UntodStttM
EnvtroflflUfitil Protoctkxi
Ag«ncy
OfflMOf
Emergency)
Sapumtor 1968
Superfund
Record of Decision:
Mid-State Disposal, Wl

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 REPORT DOCUMENTATION
        PAGE
                        1. REPORT NO.
                               EPA/ROD/R05-88/076
                                                                       1. Rwiptonl's Acc«*ston Mo.
4. Title and Subtitle
SUPERPUND  RECORD OF DECISION
U^d-State  Disposal Landfill, WI
   rst Remedial Action  -  Final
 . Authors)
                                                                       * "1T0I088
                                                                       g. Performing Organization Rapt. No.
 9. Performing Organization Name and Address
                                                                       10. Prolect/Task/Work Unit No.
                                                                       11. Contract(C) or GranttQ) No.

                                                                       (C)

                                                                       (G)
 12. Sponsoring Organization Nama and Address
 U.S. Environmental Protection Agency
 401 M Street, S.W.
 Washington, D.C.  20460
                                                                       13. Typa of Rapoit 4 Parted Covered

                                                                          800/000
                                                                       14.
 15. Supplamantary Not**
 It. Abstract (Umlt: 200 wordi)
     The Mid-State  Disposal (MSD) site  is  an abandoned  municipal and  industrial waste
 landfill located  in central Wisconsin,  in Cleveland Township, Marathon County, about  4
 miles northeast of  Stratford,  The  area  surrounding the site includes  an abandoned
 railroad track partially bounding the west and north, two offsite sludge disposal
 lagoons owned by  Weyerhaeuser, Inc. to  the northeast, and private property to the
 -nuth.  Site  runoff enters nearby waterways including the Rock Creek and the Eau Plune^
     er via unnamed tributaries.  Additionally, ground  water from  the site is believed  to
 D«  discharging  into a ravine 500  feet south of the  site.  MSD conducted landfilling
 operations from  1970-1979, receiving  municipal,  industrial and commercial wastes as well
 as  construction  and demolition debris.   Specific wastes received included papermill
 sludges, asbestos dust, solvents, pesticides, paint sludges  and  metals.  Four areas of
 contamination have been identified  at the site.   These are:  a 25-acre landfill  located
  in the center of the site and  referred to as the Old Mound area, which contains
 municipal wastes, papermill  sludges,  asbestos dust, pesticides and  solvents; a 5-acre
 Interim expansion landfill located  to the west of the Old Mound  area and referred  to  as
  the interim  Expansion area,  which reportedly contains wastes similar to the Old  Mound
  area with  the exception of papermill sludges; a  3-acre sludge  lagoon located northwest
  (See Attached Sheet)
 17. Document Analysis  a. Descriptor*
  Record of  Decision
  Mid-State  Disposal Landfill,  WI
  First Remedial Action  -  Final
  Contaminated Media:  gw,  sw,  soil
                               VOCs (PCE, TCE)
   c. COSATI Field/Group
     inability Statement
                                                       19. Security Class (This Report)
                                                             None
                                                        20. Security Class (This Page)
                                                              None
21. No. of Pages
      37
                                                                                  22. Price
(See ANSI-Z39.18)
                                        See Instructions on Reverse
                                                                                OPTIONAL FORM 272 (4-77)
                                                                                (Formerly NTIS-35)
                                                                                Department of Commerce

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EPA/ROD/R05-88/076
  •3-State Disposal Landfill, WI
  rst Remedial Action - Final

16.  ABSTRACT (continued)


of the Old Mound area which allegedly contains papermill sludges;  and an area along  the
western edge of the property where leachate ponding had occurred.   Numerous
environmental problems and permit violations were noted by the Wisconsin Department  of
Natural Resources (WDNR) during a site inspection in 1974.  In 1979,  Weyerhaeuser
Company, a generator of waste disposed at the facility, agreed to  properly abandon the
facility.  The pond leachate was removed, and the three waste disposal areas were
covered.  Leachate collection systems were installed in late 1979  for both the sludge
lagoon and the Interim Expansion area; only the leachate collected from the latter is
currently removed and treated offsite.  Subsequent investigations  revealed that ground
water has been contaminated by leachate percolating from the waste disposal areas  and
the leachate pond down to the underlying aquifer.  The primary contaminants of concern
affecting the ground water, surface water and soil are VOCs including benzene, PCE and
TCE, and metals.

   The selected remedial action for this site includes:  installation of new soil/clay
caps for the lagoon and landfills; site monitoring that includes ground water, surface
water, and landfill gas monitoring; offsite ground water monitoring;  provision of  an
alternate water supply for nearby residences; improvement of surface  water drainage;
leachate and ponded water collection and offsite treatment; access restrictions;
  stitutional controls to prevent well installation orisite; and in situ solidification/
  jbilization of sludge as necessary for cap support,  and landfill gas flaring, if
deemed necessary during pre-design.  The estimated present worth for  this remedial
action is $16,000,000 with annual O&M of $22,000 for the first year,  and $100,000  for
years 2-30.

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                             Record of Decision
 Site Name and Location

 Mid-State Disposal Landfill
 Marathon County,  Wisconsin

 Statement of Basis and Purpose

•This decision document presents  the selected remedial action for the Mid-
 State Disposal Landfill Site in  Marathon County, Wisconsin, developed' in
 accordance with CERCLA, as amended by SARA and, is consistent to the extent
 practicable, with the National Contingency Plan (NZP).  This decision is
 based on the administrative record for this  site.  The attached index-
 identifies the items which conprise the  administrative record upon which
 the selection of  the remedial action is  based.

 The State of Wisconsin concurs in the selected remedy.

 Description of the Remedy

 The selected remedial action alternative for the Mid-state site addresses
 the source of contamination through the  installation of new landfill caps
 to prevent migration of hazardous compounds, to reduce associated
 contaminated materials, and prevent direct human contact with landfill
 contents and lagoon waste.  An alternate water supply will protect those
 residents threatened by potentially contaminated groundwater.

 The major components of the selected remedy  include:

    - Site capping with a soil/clay cap that  meets State solid waste
      landfill requirements will  minimize leachate generation and prevent
      direct contact with contaminated'materials.

    - Site monitoring will be conducted that  includes groundwater,  surface
      water, and landfill gas monitoring  to determine the effectiveness of
      the above measures and provides early warning as to the need,  for other
      actions.

    - Alternate water supply to protect against potential future ingestion
      of contaminated groundwater.

    - Improvement  of surface water drainage.

    - Off-site treatment of leachate.

    - Site fencing and sign posting for security.

    - On-site road construction.

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                                    -2-

   - Institutional controls to prevent well installation within the site
     boundary.

The following components will be evaluated during the pre-design and will
be included if required:

   - Landfill gas flaring
   - Sludge stabilization

The action will require operation and maintenance activities to ensure
continued effectiveness of the remedial alternative, as well as to ensure
that the performance meets applicable State and Federal surface and
groundwater requirements.
                                *
I have determined that the action being taken- is consistent with Section 121
of SARA.  The State of Wisconsin has been consulted and concurs with the
selected remedy.

Declaration

The selected remedy is protective of human health and the environment, attains
Federal arSL state requirements that are applicable or relevant and appropriate
for this remedial action, and is cost-effective.

This remedy utilizes permanent solutions to the maximum extent practicable for
this site.  However, it was determined that treatment of either source
materials or groundwater would not be practicable at the site and,
consequently, this remedy does not satisfy the statutory preference for
treatment as a principal element of the remedy.

The size of the landfill and the fact that there are no on-site hot spots that
represent the major sources of contamination, indicate that treatment is not
practicable at the site.  Because this remedy will result in hazardous
substances above health-based levels remaining on-site, a review will be
conducted once every 5 years after commencement of the remedial action to
ensure that the remedy continues to provide adequate protection of human health
and the environment.
valdas V. Adamkus          /                   Date
Regional Administrator

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                             RECORD OF DECISION

                            ROD Decision Summary
                           Mid-State Disposal Site
                         Marathon County, Wisconsin
I. - Site Description
The Mid-State Disposal site is located in central Wisconsin, in Cleveland
Township, Marathon County, about 4 miles northeast of Stratford and about 18
miles southwest of Wausau.  The site is bounded on the west and north by the
now abandoned Chicago and Northwestern railroad track.  To the northeast are
two off-site sludge disposal lagoons owned by Weyerhaeuser, Inc.  To the
south, the site is bounded by privately owned property.  Figure 1 shows the
site in relation to the surrounding areas.  Nearby waterways include the Rock
Creek and the Eau. Pleine River which accept run-off from the site via unnamed
tributaries.

The Mid-State Disposal site consists of a 25-acre landfill, the Old Mound
area, a 5-acre interim expansion landfill, the Interim Expansion area, and a
3-acre sludge "lagoon.  In addition, there is an area along the western edge of
the property where leachate ponding had occurred in the past (Figure 2).
During the period of its operation from 1970 to 1979, the Mid-State Disposal
site received domestic, industrial, commercial, and institutional wastes, as
well as construction and demolition debris.  These wastes included papermill
sludges, coating sludges, flyash, asbestos dust, mineral core waste, glue
waste, solvents, pesticides, paint sludges, and heavy metals.

The geology of the site consists of ground moraine till overlying saprolite
(weathered zone), which is underlain by methorphic fractured-bedrock.  The
thickness of the till and saprolite varys from 0 to 23 feet and 2 to 7 feet,
respectively.  Fracturing within the bedrock extends beyond 70 feet, which was
the maximum depth of drilling performed during the RT.  The bedrock surface
slopes west along the western side of the site and east along the eastern side
of the site.  The bedrock becomes more competent about 10 feet below rock
surface, but is still weathered along zones of more intensive facturing.

Horizontal flow in the bedrock is partially controlled by two groundwater
divides.  One groundwater divide is oriented north-south below the eastern
edge of the Old Mound area, which parallels the axis of the bedrock ridge
found in this area.   West of this divide, groundwater flows at a rate of 1200
ft/'yr from the north and south toward the center of the Old Mound Area, and
then in a westerly direction.  East of this divide, groundwater also enters
the site from the north and south, but then flows to the east at a rate of 125
ft/yr.  The other groundwater divide, which is oriented east-west, lies at the
southern edge of the Old Mound area.  Although available data cannot fix the
position of this divide with great confidence, a southerly flow most probably
occurs originating at the southern end of the Old Mound area.

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                                                  MID-STATE DISPOSAL PROPERTY
                                                                  _____ v
WISCONSIN
                                           MID-STATE
                                           DISPOSAL SITE
                                                                                   4000
                                                                          2000
                                                                      SCALE IN FEET
                                                          Figure 1
                                                          VICINITY MAP
                                                          Mid-Stale Disposal Site FS  WI

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     In Icl mi
  (Mil Mound

Al C.I (l,.!(J|.Olll
                                                                                                               VMoyurliaeuser
                                                                                                                                                 SilTtMAC
                                                                                                                                                 Mm ^uie Disposal f S  K

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                                     -4-

Directly 500 feet south of the Old Mound area, across Big Rapids Road; is the
head of a ravine where groundwater is believed to be discharging in a
southerly flow from the site..

The Old Mound landfill contains municipal wastes, papermill sludge, asbestos
dust,. pesticides, and solvents.  The Interim Expansion area reportedly
contains the same types of wastes with the exception of the papermill sludges.
The sludge disposal lagoon allegedly contains papermill sludges.

II.  Site History and Enforcement Activities

Landfilling of municipal and industrial wastes at the site began in 1970
by Mid-State Disposal, Inc. after the Wisconsin Department of Natural
Resources (WDM?) granted approval for these activities.  In 1977, WDNR
approved plans for closure of the Old Mound area, and construction, of the
sludge lagoon.  Operation of the new waste disposal areas was approved in
1978.   Environmental problems and permit violations at the site were noted in
1974 when WDNR inspected the site for compliance with their new solid waste
disposal regulations.  Violations included landfilling of hazardous waste,
excessive leachate ponding, and landfilling beyond the approved area.  A large
leachate pond had also formed along the western edge of the property.  A berm
retaining leachate on-site was breached on several occasions during the late
1970s;

In'response to these violations, WEMR brought legal action against Mid-State
Disposal, Inc.  A judgement was entered against the firm in 1977 for improper
closure and abandonment of the Old Mound landfill.  Since that time, several
other legal actions and complaints have been filed against the disposal
company, including some initiated by local residents.

In 1979, an agreement was reached between the Weyerhaeuser Company, a
generator of waste disposed at the facility, and WOXDR, to properly abandon the
facility.  The existing ponded leachate was removed, and the three waste
disposal areas were covered.  In 1980, the U.S. EPA. began investigating the
site as a candidate for inclusion on the Superfund National Priorities List
(NPL).   In 1983, the State terminated its legal actions against Mid-State
Disposal, Inc. because the Corporation lacked assets.  In the fall of 1983,
U.S. EPA Superfund monies were obtained to begin remedial planning activities
at the site and, in 1984, the site was listed on U.S. EPA's NPL.
Subsequently, the  U.S. EPA Superfund monies were allocated to initiate
remedial planning activities at the site.

The Remedial Investigation (RI) was conducted between the summer of 1983 and
April 1988.  The RI focused on the collection of data relevant to the
evaluation of site environmental quality conditions, the assessments of
health and environmental risks, and the determination of the need for site
remediation.

A combination notice letter and request for information was sent to poten-
tially responsible parties on May 30, 1985.

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III. Community Relations

Copies of the Feasibility Study (FS) were made available to the public for the
Mid-State Landfill Disposal site on July 18, 1988.   The Stratford Village Hall
and the Marathon County Public Library, Stratford Branch are serving as
repositories for this and all other documents relating to this site.  The
U.S. EPA issued a press release to the Stratford Journal, Abbotsford Record-
Review, Marshfield News-Herald, Wausau Daily Herald, and other Wausau media
announcing the dates of the public comment period, and the public meeting.

