PB94-964144
EP AIROD/R05-941271
April 1995
EPA
Superfund
Record of Decision:
Conrail Rail Yard
(o.U. 2), Elkhart, IN
9/09/1994
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Hazardous Waste Collection EP A Report Collection
Information Resource Cehter Information Resource Center
US EPA Region 3 US EP A Region 3
Philadelphia, PA 19107 Philadelphia, PA 19107
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DECLARATION FOR THE RECORD OF DECISION
SITE NAME AND LOCATION
Conrail Railyard
Elkhart County, Indiana
STATEMENT OF BASIS AND PURPOSE
rhis decision document represents the selected Final Remedial
Action for the Cqnrail Railyard site in Elkhart County, Indiana.
This action was chosen in accordance with the Comprehensive
Environmental Response, Compensation and Liability Act of 1980
(CERCLA), as amended by the Superfund Amendments and
Reauthorization Act of 1986 (SARA), and to the extent
practicable, with the. National oil and Hazardous Substances
Contingency Plan (NCP). The deci~ions contained herein are based
on information contained in the administrative record for this
site.
The State of Indiana concurs with the selected remedy.
concurrence letter is attached to this Declaration.
The
ASSESSMENT OF THE REMEDY
Aqtual or threatened releases of hazardous substances from the
site, if not addressed by implementing the response action
selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare,
or the environment.
DESCRIPTION OF THE REMEDY
This remedy is intended to be the final action and is the second
of two operable units for this site. This final action fully
addresses the elimination or reduction of public exposure to
ground-water.contamination and source areas associated with the
site.
Specifically, this Final Remedial Action involves the provision
of a safe, permanent drinking water supply to residents who are
potentially at risk, taking actions to clean up the contamination
in the aquifer, and remediation of contaminated soils on the
railyard that are source areas for the ground-water
contamination. The major components of the selected remedy
include:
Institutional actions such as ground-water and air
monitoring, well abandonment, access restrictions, and
deed restrictions, to limit the potential for human
exposure to contaminated media;
Additional source investigations and remediation, as
appr?priate, to identify other source areas that could
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be contributing to ground-water contamination;
Monitoring and, if necessary, vapor abatement actions
in building floors and basements of areas north of the
railyard;
Soil vapor extraction of Volatile Organic Compound
(VOC) contamination in the Trichloroethylene (TCE)
source area, and air sparing in the saturated zone in
the carbon tetrachloride (CCI4) source area, in
conjunction with vapor extraction of the overlying
unsaturated zone, and treatment of these vapors;
Extension of the City of Elkhart municipal water supply
system to all residences in the area bounded by the
Conrail facility to the south, the St. Joseph River to
the north, Baugo Bay to the west, and Napp~nee Street
(State Route 19) to the east. Approximately 500
residences are being hooked up to city water under the
Interim Remedial Action. This final remedy will
provide this hookup to all remaining residences and
businesses in the area described ab~ve; and
Ground-water extraction and treatment to achieve ground
water standards throughout the plumes which will be
achieved by emphasizing remediation of "hot spots"
(i.e. areas of relatively high contaminant
concentrations or where DNAPL sources are identified).
Collected ground water will be treated using air
stripping and discharged to the St. Joseph River.
Exhaust from the air stripper(s) will be treated by
carbon adsorption prior to emission; spent carbon will
be disposed of properly.
STATUTORY DETERMINATIONS
This Final Remedial Action is protective of human health and the
environment, complies with Federal and State applicable or
relevant and appropriate requirements and is cost-effective.
This remedy satisfies the statutory preference for remedies that
employ treatment that reduces toxicity, mobility, or volume as a
principle element and utilize permanent solutions and alternative
treatment technologies to the maximum extent practicable for this
site.
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Because this remedy will result in hazardous ,substances remaining
on site above health-based levels, a review will be conducted to
ensure that the remedy continues to provide adequate protection
of human health and the environment within five years after
commencement of the remedial action.
~5~ fiN:;
Date r
ddd~g'
f- Valdas V. Adamkus
Regional Administrator, Region V
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RECORD OF DECISION SUMMARY
CONRAIL
I.
SITE NAME, LOCATION, AND DESCRIPTION
The Conrail Railyard site is located adjacent to and within the
southwestern city limits of Elkhart, Indiana. The site includes
the 675 acre railyard fa~ility which is approximately bounded to
the north by US33 (Franklin Stre~t), on the east by State Rou~e
19, to the south by Mishaw~ka Road, and to the west by State
Route 219. (see Figure 1), and certain areas of contamination that
extend in two directions, northeast and northwest from the
Conrail railyard. The Elkhart railyard is an electronically
. controlled hump yard which serves as a classification.
distribution yard for freight cars. It contains 72
classification tracks where cars are separated and switched to a
specific track corresponding to a particular destination. The
yard processes approximately 74 trains per day via 15 receiving
and.14 departing tracks. Car repair, engine cleaning, and diesel
refueling facilities are also located at the yard.
The study area, which includes the railyard, encompasses roughly
2,500 acres, with the topography generally being flat. The study
area is bounded on the north by the St. Joseph "River, on the west ~
by Baugo Bay, on the east by Oakland Avenue, and on the south by
the southern border of the Conrail railyard. There are several
light industrial properties located within the study area to the
north and northwest of the rail yard, as well as the numerous
light industries surrounding the study area to the east and
south. Within the above referenced study area, there are also
several residential areas, comprised mainly of single-family
homes. Approximately 3,500 people live within this study area,
within about a mile and a half of the site. Of this total, about
3,000 of the people use private residential wells for their water
supply, and another 300 get their water supply from a private
utility, whose well is also located in the study area. The
closest downgradient residenc~s to the site are those located
directly across US33, just to the north of the railyard (one or
two hundred feet away). .
The major surface water bodies in the vicinity of the study area
are the St. Joseph River and Baugo Bay. The St. Joseph River
flows westward and is located a little over a mile north of the
Conrail site. Baugo Bay flows north into the St. Joseph River,
and is located immediately to the west of the study area.
Crawford ditch originates at the site, and flows intermittently
to the St. Joseph River. Floodplains and wetland areas exist
along both the St. Joseph River and Baugo Bay.
II.
. SITE HISTORY AND ENFORCEMENT ACTIVITIES
The railyard began operations in 1956 as part of the New York.
Central Railroad, and continued operations as a subsidiary of the
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Penn Central Transportation Company until 1976. From 1961 to
1968, numerous citizen complaints regarding oil discharges from
the railyard to the St. Joseph River were filed with state and
local 'authorities. Based on interviews with ex-employees of the
railyard, and other information, between 1966 and 1969 a tank car
containing carbon tetrachloride collided with another car during
humping operations at the railyard causing the release of
approximately 16,000 gallons of carbon tetrachloride.
In 1976 operations at the railyard were transferred to the
Consolidated Rail Corporation (Conrail). From 1976 to the
present, spills and releases of oil, diesel fuel, hydrochloric
acid, caustic soda, and various petroleum-related substances have
occurred there. Reports also indicate that a track-cleaning
substance (the chemical composition of which is unknown) and
engine degreasers were used and disposed of at the railyard.
Initial Investigations and Removal Actions
In June 1986, a resident on County Road 1, just to the north of
US33, reported to U.S. EPA that his residential well contained
elevated levels of volatile organic compounds. On July 2, 1986,
U.S. EPA/Technical Assistance Team (TAT) collected and analyzed a -
water sample from this residential well. Sample analysis
indicated the presence of trichloroethylene (TCE) at 800 parts
per billion (ppb) and carbon tetrachloride (CCI4) at 485 ppb.
Based on this finding, EPA/TAT initiated a ground water sampling
program in the County Road 1 and LaRue Street areas, located to
the northwest and northeast of the railyard, respectively.
Samples were also taken at residences in the Vistula Avenue area,
to the northwest of the County Road 1 area. Ground water
sampling began on July 17, 1986. A total of 88 residential wells
were sample4 by EPA/TAT. Concurrently, 11 additional residential
wells were sampled, by individual 'well owners. TCE concentrations
as high as 4,870 ppb and CCl4 concentrations as high as 6,680 ppb
were detected. A total of 63 ground water samples showed
detectable levels of TCE,CC14, or both.
Bottled water was provided to residents whose wells were affected
by the contamination. A portion of the residents in the LaRue
Street area were later connected to a water-main extension from
the City of Elkhart. Many of the residences, however, had carbon
filter units installed to ensure a safe drinking water supply.
Two types of activated carbon filter units were installed in
,residences: point-of-use units and whole-house units. In all, 20
point-of-use and 56 whole-house units were installed. Although
homeowners are ultimately responsible for the. operation and
maintenance of these units, the Indiana Department of
Environmental Management (IDEM) assisted in their operation and
maintenance until 1992. IDEM also periodically sampled
residential wells in the area'to monitor the migration of
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contamination. During this time period, IDEM identified other
residents with contaminated wells and installed filtration
systems as needed.
EPA/TAT also conducted an inspection of the Conrail site in July
and August 1986. Seven water/liquid samples and 21 soil samples
were collected at the Conrail site on July 31 and August 1, 1986.
The results of the analyses revealed TCE concentrations as high
as 5,850 ppb "and CCl4 concentrations as high as 117 ppb in soil
samples. Based on these results, the downgradient location of
TCE- and CCl4-contaminated private wells from the railyard, and
the history of poor waste handling practices at the railyard, the
Conrail site was placed on a roster of sites proposed for
inclusion on the National Priorities List (NPL) in June 1988.
