I !r
United States
Environmental Protection
Agency
Office 01
Emergency and
Remedial Response
EPAIROD/R05-921222
September 1992
PB93-964128
&EPA
Superfund
Record of Decision:
City Disposal Sanitary Landfill,
WI
EP A Report Conection er
Information ~esource Cent
US EPA RegIOn 3
Philadelphia, PA 19107
Hazardous Waste Collection
~.'..lrIformation Resource Center
~U$'ePARegion 3
PblQdelphia, PA 19107
'RU . ~. Environmental Protection Agency
eg/o~ III Hazardous Waste
TechnIcal Information Center '
8~ 1 Ches,tnut Street, 9th Floor
(PhIladelphIa, PA 19107
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~
NOTICE.
The appendices listed in the index that ant not found in this dOcument haVe been removed at Ihe request of
the issuing agencv. They contain material which ~ but adds no furUW WtcabIe infamatiOn to
the conIent of the document. All supptementaI material is. I1aWlMll'. CCJfJIM1ed In the adminisIrative record
for this site. .
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50272.101
REPORT DOCUMENTATION 11. REPORT NO. I ~ 3. Recipient'a Acceuion No.
PAGE EPA/ROD/R05-92/222
4. Tltlund SUbtJtJ8 5. Report Date
SUPERFUND RECORD OF DECISION 09/28/92
City Disposal Sanitary Landfill, WI
6.
First Remedial Action - Final
7. Author(a) 8. Fltrfonning Organization RapL No.
II. Fltrformlng Orgalnlzatlon Narm and Addreaa 10. P,ojec\lTukIWo,k Un" No.
11. ContraCl(C) 0' Grant(G) No.
(C)
(G)
1~ Sponao,lng Organization Narmand Addreaa 13. Type o' Report & FIt,locI Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. SUppiermnl8ry -
PB93-964128
16. Abatract (UmIt: 200 worda)
The 38-acre City Disposal Sanitary Landfill site is an inactive landfill located in
Dane County, Wisconsin. The landfilled portion of the site, which occupies
approximately 24 acres, contains an estimated 700,000 cubic yards of waste. Land use
in the area is predominantly agricultural with minor wooded areas. The site is
bordered to the east by Badfish Creek. All residents in the vicinity use ground water
from private drinking water wells; however, no contamination has been detected in the
wells. From 1966-1977, City Disposal Corporation, and later Acme Services, Inc., used
the site for disposal of household, construction, debris, and industrial wastes.
Industrial wastes included solvents from the plastic fabrication industry, mixtures of
lubrication oil and water, and paint wastes. During the period of operation, the
landfill was subdivided into 12 cells, of which cells 1 and 12 were used for initial
disposal until 1975. Cells 2, 3, 4, and 6 were filled or partially filled from 1974
until closure in 1977. Cell 5 and cells 7 to 11 were never developed. After closure
of the site, both City Disposal Corporation and Acme Services, Inc., were acquired by
Waste Management of Wisconsin, Inc. (WMWI). Records indicated that cells 6 and 12 were
(See Attached Page)
17. Docurmnt Anaryala .. De8c,lplora
Record of Decision - City Disposal Sanitary Landfill, WI
First Remedial Action - Final
Contaminated Media: soil, debris, gw
Key Contaminants: VOCs (benzene, TCE, toluene, xylenes), other organics (phenols),
metals (arsenic, chromium, lead), inorganics
b. Idenmlera/Opan.End8d Ta,me
Co COSA TI Fl8ldJGroup
18. Availablilly Statement 19. Security Class (This Report) 21. No. 01 paJll!tl
None 52
20. Security Cia.. (Thia Page) ~ Price
None
Sea ANSI-Z3II.18 SH Instructions on Rl1V81N 272 (4-77)
(Formerty NTls.35)
Deportment 01 eomrmrce
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EPA/ROD/R05-92/222
City Disposal Sanitary Landfill, WI
First Remedial Action - Final
Abstract (Continued)
used to dispose of liquid industrial waste, which was subsequently mixed with refuse.
Because of the mObility and toxicity of the industrial waste, cells 6 and 12 are
considered to be the principal threats of contamination at the site. This ROD addresses
the final remedy for contaminated soil, debris, and ground water. The primary
contaminants of concern affecting the soil, debris, and ground water are VOCs, including
benzene, TCE, toluene, and xylenes; other organics, including phenols; metals, including
arsenic, chromium, lead; and inorganics.
The selected remedial action for this site includes installing a landfill gas control
system to control air emissions; treating contaminated soil and debris in cells 6 and 12
using an in-situ vapor extraction (ISVE) system with an air intrusion cut-off wall to
remove and treat VOCs; treating the extracted vapors by flaring; installing a hazardous
waste landfill cover, Design C, over cells 6 and 12, anq a solid waste landfill cover,
Design B, over the rest of the landfill; extracting ground water, and conducting
treatability studies to determine the best treatment; pretreating ground water onsite
using precipitation to remove metals, followed by treatment using chemical oxidation or
another comparable technology, with onsite discharge to Badfish Creek; monitoring ground
water and residential wells; and implementing deed, land and ground water use
restrictions. The estimated present worth cost for this remedial action is $14,851,387,
which includes an annual O&M cost of $90,978 for years 0-5 and $21,258 for years 6-25 for
source control; and $645,859 for years 0-20 and $114,487 for years 20-40 for ground water
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific ground water clean-up goals are based on Preventative Action Limits
(PALs) established in NR 140 of the Wisconsin Administrative Code and include benzene
0.067 ug/l; 2-butanone (PAL or MCL not established); 1,1 dichloroethane 85 ug/l;
methylene chloride 15 ug/l; toluene 68.6 ug/l; vinyl chloride 0.0015 ug/l; and
xylenes 124 ug/l. Air emissions from the gas control and ISVE systems will meet the CAA
requirements. RCRA standards will apply to the construction of the landfill caps.
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(Q;~~-'~
18
Declaration for the Record of Decision
Site Name and Location
City Disposal corporation Landfill
Dane County, Wisconsin
Statement of Basis and Purpose
This decision document presents the selected remedial action
f~r the. City ~isposal corpor~tion Landfill 7ite, in Dane County,
W~scons~n, wh~ch was chosen ~n accordance w~th the requirements
of the comprehensive Environmental Response, Compensation, and
Liability Act of 1980 (CERCLA), as amended by the Superfund
Amendments and Reauthorization Act of 1986 (SARA) and, to the
extent practicable, the National oil and Hazardous Substances
Pollution Contingency Plan (NCP). This decision document
explains the factual and legal basis for selecting the remedy for
this site.
The State of Wisconsin has not formally concurred with the
selected remedy as of the signature date of this Record of
Decision. The Wisconsin Department of Natural Resources (WDHR)
is expected to concur with the selected remedy. The information
supportinq this remedial action decision is contained in the
administrative record for this site.
Assessment of the site
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response action
selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare,
or the environment.
Description of the Selected Remedv
The selected remedy addresses the final remedy for the Site
and addresses the principal treats posed by the site.
The major components of the selected remedy include the
following:
For ground water:
*
Ground-water use restrictions;
*
Extraction of ground water followed by treatment of the
extracted ground water by chemical oxidation on-site
and treated ground water discharge to surface water;
and
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*
Environmental monitoring to ensure effectiveness of the
remedial action.
For the.landfill contents:
*
Resource Conservation and Recovery Act (RCRA) Subtitle
D (solid waste) landfill cover over the majority of t~e
site and a Subtitle C (hazardous waste) landfill cover
over two areas of the landfill that recieved
substantial amounts of industrial waste;
*
Landfill gas venting and treatment; and
In-Situ Vapor Extraction (ISVE) of volatile waste from
two cells of the landfill and treatment of the
extracted vapors on-site.
*
.Declaration of Statutorv 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 (or resource
recovery) technologies to the maximum extent practicable. The
remedy satisfies the statutory preference for remedies that
employ treatment that reduce toxicity, mObility, or volume as a
principal element.
Because this remedy will result in hazardous substances remaining
on site above health-based levels, a review will be conducted
within five years after commencement of remedial action to ensure
that the remedy continues to provide adequate protection of human
health and the environment.
~/u,:l,i./f92
Dat . '.
~~r;(l{ It£L
h Valdas v. Adamkus
! ,vRegional Administrator
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DECISION SUMMARY
A.
Site Loca~ion and DescriDtion
The City Disposal corpora~ion Landfill (the Site) is located on
approximately 38 acres in the southern half of section 30,
township 6 North, range 10 East in Dane County, Wisconsin (Figure
1). The landfill is approximately 1/2 mile northeast of Oregon,
Wisconsin, approximately 1/2 mile east of Hook Lake and 3-1/2
miles west of Lake Kegonsa. See Figure 1.
The landfill opened in August 1966 and operated until its closure
in January 1977. Industrial wastes were disposed there from 1966
to March 1975. The waste is comprised of a mixture of household
and industrial waste, general construction waste, and debris.
Industrial wastes included solvents from the plastic fabrication
industry, mixtures of lubrication oil and water, and paint
wastes. These wastes included such substances as xylene,
naphtha, cyclohexanone, and tetrahydrofuran.
The landfilled area occupies approximately 24 acres of land.
landfill waste volume is approximately 700,000 cubic yards.
The land surrounding the site is primarily used for agricultural
purposes, and includes minor wooded areas. The Site is bordered
to the east by Badfish Creek. The area east of the Site, between
Badfish Creek and Sandhill Road, includes residences and a cattle
farm. The nearest residences to the Site are those approximately
1,000 feet southwest of the landfill. Residences are also less
than 1,'500 feet from the eastern limits of the landfill. A
wooded section lies southeast of the Site. Pastures and farmland
are southwest and west of the site.
The
All residences in the area utilize ground water from private
drinking water wells. Residential wells close to the site were
sampled during the Remedial Investigation (RI). No contamination
from the Site was found in the residential wells sampled.
B.
site Historv and Enforcement Activities
The landfill was operated by city Disposal corporation and later
by Acme services, Inc. under a license issued by the Wisconsin
Department of Natural Resources subject to State of Wisconsin
solid waste management regulations - Chapter NRlS1, wisconsin.
Administrative Code (WAC) (NR 151 has subsequently been revised
into NR 500). After closure of the Site, both City Disposal
Corporation and Acme Services Inc. were acquired by Waste
Management of Wisconsin Inc. (WMWI).
1
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FIGURE 1. SITE LOCATION.
.
....
"
112
,
(>
..
,ca
'CO
~
~
IOWA
o
1/2
-
SCALE IN ..ILES
~
-H-
I
30
31
T. 6 N.
R. 10 E.
FIGURE 1
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The la~dfill ~as planned to be subdivided into 12 cells. During
o~erat~o~, Cells 1, 2, J, 6 and 12 were filled or partially
f~lled w~th waste. Cells 1 and 12 were used from initial
disposal until 1975. Cells 2, J, 4 and 6 were filled or
partially filled from 1974 until closure in 1977. Cells 5 and 7
through 11 were never developed or utilized, except for possible
borrowing operations. See Figure 2.
