II
United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPAIROD/R05-921218
September 1992
PB93-964133
&EPA
Superfund
Record of Decision:
Tri County Landfill, IL
EPA Report Collection
L~O~~ti°Rn f!esource Center
P. '" ~/On 3
hdadelphia, PA 19107
. Hazardous Waste Collection
~.. Informotfon Resource Center
I::, US EPA Region 3 .
~~>~,. PA 19107
u. S. Environmental Protection Agency
Region III Hazardous Waste
Technical Information Center
84 1 Chestnut Street, 9th Froor
Philadelphia, PA 19107
.'$
-------
"I
NOTICE
The appendices listed in the index that are not found in this document have been removed at the request of '
, the issuing agency. They contain material which supplement. but adds no further ~ information to
the content of the document. AJI supplemen1al material is, however, conlBilled In the admii8a.1iYe record
for this site.
-------
50272.101
REPORT DOCUMENTATION 11. REPORT NO. 1 ~ 3. Recipient'o Acc:e8oion No.
PAGE EPA/ROD/R05-92/218
4. Tille ond SubIItIot 5. Report Dol8
SUPERFUND RECORD OF DECISION 09/30/92
Tri County Landfill, IL
6.
First Remedial Action - Final
7. Author(o) 8. Performing Orgonizotion RepL No.
8. I'8rforrnlng Orplnizotlon No... ond Add- 10. ProjectlTllklWo,k Unh No.
11. Controct(C) 0' Gront(G) No.
(C)
(G)
1~ Sponoo,lng Orgonlzotlon""" ond Add- 13. Type of Report & Period Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. SUpplemonllry -
PB93-964133
.
16. Abotroct (Urnh: 2110 woraa)
The 66-acre Tri County Landfill (TCL) site comprises two former landfills the Tri
County Landfill and the Elgin Landfill, located near the junction of Kaner Cook and
Dupage Counties, Illinois. The two disposal operations overlapped to the point where
the two landfills were indistinguishable. Land use in the area is predominantly
agricultural. The local residents and businesses use private wells as their drinking
water supply. Prior to the 1940's, both landfills were used for gravel mining
operations. From 1968 to 1976, the TCL received liquid and industrial waste. State
and county inspection reports revealed that open dumping, area filling, and dumping
into the abandoned gravel quarry had occurred at the site. In addition, confined
dumping, inadequate daily cover, blowing litter, fires, lack of access restrictions,
and leachate flows were typical problems reported. In 1981, the landfill was closed
with a final cover. From 1961 to 197 6, the Elgin landfill received brush, commercial
rubbish, industrial wastes, and incinerator ash without a formal waste disposal method.
As a result of residents' complaints of suspected surface and ground water
contamination, the state ordered the landfills to stop contaminating, pay penaltiesr
(See Attached Page)
17. Document Anolyolo L Dncriptoro
Record of Decision - Tri County Landfill, IL
First Remedial Action - Final
Contaminated Media: soil, sediment, debris, gw, sw, air
Key Contaminants: VOCs (benzene, TCE), other organics (PARs, PCBs, pesticides),
metals (arsenic)
b. IdentlfieroIOpen-Ended Torrno
c. COSATI RoldlGroup
18. AveUobllity Stotemont 19. Secu,lty CIllO (Thlo Report) 21, No. of P-
None 49
20. Security CIllO (Thio Poge) 22. Price
None
272 (4- 7)
(Soe ANSI-Z38.18)
SH In8truction. on R.verse
(Formerly NT1S-35)
Department of Commerce
-------
EPA/ROD/ROS-92/218
Tri County Landfill, IL
First Remedial Action - Final
Abstract (Continued)
and post bonds. The landfills never fully complied. Further investigations revealed
contamination in the soil and ground water from VOCs, SVOCs, metals, and pesticides as
well as venting of methane gas. This ROD addresses a final remedy for the soil,
sediment, debris, ground water, surface water, and air at the site. The primary
contaminants of concern affecting these media are VOCs, including benzene and TCE; other
organics, including PARs, PCBs, and pesticides; and metals, including arsenic. .
The selected remedial action for the site includes excavating and consolidating
contaminated sediment from the leachate ditch with contaminated onsite soil and drummed
drill cuttings; installing a clay cap over these materials and regrading and revegetating
the site; installing interceptor trenches to collect contaminated onsite ground water and
leachate with pretreatment, if necessary, prior to either onsite discharge to surface
water or offsite discharge to a POTW, as determined during the RD; diverting surface
water from the waste areas, and collecting and treating surface water offsite; treating
landfill gases using a series of gas extraction wells connected to a blower/flaring
facility, prior to discharge to the atmosphere; assessing and mitigating affected
wetlands; providing for contingency measures to address changed conditions or previously
unknown contamination problems; allowing offsite contaminated ground water to naturally
attenuate; monitoring soil, sediment, and surface water; and implementing institutional
controls including deed, land, and ground water use restrictions, and site access
restrictions such as fencing. The estimated present worth cost for this remedial action
is $12,624,000, which includes an annual O&M cost of $243,500 for 2 years.
PERFORMANCE STANDARDS OR GOALS:
There are no chemical-specific standards established for soil and sediment; however,
risk-based levels or local background concentrations may be utilized. The selected
remedy will reduce potential exposure to contaminated ground water to within acceptable
risks of 1 x 10-4to 1 x 1~6 excess cancer risk and an HI of less than 1.
-------
RECORD OF DECISION
SELECTED REMEDIAL ALTERNATIVE
DECLARATION
SITE NAME AND LOCATION
Tri-CountyjElgin Landfill Site
. Elgin, Illinois
STATEMENT OF BASIS AND PURPOSE
This decision document presents the United States Environmental
Protection Agency's (U.S. EPA) selected remedial action for the
Tri-CountyjElgin Landfill Superfund Site near Elgin, Illinois.
This decision document was 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 Contingency Plan (NCP). This decision
is based on the administrative record file for this site.
The State of Illinois concurs on the selected remedy.
ASSESSMENT OP THE SITE
Actual or threatened releases of hazardous substances from
site, if not addr~sed by implementing the response action
selected in this R.QD, present an imminent and substantial
endangerment to pub~ic health, welfare, or the environment.
this
DESCRIPTION OF THE. REMEDY
This remedy is intended to be the final action for the site.
This remedy addresses all contaminated media and includes:
landfill wastes, ~taminated soil and sediment, contaminated
ground water, and the emission of landfill gases.
The major components of the selected remedy include:
Excavation and consolidation of contaminated sediments
under the landfill cap;
Construction of a iandfill cover (cap) in compliance
with Title ~5, Illinois Solid and Special Waste
Management Regulations, ~ 807.305 and RCRA Subtitle D
cover requirements, as applicable;
Collection, treatment, and disposal of contaminated
ground water;
Active collection and treatment of landfill gases;
-------
- 2 -
Comprehensive monitoring program to ensure the
effectiveness of the remedy:
Institutional controls to limit land and groundwater
use; and
provisions for contingency measures to address changed
conditions or previously unknown contamination
problems. (eg. migrating contaminant plumes)
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost effective. This remedy utilizes
permanent solutions and alternative treatment technologies to the
maximum extent practicable. However, due to the large volume and
the heterogenous distribution of waste at the site, treatment as
a principle element was not considered practicable at this site.
Thus, this remedy does not satisfy the statutory preference for
treatment that reduces toxicity, mobility, or volume as a
principal element of th~ remedy. However, treatment is a
secondary element of this remedy in that landfill gases and
contaminated ground water (if necessary) will be treated,
resulting in the destruction of contaminants.
Because this remedy will result in hazardous substances remaining
on-site above health-based levels, a review will be conducted
within five years after commencement of the remedial action to
ensure that the remedy continues to provide adequate protection
of human health and the environment.
g/~ /~Z-
Date'
-------
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
TRI-COUNTY/ELGIN LANDFILLS
ELGIN, ILLINOIS
I. .
site Name. Location. and DescriDtion
The Tri-County Landfill/Elgin Superfund site (TCL) encompasses
both the Tri-County and Elgin Landfills. The site is located in
northeastern Illinois on the east side of Kane County near the
triple junction of Kane, Cook, and Dupage counties (see Figure
l). The Tri-County Landfill consists of approximately 46 acres,
and is an inactive landfill located approxtmately 2/3 of a mile
. southeast of the Village of South Elgin. The Elgin Landfill
(approximately 20 acres) is located immediately adjacent to the
northern boundary of the Tri-County Landfill.
On the west and southwest boundaries of the site, the Tri-County
and Elgin Landfill properties are enclosed by the Prairie Path,
which is a former railroad right of way converted into a public
bicycle and footpath (see Figure 2). The east and southeast site
boundary is bordered by Route 25, along which several commercial
businesses are located. The northern property boundary of the
Elgin Landfill is bordered by agricultural land~
The land surrounding the Tri-County and Elgin Landfills to the
north and to the east is used predominantly for agriculture. The
land to the west of the site is occupied by the Woodland.
Landfill. The Woodland Landfill is an active sanitary landfill
which has accepted municipal and selected special wastes since
1976.
Most of the residential properties in the vicinity of the
Tri-County and Elgin Landfills are located in the Village of
South Elgin, approximately 2/3 of a mile west of the site, west
of the Woodland Landfill. The residences nearest the site are
located along Dunham and Stearns Roads approximately 1,000 feet
southeast of the site. A farm house is located approximately
1,200 feet north of the site. Other residences, most of which
are single-family dwellings, are scattered throughout the area
surrounding the site.. Many of the homes and businesses in the
area of the landfills rely on their own private wells to provide
drinking water and water for- general use.
Surface water features in the area surrounding the site include
the Fox River, Brewster Creek, an unnamed tributary to Brewster
Creek, and their associated wetlands. The Fox River is located
approximately one mile to the west of the site. Brewster Creek
is a small, east to west flowing stream located 1/2 of a mile
south of the site. The unnamed tributary to Brewster Creek flows
toward the site from the east, by-passes the site on the south
side, and continues to flow south to discharge into Brewster.
Creek, which flows west into the Fox River.
-------
POOR QUAUTY
/ ,
-
- --
.,- .'
" ./':"
Figure 1
Regiona' Site Location Mil
Tri-County and Elgin Landfills
,..,_:- ....
-------
I
WOOd"'"
LandHII
. .~ - "'I:
,"
,.
~
~.A.'
..... A .......
~.
POOR QUALITY
OmGT1\tAL I
,
I
,
I
I
AGRICUL TURAL I
;: fEW I . . .'
'f:::mt'P.'I.","",IIIftW.....,"",nftlW"".~'I.'I.~":P.IP.'I.'l.ftlltll"""......
I~ ,
.: :.
W .
~ Elg'n landfill
.'
.:
11---
~!
.' ~
1
? ..
~.,~
.........
,...,- .
F.. .,.....
Deep
41'. T......
. '". -
-
,
"
" .
rf
:;
'r'
,.
'.
..~ ','
.' ,tJ ". "
T;'-Cbunty landfill
AGRICUL TUi
FJELD
.. .
"
....... ~ ".'
"'.J.' .
;;'~.~''';'''':: ,:ii --~I
~,": f . -,.. 'I, " ,~, .. .
