PB96-963114
EPA/AMD/R03-96/234
March 1997
EPA Superfund
Record of Decision Amendment:
Saunders Supply Company
Superfund Site, Chuckatuck, VA
9/27/1996
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RECORD OF DECISION AMENDMENT
SAUNDERS SUPPLY COMPANY
Declaration
Site Name and Location
Saunders Supply Company
Chuckatuck, Virginia
Statement of Basis and Purpose
This decision document revises the Record of Decision (ROD) signed-dn September 30, 1991 for
the Saunders Supply Company Site (Site), in Chuckatuck, Virginia. The revised remedy was
chosen in accordance with the requirements of the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980, as amended (CERCLA), 42 U.S.C § 9601 et seq.. and,
to the extent practicable, the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP), 40 C.F.R. Part 300. This decision document explains the factual and legal basis for
revising the remedy for this Site. The information supporting this remedial action decision is
contained in the Administrative Record for this Site.
The Virginia Department of Environmental Quality concurs with the amended remedy.
Assessment of the Site
Pursuant to duly delegated authority, I hereby determine, pursuant to Section 106 of CERCLA,
42 U.S.C. § 9606, that actual or threatened releases of hazardous substances, pollutants or
contaminants from this Site, if not addressed by implementing the response action selected in this
Record of Decision Amendment, may present an imminent and substantial endangerment to
public health, welfare, or the environment.
Description of the Selected Remedy
This ROD Amendment revises the previously selected remedy by changing the methodology
for treatment of contaminated soil and sediment from onsite low temperature thermal desorption
and onsite dechlorination, respectively, to offsite incineration. This ROD Amendment will be
the final Record of Decision for the Site. Based on the information derived through the
Remedial Investigation, the Site soils pose a principal threat to human health.
The amended remedy includes the following major components:
1. Excavation and offsite incineration of the K001 sediments from the wastewater pond and
the former earthen separation pond.
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2. Excavation and offsite incineration of the Site soils and sediments from the storm sewer.
3. Treatment of the ground water during the dewatering process prior to excavating the soil
and that collected in the ground water collection trenches.
4. Removal of the top one inch of the stained areas of the concrete pad, solidification
treatment and offsite disposal of the removed material. Removal and onsite disposal of the
concrete pad hi the area requiring soil excavation.
5. Cleaning and sliplining of the storm sewer.
6. Ground water monitoring.
7. Institutional controls.
Declaration of Statutory Determinations
The selected remedy is protective of human health and the environment, complies with Federal
and State requirements that are legally applicable or relevant and appropriate to the remedial
action, and is cost-effective. This remedy utilizes permanent solutions and alternative treatment
(or resource recovery) technologies to the maximum extent practicable, and satisfies the statutory
preference for remedies that employ treatment that reduces toxicity, mobility, or volume as a
principal element.
Because this remedy will result in hazardous substances remaining onsite above health-based
levels, a review will be conducted within five years after commencement of remedial action to
ensure that the remedy continues to provide adequate protection of human health and the
environment. Such reviews will be conducted every five years thereafter until EPA determines
that the cleanup levels set forth in this ROD have been achieved, or that the hazardous substances
remaining at the Site do not prevent unlimited use and unrestricted exposure at the Site.
y/in fas
Ifhomas C. Voltag^io J ^/ Date
Director, HazardoujQJrasJe'Management
Region III
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DECISION SUMMARY
A. INTRODUCTION
The Saunders Supply Company Site (the Site) is located in the village of Chuckatuck, a
rural area of Suffolk, Virginia (see Figure 1 - Regional Location Map). The Site is a former
wood treating facility which ceased operating in June 1991. The Saunders Supply Company
facility is located in a mixed residential and commercial area. The Kelly Nursery and residence
is located immediately north of the facility. A gasoline station and a residential subdivision are
located south of the facility. Commercial establishments and residences are located east of the
facility, and a wooded area is west of the facility, beyond which agricultural activity exists. For
more information on the Site location, description, history, enforcement activities, and
community participation activities conducted prior to September 1991, refer to Sections A
through C of the Record of Decision (ROD) issued on September 30,1991.
The U.S. Environmental Protection Agency (EPA) is the lead agency for response
activities at the Site. The Virginia Department of Environmental Quality ("VDEQ") is the
support agency for response activities.
On May 23,1991, EPA released the original Proposed Plan for the Site, requesting public
comment on the alternatives identified at that time to remediate contamination at the Site, as well
as the EPA preferred alternative. Based on comments received, EPA, in consultation with
VDEQ, selected the remedy to clean up the Site in the ROD dated September 30, 1991. A
description of the major components of the remedy is provided in Section C below.
Based on new information obtained during the design of the remedy, EPA is amending
the ROD to change the method for treatment of contaminated soil and sediments from onsite low
temperature thermal desorption and onsite dechlorination, respectively, to offsite incineration
because offsite incineration would have fewer adverse impacts while still being comparable in
cost to onsite treatment.