The site was listed on the NPL in" August 1990.
Remedial Investigations/Feasibility Studies (RI/FS)
On June 27, 1988, U.S. EPA sent a special notice letter to
Conrail offering them the opportunity to undertake the RI/FS for
the site, including investigations of the ground water
contamination emanating from the site. . Since Conrail only
expressed a willingness to undertake a portion.of the RIfFS, u.s. -
EPA determined that Conrail had not presented a "good faith"
offer to conduct the entire RI/FS at the Conrail site.
Therefore, on September 30, 1988, U.S. EPA entered into a
contract to have the RI/FS conducted. The workplan for the RI/FS
was approved in July 1989, and actual investigations for the
Conrail site began shortly thereafter.
The Remedial Investigation was conducted in three phases. The.
first phase, which included a soil gas survey, soil sampling, and
ground-water sampling for TCE and CCL4, was cqmpleted in January
1990, and detailed in the April 1990 Preliminary Evaluation
Report, as well as being summarized in a June 1990 fact sheet.
The Phase I RI results indicated, inter alia, soil contamination
with TCE and CCL4 in the area of track 69 at the Conrail
railyard, and ground-water contamination with TCE and .CCL4 in the
County Road 1, Vistula Avenue, and LaRue Street areas. The Phase
I results also provided a preliminary indication of the vertical
extent of contamination. In addition, no ground-water
contamination with CCL4 was detected upgradient of the Conrail
railyard during the Phase I RI and no significant concentrations
.of TCE were detected upgradient of the railyard during the Phase
IRI. .
The second phase of the Remedial Investigation, which was
summarized in the July 1992 "Phase II RI Technical Memorandum",
was conducted to, inter alia, preliminarily identify potential
sources contributing to the County Road 1 and LaRue Street
ground-water contamination areas, evaluate the relationship
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between the County Road 1 plume and the Vistula Avenue and
Charles Avenue ground-water contamination, define the nature and
extent of the sources of contamination, preliminarily identify
the residential well usage north of the St. Joseph River, and
collect data necessary to support alternatives for an ~nterim
remedy.
The third and final phase of the RI at the Conrail Site was
conducted to, inter alia, define the path of the ground-water
contamination plume originating from the CCL4 source at track 69,
define the areal extent of the TCE source located between tracks
65 and 66 in the west end of the classification yard, investigate
reported locations of buried tank cars, further investigate the
link between the County Road 1 ground-water contamination and the
Charles Avenue ground-water contamination, identify the nature
and extent of the potential source on the railyard for the LaRue
Street ground-water contamination plume, and define the north-
'south extent of the track 69 CCL4 area source and investigate the
potential for the presence of additional sources, including dense
non-aqueous phase liquids (DNAPLs). DNAPL chemicals are
immiscible with and denser than water. Their immiscibility and
high density enable DNAPL constituents released to a porous
medium to penetrate the unsaturated zone and migrate downward
into the saturated zone as a separate nonaqueous phase. This
nonaqueous phase may persist as pooled product accumulated on a
stratigraphic unit or as residual material throughout the
vertical column of the unconsolidated deposit. Results of the
Phase III RI, as well as summaries for Phase I and II can be
found in the "Remedial Investigation Report" which was completed
in April .1994.
Collectively, results from the various investigations indicate
that:
.
Based on soil sampling data, there are two well-defined
source areas (areas of soil contamination that act as a
source of ground-water contamination) on the Conrail
facility, a CC14 source ,area in the eastern section of
the classification yard and a TCE source area in the
western section of the classification yard,
approximately 1,900 feet west of the eastern straight-
a-way between tracks 65 and 66.
.
A third potential source area with lower levels of
, contamination has been identified in the eastern
portion of the Conrail railyard, and
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.
There are two identified ground-water contaminant
plumes coming from the Conrail facility, the County
Road 1 plume and the LaRue Street plume. Refer to
. Figure 2 for the locations and approximate extent of
these contaminant plumes. The Maximum Contaminant
Levels (MCLs) for TCE and CCl4 have been exceeded in
many residential wells within the County Road 1 plume.!
Levels of contamination are discussed in Section V of this Record
of Decision.
Interim Remedial Action
Based on the Phase. I and II RI results, a Record of Decision
(ROD) for Interim Remedial Action at the Conrail site was signed
in June 1991. After issuance of special notice letters and an
attempt to negotiate a consent agreement with Conrail and the
Penn Central Transportation Corporation (Penn Central), on July
1, 1992, EPA issued a Unilateral Administrative Order for
Remedial Design and Remedial Action (Order) which requires
Conrail and Penn Central to perform remedial activities described
in the Statement of Work (SOW) attached to the Order. Only
Conrail has complied with the Order.~ The Interim Remedial
Action for the Conrail Site, as described in the SOW, consists
of the following elements:
.
Institutional Controls including deed restrictions for
future use of the railyard executed through the Elkhart
County Recorder; restrictive covenants ensuring that
property outside the Conrail railyard on which
components of the remedy will be located (e.g.,
monitoring wells, treatment facilities) will not be
disturbed; and abandonment of residential wells located
within the area of contamination;
.
Monitoring Program including ground-water monitoring in
and around the area of contamination and air monitoring
of the treatment system;
.
Ground-water Extraction, Collection, Treatment, and
MCLs for TCE and CCL4 are both 5 ug/L.
2 After several name changes, the Penn Central
Corporation recently changed its name to American Premier
Underwriters.
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Discharge System will be constructed, operated, and
maintained to prevent further horizontal and vertical
migration of contaminated ground water located
northwest, downgradient from the Conrail railyard by
extracting water from the plume, treating it using air
stripping, and discharging it to the St. Joseph River;
.
Fence installation to enclose ground-water extraction
and treatment facilities; and
.
provision of an Alternate Water Supply through the
construction and first-year operation and maintenance
of a distribution system extending from the City of
. Elkhart water supply to affected residential/business
areas located downgradient from the Conrail railyard,
and maintenance of individual water filter units or
provision of bottled water for those areas until the
distribution system is operational. Quarterly
monitoring of residential wells was also required.
The Interim Remedial Action 100% (final) Design was approved for
implementation on June 2, 1994. Construction should commence
before the end of 1994.
III.
HIGHLIGHTS OF COMMUNITY INVOLVEMENT
u.S. EPA and IDEM have been interacting with the community, in
terms of the Conrail site, since contamination was first found in
residential wells in 1986, starting with the Removal Action,
through the sampling of wells and the provision of bottled water,
carbon filters, watermain connections, etc. In addition, IDEM
has been in contact with residents since that time as a part of
its periodic sampling of residential wells, and maintenance of
the carbon filter systems.
With respect to the remedial activities, community relations
activities began in late 1988, with the development of the
Community Relations Plan. In accordance with that plan,variQus
meetings have been held, and facts sheets have been issued. An
RI/FS kickoff meeting, held in July 1989, was attended by about
150 people. Availability sessions held in the afternoon and
evening of June 26, 1990, to discuss the results of. the first
phase of investigations, were also widely attended. . A public
meeting for the Proposed Plan for the Interim Remedial Action was
held on May 1, 1991, and attended by about 150 people. Numerous
fact sheets have been issued since July 1989.
The Proposed Plan for this Final Remedial Action was released to
the public on April 14, 1994, outlining remedial alternatives,
and informing residents that the FS and all other documents
comprising the Administrative Record for the site, were available
at the public information repositories at the Elkhart Public
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Library and the Harley Holben Elementary School. The
Administrative Record Index is included as Appendix A. A public
comment period was held from April 14, 1994, to May 16, 1994, and
a public meeting was held on April 25, 1994 to discuss the
proposed remedial action with the residents. The public meeting
was attended by about 200 people, with numerous questions asked,
and several oral comments received. These comments, as well as
written comments received, and U.S. EPA's response to the
. comments are included as Appendix' B, the Responsiveness Summary.
Community interest is further evidenced by the creation of a
local community interest group, the Citizens League for
Environmental Action Now (CLEAN), which has been extensively
involved in the Conrail project, in part, through verbal and
written communications with both U.S. EPA and IDEM. Media
coverage has also been fairly extensive throughout the life of
the project, including coverage by local newspapers and
television stations.
IV.
SCOPE AND ROLE OF THE FINAL REMEDIAL ACTION
This Record of Decision (ROD) is the second and final ROD for the
Conrail site. The Interim Remedial Action, outlined in the June -
28, 1991 ROD for the Conrail site, required immediate action to
hook up residences and businesses within the ground-water
contaminant plumes (approximately 500 residences and businesses)
to city water and contain the County Road 1 plume via extraction
(and treatment) of ground water.
This final Remedial Action will fully address the contaminated
ground water and is designed to restore the aquifer as a drinking
water source, and will address all known contaminated soils on
the railyar~ which may serve as source areas for the ground water
. contamination. .To mitigate the threat to human health and the
environment, the selected remedy provides 1) an alternate water
supply to an additional estimated 700 to 1000 residences and
businesses that are located between the Conrail railyard to the
south, the St. Joseph River to the north, Baugo Bay to the west,
and Nappanee Street (SR 19) to the east that are not being hooked
up under the Interim remedial Action, 2) treating contaminated
groundwater by emphasizing extraction/treatment of contaminated
groundwater in "hot spots", and 3) remediating contaminated soil
on the railyard by soil vapor extraction/air sparging.
v.
