&EPA
United States
Environmental Protection
Agency
Solid Waste And
Emergency Response
(5201 G)
EPA/540/R-95/078
PB95-962910
9200.5-709C
May 1995
SUPERFUND:
DELAWARE
1995 UPDATE
Printed on Recycled Paper
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How to Use the NPL Book
The site fact sheets presented in this book
are comprehensive summaries that cover a
broad range of information. The fact sheets
describe hazardous waste sites on the NPL and
their locations, as well as the conditions
leading to their listing ("Site Description").
The summaries list the types of contaminants
that have been discovered and related threats
to public and ecological health ("Threats and
Contaminants"). "Cleanup Approach" pres-
ents an overview of the cleanup activities
completed, underway, or planned. The fact
sheets conclude with a brief synopsis of how
much progress has been made in protecting
public health and the environment. The
summaries also pinpoint other actions, such as
legal efforts to involve polluters responsible
for site contamination and community con-
cerns.
The fact sheets are arranged in alphabetical
order by site name. Because site cleanup is a
dynamic and gradual process, all site informa-
tion is accurate as of the date shown on the
bottom of each page. Progress is always being
made at NPL sites, and the EPA periodically
will update the site fact sheets to reflect recent
actions. The following two pages show a
generic fact sheet and briefly describe the
information under each section.
How Can You Use
This State Book?
You can use this book to keep informed
about the sites that concern you, particu-
larly ones close to home. The EPA is commit-
ted to involving the public in the decision
making process associated with hazardous
waste cleanup. The Agency solicits input from
area residents in communities affected by
Superfund sites. Citizens are likely to be
affected not only by hazardous site conditions,
but also by the remedies that combat them.
Site cleanups take many forms and can affect
communities in different ways. Local traffic
may be rerouted, residents may be relocated,
temporary water supplies may be necessary.
Definitive information on a site can help
citizens sift through alternatives and make
decisions. To make good choices, you must
know what the threats are and how the EPA
intends to clean up the site. You must under-
stand the cleanup alternatives being proposed
for site cleanup and how residents may be
affected by each one. You also need to have
some idea of how your community intends to
use the site in the future, and you need to know
what the community can realistically expect
once the cleanup is complete.
The EPA wants to develop cleanup methods
that meet community needs, but the Agency
only can take local concerns into account if it
understands what they are. Information must
travel both ways in order for cleanups to be
effective and satisfactory. Please take this
opportunity to learn more, become involved,
and assure that hazardous waste cleanup at
"your" site considers your community's
concerns.
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NPL LISTING HISTORY
Provides the dates when the
site was Proposed, made Final,
and Deleted from the NPL.
SITE RESPONSIBILITY
Identifies the Federal, State,
and/or potentially responsible
parties taking responsibility
for cleanup actions at the site.
ENVIRONMENTAL
PROGRESS
Summarizes the actions to
reduce the threats to nearby
residents and the surrounding
environment and the progress
towards cleaning up the site.
SITE NAME
STATE
EPAID# ABCOOOOOOO
Site Description
EPA REGION XX
COUNTY NAME
LOCATION
Other Names:
: xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx xxxxxxxxxxxxx :
: xxxxxxxxxx xxxx xxxxxxxx xxxx xx xxxxxxxxx xx xxxxxx xxxxxxxx 1
XXXXXXXXX?ft«fc^JXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX X XXX :
XXXXXXX XXX XXX%X*^(XXXXX XXXXX XXXXXX XXXXXXXX XXXXXXXX XXXX XXXXXXXXXX :
xxxxxxxxxxxx xxxxxxxxx'tentx^x xxx xx xxxxxxxxx xxxxx xxxx xxxx xxxxx xxxxxxx xxxxxxxx
xxxxxxxx xxxxxxxxx xxxx xxxxlOsmxxxxx xxxxxxxx xxxxx xxxx xxxxx xxx xxx xxxxxx
XXXXXXXXXXXX XX XXXXXXX XXX XXXXX)0?X**J£XX XXXXXX XX XXXX XXX XXXXX XXX XXXXX XXX XXXXX
Site Responsibility:
xxxxxx xxx xxxxx :
xxxxxx xxxxxxxxx xxxxxxxx
xxxxxxxxxxxxx xxxxxxxxx
NPL Listing History
Proposed XX/XX/XX
Final XX/XX/XX
Threats and Contaminants
xxxxxx xxx xxxxx xxxxxxxxxxxx xxxxxx xxxxxxxxx xxxxxxxx
XXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX
XXXXXXXX XXX XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX
XXX XXXXXXXXXX XXXXXXXX XXXXXXX XXX XXXXXX XXXXXX XXXXX XXXXXX
XXXXXXXX XXXX XXXXXXXXXX XXXXXXXX XXXXXXXXXXXX XXXXXXXXX XXXX X XXX
: xxxxxxxxx
XXXX XXXX XXXXX XXXXXXX XXXXXXXX XXXXXXXX XXXXXXXXX XXXX XXXX XXXXX XXXX
Cleanup Approach
XXXXXX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX XXXXXXXXXXXXX
XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX XXXXXXXX
XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX X XXX XXXXXXXX
Response Action Status
XXXXXX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX :
XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX\
XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX :
XXXXXXXX XXXXXXX XXX XXXXXX XXXXXX XXXXX XXXXXX XXXXXXXX XXXXXXXX :
XXXXXXXXXX XXXXXXXX XXXXXXXXXXXX XXXXXXXXX XXXX X XXX XX XXXXXXXXX XXXXX XXXX XXXX XXXXX
XXXXXXX XXXXXXXX XXXXXXXX XXXXXXXXX XXXX XXXX XXXXX XXXX XXXXXXXX XXXXX XXXX XXXXX XXX
XXX XXXXXX XXXXXXXXXXXX XX XXXXXXX XXX XXXXXX XX XXXXXX XXXXXXXX XXX :
Site Facts:
XXXXXX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX
XXXXXXXXX XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX
XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX X XXX
xxx xxxxxx
Environmental Progress
XXXXXX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX XXXXXXXXXXXXX XXXXXXXXX
XXXXXXXXXXXXX XXXXXXXXXX XXXX XXXXXXXX XXXX XX XXXXXXXXX XX XXXXXX XXXXXXXX XXX
XXXXXXXXXXXX XXXXX XXX XXXXXXXXXXXXX XX XXXXXX XXXX XXXXX XXXX X XXX XXXXXXXXXX
XXXXXXXX XXXXXXX XXX XXXXXX XXXXXX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX
Site Repository
XXXXXX XXX XXXXX XXXXXXXXXXXX XXXXXX XXXXXXXXX XXXXXXXX XXXXXXXXXXXXX XXXXXXXXX
\
SITE REPOSITORY
Lists the location of the primary site repository. The site
repository may include community relations plans, public
meeting announcements and minutes, fact sheets, press
releases, and other site-related documents.
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SITE DESCRIPTION
This section describes the location and history of the site. It includes descrip-
tions of the most recent activities and past actions at the site that have con-
tributed to the contamination. Population estimates, land usages, and nearby
resources give readers background on the local setting surrounding the site.
®
THREATS AND CONTAMINANTS
The major chemical categories of site contamination are noted, as well as
which environmental resources are affected. Icons representing each of the
affected resources (may include air, groundwater, surface water, soil, and
contamination to environmentally sensitive areas) are included in the margins
of this section. Potential threats to residents and the surrounding environ-
ments arising from the site contamination also are described.
CLEANUP APPROACH
This section contains a brief overview of how the site is being cleaned up.
RESPONSE ACTION STATUS
Specific actions that have been accomplished or will be undertaken to clean
up the site are described here. Cleanup activities at NPL sites are divided
into separate phases, depending on the complexity and required actions at the
site. Two major types of cleanup activities often are described: initial,
immediate, or emergency actions to quickly remove or reduce imminent
threats to the community and surrounding areas; and long-term remedial
phases directed at final cleanup at the site. Each stage of the cleanup strategy
is presented in this section of the summary. Icons representing the stage of
the cleanup process (initial actions, site investigations, EPA selection of the
cleanup remedy, engineering design phase, cleanup activities underway, and
completed cleanup) are located in the margin next to each activity descrip-
tion.
SITE FACTS
Additional information on activities and events at the site are included in this
section. Often details on legal or administrative actions taken by the EPA to
achieve site cleanup or other facts pertaining to community involvement with
the site cleanup process are reported here.
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Guide to the NPL Book Icons
The "icons," or symbols, accompanying the text allow the reader to see at a glance which envi-
ronmental resources are affected and the status of cleanup activities at the site.
Icons in the Threats
and Contaminants
Section
Icons in the Response
Action Status Section
Contaminated Groundwater re-
sources in the vicinity or underlying
the site. (Groundwater is often used
as a drinking water source.)
Contaminated Surface Water and
Sediments on or near the site.
(These include lakes, ponds,
streams, and rivers.)
Contaminated Air in the vicinity of
the site. (Air pollution usually is
periodic and involves contaminated
dust particles or hazardous gas
emissions.)
Contaminated Soil and Sludges on
or near the site. (This contamination
category may include bulk or other
surface hazardous wastes found on
the site.)