" ~., .. '1..~1 ~.p ,"N~ '
. " . ~ .......
" . - I
"",'~:<~~l - .
ARC,w';;'! >..,
. "".' .i1-' -:.~f
". '"
::-~~ .
..
- '
~~
"
, .
. .
'~.n....4 .', '.'
Dr.......,. .
O. 225 '450 .' ~"., 900 n
~Ximar. ScaJe in Feel = .. ~
LEGEND
-..- Site Propeny Bouftda,y
-.-- Propefty Boundary Berween Landfills
......... AR:wximare Oualne of Lanc:mlled Area
Fiqure 2
Site M...
Trf.County and Elgin Landfills
. . Elgin, "'Ino. .
&.......... 1OG1
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 2
:I:I.
site Historv and Enforcement Activities
The site includes two adjacent landfills, Tri-County Landfill and
the Elgip Landfill, respectively. While the two landfills
supposedly had separate operations, historical aerial photographs
indicate that the two disposal operations overlapped, to the
point where the two landfills were indistinguishable.
In May 1971, the Elgin Jaycees, with the support of the Village
of South Elgin and village residents, filed a complaint with the
Illinois Pollution Control Board (IPCB). This complaint named
the Tri-County Landfill Company and Elgin Landfill Company, which
owned and ope~ated the adjacent Elgin Landfill, as respondents.
The IPCB complaint was initiated because of suspected surface
water and ground water contamination.
On April 12, 1973, the IPCB ordered the respondents to "cease and
desist the causing of water pollution and the threat of water
pollution on their respective sites", and to pay specified
penalties and post bonds. State records indicate that several
lawsuits and appeals ensued involving both landfills subsequent
to the IPCB decision, and that the landfills continued to operate
during the pe. lency of the litigation. Apparently, the landfill
owners and operators never fully complied with all of the terms
of the decision. ,jt:'i
A short history fo~ each landfill is provided below:
Tri-County Landfill
Prior to the 1940's, the Tri-County Landfill site was part of a
gravel mining operation. Waste disposal at the Tri-County
Landfill reportedly began in April 1968 and continued until
December 1976. T~ Elgin-Wayne Disposal Company had initiated
disposal operation.~ at the landfill under a disposal permit
issued by Kane County. During the period from 1968 to 1972,'
operations at the Tri-County Landfill were managed by the
Elgin-Wayne Disposal Company. In 1970, the Tri-County Landfill
Company (the actual owner of the property on record) was issued a
permit by the Illinois Department of Health to operate the site
as a solid waste disposal landfill (Permit 1970-DS-43).
The Tri-county Landfill Company was issued an operational solid
waste disposal permit by the Illinois Environmental Protection
Agency (IEPA) in 1975 (Permit 1975-24-0P) and a supplemental
permit was issued by the IEPA in 1976 (Supplemental Permit
1976/409). Howev~r, site operations continued under the
management of the Elgin-Wayne Disposal Company until 1976.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 3
The Kane County Building and Zoning Permit, originally issued in
1970, stated that landfilling was to occur in trenches. However,
inspection records on file at the IEPA cite open dumping at the
landfill and that the "area" method of landfilling was
occasionally used. Background data suggests that waste was
disposed of directly into the abandoned gravel quarry.
Quantities and the specific nature of waste are not well known.
Most of the dumping of liquid and industrial waste reportedly
occurred at the Tri-County Landfill during the interval from 1968
to 1974. Table 1 is a list of reported wastes and their
estimated quantities that were accepted at the Tri-County
Landfill. The locations of hazardous waste disposal in the
landfill are not known. Typical problems reported at the
landfill included: confined dumping, inadequate daily cover,
blowing litter, fires, lack of access restrictions, and leachate
flows.
Although the landfill operations ceased in December of 1976, the
existing cover was not emplaced until early 1981. Correspondence
from the IEPA to Waste Management, Inc. on April 14, 1981
indicated that the landfill had been satisfactorily closed and
covered. The state did caution Waste Management, Inc. that if
problems relating to leachate, surface drainage or erosion were
to develop in the future, they should be promptly corrected.
Additional correspondence from the state of Illinois to Waste
Management, Inc. through the end of 1981 cites erosion, ponding,
and leachate problems occurring at the Tri-county Landfill.
Elqin Landfill
Like the Tri-County Landfill, the Elgin Landfill property was the
site of a sand and gravel mining business that was operated by
the Material Service Company until the late 1950's. Waste
disposal operations began in 1961 under the name of the Elgin
Landfill Company. No formal method of waste disposal was
employed at the site and it appears that irregular areas were
excavated, filled with waste and eventually covered. The Elgin
Landfill originally operated under a permit issued by Kane County
in 1961. .
Records detailing the amount and type of waste disposed either do
not exist or are not available. Reportedly, primarily brush,
residential and commercial rubbish, industrial waste and
incinerator ash were disposed of at the landfill from 1961-1976.
Table 1 presents a summary of suspected waste streams disposed of
into the Elgin Landfill.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 4
111. Hiahliahts of Communi tv Participation
Compliance with the public participation requirements of Section
113 (k) (2) (B) (i-v) of CERCLA/SARA, have been achieved for the TCL
site by:
A press release was issued announcing a public
"Remedial Investigation/Feasibility Study (RI/FS) kick-
off" meeting to be held to inform the community as to
u.S. EPA plans;
The public "RI/FS kick-off" meeting was held in
September 1988, announcing the initiation of the RI/FS;
A fact sheet was developed and distributed in
conjunction with the September 1988 meeting;
A site information repository was established at the
Gail Borden Public Library to allow local access to
site-related documents;
A fact sheet was sent to the community relations'
mailing list in January 1992, updating them on the
progress of the project;
An Administrative Record has been
the RI, Baseline Risk Assessment,
documents, and has been placed in
repository;
compiled, including
FS, and other
the site information
A formal advertisement announcing the commencement of
the public comment period, the availability of the July
24, 1992, proposed plan, and the time and place of the
August 4, 1992, public meeting was placed in the Elgin
Daily Courier, a local paper of general circulation;
The Proposed Plan for remedial action was released for
public comment and placed into the Administrative
Record on July 24, 1992.
A thirty (30) day ~omment period was established and
scheduled to end on August 23, 1992;
A pUblic meeting was held on August 4, 1992, at the
South Elgin Village Hall at which u.s. EPA and IEPA
presented the Proposed Plan to the community and
received verbal comments. A transcript was kept of the
public meeting and was made available to the public and
placed in the Administrative Record and site
repositories;
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 5
A fact sheet was developed and distributed in
conjunction with the August 4, 1992 meeting.
U.S. EPA granted a thirty (30) day extension of the
public comment period on August 18, 1992, extending the
closing date to September 22, 1992;
A fact sheet highlighting corrections to the Baseline
Risk Assessment and extension of the public comment
period was mailed in August to the persons listed in
the Community Relations mailing list;
An advertisement was placed in the local newspaper on
August 18, 1992, announcing the extension of the public
comment period to September 22, 1992;
U.S. EPA has received oral and written comments
regarding the RIjFS, Baseline Risk Assessment, and the
Proposed Plan. Significant comments have been
addressed in, the attached Responsiveness Summary.
IV.
ScoDe of the Selected Remedy
The selected remedy is a source control remedial alternative to
be implemented at the TCL site (Tri-County and Elgin Landfills),
encompassing all currently identified areas of concern at the
site. The principal threats identified at the site are
considered to be ground water contamination, contaminated soil,
sediments and gas generated from the'landfill waste materials.
In order to mitigate the threat to human health and the
environment, the selected remedy addresses the site as a
continuing source of ground water contamination.
The selected remedy will also include additional investigations
and studies to assist in the design of the remedial action, to
verify hydrogeological and other conditions noted in the RI, to
assess and mitigate impacts of remediation activities on the
environment and potential wetlands, 'to assess the nature and
extent of any off-site contaminant migration, and to evaluate the
need for and type of responses to off-site contamination which
may need to be implemented as part of the remedy.
V.
Summary of site Characteristics - Remedial Investiqation
The RI was initially implemented to characterize the nature and
extent of contamination at the Tri-County Landfill. Results from
the initial RI fieldwork identified contaminated ground water in
the northwest portion of the Tri-County Landfill. Based on the
preliminary information, it appeared that the adjacent Elgin
Landfill may be contributing to ground water impacts. Therefore,.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 6
it was necessary to expand the RI to include an investigation of
the adjacent Elgin Landfill. Specific RI field activities
include the following:
Surface geophysical investigation and evaluation of the
Tri-County Landfill
Landfill cap investigation and evaluation
Geologic investigation and evaluation
Hydrogeologic investigation and evaluation
Ground water use survey
Soil sampling and analysis
Ground water sampling and analysis
Surface water and sediment sampling and analysis
Selective test pit sampling and analysis.
The discussion below summarizes the results from the
investigation of both the Tri-County and Elgin landfills.
Hydroqeology and Hydrology
Ground water occurrence at the site is divided into three
distinct hydrogeologic units: a shallow ground water zone, an
intermediate ground water zone, and a deep bedrock aquifer (See
Figure 3). The elevation of water levels in monitoring wells
screened at different depths indicate that there generally is a
downward hydraulic gradient at the site. The ground water
occurrence and flow characteristics suggest that there is a
hydraulic connection between the shallow and intermediate ground
water, and between the intermediate ground water and deep
aquifer. u.s. EPA file documentation also supports these
interconnections.
The shallow ground water occurs at various locations within the
upper sand and gravel unit, perched on top of the middle till
unit. The occurrence and flow of the shallow ground water is not
consistent throughout the upper aquifer, and is dependant on
surface water run-off which is retained in depressions scattered
on the site, the irregular surface topography of the underlying
middle till unit, the existence of the Woodlands Landfill
facility, including the vertical clay seal and any other
components, and the possibl~ existence of higher permeability
zones within the upper unit. In much of the landfilled area, the
shallow ground water is in direct contact with landfill waste.
In the southern part of the site, the shallow ground water
generally appears to flow toward the south-southwest. In the
north, its flow direction apparently varies from west to north.
However, due to the complexity of the structure of the upper unit
and the middle till, specific flow directions may vary at
different locations throughout the site.
-------
c C'
001H 1I01l1H
o 800
.
II
~
II 180
o
160
o
140
II
110
10
LEGEND
~-:J Upper Sand and Gravel Unit
~ Middle Tillllnit. Silly Clay
100
10
L'BImIIIlower Till Unit; Sill. Interlayered
~ wilh Gravel. Sand and Silly Clay
~
~ rill Material
680
;0
r::r:::r:l Bedrock: lhneslone.
~ Oololllile and Shale
I Well Screen
o 100 200
~... .
Horlronlat Sc:aI8 In F...
V.rlle.. e. Ion. to
400
..J
."0 Wale' I .v.' h"tIC.t.d Oil DOling log
figure J
Stratigraphic Cross Section CoCo
1 Ii Counly and Elgin landfills
E kjrn, lIIinios
Y Waler level
10
AU".I991
04001 15
1 Engineering. SCI4!ACe
-------
RECORD OF DECISIDN
Tri-County/Elgin Landfill
Page 7
Intermediate ground water occurs within the lower till unit and
is semi-confined beneath the middle till unit. The primary flow
direction of intermediate ground water is toward the southwest.
