected in sufficient guantities to be
considered a threat to groundwater.

Sub-surface Soils
In areas where access was attainable, analysis of sub- surface soils indicate low
concentrations of total VOCs. In soils above the water table, a maximum of 0.050 ppm of
total VOCs was identified. The only detections of chlorinated VOCs in soil above the water
table occurred at the Sundstrand Plant in borings SB9/10-134, SB9/ 10-135 and SB9/10-137.
Tetrachloroethene, methylene chloride and TCE were the primary chlorinated VOCs detected
in soils above the water table. The highest concentration of chlorinated VOCs below the
water table was 0.154 ppm, and that was in the soil within the top ten feet beneath the
water table (39 to 41 feet bgs). The primary chlorinated VOCs detected in this sample were
1,1,1-TCA and 1,2 DCE. Table 5 summarizes the results of investigations in Area 9/10 (CDM,
2000 RI 3-61,67).

Groundwater
Of all the sources investigated, the plume of groundwater contamination emanating from
Area 9/10 has the third highest VOC concentration in the Southeast Rockford Groundwater
Contamination Superfund Site (CDM, 1995 RI 4-137). Previous investigations have identified
Area 7 as having the highest concentrations of groundwater contamination, followed by Area
8, which had the second highest concentrations. The Operable Unit Two remedial
investigation determined that groundwater contamination from Area 8 was not contributing
to the overall Southeast Rockford groundwater contamination problem and was dropped from
consideration as a part of the Superfund site.

Five monitoring wells in Area 9/10 were sampled as a part of the Operable Unit Three
remedial investigation. VOCs were detected in all five locations. Total VOCs above
detection limits for two up-gradient wells, MW202 and MW203, were 0.017 ppm and 0.009 ppm,
respectively (CDM, 2000 RI Figure 3-34). Monitoring wells MW-5 and MW-4 were installed at
the former Mid-States building (formerly Rockford Power Machinery) for a previous study in
1991 (Fehr-Graham & Associates). Total VOCs above detection limits in wells MW-5 and MW-4
(which are immediately down gradient of the former Mid- States building) are 0.028 ppm and
0.043 ppm, respectively. Groundwater samples obtained from monitoring well MW201
(installed down gradient of Sundstrand Plant #1) contained 18.27 ppm total VOCs above
detection limits. Table 5 summarizes the results of past Area 9/10 groundwater
investigations (CDM, 2000 RI 3-67, Figure 3-34).

NAPL
The concentration of 12 ppm of 1,1,1-TCA in MW201 indicates that NAPL is likely present in
Area 9/10, based on the agueous solubility limit of 1,1,1-TCA. Field studies have shown
that groundwater concentrations greater than 1 percent of a contaminant's solubility are
strongly indicative of the presence of NAPL ( National Research Council). The
concentration of 1,1,1-TCA in MW201 represents 0.8 to 4 percent of its agueous solubility
limit. The source of the dissolved 1,1,1-TCA is located a short distance up gradient
(northeast) of the well, between the north end of the Rockford Products parking lot (east
of 9th Street) and the Mid-States Industrial property. Furthermore, given the dominance of
chlorinated VOCs, which are denser than water, it is likely that a DNAPL is present in the
vicinity of MW201. Dye testing did not reveal the presence of DNAPL in the shallower
portions of the unconsolidated aguifer. However, DNAPL would not be expected to be present
-------
in the more shallow portions of the aquifer, because no confining units are present in the
top 100 feet of the aquifer (CDM, 2000 RI 3-77). Further research has revealed that
numerous releases of petroleum based fuels (JP4, mineral spirits, and fuel oil) and
chlorinated solvents from USTs have occurred within Area 9/10. Information submitted to
the Illinois EPA (in reports) reveals that LNAPL related to these releases exists or
has existed floating on the water table.
-------
Table 5. AREA 9/10 Contaminant Concentration Ranges and Preliminary Remediation
Goals
Contaminant1
SOIL (ppm)
Concentration Range in Soil
Remediation
Goal
Volatile Organics
1,1-Dichloroethene
BDL
0.002
0.06
GROUNDWATER (ppb)
Concentration
BDL-850
MCL
Above 10 feet Be ow 10 feet
1,2-Dichloroethane
BDL
BDL
0.02
BDL-6 J
1,2-Dichloroethene (total)
BDL
BDL
0.4
BDL-4600
NA
Ethylbenzene
BDL
BDL
13
BDL-19
700
Methylene Chloride
0.002-0.003
0.003-0.048
0.02
BDL
Tetrachloroethene
BDL
0.002-0.046
0.06
BDL-50 J
1,1,1-Trichloroethane
BDL
0.001-0.050
BDL-12,000
200
1,1,2-Trichloroethane
BDL
0.006
0.02
BDL-60 J
Trichloroethene
BDL
0.001-0.002
0.06
BDL-140
Vinyl Chloride
BDL
BDL
0.01
BDL-14
Semi volatile Organics
Benzo(a)anthracene 4
Benzo (b)Fluoranthene
Benzo(a)pyrene
lndeno(1,2,3-cd)pyrene
0.004-0.054 BDL-0.002
Notes:
ppm - Parts per million or milligrams per kilogram
ppb - Parts per billion or micrograms per liter
MCL - Maximum Contaminant Level developed pursuant to Safe Drinking Water Act
J - Value is estimated based on laboratory results
BDL - Below detection limit of laboratory instruments or methods
NA - Compound was not analyzed or measured in laboratory
1 Only compounds that exceed Tier 1 screening level in soil or an MCL in groundwater are included
in Table. Remediation objectives shown for all other compounds are only for informational
purposes.
2 Remediation Objective is the Tier 1 residential screening level for soil for protection of
groundwater.
3 Remediation objective for cis-1,2-Dichloroethane, no objective exists for total 1,2-Dichloroethane
4 Only Tier 1 residential screening levels for soil for direct contact are considered for semivolatiles
because semivolatiles are not currently groundwater contaminants and are not expected to
become groundwater contaminants.
32
-------
5 Compound will be evaluated further through sampling during remedial design. Although compound
exceeds Tier 1 residential screening level for soil for direct contact, it is not considered a
chemical of concern at this time because semivolatiles' are prevalent in environment and not
found in groundwater.
6 Remediation Objective is the Tier 1 residential screening level for soil for direct contact.
7 Site specific background value. For beryllium, the value is the Upper Tolerance Limit on
background data.
8 Dieldrin not included as a chemical of concern because it was not found in the groundwater.
Surface concentration is below Tier 1 residential screening level for soil for direct contact.
9 Remediation Objective is the Tier 1 residential screening level for soil for protection of
groundwater.

Source Area Eleven

Source Area Eleven (Area 11) is located east of Eleventh Street at the corner of Eleventh
Street and Harrison Avenue (see Figure 6). Area 11 is bordered on the east and west by
industrial facilities. Properties to the immediate north are industrial, while land uses
further north (north of Twenty-third Avenue) include industrial mixed with some
residences. South of Area 11 across Harrison Avenue, properties are used for both
commercial and residential purposes. Area 11 continues to be dominated by industrial
activities and is comprised of several industrial properties and one commercial property.
The Area is zoned light industrial and commercial (Dust). Future uses planned by the City
of Rockford are consistent with current uses as light industrial (Dust).
Source Area II
Propos*d Plan
Soil V«p»r Extnctum
HARRISON *V£NUi
Figure 6. Source Area 11 Map

The geology at Area 11 is unconsolidated sand and gravel to a depth of at least 62 feet
bgs, as evidenced by SB11-202 (CDM, 2000 RI Appendix D). Information from boring logs for
two borings conducted approximately one block east of Area 11 near the intersection of
Ninth and Harrison Avenue indicate that the unconsolidated sand and gravel in the general
area continues to approximately 235 feet bgs where bedrock is encountered (CDM, 2000 RI
3-55, 57). One of the boring logs from Illinois State Geological Survey well records
-------
identifies a till unit from 120 to 130 feet bgs (CDM, 2000 RI 3-55, 57). The water table
at Area 11 was encountered at approximately 20 to 25 feet bgs during the Operable Unit 2
investigation and closer to 30 to 34 feet bgs during the during Operable Unit Three
investigation (CDM, 1995 RI Appendix A, CDM, 2000 RI Appendix D).

Area 11 currently includes the Rohr Manufacturing facility (formerly Rockwell Graphics
Systems) , H and H Wood Products and Pallets, Villa Di Roma Restaurant and adjacent parking
lots. Historically, Rockford Varnish, Rockford Coatings and Rockwell Graphics Systems have
conducted manufacturing activities in Area 11 (CDM, 2000 RI 1-6).

The Rockford Coatings Corporation, formerly located at 1620 Harrison Avenue, manufactured
several paint products including enamels, lacguers and water-based paints. Whether or not
chlorinated solvents were used at the facility is unknown. The Rockford Coatings
Corporation discontinued operations in 1983 (CDM, 2000 RI 1-6).

Rockford Varnish Company, formerly located at llth and Harrison Avenue, manufactured
varnish and related products for the furniture industry from 1906 until 1983. Rockford
Varnish used VOCs, including chlorinated solvents, in its operations and stored these
compounds on site in approximately eight aboveground storage tanks. Groundwater sampling
results near the facility indicate chlorinated solvent contamination (CDM, 2000 RI 1-6).

Rockwell International Graphics, formerly located at 2524 llth Street, manufactured gears
and rollers for newspaper presses until approximately 1991. The facility used 1,1,1-TCA
for cleaning rollers until 1983. Areas of concern near the former Rockwell facility
include a dumpster located south of Rockwell that apparently leaked cutting oils onto the
ground surface and a pit to the north of the property that contained standing water with
an oil sheen. The Rockwell facility is now owned by P. H. Partners Co., who leases it to
Rohr Manufacturing. Present operations include painting industrial equipment (CDM, 2000 RI
1-6) .

Several contaminant release and migration pathways exist in Area 11. One potential
contaminant source is the eight aboveground storage tanks that previously contained VOCs
(including chlorinated solvents) at the former Rockford Varnish Facility. Potentially
leaking tanks and aboveground piping may have released contaminants to the vadose zone of
the soil (region just below ground surface where soil pores are filled with air and small
amounts of water). Also, a bunker reportedly used by Varnish Company is located in the
railroad right-of-way south of the former Rockwell property. This bunker has previously
seeped a tar-like substance. Historical reports indicate that a dumpster used by Rockwell
Graphics leaked cutting oils onto the ground surface and that a pit to the north of
Rockwell contained standing water with an oil sheen (CDM, 2000 RI 3-33).

Investigations conducted at Area 11 identified two distinct zones of subsurface
contamination. One zone is located on the western margin of Area 11, centralized beneath
Rohr Manufacturing and extending to areas north, south, and west of the building. Soil
samples within this zone indicated elevated concentrations of toluene, ethylbenzene,
xylene and acetone, as well as the presence of NAPL. A second zone of contamination exists
near the aboveground storage tanks to the northeast of the former Rockford Varnish
building. Soil samples in this zone identified elevated concentrations of toluene, xylenes
and PCE. Within both zones of elevated contamination, the high levels of BTEX masked lower
levels of chlorinated VOCs that were likely present. Table 6 summarizes the results of
past investigations in Area 11 (CDM, 2000 RI 3-45, 3-51 to 3-53).

Soil Gas
A soil gas survey was conducted at Area 11 during the 1996 Operable Unit 3 remedial
investigation to delineate the extent of VOC contamination and to identify any hot spots.
A total of 54 soil gas samples were collected. Total concentrations of BTEX in the western
zone of contamination ranged from 0.041 ppb to 2.25 ppm. Toluene and xylene are the
primary contributors to the total BTEX concentration. Total chlorinated VOCs in the
western zone ranged from less than 0.007 ppm to 0.077 ppm. Primary contributors to total
chlorinated VOC concentrations appear to be 1,1,1 TCA and PCE. Chlorinated VOC
-------
concentrations in the soil gas may be understated due to the presence of elevated BTEX in
some samples (CDM, 2000 RI Appendix D).

Total BTEX concentrations in the central zone of contamination ranged from less than 0.006
ppm to 0.180 ppm. Toluene and xylene are the primary contributors to the total BTEX
concentration in this zone as well. Total chlorinated VOCs in the central zone ranged from
less than 0.010 ppm to 0.224 ppm. Primary contributors to total chlorinated VOC
concentrations appear to be 1,1,1 TCA and PCE. As with the western zone, chlorinated VOC
concentrations in the soil gas may be understated due to the presence of elevated BTEX in
some samples (CDM, 2000 RI Appendix D).

One notable concentration of total chlorinated VOCs in soil gas was located on the north
side of the right-of-way at the southeast corner of Rohr Manufacturing. Concentrations of
total chlorinated VOCs in the soil gas sample obtained from this area reached
approximately 1.049 ppm (CDM, 2000 RI Appendix D).

No indoor air analysis was performed in Area 11 because of the industrial nature of the
area and the distance to homes.

Surface Soils
Seven surface soil samples were obtained from Area 11 in locations where elevated VOC
concentrations in soil gas were identified. The results are included in Table 6. Surface
soil samples identified PNAs, pesticides, PCBs and metals. Volatile Organic Compounds were
not detected in surface soils samples. The concentration of PNAs identified ranged from
0.042 ppm to 440 ppm. Several PNAs (phenanthrene, fluoranthene, benzo(a) anthracene,
chrysene, bis(2ethyl-hexyl) phthalate, benzo( b) fluoranthene and benzo(k) fluoranthene)
were detected in all seven samples. Several pesticides were identified, ranging in
concentrations from 0.003 ppm to 0.180 ppm. The pesticides most often detected were
Dieldrin, Methoxychlor and alphachlordane. Concentrations of PCBs ranging from 0.031 ppm
to 0.530 ppm were detected. Metals were identified at concentrations similar to background
in most cases (CDM, 2000 RI Table 3-11).

Sub-Surface Soils
Seventeen soil borings were conducted at Area 11. Sub-surface sampling results are
summarized in Table 6. VOCs, PNAs, pesticides and metals were identified in sub-surface
soils in this area. Concentrations of VOCs ranged from 0.004 ppm to 2,300 ppm. The VOCs
most often detected were xylene, toluene, ethylbenzene, and acetone. Sub-surface soils
collected from SB11-203 in the western portion of Area 11 and north of the Rohr
Manufacturing building at depths from 39-41 feet bgs tested positive for NAPL. Soils from
SB11-203 contained toluene (180 ppm), ethylbenzene (20 ppm), xylenes (110 ppm), and
acetone (5.1 ppm). In order to guantify these concentrations of VOCs in the laboratory,
the detection limit for chlorinated VOCs (1,1,1 TCA and PCE) was raised to 13 ppm.
Therefore, chlorinated compounds may be present at concentrations less than 13 ppm. Soil
samples were also taken from SB11-202 from 39-41 feet bgs and tested positive for NAPL.
SB11-202 was also located in the western portion of Area 11 but was south of the Rohr
Manufacturing building. Concentrations of VOCs within this sample were similar to that of
SB-203. Detection limits for chlorinated VOCs were also raised in this sample, to 27 ppm
for 1,1,1 TCA and PCE. The thickness of non- chlorinated VOC contamination in the western
zone ranges from 12 to 24 feet in an area measuring about 17,000 sguare feet (CDM, 2000 RI
3-45, 3-51 to 3-53) .

Sub-surface samples were also taken from the central portion of Area 11 (the central zone
of contamination) near the aboveground storage tanks northeast of the former Rockford
Varnish facility. Elevated concentrations of VOCs were also identified within this area,
with 290 ppm of toluene and 17 ppm of xylene at 35 feet bgs. The VOC contamination in this
zone is limited to the area around and west of the aboveground tanks. Although PCE was
detected in sub- surface soils at concentrations of .046 ppm at 20 feet bgs, it is not
suspected that the above ground tanks are a source. Levels of chlorinated VOCs in this
area are likely due to lateral migration of gases and volatilization from groundwater. The
extent of non- chlorinated VOC contamination in this zone extends from 35 feet bgs to an
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undetermined depth. The area of VOC contamination measures approximately 6,000 square feet
(CDM, 2000 RI 3-50, 3-51).

Subsurface concentrations of pesticides, and PNAs were significantly lower than levels
found in surface samples and were also detected less frequently. A concentration of PNAs
identified in subsurface soils ranqed from 0.045 ppm to 1.9 ppm. Concentrations of
pesticides ranqed in concentrations from 0.001 ppm to 0.009 ppm (CDM, Risk Table 10).
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Table 6. AREA 11 Contaminant Concentration Ranges and Preliminary Remediation
Objectives
Contaminant1
SOIL (ppm)
Concentration Range in Soil
Remediation
Goal
Volatile Organics
Benzene
BDL
BDL-1.5
0.1892
GROUNDWATER (ppb)
Concentration
BDL-23
MCL
Above 10 feet Be ow 10 feet
Ethylbenzene
BDL
BDL-590
7.98S2
BDL-3,900
700
Methylene Chloride
BDL
BDL-2.9
2303J
BDL
Toluene
BDL
BDL-1,400
6383
BDL-310,000
1,000
Trichloroethene
BDL
BDL-0.41
0.051'
BDL-170
Xylenes (total)
BDL
BDL-2,300
3123
Semi volatile Organics
Carbazole
BDL-67
BDL
BDL-16,000
BDL
10,000
NA
Benzo(a)anthracene
4,5
0.069-200
BDL
.96
BDL
NA
Chrysene45
0.052-240
BDL
886
BDL
NA
Benzo(b)Fluoranthene
0.086-220
BDL
.9b
BDL
NA
Benzo(k)Fluoranthene4
0.046-130
BDL
.96
BDL
NA
Benzo(a)pyrene
4,5
0.096-150
BDL
.37
BDL
NA
lndeno(1,2,3-cd)pyrene
,4,5
0.063-120
BDL
.96
BDL
NA
2-Methylphenol
BDL-0.031
Metals
Beryllium
Pesticides
Dieldrirr
Notes:
ppm - Parts per million or milligrams per kilogram
ppb - Parts per billion or micrograms per liter
MCL - Maximum Contaminant Level developed pursuant to Safe Drinking Water Act
J - Value is estimated based on laboratory results
BDL - Below detection limit of laboratory instruments or methods
NA - Compound was not analyzed or measured in laboratory
1 Only compounds that exceed Tier 1 screening level in soil or an MCL in groundwater are included in this
Table. Compounds in bold text are contaminants of concern for soil, and associated remediation
objectives shall be attained through remediation. Remediation goals shown for all other compounds are
only for information purposes.
2 Remediation goal Calculated using equation R15 of TACO that takes attenuation into account.
3 Soil Saturation Limit used. TACO stipulates that remediation objectives cannot exceed the soil saturation
limit. Therefore, when equation R15 of TACO generated a remediation goal greater than the saturation
limit, the saturation limit is used.
37
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4 Only Tier 1 residential screening levels for soil for direct contact are considered for
semivolatiles because semivolatiles are not currently groundwater contaminants and are not
expected to become groundwater contaminants.
5 Compound will be evaluated further through sampling during remedial design. Although compound
exceeds Tier 1 residential screening level for direct soil contact, it is not considered a
chemical of concern at this time because semivolatiles are prevalent in the environment and not
found in groundwater.
6 Remediation goal is the Tier 1 residential screening level for direct soil contact.
7 Site-specific background value. For beryllium, the value is the Upper Tolerance limit on
background data.
8 Dieldrin not included as a chemical of concern because it was not found in groundwater. Surface
concentration is below Tier 1 residential screening level for soil for direct contact.
9 Remediation goal is the Tier 1 residential screening level for soil for protection of
groundwater.

Groundwater
Groundwater analysis performed on samples taken from wells IW10, IW11 and MW128 indicate
the presence of VOCs and metals in groundwater down gradient of Area 11. Area 11 is a
significant source of non-chlorinated VOC groundwater contamination. Area 11 has the
highest and most extensive concentrations of BTEX compounds found in the groundwater.
Concentrations of 2 ppm (estimated) ethylbenzene, 310 ppm toluene, and 9.5 ppm xylene were
identified in groundwater in the area. Although Area 11 does contribute chlorinated VOC
contamination to the groundwater, it appears to be limited in extent and concentration.
Concentrations of TCE (0.170 ppm) were higher down gradient of Area 11 than those found up
gradient. The chlorinated VOC 1,1,1-TCA was also found in Area 11 groundwater at
concentrations up to 0.860 ppm, but could be the result of the Area 4 plume. Table 6
summarizes contaminant concentrations found in groundwater down gradient of Area 11 (CDM,
1995 RI 4-105,106,118 and Appendix H).

NAPL
The western zone (in the western margin of Area 11) is centralized beneath Rohr
Manufacturing. NAPL was detected in the western zone during field screening of SB11-203
soil samples from 39 to 43 feet bgs. A combination of black staining of soils and Sudan IV
dye testing confirmed the presence of NAPL in samples taken from 39 to 43 feet bgs.
Similar conditions were identified in SB11-202 from 39 to 45 feet bgs. The NAPL in both
soil borings was determined to be LNAPL because of its presence within the upper part of
the saturated zone. Headspace analysis conducted on samples taken beneath 45 feet bgs in
each boring decreased significantly with depth, indicating that DNAPL is not likely to be
present in this zone (CDM, 2000 RI 3-45, 51, 52, and Appendix D).

Sub-surface soil samples taken in the central zone of contamination (near the aboveground
storage tanks) indicate that VOC contamination in this zone begins at approximately 35
feet bgs. Past investigations in this zone have indicated the possibility for NAPL, but it
was not positively identified. Headspace analysis on samples obtained from soil borings
SB11-4 and SB11-8, which were advanced during phase II of the Operable Unit Two
investigation, indicates the greatest degree of VOC contamination at depths of
approximately 35 to 42 feet bgs. Soil samples SB11-4G and SB11-8G taken from these depths
indicate the possibility for NAPL. However, no staining is noted in the soil boring logs
and the Sudan IV dye test was not performed during the Operable Unit Two investigation.
Regarding the possibility for DNAPL, while minor DNAPL components do exist within soil
samples, headspace analysis below 42 feet decrease significantly indicating that DNAPL is
probably not present within this zone (CDM, 1995 Operable Unit Two RI 4-66, 4-70, Table
4-4, Appendix A).

The total depth of VOC contamination near the storage tanks cannot be positively
determined based on laboratory analysis of soil. However, soil analysis from samples taken
near this zone coupled with headspace analysis indicates that it is likely to be
approximately 10 feet thick, extending from approximately 35 to 45 feet bgs (CDM, 2000 RI
3-53).
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CURRENT AND POTENTIAL FUTURE LAND AND RESOURCES USES

The area included within the Southeast Rockford Groundwater Contamination Site currently
includes industrial, commercial and residential property. Industrial property use ranges
from what would be considered light-manufacturing facilities up to large facilities that
contain multiple underground storage tanks and units utilized in large manufacturing
operations. Commercial facilities include shopping facilities such as grocery stores and
fast food restaurants that are used as part of normal family activities, including
churches and a community center. Residential areas are mixed throughout the entire site,
including parks and other recreational facilities. Future uses of the entire area will
likely remain the same as they are today.

Source Area 4 is described as an industrial/commercial area in Southeast Rockford that
includes the former Swebco Manufacturing located at 2630 Marshall Street. Swebco
manufactured precision machine metal parts and was considered to be zoned for light
industrial. It was located in an area that included small businesses and single-family
homes. Property surrounding Area 4 is currently zoned either residential or light
industrial. The City of Rockford has indicated to the Illinois EPA that future property
use will be consistent with current use.

Area 7, located in the southeastern portion of the site, was determined to be an illegal
dumpsite. The former dumpsite includes Ekberg Park, a municipal park located at the end of
Balsam Lane, owned and maintained by the Rockford Park District. Pine Manor subdivision,
which contains single-family homes, occupies a position to the northwest of the park. Both
Pine Manor subdivision and Ekberg Park are zoned residential and the future plans for
these two areas are consistent with current use. Areas to the north, east and south of
Area 7 contain undeveloped real estate. However, discussions with Mr. Glen Ekberg, the
owner of the property to the north of the park, indicate that this property is in the
beginning phases of commercial development.

Area 9/10 is an industrial area, with history of this type of activity dating back as far
as 1926. Located in the area of Harrison Avenue and Ninth Street, it is zoned as
industrial and is designated to remain that way. However, the areas north of Twenty Third
Avenue and directly south of Area 9/10 are primarily residential single-family homes. The
City of Rockford has indicated the future use of the property in this area is consistent
with current use for Area 9/10.

Area 11 is located on the corner of Eleventh Street and Harrison Avenue and is bordered on
the west and east by industrial facilities. Currently, Area 11 is dominated by industrial
facilities but does contain one commercial property. Property to the north of Twenty Third
Avenue and south of Area 11 consists of a mix of residential, commercial and industrial
properties. Currently, the zoning of Area 11 is light industrial and commercial, and
future zoning plans are for the area to remain light industrial.

Contaminated groundwater was detected in municipal wells owned by the City of Rockford in
1981, resulting in the closing of several wells. Currently, one City of Rockford municipal
well (located within the designated site) is using granulated activated carbon (GAG)
filters to remove VOCs from potable water. The GAG unit assures that sufficient potable
water supplies exist for residents within Rockford. Residents with contaminated wells were
given the opportunity to hook up to the City of Rockford Municipal water system as part of
a time critical removal action in 1991. Through the source control measures and natural
attenuation of the groundwater, it is estimated that approximately 200 years will be
necessary for complete remediation of the groundwater and to return it to natural
conditions. Remedial activities for treatment of soil and leachate at the source areas are
expected to continue for approximately twenty-five years. During this time period and
after source removal has been completed, groundwater monitoring will continue to assess
the quality of the groundwater. The goal of the proposed remedies for the source areas,
along with natural attenuation, is to reduce the risk to human health and return the
groundwater to a natural, potable drinking water source.
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SUMMARY OF SITE RISKS

Risks to human health and the environment caused by contamination from Source Areas 4, 7,
11, and 9/10 (in the form of chlorinated solvents) were first detected in private drinking
water wells. Therefore, an evaluation was performed through a risk assessment process.
This process characterizes current and future threats or risks to human health and the
environment posed by contaminants at the site. The risks to human health and the risks to
the environment are usually evaluated separately for each site. A human health risk
assessment was conducted for all four source areas, and is discussed below in the section
entitled Human Health Risks.

Because of the industrial nature of Source Areas 4, 11 and 9/10, the Illinois EPA and U.
S. EPA determined it was only necessary to evaluate risks to the environment (often called
ecological risks) for Area 7. The results of the ecological risk assessment for Area 7 are
discussed below in the section entitled Summary of Ecological Risk Assessment.

The calculation of risks to human health and the environment posed by surface water and
sediments in the creek running north of Area 7 was problematic. Concentrations of several
contaminants (PNAs and VOCs) in the surface water and sediment at Area 7 and their
locations in relationship to the area suggest another source may be present upstream.
Results of a focused sampling event conducted in December 1998 provided more information
regarding the presence of contaminants in the creek, but were unable to establish the
contribution of upstream sources to Area 7.

The Agencies determined that it would be more efficient to further evaluate the creek
running north of Area 7 during the design phase of the project. The design phase will
likely occur in 2002. If the evaluation of risks to human health and the environment
conducted during the design phase identifies the need for remediation in addition to that
outlined within this ROD, the remedy would be appropriately altered. Depending on the
significance of the change in remedy, the Agencies may be required to hold additional
public meetings and allow public comment on the new remedy.

SUMMARY OF HUMAN HEALTH RISK ASSESSMENT

The National Contingency Plan (NCP) establishes an expectation that U. S. EPA will use
treatment to address principal threats posed by a site wherever practicable (NCP, 40 CFR
§ 300.430(a)(1)(iii)(A)). The term "principal threat" refers to source materials that are
considered to be highly toxic or highly mobile that generally cannot be reliably contained
or would present a significant risk to human health or the environment should exposure
occur (U. S. EPA, Guide 6-40). Remedial investigations conducted at the site have
identified principal threat wastes at all four source areas (Area 4, Area 7, Area 9/10,
and Area 11). Residual NAPL was positively identified at Areas 4, 7, and 11 (COM, 2000
RI). At Area 9/10, groundwater concentrations were identified that were indicative of a
significant source of groundwater contamination and NAPL presence (COM, 2000 RI 3-77). The
following text summarizes information identifying the principal threats at each Source
Area.

Human health risks posed by Source Areas 4, 7, 11, and 9/ 10 were evaluated and described
within the "Southeast Rockford Source Control Operable Unit Risk Assessment Report," dated
April 2000. The risk assessment utilized Illinois EPA's Tiered Approach to Corrective
Action Objectives (TACO) at 35 111. Adm. Code Part 742, to evaluate risks. TACO is a set
of State of Illinois regulations that specify methods for developing remediation
objectives and identifying chemicals of concern. The human health risk assessment
conducted at this site used TACO Tier 1 screening values, as well as Risk Assessment
Guidelines for Superfund ( RAGS) - site specific remediation objectives to evaluate human
health risks at each source area.

The risk assessment evaluated three exposure pathways at each source area. An exposure
pathway is a means by which a person may come in contact with site contaminants. The three
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exposure pathways evaluated in the risk assessment are: (1) Direct contact with soil
(including ingestion of soils and inhalation of vapors from soils); (2) Chemicals
transferring (leaching) from soils into groundwater; and (3) Ingestion of vegetables grown
at Area 7. The third exposure pathway was included because portions of Area 7 were used
for agricultural purposes.

The major contaminants of concern (COCs) for soil in each source area, as identified by
the RI and the Risk Assessment are listed in Table 7. Contaminants of concern are
compounds that are present at the site in sufficient guantities to present an unacceptable
risk to human health or the environment. Contaminants of concern were identified by
comparing concentrations identified within the soil or leachate at each area to
preliminary remediation goals. The preliminary remediation goals (PRGs) for this site were
generated in accordance with 40 CFR § 300.430 (e)(2)(i) of the National Contingency Plan.

The risk assessment identified conditions at all four source areas that constitute a
potential or actual threat to human health or the environment. Concentrations of
contaminants present in soil at Areas 4, 7, and 11 exist at levels that are not protective
of human health for groundwater consumption. The risk assessment also identified soils at
Area 7 that exceed direct contact PRGs for TCE and PCE. In cases where the site
concentration exceeds levels protective of human health and the environment, risks to
human health are considered unacceptable and remedial alternatives have been developed to
address the issue.

Table 7. Contaminants of Concern in Soil
Area 4
1,1,1-Trichloroethane
Area 7 Area 11
1,1-Dichloroethene Benzene
1,2-Dichloroethene (total) Ethyl benzene
Tetrachloroethene Toluene
1,1,1-Trichloroethane Xylenes (total)
Trichloroethene
Xylenes (total)
Area 9/10
None identified
As indicated in Table 7, no COCs were identified for Area 9/10. The investigation at Area
9/10 was impeded, due to limited access and concern for underground utilities in the area.
Although no soil samples were obtained that identified soil concentrations above PRGs,
remediation is still being considered for this area. Groundwater concentrations beneath
Area 9/10 were among the highest identified within the Southeast Rockford study area. The
concentration of 12 ppm of 1,1,1-TCA in MW201 indicates that NAPL is likely present in
Area 9/10, based on the agueous solubility limit of 1,1,1-TCA. The likelihood that NAPL is
present at Area 9/10 constitutes a principal threat. In accordance with the NCP at §
300.430(a)(1)(iii)(A), this ROD formulates treatment alternatives that will address the
principal threats posed at each source area.

In accordance with the NCP at 40 CFR § 300.430(a)(1)(iii)(A), this proposed plan
formulates treatment alternatives that will address the principal threats at each source
area, except for the PNAs that were identified as COCs in Areas 4, 11, and 9/10. PNAs are
not included in Table 7 as COCs and were intentionally not addressed by the alternatives
discussed within this ROD. Additional data are reguired to determine if PNAs are truly
COCs, or are simply contamination from activities not related to the management of
hazardous materials. For example, the presence of PNAs in areas with parking lots could be
attributed to the asphalt that contains PNAs. Additionally, PNAs would be expected in
areas where vehicles may leak motor oil or where scrap wood or other materials are burned.
Because PNAs were only detected in a few groundwater samples and their presence in soils
may be from normal industrial activities, PNAs are not addressed in this ROD. Additional
samples will be obtained in Areas 4, 11 and 9/10 during the remedial design phase that
will be conducted in 2002. If the evaluation identifies the need for remediation in
addition to that outlined in this ROD, the remedy would be appropriately altered.
Depending on the significance of the change in remedy, the Agencies may be reguired to
hold additional public meetings and allow public comment on the new remedy.
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In order to be protective, Illinois EPA chose to assume that all of the source areas were,
or could become residential areas. Area 7 is currently zoned residential. Areas 4, 9/10
and 11 are all zoned industrial and city plans are consistent with current use. However,
because residential areas were nearby Areas 4, 9/10 and 11, and because access to these
areas was not entirely limited, residential exposures could occur. Table 8 illustrates the
potentially exposed populations at each source area and the estimated associated risks as
identified in the Risk Assessment:
Table 8. Exposed Population at Source Areas
Source
Area
Area 4
Area 7
Area
9/10 3
Area 11
Exposed Population 1
Resident
Less than 1x10-6
- Direct Contact
and Hazard Index

of 1 2
Greater than 1x10-6 or Hazard Index of 1
Less than 1x10-6
Less than 1x10-6
and Hazard Index
and Hazard Index
of 1
of 1
Resident- Protection Of Drinking Water
Greater than 1x10-6 or Hazard Index of
Greater than 1x10-6 or Hazard Index of
1
1
Less than 1x10-6 and Hazard Index of 1
Greater than 1x10-6 or Hazard Index of
1
Notes:
1
The site worker scenario was not evaluated separately from the residential scenario. If
concentrations of COCs are protective for residents, it is assumed that concentrations are also
protective for site workers since time spent at site would be less.
Human health risks are usually evaluated as carcinogenic (those compounds that can cause
cancer), and non-carcinogenic (those compounds that can cause harm, but not cancer). For
carcinogenic risks, risks are usually guantified as a unit less probability of a person getting
cancer. U.S. EPA's generally acceptable risk range for site-related exposures is 10-4 to 10-6.
The potential for noncarcinogenic effects is evaluated by the ratio of exposure to toxicity,
called the Hazard Quotient. Adding all of the Hazard Quotients together generates the Hazard
Index. A Hazard Index less than 1 is considered acceptable in that toxic effects are unlikely.
The investigation at Area 9/10 was impeded due to limited access and concern over underground
utilities in the area.
As mentioned previously, Illinois EPA was unable to guantitatively evaluate human health
risks to residents who were exposed to creek surface water and sediments in Area 7. Data
obtained from the creek were inconclusive, as the Agencies were unable to identify
off-site impacts to the creek. Due to the intermittent nature of the creek and its shallow
depths, risks to individuals wading in the creek are expected to be low. However,
additional data will be obtained from the creek and risks to human health will be
guantitatively evaluated during the design phase.
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SUMMARY OF ECOLOGICAL RISK ASSESSMENT
AREA 7
A screening-level ecological risk assessment (ERA) was conducted for Area 7. The ERA
focused on the creek running north of Area 7. The ERA's primary purpose was to identify
contaminants in the surface water and sediment of the creek that could result in adverse
effects to present or future ecological receptors. Receptors are plants or animals that
could be impacted by contamination. The overall approach for the ERA at this site was to:
1) Identify chemicals of potential concern (COPC); 2) Identify potential receptors; 3)
Identify Exposure Scenarios and 4) Compare measured concentrations in surface water and
sediments to concentrations in laboratory tests (ecological screening benchmarks or
screening ecotoxicity values) that did not result in significant effects to relevant and
sensitive test species (CDM, Ecological).

