EPA Superfund
Record of Decision:
PB97-964112
EPA/541/R-97/114
January 1998
Scrap Processing Co., Inc.
Medford, WI
9/30/1997
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DECLARATION
SELECTED REMEDIAL ALTERNATIVE
FOR THE
SCRAP PROCESSING SITE
Medford, Wisconsin
Statement of Basis and Purpose
This decision document presents the selected remedial action for the Scrap Processing
Site, in Medford, Wisconsin, which was chosen in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA) of 1980, as
amended by the Superfund Amendments and Reauthorization Act (SARA) of 1986,
and, to the extent practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). This decision is based on the administrative record for this
site.
Assessment of the Site
Actual or threatened releases of hazardous substances from this site, if not addressed
by implementing the response action in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare, or the environment.
Description of the Selected Remedy
The purpose of this remedy is to eliminate or reduce migration of contaminants to the
groundwater and to reduce risks associated with exposure to the contaminated soils.
The major components of the selected remedy include:
• Excavation of lead-contaminated soils;
• Off-site disposal of excavated soils at a solid waste landfill;
• Use of institutional controls (such as fencing and groundwater & land use
restrictions) on site property to limit land and groundwater use;
• Installation of additional groundwater monitoring wells in the source area
next to the battery cracking building; and
• Monitoring of groundwater to ensure effectiveness of the remedial action
(soil removal) and determine if there is need for future active groundwater
remediation.
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Statutory Determinations
The selected remedy is protective of human health and the environment, complies with
Federal and State requirements that are legally applicable or relevant and appropriate
to the remedial action, and is cost effective.
Because this remedy will result in hazardous substances remaining on the site above
health-based levels, a review will be conducted within five years after commencement
of the remedial action to ensure that the remedy continues to provide adequate
protection of human health and the environment.
State Concurrence
The State of Wisconsin has indicated that it is in agreement with the selection of
Alternative E with a contingency for groundwater monitoring and remediation, if
needed, for remediation of the Scrap Processing Site and will provide U.S. EPA with a
letter of concurrence.
William E. Muno ( Date
Superfund Division Director
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TABLE OF CONTENTS
Topic
A. Site Location 1
B. Site History 1
C. Community Participation 3
D. Summary of Current Site Condition 5
E. Summary of Site Risks 21
F. Scope of the Remedy 28
G. Description of Alternatives 29
H. Summary of Comparative Analysis of Alternatives 34
I. The Selected Remedy 39
J. Documentation of Significant Changes 40
K. Statutory Determinations 40
L. Summary 44
M. Responsiveness Summary 45
N. Glossary 48
O. Administrative Record Index 50
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SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
Scrap Processing
A. SITE LOCATION AND DESCRIPTION
The Scrap Processing Site (the site) is a salvage yard and former battery cracking
facility that now operates as a scrap dealership and recycler. The site is located at 510
West Allman Street in Medford, Taylor County, Wisconsin. The site covers
approximately 15 acres and is located east of the Black River and city of Medford
property. See Figure 1.
B. SITE HISTORY AND ENFORCEMENT ACTIVITIES
The Scrap Processing Site is owned and operated by Mark and Pat Potaczek. They
are sons of the deceased original scrap yard owner and operator, Julius Potaczek. In
the mid-1950s, scrap yard operations began with activities that included crushing cars
and large appliances. From the 1950s until 1974, battery cracking occurred at a rate of
8,000 to 10,000 batteries per month. After that time, the battery cracking allegedly was
reduced, and finally ceased in the early 1980s.
In 1972, the Wisconsin Department of Natural Resources (WDNR) put the owner on
notice for mishandling batteries. As a result of citizen complaints that battery acid was
being released onto the ground and into the Black River, WDNR conducted site
inspections throughout the 1970s. In 1979, WDNR directed the owner of the Scrap
Processing site to cease battery cracking operations. Despite WDNR's directive,
cracking operations continued until the early 1980s.
WDNR obtained a 1983 court order requiring that the site owner hire an environmental
consulting firm to conduct site cleanup activities. The site owner retained Midstate
Environmental Consultants to conduct cleanup activities. Field activities began 18
months after the order was issued. Detailed information is not available about the
scope and objectives of the removal, time and money spent, or the nature and extent of
contamination. Additional removals and sampling efforts took place over the next few
years. In 1987, the last of the excavated contaminated soil was disposed properly off-
site.
In 1984, the Scrap Processing Site was officially placed on the National Priorities List
(NPL) and designated a Superfund site. In 1993, U.S. EPA requested that the site
owners clean up the site. The owners responded that it was financially impossible for
them to comply with U.S. EPA's request. In September 1993, U.S. EPA conducted an
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Figure 1 - Site Location
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emergency removal action in the area immediately surrounding the battery cracking
building (see Figure 2). Soil confirmed to have high concentrations of lead and
polychlorinated biphenyls (PCBs) was excavated from the south side of the battery-
cracking building. The outside wall of the battery cracking building, stained with PCB-
contaminated oil, was scarified with an air powered chisel. The excavated soil piles
were sent off site for proper disposal. The excavated areas were sampled to confirm
that the PCB-contaminated soils had been removed. The confirmatory samples
showed that the removal action had achieved the cleanup goals. U. S. EPA had
originally intended to address this site using its removal authorities. However, as site
activities progressed, U.S. EPA concluded that it was more appropriate to complete a
focused remedial investigation/ feasibility study (Focused RI/FS) for this site. That
Focused RI/FS was initiated in May 1992 and completed in August 1997. A proposed
plan was issued for public comment on August 25,1997 for a period of 30 days. The
Focused RI/FS and proposed plan are both in the Administrative Record.
C. COMMUNITY PARTICIPATION
The Responsiveness Summary in Section M discusses the involvement of the
community during the Focused RI/FS and remedy selection process and shows that the
public participation requirements of CERCLA Sections 113(k)(2)(i-v) and 117 have
been met at this site. This Record of Decision is based on the Administrative Record,
which is attached. In addition to the Responsiveness Summary several other activities
were done to keep the public informed and involved. Those activities include:
• Fact Sheets dated May 1992, September 1992, November 1993, and
August 1997.
• Update letters to the mailing list dated September 1,1992, August 31,
1993, March 7, 1994, April 15, 1994, June 30, 1994, and March 6, 1997.
• Public meetings held on May 12,1992, September 16,1992, November
16, 1993, and September 16, 1997. In addition, EPA representatives
attended a meeting sponsored by Taylor County on April 15,1991.
• Press releases were sent to Medford and Wausau-area media and
display advertisements were placed in the Medford Star News prior to all
public meetings.
• Information repository maintained at the Medford Public Library since
January 1992.
• Community Relations Plan completed in August 1992.
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Approximate Slt« Property LM
r;.v| Emergency Removal
Action Area
Figure 2 - Emergency Removal Area Map
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D. SUMMARY OF CURRENT SITE CONDITIONS
The Focused RI/FS Report documents the results of the remedial investigation at the
site. Additional information concerning site conditions may be found in that document,
which is in the Administrative Record.
The Scrap Processing site consists of a railroad spur, a cinder block building that
houses the office and indoor operations, a storage building where battery cracking took
place, an abandoned home, a shed, many miscellaneous piles of scrap metals, and
junked automobiles. The study area, which includes the facility property and adjacent
city property, covers about 15 acres. Land cover includes weedy vegetation, piles of
scrap materials, and unvegetated soil (see Figure 3).
Site topography is fairly flat, with some areas of irregular terrain. The western portion
of the study area slopes downhill, to city of Medford property and the Black River. This
area is swampy and lightly wooded. Several conveyances carry drainage and surface
runoff from the facility into the Black River (see Figure 3). The facility is outside the
500 year floodplain. Figure 4 is a site topography map.
Sewer, storm water, and water lines exist along AJIman Road, which is north of the
facility property. Power lines run along Allman Road, north of the site, and into a
substation. Power lines also run along the railroad tracks immediately east of the site.
A gas pipeline runs north of Allman Road.
Available geologic information indicates that the bedrock is primarily early to middle
Proterozoic crystalline igneous and metamorphic rock of the North American Pre-
cambrian shield. Numerous northeast-southwest trending faults are prominent in the
shield. Sedimentary rock units above the present-day bedrock were eroded and
removed by streams and glaciers, until no record of them remains in the region today.
The bedrock is in direct contact with overlying Pleistocene glacial moraine and outwash
deposits and recent alluvial deposits. In Taylor County, unconsolidated Pleistocene
and recent deposits (overburden) are up to 280 feet thick. The overburden is typically
thickest in northern Taylor County. In many places, no overburden is present, and
bedrock is exposed at the ground surface.
Surface water drainage throughout the region is poorly developed in the glacial terrain.
The region is characterized as geomorphically young. Area topography consists of low
rolling hills with many swampy areas in the valleys between the hills.
Streams in this region vary greatly in size and direction of flow. The south-flowing
Black River comes within about 100 feet of the northwest comer of the site. The Black
River is a tributary to the Mississippi River.
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\\ L__l Cracky I
/^s^*ju*y X
\ \ Form- StteUom
S_c-' Unlinvd Lagoon
Figure 3 - Site Drainage Locations Map
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Ground Swfe.ce Contour and
Devotion n feet Above Mean
Sea LeveL NGVD Datun
Figure 4 - Topographic Map
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On-site overburden consists of glacial ground moraine (till), with local outwash deposits
of sand and gravel. On-site borings encountered discontinuous clay, silt, sand and
gravel units in the glacial sediments. Clay and silt units are predominant.
Based on the distribution of grain sizes beneath the site, two overburden aquifers are
identified. A shallow sand and gravel aquifer extends from the surface to a depth
varying from 15 to 25 feet below ground surface and behaves as a water table aquifer.