The deep aquifer occurs within the first bedrock unit encountered
beneath the site. The flow direction of the deep ground water,
based on elevation data collected in August 1989, is toward the
southwest. Deep ground water elevation data collected in
November 1990 and February 1991 indicate a westerly direction of
flow. De-watering activities associated with the construction of
the Woodland Landfill appears to have at least temporarily
altered the flow direction of the deep ground water in the
vicinity of the site.
Surface water features in the area surrounding the site include
the Fox River, Brewster Creek, a tributary to Brewster Creek, and
their associated wetlands-type areas. On-site surface water
features include several small apparent wetlands that have
developed in surface depressions. A somewhat larger, partially
forested wetland-type area is located in the southern portion of
the site south of the landfilled area. A.leachate-filled ditch
is located along side the Prairie Path near the south end of the
site.
Municipal, Commercial, and Residential Water Use Survey
The Village of South Elgin and the Community of Valley View
obtain water from municipal wells installed in the thick
sequences of outwash sands and gravels contained in the Newark
Valley. The municipal wells serving the Village of South Elgin
are located approximately 2/3 of a mile west and northwest of the
site. The Valley View Wells are located approximately 2 miles
southwest of the site.
Almost all of the residents and businesses south and southwest of
the site have their own private wells. These wells are primarily
installed in either outwash sands and gravels or bedrock. The
outwash sands and gravels correspond to the shallow and
intermediate ground water zones beneath the site. . The bedrock
corresponds to the deep aquifer at the site. Several businesses
which rely on their own welLs to supply water are located
on-site. The residences nearest the site are located
approximately 1,000 feet southeast and approximately 1,200 feet
north of the site. .
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 8
Extent of contamination
Soils
Volatile organic compounds (VOCs), semi-volatile organic
compounds (SVOCs), and inorganic analytes were detected above
background concentrations in Tri-County and Elgin Landfill
surface and subsurface soils. Pesticides were present above
background concentrations in Elgin Landfill surface, subsurface,
and test pit soils. Elgin Landfill test pit soils contained
PCBs.
Ground Water'
The shallow ground water zone beneath and adjacent to the site
has been impacted by commingled contaminants from both landfill~.
VOCs, SVOCs, pesticides, inorganic analytes and general water
quality parameters were detected above background concentrations
in shallow ground water. Concentrations of vinyl chloride,
benzene, trichloroethene, 1,2-dichloroethene, tetrachloroethene,
arsenic, fluoride, lead, and mercury exceed their established
drinking water standards (MCLs) or action levels in the shallow
ground water samples. Three compounds (vinyl chloride,
trichloroethene, and benzene) were detected off-site in wells
located at the Woodland landfill above established MCLs. Various
inorganic analytes (iron, manganese, chloride, and total
dissolved solids (TDS» were also detected off-site above
background concentrations, however, none were detected above any
established MCLs.
Impact to the intermediate ground water zone by VOCs, SVOCs,
pesticides, inorganic analytes, and general water quality
parameters has occurred on-site. Several compounds, including
vinyl chloride, benzene, chromium, and lead were present at
concentrations exceeding their established MCLs, or action
levels, in intermediate on-site ground water samples. No organic
compounds were detected off-site above established MCLs. Again,
several inorganic analytes (barium, iron, chloride, and TDS) were
detected off-site above background concentrations but below any
established KCLs.
Concentrations of VOCs, SVOCs, inorganic analytes, and general
water quality parameters were detected above background in the
deep aquifer and the private/public wells sampled. No MCLs were
exceeded in the deep monitoring wells installed for the RI.
Chromium was present above the established MCL in one on-site
private business well installed through the Elgin landfill, Lead
was detected above the established action level in one off~site
private business well and one private residential well. No
-------
RECORD OF DECISION
Tri-County/Elgin landfill
Page 9
organic or inorganic compounds were detected off-site above
established MCLs in the bedrock aquifer.
Surface Water and Sediment
SVOC impact is present in surface water and VOC impact is present
in sediment collected from downstream unnamed tributary
locations. Neither pesticides nor PCBs were detected in surface
water. PCBs were detected in sediments collected from a small
depression in the Tri-County Landfill cap and from the Elgin
Landfill pond. Pesticides were also detected in Elgin Landfill
pond sediments.
Inorganic compound contamination was most evident in surface
water and sediments collected from a ditch containing leachate on
the southern portion of the site and in the Elgin Landfill pond.
Arsenic was detected above background concentrations in
downstream unnamed tributary sediments.
Air
During fieldwork activities, it was documented that the landfill
was venting gas. Several times during installation of monitoring
wells through the landfill, installation had to be halted because
of gas venting from the borehole. At the time of the field
investigation, appropriate gas sampling procedures had not been
established and gas sampling equipment was not available.
Therefore no chemical samples were taken of the gas. Based on
ambient air field screening equipment, the gas appeared to be
mostly methane. Methane is a common gas generated by most
landfills.
VI.
Summary of site Risks
Because the Tri-County Landfill and the Elgin Landfill have
accepted a variety of wastes, numerous chemicals have been
detected at the site. Following the RI, an analysis was
conducted to estimate the potential health or environmental
problems that could result if the' site was not cleaned up. This
analysis is referred to as the Baseline Risk Assessment (RA). In
this assessment, approximat~ly 166 contaminants representing
essentially all classes of chemicals including: inorganic,
volatile and semi-volatile organic, pesticides, polychlorinated
biphenyls (PCBs), and polynuclear aromatic hydrocarbons (PARs)
were evaluated for carrying through the risk assessment. Of
these, 71 contaminants were retained from these chemical classes
for use in assessing site risks. These chemicals can be found on
Table 2-8 of the Baseline RA report.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 10
Those contaminants contributing the most significantly to current
and future site risks included: VOCs such as vinyl chloride,
benzene, trichloroethene, and 2-butanonei various SVOCs such as
benzo(a) anthracene, benzo(a)pyrene, benzo(b)fluoranthene, .
benzo(k)fluoranthene, and chrysenei pesticides such as 4,41-DDTi
PCBs, specifically Aroclor 1242 and Aroclor 1254i and inorganics
such as arsenic, beryllium, chromium, nickel, antimony, barium,
cobalt, thallium, and manganese. Specific information can be
found in Tables 5-1 through 5-30 of the Baseline RA report.
The most highly contaminated media included the site-wide surface
soils and ground water. Lower levels of contamination were found
in the surface water and sediments.
The two landfills contain a variety of industrial and municipal
waste. Ground water monitoring wells located within and around
the landfills indicate that contaminants from both landfills are
commingled and are sources of ground water contamination.
Leachate is created at this site when rain water or melting snow
percolates through the waste of the landfills. Leachate is
either discharged through seeps or is intermixed with the local
ground water. One major leachate seep has. been identified and is
in the southern portion of the site. The seep discharges into a
ditch which eventually flows into the unnamed tributary of
Brewster Creek. Samples from the leachate ditch indicates it has
been significantly impacted by inorganic contamination, whi~h is
a typical characteristic of landfill leachate.
The RI investigation documented widespread contamination in most
media. The RI did not identify any hotspots or distinct sources.
The potential migration pathways for these contaminants include
leaching from the soils or waste material to the ground water,
movement of contaminated ground water to surface water and
sediments, volatilization of chemicals to air from water and
soils, and migration of contaminated surface soils as
particulates in the air. Evidence of contaminants potentially
leaving the site through ground water migration includes the
detection of benzene, vinyl chloride, trichloroethene, and some
inorganic analytes at low levels located across the prairie Path
in monitoring wells on the Woodland Landfill property. The only
off-site routes of migration for surface water and surface water
sediments are through the southern portion of the site, which
eventually drains into the unnamed tributary of Brewster Creek.
The leachate seeps and ground water discharges into the southern
portion of the site appear to originate from within the buried
waste of the landfills and clearly indicate a pathway for off-
site migration of contaminants.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 11
The Baseline RA evaluated the risk of exposure at the site taking
into account current uses of the site, as well as the potential
future uses (Both occupational and residential exposures). The
potential future uses assumes that the site and/or directly
adjacent properties would continue commercial operations as well
as potential being developed for residential purposes. The
Baseline RA showed that there are ten potential routes of current
and future exposure which consist of the following:
1)
2)
3)
4)
5)
Ingestion of contaminated soils,
Direct dermal contact with contaminated soils,
Ingestion of contaminated ground water,
Dermal contact with contaminated ground .water during
showering,
Inhalation of volatile contaminants from ground water
during showering,
Ingestion of contaminated surface water,
Dermal contact with contaminated surface water,
Ingestion of contaminated sediment,
Dermal contact with contaminated sediment, and
Inhalation of volatilized contaminants and contaminated
particulates.
6)
7)
8)
9)
10)
Risks at Superfund sites are typically assessed with respect to
both carcinogenic and noncarcinogenic adverse effects of a
chemical under current and future exposure scenarios. The
current and potentially exposed populations are occupational
workers at or near the site, residents living on or near the
site, and persons who may recreate on the prairie Path or on the
site itself. Cancer risks from various exposure pathways are
assumed to be additive.
The Baseline RA showed that the site poses unacceptable risks to
the public health. Unacceptable risks are those that may result
in one additional cancer case in 10,000 to 1,000,000 people
exposed over a lifetime. The primary routes of exposure which
contribute unacceptable risks are future ingestion of
contaminated ground water by occupational and residential
receptors (approximately 2 additional cancer cases in 1000),
dermal exposure to contaminants in ground water during showering
by future residential receptors (approximately 1~ additional
cancer cases in 1000), and current and future inhalation of
contaminated fugitive dust and volatile emissions by
occupational, residential, and recreational receptors
(approximately 21n additional cancer cases in 10,000). In many
cases of exposure, it is likely a person would be exposed to the
site contamination through more than one exposure route. In
these cases, the risks levels of the exposure routes are added
together resulting in higher risks due to combined exposures to
site contaminants.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 12
All of the risks are determined by exposure models. These models
utilize very conservative assumptions to indicate worst case
exposure scenarios.
The noncarcinogenic risks are evaluated with respect to a hazard
quotient, which is the ratio of the level of exposure to an .
acceptable level. If the hazard quotient for an exposed
individual or group exceeds 1.0 for a particular chemical, there
may be noncarcinogenic health effects resulting from the exposure
to that chemical. If the hazard index, which is the sum of the
hazard quotients for all chemicals in a particular medium,
exceeds 1.0 there may be a concern for potential health effects
from exposure to that medium. The Baseline RA showed that the
hazard indices at the site exceeded 1.0, suggesting that both
current and future exposures to chemicals of concern on the site
may result in excess noncarcinogenic risks to all populations.
Two of the exposure routes (Ingestion of ground water and Dermal
contact with groundwater during showering) had hazard indices
greater than 1.0. One exposure route (Ingestion of ground water)
had individual hazard quotients for individual contaminants
greater than 1.0. As with the carcinogenic risks, two or more
routes of exposure may be complete for a person exposed to the
site contamination. In these cases, the hazard index for each
case would be added together resulting in a combined hazard index
greater than 1.0. .