SUMMARY OF SITE CHARACTERISTICS
Site Geology and Hydrogeology
The information collected during the subsurface investigations is
used to describe geological conditions present in the study area.
The 52 soil borings and 77 boreholes for monitoring well
installation allowed for extensive coverage, with respect to area
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and depth of the study area. The combined results of the
subsurface soil investigations that were conducted during the
three phases of the RI show that the study area primarily
consists of unstratified sand and gravel outwash deposits.
Evaluation of the subsurface soil investigation findings also
show that silt and clay units are present as discrete and
isolated lenses or masses.
The bedrock units. beneath the overburden consist of the Coldwater
Shale of Mississippian age and the Sunbury and the Ellsworth
Shales of Devonian and Mississippian age. Shale was encountered
and sampled while drilling at seven locations and in all cases
the shale was bluish-gray to greenish-gray, pristine, dry, and
extremely dense. The approximate thickness of this overburden
ranges from 137 to 169 feet and the median depth to bedrock is
150 feet below ground surface (BGS). The median elevation of the
bedrock surface is 600 feet above mean sea level (MSL) and is
essentially horizontal under the study area. Because the bedrock
is not an aquifer and was observed to be pristine, dry, and
extremely dense, the investigation and analysis will focus on the
glacial geology.
The depth to the water table in the study area "varies from
approximately 3 feet BGS to nearly 20 feet BGS. The observed
depth to water depends on geographic location, season, and
elevation of the ground surface. A comparison of the data
recorded during at least 14 separate monitoring events over a
three-year time span indicates fluctuations of less than 3 feet
observed in the elevation of the potentiometric surface. The
relative static water levels among wells were consistent for each
monitoring event, causing the shape of the potentiometric contour
lines and horizontal ground-water gradients to remain constant in
the shallow zone (the water table to approxim~tely 35 feet BGS) ,
the intermediate zone (35 feet BGS to 85 feet BGS) , and the deep
zone (85 feet BGS to the top of bedrock). The median Phase III
horizontal ground-water gradient is 0.0020 ft/ft for the shallow
zone, 0.0019 ft/ft for the intermediate zone, and 0.0020 ft/ft
for the deep zone. The general ground-water flow direction in
all zones is to the west-northwest. In the LaRue Street area,
however, the general flow direction is north.
The vertical hydraulic gradients calculated between two wells at
various nested locations show a general downward gradient in the
study area. The vertical hydraulic gradients and the respective
locations of the monitoring wells nests in the study area are
consistent with ground water recharge in the railyard and
subseqUent ground water discharge to the St. 'Joseph River.
Hydraulic conductivity values were calculated from slug test data
collected during the Phase II investigation, and correspond to
the filter pack and aquifer material immediately surrounding the
screened interval of the tested well. As a basis for comparison,
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a hydraulic conductivity value was also derived from the pump
test conducted in the study area by a water supply contractor
(Peerless-Midwest, Inc). A hydraulic conductivity value
calculated from a pump test represents the hydraulic conductivity
of the aquifer material within the zone of influence ot the
pumping. Because of the heterogeneity of the aquifer, variation
between slug test data and a large-scale pump test's data within
one or two orders of magnitude is not unusual. The geometric
mean of Phase II slug test results gives a hydraulic conductivity
value of 69 feet per day. The Peerless~Midwest pump test result
gives a hydraulic conductivity value of 280 feet per day. The
heterogeneity in the site conditions caused variability in input
parameters that result in a velocity range for ground water of 11
feet per year to 2,200 feet per year. The mean horizontal flow
velocity of ground water, based on a hydraulic conductivity of 69
feet per day, a horizontal gradient of 0.0020, and an effective
porosity of 0.25 is 200 feet per year.
Nature and Extent of Contamination
This section discusses the nature and extent of soil and.ground-
water contamination. Discussion of source areas is based on
analytical results from Phase I II, and III s01l samples.
Soil Contamination
Fifty-two soil borings, along with subsurface soil sample
collection, were completed during three phases of field
investigation in order to determine the nature and extent of
identified and suspected source areas contributing to identified
ground-water contamination. Figure 3 shows the soil boring
locations. Based on analytical results from subsurface soil
samples, two well-defined source areas (areas of soil
contamination that act as a source of ground-water contamination)
on the Conrail facility have been identified that contain
significant levels of contamination. A third potential CC14
source area with lower levels of contamination has been
identified in the eastern portion of the Conrail railyard.
A CC14 source area was identified in the eastern section of the
classification yard based on subsurface soil samples from soil
borings B-03, B~24, 'B-25, B-26 B-40, B-41, and B-42. Based on
analytical data from soil samples collected from these borings,
.CC14 contamination was detected in an area bounded on the west
and east by B-24 and B-25, respectively (75 feet), and on the
north and south by B-41 and B-42, respectively, (30 feet). These
borings are highlighted on Figure 3. CC14 contamination was'
detected in soil samples collected from these borings between the
depths of 18 feet BGS and 25.5 feet BGS (7.5 feet). The
analytical data from these boundary locations are greater than or
equal to 1 mg/kg, suggesting that this CC14 source area extends
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beyond the approximate boundaries established,with the data to
date. This source is located in the saturated zone, in a .
stratigraphic unit that is more silty than the stratigraphic
units ~bove and below it. B-40 was drilled to the top of bedrock
(150 feet) and soil samples were collected th~oughout the length
of the borehole. CCl4 was detected only once between 58 feet and
150 feet'BGS at 16 ug/kg in the 128 to 130-foot interval sample.
Chloroform, a degradation product of CCI4, was also detected in
this interval at a concentration of 9 ug/kg. Ground-water data
and site background information indicate the presence of a CCl4
dense non-aqueous phase liquid (DNAPL) source.
A TCE source area was identified in the western section of the
classification yard, approximately 1,900 feet west of the eastern
straight-a-way between tracks 65 and 66. Approximate dimensions
of this source area are based on analytical data from subsurface
soil samples collected from soil borings B-27, B-28, B-29, B-47,
B-51, and B-52. TCE contamination was detected in an area
bounded on the w.est and east by B-29 and B-32, respectively (120
feet), and on the north and south by B-47 and B-28 (10 feet).
These borings are highlighted on Figure 3. TCE contamination was
detected in soil samples collected from these soil borings at
depths from 0 feet to 4 feet BGS. This TCE source area is
located in the unsaturated zone. However, ground- water data
from wells located directly downgradient from this source (MW49D
and MW49BR) detect TCE contamination at depths much greacer than
4 feet BGS, indicating unidentified TCE contamination deeper in
the subsurface or an unidentified DNAPL TCE source.
In the eastern portion of the site, CCl4 contamination was
detected in subsurface soil samples collected from soil borings
B-48, B-49, and B-50 located on an east-west-trending line, just
north of track 6 in the receiving yard at the eastern end of the
site, on the Conrail facility in'the LaRue Street area. CCl4 was
detected in the 0 to 2-foot BGS sample interval in soil boring B-
50. This boring is highlighted on Figure 3.
Ground-water Contamination
Seventy-seven monitoring
of field investigation.
monitoring wells and the
wells.
wells were installed during three phases
Figure 4 presents the locations of the
analytical results associated with these
CCl4 and TCE contamination were detected in ground-water samples
collected from monitoring wells screened in the shallow,
intermediate, and deep zones on the Conrail facility, at the St.
Joseph River, and in the area between these points. Ground-water
flow direction in all three zones is west-northwest, and the
County Road 1 ground-water contamination plume as defined by
ground-water samples follows this path from the Conrail facility
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to the St. Joseph River. Ground water in the Larue Street area
flows to the north. Ground-water samples collected from
monitoring wells located hydraulically upgradient of the plume
and on the Conrail facility, MW27S(shallow) and I (intermediate) ,
MW28S and I, MW29S and I, and MW31S and I, and ground-water
samples from monitoring wells MW13S and D(deep) , located
upgradient of the plume and the site, did not detect any VOC
contamination.
The maxim~m concentration of CC14 ground-water contamination was
110,000 ug/L collected from monitoring well MW46S located in the
track 69 source area. . This concentration is 13.8% of the
solubility of CC14 and suggests a CC14 DNAPL source. Site
background information and the detection of CC14 in a subsurface
soil sample at 130 feet BGS also suggest that the CC14 source
area in track 69 is a DNAPL. source.
The .maximum concentration of TCE detected in a ground-water
sample was 11,000 ug/L from monitoring well MW41, located
immediately downgradient of the Conrail facility. This
concentration is 1.4% of the solubility of TCE and suggests a TCE
DNAPL source. MW41 is side-gradient of the TCE source area
identified in the classification yard. Based on analytical and
hydrologic data, the DNAPL source is on the Conrail. property, but
is, as yet, unidentified.
CC14 was detected only in ground-water samples collected from
shallow monitoring wells in the LaRue Street plume surrounding
the identified CC14 soil contamination in the receiving yard on
the Conrail facility. The soil contamination probably
contributes to the identified CC14 ground-water contamination.
Monitoring wells upgradient of the soil contamination did not
detect CC14.
TCE was detected (MW20S- 15 ug/L) above the maximum contaminant
level (MCL) forTCE (5 ug/L) in the LaRue Street plume. TCE was
detected below the MCL in other samples throughout the plume.
Monitoring wells located directly upgradient of the Conrail.
facility did not detect TCE. Based on ground-water analytical
data, the source of the TCE contamination is on the Conrail
property, but is, as yet, unidentified.