The results of the ERA determined that at the screening level, risks to organisms
(benthic, aguatic and semi-aguatic) living in or nearby the creek were either low or not
present at all. However, concentrations of several contaminants (PNAs and VOCs) and their
locations in relationship to the site concerned the Agencies. The results did not provide
any clear trends because, at some times, concentrations were higher upstream than
downstream. This suggests another source may be present upstream.

On December 16, 1998 (after the ecological risk assessment had been conducted), Illinois
EPA obtained additional samples of the surface water and sediments within the creek. The
objective of the sampling event was to provide more information regarding the type and
source of the contaminants in the creek. Results of the December 1998 sampling event
identified several compounds that were not detected during the 1996 investigation, and
higher concentrations of several compounds that had been previously detected. Tables 3
(sediment) and 4 (surface water) compare measured concentrations in the field in 1996 and
1998 to screening ecotoxicity values to identify compounds that could potentially result
in adverse affects to organisms in Area 7.

Upon evaluation of the 1996 and 1998 data, in conjunction with screening ecotoxicity
values, the Agencies determined that a more in-depth analysis of ecological risk in Area 7
was necessary. However, because there may be an additional upstream source and the data
from the creek is inconclusive, the Agencies determined that it would be more efficient to
further evaluate Area 7 during the design phase of the project. The design phase will
likely occur in 2002. If the ecological risk evaluation conducted during the design phase
identifies the need for remediation in addition to that outlined within this ROD, the
remedy would be appropriately altered. Depending on the significance of the change in
remedy, the Agencies may be reguired to hold additional public meetings and allow public
comment on the new remedy.

Rock River

The ecological risk assessment conducted for this Operable Unit did not specifically
address the impacts that the four Source Areas would have on the Rock River. This
assessment was conducted under the RI/FS for Operable Unit Two. Modeling was conducted on
the impacts of groundwater contaminant concentrations on the Rock River through 30-and
50-year scenarios. Both scenarios showed concentrations of chlorinated VOCs entering the
river. However, the modeling indicated that even if the four source areas were not
remediated, concentrations would not exceed surface water criteria and in fact, are
expected to be two orders of magnitude below the criteria. The 50-year scenario did
indicate that source area remediation to MCLs occurring within a 10-to 20-year time span
would result in measurable reductions in contaminant mass entering the river (CDM, 1995 FS
Appendix C). A follow-up review of the modeling and any available analytical data of
discharges to the Rock River is planned. This will allow the Illinois EPA to develop a
program for monitoring any environmental changes that can be attributed to the plume.
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Based on the evaluation of human health and ecological risks, it is the Illinois EPA's
judgment that the Preferred Alternative or one of the other active remediation measures
considered in this ROD is necessary to protect public health or welfare or the environment
from actual or threatened releases of hazardous substances.
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REMEDIAL ACTION OBJECTIVES

Remedial Action Objectives (RAOs) provide a general description of what the proposed
alternative will accomplish. The following RAOs apply to all four Source Areas:

• Prevent the public from ingestion of soil, and direct contact with soil containing
contamination in excess of state or federal standards or that poses a threat to
human health;

• Prevent the public from inhalation of airborne contaminants in excess of state or
federal standards or that pose a threat to human health; and

• Prevent the further migration of contamination from the source area that would
result in degradation of site-wide groundwater or surface water to levels in excess
of state or federal standards, or that pose a threat to human health or the
envi ronment 1.

Area 7, because of its unigue characteristics as a park containing a creek, has these RAOs
in addition to the general RAOs listed above:

• Prevent the public from ingestion and direct contact with surface water containing
contamination in excess of state or federal standards or that poses a threat to
human health;

• Prevent the migration of contamination from Source Area 7 that would result in
degradation of surface water and sediment in the unnamed creek to levels in excess
of state or federal standards or that pose a threat to human health or the
envi ronment; and

• Prevent the ingestion of vegetables from Source Area 7 through the implementation of
appropriate institutional controls.

Expected. Outcomes of Each Alternative

Preliminary Remediation Goals (PRGs) are identified for each Source Area in Table 1 (Area
4), Table 2 (Area 7), Table 5 (Area 9/10), and Table 6 (Area 11). The PRGs for each area
address concentrations of COCs within source materials (contaminated soil, NAPL or
leachate).

Soil
The PRGs for soil are based on concentrations designed to be protective of human health
for: direct contact with soil (ingestion of soils and inhalation of vapors from soils);
ingestion of vegetables grown in the soil; and groundwater ingestion (chemicals leaching
from soils into groundwater, causing concentrations in groundwater to exceed either MCLs -
if they are available - or risk- based groundwater concentrations). The soil PRGs
protective of direct contact and groundwater ingestion are established in accordance with
the TACO regulations. Soil PRGs protective of ingestion of vegetables were calculated in a
manner outside the scope of the TACO regulations (Tier 3 analysis) that was approved by
Illinois EPA and U. S. EPA.
1 It should be noted that contaminant migration from the source areas has already resulted in
site-wide groundwater contamination in excess of state standards. The RAO is intended to
remediate each source area in order to prevent further migration of contaminants from the
source area.
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Leachate
The Operable Unit Two ROD required source control measures to reduce and control potential
groundwater risks to the environment. Based on the Operable Unit Two ROD requirement and
because 100% source removal (soil, NAPL, or leachate removal) was impracticable at the
four source areas, RAOs were developed with the intent of preventing further migration of
contamination from the source area that would increase site-wide groundwater
concentrations. These RAOs and resultant alternatives are identified as leachate
alternatives and are intended to contain contaminants that have reached the groundwater,
because capture at the source was either insufficient or impracticable. In order to
simplify the decision-making process, these RAOs and containment alternatives are all
identified as leachate alternatives rather than creating numerous sets of alternatives for
every possible media (NAPL, leachate, and highly contaminated groundwater) encountered
within the four source areas.

As noted previously, site-wide groundwater is already contaminated at levels above state
standards, but contaminant levels will begin to decrease due to natural attenuation
processes after source area remediation takes place. Source remediation in addition to the
creation of a groundwater management zone (GMZ) will achieve PRGs for the leachate. Four
separate GMZs (one at each source area) will be established pursuant to Illinois
groundwater regulations at 35 111. Adm. Code Section 620.450. These regulations allow for
the creation of a GMZ as a three-dimensional region containing groundwater being managed,
mitigating impairment caused by contamination. The GMZ boundary becomes a perimeter around
the site, similar to an imaginary fence, where on the outside of the boundary, groundwater
must meet state standards. The four GMZs will encompass the hot spots (and locations
surrounding the hot spots) where remediation has, or will have a measurable effect in
reducing contaminant concentrations. The PRGs for leachate are based on federal MCLs and
must be met at the GMZ boundary. This requirement conforms to the requirements set forth
in the Operable Unit Two ROD, i.e., aquifer restoration to drinking water quality and
compliance with state drinking water standards.

Intended. Use of Prel'inn-na.rv Rented'' a.tion Go^l -**

Preliminary Remediation Goals finalized within this Record of Decision are then known as
remediation goals. Remediation goals (and PRGs prior to ROD completion) for soil
protective of direct contact with soil, ingestion of vegetables grown in soil and
protective of groundwater are used as criteria, or points of reference within the ROD.
These criteria, or points or reference are used to identify technologies applicable to
each source area and to identify the extent of the hot spots that the technologies must
address. Remediation goals for soil protective of direct contact with soil and ingestion
of vegetables grown in soil shall be met in soils at each source area. However, soil
remediation goals for protection of groundwater may be superseded by valid and complete
empirical data, i.e., groundwater analyses that indicate that Applicable or Relevant and
Appropriate Requirements (ARARs) are consistently met at the GMZ boundary 2. For
example, if a remediation system at an area of concern has been in operation for a
reasonable amount of time and groundwater data show that ARARs are being met at the GMZ,
the operation of the system could be discontinued (even though soil concentrations are
above the PRGs for protection of groundwater).
2 The terms "Applicable or Relevant and Appropriate Requirements" and " groundwater management
zone" are discussed more fully within the DESCRIPTION OF ALTERNATIVES section.
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SUMMARY OF REMEDIAL ALTERNATIVES

The remedy evaluation process conducted by the agencies compared a number of potential
action alternatives and a no-action alternative for each Source Area. Upon a thorough
screening of a wide spectrum of in-place (in situ) and above ground (ex-situ) remedial
alternatives, the alternatives discussed below were selected for detailed analysis and
subjected to evaluation under nine NCP criteria. Remedial alternatives that deal with the
site contamination in situ as well as those that treat contaminants after excavation
(ex-situ) were evaluated.

Soil alternatives have been developed for Area 4, Area 7, Area 9/10 and Area 11. U.S. EPA
has developed a presumptive remedy for soils contaminated by VOCs. Presumptive Remedies
are preferred technologies for common categories of sites based on historical remedy
selection and engineering studies (U. S. EPA, Presumptive). Upon evaluation of U.S. EPA's
directive on presumptive remedies for soils contaminated by VOCs, the Agencies determined
that the presumptive remedy approach is appropriate for addressing the types of
contaminants found in the source areas at the Southeast Rockford site. The directive
produced by U.S. EPA identified three technologies as presumptive remedies for VOCs in
soil: soil vapor extraction (SVE); thermal desorption and incineration. Of the three
technologies, U.S. EPA has identified SVE as the preferred presumptive remedy. The source
area presumptive remedies considered practical for this site include SVE and thermal
desorption (incineration is usually not a cost-effective remedial alternative unless the
site is large, with large amounts of waste needing treatment). SVE works by sucking out
the contaminated air that exists in the soil pores beneath the surface. As the
contaminated soil pore air is removed, more volatile compounds move from the soil into the
soil pores, thereby cleaning up the soil as well as the soil pores. Thermal treatment
involves treating the soil by heating it up to a certain temperature where contaminants
would volatilize off the soils. Soil remedies have been assembled into remedial
alternatives for each source area and are discussed below. In addition to the presumptive
remedies for soil, ex-situ bioremediation has also been considered at Area 7 as an
alternative to thermal desorption of excavated material.

Contaminated leachate above PRGs is also present at the GMZ boundary at Area 4, Area 7 and
Area 9/10. Areas 4, 7 and 9/10 each have contaminated leachate at the GMZ boundary, and
the likely presence of NAPL. The U.S. EPA presumptive remedy for VOCs in soil does not
address contaminated leachate. Therefore, remedial alternatives were developed and
evaluated for leachate that is outside the domain envisioned by the presumptive remedy
guidance for VOCs.

No leachate alternatives were developed for Area 11. Although Area 11 has contaminated
leachate and LNAPL at the interior of the area, computer modeling conducted for Area 11
indicated that natural processes would meet RAOs for leachate at the site boundary in this
area. However, predicting the movement of LNAPLs in the subsurface is complicated. The
computer and mathematical models used for this superfund site can only account for the
movement of dissolved contaminants and cannot account for the movement of LNAPLs. Concerns
also exist at Area 11 regarding high concentrations of BTEX contaminants possibly masking
the presence of chlorinated VOCs. In order to provide real data regarding the degradation
of contaminants near the site boundary, approximately four additional monitoring wells
will be installed during the design phase. If analysis indicates contaminants are not
degrading to levels near MCLs, air sparging will be considered in addition to SVE. Air
sparging is included as an alternative to deal with leachate contamination at Areas 4, 7
and 9/10. Air sparging has the added benefit of enhancing biodegradation in both
groundwater and vadose zone soils and will address the concerns and RAOs for Area 11.

Every alternative that was selected for detailed analysis for the four source areas is
described below in the section entitled DESCRIPTION OF ALTERNATIVES. The alternatives that
are proposed by the Agencies are identified in Table 9.
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Table 9. Proposed Alternatives
Area
Area 4

Area 7

Area 9/10

Area 11

Media
Soil

Leachate

Soil
Leachate

Soil
Leachate
Name
SCS-4D

SCL-4B

SCS-7E
SCL-7B

SCS-9/10C
SCL-9/10E

SCS-11C
SCL-11A
Alternative Description
Excavation, on-site Low Temperature
Thermal Desorption
Leachate containment with collection and
treatment, surface water discharge,
monitoring, restriction on groundwater
usage
SVE and air sparging 1 at source
Multi-phase extraction (MPE) 2, leachate
containment with collection and
treatment, surface water discharge,
monitoring, restriction on groundwater
usage
SVE
Enhanced Air Sparging 3, monitoring,
restriction on groundwater usage
SVE
No Action
Notes:
1 Air sparging is a process by which air is injected into the contaminated groundwater. The
bubbles generated extract volatile contaminants from the groundwater as they rise to the
surface.
2 Multi-phase extraction (MPE) is a remedial technology whereby soil vapors and groundwater are
extracted at the same time through the same extraction point. MPE is an enhancement of SVE (
SVE just extracts soil vapors).
3 Enhanced Air Sparging - air would be injected into the subsurface to volatilize the contaminant
vapors to the vadose zone where they would be removed by vacuum extraction

An alternative that consists of no active remediation (No-Action Alternative) was
developed for each source area. The NCP reguires a No-Action alternative to be included in
the detailed analysis to provide a baseline for comparison to the other alternatives. It
should be noted that for the leachate alternatives, a true, No Action Alternative could
not be developed because groundwater monitoring was reguired within the 1995 Operable Unit
Two ROD. Therefore, for leachate, the No Action Alternative must include one action, that
of groundwater (or leachate) monitoring.

Common Elements
Under each alternative, the assumption is made that the City of Rockford's ordinance
prohibiting the installation of private wells will be enforced. Also, each alternative
reguires that a GMZ per 35 111. Adm. Code Part 620 be established. Illinois groundwater
regulations at 35 111. Adm. Code Section 620.450 allow for the creation of a GMZ as a
three-dimensional region, containing groundwater being managed, to mitigate impairment
caused by contamination. The GMZ boundary becomes a perimeter around the site, similar to
an imaginary fence, where on the outside of the boundary, groundwater must meet state
standards. The GMZ will remain in effect, providing controls such as remediation,
management and monitoring continue at the source area. During the time the GMZ is in
effect, State groundwater standards will not be applicable within the GMZ. In addition to
source area monitoring, site-wide groundwater monitoring will continue, as reguired by the
Operable Unit Two ROD. Because groundwater monitoring was reguired within the Operable
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Unit Two ROD, leachate alternatives entitled "No Action" do include monitoring and will
incur some costs.

Within the Southeast Rockford Groundwater Contamination Site there are ten known
properties that lie within areas of contaminated groundwater that are using private wells
as a water supply. Property owners were notified of the existing situation regarding
contaminated groundwater in the area by the U. S. EPA and the City of Rockford and chose
not to connect to the City of Rockford water supply system. City of Rockford officials
made further attempts and hookup services were denied by the property owners.

Institutional Controls

In order to be protective of human health and the environment, several alternatives
described within this ROD require use or access restrictions on contaminated properties
within the boundaries of the source area. Use restrictions or access restrictions would be
implemented through the use of institutional controls. Institutional controls are
administrative or legal constraints that minimize the potential for exposure to
contamination by limiting land or resource use. Specific actions taken at sites to
restrict access or use could include: Governmental Controls - such as zoning restrictions
or ordinances; Proprietary Controls - such as easements or covenants; Enforcement Tools -
such as consent decrees or administrative orders; and Informational Devices - such as deed
notices or state registries. Several types of access or use restrictions employed
simultaneously can increase the effectiveness of institutional controls. The Agencies plan
to pursue multiple types of institutional controls at each source area. The approved
feasibility study (FS) dated September 5, 2000 discusses institutional controls generally,
but often refers to them as "deed restrictions". This ROD refers to institutional controls
by name or by the terms "access restrictions" or "use restrictions."

Modeling

In order to help assess each alternative's impact and effectiveness in remediating the
soil and leachate contamination at each source area, the computer model BIOSCREEN (U.S.
EPA 1996) was used. BIOSCREEN is a program that considers the amount and type of
contaminants at a source area and simulates the spread and degradation of those
contaminants over time and distance. The program can also consider the impact an
alternative would have on the spread and degradation of contaminants at a source area.
BIOSCREEN was applied to each alternative to calculate the approximate time (in years)
that it would take for the contaminants present at each source area to meet remedial goals
at the GMZ boundary 3. It is important to note that BIOSCREEN is just a screening model
and has certain assumptions built into the program. BIOSCREEN was used at this site to
provide general criterion with which to compare the different alternatives. The results of
BIOSCREEN, or any screening model cannot be used to predict the exact time it will take
for a source area to meet remediation goals. At Areas 4, 7, and 11 each alternative was
evaluated individually by BIOSCREEN, assuming that no other alternatives will be selected
for that source area. At Areas 4, 7 and 9/ 10, two remedial alternatives are being
proposed, one to address soil contamination, and one to address leachate contamination.
Because BIOSCREEN only accounted for a single alternative at each area, and two
alternatives are actually being proposed for each area ( one for soil and one for
leachate), the estimated time frame to achieve remediation action objectives is likely
overestimated.
3 Due to the lack of information on contaminants in Source Area 9/ 10, Contaminant spread and
dilution could not be accurately modeled.
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Alternatives Involving Thermal Treatment

Several soil treatment alternatives evaluated for Areas 4, 7 and 11 involve thermal
treatment technologies. Thermal treatment technologies address contamination with heat. A
common concern regarding some thermal treatment technologies is the formation of products
of incomplete combustion such as dioxins or furans. Under certain conditions, the addition
of heat to chlorinated organic compounds in the presence of oxygen can produce dioxins and
furans. Chlorinated VOCs are present in the soils at Areas 4 and 7. If an alternative is
selected that involves thermal treatment, each unit will be pre-tested on site prior to
full- scale operation. The pre-test is often called a "proof-of-performance" test. During
the proof-of-performance test, air emissions from the stack will be sampled for: total
volatile organic compounds; dioxins; and pH. Several other parameters will also be
measured during the proof-of-performance testing to ensure that conditions are adeguate
for destruction of VOCs. These parameters are measured at specific locations within the
treatment system and are specific to each type of technology. During the proof-of-
performance test, measurements of these parameters are noted and compared with emission
rates of various compounds. These measurements are then used as a guide to show that
conditions within the treatment system are optimal for efficient system operation and VOC
destruction. Following the proof-of-performance test, results from the air sampling for
dioxins and furans will be evaluated in a risk assessment to ensure that the treatment
systems operate in a manner protective of human health and the environment. If the results
of the proof-of-performance tests show that the thermal treatment units are operating
properly, full-scale operation will begin. During the proof-of-performance test, as well
as full-scale operation, continuous monitoring (of temperature, pH and volatile organic
material) will be conducted on each thermal treatment unit. Continuous monitoring will
ensure that the unit is running properly and within the correct temperature range to
ensure efficient contaminant destruction. In addition, specific air monitoring will occur
at scheduled intervals to ensure that, if dioxins and furans are produced, the levels
emitted will be protective of human health and the environment.

If a thermal treatment technology is chosen for Area 11, a proof-of-performance test and
continuous monitoring will also be implemented there. However, because contaminants are
almost entirely non-chlorinated, dioxin/furan testing will be much less intensive.

Thermal treatment at three source areas would also involve a surface water discharge (on
site at Areas 4 and 7, off site at Area 11). Water may be utilized in the scrubber unit in
combination with a neutralizing material such as calcium sulfate. The water and calcium
sulfate serve to remove hydrochloric acid and chlorine gases formed in the thermal
treatment unit and will prevent these gases from being vented into the atmosphere.
Scrubber water would then be treated for pH and discharged to surface water. Water
discharged to the environment would be periodically monitored to ensure it meets the
substantive reguirements of the National Pollutant Discharge Elimination System (NPDES)
regulations.

DESCRIPTION OF THERMAL TREATMENT UNITS
Two types of thermal treatment technologies are included as alternatives within this ROD:
catalytic oxidation and Low Temperature Thermal Desorption (LTTD). Catalytic Oxidation is
a thermal treatment process that destroys contaminants at low temperatures (compared to
most thermal processes) through the use of a catalyst. LTTD is a thermal treatment process
that heats up contaminated media in order to volatilize off the contaminants, rather than
destroy them. Both thermal treatment technologies are discussed in more detail in the
following paragraphs.

Catalytic Oxidation
The catalytic oxidation unit would treat vapors containing compounds extracted from
contaminated soil or water. Within the catalytic oxidation unit, oxidation of the organic
compound occurs whereby oxygen reacts with the compound containing carbon and hydrogen to
form primarily carbon dioxide and water. Oxidation of a chlorinated compound within the
catalytic oxidation unit results in the formation of primarily carbon dioxide and
hydrochloric acid. The presence of the catalyst, typically a precious metal formulation
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(platinum or palladium), facilitates the oxidation reaction. The catalyst increases the
rate of reaction without being used up in the reaction. Because the catalyst increases the
rate of reaction, the reaction can occur at lower temperatures. As such, catalytic
oxidation units operate at much lower temperatures (approximately 890°F to 1000°F 4) than
thermal incineration systems (that operate at approximately 1000°F to 1400°F). The primary
components of the catalytic oxidation unit are: a liquid/vapor separator, a heat
exchanger; a burner (to indirectly pre-heat vapor to 890°F); a catalytic oxidation unit;
and a scrubber. Liguid collected in the liquid/ vapor separator will be taken off site for
disposal at a permitted facility. Water used in the scrubber unit to treat vapor for pH,
will itself be treated for pH and discharged to near- by surface water. Discharged water
would be monitored periodically to ensure it meets the substantive reguirements of the
NPDES regulations.

LTTD
LTTD would treat soils after excavation. The LTTD unit would be direct-fired and would
operate at temperatures up to approximately 900°F, which is sufficient to convert the
contaminants in the soil to the vapor phase. The LTTD unit is not intended to destroy
organic contaminants, but rather to physically separate contaminants from the soil. After
contaminants are removed from the soil, the vaporized contaminants are then directed
through a bag house to remove particulate matter prior to being introduced to the
afterburner. The concentrations of contaminants are expected to be high to reguire the use
of an afterburner. The afterburner is a separate unit that operates at temperatures
between 1,600'F and 1,800'F, which is sufficient to convert the contaminants to primarily
carbon dioxide, water vapor, and hydrochloric acid. A scrubber would be used to treat the
vapor for pH prior to release to the environment. Scrubber water would then be treated for
pH and discharged to near-by surface water. Water discharged to the environment would be
monitored periodically to ensure it meets the substantive requirements of the NPDES
regulations.

Potential ARARs for both thermal treatment technologies include:

• 35 111 Adm. Code Section 215.301 Section 215.301 states that "no person shall cause
or allow the discharge of more than 3.6 kg/hr (8 Ibs/hr) of organic material into
the atmosphere from any emission unit..." and is applicable to both thermal units;

• Clean Air Act, Section 112(a) Section 112(a) reguires that in order to be considered
a "minor" source, the emissions of Hazardous Air Pollutants (HAPs) 5 as listed in
Section 112(b) of the Clean Air Act ( AA) shall not exceed 10 tons per year of a
single HAP or 25 tons per year of any combination of such HAPs; and

40 CFR 63.1203 Relevant portions of the standards at 40 CFR 63.1203, which are
applicable to hazardous waste incinerators, will be applied to the thermal units
identified within this ROD.
4 Global Technologies Proposal for COM May 11, 2000

5 Hazardous Air Pollutants as identified within Section 112 (b) of the Clean Air Act.
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DESCRIPTION OF ALTERNATIVES FOR SOURCE AREAS

Every alternative selected for detailed analysis for the four source areas is described in
this section. The description for each alternative includes costs divided into three
categories: Capital (costs to construct the remedy); Annual Operation and Maintenance
(O&M) (costs necessary to keep remedy operational after construction is complete); and,
Total Present Worth (present value of all costs to be incurred over the life of the
remedy, assuming a 30-year period pursuant to CERCLA guidance). In addition, the
description for each alternative includes discussion of key ARARs that differ from those
reguired by other alternatives. ARARS are generally reguirements that must be met
regarding either a contaminant that is present, an action being conducted or the location
of the source area. The ARARs specified for the entire Southeast Rockford Groundwater
Contamination Superfund Site are described more fully.

SOURCE AREA 4

Source Area 4 - Soil

SCS-4A: No Action
For Alternative SCS-4A, no active measures would be undertaken to control or remediate the
soil. No use or access restrictions would be imposed. Soil contaminants would remain
on-site and would not be reduced in volume, treated or contained. Computer modeling
predicted that the time to meet state groundwater standards at the GMZ under this
alternative would be approximately 60 to 70 years. There are no costs to implement this
alternative.

SCS-4B: Limited Action (restrictions on groundwater and land usage)
Alternative SCS-4B includes placing use restrictions on the contaminated area to prevent
installation of drinking water wells and future site development within the soil source
area. Soil contaminants would remain on site and would not be reduced in volume, treated
or contained. The time to reach state groundwater standards at the GMZ under this
alternative would be the same as Alternative SCS-4A, approximately 60 to 70 years. Future
source area development would be restricted for approximately 60 to 70 years, when the
RAOs would be met. The estimated costs for this alternative are as follows:

Capital: $28,000
Annual O&M: $0
Total Present Worth: $28,000

SCS-4C: Soil Vapor Extraction with vapor treatment by catalytic oxidation
Under this alternative, contaminated soils would be remediated in situ via a SVE system
that is the preferred presumptive remedy for soils contaminated with VOCs. A blower would
provide a source of negative pressure to extract vapors from the subsurface through a
series of wells connected by underground piping. Due to the presence of residual NAPL and
a possible scenario of air sparging with steam injection as the remedial action for
leachate control, it has been assumed that the wells would be constructed of carbon steel.
A pilot-testing program would be conducted prior to the design and construction of the SVE
system to determine well spacing and well construction details. The SVE system would treat
all contaminated soils at the site above the water table to remediation goals. Pockets of
highly contaminated soils or pockets of NAPL would increase the remediation time frame.
Given the presence of residual NAPL at this source area, it is expected that significant
guantities of contaminated vapors would be extracted. Vapors extracted from soil would go
into a liguid vapor separator. The liguid would be collected in a tank and sent off site
for proper treatment and disposal. The vapors would be treated with a catalytic oxidation
unit. The time to reach state groundwater standards at the GMZ under this alternative
would be approximately 20 to 30 years. It would take approximately 20 to 30 years to meet
RAOs for this alternative. The estimated costs for this alternative are as follows:
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Capital: $479,000
Annual O&M: $135,160
Total Present Worth: $2,156,000

SCS-4D: Soil Excavation and On-Site Thermal Treatment with low temperature thermal
desorption followed by an afterburner.
Alternative SCS-4D is the proposed alternative for soil remediation at Area 4. LTTD is a
presumptive remedy for VOCs in soil, although it is not U.S. EPA's preferred technology.
Under this alternative, approximately 2,800 cubic yards of contaminated soils would be
excavated and VOCs would be removed through on- site thermal treatment in a LTTD unit.
Soil gas analysis indicates that a portion of contaminated soil may be present beneath the
former Swebco building. Excavation of soil beneath the building would likely reguire part
of the structure to be demolished and re-built following project completion. Costs for
partial building demolition and reconstruction have been included for this alternative.

The majority of the contaminated soil is located below the water table. Therefore,
Alternative SCS-4D would include the installation of well points for dewatering at a flow
rate of 15 gallons per minute (gpm) to lower the water table to expose the residual NAPL.
The water collected during the dewatering process will be contained on site in two 21,000-
gallon carbon steel tanks. The tanks would be transported to an appropriate disposal
facility at a freguency to be determined during the design phase. The soil would then be
excavated and stockpiled for processing. Due to the levels of VOCs expected during
excavation, the cost to install a temporary enclosure over the excavation for emissions
control has been included. Contaminated vapors would be collected from the temporary
enclosure and directed to the afterburner used in conjunction with the LTTD unit.

Excavated soils would first be screened to remove particles greater than four inches in
size and then conveyed to the primary treatment unit where the contaminants would be
thermally desorbed from the soil and destroyed in the afterburner. Thermally treated soil
would then be conveyed to a process unit that cools and re- hydrates the soil. The soil
would be stockpiled for testing to ensure that the clean- up goals have been achieved.
Production rate of this system is approximately 15 tons per hour, depending on soil type
and moisture content. Based on this rate, it would take approximately one month to
thermally process the soil. Excavation would be backfilled upon completion of treatment of
soil to acceptable levels and would take approximately 5 to 15 years to meet RAOs for this
alternative. Estimated costs for this alternative are as follows:

Capital: $2,121,000
Annual O&M: $1,000
Total Present Worth: $2,121,000

Source Area 4 - Leachate

Currently, no groundwater wells (potable or non-potable) exist within the GMZ of Area 4.
All Area 4 leachate remedies include institutional controls to restrict groundwater usage
within the GMZ, as well as installation of monitoring wells and implementation of a
groundwater and leachate-monitoring program. Groundwater and leachate would be monitored
at predetermined intervals for 30 years per RCRA (Resource Conservation and Recovery Act)
post- closure groundwater monitoring reguirements. Monitoring will typically consist of
collecting groundwater and analyzing for VOCs and, where appropriate, parameters that
measure biological activity.

SCL-4A: No Action (leachate monitoring, restrictions on groundwater usage)
This alternative would consist of no action with leachate monitoring and institutional
controls on groundwater usage for Area 4. Although leachate concentrations would continue
to attenuate naturally, this alternative would not comply with RAOs for 60 to 70 years.
Estimated costs for this alternative are as follows:
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Capital: $ 54,000
Annual O&M: $ 7,000
Total Present Worth: $ 269,000

SCL-4B: Hydraulic Containment (leachate monitoring, lea.cha.te containment/collection
and treatment and on-site surface discharge, and groundwater use restrictions)
Alternative SCL-4B is the proposed alternative for leachate remediation at Area 4 and
would include installation of a leachate containment system, monitoring of the source area
leachate and groundwater and implementation of groundwater use restrictions. As part of
the leachate containment system, four leachate extraction wells, piping, controls and an
air-stripping unit would be installed. Leachate would be extracted from the extraction
wells by submersible pumps and directed to an air-stripping unit at a rate of
approximately 20 gpm. An air-stripping unit would treat the collected leachate and
discharge the treated effluent to an on-site storm water ditch located approximately 200
feet north of the source. The effluent would be monitored periodically for VOCs to confirm
that the leachate is treated to acceptable levels.

The treatment method for vapors stripped from the leachate in the air-stripping unit would
depend on which soil alternative is implemented. Vapors would be directed to the catalytic
oxidation unit if SCS-4C were the chosen soil alternative. Vapors generated by the
air-stripping unit as a part of this alternative would be treated by GAG in combination
with all other soil alternatives.