B. COMMUNITY PARTICIPATION and INFORMATION AVAILABILITY
The Proposed Plan describing the amended remedy was released to the public for
comment on August 4,1996. This Proposed Plan was made available to the community in the
information repositories maintained at the EPA Region III Docket Room in Philadelphia and at
the Morgan Memorial Library in Suffolk, Virginia. The notice of availability was published in
. the Virginia Pilot and the Suffolk News Herald on August 4,1996. In addition, a public meeting
Was held on August 20,1996 in the Chuckatuck Volunteer Fire Company, 5960 Godwin
Boulevard, Suffolk, Virginia. At this meeting, representatives from EPA and the VDEQ
answered questions about conditions at the Site and the amended remedial alternative preferred
by EPA. The public comment period on the Proposed Plan was held from August 4,1996, to
September 13,1996. Although the update to the Administrative Record was received at the
Repository on August 3,1996, the update to the Administrative Record was not placed in the file
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_al__^_..
SAUNDERS
SUPPLY
COMPANY
Sourca: USGS 7.5 MbMin Strtos (Topographic) Qu«dr«ngto«: ChuckMuck. Virginia, 1979,
SCALE
0 54 1M!te
Figure 1
SAUNDERS SUPPLY COMPANY LOCATION MAP
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until August 14, 1996, ten days after the planned start of the public comment period. In order to
allow at least 30 days for review of the information in the update to the Administrative Record,
the public comment period was extended ten days from September 3,1996, to September 13,
1996. A response to the comments received during this period is included in the Responsiveness
Summary, which is part of this ROD Amendment. These activities were undertaken by EPA as
part of its public participation responsibilities under Section 117(a) of the Comprehensive
Environmental Response, Compensation and Liability Act of 1980 (CERCLA), and Section
300.435(c)(2)(ii) of the National Oil and Hazardous Substances Pollution Contingency Plan
(NCP).
The Administrative Record for this Site is maintained at the following information
repositories:
Morgan Memorial Library U.S. EPA Region HI Docket Room
443 West Washington Street Ms. Anna Butch (3HW14)
Suffolk, Virginia 841 Chestnut Building
Phone #: 804 672-4780 Philadelphia, PA 19107
Phone #: 215 566-3157
The Administrative Record includes all documents upon which the selection of the
amended response action is based. In accordance with Section 300.825(a)(2) of the NCP, this ~.
ROD Amendment will become part of the Administrative Record.
C. SUMMARY OF ORIGINAL REMEDY
The remedy selected in the September 30,1991 ROD contained the following major
components:
Excavation, Treatment, and Disposal of Pond Sediment: Excavation, treatment by
dechlorination, and offsite disposal of the sediments from the wastewater pond and the
former earthen separation pond; these sediments are listed as K001 wastes under the
Resource Conservation and Recovery Act, 42 U.S.C. §§ 6901-6992k, ("RCRA").
Excavation, Treatment, and Disposal of Soil and Sewer Sediments: Excavation, low
temperature thermal desorption treatment and offsite disposal of the Site soils and the
sediments from the storm sewer.
Ground Water: Treatment of the ground water during the dewatering process prior to
excavating the soil.
Concrete Pads: Removal of the top one inch of the concrete pads, solidification of
the removed material, and offsite disposal of the solidified material and the remainder
of the concrete pads.
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Cleaning and Lining of the Storm Sewer: The existing 8-inch concrete storm sewer
will be inspected with a closed circuit television camera, cleaned of all debris and
sediment, and lined with a flexible high-density polyethylene pipe.
Ground Water Monitoring: Ground water monitoring will be performed for thirty
years to ascertain that the remedy is protective of human health and the environment.
Institutional Controls: Institutional controls will be implemented to restrict access to
the contaminated ground water under the Site and to prevent contaminated ground
water from moving offsite. The institutional controls include deed restrictions on the
Site to prohibit using either the Columbia aquifer or the Yorktown aquifer as a source
of ground water and restrictions on offsite ground water extraction.
D. RATIONALE FOR CHANGING REMEDY SELECTED IN 19*? ROD
Soil and Sediment: Offsite disposal of treated soil was required at the time >t the ROD
because the relevant Virginia regulations were interpreted by VDEQ to prohibit onsite
backfilling of treated soil. Subsequent to issuance of the ROD, VDEQ adopted a new policy
which allows onsite disposal of soils containing RCRA-listed hazardous wastes when the soils
have been treated to reduce the contaminants to health-based cleanup levels. Since the
treatment planned for the Site would achieve these levels, VDEQ concurred with a request by
EPA to allow onsite disposal of the treated soil.
As part of the remedial design, EPA performed additional soil sampling as well as treatability
studies of the low temperature thermal desorption and dechlorination processes to assure that
these processes could achieve the soil and sediment cleanup levels in the ROD and to more
accurately determine the cost of treating the soil and sediments. The treatability studies
verified that the treatment processes would achieve the cleanup levels. However, the soil
sampling data showed that the total amount of soil requiring treatment decreased from the
25,000 tons estimated in the ROD to a new estimated total of 18,000 tons. Since the cost of
mobilizing and demobilizing the low temperature thermal desorption treatment equipment is a
fixed cost, the decrease in volume resulted in an increase in the cost per unit ton of soil
treated.