Threatened or contaminated Envi-
ronmentally Sensitive Areas in the
vicinity of the site. (Examples
include wetlands and coastal areas
or critical habitats.)
Initial, Immediate, or Emergency
Actions have been taken or are
underway to eliminate immediate
threats at the site.
Site Studies at the site to determine
the nature and extent of contamina-
tion are planned or underway.
Remedy Selected indicates that site
investigations have been concluded,
and the EPA has selected a final
cleanup remedy for the site or part
of the site.
Remedy Design means that engi-
neers are preparing specifications
and drawings for the selected
cleanup technologies.
Cleanup Ongoing indicates that the
selected cleanup remedies for the
contaminated site, or part of the site,
currently are underway.
Cleanup Complete shows that all
cleanup goals have been achieved
for the contaminated site or part of
the site.
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EPA ID
Number
DED980494496
DED980714141
DED980704860
DED980551667
DED000605972
DE8570024010
DED980693550
DED980555122
DED980830954
DED980713093
DED980552244
DED043958388
DED058980442
DED980705255
DED981035520
DED041212473
DED980494637
DED000606079
DED980705545
DED980704951
Site Name
ARMY CREEK LANDFILL
CHEM-SOLV, INC.
COKER'S SANITATION SERVICE LANDFILL
DELAWARE CITY PVC PLANT
DELAWARE SAND & GRAVEL LANDFILL
DOVER AIR FORCE BASE
DOVER GAS LIGHT CO.
E.I. DU PONT DE NEMOURS (NEWPORT LANDFILL)
HALBY CHEMICAL CO.
HARVEY & KNOTT DRUM, INC.
KOPPERS CO., INC. (NEWPORT PLANT)
NCR CORP. (MILLSBORO PLANT)
NEW CASTLE SPILL
NEW CASTLE STEEL PLANT
SEALAND LIMITED
STANDARD CHLORINE OF DE, INC.
SUSSEX COUNTY LANDFILL NO. 5
TYBOUTS CORNER LANDFILL
TYLER REFRIGERATION PIT
WILDCAT LANDFILL
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ARMY CREEK
LANDFILL
DELAWARE
EPA ID# DED980494496
Site Description
EPA REGION 3
New Castle County
2 miles southwest of New Castle
Other Names:
Llangollen Landfill
Llangollen Army Creek Landfills
The Army Creek Landfill site occupies approximately 60 acres. It was used as a landfill for
municipal and industrial wastes from 1960 to 1968. During that 8-year period, about 2 million
cubic yards of refuse were landfilled. The site previously was used as a sand and gravel quarry.
Approximately 30 percent of the waste lies below the seasonal high water table. Army Creek,
which forms the southern and eastern borders of the site, flows into the Delaware River about 1
mile east of the site. Groundwater contamination was discovered in a nearby residential well hi
1972. After studies were conducted by New Castle County, which identified alcohols and acidic
compounds in leachate, recovery wells were installed to prevent the movement of groundwater
toward public water supply wells. Approximately 3,370 people live within 1 mile of the site,
which is in a largely rural and light industrial area. Llangollen Estates, a residential
development, is several hundred feet beyond the southern edge of the site. An estimated 130,000
people living within 3 miles of the site are served by groundwater supplies. Another NPL site,
the Delaware Sand and Gravel Landfill, is located immediately across from Army Creek to the
east of the site.
Site Responsibility:
This site is being addressed through
Federal and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date: 10/23/81
Final Date: 09/08/83
Threats and Contaminants
Z1AJ
Volatile organic compounds (VOCs), such as benzene and dichloroethane, and heavy
metals, including chromium and mercury, are found in monitoring wells, recovery
wells, groundwater, and soils. The surface water of Army Creek contains heavy
metals contamination including cadmium, chromium, mercury, iron, and zinc.
Wetlands nearby the site could be adversely affected by contamination. People
working or trespassing on the site could be exposed to contaminants in the soil by
direct contact or ingestion of contaminated groundwater.
July 1995
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Cleanup Approach
Response Action Status
Emergency Actions: Tires in the vicinity of the site caught fire in the early 1980s,
and threatened to ignite nearby hazardous wastes. The fire was extinguished by New
Castle County, and the EPA provided emergency technical support and air
monitoring during the fire control efforts. New Castle County installed a groundwater recovery
system designed to capture contaminated groundwater. This series of downgradient pumping
wells is designed to prevent the contaminated plume from reaching the source of the drinking
water supply. Pumping has separated contamination from the water supply and has eliminated
migration of the plume into the drinking water source.
Source Control: Cleanup activities began in 1990 with control of the source of
contamination. Activities included: installation of a multi-layer cap over the landfill;
operation of the downgradient recovery well network; and evaluation of the cap
system and the groundwater recovery network for five years by monitoring well water levels and
by pumping water and checking the water quality. Source control activities were completed in
1994. In five years, an evaluation will be carried out to determine if installation of upgradient
controls is necessary. At the same time, the monitoring strategy for well water levels, pumping
rates, and water quality will be re-evaluated.
Groundwater: A detailed study of the nature and extent of contamination and
treatment alternatives for the water being pumped from the groundwater recovery
wells was completed in 1990, leading to the final selection of a groundwater treatment
remedy for recovery wells. Construction was completed in early 1994 and consists of the
operation of a water treatment facility, which currently treats recovered groundwater before
discharge to surface water. A plan for long-term monitoring, with respect to groundwater,
surface water, sediments, and associated wetlands is currently under development.
Site Facts: On September 18, 1990, 18 potentially responsible parties signed a Consent Decree
to implement the cleanup actions at the site and to reimburse the EPA for past response costs.
Part of the settlement required the potentially responsible parties to deposit $800,000 into a Trust
Fund. The Department of the Interior, the National Oceanic and Atmospheric Administration
(NOAA), and the State of Delaware will ensure that this money is used to create or enhance
natural resources affected by contamination at the site.
Environmental Progress
All construction is complete at the site. Actions taken to date include installing groundwater
recovery wells, responding to a site fire, and controlling the source contamination, and have
reduced immediate threats posed by the site. Groundwater treatment and monitoring will
continue until all site cleanup goals have been met.
July! 995 2 ARMY CREEK LANDFILL
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Site Repository
Delaware Department of Natural Resources & Environmental Control, Superfund Branch, 715
Grantham Lane, New Castle, DE 19720
ARMY CREEK LANDFILL
July 1995
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CHEM-SOLV, INC.
DELAWARE
EPA ID# DED980714141
Site Description
EPA REGION 3
Kent County
Cheswold
The 1 1/2-acre Chem-Solv, Inc. site served as a small solvent distillation facility beginning in
1982. The facility recycled waste solvents by placing a drum on an electric coil heater, which
distilled the solvents into a second drum. The contents of the second drum were filtered into a
third drum, and the distilled residues were stored on site. In 1984, an explosion and fire at the
site destroyed the entire distillation facility. Witnesses observed fluids flowing off a concrete pad
into the soil. After the fire, the State conducted studies of the Upper Columbia Aquifer,
underlying the site, where high concentrations of volatile organic compounds (VOCs) were found
in the upper zone of the aquifer, and low concentrations of VOCs were found in the lower zone
of the aquifer. An occupied 3-unit apartment building is located on the site. About 5,500
residents live and are served by private wells within 3 miles of the site. The site is surrounded by
farmland, residential developments, and commercial businesses.
Site Responsibility:
This site is being addressed through a
combination of Federal, State, and
potentially responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 06/24/88
Final Date: 08/30/90
Threats and Contaminants
The groundwater is contaminated with VOCs, primarily trichloroethylene (TCE) and
benzene, and heavy metals, including manganese. Soil excavation and treatment hi
1985 removed the potential for exposure to soil contamination; treated soil has been
returned to the site. The primary threat to human health is drinking contaminated
groundwater; however, levels of contamination in residential wells in the area are
within acceptable drinking water standards. In addition, data collected in 1994
indicate that concentrations of VOCs in groundwater have decreased through natural
processes. One well, however, exceeded EPA health-based TCE levels. Bottled water
is being provided until more permanent action can be taken.
July 1995
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Cleanup Approach
This site is being addressed in two stages; initial actions and a long-term remedial phase focusing
on cleanup of the entire site.
Response Action Status
Initial Actions: In 1985, the State excavated and treated 1300 cubic yards of
contaminated soil using a process that passes air through the soil to remove VOCs.
This process reduced contamination to levels that permitted the soil to be returned to
the excavated area. The State also installed a groundwater extraction system. From 1985 to
1988 groundwater was extracted and treated on site by air stripping to remove VOCs. The
treated water was discharged to a sanitary sewer system.
Entire Site: A study was conducted by a group of potentially responsible parties
from 1989 to 1991 to determine the nature and extent of contamination at the site and
to recommend alternatives for the final cleanup. In the spring of 1992, the EPA
selected a remedy calling for groundwater extraction and either discharge to a local publicly
owned treatment works or on-site treatment with discharge to local surface water (i.e., the Alston
branch of the Leipsic River). The following components are also included in the remedy: a
groundwater restriction zone in the contaminated area, deed restrictions, continued groundwater
monitoring, provisions for an alternative water supply for domestic wells should they become
contaminated before cleanup levels have been reached, and removal of existing recovery wells.