The groundwater flow direction in this aquifer is to the west-northwest based on the
October 1995 groundwater readings. This aquifer is not used as a potable water source
on site or downgradient from the site. The shallow sand and gravel aquifer is
separated from a deeper overburden aquifer by a tight clay that serves as a confining
layer. The potentiometric surface of the deep overburden aquifer is above ground
level. The groundwater flow direction within the deeper aquifer is to the southwest
based on the October 1995 groundwater readings. This aquifer is used as a potable
water source onsite and at several homes near the site.
The higher total head in the deeper aquifer in addition to the tight clay between the two
aquifers will minimize downward leakage of water from the upper aquifer into the
deeper aquifer.
Based on the fact that the shallow aquifer is unconfined and that the deep aquifer
potentiometric surface is higher than the shallow groundwater level, vertical flow of
contaminants to the deep aquifer is unlikely. Additionally, it is possible that the Black
River may be acting as a "groundwater divide" preventing shallow groundwater flow
from migrating west past the river.
Most surrounding land use from the project site is recreational; however, some land use
is residential and light industrial. Medford City Park is along the Black River, west of
the site. The park has ball fields, concession stands, picnic tables, grills, paths,
playground equipment, and camping areas. From the park, people fish and wade in the
Black River. The city of Medford, population 4,025, lies within a 2-mile radius of the
site.
A mobile home park is northwest of the site; a power substation is directly north of the
site; the Medford Rail/Trail path is northeast of the site. Walkers, joggers, and
bicyclists use this 30-mile-long trail most of the year; snowmobilers use it in the winter
months.
East of the site are railroad tracks and small industrial facilities mixed with residences.
An apartment building is east of the path's entrance.
The WDNR Bureau of Endangered Resources indicates a natural area exists along the
Black River within 15 miles downstream from the site. Natural Heritage Inventory
8
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records from the early 1980s show that, at that time, this area contained high quality
examples of northern mesic forest and flood plain forest communities. Recently, the
area has been logged, and the effects of tree removal in the natural communities are
unknown.
Area drinking water sources include municipal and private wells; however, most
Medford residents rely on the municipal water system. Municipal wells are upgradient
from the site.
Surface and Subsurface Soils
The surface soil samples at the Scrap Processing site were field screened during the
pre-remedial investigation. Twenty-six surface soil samples with suspected benzene,
ethylbenzene, toluene, xylene (BETX) or polynuclear aromatic hydrocarbons (PAH)
contamination were collected and analyzed for target compound list (TCL) constituents.
Additionally, 12 surface soil samples that were suspected to contain metals
contamination were collected and analyzed for target analyte list (TAL) constituents.
No background samples were collected for laboratory analysis during the pre-remedial
investigation; therefore, these surface sample results are compared to the subsurface
background samples.
Forty-two subsurface soil samples, collected from 20 soil borings during remedial
investigation field activities in 1993, were analyzed for TAL and TCL constituents using
Contract Laboratory Program (CLP) protocols. Ten samples were taken from an
interval less than 2 feet below ground surface; the remaining samples were taken from
various depths, up to 18-feet deep. All soil samples were collected above the shallow
groundwater surface. Five subsurface soil samples were collected from five additional
borings drilled in the northwestern comer of the site in 1994. These samples were
analyzed for Volatile Organic Compounds (VOCs) and Base Neutral Acids (BNAs)
using CLP protocols. Two background samples also were obtained from boring SB01
north of the site. Background samples were analyzed for CLP TAL constituents.
Figure 5 shows soil boring sampling locations and results.
Fifteen surface soil samples and three subsurface soil samples were collected from
residential properties surrounding the site in October 1995. The samples were
collected to determine whether residents near the site have been exposed to lead and
other metals that may have migrated off site with airborne dust. The samples were
analyzed for TAL constituents using CLP protocols. A background sample (SS13) was
collected about 0.3 mile southwest of the site. Figure 6 shows locations of residential
soil samples. Table 1 summarizes the analytical results of the residential soil samples.
The table shows all lead concentrations in the soil samples. Those samples indicated
that the nearby residences are not being impacted by the site.
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SoK Bortnn tocotion ond
Identification Number
1> Organic Compound Concentrations or* m ug/kg.
2) Inorganic Compound Concentrations ore m ng/kg.
3) Data qualifier* are defined ft Appendix A.
4) AU detected organic compound concentrations are
shown for organic parameter*. Tor inorganic analytes,
only concentrations exceeding three times background
are shown.
S> Blank space* •w*cat« -that the or-gawc conpound
WOK not detected or that the nargontc anatyte
concentration dKi not exceed three tines background.
Figure 5 - Soil Boring Locations and sample Results Map
10
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Leend
* SUOK64)
Surf*c* Soft Sonpli Locator
Idtntificatpon M***r and
L*4d Concentration fog/kg)
Submrfac* Soft Sa^*»
LocetiOfx identification Nuntorr
and L*Od Concvntf-otton Cng/kg)
Figure 6 • Residential Soil Sampling Locations Map
l\
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Several organic compounds that were detected in low concentrations may be
laboratory artifacts. Acetone, 2-butanone, and toluene, all laboratory solvents, were
detected in about half of the on-site samples. Figure 7 summarizes the analytical
results of pre-remedial investigation on-site surface soil samples. The figure shows
inorganics that exceed background; it also shows detected organics. Subsurface soils
in the northeastern comer of the site are contaminated with VOCs, semi volatile organic
compounds (SVOCs), and pesticides. The predominant organics in this area are BETX
and PAH compounds. This contamination was caused by a leaking leaded gasoline
Underground Storage Tank (LIST) removed in 1990 and is clearly separated from the
contamination caused by battery cracking operations; it will be addressed under the
Wisconsin UST program. Organic compounds were detected in other on-site sampling
locations, but are not very prevalent.
Relatively low levels of organic compounds were detected in on-site surface soils.
These compounds, primarily consisting of PAHs, phthalates, and to a lesser extent
VOCs, are present at various locations across the site and are most prevalent in the
northeastern section. This area, near the front gate, is a high traffic area for customers
and site activities. The removed UST location, the excavated soil pile from that
removal, and an existing UST are within this section of the site. Subsurface soil
samples taken from locations all over the site indicate contamination from several
inorganics. Lead is the most common contaminant, found mostly in samples taken near
the ground surface. Contamination found in the surface soil samples does not appear
to be migrating deeper, into subsurface soils. Residential surface soil samples indicate
acceptable levels of inorganic substances. Contamination in the on-site surface soil
samples does not appear to be migrating into off-site residential surface soils.
Sediment and Surface Water
Nine river sediment samples were collected and analyzed for TAL and TCL
constituents. Background sample BS01, collected several hundred feet upstream from
the site, had the following detected organic compounds: di-n-butylphthalate, carbon
disulfide, 2-butanone, toluene, and delta-BHC. Toluene and 2-butanone, detected in
all but one sample, are common laboratory artifacts. Organic compounds detected in
any sample above the contract required quantitation limit are considered
contamination. Table 2 summarizes the analytical results of Black River sediment
samples. The table shows inorganics whose concentrations exceed three times
background; it also shows detected organics.
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1> Organic cofHMMjnd concentrations ore
Hi ug/kg.
Inorganic analyte concentrations are
kt ng/kg.
3> Data qualifiers ar« d«rtn*d m Appendix A.
4) For* argaMc conpaund*. ail
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Table 1- Residential Soil samples Results
SS01
39.8
SS02
6.0
SS03
11.1
SS04
30.1
SS05
15.6
SS06
8.0
SS07
8.0
SS08
24.7
SS09
11.8
SS10
10.7
SS11
8.6
SS12
10.4
SS13
15.6
SS14
5.8
SS15
9.6
SU01
6.1
SU02
16.2
SU03
19.2
Six river water samples were collected and analyzed for TAL and TCL constituents.
Background sample BW01, collected several hundred feet upstream from the site, had
no detectable organic compounds. Table 3 summarizes the analytical results of Black
River water samples. The table shows inorganics whose concentrations exceed three
times background; it also shows detected organics. Figure 8 shows sampling locations
for surface river water and river sediment samples.
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ItERTA ST
Legend
BVOl Block River Voter
Location and Identification
BS01 Rack Mv*r S«d»
Location and Identification Nixfeer
Figure 8 - Black River Surface Water and Sediment Sample Locations
15
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Table 2-BUck River Sediment Sample* Route
s T \i ffHwirmtfTtfy ^ w ' V^^I^K
Acetone
Acenaphtbylcac
Dtethylphthalate
Fluorene
Pbenantitne
Anthracene
Di-o-butbylphthalate
Flucranthcne
Pyrene
Benzo(a)AntnraceQG
Chrysene
bis(2-Elhylbexyl)pfathalate
Benzo(b)fluorantncne
Bcnzo(k)fluonnthenc
Benzo(»)pyTene
Indeno( 1 ^3 ':-- *>&
?'-J?~ •;/,'.'
***&'<
22
62
30
68
330
U
11.6
/• ' fSf*. -.S v
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Table 3 - Black River Surface Water Samples Results
Notes:
I.
2.
Smote concentrations are in ^w/Vfi for organic* *TH* mfl^B for inoffgp**ir*
For orgmic compounds, til detected concentrations are shown. For inorganics only concentrations exceeding three times background are shown.
Sampling data indicate the Black River sediments are contaminated with a variety of
VOCs, semivolatile organic compounds (SVOCs), and pesticides. Contamination
increases from sediment sample BS03, downstream to sediment sample BS08,
Contamination increases again further downstream (sediment sample BS05). This
contamination is not consistent with onsite surface soil contamination; therefore, it may
not be site related. Black River water does not appear to be contaminated with organic
compounds. Toluene, detected in one river water sample, may be a laboratory artifact.
Several metals are present in Black River sediments. Lead appears in elevated
concentrations in samples downstream from the site, except in sediment sample BS07.
Inorganic contaminants are highest in sediment samples BS03 and BS04. However,
these detections cannot be attributed to the site, since inorganic contaminants were
detected in the background sample too. Inorganic concentrations are lower at other
sampling locations. The evaluation of this data indicated that these conditions would
not pose adverse impacts to the biological resources at the site and adjacent habitats.