A. proposed plan was made available to the public on July 24, 1988.  The public
comment period was held from July 25, 1988 to August 23, 1988.  The public
hearing to discuss the proposed plan was held July 28, 1988, at the Stratford
Community Hall.  Approximately 35 residents, local officials, and media
attended the meeting.  Representatives of the U.S.  EPA, WDNR and CH2M Hill
(EPA contractor) were also present.

The citizens took an active role in the meeting.  Their main concern was
declining property values and safe drinking water.   Many residents urged
U.S. EPA to purchase the property surrounding the site and to provide all
residents near the site an alternate water supply; however, in the absence of
a buy^-out^. the majority of the citizens support the recommended alternative.

During the RI/FS, other comnunity relations activities included kick-off and
up-date meetings, fact sheets, press releases'and advertisements.  A community
relations plan was developed prior to the start of the RI.  All documents
relating to the project have been placed in the two repositories.  U.S. EPA
has also established an Administrative Record at the Marathon County Library,
Stratford Branch, in conjunction with the repository.

IV. Scope and Role of Response Action

The selected alternative for the Mid-State site includes a soil/clay cap for
the Old Mound area and the Interim Expansion area.   The lagoon will also be
capped and the lagoon sludge will be solidified as necessary  to provide
sufficient bearing capacity to support the cap.  The cap will be
in conformance with the State of Wisconsin sanitary landfill closure
requirements.  A new water supply will be provided to protect residents
from future potential groundwater contamination.  Leachate and ponded water
collected from the existing collection systaiv in the Interim Expansion area
will be disposed of off-site.  Because of the source control measure, future
surface water collected is not expected to be contaminated and will be
directed to the natural surface water drainage ways.

During the pre-design stage, a minimum of three deep bedrock wells will be
installed to obtain additional information relating to groundwater vertical
gradients.  If a downward flow component exists, samples will be taken
to determine the extent of contamination deeper in the aquifer.  Also, off-
site monitoring wells will be installed to gather water level information and
additional data regarding off-site horizontal flow gradients.  These wells
will be included as a part, of the long-term monitoring program.

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                                     -6-

This alternative will prevent direct contact with the landfills and lagoon,
and will minimize leachate production'so that the groundwater will gradually
meet WDM? standards.  The potential risk of cancer from ingestion of
contaminated groundwater will be eliminated by furnishing near-by residents
an alternate water supply.

V.  Site Characterization

During active operation of the Mid-State Disposal site, the landfill accepted
municipal, commercial, and industrial wastes.  This included papermill sludge,
asbestos dust, solvents, pesticides, paint sludges and metals.  The major
organic and inorganic contaminants of concern are 1,1-dichloroethene,
trichloroethene, benzene, methylene chloride, tetrachloroethane, nickel, iron,
and manganese.  Table 1 presents a toxicity profile of these contaminants in
addition to other chemicals associated with the site  and their potential
effects on humans and wildlife.  Table 2 provides a list of specific
contaminants found in the groundwater and their concentration levels.

Potential pathways for contaminant migration off-site include'air,
groundwater, and surface water.  Currently, surface water and air quality have
been shown not to be adversely affected by site contamination.  However,
deterioration in the condition of the existing caps and covers over the waste
areas could result- in migration via the air and surface water pathways.

Groundwater at the site has become contaminated by leachate percolating from
the waste disposal areas down to the underlying aquifer.  The evidence of th;
is the groundwater contamination detected under the Old Mound area.  The rate
of leachate percolation is limited by the amount of precipitation infiltrat-
ing at the ground surface, since the waste is above the water table.
Potential future pathways of human health risk are shown in Figure 3.

There is evidence of ponded leachate that may be contributing to groundwater
contamination.  Many of the organic compounds detected at the site are very
mobile and may be transported at nearly the same speed as the groundwater.
The inorganic compounds have little mobility.

Leachate collection systems were installed in late 1979 and were designed to
collect leachate fron both the sludge lagoon and the  Interim Expansion area of
the site.  According to the WDNR, the present system  in the sludge lagoon
consists of a crude peripheral network of pipes, placed 3 to 4 feet below the
surface, which collected leachate from the upper part of the lagoon and
drained into a common manhole.  This system is currently not pumped.
According to the WENR, a simple french drain with two crushed rock legs
in the fill area is located on the west side of the Interim Expansion
area. This system drains into two separate manholes.   Leachate from this
system is  disposed of weekly at the Weyerhaeuser wastewater treatment
plant in Rothschild, Wisconsin, approximately 37 miles from the site.

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             i leal
Asbestos
Ksi turn
                                                                              Talile   1   (KO'/e I of  4)
                                                                       roxicm i'Rorn.is or SEI.ETTH>
                                                                                          blSWSAL Rl
                                         Aoile Tuxlclty  Suroary*
                                 Llltlr  Information available  Indicating
                                 •rule toilclty.
                                Highly  to»lc when  salts  Ingested  (dose of
                                liarliiB  chloride  lethal lo hum-ins  Is 600
                                lo 9PB.  Concentrations of J.OOO to
                                7,500 i'|.m may rt-sult In  toilc signs
                                within  1 hour.   No effects  reported
                                after acute exposure lo  IS  if>m.
       Chronic Toxlclty Summary*
No knovn dironlc nonnallgnant effect*
have been associated with th« Ingestlon
of aslicstos In Hater.   Inhalation
closure ran result In  a^licstosls, •
nonranreiiiiiu tesplratoiy disease thai
srats the IUIHJ ll^surs.  Synfitoav
ln< lu.lc ihnrlnris of blvalh ami ralrl.
Advaureil ar.heulosis aay pimlutr caidlac
failure and death.    (
Prolonged occtnpatlonal  Inhalatlun has
resulted In turlloils--a btnlgu, ravera-
Ihle luieiiaocon I os I *.  No strong deter-
mination of clironlc effects  froa
Ingest Ion en[iosure.  Possible  Increva
In cardiovascular disease and
hypertension.
The nost iBporlant effect resulting fro»
chronic trniene exposure  Is  Its
lit'aalotoilclty, the targets  being th«
(.•ells of Iliu bone urron.  At  the early
stages, Icukorvnla, anola,  or
IhiuKbocytoprnla aay be seen as veil as
any cuoblnatIon of these.  Tlie lowest
air levels of benienc de*onstratrd to
piotiure a decrease In huvan  circulating
blnod cells die In the romjc of 40 lo
SO P|IB.  Th«- Initial sycploas  Include
fatluue, headache, nausea, onJ loss of
appetite. .Continued eiposure  results In
severe bone •nrruw daaage.
                                                                                                                                  Cancer Potentlal*
Occupational eiposur* to
huaans. via Inhalation of
asbestos fibers has been  '
associated ullh Increased   '
Incidence of lung cancer and
acsolln'l ln«> (cancer of the
thin neabrane lining the
chest and jlnloacnl.  Itier*
have been Inconclusive
studies to date Indicating
that Inuestlon of asbestos lo
Hater or food Bay result In
Increased cancer risk.  An NTP
Itudy suggested possible
evidence of carrlnogenlclty
froai Ingest Ion of
Inletvedlate-range chrysotll*
fibers by aale rats.
There I* sufficient tvldence
that benien* Is carcinogenic
In anluls and that benrene
Is carcinogenic In Ban.
Occupation*! studies htve
established • relationship
betveen beniene evposur*
(Inhalation) and leukeala.
Bcntene Is carcinogenic In
rats by both the Ingest Ion
•nd Inhalation routes.
                                                                                                                                                                       Other*
Synerglatlc
Interaction between
SBoklng cigarettes and
Inhalation of asbestos
fiber In the produc-
tion of lung cancers.
                                  Tonlclty Increases with
                                  solubility.
A correlation between
benzene enposure and
chroBosoBal
observations In bone
•arrow and lymphocytes
of eiposed Individuals
has also been
observed.  Retardation
affected development
accoapanled by *
decrease In material
weight gain have been
seen  In reproduction
tonlclty studies.
                                Acute exposure symptoms of cadmltmi
                                tolclty  Include  nausea,  voBltlng,
                                diarrhea, amscular  cramps, and  saliva-
                                tion.   In severe  Intoxication,  symptoms
                                Include sensory disturbances, liver
                                Injury, and convulsions.  In  fatal
                                liitonlcal Ions, those  symptoms are
                                followed by shock and/or  renal  failure
                                and  carJIopulmonary depression.
                                Estimated acute human lethal dose Is 350 to
                                35,000  mg for • 70-kg adult.
Chronic oral exposures can  result  In
pain, osteoBalacIa, osteoiwrosls,
protelnurla, glucosurla,  and  anemia.
Kidneys tissue Is the siosl  sensitive to
low level dironlc exposure.
Lung and prostate cancer
resulted from? Inhalation of
cadmlusi by smelter workers.
No evidence of carclnogcnl-
clty froa ctironlc oral
exposure.
Cadmium does not
readily pass through
the skin.  Tlie diet Is
the major source of
human exposure to
cadalum (34 ug/day).
A nonessentlal
eleaent.
•ll< ,iltI.  elfei.l  or target  organ may I* l/a>ed on anleal  studies  and does lot  Imply
 tl.at  I lie  results of  expuiiure lo dumans vll! be the same.

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                                                                               Table
                                                                                          (Page I of 4)
          Chen Ira I
                                         Anila Toxlc'lly Sim/lry*
Cl.pptT
1,1 -Dlch)oro«thana
   iy Ibenione
lead
                                 Inhalation uf chrom.il e tall) I caul Is In
                                 Irritation anj InflummatIon uf najal
                                 •iiioia,  uli-unllun, and prrforal Ion o(
                                 nnsal  Hi'1""-  Doics of 0.5 lo 1.5 9 of
                                 H.Cr .1).  liave brrn fatal In humans.
                                 font III  with chromic acid or tliromat*
                                 tails  have rciullol In ul.eis nn.l
                                 (unlai l-lype dermatitis.  Ovciall,
                                 lu-aftvalfiit  forms aiv mole toxic (lien
                                 Irlvali-tit  loms.
                                Ciposur*  (liilialatlonl  lo copper dusts
                                n-Milts In  symptoms  similar lo Mtal
                                Iliac lever.   Exposure  to mclal fuaes
                                nv.iills In  upper  respiratory tract
                                li r Hal Ion, •*•(•) IK or swiel taste,
                                muiea, metal  fumn fuvir, anj skin and
                                liolr discoloration.  Cxpoyuic lu ilusls
                                and mlstii of  copper  ^alts results In
                                congest Ion  of  nnsal  MUCOUS armliranes,
                                soBctltes of  phtrnyii,  and occasional
                                ulccrallon  vlth uuifoial Ion of nanal
                                yrptua.  A<.~ute copier  aulfate poisoning
                                In IIUBJMS (1  to U 9 of coppci sulfalc)
                                la soartlB«]  fatal anil Incluilci
                                vufflKlnn, diarrhea,  ark] renal Injury.

                                Coiura CHS  drures^lon  vhro Inhaled at
                                lilgli cuniciitrations.   Oral ID.,, for
                                rats Ij 735 »y/»g, but other S«|itrl»enta
                                In this dose  ranQc proOiirct) no affects.
                                Inhalation  produces  anesthesia.
                                                                       SO
                                          eiie I* a skin Irritant and Its
                                 vapor Is Irritating to trie eyes at  a
                                 conrciilrat Ion of ]OU ft'*-  Atule
                                 loilclly data on oral and dermal routes
                                 In bo Hi rats anj rabbits Indicate a lo¥
                                 loilcltr for «th|rlbcner by oral
Intake.  In susceptible Individuals,
Wllsnns dlsi-dse (disorder of cvppcr keta-
bollsn) typifies chronic copper poison-
Ing »lth hfpallc cirrhosis, brain daaage,
diayellnatlon, kidney defects, and
copper deposition In the cornea.  Chronic
exposures In anlffals result In Injury to
liver, ktdnrys, and spleen.  Copper is a
gastrointestinal tract Irritant.
Relatively luv capacity to cause  liver
or kidney Injury even, after repeated
exposure.  No human exposure data.
Inhalation exposures at £00 pp» resulted
In alight changes lo liver and kidney
•eights In rats and guinea pigs, slight
changes In liver weight In monkeys, and
hlstnpathologlcal changes In the tests
of turnkeys and rabbits.  High-dose
feeding studies In rats resulted In
liver and kidney effects.  Cthylbeniene
Is not known to be toxic to the liver or
kidneys of huaani.

Chronic lo* levels of  exposure to lead
affect the heaatopolet Ic systeai, the
nervous systca, and the cardiovascular
uystea.  Lead  Inhibits several key
eniynes Involved In heae biosynthesis.
One characteristic effect of chronic
lead  Intoxication 1* anrala, vhlch  Is
exhibited by reduced tmngloliln
production and shortened erythrocyle
survival.  Animal studies Indicate  that
lead  Inhibits nervous  system develop-
ment.  In huaans, lead exposure has
resulted In nervous system  Injury,
Including reduced hand-eye  coordination,
reaction time, visual  motor performance,
and nerv* conduction velocity.  The
developing child appears especially
sensitive lo  lea.I-Induced nervous system
Injury.  Lnl.litilulo.jlr.il studies have
Indicated llut chronic lea.l exposure may
be d^soclale«l with  Increase*! blood
pressure In huaatu.
                                                                                                                                   Cancer Potential
Excess lung cancer associated
with chromate-produclng
Industry workers.  Carcino-
genic effects observed only
In lungs.  No evidence of
carcinogenic potential via
oral exposure.  Chromate
salts carcinogenic In rat*
by Inhalation.
                                                                                                                                                                        Other
                                                                                                                             Lead salts  have some evidence
                                                                                                                             of  carclnogenlclty In
                                                                                                                             animals.
                                                                                                                                                              Essential clement.
                                                                                                                                                              Toxlclty related  to
                                                                                                                                                              valence «tala.  Geno-
                                                                                                                                                              toxlc In In vivo  and
                                                                                                                                                              In  vitro studies  due
                                                                                                                                                              ToTiUlTJlndlng.
                                  Essential  nutrient.
                                  Organoleptlc threshold
                                  In water between  1  to
                                  t mg/1.
                                  Limited toxlclty  test-
                                  Ing, but one of the
                                  least toxic  of the
                                  chlorinated ethanes.
                                                                                                                                                               Some evidence of
                                                                                                                                                               reproductive effects
                                                                                                                                                               on animals.
                                                                                                                                                                                            00
                                  Children are
                                  especially  sensitive
                                  to  low level-effects.
'llrali h f
 tt.al lli>.
                or target  organ «jy l>a based on anlaal studies and does not Imply
               .Is of  exposure  lo tmaans  will  be the same.