The potentially responsible parties are designing the remedy with EPA oversight. The potentially
responsible parties conducted field work in the fall of 1993, including well installation/
abandonment, groundwater sampling, and an aquifer pump test. Groundwater sampling results
showed that, through natural processes, VOC contamination has decreased naturally since the site
study was performed in 1991, and concentrations are approaching cleanup levels established in
the remedy. The potentially responsible parties proposed a long-term monitoring program to
replace the active remedy. EPA is currently reviewing this proposal while the potentially
responsible parties continue to monitor groundwater on a quarterly basis.
Site Facts: In 1984 and 1985, the State of Delaware issued orders to one of the potentially
responsible parties to cease operations immediately, monitor groundwater, and remove all
contaminated soil; however, no actions were taken. In 1988, a Consent Order was signed by the
potentially responsible parties, the EPA, and the State, requiring the parties to conduct an
investigation into the contamination at the site. The EPA issued a Unilateral Administrative
Order (UAO) compelling the potentially responsible parties to conduct the cleanup activities. In
winter 1993, a group of potentially responsible parties notified the EPA of their intent to comply
with the terms of the UAO.
July 1995 2 CHEM-SOLV, INC.
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Environmental Progress
By treating the on-site soils in 1985, the State eliminated the immediate threat from contaminated
soils. The State's groundwater extraction and air stripping operation also reduced the potential
for exposure to hazardous materials in the groundwater. These actions have made the Chem-
Solv, Inc. site safer while EPA determines the final course of action at the site.
Site Repository
William C Jason Library, 1200 North DuPont Highway, Delaware State College, Dover, DE
19901, (302)739-3571
Delaware Department of Natural Resources & Environmental Control, Superfund Branch, 715
Grantham Lane, New Castle, DE 19720, (302) 323-4540
US EPA, Region III, Docket Room, 9th Floor, 841 Chestnut Building, Philadelphia, PA 19107,
(215) 597-3037
CHEM-SOLV, INC.
July 1995
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COKER'S
SANITATION S
LANDFILLS
DELAWARE
EPA ID# DED980704860
Site Description
VICE
EPA REGION 3
Kent County
Cheswold
Other Names:
Reichold Chem Inc. #1
Coker's Landfill #1 & #2
The two Coker's Sanitation Service Landfills cover approximately 25 acres near Cheswold.
Coker's Landfill #1 covers 10 acres, and Coker's Landfill #2 covers about 15 acres. The
landfills were used for disposal of latex rubber waste sludges from what is now the Reichold
Chemicals, Inc. plant. Coker's Landfill #1, which operated from 1962 until 1976, consists of an
unknown number of unlined trenches. Coker's Landfill #2 was operated under a State permit as
a solid waste disposal site from 1976 to 1980, and consists of 51 lined trenches, each with a
leachate collection and monitoring system and a groundwater monitoring system. The landfills
are located above two groundwater systems: the Columbia Aquifer, which is a water table
aquifer, and the Cheswold Aquifer, which is a deeper artesian aquifer. Approximately 4,000
people live within a 3-mile radius of the site, and two farms are adjacent to the landfills.
Site Responsibility:
This site is being addressed through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 04/10/85
Final Date: 07/22/87
Threats and Contaminants
On-site groundwater, leachate, and soil are contaminated with metals, volatile organic
compounds (VOCs) such as ethyl benzene, and styrene from the latex rubber wastes.
Off-site monitoring wells have shown the presence of VOCs. Potential risks to health
are direct contact with leachate or ingestion of contaminated groundwater. There is a
potential for contaminants to move off-site to nearby surface water, or into the
underlying aquifers both of which are used as public water supplies. Area wetlands
also are potentially threatened, since drainage from Coker's Landfill #1 runs through a
wetland area on the Willis Branch of the Leipsic River, and Coker's Landfill #2 is
partially bordered by wetlands.
July 1995
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Cleanup Approach
Response Action Status
Immediate Actions: In 1989, buried drums and a bin were discovered by
geomagnetic surveys during the site investigation conducted by the parties potentially
responsible for the site contamination. These materials were excavated, overpacked,
and disposed of off site.
Entire Site: The potentially responsible parties conducted an investigation of the
entire site to help determine the extent of remaining contamination and to identify
cleanup technologies. In 1990, the EPA selected a cleanup remedy, which involves
implementing deed restrictions, fencing and posting warning signs to limit access to the site,
covering leachate seeps, backfilling and seeding settled areas in Landfill #2, grouting leachate
collection wells in Landfill #2, monitoring groundwater and inspecting the landfills on an ongoing
basis. Monitoring surface water and sediments of the Willis Branch will also be conducted. If
various levels are met during the monitoring required as part of the remedial action, additional
work may be warranted. Construction of cleanup remedies was completed in late 1993.
Site Facts: An Administrative Order on Consent was signed in 1988 by the EPA and Reichold
Chemicals, Inc., Nabisco Brands, Inc., and Rapid American Corp. for an investigation to
determine the extent of contamination and to identify cleanup technologies for the site. In 1992,
the potentially responsible parties signed a Consent Decree with EPA agreeing to implement
cleanup actions.
Environmental Progress
All construction at the site is complete. In addition, long-term monitoring of surface water,
sediments and groundwater will evaluate the effectiveness of the remedy. Bi-annual monitoring
data has shown that the remedy selected is operational, functional, and protective.
Site Repository
Clayton Post Office, Railroad Avenue, Clayton, DE 19938
July 1995 2 COKER'S SANITATION SERVICE LANDFILLS
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DELAWARE CITY
PVC PLANT
DELAWARE
EPA ID# DED980551667
EPA REGION 3
New Castle County
2 miles west of Delaware City
Site Description
The 400-acre Delaware City PVC Plant site was built in 1966 and serves as a poly vinyl chloride
(PVC) production facility. In the past during plant operations, earthen lagoons were used to
dump waste PVC. Another area was used to bury PVC sludges and then was capped. The
Columbia aquifer, which has been contaminated by past plant operations, is used locally as a
domestic water supply. There are approximately 50 people living within one mile of the site,
including one residence and several businesses located on top of the plume but away from the
PVC plant. A water service company has wells within 3 miles of the site (but in a different
aquifer) and serves an estimated 100,000 people.
Site Responsibility:
This site is being addressed through
Federal, State and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 10/23/81
Final Date: 09/08/83
Threats and Contaminants
The ground water is contaminated with volatile organic compounds (VOCs), including
vinyl chloride, from the earthen lagoons. The soil is also contaminated with VOCs.
Ingesting or coming into contact with contaminated ground water or soil poses a
health threat to nearby residences.
Cleanup Approach
This site is being addressed hi four stages: immediate actions and three long-term remedial
phases focusing on cleanup of the ground water; lagoon areas and the former PVC storage area
and sludge pits; and the remaining areas of soil and groundwater contamination.
July 1995
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Response Action Status
Immediate Actions: Alternate water supplies were provided to nearby businesses
and residences that were affected by contaminated groundwater. A majority of the
PVC sludge was removed from the off-grade batch pits to eliminate the primary
source of ground water contamination.
Ground water: The remedy selected for the groundwater contamination includes:
installing groundwater recovery wells and treating the water through air stripping and
then discharging it into the Delaware River. The groundwater recovery system
continues to operate to ensure that contamination will be cleaned up to acceptable levels.
Lagoon Areas, PVC Storage Area, and Sludge Pits: The remedies selected for
cleanup of the lagoon area included: excavating sludge and contaminated soils, selling
the sludge as a product and disposing of residuals offsite; installing synthetic liners in
the aeration basins, installing a tank in the old stormwater pond, and backfilling the off-grade
batch pits. The remedies selected for the PVC storage area and sludge pits included: capping the
PVC storage area; installing a second cap over the sludge pits; and establishing a vegetative
cover over each area. All construction activities were completed in the summer of 1992.
Remaining Areas: In 1993, the potentially responsible parties submitted plans for
additional investigations of soil and groundwater to identify the nature and extent of
contamination in areas where contamination was not previously detected. These
areas requiring additional studies were discovered when cleanup actions were being taken at the
other areas of the site.
Site Facts: In 1984, the EPA and the State entered into a Consent Order with two potentially
responsible parties to perform studies of cleanup alternatives and all necessary cleanup actions to
eliminate contamination at the site. In 1987, the Consent Order was amended to outline the
details of the cleanup design and implementation.
Environmental Progress
The provision of an alternate water supply to residents and area businesses and the completion of
cleanup activities (including sludge removal, installation of liners, capping, and backfilling) at the
Delaware City PVC Plant site has reduced the potential for exposure to contaminated materials.
Further studies to identify other potential sources of contamination began in 1993.