To ensure that the revised cost was still appropriate, EPA compared the cost of onsite low
temperature thermal desorption treatment to that of offsite incineration treatment. At the time
the ROD was issued, there were no incinerators permitted to accept the K001 sediments or the
soil from the Site because they contain dioxins. Since the ROD was issued, however, several
incinerators have been permitted to accept dioxin-containing wastes. With additional
incinerators being built, the unit cost per ton of material to be incinerated has also decreased.
As a result, the cost of treating the soil and sediments at an offsite incinerator is currently at
least comparable to the onsite treatment originally required in the ROD. This is true even
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though the cost of the ROD remedy is less than originally estimated because soil could be
backfilled onsite, thus avoiding the added cost of offsite disposal in a permitted RCRA landfill.
Concrete Pad: It was assumed in the original ROD that all of the soil beneath the concrete pad
in the former wood treating area exceeded the Site-specific cleanup levels and, as such, all of
the pad had to be removed. However, soil sampling during the design phase indicated that
only certain areas under the concrete pad required excavation and treatment. Since not all of
the soil required excavation and treatment, not all of the concrete pad has to be removed. In
addition, rather than use an offsite facility to dispose of those portions of the concrete pad
which have to be removed, the concrete will be decontaminated and disposed of onsite as
backfill in the wastewater pond area.
Groundwater: EPA continued to monitor the ground water at the Site during the remedial
design. As a result of this monitoring, EPA detected migration of Site-related contaminants
towards Godwins Millpond, a nearby water supply reservoir. 'Specifically, Pentachlorophenol
(TCP") was detected in monitoring wells MW-9S and MW-11S at maximum levels of 13 ppb
and 41.6 ppb, respectively (See Table 1). The Maximum Contaminant Levels (MCLs) for
PCP established under the Safe Drinking Water Act, 42 U.S.C. §§ 300f-300j-26, for public
drinking water supply systems is 1 ppb. Because the concentrations detected in these
monitoring wells exceed the MCL, EPA is using its emergency response authority to construct
a system to collect and treat the ground water to prevent further migration of the
contamination. Since the source of the contamination will be removed through the actions
required under the ROD, EPA currently anticipates that the collection and treatment system
will be operated for less than ten years. Because EPA's emergency response authority is, in
general, appropriate for short-term operation of the ground water collection and treatment
system, EPA is proposing that the continued operation and maintenance of this system be
included as pan of this amended ROD remedy.
TABLE 1
Monitoring Well
MW-9S
MW-11S
1989-1990
ND
ND
3/95
0.96 ppb
5.80 ppb
9/95
13.0 ppb
5.2 ppb
1/96
BDL
14, 1/15.7 ppb
5/96
BDL
41.4/36.5 ppb
ND-not detected
BDL-below detection level
E. DESCRIPTION OF REVISED REMEDY
Excavation, Treatment, and Disposal of Pond Sediments: Excavation and offsite
incineration and disposal of the K001 sediments from the wastewater pond and the
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former earthen separation pond.
Excavation, Treatment, and Disposal of Soil and Sewer Sediments: Excavation and
offsite incineration and disposal of the Site soils and the sediments from the storm
sewer.'
Ground Water: Operation and maintenance of the ground water collection and
treatment system constructed under EPA's emergency response authority to prevent
further migration of Site contaminants; includes treatment of the ground water collected
during the dewatering process prior to excavating the soil. Treatment may be either
onsite or offsite.
Concrete Pad: Removal of the top one inch of the stained areas of the concrete pad,
solidification and offsite disposal of the removed material, and removal of the concrete
pad in the area requiring soil excavation with onsite disposal.
Cleaning and Lining of the Storm Sewer: The existing 8-inch concrete storm sewer
will be cleaned of all debris and sediment and lined with a flexible high-density
polyethylene pipe (the sewer was inspected with a closed circuit television camera
during the remedial design).
Ground Water Monitoring: Ground water monitoring will be performed for thirty
years to ascertain that the remedy is protective of human health and the environment.
Institutional Controls: Institutional controls will be implemented to restrict access to
the contaminated ground water under the Site and to prevent movement of the PCP
offsite. The institutional controls include deed restrictions on the Site to prohibit using
either the Columbia aquifer or the Yorktown aquifer as a source of ground water and
restrictions on offsite ground water extraction.
F. EVALUATION OF ALTERNATIVES
The following summary discusses the performance of the amended cleanup plan in terms
of nine evaluation criteria, noting how it compares to the originally selected remedy. This
summary assumes the original remedy would allow onsite disposal of treated soil and sewer
sediments. The nine criteria can be categorized into three groups: threshold criteria, primary
balancing criteria, and modifying criteria. The criteria associated with each category are as
follows:
THRESHOLD CRITERIA
Overall protection of human health and the environment;
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Compliance with applicable or relevant and appropriate requirements ("ARARs");
PRIMARY BALANCING CRITERIA
Long-term effectiveness;
Reduction of toxicity, mobility, or volume through treatment;
Short-term effectiveness;
Implementability;
Cost;
MODIFYING CRITERIA
Community acceptance;
State acceptance.
These evaluation criteria relate directly to the requirements of Section 121 of CERCLA,
42 U.S.C. § 9621, which are used to determine the overall feasibility and acceptability of the
remedy. Threshold criteria must be satisfied in order for a remedy to be eligible for selection.
