PB98-963113
EPA 541-R98-045
October 1998
EPA Superfund
Explanation of Significant Difference
for the Record of Decision:
Hunterstown Road
Straban Township, PA
8/25/1998
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EXPLANATION OF SIGNIFICANT DIFFERENCES
HUNTERSTOWN ROAD SUPERFUND SITE
I. INTRODUCTION
Site Name: Hunterstown Road Superfund Site
Site Location: Straban Township, Adams County, Pennsylvania
Lead Agency: U.S. Environmental Protection Agency, Region
III ("EPA" or the "Agency")
Support Agency: PA Department of Environmental Protection
("PADEP")
Statement of Purpose
This Explanation of Significant Differences ("BSD") is
issued in accordance with Section 117 (c) of the Comprehensive
Environmental Response, Compensation and Liability Act, as
amended ("CERCLA"), and is now a part of the Administrative
Record for the Hunterstown Road Superfund Site ("Site"). This
document explains significant differences to the remedy selected
in the' Record of Decision ("ROD") for the Site signed by the EPA
Regional Administrator on August 2, 1993. EPA has determined
that these changes to the selected remedy are necessary to
implement the remedial action in an effective manner. The ROD is
attached hereto as Exhibit 1.
II. SUMMARY OF THE SITE HISTORY, SITE CONDITIONS, AND SELECTED
REMEDY
l»» The Site is located about 1.5 miles northeast of downtown
Q Gettysburg in Straban Township, Adams County, Pennsylvania.
-y Topography in the area is gently rolling. The Site and
iff surrounding areas are semirural with both farmlands and
•^ residences adjacent to the Site. The Site occupies an
Dr- approximate area of 22 acres, and portions of the Site lie both
i east and west of Hunterstown Road.
Q Frederick Shealer, the owner of the Site and the operator of
a septic tank cleaning business, disposed of wastes from several
companies in six areas at the Site. These areas are Drum Burial
Area 1, Drum Burial Area 2, Cornfield Area, Lagoon Area, Stressed
Vegetation Area, and the Borrow Area. Fred Shealer disposed of
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liquid wastes, including solvents and paint sludges in the Lagoon
Area. Wallboard containing asbestos, and several drums were
disposed in the Borrow Area. Sludges containing toxic metals
were sprayed on the cornfields, while they were actively farmed,
and drums containing wastes were buried in the two areas referred
to as Drum Burial Area 1 and Drum Burial Area 2. Wastes
containing very high levels of heavy metals were placed in the
Stressed Vegetation Area and this waste is still present at the
Site. All areas except the Cornfields and the Stressed
Vegetation Areas have had emergency actions completed which
removed concentrated wastes.
There are three unnamed tributaries of Rock Creek which flow
adjacent to portions of the Site. These are referred to herein
as the West Stream, Middle Stream, and East Stream. The West and
Middle Streams join just north of Shealer Road, and the East
Stream joins the other combined streams approximately 0.2 miles
south of Shealer Road.
Ground water near the Site is a class II aquifer and is used
by nearby residents for drinking water if they are not in the
area served by the public water supply.
Based on the Remedial Investigation, the most significant
contaminants for ground water contamination at the Site have been
identified as: trichloroethene (TCE), 1,1,1-trichloroethane
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Lead
Mercury
Vinyl
Chloride
1,1 - DCE
X
X
X
X
X
X
X
X
X
The primary contaminants in East Stream sediments are lead,
chromium, copper, zinc and barium.
A complete description of the selected remedy as well as
EPA's rationale for the decision is presented in the August 2,
1993 ROD which is attached hereto as Exhibit 1. The major
components of the selected remedy are:
Ground Water
Extraction wells to capture all ground water above a
depth of 800 feet contaminated with Volatile Organic
Hydrocarbons (VOCs).
Treatment of contaminated ground water by air stripping
followed by destruction of contaminants in the air stream
using catalytic oxidation.
Discharge of the treated water to an on-Site stream in
compliance with NPDES limits.
Deed restrictions prohibiting the use of wells on the
Shealer property.
Ground water monitoring, including identification and
installation of monitoring wells in the regional ground
water discharge area from the Site and residential well
sampling.
Soils / Sediments
LAGOON AND STRESSED VEGETATION AREAS - Excavation and
off-Site treatment of two feet of soil, backfill excavation
and installation of a one foot deep soil cover.
CORNFIELDS AND BORROW AREAS - Installation of a one foot
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deep soil cover over a geotextile and subsequent
revegetation to prevent contact with contaminated soils.