Additionally, results from quarterly monitoring of residential
wells by Conrail under the 1992 Unilateral Administrative Order
have indicated that many of the residential wells in the County
Road 1 plume are consistently over the MCLS for TCE or CC14, or
both, and that low levels of 1,1,1-trichloroethane were found in
the Harley Holben Elementary School drinking water.
VI: .
SUMMARY OF SI:TE RISKS
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12
Based on the findings of the RI, a baseline risk assessment was
performed to evaluate the risks posed to human health and the
surrounding ecological environment by site contamination. The
baseline risk assessment followed the guidance provided in u.s.
EPA's Risk Assessment Guidance for Superfund (RAGS): Volume I,
Human Health Evaluation Manual. Risk assessment guidelines
developed by the State of Indiana were also applied. The
findings of this assessment, in addition to the procedures,
. methods, and assumptions used during the risk assessment process,
are described in detail in the April 1994 RI Report. The risk
assessment determined that site contamination does not pose
significant risks to ecological receptors (e.g., sensitive
species), but does pose significant risks to human. health. With
regard to human health, the risk assessment identified and
focussed on the following source areas for the Conrail Site:
o
VOC contamination in the ground water and subsurface
soil beneath the railyard.
o
VOC contamination of ground water in the County Road 1
plume area, extending north and west from the central
portion of the railyard. This plume potentially
affects an area that encompasses the 'County Road 1,
Charles Avenue, and Vistula Street residential areas.
o
VOC contamination of ground water in the LaRue Street
plume area, extending north from the eastern portion of
the railyard. This plume potentially affects the LaRue
Street residential area.
From these source areas, the risk assessment identified the
following exposure pathways that appear to have the greatest
potential to produce adverse human health effects: direct contact
with contaminated soil or ground water (dermal contact or
accidental ingestion) and inhalation of contaminants volatilized
from the soil or ground water. This risk assessment .
quantitatively evaluated two groups of receptors; adult workers
and visitors exposed'to existing site conditions, and local
residents of potentially affected areas. The risks to the site
workers and visitors consist of inhaling contaminants volatilized
from ground water and subsurface soils, and possible direct
contact during any excavation activity in contaminated areas.
The risks to the residents in the areas of the County Road 1
plume and LaRue Street plume are from ingestion, dermal exposure,
and vapor inhalation of ground water used for domestic purposes,
and inhalation of compounds volatilized from the groundwater and
infiltrating basements. or other enclosed areas. It was assumed
that there will be no change in use of the site in the
foreseeable future, and no new residences constructed any closer
to the site than already exist.
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13
The risk assessment evaluated the following VOCs as contaminants
of potential concern: acetone, 2-butanone, CCI4, chloroform,
chloromethane, 1,1-dichloroethane, 1,1-dichloroethene, 1,2- .
dichloroethene, ethylbenzene, methylene chloride, methyl isobutyl
ketone, tetrachloroethene, 1,1,2-trichloroethane, 1,1,1-
trichloroethane, TCE, toluene, vinyl chloride, and xylenes. Of
these contaminants of potential concern, it was determined that
CCI4, chloroform, 1,1-dichloroethene, 1,2-dichloroethene, TCE,
and vinyl chloride contribute significantly to human health
risks. Both categories of human health risks, carcinogenic
(cancer) and non-carcinogenic (e.g., organ immunological effects,
birth defects, skin irritation), were evaluated. Some
contaminants mar pose both types of risks.
According to the risk assessment,' contaminants in three areas at
the site pose carcinogenic risks that exceed the 1 x 10~ level
established by EPA as a point of departure for determining
protective cleanup levels. These areas and the contaminants that
pose these risks include:
o
The railyard area-due to subsurface soil contamination
(vinyl chloride, and to a lesser extent TCE) and due to
,ground-water contamination (CC14t and'to a lesser
extent TCE) .
o
The County Road 1 plume area-due to CC14, chloroform,
1,1-dichloroethene, TCE, and vinyl chloride in the
ground water.
o
The LaRue Street plume area-due to CCI4, chloroform,
and TCE in the ground water.
Contaminants and exposure scenarios which pos,e significant
carcinogenic risks are summarized in Table 1. The risks shown
are for reasonable maximum exposure (RME) scenarios. The highest
potential cancer risks are posed to residents in the County Road
1 plume area due to ingestion of CC14 and TCE in ground water.
The'reduction of contaminant concentrations to levels at which
they pose an excess lifetime cancer risk between 1 x 104 and 1 x
10~ has been determined by EPA to be an acceptable cleanup level.
On the basis of the results of the risk assessment, the more
conservative risk (1 x 10~ as established in the NCP as a point
of departure for establishing cleanup levels) can be achieved by
reducing the contaminant concentrations in on-site soils and in
ground water to the risk based concentrations shown in Table 1.
However, the values presented in Table 1 represent the
conservative end of the range (104 to 10~) of risks that are
acceptable for cleanup levels. Values as high as 100 times the
risk-based concentrations shown on Table 1 would still fall
within 'the acceptable range.
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14
The risk-based concentrations are calculated values based upon
excess cancer risks determined to be posed by the RME input
concentrations. The RME input concentrations, the resulting
calculated cancer risks, and concentrations at which risks would
be reduced to the 1 x 10~ level are shown in Table 2. 'These
calculations have been performed for each compound in each
pathway and the results (risk-based concentrations) are listed in
Table 1.
The assessment of non-carcinogenic risks determined that
significant risks (hazard indices exceeding 1.0) were posed by
CC14 and 1,2-dichloroethene as a result of ground water use by
residents in the County Road 1 plume and LaRue Street plume
areas. In order to reduce the hazard indices below 1.0 (the
level below which no adverse health effects are anticipated),
contaminant concentrations must be decreased to the levels shown
in Table 2. The risk-based concentrations listed in Table 2 were
calculated using the same approach used in Table 1.
Ecoloqical Assessment
Ecological impacts from site-related contamination were also
evaluated. The objective of the Ecological Assessment (EA),
which can be found in the final RI report, was to screen the
surface waters and sediments of nearby aquatic and wetland
habitats for site-related contaminants to estimate the potential
risk that contaminants pose to the natural environment. Results
of the EA indicate that few organic compounds were detected above
detection limits in the St. Joseph River downstream of Crawford
Ditch, Baugo Bay and the ponds. Singular detections of some
site-related contaminants, such as CCL4 and DCE were found in
sediments samples from the St. Joseph River. Based on the many
sediment samples taken, the singular detections suggest no
pervasive sediment contamination present that would likely
contribute a significant risk to aquatic life.
In summary, actual or threatened releases of hazardous substances
from this site, if not addressed by implementing the response
action selected. in this ROD, may present an imminent and
substantial endangerment to public health, welfare, or the
environment. Additionally, by reducing site contaminant
concentrations to the risk-based concentrations shown in Tables 1
and 2, residual contaminant concentrations would be unlikely to
pose significant adverse health effects through the exposure
pathways evaluated in the risk assessment.
VII.
DESCRIPTION OF ALTERNATIVES
Remedial action objectives and numerical cleanup goals were
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15
established to define the objectives of the remedial action, in'
order to determine what types of remedial responses were
appropriate for the Conrail site and the extent to which
remediation needs to be implemented. These objectives were
established taking into consideration regulations and guidance
(ARARs and.TBCs) from federal and state regulatory agencies and
the find~ngs of the site-specific human health and ecological
risk assessment to ensure that cleanup goals will be sufficiently
protective of human health and the environment.
The general remedial action objectives that were established for
the Conrail site include:
o
Minimizing potential for human exposure to contaminants
by eliminating significant exposure routes and/or
reducing contaminant concentrations;
o
Minimizing further degradation of the ground water
beneath the Conrail facility;
o
Minimizing further degradation of the ground water
downgradient from the Conrail facility (outside of the
railyard property boundaries); and
'-
o
Restoring the ground water to its original use as a
drinking water source.
The following soil cleanup standards were established for the
Conrail site:
o
CCl4 - 5 mg/kg,
TCE - 3 mg/kg, and
o
o
vinyl chloride - 0.010 mg/kg
The foll.owing ground water cleanup standards were established for
the Conrail Site:
o
CCl4 - 5 ug/L,
TCE - 5 ug/L,
o
o
1,1-dichloroethene - 7 ug/L,
o
1,2-dichloroethene- 70 ug/L,
chloroform - 6 ug/L,
o
o
tetrachloroethene - 5 ug/L,. and
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16
o
vinyl chloride - 2 ug/L.
The FS identified and evaluated alternatives that could be used
to address threats and/or potential threats to human health and
the environment at the Conrail Site. It should be noted that
these alternatives are for the Final Remedial Action only. These
alternatives are designed to be consistent with the Interim
Remedial Action; however, the costs of the Interim Remedial
Action are not included in the cost estimates listed below.
Alternative 1:
No Action
The no action alternative includes no remedial actions. Even
though certain actions will be implemented at the site under the
Int~rim Remedial Action, these actions have not been instituted
to date. Therefore, in compliance with the NCP, the no action
alternative is developed and evaluated to serve as a baseline for
comparison with other alternatives. Under the no action
alternative, no efforts (other than those planned for the Interim
Remedial Action) would be made to mitigate the effects of or
control the migration of contaminants identified at the Conrail
Site.
.
.