-------
                                                                               Table   1   (Page  3  of  «)
                                          Aiiil* Toxlcllv
                                                                                      Chronfc
                                                                                                    lly  Smeary*
                                                                                                                                    Cancer Potential
                                                                                                                                                                          Other
III. k,:l
                                 Hdi>jaiic:i« !'•» a very  I"* oidei of acute
                                 i.ial li»li Ity.  Hals  arc alfecled at
                                 ],mill |'|« In Id* dill.  Acute  Inlulolloo
                                 e»i'o:.ul«*:J lo very hl'lli concent lat Ions
                                 fun raule •ongaiii-»e pni-u»irilt Is,
                                 InrixicJ nu-.,r<|'l Iblllty to respiratory
                                 <1l:.fj-.r( and |iatholoqlc cttangey,
                                 li.. liidldg «-|il I h«:l lei  ncirukl)  arid
                                 u.iiK-nitclf.ii |iiolId'i«l Ion.
                                 Nlikcl ami nlitel salts have lelotlvely
                                 li>w acute lonlirlty  In various species of
                                 anl«als when attain!it ei e»l uiJlly.  flajor
                                 slijus ol anile nlcki'l loxlclty consist
                                 ol hyi'i'lijlyi'eala ant) yojl loliil est Inal
                                 an.l cc-nllal liei VIHI-J syMee vllrtls.
                                 Ai-ulc ri|>o^uir* lo nit ftrl-LX>II| j| lilnij
                                 Jn:.t aay fc^iill In itiL'Blral |iiimaonlt Is.
                                 £>huit-teiB InlialatIon vijiosure In huaajis
                                 ciui iv&ult In depression of th« central
                                 nt-TWiiis syktta characlerlieO by
                                 dlulneis, l>[Mltra iraoiy, contusion,
                                 lirltahlllly, "Incbilatlun-llkc*
                                 svU'toas, Irtuori, and nu«bness.  Kidney
                                 UltuliBcnl, hi'iiatltls, anj rnlarytaent
                                 ul Hie sple.ii and liver have teen
                                 lt|H>ltrd.
                                 Anlaial utudles Indicate the Main tonic
                                 el'Irct ol a^ite Inhalation Is upon the
                                 cvntral nvrvous systi*.  Toluene-Induced
                                 hrarlng lor.i In rots alter short-ton,
                                 Mn-lIke ^y«itt(«ns.  Long-terv
                                 dbii^c of tolui-ne has resulted In
                                 icotlonal and Intelli-clual dlstuibances
                                 as «i:ll BJ CNJ lap*Intent.
                                                               Clirunlc •anqnrM--j» poisoning results froai
                                                               Inhalation  of  hlgli conr-rntrations of
                                                               •angancse dust.   Chronic oangancse
                                                               poisoning Is cluioctcrlied by
                                                               progressive deterioration of the central
                                                               nervous systen.   Chronic effects of
                                                               •Angancse poisoning are slallar to those
                                                               of Parkinson's disease,  l.lver changes
                                                               are also freqtM'iilly seen.  Individuals .
                                                               with an Iron deficiency ajy be *iue
                                                               susi-i-pt Ible to ( hronlc |iolsonliig.
                                                               fhri'iilc toilclly  frua  driiiklng nater has
                                                               nut been reported.

                                                               AnlBjl studies Indicate that nickel has
                                                               low rhronlc oral  toilclty.  Rhinitis,
                                                               n^s^l sinusitis,  and nasal •tirosal
                                                               Injury are  aaong  the effects leportcd
                                                               aai>ng workers  chronically eni>oseJ to
                                                               various nickel conpounds.  Ocrvatltls
                                                               and othirr dcraatolnglcal effcils arc the
                                                               •ost frequent  effects  of exposure
                                                               (d«iBal) to nickel and nickel-containing
                                                               cMpourkls.  These are  usually the result
                                                               uf Industrial  eNpi>surt.-s or ek|>u^uies to
                                                               nlc kel-rxwtalnlng alloys In coKcerclal
                                                               products sucri  as  jewelry.
                                                               Very  little data  are available concern-
                                                               Ing  long-ten  e»posure to PCE.  Hepa-
                                                               totoilc effects have been documented for
                                                               long-tera  Inhalation exposures to
                                                               workers as have hepatitis, cirrhosis,
                                                               liver-cell necrosis, enlarged liver, and
                                                               kldnry disease.  Oral exposures In
                                                               en|H:rlaental anlnals resulted In alnor
                                                               liver  Impacts  In  rats but oore signifi-
                                                               cant  effects In alee.

                                                               Long-teia  Ingest Ion studies In various
                                                               anlul species resulted In no adver&e
                                                               effects.   In general, tbere are Malted
                                                               data  on oral ciposures.  Long-ten huian
                                                               exposure to vapors 80 to 160 upa
                                                               produced no dianges In blood or liver In
                                                               workers.
Tliere Is eilenslv* epldevlo-
loglcal evidence Indicating
e»cess cancer of the lung and
na:.al cavlly lor workers of
nli-kel refineries and
tcelters, arid weaker evldenc*
In workers at nickel electro-
plating and polishing opera-
tions.  Nickel coapoiuidl
lapllcated as having carcino-
genic potential Include
Insoluble dusts of nickel
subsulflde and nickel onldes,
vapor of nickel carbonate and
soluble aerosols of nickel
sulfate and nickel carbonate.
Tlier* Is no evldenc* that
nlcktl compounds an carcino-
genic In anluls after oral
exposure.

Found to produce liver cancer
In sice.  Inhalation studies
with rats have yielded evi-
dence of carclnogenlclly
(leukeaila).  No epldenlologl-
cal studies conclusively
linking human exposure to
carclnogenlclty.
No evidence of carclnogenl-
clty.
                                  Hangancse Is  on essen-
                                  tial nutrient. • Mangan-
                                  ese concentrations In
                                  water  above SO  ug/1
                                  My exhibit undesir-
                                  able taste and  dis-
                                  coloration.
So«e forts are «uta-
genlc.  Hay or «ay  not
be an essential
element.
Anlial studies suggest
potential teratogenlc
and eabryotoilc effects.
Efcbryotoxlc  In
anlials, possible
anlnal teratogen.
or Tai get orgjn may
   of cHpusurc lo l.u
                                       based on onlaal studies and does not Ifcply
                                      jis will be the saae.

-------
                                                                                  Tdbl«    1  Ue.je I of 4)
                                                                                         riiioiijc Tuxlclly  Suaajry*
                                                                                                                                         roncer t*otentlal
 ll Itl.lon.i ll.rl.e
Vinyl  Chloride
                                  Hinll<"ita< Inn i>f Tit i>|«.. nit- III d«-|ires-
                                  ilnii of Hit (Mi, ulilili It ik»y
                                  dlilli>:.^,  heailiii In', visual anrrs,
                                  In. .,,,1,11 nil Inn slKlldl lu (li.it Induced
                                  l,y  tliiihul, c,)lll>llir»%, lir»i>rs, nausea,
                                  Ami vi«llli,ij.  ('aiiHac. ar iliylljilds diid
                                  Jri«il  I'jU *\  i«-:.ulli.l In anilo kUniy
                                  Inlluiif  i-llal'j, ami llvrr un i a.i ;r Illllalluli lu tyi-J,
                                  A* nl t-  ordifMil luiiui  fiiiOMiii' U> liltjli con'
                                  t'fiit r.il Itiii-i uf vlfiyl  ihluilili- «'jn
                                  |no«1u>'c syin'tua^ ul  ikiliv:.)^ In. ImaJli^.
                                  l;  yjilolile cflixls
                                  i.ii  ll,o  llvri anj kliliuy)  anj Uillant
                                  idiclj  en (lie yustrulntcsllnal tiacl.
   Trolonijitl i>c(iii>al lunal eKposuiea to
   v<|ioru  (Ml  lu 400 |>|>.) iei.ult<-J In CNS
   ayi^ituas liu ludlnij tie^Jjchf,  dlizlness,
   n«iiM-a, tiraors,  slet-plnr&s,  [allque,
   ami voalllni).   Tlie.se were  revcrslhle.
   Loner liun.iii  rx|>osurrs  IIOO  to 200 \-ftm)
   resullitj lii  blochi-nlral <*lianqi-s  In liver
   function.  In  test anlaals, chronic
   eKIxi&iire lu  T('t Induces Ion to •tuleiate
   llvpr and kidney  toxlclty.  fruloncji>il
   lijidljtlon vKfusures to tfi.1  onlKul^ at
   levels gredler than J»f)OO •,]/•'  resulted
   In rrnal lunlclty, licpdlnloilclly, and
   nfurot oiilcl t y.

   lluidn health rffecli a^soclalej  vllh
   chronic exposure  to vinyl chloride
   Include hrpalItls-1Ike liver  rhAnqea,
   del ic.isf^i blood platelets,  i-nlurged
   spleens, decreased puliondiy  lunrlIon,
   acinoutouly^ls, sclerotic- syndrome, and
   IhioKliocyt openld.
   Data on the effects of lung-tei* lai»An
   etpojuie to nyluiK are prlijilly hloli-
   li-vel occiipdt lonal liilialallon  okposurvs
   that luvc  resulted In CHS t-lfi'di,,
   Inroon1ln.it Ion,  ndusea, v,«lllng, and
   aMrjBlndl pain.   Ingest Inn data «as of the brain
have teen  Induced In
lalKiiatory anlcals by
Inhalation.

No evidence of carclnogenl-
clty.
Vinyl ctilorlde la
•utagenlc In several
test systems.
CTiroBosoBe aberrations
have been reported In
exposed  workers.   In
huians,  possible
relationships  between
exposure and birth
dufvcls  and fetal
dc.it h.   No anleal
evidence for
teratogcnlc effects.
*Hi-.illh  elfii;/>n may In.  banixl on onlodl  ^Indies Mid does nut
 Hut  the results of  eipo:.iiri; to haaoiis will be the saae.
l.ply
WI'H3bl/LX)4

-------
                                                                  Tat.'   2
                                    SUMMARY OF COMPARISON OF MONITOR*    ELL DATA EXCEEDING STANDARDS TO
                                                U.S. EPA STANDARDS, CKil'ERIA, AND GUIDELINES
                                                            MID-STATE DISPOSAL HI
                                            Maximum Contaminant levels
Ambient Hater Qual-
  Ity Criteria for
  Drinking Hater"
Office of Drinking Hater Health Advisories^





1




Chemical

, 1 -Olchlorocthcne

Benzene


Maximum
Do tec leil
Groiintlwatcr
Concent i 
-------
                                                                   Table  2
                                                                  (Continued)
     Chemical
 MaxI mum
 Detected
Groiuiilu.itcr
     l i ,il Ion  Hell
                              9.0
                              7.2
                              7.2
                              7.2
                              5.4
                              7.2
Iron1
Manqanese
   1,020
   2,650
     302
  10,400
  12,200
     415
     551
   2,030
   1,120
   1,*>22

     616
     602
     275
      63
   7,5 20
      51
  17,200
     9H1
     146
     325
     120
     309
     830
     498
     277
MW-1
MU-3
HW-6
HH-B
Mil-13
Mil-15

MH-3
MW-5
HH-6
HM-7
Hll-9
MU-11
MW-13
MH-14
MH-15
MH-21D

MH-1
MH-3
HH-5
HH-6
MH-7
MH-8
HH-9
MW-10
HH-11
MH-12
MH-13
MW-14
MH-15
MM-20D
MW-21D
                                             H.ixlraiim Contaminant levels
                                                   Ambient  Hater Qual-
                                                      ity Criteria for
                                                      Drinking  Hater
                                                             Office of Drinking Hater Health  Advisories
        Primary
          MCI.

          10
                                                       Secondary
                                                          MCI,
MCLG
  .f
 Toxlclty
Protection

    10
1 x 10
Excess
Cancer
 Risk
                                                                                              -6
                   Longer
One-day  Ten-day   Tern
 10-kg    10-kg    10-kg -
 Child    Child    Child
                                                                                                     43
                                                                                       43
Longer
 Term    Lifetime
 70-kg    70-kg
 Adult     Adult

    18
                                   300
                                                            50
Dote:   All  concentrations In |ig/l.
J'H nd 1  HCI.s and MCLGs published In 40 CFH 141  and 52  FR 25690-25717.   Proposed MCl.s and MCLGs published  In  50  FR 46936-47022.
1 U.S.  KTA,  Quality Criteria for Hater,  1986,  EPA 440/5-86-001, May  1,  1986.
l'll.S.  Ill A,  IlcaTth Advisories 7or I.oglonclla and Seven Inorganics, March,  1987, NTIS PB87-235586; Health  Advisories 'for 25 Organtcs,
 lluich l''f>7", IJT1S Pnd7-23557H;"llealth Advisories for  16 Pesticides, March 1987, IITIS Pn-200176.
 I'.ackijrouriJ concentration of Ltnzene Is 3 |jq/l.
L'lvickgroiiiul concc-iitrjUon of Iron Is 1,166 |ig/l.
' I'u>po:;oil MCI.O
-llo 11 I L>:i i.i aval lable
III-U2H3/033

-------
^^^m    . 1
•out IN i it r
    Gas Releases      ,'
(Existing and Future)   i
   Extent Unknown
                    I MW-2
                                                                                                                                  LEGEND
                                                                            I      |
                                                                                                                                        Future Dlrcel Coniacl ^llsk

                                                                                                                                        Enisling Gioundwalcr Ingcsllon

                                                                                                                                        Future Groundwaler Ingcstlon
                                                                                                                                         Risk
                                                                                                                                        Boundary ol Bisk Estimated

                                                                                                                                        Boundary of Risk Unknown
                                                                                                                                  HW   Existing Residential Well
                                                                                                                                 Figure  3
                                                                                                                                 AREAS OK POfLNIIAI PUDIIC
                                                                                                                                 MLAI fll niSK UNDLII NO ACTION
                                                                                                                                 Mid Suie Disposal FS

-------
                                     -14-

A leachate collection system was not installed at the Old Mound area of the
site.