A portion of Cell 12 was designated for industrial waste
disposal. Industrial wastes were disposed of in Cell 12 from
1966 through March 1975. Records indicate that drums of liquid
wastes were drained into the cell. The liquids were mixed with
solid-form waste in the cell. RI ground-water contaminant data
suggests that industrial waste may also have been placed in Cell
6.
On June 9, 1981, WMWI submitted a Notification of Hazardous Waste
Site pursuant to CERCLA Section 103 (c). The site was proposed
for inclusion on the National Priorities List (NPL) by the WDNR.
.The Site was placed on the NPL on September 21, 1984.
On August 25, 1987, the United States Environmental Protection
Agency (U.S. EPA), WDNR and WMWI entered into an Administrative
Order on Consent (AOC) for performance of a Remedial
Investigation/Feasibility Study (RI/FS) by WMWI. In August 1988,
the following generator Potentially Responsible Parties (PRPs)
joined in the RIfFS AOC: Sara Lee Corporation, Graber Industries
Inc., Inland container corporation, Ohmeda, Sub-Zero Freezer
Company, and Webcrafters Inc.
C.
Communitv Partici~ation
The RI and FS Reports and supporting documents were made
available to the public in the administrative record maintained
at U.s. EPA offices in Region 5 and the Dunn Town Hall (near the
site) at 4156 County Trunk Highway B, McFarland, WI. U.S. EPA's
Proposed Plan was mailed to approximately 400 persons on the site
mailing list. A notice of availability of the administrative
record and Proposed Plan was published in the Wisconsin State
Journal, Madison capital Times, and Stoughton Courier-Hub
newspapers on May 14, 1992. Press releases were also sent to all
local media. A public comment period on the Proposed Plan and
administrative record was held from May 18 to June 18, 1992. In
addition, a public meeting was held on June 3, 1992. At this
meeting, representatives from U.S. EPA and WDNR answered
questions about the site and the remedial alternatives under
consideration. Formal oral comments on the FS and Proposed Plan
were also documented by a court reporter. A verbatim transcript
of this public meeting has been placed in the information
repository and administrative record at the Dunn Town Hall. At
the meeting, a request for a comment period extension was made.
2
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A
N
"K .. '\A,.
...,... M Gnft
... -.
~
A
.
City Dispos..
Corporation Landfill
Dunn Township, Wisconsin
.... Te .....
:f
4~ ~
III
.~.. en
OispoMJ eel L0C8r»ns
-+
~
.'t'
~MGniI
...~
~'-
Rguf81
I----T----r---~--\
I I I I \
: 5 : 7 : 9 : 10 \
I I I I \
.. - - - -'- - - -.... - - -.. - - - .',
I I \
, I I 8 I \ LItIdfiIl
: : :: \B~~
L_- -'----~- --~---
: 3: 2~
I I Area of Concern
I I
1__-
FIGU?.E 2
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U.S. EPA granted an extension through July 20, 1992. Notice of
the extension was published in the Stoughton Courier-Hub and
Oregon Observer newspapers on June 11, 1992. Responses to the
comments received during the public comment period are included
in the Responsiveness Summary, ~hich is part of this ROD.
Prior to the completion of the FS, U.S. EPA conducted additional
community relations activities. When the RI was completed, U.S.
EPA sponsored a public meeting on December 4, 1991 at the Dunn
Town Hall to update the community on its findings. An RI update
fact sheet was sent to persons on the mailing list. Notice of
this meeting was published in the Madison capital Times on
November 28, 1991 and in the Stoughton courier-Hub on November
27, 1991. Press releases were also sent to all local media.
u.s. EPA also
informational
the RI. This
Town Hall. 'A
,to persons on
participated in a Town of Dunn-sponsored
meeting to update the community on the progress of
meeting was held on September 26, 1990 at the Dunn
fact sheet was sent in conjunction to this meeting
the mailing list.
u.s. EPA participated in another Town-sponsored update meeting on
April 6, 1989 to update the community on the beginning of
Spring/Summer fieldwork. A press release was sent to all local
media to announce the start of fieldwork at City Disposal (and
other Dane county sites) on March 27, 1989.
A press release was sent November 14, 1988 to all local media to
announce the start of fall field activities. An'RI "kickoff"
meeting was held on September 29, 1988 at the Dunn Town Hall.
Advertisements were placed in the local newspapers and press
releases were sent to all local media. A fact sheet was sent in
conjunction to this meeting to all persons on the mailing list.
A press release was also sent to all local media on June 3, 1987
to announce the signing of the consent order.
The information
in Summer 1987.
include monthly
documents.
repository was established at the Dunn Town Hall
The repository has been regularly updated to
reports, applicable laws and other site-related
A Community Relations Plan (CRP) was completed in July 1988. The
CRP contains community concerns raised during personal interviews
in January 1988. It also outlines a community relations strategy
to be followed through completion of the RIfFS.
The public participation requirements of CERCLA Sections 117 and
113 (k) (2) (B) (i-v) have been satisfied.
3
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D.
Sco~e and Role of Response Action Within Site StrateQY
This ROD addresses the final remedy for the Site. The threats
posed by this Site to human health and the environment are
landfilled waste and con~aminated ground water.
The landfilled waste is the source material for contamination
from the Site. Liquid industrial waste located in landfill cells
6 and 12 are considered a principal threat waste due to their
mobility and toxicity. Other wastes placed into the landfill are
considered low-level threat wastes.
E.
Summarv of Site Characteristics
Pursuant to its authority under the Comprehensive Environmental
Response, Compensation and" Liability Act of 1980, as amended
(CE?CLA) and the National Oil and Hazardous Substances Pollution
Cor. ~gency Plan (NCP), a Remedial Investigation (RI) and
Feas~bility Study (FS) were conducted at the Site.
The following conditions were observed at the Site:
1.
Topography
Landforms in the vicinity of the Site are the result of the
action of glaciers, which advanced and retreated across the
area, transporting rock and debris. Landforms have been
modified by subsequent erosion. The dominant physiographic
feature in the area is the Milton Moraine, on which the
landfill is located. The Milton Moraine trends northwest
throughout the area, is poorly drained, and typically
exhibits irregular, hummocky topography with numerous closed
depressions, or kettles. .
The relief of the land surface is approximately 100 feet in
the vicinity of the Site. Elevation varies from around 920
National Geodetic Vertical Datum (NGVD) at Badfish Creek and
Grass Lake to approximately 1,020 NGVD north of the
landfill. Badfish Creek and Grass Lake are the two
preaominant surface-water features in the vicinity of the
landfill.
The Site lies in the Rock River drainage basin. Surface-
water runoff at the Site drains predominantly toward the
northeast and east, to Badfish Creek. The Madison sev~ge
treatment plant discharges treated effluent into Badf~3h .
Creek at the rate of 24 to 52 million gallons per day, Wh1Ch
constitutes the majority of normal flow of the cr7ek.
Badfish Creek flows southeast toward the Yahara R1ver, a
tributary of the Rock River.
4
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v
2.
Geology
construction of the landfill occurred within the Milton
Moraine. The glacial drift at the landfill was deposited on
top of bedrock during periods of advance, stagnation and
retreat of glaciers. Two principal glacial deposits are
identified at the landfill: (a) a lower basal till
consisting of compact, clay-rich, sandy and gravelly
deposits that are 0 to 66 feet thick, and (b) overlying the
basal till, a series of complex, interbedded, clast-
supported diamictons from ice marginal and supraglacial ice-
contact and fluvial deposits. Ice marginal and proglacial
deposits are developed to the immediate south of the
landfill, while englacial and supraglacial deposits
predominate north of the landfill's southern-most boundary.
3.
Landfill
The waste placed into the landfill was comprised of a
mixture of household and industrial waste, general
construction waste and debris. Industrial wastes included
solvents from the plastic fabrication industry, mixtures of
lubrication oil and water, and paint wastes. These wastes
included chemicals such as xylene, naphtha, cyclohexanone
and tetrahydrofuran.
The landfill was subdivided into 12 cells of which Cells 1,
2, 3, 6 and 12 were filled or partially filled with waste.
Cells 5 and 7 through 11 were never developed or utilized,
except for possible borrowing operations.
A portion of Cell 12 was designated for industrial waste
disposal. Industrial waste arrived at the landfill in
drums. The drums were staged near the edge of Cell 12, the
bungs were removed and the drums then laid into the open
cell to drain. Refuse was then placed in Cell 12, mixed
with the liquids and "drums and compacted. Discrete areas of
concentrations of disposed drums were not found during the
investigation. Records indicate that empty drums were also
placed into Cell 6 after their contents were drained into
Cell 12. No records of drum stacking or drum trenching
activities have been found.
The existing landfill cover consists of soil and varies in
thickness and composition. The construction of the existing
landfill cover is inadequate for long-term minimization of
5
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the-movement of water from the surface into the landfilled
waste.
The thickness of the cover ranges from 0.5 foot to 4.2 feet
at points sampled. The mean value of the thickness of the
cover a~ the sampling points is 1.7 feet. The cover is
absent at several points at which exposed waste was
observed. Samples of the cover soil were collected from
several points on the cover. The cover does not comply with
current solid waste and hazardous waste landfill closure
requirements.
The thickness of the waste ranges from 15.0 feet to 22.7
feet. The waste mass within the landfill is above the water
table. The water table lies between 5 and 20 feet below the
waste. .
Leachate was not found within the landfill. It appears that
the bottom of the landfill does not prevent downward
movement of liquid or leachate. Results of the
investigation suggest that the chemical character of
absorbed moisture in the waste in Cell 12 is different than
that of other cells. This suggests that some of the
industrial waste placed into the cell remain absorbed in the
waste of the cell.
4.
contamination
contamination at the site results from the source material
(landfilled waste) and impacts both ground water and soils.
a.
Source.
The source of contamination from this site is the
landfilled waste. The landfill lacks a bottom liner
system to prevent liquid waste and landfill-producea
leachate from moving downward from the waste in~o the
qr9und water.
Investiqation data indicate that liquid industrial
waste placed in Cell 12 appears to be absorbed into the
solid-form waste and continues to .be a source for
qround-water contamination. The source of the majority
of ground-water contamination appears to be ce~ls 6 and
12. This indicates that the solid-form waste 1n Ce~l 6
has also absorr!d liquid industria~ waste or that
liquid waste w~; also dispc-ad there and conti~ues.to
be a significan~ source of ground-water contam1nat1on.
The investigation data indicates that a ~umber o~
Volatile organic Compc_;nds (VOCs) were d1sposed 1n the
6
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"landfill. These VQCs include Benzene, Methylene
chloride, 2-Butanone, Tetrachloroethylene,
Tetrahydrofuran, Toluene, Trichloroethylene, Vinyl
Chloride, Xylene, Dichloroethane and Dichloroethylene.
The investigation data indicate that the solid waste
placed in the landfill is not producing significant
amounts of methane gas. Low concentrations of total
volatiles were sporadically detected around the
periphery of the landfill.
b.
Ground Water.
Aquifers beneath the Site consist of two systems:
Glacial Deposits and Bedrock.
i.
Glacial Deposits. The landfill has
contaminated ground water" contained in the
glacial deposits around the landfill.
Ground-water wells installed to monitor the
glacial deposits are designated as Shallow
and Intermediate (S&I) wells.