Site Repository
Delaware Department of Natural Resources and Environmental Control, Superfund Branch, 715
Grantham Lane, New Castle, DE 19720
July 1995
DELAWARE CITY PVC PLANT
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DELAWARE m E™ cREtp'ONt 3
/-^ r- New Castle County
S AN D &
LANDFILL o,he,N,meS:
_^_. _ i«| A DC L-^-^l/^N, Delaware Sand & Gravel Co. Landfill
ULLAWAnb V^ Delaware Sand & Gravel-Llangollen
EPA ID# DED00060597 Army Creek Landfills
Site Description
The 27-acre Delaware Sand & Gravel Landfill site is an inactive industrial waste landfill located
adjacent to another NPL site, the Army Creek Landfill. The site has four disposal areas, referred
to as the Drum Disposal, Inert Disposal, Ridge, and Grantham South areas. Between 1968 and
1976, the site accepted household, construction, and industrial wastes including at least 7,000
drums containing liquids and sludges from perfume, plastics, paint, and petroleum refining
processes. The Drum Disposal area contains thousands of buried drums and is a major source of
organic contamination of the groundwater. The Ridge area consists of contaminated surface soil.
The Inert Disposal area contains various construction and industrial wastes buried 25-40 feet
thick; cars, trucks, and storage tanks are scattered on the surface. The Grantham South area
contains construction debris and mixed chemical wastes. Approximately 2,000 people live within
a mile of the site. The site is located in a mixed residential and lightly industrialized area.
Properties adjoining the site include two residences and a maintenance garage. The nearest
residence is about 30 feet from the edge of the landfill. The Llangollen Estates housing
development is about 1A mile southwest of the site. Underlying the landfill is the Potomac
Aquifer, which is accessed by about 1 '4 miles south of the site and is used as a public water
source. Groundwater recovery wells located between the site and the public supply wells are
effectively capturing groundwater borne contaminants. The recovered groundwater is routed
through an on-site water treatment plant prior to its discharge into an adjacent stream.
_,. _ ..... _...,. ,, , .. . NPL LISTING HISTORY
Site Responsibility: This site is being addressed through
Federal, State and potentially
responsible parties actions.
Threats and Contaminants
Proposed Date: 10/23/81
Final Date: 09/08/83
The groundwater is contaminated with volatile organic compounds (VOCs),
semi-volatile organic compounds, and heavy metals. The soil is contaminated with
VOCs, polychlorinated biphenyls (PCBs), and heavy metals. Specific contaminants
exceeding surface water quality standards in Army Creek include cadmium,
chromium, mercury, iron, and zinc. The greatest threat to health is accidental
ingestion of groundwater. Workers, trespassers, and nearby residents may be exposed
to contaminants in the soil and water.
August 1995
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Cleanup Approach
This site is being addressed in four stages: immediate actions and three long-term remedial
phases focusing on cleanup of the Grantham South Area, Ridge and Drum Disposal Areas and
the Inert Area.
Response Action Status
Immediate Actions: To reduce the threat of groundwater contamination, New
Castle County installed a groundwater recovery system downgradient of the site to
prevent contaminated water from reaching the nearby public water supply well field.
A water treatment plant is currently treating the recovered groundwater prior to its discharge to
Army Creek and Army Pond. Continued monitoring in the area indicates that the groundwater
recovery system has been effective in controlling the migration of contaminated groundwater. In
1984, the EPA removed approximately 600 drums from the surface of the Drum Disposal area.
The flammable solids and PCB materials were bulked, drummed, and safely disposed of. Air
monitoring was conducted to determine the affect of site activities on ambient air. Work areas of
the site were regraded, hydroseeded, and spread with mulch. In 1991, a security fence was
installed around the drum disposal area. A slurry wall around the drum disposal area to keep
contaminants contained prior to final cleanup is currently under construction.
Grantham South Area: In 1991, the EPA completed the construction of a cap
over the Grantham South Area to contain the source of contamination.
Drum Disposal and Ridge Areas: In the fall of 1993, the EPA revised the
cleanup remedy. The selected remedy includes: excavation and off-site disposal of
buried drums; treatment of contaminated soils using soil vapor extraction and
bioventing technologies; and containing any residually contaminated soils with a slurry wall
enclosing the drum disposal area and a multi-layer cap. Design activities began in the fall of
1994. Construction of the slurry wall was completed in December 1994. Drum excavation is
scheduled for 1995 and treatment of contaminated soils will begin in 1996.
Inert Area: The selected action for the Inert Area includes removal and off-site
disposal of all surface debris and construction of a multi-layer cap. The design of
the multi-layer cap is complete and construction is expected to begin shortly.
Site Facts: In 1976, the state issued an enforcement action requiring the site owner to
discontinue disposal activities. In accordance with a 1992 Administrative Order on Consent,
some of the potentially responsible parties completed the design of a multi-layer cap for the Inert
Area and constructed a slurry wall around the Drum Disposal area. In accordance with a 1995
Consent Decree, a group of potentially responsible parties agreed to design and perform the
remaining cleanup activities.
August 1995 2 DELAWARE SAND & GRAVEL LANDFILL
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Environmental Progress
Numerous cleanup activities have been completed at the Delaware Sand & Gravel Landfill site,
including fencing; surface drum removal; capping; and construction of a slurry wall around, the
Drum Disposal area. The groundwater recovery and treatment system is controlling the spread of
contamination from the site while final cleanup actions are being completed.
Site Repository
Delaware Dept. of Natural Resources & Environmental Control, Superfund Branch,
715 Grantham Lane, New Castle, DE 19720
DELAWARE SAND & GRAVEL LANDFILL
August 1995
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DOVER AIR FOR
BASE
DELAWARE
EPA ID# DE8570024010
Site Description
EPA REGION 3
Kent County
Dover
The 3,700-acre Dover Air Force Base (AFB) site is the base of operation for the 436th Military
Airlift Wing. The base contains 23 areas on site that were used to dispose of industrial waste.
An estimated 23,000 cubic feet of waste were disposed of from 1951 to 1970. The base's
operations generated numerous wastes, some in drums, including paints, solvents, waste fuels,
and oil. These wastes were disposed of in various on-base locations including 12 landfills and
three fire training areas. All disposal sites are earth-covered to a depth of 3 feet, with the
exception of the construction debris landfill. Access to the site is restricted. There are
approximately 1,000 people living on base, and 39,000 people living within a 3-mile radius of the
site. The distance from the base to the nearest residence is about l/2 mile, and the site is located
hi a commercial and residential area that is densely populated. The base well system serves
about 10,000 people and is routinely monitored by the Air Force. Contaminants have not been
found in this system.
Site Responsibility:
This site is being addressed through
Federal and State actions.
IMPL LISTING HISTORY
Proposed Date: 10/01/84
Final Date: 03/13/89
Threats and Contaminants
Shallow on-site groundwater is contaminated with heavy metals including arsenic and
cadmium and volatile organic compounds (VOCs) from former waste disposal
practices. A variety of VOCs have been detected in off-site groundwater including
trichloroethylene (TCE), tetrachlorethylene (PCE) and carbon tetrachloride. VOCs
also have been detected hi the sediments. VOCs and heavy metals including mercury,
chromium, and cadmium have been detected in on-site stream waters. Potential health
threats include exposure to contaminated groundwater used for drinking water and
ingestion of contaminated fish and wildlife. Direct contact with contaminated surface
water or sediments during recreational or site activities by area residents and workers
also is a concern. A nearby freshwater wetlands is threatened by site contamination.
Cleanup Approach
This site is being addressed in four stages: initial actions and three long-term remedial phases
focusing on cleanup of Fire Training Area #3, the Industrial Area, and on-site groundwater.
November 1994
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Response Action Status
Initial Actions: The Air Force has cleaned up the industrial waste basins and a
drum site, and has provided an alternate water supply to affected residents. A
landfill and some hazardous waste areas were excavated during the runway extension
in 1988 and 1989.
Fire Training Area #3: Cleanup activities began early in 1992. An underground
storage tank, oil/water separator, and all associated piping were removed from the
site. Contaminated soils surrounding the tanks and underlying the fire training pit
also were removed. The area was capped in the fall of 1993.
Industrial Area: In 1990, the Air Force began an investigation into the nature and
extent of contamination and to identify cleanup alternatives. The area is comprised of
source areas including treatment units, buildings, hangars, and industrial sewer lines
that are close together. The Air Force has proposed cleanup plans for source control and the
removal of contamination floating on the water table, as well as the removal of contaminated
soils. A final decision on the remedy is expected in 1995.
On-Site Groundwater: Groundwater monitoring currently is underway as part of
the ongoing site studies. In 1990, the Air Force began an investigation into the extent
and nature of groundwater contamination. A decision on the remedy was made in
mid-1994, which includes removal of the sources of contamination. The design activities are
completed, and the cleanup activities are scheduled to be completed in 1996.
Site Facts: The EPA, the Air Force, and the State of Delaware have entered into an
Interagency Agreement (IAG) for comprehensive cleanup and compliance with Federal standards.
The Dover Air Force Base also is participating in the Installation Restoration Program, a
specially funded program established by the Department of Defense (DOD) in 1978 to identify,
investigate, and control the migration of hazardous contaminants at military and other DOD
facilities.
Environmental Progress
By cleaning up the industrial waste basins and drum sites, providing an alternate water supply to
residents and workers at the Base, and cleaning up the Fire Training Areas, the Air Force has
reduced the risk of immediate threats from the Dover Air Force Base site while further cleanup
activities are being conducted.
Site Repository
Dover Air Force Base, 436 Military Airlift Wing, Dover, DE 19902
November 1 994
DOVER AIR FORCE BASE
-------
DOVER GAS
LIGHT CO.