V.  Summary of Site Risks

A risk assessment was conducted to assess the potential human health and
environmental effects associated with the no-action alternative.  The no-
action alternative assumes that no corrective actions will take place at the
site and there are no restrictions placed on future use of the site.
The risk assessment showed contamination on the site.  No contamination was
found off-site at levels posing a significant risk to human health or the
environment.

The assessment indicates that primary Maximum'Contaminant Levels (MCLs) for
ingestion of drinking water were exceeded for 1,1-dichloroethene and
trichloroethene, and secondary MCLs were exceeded for iron and manganese.  The
water quality criteria (M2C) for toxicity protection of aquatic life was
exceeded for nickel; the WQC for drinking water for protection against cancer'
exceeding the 1CT6 excess lifetime cancer risk level was exceeded for benzene,
1,1-dichloroethene, methylene chloride, tetrachloroethane, and trichloro-
ethene.  The 10~6 level means one person in one million may develop cancer.
The 10-day" chronic-health advisory for protection of children was exceeded for
cadmium.  The State of Wisconsin enforcement standards for groundwater
(Groundwater Quality Regulations KR 140) were exceeded for iron, manganese,
benzene, and trichloroethene.  Again, these risks presently are limited to
areas within the boundary of the site.

Future potential exposures associated with ground-water ingestion are the
primary concern at the Mid-State Disposal site.  See Table-2.

Site specific concerns are as follows:

   Lifetime cancer risk associated with ingestion of groundwater
   flowing to the west is 2 x 10~6.

   Lifetime cancer risk associated with ingestion of groundwater flowing
   to the south/southeast is 1.5 x l(T3.

   Qn-site ground-wetter flowing to the west contains manganese at
   concentrations that would result in daily intake rates in excess of the
   reference dose level (RED).

   On-site ground-water has known carcinogens which includes benzene at
   concentrations that equal the primary MIL and exceed the State of Wisconsin
   enforcement standard.

   Qn-site groundwater contains 1,1-dichloroethene and trichoroethene in
   concentrations that exceed their respective MCLs and State of Wisconsin
   enforcement standards.

-------
                                    -15-

Other site specific concerns include:•

   Landfill gas contains vinyl chloride and other organic compounds.

   Surface seeps from both landfills are associated with areas of erosion.

   Erosion of landfill covers promotes direct contact with waste and increased
   precipitation/infiltration.

The excess lifetime cancer risk to humans from ingestion of groundwater to the
west and south/southeast was calculated very conservatively, based on summing
the individual chemical risk for the maximum concentration found in these
areas.  The risk to the south is based mainly on a one-time high detection of
1,1-dichloroethene.  (Table 3 and Table 4.)

The potential risk exists for: 1. future migration of contaminated ground-water
to off-site users; 2. future leachate run-off to nearby waterways resulting in
environmental degradation and detrimental impacts on aquatic life; and, 3.
exposure to contaminated groundwater by ingestion and direct contact through
future development of the site.

VII.  Description'of Alternatives

The assembled remedial action alternatives represent a range of possible
remedies evaluated across the board against a given set of criteria.
Figure 4 illustrates the major components of the assembled alternatives.  The
selected alternative will undergo further refinement during the final pre-
design and design phases.  The extent of the refinements or modifications will
be determined by the results of additional sampling and treatability studies.
This will be examined in detail in the discussion on the selected alternative
in this section.

All the alternatives, except the no-action alternative, incorporate the
following features:

    Pre-design activities will include the installation of a minimum of three
    deep bedrock wells to obtain information about the groundwater vertical
    gradients; seven shallow wells will be installed to gain additional
    information on horizontal flow gradients and migration of contaminants;
    samples from residential wells will be taken and their depth to casing
    win be determined; and the sludge will sampled for permeability and
    hazardous constituent contamination.  The extent of the activities will
    depend on the technologies identified in the alternative.

    Institutional controls, as needed, will be placed on the site property to
    control soil excavation and on-site well installation.  Existing WDNR
    regulations will be used to control off-site well installation within
    1200 feet of the landfill.  The timing and extent of institutional
    controls win be determined in the design phase of the remedial
    action.

-------
                                                              Table   3
                                         EXCESS LIFETIME CANCER RISK DRINKING HATER INGFSTION
                                                         MID-STATE DISPOSAL RI

Chemical
liMiizene
IUs{2-cthylhcxyl)|il|tlialatc
1 , 1 -Dlclilnroelheni!
Mot liy Inn; chloi lili.-
To( I nclilorocl IIIMIO
Ti !<:liloro,:tlicnc

(I
Carcln-
Clasal-
1 icat Inn
A
1)2
112
112
1*2
H2
5
6
y
5
1
.s.
El'A Flow to West Flow
fanc<;r Median
Potency Reported
Factor Concentration
ko-day/mg l'9/l
.2
.n4
.5
.1
.1
x
x
(
x
x
x
iolj
10, ND
"'-S
10 ,
10 j
\n
Maximum Median
Reported Excess0 Reported
Concentration Lifetime Concentration
|ig/l Cancer Risk |i - Hondotcctable
Jluc)u.los data  from monitoring wells MH-5, MH-6, MH-7, MH-lt, and HW-9.
''includes d.ita  from monllorlng wellu MH-1, HH-3, and MW-10.
ch.iscd on inaxlmuiii repot tcil concentrations.  I.llctlme average drinking water Intake Is assumed to be 2 I/day; body weight  Is
 .i^uiucd lo  be  70 kg.
 1,1-Dlcliloroetbeno was detected In one monitoring well sample only.
IJDR283/072

-------
                                                                        17.
                                                                    Table  4
                                                   C3WAR1SCN OF DAILY IKTAKE TO RTTCvDJCI  DOSE4
                                                             DRINKING HATS! DiGESTION
                                                               HID-STATX DISPOSAL RI
    C!:e»ieBi

Sariua

Bls(2-et2ylbixyl)
CSrcaius  (»3P

Ctrsriaa  («6r
TiT.-butyl
 , 1-31C.-.1
  etr.ece
HA^qareie

Kev.yler.e
Reference
. Sose
s.: x ic-J
: x ic':
:.9 x 1C'4
i.c , ::=
I.C x 13'-
i.- x i;':
. . Z x 13 "
..: x 13 '
'.•_• x ::'•
..; x ic'3
.* x '.Z ~
.: x i:--'
.Z x '.Z ~
.c x :;-:
.: x ::-•"
. C x 1C "
" x ' '"' "
r.ov
Median Maxlaus
Reported Repartee
Concentration Coacestratioc
64 456
sr 1:4
NE 7.:
to 11
NS 11
* so
!C .-O
NV sr
j=
«
6; ir,:c3
• s:
5.5 6e
sr ;c
NT See.
e
• 56
d
'_o West
Cstloated
Daily I.-.LaXi
(Dl;
1.3 x 10"2
4.0 x 10"3
2.1 x 10'4
3.: x io'4
3.: « 1C"4
Neq.
Nea.
Nee.
Sec.
1.4 x 13"4
4.? x 10":
Nee.
1.3 x 1C":
'. .i X 1C
Neq.
- - .„-«
... x .3
1.7 x 10*"

DI/PfD
0.16
o.;c
O.T:
Nee.
3.36
Neq.
N«.
N.q.
Neq.
3.10
:..'j
Seq.
C. 19
:.:&
Seq .
See.
:.:i

DI
Exceeds
?.f:?
No
No
No
No
No
No
No
No
So
No
Yes
No
No
So
No
No
No
                                                         Mediae
                                                       Reported
                                                      oncentrati
                                                        (us/II

                                                          58
                                                          ND

                                                          ND

                                                          ND

                                                          ND

                                                          ND


                                                          ND


                                                          ND


                                                          ND

                                                           *


                                                          60:
                                                          NC


                                                           5

                                                          ND
   Maxiaua
   Reported
Concentration
    ILC/'.I

     ICO
                                                                                                                 No

                                                                                                                  9

                                                                                                                  6
                                                                                                                          Litisdicl
                                                                                                                            Dally
                                                                                                                           Intajce
                                                                                                                 5.6
                                                                                                                          •. „   ,,•«  .
                                                                                                                          ..9 x 1C    Sec.
               1.5  x  1C

                 Neq.

               3.C  x  1C""
              1.6 x  1C"*

              I.C x  1C

              1.6 x  1C"2
                                                                                                                                      Seq.
                                                                                                                                                c:
                                                                                                                                              Lxce*:
Nc

Sc

Nc

So

S:


Nc


So


So

Sc

So


Nc

Sc

Sc


No

Sc

So
*ll!e'.i:e averace crlzJtir.;
 tc ;e 73 kc.
 is assures -.3 ie C l/, iii .>«-9.
'lulusei data iro= :o:i;3r:i; »ells m-\, '&-1, iii W-iC.
Sec.
     « J:» er sore ai  :azi:*s  -ai  So:-ietecia±:* ;:;ceitrstlo=s =£ '_'.e iecs;;;ue=t.
       C^^Sc" ^e :et.emze^ recau»e  ::'  "^rsc&c'ial  ;oct££«a:.i32 oi sanies.

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                                            18.
COMPONENTS
LANDFILL CONTENTS
Repair Existing Cap
Soil/Clay Cap
Multilayer Cap
Surface Water Controls
LAGOON WASTES
Insitu Solidification
Lagoon Cap
GROUNDWATER
Alternate Water Supply
Extraction
Onsite Treatment
Offsite DischargeTo
Surface Water
PONDED LEACHATE
AND INTERIM
EXPANSION AREA
LEACHATE
Control/ Collection
Onsite Treatment,
Offsite Discharge to
Surface Water
Control'Collection
Offsite Treatment
SITE-WIDE
COMPONENTS
Predesign Investigations
Monitoring
Fence
Institutional Controls
Road Work
Present Worth ($1000)
ALTERNATIVES
1



N
O
A
C
T
I
O
"- N




*
•


180
2


•

•


*

•
•
•
•
3,400
3


•r

•

*


•
•
•
•
7,500
4


•
I
•

•


•
•
•
•
12,000
5
•

• •
;
•


•
.
• •
•
•
•
16,000
6
•

•
•
•

•


•
•
•
•
19,000
7

•
•
;
•

•


•
•
•
•
22,000
* Includes monitoring of two residential wells.
                                                                Figure  4
                                                                PRESENT WORTH COST OF
                                                                ASSEMBLED ALTERNATIVES
                                                                Mid-Stale Disposal FS

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                                    -19-

    Up to 236,000 gallons of ponded surface water consisting of leachate
    diluted with precipitation will be collected and treated during the first
    year.  For those alternatives without an on-site treatment system,  vacuum-
    trucks will be used to collect the leachate and dispose of it off-site to
    a POIW or industrial treatment facility.  For the alternatives with an on-
    site treatment system, the leachate will be collected and transferred to
   - the treatment facility by a series of hoses and pumps.

    The Interim Expansion area leachate collection system will continue to
    operate and approximately 5,000 to 10,000 gallons of leachate per week
    will be treated on-site or taken off-site to a POIW or an industrial
    treatment facility depending on the alternative.  Leachate collection will
    continue for as long as the groundwater is extracted or until leachate is
    no longer generated.

    It will be necessary to reconstruct as much as 800 feet of road near the
    sludge lagoon.

    Fencing will be installed around the perimeter of the site to restrict
    public access.  Signs warning of the presence and potential danger  of
    hazardous materials will be posted on the fence to further discourage
    unautborized access to the site.  The fence for the no-action alternative
    encompasses only the areas of contamination; the fence included in  the
    final remedial action encompasses the areas of proposed activities.

    Regular monitoring of groundwater, surface water, and landfill gas  will
    be considered as a part of all the alternatives except the no-action  .
    alternative.  Seven new groundwater monitoring wells will be installed
    off-site, and ten landfill gas monitoring wells will be installed around
    the perimeter of the site to monitor sub-surface gas migration.  Data.
    from new and existing wells and from surface water will be used to
    monitor the remedial action.

ALTERNATIVE 1 - NO-ACTION

The no-action alternative provides a baseline for comparing the alternatives.
The risk assessment shows that the greatest risk under the no-action
alternative is by exposure either through further migration of the
contaminated groundwater to the southeast and west, or through future
development of the site or properties to the west of the site.  To offer some
protection to the public, the no-action alternative includes a fence and an
additional round of residential well sampling.

Alternative 1 does not meet any State or Federal ARARs.  See Table 5.

ALTERNATIVE 2 - ALTERNATIVE MATER SUPPLY. REPAIR CAP

Alternative 2 consists of repairing and maintaining the existing landfill

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                                                                                           Table-5
                                                                       CGKPLIAMCC MITO ARABS EVALUATION or flNAL ALTERMATI VIS*
                                                                                       hID-STATE DISPtbAJ. fS
Crllarla
*et ground*
•alar protection
ARARi el In* all*
boundary. Itinltor—
Ing and allainala
will* aur* ARARi «r»
Alt*rnatl»* 1
Croundnalar Rr*rdl*-
tlon. Repair Cap
Mould clean the ground-
water to drinking
Malar lUmUrdj at tbe
• II* bouniuiry. Tl>*
• ftluant oould ar»t
•uifare «alar gualltf
dlacharg* Malta.
 >cat loo-a  I.
Mould aia«t actloo-
a[«cl(lc ARARj for
groundwalrr trealaenl
•yatema and •onllorlng.
Mould nut aw«t alat*
ARARs tor cap
oooatructlon.