Table 1 summarizes the chemicals and
concentrations found in the glacial deposits
aquifer.
Movement of ground water within this aquifer"
is complex, due to the variability of the
glacial deposits, and the flow of ground
water from Badfish Creek toward the Site.
The dominant directions of movement of ground
water are northeast under the eastern portion
of the landfill, and predominantly northward
under the western portion of the landfill.
There is a north-south trending ground-water
divide in the east~rn portion of the
landfill, west of Cell 12. Figure 3
illustrates the direction of ground-water
movement in the glacial deposits.
Horizontal ground-water gradients are very
small in value. Ground-water velocities vary
around the Site. Velocities range from 8.3
to 380.8 feet per year. The mean velocity
of ground water is very slow.
Investigation data indicates a ground-water
depression northeast of the site.
7
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TABLE 1
SUMMARY OF CHEMICALS DETECTED !N GROUNDWATER
~T C:~Y DISPOSAL CORPORATION LANDFIL~
SHALLOW AND !NTERMEDIATE WELLS
(Concen~ra~ions repor~eQ in ug/L)
CHEMICAL
ORGANICS:
Frequency of
Detection fa)
Range of DetecteQ
On-Site Concentra~ions
Range of RI
Background
Concen~ration (f)
i ;"cetone 38/53 3.1 - 102.650 5.7 - 10
I
Benzene 18/41 1.5 - 8.8 ND
Benzoic Acid 3/17 10.6 - 294.5 ND
2-Butanone; 10/41 ~4.2 - 622.:;:0 ND
Carbon Tetrachloride 1/41 162.8 ND
Chloroethane 12/41 3.2 - 33.5 ND
1.1-Dichloroethane 18/44 1.8 - 249.5 ND
1,2-Dichloroethane 1/41 1,306.3 ND
trans-1,2-Dichloroethene 21/43 1.9 - 1.646.3 ND
1.2-Dichloro~ro~ane 7/41 1.4 - 2.7 ND
Diethyl~hthalat. 1/17 4.1 ND
Ethvlben:ene 13/41 1.5 - 1,070 ND
2-Hexanone 2/41 7.4 - 8.6 ND
Isophorone 1/17 1.9 ND
4-Methyl-2-pentanone 13/48 1.4 - 3,400 NO
Methvlene Chloride 39/51 1 - 767 1.7 - 6.8
2-Methvlt)henol 2/17 3.6 - 21 NO
4-Methvlt)henol 5/17 2.1 - 253 NO
NaOhthalene 1/17 18 NO
Phenol 3/17 1. 5 - 48 NO
1,l,2,2-Tetrachloroethane 2/48 1.2 NO
Tetrachloroethene 16/44 0.8 - 119 NO
Tetrahydrofuran 23/42 16.3 - 199,500 NO
Toluene 17/46 0.9 - 25,900 ND
1, 1, l-Trichloroethane 10/44 0.9 - :'7.5 NO
-
Trichloroethene 23/46 1.4 - 277 NO
Vinyl Acetate 1/41 3.9 NO
Vinyl .Chloride 4/41 1.5 1,250 NO
m-Xylene 10/41 1.7- 1,790 NO
o&p-xy1ene 14/41 1.6 - 1,880 NO
Also known as Methyl Ethyl Ketone (MEK)
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TABLE 1 con't
SUMMARY OF CHEMICALS DETECTED IN GROUNDWATER
AT CITY DISPOSAL CORPORATION LANDFIL~
SHALLOW AND INTERMEDIATE WELLS
(Concentrations reported in ug/L)
CHEMICAL
:norcan1.cs:
Frequency of
Detection (a)
Range of Detected
On-Site Concentrations
Range of RI
Background
Concentration If)
-
Aluminum 1/17 37 ND
Arsenic 10/17 2.8 - 63 8.2 - 9.6
Barium 19/20 11 - 670 51 - 260
Berv 11 ium 10/20 0.3 - 0.4 0.3
Boron 20/20 5.7 - 280 28 - 89
Cadmium 13/20 0.5 - 4.4 1.6 - 2.1
Calcium 53/53 44000 - 280,000 68,000 - 104,000
Chloride 53/53 2400 - 208,700 4,400 - 35,900
Chromium 6/20 1.3 - 2.5 ND
Cobalt 6/17 7.3 - 27 ND
Copper 18/20 2 - 13 5 - 6.9
Cyanide 19/19 0.3 - 3.1 1.3 - 3.2
Fluoride 50/53 100 - 500 100 - 500
Iron 43/53 22 - 52,900 93 - 6,400
Lead 4/17 1 - 1.5 ND
Magnesium 53/53 5,600 - 132,000 33,00 - 55,200
Mangane8e 50/53 3.3 - 3,700 17 - 1,090
Nickel 11/17 3.4 - 34 4.3 - 6.6
Nitrate 9/20 200 - 17,650 300
Potassium 45/53 520 - 12, 000 1,500 - 4,100
Selenium 1/17 0.6 1.3
Silver 12/20 2.6 - 9.3 3 - 5.3
Sodium 53/53 2,400 - 62,000 3,000 - 17,000
Sulfate 12/12 5,790 - 28,800 12 ,000 - 50,900
Vanadium 13/20 4.6 - 18.5 10
Zinc 13/20 7.8 - 140 11 - 20,
-------
-700
00
-JOO
. 1110
00
00
iOO -
lOO -
200
600
:JOO
FIGlffiE 3
800
1300
1700
2100
Land fi 11 IlouJldary
~
Oirect ion oj" Ground-Waler Movement mad" I UepoRi ts
"nn
.,nn
,-rn"
"'t(\n
2~00
IUIJU
I filii
101111
1//
I ,/"1
&.'1
I \ L-
hi
"!Crtn
-------
It appears that this low is an expression of
near stagnation of ground-water movement that
results from ground-water flow from two
opposing directions (from the southwest and
the northeast).
ii.
Bedrock Aquifer. The landfill has
contaminated ground water in the bedrock.
Ground-water wells installed to monitor the
bedrock are designated as bedrock wells.
Table 2 summarizes the chemicals and
concentrations found in the bedrock aquifer.
The direction of ground-water movement in the
bedrock aquifer is, in general, toward the
north.
The potentiometric surface of the bedrock
aquifer is generally lower in elevation
relative to the glacial deposits aquifer.
There is no significant consistent aquitard
preventing ground-water movement from the
glacial deposits aquifer down into the
bedrock aquifer. Ground-watercontamination
in the glacial deposits moves into the
bedrock aquifer.
iii.
Private Wells. Water samples from private
wells near the site were collected and
analyzed. Site related contaminants were not
found in the private wells tested.
The known area of ground-water contamination is
indicated on Figure 4. Additional data will be
necessary to delineate the total extent of the
ground-water contamination.
c.
soils
Surficial soil samples were collected and analyzed
from on and around the landfill. . VOCs were found
at downslope locations from the landfill and at
isolated locations on the landfill surface.
Transport of contaminated soils is very limited
due to the significant vegetation of the site.
8
-------
!'ABLE 2
SUMMARY OF CHEMICALS :)E!'ECTED r:l GROUNDWATER
AT CITY DISPOSAL CORPORATION L~DFI~~
3EDROCI< WELLS
(Concentrat~ons reported in ug/L)
:!".emJ.cals
a:::c::an~cs:
Freqency of
Detection/a)
Range of Detected
On-Site Concentrations
Range of RI
Background
Concentrations (d)
Acetone 4/8 1 4 - 24.5 NIl
C!".l:: rocen:tene 1/4 I - m> I
:,:-~ichloroethane 2/8 0.7 - 6.3 ND
~rans-l,2-Dichloroethene 3/8 13.7 - 84.1 NIl
2-Hexanone 1/4 4.6 NIl
4-Methvl-2-gentanone 1/4 5.5 NIl
Methylene Chloride 6/8 1.9 - 4.6 NIl - 12.6
1,1,2,2-Tetrachloroethane 1/4 2.8 NIl
Tetrachloroethene 1/4 8 NIl
Tetrahvdrofuran 3/4 - 12.3 - 53.5 NIl
Toluene 1/4 0.9 NIl
l,l,l-Trichloroethane 1/4 3.2 ND
Trichloroethene 5/4 2.1 - 74.2 ND
o&p-Xylene 1/4 1.1 ND
Inorgan1.ca:
Barium 3/3 24 - 73 110
Bervllium 1/2 0.2 ND
Boron 3/3 8.3 - 37 40
Cadmium 2/2 0.9 - 1.1 NO
Calcium 8/8 63,400 - 120,000 78,700 - 81,000
Chloride 7/8 2,600 - 9,100 42,800 - 81,000
Chromium 1/2 2.5 NO
Copper 3/3 2 - 3.2 NO
Cyanide 3/3 0.1 - 0.7 0.6
Fluoride 8/8 100 - 200 100
Iron 6/8 34.5 - 1,400 ND
Magne8ium 8/8 31,000 - 59,000 39,000 - 42,200
Manganeae 7/8 2.7 - 94 2.3
Nitrate 1/2 700 3,700
Potassium 6/8 780 - 2,200 1,800
Selenium 1/2 1.4 ND
Sodium 8/8 3,000 - 4,200 18,000 - 21,000
Sulfate 8/8 23,000 - 31,000 25,300 - 26,000
Vanadium 1/2 5.9 ND
Zinc 3/3 13 - 31 16
-------
..100
1600
.400 -
1000 -
FIGIJI!E 4
100
-300 -" -, ---.-.
- I -r ,-- r
~
,---,- ---I
800
I
1300 -,
I ,--
2100
1100 --- --- T - r- ,
-.--r ,
1 :.00
I -", - I
- 1600
- 1400
Un.-Ih
1
- 1000
-/
- APPROXIMATE LIMITS OF Fill
'-.1_1
I - L_-J--'-"J_- 100
1-- -- -Joo
LJ-_I
~
I
lOll
1
1300
'--I _"I
I
1700
I .. - , - -.1- I -- - - 6no
I_L--L-- ,- - 1:100
1100
C:ontiu-Ii llil L j Oil
r.rOIlJld-!/i11 er- .
Area of Knmffi ->
ro)(il'l
-------
F.
Summarv of Site Risks
Pursuant to the NCP, a baseline risk assessment was performed
based on the present condition of the Site. The baseline risk
assessment assumes no corrective action will take place and that
no site-use restrictions or institutional con~rols such as
fencing, ground-water use restrictions or construction
r~strictions will be imposed. The risk assessment then
determines actual or potential risks the chemical contaminants at
the Site pose under current and future land use assumptions. .
The first step of the risk assessment was to select chemicals, or
contaminants of potential concern. Subsequent steps include
identifying ways that humans might be exposed to the site
contaminants and calculating the potential risks.
1.
Contaminant Identification
The media of concern for human exposures were identified
primarily as ground water and soils. As stated earlier,
waste disposed of at the landfill has caused significant
ground-water contamination and isolated areas of soi~
contamination.