DELAWARE
EPA ID# DED980693550
EPA REGION 3
Kent County
Dover
Site Description
The 1-acre Dover Gas Light Co. site operated as a coal gasification plant in Dover, Delaware
from 1859 to 1948 and produced gas for street lamps from coal. When the plant was closed in
1948, all of the structures except a brick garage were demolished. Much of the plant was
removed, but sections of the tanks and other process equipment containing coal oil, coal tar, and
coke were buried on site. In 1984, remains of this coal gasification plant were found. The site
currently is used as an unpaved parking lot, with a museum immediately adjacent. Also, a
cemetery and historic church are nearby. Approximately 10,000 people are within 1 mile of the
site and an estimated 45,000 people are served by public and private wells within 3 miles of the
site. Seven of Dover's 14 municipal supply wells are located within one mile of the site;
however, the Dover municipal system draws water from a lower, uncontaminated aquifer. The
municipal wells were sampled in 1988 and 1991 and did not show signs of contamination.
Site Responsibility:
This site is being addressed through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 01/22/87
Final Date: 10/04/89
Threats and Contaminants
ZGJ
On-site soils are heavily contaminated with polycyclic aromatic hydrocarbons (PAHs)
and xylene. Groundwater in the Columbia Aquifer is contaminated with PAHs and
xylene. Chlorinated organic compounds have also been detected in groundwater and
are believed to have originated from several dry cleaning establishments in the area.
Sediments in the nearby Tar Branch and St. Jones River are contaminated with low
levels of volatile organic compounds (VOCs), PAHs, metals, and pesticides. The
sediments are not threatening aquatic organisms. Possible health threats include
ingestion of or direct contact with the contaminated groundwater or soil. Although
municipal supply wells are nearby, sampling has indicated that contamination in the
upper aquifer does not pose a threat to Dover's water supply, which is drawn from a
lower, uncontaminated aquifer.
August 1995
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Cleanup Approach
This site is being addressed in a long-term remedial action focusing on cleanup of the entire site.
Response Action Status
Site Studies: In 1990, one potentially responsible party began an investigation to
determine the nature and extent of contamination and to identify cleanup alternatives
for soil, groundwater, and potential river sediment contamination at the site. The
investigation was completed in the summer of 1994, at which time EPA selected a remedy to
address contamination associated with the site. The remedy selected for the site includes:
excavation of contaminated soil with thermal treatment off site; natural attenuation of
contaminated portions of the groundwater plume; recovery of the non-aqueous phase liquid
(NAPL) material from the groundwater, and groundwater monitoring. An additional study began
in the summer of 1994 to determine the extent of contamination from the former dry cleaner.
Site Facts: In 1990, one potentially responsible party entered into an Administrative Order on
Consent with EPA and the Delaware Department of Natural Resources and Environmental
Control (DNREC) whereby the potentially responsible party agreed to perform an investigation to
determine the nature and extent of contamination at the site and to develop, evaluate, and screen
potential cleanup options.
Environmental Progress
After listing the Dover Gas Light Co. site on the NPL, EPA determined that site conditions do
not present an immediate threat to nearby residents or the environment while a potentially
responsible party is conducting investigations and cleanup activities at the site.
Site Repository
Dover Public Library, 45 S. State Street, Dover, DE 19901, (302) 736-7094.
U.S. EPA, Region 3, Docket Room, 841 Chestnut Building, Philadelphia, PA 19107, (215) 597-
3037.
August 1 995 2 DOVER GAS LIGHT CO.
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E.I. DuPONT DE
IVI CZ IWI Q II D C
(NEWPORT
DELAWARE
EPA ID# DED980555122
EPA REGION 3
New Castle County
long the Christina River in Newport
Other N,meS
Newport Pigments
DuPont-Newport
Site Description
The E.I. DuPont de Nemours site is a pigment manufacturing facility consisting of two industrial
landfills: the 7-acre North Landfill and the 15-acre South Landfill. From 1902 to 1929, the plant
manufactured Lithopone, a white inorganic pigment. In 1929, DuPont purchased the plant and,
over the next several decades, phased-out production of Lithopone while beginning production of
other organic and inorganic pigments. Other miscellaneous products have been produced at the
site including chromium dioxide, which continues to be produced today. As part of the plant
operations, waste was disposed of in the landfills. Ciba-Geigy purchased the pigment plant in
1984, while DuPont retained the chromium dioxide manufacturing facility. Approximately 21,000
people reside within a 3-mile radius of the site. Also located within 3 miles of the site are three
public water supply wells which are part of an approximately 40 well system serving about
150,000 people. Approximately 10 residential wells are threatened by groundwater
contamination. The site is within a 100-year flood plain. Contaminated wetlands are located
immediately adjacent to both landfills. The Christina River, which has contaminated sediments,
flows between the landfills and is used for recreational purposes.
Site Responsibility:
This site is being addressed through
Federal and potentially responsible
parties' actions.
Final Date: 02/21/90
Threats and Contaminants
ZLS
Heavy metals, including lead, and chlorinated solvents from past operations and
disposal practices have been detected in the groundwater. Monitoring well information
indicated contamination of the underlying Columbia and Potomac aquifers. Heavy
metals have been detected at the landfills, underneath the Ciba-Geigy plant, and in
wetland and river sediments and surface water. Thoriated nickel is buried in the north
landfill. An organic heat transfer oil is seeping from the north bank of the Christina
River and is causing an intermittent sheen on the river. The contaminated
groundwater may migrate and eventually pose a threat to owners of nearby private
wells. The groundwater and sediment contamination also pose a threat to aquatic life
in the Christina River and the wetlands. Soil contamination poses a threat to wildlife
and to workers who come in direct contact with contaminants on the unpaved portions
of the plant, or to people using the adjacent ballpark.
August 1995
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Cleanup Approach
This site is being addressed in two stages: initial actions and long-term remedial phase focusing
on cleanup of the entire site.
Response Action Status
Initial Actions: One potentially responsible party is undertaking actions to address
the oil seeps along the north bank of the Christina River, including driving sheet
piles along the river bank to limit the oil seepage.
Entire Site: The EPA selected a remedy in the summer of 1993, which includes
capping the north landfill, treating waste and then capping the South Landfill,
installing a groundwater barrier wall along the north river bank, dredging the river
and adjacent wetlands, and installing a public water supply line. The design of the remedy began
in mid-1994.
Site Facts: DuPont entered into an agreement with the EPA hi 1988, under which Dupont
agreed to perform a study to determine the nature and extent of the contamination and to identify
alternative cleanup technologies. DuPont also entered into an agreement with the EPA in 1993,
under which the party agreed to prevent the oil seeps from entering the Christina River. In 1994,
the EPA issues a Unilateral Administrative Order (UAO) to DuPont and Ciba-Geigy requiring
that the companies implement the selected remedy.
Environmental Progress
Several actions have been taken to alleviate potential threats while decisions are made regarding
the long-term cleanup actions. These include sampling of the nearest residential wells and
installing a snow fence around a small pond at the north landfill to prevent animals from drinking
the water. Also, oil absorbing booms have been placed along the north bank of the Christina
River as a temporary measure to limit any oil sheen on the river.
Site Repository
Kirkwood Highway Library, 600 Kirkwood Highway, Wilmington, DE 19808
August 1995 2 E.I. DuPONT DE NEMOURS
(NEWPORT LANDFILL)
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HALBY
CHEMICAL CO.
DELAWARE
EPA ID# DED980830954
Site Description
EPA REGION 3
New Castle County
Wilmington
The 14-acre Halby Chemical Co. site operated as a chemical production facility from 1948 to
1977. The site includes the former chemical manufacturing plant area and approximately 10
acres of undeveloped land. The plant area includes: a building with four laboratories, several
offices, and a warehouse; a chemical process area; and a tank farm. Wastewater from the
production of sulfur compounds at the plant was discharged into a 1 1/2-acre unlined lagoon and
then drained into a tidal marsh leading to the Christina River. There are high concentrations of
inorganic and organic contaminants in soils, surface water, sediments, and groundwater.
Approximately 1,800 people live within a mile of the site. Area residents receive water from the
Artesian Water Company, which draws water from several uncontaminated wells. There are
only one residential well and one public well within 3 miles of the site.
Site Responsibility:
This site is being addressed through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 09/18/85
Final Date: 06/10/86
Threats and Contaminants
The groundwater is contaminated with volatile organic compounds (VOCs), carbon
disulfide, and heavy metals including arsenic and zinc. The contaminant plume does
not present an immediate threat to any wells used for potable water. Heavy metals
including arsenic and zinc, and polycyclic aromatic hydrocarbons (PAHs) also were
detected in the soil. Sampling of the lagoon sediments identified high levels of carbon
disulfide, ammonia, zinc, arsenic, and lead. Tests indicate that lagoon sediments may
cause stress (toxicity) to the aquatic life. The surface water is contaminated with
heavy metals including arsenic, lead, and cadmium. Chemicals identified in an
abandoned laboratory and former chemical production area present a threat due to the
potential for fire and explosion, and subsequent release of chemicals to the
environment.
July 1995
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Cleanup Approach
This site is being addressed in three stages: immediate actions and two long-term remedial
phases focusing on cleanup of soil, and the surface water, groundwater, and sediments.