This alternative would comply with RAOs after approximately 35 to 45 years. Estimated
costs for this alternative account for vapor treatment by GAG and are as follows:

Capital: $ 249,000
Annual O&M: $ 47,000
Total Present Worth: $1,117,000

SCL-4C: Install Injection Wells Along Northwestern Boundary of the GMZ/Install Air
Sparging Unit/Inject Air/Restriction On Groundwater Usage
Alternative SCL-4C includes the installation of air injection wells and an air-sparging
unit. The injection wells would be installed down gradient along the northwestern boundary
of the GMZ and screened in the saturated zone. Air would be injected into the subsurface
to volatilize the contaminant vapors to the vadose zone, where they would be removed by
vacuum extraction. The air sparging system would be reguired to operate in conjunction
with an SVE system, as described in alternative SCS-4C. Vapors produced by air sparging
would be collected in the SVE system and directed to the catalytic oxidation unit. Air
sparging without SVE would cause migration of the vapors away from the site and might
create unacceptable risks to human health and the environment. This alternative would
comply with RAOs after approximately 15 to 25 years. The estimated costs for this
alternative are as follows:

Capital: $2,037,000
Annual O&M: $ 57,000
Total Present Worth: $2,522,000

SCL-4D: Reactive Barrier Wall/'Leachate Monitoring/ Groundwater Use Restrictions
Alternative SCL-4D would include the installation of a 300-foot reactive barrier wall to
an average depth of 60 feet bgs down gradient of the source area (on the northwestern
boundary of the GMZ). The reactive barrier wall would have a thickness of 2 feet, be
comprised of a permeable reactive iron media and be positioned such that it is able to
treat the corresponding leachate plume. As the contaminated leachate moved passively
through the treatment wall, the contaminants would be removed by sorption onto the iron
media. During reactive wall construction, two jetting wells would be installed within the
iron media. These jetting wells would allow for rejuvenating the iron media by flushing
out solids or biological growth that could foul or clog the reactive wall. The
implementation of this alternative would likely be more difficult than the other leachate
alternatives, due to reguired depth of excavation and the presence of underground
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utilities. This alternative would comply with RAOs for leachate down gradient of the wall
immediately upon completion of installation. However, soil concentrations up gradient
of the wall would not meet RAOs for some time. The estimated costs for this alternative
are as follows:

Capital: $5,659,000
Annual O&M: $ 7,000
Total Present Worth: $5,911,000

SCL-4E: Install Injection Wells Along the Northwestern Boundary of the GMZ and Within the
Source Area/Install Air Sparging Unit/Inject Air Restriction On Groundwater Usage
Alternative SCL-4E includes the same elements as SCL-4C. In addition to the air injection
wells installed at the GMZ boundary under SCL-4C, this alternative would include air
injection wells located at the source. The addition of air injection wells at the source
make this alternative more effective but more costly than alternative SCL-4C. This
alternative would comply with RAOs after approximately 10 to 20 years. The estimated costs
for this alternative are as follows:

Capital: $2,306,000
Annual O&M: $ 57,000
Total Present Worth: $2,796,000

SOURCE AREA 7

Source Area 7 - Soil

SCS-7A: No Action
For Alternative SCS-7A, no remedial actions would be undertaken. Soil contaminants would
remain on site and would not be reduced in volume, treated or contained. Computer modeling
predicted that the time to meet state groundwater standards at the GMZ under this
alternative would be approximately 80 to 90 years. There are no costs to implement this
alternative.

SCS-7B: Li mi ted Action (restrictions on soil usage)
Alternative SCS-7B includes placing access and use restrictions on contaminated soils.
Access and use restrictions would be instituted to prevent future site development.
Warning signs and fencing would be installed to discourage unauthorized persons from
excavating soils. As with SCS-7A, soil contaminants would remain on site and would not be
reduced in volume, treated or contained. This alternative would not comply with RAOs for
80 to 90 years. Estimated costs for this alternative are as follows:

Capital: $ 69,000
Annual O&M: $ 200
Total Present Worth: $275,000

SCS-7C: Soil Excavation with Ex-Situ, Biological Treatment in Biopiles
Under this alternative, contaminated soils would be excavated and treated on site.
Alternative SCS-7C would include dewatering and excavation of approximately 57,000 cubic
yards of material for on-site biotreatment. Although bioremediation is not a presumptive
remedy for VOCs in soil, this technology would achieve remediation goals. Alternative
SCS-7C would include the installation of well points for dewatering at a flow rate of 10
gpm to lower the water table to expose the residual NAPL. Water collected during the
dewatering process would be contained on site in two 21,000-gallon carbon steel tanks and
transported to an appropriate disposal facility at a freguency to be determined during the
design phase. Soil would then be excavated and stockpiled for processing. Due to the
levels of VOCs expected during excavation, the cost to install a temporary enclosure over
the excavation has been included. Contaminated vapors would be collected and passed
through granular activated carbon prior to release to the atmosphere.

Excavated soil would be screened to remove all particles greater than two inches in size,
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although slightly larger particle sizes may be allowable. On-site staging areas would be
constructed and soils would be piled on high- density polyethylene (HDPE) liners with fine
sand layers above and below to maintain liner integrity. Approximate soil pile dimensions
would be six feet tall with the base of the pile measuring 16 feet across and the top of
the pile measuring five feet across. Water and nutrients (nitrogen and phosphorus) would
be added periodically, as needed, for optimal biological activity. In addition, pH would
be controlled by the addition of lime and/or acid. Piping would be installed below the
piles within the fine sand layer above the HDPE lines to collect leachate produced by the
piles. Following collection, the leachate would be recycled and used for watering the
piles, as previously described. A mechanical mixer would blend the soil to enhance
microorganism/contaminant interactions and aeration, thereby enhancing biodegradation
rates of contaminants. Soils that meet the remediation goals would be placed back into the
excavated areas upon approval by the Agencies. Estimated duration for the treatment of the
57,000 cubic yards of soil would be approximately 5 years. Although actual soil treatment
would be completed in 5 years, this alternative would comply with RAOs after approximately
15 to 25 years when ARARs are met at the GMZ. Estimated costs for this alternative are as
follows:

Capital: $15,647,000
Annual O&M: $ 627,000
Total Present Worth: $18,218,000

SCS-7D: Excavation and On-Site Thermal Treatment with low-temperature thermal desorption
followed by afterburner
Under this alternative, approximately 57,000 cubic yards of contaminated soils would be
excavated for on-site thermal treatment via a LTTD unit. LTTD is a presumptive remedy for
VOCs in soil, although it is not U.S. EPA's preferred technology. In this alternative,
soils excavation, site dewatering/treatment and excavation enclosure would all be
performed as described for alternative SCS-7C. Excavated soils would be screened to remove
particles greater than four inches in size and then conveyed to the LTTD unit. Following
the primary treatment unit where the contaminants would be vaporized from the soil,
contaminant vapors would be destroyed in the afterburner. Treated soil would then be
conveyed to a process unit that cools and re-hydrates the soil and stockpiles the soil for
testing (to ensure that the clean-up goals have been achieved). The production rate of
this system ranges from 80 to 120 tons per hour, depending on soil type and moisture
content. Based on this rate, the estimated duration of the thermal treatment would be
eight months. Although actual soil treatment would be completed in eight months, this
alternative would comply with RAOs after approximately 10 to 20 years. Estimated costs for
this alternative are as follows:

Capital: $15,124,000
Annual O&M: $ 85,000
Total Present Worth: $15,209,000

SCS-7E: Soil Vapor Extraction and Air Sparging System with vapor treatment by catalytic
oxidation
Alternative SCS-7E is the proposed alternative for soils at Area 7. SVE is the preferred
presumptive remedy for soils contaminated with VOCs. This alternative would combine soil
vapor extraction and air sparging technologies to address contaminants in unsaturated and
saturated soil and leachate in Source Area 7. Under this alternative, unsaturated and
saturated contaminated soils would be remediated in situ via a vapor extraction system.
This alternative would consist of the installation of a series of wells connected by an
underground piping system. A blower would provide a source of negative pressure to extract
vapors from the subsurface. Sixteen vacuum extraction wells would be placed in the
suspected source areas. Extraction wells would be constructed to a depth of up to 25 feet
and screened in the vadose zone, where they would extract volatile contaminants from the
unsaturated zone, as well as some leachate contaminants, which are able to volatilize from
the surface of the water table. The estimated flow rate for the SVE system would be 1200
standard cubic feet per minute (scfm). A pilot test would be conducted prior to system
design to determine well construction, extraction flow rate, and spacing.
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The air sparging system would be constructed to volatilize VOCs from saturated soils and
leachate through the injection of air and the collection of VOCs using vapor extraction
wells. A total of 53 air sparging wells would be constructed to a depth of 50 feet bgs.
Camp Dresser and McKee has assumed a radius of influence of 25 feet for the air sparging
wells. Two air compressors would be used to inject air to the subsurface, each at a rate
of 400 scfm, for a total of 800 scfm. However, a pilot study would be conducted to verify
flow rate and the radius of influence prior to full-scale implementation.

Given the presence of residual NAPL, it is expected that significant concentrations of
contaminated vapors would be extracted. The extracted vapors would be treated with a
catalytic oxidation unit. Carbon adsorption would not be a cost-effective technology for
treating the vapor upon startup of the soil vapor extraction systems. However, carbon
adsorption could be used to address contaminants in the vapor after contaminant levels
were reduced by catalytic oxidation for a period of up to six months to one year. This
alternative would comply with RAOs after approximately 15 to 25 years. Estimated costs for
this alternative are as follows:

Capital: $3,071,000
Annual O&M: $ 320,000
Total Present Worth: $5,624,000

Source Area 7 - Leachate

Area 7 leachate remedies include institutional controls on groundwater usage within the
GMZ, as well as installation of monitoring wells and implementation of a groundwater and
leachate-monitoring program. Groundwater and leachate would be monitored at predetermined
intervals for 30 years per RCRA post-closure groundwater monitoring reguirements.
Monitoring would typically consist of collecting groundwater and analyzing for VOC and,
where appropriate, parameters that measure biological activity.

SCL-7A: No Action (leachate monitoring and restrictions on groundwater)
This alternative would consist of no action, with leachate monitoring and institutional
controls on groundwater usage for Area 7. Leachate concentrations would continue to
attenuate naturally. This alternative would comply with RAOs after approximately 80 to 90
years. Estimated costs for this alternative are as follows:

Capital: $ 67,000
Annual O&M: $ 9,000
Total Present Worth: $347,000

SCL-7B: Multi-Phase Extraction/Leachate Containment/Collection with Treatment by Air
Stripping/On-site Surface Discharge/'Groundwater Use Restrictions
Alternative SCL-7B is the proposed alternative for Area 7 leachate. This alternative was
designed to complement soil alternative SCS-7E and would include the installation of a
multi-phase extraction (MPE) system in the source and a leachate containment system along
the downgradient side of the GMZ. The leachate containment system would consist of eight
leachate extraction wells, a central pump station, an air-stripping unit, piping and
controls. Source area leachate would be collected via the leachate extraction wells to be
located northwest of the park play ground area. The leachate would be extracted and pumped
to the air-stripping unit at a rate of 10 gpm, with the treated effluent from the air
stripper discharged to the unnamed creek located approximately 450 feet north of the
source. The treated effluent would be periodically monitored to confirm discharge criteria
are being met. Vapors from the air-stripping unit would be treated in the catalytic
oxidation unit installed as a component of Alternative SCS-7E.

Ten MPE wells (approximately 25 feet deep) would be installed in the source and connected
by underground piping to a central vacuum pump/ vapor treatment system enclosure. The
enclosure would include an air/water separation system, with the water pumped to the
leachate containment system air stripper. Air from the air/water separation system would
be sent to the catalytic oxidation unit. This alternative would comply with RAOs after
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approximately 30 to 40 years. Estimated costs for this alternative are as follows:

Capital: $1,435,000
Annual O&M: $ 128,000
Total Present Worth: $2,637,000

SCL-7C: Reactive Barrier Wall/Leachate Monitoring/Groundwater Use Restrictions
Alternative SCL-7C would include the installation of a two-foot-thick reactive barrier
wall that would consist of a funnel and gate system. The funnel wall component of the
funnel and gate system would direct the contaminated leachate plume to the reactive
treatment wall. The reactive barrier wall is comprised of a permeable reactive iron media
that would be able to treat the corresponding leachate contaminants to acceptable levels.
The reactive wall would include jetting wells that would flush out particulate matter or
biological growth that could clog or foul the iron media. Alternative SCL-7C also requires
the installation of 310-and 420-foot funnel walls north and west of the source area
leachate plume. The two funnel walls would be joined together with a 210-foot reactive
gate positioned between the walls. The western funnel wall would be tied into bedrock at
approximately 50 feet bgs, while the northern funnel wall and reactive gate would be
extended to a depth of 80 feet bgs. This alternative would comply with RAOs for leachate
on the down-gradient side of the wall immediately, upon completion of installation.
However, soil concentrations up gradient of the wall would not meet RAOs for some time.
Estimated costs for this alternative are as follows:

Capital: $4,104,000
Annual O&M: $ 8,000
Total Present Worth: $4,391,000

SOURCE AREA 9/10

The description of each alternative for Areas 4 and 7 contains estimates based on computer
modeling of the time required to meet state groundwater standards at the GMZ boundary.
However, no computer modeling could be performed for Area 9/10 soil and leachate
alternatives, because of the inability to gather data in the area. Therefore, the time to
meet RAOs under each alternative for Area 9/10 is discussed qualitatively, in comparison
to one another.

Source Area 9/10-Soil

SCS 9/1OA No Action
For alternative SCS-9/10A, no remedial actions would be undertaken. Soil contaminants
would remain on-site and would not be reduced in volume, treated, or contained. There are
no costs to implement this alternative.

SCS-9/10B Li mi ted Action (restrictions of future development)
Alternative SCS-9/10B includes placing use restrictions on the contaminated area to
prevent future site development. As with SCS-9/10A, soil contaminants would remain on-
site and would not be reduced in volume, treated or contained. This alternative would take
the same amount of time as alternative SCS-9/10A to reach RAOs. Estimated costs for this
alternative are as follows:

Capital: $28,000
Annual O&M: $ 0
Total Present Worth: $28,000

SCS-9/10C: Soil Vapor Extraction with vapor treatment using activated carbon
Alternative SCS-9/10C is the proposed alternative for soils at Area 9/10. Under this
alternative, contaminated soils would be remediated in situ via a SVE system. SVE is the
preferred presumptive remedy for soils contaminated with VOCs. This alternative would
consist of the installation of a series of wells connected by an underground piping
system. A blower would provide a source of negative pressure to extract vapors from the
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subsurface. Extraction wells would be screened in the vadose zone, where they would remove
the contaminants from the unsaturated zone, as well as leachate contaminants that might
diffuse from the surface of the water table. A pilot program would be conducted prior to
the design of the SVE system to determine well spacing and in situ air permeability.

Vapors collected from the SVE unit would be treated through the use of activated granular
carbon. Activated granular carbon could be used to treat vapors at this area (as opposed
to catalytic oxidation at Areas 4 and 7) because of the lower-expected concentrations of
contaminants from soils. The vapor treatment scenario may have to be reevaluated based
upon additional data collection from Area 9/10 and the results of the SVE pilot program.
This alternative would meet RAOs in the shortest period of time of all other Area 9/10
soil alternatives. Estimated costs for this alternative are as follows:

Capital: $ 225,000
Annual O&M: $ 329,000
Total Present Worth: $4,308,000

Source Area 9/10 - Leachate

All Area 9/10 leachate remedies include institutional controls on groundwater usage within
the GMZ, installation of monitoring wells and implementation of a groundwater and leachate
monitoring program. Groundwater and leachate would be monitored at predetermined intervals
for 30 years, per RCRA post-closure groundwater monitoring reguirements. Monitoring would
typically consist of collecting groundwater and analyzing for VOCs and, where appropriate,
parameters that measure biological activity.

SCL-9/10A: No Action (leachate monitoring and restrictions on groundwater usage)
This alternative would consist of no action with leachate monitoring and institutional
controls on groundwater usage. Leachate concentrations would continue to attenuate
naturally. Future source area development would be restricted for the longest period time
under this alternative, as it would take the longest to reach RAOs. Estimated costs for
this alternative are as follows:

Capital: $ 60,000
Annual O&M: $ 5,000
Total Present Worth: $217,000

SCL-9/10B: Hydraulic Containment (leachate monitoring, leachate containment collection
and treatment by air stripping, off-site surface discharge and groundwater use
restrictions)
The Hydraulic Containment alternative would include installation of a leachate containment
system. As part of the leachate containment system, 55 leachate extraction wells, piping,
controls and an air-stripping unit would be installed. Wells would be used, rather than a
deep trench to protect the adjacent building structure. Source-area leachate would be
collected in leachate extraction wells installed west and south of the Sundstrand Plant
#1. Extracted leachate would be sent via pumps to the air- stripping unit at a rate of 50
gpm. Vapors collected from the air- stripping unit would be treated by granular activated
carbon and released to the atmosphere. Treated water from the air-stripping unit would be
discharged off site to a storm water ditch located approximately 2,000 feet south of the
source. This leachate alternative would achieve RAOs more guickly than SCL-9/10A, but not
as guickly as the air sparging conducted under alternative SCL-9/10C. Estimated costs for
this alternative are as follows:

Capital: $1,326,000
Annual O&M: $ 42,000
Total Present Worth: $2,440,000

SCL-9/10C: Install Injection Wells along the Southwestern GMZ Boundary/Install Air
Sparging Unit/Inject Air/Restriction On Groundwater Usage
Alternative SCL-9/10C includes the installation of air injection wells (along the
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southwestern boundary of the GMZ) and an air-sparging unit. Injection wells would be
installed along the GMZ boundary to contain and treat the source area leachate. Air would
be injected into the subsurface to volatilize the contaminant vapors to the vadose zone,
where they would be removed by vacuum extraction. The air sparging system would be
reguired to operate in conjunction with an SVE system such as described in alternative
SCS-9/10C. Vapors produced by air sparging would be collected in the SVE system. This
alternative would achieve RAOs in a short amount of time, but slightly longer than that
reguired by SCL-9/10E. Estimated costs for this alternative are as follows:

Capital: $2,293,000
Annual O&M: $ 65,000
Total Present Worth: $3,208,000

SCL-9/10D: Reactive Barrier Wall/Leachate Monitoring/Restrictions on Groundwater Usage
SCL-9/10D was the proposed alternative for leachate at Area 9/10. Alternative SCL-9/10D
would include the installation of a reactive barrier wall that would consist of a funnel
and gate system. The reactive barrier system would be constructed of iron media to treat
the leachate as it flows through the reactive wall. Reactive barrier wall construction
would include jetting wells to flush-out particulate matter or biological growth that
could foul or clog the iron media. This alternative would comply with RAOs for leachate
immediately upon completion of installation. However, soil concentrations up gradient of
the wall would not meet RAOs for some time. Estimated costs for this alternative are as
follows:

Capital: $3,329,000
Annual O&M: $ 5,000
Total Present Worth: $3,523,000

SCL-9/10E: Install Injection Wells Along Boundary of the GMZ and Source Area/Install Air
Sparging Unit/Inject Air/Restriction On Groundwater Usage
Alternative SCL-9/10E is essentially the same as Alternative SCS9/10C, except that
additional air sparging wells would be installed at the source area in addition to the GMZ
boundary. As with Alternative SCS-9/10C, the air sparging system would be reguired to
operate in conjunction with an SVE system as described in alternative SCS-9/10C. Vapors
produced by air sparging would be collected in the SVE system. This alternative would
achieve RAOs in a relatively short amount of time, second only to Alternative SCL-9/10D.
Estimated costs for this alternative are as follows:

Capital: $2,697,000
Annual O&M: $ 65,000
Total Present Worth: $3,619,000

SOURCE AREA 11

Computer modeling performed for Area 11 predicted that for any alternative, dissolved
contaminants would meet state groundwater standards at the GMZ boundary prior to
intersecting the GMZ boundary. However, free product NAPL exists at the interior of the
site and represents a principal threat. With the exception of SCS-11A (No Action), the
alternatives evaluated for Area 11 are designed to address overall soil contamination,
including free product NAPL.

Source Area 11 - Soil

SCS-11A: No Action
For Alternative SCS-11A, no remedial actions would be undertaken. Soil contaminants would
remain on-site and would not be reduced in volume, treated or contained. Free product NAPL
is present at the interior of Area 11 and soil remediation objectives would not be met for
some time. This alternative would take the longest amount of time to meet soil remediation
objectives and RAOs at the interior of the site. There are no costs to implement this
alternative.
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SCS-1IB: Li mi ted Action (restrictions on future site development)
Alternative SCS-11B includes placing use restrictions on the contaminated area.
Institutional controls would be implemented to prevent future site development. As with
alternative SCS-11A, soil contaminants would remain on site and would not be reduced in
volume, treated or contained. This alternative would require the same amount of time to
achieve soil remediation objectives and RAOs as alternative SCS-11A. The estimated costs
for this alternative are as follows:

Capital: $28,000
Annual O&M: $ 0
Total Present Worth: $28,000

SCS-11C: Soil Vapor Extraction with vapor treatment, using catalytic oxidation
This is the proposed alternative for Area 11 soils. Soil Vapor Extraction is the preferred
presumptive remedy for soils contaminated with VOCs. Under this alternative, contaminated
soils would be remediated in situ via a vapor extraction system. This alternative would
consist of the installation of a series of wells connected by an underground piping
system. A blower would provide a source of negative pressure to extract vapors from the
subsurface. Five vacuumextraction wells would be placed in the source area. The extraction
wells would be screened in the vadose zone, where they would remove volatile contaminants
from the unsaturated zone, as well as some leachate contaminants that may diffuse from the
surface of the water table. Due to the presence of NAPL, it has been assumed that the
wells would be constructed of carbon steel in case steam injection is required. A pilot
program would be conducted prior to system design to determine well construction, spacing
and in situ air permeability.

Given the presence of residual NAPL, it is expected that significant quantities of
contaminated vapors would be extracted. The vapors would initially be treated with a
catalytic oxidation unit. Carbon adsorption would not be a cost-effective technology for
treating the vapor upon startup of the soil vapor extraction system. It is possible that
carbon adsorption could be used to address contaminants in the vapor after contaminant
concentration levels were reduced by using catalytic oxidation for a period of six months
to one year. This alternative would achieve soil remediation objectives and RAOs in the
shortest amount of time of all alternatives evaluated for Area 11. Estimated costs for
this alternative are as follows:

Capital: $ 543,500
Annual O&M: $ 212,880
Total Present Worth: $3,185,500

Source Area 11 - Leachate

No remedial alternatives (with the exception of the No Action Alternative) were developed
for Area 11 leachate. The BIOSCREEN results indicate that even though LNAPL is present in
the interior of the area, groundwater would meet state groundwater standards at the GMZ
boundary. BIOSCREEN accounted for the 150 feet between the hot spot at Area 11 and the GMZ
boundary. Modeled concentrations of benzene, xylene and TCE dropped below groundwater
standards within 75 feet down gradient of the elevated soil concentrations (CDM, 2000 RI
Appendix B). However, due to the presence of free product NAPL at the interior of the
site, institutional controls on groundwater usage within the GMZ would be implemented,
approximately four monitoring wells would be installed and a groundwater and leachate
monitoring program would be executed.
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SCL-11R.: No Action (leachate monitoring and restrictions on groundwater usage)
This alternative would consist of no action with leachate monitoring and institutional
controls on groundwater usage. Leachate concentrations would continue to attenuate
naturally. The groundwater and leachate would be monitored at predetermined intervals for
30 years per RCRA post-closure groundwater monitoring reguirements. Monitoring would
typically consist of collecting groundwater and analyzing for VOCs and, where appropriate,
parameters that measure biological activity. Future area development would be restricted
under this alternative. Estimated costs for this alternative are as follows:

Capital: $ 54,000
Annual O&M: $ 8,000
Total Present Worth: $297,000
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COMPARATIVE ANALYSIS OF ALTERNATIVES

This section explains the Illinois EPA's rationale for selecting the preferred
alternatives. The U. S. EPA has developed nine criteria to evaluate remedial alternatives
to ensure that important considerations are factored into remedy-selection decisions.
These criteria are derived from the statutory requirements of CERCLA Section 121, as well
as other technical and policy considerations that have proven to be important when
selecting remedial alternatives. The nine criteria are identified and described in the
chart below.

The FS for Operable Unit Three presented detailed analysis for 28 different alternatives.
Because the two Modifying Criteria cannot be fully evaluated until public comment is
received, they were not evaluated in the FS. The reader is urged to read the
responsiveness summary for more detailed discussion of public comment received. Detailed
analysis of the remaining 7 criteria for each alternative is summarized below. Due to the
large number of alternatives, an in-depth, detailed analysis for each is not provided.
Additionally, the alternatives are evaluated in groups, by source area and media (soil or
leachate). The No Action Alternative will only be discussed for Area 11 leachate, as it
failed to be protective of human health and the environment in all other cases. References
to all alternatives in discussions below should be considered to exclude the No Action
Alternative, as well as any other alternatives specific to the subject source area and
media that do not meet threshold criteria.

DESCRIPTION OF EVALUATION CRITERIA

Threshold Criteria
The two most important criteria are statutory requirements that must be satisfied by any
alternative in order for it to be eligible for selection.

1. Overall protection of human health and environment addresses whether or not a remedy
provides adequate protection and describes how risks posed through each pathway are
eliminated, reduced or controlled through treatment, engineering controls or
institutional controls.

2. Compliance with ARARs addresses whether or not a remedy will meet all of the
Applicable or Relevant and Appropriate Requirements of other Federal and State
environmental statutes and/or provide grounds for invoking a waiver.

Primary Balancing Criteria
Five primary balancing criteria are used to identify major trade-offs between remedial
alternatives. These trade-offs are ultimately balanced to identify the preferred
alternative and to select the final remedy.

1. Long-term effectiveness and permanence refers to the magnitude of residual risk and
the ability of a remedy to maintain reliable protection of human health and the
environment over time, once cleanup goals have been met.

2. Reduction of toxicity, mobility, or volume through treatment is the anticipated
performance of the treatment technologies that may be employed in a remedy.

3. Short-term effectiveness refers to the speed with which the remedy achieves
protection, as well as the remedy's potential to create adverse impacts on human
health and the environment that may result during the construction and
implementation period.

4. Implementability is the technical and administrative feasibility of a remedy,
including the availability of materials and services needed to implement the chosen
solution.
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5. Cost includes capital and operation and maintenance costs.

Modifying Criteria
These criteria may not be considered fully until after the formal public comment period on
the Proposed Plan and RI/FS Report are complete. However, Illinois EPA and U. S. EPA work
closely with the community throughout the project.

1. State Acceptance indicates whether, based on its review of the RI and Proposed Plan,
the State concurs with, opposes or has no comment on the preferred alternative.
While the NCP speaks in terms of State Acceptance, in this instance, Illinois EPA is
the lead agency, with the support of the U. S. EPA. Hence, for this case, the term
"Support Agency" is more appropriate.

2. Community Acceptance will be assessed in the Record of Decision following a review
of the public comments received on the RI report and the Proposed Plan

AREA 4 SOIL

In addition to the No Action alternative, Alternative SCS-4B will not be discussed within
this section because it failed to meet either of the threshold criteria. A summary of the
detailed analysis for Area 4 Soil is provided below for Alternatives SCS-4C (SVE) and
SCS-4D (Excavation with LTTD).

Overall Protection of Human Health and the Environment
Both SCS-4C and SCS-4D are protective of human health and the environment. SCS-4D achieves
soil remediation objectives in less than 1 year.

Compliance with ARRRs
Both alternatives comply with ARARs.

Long-term Effectiveness and Permanence
Alternative SCS-4D is more permanent (soils are removed and treated) than SCS-4C and has
less residual risk once excavation is complete. Also, SCS- 4D does not reguire any long-
term operation and maintenance, whereas the SVE system under SCS-4C would reguire
maintenance until remediation objectives are met after approximately 20-30 years.

Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative SCS-4D achieves a higher degree of reduction of toxicity, mobility and volume
of contaminants as opposed to SCS-4C. Under SCS-4D, greater than 90% of contaminant mass
would be removed as compared to 85% removal using SCS- 4C.

Short-term Effectiveness
Alternative SCS-4C results in a smaller short- term health risk to on- site workers and
the surrounding community, as the contaminants are left in place. Under the SCS-4D, the
contaminants would be excavated, providing more of an opportunity for exposure, but
improved rate of contaminant removal.

Implementation
Both alternatives are technically easy to implement. Some space considerations must be
made with alternative SCS-4D, as the treatment unit will be larger than that under SCS-4C.

Cost
The total present worth costs for Alternative SCS-4C is $2,156,000 as compared to SCS-4D's
$2,121,000.

AREA 4 T.-RArHATE

The summary of the detailed analysis for Area 4 Leachate is provided below for
Alternatives SCL-4B (Hydraulic Containment); SCL-4C (Air Sparging at GMZ Boundary); SCL-4D
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(Reactive Barrier Wall) and SCL-4E (Air Sparging at Source and GMZ Boundary).

Overall Protection of Human Health and the Environment
All alternatives evaluated for Area 4 Leachate are protective of human health and the
environment. However, only SCL-4D stops contaminants entirely (and in an immediate manner)
from moving outside the GMZ boundary for Area 4.

Compliance with ARARs
All alternatives comply with ARARs. Alternative SCL-4D complies with ARARS in the shortest
amount of time.

Long-term Effectiveness and Permanence
All alternatives reguire some degree of operation and maintenance. Alternative SCL-4E is
the most effective as it addresses contaminants within hot spots.

Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative SCL-4B provides the least reduction in toxicity, mobility and volume of
contaminants as opposed to all others. Alternative SCL-4D provides the highest degree of
reduction in toxicity, mobility and volume of contaminants, as contaminants are treated
while passing through the reactive barrier wall.

Short-term Effectiveness
All alternatives cause limited exposure to subsurface contaminants during construction.
Alternative SCL-4D is the most effective in the short term.

Implementation
Alternative SCL-4D is the most difficult to implement due to excavation and dewatering
reguirements. Alternative SCL-4B is the easiest.

Cost
The total present worth costs for Area 4 Leachate alternatives are as follows: SCL-4B
($1,117,000); SCL-4C ($2,522,000); SCL-4D ($5,911,000); SCL-4E ($2,796,000).

AREA 7 SOIL

In addition to the No Action Alternative, Alternative SCS-7B will not be discussed within
this section because it failed to meet either threshold criterion. The summary of the
detailed analysis for Area 7 Soil is provided below for Alternatives SCS-7C (Excavation
and Biological Treatment); SCS-7D (Excavation and On- site Low Temperature Thermal
Desorption) and SCS-7E (Soil Vapor Extraction and Air Sparging).

Overall Protection of Human Health and the Environment
All alternatives evaluated for Area 7 Soil are protective of human health and the
environment. However, SCS-7C and SCS-7D achieve soil preliminary remediation goals in 2
years or less, as opposed to the 15 to 20 years reguired for SCS-7E.

Compliance with ARARs
Alternative SCS-7D complies with ARARS immediately upon the completion of excavation. All
other alternatives would reguire additional time to meet ARARs.

Long-term Effectiveness and Permanence
All alternatives provide adeguate effectiveness and permanence. Alternative SCS-7E is the
least effective and permanent, because contaminants are treated in situ, and therefore
rely on operation and maintenance of a SVE system. Alternative SCS-7D is the most
permanent, as contaminants would be excavated and thermally destroyed above ground.

Reduction of Toxicity, Mobility, or Volume through Treatment
All alternatives would provide adeguate reduction in toxicity, mobility and volume of
contaminants. Alternative SCS-4E would provide the least reduction in toxicity, mobility
and volume of contaminants (approximately 85%) as opposed to all others. However, after
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extraction, the thermal treatment unit would provide greater than 95% reduction in
contaminant volume within the vapors. Alternative SCS-7D would provide the largest overall
reduction in toxicity, mobility and volume of contaminants at greater than 90%
effectiveness.

Short-term Effectiveness
Alternatives SCS-7C and SCS-7D are very effective in the short term, as contaminants would
be removed through excavation. However, these alternatives also have the highest
short-term risks to on-site workers and the community, as VOCs could be released during
the excavation.

Implementability
All alternatives would be relatively easy to implement and are technically feasible.

Cost
The total present worth costs for Area 7 Soil alternatives are as follows: SCS-7C
($18,218,000); SCS-7D ($15,209,000) andSCS-7E ($5,624,000).

AREA 7 T/FACHATE

A summary of the detailed analysis for Alternatives SCL-7B (Multi-phase Extraction/
Leachate Containment and Treatment) and SCL-7C (Reactive Barrier Wall) is provided below.

Overall Protection of Human Health and the Environment
Both alternatives evaluated for Area 7 Leachate are protective of human health and the
environment. However, only SCL-7C, the reactive barrier wall, stops contaminants entirely
(and in an immediate manner) from moving outside the GMZ boundary for Area 7.

Compliance with ARRRs
Both alternatives comply with ARARs. Alternative SCL-7D complies with ARARS in the
shortest amount of time.

Long-term Effectiveness and Permanence
Both alternatives would provide an adeguate degree of effectiveness and permanence.
Alternative SCL-7B would provide a higher degree of permanence, as the NAPL is addressed
directly through extraction.

Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative SCL-7B would provide the greatest reduction in toxicity, mobility and volume
of contaminants, as treatment occurs within the hot spots.

Short-term Effectiveness
Alternative SCL-7C is the most effective in the short term, as contaminants would be
treated immediately as they pass through the barrier wall.

Implementation
Alternative SCL-7C is the most difficult to implement due to excavation and dewatering
reguirements to install the wall within the trench.

Cost
The total present worth costs for Area 7 Leachate alternatives are as follows: SCL-7B
($2,637,000) and SCL-7C ($4,391,000).

AREA 9/10 SOIL

In addition to the No Action Alternative, Alternative SCS-9/10B will not be discussed
within this section because it failed to meet either threshold criteria. A summary of the
detailed analysis for Alternative SCS-9/10C (Soil Vapor Extraction) is provided below.
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Overall Protection of Human Health and the Environment
Alternative SCS-9/10C is the only alternative that is protective of human health and the
environment.

Compliance with ARARs
Alternative SCS-9/10C would comply with ARARS in a reasonable time frame.

Long-term Effectiveness and Permanence
Alternative SCS-9 IOC is the most effective and permanent, although contaminants would be
treated in situ, and therefore would rely on operation and maintenance of a SVE system.

Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative SCS-9/10C would provide the greatest reduction in toxicity, mobility and
volume of contaminants (approximately 85%) as opposed to all others.

Short-term Effectiveness
Alternative SCS-9/10C would provide a medium level of short- term effectiveness. The SVE
system would reguire a certain amount of time to achieve remediation goals. Short-term
risks to on-site workers and the community would be minimal, as soils would be treated in
situ.

Implementation
Soil Vapor Extraction under SCS- 9/ IOC would be relatively easy to implement, however,
space considerations exist.

Cost
The total present worth costs for Alternative SCS-9/10C is $4,308,000.

AREA 9/10 JLEACHATE

A summary of the detailed analysis for Area 9/10 Leachate is provided below for
Alternatives SCL-9/10B ( Hydraulic Containment); SCL-9/10C (Air Sparging at GMZ Boundary);
SCL-9/10D (Reactive Barrier Wall) and SCL-9/10E (Air Sparging at Source and GMZ Boundary).

Overall Protection of Human Health and the Environment
All alternatives evaluated for Area 9/10 Leachate are protective of human health and the
environment. However, SCL-9/10E would remediate the contamination to a level where natural
attenuation will allow ARARs to be met outside the GMZ boundary for Area 9/10.

Compliance with ARARs
All alternatives comply with ARARs. Alternative SCS-9/10E complies with ARARS in an
appropriate time frame.

Long-term Effectiveness and Permanence
All alternatives reguire some degree of operation and maintenance. Alternative SCL-9/10E
best meets this criterion, as the degree of residual risk after remediation objectives are
achieved would be small. This is because SCL-9/10E would address contaminants within hot
spots.

Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative SCL-9/10E would provide enough reduction in toxicity, mobility and volume of
contaminants to allow ARARS to be met in the time frame set forth in this ROD.

Short-term Effectiveness
All alternatives cause limited exposure to subsurface contaminants during construction.
Alternative SCL-9/10E is effective in the short term.

Implementation
Alternative SCL-9/10E is difficult to implement due to excavation and dewatering
reguirements. Alternatives SCL-9/10C, SCL-9/10D and SCL-9/10E all face some difficulty,
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due to construction beneath 9th Street. Alternative SCL-9/10B would be the easiest to
implement.

Cost
The total present worth costs for Area 9/10 Leachate alternatives are as follows:
SCL-9/10B ($2,440,000); SCL-9/10C ($3,208,000); SCL-9/10D ($3,523,000) andSCL-9/10E
($3,619,000).

The Contingent Remedy for Leachate Area 9/10 is SCL-9/10B (Hydraulic Containment/Leachate
Containment/Collection and Treatment by Air Stripping). SCL-9/10B by itself is a limited
action that meets necessary reguirements for overall protection of human health and the
environment. However, this alternative would not meet ARARS as guickly as SCL-9/10E
enhanced air sparging so it was not selected for the preferred remedy. This alternative,
while providing some protection to down- gradient receptors, by itself would comply with
ARARs at the property boundary. However, as a contingent remedy used if necessary in
conjunction to SCL-9/10E to address NAPL or higher concentrations of contaminated leachate
it will assist in the meeting of ARARs through source reduction in the proposed time
frames.

Overall Protection of Human Health and the Environment
All alternatives evaluated for Area 9/10 Leachate are protective of human health and the
environment. However, SCL-9/10B would remediate the contamination to a level where natural
attenuation will allow ARARs to be met outside the GMZ boundary for Area 9/10.

Compliance with ARARs
All alternatives comply with ARARs. Alternative SCS-9/10B complies with ARARS in an
appropriate time frame it is not as effective as the preferred remedy of SCL-9/10E.
Therefore it is proposed only as a contingent remedy to the proposed leachate remedy.

Long-term Effectiveness and Permanence
All alternatives reguire some degree of operation and maintenance. Alternative SCL-9/10B
meets this criterion, as the degree of residual risk after remediation objectives are
achieved would be small. This is because SCL-9/10B would address contaminants within hot
spots.

Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative SCL-9/10B would provide sufficient reduction in toxicity, mobility and volume
of contaminants to allow ARARS to be met at the designated GMZ boundaries in the time
frame set forth in this ROD.

Short-term Effectiveness
All alternatives cause limited exposure to subsurface contaminants during construction.
Alternative SCL-9/10B is effective in the short term at the property boundaries where it
would be implemented, but not as effective in contaminant control down-gradient from the
source area. The proposed remedy SCL-9/10E is considerably more effective and SCL-9/10B
would be designed to supplement and assist SCL-9/10E if construction is necessary.

Implementation
Alternative SCL-9/10B would be the easiest to implement, however would face some problems
from the placement of the extraction wells and utilities. Alternatives SCL-9/10C,
SCL-9/10D and SCL-9/10E all face some difficulty, due to construction beneath 9th Street.

Cost
The total present worth costs for Area 9/10 Leachate alternatives are as follows:
SCL-9/10B ($2,440,000); SCL-9/10C ($3,208,000); SCL-9/10D ($3,523,000) andSCL-9/10E
($3,619,000).

AREA 11 SOIL

In addition to the No Action Alternative, Alternative SCS-11B will not be discussed within
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this section because it failed to meet either threshold criteria. The summary of the
detailed analysis for Area 11 Soil is provided below for Alternative SCS-11C (Soil Vapor
Extraction).

Overall Protection of Human Health and the Environment
Alternative SCS-11C is the only alternative that is protective of human health and the
environment.

Compliance with ARRRs
Alternative SCS-11C would comply with ARARS in a reasonable time frame.

Long- term Effectiveness and Permanence
Alternative SCS-11C is the most effective and permanent, although contaminants are treated
in situ and therefore rely on operation and maintenance of a SVE system.

Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative SCS-11C provides the greatest reduction in toxicity, mobility and volume of
contaminants (approximately 85%) as opposed to all others.

Short-term Effectiveness
Alternative SCS-11C provides a medium level of short-term effectiveness. The SVE system
will reguire a certain amount of time to achieve remediation goals. Short-term risks to
on-site workers and the community are minimal, as soils would be treated in situ.

Implementability
Soil Vapor Extraction under SCS-11C is relatively easy to implement, however, space
considerations exist.

Cost
The total present worth costs for Alternative SCS-11C is $ 3,185,500.

AREA 11 T/FACHRTE

The summary of the detailed analysis for Area 11 Leachate is provided below for
Alternative SCL-11A (No Action)

Overall Protection of Human Health and the Environment
The No Action alternative is protective of human health and the environment.

Compliance with ARARs
Alternative SCL-11A complies with ARARs.

Long-term Effectiveness and Permanence
Alternative SCL-11A reguires a degree of operation and maintenance as on-going groundwater
sampling will be reguired. Alternative SCL-11A meets this criterion. Groundwater
contamination will continue to degrade naturally.

Reduction of Toxicity, Mobility, or Volume through Treatment
Alternative SCL-11A will reduce toxicity, mobility and volume of contaminants through
natural degradation.

Short-term Effectiveness
Alternative SCL-11A is effective in the short term. Low- level exposure to subsurface
contamination may occur during installation of monitoring wells and sampling events.

Implementation
Alternative SCL-11A is straightforward to implement.

Cost
The total present worth costs for Alternative SCL-11A is $297,000.
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PRINCIPAL THREAT WASTES

The National Contingency Plan (NCP) establishes an expectation that U. S. EPA will use
treatment to address principal threats posed by a site wherever practicable (NCP, 40 CFR
§ 300.430(a)(1)(iii)(A)). The term " principal threat" refers to source materials that are
considered to be highly toxic or highly mobile that generally cannot be reliably contained
or would present a significant risk to human health or the environment should exposure
occur (U. S. EPA, Guide 6-40). Remedial investigations conducted at the site have
identified principal threat wastes at all four source areas (Area 4, Area 7, Area 91/10
and Area 11). Residual NAPL was positively identified at Areas 4, 7 and 11 (CDM, 2000 RI).
At Area 91/10, groundwater concentrations were identified that were indicative of a
significant source of groundwater contamination and NAPL presence (CDM, 2000 RI 3-77). The
following text summarizes information identifying the principal threats at each Source
Area.

AREA 4

Soil boring SB4-202 taken in the northern part of Swebco's parking lot tested positive for
the presence of a LNAPL directly above and within the top portion of the saturated zone
(CDM, 2000 RI 3-14). Laboratory analysis of soil within boring SB4-202 contained 510 ppm
of 1,1,1-TCA (CDM, 2000 RI 3-14). LNAPL was found present at the source from 27 to 35 feet
bgs but was not found in deeper portions of SB4-202 (CDM, 2000 RI 3-14) . The extent of
NAPL contamination was not identified. The estimated volume of contaminated soil at Area 4
is 155,400 cubic feet (CDM Operable Unit Three FS Appendix C).

AREA 7

Subsurface sampling results obtained at Area 7 suggest the presence of NAPL in two hot
spots located in the northern and southern portions of the area. In the southern hot spot,
PCE concentrations of 260 ppm in soil sample SB7-8D suggest the presence of a NAPL (CDM,
1995 RI 4-48). Concentrations of VOCs such as xylene, naphthalene and 2-methyl naphthalene
were also identified within soil boring SB7-8 at concentrations high enough to exist as
NAPL (CDM, 1995 RI 4-48). Additionally, the SB7-8D soil-boring log indicates an elevated
headspace and a strong solvent odor for sample SB7-8D (CDM, 1995 RI Appendix A). Specific
tests designed to positively identify NAPL were not performed on soils in the southern hot
spot.

AREA 9/10

The concentration of 12 ppm of 1,1,1-TCA in MW201 indicates that NAPL is likely present in
Area 9/10, based on the agueous solubility limit of 1,1,1-TCA. The concentration of
1,1,1-TCA in MW201 represents 0.8 to 4 percent of its agueous solubility limit. Dye
testing did not reveal the presence of NAPL in the more shallow portions of the
unconsolidated aguifer. However, DNAPL would not be expected to be present in the more
shallow portions of the aguifer, because no confining units are present in the top 100
feet of the aguifer (CDM, 2000 RI 3-77).

Further research has revealed that numerous releases of petroleum based fuels (JP4,
mineral spirits and fuel oil) and chlorinated solvents have occurred from underground
storage tanks (USTs) in Area 9/10. Reports submitted to the Illinois EPA reveal that LNAPL
in relation to the above-mentioned releases exists or has existed floating on the water
table. In addition, PCE, TCE and metals are present in soil at concentrations that would
be considered a threat to contaminate groundwater above the Class I Groundwater Standards.
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AREA 11

Subsurface sampling results obtained at Area 11 suggest the presence of NAPL in two hot
spots located in the western and central portions of the area. NAPL was detected in the
western zone during field screening of SB11-203 soil samples from 39 to 43 feet bgs. A
combination of black staining of soils and Sudan IV dye testing confirmed the presence of
NAPL in samples taken from 39 to 43 feet bgs. Similar conditions were identified in SB11-
202 from 39 to 45 feet bgs (CDM, 2000 RI 3-45, 51).

Soil samples taken in the central zone of contamination, SB11-4G (total VOCs 307 ppm) and
SB11-8G (total VOCs 42 ppm) indicate the possibility for NAPL (CDM, 1995 RI 4-70, Table
4-4). However, no staining is noted in the soil boring logs and the Sudan IV dye test was
not performed during the Operable Unit 2 investigation. The extent of NAPL contamination
was not identified. The total estimated volume of soil at Area 11 is approximately 237,084
cubic feet (CDM, 2000 FS Appendix E).
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SELECTED REMEDY

This section describes the rationale and the preferred alternatives for each source area
and provides Illinois EPA's reasoning behind its selection. Alternatives can change or be
modified if new information is made available to Illinois EPA through further
investigation or research. An appropriate range of alternatives was developed, based upon
the initial screening of technologies, the potential for contaminants to impact the
environment and specific criteria for the source areas.

SOIL SOURCE CONTROL

The U. S. EPA has developed presumptive remedy directives with the objectives of
streamlining site investigations and facilitating the selection of remedial actions. The
directive on presumptive remedies for soils contaminated by VOCs is appropriate for
addressing the types of contaminants found in the source areas at the Southeast Rockford
site. Presumptive remedies that were considered and would be implemented for this site
include soil vapor extraction and thermal desorption. Ex situ bioremediation was also
considered for Area 7 as an alternative to thermal desorption of excavated material. For
this source area, ex situ bioremediation would reguire a longer timeframe than soil vapor
extraction to achieve ARARs. However, ex situ bioremediation would be more advantageous
than ex situ soil vapor extraction, since bioremediation would not reguire treatment of
contaminants in the vapor stream

T/FACHRTE SOURCE CONTROL

To assemble alternatives, general response actions were combined to form complete remedial
responses for the media of concern in each source area. A detailed remedial approach
considered the specific extent, depth and mobility of contaminants, as well as site-
specific area constraints and hydrogeology for the individual source areas. Leachate
source control would address residual contamination not addressed by soil remediation
alternatives (other than No Action).

Leachate, source control includes contaminated leachate in the shallow water-bearing zone.
Leachate is assumed to be contamination that originated from the soil source areas and has
migrated to the unconsolidated aguifer within the designated source areas. Contaminated
source leachate is defined in the FFS and hereafter as shallow groundwater located inside
each source area. Groundwater located outside the potential GMZ of the source areas was
evaluated as part of management of migration of site-wide groundwater, and is not
addressed as part of the FFS.

Leachate source control alternatives were formulated to address the remediation for each
source area. Leachate source control alternatives were developed for Source Areas 4, 7 and
9/10, as noted in the fate and transport analysis (Final RI, SCOU 7/25/2000) . Source Area
11 does not reguire leachate source control, based on modeling results that indicate ARARs
are attained at the GMZ boundary.

GROUNDTflaTER MflNAGEMENT ZONES (GMZ)

Fact Sheets and the proposed plan presented by the Illinois EPA proposed the use of
Groundwater Management Zones pursuant to 35 111. Adm. Code 620.250 for each source area.
As defined by Illinois EPA regulations, "a GMZ may be established as a three dimensional
region containing groundwater being managed to mitigate impairment caused by the release
of contaminants from a site". Groundwater Management Zones are used and established for
sites undergoing corrective action that is approved by the Illinois EPA. The Focused
Feasibility Study prepared for the Illinois EPA by Camp Dresser & McKee dated September 5,
2000 Volume I, Section 3-1, figures 3-1 through 3-4, presents boundaries of the proposed
GMZ for each source area. For source areas 4, 7, and 11, the GMZ boundary was set to areas
surrounding contaminated soil. In addition, the GMZ boundaries were set where it was
possible for the proposed remedial action to achieve ARARs. The GMZ boundary for Source
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Area 9/10 was established knowing that site characterization of soil contamination was
incomplete. Therefore, the GMZ boundary would encompass an area in which the Illinois EPA
believes soil contamination is present, including United Technologies Corporation/
Hamilton Sundstrand (UTC/HS) Corporation Plant No. 1, former Mid States Industrial and
Rockford Products east of Ninth Street.

Volume 1, Section 7.1 of the Focused Feasibility Study, dated September 5, 2000 states,
"Groundwater that lies beyond the GMZ of each source is considered part of the site-wide
groundwater." During the time needed for remediation of the source areas, groundwater that
exceeds the Class I Groundwater Quality Standards will exist below the entire area. As
part of the GMZ, its boundaries will act as points of compliance set forth as part of the
GMZ. It is the intention of the Illinois EPA that Class I Groundwater Quality Standards be
met as part of the remediation goals. However, since it is possible that Class I
Groundwater Quality Standards can not be achieved in the time frame established for
remediation of the source areas, it may become necessary for the temporary establishment
of alternative groundwater standards, pursuant to 35 111. Adm. Code Part, 620. This may
occur for source areas where contaminated groundwater is flowing from an up-gradient
position onto a source area. Therefore, compliance with GMZ reguirements can be
accomplished by the establishment of background conditions from groundwater located up
gradient of the source area that it is migrating below the source area in guestion.
Background concentrations in groundwater shall be established for the Southeast Rockford
Groundwater Contamination Site pursuant to 35 111. Adm. Code 724, Subpart F and only for
those groundwaters found to be significantly over Class I Groundwater Standards.

It is the intention of the proposed remedies in this ROD to meet the desired goals of
Class I Groundwater Standards for the source areas, as well as the entire Southeast
Rockford Area. However, due to continuing migration of contaminated groundwater below the
entire site, exceedences of the Class I Groundwater guality may occur beyond GMZ
boundaries until such time that the proposed remedies are fully operational and
functional. Part of the proposed remedy is natural attenuation of already-contaminated
groundwater beyond the source areas, however, to achieve this, adjustments shall be made
for compliance with Groundwater Quality Standards, in accordance with 35 111. Adm. Code
Part 620. The Illinois EPA acknowledges that the groundwater will not meet Class I
Groundwater Standards until enough natural degradation of contamination occurs. Natural
attenuation is a major part of the remedy proposed for the overall remediation of the
entire site. Groundwater monitoring would be carried out during the entire remediation
process to assess the effectiveness of the remedies proposed in the ROD. Pursuant to 35
111. Adm. Code 620.250(c), "The Agency shall review the on-going adeguacy of controls and
continued management at the site if concentrations of chemical constituents, as
specified in Section 620.250(a) (4) (B) , remain in groundwater at the site following
completion of such action. The review must take place no less than every five years." This
part of Illinois regulations is concurrent with the policies of the CERCLA and the NCP
that will allow the Illinois EPA the opportunity to adjust remediation activities to meet
the desired remediation goals.

AREA 4

Alternatives SCS-4D (Excavation and On- site Low Temperature Thermal Desorption) and
SCL-4B (Hydraulic Containment) are the preferred alternatives for Area 4. The combination
of these alternatives achieves substantial risk reduction by removing the source materials
that constitute principal threats, as well as removing contaminated soil and groundwater
surrounding the source materials. The excavation of contamination and thermal treatment,
coupled with leachate containment reduces risks more guickly and cost effectively than the
other alternatives.

Under these alternatives, approximately 2,800 cubic yards of contaminated soils would be
excavated and VOCs would be removed through on- site thermal treatment via a LTTD unit.
Excavated soils would be conveyed to the primary treatment unit, where the contaminants
are thermally desorbed from the soil. It would take approximately one month (estimated) to
thermally process the soil. Due to the levels of VOCs expected during excavation, the cost
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to install a temporary enclosure over the excavation (for emissions control) has been
included. Contaminated vapors would be collected from the temporary enclosure and directed
to the afterburner used in conjunction with the LTTD unit. Vapors produced within the
thermal desorption unit would thus be destroyed in the afterburner. The treated soil would
then be conveyed to a process unit that cools and re-hydrates the soil. Treated soil would
be stockpiled, and following testing to ensure that remediation goals have been achieved,
would be placed back into the excavation.

Well points would be installed to lower the water table and thus expose the residual NAPL.
Water collected during this dewatering process would be contained on site in two 21,000-
gallon carbon steel tanks and transported to an appropriate disposal facility (at a
freguency to be determined during the design phase).

Following the completion of the soils excavation and thermal treatment, the leachate
containment and treatment system would be installed. Leachate would be contained and
extracted at a rate of approximately 20 gpm through a series of six leachate extraction
wells, submersible pumps, piping and controls. An air-stripping unit would then treat the
extracted leachate. The treated effluent would be discharged on site to a storm water
ditch. Effluent would be monitored periodically for VOCs to confirm that the leachate is
treated to acceptable levels. Vapors stripped from the leachate in the air-stripping unit
would be directed to an on-site GAG unit. It is expected that under these alternatives,
Area 4 would meet RAOs in less than 15 years.

Institutional controls would be placed on groundwater usage within the GMZ, monitoring
wells would be installed and a groundwater-and leachate-monitoring program would be
implemented. The total present worth cost of these alternatives is $3,238,000.

PNAs were identified as COCs in soils at Area 4. PNAs are not directly addressed by
SCS-4D, although some remediation may occur incidentally (LTTD is not 100% effective on
PNAs). Additional data will be obtained during remedial design to determine if PNAs are
truly COCs due to industrial activities at Area 4, or simply contamination from other
activities (i.e. naturally occurring sources or non-industrial human activities). If the
PNA evaluation conducted during remedial design identifies the need for additional
remediation, the remedy would be appropriately altered. Depending on the significance of
the change in the remedy, the Agencies may be reguired to hold additional public meetings
and allow public comment on the new remedy.

Proposed alternatives for Area 4 will meet all RAOs for Area 4. Table 10 describes each
RAO and how the alternatives would meet them.

Excavation of soils and NAPL followed by LTTD would remove and treat the principal threat
wastes from Source Area 4. Based on information currently available, the lead agency
believes the Preferred Alternative meets the threshold criteria and provides the best
balance of tradeoffs among the other alternatives with respect to the balancing and
modifying criteria. The Illinois EPA expects the Preferred Alternative for Area 4 to
satisfy the following statutory reguirements of CERCLA § 121( b): (1) be protective of
human health and the environment; (2) comply with ARARs (or justify waiver); (3) be cost
effective; (4) utilize permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable and (5) satisfy the
preference for treatment as a principal element, or explain why the preference for
treatment will not be met.
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Table 10. Area 4 Remedial Action Objectives

Remedial Action Objective -- Prevent the public from contact with soil containing
contamination in excess of state or federal standards or that poses a threat to
human health.

How Alternative will meet RAO -- Soils containing contamination in excess of
state or federal standards or that poses a threat to human health will be
excavated and treated by LTTD.

Remedial Action Objective -- Prevent the public from inhalation of airborne
contaminants in excess of state or federal standards or that pose a threat to human
health.

How Alternative will meet RAO -- Soils containing contamination in excess of
state or federal standards or that poses a threat to human health will be
excavated and treated by LTTD.

How Alternative will meet RAO -- The removal of free product NAPL, as well as
those soils containing contamination in concentrations contributing to
groundwater contamination in excess of ARARs will be excavated and treated.
Following the LTTD, the leachate containment system will extract remaining
leachate contamination until ARARs are met at the GMZ boundary.

AREA 7

Alternatives SCS-7E (Soil Vapor Extraction and Air Sparging) and SCL-7B (Multi-phase
Extraction with Leachate Containment and Treatment) are the preferred alternatives for
Area 7. These alternatives are recommended because they would achieve substantial risk
reduction in consideration of cost. Alternatives SCS-7E and SCL-7B reduce risks
substantially by treating the source materials constituting principal threats at the site.

Under these alternatives, the in situ technologies soil vapor extraction, air sparging,
and multiphase extraction would work in concert to treat contaminants in unsaturated and
saturated soil and leachate in Source Area 7. The SVE system would extract vapors from
suspected hot spots through sixteen vacuum extraction wells. Wells would be constructed to
a depth of up to 25 feet and screened in the vadose zone, where they will extract volatile
contaminants from the unsaturated zone, as well as some leachate contaminants that are
able to volatilize from the surface of the water table. The estimated flow rate for the
SVE system is 1200 scfm.

An air sparging system would be constructed to volatilize VOCs from saturated soils and
leachate through the injection of air. VOCs would be collected through the SVE system from
contaminated soil. A total of 53 air-sparging wells would be constructed to a depth of 50
feet bgs. COM has assumed a radius of influence of 25 feet for the air sparging wells. Two
air compressors would be used to inject air to the subsurface, each at a rate of 400 scfm,
for a total of 800 scfm.

A MPE system would focus on the hot spot areas where either highly contaminated soils or
NAPL exists. The MPE system would extract a combination of the following phases: NAPLs;
groundwater (leachate) ; and soil vapor. Ten MPE wells would be installed into the hot
spots to a depth of approximately 25 feet.

Lastly, a leachate containment system consisting of eight leachate extraction wells, a
-------
central pump station, an air-stripping unit, piping and controls would be installed. A
containment system would focus on contaminated leachate along the down-gradient side of
the GMZ.

Leachate would be collected in the extraction wells and pumped to the air- stripping unit
at a rate of 10 gpm.

The SVE, MPE and leachate containment systems would pipe contaminants to a central
treatment building in the form of vapors, NAPL and leachate. Vapors would be sent directly
to a catalytic oxidation system for treatment. Leachate and NAPL would be separated from
each other through an oil/water separator. NAPL that is collected will be sent off site
for treatment and leachate will be directed to an on- site air stripper. Vapors from the
air stripper containing VOCs stripped from the leachate would be directed to the catalytic
oxidation system for treatment. Treated water collected in the central treatment unit
would be discharged on site to the unnamed creek located approximately 450 feet north of
the hot spots.

Recovered NAPLs, groundwater and soil vapor would be piped underground to a central vacuum
pump/vapor treatment system enclosure. The enclosure would also include an air/water
separation system, with the separated water pumped to the leachate containment system air
stripper. This alternative should comply with RAOs after approximately 15 to 25 years.

Institutional controls would be placed on groundwater usage within the GMZ, monitoring
wells would be installed and a groundwater and leachate- monitoring program would be
implemented. Estimated total present worth cost for these alternatives is $8,261,000.

Because the Illinois EPA was unable to guantitatively evaluate human health risks to
residents who were exposed to creek surface water and sediments in Area 7, additional data
from the creek will be obtained during the design phase (likely during 2002). Following
data collection, risks to human health will be guantitatively evaluated. However,
activities of the current owner have resulted in modification of the flow of the creek.
This activity may hinder or potentially eliminate the ability of the Illinois EPA to
collect additional samples necessary to perform a complete risk assessment.

Similarly, additional data will be collected from the creek during the design phase of the
project to complete the ecological risk assessment. If the additional human health or
ecological risk evaluations conducted during design identify the need for remediation in
addition to that outlined within this ROD, the remedy will be appropriately altered.
Depending on the significance of the change in remedy, the Agencies may be reguired to
hold additional public meetings and allow public comment on the new remedy. The proposed
alternatives for Area 7 would meet all RAOs for Area 7. The following table describes each
RAO and how the alternatives would meet them.

Table 11. Area 7 Remedial Action Objectives

Remedial Action Objective -- Prevent the public from contact with soil containing
contamination in excess of state or federal standards or that poses a threat to
human health.

How Alternative will meet RAO -- Soil containing contamination in excess of
state or federal standards or that poses a threat to human health will be
treated by a combination of SVE and MPE. Increased airflow caused by SVE and
MPE will remove contaminants from soils and promote biodegradation.

Remedial Action Objective -- Prevent the public from inhalation of airborne
contaminants in excess of state or federal standards or that pose a threat to human
health.

How Alternative will meet RAO -- Soil containing contamination in excess of
state or federal standards or that poses a threat to human health will be
-------
treated by a combination of SVE and MPE. Increased airflow caused by SVE and
MPE will remove contaminants from soils and promote biodegradation.

How Alternative will meet RAO -- A combination of SVE, MPE, and air sparging
will remove free product and the contamination from soils that contain
concentrations contributing to site-wide groundwater contamination in excess
of ARARs. Leachate and soil contaminants below the water table will be treated
by a combination of air sparging, and leachate containment, which will be
achieved by leachate collection via extraction wells. The leachate containment
system will extract remaining leachate contamination until ARARs are met at
the GMZ boundary.

Remedial Action Objective -- Prevent the public from ingestion and direct contact
with surface water containing contamination in excess of state or federal standards
or that pose a threat to human health.

How Alternative will meet RAO -- The removal of free product, contaminated
soils, and contaminated groundwater will reduce the possibility that Area 7
groundwater contamination might impact the creek north of the park. Additional
sampling will determine if levels within the creek pose a threat to human
health.

Remedial Action Objective -- Prevent the migration of contamination from Source Area
7 that would result in degradation of surface water and sediment in the unnamed
creek to levels in excess of state or federal standards or that pose a threat to
human health or the environment

Remedial Action Objective -- Prevent the migration of contamination from Source Area
7 that would result in the contamination of home-grown vegetables at concentrations
which would pose a threat to human health.

How Alternative will meet RAO -- The removal of free product, contaminated
soils, and contaminated groundwater will reduce the possibility that Area 7
contamination might impact homegrown vegetables and fruits.

Extraction of NAPL and implementation of SVE in combination with air sparging would remove
and treat the principal threat wastes from Source Area 7. Based on information currently
available, the Illinois EPA believes the Preferred Alternative for Area 7 meets the
threshold criteria and provides the best balance of tradeoffs among the other alternatives
with respect to the balancing and modifying criteria. The Illinois EPA expects the
Preferred Alternative to satisfy the following statutory reguirements of CERCLA § 121(b):
(1) be protective of human health and the environment; (2) comply with ARARs (or justify
waiver); (3) be cost effective; (4) utilize permanent solutions and alternative treatment
technologies or resource recovery technologies to the maximum extent practicable; and (5)
satisfy the preference for treatment as a principal element, or explain why the preference
for treatment will not be met.
-------
AREA 9/10

Alternatives SCS-9/10C (Soil Vapor Extraction) and SCL-9/10E (Enhanced Air Sparging) are
the preferred alternatives for Area 9/10. These alternatives are recommended, because
following a more thorough investigation, they would provide substantial risk reduction by
treating the source materials constituting principal threats at the site. The combination
of SVE and enhanced air sparging would reduce risks in a reasonable amount of time, for a
reasonable cost. Enhanced air sparging would take a slightly longer period of time to
complete remediation objectives, as opposed to the reactive barrier wall. As part of the
design phase in area 9/10, further investigation would be conducted to determine the most
efficient means of implementing the remedies selected. To ensure efficiency in placement
of the leachate remedy selection (SCL-9/10E) in effective source control, the leachate
remedy would be made in conjunction with further investigation of Source Area 9/10. Upon
the implementation of the Soil Vapor Extraction (SCS-9/10C and SCL-9/10E), should the
results of the investigation indicate that additional corrective action is reguired, a
contingent multi-phase pump and treat remedy (SCL-9/10B) or similarly designed system
would be implemented to assist the selected remedy.

The SCL-9/10B was designed for Source Area 9/10 as a limited action response by itself,
however, as a contingent remedy it's purpose would be to supplement the proposed leachate
remedy (SCL-9/10E) enhanced air sparging. Implementation of the contingent pump and treat
remedy (SCL-9/10B) could be made, pending the results of further characterization and
effectiveness of the selective remedy. However, if further site characterization should
discover that DNAPLs (free product), or higher (than previously expected) leachate
concentrations exist below Source Area 9/10, the contingent remedy should be implemented
as soon as possible. Designing a low volume vacuum extraction multi-phase system that
would include a pump and treat system at 50 gallons per minute would allow the treatment
of DNAPLs contained within the leachate. Should high enough concentrations of NAPL exist
it may be necessary to collect the free product separately in a tank and dispose of it
separately at a facility gualified and licensed for this type of work. The presence of
DNAPLs would indicate that further contamination of the groundwater would occur, for a
longer period of time, thus reguiring the removal of that source to meet Class I
Groundwater Standards. In addition, another trigger is if groundwater monitoring
should reveal that concentrations of contaminants in groundwater are not decreasing after
a period of time from operation of the soil remedy SVE. Design and construction of the
contingent leachate remedy would be made on analysis of the results from additional
characterization. Therefore, implementation of the contingent pump and treat remedy
(SCL-9/10B) or a similarly designed system would be necessary based on proposed further
characterization and results of the proposed remedial actions (SCS-9/10C and SCL-9/10E)
for source control to meet ARARs in the proposed time frame.

Under these alternatives, contaminated soils would be remediated in situ via an SVE system
and leachate would be treated through the use of enhanced air sparging. At least four
vacuum-extraction wells will be screened in the vadose zone, where they will remove
volatile contaminants from the unsaturated zone, as well as some leachate contaminants
that may diffuse from the surface of the water table. Vapors collected from the SVE unit
will be treated using granular activated carbon. Following treatment, the vapors will be
released to the atmosphere.

A thorough investigation could not be completed at Area 9/10, due to concern over
underground utilities. Therefore, additional data will need to be collected in this area
prior to constructing and designing the remedy. The vapor treatment scenario may have to
be reevaluated, based on the results of additional data collection from Area 9/10 and the
results of the SVE pilot program.

Originally, the leachate treatment remedy (SCL-9/10D) involved the construction of a
Reactive Barrier Wall down gradient of the groundwater management zone (GMZ). Iron filings
placed into a slurry react with contaminated groundwater passing through it, breaking down
the VOCs into harmless compounds. However, research and additional information collected
during the public comment period for the ROD has led the Illinois EPA to conclude that a
-------
different remedy should be used.

The information below led the Illinois EPA to first conduct additional investigations into
the effectiveness of the proposed Reactive Barrier Wall. Information obtained from record
searches indicated that numerous releases (mostly involving JP4 jet fuel) have occurred in
Area 9/10. Research revealed that the iron filings of the barrier wall would not react
with JP4 (and other petroleum based fuels), and would allow the JP4 to pass through the
wall untreated. In addition, it is possible that the presence of JP4 may actually block
the iron filings from reacting with chlorinated solvents (jet fuel could clog and foul the
iron filings and thus inhibit the desired chemical reactions).

Further investigation supplied from sites in the Rockford area with similar natural
groundwater chemistry indicated that groundwater passing through the barrier wall may very
well result in the formation of a skin of calcium carbonate on the face of the reactive
wall. This would result in a loss of permeability, leading to contaminated groundwater
finding alternative paths through and around the system. Clogging and fouling up of
barrier walls is now coming to be seen as a problem as use of barrier walls increases. The
formation of mineral precipitates and/ or biological fouling would likely result in a
reduction of longevity and efficiency of the reactive barrier wail.

Research has shown that other potential contaminants (metals and other petroleum based
fuels) exist in concentrations that present a concern to the Illinois EPA. The current
design of the barrier wall will not accommodate these types of contaminants. Additional
reactive gates would be reguired to remediate these newly identified contaminants.