The contaminants of concern selected for risk
characterization in ground water were:
Acel- 88nZ-
2'1111:-- Carbon TllrecMoride
ChLoroel"- 1.1-0icMoroettl-
Irena'1.Z-0ictlLoroelftane
1.Z.0tctlLoropropane OlllftyLphtftaLate
2."1- ..optIor-
MethyL- ctILoride 2.MelftyLphenol
N_t...Lane PhenoL
Tetr8chLor08lftene Telranydrofuran
1.1.1.TricftLor08lftane TrtctlLor08lft-
VinyL ChLoride III-xyLane
SeryH hll Caclllhil
ChL~ide ~r~i~
Copper Cyanide
Iron LeM
Manganne NickeL
Pot...i~ SeLeni~
SodiUl Sulfale
Zinc
S8nZoic acid
~lorobenZane
1.2-0icnLorOilhane
etftyLbenzane
4-MeI"yL-2-pent~
4 -Melhyl pheno l
1.1.2.2-TelracnlorOiltlane
10L.,.,.
VinyL AClll1e
oIp-xylenes
C.Lci~
C0b8ll
Fluoride
....,.. i UI
Nilrale
Si Lver
vanadiUl
. .
Note: Z.Sutanone is aLso CQmlDnLy called
M.lftylelftyLket- (MEIC).
9
-------
The .contaminants of concer~ selected for risk
characterization from surface soils were:
..ceton.
ButyLbenZylpnthaLate
Oibenzofuran
2-MethyLnagnfhaLene
Tetrahydrofuran
o6p-XyLenes
Arsenic
Boron
ChromiUII
Cyanide
Ma8nniua
~ick.l
Sodi",
BenzoIc aCla
D;-n-autyLgntnalate
EthyLbenzene
NaphthaLene
Toluene
A l uni nun
Bariun
CaC8llillll
Cobl l t
Iron
Manganese
Po tlSS i UII
Vanaaillll
ois<2-Etyylhexvl)pnthalate
O;-n-octylpnthalate
Fluorene
PhenoL
m-Xylene
~ntimony
aerylliun
Calc hili
CQR'er
I.eaa
Mercury
Si lnr
Zinc
2.
Exposure Assessment
The baseline risk assessment examined potential pathways of
concern to human health under both current and future
landfill proper~y and surrounding land-use scenarios.
The following pathways .were selected for detailed evaluation
under current-use conditions:
Inhalation of VQCs emitted from the landfill by
trespassers on the Site for two receptor populations
(children/teenagers and adults),
Inhalation of VOCs emitted from the landfill by nearby
residents,
Incidental ingestion of surface soil by trespassers on
the Site,
Dermal absorption of surface soil by trespassers on the
Site,
Incidental ingestion of surface soil by nearby
residents,
Ingestion of ground water by nearby residents, and
Inhalation of VOCs while showering by nearby residents.
10
-------
The following pathways were selected for detailed evaluation
under future-use conditions:
Inhalation of VQCs emitted from the landfill by a
hypothetical future resident on landfill property,
Incidental ingestion of surface soils by a hypothetical
future resident on landfill property,
Dermal absorption of surface soils by a hypothetical
future resident on landfill property,
Ingestion of ground water by a hypothetical future
resident on landfill property,
Inhalation of VOCs by a hypothetical future resident on
landfill property while showering, and
Ingestion of dairy milk by residents from cattle
grazing on landfill property and consuming landfill
property ground water.
3.
Risk Characterization
For each of the potential receptors, the risks associated
with ingestion, inhalation and dermal absorption to the
site-specific contaminants from different routes of exposure
were evaluated. Both non-carcinogenic and carcinogenic
health effects were also estimated.
Reference doses (RfDs) have been developed by U.S. EPA for
indicating the potential for adverse health effects from
. exposure to chemicals exhibiting non-carcinogenic effects.
RfDs, which are expressed in units of mg/kg-day, are
estimates of lifetime daily exposure levels for humans,
including sensitive individuals. Estimated intakes of
chemicals from environmental media (e.g., the amount of a
chemical ingested from contaminated drinking water) can be
compared to the RfD. RfDs are derived from human
epidemiological studies or animal studies to which
uncertainty factors have been applied (e.g., to account for
the use of animal data to predict effects on humans). These
uncertainty factors help ensure that the RfDs will not
underestimate the potential for adverse non-carcinogenic
effects to occur.
Potential concern for non-carcinogenic effects of a single
contaminant in a single medium is expressed as the Hazard
Quotient (HQ) {or the ratio of the estimated intake derived
from the contaminant concentration in a given medium to the
11
-------
contaminan~'s reference dose). By adding ~he HQs for all
contaminan~s ~ithin a medium or across all media to which a
given population ~ay reasonably be exposed, the Hazard Index
(HI) can be genera~ed. The HI provides a useful reference
point for gauging ~he poten~ial significance of multiple
contami~an~ exposures within a single medium or across
media. Any HI value grea~er than 1.0 suggests that a non-
carcinogen po~entially presents an unacceptable health risk.
Cancer Potency Factors (CPFs) have been developed by U.S.
EPA's Carcinogenic Assessment Group for estimating exeess
lifetime cancer risks associated with exposure to
potentially carcinogenic chemicals. CPFs, which are
expressed in units of (mg/kg-day)"', are mUltiplied by the
estimated intake of a potential carcinogen, in mgjkg-day, to
provide an upper-bound estimate of the excess lifetime
cancer risk associated with exposure at that intake level.
'£he term "upper bound" reflects the conservative estimate of
~he risks calculated from the CPF. Use 'of this approach
makes underestimation of the actual cancer risk highly
unlikely. CPFs are derived from the results of human
epidemiological studies or chronic animal bioassay to which
animal-to-human extrapolation and uncertainty factors have
been applied (e.g., to account for the use of animal data to
predict effects on humans).
Excess lifetime cancer risks are determined by multiplying
the intake level with the cancer potency factor for each
contaminant of concern. These risks are probabilities that,
are generally expressed in scientific notation
(e.g. 1 X 10"0). An excess lifetime cancer risk of
1 X 10.6 indicates that, as a plausible upper bound, an
individual has a one in one million chance of developing
cancer as a result of site-related exposure to a carcinogen
over a 70-year lifetime under the specific exposure
conditions at a site.
U.S. EPA generally attempts to reduce the excess lifetime
cancer risk posed by Superfund sites to a range of 1 X 10.4
to 1 X 10-6 (1 in 10,000 to 1 in 1 million), with an
emphasis on the lower end, 1 X 10-6, of the scale.
When a baseline risk assessment indicates that a cumulative
site risk to an individual using reasonable maximum exposure
assumptions for either current or future land use exceeds
the 1 X 10.4 lifetime excess cancer risk end of the range,
action under CERCLA is generally warranted at the site.
Table 3 summaries the excess lifetime cancer risks and HI
for the current land-use scenario. Table 4 summaries the
excess lifetime cancer risks and HI for the future land-use
scenario.
12
-------
TABLE 3
SIJMMI\I{,{ OF I'O'1'E~T I AL UEAL TH RISKS ASSUC I ATED W I 'I'll
TilE CITY DISPOSAL CORPORATION LANDFIl.L SITE
CURRENT LAND USE CONDITIONS
. '---'---------~-_._."
Upper Bound Excess Lifetime Cance~
Risk"
lIazard Index fUI- N'"ICdITill'''J.-1I1'
J::ffeclsb
--- ....-_.. ----..- _.-- - - -
Exposure Pathway
--.. -.-----
Inhalation of Landfill Emissions
Landfill Property Child/Teenage Trespassers
Landfill Property Adult Trespassers
-Nearby Residents
.;)
<1
<1
Surface Soil Ingestion
Landf ill Property rid l,J/Teena'Je Trespassers
Landfill Property Adult Trespassers
-Nearby Residents
Dermal Absorption
Landfill Property
Landfill Property
-Nearby Residents
from Surface Soil
Child/Teenage Trespassers
Adult Trespassers
SXlO-' <)
4XlO' <1
I Xl O' <1
4XlOII <)
IX 10 10 1
2XI0~
..:)
<1
<1
<1
Inhalation of VOCs While Showering
- S&I North Downgradient
- S&I Northeast Downgradient
- Bedrock Downgradient
JXlO-'
IXlO-'
6XI0'
<1
<1
<1
. The upper bound individual excess lifetime cancer risk represents the additional probability that an individual fII
-------
TABLE 4
SIIMMAIIY 0'" POTENTIAL IIEAI.TII RISKS ASSOCIATI,:(J WITII
TilE CITY DISPOSAL CORPOHATION LI\ND~'IJ.L SITE
~'UTURE LAND USE CONDITIONS
--- -.-------- --.
Upper Bound Excess Litelime Cance~
Risk"
tlazal"d I ndt~K f(,." NtJlICd."C i." IIJCIII ,:
Etft.!ClSb
...------
--..-."..---.. ..-- ..
Exposure Pathway
Inhalation of Landfill Emissions
Landfill Property Resident
< I
Ingestion of Surface Soil
Landfill proerty Resident
4XIO.
1
<1
Inhalation of VOCs while Showering
Landfill Property 5&1 wells
Landfill Property Bedrock wells
2 X 1 0')
aXIO'
>1
lIll i 1\
health effects.
ddv':1 :i,~
Not applicable.
Chemical of potential concern for this pathway do not exhibit carcinoqellic eftecls.
-------
4.
Risk Summary
The HIs for humans interacting with the Site exceed the
acceptable hazard index of 1.0, principally from the use of
contaminated ground water under current and future-use
scenarios. This represents unacceptable potential risks to
human health.
The potential excess lifetime cancer risk posed by the Site
exceeds the acceptable risk range of 1 X 10.10 to 1 X 10.6
principally from the use of contaminated ground water under
the future use scenario. This represents unacceptable
potential risks to human health.
5.
Environmental Risks
An ecological risK assessment was conducted to evaluate
potential impacts on nonhuman receptors associated with the
Site. This evaluation involved the identification of
potential receptors and exposure pathways, including
determination of the presence of endangered or threatened
species in the area.
Absolute conclusions regarding the potential environmental
impacts of the Site cannot be made because there are many
uncertainties surrounding the estimates of toxicity and
exposure for these organisms. The risk assessment concluded
that, based on the available data "and limitations, no
adverse effects to plants, soil organisms and livestock are
expected.
Based on available information from the U.S. Fish and
Wildlife Service, endangered species which may occur in Dane
County will not be adversely affected by the site. Finally,
according to the Wisconsin Wetland Inventory map, there are
no wetlands identified on the landfill property.
J:L..
Rationale for Further Action
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementation of the response action
selected by this ROD, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
Therefore, based on the findings in the RI report and the
discussion above, a Feasibility study (FS) was performed to focus
on the development of alternatives to address the threats at the
site. The FS report documents the evaluation of the magnitu~e of
site risks, site-specific applicable or relevant and appropr1ate
13
-------
requiremeh~s, and the requiremen~s of CERCLA and the NCP in the
derivation of remedial alter~a~ives for the Site.
L.
Descri~tion of Alterna~ives
The remedies for environmen~al contamination resulting from the
landfill can bes~ be described by discussing remedies for
addressing the landfilled waste (source of contamination at the
Site) and remedies for addressing contaminated ground water at
the site.
Source Control Alternatives
The purpose of the source control portion of the final remedy is
to minimize the migration of hazardous substances into other
environmental media and to eliminate exposure pathways to the
public. The F5 Report described a detailed analysis of four
source control alternatives. The Proposed Plan identified these
'alternatives as Sl, 52, S3 and 541.