Primary balancing criteria are used to weigh major trade-offs between remedies. Support agency
and community acceptance are modifying criteria which are taken into account after public
comment is received on the Proposed Plan.
Overall Protection of Human Health and the Environment
Soil and Sediment: Both the original and the amended cleanup plan provide overall protection of
human health and the environment. Under both plans, all areas of the Site which exceed the Site-
specific cleanup levels will be excavated and treated, thereby eliminating all unacceptable risks
associated with direct contact with the soil.
Ground Water: Although the original cleanup plan was protective of human health and the
environment with respect to ground water at the time it was selected, it is no longer protective.
New information has demonstrated that contaminants are now migrating through the ground
water aquifer and must be addressed to achieve overall protection. EPA is using its emergency
response authority to address this need during the short-term. The amended cleanup plan
provides for operation of the system for the long-term and is, therefore, fully protective of human
health and the environment.
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Compliance with ARARs
Soil and Sediment: Treatment and disposal of the K001 sediments will meet all ARAR.:
treating the sediments at an incinerator permitted to accept this material. The key ARAR
associated with contaminated soil at the Site is the RCRA Land Disposal Restriction
requirements (see 40 C.F.R. Part 268) that limit the type and concentration of hazardous wastes
that can be land disposed. These requirements are applicable because hazardous wastes regulated
under RCRA are present at the Site and are being placed in a land disposal unit or facility.
Virginia also has similar land disposal restrictions under its hazardous waste management
regulations. Although the Site soils contain F032 and F035 listed wastes, RCRA Land Disposal
Restrictions have not been promulgated for these listed wastes. The original cleanup plan
complied with all ARARs, including the RCRA Land Disposal Restrictions and the Virginia
requirements, including the disposal of the treated soil. The revised remedy will also comply
with all ARARs by utilizing only an incinerator permitted to accept such contaminants and one
that is in compliance with its permit. Transportation to the incinerator will be in accordance with
RCRA regulations at 40 C.F.R. Parts 262 and 263, the Department of Transportation regulations
of Title 49 of the Code of Federal Regulations, and Part 7 of the Virginia Hazardous Waste
Management Regulations.
Ground Water: Treatment of the collected ground water under both the original and the amended
remedy may either be accomplished at an onsite treatment system or at an offsite facility. In ~ "
order td meet all ARARs, ground water being treated at an offsite facility will meet the facility's
pretreatment requirements while treatment at an onsite system will meet the chemical-specific
discharge limits established by VDEQ under the Virginia Pollutant Discharge Elimination
System regulations. Onsite treatment of ground water may result in the generation of sludges or
other metal-containing waste. These wastes will be evaluated in accordance with the hazardous
waste identification requirements and disposed of as required under the Virginia Hazardous
Waste Management Regulations.
Long-Term Effectiveness and Permanence
Soil and Sediment: Both plans would remove and destroy PCP in the soil to levels which would
result in acceptable risks to human health from direct contact. However, the amended plan
provides a greater degree of long-term effectiveness and permanence than the original cleanup
plan by providing a higher level of treatment (incineration) and offsite disposal of the treated
soil. In contrast, the original plan provides for treatment of the soil to the Site-specific cleanup
level of 1.46 ppm and onsite disposal. Although the treated soil would not pose any
unacceptable risks to human health through direct contact, low levels of contamination would
remain at the Site.
Ground Water. As indicated above, the original remedy does not provide a ground water remedy
that would be effective in the long-term or be permanent given the new information showing
migration of Site contaminants in the ground water. The amended cleanup plan, however, does
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provide a remedy that is protective in the long-term and permanent by collecting contaminated
ground water and treating it (either onsite or offsite) to health-based cleanup levels. The system
will be maintained and operated until the ground water cleanup levels have been achieved.
Short-Term Effectiveness
Soil and Sediment: Overall, the amended cleanup plan presents fewer short-term risks to the
onsite workers and the surrounding community than the original remedy. Although the amended
cleanup plan requires additional truck traffic, it will take much less time to implement (2 months
rather than 12 months) and does not include the disruptions associated with onsite soil treatment
(e.g., staging of the soil prior to and after treatment, and the noise associated with the treatment
system itself).
Ground Water: The short-term risks associated with operation and maintenance of the ground
water collection and treatment system are expected to be minimal. Proper health and safety
practices will be implemented.
Reduction of Toxicity, Mobility, or Volume through Treatment
Soil and Sediment: The amended cleanup plan results in a greater reduction in toxicity, mobility,
and volume of Site contaminants through treatment than the original plan because incineration,'
through the use of higher temperatures, will remove and destroy more of the contaminants in the
soil than will low temperature thermal desorption.
Ground Water: The amended cleanup plan also provides a higher degree of contaminant
reduction by collecting and treating the ground water.