.~~~
In conclusion, the Baseline RA documents that releases of
hazardous substances from this site, if not addressed by the
remedy, present an, 'imminent and substantial endangerment to
public health, welfare, and the environment.
Ecological impacts from site related contamination were also
evaluated. Surveys of flora and fauna populations were taken in
a qualitative attempt to assess adverse impacts. These findings
established some ~pacts to the local ecosystem. The impact was
generally associated with elevated levels of zinc and mercury
above established Ambient Water Quality criterion in the surface
water. The Baseline RA concluded that all of the remedial
alternatives considered in the FS, except the "No .Action"
alternative, addressing the risks to public health would address
the ecological impacts as w~ll.
VII. Rationale for Action
The U.S. EPA considers several sources of information in
determining whether or not to take action at a site. Based on
the data gathered. in the RI, the u.s. EPA performs a risk
assessment to determine if adverse health conditions, current or
potential future conditions, threaten human health and/or the
environment. The u.s. EPA also evaluates the site conditions in
-------
RECORD OF DECISION
Tri-County/Elgin landfill
Page 13
relation to Federal and state environmental statutes and
policies, in addition to the statutory mandates promulgated in
CERCLA and the goals and expectations identified in the NCP. The
primary criteria with respect to the Tri-County and Elgin
landfills are presented below.
A.
Risk Summary
Total lifetime excess carcinogenic risk and total hazard indices
by media and for the entire site are estimated to be:
contaminated Current Use Future Use
Media CR HI CR HI
site wide Soils 6.0 x 10-4 0.28 5.1 x 10-4 0.76
Ground Water 1.7 x 10-4 14 3.4 x 10-3 150
On-site SW 1.7 x 10-6 0.2 1.7 x 10-6 0.2"
On-site Sediment 9.5 x 10-6 0.075 9.5 x 10-6 0.075
Tributary SW 2.5 x 10-6 1.5 2.5 x 10.6 1.5
Tributary Sediment 1.6 x 10-4 0.25 1.6 x 10-4 0.25
Air Inhalation 4.6 x 10-5 0.054 3.6 x 10-4 0.36
site Totals 9.9 x 10-4 16.36 4.4 x 10-3 153.1
CR = Carcinogenic Risk
HI = Hazard Index
The relative contribution to the total site risks and total
hazard indices from each media are summarized as follows:
Contaminated
Media
CR = Carcinogenic
HI = Hazard Index
Current Land Use Future Land Use
CR HI CR HI
60.6 % 1.7 % 11.6 % 0.5 %
17.2 % 85.6 % 77.3 % 98.0 %
0.2 % 1.2 ~ 0.04 % 0.1 %
0
1.0 % 0.5 % 0.2 % 0.05 %
0.3 % . 9.2 % 0.06 % 0.98 %
16.2 % 1.5 ~ 3.6 ~ 0.2 %
0 0
4.6 % 0.3 % 8.2 % 0.2 %
Risk.
site wide Soils
Ground Water
On-site SW
On-site Sediment
Tributary SW
Tributary Sediment
Air Inhalation
The potential risks at the site exceed the acceptable risk range
of 1 x 10.4 to 1 X 10-6, and thus present unacceptable current and
potential future risks to human health.
The total hazard index for the site is estimated to be 16.36
currently, and 153.1 for potential future use. Individual media
resulted in hazard indices as great as 14 currently and 150 for
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
. Page 14
potential future use of the site. Individual contaminants of
concern resulted in hazard indices as high as 12 for current use
and 82 for potential future use of the site. U.S. EPA considers
HIts greater than 1 to be an unacceptable risk.
B.
Environmental Standards Exceeded at the site
In addition to posing unacceptable risks to receptors, the TCL
site does not meet certain applicable or relevant and appropriate
Federal or State environmental standards (ARARs) at this time.
1.
Cap
The existing landfill cap does not meet the substantive
requirements of Title 35, Illinois Solid and Special Waste
Management Regulations, 807.305, for final cover. These
provisions have been determined to be ARARs for the site.
2.
Ground water
The shallow ground water zone contains levels of volatile
organics and metals exceeding or violating ARARs, including
ground water quality standards and Federal drinking water
standards.
state
C.
Summary
Actual and threatened releases of hazardous substances are
occurring from this site. If not addressed, these" releases may
present an imminent and substantial endangerment to public
health, welfare or the environment. Thus, it is necessary that
corrective and mitigative action be taken to address the threats
posed by the actual or threatened releases.
The RI and Baseline RA conducted for the site established that
there are unacceptable risks associated with the contaminated
ground water, surface soils, and sediments as well as a problem
of venting landfill gas. The source of the risks originate from
commingled contaminants within and emanating from both landfills.
Since the wastes contained in and emanating from both landfills
are co-mingled and both landfills have resulted in a combined
impact to the environment, both landfills are being treated as
one site for the purpose of remediation. Therefore, the site is
defined as including both the Tri-County Landfill, the Elgin
Landfill, and adjacent impacted areas for purposes of the
remedial design and remedial action.
The response action to be taken will be designed to address known
unacceptable risks associated with the site. The response action.
-------
RECORD OF DECISION
Tr;-County/Elg;n Landfill
Page 15
would address: 1) the contaminated ground water currently
migrating into adjacent low-lying areas, surface waters, soils,
sediments, as well as off-site, 2) the contaminated sediments.
located in the leachate ditch, 3) the contaminated surface soils
which create an inhalation risk, 4) treat or control the
emissions of landfill gases, and 5) cover and close both
landfills in accordance with established applicable state and
Federal laws and regulations.
VIII.
DescriDtion of Alternatives
Based on the results of the RI, a list of alternatives was
assembled to address the site remedial action objectives and
ensure compliance with the requirements of the NCP. These
alternatives are presented in the Feasibility Study prepared for
theTCL site. The alternatives include those which would provide
no action (as statutorily required), waste containment, and/or
waste treatment. Since the site has contaminated soil, ground
water, sediments, landfill wastes, and landfill gases which need
to be addressed, alternatives are developed for each contaminated
medium. This was done to simplify the eva.luation between the
different alternatives. However, since an alternative for one
contaminated medium may affect the other contaminated media,
selecting the final response action for the site was also based
on the best overall combination among the different alternatives.
The following remedial alternatives were developed for the site,
and are briefly described below.
ALTERNATIVE ONE: NO ACTION
Alternative One is the No Action Alternative and serves as a
basis to which all other alternatives can be compared. Under
this remedial alternative, no active remedial action or
institutional action would be taken regarding the site.
According to the National contingency Plan (NCP), the No Action
Alternative must be carried through to the detailed analysis of
alternatives.
Estimated
Estimated
Estimated
Estimated
Capital .cost:
Annual O&M Cost:
Present Worth:
Time to Implement
$
$
$
o
o
o
none
SOIL AND WASTE MATERIAL ALTERNATIVES
These alternatives address the containment of impacted soils and
waste material on-site. Containment would be achieved by
capping. Two types of capping systems are proposed: a clay cap, .
-------
RECORD DF DECISION
Tri-County/Elgin Landfill
Page 16
and a multilayer cap. These alternatives will also provide
protection of ground water by limiting the infiltration of
precipitation into the waste material'and will prevent the
uncontrolled emission of landfill gas from the site.
Institutional controls to restrict access, use, and development
of the site would be included in each of the alternatives.
Fencing would be used to control access to the site and to
protect the cap from unauthorized human activities.
A1ternative 8W-1:
containment of Soils and Waste via cappinq of
the. site with a clay cap
containment of the soils and waste material would consist of
capping and surface water diversion. Surface water diversion
would be achieved by regrading the site to eliminate depressions
where precipitation currently accumulates. A 24 inch clay cap
would then be installed to conform with applicable regulations
for closure of general refuse solid waste facilities (35 Ill.
Adm. Code 807 and RCRA Subtitle D). An 8-inch topsoil layer
would be placed over the clay to support vegetation and stabilize
the cap, minimizing erosion. Section 3.4.1 of the FS contains a
detailed description of the capping system.
Estimated
Estimated
Estimated
Estimated
Capital Cost:
Annual O&M Cost:
Present Worth:
Time to Implement:
$
$
$
6,400,000
6,500
6,500,000
2 years
Alternative SW-2:
containment of Soils and Waste via Capping of
the site with a Multilayer cap
containment of the soils and waste material under this
alternative would also consist of surface water diversion and
capping. Surface water diversion would be achieved by regrading
the site to eliminate depressions where precipitation is
currently accumulating. A multilayer cap would then be installed
to conform with applicable regulations for closure of chemical
and putrescible waste facilities (35 111. Adm. Code 811 and RCRA
Subtitle C). The cap would consist of a 36-inch clay layer and
an 18-inch sand drainage layer; an 18-inch topsoil layer would be
placed over the drainage layer to support vegetation and to
stabilize the cap and minimize erosion. section 3.4.1 of the FS
contains a detailed description of the capping system and Figure
3.2 of the FS shows a cross-section of this system.
Estimated
Estimated
Estimated
Estimated
Capital Cost:
Annual O&M Cost:
Present Worth:
Time to Implement:
$ 12;500,000
$ 6,500
$ 12,600,000
2 years
-------
RECORD OF DECISION
Tri-County/Elgin landfi II
Page 17
GROUND WATER AND LEACHATE ALTERNATIVES
All of the alternatives include a ground water and leachate
collection system. The collected ground water and leachate would
be discharged to surface water or the public owned treatment
works (POTW). It is unknown at this time whether the recovered
ground water and leachate would require treatment prior to
discharge. Recovered ground water would be analyzed during the
Remedial Design phase of the project to determine the necessity
of treatment. Treatment of recovered ground water may consist
of variety of processes. These processes and their applicability
are discussed in the FS.
All of the ground water alternatives with the exception of the No
Action Alternative include a ground water collection system.
Regardless of which ground water alternative is selected, a
ground water monitoring system will be established to monitor the
effectiveness of the remedy being implemented. Also, a
monitoring well network will be designed as an early warning
system to detect contamination migrating downgradient of the
operating Woodland Landfill, to be located upgradient of the
residential area located west of Gilbert Street.
Alternative GW-l:
,ji.~"/
containment and Collection of On-site Ground
Water and Leachate via Interceptor Trenches
Under this altern~tive ground water and leachate would be
collected using ipterceptor trenches. The interceptor trenches
would be constructed along the north, northwest, and southwest
borders of the landfills. Interceptor trenches would consist of
drainage pipe placed 30 tq 40 feet below grade, on top of the
silty clay layer. The drainage pipe would be surrounded by
approximately two feet of peastone gravel. The size of the
drainage pipe wiLrvary depending on the area where the
interceptor trench" is located. The intercepted ground water and
leachate would be conveyed through the drainage pipe to a
collection sump. A pump in the collection sump would transfer
the collected water to a common lift station through a
transmission pipe. An average rate of approximately 100 gallons
per minute of ground water a~d leachate would be collected by
this system. From the lift station, the collected ground water
and leachate would be transferred to the surface water discharge
location or the POTW.