Estimated Cost: $0
Estimated Construction Time Frame: 0 months
(O & M: 0 years)
Alternative 2: Institutional Actions, Additional Source
Investigation, Vapor Abatement, Ground-water Containment
This alternative, and each remaining alternative, includes
several institutional actions intended to limit the potential for
human exposure to contaminated media. Institutional actions
include ground-water and air monitoring, water supply extension
and well abandonment, restrictive covenants, access restrictions,
and deed restrictions. Deed restrictions and restrictive.
covenants will be implemented on the railyard and the property
where the groundwater extraction facilities and monitoring wells
are installed, pursuant to Indiana Code (IC) 13-7-8..7-12 and 310
IAC 16-10-2. The main difference .between alternative 2 and the
Interim Remedy is that alternative 2 provides for additional
alternate water supply hook-ups to businesses and residences, as
necessary, based on on-going groundwater monitoring.
Groundwater monitoring is necessary since groundwater
contamination will not decrease significantly in a short time
frame~ regardless of which remedial alternative is selected and
implemented at the site. Groundwater monitoring can also be used
to evaluate the effectiveness of on-going groundwater remedial
efforts. Such monitoring would consist of collecting and
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17
analyzing groundwater samples from monitoring wells at regular
intervals, and reporting monitoring results.
Groundwater monitoring requirements would have to be changed over
time due to changes in groundwater contaminant concentrations and
groundwater flow direction.
.Air monitoring would be conducted in buildings and basements
within the site area to determine if significant VOC .
concentrations are accumulating in basements or buildings, and to
determine any changes in VOC vapor concentrations in buildings
and basements as a result of changes in groundwater VQC
concentrations. In the event that air monitoring reveals the need
for vapor abatement in buildings within the Conrail Site study
area, appropriate actions would need to be considered and
implemented. Vapor abatement actions could include sealing
building floors or basements (e.g., grouting cracks or seams)
and/or the installation and operation of venting systems to
ensure sufficient air flow to avoid VOC accumulation. The type
and extent of actual vapor abatement actions would be specified
after the need for action is determined and the types of
buildings affected and levels of VOCs are established. Because
the need for vapor abatement has not been established, and
because the magnitude of any necessary actions cannot be
predicted at this time, no costs have been included for vapor
abatement. for the purposes of cost estimates in this ROD.
The water supply extension under alternative 2 includes the
provision for hookup of additional residences or businesses that
are found, through ground-water monitoring, to be contaminated
over MCLs after the Interim Remedial Action is implemented.
Additionally, this, and each remaining alternative, includes
provisions for additional source investigations to identify other
source areas that could be contributing to ground-water
contaminati.on.
Also under this alternative, the groundwater extraction/treatment
system operating under the Interim Remedy, which includes 6
extraction wells, would be continued to contain the County Road 1
plume identified northwest of the railyard. In addition, a
similar groundwater extraction/treatment system, which would
consist of one extraction well, would be operated to contain the
contaminated groundwater plume in the La Rue Street area.
Ground water in both the La Rue Street and the County Road One
areas would be collected primarily to change ground water flow
patterns to restrict further migration of ' contaminants from the
facility to areas downgradient from the facility and tQ limit any
further expansion of ground-water plumes downgradient from the
facility, but also to allow treatment of contaminated ground
water. R~fer to Figure 5 for approximate extraction well
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18
locations for this alternative. Collected ground
treated using air stripping and discharged to the
River. Exhaust from the air stripper(s) would be
vapor phase carbon adsorption prior to emission.
would be disposed of properly.
water would be
St. Joseph
treated by
Spent carbon
.
Estimated cost: $3,000,000 present worth ($1,300,000
capital cost, $135,000 annual O&M cost)
Estimated Construction Time Frame: 6 to 9 months
(0 & M: 30 years) .
.
Alternative 3: Institutional Actions, Additional Source
Investigation, Vapor Abatement, In Situ Soil Remediation,
Hookup to Alternative Water Supply, Ground-Water.
Extraction/Treatment/Discharge
Full
This alternative includes the institutional actions, additional
source investigation, and vapor abatement aspects described in
alternative 2.
Under this alternative, soil contamination source areas
identified at the site would be addressed using in situ treatment
technologies, which include soil vapor extraction and air
sparging.. VOC contamination in the TCE source area in the
unsaturated zone would be treated using vapor extraction. The
CCl4 contamination in the one saturated zone would be treated
using air sparging, in conjunction with vapor extraction in the
overlying unsaturated zone. Known source areas are identified in
Figure 3. Additional source areas may be identified during
further investigation at the site. Any additional source areas
may be included in the soil remediation action, as determined
during the remedial design.
. .
This alternative would also include extension of the City of
Elkhart municipal water supply system to all residences in the
area bounded by the Conrail facility to the south, the St. Joseph
River to the north, Baugo Bay to the west, and Nappanee Street
(State Route 19) to the east. Approximately 500 residences are
being hooked up to city water under the Interim Remedial Action;
this alternative would provide this hookup to all remaining
residences in the area described above. The number of additional
residences/businesses to be hooked up under this alternative is
between 700 and 1000. Private wells within this area would be
abandoned once the water supply extension is operational.
Ground-water extraction/treatment under this alternative would
restore contaminated groundwater beneath anddowngradient of the
facility with extraction emphasized in "hot spots". "Hot spots"
may occur in contaminated groundwater as DNAPLs or as "slugs" of
contamination. Refer to Figure 6 for approximate extraction well
locations for alternative 3. The groundwater treatment system
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19
shall be operated until groundwater standards are met throughout
the plume. The ground-water extraction, treatment, and discharge
system, including any associated air treatment, would be the same
as for alternative 2, except with respect to the number and
location of extraction wells.
.
Estimated cost: $7,700,000 present worth ($5,000,000
total capital cost, $213,000 annual O&M cost)
Estimated Construction Time Frame: 12 to 18 months
(0 & M: 30 years)
.
Alternative 4: Institutional Actions, Additional Source
Investigation, Vapor Abatement, In Situ. Soil Remediation, Ground-
~ater Containment Beneath Facility, Ground-water Restoration Off-
Facility.
This alternative includes the institutional actions, additional
source investigation, and vapor abatement measures described
under alternative 2, and the in situ soil treatment described
under alternative 3. This alternative does not include
additional water main hook-ups, as set forth under alternative 3.
The ground-water extraction/treatment system for this alternative -
is similar to that for alternative 3, differing in that the
number of extraction wells would be increased downgradient from
the facility. Due to the additional extraction wells,
alternative 4 should attain cleanup goals more. quickly
downgradient of the facility. Also, an additional extraction
well would be installed immediately downgradient from the CCl4
source ar~a on the railyard to assist in containing and capturing
contaminants mobilized by the air sparging system.
Refer to Figure 7fo~ approximate extraction well locations.
.
Estimated Cost: $6,900,000 present worth ($3,000,000
total capital cost, $307,000 annual O&M cost)
Estimated Construction Time Frame: 6 to 12 months
(0 & M: 30 yea~s)
.
Alternative 5: Institutional Actions, Additional Source
Investigation, Vapor Abatement, Soil Excavation and On-Site
Thermal Desorption,. Ground-water Restoration
This alternative differs from the previous alternatives in that
it attempts to restore the aquifer beneath and downgradient from
the facility more quickly through ground-water extraction,
treatment, and discharge. Refer to Figure 8 for approximate
extraction well locations. Additionally, soil contamination on
the facility is addressed by excavation and on-site thermal
. desorption.
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20
This alternative includes the institutional actions, additional
source investigation, and vapor abatement measures described
under alternative 2.
.-
Estimated Cost: $10,200,000 present worth ($5,500,000
total capital cost, $382,000 annualO&M cost)
. Estimated Construction Time Frame: 12 to 18 months
(0 « M: 30 years)
.
VIII.
SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
The NCP requires that the alternatives be evaluated on the basis
of the following nine evaluation criteria: (1) Overall protection
of human health and the environment; (2) Compliance with
applicable or relevant and appropriate requirements (ARARs); (3)
Long-term effectiveness and permanence; (4) Reduction of
toxicity, mobility, or volume through treatment; (5) Short-term
effectiveness; (6) Implementability; (7) Cost; (8) State
acceptance; and (9) Community acceptance. This section compares
to the alternatives with regard to these nine evaluation
criteria.
Threshold Criteria
1.
Overall Protection of Human Health and the Environment
addresses whether a remedy provides adequate protection of
human health and the environment and describes how risks
posed through each exposure pathway are eliminated, reduced
or controlled through treatment, engineering, or
institutional controls. The selected remedy must meet these
criteria.
The no action "alternative provides no protection to human health
and the environment which would allow risks to human health tp
continue unabated. For alternative 2, significant human exposure
to contaminated ground water would be essentially eliminated for
those users connected to the water supply system.. However ,. not
all residents that may potentially be at risk are hooked up to
the water supply, the risks posed to site workers by vapor
inhalation w~:)Uld continue to exist, and soil contamination
beneath the facility would continue to contribute to ground-water
contamination.
Alternatives 3,4, and 5 would be fully protective of human health
and the environment, with one exception. For alternatives 4 and
5, which do not provide for an extension of the alternate water
supply, the possibility exists that the wells of residents that
are not hooked up to the water supply system under the Interim
Remedial Action may become contaminated either by ineffective
plume containment or additional contaminant sources outside of
the current plume areas. If this situation occurs, residents
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21
would be exposed to contamination.