Implementability
Soil and Sediment: Overall, both the original cleanup plan and the amended plan can be readily
implemented, however, the amended plan is easier to implement because onsite treatment of soils
is not required. Regarding the original cleanup plan, bench-scale treatability testing conducted
during the pre-design phase has shown that low temperature thermal desorption can meet the
health-based cleanup levels for organics set forth in the ROD. If treatment standards for F032
and F035 listed wastes are promulgated prior to cleanup at the Site, the contaminated soil would
have to be treated to these new levels. Although low temperature thermal desorption is likely to
meet the new levels for organic contaminants, treatment levels established for arsenic could be a
problem because arsenic is not effectively removed in the low temperature thermal desorption
process.
Ground Water: Technologies to collect and treat the ground water are readily available.
Operation and maintenance of the treatment system can also be readily implemented. The
particular technologies to be used will be determined as part of the emergency response action
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implemented by EPA.
Cost
Soil and Sediment: The cost to treat and dispose of an estimated 18,000 tons of contaminated
soil and sediments using offsite incineration is approximately $13,883,200; As determined
through a treatability study, the cost to treat the same volume using onsite low temperature
thermal desorption and onsite disposal of the treated soil is approximately $14,560,000.
Ground Water. The estimated cost to operate and maintain the ground water collection and
treatment system has not been determined at this time.
State Acceptance
VDEQ served as the lead agency for the Commonwealth of Virginia for the CERCLA
response activities at the Saunders Supply Company Site. VDEQ has reviewed the remedial
alternatives under consideration for the Site and has provided EPA with technical and
administrative requirements for the Commonwealth of Virginia. VDEQ has reviewed the
amended ROD and concurs with the amendment as discussed below.
Community Acceptance
The Proposed Plan to Amend the ROD was released on August 4,1996 to solicit public comment
regarding the proposed revised cleanup plan. At that time, a 30-day comment period was
opened. A public meeting on the Proposed Plan was held on August 20,1996 at the Chuckatuck
Volunteer Fire Company. Comments raised at the public meeting and during the public
comment period are summarized in the Responsiveness Summary which is included in the ROD
Amendment. None of rhe comments made at the puiblic meeting were in opposition to EPA's
proposal to amend the ROD for this Site. Of the written comments received, two asked that EPA
not change the remedy for the Site.
G. AMENDED REMEDY
Following review and consideration of the information in the Administrative Record file,
the requirements of CERCLA, the NCP, and public comment, EPA has selected the revised
cleanup plan as the selected remedy. It provides the best balance of tradeoffs with respect to the
criteria evaluated above. Specifically, the selected remedy, which satisfies Section 121 of
CERCLA, 42 U.S.C. § 9621, includes:
Excavation, Treatment, and Disposal of Pond Sediments: Excavation and offsite
incineration and disposal of the K001 sediments from the wastewater pond and the
former earthen separation pond.
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Excavation, Treatment, and Disposal of Soil and Sewer Sediments: Excavation and
offsite incineration treatment and disposal of the Site soils and the sediments from the
storm sewer.
Ground Water. Operation and maintenance of the downgradient ground water
collection and treatment system constructed under EPA's emergency response authority
to prevent further migration of Site contaminants; includes treatment of the ground water
collected during the dewatering process prior to excavating the soil. Treatment may be
either onsite or offsite.
Concrete Pad: Removal of the top one inch of the stained areas of the concrete pad,
solidification treatment and offsite disposal of the removed material, and removal of the
concrete pad in the area requiring soil excavation with onsite disposal.
Cleaning and Lining of the Storm Sewer: The existing 8-inch concrete storm sewer will
be cleaned of all debris and sediment and lined with a flexible high-density polyethylene
pipe (the sewer was inspected with a closed circuit television camera during the remedial
design).
Ground Water Monitoring: Ground water monitoring will be performed for thirty
years to ascertain that the remedy is protective of human health and the environment.
Institutional Controls: Institutional controls will be implemented to restrict access to
the contaminated ground water under the Site and to prevent movement of the PCP
offsite. The institutional controls include deed restrictions on the Site to prohibit using
either the Columbia aquifer or the Yorktown aquifer as a source of ground water and
restrictions on offsite ground water extraction.
Performance Standards
The selected remedy addresses all of the contaminated media at the Site. By instituting
all of these components, the Site risks will be reduced to within EPA's acceptable risk range.
The performance standards for the major components of the selected remedy include the
following:
To reduce the risk to human health and the environment via the exposure pathways
attributed to the K001 sediments, approximately 700 tons of sediments from the
wastewater pond and the former earthen separation pond shall be excavated, transported
offsite, and treated by incineration. The wastewater pond shall be filled with
decontaminated concrete from the concrete pad, and both areas shall be covered with
clean soil and contoured to promote run-off.
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To reduce the risk to human health and the environment via the exposure pathways
attributed to the contaminated soil and storm sewer sediments, approximately 18,000 tons
of surface and subsurface soils exceeding the soil cleanup level of 1.46 mg/kg of PCP
(corresponding to a 10"6 risk level) and the sediments from the storm sewer along Godwin
Boulevard shall be excavated, transported offsite, and treated by incineration. The storm
sewer was inspected during the design phase with a closed circuit television camera to
identify any obstructions. The sewer shall be thoroughly cleaned to remove all the
sediments.