DRUM BURIAL AREAS - No additional action (Previous
Removal Action Completed)
EXTENDED SOIL COVER - Soil cover extended over
contaminated soils between Lagoon Area, Stressed
Vegetation Area and East Stream.
EAST and WEST STREAM CONTAMINATED SEDIMENTS - Excavation
and off-Site treatment and disposal.
Fencing around soil covers and landscaping along fencing
to minimize the visual impact on the community.
Surface Water
No Current Action - The Selected Remedial Actions for
other media will reduce contaminant levels in streams by
preventing migration of contaminants via surface water
runoff and ground water discharge.
Wetlands
Replace Wetlands Permanently Damaged by Remedial Action
and Restore Impacted Wetlands Areas.
III. DESCRIPTION OF SIGNIFICANT DIFFERENCES
Since the issuance of the ROD, EPA has determined that a
procedural change should be made to the remedy set forth in the
ROD. This change is identified as a Significant Difference and
does not constitute an amendment, as that term is used in 40
C.F.R. §300.435(c) (2) (ii), to the ROD because this change does
not fundamentally alter the overall approach intended by the
selected remedy for the Site. The Significant Difference between
the remedy presented in the ROD and the remedy that will be
implemented is discussed below. Except for the specific changes
discussed below, all terms of the ROD remain in effect.
For ground water contamination, the ROD states that all of
the ground water plumes associated with the Drum Burial Areas and
the Lagoon Area with detections of VOC contamination above a
depth of 800 feet will be captured and remediated to background
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levels of contamination, practically defined as no detection of
VOCs using EPA Method 524.2 Practical Quantitation Limits. This
ground water clean up standard was based on Pennsylvania
regulations identified at the time of the ROD. The ROD also
states that EPA recognizes that such an attempt may not be
successful, and that after the remedial action is implemented and
several years of data are collected, EPA, in consultation with
the Pennsylvania Department of Environmental Protection
("PADEP"), may revise the cleanup goals for the ground water
above a depth of 800 feet. Specifically, the ROD states that
such a revision could include the waiver of the Pennsylvania
background ground water remediation requirement on the basis that
it may be technically impracticable from an engineering
perspective. See, Section 121(d)(4)(C) of CERCLA.
EPA has determined that it may be possible to make a
determination as to the engineering feasibility and
practicability of remediating the aquifer at a depth above 800
feet during remedial design as opposed to after the remedial
action has commenced and several years worth of data are
collected. Such a determination would be based upon a hydro-
geologic investigation conducted during the pre-design phase of
the ground water pump and treat remedial design. Therefore, this
ESD makes a procedural change to the 1993 ROD which would allow
EPA, in consultation with PADEP, to make a "technical
impracticabilty" determination, if appropriate, regarding the
dlean up goals for ground water prior to commencement of the
remedial action.
IV. PUBLIC PARTICIPATION
This ESD and the information upon which it is based have
been included in the Administrative Record file for this Site.
The Administrative Record also includes the ROD and all documents
that formed the basis for EPA's selection of the remedy. The
Administrative Record is available for public review at the
locations listed below:
U.S. EPA, Region III
1650 Arch Street
Philadelphia, PA 19103
Hours: Mon.-Fri., 9:00 am to 4:00 pm
and
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Adams County Public Library
59 East High Street
Gettysburg, Pennsylvania 17325
Hours: Mon.-Thu., 9:00 am to 8:30 pm
Fri.-Sat., 9:00 am to 5:00 pm
Sun., 1:00 pm to 5:00 pm
Questions and comments on EPA's action and requests to
review the Administrative Record can be directed to:
John Banks
Remedial Project Manager
Mailcode: (3HS22)
U.S. EPA, Region III
1650 Arch Street
Philadelphia, PA 19103
(215) 814-3214
V. SUPPORT AGENCY REVIEW
The Pennsylvania Department of Environmental Protection has
concurred with the proposed Explanation of Significant
Differences in a letter dated August 13, 1998.
VI. AFFIRMATION OF STATUTORY DETERMINATION
Considering the new information that has been developed and
the changes that have been made to the scope of the selected
remedy, the EPA and PADEP believe that the revised remedy remains
protective of human health and the environment, complies with
Federal and State requirements that are applicable or relevant
and appropriate to this remedial action, and is cost-effective.
In addition, the revised remedy utilizes permanent solutions
and alternative treatment (or resource recovery) technologies to
the maximum extent practicable for the Site.
Date ,/p\Abraham Ferdas, Dareccbr
Hazardous Site Cleanup
Division
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