2 .
Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs) addresses whether a remedy will meet
applicable or relevant and appropriate federal and state
environmental laws and/or justifies a waiver from such
requirements. .The selected remedy must meet this criteria
or waiver of the ARAR must be attained.
. Alternatives 3,4, and 5 are intended to fully comply with all
ARARs. However, alternatives 4 and 5, with more aggressive
ground-water extraction systems, may achieve ground-water ARARs
more quickly than alternative 3. The no action alternative and
alternative 2 would not achieve the cleanup goals for soil and
gro~nd water that have been established as ARARs since
alternative 1 provides no action and alternative 2 does not
address contaminated soil and only .contains contaminated ground
water, as opposed to pumping and treating contaminated ground
water to achieve cleanup goals throughout the contaminant plumes.
Primary Balancinq Criteria
3 .
Long-Ter.m Effectiveness and Permanence refers to expected
residual risk and the ability of a remedy to maintain
reliable protection of human health and the environment over
time, once cleanup levels have been met.
The no action alternative does not provide an effective or
permanent means of .achieving the remedial action objectives.
Significant risks would continue to be posed by site contaminants
for a long time period. Alternative 2 does not provide a
permanent remedy for the site. The LaRue Street plume and risks
posed to site w6rkersfrom contamination in soils present at the
site are not addressed under alternative 2.
To the extent possible at this site, alternatives 3, 4,. and 5
would provide a permanent, effective remedy. Given the potential
at the Conrail site for the presence of previously unidentified,
additional sources that may contribute to ground-water
contamination, and the potential future releases of .contaminants
.resulting from ongoing rail operations,' no alternative for this
site can absolutely be considered permanent; however, the
additional investigations included in alternatives 3, 4, and 5
will attempt to correct this potential shortfall.
4.
Reduction of Toxicity, Mobility, or Volume Through Treatment
addresses the statutory preference for selecting remedial
actions that employ treatment technologies that permanently
and significantly reduce toxicity, mobi~ity, or volume of
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22
the hazardous substances as their principal element. This
preference is satisfied when treatment is used to reduce the
principal threats at the site through destruction of toxic
contaminants, reduction of the total mass of toxic
contaminants, irreversible reduction in contaminant
mobility, or reduction of total volume of contaminated
media. .
.The no action alternative includes no treatment and, therefore,
provides no reduction in toxicity, mobility, or volume of
contaminants.
Implementing alternative 2 is designed to decrease the mobility
of contaminants downgradient from the facility. Extraction of
contaminants in the County Road 1 plume and LaRue Street plume
would decrease the total volume of contaminants in the
environment and the air stripping, collection of vapor phase
contaminants using carbon adsorption, and the regeneration of
carbon would provide destruction of extracted contaminants.
Alternatives 3, 4, and 5 would provide a greater degree of
reduction in mobility, volume and toxicity of hazardous
substances in the ground water than alternative 2, since
alternatives 3,4 and 5 are designed to pump and treat groundwater
to meet MCLs throughout the plume, as opposed to only containing
the plumes as provided under alternative 2.
Alternative 5 would also contain and extract ground-water
contamination on the railyard. Alternatives 3, 4, and 5 would
also significantly reduce contaminant concentrations and mass in
the two identified soil source areas through soil treatment
processes (soil vapor extraction or thermal desorption) .
5.
Short-Term
to achieve
health and
levels are
Effectiveness addresses the period
protection and any adverse impacts
the environment that may be posed,
achieved. .
of time needed
on human.
until cleanup
The no action alternative has the greatest short-term
effectiveness since it takes no time to implement and has no
adverse effects from its implementation. The remaining
alternatives, in order of greatest to least short-term
effectiveness, are 2, 3, 4, and 5, since each successive
alternative involves a greater degree of remedial activity and,
thus, a greater potential for adverse impacts during
implementation. Even though alternative 3 takes longer to
implement than alternative 4, it still has greater short-term.
effectiveness since it"provides absolute short-term protection to
all residents in the site area by providing a clean, alternative
drinking water supply.
6.
Impl~entability is the technical and administrative
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23
feasibility of a remedy, including the availability of
materials and services needed to implement a particular
option.
The no action alternative and alternative 2 are readily
implementable. Alternatives 3 and 4 are implementable; however,
piping, ground-water extraction wells, and soil treatment systems
on the railyard would need to be installed in such a manner as to
minimize interruption of rail use, and treatability testing would
need to be conducted to verify the effectiveness of air
sparing/vapor extraction for the site. Alternative 5 would be
difficult to implement due to the need for removal of
contaminated soil areas with active rails on top of them. Rail
service would be disrupted during excavation, t.reatment, and
backfilling of soils.
7.
Cost includes estimated capital and operation and
maintenance (O&M) costs, also expressed as net present
worth.
Specific details regarding the costs of the alternatives are
available in the FS.
Alternative 1 (no action) costs nothing. Alternative 2 costs
approximately $3,000,000. Alternative 3 costs. approximately
$7,700,000. The increase in costs is primarily due to the
extension of the alternate water supply system. Alternative 4
costs approximately $6,900,000 and alternative 5 costs
approximately $10,000,000. The relatively high cost of
alternative 5 is primarily due to the cost of excavating
contaminated soil.
Modifyinq Criteria
8.
State Acceptance
IDEM has been involved throughout the investigations of the
Conrail site and concurs with the. selected remedy (alternative
3) .
9 .
Community Acceptance
Community acceptance of the selected remedy is discussed in the
Responsiveness Summary, which is attached as Appendix B.
Basically, CLEAN and the majority of persons who submitted oral
or written comments, support the selected remedy (alternative 3) .
A complete summary of public comments can be found in the
attached Responsiveness Summary.
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24
IX.
THE SELECTED REMEDY
Based on the information collected and developed in the RI/FSs,
and using the comparative analysis of alternatives described
above, u.S. EPA and IDEM have selected alternative 3 as the most
appropriate Final Remedial Action for addressing contamination at
the Conrail site. '
Alternatives 1 and 2 do not provide acceptable Overall Protection
of Human Health and the Environment and do not meet ARARs, and
alternative 5 is more expensive, difficult to implement and does
not provide any significant advantages over alternatives 3 and 4
with respect to the other seven criteria.
Alternatives 3 and 4 compare nearly equally in the first seven
criteria, with alternative 3 having a slight advantage in Overall
Effectiveness and Long-Term and Short-Term Effectiveness, and
.alternative 4 having a slight advantage in estimated Cost and may
achieve ARARs. more quickly. u.S. EPA selected alternative 3 in
the Proposed Plan primarily due to the fact that there is
significant uncertainty at the Conrail site with respect to
possible future ground-water contamination, and alternative 3 is
the only alternative that provides absolute protection of public
'health by providing a clean alternate water supply. The possible
presence of DNAPLs (which may move in directions counter to the
ground water flow and then contaminate previously clean areas of
the aquifer), the possibility of additional sources of
contamination both on and off the railyard, and the possibility
of further migration of the County Road 1 and LaRue Street plumes
if containment measures are not fully effective are all examples
of this potential for further contamination of the ground water
that is only fully addressed by alternative 3. The recent
discovery of low levels of TCE and/or CCl4 in several wells under
the additional residential well sampling program (report cover
letter August 12, 1994) and l,l,l-trichloroethane in the Harley
Holben Elementary School drinking water, which is outside of the
estimated plume boundaries, exemplifies the unpredictable nature
of ground-water contamination at this site, and supports the
selection of alternative.3 as the selected remedy. State
concurrence on and community acceptance of alternative 3 further
support the decision that alternative 3 provides the best balance
of the nine criteria used by u.S. EPA for remedy selection.
Four minor changes were made to alternative 3 in response to
concerns +aised at the April 25, 1994 public meeting and. written
and oral comments received during the public comment period.
These changes, which are underlined, are as follows:
1)
Treated ground water will be discharged to the St. Joseph
River. If Crawford Ditch has insufficient capacity for the
volume of treate? water. an alternate system for a permitted
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25
discharqe will be used;
2)
Treatability testing will need to be conducted to verify the
effectiveness of air sparging/vapor extraction for the site.
If such testinq indicates that air sparqinq is not suitable
for use, a continqency plan will be developed to evaluate
and.implement other alternatives as appropriate;
3)
Additional investigations will be performed to delineate
additional source areas, if any, both on and outside of the
railyard, at the Conrail site that have not been identified
to date; and
4)
Alt.houqh alternative 3 does not employ as many extraction
wells as alternatives 4 and 5. it is intended to fully
achieve the qround-water ARARs. primarily bv focussinq on
"hot spots" and. if present, any DNAPL source areas.
The selected remedy, including the changes resulting from public
comments, is summarized below:
Expanded Institutional Actions
Institutional actions to be implemented at the site include
ground-water monitoring, air monitoring, restrictive covenants,
access restrictions, deed restrictions, water supply extension,
and well abandonment.
Ground-water monitoring is necessary to assess the effectiveness
of the extractions system in containing the two contaminant
plumes, to determine when cleanup standards have been achieved in
the aquifer, and to determine if contamination occurs .in
. previously uncontaminated areas. . Such monitoring will be
consistent with the monitoring currently being performed by .
Conrail under the 1992 Unilateral Administrative Order and will
consist of the collection and analysis of ground-water samples
from monitoring wells at regular intervals, and reporting of
monitoring results. .