Black River water does not appear to be contaminated with inorganics. Aluminum was
detected in one river water sample at an elevated concentration.
Groundwater
In December 1992, efforts to sample existing monitoring wells MBS, MBD, MW1S,
MW2S, MW2D, and MP1-MP4 were partially successful. The deep wells, screened in
an artesian aquifer, were completely frozen shut in the casing. In October 1993, the
deep wells MBO, MW1D, and MW2D, were sampled. Two new shallow wells, MP5 and
MP6, also were sampled at this time. A second round of sampling was conducted in
April 1994. Monitoring well samples were analyzed for TAL and TCL constituents using
CLP protocols. Figure 9 summarizes the analytical results of both groundwater
sampling efforts and identifies monitoring well locations. The figure shows inorganics
with concentrations exceeding three times background; it also shows detected
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Concentration in uo/L
Concentration In ua/L
B-n-butyHahtholot
Concentration n uo/L
12-DkrtaroetheiK ZJ
Tnchioroe
TetracMaroe
I) All concentrations are « ug/L.
Data Qualifiers ore defMd m Appendix A.
3) Ml detected organic canpoml concentrations arc
shorn on tttt figure. Far MorgaNc analytes, only
concentrations exceedea three tMes backgrouxd
Wisconsin P*Ls and ESs are sho.n.
and/or the
4) Blank spaces matcate that the orpAnc compound
•am not detected or that the noraanlc analyic
concentration da not exceed three tines
backgroutd or the Wisconsin PALs and ESs
S) Concentrations enclosed m a dark box exceed
Wisconsin PALs. Concentrations that are shaded
exceed Wisconsin CS*.
Honltoma Well Location
and Identification Nunber
Figure 9 - Monitoring Wells Location and Sample Results Map
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organics. The shallow monitoring wells include wells MBS, MW1S, MW2S, and MP1
through MP6. Deep monitoring wells include MBD, MW1D and MW2D.
Three municipal wells, three private domestic wells, a Medford City Park well, and the
Scrap Processing facility well were sampled. The facility well sample was analyzed for
TCL and TAL groundwater parameters while the other well samples were analyzed for
TCL and TAL drinking water constituents. The wells are northeast and northwest of the
site. Figure 10 shows residential well locations. Table 4 below summarizes the
analytical results of residential well sampling. The table shows inorganics with
concentrations exceeding three times background; it also shows detected organics.
Based on the sample results from the currently installed monitoring wells it does not
appear that the shallow groundwater is contaminated with organic compounds above
NR 140 standards. However, the currently installed groundwater monitoring system
was not designed to specifically address the potential impacts to groundwater
associated with the leaking UST site. Two on-site monitoring well samples had
concentrations of chlorinated solvents below the quantitation limit. No organic
compounds were detected in the shallow background well sample. Acetone and
methylene chloride, common laboratory artifacts, also were detected at low
concentrations in the MW2S sample. During the 1993 sampling event, two organic
compounds were detected in low concentrations. Di-n-butylphthalate, detected in the
rinsate blank and in MP6, may not be attributed to the site and could be a laboratory
artifact. Toluene, detected in MP5, could be related to the UST contamination, which
will be addressed by the state UST program. Deep well samples do not indicate
contamination by organic compounds. Residential wells do not appear to be
contaminated by organic compounds. In one sample, 4,4'-DDT was detected below the
contract required quantitation limit.
Shallow groundwater appears to have elevated levels of several inorganic constituents,
including lead. Comparison with the Wisconsin Preventive Action Limits (WPAL) and
the Wisconsin Enforcement Standards (WES), public health groundwater quality
standards, indicate WPALs are slightly exceeded for five metals in six wells while WES
are not exceeded in any wells, except for iron and manganese which exceeded NR 140
WESs. However, it should be noted that iron and manganese were also detected at
high levels in the background wells, indicating that the exceedances are probably
related to natural groundwater quality. It should also be noted that the background
wells slightly exceed the lead WPAL of 1.5 //g/l. The deep background well sample has
the highest lead concentration of all well samples at 12.6 //g/l, while the shallow
background well has a lead concentration of 3.2 //g/l. Well samples collected from
MP5 and MP6 in October 1993 are the only filtered metals results. The samples were
the only ones filtered because they were very turbid. Deep monitoring well samples do
not indicate contamination with inorganic compounds. Lead concentrations in MBD
19
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Legend
RVD4 R««d«ntlal W»ll Sonpl* Location and
Idmtifica-ttOT Nuntwr.
Figure 10 - Residential Wells Location Map
20
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Table 4 - Residential Well Sample Results
Contaminants
4,4'-DDD
4,4'-DDT
Iron
Lead
Manganese
Sampling Locations
RW-01
0.0055
RW-09
4310
6
176
BttMO
0.0048
ceMntians arc shown. For moqganic antlyta, coocentntiacB exceeding three times backpmnd or the WPAL* and WES* are
Notes:
1. Concenbitians are in ug/1
2. For organic compound*, all detect
shown.
3. Conoentnlins highlited exceed either WPALs or WESs
(12.6 //9/I), the background well, and MW2D (5.2 Mg/l) slightly exceeded the WPAL.
Inorganic constituents were not detected in residential well samples.
E. SUMMARY OF SITE RISKS - (See Glossary in section N for definitions of
terms used in this section)
Based on analytical data collected during the Rl, a baseline risk assessment was
performed using site related contaminants. The baseline risk assessment assumes no
corrective action will take place and that no site use restrictions or institutional controls
such as fencing, ground water use restrictions or construction restrictions will be
imposed. The risk assessment determines actual or potential carcinogenic risks and/or
toxic effects the chemical contaminants at the site pose under current and future land
use assumptions using a four step process. The four step process includes:
contaminant identification, health effects assessment, exposure assessment, and risk
assessment.
1.
Contaminant Identification
The levels of contamination found in different media at the Site can be found in
Chapter 2.5 of the Focused RI/FS. Indicator parameters or chemicals of
potential concern were selected based on their toxicities, level of concentration
and widespread occurrence. The chemicals of potential concern are listed in
Table 5.
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Table 5 - Chemicals of Potential Concern
SemivolttileCOPCs
4-Methytphenol
Naphthalene
2-Metfiylnapbthalene
_. .• i i -• • •
i/ietnytpntnaiate
Fluorene
4-Nhroaniline
Pneiiaftuifeiie
Anthracene
Caibazok
Di-n-butylphthalate
Fluorantheoe
Pyrene
Butylbenzylphthalate
Bemo(a)Antfaraoene
Chrysene
bis(2-Etbylhexyl) phthalate
Benzo(b)fluonuithene
Benxo(k)fluorantheoe
Bemo^ajpyreoe
lndeno(l,2P3-cd)pyrcne
Benzo(g4U)perylene
Volatile COPCs
Methylene Chloride
Acetone
2-Butanone
Toluene
Xyfcne (total)
Pesteide/PCB COPCs
Heptachlor
AJdrin
Heptachlor Epoxide
Endosulfan I
Dteldrin
4,4'-DDE
Endrin
Endosulfan H
4,4-DDD
4.4--DDT
Endrin Aldehyde
Gamma-Chlordane
Aroclor-1254
Aroclor-J26JJ_.
Maximum
6000
.12000
16000
J-fW1
OOOU
6000
15000
6000
6000
6000
6000
6000
5500
5700
6000
5500
5500
6000
6000
6000
6000
6000
Maximum
3600
25000
3600
8800
360000
Maximum
6
6
14
11
11.5
32
37
22
44
97
22
20
1100
94Q
Minimum
175
22
23
o"n
as it
1961
5969
2347
3663
2465
4461
2293
1951
3253
2151
1428
3178
2181
2215
2202
2202
2346
95%UCL
1439
200415
286
3154
7832
95%UCL
2
2
3
3
4
13
9
9
23
20
7
4
204
259 .
22
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Metal OOPQj
Maximum Concentratinn f^g/frg}
Barium
ryllium
Cadmium
Chromium
Cobalt
Copper
Lead
23
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Table 6 - Health Effects of Site Contaminants Of Concern
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?ZS>''I''"'P ',, (r> ' - <: ,... '. " '""' ' ;^*0-
-------
2. Human Health Effects
The health effects for the contaminants of concern may be found in Table 6
above.
3. Exposure Assessment
The baseline risk assessment examined potential pathways of concern to human
health under both current and future land-use scenarios for the immediate site
property and surrounding area.
Pathways were selected for detailed evaluation under the following current-use
and future-use scenarios:
• Current and future site worker exposure to site surface soil contaminants
through incidental ingestion of soil, dermal contact, and inhalation of dust-
borne contaminants.
• Current and future site worker exposure to groundwater through
ingestion, dermal contact, and inhalation.
• Current and future site trespasser exposure to site surface soil
contaminants through incidental ingestion of soil, dermal contact, and
inhalation of dust-borne contaminants.
• Current and future resident exposure to groundwater from the Cook Well
(off-site residential well) through ingestion, dermal contact, and inhalation.
• Current and future child recreational visitor playing in the off-site area;
exposure to off-site and shoreline surface soil through incidental ingestion
of soil, dermal contact, and inhalation of dust-borne contaminants.
• Current and future adult recreational visitor walking the shoreline with
exposure to shoreline surface soil through incidental ingestion of soil,
dermal contact, and inhalation of dust-borne contaminants.
• Current and future child and adult recreational visitor fishing with
exposure to shoreline surface soil through incidental ingestion of soil,
dermal contact, and inhalation of dust-borne contaminants.
• Current and future child and adult recreational visitor fishing with
exposure to Black River water and sediment contaminants through dermal
contact.
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• Future exposure of on-site residents to contaminants in surface soil
through incidental ingestion of soil, dermal contact, and inhalation of dust-
borne contaminants.
• Future exposure of on-site residents to contaminants in groundwater
through ingestion, dermal contact, and inhalation.