To reduce the risk to human health and the environment via the exposure pathways
attributed to the water in the wastewater pond, the pond shall be drained and the water
treated prior to discharge. The water shall either be treated onsite and discharged to
Chuckatuck Creek or treated and discharged offsite. If treated onsite, the discharge to
Chuckatuck Creek shall meet VPDES permit limits. If treated and discharged offsite, the
treatment shall meet the levels as set by the receiving facility.
To reduce the risk to human health and the environment attributed to the concrete pads,
the stained areas of the concrete pads shall be scarified and disposed of offsite and the
concrete pad in the area requiring soil excavation shall be removed and disposed of
onsite. If the removed material is determined to be a RCRA characteristic hazardous
waste using the Toxicity Characteristic Leaching Procedure (TCLP), the material shall be
solidified prior to offsite disposal in a landfill as directed by Part 8 of the VSWMR.
During the scarification process, the following dust control techniques shall be
implemented to control the possible release of contaminated material: pre-wetting the
concrete, equipping the scabbier with a sprayer, and using a vacuum attachment for dust
collection. The portion of the concrete pads which must be removed to allow for
excavation of the soil beneath the pad shall be cleaned of any residual soil and disposed
in the wastewater pond.
To reduce the risk to human health and the environment attributed to the existing 8
inch concrete storm sewer, the sewer shall be sliplined with a flexible high-density
polyethylene pipe of a slightly smaller diameter. The service connections shall then be
reconnected to the new liner. The annulus between the old and the new pipeline may be
filled with grout.
To ascertain that the remedy is protective of human health and the environment, long-
term ground water monitoring shall be performed for thirty years. The ground water
monitoring shall include sampling for PCP, arsenic, and chromium which were the only
contaminants associated with the operations at the Site detected at elevated levels in the,
ground water. EPA will determine the appropriate number and location of the monitoring
wells. The monitoring shall determine if the cleanup level of 1 ppb of PCP, the proposed
MCL, is being met throughout the plume in both the Columbia aquifer and the Yorktown
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aquifer. The purpose of ground water monitoring under the original remedy was to
determine if the PCP cleanup level was being met at the Site boundary because the soil
cleanup level for PCP might allow for partioning to ground water at levels exceeding the
cleanup level for ground water. Since the amended remedy does not include backfilling
of treated soil, the ground water monitoring will be performed to determine if the cleanup
level is being met throughout the plume.
To restrict access to the contaminated ground water under the Site and to prevent
accelerated movement of the PCP offsite, institutional controls shall be implemented.
The institutional controls include deed restrictions on the Site to prohibit using either the
Columbia aquifer or the Yorktown aquifer as a source of ground water and restrictions on
offsite ground water extraction which might cause additional movement of contaminated
ground water.
EPA may modify or refine the selected remedy during the remedial design and
construction. Such modifications or refinements, if any, would generally reflect results of the
engineering design process.
H. DOCUMENTATION OF SIGNIFICANT CHANGES
The Proposed Plan, which identified the revised cleanup plan as EPA's preferred
alternative for the Site, was released for public comment on August 4,1996. EPA has reviewed
the verbal comments expressed at the August 20,1996 meeting with the city of Suffolk
Department of Public Utilities and at the August 20,1996 public meeting and the written
comments submitted to EPA during the public comment period which ended September 13,1996
and determined that no significant change to the remedy identified in the Proposed Plan is
necessary.
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SAUNDERS SUPPLY CO. SITE
CHUCKATUCK, VIRGINIA
RESPONSIVENESS SUMMARY
September 1996
This Responsiveness Summary documents public concerns and comments expressed
during the public comment period. The Summary also provides EPA's responses to those
comments. The information is organized as follows:
Overview
Summary of Comments and Questions Expressed During Public Meeting and EPA
Responses
Summary of Written Comments Submitted During Public Comment Period and EPA
Responses
I. Overview
The public comment period for the amended remedy for the Saunders Supply Co. Site
(Site) began on August 4, 1996 and was originally scheduled to end on September 3,1996.
Although the update to the Administrative Record was received at the Site Repository in the
Morgan Memorial Library on August 3,1996, the update to the Administrative Record was not
placed in the file until August 14,1996, ten days after the planned start of the public comment
period. In order to allow at least 30 days for review of the information in the update'to the
Administrative Record, the public comment period was extended ten days from September 3,
1996, to September 13,1996. To facilitate commenting, EPA held a public meeting on August
20, 1996 at the Chuckatuck Volunteer Pure Company located at 5960 Godwin Boulevard in
Suffolk, Virginia.
At the August 20,1996 public meeting, EPA presented the Proposed Plan to amend the
remedy for the Site from onsite thermal desorption of the soil and onsite dechlorination of the
sediments to offsite incineration of both the soil and sediments. EPA explained that, since the
time of the original Record of Decision (ROD), several new incinerators have been permitted that
can now accept the soil and sediments from the Site. Offsite incineration has a much shorter
construction period so the impacts to the two businesses impacted by the cleanup will be greatly
reduced. Also, offsite incineration is comparable in cost to the onsite treatment and resolves an
issue associated with onsite disposal of soil which has been treated to remove pentachlorophenol
(PCP) but may still contain levels of arsenic which exceed the Site-specific cleanup level.