Estimated
Estimated
Estimat:ed
Estimated
Capital Cost:
Annual O&M Cost:
Present Worth:
Time to Implement:
$
$
$
1,600,000
87,000
3,000,000
2 years
-------
RECORD OF DECISION
Tr;-County/Elg;n Landfill
Page 18
Alternative GW-2:
containment and Collection of On-site and
Off-site Ground Water and Leachate via
Interceptor Trenches
This alternative is similar to Alternative GW-1 with the
exception that an additional interceptor trench would be
constructed adjacent to the northwestern corner of the site on
the Woodland Landfill property. The location of this trench
would allow for impacted ground water located northwest of the
Elgin Landfill to be collected. It has been assumed that the
flow rate for this system would be approximately the same as that
of Alternative GW-1. Although this alternative may produce
slightly more. water, the quantity is not anticipated to be
significant (10%) from a conceptual design standpoint and will
not greatly affect the accuracy of cost for the collection,
transport, and treatment systems.
Estimated
Estimated
Estimated
Estimated
Capital Cost:
Annual O&M Cost:
Present Worth:
Time to Implement:
$
$
$
1,700,000
88,000
3,100,000
2 years
Alternative GW-3: containment of Ground Water with a Slurry Wall;
Collection of Leachate Using Cistern Wells
Under this alternative a slurry wall would be constructed around
approximately 50% of the site to prevent g~ound water from
flowing into the site. The slurry wall would be composed of a
soil/bentonite mixture. Off-site soils would probably have to be
used in order to meet the specified requirements for such
mixtures. Sand and gravel are specified for these mixtures. The
slurry wall would be keyed into the silty clay layer which is
located approximately 30 to 40 feet below the current grade of
the site. cistern wells would be installed in the landfill to
collect leachate and ground water from within the landfill.
It has been estimated that 50 gallons per minute of leachate
would be collected by this system. Each well would have a .
submersible pump with a level control system. The level control
system will turn the pump on and off and maintain the ground
water table depression in the area of the well, inducing a
hydraulic gradient to the well. The flow rate is expected to
decrease after approximately six months as the landfills become
dewatered. From the lift station, the collected ground water and
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 19
leachate would be transferred to the surface water discharge
location or the POTW.
Estimated
Estimated
Estimated
Estimated
Capital Cost:
Annual O&M Cost:
Present Worth:
Time to Implement:
$
$
$
4,100,000
87,000
5,500,000
2 years
LANDFILL GAS AND AMBIENT AIR ALTERNATIVES
The RI had documented that the landfills are releasing
significant amounts of landfill gas. Regardless of which
alternatives are selected for the other media, it is obvious that
the release of the landfill gas has to be controlled to protect
the recreational users of the prairie Path and employees at the
commercial businesses located on or near the landfill. It is not
known what chemical contaminants are contained in the gas.
However, based on the limited data from the ambient air field
screening equipment, the gas appears to be mostly methane. Two
alternatives were developed in the FS to control the release of
landfill gas and are described below..
Alternative LG-l:
Collection of Landfill Gas Using an Active
Gas Collection System and On-site Treatment
This system would consist of a series of gas extraction wells
connected to a blower/flaring facility by a series of ducts.
blower would create a vacuum within the extraction well and
landfill gas would be conveyed to the flaring facility. The
landfill gas would then be passed through a condensate tank to
remove moisture. The landfill gas would then be treated by
flaring and discharged to the atmosphere.
The
Estimated
Estimated
Estimated
Estimated
Capital Cost:
Annual O&M Cost:
Present Worth:
Time to Implement:
$
$
$
610,000
150,000
3,100,000
2 years
Alternative LG-2:
Collection of Landfill Gas using a Passive
Gas Collection system.
A passive system would be a combination of both venting wells and
a trench vent. The venting wells were assumed to have the same
arrangement as the extraction wells for the active system. It
was assumed that no ducting or blower/flare facility would be
required, thus, this system may not meet air pollution control
requirements. A trench vent would be placed along the western
edge of the building on the Tri-County and Elgin Landfills. The
trench vents would consist of thirty-five foot deep trenches
backfilled with gravel. A synthetic membrane would be used to
-------
RECORD OF DECISION
Tri -County/Elgin Landfi II
Page 20
line the side of the trench opposite the landfill, this
help to prevent migration of gas past the trench. Vent
would be placed everyone hundred feet along the trench
gas to be vented to the atmosphere.
would
pipes
to allow
Estimated
Estimated
Estimated
Estimated
Capital Cost:
Annual O&M Cost:
Present Worth:
Time to Implement:
$
$
$
1,000,000
17,000
1,300,000
2 years
Surface Water and Sediments Alternatives
It is anticipated that the surface water bodies on the Tri-County
and Elgin Landfills would. be drained as part of any of the soils
and waste material action alternatives which include grading and
capping. These surface water bodies were formed as a result of
the landfill settling. These areas are topographic lows which
collect precipitation and surface run-off from the higher areas
of the landfill. The total volume of surface water is relatively
low, therefore, on-site treatment was screened out of the
analysis as cost prohibitive. Therefore, all alternatives
contain off-site treatment for the surface water.
The sediments associated with the surface water bodies also
contain low levels of contamination. However, since these
sediments are located on top of the landfill, any capping remedy
would contain the contamination below the cap.
The contaminated sediments located in the leachate ditch on the
southern portion of the site do represent an unacceptable risk.
since any capping remedy would not contain this contamination,
these sediments have to be addressed. These sediments would be
excavated and consolidated on-site prior to capping or disposed
at an appropriate off-site facility.
with any action taken at the site, the drummed drill cuttings
generated during the RI activities will have to be addressed.
These drums are currently stored on-site in a secured area. The
drill cuttings would be handled the same as the contaminated
sediments during the remedial action.
Alternative 8S-1:
Collection and Off-site Treatment of Surface
water, and Consolidation and containment of
Sediments on-site
Estimated
Estimated
Estimated
Estimated
Capital Cost: .
Annual O&M Cost:
Present Worth:
Time to Implement:
$
$ .
$
24,000
o
o
6 months
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 21
Alternative SS-2:
Collection and Off-site Treatment of Surface
Water and Consolidation and containment of
Sediments Off-site
Estimated
Estimated
Estimated
Estimated
Capital Cost:
Annual O&M Cost:
Present Worth:
Time to Implement:
$
$
$
34,000
o
o
6 months
IX.
Evaluation of Alternatives
The NCP requires that the alternatives be evaluated against nine
evaluation criteria. This section summarizes the relative
performance of the alternatives by highlighting the key
differences among the alternatives in relation to these criteria.
The nine evaluation criteria which are categorized as: (1)
Threshold Criteria; (2) Primary Balancing Criteria; and (3)
Modifying criteria. Each of these terms is described as follows:
Threshold criteria
1) Overall protection of human health and the
environment addresses whether a remedy provides
adequate protection. of human health and the
environment and describes how risks posed through
each exposure pathway are eliminated, reduced or
controlled through treatment and engineering
controls. The selected remedy must meet this
criteria.
2) Compliance with applicable or relevant and
appropriate requirements (ARARs) addresses whether
a remedy will meet federal and state environmental
laws and/or justifies a waiver from such
requirements. The selected remedy must meet this
criteria or waiver of the ARAR must be obtained.
Primarv Balancinq criteria
3) Lonq-term effectiveness and permanence refers
to expected 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.
4) Reduction of toxicity, mObility, and volume
through treatment is the anticipated performance
of the treatment technologies.a remedy may employ.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 22
5) Short-term effectiveness addresses the period
of time needed to achieve protection and any
adverse impacts on human health and the
environment that may be posed, until cleanup goals
are achieved.
6) Implementability is the technical and
administrative feasibility of a remedy, including
the availability of materials and services needed
to implement a particular option.
7) Cost includes estimated capital and operation
and maintenance (O&M) costs, also expressed as net
present-worth cost.
Modifvinq criteria
8) support Agency (IEPA) acceptance reflects
aspects of the preferred alternative and other
alternatives the IEPA favor or object to, and any
specific comments regarding federal and state
ARARs or the proposed use of waivers.
9) Community acceptance summarizes the pUblic's
general response to the alternatives described in
the proposed plan and in the RIjFS, based on
public comments received.
A detailed discussion of the evaluation of the alternatives'
against the nine criteria has been provided in the FS. The
alternatives are grouped according to the corresponding
contaminated medium. The NCP requires that the "No Action"
alternative be evaluated to establish a baseline against which
all other alternatives are measured. A summary of the evaluation
discussion is provided below.
Ho Action Alternative
Based upon the detailed analysis, it was concluded that
Alternative One - No Action,' would not satisfy the criterion of
ensuring the overall protection of human health and the
environment.. The Baseline RA has documented unacceptable risks
present at the site and Alternative One does not meet this
criterion because no remedial action would be taken to address
the present and future uses of the site and contaminant migration
from the site.
-------
RECORD OF DECISION
Tr;-County/Elg;n Landfill
Page 23
Compliance with ARARs does not apply for a "No Action" remedy.
ARARs only apply when actions are taken at a site to address
risks to human health or the environment.
since Alternative One does not satisfy a Threshold Criterion, no
further evaluation against the Primary Balancing or Modifying
criteria is needed. Alternative One will not be chosen for the
site.
Znter-relationship of Remedies for the Different Media
Selection of
selection. of
the analysis
remedies for
a remedy for the soil and waste may affect the
a remedy for the ground water and leachate. After
of the alternatives, the best overall combination of
the different media need to be selected.
It is assumed that one of the soil and waste alternatives for
capping would be chosen along with any ground water remedy. The
various combinations would have differing impacts. Therefore,
when selecting the overall site remedy, the impacts of the
remedies on different media need to be taken into account. For
example, if the intent is to dewater the landfill, the multilayer
cap would be chosen over the single layer cap since it would be
more effective in preventing infiltration. On the other hand, if
ground water would be collected as it migrates off-site and the
landfill is not dewatered, then there is little reason to select
the mUltilayer cap.
Threshold criteria
1) Overall Protection of Human Health and the Environment
SOIL AND.WASTE MATERIAL ALTERNATIVES
Alternative SW-1:
This alternative would be protective by
reducing the amount of precipitation which
percolates through the cap and thereby,
reduce the amount of leachate that is
produced. Also, the cap would eliminate the
greatest risk due to inhalation of
contaminated particulates by eliminating the
route of exposure.
Alternative SW-2:
This alternative would be slightly more
protective than SW-l since a multilayer cap
would be more effective in limiting
infiltration of precipitation into the
landfill.
-------
RECORD OF DECISION
Tr;-County/Elg;n Landfill
Page 24
Alternative GW-l:
GROUND WATER AND LEACHATE ALTERNATIVES
Alternative GW-2
Alternative GW-3
This alternative would be protective by
preventing further degradation of the local
aquifers by collecting the contaminated
ground water as it leaves the site.
Collected ground water would be treated, if
necessary, prior to surface water discharge
or discharge to the POTW. However, this
alternative would not address the
contaminated ground water located off-site.
It is anticipated that the generally low
levels of contamination in the off-site
ground water would decline below ground
compliance levels within a short period
time after the known contaminant source
contained.
water
of
is
This alternative would be slightly more
protective than GW-l since the off-site
contaminated ground water would be collected.