Public comment and research conducted by the Illinois EPA led to the conclusion that
substantial cost would be incurred to redesign the Reactive Barrier Wall system. A new
barrier wall design would reguire additional reactive walls, gates and materials to
remediate different forms of contamination. In addition, an increase in maintenance costs
to both the reactive portions of the wall and to any surrounding structures would result.

A comment made to the Illinois EPA (by Rockford Products) during the public comment
process stated that placement of reactive barrier wall on their property would constitute
a taking of Rockford Products Property. This issue was investigated and brought to the
attention of the Department of Legal Counsel of the Illinois EPA and representatives of
the Illinois Attorney General's Office. They concluded that placing the Reactive Wall
Barrier on Rockford Products Property might very well constitute a taking of Rockford
Products property. A takings issue does not automatically preclude usage of a given
alternative. However, it adds complicating factors for which access and/or appropriate
compensation must be negotiated. The City of Rockford, in a comment to the Illinois EPA,
expressed its concern about the utilities ( infrastructure) that lie below Kishwaukee
Avenue. This is a problem that would need to be addressed during the design phase; the
real possibility of increased hydraulic pressure of groundwater may present a problem
in dealing with the city utilities. Additional gates from a redesigned barrier wall would
reguire a higher degree of rerouting of city utilities or design problems with the
multiple gate system.

It is the decision of the Illinois EPA to select an alternative remedy for the treatment
of leachate in Area 9/10 that meets the nine criteria specified by CERCLA. The Illinois
EPA has selected alternative SCL-9/10E - Enhanced Air Sparging - as its preferred remedy.
Enhanced Air Sparging would involve the placement of air injection wells down gradient and
in the more highly-contaminated areas. Air would be injected into the contaminated
groundwater, causing the contaminants to volatilize into air pockets in the soil above the
water table. The air sparging would have to be operated in conjunction with the Soil Vapor
Extraction System SCS-9/10C. Vapors would be collected underground prior to their
treatment with activated carbon. Depending upon the further site characterization
necessary in Area 9/10, it may be necessary to design a pump and treat system that will
collect and remediate DNAPL or LNAPL in conjunction with one of the systems in the
proposed plan.
-------
SCL-9/10E: Install Injection Wells Along Boundary of the GMZ and Source Area /Install Air
Sparging Unit/Innect Air/Restriction on Groundwater Usage
This alternative includes the installation of air injection wells along the southwestern
border of the GMZ and an air-sparging unit. Additional injection wells would be installed
into hot spots of contamination (that may include areas where contaminants exist in the
form of NAPLs). Air injection into the wells would volatilize VOCs from the leachate that
would then be extracted by vacuum extraction. Air sparging would be operated in
conjunction with the SVE, with the vapors being passed through granulated organic carbon
and then released into the atmosphere. Capital costs for this method are $2,697,000;
annual operation and maintenance $65,000; total cost is $3,619,000.

The original selection of the Reactive Barrier Wall as the preferred remedy was based upon
the information available at the time and was made to remediate the entire source area 9/
10, not a particular facility. New information obtained by the Illinois EPA warrants the
selection of a new remedy, as suggested above, or a possible combination of researched
remedies. It is also possible that after further collection of information during the
design phase, additions and modifications to the preferred remedy may be reguired.

Institutional controls would be placed on groundwater usage within the GMZ, monitoring
wells would be installed and a groundwater and leachate-monitoring program would be
implemented. The estimated present worth cost for these alternatives is $7,831,000.

PNAs were identified as COCs in soils at Area 9/10. PNAs are not addressed by SCS-9/10C.
Additional data will be obtained during remedial design to determine if PNAs are truly
COCs because of industrial activities at Area 9/10, or simply contamination from other
activities (naturally occurring sources or non-industrial human activities).

If the evaluations conducted during design identify the need for remediation in addition
to that outlined within this ROD, the remedy would be appropriately altered. Depending on
the significance of the change in remedy, the agencies may be reguired to hold additional
public meetings and allow public comment on the new remedy.

The proposed alternatives for Area 9/10 will meet all RAOs for Area 9/10. Table 12
describes each RAO and how the alternatives will meet them.

Table 12. Area 9/10 Remedial Action Objectives

Remedial Action Objective -- Prevent the public from contact with soil containing
contamination in excess of state or federal standards or that poses a threat to
human health.

How Alternative will meet RAO -- Soil containing contamination in excess of
state or federal standards or that poses a threat to human health will be
treated by SVE. Increased airflow caused by SVE will remove contaminants from
soils and promote biodegradation.

Remedial Action Objective -- Prevent the public from inhalation of airborne
contaminants in excess of state or federal standards or that pose a threat to human
health.

Remedial Action Objective -- Prevent the migration of contamination from the source
area that would result in degradation of site- wide groundwater or surface water to
levels in excess of state or federal standards or that pose a threat to human health
or the environment.
-------
How Alternative will meet RAO -- Soil Vapor Extraction will remove free
product and the contamination from soils with concentrations contributing to
site-wide groundwater contamination in excess of ARARs. Enhanced air sparging
may be used to treat leachate to concentrations that meet ARARs at the GMZ
boundary.

Following a more thorough investigation, the extraction of NAPL and implementation of SVE
in combination with the enhanced air sparging would remove and treat the principal threat
wastes from Source Area 9/10. Based on information currently available, the Illinois EPA
believes the Preferred Alternative meets the threshold criteria and provides the best
balance of tradeoffs among the other alternatives with respect to the balancing and
modifying criteria. The Illinois EPA expects the Preferred Alternative to satisfy the
following statutory reguirements of CERCLA § 121(b): (1) be protective of human health and
the environment; (2) comply with ARARs (or justify waiver); (3) be cost effective; (4)
utilize permanent solutions and alternative treatment technologies or resource recovery
technologies to the maximum extent practicable; and (5) satisfy the preference for
treatment as a principal element, or explain why the preference for treatment will not be
met.

SCL-9/10B Contingent Remedy: Hydraulic Containment (leachate monitoring, containment/
collection and treatment by air striping, off-site surface discharge, and groundwater
use restrictions)

The system is designed as a leachate containment system that would consist of extraction
wells and an air-stripping unit. Leachate extracted by pumps would be sent to an
air-stripping unit at approximately 50 gallons per minute with the vapors treated with
granular activated carbon and the treated vapor being released to the atmosphere. Exact
placement of the extraction wells would be designed to treat higher concentrations of
contaminated leachate or NAPL as determined from further characterization. In addition the
pumping of leachate would also act as a hydraulic control and containment in areas of
higher contamination. Treated water from the air-stripping unit would be discharged to
off-site storm water ditch. Implementation of this system would be dependent upon the
further characterization proposed in this ROD for Source Area 9/10. Design and
construction may be tied directly into already proposed remedial design systems SCS-9/10C
and SCL-9/10 E thus constructing a multi-phase design system

AREA 11

Alternative SCS-11C (Soil Vapor Extraction) and SCL-11A (No Action) are the preferred
alternatives for Area 11. These alternatives are recommended because they would provide
substantial risk reduction by treating the source materials constituting principal threats
at the site. Alternative SCS-11C would reduce risks in the shortest amount of time for a
reasonable cost.

Under these alternatives, contaminated soils would be remediated in situ via a vapor
extraction system. Five vacuum extraction wells would be installed in locations of the hot
spots in the area. Wells would be screened in the vadose zone, where they would remove
volatile contaminants from the unsaturated zone, as well as some leachate contaminants
that may diffuse from the surface of the water table. Due to the presence of NAPL, it has
been assumed that the wells would be constructed of carbon steel, in case steam injection
is reguired. Given the presence of residual NAPL, it is expected that significant
guantities of contaminated vapors will be extracted. The vapors will be treated with a
catalytic oxidation unit.

The No Action Alternative has been selected for leachate. Institutional controls would be
placed on groundwater usage in the GMZ, approximately four additional monitoring wells
would be installed and a groundwater-and leachate-monitoring program would be implemented.

If analysis indicates that contaminants are not degrading to levels near MCLs or risk
based corrective action levels, air sparging will be considered in addition to SVE. Air
-------
sparging has the added benefit of enhancing biodegradation in both groundwater and vadose
zone soils and will address the concerns and RAOs for Area 11. The approximate additional
present worth costs for an air-sparging unit at area 11 would be $1,003,000. These costs
are not included in the current cost estimate for the preferred Area 11 alternatives.

PNAs identified as COCs in soils at Area 11 are not addressed by SCS-11C. Additional data
will be obtained during remedial design to determine if PNAs are truly COCs because of
industrial activities at Area 11, or simply contamination from other activities (naturally
occurring sources or non-industrial human activities). If the PNA evaluation conducted
during design identifies the need for remediation in addition to that outlined within this
ROD, the remedy would be appropriately altered. Depending on the significance of the
change in remedy, the agencies may be reguired to hold additional public meetings and
allow public comment on the new remedy.

The estimated total present worth cost for the Area 11 alternative is $3,482,500. The
proposed alternative for Area 11 will meet all RAOs for Area 11. Table 13 describes the
RAOs and how the Alternative will meet them.

Table 13. Area 11 Remedial Action Objectives

Remedial Action Objective -- Prevent the public from contact with soil containing
contamination in excess of state or federal standards or that poses a threat to
human health.

Remedial Action Objective -- Prevent the public from inhalation of airborne
contaminants in excess of state or federal standards or that pose a threat to human
health.

How Alternative will meet RAO -- SVE will remove free product and the
contamination from soils with concentrations contributing to site- wide
groundwater contamination in excess of ARARs. Computer modeling coupled with
groundwater analysis will ensure that groundwater contamination will
biodegrade at rates such that Area 11 leachate will not result in degradation
of site-wide groundwater.
Soil Vapor Extraction would promote the continued natural attenuation of the principal
threat wastes and treat the surrounding materials. Based on information currently
available, the lead agency believes the Preferred Alternative meets the threshold criteria
and provides the best balance of tradeoffs among the other alternatives with respect to
the balancing and modifying criteria. The Illinois EPA expects the Preferred Alternative
to satisfy the following statutory reguirements of CERCLA § 121( b): (1) be protective of
human health and the environment; (2) comply with ARARs (or justify waiver); (3) be cost
effective; (4) utilize permanent solutions and alternative treatment technologies or
resource recovery technologies to the maximum extent practicable; and (5) satisfy the
preference for treatment as a principal element, or explain why the preference for
treatment will not be met.
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COST ESTIMATE
Table 14
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT AREA 4
ALTERNATIVE SCS-4D REVISED 2: TOTAL DEMOLITION, EXCAVATION, AND ON-SITE
THERMAL TREATMENT DETAILED COST ESTIMATE - COMMENTS
COST COMPONENT COMMENTS
General
construction trailer (rental and
delivery)
Mobilization
Demobilization
decon trailer
vehicle decon station
vehicle decon equipment
health and safety equipment
electrical power service supply
dust control
Demolition
Total Demolition
Excavation and On-Site Thermal
Treatment
mobilization/demobilization
pad for staging
temporary enclosure (rental - 88' wide
by 200' long)
Excavation
soil treatment
backfill and compaction
water supply
sheet piling
Excavation Dewatering (well point
system)
Completely furnish, install, operate,
and remove system: well points spaced
20' O.C.
Analytical
T&D cost (15 GPM produced)
rental of (2) 21,000 gallon tanks
Post Treatment Sampling
Analytical for Volatile
Organic Compounds (soils)
shipping and handling

50' x 12' construction trailer - $1 .65/mi delivery fee (lOOmi) - rental allowance per 1996 Means
Heavy equipment and trailers, per vendor estimate
Allowance for trailer and equipment demobilization
Allowance based on COM equipment rates
20' x 20' gravel pad over 1 1 mil plastic with plywood and joist deck per 1996 Means
Steam cleaning and water tank per 1996 Means
Allowance based on CDM equipment rates
Based on expected electrical costs per month for this alternative
Water truck per 1996 Means

Building Demolition, large urban projects, mixture of materials types per Means 1999

Transportation of the Indirect Heat and Volatilization unit (IHV), front loader, and the time
involved for set-up for set up and tear down (vendor estimate)
Pad size approx. 200'x200' crushed stone or asphalt (vendor estimate)
Sprung Instant Structure - vendor estimate; construct/install, costs include labor and heavy equip.
Excavation cost (vendor estimate)
Vendor Estimate for Direct Fired Low Temperature Thermal Desorption (includes providing a loader and
loader and operator to place contaminated soil into the cold feed bin and for restockpiling the clean
processed reprocessed soil);
Backfill and compaction of clean soil from stockpiling (vendor estimate)
10 GPM is needed for operation of the thermal treatment system (4,800 gpd if run for 8hrs/day),
costs based on constructions site water average per 1996 Means - typical
based on
Steel sheets, approx. 4' x 40' around perimeter of excavation; as per CDM experience

Based on vendor estimate - More Trench American (June 1998); System operation 24 hours/day,
days/week with diesel pumps.
7
Based on CDM Experience
Based on CDM Experience
Based on CDM Experience

Based on 1998 sample analysis costs from Midwest laboratories; samples collected on a grid of :
sample/250cy; 1 sampling grid per month (including QA/QC samples)
grid of 1
Cost associated with transporting samples from site to laboratory twice per month
In general, a bulk density of 1.5 tons/yd
of material is given in cubic yards.
was assumed for soils material - this conversion was used for conversion of pricing given per ton, where volume
95
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Table 15
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT - AREA 4
ALTERNATIVE SCS-4D REVISED 1: PARTIAL DEMOLITION, EXCAVATION, AND ON-SITE
THERMAL TREATMENT DETAILED COST ESTIMATE
COST COMPONENT
General
construction trailer (rental and
delivery)
Mobilization
Demobilization
decon trailer
vehicle decon station
vehicle decon equipment
health and safety equipment
electrical power service supply
dust control
Demolition
Partial Demolition
Excavation and On-Site Thermal
Treatment
mobilization/demobilization
pad for staging
temporary enclosure (rental - 88'
wide by 200' long)
Excavation
soil treatment
backfill and compaction
water supply (10 GPM)
sheet piling
Excavation Dewatering (well point
system)
Completely furnish, install, operate,
and remove system: well points
spaced 20' O.C.
analytical
T&D cost (15 GPM produced)
rental of (2) 21,000 gallon tanks
Post Treatment Sampling
Analytical for Volatile Organic
Compounds (soils)
shipping and handling
Unit No. Units Unit Cost

Mo
Is
Is
Ea
Ea
Ea
Mo
Mo
Mo

Ls
Ls
Mo
Ton
Ton
Ton
Mo
Lf

Mo
Batch
Gallon
Mo

Ea
Ea

3
1
1
1
1
1
3
3
3

30,000

1
1
3
12,579
4,080
12,579
3
360

1
52
1,132,900
3

58
4

$275
$10,000
$10,000
$5,000
$10,000
$570
$4,500
$400
$230

$0.25

$23,500
$10,000
$9,563
$5.00
$53.00
$2.00
$1,500
$800

$250,000
$1,000
$0.20
$1,000

$200
$50
Capital Cost Construction/ Annual Start-up &
Installation O&M Baseline
Costs Costs Costs
$51,785
$825
$10,000
$10,000
$5,000
$10,000
$570
$13,500
$1,200
$690
$7,500
$7,500
$658,982
$25,500
$10,000
$28,689
$62,895
$216,240
$25,158
$4,500
$288,000
$281,580

$52,000
$226,580
$3,000
$11,800
$11,600
$200
$0

$60,000

$250,000
$250,000

96
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Table 16
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT
ROCKFORD, ILLINOIS
FEASIBILITY STUDY

SOURCE AREA 4
ALTERNATIVE SCS-4D REVISED 1: PARTIAL DEMOLITION, EXCAVATION, AND ON-SITE THERMAL
TREATMENT
Item/Description
Total Cost
CAPITAL COSTS
General
Demolition/ Construction
Excavation / On-Site Thermal Treatment
Excavation Dewatering
Post Treatment Sampling
SUBTOTAL CONSTRUCTION COSTS (1)
$52,000
$99,000
$719,000
$532,000
$12,000
$1,414,000
Bid Contingency (15%)
Scope Contingency (15%)
Engineering and Design (15%)
Oversight/Health and Safety (5%)
TOTAL CAPITAL COSTS
$212,000
$212,000
$212,000
$71,000
$2,121,000
ANNUAL OPERATING AND MAINTENANCE COSTS
General Maintenance ofThermal Treatment System
TOTAL ANNUAL COSTS
$0
$0
REPLACEMENT COSTS
TOTAL REPLACEMENT COSTS (2)
$0
PRESENT WORTH ANALYSIS
Total Capital Costs (from above)(3)
Present Worth Annual O&M Costs (4)
Present Worth Replacement Costs
TOTAL PRESENT WORTH
(1) Capital costs for construction items do not include oversight fees, which are accounted for separately.
(2) Replacement costs include construction and oversight capital costs.
(3) Capital costs represent the present worth of the given alternative.
(4) Present worth of annual O&M costs is based on a 7% annual discount rate over a project life of 3 months.
$2,121,000
$0
$0
$2,121,000
97
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Table 17
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT
FOCUSED FEASIBILITY STUDY
ROCKFORD, ILLINOIS
AREA 4 -LEACHATE
ALTERNATIVE SCL-4B: LIMITED ACTION / LEACHATE MONITORING / LEACHATE COLLECTION AND
TREATMENT BY AIR STRIPPING UNIT / OFF-SITE SURFACE WATER DISCHARGE / GROUNDWATER USE
RESTRICTIONS
COST SUMMARY
Item/Description
Total Cost
CAPITAL COSTS
Groundwater Use Restrictions
Leachate Containment System
Leachate Monitoring Wells
SUBTOTAL CONSTRUCTION COSTS (1)
$25,000
$118,000
$18,000
$161,000
Bid Contingency (15%)
Scope Contingency (20%)
Engineering and Design (15%)
Oversight/Health and Safety (5%)
TOTAL CAPITAL COSTS
$24,000
$32,000
$24,000
$8,000
$249,000
ANNUAL OPERATING AND MAINTENANCE COSTS
Leachate Containment System
Granular Activated Carbon
Leachate Containment System Sampling and Analysis (per event)
Leachate Sampling and Analysis (per event)
TOTAL ANNUAL COSTS
$7,000
$31,000
$4,000
$5,000
$47,000
REPLACEMENT COSTS (2)
Leachate Containment System (every 15 years)
Monitoring Well Replacement (every 15 years)
TOTAL REPLACEMENT COSTS
$78,000
$29,000
$107,000
PRESENT WORTH ANALYSIS
Total Capital Costs (from above)(3)
Present Worth Annual O&M Costs (4)
Leachate Containment System
Quarterly Sampling - years 1 through 30
Leachate Monitoring Wells
Quarterly Sampling - years 1 and 2
Semi-annual Sampling - years 3 through 30
Present Worth Replacement Costs (5)
TOTAL PRESENT WORTH
$249,000
$472,000

$200,000

$37,000
$106,000
$53,000
$1,117,000
(1) Capital costs for construction items do not include oversight fees.
(2) Replacement costs include construction and oversight capital costs.
(3) Capital costs represent the present worth of the given alternative.
30-year projection (Based on RCRA Closure Guidelines).
monitoring wells replacement and leachate collection system (including
extraction wells, piping, pumps, and air stripping unit) every 15 years.
98
-------
Table 18
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT, AREA 7 - ALTERNATIVE SCL-7E: SOIL VAPOR
EXTRACTION (SVE)/AIR SPARGING (AS) ALONG GMZ BOUNDARY AND SOURCE AREA / MONITORING /
GROUNDWATER USE RESTRICTIONS DETAILED COST ESTIMATE COMMENTS
COST COMPONENT COMMENTS
Groundwater Use Restrictions
legal fees
General
construction trailer (rental and delivery)
Mobilization
Demobilization
decon facilities
health and safety equipment
electrical power service connection
electrical power service supply
water supply
Monitoring Wells
Leachate monitoring well installation and materials
Performance monitoring well installation and materials
Leachate and Containment System Sampling
and Analysis
Labor
Vehicle
Equipment
Miscellaneous
leachate laboratory analysis
Vapor Recovery System (VRS)
VRS well installation
VRS main system
VRS control panels
6" carbon steel pipe
4" carbon steel pipe
Excavation for piping placement (4 foot depth)
electrical power requirements (10 HP)
VRS treatment building
air/water separator tank
air/water separator tank - condensate disposal
catalytic oxidation
Natural Gas

Cost based on CDM experience

50' x 12' construction trailer. $1.65/mi delivery fee (lOOmi), rental allowance per 1996
Means
Heavy equipment and trailers, per vendor estimate
Allowance for trailer and equipment demobilization
Based on level of personal and vehicle decontamination anticipated for this alternative
Allowance based on CDM equipment rates
Based on CDM experience
Based on expected electrical costs per month for this alternative
Based on expected use per month for this alternative (e.g., decon, personnel use)

Cost based on CDM experience in monitoring well installation
Cost based on CDM experience in monitoring well installation

Based on 10 hour work day at average CDM labor rate of $60 for oversight personnel
Based on $300/week rental fee for a field vehicle
Based on CDM equipment rental rates
Incidental expenses (minor repairs, replacement of equipment, local purchases, etc)
Based on average cost incurred for VOC analysis; One duplicate and one blank will be
collected per 10 samples.

Cost associated with installation of SVE wells. Based on CDM experience.
Vendor: includes blower, exp motor, inline air filter, silencers, dilution valve, moisture
separator, condensate transfer pump, high condense, level alarm, vac. relief valve, vac.
gauges, skid mounting, interconnecting piping and man, motor start switch
Vendor estimate - NEEP (May 1998)
Based on CDM experience
Based on CDM experience
12" wide trench and backfill, 48" deep as per 2000 Means
Based on 3-phase power, working 24 hrs/day, $0.09/kW-hr
Basic prefabricated building on concrete pad. Based on CDM experience.
Based on CDM Experience
Based on CDM experience
Based on CDM experience
Based on CDM experience
99
-------
Table 18 Continued
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT, AREA 7 - ALTERNATIVE SCL-7E: SOIL VAPOR
EXTRACTION (SVE)/AIR SPARGING (AS) ALONG GMZ BOUNDARY AND SOURCE AREA / MONITORING /
GROUNDWATER USE RESTRICTIONS DETAILED COST ESTIMATE COMMENTS
COST COMPONENT COMMENTS
Air Sparging (AS)
As well installation
AS main system
AS control panels
6" carbon steel piping
4" carbon steel piping
excavation for piping placement
condensate disposal
electrical power requirements (25 HP)
AS treatment building
air/water separator tank
Catalytic oxidation treatment

Cost associated with installation of AS wells. Based on CDM experience.
Vendor: includes blower, exp motor, inline silencer, pressure relief valve, unitized base,
pressure gauge and a manual motor starting switch.
Vendor estimate
Based on CDM experience
Based on CDM experience
12" wide trench and backfill, 48" deep as per 2000 Means
Based on CDM experience
Based on 3-phase power, working 24 hrs/day, $0.09/kW-hr
Costs for AS treatment building included with corresponding VRS
Costs for air/water separator tank included with corresponding VRS
Costs for catalytic oxidation treatment included with corresponding VRS
100
-------
Table 19
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT, AREA 7 ALTERNATIVE SCL-7E: SOIL VAPOR
EXTRACTION (SVE)/AIR SPARGING (AS) ALONG GMZ BOUNDARY AND SOURCE AREA / MONITORING /
GROUNDWATER USE RESTRICTIONS DETAILED COST ESTIMATE COMMENTS
COST COMPONENT COMMENTS
Groundwater Use Restrictions
legal fees
General
construction trailer (rental and delivery)
Mobilization
Demobilization
decon facilities
health and safety equipment
electrical power service connection
electrical power service supply
water supply
Monitoring Wells
Leachate monitoring well install. & materials
Performance monitoring well install. & matl.
Leachate and Containment System
Sampling and Analysis
Labor
Vehicle
Equipment
Miscellaneous
leachate laboratory analysis
Vapor Recovery System (VRS)
VRS well installation
VRS main system
VRS control panels
6" carbon steel pipe
4" carbon steel pipe
Excavation-piping placement (4 foot depth)
electrical power requirements (10 HP)
VRS treatment building
air/water separator tank
air/water separator tank condensate disposal
catalytic oxidation
Natural Gas

Cost based on CDM experience

50' x 12' const, trailer, $1.65/mi delivery fee (lOOmi), rental allowance per 1996 Means
Heavy equipment and trailers, per vendor estimate
Allowance for trailer and equipment demobilization
Based on level of personal and vehicle decontamination anticipated for this alternative
Allowance based on CDM equipment rates
Based on CDM experience
Based on expected electrical costs per month for this alternative
Based on expected use per month for this alternative (e.g., decon, personnel use)

Cost based on CDM experience in monitoring well installation
Cost based on CDM experience in monitoring well installation

Cost associated with installation of SVE wells. Based on CDM experience.
Vendor: includes blower, exp motor, inline air filter, silencers, dilution valve, moisture
separator, condensate transfer pump, high condense, level alarm, vac. relief valve, vac.
gauges, skid mounting, interconnecting piping and manual motor start switch
Vendor estimate - NEEP (May 1998)
Based on CDM experience
Based on CDM experience
12" wide trench and backfill, 48" deep as per 2000 Means
Based on 3-phase power, working 24 hrs/day, $0.09/kW-hr
Basic prefabricated building on concrete pad. Based on CDM experience.
Based on CDM experience
Based on CDM experience
Based on CDM experience
Based on CDM experience
101
-------
Table 19 Continued
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT, AREA 7 ALTERNATIVE SCL-7E: SOIL VAPOR
EXTRACTION (SVE)/AIR SPARGING (AS) ALONG GMZ BOUNDARY AND SOURCE AREA / MONITORING /
GROUNDWATER USE RESTRICTIONS DETAILED COST ESTIMATE COMMENTS
COST COMPONENT COMMENTS
Air Sparging (AS)
As well installation
AS main system
AS control panels
6" carbon steel piping
4" carbon steel piping
excavation for piping placement
condensate disposal
electrical power requirements (25 HP)
AS treatment building
air/water separator tank
catalytic oxidation treatment

Cost associated with installation of AS wells. Based on CDM experience.
Vendor: includes blower, exp motor, inline silencer, pressure relief valve, unitized base,
pressure gauge and a manual motor starting switch.
Vendor estimate
Based on CDM experience
Based on CDM experience
12" wide trench and backfill, 48" deep as per 2000 Means
Based on CDM experience
Based on 3-phase power, working 24 hrs/day, $0.09/kW-hr
Costs for AS treatment building included with corresponding VRS
Costs for air/water separator tank included with corresponding VRS
Costs for catalytic oxidation treatment included with corresponding VRS
102
-------
Table 20
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT -AREA 7 ALTERNATIVE SCL-7E SOIL VAPOR
EXTRACTION (SVE) AIR SPARGING (AS) ALONG GMZ BOUNDARY AND SOURCE AREA/MONITORING/
GROUNDWATER USE RESTRICTIONS DETAILED COST ESTIMATE
COST COMPONENT Unit No. Units Unit
Cost
Groundwater Use Restrictions
legal fees
General
Const, (rental and delivery)
Mobilization
Demobilization
Decon facilities
health and safety equipment
Electrical pwr service connection
Electrical pwr service supply
Water supply
Pilot Scale Study
Monitoring Wells
Monitoring well install. & materials
Monitoring well install. & materials
Monitoring Well Sampling
Analysis (per Sampling event)
Labor
Vehicle
Equipment
Miscellaneous
Leachate laboratory analysis
Quarterly reports
Vapor Recovery System (VRS)
VRS well installation
VRS main system
VRS control panels
6" carbon steel piping
4" carbon steel piping
Excavation for piping placement
Electrical pwr reqmnts (10 HP)
VRS treatment building (2 bldgs)
Air/water separator tank
Air/water separator tank
cond.disp.-
Catalytic Oxidation System
Natural Gas

mo
Is
Is
e
M
Is
M
M
Is

Well
well

Hours
Day
Is
Is
Each
Each

Each
Is
Is
ft.
ft
ft.
yr.
yr
Is
Gal
Is
Is

3
1
1
1
3
1
3
3
1

5
15

40
2
1
1
20
4

16
2
2
3000
500
3500
1
800
2
260
1
1

$25,000

$275
$1000
$1000
$1000
$2000
$5000
$400
$200
$150,000

$6000
$6000

$60
$60
$600
$1000
$230
$5000

$6000
$50,000
$10,000
$57
$32
$4.41
$20,000
$180
$10,000
$25
$200,000
$10,000
Capital Cost Construction / Annual Start-up &
Installation O&M Costs Baseline
Costs Costs
$25,000
$25,000
$76,625
$825
$1,000
$1,000
$1,000
$6,000
$5,000
$1,200
$600
$60,000
$0

$671,000

$100,000
$20,000
$171,000
$16,000

$144,000
$20,000

$200,000

$40,000

$40,000
$120,000
$30,000
$90,000
$0

$132,435
$96,000
$20,000
$1,000

$15,435

Included

$24,000

$28,000
$2,400
$120
$600
$500
$4,600
$20,000
$112,700

$20,000
$4,000
$5,000
$3,200

$20,000

$4,000
$6,500
$40,000
$10,000
$0

$50,000

$50,000
$0

$25,000

103
-------
Table 20 Continued
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT -AREA 7 ALTERNATIVE SCL-7E SOIL VAPOR
EXTRACTION (SVE) AIR SPARGING (AS) ALONG GMZ BOUNDARY AND SOURCE AREA/MONITORING/
GROUNDWATER USE RESTRICTIONS DETAILED COST ESTIMATE
COST COMPONENT
Air Sparging (AS)
As well installation
AS main system
AS control panels
6" carbon steel piping
4" carbon steel piping
Excavation for piping placement
Condensate disposal
Electrical pwr. Reqmnts. (25 HP)
AS treatment building
Air/water separator
Catalytic oxidation treatment
Unit
Each
Is
Is
If
If
If
Gal
year

No. Units
57
1
1
3000
500
3500
520
1

Unit
Cost
$6,000
$100,000
$3,000
$57
$32
$4.41
$25
$25,000

Capital Cost
$290,000

$100,000
$3,000
$171,000
$16,000

Construction /
Installation
Costs
$378,935
$342,000
$20,000
$1,500

$15,435

Annual
O&M Costs
$96,000

$20,000
$600
$34,200
$3,200

$13,000
$25,000

Start-up &
Baseline
Costs
$25,000

$25,000

104
-------
Table 21
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT
ROCKFORD, ILLINOIS
FOCUSED FEASIBILITY STUDY
SOURCE AREA 7
ALTERNATIVE SCS-7E: SOIL VAPOR EXTRACTION (SVE)/AIR SPARGING (AS) ALONG SOURCE AREA /
MONITORING / GROUNDWATER USE RESTRICTIONS
COST SUMMARY
Item/Description
Total Cost
CAPITAL COSTS
Groundwater Use Restrictions
General
Leachate Monitoring Wells
VRS
Air Sparging
SUBTOTAL CONSTRUCTION COSTS (1)
$25,000
$167,000
$120,000
$828,000
$694,000
$1,834,000
Bid Contingency (15%)
Scope Contingency (20%)
Engineering and Design (15%)
Oversight/Health and Safety (5%)
TOTAL CAPITAL COSTS
$275,000
$367,000
$275,000
$92,000
$2,843,000
ANNUAL OPERATING AND MAINTENANCE COSTS
General $24,000
VRS Regular Maintenance/Electrical $113,000
Leachate Sampling and Analysis (per event) $28,000
Regular System Maintenance/Electrical $96,000
TOTAL ANNUAL COSTS $237,000
REPLACEMENT COSTS
Leachate Monitoring Wells (every 15 years)
Equipment Replacement (e.g., motors, blowers) -
every 15
TOTAL REPLACEMENT COSTS (2)
$29,000

$30,000
$59,000
PRESENT WORTH ANALYSIS
Total Capital Costs (from above)(3)
Present Worth Annual O&M Costs (4)
Leachate Sampling
Quarterly Sampling - years 1 and 2
Semi-annual Sampling - years 3 through 10
Present Worth Replacement Costs (5)
TOTAL PRESENT WORTH
$2,843,000
$1,636,000

$207,000
$295,000
$4,981,000
(1) Capital costs for construction items do not include oversight fees, which are accounted for separately.
(2) Replacement costs include construction and oversight capital costs.
(3) Capital costs represent the present worth of the given alternative.
(4) Present worth of annual O&M costs is based on a 7% discount rate over 10 years.
(5) Present worth of replacement costs is based on a 7% annual discount rate and no replacement of leachate monitoring wells and system
equipment.
105
-------
Table 22
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT AREA 7 LEACHATE ALTERNATIVE SCL-7B
MULTI-PHASE EXTRACTION / COLLECT LEACHATE AND TREAT BY AIR STRIPPING UNIT / DISCHARGE TO
ON-SITE SURFACE WATER / GROUNDWATER USE RESTRICTIONS / MONITORING
DETAILED COST ESTIMATE - COMMENTS
COST COMPONENT
Groundwater Use Restrictions
legal fees
Leachate Containment System
mobilization/demobilization for all
treatment building
electrical supply
extraction well installation
pump materials installation
2" dia. carbon steel pipe, from well to
header
4 " dia. carbon steel header pipe to Central
Pump Station
Central Pump Station
4" dia. carbon steel pipe from Central
Pump Station to air stripper unit
air stripping treatment unit and installation
4 " discharge pipe to creek
Leachate Monitoring Wells
well installation and materials
Leachate Treatment System Sampling and Analyst
Labor
Vehicle
Equipment
Miscellaneous
leachate treatment system laboratory
analysis
Leachate Monitoring Well Sampling and Analysis
Labor
Vehicle
Equipment
Miscellaneous
leachate laboratory analysis
COMMENTS