Air monitoring will be conducted in buildings and basements
within the Conrail site study area to determine if significant
VOC concentrations ("significant" will be defined during remedial
design) are accumulating in basements or buildings, and to
determine what, if any, changes in VOC vapor concentrations in
buildings and basements occur as a result of changes in ground-
water VOC concentrations. Air monitoring will consist of
sampling with portable analytical equipment capable of detecting
VOCs and/or collection of air samples for laboratory analysis for
VOCs.
Access restrictions, such as fencing to limit access to ground-
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26
water extraction and treatment facilities, and deed restrictions
will be implemented to limit future use of ground water and
future use of contaminated areas within the Conrail railyard.
Abandonment of water wells will be performed pursuant to 310 IAC
16-10-2, and restrictive covenants pursuant to IC 13-7-8.7-12 may
be used for the railyard and property where the ground-water .
extraction facilities and monitoring wells are located.
The alternate water supply' (to be implemented under the Interim
Remedial Action) will be expanded to provide service to
residences and businesses in the entire area bounded by the
. Conrail railyard to the south, the St. Joseph River to the north,
Baugo Bay to the west, and Nappanee Street (State Route 19) to.
the east. All private wells in the area to be hooked up will be
abandoned. The only exception to this requirement that has been
allowed by U.S. EPA under the Interim Remedial Action is for
legitimate home cooling systems that utilize ground water.
Additional Investiqations
Additional investigations will be performed to delineate
suspected source areas, both on and outside of .the railyard at
the Conrail site, that have not been identified to date. Any
newly discovered source areas will be remediated consistent with
the other provisions of this selected remedy, as appropriate.
Vapor Abatement
In the event that air monitoring reveals the need for vapor
abatement in buildings within the Conrail Site study area,
appropriate actions will be considered and implemented. Vapor
abatement actions could include sealing building floors or
basements (e.g., grouting cracks or seams) and/or the
installation and operation of venting systems to ensure
sufficient air flow to avoid VOC accumulation. Operation and
installation of venting systems will meet the substantive
requirements of the Clean Air Act (CAA) and Indiana Regulations
for Establishing Emission Levels for VOCs. The type and extent
of actual vapor abatement actions will be specified after the
need for action is determined and the types of buildings affected
and levels of VOCs are established. . .
In Situ Soil Remediation
The soil contamination source areas identified at the site will
be addressed using in situ treatment technologies. Additional
source areas may be identified during additional investigation at
the site which may be included in the soil remediation action, as
determined during the remedial design. VOC contamination in the
TCE source area in the unsaturated zone will be treated using
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27
vapor extraction. The CCl4 contamination in the one saturated
source area will be treated using air sparging, in conjunction
with vapor extraction in the overlying unsaturated zone.
Treatability testing will need to be conducted to verify the
effectiveness of air sparging/vapor extraction for the site. It
is anticipated that vapor extraction will be implementable; the
success of air sparging is more uncertain. Therefore, if
treatability testing indicates that air sparging (or vapor
.extraction) is not suitable for use at the site, a contingency
plan will be developed to evaluate and implement other
alternatives, as appropriate. Operation and installation of
vapor extraction systems and treatability testing will meet the
substantive requirements of the CAA and Indiana Regulations for
Establishing Emission Levels for VQCs. Contaminants collected by
the vapor extraction system(s) "will be disposed of properly and
will meet the substantive requirements under RCRA and Indiana
Regulations for the Treatment and Disposal of Hazardous Waste.
Thermal destruction is the preferred method of disposal.
In situ soil remediation will continue until the soil cleanup
goals in Section VII are achieved; verification sampling will be
performed to assess progress and demonstrate that cleanup goals
have been achieved.
Ground-Water Extraction/Treatment
The ground-water extract.ion/treatment/discharge system that was
designed under the Interim Remedial Action for the site will be
modified, as appropriate, and operated to contain and remediate
the County Road 1 plume identified northwest of the facility.
The design for the extraction/treatment/discharge system under
the Interim Remedial Action was suspended by U.S. EPA on June 2,
1994 due to compatibility/capacity concerns with the additional
extraction/treatment/discharge required by this Final Remedial
Action. In addition, a ground water extraction/treatment/ .
discharge system will be installed and operated to contain and
remediate ground-water contamination identified to the northeast
of the facility (the "LaRue Street plume) .
Groundwater will be extracted by being pumped from approximately
nine extraction wells (eight in the County Road 1 plume area and
one in the LaRue Street plume area), treated using air stripping,.
and discharged under an appropriate NPDES permit to the St.
Joseph River. If Crawford Ditch has insufficient capacity for
the volume of treated water, an alternate system will be used for
discharge. Vapor emissions from the air stripping system will be
treated using vapor-phase carbon to ensure capture, and
subsequent proper disposal, of VOCs. Approximate extraction well
locations are shown on Figure 6. Results of sampling during the
design for the remedial action will be used to determine actual
well locations, which will al~o take into consideration "hot
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28
spots" {i.e. areas of relatively high contaminant concentrations
or where DNAPL sources are identified), to the extent possible.
The actual number and locations of extraction wells, ground-water
pumping rates, and location of treatment facilities and discharge
lines will be determined during the design phase for the remedial
action.
The extraction/treatment system will be operated until the
ground-water .cleanup standards in Section VII are achieved
throughout the plume. Verification sampling will be performed to
assess progress and demonstrate that cleanup standards have been
met. All groundwater extraction/treatment and discharge will
meet the substantive requirements under the SDWA, CWA,CAA, and
all state ARARS identified in section X.
X.
STATUTORY DETERMINATIONS
EPA's primary responsibility at Superfund sites is to select
remedial actions that are protective of human health and the
environment. CERCLA also requires that the selected remedial
action for the site comply with applicable or relevant and'
appropriate environmental standards established under Federal and-
State environmental laws, unless a waiver is granted. The
selected remedy must also be cost-effective and utilize permanent
treatment technologies or resource recovery technologies to the
maximum extent practicable. The statute also contains a
preference for remedies that include treatment as a principle
element. The following section discusses how the selected remedy
at the Conrail site meets these statutory requirements.
Protection of Human Health and the Environment
The selected remedy protects human health and the environment
through providing an alternate water supply to affected and
potentially affected residents and businesses, and extracting and
treating contaminated groundwater. As previously indicated,
residents using the ground water can be exposed to the
contaminants it contains or may contain in the future. The
Interim Remedial Action was designed to provide alternative water
supply to all residents within the area of the two identified
contaminant plumes. The most significant exposures generally
result from direct consumption of the water itself and beverages
made with the water, and through dermal contact with the water
and inhalation of vapors from the water while bathing. The
selected remedy provides absolute protection of human health by
providing an alternate water supply to all residents, between the
Conrail railyard, the. St. Joseph River, Baugo Bay, and Nappanee
Street (State Route 19), vapor abatement measures, if necessary,
in situ remediation of identified soil contamination in the
railyard, extraction and treatment of contaminated ground water,
and imposition of access restrictions to contaminated ground
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29
water until aquifer remediation is attained.
Implementation of the selected remedy will reduce contaminant
concentrations to levels (hazard indices not exceeding 1.0 and
carcinogenic risks not exceeding the range of 1x104 to 1x10~)
that would be unlikely to pose significant adverse health effects
through the identified exposure pathways.
Use of emissions controls (i.e. capture of emissions from air
strippers using vapor-phase carbon, and subsequent proper
disposal) will meet the substantive requirements under the CAA
and the state ARARS identified below, and will protect against
short-term exposure to contaminants during the remedial action.
No environmental impacts due to site contamination have been
identified to date, and discharge of water to the St. Joseph
River will be regulated by NPDES to ensure that the remedial
action does not affect aquatic life;
Compliance with ARARs
The selected remedial action will meet all identified applicable,
or relevant and appropriate Federal and more stringent State
requirements. ARARs for the selected remedy and are categorized
as chemical, action, and location specific below:
Chemical Specific
SDWA National Primary Drinking Water Standards (40 CFR
Part 141), and Indiana Drinking Water Quality Standards
( 3 2 7 lAC 8) .
CAA National Ambient Standards for Hazardous Air
Pollutants (NESHAPs) ( 40 CFR 61) .
CAA National Ambient Air Quality Standards (NAAQS)
CPR Part 50).
(40
Indiana Regulations for Establishing Emission Levels
for VOCs (326 lAC 2, and 326 IAC 8) .
Action Specific
Clean Water Act (CWA) NPDES Permit Regulations (40 CFR
Parts 122 and 125) .
CWA State Enforcement Jurisdiction (40 CPR Part 131).
CWA Sample Preservation Procedures (40 CPR Part 136).
RCRA Definition and Identification of Hazardous Waste
(40 CFR Par~ 261).
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30
RCRA Standards for Generators of Hazardous Waste (40
CFR 2 6 2) .
RCRA Standards for Transporters of Hazardous Wastes (40
CFR Part 263)
RCRA Land Disposal Restrictions (LDRs)
268) .
(40 CFR Part
Occupational Safety and Health Act (OSHA) Regulations
for Workers involved in Hazardous Waste Operations (29
CFR Part 1910).
Indiana Regulations for the Treatment and Disposal of
Hazardous Waste (329 lAC 3.1) .
Indiana Regulations for Permitting of Air Strippers
(326 lAC 2, and 326 lAC 8).
Indiana Regulations for Construction Permits for Water
Treatment Facilities (327 lAC 3).
Indiana NPDES Permit regulations (327. lAC 5 and 327 lAC
2) .