4. Risk Characterization (see Glossary in section N for definitions of
risk terms used in this section)
For each potential human receptor, site-specific contaminants from all relevant
routes of exposure were evaluated. Both non-carcinogenic health effects and
carcinogenic risks were estimated. Additionally, a lead risk characterization was
performed. U.S. EPA does not provide toxicity data for lead because of unique
considerations related to the toxicology of this element. As an alternative to the
traditional risk assessment approach, U.S. EPA recommends modeling blood-
lead levels and comparing them to acceptable blood-lead concentrations. The
Integrated Exposure Uptake Biokinetic Model (IEUBK) and the expanded
methodology presented in the EPA Technical Review Workgroup for Lead
(TRW) "Review of a Methodology for Establishing Risk-Based Soil Remediation
Goals for Commercial Areas of the California Gulch Site", Leadville, Colorado
(California Gulch) were evaluated. The recommendations in the latter review
report have since been formalized in a more cohesive form in the EPA TRW
report "Recommendations of the Technical Review Workgroup for Lead for an
Interim Approach to Assessing Risks Associated with Adult Exposures to Lead in
Soil".
a. Non-Carcinogenic Health Risks
The hazard index for current and future site worker and future on-site
resident exceed the acceptable hazard index of 1.0. The combined
hazard index for soil and groundwater exposure is 2.1 for current and
future site workers. The combined hazard index for soil and groundwater
exposure pathways for a future on-site resident is 6.0.
b. Carcinogenic Health Risks
The potential excess lifetime cancer risk posed by the site exceeds the
acceptable risk range of 1X10"* to 1X10^ for the soil exposure
pathways under the future resident use scenario. Risks from soil
exposure pathways present carcinogenic risks in the range of 2 X 10 "*.
Carcinogenic effects are not a concern for any of the off-site populations.
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c. Lead Risk Evaluation
Because it was not possible to include lead in the risk estimates, lead
concentrations in soil were compared with levels recommended by the
State of Wisconsin NR 720. The reasonable maximum exposure (RME)
lead concentrations observed in on-site soils (4,570 mg/kg) and off-site
soils (1,300 mg/kg) are above the recommended soil cleanup level of 500
mg/kg- The Black River water had lead concentrations of 2.1 ug/L. Lead
was not detected in any of the deep groundwater wells. In addition, the
IEUBK and the recommendations in the TRW Review of a Methodology
for Establishing Risk-Based Soil Remediation Goals for Commercial
Areas at California Gulch were evaluated.
To determine if the IEUBK model would be utilized, additional surface soil
sample collection was required to determine whether lead had migrated
off-site via transport by airborne dust. The results of this sampling effort
were also used to determine whether dust analysis of indoor and outdoor
air was required which would be utilized in the IEUBK model calculations.
If off-site soil concentrations exceeded the background soil
concentrations, this would indicate that lead has migrated off site and that
the dust analysis would be warranted to support the use of the IEUBK
model and the methodology used at California Gulch to determine soil
cleanup levels. If the off-site soil concentrations did not exceed the
background concentration, then the current on-site surface soil results
would be used solely to determine cleanup levels with an expansion of
the methodology used at the California Gulch Superfund Site. The IEUBK
model is used to model lead exposure to a child while the methodology
used at California Gulch is used to model exposure to the fetus of a
female worker exposed on site.
Off-site surface soil sampling was conducted to determine if off-site
migration of lead had occurred. The highest off-site concentration was
found to be 39 parts per million (ppm) and the national background
concentration is 50 ppm in soil. Based on this sampling event and the
background concentrations, no additional sampling is required to support
the use of the IEUBK model since it is not required to determine offsite
cleanup levels.
The TRW recommendations to the California Gulch methodology were
utilized to determine an on-site soil cleanup level for lead. Risk based
remediation goals were calculated using an expansion of the
methodology used at the California Gulch Superfund Site. Based on site-
specific information, several parameters were varied, and it was
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determined that an individual geometric standard deviation (GSDi) of 1.7
and a soil and dust ingestion rate of 50 and 100 mg/day, and an absolute
absorption fraction of 0.1 and 0.12 would be most applicable to the Scrap
Processing site. These parameters provide risk based remediation goals
(RBRGs) in the range of 768 - 2148 mg/kg. If a conservative GSDi value
of 1.8, an intermediate absorption value of 0.1 (10%), and a conservative
ingestion rate of 100 mg/day is used, a RBRG of 922 mg/kg is obtained.
This value is considered to be appropriate for use at the Scrap
Processing Superfund Site. The calculated RBRG exceeds the
recommended soil clean up level of 500 mg/kg for lead in the State of
Wisconsin NR 270, and the final site RBRG is based on Wisconsin
ARARs.
The RBRG was used to identify the need to take a response action at the
site. The primary risk at the site is due to lead exposure. While the
Hazard Index (HI) and carcinogenic risk calculations indicate elevated
risk levels, the scenario that drives these levels is the future on-site
residential use scenario. Future on-site residential use of the property
would not be the reasonably expected future land use at a currently
operating industrial facility. As such, the basis for an action at the site is
derived from the fact that soils at the site exceed the RBRG calculated for
future industrial use.
d. Environmental Risks
An ecological risk assessment was conducted to characterize the
biological resources at the site and adjacent habitats, and to identify
actual and potential impacts to these resources associated with releases
of hazardous substances from the site.
F. RATIONALE FOR ACTION AND SCOPE OF THE SELECTED REMEDY
This ROD addresses the final remedy for the site. The contaminated soil at the site is
considered low level threat waste. The selected remedial alternative will address the
low level threat waste at the site. However, groundwater also appears to be impacted
and is being addressed by the inclusion of a contingency remedy for groundwater.
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G. DESCRIPTION OF ALTERNATIVES
ALTERNATIVE A: No Action
Under the no-action alternative, the site would be left "as is" and no action would be
taken to meet the remedial action objectives. This alternative is required by the NCP
and serves as a baseline against which other alternatives can be compared.
Alternative B: Consolidation and On-Site Landfill Disposal
Alternative B involves excavation, consolidation, and capping of the lead contaminated
soils in a solid waste landfill constructed on site. Drainage controls, vegetation, and a
security fence would be provided to minimize erosion and limit disturbances. Deed
restrictions would be placed on the site to limit future land uses. It is estimated that
approximately 7,740 cubic yards of contaminated soil would be excavated, which
represents the volume of soil with lead levels over 500 mg/kg. 500 mg/kg is the
cleanup standard for lead in soil for an industrial scenario under Wisconsin's NR 720.
Long-term inspection and maintenance programs would be implemented to verify and
maintain the integrity of the cap, fencing, and drainage controls. Long-term
groundwater and leachate monitoring programs would be implemented to monitor the
effectiveness of the cap, liner system, and overall long-term groundwater quality.
Excavated site areas would be backfilled with clean soil and revegetated.
Alternative C: Excavation and On-Site Treatment by Metal Recovery Process
Alternative C involves excavation of 7,740 cubic yards of lead contaminated soils and
on-site treatment using an innovative lead removal process developed by Brice
Environmental Services Corporation (BESCORP). The lead removal process is an
innovative technology that leaches lead from contaminated soils by using a leaching
solution and recovers the lead from the solution after it is separated from the soil. A
metals recovery process, such as solvent extraction, resin ion exchange, or direct
reduction, would remove lead ions from the solution. The leaching solution would be
reused, and recovered lead would be recycled. Treated soil would be neutralized and
tested to ensure that soil lead concentrations have been reduced to 500 mg/kg. 500
mg/kg is the cleanup standard for lead in soil for an industrial scenario under
Wisconsin's NR 720. Treated soil would be returned to excavated areas. A long-term
groundwater monitoring program also would be implemented as part of this alternative
to assess effectiveness of the soil cleanup, the overall groundwater quality in the
vicinity of the site, and the need for additional future actions.
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Alternative D: Consolidation and On-Site Containment by Concrete Paving
Alternative D involves excavation and consolidation of 7,740 cubic yards of lead-
contaminated soils, and construction of permanent concrete paving over the
consolidated soils. It is estimated that approximately 7,740 cubic yards of
contaminated soil would be excavated, which represents the volume of soil with lead
levels over 500 mg/kg. 500 mg/kg is the cleanup standard for lead in soil for an
industrial scenario under Wisconsin's NR 720. The lead-contaminated surface soils in
the southern and western portions of the site would be excavated and relocated to the
northern half of the site, where the majority of the lead contaminated soil is present.
The northern half of the site would then be paved with wire-reinforced concrete to
prevent direct contact with contaminated soil, minimize infiltration to the shallow
aquifer, and provide a stable working surface for the current site operations.
Additionally, drainage controls, security fencing, deed restrictions, and inspection and
maintenance programs would be implemented to protect and maintain the concrete
paving. Excavated areas would be backfilled with clean soil and revegetated. A long-
term groundwater monitoring program also would be implemented as part of this
alternative to assess effectiveness of the soil cleanup, the overall groundwater quality
in the vicinity of the site, and the need for additional future actions.
Alternative E: Excavation and Off Site Landfill Disposal
Alternative E involves excavation of lead-contaminated soils and their transport to an
offsite solid waste landfill for disposal. It is estimated that approximately 7,740 cubic
yards of contaminated soil would be excavated, which represents the volume of soil
with lead levels over 500 mg/kg. 500 mg/kg is the cleanup standard for lead in soil for
an industrial scenario under Wisconsin's NR 720. Sampling would be required to verify
that the excavated soils meet solid waste landfill requirements. Excavated site areas
would be backfilled with clean soil and revegetated. Revegetation is used to prevent
surface run-off and soil erosion. A site security fence and deed restrictions would be
implemented. A long term groundwater monitoring program also would be implemented
as part of this alternative to assess effectiveness of the soil cleanup, the overall
groundwater quality in the vicinity of the site, and the need for additional future actions.