Cost based on CDM experience

Cost based on CDM experience
Based on 20 foot x 20 foot bldg. - cost based on Butler Building April 1998 estimate
Based on CDM experience
4" diameter, stainless steel construction, 35 foot depth with 10 foot screen - cost based on CDM
experience of average extraction well installation costs.
1 pump per well (2 spare) @ 1 .2 to 7 gpm flow with/control box each pump - costs based on April
1998 Grundfos cost estimate
2" diameter carbon steel pipe, 10 foot linkages from each of the 9 wells to treatment unit (with
15% contingency) - cost based on CDM experience
4" diameter carbon steel pipe, 10 foot linkages from header pipe to Central Pumping Station (with
15% contingency) - cost based on CDM experience
Includes controls - cost based on CDM experience
4" diameter carbon steel pipe, 10 foot linkages from Central Pumping Station to treatment unit
(with 15% contingency) - cost based on CDM experience
Shallow Tray air stripper model 263 1 with options - cost based on April 1998 North East
Environmental Products, Inc. cost estimate
4" diameter carbon steel pipe, 10 foot linkages from treatment unit to Creek (with 15%
contingency) - cost based on CDM experience

Cost based on CDM experience in monitoring well installation
s (per sampling event)
Based on 10 hour work day at average CDM labor rate of $60 for oversight personnel
Based on $60/day rental fee for a field vehicle
Based on CDM equipment rental rates
Incidental expenses (minor repairs, replacement of equipment, local purchases, etc)
ts analysis; One duplicate and one blank will be collected per 10 samples.
per sampling event)
Based on 10 hour work day at average CDM labor rate of $60 for oversight personnel
Based on $60/day rental fee for a field vehicle
Based on CDM equipment rental rates
Incidental expenses (minor repairs, replacement of equipment, local purchases, etc)
Based on average cost incurred for volatile organic compound analysis; One duplicate and one
blank will be collected per 10 samples.
106
-------
Table 22 Continued
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT AREA 7 LEACHATE ALTERNATIVE SCL-7B
MULTI-PHASE EXTRACTION/ COLLECT LEACHATE AND TREAT BY AIR STRIPPING UNIT / DISCHARGE TO
ON-SITE SURFACE WATER / GROUNDWATER USE RESTRICTIONS/MONITORING
DETAILED COST ESTIMATE - COMMENTS
COST COMPONENT
Multi-Phase Extraction in Source Areas
Multi-Phase Wells (40ft., 4 inch PVC with
development
MPE System including enclosure
Piping (2 in. PVC @ 3ft. bgs)
Air Stripper System Expansion
Pilot Study
O&M Materials andLabor
Electricity
Expanded Air Stripper O&M
Expanded Air Stripper / Catalytic Oxidation
Natural Gas
Multi-Phase Extraction Monitoring
Multi-Phase Extraction Monitoring Wells
Continuous Recorders Multi-Phase MWs
Pressure Monitoring Points
Geophysical Survey
Mob/Demob
Per Diem
Gamma Ray Logs
EM-39Logs
SIP and VIP offset Logging Stations
COMMENTS

Based on CDM experience
Based on Carbon Air cost estimate
Based on CDM experience
Based on Carbon Air cost estimate
Based on CDM experience
Based on Carbon Air cost estimate
Based on Carbon Air cost estimate
Based on Carbon Air cost estimate
Based on Carbon Air cost estimate

Based on CDM experience
Based on CDM experience
Based on CDM experience

Based on Ground Truth Environmental cost estimate
Based on Ground Truth Environmental cost estimate
Based on Ground Truth Environmental cost estimate
Based on Ground Truth Environmental cost estimate
Based on Ground Truth Environmental cost estimate
107
-------
Table 23
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT AREA 7 LEACHATE ALTERNATIVE SCL-7B
MULTI-PHASE EXTRACTION/ COLLECT LEACHATE AND TREAT BY AIR STRIPPING UNIT/DISCHARGE
TO ON-SITE SURFACE WATER / GROUNDWATER USE RESTRICTIONS/MONITORING
DETAILED COST ESTIMATE
COST COMPONENT Unit No. Units Unit
Cost
Groundwater Use Restrictions
legal fees
Leachate Containment System
mobilization/demobilization
treatment building
electrical supply
extraction well materials and installation
pump materials and installation
2" dia. carbon steel pipe from well to
header pipe
4 " dia. carbon steel header pipe to
Central Pump Station
Central Pump Station
4" dia. carbon steel pipe from Central
Pump Station to air stripper unit
air stripping treatment unit and
installation
4 " carbon steel discharge pipe to creek
Leachate Monitoring Wells
well installation and materials
Leachate Treatment System Sampling
and Analysis (per sampling event)
labor
vehicle
equipment
miscellaneous
leachate treatment system laboratory
analysis
Leachate Monitoring Well Sampling
and Analysis (per sampling event) (1)
labor
vehicle
equipment
miscellaneous
leachate laboratory analysis

Is
Is
Is
Is
well
pump
feet
feet
Is
feet
unit
feet

well

hours
day
Is
Is
each

hour
day
Is
Is
each

1
1
1
1
8
10
160
2,000
1
300
1
500

10
1
1
1
9

60
3
1
1
11

$25,000
$5,000
$40,000
$5,000
$5,800
$2,000
$25
$32
$54,500
$32
$50,000
$32

$4,500

$60
$60
$600
$1,000
$1,000

$60
$60
$600
$1,000
$130
Capital Cost Construction/ Annual Start-up &
Installation O&M Costs Baseline
Costs Costs
$25,000
$25,000
$268,100
$5,000
$40,000
$5,000

$20,000
$40,000
$64,000
$54,500
$9,600
$50,000
$16,000
$0

$0
$52,400

$46,400
$1,000

$5,000

$22,500
$22,500
$0

$0
$17,500

$2,500

$5,000

$10,000

$3,760
$600
$60
$600
$500
$2,000
$6,310
$3,600
$180
$600
$500
$1,430
$0
$0

108
-------
Table 23 Continued
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT AREA 7 LEACHATE ALTERNATIVE SCL-7B
MULTI-PHASE EXTRACTION/ COLLECT LEACHATE AND TREAT BY AIR STRIPPING UNIT/DISCHARGE
TO ON-SITE SURFACE WATER / GROUNDWATER USE RESTRICTIONS/MONITORING
DETAILED COST ESTIMATE
COST COMPONENT Unit No. Units Unit
Cost
Multi-Phase Extraction in Source Areas
Multi-Phase Wells (40ft., 4 inch PVC with
development
MPE System including enclosure
Piping (2 in. PVC @ 3ft. bgs)
Air Stripper System Expansion
Pilot Study
O&M Materials andLabor
Electricity
Expanded Air Stripper O&M
Expanded Air Stripper / Catalytic Oxidation
Natural Gas
Multi-Phase Extraction Monitoring
Multi-Phase Extraction Monitoring Wells
Continuous Recorders for Multi-Phase MWs
Pressure Monitoring Points
Geophysical Survey
Mob/Demob
Per Diem
Gamma Ray Logs
EM-39Logs
SIP and VIP offset Logging Stations

Each
Ls
Lf
Ls
Ls
Ls
Ls
Ls
Ls
Ls

Each
Each
Each

Ls
Ls
Well
Well
Station

10
1
2000
1
1
1
1
1
1
1

6
6
9

1
1
6
6
612

$6,000
$200,000
$20
$75,000
$50,000
$55,000
$9,500
$7,000
$7,000
$14,000

$4,500
$2,000
$500

$2,000
$5,000
$175
$175
$125
Capital Cost Construction/ Annual Start-up &
Installation O&M Costs Baseline
Costs Costs
$425,000
$60,000
$200,000
$40,000
$75,000
$50,000

$43,500
$27,000
$12,000
$4,500
$85,600
$2,000
$5,000
$1,050
$1,050
$76,500
$0

$92,500

$55,000
$9,500
$7,000
$7,000
$14,000
$0

TOTAL OF ALL ITEMS LISTED BELOW PER ALTERNATIVE
(1) The monitoring schedule over 30 years was assumed as:
Years 1,2 = quarterly sampling: Years 3 through 30= semi-annual sampling (Based on RCRA Closure Guidelines)
These costs are incorporated in each alternative's cost summary under "Annual Operation and Maintenance."
109
-------
Table 24
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT FOCUSED FEASIBILITY STUDY
AREA 7 LEACHATE ALTERNATIVE SCL-7B: MULTI-PHASE EXTRACTION/COLLECT LEACHATE
AND TREAT BY AIR STRIPPING UNIT / DISCHARGE TO ON-SITE SURFACE WATER / GROUNDWATER USE
RESTRICTIONS/MONITORING
COST SUMMARY
Item/Description
Total Cost
CAPITAL COSTS
Groundwater Use Restrictions
Leachate Containment System
Leachate Monitoring Wells
Multiphase Extraction in Source Areas
Multiphase Extraction Monitoring
Geophysical Survey
SUBTOTAL CONSTRUCTION COSTS (1)
Bid Contingency (15%)
Scope Contingency (20%)
Engineering and Design (15%)
Oversight/Health and Safety (5%)
TOTAL CAPITAL COSTS
$25,000
$321,000
$23,000
$425,000
$44,000
$924,000
$139,000
$185,000
$139,000
$46,000
$1,433,000
ANNUAL OPERATING AND MAINTENANCE COSTS
Leachate Containment System
Leachate Treatment System Sampling and Analysis (per sampling event)
Leachate Sampling and Analysis (per sampling event)
Multi-Phase Extraction in Source Areas
TOTAL ANNUAL COSTS
$18,000
$4,000
$6,000
$93,000
$121,000
REPLACEMENT COSTS (2)
Leachate Containment System (every 15 years)
Monitoring Well Replacement (every 15 years)
TOTAL REPLACEMENT COSTS
$281,000
$44,000
$325,000
PRESENT WORTH ANALYSIS
Total Capital Costs (from above)(3)
Present Worth Annual O&M Costs (4)
Leachate Treatment System Sampling
Quarterly Sampling - years 1 through 30
Leachate Sampling
Quarterly Sampling - years 1 and 2
Semi-annual Sampling - years 3 through 30
Present Worth Replacement Costs (5)
TOTAL PRESENT WORTH
$1,433,000
$467,000

$200,000

$44,000
$128,000
$150,000
$2,422,000
(1) Capital costs for construction items do not include oversight fees.
(2) Replacement costs include construction and oversight capital costs.
(3) Capital costs represent the present worth of the given alternative.
(4) The "Present Worth Annual O&M Cost" line item includes all annual costs except for costs per sampling and analysis event. Costs incurred for
sampling and analysis are broken down per sampling schedule as listed. Sampling and analysis costs are based on a 7% discount rate over a 30
year projection for the Multi-Phase Extraction System (Based on RCRA Closure Guidelines).
(5) Present worth of replacement costs is based on a 7% annual discount rate and replacement of monitoring wells and leachate containment
system (including central pump station, extraction wells, piping, pumps, and air stripping unit) every 15 years (twice over 30-year projection)
110
-------
Table 25
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT SOURCE AREA 11 LEACHATE
ALTERNATIVE SCL-11A: NO ACTION / LEACHATE MONITORING / NATURAL ATTENUATION /
GROUNDWATER USE RESTRICTIONS
DETAILED COST ESTIMATE - COMMENTS
COST COMPONENT
legal fees
Leachate Monitoring Wells
well installation and materials
Leachate Monitoring Well
Sampling and Analysis (per sampling event)
labor
vehicle
equipment
miscellaneous
leachate laboratory analysis
Air Sparging (AS)
AS well installation
AS main system
AS control panels
6" carbon steel piping
4" carbon steel piping
excavation for piping placement
condensate disposal
electrical power requirements (25 HP)
AS treatment building
air/water separator tank
catalytic oxidation treatment
COMMENTS

Cost based on CDM experience

Cost based on CDM experience in monitoring well installation

Based on 10 hour work day at the average CDM labor rate of $60 for over site personnel
Based on $60/day rental fee for a field vehicle
Based on CDM equipment rental rates
Incidental expenses (minor repairs, replacement of equipment, local purchases, etc)
Based on average cost incurred for VOCs and bioparameters; One duplicate and one blank will be
collected per 10 samples.

Cost associated with installation of AS wells. Based on CDM experience.
Vendor: includes blower, exp motor, inline silencer, pressure relief valve, unitized base, pressure
gauge and a manual motor starting switch.
Vendor estimate
Based on CDM experience
Based on CDM experience
12" wide trench and backfill, 48" deep as per 2000 Means
Based on CDM experience
Based on 3-phase power, working 24 hrs/day, $0.09/kW-hr
Costs for AS treatment building included with corresponding VRS
Costs for air/water separator tank included with corresponding VRS
Costs for catalytic oxidation treatment included with corresponding VRS
111
-------
Table 26
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT SOURCE AREA 11 - LEACHATE
ALTERNATIVE SCL-11A: NO ACTION /LEACHATE MONITORING /NATURAL ATTENUATION/GROUNDWATER
USE RESTRICTIONS
DETAILED COST ESTIMATE
COST COMPONENT Unit No. Units Unit Cost
Groundwater Use Restrictions
legal fees
Leachate Monitoring Wells
Well installation and materials
Sampling and Analysis (per
sampling event)
Labor
Vehicle
Equipment
Miscellaneous
Leachate laboratory analysis
Air Sparging
AS well installation
AS main system
AS control panels
6" carbon steel piping
4" carbon steel piping
Excavation for piping placement
Condensate disposal
Electrical power requirements
AS treatment building
air/water separator tank
catalytic oxidation treatment

Is
well
hours
day
Is
Is
each

each
Is
Is
If
If
If
gal
year

1
4
60
3
1
1
8

13
1
1
500
100
600
100
1

$25,000
$4,500
$60
$60
$1,000
$1,500
$380

$6,000
$100,000
$3,000
$57
$32
$4.41
$25
$25,000
Capital Cost Construction Annual O&M Costs Start-up &
/ Installation Baseline
Costs Costs
$25,000
$25,000
$0
$0

$134,000

$100,000
$3,000
$28,500
$3,200

$0
$18,000
$18,000
$0

$102,146
$78,000
$20,000
$1,500

$2,646

$0
$7,920
$3600
$180
$600
$500
$3040
$54,440

$20,000
$600
$5,700
$640

$2,500
$25,000
$0
$0
$0

$25,000

Costs for AS treatment building included with corresponding VRS
Costs for air/water separator tank included with corresponding VRS
Costs for catalytic oxidation treatment included with corresponding VRS
112
-------
Table 27
FOCUSED FEASIBILITY STUDY, SOURCE AREA 11 - LEACHATE
ALTERNATIVE SCL-11A: NO ACTION/LEACHATE MONITORING/NATURAL
ATTENUATION/GROUNDWATER USE RESTRICTIONS
COST SUMMARY
Item/Description
Total Cost
CAPITAL COSTS
Groundwater Use Restrictions
Leachate Monitoring Wells
Air Sparging
SUBTOTAL CONSTRUCTION COSTS
$25,000
$18,000
$262,000
$305,000
Bid and Scope Contingency (20%)
Oversight/Health and Safety (5%)
TOTAL CAPITAL COSTS
$61,000
$15,000
$381,000
ANNUAL OPERATING AND MAINTENANCE COSTS
Leachate Sampling and Analysis (per event)
Air Sparging
TOTAL ANNUAL COSTS'
$8,000
$54,000
$62,000
REPLACEMENT COSTS (2)
Monitoring Wells Replacement (every 15 years)
TOTAL REPLACEMENT COSTS
$29,000
$29,000
PRESENT WORTH ANALYSIS
Total Capital Costs (from above)(3)
Present Worth Annual O&M Costs (4)
$381,000
$379,000
$59,000
$170,000
$14,000
$1,003,000
Leachate Sampling
Quarterly Sampling - years 1 and 2
Semi-annual Sampling - years 3 through 30
Present Worth Replacement Costs (5)
TOTAL PRESENT WORTH
(1) Capital costs for construction items do not include oversight fees.
(2) Replacement costs include construction and oversight capital costs.
(3) Capital costs represent the present worth of the given alternative.
(4) The "Present Worth Annual O&M Cost" line item includes all annual costs except for costs per sampling and analysis event. Costs incurred for
sampling and analysis are broken down per sampling schedule as listed. Sampling and analysis costs are based on a 7% discount rate over a 30-
year projection (Based on RCRA Closure Guidelines).
(5) Present worth of replacement costs is based on a 7% annual discount rate and replacement of monitoring wells replacement every 15 years.
113
-------
Table 28
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT
AREA 9/10 - SOIL
ALTERNATIVE SCS-9/10C: SOIL VAPOR EXTRACTION (SVE)
DETAILED COST ESTIMATE - COMMENTS
COST COMPONENT
General
Construction Trailer (rental and delivery)
Mobilization
demobilization
Decon facilities
Health and safety equipment
Electrical power supply
Water supply
Soil Vapor Extraction (SVE)
SVE well installation
SVE main system
SVE control panels
6" carbon steel piping
4" carbon steel piping
Excavation for piping placement
Electrical power requirements 25 HP
SVE treatment building
Air/water separator tank
Activated carbon emissions treatment
Activated carbon recharge (1600 Ib unit)
Activated carbon disposal
Sampling
Post Treatment Sampling
Test kits/Field Screening (per year)
Laboratory analysis (VOCs N,P) (per year)
Shipping and handling (per year)
COMMENTS

Heavy equipment and trailers, per vendor estimate
Allowances for trailer and equipment demobilization

Allowances based on CDM equipment rates
Based upon expected electrical costs per month for this alternative
Based upon expected use per month for this alternative

Cost associated with installation of SVE wells. Based on CDM experience
Vendor: Includes blower, exp motor, inline air filter, silencers, dilution valve, moisture separator,
condensate transfer pump, high condense, level alarm, vac. Relief valve, vac. gauges, skid
mounting, interconnecting piping and a manual motor switch.
Vendor estimate-NEEP (May 1998)
Based on CDM experience
Based on CDM experience
12" wide trench and backfill, 36" deep as per 1996 means
Based on 3-phase power, working 24 hrs/day, $0.09/kW-hr
Based on prefabricated building on concrete pad. Based on CDM experience
Based on CDM experience
Based on an estimate form Carbtrol (6/98) for a G-7 Absorber carbon unit w/1600 Ibs of vapor
phase activated carbon designed for 2000 cfm flows
Based on carbon use 3 Ib/day and 365 days/year, rate of 1 .50/lb carbon recharge
Based on carbon used per 365/year, rate of $2.00 per Ib of carbon
Based on CDM experience

Based on CDM experience and average test kit costs-25 samples per test kit, samples collected on
a grid of 1 sample/250cy contamination, material; 1 sampling grid per 2weeks
Based on 1998 sample analysis costs from Midwest laboratories; samples collected on a grid of 1
sample/250cy contamination, material; 1 sampling grid per 2weeks
Costs associated with transporting samples from site to laboratory twice per month
114
-------
Table 29
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT
SOURCE AREA 9/10-
ALTERNATIVE SCS-9/10C: SOIL VAPOR EXTRACTION(SVE)
DETAILED COST ESTIMATE
COST COMPONENT Unit No. Unit Cost
Units
General
Construction trailer(rental and delivery)
Mobilization
Demobilization
Decon facilities
Health and safety equipment
Electrical power
Water supply
Soil Vapor Extraction
SVE well installation
SVE main system
SVE control panels
6" carbon steel piping
4" carbon steel piping
Excavation for piping treatment
Electrical power requirements (25 H. P.)
SVE treatment building
Air/water separator
Activated carbon emissions treatment
Activated carbon recharge (1, 600 Ib recharge)
Activated carbon disposal
Sampling
Post Treatment Sampling
Test kits/Field Screening (per year)
Laboratory Analysis (VOCs,N,P) (per year)
Shipping and handling (per year)

Mo
Is
Is
Ea
Yr
Yr
yr

ea
unit
unit
Ft
Ft.
Ft.
Is
sf
Is
Is
yr
yr
ea

samples
samples
shipmt

1
1
1
1
1
1
1

4
1
1
720
50
770
1
500
1
1
30
30
8

34
672
24

$3,300
$1,000
$1,000
$1,000
$9,000
$3,600
$2,000

$6,000
$18,000
$3,000
$57
$32
$0.67
$25,000
$100
$5,000
$7,500
$1,640
$2,190
$1,500

$3000
$200
$100
Capital Cost Construction Annual Start-up &
/ Installation O&M Baseline
Costs Costs Costs
$3,000

$1,000
$1,000
$1,000

$126,140

$18,000
$3,000
$41,040
$1,600

$50,000
$5,000
$7,500

$32,016
$24,000
$6,000
$1,500

$516

included

$18,300
$3,300

$9,000
$3,600
$2,400
$163,900

$500

$25,000

$500
$1,000
$49,200
$65,700
$12,000
$147,000
$10,200
$134,400
$2,400
$0

115
-------
Table 30
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT
SOURCE AREA 9/10
ALTERNATIVE SCS-9/10C SOIL VAPOR EXTRACTION
COST SUMMARY
Item/Description
Total Cost
CAPITAL COSTS
General
Soil Vapor Extraction (w/emission controls)_
SUBTOTAL CONSTRUCTION COSTS
$3,000
$158,000
$161,000
Bid Contingency (10%)
Scope Contingency (10%)
Engineering and Design (15%)
Oversight/Health and Safety (5%)
$16,000
$16,000
$24,000
$8,000
ANNUAL OPERATING AND MAINTENANCE
COSTS
General
Regular System Maintenance/Electrical
Post Treatment Sampling
TOTAL ANNUAL COSTS
$18,000
$164,000
$147,000
$329,000
REPLACEMENT COSTS
TOTAL REPLACEMENT COSTS
$0
PRESENT WORTH ANALYSIS
Total Capital Costs
Present Worth Annual O&M Costs
Present Worth Replacement Costs
TOTAL PRESENT WORTH
$225,000
$4,083,000
$0
$4,308,000
116
-------
Table 31
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT AREA 9/10
ALTERNATIVE SCL-9/10E: AIR SPARGING(AS) ALONG GMZ BOUNDARY AND SOURCE AREA/MONITORING
/GROUNDWATERUSE RESTRICTIONS
DETAILED COST ESTIMATE - COMMENTS
COST COMPONENT
Groundwater Use Restrictions
Legal fees
General
Construction trailer (rental and delivery)
mobilization
demobilization
Decon facilities
Health and safety equipment
Electrical power service supply
Water supply
Leachate Monitoring Wells
Well installation and materials
Leachate and Containment
System Sampling and Analysis
labor
vehicle
Equipment
miscellaneous
Leachate laboratory analysis
Vapor Recovery System (VRS)
VRS installation
VRS Main System
VRS control panels
6" carbon steel pipe
4" carbon steel pipe
Excavation for piping placement
Electrical power requirements 10 h.p.
VRS Treatment building
Air/water separator tank
Activated carbon
COMMENTS

Cost based on CDM experience

50 X 12 ft const, trailer -$1 .65/mi delivery fee (lOOmi)-rental allowance per 1996 means
Heavy equipment and trailers, per vendor estimate
Allowance for trailer and equipment demobilization
Based upon level of personal and vehicle decontamination anticipated for this alternative.
Allowance based on CDM equipment rates.
Based on expected electrical costs per month for this alternative
Based on expected use per month for this alternative (e.g. decon, personnel Use)

Cost based upon CDM experience in monitoring well installation.

Based on 10 hour work day at the average CDM labor rate of $60 for oversight personnel
Based on $300/week rental fee for a field vehicle
Based on CDM equipment rental rates
Incidental expenses (minor repairs, replacement of equipment, local Purchases, etc.)
Based on an average cost incurred for VOC analysis; One duplicate and one blank will be
collected per 10 samples.

Cost associated with installation of SVE wells. Based on CDM experience
Vendor: includes blower, exp motor, inline filter, silencers dilution valve Moisture separator,
condensate transfer pump, level alarm, Vacuum gauges, skid mounting, interconnecting piping
and manual motor start switch.
Vendor estimate-NEEP (May 1996)
Based on CDM experience
Based on CDM experience
12" wide trench and backfill, 36" deep as per 1996 means
Based on 3-phase power working 24 hours/day, $0.09 kW-hr
Basic prefabricated building on concrete pad. Based on CDM experience.
Based on CDM experience
Based on CDM experience
117
-------
Table 31 Continued
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT AREA 9/10
ALTERNATIVE SCL- 9/10E: AIR SPARGING(AS) ALONG GMZ BOUNDARY AND SOURCE AREA/MONITORING
/GROUNDWATERUSE RESTRICTIONS
DETAILED COST ESTIMATE - COMMENTS
COST COMPONENT
Air Sparging (AS)
AS well installation
AS min system
AS control panels
6" carbon steel piping
4" carbon steel piping
Excavation for piping placement
Electrical power requirements (25 HP)
AS treatment building
Air/water separator tank
Activated carbon treatment
COMMENTS

Cost Associated with installation of AS wells. Based on CDM experience
Vendor: includes blower, exp motor, inline silencer, pressure relief valve Unitized base, pressure
gauge and a manual motor switch.
Vendor estimate
Based on CDM experience
Based on CDM experience
96 Means
Based on 3 phase power, working 24 hours/day, 0.09kW-hr
Costs for AS treatment building included with corresponding VRS
Costs for air/water separator tank included with VRS
Costs for carbon air treatment included with corresponding VRS
118
-------
Table 32
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT SOURCE AREA9/10
LEACHATE ALTERNATIVE SCL-9/10E, AIR SPARGING (AS) ALONG GMZ
BOUNDARY AND SOURCE AREA/ MONITORING/GROUNDWATER USE RESTRICTIONS
DETAILED COST ESTIMATE
COST COMPONENT Unit No. Units Unit Cost
Groundwater Use
Restrictions
Legal fees
General
trailer (rental and delivery)
mobilization
demobilization
Decon facilities
Health and safety equipment
Electrical power service
supply
Water supply
Leachate Monitoring
Wells
Well installation and
materials
Leachate Monitoring Well
Sampling And Analysis (per
event)
labor
vehicle
equipment
miscellaneous
Leachate laboratory analysis
Vapor Recovery System
VRS well installation
VRS main system
VRS control panels
6" carbon steel piping
4" carbon steel piping
Excavation- piping placement
Elect. Pwr. Requirements 10 hp
VRS treatment building (2)
Air/water separator tank
Carbon adsorption, emissions

mo
Is
Is
Ea
Mo
Mo
mo

well

hours
days
Is
Is
each

ea
Is
Is
Ft
Ft
Ft
yr
sf
Is
Is

360
1
1
1
360
360
360

20
1
1
1
7

10
2
2
1530
50
1580
1
800
9
2

$25,000

$275
$1,000
$1,000
$1,000
$2,000
$400
$200
SO
$4,5000

$60
$60
$600
$1,000
$130

$6,000
$14,000
$3,000
$57
$32
$0.67
$20,000
$100
$5,000
$80,000
Capital Cost Construction/ Annual Start-up &
Installation Costs O&M Costs Baseline Costs
$25,000
$25,000
$1,038,000
$99,000
$1,000
$1,000
$1,000
$720,000
$144,000
$72,000
$0
&0
$0

$355,000

$14,000
$3,000
$87,210
$1600

$80,000
$10,000
$160,000

$22,500
$22,500
$0

$67,059
$60,000
$5,000
$1,000

$1,059

included

$3,270
$1,200
$60
$600
$500
$910
$25,500

$10,000
$500

$10,000

$1,000
$4,000

119
-------
Table 32 Continued
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT SOURCE AREA9/10
LEACHATE ALTERNATIVE SCL-9/10E, AIR SPARGING (AS) ALONG GMZ
BOUNDARY AND SOURCE AREA/ MONITORING/GROUNDWATER USE RESTRICTIONS
DETAILED COST ESTIMATE
COST COMPONENT Unit No. Units Unit Cost
Air Sparging (AS)
AS well installation
As main system
As control panels
6" carbon steel piping
4" carbon steel piping
Excavation - piping
placement
Elect. Pwr. requirements25 hp
AS treatment building
Air/water separator tank
Activated carbon treatment

ea
Is
Is
If
If
If
year
Included
above
Included
above
Included
above

15
1
1
1750
350
2100
1

$6,000
$18,000
$3,000
$57
$32
$0.67
$25,000

Capital Cost Construction/ Annual Start-up &
Installation O&M Costs Baseline Costs
Costs
$131,950

$18,000
$3,000
$99,750
$11,200

$98,907
$90,000
$6,000
$1,500

$1407

$35,500

$10,000
$500

$25,000

120
-------
Table 33
SOUTHEAST ROCKFORD SOURCE CONTROL OPERABLE UNIT SOURCE AREA 9/10
LEACHATE ALTERNATIVE SCL-9/10E AIR SPARGING (AS) ALONG GMZ BOUNDARY AND
SOURCE AREA/LEACHATE MONITORING/GROUNDWATER USE RESTRICTIONS
COST SUMMARY
Item/Description Total Cost
CAPITAL COSTS
Groundwater Use Restrictions $25,000
General $1,038,000
Leachate Monitoring Wells $23,000
VRS $423,000
Air Sparging $231,000
Subtotal Construction Costs $1,740,000
Bid Contingency 15% $261,000
Scope Contingency 20% $348,000
Engineering and Design 15% $261,000
Oversight/Health and Safety $87,000
Total Capital Costs $2,697,000

Annual Operating and Maintenance Costs
VRS Regular Maintenance/Electrical $26,000
Leachate Sampling and Analysis per event $3,000
Regular System Maintenance/Electrical $36,000
Total Annual Costs $65,000

Replacement costs
Leachate Monitoring Wells (every 15 years) $29,000
Equipment (eg. Blowers motors) every 15 years $30,000
Total Replacement Costs $59,000
Present Worth Analysis
Total Capital costs (from above) $2,697,000
Present Worth Annual O&M Costs $807,000
Quarterly Leachate Sampling-years 1&2 $22,000
Semi-annual Sampling-years 3 through 30 $64,000
Present Worth Replacement Costs $29,000
Total Present Worth $3,619,000
(1). Capital costs for construction items do not include oversight fees, which are accounted for separately.
(2). Replacement costs include construction and oversight capital costs
(3). Capital costs represent the present worth of the given alternative
(4). Present worth of annual O&M cost is based on a 7% discount rate over a life of 30 years.
(5). Present worth of replacement costs is based on a 7% annual discount rate and replacement of system equipment
every 15 years (once over a 30 year projection)
121
-------
STATUTORY DETERMINATIONS

PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT

The risk posed by drinking contaminated groundwater and the risk posed by the contaminated
soil in the four source areas were considered separately by the Illinois EPA and U. S. EPA
for the Southeast Rockford Groundwater Contamination project. In October 1995, after
carefully considering public comment, the Illinois EPA and U. S. EPA chose "Use
Restrictions" as the remedy for the area groundwater that predictably would be impacted by
contamination within the next 70 years. The remedy for the groundwater was implemented in
1998.

A human health risk assessment was conducted on the soil in each of the four source areas.
The human health risk assessment followed a tiered approach, in conformance with Tiered
Approach to Corrective Action Objectives (TACO). TACO is a program used by the Illinois
EPA for developing remediation objectives for contaminated soil and groundwater.
Development of these remediation objectives includes protecting human health and the
environment and takes into account site conditions and land use. TACO must work within
existing laws and regulations, therefore, the use of TACO for the development of
remediation objectives for the Southeast Rockford Groundwater Contamination Site needed to
meet guidelines in accordance with CERCLA, RAGS, RCRA, and 35 111. Adm. Code Part 620.

Three exposure pathways were considered in this assessment: (1) direct contact with soil
(including ingestion and inhalation); (2) the soil component of the groundwater ingestion
pathway; and (3) ingestion of vegetables. An evaluation was conducted for the direct
contact with soil pathway and the soil component of the groundwater pathway. Chemical
concentrations found at the site were compared to a combination of pre-established
screening values, background concentrations and practical guantitation limits (PQLs). A
PQL is the level at which a chemical can be reliably measured in the laboratory.

A risk assessment was also conducted for the soil component of the groundwater pathway
(for chemicals which exceeded values established under Tier 1 assessment) and the
ingestion of vegetables pathway for Area 7 only. Based on land use in this area, the close
proximity of farmland, and the absence of institutional controls, it was determined that
an agricultural scenario could not be ruled out.

Sampling data collected from the surface and subsurface soil of each of the four source
areas were compared to the Tier 1 Exposure Route-Specific Values (ingestion and
inhalation) for soil protective of residential areas and the Soil Component of the
Groundwater Ingestion Exposure Route Values for Class I groundwater. The direct contact
(ingestion and inhalation) values are protective of direct contact with soil, while the
soil component of the groundwater protection values are protective of groundwater impacted
by contaminants that could leach from soil.

As directed by Illinois EPA, it was assumed that all four-source areas were, or could
become, residential areas. Currently, no land use restrictions are in place to prevent
residential development or expansion. Therefore, it was necessary to employ soil remedial
objectives that would be protective of residential land use. Because the exposure
assumptions for the residential scenario are standardized, with few site-specific
modifications, there was no advantage in developing Tier 3 values. Therefore, Tier 1
values were used.