Indiana regulations for the Registration of Groundwater
Extraction Wells Which Have a Combined Capability of
Pumping Greater Than 70 Gallons per Minute (Indiana
Code 13-2-6.1)
Indiana Fugitive Dust Rules (326 lAC 6) .
Indiana Incinerator Rules (326 lAC 4) .
Indiana Rules Regarding Permanent Abandonment of Wells
(310 lAC 16-10-2).
Location Specific
Construction Within 100-year Floodplain (40 CFR 264) .
u.S. EPA's Statement of Procedures on Floodplain
Management and Wetlands Protection (40 CFR Part 6,
Appendix A) .
Indiana Regulations Governing Construction in a
Floodway (Indiana Code 13-2-22)
To Be Considered Criteria
u.S. EPA's OSWER Directive 9355.0-28 - Control of Air
Emissions from Superfund Air Strippers.
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31
Elkhart County Groundwater Protection Ordinance.
Pursuant to the Safe Drinking Water Act, EPA has published
maximum contaminant levels (MCLs) allowable in regulated public
water supplie~, 40 CFR Part 141. The MCLs are ARARs at the site
since the aquifer is currently used as a drinking water supply
for those residences who were 'not hooked up the alternate water
supply provided under the Interim Remedial Action. The selected
remedy is intended to meet MCLs for groundwater throughout the
plumes by pumping and treating contaminated groundwater. Points
of compliance will be throughout the contaminated aquifer and may
include extraction wells. Exact locations of points of
. compliance will be determined during the remedial design.
Extraction of groundwater in hot spots will accelerate attainment
of MCLs. The groundwater extraction system portion of the
selected remedy' will meet NPDES permitting/discharge requirements
(40 'CFR Parts 122, 125, 131, and 136; and IAC 327), and will
utilize the best available demonstrated control technology .for
treatment and discharge of the groundwater to surface water. For
air stripping facilities, IAC 326 establishes permitting
requirements for emissions of VOCs, requiring Best Available
Control technology (BACT) for new sources with.potential
emissions exceeding a specified threshold value. u.s. EPA's
OSWER Directive 9355.0-28, relating to the control of air
emissions at Superfund groundwater sites will also be considered
to the extent that it is suitable to VOC air emissions for the
groundwater treatment process. In addition, if off-site
landfilling of residuals is considered, all Federal (40 CFR Part
268) and State (329 IAC) requirements for landfilling hazardous
wastes must be met. For off-site disposal of spent carbon to an
approved generation facility, the manifest requirements under the
Resource Conservation and Recovery Act (40 CFR Part 262) and the
Indiana Administrative Code .(Section 329) are applicable.
Cost-Effectiveness
u.S. EPA believes that the selected remedy is cost-effective in
mitigating the risks posed by contact with contaminated. ground
water and soil, within a reasonable period of time. . Section
300.430(f) (ii) (D) of the NCP requires u.S. EPA to evaluate cost-
effectiveness by comparing all the alternatives which meet the
threshold criteria: protection of human health and the
environment; and compliance with ARARS, against three additional
balancing criteria: long-term effectiveness and permanence;
reduction of toxicity, mobility or volume through treatment; and
short-term effectiveness. The selected remedy meets these
criteria and provides the greatest overall effectiveness in
proportion to its cost. The estimated cost for the selected
remedy is $7,700,000.
Utilization of Permanent Solutions and Alternative Treatment
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32
Technologies or Resource Recovery Technologies to the Maximum
Extent Practicable
u.s. EPA and IDEM believe that the selected remedy represents the
~aximum extent to which permanent solutions and treatment
technologies can be utilized in a cost-effective manner for the
Conrail site. Of those alternatives that are protective of human
health and the environment and comply with ARARS, u.s. EPA and
,IDEM have determined that the selected remedy provides the best
balance of trade-offs in terms of long-term effectiveness;
reduction in toxicity, mobility or volume achieved through
treatment; short-term effectiveness; implementability; and cost,
taking into consideration the statutory preference for treatment
as a principal element and considering State and community
acceptance. '
Preference for Treatment as a Principal Element
Ground-water and soil remediation are the principal elements of
the selected remedy, and the selected remedy employs both ground-
water and soil treatment technologies.
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!/
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60URCE:Ec:ology and Envlro,im.nl. Ino.. 1H3i BASE MAP8:.U8GI. Elch.rl. IN a..adrangl.. 7.5
Minute 98,18'. 1881. PholoNVI..d 1981; USGS, 08e80Ia. IN auad,anu". 7.5 Minute
Sen.o, 1969, Pholo,evls8d 1880.
o
SCALE
y;:,
110111 ~
~
fiGURE 1
CONRAIL SITE STUDY AREA lOCATION MAP
-------
s
1
,~
SCALE"
\. 3 1200'
~
nGURE 2
APPROXIMATE EXTENT
or GROUNDWAT£R
. CONTAMINATION
-------
~ '-I,-e. 3 .
,n LOGc(-\~t)n~
(uur~J
II
829
;..
a
o
B03
B27
. SCALE:
1" = 800'
KEY:
. - SOIL BORING LOCA TWN .
)( - S~\lRC.E ARt:A ~t)\L ~
-------
. OCA 110NS
1[ lXII
-------
-.-.
'1
...\
SC~[-'-
I" a 1200'
~.
FIGURE ~
Af~x.wA'm'\1TfACTION
GROUND 5
WEll LOCATION V[ .1
FOR ALTERNATI
-------
@~D
La.-'<,.'<<' /-::?'
-........ -,,' '--\ - ....-::::."
/;~TUa -~~
/
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~1/.
./:.<~/
. .~. /](
/ . . _~~II~ ~~~J--
>/--i~ AREA
)
. -
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9
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111- AI'I'ROXIMAIl !."mACIiON WEll LOCAflONS )
(2 10 4 AOOIIIONAL WELL LOCAnONS NOT SHOv.tl
SCALE:
," » 1200.
FIGURE 8
. AmOX'M"TE
GROUNDWATER EXTRACTION
WEll LOCATIONS
. rOR ALTERNATIVE 5
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~
Page 1 of 1
Table 1
SUMMARY OF ESTIMATED EXCESS CANCER. RISKS AND
RESULTING RISK-BASED CONCENTRATIONS
DIE Iapa& EDIII RIIk-B8led
P'IIdh_y C"h.R.....1 COllI r- .. ..ri._J" Caacer Risk C-...ta--' _h
OD Site Worbr "'~HIU'e (Soil)
"lnh_lninQ T~ 7. 7f17 I&IIkI 2.58S06 2.990 I&IIka
Vmyl cb10ride 8 .I&IIkg 1.Q2E'()5 0.78 I&IIka
OD Site Worbr "'~...re (GroaIIdwater)
Inh_l_rinQ Carbon 8eU'Id21oride 94.500 ,.JL 4.15B.04 228 HIL
TricbIoroecbeae ~.I00,.JL 3.81E.()6 1.860 J&8/L
Neuby R..w-.lal R~ft . COIIIdy a.d 1 PbaDe (Graaadwater)
GrO\idGftIIeI' asap Carbon 1eUICbIoride 2.475 ,.JL 5.46E-03 0.45 J&8/L
aaJotof~~ 148 ,..n. 1.56B.()4 0.95 I&IIL
1.1~ 48 ,..n. 4.12&04 0.10 ~gIL
TrIcbIoroedIeae 13.000 p.aIL 4.43B.()3 23 ,.,a.
. ViayI c:bIoride 7 I'IiL 1.80&04 0.04 I&IIL
Inh_I_""o (indoor air) CarboD IeU8CbIoride 655 I'IiL 1.59B-04 4.1 J&8/L
Chloroform 25 ,.JL 1.12E.()6 23 J&8/L
1.1-clK:b1oroemeue 8 ,.JL 8.268-06 0.97 "gIL
Tricb1oroetit- 93 ,.JL 2.75E.()6 34 "gIL
Narby P"'
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"
Page 1 of 1
#
Tillie 2
SUMMARY OFESI'IMATED HAZARD INDICES AND
RESULTING RISK-BASED CONCENTRA110NS
RMB IDpat s--d ~-""
",,,,., "-'-I c- J---.1.-11 IIIIIa C...... .I'f-~ __h
OIl Sire Worbr ~ (SaiIIGrov.........)
Inh.l.riftn TGIa1 - 1-'2&02 -
Nearby p..w .....1 ~..."' - Coaa&r Ra8d 1 ....
GroImctwaaer asap Carbon IeII8dIIDride 2A7S f&I/L l.01E+02 2.S IIIIL
1.2~- 20S IIIiL 1.23B«) 165 IIIIL
Inh.l.rinft (iDdoor air) TOlai - 7.23E002 --
Nearby Jl..w .....1 "1~1IUk - La Rae Str8& PIIIIDe .
Gro1IIIdwaIer usage Carbon aacbIoride 76 qIL 3.10E-OO 25 I&IIL
Inh.l.rinn (IDdoor air) Toau -. 2.791!.Q3 -
a Derivuion of Ibae vaJua is aplaiDcd in die risk ,,---. poniDD of die RIIIIItliDlbivati,1IIiDII Reptm
(E ck E 1993).
b C~1IIir.- were ~....htM OD . Deed 10 redace die Haard Jadg 10 1 for acb oa.......nd
Soun::e: Ecology &lid EDY~(iIll&8illi.IDc. 1994.
.. --
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