Sa* AltaroallTa ].
                                                                                             See Alternative I.
                                                                                             S*« AllematUa ].
                                                                                             Sa« Altartutlt* I.
                                                                                                                           AllamalUa }
                                                                                                                       Soll/Clar Cap, Sludg*
                                                                                                                          Golldlflrallon.
                                                                                                                          Altarnata Uatar
                                                                                                 Mould avcntuallf aw«t
                                                                                                 groundvatar
                                                                                                 piotactlon ARARa at
                                                                                                 tlic  all* boundary
                                                                                                 through natural
                                                                                                 altenuallon.   until
                                                                                                 thiHi, •onltorlag «nd
                                                                                                 all«inat* vater
                                                                                                 • u|>ply ansur*  AAAJta
                                                                                                 • r*  not oc*«Nlad lo
                                                                                                 drinking *>tar.

                                                                                                 9M  Altarnatlr* I.
                            Hr*U tha atata
                            rvgulatlona
                            concerning
                            construct loo of •
                            •olid »a«ta lit* cap.
                                                                                                                       S*a Altamatlta ].
                                                                                                            AllenuitUa 4
                                                                                                         Soll/Clar Cap, Sludge
                                                                                                          Sol 141 dial Ion. and
                                                                                                        G»ound»ater B«»>dlal loo
                                                                                                                         t
                                                                                                       SM AltarutUa 1.
                                                                                                                Allaroatl>* T
                                                                                                               Hultllafer  Cap,
                                                                                                            liidgn Solldlflratlon,
                                                                                                               and Groundwalar
                                                                                                                 Rtarill.l Inn

                                                                                                             SM AltaiD*tl>* 1.
                                                                                                                                                 SM AltarealUa 1.
Mould »eel groundvattr
IrMtMnt, Bonltorlng,
and c«p oonatructlon
ARARa.
                                                                                                                                                 SM Altaroatlfa J.
                                                                                                                                                                              8*« Allcnutlt*  1.
                                                                                                                                                                              S«a AltamatUa 6.
                                                                                                                                                                              SM AllamaUra 1.
              2  through 7 contain an altarnat* velar aupplf, e>ooltorlng,  and fane log.
I*U16/0)9

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                                     -21-

caps, regrading the lagoon cover, and installing new wells in uncontaminated
areas for potentially affected residents.  The leachate collection system in
the Interim Expansion Area would be continually pjmped and the leachate would
be treated off-site at a POIW or industrial waste-water treatment facility.
Surface water run-off from the landfills would be directed off-site.   Leachate
surface seeps would be collected by a separate drainage system and treated
off-site with other collected leachate.  Landfill gas monitoring wells would
be installed near the perimeter of the site.

In this alternative, the landfills and lagoon are covered to prevent direct
contact, to deter further contamination of groundwater, and to prevent
leachate from contaminating the off-site surface water to levels which exceed
chronic Federal Water Quality Criteria for the protection of aquatic
organisms.  In addition, this alternative will prevent ingestion of
contaminated groundwater which exceeds WDNR health standards or poses' a
potential risk of cancer in excess of 10~6.

Prerdesign activities for this alternative would include the development of a
v/ork plan, landfill gas sampling and air quality modeling, along with the
additional investigations previously mentioned.

Alternative 2 does not meet WOMR solid waste regulation ARARs' for cap
construction.  See Table 5.

                   UNEfrJATER REMED3

This alternative includes groundwater extraction and treatment in addition to
an alternative water supply.  The extraction rate is estimated to be 100 gpm,
which is based on 9 gpm from each of eleven extraction wells.  The treatment
system would consist of aeration and filtration.  This alternative also
includes repairing the existing caps through some minor grading and filling,
as well as constructing surface water collection trenches.  No additional
source control actions would be implemented with this alternative.  The
existing leachate collection system would be pumped and the leachate taken to
the on-site treatment system.  The groundwater extraction and treatment
systems will need to operate for as long as the landfills remain a threat to
the environment and public health, which is estimated at more than 30 years.
Since seepage of leachate may continue in the future, existing ponded
leachate, future leachate, and surface water collected from the site will be
treated in the on-site treatment system.  It has been assuimed that this flow
will be small compared to the groundwater flow and, therefore, will have
little hydraulic effect on the treatment system.

This alternative would: 1. provide new covers on the landfills and lagoon to
prevent direct contact, 2. protect against ingestion of contaminated ground-
water, and 3. protect against further off-site migration of contaminated
groundvater.

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                                     -22-
Pre-design activities would include work plan development, landfill gas
sanpling and air quality modeling, groundwater treatability studies, and
aquifer testing including the further investigations previously mentioned.

Alternative 3 does not meet WENR solid waste regulation ARARs'for cap
construction.  See Table 5.

ALTERNATIVE 4 - SLUDGE SCLiTOIFICATION. GROUNDMATER REMEDIATION, REPAIR CAP'

Alternative 4 incorporates the groundwater extraction and treatment system of
Alternative 3 and in addition, provides for solidification of the sludge in
the lagoon.  This would be determined during pre-design.  Solidification may
be necessary to provide bearing capacity for the cover.  Several engineering
technologies may be explored for stabilization of the lagoon sludge.
Stabilization will occur only as an engineering requirement if necessary to
support the cap.  A new soil/clay cap will be constructed in either event that
will fulfill federal and state landfill cap requirements.

Ponded leachate would be treated in the on-site groundwater system and
repair/grading and revegetation of the current landfill caps would be done to
control erosion and minimize further ponding of surface water.

A monitoring program would be designed to provide information for the design
and operation of the extraction systems.  Operation and maintenance of this
alternative would be required for as long as the landfills remain a hazard to
public health and the environment.  The goals of this alternative are: 1.
provide cover for the landfills; 2. prevent direct contact; 3.  increase the
bearing capacity of the sludge if necessary so a soil/clay cap could be
installed; 4. mitigate further groundwater contamination, which would reduce
off-site migration of contaminated groundwater, and 5. prevent leachate from
contaminating the off-site surface water.

Alternative 4 also includes pre-design activities, such as developing a work
plan, landfill gas sampling, air modeling, groundwater and sludge treatability
testing, aquifer testing, and further investigations.

Alternative 4 does not meet WENR solid waste regulations.

ALTERNATIVE 5 - SOIL/CLAY CAPS. SLUDGE SOLIDIFICAnCM. AND'ALTERNATIVE
r.vATER SUPPLY

Alternative 5 includes a new soil/clay cap over the Old Mound and Interim
Expansion Landfills.  This alternative also includes a new cap over the sludge
lagoon and solidification/stabilization of the sludge, if necessary, as
described in Alternative 4.  An alternate water supply, as well as
institutional controls and monitoring of groundwater; will be included.

Within a year after installing the cap and solidifying the sludge lagoon,
leachate production is expected to decrease significantly.  Residents will
be protected from potentially contaminated groundwater by new water supply
-.veils.  (!•£•,/ users would be protected by institutional controls, groundwater

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                                     -23-

 monitoring,  and connection into the alternate water supply.)  Because there
 would'be no off-site migration control,  there may be some degree of  future
 risk from drinking water off-site.   However, the RI showed no off-site
 contamination in the shallow portion of  the aquifer and the risk from
 contaminated groundwater on-site was estimated  to be quite low.  In  addition,
 natural attenuation is anticipated to reduce contaminant -levels since
 continued leachate production would be curtailed as a  result of the  caps.
 Ponded leachate, and leachate collected  in the  Interim Expansion area would be
.taken off-site and disposed at a POIW or industrial wastewater treatment
 plant.  As a result of the source-control action, future surface water
 collected on-site is anticipated to be .clean and would be directed to natural
 surface water drainage ways.

 The goals of Alternative 5 are:   1.  prevent direct contact with the  landfills
 and lagoon,  while minimizing leachate production.  As  leachate production
 decreases, the groundwater will gradually meet  WDNR standards and  10~6 cancer*
 risk levels for ingestion.   If the sludge bearing capacity is not  sufficient
 to allow installation of the cap, the sludge will be stabilized.   Pre-design
 activities will determine if this is necessary; 2. protect against ingestion
 of contaminated groundwater and, 3.  prevent leachate from contaminating the
 off-site surface water.

 The pre-design activities required to implement Alternative 5 include
 developing a work plan,  landfill gas sampling and air  quality modeling,
 sludge treatability testing,  and testing of the existing cap to determine  if
 it is in suitable condition to use as a  barrier layer  with the new cap.

 In addition, as previously mentioned, pre-design activities for this selected
 alternative also include the installation of a  minimum of three deep bedrock
 wells to obtain information about the groundwater vertical gradients.  If
 there is a downward flow component,  samples will be taken to determine if
 there is contamination in the lower portion of  the aquifer.

 A monitoring program will be developed to monitor potential future off-site
 migration of contaminants.   An initial round of samples will be taken and.
 analyzed for hazardous compounds found on-site.

 Approximately seven new off-site monitoring wells will be installed  to gather
 water level information to supplement existing  information relating  to off-
 site horizontal flow gradients.   The wells will also serve as a way  to monitor
 potential future off-site migration of contaminants.   An initial round of
 samples will be taken from these wells and analyzed for hazardous  compounds
 during pre-design activities.

 I-t>re information about the residential wells adjacent  to the site  will be
 collected, either in the form of well logs or by using a downhole  magnet to
 find the depth of casing.  In addition,  another round  of samples will be drawn
 and analyzed.

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                                     -24-

New soil/clay caps will be designed to meet WENR solid waste ARARs.
Groundwater ARARs are expected to be met over time. The performance of the
remedy will be monitored and if groundwater ARARs are not attained, a
supplemental study will be conducted.  Until then, monitoring and. an alternate
water supply will ensure ARARs are not exceeded in drinking water.  See
Table 5.

ALTERNATIVE 6 - SOIL/CT-AY ("APS, SLUDGE SOLIDIFICATION. AND' GRQUMXvATER
RET-FTXDVnOIM

This alternative provides a soil/clay cap over the three areas, as well as
the groundwater remediation and the alternate water supply in Alternative 3.
By including a source control measure that limits water infiltration through
the waste, groundwnter contamination under the site is expected to be reduced
significantly in 10 to 20 years.  The groundwater extraction and treatment
system will prevent future off-site migration of the contaminants.  Once the
groundwater treatment system is discontinued, monitoring of the groundwater
will continue on an annual basis.  When five consecutive years of monitoring
has shown the groundwater is reduced to the acceptable standards, the
monitoring would be reduced to once every 5 years.  Ponded leachate collected
on the site arid leachate from the Interim Expansion area will be treated in
the grourSwater treatment system.  The surface water collected during future
activities will be directed to the surface water bodies.

The goals of Alternative 6 are the same as those of Alternative 5, in addition
to initially preventing off-site migration of groundwater exceeding WENR
standards and 10~^ cancer risk levels' for ingestion.

Pre-design activity requirements are anticipated to be those described in
Alternative 4 plus some testing of the existing cap to determine its suit-
ability for use in a new cap.

Alternative 6 complies with all ARARs:  See Table 5.

ALTERNATIVE 7 - MULTILAYER CAP. SLUDGE SOLIDIFICATION . AND' GRQUMKvATER
This alternative is the same as Alternative 6 except a multilayer cap is used
over the landfills and the solidified sludge.  This cap provides more
protection and reliability; however, it is not anticipated to noticeably
affect the time estimate for the groundwater action to achieve clean-up
standards.  Leachate production would decrease significantly over the existing
conditions (over 99 percent) , resulting in reduced future contaminant levels
in the groundwater.  Therefore, the prospect of meeting acceptable standards
in the aquifer below the site through groundwater extraction and treatment is
greater with this alternative than with Alternative 6.  All time estimates are
based on limited data and would need revision after additional aquifer test
results were available.  This alternative contains the other components as
described in Alternative 6 including the same goals and pre-design
requi rements .

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                                    -25-

Alternative 7 complies with all ARARs;  See Table 5.

VIII.-  SUM^XRY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES

The alternatives are evaluated by balancing technical considerations
(implementability) with the cost and protectiveness (effectiveness)  of
the alternatives.  This evaluation determines the most cost-effective
alternative that will meet the objectives of the feasibility study for
implementation at the Mid-State Disposal Site.  The alternatives are evaluated
against the nine criteria recommended by U. S..EPA (U.S. EPA, 1987).   The
criteria are as follows: overall protection of public health and the
environment; compliance with State and Federal regulations, which are referred
to as Applicable or Relevant and Appropriate Regulations (ARARs) ; long term
effectiveness; implementability; short-term effectiveness; reduction of
toxicity, mobility and volume; cost; state acceptance; and community
acceptance.  See Table 6.

A.  Overall protection of human health and the environment.

    A' no-action alternative would not be effective in protecting either human
    health or the- environment.  Alternative 1 provides some protection through
    limited access by fencing and through residential monitoring.

    Alternative 2 protects public health and the environment through
    maintenance of caps, an alternate water supply, institutional controls and
    by controlling surface run-off.

    Alternatives 3 and 4 protect the public health and the environment through
    maintenance of the caps and groundwater extraction and treatment.
    Alternative 4 offers added protection by stabilizing the sludge and
    constructing a nev cap for the lagoon.

    Alternative 5 provides greater protection to the public health and the
    environment than alternatives 1 through 4 by combining the effects of an
    alternate water supply, stabilization of the sludge in the lagoon and the
    construction of ne«r caps.
    Alternate 6 includes provisions of alternative 5 and Arids groundwater
    remediation for the protection against potential future groundwater
    contamination.