All four source control alternatives, including Sl the "No-
Action" Alternative, employ a network of active gas extraction
trenches over the entire landfill to control landfill gas.
Chapter NR 506.08 WAC requires active landfill qas control at
landfills with waste volumes greater than 500,000 cubic yards.
The active gas extraction trench system could be designed as a
network of buried slotted pipes, with gravel backfill beneath the
landfill cap designed to conduct landfill gas to flares on the
landfill. A blower could be used to produce a vacuum on the
system to actively remove landfill gas. The collected landfill
gas could be flared to achieve air emission standards of Chapters
NR 400-499 WAC and the Federal Clean Air Act, 42 U.S.C.A.
Sections 7401 to 7642. .
The Proposed Plan titles for alternatives differ from the Feasibility Study Report titles for
tha same Iltlrnltives. The alte~tives rellce 15 follows:
Proposed Plan Alternatives
Feasibility 5tudy Repor~ Alternatives
51 --------------------------- I
52 --------------------------- V
53 --------------------------- VI
54 --------------------------- VII
GW1 -------------------------- 0
GW2 -------------------------- 7
GW3 -------------------------- 8
GW4 -------------------------- 9
GWS -------------------------- 10
14
-------
The first source control alterna~ive, ~l, is known as a "no-
action" alternative which generally e~~~oys no measures, other
than the requ~=ed landfill gas con~rol ~easure previously
described, to address the landfill con~en~s. The remaining three
source control alternatives 52, 53 and 54 include measures to
address the landfill contents.
Alternatives 52, 53 and S4 include elements ~~ address the
landfill contents that are common to each of the three
alt~-~atives. All three alternatives include:
-nstitutional controls, including deed restrictions
~iting the land use of the landfill and landfill
perty.
An in-situ vapor extraction and treatment system to
remove and treat VOCs from the two areas within the
landfill that contain significant amounts of liquid
industrial wastes, cells 6 and 12. This system would
remove and destroy significant amounts of contaminants
from the waste mass preventing their eventual migration
into the environment.
This system would be comprised of vent wells drilled
into the landfilled waste in Cells 6 and 12. The vent
wells would be connected to header pipes. The header
pipes would be connected to a blower to produce a
vacuum on the vent wells.
The extracted vapors would be treated to achieve air
emission standards of Chapters NR 400-499 WAC and the
Federal Clean Air Act by flaring.
An air intrusion cut-off wall would be constructed to
reduce the amount of air being drawn laterally into
Cells 6 and 12 during operation of the vapor extraction
system. This cut-off wall would control air movement
through the waste reducing the possibility of
uncontrolled oxidation of the waste.
This cut-off wall would be comprised of a geomembrane
anchored into the landfill cover for Cells 6 and 12 an~
extendinqinto a 6-foot deep trench excava~ed around
the perimeter of the two cells.
15
-------
The difference between 52, 53 and 54 is ~he type of landfill
cover that would be u~ilized.
The purpose of a landfill cover is ~o reduce the amount of
precipitated. water that migrates down through landfilled waste.
Water migrating down through waste leaches hazardous constituents
from the waste and carries ~hese cons~ituen~s out of the landfill
and into soils, surface waters and ground waters.
Two of the major potential Applicable or Relevant and Appropriate
Requirements (ARARs) for the landfill cover portion of the source
control alternatives are Chapter NR 504.07 WAC (solid waste
landfill cover requirements) and Chapter NR 660.16 WAC (hazardous
waste landfill cover requirements). Resource Conservation and
Recovery Act (RCRA) Subtitles C and D include landfill cover
requirements. RCRA Subtitle C regulates hazardous waste
management and Subtitle D regulates solid waste management. The
State of Wisconsin is currently authorized to fully administer
RCRA Subtitles C and D within ~he.state. Therefore, the State of
'Wisconsin's promulgated RCRA requirements replace equivalent or
less stringent federal requirements as potential ARARs.
wisconsin has promulgated regulations governing the subject
matter of RCRA Subtitle C and D - Chapter NR 600 WAC addressing
hazardous waste management, and Chapter NR 500 WAC addressing
solid waste management.
The landfill contains wastes that are similar or identical to
RCRA solid wastes. These solid wastes will continue to be
managed at the landfill. Therefore, Chapter NR 504.07 WAC
requirements on the closure of the entire landfill are both
relevant and appropriate.
The landfill ceased accepting waste for disposal in 1977 before
the 1980 effective date of hazardous waste management
requirements under RCRA Subtitle C. Therefore, Chapter NR 660.16
WAC requirements are not applicable. The landfill, howev~r, does
contain industrial wastes that are similar or identical to RCRA
hazardous waste. Therefore, Chapter NR 660.16 WAC requirements
are relevant. site investigation data indicates that the
majority of the industrial waste was placed into Cells 6 and 12.
Based on investigation data that suggests that the majority of
the VOCs in ground water are being released from Cells 6 and 12,
u.S. EPA has determined that the landfill closure requirements ot
Chapter NR 600 WAC are appropriate for Cells 6 and 12.
Therefore, the hazardous waste landfill closure requirements of
Chapter NR 660.16 WAC are relevant and appropriate for Cells 6
and 12.
16
-------
Alternative 51
Alternative Sl is comprised of Ac~ive Gas Extraction Trenches
previously described, Nith no o~her ac~ion to be taken.
The installation of the Active Gas Extraction Trenches would take
6 weeks.
as,
Assuming some soil materials can be obtained from landfill
property, the ~~timated number of 10-cubic-yard truckloads of
material needed to be transported to the Site is 80.
The estimated costs for this alternative are:
Capital cost: $366,000, .
Operation and Maintenance (O&M) annual costs:
$42,500 for each of the first 2 years
$10,200 per year an additional 28 years,
Net Present Value of Capital and O&M costs: $587,700.
Alternative 82
Alternative S2 includes the common "source control" elements
previously described and utilizes Landfill Cover Design A over
the entire landfill. A cross section of the proposed landfill
cover design is included on Figure 5. This cover design does not
comply with Chapter NR 504.07 WAC (solid waste landfill cover
requirements) or Chapter NR 660.16 WAC (hazardous waste landfill
cover requirements).
Chapters NR 504 and NR 660 WAC require that final solid waste and
hazardous waste landfill cover designs include a clay capping
layer that is a minimum of 24 inches thick with a permeability of
1 X 10.7 cm/sec or less. Alternative S2 does not include this
24-inch clay layer.
The estimated construction time for this alternative is 4 months.
The estimated length of time that the in-situ vapor extraction
and treatment system would be operated is 5 years.
Assuminq some soil materials can be obtained from landfill
property, the estimated number of 10-cubic-yard truckloads of
material needed to be transported to the Site is 10,027.
The estimated costs for this alternative are:
Capital cost: $3,359,030,
O&M annual costs:
$90,978 for each of the
$21,258 per year for an
Net Present Value of capital
first 5 years
additional 25 years,
and O&M costs: $3,905,226
17
-------
----- -
- - ..;,-L''''':''
Cross.Section of Cover A
VEGETATED COVER
~......t»L...1li'---11 I
-. I
TOP SOL 16" I
I
I
118"
I
: 112"
f
: 1..
SAND LAYER
GEOTEXTU I
LAYER
---..
SYNTHETIC !
MEMBRANE I
1125' (CO 11111 I
---..
DRAINAGE LAYER
SOIA:LAY LAYER
nallO -
VEGETATED COVER
~U>-..i.'ti..~,
TOP SOL t 6"
. .f
Cross-Section of Cover C
VEGETATED COVER
~.d- L-iti...~..,
. TOP SOIL ! 6"
Cro.s-Sectlon 01 Coyer B
SAND LAYER
; 18"
i
GEOTEX1U I
LAYER
~
i
SyNTHETIC I DRAINAGE LAYER 12"
IWI8RAHE I I
SAND LAYER
I 1r
I
.".
~ ,
GRADING LAYER
GRADING LAYER
"0110 SCal.
nallO SC818
-------
Alternative 53
Alternative S3 includes the common source control elements
described above and utilizes Landfill Cover Design B (solid waste
landfill cover) over the majority of the landfill and in addition
Landfill Cov~r Design C (hazardous waste landfill cover) over
Cells 6 and 12. Cross sections of the designs are included on
Figure 5. Both designs comply with NR 504.07 (state solid waste
landfill cover requirements). Landfill Cover Design C (for Cells
6 and 12) complies with Chapter NR 660.16 WAC (hazardous waste
landfill cover requirements).
The estimated construction time for this alternative is 6 months.
The estimated length of time that the in-situ vapor extraction
and treatment system would be operated is 5 years.
Assuming some soil materials can be obtained from landfill
property, the estimated number of 10-cubic-yard truckloads of
material needed to be transported to the Site is 12,692.
The estimated costs for this alternative are:
Capital cost: $3,379,566, .
O&M annual costs:
$90,978 for each of the
$21,258 per year for an
Net Present Value of Capital
first 5 years
additional 25 years,
and O&M costs: $3,925,008
Alternative 84
Alternative 54 includes the common source control elements
described above and utilizes Landfill Cover Design B (solid waste
landfill cover) over the entire landfill. A schematic of
Landfill Cover Design B is included on Figure 5. This cover
design complies with Chapter NR 504.07 WAC (solid waste landfill
cover requirements), but does not comply with Chapter NR 660.16
WAC (hazardous waste landfill requirements) for the portion of
the cover over Cells 6 and 12.
The estimated construction time for this alternative is 4 months.
The estimated lenqth of time that the in-situ vapor extraction
and treatment system would be operated is 5 years.
Assuminq some soil materials can be obtained from landfill
property, the estimated number of 10-cubic-yard truckloads of
material needed to be transported to the site is 11,982.
18
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~he es~ima~ed cos~s for ~his alterna~ive are:
Capital c~s~: $3,060,057,
O&M annual cos~s: .
$90,978 for each of ~he
$21,258 per year for an
Net Presen~ Value of Capi~al
first 5 years
additional 25 years,
and O&M costs: $3,617.224
Ground-Water Alternatives
The purpose of the ground-water portion of the final remedy is to
return usable ground water at the site to its beneficial use, as
an actual or potential ground-water source, within a reasonable
time. The FS Report described a detailed analysis of five
ground-water alternatives. The Proposed Plan identified these
alternatives as GW1, GW2, GW3, GW4 and GW5.
Contaminated ground water will be returned to its beneficial use
when the concentrations of ground water meets the ground-water
cleanup standards set by this ROD. The ground-water cleanup
.standards are the Preventive Action Limits (PALs) established in
NR 140 WAC. The ground-water cleanup standards of NR 140 WAC are
ARARs for the ground-water cleanup. These ground-water cleanup
standards are listed in Table 5.
The location of the point of compliance for the ground-water
cleanup standards is the edge of the landfilled waste. Ground-
water cleanup stanaaras shall be attained throughout the
contaminated plume excluding the area underneath the landfilled
waste. This area of attainment includes areas outside of the
landfill property as well as the area within the landfill
property up to the landfilled waste.