Treated sediments would be disposed of offsite whether treated onsite or offsite because the
sediments are a listed waste (K001 waste) under the Resource, Conservation and Recovery Act
(RCRA). EPA also explained that ground water contamination had begun migrating from the
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Site toward Godwins Millpond. Because of this migration, EPA will utilize its removal authority
to collect, treat, and dispose of the contaminated ground water.
The August 20, 1996 public meeting also provided the public an opportunity to ask
questions and express opinions and concerns. The comments and questions expressed during
that meeting and EPA's responses to those comments and questions are described in the
following summary.
II. Summary of Comments and Questions Expressed During Public Meeting and
EPA's Responses
Questions presented at the August 20, 1996 public meeting are summarized briefly in this section
and are grouped according to subject. The EPA response follows each question presented.
1. A citizen asked for an explanation of why PCP levels detected in monitoring well
MW-9S varied over time, from no detection 1988-1989, to 0.96 parts per billion
(ppb) in March 1995, to 13 ppb in September 1995, to below detection levels in 1996.
EPA Response: The variation in PCP levels at monitoring well MW-9S may be more
closely associated with the amount of rainfall prior to the sampling events than with the
movement of PCP-contaminated water in the aquifer (called a "plume"). The highest level of
contamination detected, 13 ppb, was from the sampling event which occurred toward the end of
the 1994-1995 drought. The higher level of PCP may be due to the lack of water in the aquifer.
The best indication of the movement of the plume in the aquifer is the level of PCP detected at
monitoring well MW-1 IS. This well is more downgradient from the source of contamination
than MW-9S. The levels of contamination found at MW-1 IS have been constantly increasing
since 1991, indicating movement of the plume away from the Site. MW-9S is more side-
gradient than downgradient from the source of contamination, and therefore not as good an
indicator of the movement of the plume.
2. A citizen asked what caused the ground water plume to start migrating.
EPA Response: The Saunders Supply Company installed several wells on the Site many
years ago. One well, the owner's recovery well, was constructed through an impermeable layer
of clay that separates the upper and lower aquifers. This well was routinely pumped out, with the
recovered water being used in a wood treating process. It is thought that this well was acting as a
sump. The PCP would flow to that area because the break in the clay layer was a low point and
the act of pumping would draw more PCP to the area. At the beginning of the design phase,
EPA removed all of the wells installed by Saunders Supply Co., including the owner's recovery
well. With the owner's recovery well plugged, the PCP migrated downgradient, away from the
Site.
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3. A citizen asked if EPA would try to capture the PCP which has already migrated
beyond the Site.
EPA Response: Yes. At the time of the Proposed Plan, EPA had planned to utilize its
removal authority to install one trench at the property line of the Saunders Supply Co. to collect
and treat PCP before it migrated offsite. Prior to the public meeting, EPA held a meeting with
the city of Suffolk Department of Public Utilities. At this meeting, the Department of Public
Utilities expressed concern that the PCP which had already migrated may impact Godwins
Millpond. They recommended that EPA install a second trench further downgradient from the
Site, as close as possible to Godwins Millpond. Based on the verbal and written comments made
by the department and the citizen who asked this question, EPA decided to construct two
trenches, including one trench as close as possible to Godwins Millpond. The trench closest to
Godwins Millpond is intended to capture as much as possible of the PCP that has already
migrated beyond the Saunders Supply Company property.
4. A citizen asked EPA to explain the movement of PCP through the aquifer.
EPA Response: PCP is approximately two and a half times heavier than water. Under the
force of gravity, PCP tends to migrate down through the aquifer until it encounters an
impermeable layer. In this case, PCP migrated through the aquifer until it encountered the clay-
layer approximately 15 to 20 feet below the surface. At that point, the PCP migrated along the
top of the clay layer under the force of gravity. Because it is more dense than water, PCP will
tend to pool in any low points or depressions in the clay layer. PCP strongly adheres to soils; the
extent of sorption depends on organic content, pH, and the type of soil involved. The amount of
PCP that will adhere to soils is directly proportional to the amount of clay and organic material in
the soil matrix. Since the soil at the Site is sandy, adsorption does not occur at a high rate.
5. A citizen asked if any cleanup has been performed at the Site.
EPA Response: Yes. Following an investigation by the Virginia State Water Control
Board, the Saunders Supply Company was required to excavate some contaminated soil around
the conical burner area. They disposed of the contaminated soil into the John Holland landfill.
Since the Site was placed onto the National Priorities List, EPA conducted a full investigation of
the contamination at the Site, designed the remedy, and is now almost ready to begin cleanup of
the remaining areas of contamination.
6. A citizen asked if EPA knew where the edge of the PCP contamination is located.
EPA Response: At this time, EPA has collected ground water samples which showed PCP
contamination at MW-11S but not at MW-19D. We have also collected additional "screening"
samples using a geoprobe. The screening results did show some PCP present downgradient of
MW-1 IS at levels below the cleanup level of 1 ppb. From this, it appears that the edge of the
PCP contamination has passed MW-1 IS.
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7. A citizen asked if the ground water collection trenches will be constructed at the
same time as the excavation of soil.