Response Action Status
Immediate Actions: A removal action is underway to dispose of process lines and
equipment vessels, drums, and other containers located at the former chemical
production area, and to stabilize and remove chemicals in tanks.
Soil: Based on the EPA's investigations, a remedy for the soil inside the process
plant area was selected in 1991. The remedy includes: consolidating all debris;
excavating, stabilizing, and backfilling the top 6 inches of contaminated surface soil;
placing an asphalt cap over the stabilized soil; implementing deed restrictions; and initiating
public education programs. After the construction phase is completed, long-term monitoring and
site maintenance will ensure the effectiveness of the remedy. Design of the remedies is
scheduled for completion in 1995 after future land-use issues are resolved.
Surface Water, Groundwater, and Sediments: In 1993, the EPA began an
investigation of the nature and extent of contamination in the surface water,
groundwater, and sediments in the outfall area and tidal marsh area. This study is
scheduled for completion in 1995, at which time a remedy will be selected.
Site Facts: The EPA and the Witco Corporation signed a Consent Decree in early 1992 under
which the party has agreed to perform the soil cleanup actions required at the process plant area.
Environmental Progress
Immediate threats to public health or the environment are being addressed by the immediate
actions. Investigations and design activities also are underway to address longer-term issues
associated with site contamination.
Site Repository
Wilmington Institute Library, 10th and Market Streets, Wilmington, DE 19801
July 1995 2 HALBY CHEMICAL CO.
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HARVEY & KNOTT* EPA REG'°N 3
•f / New Castle County
DRUIVI INC II r, r About 5 miles from Kirkwood
DELAWARE
EPA ID# DED980713093
Site Description
The Harvey & Knott Drum, Inc. site operated as an open dump and burning area between 1963
and 1969 on a portion of a 20-acre site. The facility accepted sanitary, municipal, and industrial
wastes believed to be sludges, paint pigments, and solvents. Wastes were emptied onto the
ground surface into excavated trenches or left in drums, some of which were buried on site.
Several hundred drums have been removed from the site. A security fence, enclosing about 2
1/2 acres, was erected around the most visible areas of contamination. The enclosed area
included drum stockpiles, waste piles, and a small pond. Trailer homes and a residential
development are located to the north of the property. Water supplies for some of the nearby
residences are obtained from a shallow water-table aquifer. There are approximately 300 people
living within 1 mile of the site. The site facility is set back several hundred feet from the
highway in an open field in a relatively undeveloped area and is surrounded by woodlands.
Wetlands are located to the south of the site.
Site Responsibility: This site is being addressed through
i- j i j * *• 11 ui NPL LISTING HISTORY
Federal and potentially responsible proposed Date; Q7/23/82
parties' actions.
Final Date: 09/08/83
Threats and Contaminants
Specific contaminants detected in the groundwater include volatile organic compounds
(VOCs) such as ethyl benzene and toluene and heavy metals including arsenic,
cadmium, and lead. Heavy metals were detected in on-site sediments and surface
water. Contaminants detected in soils and sediments include VOCs, heavy metals,
and poly chlorinated biphenyl (PCBs). The site is in a stabilized condition because the
source of contamination (surface and subsurface drums) has been removed. Lead
contamination of the soils is limited to "hot spots" within the fenced area.
Contamination of the groundwater with VOCs is localized and is being intercepted by
the adjacent wetlands. Potential health threats exist through accidental ingestion of,
inhalation of, and direct contact with contaminated soil.
HARVEY & KNOTT DRUM, INC. 1 July 1995
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Cleanup Approach
Response Action Status
Immediate Actions: The State supplied emergency drinking water to affected
residents in 1981. In 1982, the EPA completed immediate measures which included
installing a security fence, overpacking and staging 43 leaking drums, and conducting
a sampling survey. In addition, 17 monitoring wells were installed to identify the nature and
extent of groundwater contamination. In 1983 and 1984, 46 drums were removed and disposed
of off site, a soil berm and a surface drainage ditch around a PCB-contaminated waste pile were
constructed, 500 empty drums were crushed and staged, and 200 partially filled drums were
staged.
Drum Removal and Monitoring: General Motors (GM) began site cleanup in early
1988, under EPA monitoring. Over 100 drums and 955 cubic yards of contaminated
soil were excavated and removed to an off-site, licensed disposal facility.
Approximately 180,000 gallons of water was pumped from the pond located in the disposal area.
In 1990, GM finished removing hazardous waste from the site. EPA has concluded that the
removal of all surface and subsurface drums coupled with natural dissipation over time have
significantly cleaned up the groundwater contamination at the site. Soil within the fenced area is
contaminated with lead; however, the lead-contaminated soils were capped; pond sediments were
excavated; and a decontamination pad was dismantled and removed. Groundwater and surface
water monitoring are ongoing to ensure that these actions are effective in cleaning up the site.
Site Facts: In 1987, EPA reached a settlement with GM requiring the party to design and
implement the remedy selected. In 1988, an agreement was signed with another potentially
responsible party, Harvey and Harvey, Inc., in which the party will contribute financially to the
remedy.
Environmental Progress
All construction at the site is complete. By providing an emergency drinking water supply to
affected residents, installing a security fence around the site, and removing all the surface and
subsurface drums, contaminated soils, and sediments the EPA reduced the potential for exposure
to hazardous materials at the Harvey & Knott Drum, Inc. site. Capping of the contaminated
soils; implementing a groundwater and surface water monitoring plan; and implementing
institutional controls will ensure that the remedy continues to be protective of human health and
the environment.
July 1995 2 HARVEY & KNOTT DRUM, INC.
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Site Repository
Delaware Department of Natural Resources & Environmental Control, Superfund Branch, 715
Grantham Lane, New Castle, DE 19720
HARVEY & KNOTT DRUM, INC.
July 1995
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KOPPERS CO., INC.
(NEWPORT PLANT) ^
DELAWARE
EPA ID# DED980552244
Site Description
The 317-acre Koppers Co., Inc. (Newport Plant) site operated as a wood preserving plant from
1929 until 1971. During operations, Koppers loaded railroad ties and telephone poles into
cylinders and pressure-injected them with either creosote or a mixture of No. 2 fuel oil and
pentachlorophenol (PCP). The site contains a pond located on the northwest corner of the
property that was used for fire protection, and two effluent holding ponds and two sumps that
discharge effluent into wetlands. In 1971, Koppers sold the site to DuPont. As part of the sales
agreement, the process equipment was removed. All structures were removed from the site; the
site currently is vacant. Two potential historical homesteads exist on the property. In 1984, the
EPA detected creosote compounds in on-site soil and in nearby creek sediments. The Artesian
Water Company draws drinking water from three wells within 3 miles of the site and combines
the water with other water to serve its 150,000 customers. The three wells tap the Lower
Potomac Formation, hydraulically connected to the overlying Columbia Formation, permitting
water to move between them. Wetlands are found both on and around the site.
_. _ ..._ __ . . . , • ,, . «. . NPL LISTING HISTORY
Site Responsibility: This site is being addressed through proposed Date. 1Q/26/89
Final Date: 08/30/90
Federal, State, and potentially
responsible parties' actions.
Threats and Contaminants
Soil and nearby creek and pond sediments are contaminated with polynuclear aromatic
hydrocarbons (PAHs) from the wood preserving treatment processes. Some of the
PAHs found on-site are potential carcinogens. Potential health threats include
accidental ingestion of, and direct contact with, contaminated soil and sediments.
Churchmans Marsh, the Christina River, Hershey Run, White Clay Creek and their
associated wetlands and habitats also may be threatened.
July 1995
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Cleanup Approach
This site is being addressed in a long-term remedial phase focusing on cleanup of the entire site.
Response Action Status
Entire Site: In 1991, an investigation began to determine the nature and extent of
contamination at the site. Currently, a work plan and schedule are being negotiated
with the potentially responsible parties to complete the investigation. Once the
investigation is completed, final cleanup remedies will be selected.
Site Facts: In 1991, EPA issued an Administrative Order requiring the parties potentially
responsible for site contamination to conduct the investigation into contamination.
Environmental Progress
The EPA assessed conditions at the Koppers Co., Inc. (Newport Plant) site and determined that
no immediate actions were required; however, an evaluation of potential off-site migration is
necessary.
Site Repository
Not yet established.
July 1995
KOPPERS CO., INC. (NEWPORT PLANT)
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NCR CORP.
(MILLSBORO PL
DELAWARE
EPA ID# DED043958388
Site Description
EPA REGION 3
Sussex County
1/2 mile southeast of Millsboro
Other Names:
First Freedom Center
NCR Corporation manufactured cash registers from 1967 to 1975 and electronic equipment from
1975 to 1980 on a portion of this 140-acre site, which is located 1/2 mile southeast of Millsboro.