As with the source control alternative described earlier, the
ground-water alternatives include a number of common elements
(with the exception of GW1 or "No-Action" Alternative). All four
alternatives include:
Institutional controls such as ground-water use and
land use restrictions to prevent the use of
contaminated ground water until ground-water cleanup
standards are met.
A ground-water extraction system designed to remove
ground water that exceed PALs from the area of
attainment and to prevent the further migration of
contaminated ground water.
19
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-~..... -
GROUND-WATER CLEAN-UP STANDARDS
Chemical Organics:
concentration i~ cpb:
-
Acetone .
Ben zene ' 0.067
Benzoic Acid .
2-Butanoneb . .
Carbon Te ,chloride 0.5
Chloroethar. .
1,1-Dichloroe~hane 85
1,2-Dichloroethane 0.05
trans-l,2-Dichloroethene 20
'1,2-Dichloropropane 5-
Diethylphthalate .
Ethylbenzene 272
.2-Hexanone .
Isophorone .
4-Methyl-2-pentanone .
Methylene Chloride 15
2-Methylphenol .
4-Methylphenol .
Naphthalene .
Phenol .
1,1.2.2- .
Tetrachloroethane
Tetrachloroethene 0.1
Tetrahydrofuran :0
Toluene 68.6
l,l,l-Trichloroethane 0.06
Trichloroethene 0.18
Vinyl Acetate .
Vinyl Chloride 0.0015
m-Xylene 124
o&p-Xylene 124
b
MCL or PAL not established.
Also known as Methyl Ethyl Ketone (MER)
...
PAL not established.
Clean-up standard is MCL
-------
TAB!.£; ::,
GROUND-WATER CLEAN-UP STANDARDS
Chemlcal Organics:
Concen~ra~ion Ground Wa~er :~ ug/l:
Aluminum 200 I
Arsenic 5 I
Barium 0.2
Beryllium . 1
Boron 1
Cadmium 1
Calcium 1
Chloride 125
Chromium 5
Cobalt .
Copper 0.5
Cyanide 40
Fluoride 0.44
Iron 0.15
Lead 5
Magnesium .
Manganese 25
Nickel 100
Nitrate 2,000
Potassium .
Selenium 1
Silver 10
Sodium I
Sulfate 125
Vanadium I
Zinc 2,500
MCL or PAL not established.
-------
. This system would be comprised of ground-water
production wells. The number, production rate and
loc~tion of these wells shall be established during the
des~gn of the remedial action.
The time required for alternatives GW2 through GW5 to
ac~ieve ground-water cleanup standards is determined by
th~s common element of the alternatives, the ground-
water extraction system. For the pu~pose of estimating
the cost of the alternative, the FS assumed that the
ground-water extraction system (and the system for
treatment of extracted ground water discussed later in
this section) would be operated for 20 years. The
actual length of time that these systems will be
operated will be determined by U.S. EPA, after review
of ;round-water contaminant data gathered during actual
operation of the system.
Additional ground-~ater data and testing may be
necessary to design the extraction system.
A ground-water monitoring program designed to detect
changes in concentration of hazardous constituents in
the ground water and to detect the presence and
concentration of site-related contamination in
residential drinking water wells near the Site.
Discharge of treated ground water to Badfish Creek.
The discharge of treated ground water shall comply with
surface-water discharge requirements of Chapters 102,
103, 104, 105, 106, 108 and 207 of the WAC. Discharge
of treated water would occur "on-site" therefore, only
the sUbstantive portions of surface-water discharge
requirements will need to be met. No Wisconsin
Pollutant Discharge Elimination system (WPDES).permit
will be required.
Treatability testing on the extracted ground water may
be necessary to design the treatment system.
The difference between ground-water
is the type of treatment technology
treat the hazardous constituents in
prior to surface-water discharge.
Alternatives GW2 through GW5
that would be utilized to
the extracted ground water
Al1:erna1:iv8 GW1
Alternative GW1 -- a "No-Action" Alternative. No measure would
be taken to remedy ground-water contamination. However, s~ate.of
Wisconsin regulations currently require a ground-water mon1tor1ng
program at the landfill. This state-required ground-water
20
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~onitoririg program may r.o~ ~ecessarily be as broad as the ground-
Na~er monitoring program common ~o ~he ground-water alterna~ives
described above.
An estimate has not been made on ~he length of time that it would
take before ~he natural attenua~ion processes could reduce
hazardous cons~ituent concen~ra~ions to the ground-water cleanup
standards. Significant ground-water contamination has occurred
at this Site. Natural ground-water movement will result in the
spread of ground-water contaminants.
The estimated costs for this alternative are:
Capital cost: $0
Operation and Maintenance (O&M) annual costs: $114,216
Net Present Value of capital and O&M costs: $2,350,837
Alternative GW2
Alternative GW2 includes the common elements of the ground-water
. alternatives previously discussed and a treatment system for the
extracted ground water that utilizes air stripping, activated
carbon and catalytic oxidation.
The air stripping/activated carbon/catalytic oxidation treatment
system components include an air stripping tower followed by
activated carbon filtration units for effluent water polishing.
Air emissions from the stripping tower would be treated by
catalytic oxidati~n before discharge to the atmosphere.
Pretreatment of the water, by precipitation, would likely be
required for removal of metals and inorganic ions.
ARARs for this treatment system include state requirements for
air discharges (Chapters NR 400-499 WAC) from the air tower; and
for the spent activated carbon and precipitated metals,
treatment, storage and disposal of hazardous waste (the
NR 600 rule series). RCRA Land Disposal Restrictions (LDRs) is
an ARAR if the spent activated carbon is land disposed instead of
regenerated in a RCRA-compliant unit.
The estimated costs for this alternative are:
capital cost: $2,707,500
O&M annual costs:
. $1,514,659 for each of the first. 20 years
$114,487 per year for an additional 20 years,
Net Present Value of Capital and O&M costs: $19,992,307
21
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Alternative GW3
Alternative GW3 includes the common elements of the ground-water
alternative previously discussed and a treatment system for
extracted ground water that utilizes air stripping and activated
carbon.
~he air stripping/activated carbon treatment system components
lnclude an air stripping tower followed by activated carbon
filtration units for effluent water polishing. Air emissions
from the stripping tower Nould be treated with activated carbon
before discharge to the atmosphere. Pretreatment of the water
would likely be required for removal of metals and inorganic
ions. .
. ARARs for this treatment system include state requirements for
air discharges (Chapters NR 400-499 WAC) from the air tower; and
for the spent activated carbon and precipitated metals,
treatment, storage and disposal of hazardous waste-(the
NR 600 rule series). RCRA LDRs is an ARAR if the spent activated
. carbon is land disposed instead of regenerated in a RCRA-
compliant unit.
The estimated costs for this alternative are:
Capital cost: $2,062,500
OiM annual costs:
$1,071,859 for each of the first 20 years
$114,487 per year for an additional 20 years,
Net Present Value of capital and OiM costs: $16,842,038
Alternative GW4
Alternative GW4 includes the.common elements of the ground-water
alternative previously discussed and a treatment system for
extracted ground water that utilizes above-ground biological
degradation.
The above ground biological treatment system components include a
suspended growth (activated sludge) biological reactor, a
settling basin for liquid separation and sludge handling
facilities. A pretreatment phase for metals precipitation is
anticipated.
ARARs for this treatment system include state requirements for
air discharges (Chapters NR 400-499 WAC) from the biological
reactor; and for sludge disposal and precipitated metals
treatment, storage and disposal of hazardous waste- the NR 609
series rules. LDRs is an ARAR if the spent activated carbon 1S
land disposed instead of regenerated in a RCRA-compliant unit.
22
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The es~ima~ed cos~s for ~his alterna~ive are:
Capi~al cos~: 52,325,000
O&M annual cos~s:
$561,859 f::r
5114,487 per
Net Presen~ Value
each of ~~e f:rs~ 20 years
year for an addi~ional 20 years,
of capital and O&M cos~s: $10,301,833
Alternative GWS
Alternative GW5 includes ~he common elements of the ground-water
alternative previously discussed and an extrac~ed ground-water
treatment system that utilizes chemical oxidation.
The FS evaluated a chemical oxidation treatment system that
utilizes ultraviolet light as an energy source. This ultraviolet
light chemical oxidation system would include flow equalization,
a closed reactor vessel and a hydrogen peroxide feed system
and/or ozone generator and catalytic converter, depending on the
specific system and equipment selected. A pretreatment phase for
, metals precipitation is anticipated.
ARARs for this treatment system include state requirements for
air discharges (NR 400-499) from chemical oxidation; and for the
treatment, storage and disposal of hazardous waste- NR 600 for
precipitated metals. .
The estimated costs for this alternative are:
capital cost: $1,807,500
operation and Maintenance (O&M) annual costs:
$645,859 for each of the first 20 years
$114,487 per year for an additional 20 years,
Net Present 'Value of Capital and O&M costs: $10,926,379
~
ComDarative Analvsis of Alternatives:
The Nine Criteria
In accordance with the National oil and Hazardous Substances
Pollution Contingency Plan (NCP), the relative performance of
each alternative is evaluated using the nine criteria, Title 40
of the Code Federal Regulations (40 CFR) Section
300.430(e) (9) (iii), as a basis for comparison. An alternative
providing the "best balance" of trade-offs with respect to the
nine criteria is determined from this evalua~ion.
23
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The following ~NO threshold cri~eria; overall protec~ion of
health and the environmen~, and compliance with ARARs, are
criteria ~ha~ ~~3~ be ~e~ :n order for an alternative to be
selected.
human
1.
Ov~rall Protection of Human Health and the Environmen~
Overall protection of human health and the environment
addresses whether a remedy eliminates, reduces, or controls
threats to human health and to the environment.
The major exposure pathways of concern at the 5i~e are the
ingestion, inhalation, and contact with contaminated ground
water and inhalation and contact with contaminated waste and
soils.
Source control alternatives 52, 53 and 54 are protective of
human heath and the environment by preventinq direct contact
with landfilled waste and minimizing water intrusion through
the waste thus limitinq leachate production and ground-water
contamination. The landfill covers prevent direct contact
with the landfilled waste.
Alternative 51 does not include a landfill cover. This
alternative is not protective, since it does not minimize
leachate production and ground-water contamination and
direct contact with the waste. Since Alternative 51 does
not satisfy this threshold criterion, it may not be selected
as a remedy and will not be evaluated further.
Ground-water control alternatives GW2, GW3, GW4 and GWS are
protective of human heath and the environment by preventing
the use of contaminated ground water while returning the
aquifers to beneficial use by extraction and treatment of
contaminated ground water. Since Alternative GW1 is not
protective, since it does not prevent use of contaminated
ground water and does not include remediation of ground
water within a reasonable time. GW1 does not satisfy this
threshold criterion, it may not be selected as a remedy and
will not be evaluated further.
Compliance with Applicable or Relevant and Appropriate
.Requirements
This criterion evaluates whether an alternative meets ARARs
set forth in federal, or more strinqent state, environmental
standards pertaininq to the site or proposed actions.
2.
Only Alternative 53 complies with the source control
alternative ARARs (Chapters NR 504.07 and NR 660.16 W~C~ for
closure of the Site. Since Alternatives 52 and 54 ut111ze
24
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landf ill covers '..;hich do n01: comply '..;i th ARARs, 1:hey do not
sa1:isfy this threshold criterion, and ~ay n01: be selected as
a remedy, and ~herefore Nill ~01: be evalua1:ed fur1:her.