EPA Response: No. Because the purpose of the trenches is to prevent more PCP from
migrating from the Site and to protect Godwins Millpond, EPA intends to complete the design
and installation of the trenches before starting the soil excavation. Installation of the ground
water collection trenches should be completed by November 30,1996.
8. A citizen asked if EPA has implemented this type of soil remediation at other Sites.
EPA Response: Yes, it has. In the spring of 1996, approximately 15,000 tons of
contaminated soil was excavated from the Greenwood Chemical Superfund Site in Albermarle
County, Virginia, transported by truck to a railroad siding where it was placed on rail cars,
shipped to Tooele County, Utah, and incinerated at the Clive Incinerator. In addition, many
other sites across the country have required excavation and offsite treatment of contaminated soil
and sediment.
9. A citizen asked where the soil from the Site will be incinerated.
EPA Response: The exact location will be determined in the future. As with the
Greenwood Chemical Site, EPA will utilize the services and expertise of the U.S. Army Corps of
Engineers to advertise for bids, award the contract, and perform construction management
services during construction. The decision as to which incinerator will be used will be made
after the award of the construction contract. EPA and the U.S. Army Corps of Engineers will
evaluate the incinerator proposed by the contractor to ensure that it is permitted to accept the
contaminated soil and sediments from the Site and that it is in compliance with its permit.
10. A citizen asked how much money has been spent to date on the Site.
EPA Response: Although EPA maintains cost accounting information on every Superfund
site, EPA did not anticipate this question and did not have the information available for the
public meeting. EPA did, however, agree to obtain the information and submit it to everyone on
the sign-in sheet for the meeting.
11. A citizen asked if any restrictions will be placed on either the Saunders Supply
Company property or the Kelly Nursery property.
EPA Response: After all of the contaminated soil is excavated and backfilled, there would
be no restrictions placed on the use of either property. However, restrictions on the use of the
ground water is necessary. On the Saunders property, the ground water will not be able to be
used for any purpose. On the Kelly property, a restriction will be required to prohibit pumping
which may cause further migration of site contamination beyond the boundary of the Site.
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12. A citizen asked how many trucks would be used to transport the soil off of the Site.
EPA Response: At the Greenwood Chemical Site referred to previously, 16 truckloads per
day were taken out of the site during the initial phase of the project while the truck traffic was
restricted to the hours of 9:00 AM to 2:00 PM (because of safety concerns associated with school
buses on the narrow roads in the area of the site). After the school year ended, the number of
truckloads increased to 20 per day. The experience at the Saunders Supply Company Site may
be similar to that at the Greenwood Chemical Site.
13. A citizen raised a concern that the truck traffic coming out of the Site might
interfere with the operation of the Chuckatuck Volunteer Fire Company located
directly across Godwins Boulevard from the Site.
EPA Response: EPA and the U.S. Army Corps of Engineers will work with the
Chuckatuck Volunteer Fire Company to make any revisions/restrictions necessary in the design
documents to make sure that Site operations do not interfere with the operation of the Volunteer
Fire Company, especially during periods when the fire trucks are hi use.
III. Summary of Written Comments Submitted During Public Comment Period and
EPA's Responses
1. Two commenters asked that EPA not change the remedy selected in the 1991 ROD
because the thermal desorption/dechlorination processes can meet the cleanup level
for PCP at a lower cost than offsite incineration.
EPA Response: First, EPA uses nine criteria to evaluate different alternatives, with cost
being one of the nine. As indicated previously, offsite incineration is rated higher based on all
of the nine criteria than the original remedy selected in the 1991 ROD, especially in view of off-
site incineration's long-term effectiveness, short-term effectiveness, reduction of toxicity,
mobility and volume through treatment, implementability, and community acceptance. Offsite
incineration's superiority is primarily due to (i) higher temperatures destroying all of the organic
contamination, (ii) offsite disposal of the treated material, (iii) work being completed hi much
less time than with onsite treatment, and (iv) minimal operations talcing place on the Site.
Second, offsite incineration also resolves the issue of whether the thermally treated soil meets the
cleanup level for arsenic to permit onsite disposal. All soil that did not meet the arsenic cleanup
level under the original remedy would have to be disposed of offsite hi a landfill, thus resulting
in additional costs beyond that in the original cost estimate. The soil under the concrete pad is
not expected to contain arsenic since the concrete pad was placed before Saunders Supply
Company initiated the copper, chromium, and arsenic wood treatment process. In order to meet
the arsenic cleanup level under the original remedy, EPA planned to blend the treated soil from
those areas which contained arsenic contamination with treated soil from under the concrete pad
(which did not contain arsenic.) During design we eliminated most of the soil under the concrete
pad from requiring treatment because the soil does not exceed any of the site-specific cleanup
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levels. Therefore, most of the soil to be treated now is contaminated with arsenic and, as such,
is not available for blending.
2. Two commenters requested that EPA place two ground water collection trenches as
part of the work performed under the removal authority.
EPA Response: EPA has decided to install two ground water collection trenches-one at
the Saunders Supply Company property boundary and another closer to Godwins Millpond.
EPA has decided to do so in response to these comments, even though the installation of the
ground water trenches was not part of the Proposed Plan on which EPA was requesting
comment.
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