Enameling, plating, and degreasing operations also were conducted at the NCR plant. The
solvent, trichloroethylene (TCE), used in degreasing operations, was stored in a tank outside the
manufacturing building. Waste suspensions from the plating operation were discharged to on-site
concrete lagoons for sedimentation and clarification. The chromium-bearing sludge that
accumulated in the lagoons was disposed of in a pit on the NCR property. In 1981, prior to the
sale of the property, the chromium sludge was excavated and disposed of off site. The State
required NCR to monitor groundwater after the sludge was removed. The monitoring revealed
that groundwater under the property was contaminated with TCE and other volatile organic
compounds (VOCs), and chromium. The contaminated groundwater discharges to Iron Branch
Creek, which flows into the Indian River. Chromium and TCE have also been found in the
surface water and sediments of Iron Branch Creek. Communities located close to the site rely on
groundwater as a primary source of drinking water. Quarterly groundwater monitoring has
shown that the contaminant levels in the residential wells remain within acceptable drinking water
standards. Annual stream monitoring results indicate that the concentrations of TCE and
chromium in the Iron Branch remain within levels that EPA has determined are protective of
aquatic life.
Site Responsibility:
This site is being addressed through a
combination of Federal, State, and
potentially responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 04/10/85
Final Date: 07/22/87
Threats and Contaminants
The groundwater is contaminated with VOCs including TCE, and with trivalent and
hexavalent chromium. A plume of groundwater contamination has reached Iron
Branch Creek, but domestic supply wells have not been adversely affected. People
who come into direct contact with or ingest contaminated groundwater or surface
water may be at risk.
August 1 995
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Cleanup Approach
The site is being addressed in two stages: initial actions and a long-term remedial phase directed
at cleanup of the entire site.
Response Action Status
Initial Actions: NCR excavated chromium-bearing sludge from a bentonite-lined pit
and drained and removed toxic materials from two concrete-lined storage lagoons in
1981. NCR also installed 28 monitoring wells and implemented a groundwater
monitoring program. In 1988, a groundwater recovery well and an air stripper were put into
operation to prevent off-site migration of contaminants.
Entire Site: Between 1988 and 1991, under State supervision, NCR conducted an
intensive study of stream and groundwater contamination at the site and potential
continuing sources of groundwater contamination. In 1991, a remedy was selected
including treatment of VOC contamination in groundwater by air stripping; treatment of
chromium contamination by chemical reduction, coagulation precipitation and filtration, as
necessary; discharge of treated groundwater to on-site groundwater infiltration galleries or Iron
Branch; quarterly groundwater monitoring; annual monitoring of Iron Branch; and
implementation of groundwater use restrictions within the area of the contaminated plume. The
design of the groundwater remediation system was completed in the fall of 1994. Construction of
selected cleanup remedies began in 1994, and is expected to be completed in early 1997.
Site Facts: In 1981, the State of Delaware ordered NCR to excavate sludges and dispose of the
waste off site. In 1988, the State and NCR signed a Consent Order under which NCR agreed to
conduct initial response actions and a study to determine the nature and extent of site
contamination and options for cleanup. In 1992, EPA issued a Unilateral Administrative Order
compelling the potentially responsible parties to design, construct, operate and maintain the EPA
selected remedy.
Environmental Progress
The removal of contaminated sludge, the construction and operation of an air stripper and
recovery well, and the installation of monitoring wells to chart contaminant levels have reduced
the potential for exposure to hazardous materials at the NCR site while the final remedy is being
implemented.
Site Repository
Millsboro Town Hall, 322 Wilson Highway, Millsboro, DE 19966
August 1995 2 NCR CORP. (MILLSBORO PLANT)
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NEW CASTLE SPILL
DELAWARE
EPA ID# DED058980442
Site Description
EPA REGION 3
New Castle County
New Castle
Other Names:
Witco Chem. Co.
TRIS Spill Site
Beginning in 1954, the now inactive Witco Chemical Company processed materials used in the
production of plastic foam on this 6-acre site. Operators stored drums containing pre-polymer
feedstocks and spent solvents on the southern boundary of their property adjacent to the New
Castle Board of Water and Light (NCBW&L) property. In 1977, employees of NCBW&L
noticed dead grass near the drum storage area. Shortly after sampling, during which contaminants
at levels above the accepted State and EPA levels were found, the NCBW&L was directed by the
Delaware Department of Natural Resources and Environmental Control (DNREC) to pump the
shallow aquifer and to discharge the water to the nearby wetlands. The surrounding area is
industrial and residential; 5,500 people live within 3 miles of the site. The closest home is 750
feet from the site. The shallow aquifer being used by the NCBW&L was taken out of service,
and measures are being taken to prevent its future use. Approximately 7,000 people now are
served by another source for their potable water supply.
Site Responsibility:
This site is being addressed through a
combination of Federal, State, and
potentially responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 12/30/82
Final Date: 09/08/83
Threats and Contaminants
Trichloroethylene (TCE) is found in the ground water, but is believed to be from an
off-site source now under investigation by the State. The groundwater is also
contaminated with other volatile organic compounds (VOCs) including acetone and
tris-chloropropyl phosphate (TRIS), a semivolatile organic compound. TRIS, a flame
retardant, which can be related back to Witco's activities, was detected in soils near
the drum storage area. On-site soil is contaminated with VOCs, poly chlorinated
biphenyls (PCBs), TCE, creosote, and phthalates from plastics production. However,
soil contamination was not determined to pose a significant threat to human health and
to the environment. Drinking contaminated groundwater could pose a health threat;
however, a new water supply has been provided to residents found to be at risk.
Wetlands adjacent to the site have not been adversely impacted by TRIS
contamination. The site is secured by a locked fence.
August 1995
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Cleanup Approach
The site is being addressed in a long-term remedial phase focusing on cleanup of the entire site.
Response Action Status
Initial Actions: The shallow aquifer used by the NCBW&L was taken out of
service and affected residents were provided an alternative water source. From 1977
to 1978, the NCBW&L, under the DNREC's instruction, pumped the groundwater
from the shallow aquifer to prevent migration of TRIS into aquifers below the Columbia, the
most shallow aquifer beneath the site.
Entire Site: In 1989, the EPA selected a remedy requiring quarterly monitoring of
TRIS in the shallow groundwater aquifer until the accepted safe level is reached,
through natural attenuation, in an estimated four to five years. In addition, the
remedy requires annual monitoring of the deeper groundwater aquifer, surface water, and
sediments of the wetland; establishing institutional controls; and reviewing the effectiveness of the
remedy in five years. Quarterly groundwater, surface water and sediment monitoring began in
1992. The State has established the institutional controls by restricting the installation of wells in
the shallow aquifer within 1/2 mile of the site. TRIS levels in the groundwater have decreased
considerably hi the most highly contaminated area of the site. TRIS levels in the surface water
and sediment samples have consistently been well below cleanup levels. Monitoring will
continue until clean-up levels are achieved through out the contaminated area.
Site Facts: An Agreement was signed in 1990, in which the potentially responsible parties will
conduct the five-year review of the remedy to confirm that it continues to be protective of human
health. The Agreement was recognized by the courts in April 1991.
Environmental Progress
By providing an alternative municipal water source and by limiting the future use of the
groundwater until the cleanup levels have been reached, the potential for exposure to hazardous
materials at the New Castle Spill site has been reduced while continued monitoring of
groundwater, surface water, and sediments is underway.
Site Repository
Delaware Dept. of Natural Resources & Environmental Control, Superfund Branch,
715 Grantham Lane, New Castle, DE 19720, (302) 323-4540.
U.S. EPA, Region III, Docket Room, 9th Floor, 841 Chestnut Building, Philadelphia, PA 19107,
(215) 597-3037.
August 1995 2 NEW CASTLE SPILL
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NEW CASTLE
STEEL PLANT
DELAWARE
EPA ID# DED980705255
EPA REGION 3
New Castle County
Near the Delaware River in the
City of New Castle
Other Names:
Deemer Steel Company
Site Description
The New Castle Steel site is a 3-acre disposal landfill which received foundry wastes from the
Deemer Steel Company beginning in 1907. The waste consisted of black sands, slag, coke, iron
oxide scale, fine sand dust and metal scrap. In 1955, an electric furnace was put into operation
and in 1973 a baghouse system was installed to control dust emissions from the furnace. This
baghouse dust was mixed with black sand and spread over the disposal area from 1973 to 1980.
In 1980, the plant began to recycle the dust until the plant closed in 1987. Regulations in 1980
indicated that the baghouse dust was a hazardous waste because of unacceptable levels of heavy
metals including cadmium, chromium, and lead. The site was placed on the NPL in 1982 because
of potential groundwater contamination. Since 1982, it has been determined that baghouse dust
does not pose a serious health threat; therefore, it is no longer classified as a hazardous waste by
the EPA. Although metals associated with the site have entered soils, sediments, surface water,
and groundwater, the EPA and the State have determined through studies that contamination
levels at the site are not threatening and do not require cleanup actions. A number of the metals
of concern including cadmium, chromium, and lead are naturally occurring.
Site Responsibility:
This site was addressed through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 12/30/82
Final Date: 09/08/83
Deleted Date: 03/17/89
Threats and Contaminants
The groundwater, sediments, soil, and surface water were contaminated with low
levels of heavy metals including arsenic, chromium, lead, cadmium, and nickel from
the wastes disposed of on site. However, contamination levels were very low and it
was determined that they did not pose threats to nearby residents or the environment.