Because several chemicals (that could impact groundwater) exceeded Tier 1 objectives for
soil, Tier 3 soil remediation objectives (SROs) were developed. Tier 3 risk-based soil
levels protective of groundwater are presented in Tables in this ROD for each Source Area.
The SROs are back-calculated from the Groundwater Remediation Objective (GRO) presented
for Class I Groundwater in Section 742, Appendix B: Table F of TACO. While most of the
GROs are based on a hazard index of 1.0 or a cancer risk of one in one million, in some
cases, the GRO is based on a higher cancer risk. Therefore, a mixture assessment was
-------
conducted according to the Illinois EPA mixture rule issued under Docket C of the Illinois
Pollution Control Board (December 4, 1997) to determine what the risks would be if all of
the SROs for the soil to groundwater pathway were achieved. This assessment demonstrated
that, in accordance with TACO, total cancer risk associated with the SROs for the soil to
groundwater pathway would not exceed an excess lifetime risk of one in ten thousand or a
hazard index of 1.0 if all SROs were achieved.

RESULT OF THE DIRECT PATHWAY (TIER 1)
The results of the Tier 1 assessment of the direct contact pathway can be summarized as
follows:

• Maximum concentrations of volatile organic compounds (VOCs) did not exceed their
respective Tier 1 values in any of the focus areas.

• Maximum concentrations of semi-volatile organic compound (SVOCs) and inorganics
exceeded their respective direct contact ( ingestion and inhalation) Tier 1 values
in all four areas.

• Maximum concentrations of inorganics and one SVOC in Area 7, (benzo (a) pyrene),
were dropped from further evaluation, because detected concentrations were less than
or consistent with background concentrations. Risk associated with these chemicals
are below 1 x 10-6 (1E-06, one in one million) and/or a hazard index of 1.0.

Selected samples in Areas 4 (SS4-201, SS4-203, SS4-203D) and 11 (SS11-206, SS11-207)
were identified as "hot spots" that exceeded a Tier 1 value and the Practical
Quantitation Limit (PQL).

Three out of four samples in Area 9/10 (SS910-101, SS910-103, SS910-104) exceeded
one or more Tier 1 values. These data are presented in Appendix B. The " hot spots"
in Areas 4 and 1 1 and the samples exceeding a Tier 1 value in Area 9/ 10 will be
addressed in the FFS. The FFS will evaluate whether or not additional SVOC data may
be needed in the remedial design phase to better characterize risk and the extent of
contamination. Based on the results of sampling, if necessary, remedial alternatives
that address SVOCs would be developed and evaluated. The presence of these hot spots
represents a potential exceedence of risk limits established by the U.S. EPA (a
noncancer hazard index of 1.0 and cancer risks of between one in one million and one
in one hundred thousand) and the Illinois EPA (a noncancer index of 1.0 and cancer
risks of one in one million used to develop the Tier I values), depending on actual
exposure.

RESULTS OF THE SOIL TO GROUNDTflRTER PATHWAY (TIER 1)
The results of the Tier 1 assessment of the soil to groundwater pathway can be summarized
as follows:

• Several chemicals were dropped from further evaluation for the soil to groundwater
pathway because they were not detected in groundwater (Dieldrin, carbazole and
several SVOCs).

• VOCs in surface soil in Area 4 and VOCs in subsurface soil in all four areas
exceeded Tier 1 soil component of the groundwater protection values. These VOCs were
further evaluated in Tier 3. A Tier 3 assessment was conducted for those chemicals
that exceeded a soil component of the groundwater protection value and were detected
in groundwater during past sampling events at greater than 5 percent freguency of
detection. The Tier 3 assessment consisted of calculating soil concentration
protective of groundwater at a designated point of compliance.

RESULTS OF THE SOIL COMPONENT OF THE GROUNDTOVTER INGESTION PATHWAY (TIER 3)
The results of the Tier 3 assessment of the soil component of the groundwater ingestion
pathway can be summarized as follows:
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• Chemicals of concern in Areas 4, 7, and 11 exceed their respective SROs. Two
additional chemicals of concern in Area 11 exceed their respective saturation
concentrations, but not the calculated SRO. Risks associated with chemicals that
exceed an SRO in Areas 4, 7 and 11 exceed Illinois EPA cancer risk limits of one in
one million or a hazard index of 1.0.

• All areas where detected concentrations exceeded the lower of the SRO or saturation
concentration were further evaluated in the FFS. Volumes estimates were developed
for these areas for excavation or remediation purposes.

• Area 7 borders land currently used for agricultural purposes, and no current zoning
restrictions prevent conversion of some of the undeveloped portions of Area 7 to
agricultural use. For these reasons, a semi-quantitative evaluation was conducted to
determine whether the use of Area 7 for growing vegetables or fruits would result in
an unacceptable risk to human health. Based on this evaluation, it is concluded that
ingestion of vegetables (or fruits which have a fresh weight consumption rate lower
than vegetables, i.e., 88 mg/day) would not result in exceedence of either a hazard
index of 1.0 or a cancer risk of 1E-06 (one in one million), which are the risk
limits on which the Tier 1 values are based.

CONCLUSION
A combination of a Tier 1 and Tier 3 assessment was used to assess risks to human health.
At Areas 4, 7, 9/10 and 11, Tier 1 was used to evaluate the direct contact pathway and the
migration of soil to groundwater. Tier 3 was used to evaluate the migration of soil to
groundwater pathway (for those chemicals that exceeded Tier 1 values) and the ingestion of
vegetables pathway (for Area 7 only). The Tier 1 assessment resulted in the identification
of SVOCs above Tier 1 values in Areas 4, 9/10 and 11. If these SVOCs were removed, all
remaining concentrations of SVOCs would be less than the higher of the PQL or Tier 1
concentration. The Tier 3 Assessment resulted in remediation goals for VOCs in all
four-source areas and was also used to develop a remediation plan.

SUMMARY OF ECOLOGICAL RISK ASSESSMENT OF SOIL IN AREA 7
Although the 1995 groundwater ROD concluded that the contaminated groundwater did not pose
a long-term environmental (ecological) risk to the Rock River, Illinois EPA is required to
consider the ecological risk of the contaminated soil in the source areas. However, TACO
may not be used to establish ecological remediation goals. Therefore, an ecological
assessment was conducted at Area 7 per U. S. EPA guidelines. Ecological assessments were
not conducted at Areas 4, 9/10 and 11, because site characteristics (consisting mostly of
pavement and buildings) are not highly suitable as habitat for significant populations of
plants and animals. Also, some corrective action objectives cannot be used because, as
they are currently designed, TACO values only consider human health risk and not
environmental risk.

An Ecological Risk Assessment (ERA) was conducted at Area 7 to evaluate the likelihood
that adverse ecological effects may occur (or are occurring) at the site as a result of
exposure to single-or multiple-chemical stressors. Risks result because of contacts
between ecological receptors and stressors that are sufficiently long in duration and of
sufficient intensity to elicit adverse effects. The primary purpose of this
screening-level ERA is to identify contaminants in surface water and sediment that can
result in adverse effects to present or future ecological receptors.

This ERA is based primarily on a screening-level approach in which measured chemical
concentrations in surface water and sediment are compared to relevant-effect
concentrations. This ERA is intended to provide information that can help establish
remedial priorities and serve as a scientific basis for regulatory and remedial actions
for the site. The general approach used to conduct this ERA is based on site-specific
information and on recent EPA guidance, primarily Ecological Risk Assessment Guidance for
Superfund: Process for Designing and Conducting Ecological Risk Assessments (EPA 1997a) ,
supplemented by Guidance for Ecological Risk Assessment (EPA 1998).
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Risks to ecological receptors are summarized below, within categories designated as low
risk and risk. No sources of moderate or high risks are identified for this ERA. The
differentiation of low and no risks is used to evaluate the relative risks associated with
specific stressors compared to all other potential contributors to risks. These
designations are based on both the guantitative risk estimates presented previously and
best professional judgment.

LOW RISK
• Sensitive aguatic biota such as benthic invertebrates can be adversely affected by
direct contact with surface water in the creek adjacent to Area 7. The only COPC of
concern in water at this location is:
1,1,1-trichloroethane

• Similar organisms may be additionally at risk from direct contact with creek
sediments. Major sediment-associated COPCs at this location include:
benzo(a) anthracene
methoxychlor
chrysene

NO RISK
• Aguatic and semi-aguatic organisms do not appear to be at significant risk from any
other COPCs identified at this site.

• Consumers of aguatic and semi-aguatic organisms (e. g., piscivorous birds,
omnivorous upper trophic level predators), represented by belted kingfisher and red
fox, respectively, do not appear to be at significant risk.

APPLICABT/F. OR RET .WANT AND APPROPRIATE REQUIREMENTS (ARARs)

The remedies for the ROD are subject to federal Applicable or Relevant and Appropriate
Reguirements (ARARs) and any more stringent state regulations. The determination of ARARs
has been made in accordance with Section 121(d)(2) of CERCLA, as amended by the Superfund
Amendments and Reauthorization Act (SARA) of 1986, and the Small Business Liability Relief
and Brownfields Revitalization Act of 2002. These ARARs are also consistent with the
National Contingency Plan (NCP) 40 CFR Part 300; amended March 8, 1990. ARARs are federal,
or more stringent state reguirements, that the remedial alternative(s) must achieve, that
are legally applicable to the substance or relevant and appropriate under the
circumstances. Administrative reguirements such as obtaining permits and agency approvals,
record keeping, reporting and offsite activities such as waste disposal regulated by state
or municipalities would also be considered applicable or relevant and appropriate
regulations. It is important to note that, as identified at Section 121(e) of CERCLA, and
in the NCP at 40 CFR 300.400(e), no federal, state, or local permits are reguired for any
remedial actions conducted entirely on-site. However, all on-site emissions and/or
discharges would need to attain a level of treatment and management meeting all
substantive technical reguirements that might otherwise be included in a permit. Any
emissions or discharges that leave the site or any response actions that are conducted
off-site are subject to all applicable permitting reguirements.

The status of a reguirement under Section 121(d) of CERCLA and other environmental laws,
both federal and state, may be either applicable or relevant and appropriate to the
remedial alternative, but not both. The NCP (40 CFR 300.5) defines these terms as follows:

APPLICABLE REQUIREMENTS
Those clean-up standards, standards of control, and other substantive reguirements,
criteria, or limitations promulgated under federal or state environmental or facility
siting laws that specifically address a hazardous substance, pollutant, contaminant,
remedial action, location, or other circumstance found at a CERCLA site. Only those state
standards that are identified by a state in a timely manner and that are more stringent
than federal reguirements may be applicable.
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RELEVANT OR APPROPRIATE REQUIREMENTS
Those clean-up standards, standards of control and other substantive requirements,
criteria or limitations described above, that, while not applicable, address problems or
situations sufficiently similar to those encountered at a CERCLA site that their use is
well- suited to the particular site.

In addition to ARARs, the U.S. EPA has identified federal and state non-promulgated
criteria, advisories and guidance as requirements to be considered (TBC) as part of the FS
analysis. TBCs are used on an as appropriate basis in developing clean-up standards. TBCs
do not have the same status as ARARs and are not considered to be required clean- up
standards because they are not promulgated regulations.

OTHER REQUIREMENTS TO BE CONSIDERED (TBCs)
Non-promulgated federal and state advisories or guidance documents do not have status as
potential ARARs; however, these advisories or guidance documents may be considered in
determining the necessary level of cleanup for the protection of health or the
environment. As specified in 40 CFR 300.430(f)(1)(ii)(C)(l)-(6), a remedial alternative
that does not meet an ARAR under federal or state environmental laws can still be selected
given any of the following six limited circumstances:

• The alternative is an interim measure and will become part of a total remedial
action that will attain the applicable or relevant and appropriate federal or state
requirement;

• Compliance with the requirement will result in greater risk to human health and the
environment than other alternatives;

• Compliance with the requirement is technically impracticable from an engineering
perspective (e.g., technical impracticability waiver for groundwater);

• The alternative will attain a standard or performance that is equivalent to that
required under an otherwise applicable standard, requirement, or limitation through
the use of another method or approach;

• With respect to a state requirement, the state has not consistently applied, or
demonstrated the intention to consistently apply, the promulgated requirement in
similar circumstances at other remedial actions within the state; and

• For Superfund-financed response actions only, an alternative that attains the ARAR
will not provide a balance between the need for protection of human health and the
environment with the availability of fund monies to respond to other sites that may
present a threat to human health and the environment.

TYPE/STATUS OF ARARs
ARARs are divided into three types of requirements: chemical specific; location specific;
and action specific. This distinction is based on the factors that trigger the requirement
(e.g., emission of a chemical or particular action such as transportation of a chemical).
These types of ARARs are defined as follows:

• Chemically Specific Requirements are set health or risk-based concentration limits
or ranges in various environmental media for specific hazardous substances,
pollutants or contaminants that is acceptable in the ambient environment. Examples
of chemical specific ARARs are National Ambient Water Quality Standards.

• Location Specific Requirements are set restrictions on activities, depending on the
characteristics of a site or its immediate receptors. A remedial alternative may be
restricted or eliminated due to the location or characteristics of the site and the
requirements that apply to it. Examples of location specific ARARs are regulations
based on proximity to wetlands and flood plains.
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• Action Specific Requirements are set controls or restrictions on particular kinds of
activities related to the management of hazardous substances, pollutants or
contaminants. These requirements are not triqqered by specific chemicals at a site,
but rather by the particular activities to be conducted durinq the implementation of
the remedial alternative (technoloqy or activity-based requirements). Examples of
action specific ARARs are transportation and handlinq requirements.

Only chemical specific ARARs are candidates for site cleanup qoals. Action specific and
location-specific ARARs apply to the execution of the selected remedial alternative.

Identification of Federal ARARs for the S. E. Rockford Site
This section presents a summary of those federal requlations that may be found to be
applicable or relevant and appropriate to the S. E. Rockford site, specifically:

• Comprehensive Environmental Response, Compensation and Liability Act (CERCLA),
includinq the Superfund Amendments and Reauthorization Act (SARA) of 1986, the Small
Business Liability Relief and Brownfields Revitalization Act of 2002 and subsequent
amendments;

• Resource Conservation and Recovery Act of 1996, as amended (RCRA);

Hazardous and Solid Waste Act Amendments of 1984 (HSWA);

The Clean Water Act (CWA) and Amendments;

The Safe Drinkinq Water Act (SDWA) ;

The Clean Air Act (CAA);

The National Environmental Policy Act of 1969 (NEPA) ; and

• The Hazardous Materials Transportation Act.

The Comprehensive Environmental Response, Compensation and Liability Act
CERCLA, last amended in January 2002, provides the U.S. EPA Administrator the authority to
respond to any past disposal of hazardous substances and any new uncontrolled releases of
hazardous substances. Within CERCLA, a trust fund has been established for cleanup of
abandoned past disposal sites and leakinq underqround storaqe facilities, as well as the
authority to brinq civil actions aqainst violators of this act. The National Continqency
Plan (NCP), which quides removal and remedial actions at Superfund sites, was developed
subject to this act. The Superfund Amendments and Reauthorization Act (SARA) of 1986
extensively amended CERCLA. The major qoals of SARA were to include more public
participation, and to establish more consideration of State clean-up standards, with an
emphasis on achievinq remedies that permanently and siqnificantly reduce the mobility,
toxicity, or volume of wastes.

The Resource Conservation and Recovery Act
RCRA requlates the manaqement and land disposal of hazardous waste and solid waste
material and the recovery of materials and enerqy resources from the waste stream. RCRA
requlates the qeneration, transportation, treatment, storaqe and disposal of hazardous
wastes, as well as solid waste disposal facilities. RCRA applies to remedial actions that
include disposal, treatment, storaqe or transportation of requlated wastes. Remedies that
include on-site disposal of hazardous wastes will be required to meet RCRA desiqn,
monitorinq, performance, e.q., air emission standards 35 111. Adm. Code 724, and closure
standards. Off-site transportation of requlated wastes, whether as part of a remedial
action or as qenerated durinq the investiqation, will require use of the manifest system,
a RCRA-licensed transporter and proof of acceptance at a licensed facility approved for
the particular wastes.
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The Hazardous and Solid Waste Act Amendments
The Hazardous and Solid Waste Act Amendments (HSWA) of 1984 impose new and more
stringent requirements on hazardous waste generators, transporters, and owner/operators of
treatment, storage, and disposal facilities. Land disposal restrictions, as described in
40 CFR 268, identify hazardous wastes that are restricted from land disposal and define
those limited circumstances under which an otherwise prohibited waste may continue to be
land disposed.

The Clean Water Act
The Federal Water Pollution Control Act, amended by the Clean Water Act of 1977, was last
amended October 1992, and is commonly referred to as the Clean Water Act (CWA). Federal
Ambient Water Quality Criteria documents have been published for 65 priority pollutants
listed as toxic under the CWA. These criteria are guidelines that may be used by states to
set surface water quality standards. Although these criteria were intended to represent a
reasonable estimate of pollutant concentrations consistent with the maintenance of
designated water uses, states may appropriately modify these values to reflect local
conditions. Under SARA, however, remedial actions must attain a level or standard of
control that will result in surface water conditions equivalent to these criteria, unless
a waiver has been granted.

The water quality criteria are generally represented in categories that are aligned with
different surface water-use designations. These criteria represent concentrations that, if
not exceeded in surface water, should protect most aquatic life against acute or chronic
toxicity. For many chemical compounds, specific criteria have not been established because
of insufficient data. The criteria are used to calculate appropriate limitations for
discharges to surface water. These limitations are incorporated in the National Pollutant
Discharge Elimination System (NPDES) permits.

The provisions of the CWA are potentially applicable to uncontrolled landfill leachate and
groundwater discharges to surface water bodies and to remedial actions that include a
discharge of treated water to surface water.

Appendix A of 40 CFR Part 6 describes the requirements for flood plain/wetlands review of
proposed U.S. EPA actions. These regulations are potentially applicable for work to be
done in the creeks or other wetland areas, and for remedial activities within the flood
plain, such as the unnamed creek in Area 7.

The Safe Drinking Water Act
The Safe Drinking Water Act of 1974 (SDWA) regulates the quality of water collected,
distributed or sold for drinking purposes. Standards are set for MCLs permissible in water
delivered to any user of public drinking water. The SDWA also has been broadened to
protect groundwater and public drinking water supplies against contamination.

National primary drinking water standards established under the SDWA are promulgated as
MCLs that represent the maximum allowable levels of specific contaminants in public water
systems. MCLs are generally based on lifetime exposure to the contaminant for a 70 kg (154
pound) adult who consumes two liters (0.53 gallons) of water per day.

The SDWA provides for primary drinking water regulations to be established for maximum
contaminant level goals (MCLGs), with MCLs as close to MCLGs as feasible. MCLGs are
non- enforceable health goals at which no known or anticipated adverse effects on the
health of persons would be expected to occur, thus allowing an adequate margin of safety.
MCLGs only serve as goals for U. S. EPA in the course of setting MCLs and, therefore, are
initial steps in the MCL rule-making process.

MCLs and MCLGs for contaminants of concern at the SCOU are established in the final Risk
Assessment (COM 1998).

The Clean Air Act
The Clean Air Act, as amended (CAA), was enacted to protect and enhance the quality of air
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resources to protect public health and welfare. The CAA is intended to initiate and
accelerate national research and development programs to achieve the prevention and
control of air pollution. Under the CAA, the Federal Agencies are to provide technical and
financial assistance to state and local governments for the development and execution of
their air pollution programs. The U. S. EPA is the administrator of the Act and is given
the responsibility to meet the objectives of the Act. The Act establishes emission levels
for certain hazardous air pollutants that result from treatment processes.

Reguirements of the CAA are potentially applicable to remedial actions that result in air
emissions, such as excavation and treatment activities.

The Hazardous Materials Transportation Act
The Hazardous Materials Transportation Act (HMTA) of 1981, as amended, was enacted to
regulate the shipping, marking, labeling, and placing of hazardous materials that are
transported on public roadways. Pursuant to the HMTA, the Department of Transportation
(DOT) has promulgated regulations pertaining to transportation of hazardous materials. DOT
also has jurisdiction over the packaging of hazardous materials prior to shipment.

Hazardous soils, residues, wastewaters, or wastes that are transported off-site from the
SCOU site will be handled according to HMTA and DOT regulations.

Identification of State ARARs for the S. E. Rockford SCOU

The purpose of this section is to identify ARARs that exist based on Illinois state
regulations that must be complied with when performing a remedial action. The agency
charged with developing and enforcing environmental regulations for Illinois is the
Illinois EPA, in conjunction with the Illinois Pollution Control Board. Specifically,
these potential ARARs include:

• Illinois Groundwater Protection Act

• Illinois Solid Waste Management Rules; and

• Illinois Air Pollution Control Regulations

Illinois Groundwater Protection Act
The Illinois Groundwater Protection Act (IGPA) was enacted on November 7, 1991 (amended in
1994) by the Illinois General Assembly ( IGA) as an outgrowth of long-standing concern by
the IGA and the citizens of Illinois that the State's rich and valued groundwater
resources be protected. The IGPA is a multi-faceted groundwater policy and program
statement designed to provide such protection and to assure the continued viability of the
State's groundwater resources. In order to restore, protect, enhance and manage the
groundwater of Illinois, the IGPA proposes regulations that establish comprehensive water
guality standards specifically for the protection of groundwater.

Groundwater impacted by activities at the SCOU will be compared to the Illinois
groundwater guality standards to determine the need for corrective actions, if any. The
IGPA is incorporated into the Illinois Administrative Code in Title 35, Subtitle F (Public
Water Supplies), Part 620 Groundwater Quality; groundwater guality standards are given in
Subtitle D of this Part 620.

Illinois Water Quality Standards (35 111. Adm. Code Subtitle C: Water Pollution and
Subtitle F: Public Water Supplies)
These regulations pertain to all waters in the state and are intended to restore and
maintain the chemical, physical and biological integrity of the waters of the state. The
regulations include:

• Specific water guality standards and minimum treatment reguirements that apply to
all waters of the state (see Subtitle C: Part 302 water guality standards). These
include minimum surface water guality standards, effluent standards and general use
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water quality standards.

• Regulations applying to industrial wastewater programs (National Pollutant Discharge
Elimination System - NPDES);

• Water quality standards for water distributed through public water supply systems
(Subtitle F, specifically). These include primary drinking water standards and
groundwater monitoring requirements; and

• Groundwater quality standards for Class I-IV groundwater (defined in Subtitle F:
Part 620) with potential for use in public water supply systems.

The procedures for developing water quality criteria based on toxicity are included in
111. Adm. Code Subtitle C: Part 302, Subpart F, as are procedures for evaluating the
characteristics of receiving waters. These procedures are used to determine discharge
concentrations, which if not exceeded, will maintain the quality of the receiving waters.
Note that Subpart F: Section 620.130 exempts groundwater from the General Use Standards or
Public and Food Processing Standards of Subparts B and C of 35 111. Adm. Code 302. It is
the purpose of all of the mentioned water quality regulations to meet the requirements of
Section 402 of the Federal Clean Water Act (CWA) .

Illinois Solid Waste Management Rules ( 35 111. Admin. Code Subtitle G: Waste Disposal)
These regulations specify requirements that apply to solid waste and hazardous waste
facilities. These include solid waste management requirements, hazardous waste management
permitting and related hazardous waste operations requirements. The solid waste
regulations are given specifically under Subchapter I: Solid Waste and Special Waste
Handling, Parts 807-880. These regulations include design and disposal regulations as well
as monitoring requirements and standards for groundwater protection applicable to solid
waste and special waste landfills. The hazardous waste regulations were developed pursuant
to the requirements of RCRA and are given specifically in Parts 700-750 of Subtitle G.
These hazardous waste regulations pertain to generators and transporters of hazardous
waste and owners or operators of hazardous waste facilities. Regulations regarding
Underground Injection Control (UIC) and the handling of Universal Wastes are also included
in this section.

Illinois Air Pollution Control Regulations (35 111. Admin. Code Subtitle B: Air Pollution)
The Illinois air pollution control regulations were developed pursuant to the Federal
Clean Air Act (CAA). The regulations contain specific emission levels and requirements for
monitoring emissions. They contain regulations for specific types of operations (such as
burning) and types of industry as well as permitting requirements. There are also specific
emissions standards for hazardous air pollutants. Subchapter F, Part 232 provides
information regarding toxic air contaminants and Subchapter L, Part 243 of these
regulations give Air Quality Standards.

IDENTIFICATION OF ARARS

The regulatory groups previously described were considered during the ARAR identification
process. This includes federal and state requirements (applicable or relevant and
appropriate). Other information to be considered (TBCs) include federal and state
criteria, advisories and guidance documents. The identification of ARARs presented in this
section was based on current knowledge of the site, available analytical data and review
of ARARs established for sites with similar contamination. The ARARs from other sites were
derived by reviewing EPA RODs from sites both within and outside of Region V, based on
selected remedial alternatives and final ARARs chosen for these sites.

Table 35 provides a summary of potential ARARs at the SCOU. Based on the anticipated
remedial actions at the site, some of these potential ARARs may not apply and are marked
in the last column of Table 35. The ARARs that will apply have a direct effect upon the
remedial actions selected. The following paragraphs discuss some examples of this direct
effect.
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NPDES, Illinois Underground Injection Control (UIC) and Illinois Air Emission Source
Construction permits can be obtained, but may take considerable lengths of time. The
Illinois EPA Division of Air Pollution Control will reguire off-gas containment of any air
stripper that exceeds a total volatile emission rate of 8 pounds per hour. Any groundwater
that is remediated will reguire treatment to MCLs or IGWPA levels, whichever is more
stringent; or to NPDES discharge levels, depending on the discharge option selected. MCLs
and IGWPA Class I Groundwater Standards for all VOCs that exceed MCLs in groundwater are
provided in tables in this ROD.

The IGWPA was set up in 1987 to respond to the need to manage groundwater guality by
prevention-oriented processes. It establishes comprehensive water guality standards for
groundwater, provides for the use of water well protection zones and allows for the
establishment of groundwater management zones (GMZs) within any class of groundwater. A
GMZ can be established where groundwater is being managed to mitigate against effects
caused by the release of contaminants from a site. GMZ provisions recognize the practical
limitations commonly associated with remediating groundwater contamination and links
technological approaches and practices with standards regulation. The area of a GMZ can be
established with reference to a given point of compliance and an appropriate period of
time to achieve compliance. The groundwater within the study area is considered Class I
groundwater, under the definitions provided by the Act.

Publicly Owned Treatment Works (POTWs) are designated to treat domestic wastewater or
sewage. In general, POTWs are not designated to treat heavy metals, solvents, organics and
other types of toxic pollutants. POTWs are certainly not for off-site treatment or
disposal of contaminated groundwater. The treatment of toxic pollutants, if it occurs at
all in a POTW treatment plant, is incidental to the design of most POTWs and involves, to
a large extent, taking advantage of the treatment system's ability to dilute non-domestic
or industrial discharges, as well as adsorption of toxic pollutants to particles that
settle out into the sludge. Thus, a significant portion of the heavy metals and organic
compounds that are introduced into the head- works of a POTW treatment plant end up in the
POTWs sewage sludge. Therefore, this ROD has assumed that discharge to the POTW is not
acceptable, unless appropriate pre-treatment steps were taken. It is noted that the local
POTW has indicated that it would not accept any contaminated leachate collected from the
SCOU.

Illinois EPA Bureau of Water regulations governing the construction and operation of
treatment units are found at 35 111. Adm. Code Sections 302, 304, and 309. Section 302
contains water guality standards, Section 304 contains effluent limitations and Section
309 deals with permitting reguirements.

The construction of a groundwater treatment system in most cases reguires a permit from
the Bureau of Water. A burden of proof is placed upon the permittee to justify that the
proposed treatment system is capable of meeting either the surface water discharge
standards or general pretreatment standards for discharge to a sanitary sewer. It is also
reguired that the selected remedy is the correct technology and design specifications are
correct for the contaminants of concern.

The National Pollutant Discharge Elimination System (NPDES) is utilized when a discharge
is made to any surface water. The NPDES program provides for a non-degradation analysis of
the receiving stream water guality analysis, and a review of the parameters of concern to
determine the appropriate limits and monitoring reguirements. Permit limits are derived
from the more stringent applicable water guality standards, technology based effluent
limits, and federal categorical limitations (not applicable in this case) .

Air Strippers are part of the selected remedy for Source Areas 4 & 7 and have been
determined by the Illinois EPA Bureau of Water to be an appropriate effective technology
for the removal of VOCs. VOCs in both areas are the primary contaminants of concern,
however, the effectiveness of the air-stripping system will be deferred until the design
is completed and submitted.
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A permeable reactive barrier wall was the proposed remedy for remediation of the leachate
in Source Area 9/10. The Illinois EPA, however, modified the remedy used for leachate
control in this area, based on additional data and analysis of the potential sources of
contamination and public comment. The remedy will be designed to meet regulations of
Public Water Supplies and 35 111. Adm. Code Part 620 Class I Groundwater Standards for
potable water supplies.

Sampling reguirements vary from site to site, however, a protocol that has worked well for
remediation systems is to reguire more freguent initial monitoring. Once consistency is
established, the freguency of sampling may be reduced. One method freguently used is to
reguire weekly sampling during the first two months of operation, twice a month sampling
during the next two months and finally monthly sampling thereafter. A shutdown of the
system would reguire a return to weekly sampling for a period of time, before returning to
the previous sampling freguency. Situations may call for a variance in the freguency of
sampling, reguiring more sampling following a period of shutdown. The additional sampling
will allow for adjustments to be made in the establishment of system eguilibrium.

Discharge Limits are based upon the most up-to-date information gathered for the
parameters of concern. Table 34 includes both aguatic toxicity and human-health-based
criteria. In most cases, the AATC (acute criteria) is used as the daily maximum
guality-based limit. In some rare cases, a human-health-based limit may be used as the
monthly average limit, depending on the potential for longer-term exposure. Discharge
would be to a storm ditch, which would most likely be a zero low flow stream and
therefore, water guality criteria would apply at the end of the pipe and would be the
permit limits.

Table 34. Discharge Limits
Parameter

1,1 dichloroethylene
1, 2-dichloroethylene
ethyl benzene
tetrachloroethylene
toluene
1,1, 1-trichloroethane
1,1, 2-trichloroethane
trichloroethylene
xylenes
Acute Criteria

3000 ug/1
14 mg/1
210 ug/1
1.2 mg/1
2000 ug/1
4900 ug/1
19 mg/1
12 mg/1
0.92 mg/1
Chronic Criteria

240 ug/1
1.1 mg/1
17 ug/1
0.15 mg/1
230 ug/1
390 ug/1
4 . 4 mg/1
0.94 mg/1
0.073 mg/1
Human Health

0.95 ug/1
-
9.3 mg/1
2.8 ug/1
62 mg/1
-
12 ug/1
25 ug/1
62 mg/1
Note: Technology based (BAT) limits are normally used for Benzene (0.05 mg/1) and Total
BTEX (benzene, ethylbenzene, toluene, and xylenes) (0.75 mg/1).