Since, at this site, the levels of off-site
groundwater contaminants appear to be only
slightly above acceptable levels, it is
thought that collection of the impacted off-
site ground water is not significantly more
protective than GW-l.
This alternative would be as protective as
GW-l but may not be as protective as GW-2.
with the installation of a slurry wall, there
would be a permanent horizontal barrier to
severely reduce the amount of uncontaminated
ground water from flowing into the site area
preventing additional contaminated ground
water from migrating off-site. The slurry
wall combined with cistern wells would
practically dewater the landfill .and prevent
direct contact with the wastes, thereby
reducing the potential of significant release
to the ground water. By dewatering the
landfili, GW-3 would also be more protective
of the lower aquifers by preventing further
degradation by significantly reducing any
downward gradient.
Alternative LG-l:
LANDFILL GAS AND AMBIENT AIR ALTERNATIVES
This alternative would be protective by
installing an active gas collection system
-------
Alternative LG-2:
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 25
and treating the gas by flaring prior to its
release to the atmosphere. LG-1 is more
protective than LG-2 since the collected gas
is treated prior to its release. '
This alternative would be protective by
installing a passive gas collection system,
thereby controlling the release of gas
generated by the landfills. The trench vents
would prevent the horizontal migration of
gas, addressing the potential problems of the
adjacent businesses. This alternative would
also prevent the gas generated by the
landfill from breaching any cap selected for
landfill.
Alternative 88-1:
SURFACE WATER AND SEDIMENTS ALTERNATIVES
Alternative 88-2:
This alternative would be protective by
collecting and treating the standing surface
water on the landfill, and also containing
the contaminated sediments on-site underneath
the cap. This alternative would prevent the
contaminated sediments from becoming airborne
particulates.
This alternative is as protective as 88-1,
with the exception that the contaminated
sediments would be transported to an off-site
disposal facility. This transportation may
increase the risks of accidents due to
increased traffic around the site. If an
accident should occur, risks to the
surrounding population would be increased.
2) ComDliance with ARARs
Alternative SW-l:
SOIL AND WASTE MATERIAL ALTERNATIVES
Alternative SW-2:
This alternative would comply with all
chemical, action, and location specific
ARARs. -
This alternative would comply with all
chemical, action, and location specific
ARARs .
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 26
Alternative GW-l:
GROUND WATER AND LEACHATE ALTERNATIVES
Alternative GW-2:
Alternative GW-3:
This alternative would comply with all action
and location specific ARARs. Chemical
specific ARARs would be met with the
exception of the off-site contaminated ground
water. However, it is expected that chemical
specific ARARs would be met within a short
period of time through natural attenuation
once the source is' addressed.
. .
This alternative would comply with all
chemical, action, and location specific
ARARs.
This alternative would comply with all action
and location specific ARARs. For chemical
specific ARARs, this alternative is the same
as GW-l.
Alternative LG-l:
LANDFILL GAS AND AMBIENT AIR ALTERNATIVES
Alternative LG-2:
This alternative would comply with all
chemical, action and location specific ARARs
for air emissions.
Since this alternative does not involve
treatment, LG-2 may not comply with ARARs for
air emissions. The quality of the landfill
gas would need to be determined during RD.
SURFACE WATER AND SEDIMENTS ALTERNATIVES
Both 88-1 and 88-2 would comply with chemical, action, and
location specific ARARs.
Primary Balancina criteria
3) Lonq-term effectiveness and permanence
SOIL AND WASTE MATERIAL ALTERNATIVES
Capping the landfill would contain the surface soils and wastes
effectively. A cap would permanently reduce infiltration into
the landfill. 8W-2 would provide a more effective barrier to
preventing infiltration than SW-l. However~ ,since the waste mass
is in contact with groundwater, the more effective infiltration
reduction achieved by 8W-2 over SW-l is not felt to be
significant. This is due to the fact that contaminants will'
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 27
continue to be transferred from the waste mass to groundwater,
regardless of the type of cap.
GROUND WATER AND LEACHATE ALTERNATIVES
All three alternatives would be effective in preventing off-site
migration of contaminated ground water. GW-2 would be more
effective than GW-l and GW-3 by collecting off-site contaminated
ground water. GW-3 would be the most effective in preventing
off-site migration since a slurry wall would provide a permanent
horizontal barrier and the landfill would be dewatered, thereby
reducing the amount of leachate generated by the landfill.
LANDFILL GAS AND AMBIENT AIR ALTERNATIVES
Both LG-l and LG-2 would be effective in controlling horizontal
migration of. landfill gas. LG-l would be more effective than LG-
2 since the gas would be actively collected to a central area and
then treated prior to being released to the atmosphere. However,
LG-l would require yearly maintenance to ensure long term
effectiveness.
SURFACE WATER AND SEDIMENTS ALTERNATIVES
Both alternatives would be effective for addressing the surface
water and sediments.
4) Reduction of toxicity. mobility. and volume
SOIL AND WASTE MATERIAL ALTERNATIVES
Neither alternative would "reduce toxicity or volume of the wastes
since both are containment alternatives. However, both would
reduce the mobility of the contaminants by preventing
infiltration. SW-2 would reduce mobility slightly more than SW-l
by preventing less infiltration.
GROUND WATER AND LEACHATE ALTERNATIVES
All three alternatives would reduce the mobility of the.
contaminants. It is unknown at this time whether treatment of
the water is required. Therefore, at this time, none of these
remedies would reduce the toxicity or volume of contaminants.
GW-3 would reduce the mobility of the contaminants the most by
reducing the amount of leachate generated. GW-2 would reduce the
mobil~ty of the off-site contamination.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 28
LANDFILL GAS AND AMBIENT AIR ALTERNATIVES
Both LG-l and LG-2 would be effective in controlling the mobility
of the landfill gas. LG-l would reduce the toxicity and volume
of contaminants by treatment of the gas prior to its release to
the atmosphere. LG-2 would not reduce the toxicity or volume of
the gas. LG-1 would result in the destruction of contaminants.
SURFACE WATER AND SEDIMENTS ALTERNATIVES
Both S5-1 and 55-2 would reduce the mobility of the contaminants
by containment. Neither would reduce the toxicity or volume of
the contaminants.
5) Short-term Effectiveness and 6) Implementabilitv
SOXL AND WASTE MATERIAL ALTERNATIVES
Both alternatives would be effective in the short-term by
providing measures to protect workers and the local community.
SW-2 would result in increased truck traffic which would increase
the potential for traffic accidents.
Both alternatives can be readily implemented.
GROUND WATE~ LEACHATE ALTERNATIVES
All three alternatives would be effective in the short-term by
providing measures to protect workers and the local community.
GW-3 would result 'in significantly increased truck traffic which
would increase the potential for traffic accidents.
All three alternatives can be readily implemented. However, GW-l
and GW-2 would pr~~nt slightly greater construction difficulties
due to the size and depth of the trench required. GW-2 may be
less implementable-than GW-1 because of the potential
interference with the operations of. the adjacent Woodland
Landfill.
LANDFILL GAS AND AMBIENT AIR ALTERNATIVES
Both LG-l and LG-2 may result in uncontrolled landfill gas
emissions during construction activities. Uncontrolled emissions
would be greater for LG-2, resulting from the construction of the
trench vents.
Both LG-l and LG-2 are readily implementable. LG-2 would result
in the most difficulties due to the construction of the trench
vents.
-------
RECORD DF DECISION
Tri-County/Elgin Landfill
Page 29
SURFACE WATER AND SEDIMENTS ALTERNATIVES
Both SS-1 and SS-2 would reduce the mobility of the contaminants
by containment. Neither would reduce the .toxicity or volume of
the contaminants.
7) Cost
Specific details regarding the costs of the remedies are
available in the FS. Also, the cost summary for each alternative
has been presented in section VIII of this Proposed Plan.
SOIL AND WASTE MATERIAL ALTERNATIVES
The costs associated with SW-2 are approximately twice the costs
associated with SW-1. The increase is due solely to the multi-
layer cap versus the single layer cap. The O&M costs are the
same for both alternatives.
GROUND WATER AND LEACHATE ALTERNATIVES
The costs for alternatives GW-1 and GW-2 are approximately the
same. GW-3 is approximately $ 2,500,000 more than either GW-1 or
GW-2. The O&M costs for the three alternatives are similar.
LANDFILL GAS AND AMBIENT AIR ALTERNATIVES
The costs for the two alternatives vary greatly. Capital costs
for LG-1 ($ 610,000) are approximately 1/2 of the capital costs
for LG-2 ($ 1,000,000). These costs are associated mainly with
the installation of the trench vents for LG-2. However, the O&M
costs of LG-l ($ 150,000jyear) are almost ten times the O&M costs
for LG-2 ($ 17,000jyear). The total cost for LG-1, assuming 30
years of operation, are approximately twice the total costs for
LG-2. However, if the O&M costs for LG-1 could be reduced by
50%, the costs for LG-l and LG-2 are within $ 500,000. One
option to note, 0 & M costs may be able to reduced significantly
by generating electricity .from the operation of the flares and
utilize it to run the blower.
SURFACE WATER AND SEDIMENTS ALTERNATIVES
The costs of SS-l and SS-2 are essentially the same, with a
$10,000 savings for on-site consolidation. No O&M costs are
associated with either alternative.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 30
x.
The Selected Remedv
The u.s. EPA and IEPA have conducted an analysis of the potential
remedies and have developed a remedial action plan for the site.
The remedy, is a combination of alternatives developed for the
various contaminated media (See Figures 4, 5, and 6). The
components of the remedy provided below.
soil and Waste Material Preferred Alternative
SW-1
Ground Water and Leachate Preferred Alternative
GW-l
Landfill Gas and Ambient Air Alternative
LG-1
Surface Water and Sediments Alternative
SS-l
The selected remedy includes a wetlands assessment to
specifically delineate the actual extent of wetlands (including
the presence.of any state or federal endangered species), a study
of potential impacts on wetlands by the remedy, and a program to
mitigate, replace and/or restore wetlands which are impacted by
the remedy in compliance with Executive Order 11990 for
protection of wetlands.
The remedy will include draining the standing surface water on
the landfills and a small portion of the standing water in the
low lying area on the southern portion of the site. This water
will be used as dust control within the landfills during
remediation activities or transported and treated off-site. The
contaminated sediments in the drainage ditch will be excavated
until local background concentrations are met, as determined by
u.s. EPA. The contaminated sediments and the drummed drill
cuttings stored on-site will be consolidated within the landfill
area prior to construction of the cap.
The landfill cap will be constructed of a minimum of 24 inches of
low permeability clay overlain with.a minimum of 8 inches of
topsoil to support vegetation. Precipitation run-off will be
drained to the low area on the southern portion of the site to
compensate for the loss of ground water discharge to the area.
The cap would comply with substantive requirements of Title 35,
Illinois Solid and Special Waste Management Regulations, 807.305,
for final cover, as applicable. Additionally, the constructed
cap will comply with RCRA Subtitle D landfill cover requirements,
as applicable.