Ground-wa1:er Con1:rol Alternatives GW2, GW3, GW4 and GW5
appear ~apable of complying with ARARs. All four
alternatives rely on an identical ground-water eX1:raction
system to a1:tain ground-wa1:er cleanup standards. The four
alternatives differ in 1:he treatmen1: system that would be
employed. Each of the ground-water treatment sys1:ems are
expected to be able to meet surface-water discharge, air
discharge and waste management requirements.
The biological treatment system of GW4 may be susceptible to
periodic exceedances of surface water discharge standards
since variances in concentration of contaminants in ground
water may cause drastic changes in the population of the
bacteria used to treat the contaminants. The bacteria
populations may not be able to change as quickly as the
concentration of con1:aminants in extracted water.
J.
Long-Term Effectiveness and Permanence
This criterion refers to the
maintain reliable protection
environment over time (lower
goals have been met.
ability of an alternative to
of human health and the
residual risk) once the cleanup
Alternative S3 includes the use of landfill covers designed
to satisfy the requirements of closure of landfills
containing solid waste and hazardous waste. The ARARs NR
504.07 and NR 660.16 require cover designs that are
considered effective and reliable in the long term. By
employing an in-situ vapor extraction and treatment system
to portions of the waste mass, less contaminant mass will
remain in the landfill, reducing threats posed by the
landfilled waste.
Alternatives GW2, GWJ, GW4 and GW5 differ only in the
treatment system for extracted ground water. All four have
the same ground-water extraction system therefore, all have
the same degree of long-term effectiveness and permanence.
4.
Reduction of Toxicity, Mobility, or Volume Through
Treatment.
This criterion evaluates treatment technology performance in
the reduction of chemical toxicity, mobility, or volume.
This criterion addresses the statutory preference for
selecting remedial actions which include, as a principal
25
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element, ~rea~men~ tha~ per~anen~ly and significantly
reduces the volume, ~oxicity, or ~obility of the hazardous
substances, pollutants, and contaminants.
Alternative 53 includes extraction and treatment of
landfilled VOCs through vapor extraction and oxidation.
These systems would permanently and significantly reduce the
volume of VOCs in the landfill and permanently and
significantly reduce the toxicity of the VOCs once treated.
Alternatives GW4 and GWS provide on-site destruction of
organic contaminants extracted from the ground water. The
treatment systems employed would permanently and
significantly reduce the toxicity of the contaminants
recovered from the ground water.
Alternatives GW2 and GW3 transfer at least a portion of the
organic contaminants from the ground water to activated
carDon. The carDon must be regenerated by removing and
destroying the contaminants, as opposed to disposal of the
carDon and attached contaminants, for the toxicity of these
contaminants to be considered permanently reduced.
5.
Short-Term Effectiveness
Short-term effectiveness considers the time to reach cleanup
oDjectives and the risks an alternative may pose to site
workers, the community, and the environment during remedy
implementation until cleanup goals are achieved.
construction of Alternative 53's cover is estimated to take
6 months. The in-situ vapor extraction system is estimated
to be operated for 5 years.
It is estimated that 12,692 10-cubic-yard truckloads of
cover material will be needed. The transport of this
material may pose some short-term impact on the community.
These impacts include safety of persons sharing the roadway
with trucks transporting site cover material, noise, debris
and road damage. Impacts can be minimized by adherence to
federal and state transportation requirements, use of
suitable clays and soils found near the landfill,and
adherence to reasonable and customary (as determined by
U.S. EPA) County and Township roadway safety, cleanup and
repair requirements.
Construction of the cover system involves significant earth-
moving activities at the landfill. Construction hazards to
workers will be minimized by using construction worker
safety practices.
26
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Alternati ves G~'l2, ~W3, ::;W4 and GW5 have the same short:-,:ert:1
effect:iveness due ':0 ':heir co~mon ground-wat:er ext:ract:ion
component. It is assu~ed, :or the purposes of the FS, that:
ground-wat:er ext:ract:ion and ~=eat:ment: will be operat:ed for
20 years.
6.
Implementability
This criterion considers the t:echnical and administrative
feasibility of implement:ing an alternat:ive.
Alternative 53's landfill cover is considered implementable
utilizing proven designs and const:ruction techniques. The
in-situ vapor extract:ion and treatment systems have been
used at other sites and are considered implementable.
Alternatives GW2, GW3, GW4 and GW5
nave been previously installed and
5 utilizes a technology that has a
installation.
utilize technologies that
operated. Alternative GW
shorter record of
u.s. EPA does not anticipate any problems securing access to
property needed to implement the alternatives.
7.
Cost
This criterion compares the capital, O&M, and present worth
costs of implementing the alternatives at the Site.
The costs for the eligible source control alternative are:
A I ternat i ve C~ital Cost Annual o&M Cost Net Present
yrs '-5 / 5-30 Value
53 13,379,566 $90.978 / $21.258 $3.925.008
The costs for the eligiile ground-water alternatives are as
follows:
Alternative Capital Cost Amual o&M Cost Net Present
yrs 1-20 I 20-'0 Value
GW2 $2,707.500 $1.51'.659 / $11'.'87 $19,992.307
GW3 $2,062,500 $1,071.859 I $11'.~7 $16,842,038
GW4 $2,325,000 $561.859 / $11',~87 $10,301.833
GW5 S1,807,500 1645.859 / $11'.'87 $10.926.379
27
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Calculation of Net Present Value ;s an estimate of the value of money usee to ~y future costS In
"tcaay's" dollars. ~he calculation IS oasee on tne assUTCt10n [nat an existing aollar ",ill earn
interest ana therefore has a greater vaLue than a future aollar.
s.
Sta~e Acceptance
No formal notification of State concurrence has been
received at the time of ROD signature. The WDNR is expected
to concur with U.S. EPA's decision on the selec~ed remedy.
9.
Community Acceptance
Community concerns have been reviewed and are addressed in
the attached Responsiveness Summary.
J.
Selected Remedy
Based upon considerations of the requirements of CERCLA and the
NCP, balancing of the nine criteria, and public comment, Q.S. EPA
has determined that Alternatives S3 and GW5 create the most
appropriate remedy for the site.
This determination is based on:
Alternative S3 is the only source control alternative
reviewed that complies with ARARs.
Alternative GW5 strikes the best balance of the
evaluation criteria. GW5 offers: expected reliability
on continual attainment of surface-water discharge
standards, "on-site" destruction of contaminants, and
the net present value is second lowest of eligible
alternatives.
The components of the selected remedy are:
A landfill gas control system designed and operated to
comply with Chapter NR 506.08 WAC and state air-
. discharge standards to control landfill gas.
Institutional controls including deed restrictions
limiting the land use of the landfill and landfill
property, and ground-water use restrictions.
An in-situ vapor extraction and treatment system to
remove VOCs from landfill Cells 6 and 12.
28
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- An air in~rusion cu~-off ~all, ~o reduce the amount of
air from being drawn laterally into Cells 6 ~nd 12
during operation of ~~e vapor ex~rac~ion system.
A landfill cover designed to comply ~ith Chapter NR
304.07 WAC over the entire landfill and designed to
cocply with Chapter =:R 660.16 WAC over Landfill Cells 6
and 12.
A ground-water extraction system designed to (a) remove
ground water that attains or exceeds the ground-water
cleanup standards set by this ROD, see Table 5, from
the area of attainment, and (b) prevent the further
migration of contaminated ground water. Once the
ground-water cleanup standards are achieved the
continued operation of all of or portions of the
ground-water extraction system may be required to
maintain concentrations of hazardous constituents below
the ground-water cleanup standards.
During operation of the ground-water extraction system,
u.s. EPA may make modifications to the system or
system's operation. These modifications may include
any or all of the following:
at individual wells where cleanup standards have
been attained, pumping may be discontinued;
alternating pumping at wells to eliminate
stagnation points;
pulse pumping to allow aquifer equilibration and
to allow adsorbed and or absorbed contaminants to
partition into ground water; and
installation of additional extraction wells to
facilitate or accelerate cleanup of the
contaminant plume.
To ensure that cleanup standards continue to be
maintained, the ground water will be monitored at those
wells where pumping has ceased. These wells shall be
sampled and ground water analyzed a minimum of once a
.year following discontinuation of pumping.
A chemical oxidation or other comparable technology
treatment system to treat extracted ground water to
comply with surface-water discharge, air emissi~n and
waste management standards and requirements.
u.s. EPAwill decide when a technology is comparable to
chemical oxidation. The bases for the decision would
29
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~nclude, bu~ ~o~ be limited to, (a) effectiveness, (b)
lmplementablllty, and (C) cos~ as described at 40 CFR
300.430(e) (7) (i).
Discharge of treated wa~er ~o Badfish Creek.
A ground-wa~er monitoring program designed to detect
changes in concen~ration of hazardous cons~ituen~s in
the ground wa~er and to detec~ the presence and
concentration of slte related contamination in
residential drinking water wells near the Site.
The ground-water monitoring program shall continue for
30 years after the attainment of the ground-water
cleanup standards.
Residential well sampling and analysis for
Tetrahydrofuran, Target Analyte List (TAL) analytes,
and Target Compound List (TCL) analytes shall occur at
a minimum frequency of twice a year.
Residential well sampling shall commence as soon as
possible. Residential well sampling shall be conducted
during design of the remedy, using standard drinking
water well sampling and analytical procedures until
site specific procedures are approved by u.S. EPA.
u.S. EPA shall select residential wells nearest the
site for sampling and analysis during the remedial
design until a list of residential wells is approved by
u.s. EPA for long-term monitoring.
The estimated total Net Present Value for the selected
remedy is $14,851,387.
K.
Statutory Determinations
Under its legal authorities, u.s. EPA's primary responsibility at
Superfund sites is to undertake remedial actions that achieve
adequate protection of human health and the environment. In
addition, Section 121 of CERCLA establishes several other
statutory requirements and preferences. These specify that, when
complete, the selected remedial action for this site must comply
with applicable or relevant and appropriate environmental
standards established under federal and state environmental laws
(ARARs) unless a statutory waiver is justified. The selected
remedy also must be cost-effective and utilize permanent
solutions and alternative treatment technologies or resource
recovery technologies to the maximum extent practicable.
Finally, the statute includes a preference for remedies that
30
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employ treatment as a principle element that permanently and
significantly reduce the volume, toxicity, ~r mobility of
hazardous substances. The following sections discuss how the
selected remedy meets these statutory requirements.
1.
Pr~tection of Human Health and the Environment
~he selected remedy protects human health and the
environment by combining source containment, source removal,
and remediation of contaminated ground water.
Source containment will be implemented by covering the
landfill waste. This cover minimizes production of leachate
within the landfill thus reducing leachate contamination of
ground water. The landfill cover will also prevent direct
contact with site contaminants. Landfill gas control
measures will minimize the risks posed by landfill-generated
gases.
Source removal will be accomplished by utilizing vapor
extraction and treatment. The vapor extraction system will
remove VOCs from the waste for treatment, which will also
reduce the VOCs' toxicity.