COST EFFECTIVENESS

The types of costs that will be assessed include the following:

• Capital costs, including both direct and indirect costs;

• Annual operation and maintenance costs (O&M);
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Table 35
Summary of ARARS
Southeast Rockford SCOU Focused Feasibility Study
Act/Regulation
Federal or State
Type of ARAR
Parameter/
Program
Description
Probably Will Not Apply

Action Specific
Air Pollution
Emission Control
Regs. (63)
Air - Pollution
Control Board (64)
Air - Pollution
Control Board (65)
CWA(50)
CWA/RCRA (49-51)
CWA(49)
CWA(56)
CWA(50)
CWA(51)
CAA(34)
CWA(52)
CWA(53)
S
S
S
F/S
F/S
F
F
F
F/S
F
F/S
F/S
Action
Action
Action
Action
Action
Action
Action
Action
Action
Action
Action
Action
Air emission
Air emission
Air emission
NPDES
POTW
NPDES
NPDES
National pre-
treatment
standards
National pre-
treatment
standards
Air quality
NPDES
NPDES
Permit required
for all emissions.
Requires control of
off-gas if emission >
8 Ibs/hr
No person shall cause
or threaten or allow
the discharge or
emission of any
contaminant
Regulates particulate
matter emissions
Discharge permit
required (to Rock
River)
Regulates discharge to
POTW
POTW pre-treatment
standards relating to
Superfund site
leachate
Establishes Water
Quality Based
Effluent Limitations
Discharge to POTW
restrictions
National pre-
treatment program
requirements for
POTWs
Sets max. primary and
secondary 24-hour
particulate
concentrations
Permit must include
proposed action and
list all other permits
Establish standards,
limitations and other

137
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conditions

Table 35 Continued
Summary of ARARS
Southeast Rockford SCOU Focused Feasibility Study
CWA(54)
CWA(61)
CWA(56)
CWA(57)
CWA(60)
CWA(58)
DOT(36)
Fish and Wildlife
Coordination
Act(62)
Noise Control
Act(37)
Protection of
Archeological
Resources(38)
RCRA
RCRA(48)
F
F
F/S
F/S
F/S
F/S
F
F
F
F
F/S
F/S
Action
Action
Action
Action
Action
Action
Action
Action
Action
Action
Action
Action
NPDES
Env. sampling
NPDES
NPDES
Surface water
NPDES
Haz. mat.
transportation
Surface Water
Construction
noise emission
standards
Archeological
resource
protection
UIC
T&D
standards
BAT for toxic and
non-conventional
wastewater or BCT
for conventional
Requires adherence
to sample
preservation,
container type, and
holding times
Effluent limitations
and standards;
permit requirements
for discharge to
storm sewer
Establish discharge
limits for toxins
exceeding BAT/BCT
standards
States granted
enforcement
jurisdiction over
discharges to surface
waters
Requires monitoring
to ensure compliance
Procedures for
packaging, labeling
and transportation of
hazardous materials
Any fed. agency
must consult U.S.
Fish and Wildlife if a
surface water body is
modified
Sets standards for
construction noise
emissions
Procedures for
archeological
resource protection
Regulates injection
ofgroundwater
Interim storage or
treatment of haz.
waste in containment
buildings

X
X

138
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Table 35 Continued
Summary of ARARS
Southeast Rockford SCOU Focused Feasibility Study
RCRA(47)
RCRA(46)
RCRA(45)
RCRA(44)
RCRA(43)
RCRA(42)
RCRA(41)
RCRA(40)
RCRA(39)
UIC Regulations
(72 - 74)
Illinois Groundwater
Protection Act (79)
RCRA (69)
F/S
F/S
F/S
F/S
F/S
F/S
F/S
F/S
F/S
S
S
F/S
Action
Action
Action
Action
Action
Action
Action
Action
Action
Action
Action/
Chemical
Action/ Chemical
T&D
standards -
haz. waste
storage
T&D
standards
T&D
standards -
groundwater
T&D
standards
UST regs.
RCRA land
disposal
restriction
T&D
standards
Haz. waste
transport and
disposal
(T&D)
Land disposal
of solid waste
UIC
Groundwater
Spent Carbon
Standards for haz.
waste storage in
containers, surface
impoundments and
landfills
Requirements for
closure and post-
closure of haz. waste
facilities
Requirements for
groundwater
monitoring program
Sets standards for T
& D facility storage
and treatment,
design, emergency
and preparedness
plans
Sets requirements for
UST closure
Defines haz. waste
debris and applies to
wastes disposed off-
site
Sets requirements for
haz. waste man. unit
closure
Sets standards for
haz. waste generators
and transporters
Solid, nonhaz.
remediation derived
waste disposal
procedures
Permit and controls
required
Establishes
groundwater
management zones
Manifest/Transport/
Regenerate Spent
Carbon

Chemical Specific
CAA(l)
F
Chemical
Air emission
Sets regs. On
national primary and
secondary air quality
standards

139
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Table 35 Continued
Summary of ARARS
Southeast Rockford SCOU Focused Feasibility Study
CWA(2)
Air - Pollution
Control Board (8)
Air - Pollution
Control Board (9)
Air - Pollution
Control Board (10)
Air - Pollution
Control Board (11)
Air - Pollution
Control Board (12)
Air - Pollution
Control Board (13)
CAA(l)
Public Water
Supplies Poll.
Control Board (20)
Public Water
Supplies Poll.
Control Board (19)
SDWA (3)
RCRA (5)
RCRA (4)
RCRA (6)
RCRA (7)
F/S
S
S
S
S
S
S
F
S
S
F
F/S
F/S
F/S
F/S
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Water quality
Air permits
and provisions
Air permits
and provisions
Air permits
and provisions
Air permits
and general
provisions
Air emissions
Air emissions
VC
Primary
Drinking
Water
Standards
Illinois
Groundwater
Quality
MCLs
Solid Waste
Solid waste
Solid Waste
Solid Waste
Establishes water
quality standards
Lists provisions for
new sources
requiring permits
Defines emission
sources and sets
limitations
Sets air quality
standards and
measurement
methods for lead,
CO, nitrogen and
sulfur oxides
Sets provisions and
procedures for id.
and evaluating toxic
air contaminants
VOM emissions
limited to <20 ppm
CO emissions from
incinerators limited
to <500 ppm
VC emissions
limited to <10 ppm
MCLs, primary
drinking water
standards, analytical
requirements
Illinois groundwater
quality standards,
class designations
Sets MCLs for
public drinking
water
Sets criteria for
identifying haz.
waste
Sets treatment
standards for waste
extract incl.
hazardous waste
Identifies charac. of
haz. waste
List of haz. waste
from sources

140
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Table 35 Continued
Summary of ARARS
Southeast Rockford SCOU Focused Feasibility Study
Waste Disposal -
Pollution Control
Board (76)
Waste Disposal -
Pollution Control
Board (16)
Waste Disposal -
Pollution Control
Board (17)
Waste Disposal -
Pollution Control
Board (14)
Waste Disposal -
Pollution Control
Board (15)
Water - Pollution
Control Board (19)
Water - Pollution
Control Board (18)
S
S
S
S
S
S
S
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Chemical
Solid waste
and special
waste hauling
Hazardous
waste landfill
disposal
Hazardous
waste lists and
criteria
Hazardous
waste lists and
criteria
Hazardous
waste landfill
disposal
Effluent
Standards
Water Quality
Standards
Solid waste
permitting, san.
landfill closure and
post-closure, and
waste classification
Describes haz. waste
restrictions on
halogenated solvents
and liquid wastes
Solid waste
permitting, sanitary
landfills, closure &
post closure care,
and special waste
classifications
Identifying and
listing hazardous
waste (includes PCB
wastes under TSCA)
Defines landfill
waste disposal
restrictions,
treatment standards
and prohibitions
General and temp.
effluent standards
incl. NPDES
Water quality
criteria, public and
food processing
water supply

X
Location Specific
CWA (22)
Air - Pollution
Control Board (30)
Air - Pollution
Control Board (29)
Fish and Wildlife
Coordination Act
(23)
F
S
S
F
Location/Action
Location
Location
Location
Wetland
dredge and fill
permits
Air emissions
standards
Construction
permitting
Water body
modification
Requires no wetland
alteration if practical
alternative available
Distinguishes air
emissions standards
for Chicago and
Metro East Area
Application for
construction and
operating premits
including review
Any federal agency
must consult U.S.
Fish and Wildlife
prior to water body
modification
X

141
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Table 35 Continued
Summary of ARARS
Southeast Rockford SCOU Focused Feasibility Study
Flood Control Act
(27)
NEPA(25)
NEPA(24)
RCRA(27)
Waste Disposal -
Pollution Control
Board (31)
Water - Pollution
Control Board (33)
Water - Pollution
Control Board (32)
F
F
F
F/S
S
S
S
Location
Location
Location
Location
Location
Location
Location
Flood plain
construction
Floodplain
Management
Protection of
Wetlands
100 year
floodplain
RCRA permit
NPDES and
water related
permitting
Water use and
site specific
standards
Req. approval for
any construction in
floodway outside
Superfund boundary
Req. fed. agencies to
mitigate flooding
and preserve flood
plains
Requires federal
agencies to minimize
degradation and
preserve wetlands
Controls type of
construction in 100
year floodplain
RCRA permit
application rules,
applicability and
information
Includes NPDES
permit provisions
and other water
related permitting
Establishes site
specific water quality
standards in Illinois

142
-------
• Cost of periodic replacement of system components; and

• Net present value of capital and O&M costs based on a 30-year period.

Capital costs consist of direct (construction) and indirect (non-construction and
overhead) costs. Direct costs include expenditures for the equipment, labor, and materials
necessary to install remedial actions. Indirect costs include expenditures for
engineering, financial and other services that are not part of actual installation
activities, but are required to complete the installation of remedial alternatives. A bid
contingency of 10 to 15 percent, a scope contingency based on the level of difficulty to
implement the alternative and costs for engineering design and implementation of the
alternative were included as indirect costs.

Annual operation and maintenance costs are post-construction costs necessary to ensure the
continued effectiveness of a remedial action. Periodic replacement costs are necessary
when the anticipated duration of the remediation exceeds the design life of the system
component.

A present worth analysis is used to evaluate expenditures that occur over different time
periods, by discounting all future costs to a common base year, usually the current year.
A discount rate of seven percent was used for the present worth analysis. This allows the
cost of remedial action alternatives to be compared on the basis of a single figure
representing the amount of money that, if invested in the base year and disbursed as
needed, would be sufficient to cover all costs associated with the remedial action over
its planned life. The total present worth costs presented in this section were estimated
as accurately as possible, but were prepared for comparative purposes only. The actual
costs for each alternative may change upon detailed design and implementation, but the
overall cost difference of one alternative relative to another should not vary
significantly.

CHEMICAL SPECIFIC REQUIREMENTS

Federal
(1) Clean Air Act (42 U.S.C. §§ 7401 et seq.), National Primary and Secondary Ambient
Air Quality Standards (40 CFR 50), U.S. EPA regulations on National Primary and
Secondary Ambient Air Quality Standards.
(2) Clean Water Act (33 U.S.C. §§ 1251 et seq.), Water Quality Standards (40 CFR 131),
U.S. EPA regulations on establishing water quality standards.
(3) Safe Drinking Water Act (42 U.S.C. §§ 300f et seq.), Maximum Contaminant Levels (40
CFR 141.11-141.16), sets standards for contaminants in public drinking water
supplies.

(4) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Land Disposal
Restrictions (40 CFR 268) Subpart D, Treatment Standards, sets the treatment
standards for waste extract, specified technology and hazardous waste debris.
(5) Solid Waste Disposal Act, (42 U.S.C. §§ 6901 et seq.), Identification and Listing of
Hazardous Waste (40 CFR 261) Subpart B, Criteria for Identifying the Characteristics
of Hazardous Waste and for Listing Hazardous Waste, sets criteria for identifying a
hazardous waste.
(6) Solid Waste Disposal Act, (42 U.S.C. §§ 6901 et seq.), Identification and Listing of
Hazardous Waste (40 CFR 261) Subpart C, Characteristics of Hazardous Waste,
identifies the characteristics of a hazardous waste.
(7) Solid Waste Disposal Act, (42 U.S.C. §§ 6901 et seq.), Identification and Listing of
Hazardous Waste (40 CFR 261) Subpart D, List of Hazardous Waste, list of hazardous
waste from sources.

State
(8) Air — Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 35), Subtitle B - Subchapter A, Part 201: Permits and General
Provisions, lists general provisions for new sources requiring permitting.
-------
Exemptions from permit requirement are also given.
(9) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 35), Subtitle B - Subchapter C Emission Standards and
Limitations for Stationary Sources, Part 211: Definitions and General Provisions,
defines emission sources and related items; Part 212 Visible and Particulate Matter
Emissions sets emission limitations for particulate matter for a variety of
operations, i.e., incinerators or waste storage piles. Also see Parts 214- 219,
which gives information regarding specific types of emissions per operation e.g.,
sulfur, organic material, carbon monoxide and nitrogen oxide emissions.
(10) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 35), Subtitle B - Subchapter L, Part 243: Air Quality
Standards, sets air quality standards and measurement methods for PM-10,
particulates, sulfur oxides, carbon monoxide, nitrogen oxides, ozone and lead.
(11) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 35), Subtitle B - Subchapter F, Part 232: Toxic Air
Contaminants, sets provisions and procedures for identifying and evaluating toxic
air contaminants; exceptions are also given here.
(12) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 35), Subtitle B — Air Pollution, Part 215: Organic Material
Emissions Standards and Limitations, sets emission standards for volatile organic
material for a variety of operations.
(13) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 35), Subtitle B — Air Pollution, Part 216: Carbon Monoxide
Emissions, sets emission standards for carbon monoxide for a variety of operations.
(14) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board ( Title 35), Subtitle G - Subchapter C: Hazardous Waste
Operating Requirements, Part 721: Identification of Listing of Hazardous Waste,
includes PCB wastes regulated under TSCA, universal wastes, criteria for identifying
and listing hazardous waste, and lists of hazardous waste.
(15) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter C: Hazardous Waste
Operating Requirements, Part 728: Land Disposal Restrictions, defines land disposal
restrictions for wastes, waste specific prohibitions, treatment standards, and
prohibitions on storage.
(16) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter C: Hazardous Waste
Operating Requirements, Part 729: Prohibited Hazardous Wastes in Land Disposal
Units, describes general hazardous waste restrictions and restrictions on
halogenated solvents and liquid hazardous wastes in landfills.
(17) Waste Disposal - Illinois Environmental Protection Act, Section 21 (15 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter I: Solid Waste and
Special Waste Hauling, Part 807 includes information on solid waste permitting,
sanitary landfills and closure and post- closure care; Part 808 includes information
on special waste classifications.
(18) Water - Illinois Environmental Protection Act, Section 12 (415 ILCS 5/12), Pollution
Control Board (Title 35), Subtitle C - Part 302: Water Quality Standards, provisions
and water quality standards for general use, public and food processing water
supply, secondary contact and indigenous aquatic life and Lake Michigan. Procedures
for determining Water Quality Criteria are also in this Part.
(19) Water - Illinois Environmental Protection Act, Section 12 (415 ILCS 5/12), Pollution
Control Board (Title 35), Subtitle C - Part 304: Effluent Standards, general and
temporary effluent standards including NPDES effluent standards.
(20) Public Water Supplies - Illinois Environmental Protection Act, Section 14 (415 ILCS
5/14), Pollution Control Board (Title 35), Subtitle F - Part 611: Primary Drinking
Water Standards, includes provisions of the primary drinking water standards as well
as maximum contaminant levels ( MCLs)/goals, and analytical requirements.
(21) Public Water Supplies - Illinois Environmental Protection Act, Section 14 (415 ILCS
5/14), Pollution Control Board ( Title 35), Subtitle F - Part 620: Groundwater
Quality, includes Illinois groundwater quality standards as well as definition of
groundwater class designations.
-------
Location-Specific Requirements

Federal
(22) Clean Water Act, (33 U.S.C. §§ 1251 et seq. ) , Permits for Dredge or Fill Material
(Section 404), requires that no activity that adversely affects a wetlands shall be
permitted if a practicable alternative that has less effect is available.
(23) Fish and Wildlife Coordination Act (16 U.S.C. §§ 661 et seq.), requires that any
federal aqency that proposes to modify a body of water must consult U. S. Fish and
Wildlife Services.
(24) National Environmental Policy Act (42 U.S.C. § 4321) Executive Order 11990,
Protection of Wetlands, requires federal agencies to minimize the destruction, loss,
or degradation of Wetlands and preserve.

(25) National Environmental Policy Act (42 U.S.C. § 4321) Executive Order 11988,
Floodplain Management, requires federal agencies to reduce the risk of flood loss,
to minimize impact of floods, and to restore and preserve the natural and beneficial
value of flood plains.
(26) National Environmental Policy Act (42 U.S.C. § 4321) Statement of Procedures on
Floodplain Management and Wetland Protection ( 40 CFR 6) Appendix A to Part 6,
promulgates Executive Orders 11988 and 11990 regarding wetlands and flood plains.

State
(27) Flood Control Act (ILCS 14-28-1), requires formal approval for any construction,
excavation or filling in the floodway outside of the Superfund boundary.
(28) Water Resources Management Act (ILCS-14-25-7), requires registration of any
significant water withdrawal facility with the Department of Natural Resources. A
significant water withdrawal facility is defined as any water withdrawal facility
that, in the aggregate from all sources and by all methods, has the capacity to
withdraw more than 100,000 gallons of groundwater or surface water or a combination
of the two in one day. This would also include any potable pumps employed by the
facility.
(29) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 35), Subtitle B - Subchapter A, Part 201, Subpart D: Permit
Application and Review Process, describes contents of the application for
construction and operating permits and the review process.
(30) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 35), Subtitle B - Subchapter C Emission Standards and
Limitations for Stationary Sources, Part 218: Organic Material Emission Standards
and Limitations for the Chicago Area; Part 219: Organic Material Emission Standards
for the Metro East Area, distinguishes emission standards for the Chicago Area and
the Metro East Area - see detailed regulation for applicability to the S. E.
Rockford site.
(31) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter B: Permits, Part 703:
RCRA Permit Program, rules on application for and issuance of RCRA permits;
applicability and information requirements.
(32) Water - Illinois Environmental Protection Act, Section 12 (415 ILCS 5/12), Pollution
Control Board (Title 35), Subtitle C - Part 303: Water Use Designations and Site
Specific Water Quality Standards, provisions and site specific water quality
standards for water bodies throughout Illinois.
(33) Water - Illinois Environmental Protection Act, Section 12 (415 ILCS 5/12), Pollution
Control Board (Title 35), Subtitle C - Part 309: Permits, Subpart A includes
provisions for NPDES permits and Subpart B includes provisions for all other water
related permitting.

ACTION-SPECIFIC REQUIREMENTS

Federal
(34) Clean Air Act, (42 U.S.C. §§ 7401 et seq.), National Primary and Secondary Ambient
Air Quality Standards (40 CFR Part 50), specifies maximum primary and secondary 24-
-------
hour concentrations for particulate matter.

(35) Clean Water Act, (33 U.S.C. §§ 1251 et seq.), Permits for Dredge or Fill Material
(Section 404), provides requirements for discharqes of dredqed or fill material.
Under this requirement, no activity that affects a wetland shall be permitted if a
practicable alternative that has less impact on the wetland is available. If there
is no other practicable alternative impacts must be mitigated. A Section 401 water
quality certification may be required from Illinois EPA if wetlands or other waters
of the state are impacted.
(36) Department of Transportation Rules for Transportation of Hazardous Materials, (49
CFR Parts 107, 171.1-171.5), outlines procedures for the packaging, labeling, and
transporting of hazardous materials.
(37) Noise Control Act, as amended (42 U.S.C. §§ 4901 et seq.); Noise Pollution and
Abatement Act (40 U.S.C. §§ 7641 et seq.), Noise Emission Standards for Construction
Equipment (40 CFR 204), the public must be protected from noise that jeopardizes
health and welfare.
(38) Protection of Archeological Resources (32 CFR Part 229, 229.4; 43 CFR Parts 107,
171.1-171.5), develops procedures for the protection of archeological resources.
(39) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Guideline for the
Land Disposal of Solid Wastes (40 CFR 241), Part B - Requirements and Recommended
Procedures, solid, nonhazardous wastes generated as a result of remediation must be
managed in accordance with federal and state regulations; this is applicable to
waste generated by the remedial action.
(40) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Standards for
Hazardous Waste Generators (40 CFR 262) and Standards for Hazardous Waste
Transporters (40 CFR 263); general requirements for packaging, labeling, marking,
and manifesting hazardous wastes for temporary storage and transportation offsite.
Any residues determined to be RCRA hazardous waste destined for offsite disposal are
subject to manifest requirements. Remedial actions involving offsite disposal of
RCRA listed wastes will be subject to this requirement.
(41) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Interim Status
Standards for Owners and Operators of Hazardous Waste Treatment Storage and Disposal
Facilities (40 CFR 265), Storage, and Disposal General Facility Standards, Subpart
G, Closure and Post-closure, sets general requirements for closure of interim status
hazardous waste management units.
(42) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Land Disposal
Restriction- RCRA (40 CFR 268), RCRA Land Disposal Restriction, defines hazardous
waste debris. This requirement is applicable to those RCRA hazardous wastes that
will be disposed offsite.
(43) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Technical
Standards and Corrective Action Requirements for Owners and Operators of Underground
Storage Tanks (40 CFR 280), Subpart G, Out- of- Service UST Systems and Closure,
sets requirements for temporary and permanent UST closure, and assessing the site
closure.
(44) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Standards for
Owners and Operators of Hazardous Waste Treatment Storage, and Disposal Facilities (
40 CFR 264), Subpart B, General Facility Standards; Subpart C, Preparedness and
Prevention; Subpart D, Contingency Plan and Emergency Procedures; Subpart E,
Manifest System, Record Keeping and Reporting, establishes general requirements for
storage and treatment facility location, design and inspection, waste compatibility
determination, emergency contingency plans, preparedness plans, and worker training.
(45) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Standards for
Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities
(40 CFR 264) Subpart F, Releases from Solid Waste Management Units, details
requirements for a groundwater monitoring program to be installed at the site.
(46) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Standards for
Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities
(40 CFR 264) Subpart G, Closure and Post-Closure, defines specific requirements for
closure and post-closure of hazardous waste facilities.
(47) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seq.), Standards for
-------
Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities
(40 CFR 264), Subpart I, Use and Management of Containers; Subpart J, Tank Systems;
Subpart K, Surface Impoundments; Subpart L, Waste Piles; and Subpart N, Landfills.
Containers, surface impoundments, and landfills used to store hazardous waste must
be closed and in good condition. Tank systems must be adeguately designed and have
sufficient structural strength and compatibility with the wastes to be stored or
treated to ensure that it will not collapse, rupture, or fail, including secondary
containment. Waste piles must be designed to prevent migration of wastes out of the
pile into adjacent subsurface soil or groundwater or surface water at any time
during its active life. Disposal of special wastes in landfills must be done in
accordance with reguirements.
(48) Solid Waste Disposal Act, as amended (42 U.S.C. §§ 6901 et seg.), Standards for
Owners and Operators of Hazardous Waste Treatment, Storage, and Disposal Facilities
(40 CFR 264), Subpart DD, Containment Building. Hazardous waste and debris may be
placed in units known as containment buildings for the purpose of interim storage or
treatment.

The following is a list of potential ARARs for Superfund sites that discharge treated
groundwater to Publicly Owned Treatment Works (POTW) :

(49) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), National Pollutant Discharge
Elimination System (NPDES) Permit Regulations [40 CFR 122.42 (b)], reguires
notification of issuing authority of re-evaluation of POTW pretreatment standards.
In the event that the POTW does not have a local limitation for a particular
pollutant found in the leachate from a Superfund site, it must re-evaluate its local
limitations, and develop a limitation if necessary to protect the POTW from
interference, pass-through, or contamination of the sewage sludge.
(50) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), National Pretreatment Standards (40
CFR 403.5), discharge to a POTW must not interfere, pass through untreated into the
receiving waters, or contaminate sludge.
(51) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), National Pretreatment Program
Reguirements for POTWs (40 CFR 403.8 (f)) .

The following is a list of potential ARARs for Superfund sites that discharge treated
groundwater to surface water bodies:

(52) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), NPDES Permit Regulations (40 CFR
122.21), permit application must include a detailed description of the proposed
action including a listing of all reguired environmental permits.
(53) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), NPDES Permit Regulations (40 CFR
122.44), establishes limitations, standards and other NPDES permit conditions,
including federally approved State water guality standards.
(54) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), NPDES Permit Regulations (40 CFR
122.44(a)), Best Available Technology (BAT) for toxic and non- conventional
wastewater or Best Conventional Technology (BCT) for conventional pollutants.
(55) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), NPDES Permit Regulations (40 CFR
122.44(b)), effluent limitations and standards reguirements under Section 301, 302,
303, 307, 318 and 405 of the Clean Water Act (CWA) .
(56) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), NPDES Permit Regulations, Water
Quality Standards and State Reguirements ( 40 CFR 122.44 ( d)), Water Quality Based
Effluent Limitations (WQBELs), any reguirements in addition to or more stringent
than promulgated effluent limitations and guidelines or standards under Section 301,
304, 306, 307, 318 and 405 of the CWA.
(57) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), NPDES Permit Regulations, Technology
Based Controls for Toxic Pollutants (40 CFR 122.44 ( e)), discharge limits
established under paragraphs (a), (b), or (d) of 40 CFR 122.44 must be established
for toxins to be discharged at concentrations exceeding levels achievable by the
technology-based (BAT/BCT) standards.
(58) Clean Water Act, (33 U.S.C. §§ 1251 et seg.), NPDES Permit Regulations (40 CFR
122. 44 (i)), reguires monitoring of discharges to ensure compliance.
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(59) Clean Water Act, (33 U.S.C. §§ 1251 et seq.), NPDES Permit Regulations (40 CFR
125.100), the site operator must include a detailed description of the proposed
action including a listing of all required environmental permits.
(60) Clean Water Act, (33 U.S.C. §§ 1251 et seq.), (40 CFR Part 131), states are granted
enforcement jurisdiction over direct discharges and may adopt reasonable standards
to protect or enhance the uses and qualities of state surface water bodies.
(61) Clean Water Act, (33 U.S.C. §§ 1251 et seq.), (40 CFR 136.1-136.4), requires
adherence to sample preservation procedures including container materials and sample
holding times.
(62) Fish and Wildlife Coordination Act, (16 U.S.C. §§ 661 et seq.), requires that any
federal agency that proposes to modify a body of water must consult the U. S. Fish
and Wildlife Services.

State
(63) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board ( Title 35), Subtitle B - Subchapter C Emission Standards and
Limitations for Stationary Sources, Part 211: Definitions and General Provisions
(defines emission sources and related items); Part 112 Visible and Particulate
Matter Emissions, sets emission limitations for particulate matter for a variety of
operations, i.e., incinerators or waste storage piles. Also see Parts 214-219 that
gives information regarding specific types of emissions per operation (e.g., sulfur,
organic material, carbon monoxide and nitrogen oxide emissions). These regulations
may apply to some of the presumptive remedies in which emissions will be a factor,
e.g., incineration.
(64) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 55), Subtitle B - Permits of Air Pollution, Part 201:
Prohibition of Air Pollution, no person shall cause or threaten or allow the
discharge or emission of any contaminant into the environment.
(65) Air - Illinois Environmental Protection Act, Section 9 (415 ILCS 5/9), Pollution
Control Board (Title 35), Subtitle B - Air Pollution, Part 212; Visual and
Particulate Matter Emission, emission standards for incinerators.
(66) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter B: Permits, Part 703:
RCRA Permit Program, rules on application for and issuance of RCRA permits;
applicability and information requirements.
(67) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter C: Hazardous Waste
Operating Requirements, Parts 722 and 723, includes standards applicable to
generators and transporters of hazardous waste, respectively.
(68) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter C: Hazardous Waste
Operating Requirements, Parts 724 and 725, includes standards applicable to owners
and operators of hazardous waste treatment, storage and disposal facilities (Part
735 is for Interim Status) - corresponds to 40 CFR Parts 264 and 265.
(69) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter C: Hazardous Waste
Operating Requirements, Part 726, includes standards for the management of specific
hazardous waste and specific types of hazardous waste management facilities; often
applies to hazardous waste being used in such a way as to constitute disposal.
(70) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter C: Hazardous Waste
Operating Requirements, Part 728: Land Disposal Restrictions, defines land disposal
restrictions for wastes, waste specific prohibitions, treatment standards, and
prohibitions on storage.
(71) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board ( Title 35), Subtitle G - Subchapter C: Hazardous Waste
Operating Requirements, Part 729: Prohibited Hazardous Wastes in Land Disposal
Units, describes general hazardous waste restrictions and restrictions on
halogenated solvents and liquid hazardous wastes in landfills.
(72) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
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Pollution Control Board (Title 35), Subtitle G - Subchapter D: Underground Injection
Control and Underground Tank Storage Program, Part 731: Underground Storage Tanks,
regulations regarding USTs.
(73) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter D: Underground Injection
Control and Underground Tank Storage Program, Part 740: Site Remediation Program,
procedures established for investigation and remediation at sites where there is a
release, or suspected release of hazardous substances, pesticides, or petroleum for
review and approval of these activities.
(74) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter D: Underground Injection
Control and Underground Tank Storage Program, Part 742: Tiered Approach to
Corrective Action Objectives, procedures for evaluating the risk to human health
posed by environmental conditions and develop remediation objectives that achieve
acceptable risk level. Also, to provide for adeguate protection of human health and
the environment based on risks to human health posed by environmental conditions
while incorporating site related information.
(75) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter H: Illinois "Superfund"
Program, Part 750: Illinois Hazardous Substances Pollution Contingency Plan,
regulation which is applicable whenever there is a release or a threat of a release
at a site; this part assigns responsibility, organization and guidelines for phased
hazardous substance response including development of remedial alternatives and
engineering methods for on-site actions and remedying releases.
(76) Waste Disposal - Illinois Environmental Protection Act, Section 21 (415 ILCS 5/21),
Pollution Control Board (Title 35), Subtitle G - Subchapter I: Solid Waste and
Special Waste Hauling, Part 807 includes information on solid waste permitting,
sanitary landfills and closure and post-closure care; Part 808 includes information
on special waste classifications.
(77) Water - Illinois Environmental Protection Act, Section 12 (415 ILCS 5/12), Pollution
Control Board (Title 35), Subtitle C - Part 304: Effluent Standards, general and
temporary effluent standards including NPDES effluent standards.
(78) Water - Illinois Environmental Protection Act, Section 12 (415 ILCS 5/12), Pollution
Control Board (Title 35), Subtitle C - Part 309: Permits, Subpart A includes
provisions for NPDES permits and Subpart B includes provisions for all other water
related permitting.
(79) Public Water Supplies - Illinois Environmental Protection Act, Section 14 (415 ILCS
5/14), Pollution Control Board (Title 35), Subtitle F - Part 620: Groundwater
Quality, prescribes various aspects of groundwater guality including methods of
classification of groundwater, non-degradation provisions, standards for guality of
groundwater and various procedures and protocols for the management and protection
of groundwater.

Other Requirements to be Considered (TBCs)

Federal
(80) Geological Survey Professional Paper 579-0, Elemental Composition of Surficial
Materials in the Conterminous United States, 1971. Schacklette, H. T., J. C.
Hamilton, J. G. Boerrgen and J. M. Bowles, provides background levels of metal in
soils for the United States.
(81) Occupational Safety and Health Administration Standards (29 CFR Part 1910;
1910.1000), Subpart Z, Toxic and Hazardous Substances, sets worker exposure limits
to toxic and hazardous substances and prescribes the methods for determination of
concentrations.
(82) Occupational Safety and Health Administration Standards (29 CFR Part 1910; 1910.95),
Subpart G, Occupational Noise Exposure, sets limits of worker exposure to noise
during the performance of their duties.
(83) Occupational Safety and Health Administration Standards (29 CFR Part 1910;
1910.120), Hazardous Waste Operations and Emergency Response, sets the standards for
workers conducting hazardous waste operations and emergency response.
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(84) Occupational Safety and Health Administration Standards (29 CFR Part 1926),
specifies the type of safety equipment and procedures to be followed during site
remediation.
(85) Occupational Safety and Health Administration Standards Record keeping, Reporting
and Related Regulations (29 CFR Part 1904), establishes Record keeping and reporting
requirements for an employer under OSHA.
(86) OSWER Directive 9355.0-48FS - Presumptive Remedies: Site Characterization and
Technology Selection for CERCLA Sites with Volatile Organic Compounds in Soil,
September 1993, addresses the vadose zone only.
(87) OSWER Directive 9355.3-01, October 1988 Interim Final - Guidance for Conducting
Remedial Investigations and Feasibility Studies under CERCLA Development and
Screening of Remedial Alternatives, development of the FS Work Plan.
(88) OSWER Directive 9355.4-01-Guidance on Remedial Actions for Superfund Sites with PCB
Contamination, sets soil PCB clean-up levels and management controls for PCB
concentrations at Superfund sites.
(89) OSWER Directive 9355.4-12-Revised Interim Soil Lead Guidance for CERCLA Sites and
RCRA Sites and RCRA Corrective Action Facilities, sets soil lead clean- up levels
for Superfund sites.
(90) Safe Drinking Water Act (42 U.S.C. §§ 300f et seq. ) , Subpart F, Maximum Containment
Level Goals (40 CFR 141.50-141.51), establishes enforceable clean-up goals for
drinking water based on technology and health risk.
(91) Threshold Limit Values, consensus standards for controlling air quality in work
place environments; used to assess site inhalation risks for soil removal
operations.
(92) U. S. Environmental Protection Agency, RCRA Guidance Manual for Subpart G Closure
and Post-Closure Standards and Subpart H Cost Estimating Requirements, January 1987.
Provides guidance on closure and post- closure standards and cost estimating
requirements for hazardous waste management units.
(93) U. S. Environmental Protection Agency, Disposal of Polychlorinated Biphenyls,
Proposed Rule, December 6, 1994. Provides for disposal of non-liquid PCB remediation
waste generated by clean-up process of their existing concentration; provides for a
risk-based remediation option for PCB remediation waste.
(94) U. S. Environmental Protection Agency, Soil Screening Guidance, December 1994.
Provides generic risk-based soil screening values for Superfund sites.
(95) U. S. Environmental Protection Agency Region III, Risk-Based Concentration Table,
Smith R., 1995. Provides risk-based screening values for groundwater and soil
concentrations.
(96) U. S. Environmental Protection Agency, Integrated Risk Information System (IRIS),
1995-1996. Provides reference doses and cancer potency slopes for calculating the
hazard index or incremental cancer risk for specific site contaminants.

(97) U. S. Environmental Protection Agency, Interim Policy for Planning and Implementing
CERCLA Off-Site Response Actions, November 5, 1995. Specifies appropriate method of
off-site treatment on disposed of waste from a Superfund site.
(98) U. S. Environmental Protection Agency, Summary Quality Criteria for Water, Office of
Science and Technology, 1992. Provides ambient water quality criteria.
(99) U. S.. Environmental Protection Agency, Quality Criteria for Water, Office of Water
Regulation and Standards, U. S. EPA 440/5-86-001, 1986. Provides ambient water
quality criteria.
(100) U. S. Environmental Protection Agency, Ambient Water Quality Criteria for
Polychlorinated Biphenyls, U. S. EPA 440/ 5- 80- 068, 1980. Provides ambient water
quality criteria for PCBs.
(101) U. S. Environmental Protection Agency, Risk Assessment Guidance for Superfund:
Environmental Evaluation Manual, Volume II, Final Report, EPA/540/1-89/002, 1989.
Provides guidance for conducting ecological risk assessments.
(102) U. S. Environmental Protection Agency, Risk Assessment Guidance for Superfund.
Volume I. Human Health Evaluation Manual Supplemental Guidance. Standard Default
Exposure Factors, Interim Final, March, 1991. OSWER Directive # 9285.6-03, 1991.
Provides exposure factors for estimating hazard or risk in human health risk
assessments.
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(103) U. S. Environmental Protection Agency, Risk Assessment Guidance for Superfund.
Volume I: Human Health Evaluation Manual, Part A, December, 1989. U. S. EPA
540/1-89/002. Office of Emergency and Remedial Response. Provides guidance on
preparing a baseline human health risk assessment using the four steps, data
evaluation, exposure assessment, toxicity assessment, risk characterization.
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