ADD-ON OPTIONS
1) Treatment by Stabilization
As part of the 1993 removal action performed by U.S. EPA, soils that failed toxicity
characteristic leaching procedure (TCLP) testing were removed. Therefore, the lead-
contaminated soils remaining on site are anticipated to be classified as nonhazardous.
However, it is still possible that some lead-contaminated soils remaining on site may
fail TCLP testing. If soils are determined to be Resource Conservation and Recovery
Act (RCRA) hazardous by toxicity characteristic, on-site stabilization could be added to
alternatives B, D, and E as necessary to treat soils and render them nonhazardous.
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This add-on option uses either on-site or off-site (whichever is more cost effective)
exsitu stabilization to immobilize contaminants. The stabilized matrix would be tested
for TCLP lead to verify the effectiveness of the stabilization process. The stabilized
matrix would be contained or disposed as specified in alternatives B, D, or E.
2) Long-Term Groundwater Monitoring and Assessment Program
Active intervention in the spread of groundwater contamination will not be done until
there is an opportunity to evaluate the ability of the source control measures to provide
protection of human health and the environment. A long-term groundwater monitoring
program will be implemented along with the soil remedial action. The program will
include modifications to the existing monitoring well network, groundwater sampling
and analysis on a quarterly basis, and data interpretation and evaluation. At the
completion of contaminated soil excavation, as outlined in Alternatives B, C, D, and E,
groundwater monitoring wells will be installed in the area of the former battery cracking
operations and several existing damaged wells will be replaced. Groundwater samples
will be collected from each of the monitoring wells on a quarterly basis for a minimum of
two rounds. These samples will be analyzed for the full TCL, TAL, and PCB/pesticide
parameter lists using CLP or central regional laboratory (CRL) laboratories and
protocols. The laboratory methods selected should provide detection limits that provide
data suitable to be compared to Wisconsin's Administrative Code NR 140 WPALs
groundwater standards. At the conclusion of the initial two rounds of sampling, a report
will be prepared to present an evaluation of the collected data. If no compounds of
concern (other than those directly related to petroleum product release) are found to
exceed NR 140 WPALs, further monitoring will be discontinued and further
groundwater remedial actions will not be performed by U.S. EPA. If any NR 140
WPALs are exceeded for the compounds of concern, quarterly monitoring will be
continued for the full parameter list for an additional six rounds, providing quarterly data
for two full years.
At the end of the two years of quarterly sampling another decision point will be
reached. At that time a report presenting the collected information will be prepared.
U.S. EPA and WDNR will jointly evaluate the groundwater sampling data. Again,
should the NR 140 WPALs not be exceeded at all sampling points for compounds of
concern, further monitoring will be discontinued and an active groundwater remedy will
not be implemented. Should WPALs or WES be exceeded monitoring will be
continued. However, U.S. EPA in consultation with WONR will determine if the
analytical parameter list can be reduced and if the monitoring frequency or number of
sampling points can be reduced. If it is apparent that groundwater conditions are not
improving or if the contaminant plume is migrating off site, U.S. EPA and WDNR shall
evaluate the advantages or disadvantages of implementing an active remediation
system at this time.
If it is determined that further monitoring is necessary at the end of the two-year period,
monitoring will be performed on a semi-annual basis at a minimum. Monitoring will
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continue for an additional three years, providing a total of five years of groundwater
sampling data. As part of U.S. EPA's five-year review process, this data will be
evaluated by U.S. EPA and WDNR. Should concentrations of compounds of concern
at all sampling points be below NR 140 WPALs at the end of the five-year period,
further monitoring will be discontinued and no active remediation measures will be
taken. If concentrations of contaminants of concern are above the WPALs, a more
detailed evaluation of the data will be required to determine whether there is a need for
additional remedial actions to reduce cleanup times. The five-year review may also
evaluate the technical impracticability of attaining WPALs in the groundwater. At this
time there is not enough information to make such a determination. To the extent U.S.
EPA's five-year review indicates that it is not technically or economically feasible to
achieve WPALs, NR 140.28 provides for substantive standards for granting exemptions
from the requirement to achieve WPALs. Such exemption levels may not be higher
than the WESs. If U.S. EPA in consultation with WDNR determines that it is technically
impracticable to achieve WPALs or other standards, and for some reason the
exemption allowed within NR 140.28 is not appropriate, a Technical Impracticability
applicable or relevant and appropriate requirements (ARAR) waiver under CERCLA
may be granted for the site.
Completion of the selected source control alternative, addressing the impacted soils, is
considered an initial step in addressing the identified groundwater impacts. Evaluation
of groundwater data obtained from existing monitoring wells and additional wells as
proposed in the focused RI/FS will be used by U.S. EPA in consultation with WDNR to
evaluate the effectiveness of the source remedial action in affecting the quality of the
groundwater. This effectiveness evaluation will be part of U.S. EPA's five-year review
process.
The evaluation of the groundwater conditions and the effectiveness of the source
control remedial alternative will be based on the following:
1) Comparison of existing contaminant levels throughout the plume to NR
140 WPALs and WESs or Maximum Contaminant Levels (MCLs).
2) Trends in contaminant concentrations, if present.
3) Migration of the contaminated groundwater plume.
At the end of the five-year monitoring period, several options to address the situation
will be available based on the groundwater quality at the site. The options available
are:
1) Discontinue further monitoring and decide not to install an active
groundwater remediation system (No Further Action).
2) Postpone installation of an active groundwater system (Continued
Monitoring).
3) Install an active groundwater remediation system (Active Remediation).
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The following will be taken into account at the end of the initial five-year review when it
appears that concentrations are decreasing but cleanup goals are not yet met.
1) If based on the trend of the contaminant concentrations, it can be
demonstrated (using appropriate statistical analysis) that remaining
impacts will be at concentrations less than the WPALs within an
additional five-year period, then Continued Monitoring to document the
decrease would be selected and performed.
a) If after the additional five years of monitoring, contaminant
concentrations are found to be above NR 140 WESs Active
Remediation would be implemented.
b) If after the additional five years, the remaining groundwater
contamination plume is limited in extent (and within the
Scrap Processing property boundary), not migrating toward
a receptor and concentrations are below NR 140 WESs (but
above WPALs) Continued Monitoring would be performed,
as well as developing a new estimate on when the cleanup
goals would be reached. Monitoring would be continued
until the NR 140 WPALs are reached or concentrations
become asymptotic.
2) If based on the contaminants of concern concentrations in groundwater it
is demonstrated that cleanup goals cannot be reached within an
additional five-year period (for example, if it is shown that it would take 50
years to reach WPALs) Active Remediation would be implemented. As
part of the five-year review process, an evaluation will be conducted to
determine whether it is not technically or economically feasible to achieve
WPALs. NR 140.28 provides for substantive standards for granting
exemptions from the requirement to achieve WPALs. Such exemption
levels may not be higher than the WESs. If the exemption is
inappropriate, and U.S. EPA in consultation with WDNR determines that it
is technically impracticable to achieve WPALs, a Technical
Impracticability waiver under CERCLA may be granted for the site.
The following system may be designed and installed should it be determined, based on
the above criteria, that active groundwater remediation would be implemented:
The system may consist of the construction of groundwater collection trenches or
installation of extraction wells. Treatment of collected groundwater to meet discharge
requirements includes such methods as reverse osmosis or the use of activated
carbon. The discharge may be directed to the Black River after meeting state
discharge standards (this is considered an on-site discharge, so no state Wisconsin
Pollution Discharge Elimination System (WPDES) permit would be required, but the
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substantive requirements of such permit would be met) or to the Medford sewage
treatment facility after meeting applicable pretreatment standards. It is recognized that
it may be necessary to issue an Explanation of Significant Differences (ESD) document
to describe any significant variations in the active system design. If an alternative
treatment system becomes available that is more cost effective it will be implemented.
If U.S. EPA, in consultation with WDNR, determines that a fundamental change is
appropriate to the active remediation system, a ROD amendment would be necessary.
H. Summary of Comparative Analysis of Alternatives
The relative performance of each remedial alternative was evaluated in the focused
RI/FS and using the following nine criteria set forth in the NCR at 40 C.F.R. §300.430.
An alternative providing the "best balance" of tradeoffs with respect to the nine criteria
is determined from this evaluation.
Threshold Criteria
1. Overall Protection of Human Health and the Environment
Overall protection of human health and the environment addresses whether a remedy
eliminates, reduces, or controls threats to human health and to the environment:
With the exception of the no-action alternative, each of the remedial action alternatives
would address the lead-contaminated soil in some fashion and monitor groundwater to
provide protection to human health and the environment. Alternative A would not
reduce or control the potential for exposure or migration of contaminated soil because
no action would be taken; therefore, this alternative would not provide adequate
protection of human health or the environment. Alternatives B and D would protect
human health and the environment by isolating the contaminated soil using engineering
and institutional controls, thereby reducing the potential for direct contact with and
migration of the contaminants. However, some long term residual risk would be
associated with these alternatives because the contaminated soil would remain on-site
and would only be contained rather than treated or destroyed.
Alternative E is similar to Alternative B, except that the landfilling is performed off site.
Removing the contaminated soil from the site would eliminate the potential for exposure
or contaminant migration through all pathways, thereby protecting human health and
the environment at the site. Protection of human health and the environment at the off-
site disposal location under Alternative E would be similar to the protection of human
health and the environment on-site under Alternative B.
Alternative C would recover and recycle the lead in the site soils, thus providing an
additional measure of permanence not achieved by the other alternatives. All of the
alternatives, except Alternative A, would be protective of human health and the
environment.
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2. Compliance with Applicable or Relevant and Appropriate Requirements (ARARs)
This criterion evaluates whether an alternative meets ARARs set forth in federal, or
more stringent state, environmental standards pertaining to the site or proposed
actions.
