PB98-963140
EPA 541-R98-152
March 1999
EPA Superfimd
Explanation of Significant Difference
for the Record of Decision:
Galen Myers Dump/
Drum Salvage
Osceola, IN
9/30/1998
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EXPLANATION OF SIGNIFICANT DIFFERENCES
GALEN MYERS DUMP/DRUM SALVAGE SITE
OSCEOLA, IN
AUGUST 1998
INTRODUCTION
This Explanation of Significant Differences (ESD) is for the Galen Myers Dump/Drum Salvage
Superfund Site, located in Penn Township, St. Joseph County, Indiana. This ESD is being issued
pursuant to Section 117 of the Comprehensive Environmental Response, Compensation and
Liability Act, and Section 300.435(c)(2)(i) of the National Contingency Plan (NCP) by the
Indiana Department of Environmental Management (IDEM) in cooperation with the United
States Environmental Protection Agency (U.S. EPA). IDEM is the lead agency for this site and
U.S. EPA is the support agency.
This ESD provides an explanation of significant differences in the following components of the
remedy selected in the September 29, 1995, Record of Decision (ROD): "estimates of soils
exceeding the soil preliminary remediation goal (PRG) requiring excavation." Based on the data
gathered during Remedial Design (RD), soil excavation is no longer necessary. This ESD shall
be part of Administrative Record and will be available for viewing at the Information
Repositories for this site.
SITE BACKGROUND
The Galen Myers Site is located at 11303 Edison Road in Penn Township, St. Joseph County,
Indiana, is surrounded primarily by agricultural land. A residence and commercial business are
adjacent to the site, and Edison Road is the southern border.
Mr. Galen Myers, former owner of the property, operated a drum reclamation operation from
about 1970 to 1983. Mr. Myers acquired 55-gallon drums from local industries and recycled the
drums into trash containers by removing the tops and dumping the drum contents into unlined
pits and onto the ground surface from the driveway. Both semi-volatile organic compounds
(SVOCs) and volatile organic compounds (VOCs) were released into the environment.
The U.S. EPA found numerous empty and several partially filled drums throughout the property.
The Myers family indicated its intent to dispose of the drums since the business was no longer in
operation; however, no efforts were made to clean up the property.
The Site was placed on the National Priority List in 1989. Remedial Investigation (RI) sampling
was performed both on-site and in the residential areas to the south from July 1993 to October
1994. Surface soil, subsurface soil, and vapor samples were collected to determine if residential
contamination remained after the U.S. EPA removal actions. The major contaminant of concern
for soil and groundwater is a VOC, Trichloroethene or TCE.
Groundwater sample results confirmed that TCE contaminated groundwater was moving
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downgradient (to the south) and posed unacceptable threats to human health through ingestion of
contaminated groundwater. Inorganic contaminants were detected in residential wells, but are
suspected to be associated with the background quality of the groundwater. Soil sample results
did not indicate unacceptable threats to human health from direct contact with the soils, but did
show that TCE may migrate out of soil to the groundwater at levels higher than the Maximum
Contaminant Levels (MCLs) set by the Safe Drinking Water Act.
The Feasibility Study (FS) identified and evaluated alternatives that could address the
contamination identified near the site area. Four cleanup alternatives for groundwater and three
for soil contamination were considered for this site. IDEM and U.S. EPA evaluated the
alternatives on the basis of the nine criteria of the NCP, including effectiveness in protecting the
public health and the environment, compliance with federal and State regulations, and cost. A
public meeting and public comment period were held and public comments were considered
prior to selection of the remedy. In the original 1995 ROD IDEM selected excavation of TCE-
contaminated soil on-site, provision of an alternate water supply to affected and potentially
affected residents, natural attenuation of groundwater, ground water monitoring and institutional
controls. Once the ROD was signed, IDEM began Remedial Design activities.
DESCRIPTION OF SIGNIFICANT DIFFERENCES AND BASIS FOR THE
DIFFERENCE
The primary reason for this ESD is to document a significant difference in the selected remedy.
The major difference between the remedy selected in the ROD and this ESD is that based upon
sampling conducted during the RD the volume of soils from the test pit area exceeding the soil
PRG has decreased significantly. These sampling results indicate that no soils in excess of the
PRO exist within that area. As such, it is not necessary to implement the soil excavation
component of the remedy.
The other key provisions of the 1995 ROD that will remain the same are:
Natural attenuation of groundwater;
Installation of additional groundwater monitoring wells;
Long-term monitoring of groundwater and the St. Joseph River;
Alternate water supply to the residential area (completed in early 1996); and
Institutional Controls, such as prohibiting installation of we.lls on the site or in the
residential area affected by TCE- contaminated groundwater.
Based on the RI and FS conclusions, the original ROD recommended excavation and off-site
disposal of soil in areas where soil exceeded the PRGs of 110 parts per billion (ppb) of TCE. The
RI risk assessment showed that the risks to future residents and/or construction workers from on-
site soil contact were within acceptable ranges for carcinogenic risk. Therefore, during the FS the
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residual leaching threats from soil to groundwater were considered. U.S. EPA's Soil Screening
Levels guidance was used to develop PRGs. TCE levels were above the PRGs and remediation of
the soils to address the residual leaching effect was considered.