The remediation of ground water will stop the migration of
contaminants in the ground water and reduce the
concentration of ground-water contaminants to below health
based levels.
The selected remedy will r~duce all site related risks to
the acceptable risk ranges of 1 X 10-4 to 1 X 10-6 for excess
lifetime cancer risk and a hazard index of < 1 for non-
carcinogenic risks.
Short-term risks posed by construction at the .Site and
operation and maintenance of the remedy components can be
controlled by the adherence to transportation and
construction safety practices.
2.
Compliance with ARARs
The selected remedy will comply with the federal and more
stringent state ARARs listed below:
a.
Chemical Specific ARARs
Chemical-specific ARARs regulate the release to the
environment of specific substances having certain
chemical characteristics. Chemical-specific ARARs
typically determine the extent of cleanup at a site.
31
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~.
Surface water
Federa 1 ;".RARs
Surface water ~uality standards for the protection
of human health and aquatic life were developed
under Section ;04 of the Federal Water Pollution
Control Act, 33 U.S.C. SS 1251 to 1387. The
Federal Ambient Water Quality Criteria (AWQC) are
nonenforceable guidelines that set pollutant
concentration limits to protect surface waters.
The AWQC are applicable to point source
discharges, such as from industrial or municipal
waste water streams.
State ARARs
The State has promulgated Wisconsin Water Quality
Standards and Criteria (WWQC) under Chapters NR
102, NR 103, and NR 105 WAC, and the procedures
for calculating the toxic effluent limits under
Chapter NR 106 WAC, based on the Federal AWQC
developed by U.S. EPA. Chapters NR 104, NR 108,
and NR 207 WAC, also apply in determining water
quality based limits. The state WWQC and the
anti-degradation standards in Chapter NR 207 WAC,
are applicable if contaminated ground water from
the site is pumped, treated and discharged into
the wetlands or a surface water body.
The state is authorized to implement the National
Pollutant Discharge Elimination system (NPDES)
program. The applicable or relevant and
appropriate requirements for discharge of treated
water are dependent on the point of discharge.
The procedural requirements of a Wisconsin
Pollutant D~s:harge Elimination system (WPDES)
permit, under Chapter NR 220 WAC, do not apply to
the discharge of water into a surface water body
at the Sit~, since the discharge point into
Badfish creek is considered "on-site." Subject to
the approval of U.S. EPA, effluent limits for
surface water discharge will be established by the
WDNR. Chapter NR 220 WAC requires that the
effluent limits be based on the application of
best available technology (BAT) prior to
discharge. .
32
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ii.
Air Emission Standards
:ederal ~RARs
The Clean Air Ac~, ~2 c.s.c. Sec~ion 7401 et
sea., is applicable ~o any off-gases prod~ced by
~he gas con~rol sys~em, vapor treat~ent, or ground
water ~reatment systems.
state ARARs
Chapter NR 445 WAC, provides air pollution con~rol
standards and is applicable to any off-gases
produced by the gas control system, vapor
treatment, or ground water treatment systems.
iii.
Land Disposal Restrictions
Federal ARARs
The Land Disposal Restrictions, 40 CFR Par~ 268,
are applicable to treatment residuals which are
RCRA-characteristic under the Toxicity
Characteristic Leaching Procedure (TCLP) and will
be disposed on land.
State ARARs
Chapter NR 675.20 WAC, provides land disposal
restrictions treatment standards that are
applicable for treatment residuals which are RCRA-
characteristic under the TCLP and will be disposed
on land.
iv.
Ground water
Ground-water Oualitv Standards
The state is authorized to administer the
implementation of the Federal Safe Drinking Water
Act, 42 U.S.C.A. SS 300f to 300j-26. The State
has promulgated ground-water quality standards in
Chapter NR 140 WAC, which, according to WDNR, are
consistently applied to all facilities, practices,
and activities regulated by WDNR and which may
affect ground-water quality in the state. Chapter
160, wis. Stats., directs WDNR to take action to
prevent the continuing release of contaminants at
levels exceeding standards at the point of
standards application. Ground-water quality
standards established pursuant to Chapter. NR 140
WAC, are known as preventive action levels (PALs).
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PALs contained in Chapter NR 140.10 WAC, are
generally more stringent than corresponding
federal standards and are therefore applicable to
the Site.
The point of. compliance for the ground-water
cleanup standards, or PALs, is the boundary of the
landfill waste. u.s. EPA established this as the
point of compliance for CERCLA response actions on
page 8753 of the preamble for the NCP published in
the Federal Reaister on March 8, 1990,
"...remediation levels should generally be
attained throughout the contaminant plume, or at
and beyond the edge of the waste management area,
when waste is left in place."
The implementation of the selected remedy at the
Site will comply with Chapter NR 140 WAC, in that
PALs will be met in the ground water. These
standards, in accordance with the NCP, will be met
at the boundary of the landfill waste.
b.
Location-specific ARARs
Location-specific ARARs are those requirements that
relate to the geographical position of a site. These
include: .
1.
Federal ARARs
Executive Order No. 11990 - Wetlands Protection -
is applicable for this site if treated leachate
and ground water is discharqed to wetlands.
Section 404 of the Federal Water Pollution Control
Act regulates the discharge of dredge or fill
material to waters of the united states.
Construction of surface water discharge points may
be regulated under Section 404; therefore, the
substantive requirements of Section 404 are
relevant and appropriate to the remedial action it
the discharqe of treated qround water is to
wetlands or a surface water body.
ii.
State ARARs
Chapter NR 115 WAC, (Wisconsin's County Shore land
Protection Program), Chapter NR 1.95 WAC,
(Wetlands Preservation, Protection, and
Management), and Chapter NR 103 WAC (Water Quality
Standards for Wetlands) are applicable to this
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=emedial ~c~ion if trea~ed leacha~e is discharged
~o we~lanas, :f any s~ruc~ure is built or any fill
is placed in a we~land area, or if any
cons~ruc~ion is perforned in a shoreland area.
c..
Action-specific ARARs
Ac~ion-specific ~~s are requiremen~s ~ha~ define
accep~able ~rea~ment and disposal procedures for
haz~rdous subs~ances.
i. Landfill Conten~s
Federal ARARs
RCRA Subtitle D requirements are relevant and
appropriate for landfill closure because the
majority of waste placed in the landfill was
municipal waste. The current cap on the landfill
does not meet RCRA Subtitle D requirements for
closure of a solid waste landfill.
RCRA Subtitle C requirements are relevant and
appropriate for closure of landfill Cells 6 and
12. The waste disposed in these two cells was
similar or identical to RCRA hazardous waste and
appears to be the major contributor to ground-
water contamination.
RCRA Land Disposal Restrictions are applicable to
any treatment residuals from the landfill
determined to be a RCRA-characteristic waste and
will be disposed on land.
The solid waste disposal requirements of 40 CFR
Part 257 are applicable to disposal of solid waste
associated with this remedial action. .
Federal regulations at 40 CFR Section
regarding post-closure care to ensure
Site is maintained and monitored, are
relevant and appropriate.
264.310,
that the
also
State ARARs
Chapter NR 30 WAC regulates dredging, relocation,
enlargement, grading and structures in or near
navigable waters of the state. These statutes
would be applicable for any structures built in or
near a surface water body. Such structures may be
needed at the Site for discharge of treated
leachate.
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The discharge of ~aste water (treated ground
water) to the land or surface waters; effluent
limits; discharge permits; and sampling/testing
methods are regulated by Chapter 147, Wis. Stats.
(Pollution Discharge Elimination), Chapters NR
102, NR 103,NR 104, NR 105, NR 106, NR 108, NR
207, and NR 220 WAC. These requirements are all
applicable to the discharge of treated ground
water to wetlands or a surface water body.
Chapter NR 220 WAC, provides that no discharge
shall contain quantities of listed pollutants
greater than that would remain after subjecting
the water to best available technology .
economically achievable (BAT).
Wisconsin's Solid and Hazardous Waste Programs are
regulated by Chapter 144, Wis. Stats. The Solid
Waste regulations are found at Chapters NR 500 to
NR 520 WAC. These regulations are relevant and
appropriate at this site.
Chapters NR 504.07, NR 506.08(3), NR 514.07, and
NR 516.07 WAC (Landfill capping and Closure
Requirements), are relevant and appropriate at
this site. The cover system contained in the
selected remedy is necessary to abate and prevent
exceedence of the ground-water standards found in
Chapter NR 140, WAC.
Chapter NR 508 WAC (Landfill Monitoring
Requirements), is relevant and appropriate to this
site for the long-term ground water monitoring
contained in the selected remedy.
Chapters NR 504.04(4) (e) & (f), NR 506.07(3), and
NR 508.04(2) WAC are relevant and appropriate to
this site for controlling explosive gas migration
levels and for soil gas monitoring. Chapter NR
506.08 WAC, which regulates active gas extraction
systems that collect and combust landfill gas, is
relevant and appropriate for this site.
Chapter NR 506.08(3) (b) WAC regulates storm water
runoff and is relevant and appropriate to this
site.
Chapter NR 504.05 WAC is relevant and a~p~opriate
for this site because it provides the m~n~mum
design criteria for all aspects of the remedial
measures.
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Chap~er ~R 660.16 ~AC. is relevan~ and appropria~e
:or ~he hazardous ~as~e landf~~l cover design over
Cells 6 andl2.
Chap~ers NR 400 to NR 499 WAC provides air
pollution con~rol s~andards that are applicable to
any off-gases produced by the gas extraction
system or ~as~e water treatment sys~em at the
Site.
Chapter NR 141 WAC regulates the installation of
ground water monitoring wells. Chapter NR 112 WAC
regulates the installation and operation of
extraction wells. Both of these provisions are
relevant and appropriate to the remedial action.
Chapter NR 149 WAC regulates the State's
laboratory certification program. This
requirement is applicable to 'any analytical
testing performec ~~ the Site.
3.
Cost Effectiveness
The selected remedy for this site is cost effective because
it provides the best overall effectiveness proportional to
its costs in comparison to the other alternatives evaluated.
4.
Utilization of Permanent Solutions and Alternative
Treatment Technologies (or Resource Recovery
Technologies) to the Maximum Extent Practicable
The selected remedy represents the maximum extent to which
permanent solutions and treatment technologies can be
utilized for management of the landfill waste and.
remediation of the contaminated ground water at this site.
The selected remedy provides the best balance of tradeoffs
in terms of long-term effectiveness and permanence,
reduction in toxicity, mobility, or volume achieved through
treatment, short-term effectiveness., implementability, and
cost, while considering the statutory preference for
treatment as a principal element and state and community
acceptance.
The selected remedy for the site will significantly reduce
the inherent hazards posed by the waste mass by covering the
landfill, extracting and treating VOCs from the landfill
waste in Cells 6 and 12, and controlling landfill gas. The
remedy will significantly reduce risks posed by contaminated
ground water by remediating the ground water through
extraction and treatment.
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5.
Preference for Treatmen~ as a Principal Elemen~
The selected remedy satisfies the s~atu~ory preference for
treatmen~ as a principal element of a remedy. This
statutory preference is satisfied by ex~racting and treating
VQCS, waich are considered the principal threat waste in the
landfill, and by treating ground water contaminan~s.
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