    Alternative 7 includes the provisions of alternative 6, but it would
    provide only slightly greater protection of poblic health and the
    environment through the increased effectiveness of multilayer caps.

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                                                                                         Tabled
                                                                      suwunr or DCTAII.ID rvAi.iiATinN or riwu. ALTBIMATIVIS"
                                                                                     MID-STATE DISPOSAL fS
     Criteria
Shnrt-tara
effectiveness.
Long-tens
e f feel I vrn
per f oraMvui
            «a
Reduction of  IOB-
Icily, e«rf.lllty.
and volume.
Coapltaooa  with
ABAHa.
Overall  protection
of public hraltb
and environment.
                          Alternative 1
                      	Ho Art Inn	

                      Hot effective U pro-
                      tact Ing (Mibllc n*altb
                      anil environment.   Ho
                      worker a lo protect.
Hot protective or
effective.  Haa I ha
giMlesl amount of
future rl»k.
00 Innu-ter*
tenance.
                                                 Alternative )
                                               Crouodwatrr Remediation,
                                                    Bfpalr Cap	 .
                                                                            Alternative 4          Alternative 5
                                                                        Sludqe Soll'dlfInetlon,     Soil/Clay Cap,
                                                                        Groundwater Reacdla-   Sludge Solidification,
                                                                           tlon. Rejialr Cap    Alternate Hater Supply.
                                                                     See Alternative I.
                            Alternative 1
                           Allrinet a Mater
                          Supply,  Rrfalr Cap

                        Greatly rexlune*
                        future rlak reliably.
                        Mould be en ongoing
                        alternative.  Htial
                        protective of
                        c««aninlt* and worker*
                        during Implementation.
Greatly reduce* future  Crestly  r*duc** future   Stiller to Alternative Provide* Improved re-
future rlek reliably,   rlik  reliably.  Regulr** 1 eicrpt greater lell- liability of aounre
yet leguliea  long-lera  ealotanance of treat*    ability that sludge    control actions.
                                                Sludge solidification
                                                •ay produce odor*
                                                during
                                                laplraentatlon.  Hay
                                                be some risk to
                                                community and worker*, production 75%.
                                                                       Potential risk to
Provide* further
reduction In future
rlak than Alterna-
tives 2, ), 4 by
reducing laachate
                                                                                                                     worker* and community
                                                                                                                     during Implementation.
                                    Also ha*  monitoring and ealnle-  eent system.
                                              nance of  cxnrara.  Re-
                                              liability of Institu-
                                              tional controls I*
                                              less than an e»tract loo
                                              ayslee.
                                                                                              will no longer1 affect   Reliability of Instl-
                                                                                              tbe environment.        tut local controle I*
                                                                                                                     l*a« than an antract-
                                                                                                      i '              Ion ayateai.
Ho reduction of toi-
Iclty, anblllty, or
volume.
                      Vary easy lo Imple-
                      ment.
Doe* not meet any
AJtAAS.
                      la tha least  protec-
                      tive  of  public hraltb
                      and tha  milrniaient.
                                              Baa Alternative I
                                                   ta construct
                                             and oparat*.
                                                                     taducaa loluaa of ooo-
                                                                     taalnatad growujvatar.
                                                Reduce* volume of con- Reduce* mobility of
                                                tamlnsted groundwater. oootasilnanla by u*e
                                                Solidification reduce* of solidification.
                                                •obllliatlon of conla- Alao reduce* amount
                                                • Inuta In the cludg*. of leechate produced
                                                                       by 75 percent.

                        tasy lo construct.       Difficult to solidify  Difficult  to ooo-
                        oprrallon of  treataent   laqoon because of con- alruct cap, easier
                        syste* requires  revular  alilerabl* aaterlal*    to operate becaua*
                        attention to  eanf        handling.  Difficult   of no treatment
                        detail* for • long llae. to operate treaLaeot   *7*t*si.
 Praaanl-vortb coat.  J1BO.OOO
                        Doae not  evet NTMR
                        Solid Naate regula-
                        tlona. Ma* not a*at
                        crtra>lcal-ap«clf Ic
                        AHARa for drlnllog
                        •alar.

                        Provide*  protection
                        agalnat rlak to buaan
                        health througb
                        alternate xaler
                        anpplfi Inat Itutlootl
                        controle, and
                        maintaining, corert.
                        Protectt  eurface vatar
                        by control ling aurfaoa
                        runoff.
                                              i1,400.000
                                                                     Coaplla* »lth ground-    fie* Altemattr* 1.
                                                                     •ater ctxaelcal-
                                                                     •pvclflc dlichar4*
                                                                     Haiti.  Doea not  Met
                                                                     W>K» Solid Hajte
                                                                     ragulallooa.
                                                                                                                          lM »llb all
                                                Protect* huaan health
                                                and Ibe enotronaent
                                                througb eource control
                                                actions and groundoatar
                                                eilractlon.  CXnctluo
                                                •or* reliable than
                                                InatItullonal controls
                                                for protecting potential
                                                oav uaaa of the
                                                aquifer.
                                                                                              Se* Alternatlir* }.
                                                                                                                                                Alt a mat IT* t            Alternative  7
                                                                                                                                             Boll/Clay Cap. Sludge   Multilayer  Cap,  Sludge
                                                                                                                                              Solidification, and      Solidification,  and
                                                                                                                                              Croundwatar Reaedtatton Groundwater  Remediation
                                                                      J7,iOO,OOO
                                                                                              SI], 000,000
                                                                                                                     $16,000,000
                                                                                                                        HIM Met atandarda for
                                                                                                                        offalt* grouDdvatar ID
                                                                                                                        10 to 10 yaaxa.  Much
                                                                                                                        reduction of future
                                                                                                                        rlik.  Potential rtik
                                                                                                                        lo  norkeri and
                                                                                                                        coaaunltf.  Laachata
                                                                                                                        production r«duc*d 75%.
                                                                                                                        Pro*ld*« locreaaed
                                                                                                                        reliability and !•••
                                                                                                                        long-ten ainigiaant.
                                                                                                                     ARARa.
                                                                                               Elallar to Alternative
                                                                                               I.  Cap would reduce ,
                                                                                               future contaalnatIon of
                                                                                               aquifer even further
                                                                                               than exletlng cover.
                                                                                                                                                 Slallar to Alterna-
                                                                                                                                                 tive 4, eioepl ajore
                                                                                                                                                 llkalf to aret *tan-
                                                                                                                                                 darda ID tlM eallaate.
                                                                                                                                                 Leactiale production
                                                                                                                                                 nducvd 99 percent.
                                                                                                                                                 Potential rlek to
                                                                                                                                                 •orkar* and coaanmlty.
                                                                                                                                                 Blallar to Alternative
                                                                                                                                                 i.  Long-lane rellUilllty
                                                                                                                                                 of aultlleyer cap batter
                                                                                                                                                 tbaa loll/clay cap.
                                                                                                                        Slallar to Alterna-
                                                                                                                        tive! 1 and 4.  Al.o
                                                                                                                        reduce! leadiate
                                                                                                                        product loo by 75%.
                                                                                                                        Mor* difficult to
                                                                                                                        coojtruet Altematlva*
                                                                                                                        1 - i.  Operation
                                                                                                                        requlr*B*nta alallar to
                                                                                                                        Alternative J.
                                                                                                                                              SM Alternative S.
                                                                                                H0at protective becaua*
                                                                                                of active aquifer
                                                                                                rretoratloo and
                                                                                                laachat* reduction.
                                                                                                                                                 Slallar to Alterna-
                                                                                                                                                 tives I and I.  Alao
                                                                                                                                                 reduce* leadiate
                                                                                                                                                 production by 99*.
                                                                                                                                                 Moat difficult altani*-
                                                                                                                                                 tlve to cooitruct
                                                                                                                                                 becauae of liner.
                                                                                                                                                 Operation requlreaaota
                                                                                                                                                 aUllar to Alternative
                                                                                                                                                 1.

                                                                                                                                                 See Alternative 5.
                                                                                                                                                                       See Altematlvi
                                                                                                                                              $n,OOO,OOO
 *Allernatlvra 3 througb 7 contain an alternate water *uppl>,  Bonltorlng, and fencing.

 Cleanup period* and percent leecbata reduction are  belt  eitlaatea bated on eany (lapllfylng aaiuaiptloD* and are presented for cooperative purpoaea only.
                                                                                                                                                                       SI], 000,000
 Muuw/oce

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                                    -27-

B.  Compliance with State and Federal Regulations (ARARs)

    SARA requires that remedial actions meet legally applicable or relevant
    and appropriate requirements of other environmental laws.   These laws
   • may include:  The Toxic Substances Control Act, the Safe Drinking Water
    Act, the Clean Air Act, the Clean Water Act, the Solid Waste Disposal
    Act (RCRA), and any State law which has stricter requirements than the
    corresponding Federal law.          <

    Applicable requirements are clean-up standards, standards of control,
    and other substantive environmental protection requirements, criteria or
    limitations promulgated under Federal or State Law that specifically
    address a hazardous substance, pollutant, contaminant, remedial action,
    location or other circumstance at a site.  A requirement is "applicable"
    if the remedial action or circumstances at the site satisfy all the  .
    jurisdictional pre-requisites of the requirement.

    Relevant and/or appropriate requirements are clean-up standards,
    standards -of control, and other environmental protection requirements,
    criteria or limitations promulgated under Federal or State law that,
    while not legally "applicable" to a hazardous substance, pollutant,
    contaminant, remedial action, location or circumstance at a site, address
    problems or situations sufficiently similar to those encountered at the
    site that their use is well suited to that site.

    "A requirement that is judged to be relevant and appropriate must be
    complied with to the same degree as if it were applicable.  However, there
    is more discretion in this determination;  it is possible for only part
    of a requirement to be considered relevant and appropriate, the rest
    being dismissed if judged not to be relevant and appropriate in a given
    case" (Interim Guidance on Compliance with Applicable or Relevant and
    Appropriate Requirements, 52 FR 32496, August 27, 1987).

    The remedial actions developed in the feasibility study (FS) were
    analyzed for compliance with ARARs, based on the statutory requirements
    outlined above.  There are three divisions of potential ARARs identified
    for review; chemical-specific, action-specific, and location-specific.

    Chemical-specific ARARs are based on exposure levels for public health
    and the environment.  Action-specific ARARs include established technology
    and performance, design or other similar action specific controls or
    regulations.  Location-specific requirements include design  requiranents
    or activity restrictions based on geographical or physical position of the
    site and its surrounding area.  No location-specific ARARs were identified
    for the Mid-State site.  See Table 5 for compliance with ARARs evaluation
    of final alternatives.

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                                     -28-

The following ARARs are potentially applicable or relevant and appropriate for
the Mid-State site.
       ARARS
      CQMMEM'S
State
Groundwater Quality Regulations
(NR 140)

Solid Waste Regulations (NR 500-520)
NR 508

NR. 506.07(3), NR 504.04(e)
NR 508.04(2)

NR 506  .08(3), NR 504.07 NR 514.07
CH 516

NR. 200, NR 217", NR 219, CH 147
Water Quality standards (IR 100
102, 107, 108) NR 102, NR 104

NR 108
Groundwater E>ctraction Wells
(NR 112)
Air Pollution Control Standards
(CH 400-499)
Federal

C-.A—40 CFR Parts 122,125,403'
CAA—National Air Quality
Standards for Total Suspended
Particulates (40 CFR Part 129.105,
750)

OSHA—General Industry Standards
(29 CFR Part 9010)
Groundwater standards and
monitoring requirements.

Monitoring requirements for
solid waste landfills.

Landfill gas standards and
requirements.

Solid waste landfill cap
standards and requirements.

Discharge of wasted/otter to
surface water requirements.

Stream classifications and
standards.

Wastewater treatment or
pretreatment plan review and
standards.

Prohibits injection wells.
Standards for series of wells
withdrawing more than 70 gpm.

Monitoring requirements.
Standards for release to air
via vents, flares, strippers.
Requirements for discharge to
the Rock Creek, Eau Pleine
River, or their tributaries.

IVfey be applicable during cap
installation and sludge
solidification.
Applicable to worker safety.

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                                     -29-

OSHA—Recordkeeping, Reporting and              Applicable to construction
Related Regulations                             records.

D.O.T. Rules for the Transportation             Transport of contaminated
of Hazardous Materials (49 CFR Parts            material requirements.
107,171.1-171.500)

   Alternatives 5 through 7 meet and are expected to continue'to meet, all
   applicable or relevant and appropriate requirements (ARARs).

   The-State of Wisconsin Groundwater-Quality Regulation (NR 140) is an ARAR
   that specifies groundvater enforcement standards.  Compliance must be met
   within 300 feet of the waste disposal unit or the site property boundary,
   which ever is less.

   A monitoring program will be implemented to insure NR 140 is met.

   Alternatives 2 and 5 are expected to comply with NR 140 through natural
   attenuation over time.  An alternate water supply will ensure ARARs are
   not exceeded in drinking water for those furnished the alternate water
   supply^.  Alternatives 3, 4, 6, and 7 will comply with NR 140 through
   groundvSater extraction and treatment.  Alternatives 5-7 meet WDNR
   requirements for solid waste landfill caps, alternatives 2-4 do not.

   As part of the solid waste regulation air emissions from landfill gas
   will be monitored, and if limitations are exceeded at the point of
   emission for carcinogens, flaring will be necessary to meet this portion
   of the ARAR.   If emission limits for carcinogens are met, estimates
   will be made of the ambient air impact through dispersion modeling using
   emission rates for acute toxics.

   The regulations promulgated pursuant to the Resource Conservation and
   Recovery Act (RCRA), 42 U.S.C. Sections 6901, et seq., are not
   "applicable" to this site.  The RCRA regulations which governs,
   Hazardous Waste Treatment, Storage and Disposal Facilities  (40 CFR
   Parts 264 and 265) did not become effective until November 19, 1980.
   The landfill ceased accepting wastes prior to that date.