The remedy will also include a hydrogeological study to further
delineate the interrelationship between the Woodland Landfill
property, the site, the underlying aquifers, and ground water
contamination. This study will provide the information needed
-------
-
... .'. .: ..:.'t.
"
F"lNAL' -
GRACE. :
"oJ" .".
'w. .:,w
,.., , ,:':.~~.f"':"::" .
W
'-V
'-V
W
'-V
W
'-V
'-V
'-V
Figure 4
CLA Y CAP
iRl-COUNTY LNlDFTLl
-------
,~
/
\
Q
~
.:::
,
i
,
\
I
f' ,'.~
I I~
\ : i
i i \
>... I~\'
.0
"'-.. \
I
. ;-/ ~
. / ~
,I I
I :
I I
~ i I
.~ \ \..--
'Je.o -
~
~""'~
- mENCH LOCI. 110M
- 'TRAHSWISSIOM PIPE
- PREDIC'rm GROUND WA TiR CONTOUR
I-~
IIIt03:!
o
,
1!D
5GD
1000
~
Figure 5
ON-SITE GROUND WA TE
INTERCEPTOR TRENCH
---
731.0 -
.-r./'IIINTV ANn ~.ClN t..4NDF'tLlS
-------
.~GRIC:';:" 7'JRAL
:-:E!..J :ANFlE":"=S \1 .
, =EVERAGE
! COMPANY ,;
"r=--'-.-.-.-, . .. 'I
~)I/ 8 I I I I , ~.;;
"f , rOX VI>.lJ.E.Y'I!
:' II I I =iGIN lLANdFiLL ' ! II ~OOR 'J:Q
'1/. I I . . .. ' t...J
1'1 I , 'I , J I , / / ~
fr=:' I - ~ ----!- - -! ---!... - -'----t J //1 Q: ~L'S ';"RUCK REPAIR
= . . .. It I' .
~I I I , I 8 I' ~I I
;::h' . , , I , I U ~GIN-W"'YNE
111 ! i JISPOSAl
: I( ,~ ill
.11' ''"'RI ICOUNTY' r I ~IIFLARING
\,,\\ t 'I :- 8' :..A~DFiLt- 'I: ~ 'il! S,A110N
\\ AGRICUL ruRAL
\ ~~
,~~
"
, ~ '
~.
o ~.. .~\ .
fj~.~
!I
;;::
-----
...::!!!:...
\
.---.-/
,'/c c: :..A:~D
_.~ N D F: L.i..
LEGEND
, ~ I>.L.l.SJo,tAN
" RESTAURANT
I
~
-:\"
o
I
Z.5O
1000
,
500
SCA1.£ IN FE£T
- , - , - - sm: PROPERTY BOUNDARY
- ~1E 0IJ1\JN£ OF LAHOf'IU.ED AREA
- - - - - PltCPatT't BOUNDARY BEnIE!H LNCIF1U.S
...-C
LWI0324
Figure 6
8
- MEADa fIR'
- ..un WIIJ.
ACTIVE GAS COLLECT10~
SYSTEM LAYOUT
-" -- -.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 31
to, among other things, determine the optimal placement of the
monitoring wells downgradient of the Woodland Landfill and the
ground water and leachate collection trenches. This study will
also attempt to verify if the active Woodland Landfill is also
adversely impacting the ground water.
A ground water and leachate collection system will be installed
to collect contaminated ground water as it leaves the landfills.
The purpose of the system is to prevent migration of contaminated
groundwater to nearby low-lying areas, surface waters, soils,
sediments and off-site groundwater. The system is also intended
to prevent migration of contaminated ground water from the upper
to the intermediate aquifer.
The need for treatment of the collected ground water prior to
discharge is not known at this time. This information would be
determined during the RD phase of the project. However, since it
is probable that the contaminated ground water will need some
sort of treatment prior to surface water discharge, provisions
will be included for discharging the contaminated ground water to
the local POTW. This may require the construction of a
transmission pipe to transfer the water to the sanitary sewer
system of South Elgin. It is anticipated that a lift station
would be need to be upgraded in order to handle the increase
water flow from the site. It may be possible that the water may
need some limited form of pre-treatment prior to discharge to the
POTW. This will be determined during RD and, if necessary, a
treatment system would be constructed on-site to meet any
required discharge standards established by the POTW. Provisions
will also be made for discharge to surface waters or other
disposal methods, in accordance with applicable laws and
regulations, in the event acceptance by thePOTW is not obtained.
The specific design details and parameters of the selected
groundwater collection system shall include consideration of the
results of the pre-design and design investigations which will be
conducted to further define the complex site hydrogeology and
extent of contamination related to the site. U.S. EPA may set
schedules for installation of the selected groundwater collection
system which allow for phased or delayed installation of the
system. Furthermore, U.S. EPA may consider replacing the
selected component with an alternative remedial groundwater
component, in the event U.S. EPA determines, based on pre-design
and design investigations and available information, that the
selected groundwater collection system is. not appropriate for
site conditions, or that another groundwater approach would be
equally or more protective than that selected and is warranted.
Any such alteration would be made in compliance with CERCLA
procedures, including provisions for issuance of an Explanation
of Significant Difference or a ROD amendment, as applicable;
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 32
Regardless of final design, the collection system will be
operated to contain the leachate and contaminated groundwater.
The collection system will be operated until such time that U.S.
EPA determines that the leachate/ground water beneath the site no
longer poses a threat to human health and the environment. If
U.S. EPA approves shut-down of the system, the ground water will
be, at a minimum, monitored quarterly to document that the
leachate/ground water beneath the site meet ARARs or other
appropriate health-based concentrations, as determined by U.S.
EPA. If the contaminant levels in leachate/ground water beneath
the site exceed acceptable levels, the collection system shall be
re-activated. .
Contaminated ground water located off-site (adjacent to the
northwest portion of the site) will not be collected even though
it is contaminated above MCLs. Since the levels of contamination
in the off-site ground water are relatively low and near MCLs and
health based levels, and since the effectiveness of off-site
collection appears to be limited by the irregular topography of
the clay layer and the location, design, and activities of the
Woodland Landfill, an off-site collection system is not believed
to be an effective approach at this time. It is expected that
the relatively low levels will naturally attenuate in a short
period of time, as designated by u.s. EPA (e.g. approximately 5
years) once the remedy is implemented and the contaminant source
is cut-off.
However, if predesign studies indicate that such a system may be
feasible, or if the levels of off-site contamination do not
appear to be approaching the ground water compliance levels at a
satisfactory rate, or are increasing, this decision will be re-
evaluated.
Additionally, the remedy will include contaminant fate and
transport modelling based on existing and newly-generated data to
assist U.S. EPA in determining if a satisfactory attenuation rate
is being achieved and to evaluate potential off-site contaminant
impacts.
Impacts to nearby media, including surface water, soils and
sediments, especially those -in the southern portion of the site,
will also be addressed by the groundwater collection system. The
trenches will intercept contaminated groundwater flowing from the
waste mass into lower-lying areas, thus preventing the transfer
of contaminants from the waste mass, through the groundwater,
into off-site groundwater and other media.
A monitoring program will be established to monitor the
effectiveness of the remedy and to provide assurance that the
local residential and public wells are not being adversely
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 33
impacted by contaminated ground water from the site. The system
will include, at a minimum, sampling of existing monitoring
wells, installation of new monitoring wells at needed locations,
and ground water sampling and monitoring of potentially affected
pUblic/private drinking water wells. Monitoring of soils,
sediments and surface water will also be established to assess
the effectiveness of the remedy with regard to these media, as
determined by u.s. EPA.
The monitoring well system will include installation of
monitoring wells downgradient of the operating Woodland Landfill
and upgradient of the any potential residential areas. This
system will be designed to be an early warning system for
detection of migrating groundwater contamination before it would
impact the residential wells. The details of the monitoring
system will be determined during the design of the remedy based.
on the results of the hydrogeological studies, and other
available information.
The point-of-compliance for groundwater compliance standards
shall be adjacent to the Site perimeter, as measured through a
series of u.s. EPA designated monitoring wells. The point of
compliance shall include EPA designated monitoring wells within
the groundwater immediately adjacent to the northwestern corner
of the site where slight exceedances of MCLs were previously
detected.
Groundwater compliance standards must be met at all times at all
monitoring wells at and beyond the point-of-compliance, with the
exception of the contaminated groundwater located adjacent to the
northwest corner of the site, unless otherwise provided by EPA.
For this area, based on contaminant fate and transport modelling
and other available information, EPA shall designate a time
period (to begin after completion of construction of the remedial
action) during which theexceedances detected therein will be
allowed to naturally attenuate down to groundwater compliance
standards. .
If it is indicated that contaminant levels (including those in
the low-lying southern portion of the site) are not being reduced
by containing the source of the contamination, or if they are
seen to be increasing, or if contaminants are migrating further
downgradient from the site (e.g. towards or past the Woodland
Landfill property), or if ground water compliance standards are
exceeded in any well at or beyond the point-of-compliance
(including, after expiration of the time period to be set by EPA,
monitoring wells within the area adjacent to the northwest corner
of the site), or if other off-site impacts are not being
mitigated at or beyond the point of compliance, further remedial
action may be taken in accordance with CERCLA, possibly including'
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 34
a downgradient ground water collection system. Contingency
provisions for any additional remedial activities will be
included in the design plans.
The emission of landfill gas will be controlled by an active
collection system. The gas will be collected by extraction wells
connected to a blower facility. The gas would pass through a
condensate tank to remove moisture, and would then be treated on-
site by flaring prior to being discharged to the atmosphere. The
emission of the treated landfill gas will comply with the
substantive requirements of Part 811 (Title 35 Ill. Adm. Code)
for control of landfill gas, as applicable. The flaring system
will be operated in compliance with National Primary and
Secondary Ambient Air Quality standards (NAAQS) and National
Emission Standards for Hazardous Air Pollutants (NESHAPs).
The remedy would also include institutional controls as
appropriate such as deed restrictions, and a ground water
monitoring program. Deed restrictions or other appropriate
controls will be established to prevent future development or
installation of drinking water wells.
The remedy will also include a program to assess whether all off-
site impacts (e.g. in the downstream unnamed tributary and other
areas, including the low-lying areas in the southern portion of
the site) from the landfills are being mitigated by the remedy.
The remedy will also include further investigation to ascertain
the location and nature of any other sources of contamination in
the vicinity of the site.
The remedy will require installation of a site-perimeter fence
and provision of site security during remedial construction. The
fence would restrict access preventing trespassing on the site
which may jeopardize the integrity of the cap.
Finally, the design of the remedy will consider the impact of the
remedy on the businesses which are located within, and adjacent
to, the site perimeter.
The combined cost of this remedy is estimated below:
Estimated Capital Costs:
Estimated Annual O&M Cost:
Total Present Worth:
Estimated Time to Implement:
$
$
$
8,634,000
243,500
12,624,000
2 - 3 years
The U.S. EPA, in consultation with IEPA, has determined that the
selected alternative is the best balance of desirable
characteristics among the alternatives with respect to the nine
criteria. Based on information availabl~ at this time, the
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 35
U.S.EPA and IEPA believe the preferred alternative offers the
best protection of human health and the environment, complies
with ARARs, eliminates long-term risks, reduces toxicity,
mobility or volume to the extent practicable, is implementable .
and is cost effective. By cutting off leachate discharges to the
southern portion of the site, the sediment and the surface water
quality will be improved, benefiting the local environment.