Alternative A would not comply with chemical-specific ARARs because lead
concentrations in the site soils would remain above the state soil cleanup standard
without any remedial action. The on-site disposal cell in Alternative B would not meet
some of Wisconsin's solid waste landfill location standards because the disposal cell
would be located within 1,200 feet of public and private water supply wells and, unless
the subbase for the disposal cell is built up, the separation distance between the
seasonal high water table and the bottom of the clay liner would foe less than the
minimum requirement of 10 feet. Waivers would be required from the state solid waste
management regulations for the on-site disposal cell. If some of the contaminated soils
are determined to be hazardous by characteristic, alternatives B, D, and E would
require the add-on stabilization option to meet Wisconsin's hazardous waste
requirements. Alternatives C, D, and E would comply with ARARs if they are designed
and implemented properly.
Primary Balancing Criteria
3. Long-Term Effectiveness and Permanence
This criterion refers to expected residual risk and the ability of an alternative to
maintain reliable protection of human health and the environment over time once
cleanup levels have been met.
Alternative A would not provide any long-term effectiveness or permanence because no
remedial activities would occur. The other alternatives include excavation and
containment, treatment, or removal of the contaminated soil, thus reducing the potential
for human exposure or contaminant migration and protecting human health and the
environment. Some residual risk is associated with all the alternatives because the
lead cleanup goal is based on an industrial land-use classification. Access and deed
restrictions are included with all the alternatives, except Alternative A, to manage the
risk. Because contaminated soil would remain untreated and on-site under Alternatives
B and D, more long-term residual risk is associated with these options. This risk would
be minimized through proper design, construction, maintenance, and monitoring of the
solid waste disposal cell or concrete pavement. The disposal cell (Alternative B) and
concrete pavement (Alternative D), however, would have estimated finite design lives
and require post remedial action site control measures to inspect and maintain them.
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Alternative C incorporates treatment as part of the remedial action; therefore, it would
provide a higher degree of long-term protection. Alternatives C and E provide solutions
that would remove the contaminants from the site. Alternative C would be the most
effective because the lead would essentially be reclaimed and recycled. Alternative E
would remove the contaminants from the site; however, potential long-term liability is
associated with disposing of the contaminated soil in an off-site landfill. As noted
above, steps would be taken to ensure that any soils that fail TCLP will be stabilized
prior to landfilling.
All alternatives, except Alternative A, require post remedial action site control for
security fence maintenance and to conduct the long-term groundwater monitoring
program. Alternative 0 requires additional post remedial site control measures to
inspect and to maintain the concrete pavement. Alternative B would require the most
post remedial action site control measures.
4. Reduction of Toxicity, Mobility, or Volume through Treatment
This criterion evaluates treatment technology performance in the reduction of chemical
toxicity, mobility, or volume. This criterion addresses the statutory preference for
selecting remedial actions which include, as a principal element, treatment that
permanently and significantly reduces the volume, toxicity, or mobility of the hazardous
substances, pollutants, and contaminants.
Alternative A would not provide any reduction in toxicity, mobility, or volume of the
contamination in the site soils. Alternatives B, D, and E would provide for containment
of the lead-contaminated soils, thereby reducing the potential for exposure or
contaminant migration and indirectly reducing contaminant mobility. Under alternatives
B and D, the contaminants would remain on site at their present concentrations and
would not be treated; therefore, the contaminant toxicity and volume would not be
reduced. Under Alternative E, the contaminated soil would be disposed off site,
thereby reducing the contaminant volume and mobility at the site.
Alternative C incorporates treatment as part of the remedial action and reduces mobility
and volume. Alternative C would reclaim lead from the soils in a concentrated form
suitable for recycling; therefore, this option would reduce contaminant volume and
eliminate the possibility of contaminant migration. The toxicity would not be reduced
directly because the contaminants are not destroyed; however, the potential for
exposure or migration on-site would be eliminated because the contaminants are
removed from the site.
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5. Short-Term Effectiveness
Short-term effectiveness considers the time to reach cleanup objectives and the risks
an alternative may pose to site workers, the community, and the environment during
remedy implementation until cleanup goals are achieved.
Implementation of Alternative A would not create any short-term risks to workers or to
the community because no remedial activities would occur. Alternatives 6, C, D, and E
would create similar risks to the community and environment during construction and
implementation because all of these alternatives include contaminated soil excavation.
Potential short-term effects associated with these alternatives include the release of
dust and air pollutants during excavation and handling of the contaminated soil,
increased noise levels, increased traffic around the site, and surface-water runoff
during excavation. However, these risks would be controlled through air monitoring,
the use of dust suppressants, and surface-water run on and runoff control measures,
such as berms and ditches. Alternative D would create the least short-term risks
because it involves excavation of only a portion of the contaminated soil. The short-
term risks associated with Alternatives B and C would be slightly greater than
Alternative E because those alternatives involve more construction activities and/or on-
site treatment. Alternative E, however, would create the potential for contaminant
release during transportation of soil to an off-site disposal facility; this would be
minimized by placing tarps over filled trucks and using a state-licensed solid waste
collection and transportation contractor. Additionally, a plan will be in place to address
any spills associated with the transport of contaminated soils. Workers could
potentially be exposed to contamination during implementation of any of the
alternatives, but risks would be minimized through adherence to Occupational Safety
and Health Administration guidelines and requirements.
6. Implementability
This criterion addresses the technical and administrative feasibility of implementing an
alternative, and the availability of various services and materials required for its
implementation.
The Implementability criterion is not applicable to Alternative A because no remedial
activities would occur. Alternative B would be relatively simple to implement. The on-
site disposal cell would be constructed using conventional methods. Equipment,
materials, and personnel are readily available. Disposal cells have been constructed
on a large scale. Alternative B would be more difficult to implement if waivers from the
state solid waste landfill location standards are necessary, since, such waivers cannot
be obtained without adequate technical justification.
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Alternative D would be relatively simple to implement technically but not very simple
administratively. It would be easier to construct than Alternative B because less soil
would be excavated. The concrete pavement would be constructed using conventional
methods. Equipment, materials, and personnel would be readily available. However,
inspections and maintenance of a concrete cover at an active salvage yard may be
difficult to cany out consistently over time, given the legal and physical problems
associated with gaining access to the site to perform inspections and maintenance.
Alternative E also would be technically and administratively easy to implement. Off-site
landfilling is a proven method for waste containment and disposal. Suitable state-
licensed solid waste disposal facilities have been identified in the State of Wisconsin.
Alternative C would be the most difficult alternative to implement. This alternative
involves the use of an innovative technology to remove lead from the soil. Because the
process is a relatively new technology, it does not have an extensive track record, and
unforseen technical difficulties could affect its effectiveness and implementability.
However, the process has been successful at the bench scale level on soils from
several sites and has been implemented on a full-scale basis with positive results at a
Superfund site. The process is unusable at freezing temperatures, so the schedule
would have to be coordinated accordingly to avoid delays. Also, this innovative
technology requires specialized processes and personnel available from only a few
contractors; therefore, contractor availability to perform the work could affect the
schedule.
All alternatives include deed restrictions; they would have to be coordinated through
the local jurisdictions and might be difficult to obtain. Post remedial action site control
measures for all alternatives would be conducted by a local contractor.
7. Cost
This criterion compares the capital, operation and maintenance (O&M), and present
worth costs of implementing the alternatives at the site. Table 7 shows the cost
summary.
TABLE 7 - SUMMARY OF COSTS
COSTS
Capital Cost
O&M/yr (SOyrs.)
Present Worth
Alternative
A
$0
$0
$0
Alternative
8
$2,399.000
$ 104,000
$3,998,000
Alternative
C
$4,112,000
$ 47,600
$ 4,844,000
Alternative
$1,989,000
$ 64,000
$2,973,000
Alternative
; E
$1,508,000
$ 47,600
$2,240,000
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Modifying Criteria
8. State Acceptance
The State of Wisconsin has indicated to be in agreement with the selection of
Alternative E with a contingency for groundwater monitoring and remediation, if
needed, for remediation of the Scrap Processing Site and will provide U.S. EPA with a
letter of concurrence.
9. Community Acceptance
Comments have been submitted by the community, local government officials, and
potentially responsible parties (PRPs). Comments and responses to those comments
are described in the Responsiveness Summary, Section M.
I. The Selected Remedy
Based upon considerations of the requirements of CERCLA, the NCP and balancing of
the nine criteria, U.S. EPA has determined that Alternative E is the most appropriate
remedy for the site. The components of the selected remedy are:
Excavation and Off-Site Landfill Disposal - Approximately 7,740 cubic yards of
lead-contaminated soils would be excavated and transported to an off-site solid
waste landfill for disposal. Before excavating the soil, sampling and analysis
would be conducted to verify the waste characteristics meet landfill
requirements. Excavated site areas would be backfilled with clean soil and
revegetated. Revegetation is used to prevent surface run-off and soil erosion.
Groundwater Monitoring - A groundwater monitoring program shall be designed
and implemented to detect changes in concentration of site-related
contamination near the site. The program would include modifications to the
existing monitoring well network, groundwater sampling and analysis on a
quarterly basis, and data interpretation and evaluation. Active intervention in the
spread of groundwater contamination will not be made until there is an
opportunity to evaluate the ability of the source control measures to provide
protection of human health and the environment for groundwater. An evaluation
of groundwater information gathered at the five-year review will be used to
determine whether or not there is a need for additional actions to reduce cleanup
times. The five-year review may also evaluate the technical impracticability of
attaining WPALs in the groundwater. To the extent U.S. EPA's five-year review
indicates that it is not technically or economically feasible to achieve WPALs,
NR 140.28 provides for substantive standards for granting exemptions from the
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requirement to achieve WPALs. Such exemption levels may not be higher than
the WESs. If U.S. EPA in consultation with WDNR determines that it is
technically impracticable to achieve WPALs, and the exemption is inappropriate,
a Technical Impracticability ARAR waiver under CERCLA may be granted for the
site. A detailed description of the monitoring program is provided above, in
section G, add-on option 2 of this decision document.