   Those RCRA regulations addressing solid waste disposal activities  (40
   CFR Parts 241 and 256, primarily) do not have direct application to
   individual facilities but rather provide for an enforcement program to
   be administered by the states pursuant to a Solid Waste Management
   Plan.

   Though both Subtitle C and Subtitle D are relevant to the remedy for
   the Mid State Landfill, the Subtitle D provisions relating to
   capping/covering the landfill are deemed more appropriate.  (None of
   the alternatives under consideration involve excavation, physical
   redistribution, or treatment of the waste which would make those

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    Subtitle C  regulations applicable to  "management" of waste).  The
    appropriateness determination  is dependent on whether substantive
    requirements are meant to address sufficiently similar circumstances
    as  those present at the specific site to make them particularly well
    suited to that site.  The caps that will be installed will meet the
    performance standards for landfill/surface impoundment covers as
    required in MR 504, MR 506, NR 514 and NR 516.

    At  this  time it is not anticipated that any ARAR waivers will be
    needed for  the alternatives evaluated.

C.  Bnplementability

    All the  alternatives are easily implemented and do not have any
    significant obstacles.  The alternatives implementing capping utilize
    proven techniques.  Groundwater extraction and treatment is also a
    proven technology and -will require extensive monitoring.  Stabili-
    zation vill require some effort to implement and will require odor
    control.  Leachate collection  and gas venting techniques used for
    alternatives 2 through 7 are also commonly used and proven
    techniques.

D.  Short-Term  Effectiveness

    Alternative 1 is not effective in protecting the public health and the
    environment because there is no reduction of risk.  Remedial
    objectives  in the FS will not  be obtained and, in addition, water
    quality  criteria will not be met.

    Alternatives 2 and 3 greatly reduce future risk.  Risk to community and
    workers  during implementation  is limited.

    Alternatives 4 through 7 may cause odors during stabilization and may
    involve  some risk to workers.

    Alternatives 5 through 7 provide further protection by reducing
    leachate production by at least 75%.

'E.  Long-Term Effectiveness

    Alternative 1 wr>uld not be effective  in addressing contamination at
    the site as it does not reduce exposure risks to the receptor
    population.  The alternate water supply in alternatives 2 through 7
    greatly  reduces exposures of ingestion to potential receptors.

    Alternative 4 is similar to alternative 3, but alternative 4 provides
    greater  reliability because the stabilization and capping of the
    sludge vill prevent direct contact of the waste and limit the
    production  of leachate.

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                                   -31-

   Alternatives 5 through 7 provide reliability of source control through
   new caps.  Alternative 7 has the greatest reliability for source
   control with the multi-layer caps as compared to soil/clay caps.
   Alternatives 6 and 7 provide greater reliability with the extraction
   system as compared to institutional controls in alternatives 2 and 5.

   Alternatives 2 through 7 would require long-term maintenance in order
   to retain their effectiveness.

F. Reduction of Toxicity, Mobility, and Volume.

  •None of the alternatives will reduce the toxicity or volume of the
   wastes at the site because all landfill waste, which will remain in
   place, are not subject to on-site treatment.

   Alternatives 1 and 2 will have no effect on the mobility of the wastes.

   Alternatives 3, 4, 6, and 7 reduce the volume of contaminated
   groundwater through extraction and treatment.

   Alternatives 5r 6 and 7 are all designed to reduce the mobility of the
   wastes.  As the quality of the cap is inproved from alternative 5 to
   alternative 7, the reduction in mobility becomes more effective.

G. Cost

   Each alternative was evaluated for estimated costs of implementation.
   Estimated costs include capital costs as well as annual operation and
   maintenance costs.  The net present worth of these cost, provides the
   basis for cost comparison.

   The present worth analysis was performed on all remedial alternatives
   using a 5 percent discount (interest) rate over a period of 30 years.

   Inflation was not considered in preparing the present worth costs and
   a depreciation of 100 percent was assumed.  The present worth costs
   for each alternative are summarized in Table 7.

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                                    -32-


                                 Table 7.

                   COST EVALUATION OF FINAL ALTERNATIVES

Criteria     Total capital    First year   Subsequent years    Present-worth
                 cost          O&M cost       O&M cost             cost

Alternative   $119,000       $27,700          $2,100             $180,000
1 No Action

Alternative   $1,800,000     $220,000'         $100,000           $3,400,000
2 Alternate
Water Supply,
Repair Cap

Alternative   $4,000,000     $370,000         $210,000           $7,500,000
3 Groundwater
Remediation
Repair Cap

Alternative   $8,600,000     $390,000         $220,000           $12,000,000
4 Sludge
Solidification
Groundwater
Remediation,
Repair Cap                                                    '

Alternative   $14,000,000    $220,000         $100,000           $16,000,000
5 Soil/Clay
Cap, Sludge
Solidification
and Alternate
Water Supply

Alternative   $16,000,000    $380,000'         $210,000           $19,000,000
6 Soil/Clay
Cap, Sludge
Solidification
and Groundvater
Remediation

Alternative  $19,000,000      $380,000        $210,000           $22,000,000
7 r-Uiti layer
Cap, Sludge
Solidification
and Ground^Hter
Rerriediation

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                                     -33-

  H.   State Acceptance

      The Wisconsin Department of Natural Resources  (WDNR)  is supportive
      of remediation at the Mid-State Disposal Inc.  site.   WDNR  fully
      concurs with installation of new  caps and the  stabilization of  the
    •  lagoon sludge.   The WDNR believes less expensive technologies than
      solidification with fly ash and kiln  dust may  be appropriate for  the
      lagoon sludge.   These technologies will be explored during pre-design.
      The U.S. EPA and the WDNR agree that  the most  cost effective tech-
      nology that will meet the objectives  of the feasibility study will
      be implemented.

      Although contamination was not found  off-site, it is  not certain  that
      the plume did not sink through fractures in the bedrock.   To better
      understand the ground-water conditions, a minimum of three  deep  wells
      will be installed in the bedrock  section of the aquifer during  pre-
      design activities.   In the event  contamination is found at levels that
      exceed Federal or State standards for groundwater, a  phased feasibility
      study addressing groundwater conditions will be developed  and the need
      for remediation will be determined.   In addition, U.S. EPA has  agreed
      to model the movement of contaminated groundwater coining from the
      landfills and the lagoon in the shallow portion of the aquifer.

  I.   Community Acceptance

      A public comment period was opened from July 25, 1988 through August
      23, 1988 and a public meeting was held July 28, 1988  to explain the
      preferred remedy and solicit comments from the public.  The results of
      the meeting and comments received from the public show the community  is
      extremely concerned about their property values. Their main interest
      is for the U.S. Government to purchase all the properties  surrounding
      the site and offer an alternate water supply.   In the absence of  a  buy-
      out, the majority of the citizens support the  recommended  alternative.
      These comments will be addressed  in the attached Responsiveness
      Summary.

DC.  SFTFYTFT)
  The U.S. EPA, in conjunction with the WDNR,  selects Alternative 5  as the
  final remedy for the site based on an across the board evaluation  of
  all alternatives against selected criteria which include SARA Section
  121 requirements, implementability, long and short term effective-
  ness, cost effectiveness, public health, and environmental impacts.
  Section 121 of SARA requires that all ren>edies for Superfund sites be
  protective of human health c_- -1 the environment, and comply with applicable
  or relevant and appropriate Federal and State requirements.   The selected
  remedy at the Mid-State site has the following major components:

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                                   -34-

                  - Alternate residential water supply.

                  - New soil/clay caps for the lagoon and landfills.

                  - Improvement of surface water drainage.

                  - Off-site treatment of leachate.

                  - Site fencing and sign posting.

                  - On-site road reconstruction.

                  - Institutional controls.

                  - Long-term monitoring of groundwater,  surface water
                    and landfill gas to determine the effectiveness of
                    above measures and to provide an early indication of
                    the need for further actions.

The following components will be evaluated during the pre-design stage:

                  - Landfill gas flaring.

                  - Sludge Stabilization.

The pre-design work at the Mid-State site will entail the collection of
additional field data.  Based on an evaluation of these data, the above two
(2) components may be implemented.

As part of the pre-design activities for this selected remedy, a minimum of
three bedrock wells will be installed to determine if any contamination
exists in the deeper portion of the aquifer.  An analyses will be conducted
on samples from these wells.  If contamination is found,  a report will be
prepared analyzing the significance of the results and recommending any
necessary additional investigation to determine the extent of bedrock
contamination.  Based on the results of this report, if concentrations are
in excess of Federal or State groundwater standards, a phased feasibility
study will be prepared, will evaluate alternatives,  and if necessary, will
remedy the groundwater.

It is expected that the new caps over the lagoon and landfills will
decrease leachate production by 75% and thereby decrease the potential for
further contamination of groundwater on site.  With less contaminated
groundwater on site, the potential for contaminated groundwater moving off
site  is also decreased.  In addition, it is expected that biodegradation
and attenuation will cause contamination levels to decrease over time.
Consequently, the U.S. EPA predicts compliance with the State of
Wisconsin's Groundvater Quality Regulation (NR 140)  over time.  Approxi-
mately seven new wells will be installed to be used in conjunction with
existing monitoring wells to monitor remedy perfonrwr.ee.   In addition,

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                                    -35-

these wells will gather  information concerning off-site horizontal flow
gradients.  If the caps  are not effective in decreasing groundwater
contamination to comply  with MR 140 in the shallow- aquifer, a phased
feasibility study will be prepared and will evaluate alternatives to remedy
the groundwater.

It  is expected the new cover will protect potential receptors from
unacceptable  cancer  risk levels by a significant reduction of direct
.contact  exposure.

Section  121  (c) of SARA  requires that on sites where contaminants remain,
the remedial  action  will be reviewed at least every five years to assure
human health  and the environment are protected.  This requirement will be
fulfilled through monitoring.

In  addition,  the Mid-State disposal site shall not be deleted from the
National Priorities  List (NFL) until all of the above concerns are
satisfied.

X.  STATUTORY '-DETERMEMATIONS

    The remedy selected must satisfy the requirements of section  121 of SARA
    and meet the following requirements:

A.  Be protective of Human Health and the Environment

    The  remedy selerted  is based on potential future endangerment to public
    health, welfare  and  the environment.  Site file records provide
    reasonable evidence  that substantial quantities of hazardous substances
    and  pollutants exist in the landfill waste.

    The  chosen alternative is protective of human health and the environ-
    ment.  The fencing,  institutional controls and capping all provide
    protection from  direct contact with contaminated materials.  Capping of
    the  landfills and lagoon also reduces percolation and significantly
    reduces the migration of contaminants into groundwater and surface
    water.

    The  alternate residential water supply will protect the public from the
    threat of potential  exposure to contaminated groundwater.  Monitoring
    of the groundwater and surface water will identify any failures of the
    containment system installed at the landfill.  Should elevated levels
    of contaminants  be detected, additional corrective measures  will be
    taken to  abate any threat.

B.  Attain Applicable or Relevant and Appropriate Requirements (ARARs)

    The  U.S.  EPA's selection of site capping will comply with applicable
    state solid waste landfill regulations.

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                                   -36-
                                   **,.
    The selected remedial alternative will also comply with specific
    public  health and environmental requirements.   These ARARs are called
    "chemical-specific" requirements.  Public health and environmental
    ARARs expressed as chemical-specific limits or requirements will be
    addressed by routine monitoring of groundwater, surface water, and
    vented gas.

C.  Be Cost-Effective

    The selected remedy will comply with relevant portions of the WDNR
    solid hazardous waste landfill closure and post-closure ARARs.  The
    range of alternative actions that meet closure and post-closure
    requirements is very limited.  The chosen alternative is cost-
    effective since it is the least expensive alternative that satisfies
    the regulations.  Cost-effectiveness of Alternative 5, the chosen
    alternative, is established relative to alternatives 6 and 7, which
    would cost more and essentially meet the same ARARs without signifi-
    cant increase in benefit to human health and the environment.

    Alternative 7 has the highest capital cost due to the multi-layer
    cap.  The multi-layer cap does not provide a significant increase of
    protection to -justify the added cost over alternative 5.  The
    alternatives with the extraction and treatment system have the highest
    operation and maintenance cost.

    Although an extraction and treatment system for groundwater is very
    protective, the extra costs are not warranted because there is no
    contamination off-site and the alternate water supply provides
    protection against drinking groundwater that exceeds a 10~6 cancer risk
    level.  Therefore, alternative 5 has been selected as the most cost
    effective alternative which will meet all ARARs over time.

D.  Utilize Permanent Solutions and Alternative Treatment.Technologies or
    Resource Recovery Technologies to the Maximum Extent Practicable

    A permanent remedy involving treatment or recovery technologies was not
    selected for the Mid-State Disposal site.  Permanent remedies including
    pumping and treatment of groundwater, and incineration of the sludge in
    the lagoon were evaluated and judged to be not practicable for the
    Mid-State Disposal site.

E.  Address whether the preference for treatment that reduces toxicity,
    mobility, or volume as a principle element is satisfied.

    SARA mandates a preference for the selection of a remedy that
    permanently and significantly reduces the volume, toxicity or  mobility
    of the hazardous substance, pollutant and contaminant.

    Application of treatment technologies that satisfy this preference
    were evaluated for the Mid-State Disposal si*-" and round to be imprac-
    ticable tor the following reasons:

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                            -37-
                 "*.

Current data indicates that contaminated groundwater exists only
within the legal boundaries of the site at very low levels.  The
threat to nearby residences is considered low and as a result of the
alternate  water supply and the new soil/clay caps proposed in
alternative 5,.the threat is virtually eliminated.  Consequently,
pumping and treatment of groundwater for contaminants is not cost
effective.

The size of the landfills would cause the cost of removal and
treatment or disposal to be extremely high (over 30 million dollars
in construction costs).  In addition, segregation of hazardous "waste
from non-hazardous waste would be impractical.  The volume of sludge
material, 28,000 cubic yards,  makes incineration not feasible when
other technologies will provide protection and be more cost
effective.