The RD phase began in April 1997, when IDEM hired a contractor to perform the design phase
activities of the selected remedy. These activities included soil sampling and groundwater
screening to determine long-term monitoring well locations.
Soil samples were collected to determine the horizontal extent of TCE contamination around the
test pit within the Galen Myers property through the use of a GeoProbe rig. Samples for the
analysis. Soil samples were collected at 15 locations from a 20-foot interval grid area
surrounding the test pit location. The soil samples were collected continuously to the top of the
water table which was encountered between 5.5 to 6 feet below ground surface at 4 foot intervals.
The soil samples were analyzed in accordance with the Quality Assurance Project Plan procedures
established for analytical work at this site. The on-site lab analyses revealed TCE contamination
at only two locations, with concentrations at 106 and 6 ppb. The TCE concentrations are below
the action levels that would have triggered excavation and disposal as required in the 1995 ROD.
The required action level for soil excavation and removal mentioned in the 1995 ROD is 110 ppb.
IDEM conducted confirmatory sampling in March 1998 and analyzed the sample at a
conventional lab using CLP procedures. The analytical results showed TCE concentrations at 47
and 89 ppb, which are again below the action levels mentioned in the ROD.
The decrease of TCE concentrations in the unsaturated (vadose) soil zone is likely to be the result
of two combined processes: volatilization causing TCE to move from the soil particles into the
soil gas in the soil pore spaces; and removal of the TCE from the vadose zone by water
(precipitation) soaking its way through the vadose zone to recharge the groundwater.
After confirmation of the existing TCE concentrations in the soil at the Galen Myers Site, IDEM,
in consultation with U.S. EPA has determined that the excavation is not necessary. The existing
soil contamination concentration levels do not pose any residual threat to the environment or
human health, and, based upon modeling work completed in the FS, should not pose a residual
threat to the groundwater. The well installation work for long-term groundwater monitoring will
continue as stated in the 1995 ROD.
COST
The change in the Scope of Work (SOW) discussed in this document decreases the cost of the
original remedy by $164,000. The estimated total cost of the remedy was $1,730,000, not
including an estimated $5.3 M in costs for any prior U.S. EPA response actions.
AFFIRMATION OF STATUTORY DETERMINATIONS
The modified remedy continues to satisfy statutory requirements. Considering the new
information that has been developed and the change that has been made to the selected remedy,
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IDEM and U. S. EPA believe that the remedy remains protective of human health and the
environment, complies with the Federal and State requirements that are applicable or relevant
and appropriate to this remedial action, and is cost effective. In addition this revised remedy
utilizes permanent solutions and alternative treatment (or resources recovery) technologies to the
maximum extent practicable for this site.
PUBLIC PARTICIPATION ACTIVITIES
The IDEM held a meeting in August 1995 to announce the completion of Remedial Investigation
and Feasibility activities and explained the Record of Decision components for final remedial
action at the site. Copies of the original ROD and other site related documents including this
ESD are available at the information repositories mentioned below:
Mishawaka Perm Public Library
Bittersweet Branch Library
602 Bittersweet Road
Mishawaka, IN
IDEM's File Room (2nd Floor)
2525 North Shadeland Avenue
Indianapolis, IN 46219
Hours: 8 a.m. - to 4:30 p.m. (12/1 p.m. closed)
Mary'Beth Tuohy Date
Assistant Commissioner, OER, IDEM
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SUPPORT AGENCY COMMENTS
The U.S. EPA concurs with the ESD.
William E. Muno, Dir
Superfund Division, U.S. EPA
Date
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Table 1
Galen Myers Dump/Drum Salvage Site Comparison of Evaluation Criteria for Soil Removal
Action
Evaluation Criteria
Overall Protection of Human
Health and the Environment
Compliance with ARARs
Long-Term Effectiveness and
Permanence
Reduction of Toxicity,
Mobility, an Volume Through
Treatment
Short-Term Effectiveness
Implementability
Cost
1995 Remedy
Excavation and Off-site Disposal
Would be protective of human health and
the environment.
Would eliminate the potential for
chemicals in soil to migrate to
groundwater.
Activities will comply with ARARs.
Will comply with ARARs (re: LDRs,
OSHA)
Will provide long-term effectiveness and
permanence.
Soils exceeding PRGs will be removed
from the site.
The toxicity, mobility, and volume of
contaminants will be reduced.
Controls to protect workers and the
community will be implemented during
construction activities.
Excavation and disposal will be effective
in the short-trem.
Can be implemented easily.
Excavation and disposal activities are
conventional.
$806,000 (Hazardous); $164,000(Non-hazardous)
No soil excavation
There are no unacceptable human health
risks associated with exposure to site soils.
No ARARs for soil
Soils do not exceed PRGs.
Will provide long-term effectiveness or
presence.
No treatment necessary, therefore no
reduction in toxicity, mobility or volume
of contaminants would be achieved.
No impacts to community.
Will not exceed PRGs.
There are no technical or administrative
considerations.
There is no cost for this alternative.
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