Active Groundwater Remediation - Based on the results of the groundwater
monitoring, it may be necessary to design and implement an active groundwater
remediation system. Should that be found to be necessary using the criteria
outlined in Section G, add-on option 2 of this ROD, the system may consist of
the construction of groundwater collection trenches or installation of extraction
wells. Treatment of collected groundwater to meet discharge requirements
includes such methods as reverse osmosis or the use of activated carbon. The
discharge may be directed to the Black River after meeting state discharge
standards (this is considered an on-site discharge, so no state WPDES permit
would be required, but the substantive requirements of such permit would be
met) or to the Medford sewage treatment facility after meeting applicable
pretreatment standards. It is recognized that it may be necessary to issue an
ESD document to describe the minor variations in the active system design. If
an alternative treatment system becomes available that is more cost effective it
will be implemented.
Access Restrictions and Institutional Controls - Access restrictions and
institutional controls would be implemented, which include installation of a fence
around the Site to limit site access and deed restrictions limiting the site's future
land use as well as restrictions on groundwater use in the site vicinity. The on-
site residential well will be abandoned.
J. Documentation of Significant Changes
U.S. EPA released a Proposed Plan for public comment on August 25,1997. The
Proposed Plan identified excavation of lead-contaminated soils and their transportation
to an off-site solid waste landfill for disposal, institutional controls such as site fencing
and groundwater and land-use restrictions, and long-term groundwater monitoring to
determine effectiveness of site cleanup and the need for possible future actions as the
preferred remedy for the site. There are no significant changes to the proposed
remedy, which this ROD selects.
K. Statutory Determinations
U.S. EPA's primary responsibility at Superfund sites is to undertake remedial actions
that protect human health and the environment. Section 121 of CERCLA has
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established several statutory requirements and preferences. These include the
requirement that the selected remedy, when completed, must comply with all ARARs
imposed by Federal and State environmental laws, unless the invocation of a waiver is
justified. The selected remedy must also provide overall effectiveness appropriate to
its costs, and use permanent solutions and alternative treatment technologies, or
resource recovery technologies, to the maximum extent practicable. Finally, the statute
establishes a preference for remedies which employ treatment that significantly
reduces the toxicity, mobility or volume of contaminants.
1. Protection of Human Health and the Environment
Implementation of the selected remedy will protect human health and the environment
by reducing the risk of exposure to hazardous substances present in surface soils at
the site. Excavation and off-site landfill disposal of lead-contaminated soils will reduce
the direct contact risk of exposure to hazardous substances present in soil at the site.
Additionally, it will reduce the risk that hazardous substances, pollutants, and
contaminants present in the soil will migrate and contaminate the aquifer. Groundwater
monitoring will be required to provide early warning against the risk that the hazardous
substances present in the soil may migrate and contaminate the aquifer. Institutional
controls will be imposed to restrict uses of the site to prevent exposure to hazardous
substances and contaminants in the soil and groundwater. No unacceptable short-
term risks will be caused by implementation of the remedy. The community and site
workers may be exposed to dust and noise nuisances during excavation and off-site
disposal of lead-contaminated soil. Mitigative measures will be taken during remedy
construction activities to minimize such impacts of construction upon the surrounding
community and environs. Ambient air monitoring will be conducted and appropriate
safety measures will be taken if contaminants are emitted.
2. Compliance with ARARs
The selected remedy will comply with all identified applicable or relevant and
appropriate federal requirements, and with those state requirements which are more
stringent, unless a waiver is invoked pursuant to Section 121(d)(4)(B) of CERCLA.
For a complete list of ARARs and to be considered (TBCs) for all of the alternatives at
this site, see Tables 3-2, 3-3, and 3-4 of the Focused RI/FS Report. A discussion of
the key ARARs for the selected remedy follows.
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RCRA
1. Not applicable, but relevant and appropriate
RCRA requirements are not applicable because the wastes were disposed of prior to
November 19, 1980. RCRA requirements which have been delegated to the State of
Wisconsin would be relevant and appropriate because lead-contaminated soils may
exhibit characteristic toxicity. Listed contaminants have not been identified as having
been disposed of at the site. The selected remedy will comply with this ARAR.
RCRA Action-specific
1. Land Disposal Restrictions
This regulation has been delegated to the State of Wisconsin. Land disposal
restrictions will be applicable if it is determined during the pre-design activities that the
lead-contaminated soil to be disposed of exhibits characteristic toxicity. If these
restrictions are determined to be applicable, the selected remedy will comply with them.
Clean Air Act
Air quality goals called National Ambient Air Quality standards (NAAQS) are
established for criteria pollutants under Sections 108 and 109 of the Clean Air Act
(CAA). Under the CAA, each state must adopt a state implementation plan to
demonstrate how it will meet its statutory obligation to attain and maintain NAAQS.
Emission standards called New Source Performance Standards (NSPS) are
promulgated under the regulatory authority of Section 111 of the CAA. The emissions
threshold for a major source is 100 tons per year for areas that have not attained the
NAAQS. Major new sources must meet Lowest Achievable Emission Requirements
(LAERs). If emissions from the site exceed 100 tons of VOCs, LAERs will be relevant
and appropriate to the site, and the selected remedy will comply with them.
Executive Order 11990 - Protection of Wetlands
The requirements of Executive Order 11990 are applicable because the selected
remedy either affects or may affect wetlands adjacent to or downstream of the site.
Executive Order 11990 requires that actions at the site be conducted in a manner
minimizing the destruction, loss, or degradation of wetlands. The selected remedy will
be implemented in a manner such that it does not have an adverse impact on nearby
wetlands.
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Wisconsin Groundwater Standards (NR 140)
NR 140 establishes groundwater remediation goals for Wisconsin's groundwaters.
Groundwater will be monitored to determine the effectiveness of the soil remedial
action. Based on the criteria outlined in Section G, add-on option 2, above, the results
of this monitoring program will be used to determine if active groundwater remediation
is needed. This groundwater contingency plan meets the intent of ch. NR 140, Wis.
Adm. Code.
Wisconsin Soil Cleanup Standards (NR 720)
NR 720 establishes cleanup standards for the remediation of soil contamination that
are protective of public health, safety, welfare, and the environment. Soil
contamination will be addressed by the remedial action. The cleanup standard for lead
in soil for the direct contact exposure route at an industrial scenario is 500 ppm.
Specific soil residual contaminant levels (RCL) numbers for the groundwater pathway
were not developed. However, it is expected that the groundwater contingency plan
will address the groundwater pathway, and providing a clean soil vegetated cover over
excavated and backfilled areas will address the potential for impacts to surface water
from runoff. Additionally, an RCL for PCBs was not calculated due to the previous
removal of PCB impacted soils and the use of deed restrictions as a performance
standard.
3. Cost Effectiveness
Cost effectiveness compares the effectiveness of an alternative in proportion to its cost
of providing environmental benefits. Costs associated with the implementation of the
selected remedy are listed below.
Total estimated costs for the selected remedy at the Scrap Processing Site:
Total Total Total
Alternative Capital Cost O&M/Yr. Present Worth
E $1,508,000 $47,600 $2,240,000
The selected remedy for this site is cost effective because it provides the greatest
overall effectiveness proportionate to its costs when compared to the other alternatives
evaluated, the net present worth being $2,240,000. The estimated cost of the selected
remedy is comparable to Alternative D, and assures a high degree of certainty that the
remedy will be effective in the long term due to significant reduction of the mobility of
the contaminants achieved through excavation and off-site disposal of the source
material. Alternative D leaves the source on site. The uncertain effectiveness of a
concrete cap in preventing migration of contaminants to the groundwater does not
justify the additional cost for this alternative.
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4. Utilization of Permanent Solutions and Alternative Treatment Technologies or
Resource Recovery Technologies to the Maximum Extent Practicable
The selected remedy represents the maximum extent to which permanent solutions and
treatment technologies can be used in a cost-effective manner at this site. Of those
alternatives that are protective of human health and the environment and that comply
with ARARs, U.S. EPA has determined that the selected remedy provides the best
balance in terms of long-term effectiveness and permanence, reduction of toxicity,
mobility, or volume of contaminants, short-term effectiveness, implementability, and
cost, taking into consideration State and community acceptance.
The excavation and off-site disposal at a solid waste landfill of lead-contaminated soils,
groundwater monitoring and subsequent remediation if needed, and restriction of site
access through installation of a fence and institutional controls, will provide the most
permanent solution practicable, proportionate to the cost.
5. Preference for Treatment as a Principal Element
Based on current information, U.S. EPA and the State of Wisconsin believe that the
selected remedy is protective of human health and the environment and utilizes
permanent solutions and alternative treatment technologies to the maximum extent
possible. The remedy, however, does not satisfy the statutory preference for treatment
of the hazardous substances present at the site as a principal element because such
treatment was not found to be practical or cost effective. However, it is still possible
that some lead-contaminated soils remaining on site may fail TCLP testing. If soils are
determined to be RCRA hazardous by toxicity characteristic, on-site stabilization could
be added as necessary to treat soils and render them nonhazardous, thereby satisfying
this preference.
L. Summary
The selected remedy will satisfy the statutory requirements established in Section 121
of CERCLA, as amended by SARA, to protect human health and the environment, will
comply with ARARs, will provide overall effectiveness appropriate to its costs, and will
use permanent solutions and alternate treatment technologies to the maximum extent
practicable.
Treatment is not a component of the selected remedy since hazardous substances
present at the site in soils are considered low level threat wastes. Consistent with the
NCP, low level threat wastes should be contained since treatment is generally not
considered practical or cost effective.
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M. RESPONSIVENESS SUMMARY
The public participation requirements of CERCLA sections 113 (k) (2) (i-v) and 117 of
CERCLA have been met during the remedy selection process. Section 113(k)(2)(B)(iv)
and 117(b) of CERCLA requires the U.S. EPA to respond "...to each of the significant
comments, criticisms, and new data submitted in written or oral presentations" on a
proposed plan for a remedial action. The Responsiveness Summary addresses
concerns expressed by the public, potentially responsible parties (PRPs), and
governmental bodies in written and oral comments received by U.S. EPA and the State
regarding the proposed remedy for the Scrap Processing site.