Full ARAR compliance will be achieved over time by landfill closure
which would be protective of human health and be cost effective.

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                          Responsiveness Summary
                            Mid-State Disposal
The U.S. EPA must consider public Garments before making the final
decision to select and implement a remedial action.   Public participation
is required in Superfund projects according to the Comprehensive
Environmental Response, Compensation, and Liability Act of 1980 (CERCIA)
as amended by the Superfund Amendments and Reauthorization Act of 1986
(SARA).

The comment period for the Mid-State Disposal site was from July 24,  1988
to August 23, 1988.  During that time, comments on the proposed plan were
received from the public through the public meeting and through written
coirments.  A report developed by .the PRP's consultant was also submitted
detailing concerns with the RI and FS reports and suggesting technologies
for use at the site.  The comments from these sources have been grouped
and summarized.  Garments on the RI are responded to, followed by comments
on the FS and then comments on the Proposed Plan.

RET-EDLM, INVESTIGATION COMVENTS

1.  Specific areas of incomplete data were identified in a comment.  These
areas included extent of groundwater contamination with depth, proximity
of waste rfeterials- to bedrock and upper aquifer, definition of the
groundwater mound within the landfill, existence of a contaminant plume
migrating off-site, the depths of the aquifer, and the characteristics of
the sludge in the sludge lagoon.

Response.  The issues of the proximity of the waste to groundwater and
the existence of a groundwater mound have been determined.  Any mound
under the landfill is not significant enough to saturate any of the waste
as evidenced by the borings for two landfill wells and calculations made.
The other issues will be further investigated during the predesign
activities.

2.  Comments were raised about the use of qualified data in the RI report,
including the risk assessment.

Response.  No data that were qualified as present due' to contamination of
blanks were used in the report or in the risk assessment.  Other qualified
data were used with caution; however, the qualification was for the actual
concentration number and not for the contaminant's presence at the
approximate level indicated.  Of the seven data used in determining the
excess cancer risk for ingesting the groundwater (see Table 5-12 in the RI
report), only one concentration was qualified.  The other concentrations
used were without any type of qualification.

3.  No exposure concentration modeling was performed for use in the risk
assessment.  There was some concern over concentrations used..

Response.  The no-action scenario assumes access to the site, regardless
of )>ow unlikely such access would be.  Concentrations trom wells directly
under the landfill were not used since it is more likely new wells would

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                                    -2-

be installed next to the landfill instead of on the landfill.   Also infor-
mation was only used from onsite wells that represented groundwater that
would be flowing in the directions indicated in the risk assessment.  No
concentrations from these wells were discarded from use in the risk
assessment unless there was evidence that the data were incorrect.   Even
if a value was high, it was included in keeping with EFA's policy of using
best estimates and conservative upper bound estimates for all exposure
point chemical concentrations.  Maximum values were used to provide a
conservative estimate.  The possible over- or under-estimates caused by
using these assumptions were addressed in the risk assessment in tables
5-19 and 5-20.

4.  A comment was made about some of the difficulties experienced during
the RI, such as difficulty of obtaining background data and not filtering
samples from residential wells.

Response.   Because of the poor housekeeping at the site, there were some
difficulties in collecting background soil data.  The residential well
samples were not filtered, so a direct comparison with onsite metal levels
could not be made.  However, as the commentor said, these difficulties do
not affecfe the conclusions of the report.  The risk assessment (which
compares the data to health based levels and not to background or other
data) did not identify a significant risk from the on-site soil using
existing data or from the residential wells using unfiltered data.

5.  A comment was made that leachate sampling and analytical results from
the RI were not compared to typical leachate quality from aging landfills.

Response.   Comparing leachate results to results from another landfill is
difficult since each site is unique and the results of that comparison may
lead to erroneous conclusions.  There are no truly "typical" leachate
quality results.

6.  Concerns were raised about the calculations made for hydraulic
conductivity, specifically over the consideration of the radial difference
in the borehole versus the standpipe.  Also there was a concern that the
values did not match the soil-rock description given.

Response.   The correct radius for the well casing and the sand pack were
used in calculating hydraulic conductivity.  The equation on page 9 of
Appendix C shows the squared radius in the numerator is for the well
casing and the radius in the denominator of the first logarithmic term is
for the sand pack.

The soil descriptions used in Table 11-1-4-4 and Table 6 of Appendix G were
not meant to identify the material as part of a soil classification
system.  Rather they were intended to show which of the geologic strata at
the site were being tested and are only provided for the convenience of
the reader.

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                                   -3-
 7.   Two comments  were made  about the  limited reference list in the FS and
 about lack of  details on some assumptions and models used.

 Response.   The FS was "based on available information and the RI report;
 however, standard engineering operating procedures were not referenced.
 To  further clarify the  sources of  information in the FS the following
 references are provided:

.CH2I-I HILL, Inc. ,  REM IV COST ESTIMATING GUIDE'. March 1987

 CH2M HILL, Inc. Internal-Technology Data Base, 1986

 U.S.  EPA Environmental  Protection  Agency, Evaluating Cover Systems for
 Solid and  H^.arriniic; waste.  EPA-IAG-D7-1097.  MERL, September 1982.

 The details of models used  are part of the  files but were not included in
 the report to  keep the  report readable.

 8.   A comment  wasMnade  that the state regulations  (NR 500) could be met by
 augmenting the existing cap with sufficient cover to establish the re-
 quired frost protection and root zone.

 Response.   On  page 5-8  of the FS report it  is said, "It may be possible to
 use some of the existing cap as a  barrier layer if it is in good
 condition. However, for ... cost,  it  was assumed that the integrity of the
 existing cap is not sufficient."   To  meet NR 500 standards, the clay
 barrier layer  needs a saturated hydraulic conductivity of 10-7 cm/s.  It
 is  unlikely that  the two foot cap  that has  not been protected from the
 elements for 8 years has such a stringent conductivity.  Predesign
 activities will be conducted to determine the integrity of the existing  •
 cap to determine  if it  can  be used as the barrier layer in the soil/clay
 cap.

 9.   There  UBS  some concern  over the details of the proposed soil/clay cap.
 It  was thought that the cap included  too many components.

 Response.   The cap components such as the 3.5 feet of soil and the
 drainage layer were based on a review of existing state standards to
 establish  the  required  frost protection and root zone, and on good
 engineering judgement,  to provide  drainage  of surface water to preserve
 the integrity  of  the barrier layer.

 10.   A comment was made suggesting that landfill gas collection be limited
 to  existing hot spots of gas production.  This would reduce the cost of
 gas collection.

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                                    -4-

Response. . While areas of the landfill containing the most biodegradable
materials may be producing the most gas at the current time, in a few
years, these materials will be degraded and other less biodegradable
materials will be producing gas in greater quantities in other areas of
the landfill.  It would be inefficient to then install gas collection
pipes in those areas through the new cap.  If there are hot spots of gas
production in the landfill at this time, it would be efficient to install
a collection well at that spot in addition to the proposed collection
system.  If the collection trenches are properly placed, the additional
well may not be necessary.

11.  It was commented that because of gas pressures in the sludge lagoon,
the proposed stabilization technique would not be "successful".  Another
stabilization technique based on experience with the nearby Weyerhaeuser
sludge lagoons was suggested which included a bark layer followed by a
reinforcing geotextile, sand/gravel layer, impermeable geomembrane, and
soil.

Response.  Nothing in the comment indicated to EPA. that the proposed
stabilization-technique in the FS report would not be effective in
increasing the bearing capacity of the sludge.  This technique is
conservative and depending on results of bearing capacity tests and other
sludge characterization tests, other technologies would also be invest
tigated during the design of the action.  There is some concern that the
bark proposed in the comment would not be effective at stabilizing the
sludge.  Bark materials eventually decompose.  The process of decom-
position usually results in a significant loss of volume wnich would
ultimately cause the cap to sink into the sludge.  Because the comment
made indicated that the conmentor had experience with the suggested
technology, EPA would be pleased to review the details of this technology
and review the existing data on its effectiveness.

12.  A comment was made that because of the low concentrations of
contaminants and because contamination was not found outside of the design
management zone (DMZ) (as determined by WDNR) there was little impetus for
groundwater extraction and treatment.

Response.  EPA agrees that health based standards (primary MCLs and WOSIR
standards) have not been exceeded outside the DMZ and therefore has not
selected an alternative with groundwater extraction and treatment at this
time.  However, EPA. will continue monitoring and will provide an alternate
water supply as a protective measure.

13.  There was a question about the purpose of the groundwater treatment
cjvTil-p'Ti rlpc;rrihpri in 1-ho P.^ rpr-nr-i-
system described in the FS report.
Response.  The goal of the groundwater treatment system was to be
protective of aquatic organisms in the tributary proposed to receive the
extracted ground-.v-ater.   While iron is not a health threat to humans, it is
to aquatic organisms.  There are federal standards regulating the iron
concentrations allowed to discharge into surface water bodies.  The

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                                   -5-

groundwater would be extracted because of possible future health threats
to humans posed by organic compounds.

14.  A comment was made that individual home treatment units would be a
more cost-effective treatment than an onsite treatment system.

Response.  EPA feels that an alternate water supply would be more
protective in the long-term than hone treatment units and therefore
developed alternatives around that component.  However, EPA agrees with
the comment that an alternate water supply is more cost-effective than
groundwater extraction and onsite treatment and therefore has selected an
alternative with an alternate water supply.

15.  A perimeter drain with onsite or offsite treatment of the leachate to
mitigate the impacts of the groundwater was suggested.

Response.  If the comment is suggesting a perimeter drain at the site
boundary, the FS has considered this possibility.   However, for the drain
to intercept the potentially contaminated groundwater, it needs to be
fairly deep and excavated into the bedrock, (very expensive) (see the
discussion on "page 5-23 entitled extraction trenches).  If the comment is
referring*-to a perimeter drain around the landfills, this may decrease
future groundwater contamination by collecting leachate from surface
seeps; however, the proposed gravel blankets used under the new caps would
collect this leachate.  EPA will reconsider the use of groundwater
extraction drains after predesign activities.

16.  A comment was made that the FS did not describe the rationale used to
select final alternatives from the operable unit alternatives remaining
after screening.

Response.  As EPA policy dictates, operable unit alternatives were
evaluated with respect to effectiveness, implementability, and cost.  Once
these alternatives vere screened to the most cost-effective alternatives
that would be protective and would meet the response objectives, they were
combined into site-wide alternatives.  The rationale for the types of
combinations used was based on common sense and on the same criteria
mentioned above.  It was necessary to develop a reasonable number of
alternatives that would still be cost-effective while meeting the response
objectives.  Most of the possible combinations were evaluated if it is
assumed that certain combinations of components are necessary (such as
onsite treatment of leachate with onsite groundwater treatment).  One that
was not evaluated vas use of the multi-layer cap with no sludge solidifi-
fication.  This would be very expensive yet there would be little control
over the sludge lagoon.  This was not considered a cost-effective
alternative.

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                                    -6-
PRDPOSED PLAN COMMENTS

17.  The majority of comments on the Proposed Plan expressed the desire of
the comnunity to have the U.S. Government buy all the property surrounding
and near the site.

Response.

Section 111 of the Comprehensive Environmental Response Compensation, and
Liability Act of 1980 (CERCLA) as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA) addresses acquisition costs under
Section 104.  Section 104(j) states that property may be purchased if it
is necessary to conduct a remedial action.  At the Mid-State site, it is
not necessary to purchase property to conduct a remedial action. To do so
would be an unauthorized use of the fund.  Although the Government cannot
pirchase the property surrounding the Mid-State site, the U.S. EPA will
ensure protection of public health and the environment through
implementation of the selected remedial action alternative.

18.  An additional proposed alternative was identified by a commentor.
The suggestion included repairing and upgrading the existing cap,
installing a perimeter leachate collection system, and using the materials
proposed in an earlier comment to stabilize the sludge lagoon.

Response.  The individual components of this proposed alternative were
addressed under the comments where they were first mentioned.  EPA
assumes that the commentor agrees with other components of the proposed
plan such as the proposed monitoring program, the alternate water supply,
the fence, the site perimeter landfill gas wells, etc.  Based on results
of pre-design activities, this proposed alternative may be investigated
since the axisting cap may meet MR 500 standards (although unlikely) and
elements of the commentors sludge stabilization technique may be usable
once-more information about its effectiveness is available.

19.  Several commentors remarked that the alternate water supply was a good
idea since it would be protective and may help increase property values.
It has been suggested that an alternate water supply be provided to all
residents near the landfill to promote good feelings among the residents.

Response.

U.S. EPA agrees that the alternate water supply is a useful component of
the alternative.  There are approximately nine residents near the site.
All of these residences will receive an alternate water supply rather tlian
the initial three of four considered that are downgradient.  Groundwater
contaminant modeling may be done to estimate the future flow of
ground-^ater.

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                                   -7-
20.  A comment was made that federal funds should be used if necessary to
remedy the site to the extent possible.

Response.

EPA agrees that federal funds will be used, if•necessary, to provide the
most cost-effective alternative to remedy the site.

21. It was suggested that contaminated groundwater/leachate may be
migrating north through the backfill material of the natural gas pipeline
that passes through the site.  A well should be installed during predesign
activities to determine if this is true.

Response.

The pipeline company was contacted and they say that natural materials
were used to backfill the trench once the pipeline was laid.  In this
case, it is not likely that contaminated groundwater would have
preferential migration along the pipeline to the north since this
direction is up-gradient (against) the natural flow directions, however,
EPA agrees this should be verified.  It will be added to pre-design
activities''.

MISTTTJANEOUS

22.  The Town of Cleveland feels they should not be a PRP at this site.

Response.

EPA is currently revising it's list of PRP parties.  There has not yet
been an agency decision as to whether the Town of Cleveland should be
deleted from the list of PRPs.

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