XI.
statutory Determinations
The selected remedy must satisfy the requirements of Section 121
of CERCLA to:
A.
B.
C.
D.
Protect human health and the environment;
Comply with ARARs:
Be cost-effective:
utilize permanent solutions and alternate treatment
technologies to the maximum extent practicable; and
Satisfy the preference for treatment as a principle
element of the remedy.
E.
The implementation of the selected remedy at the TCL site
satisfies the requirements of CERCLA as detailed below:
Protection of Human Health and the Environment
A.
Implementation of the selected remedy will reduce and control
potential risks' to human health poseq by exposure to contaminated
ground water, soil, landfill waste, landfill gases, surface
water, and sediments. The selected remedy will reduce potential
exposure to contaminated ground water to within acceptable risks
of 1 x 10.4.to 1 X 10-6 excess cancer risk and a Hazard Index of
less than 1.0. The selected remedy also protects the environment
from the potential risks posed by site chemicals discharging to
ground water, the unnamed tributary of Brewster Creek,
surrounding soils, sediments, and potential wetlands.
Institutional controls will be implemented to protect against
drinking of contaminated ground water at the site.
Capping the landfill, in ad~ition to reducing the potential
posed by exposure to landfill contaminants, will reduce
precipitation infiltration through the cap. Ground water
contaminant loading would then be reduced.
risk
Gas extraction and destruction will reduce the volume of
contaminants in the landfill waste and will. reduce current and
potential risks due to the landfill gases.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 36
Excavation and consolidation, under the landfill cap, of
contaminated sediments will reduce the excess cancer risk due to
exposure to soil and sediments to within acceptable risks of 1 x
10~ to 1 X 10-6 excess cancer risk and a Hazard Index of less
than 1. 0 .
No unacceptable short-term risks will be caused by implementation
of the remedy. The nearby community, and site workers, may be
exposed to noise and dust nuisances during construction.
Standard safety measures should manage any short-term risks.
Dust control measures would mitigate risk$.as well. Mitigative
measures will be taken to prevent and address adverse
environmental impacts. .
B.
Compliance with ARARs
with respect to any hazardous substances, pollutants or
contaminants that will remain on-site, CERCLA (~ 121 (2) (A»
requires the u.s. EPA to select a remedial action which complies
with legally applicable or relevant and appropriate standards,
requirements, criteria or limitations (ARARs). The selected
remedy will comply with Federal ARARs or State ARARs where State
ARARs are more stringent, as determined by u.s. EPA. The remedy
will be implemented in compliance with applicable provisions of
CERCLA and the NCP.
1.
Chemical-Specific ARARs
Chemical-specific ARARs regulate the release to the environment
of specific substances having certain chemical characteristics.
Chemical-specific ARARs typically define the extent of cleanup at
a site.
a.
Soils/Sediments
There are no chemical-specific standards established for soils
and sediments. However, risk-based levels or local background
concentrations may be utilized in establishing chemical-specific
cleanup goals for soils and sediments and are factors "to-be-
considered" in designing a protective remedy for this site.
b.
i) .
Ground Water
Federal ARARs
Maximum contaminant Levels (MCLs), and to a certain extent,
Maximum contaminant Level Goals (MCLGs), the. Federal drinking
water standards promulgated under the Safe Drinking Water Act
(SWDA), are ARARs for the site. MCLGs are relevant and
-------
RECORD OF DECISION
Trj-County/Elgin Landfill
Page 37
appropriate when the standard is set at a level greater than zero
(noncarcinogens), otherwise MCLs are relevant and appropriate.
ii). state ARARs
The state of Illinois is authorized to administer the
implementation of the Federal SDWA. The State has also ground
water quality standards promulgated under Title 35, subtitle F,
Chapter I, Part 620. These state ground water quality standards
are ARARs for the ground water at the TCL site.
c.
Surface Water
i) .
Federal ARARs
CERCLA Section 121(d) (2) (B) (i) requires the u.s. EPA to consider
whether water quality criteria for human health and aquatic life
protection developed under the Clean Water Act (CWA) Section 304
would be relevant and appropriate considering the designated or
potential use of ground water or surface water, the environmental
media affected, the purposes for which such criteria were
developed, and the latest information available.
Federal water quality criteria (wQC) are guidelines that set
pollutant concentration limits to protect surface waters that are
applicable to point source discharges, such as from industrial or
municipal wastewater streams. At a Superfund site, the Federal
WQC would not be applicable except for pretreatment requirements
for discharge of treated water to a PUblicly Operated Treatment
Works (POTW). Since the selected remedy plans to discharge to
the local POTW, these requirements are applicable for the TCL
site. The AWQCs for protection of f.reshwater aquatic organisms
are relevant and appropriate to the TCL site remedy for any
direct discharges to the unnamed tributary, Brewster Creek, or
the Fox River.
ii). State ARARs
The State of Illinois has been authorized to implement the
National Pollutant Discharge Elimination System (NPDES)
established under the CWA. .For any discharge to waters of the
State of Illinois, the chemical specific standards of Title 35,
Subtitle C, ~ubpart B, Section 302.20B and toxic substances
standards of Section 302.210 of the Illinois Administrative Code
establishing General Use Water Quality Standards would be ARARs.
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 38
2.
Location Specific ARARs
Location-specific ARARs are those requirements that relate to the
geographical position of a site. These include:
a.
Federal ARARs
Executive Order 11990 - Protection of Wetlands is an ARAR for any
remedial action taken within wetlands. This ARAR requires that
activities required in a wetland must minimize the destruction,
loss, or degradation of the wetland. In addition, any affected
wetlands may be restored, as appropriate.
Endangered Species Act (16 USC 1531) - The Endangered Species Act
requires that actions must be performed to conserve the
endangered or threatened species located in and around the TCL .
site. Activities must not destroy or adversely modify the
critical habitat upon which endangered species depend. The
selected remedy will be implemented in compliance with this
regulation. Prior to conducting remedial activities, a survey of
the subject areas will be conducted to determine whether or not
endangered or threatened species will be affected.
b.
State ARARs
Endangered Species Protection Act, Title 17 Conservation Chapter
1, Subchapter C, Part 1075 Illinois Administrative Rules - Under
this requirement, actions must be performed to conserve the
endangered or threatened species located in and around the TCL
site. Activities must not destroy or adversely modify the
critical habitat upon which endangered species depend. The
selected remedy will be implemented in compliance with this
regulation. Prior to conducting remedial activities, a survey of
the subject areas will be conducted to determine whether or not
endangered or threatened species will be affected.
3.
Action Specific ARARs
Action-specific ARARs are requirements that define acceptable
treatment and disposal procedures for hazardous substances.
It is unknown at this time whether or not the collected ground
water will require treatment prior to discharge to the POTWar a
surface water body. If required, any treatment system utilized
will be operated in compliance with ARARs.
a.
Federal ARARs
RCRA Subtitle D establishes requirements for final cover and gas
control from solid waste landfills. The selected remedy will
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 39
comply with these ARARs, as applicable. In this case, since the
waste mass is in contact with groundwater, a subtitle D cap was
selected rather than a Subtitle C cap, since the more effective
infiltration reduction achieved a "C" cap over a "D" cap is not
felt to be significant. This is due to the fact that
contaminants will continue to be transferred from the waste mass
to groundwater, regardless of the type of cap.
New Federal Regulations for solid waste landfills were
promulgated in the Federal Register of October 9, 1991. These
regulations pertain to minimum cover requirements for caps
constructed after October 9, 1993 and post closure care. Post
closure care includes maintenance of the cap, ground water
monitoring, leachate collection, and quarterly monitoring of
methane gas concentrations. Post closure care must be conducted
for a period of 30 years. These remedy will be implemented in
compliance with these requirements as specified in 40 CFR Part
258, Subpart F.
The new Federal Regulations for solid waste landfills as
specified in 40 CFR S 258.23 for explosive gas controls would be
relevant and appropriate to the active landfill gas extraction
and treatment. These requirements establish maximum methane
concentrations in facility structures and property boundary as
well as establishing a methane monitoring program. The remedy
will be implemented in compliance with' these requirements.
Land Disposal Restrictions ("LDR" or "Land Ban") would not be
applicable because no placement of RCRA hazardous wastes will
occur and no listed wastes are documented at the site. The
contaminated sediments excavated and reconsolidated within the
landfill will be tested to determine if they are RCRA
characteristic by the TCLP test. If they are determined to be
characteristic, the sediments will be stabilized prior to be
consolidated within the landfill.
Federal Clean Air Act - This act authorized the establishment of
National Primary and Secondary Ambient Air Quality Standards
(NAAQS) for air pollutants (40 CFR Part 50) and National Emission
Standards for Hazardous Air Pollutants (NESHAPs) (40 CFR Part
61). Also under 40 CFR 60.18, new source performance
requirements are established for solid waste landfills.
Compliance with these standards will be met during excavation and
landfill gas flaring activities.
b.
State ARARs
The State of Illinois is authorized to implement the Subtitle D
solid waste requirements of RCRA. The selected remedy will
comply with substantive requirements of Title 35, Illinois Solid'
-------
RECORD OF DECISION
Tri-County/Elgin Landfill
Page 40
and Special Waste Management Regulations, section 807, Subpart C
for closure of solid wastes landfills, specifically relating to
final cover (minimum of 24 inches of suitable material), air
pollution, and closure requirements, as applicable.
C.
Cost Effectiveness
Cost effectiveness is determined by evaluating the following
three of the five balancing criteria to determine overall
effectiveness: long-term effectiveness and permanence, reduction
of toxicity, mobility or volume through treatment, and short-term
effectiveness. Overall effectiveness is then compared to cost to
ensure that the remedy is cost effective.
The selected remedy provides overall cost effectiveness because
it provides adequate long-term effectiveness and permanence.
Secondary reduction in toxicity, mobility, and volume is
accomplished through treatment of the ground water and landfill
gases. No unacceptable short-term risks will be caused by
implementation of the remedy.
D.
Utilization of Permanent Solutions and Alternative Treatment
Technoloaies or Resource Recoverv Technologies to the
Maximum Extent Practicable
The selected remedy utilizes permanent solutions and alternative
treatment technologies to the maximum extent. practicable ("MEP").
This finding was made after evaluati9n of the protective and
ARAR-compliant alternatives for the TCL site remedial action and
comparison of the.lltrade-offs" (advantages vs. disadvantages)
among the.remedial alternatives with respect to the five
balancing criteria (see discussion above).
E.
Preference for Treatment as a Principle Element
The principle threats at the TCL site are the contaminated ground
water and contaminated soil and landfill waste. The selected
remedy uses treatment as a secondary element of the remedy
through: 1) collection and treatment of leachate and
contaminated groundwater as it leaves the landfills, and 2)
extraction and treatment of landfill gases. As previously noted,
treatment of the landfill waste is considered technically
impracticable.
------- |