Background
U.S. EPA issued a fact sheet to the public in May 1992, at the beginning of the
remedial investigation. The Agency also hosted a public meeting on May 12, 1992, to
provide background information on the Scrap Processing site, explain the Superfund
process, and provide details of the upcoming investigation. The remedial investigation
was completed in August 1995. In September 1992 and November 1993, U.S. EPA
issued additional fact sheets to summarize the results of the investigation. U.S. EPA
also hosted public meetings on September 16,1992 and November 16,1993 to discuss
the results of the investigation in greater detail, and answer any questions.
The Focused RI/FS reports and the Proposed Plan for the Scrap Processing site were
released to the public for review in August 1997. The information repository has been
established at the following location: Medford Public Library, 104 East Perkins Street,
Medford. The Administrative Record has been made available to the public at the U.S.
EPA Docket Room in Region 5 and at the information repository.
A public meeting was held on September 16, 1997 to discuss the Focused RI/FS and
the Proposed Plan. At this meeting, representatives from the U.S. EPA and WDNR
answered questions about the site and the remedial alternatives under consideration.
Formal oral comments on the Proposed Plan were documented by a court reporter. A
verbatim transcript of this public meeting has been placed in the information repository
and Administrative Record. Written comments were also accepted at this meeting.
The meeting was attended by approximately five local residents.
The Focused RI/FS and Proposed Plan were available for public comment from August
25 through September 24,1997. Comments received during the public comment
period and the U.S. EPA's responses to those comments are included in the attached
Responsiveness Summary, which is a part of this ROD. A display advertisement
announcing the availability of the Proposed Plan and start of the comment period was
published in the Medford Star News.
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During the comment period, U.S. EPA received one written submittal of comments and
three oral comments concerning the proposed plan.
Summary of Significant Comments
Comment 1:
Response:
Comment 2:
Response:
Comment 3:
Response:
One person said that the community of Medford needs Scrap
Processing and that he would not like to see the salvage yard
financially burdened in the future, because this may cause it to go
out of business and the community needs the salvage and
recycling services it provides.
CERCLA as amended by SARA requires the U.S. EPA to
determine the financial ability of the PRPs to undertake
investigative and remediative actions at Superfund sites. At the
Scrap Processing site the PRP search performed by the U.S. EPA
has not identified PRPs that are financially capable of
implementing the cleanup plan at the site. U.S. EPA will use
federal monies available from the Superfund to implement the
cleanup actions for the site; therefore at this time, the owners of
Scrap Processing will not be financially burdened. However, if
circumstances at the site change, or it is otherwise warranted, U.S.
EPA reserves the right to reconsider this enforcement decision.
Another person proposed to select No Action as the preferred
response action for the site.
The remedial investigation indicated that there is widespread lead
contamination in the site soils. The risk assessment performed
using the results from the remedial investigation indicated that the
site conditions may pose a threat to human health and the
environment in the long term. Because of the future threat posed
by the site soils to human health and the environment, No Action is
not an acceptable way of addressing the risks posed by the site.
Another person stated that although the site does not present an
imminent threat, it should be cleaned up. Additionally, he
expressed similar concerns with respect to possible groundwater
contamination.
U.S. EPA selected the cleanup plan outlined in this ROD to
address the risks posed by the site. Additionally, groundwater
monitoring will be implemented to determine if the groundwater is
contaminated and if there is a need for future active remediation.
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Comment 4:
Response:
Comment 5:
Response:
A written comment requested the placement of additional
groundwater monitoring wells in the source area to determine if
groundwater is contaminated.
As part of the groundwater monitoring program selected for the site
in this ROD, new monitoring wells will be installed in and near the
source area.
The same person had concerns with how long the project has
taken and expected it to proceed faster in this next phase.
This project will be financed using Federal funds. Those funds are
limited. Sites needing Federal funding have to compete nationally
to obtain it. The implementation of the cleanup plan may be
delayed if the site does not get funded in the near future.
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N. GLOSSARY
Applicable or Relevant and Appropriate Requirements.
Section 121 (d) of CERCLA requires that remedial actions meet legally applicable or
relevant and appropriate requirements (ARARs) of other environmental laws. Legally
"applicable" requirements are those cleanup 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 circumstances at a CERCLA site.
"Relevant and appropriate" requirements are those requirements that, while not legally
applicable to the remedial action, address problems or situations sufficiently similar to
those encountered at the site that their use is well suited to the remedial action.
Non-promulgated advisories or guidance documents issued by federal or state
governments ("to-be-considered or TBCs") do not have the status of ARARs; however,
where no applicable or relevant and appropriate requirements exist, or for some reason
may not be sufficiently protective, non-promulgated advisories or guidance documents
may be considered in determining the necessary level of clean up for protection of
human health and the environment.
Baseline Risk Assessment
The baseline risk assessment is an analysis of the potential adverse health effects
caused by hazardous substance releases from a site in the absence of any actions to
control or mitigate these releases. The baseline risk assessment assumes no
corrective action will take place and no site-use restrictions or institutional controls
such as fencing, ground water use restrictions or construction restrictions will be
imposed. There are four steps in the baseline risk assessment process: data
collection and analysis; exposure assessment; toxicity assessment; and risk
characterization.
Cancer Potency Factors fCPFs)
Cancer potency factors (CPFs) have been developed by EPA's Carcinogenic
Assessment Group for estimating excess lifetime cancer risks associated with exposure
to potentially carcinogenic chemicals. CPFs, which are expressed in units of (mg/kg-
day)'1, are multiplied by the estimated intake of a potential carcinogen, in mg/kg-day, to
provide an upper-bound estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term "upper bound" reflects the conservative
estimate of the risks calculated from the CPF. Use of this approach makes
48
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underestimation of the actual cancer risk highly unlikely. Cancer potency factors are
derived from the results of human epidemiological studies or chronic animal bioassays.
Excess Lifetime Cancer Risks
Excess lifetime cancer risks are the sum of all excess cancer lifetime risks for all
contaminants for a given scenario. Excess Lifetime Cancer Risks are determined by
multiplying the intake level by the cancer potency factor for each contaminant of
concern and summing across all relevant chemicals and pathways. These risks are
probabilities that are generally expressed in scientific notation (e.g. 1 X10"6). An
excess lifetime cancer risk of 1 x 10"6 indicates that a person's chance of contracting
cancer as a result of site related exposure averaged over a 70-year lifetime may be
increased by as much as 1 in one million.
Hazard Index (HI)
The Hazard Index (HI), an expression of non-carcinogenic toxic effects, measures
whether a person is being exposed to adverse levels of non-carcinogens. The HI
provides a useful reference point for gauging the potential significance of multiple
contaminant exposures within a single medium or across multiple media. The HI for
non-carcinogenic health risks is the sum of all contaminants for a given scenario. Any
Hazard Index value greater than 1.0 suggests that a non-carcinogen potentially
presents an unacceptable health risk.
Reference Doses (RfDs)
Reference doses (RfDs) have been developed by U.S. EPA for indicating the potential
for adverse health effects from exposure to chemicals exhibiting non-carcinogenic
effects. RfDs,- which are expressed in units of mg/kg-day, are estimates of average
daily exposure levels for humans, including sensitive individuals. Estimated intakes of
chemicals from environmental media (e.g., the amount of a chemical ingested from
contaminated drinking water) can be compared to the RfD. RfDs are derived from
human epidemiological studies or animal studies to which uncertainty factors have
been applied (e.g., to account for the use of animal data to predict effects on humans).
These uncertainty factors help ensure that the RfDs will not underestimate the potential
for adverse non-carcinogenic effects to occur.
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ADMINISTRATIVE RECORD INDEX
50
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U.S. ENVIRONMENTAL PROTECTION AGENCY
REMOVAL ACTION
ADMINISTRATIVE RECORD
FOR
SCRAP PROCESSING, INC
MEDFORD, WISCONSIN
June IB, 1993
DATE
05/03/92
07/30/92
11/16/92
07/26/93
AUTHOR
Korzenecki,
P., E & E
Ecology &
Environment
Encole, L.,
IEA
Nolan, C.,
U.S. EPA
RECIPIENT
Scare, S.,
E & E
U.S. EPA
Ripp, M.J.
E & E
Muno, W.,
U.S. EPA
TTTLE/nESCRIPTIQN PAqES
Inorganic Data 16
Quality Assurance
Review
Removal Action Plan "120
Analytical Results 12
Received on October
22, 1992
Action Memorandum
17
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U.S. BNVIRONMBNTAX. PROTECTION AGENCY
ACTION
AnGENI8TRATXVB RECORD
FOR
SCRAP PROCESSING SITE
•FORD, TAYLOR COUNTY, WISCONSIN
UPDATE f1
XUOUST 25, 1997
HO.. PACT
*
1 08/00-/97
08/00/97
AUTHOR
'RECIPIENT
3 08/00/97
4 OB/07/97
5 09/24/97
6 09/00/97
8 05/00/92
9 11/00/93
Black & Veatch U.S. EPA
Special Projects
Corp.
Black & Veatch U.S. EPA
Special Projects
Corp.
U.S. SPA
Koehn, T.,
WDNR
Peterson, L.
Kraemer &
Associates
U.S. EPA
U.S. EPA
Public
Valentin, P.,
U.S. EPA
U.S. EPA
U.S. EPA
Public
Public
TITLB/DKSCRIPTIOH
Final Focused Remedial 677
Investigation/Feasibility
Study for the Scrap
Processing Site
Drawings: Final Focused
Remedial Investigation/
Feasibility Study for
the Scrap Processing
Site
Proposed Plan for the
Scrap Processing Site
Letter re: Proposed
Oroundwater Contingency
Measures at the Scrap
Processing Site
Comment Letter 1
Transcript of
Public Meeting
Scrap Processing .M-
Investigation Begins
at Scrap Processing 8
Site Investigation
Cleanup Progress 4
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