August 1995
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Cleanup Approach
Response Action Status
Entire Site: After years of data collection and study, including an intensive
investigation undertaken by the Deemer Steel Company, both the EPA and the State
determined that this site does not constitute a threat to human health or the
environment. Therefore, it was determined that no cleanup actions were required to clean up the
site. EPA is in the process of conducting a Five Year Review of the site. Five Year Reviews
are intended to evaluate whether any actions taken at the site remain protective of public health
and the environment.
Environmental Progress
Because the site studies have indicated that site contamination does not pose a risk to people or
the environment, the EPA, in conjunction with the State, deleted the New Castle Steel Plant site
from the NPL in 1989.
Site Repository
Information is no longer available.
August 1995
NEW CASTLE STEEL PLANT
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SEALAND
LIMITED
DELAWARE
EPA ID# DED981035520
EPA REGION 3
New Castle County
Mount Pleasant
Site Description
Operations at the 2-acre Sealand Limited site began in 1971, when Adams Laboratory rented the
property from Conrail, Inc. to operate a rendering plant. In 1979, the owner reportedly cleaned
up the property after its tenant abandoned the plant. The property remained unused until 1982
when it was leased to Sealand Limited, Inc., to operate a waste oil recycling plant. The operation
accepted coal tar, gas tar, and ink oil wastes, allegedly for recycling, and stored them on site in
tanks and drums. When the tenants abandoned the facility in 1983, the site contained 22 storage
tanks, a boiler house, mixing chambers, pressure vessels, several hundred 55-gallon drums
containing assorted creosote-related chemicals, and a 10,000-gallon wooden storage tank. A State
investigation in 1983 revealed that the wooden tank and numerous drums were leaking. Analyses
of the contents of the tanks and drums and site soil detected polycyclic aromatic hydrocarbons
(PAHs), creosotes, solvents, and other toxic organic compounds. A combined State and EPA
study in 1984 showed contaminants in an on-site monitoring well. However, groundwater
contamination was not found during investigations completed in 1991. The area surrounding the
site is primarily agricultural and residential. Private wells within 3 miles of the site provide
drinking water to an estimated 1,000 people.
Site Responsibility:
This site is being addressed through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 06/24/88
Final Date: 08/30/90
Threats and Contaminants
Low levels of PAHs, creosotes, solvents, and other toxic compounds from the former
recycling operation were found in on-site soils. However, because of the emergency
actions undertaken by EPA, soil contamination is now within acceptable health
standards and does not pose a risk to individuals who may come into contact with the
soil.
August 1 995
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Cleanup Approach
The site was addressed through emergency actions; further investigations showed that no other
cleanup actions are required.
Response Action Status
Emergency Actions: In 1983, in response to an imminent threat to human health,
the EPA removed 240,800 gallons of coal tar, 320 drums, and 80 cubic yards of
solid waste. Workers transported the hazardous materials to an EPA-approved
facility, cleaned the storage tanks, and capped the site with a layer of clay and topsoil to keep
rainwater and runoff from spreading pollutants.
Entire Site: Under EPA oversight, the parties potentially responsible for the site
contamination completed an intensive study of the nature and extent of site
contamination in 1991. The study showed that, because of the emergency actions
undertaken by EPA, the site no longer poses an unacceptable risk to human health and the
environment. EPA will review conditions at the site in 1996 to ensure that its decision for no
further action remains protective. In the meantime, the State will conduct additional ground water
studies under its Hazardous Substance Cleanup Act.
Site Facts: In December of 1988, EPA and 15 potentially responsible parties entered into an
Agreement for the responsible parties to conduct investigations to determine the nature and extent
of contamination at the site.
Environmental Progress
By removing contaminated materials from the Sealand Limited site, EPA eliminated the risk to
area residents and the environment. EPA has determined that no further cleanup activities are
necessary at the site.
Site Repository
Appoquinimink Public Library, 218 North Broad Street, Middletown, DE 19709
August 1995 2 SEALAND LIMITED
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STANDARD CHLORIN
OF DELAWARE, INC.
DELAWARE
EPA ID# DED041212473
EPA REGION 3
New Castle County
Delaware City
Site Description
Standard Chlorine of Delaware, Inc. is a manufacturer of chlorinated benzene compounds. The
46-acre Standard Chlorine site was listed on the NPL due to a 1981 benzene spill that occurred
while workers were filling a railroad tanker car onto the property. An additional spill occurred in
1986; 569,000 gallons of various volatile organic compounds (VOCs) spilled after a
375,000-gallon tank of VOCs split open, collapsed, and damaged three nearby tanks of VOCs,
causing the latter tanks to partially spill. About 152,000 people draw groundwater from public
and private wells within a 3-mile radius of the site. Approximately 30 people reside within a mile
of the site.
Site Responsibility:
This site is being addressed through
Federal, State, and potentially
responsible parties' actions.
NPL LISTING HISTORY
Proposed Date: 09/18/85
Final Date: 07/22/87
Threats and Contaminants
Chlorobenzenes from spilled material have been found in the groundwater, soil, sediments,
and surface water. People may be exposed to the chemicals by direct contact with
contaminated soil or ingestion of contaminated soil or water. Wetlands near the site are
threatened by contamination emanating from ihe spill areas. The levels of contamination in
the soils, surface water, and sediment may impact the quality of the wildlife and the
ecosystems along the nearby Red Lion Creek.
August 1995
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Cleanup Approach
This site is being addressed in two stages: emergency actions and a long-term remedial phase focusing on
contamination at the entire site.
Response Action Status
Emergency Actions: The Delaware Department of Natural Resources and Environmental
Control (DNREC) and Standard Chlorine took the following emergency actions in response
to the January 1986 spill: (1) built a filter fence along the mouth of the wetland coves; (2)
recovered some of the material which had flowed off site; (3) performed pre-excavation sampling and
constructed an earthen dike to isolate the upper portions of the wetland from contaminants; (4) excavated
contaminated soils and sediments upstream of the dike; and (5) constructed a double-lined containment
pond to store dredged materials.
Entire Site: Under State order, Standard Chlorine conducted an intensive study of the effect
the spill had on local groundwater quality, soil, and wetland contamination. The investigation
explored the nature and extent of the contamination and identified the best strategies for
cleanup. The study was completed in the Fall of 1993. A proposed plan was issued in the Spring of 1994
and the final remedy was selected in early 1995.
Site Facts: In 1988, the DNREC entered into an agreement with Standard Chlorine of Delaware, Inc.
to conduct preliminary cleanup and perform site investigations to determine the nature and extent of the
contamination.
Environmental Progress
Emergency actions undertaken by the DNREC and Standard Chlorine have reduced the risk of
contamination at the site while final cleanup actions are underway.
August 1995
STANDARD CHLORINE OF DELAWARE, INC.
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SUSSEX COUNTY
LANDFILL NO. 5
DELAWARE
EPA ID# DED980494637
Site Description
The inactive 37 1/2-acre Sussex County Landfill No. 5 operated from 1970 until 1979. The
landfill accepted mixed municipal and industrial wastes and, according to a 1978 Congressional
report, an unknown quantity of various volatile organic compounds (VOCs). In certain areas of
the landfill, wastes were deposited in the ground below the water table, threatening groundwater.
In 1986, the EPA detected several organic chemicals and solvents in on-site monitoring wells.
The landfill overlies the Columbia Formation, which is connected to and recharges the Manokin
Aquifer. Together, the two units provide drinking water to people within 3 miles of the site. A
private well is located 1,000 feet from the site. Public and private wells within 3 miles of the site
provide drinking water to an estimated 5,700 people and irrigate 5,100 acres of cropland.
„. « •,-•,• ™.- • • u -A A A ^ u NPL LISTING HISTORY
Site Responsibility: This site is being addressed through a
combination of Federal, State, and
local actions.
Proposed Date: 06/24/88
Final Date: 10/04/89
Threats and Contaminants
Several groundwater monitoring wells have shown contamination from VOCs,
including benzene and vinyl chloride, from former disposal practices. Possible health
threats include drinking or coming in direct contact with the contaminated
groundwater. One domestic well to the north of the landfill was found to be
contaminated with low levels of VOCs. Sussex County has provided this residence
with bottled water and a water purification system to alleviate the risk presented by
the contaminated water supply. All other residential wells in the area which have
been sampled during investigations at the site have not shown contamination at levels
of concern. Bioaccumulation of contaminants in locally raised crops is a potential
threat if contaminated groundwater is used for watering or irrigation.
Cleanup Approach
This site is being addressed in a single long-term remedial phase focusing on cleanup of the
entire site.
August 1995
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Response Action Status
Initial Actions: The landfill was closed by the Delaware Department of Natural
Resources and Environmental Control (DNREC) in 1979. Sussex County installed a
carbon treatment unit to eliminate VOC contamination. Plans are being developed for
the County to install a water line to supply residents downgradient of the landfill with public
water, continue ground water monitoring, and maintain the cover on the landfill. These actions are
expected to eliminate any potential future risk associated with possible exposure to VOCs in the
groundwater.
Entire Site: The DNREC installed monitoring wells on the site as a part of a
groundwater assessment program. In 1984, the DNREC conducted a preliminary
assessment, which indicated that a leachate plume extended 400 to 500 feet
downgradient of the site. In 1984, the EPA inspected the site and detected elevated levels of
VOCs in the groundwater. Several more wells have been installed in the vicinity of the landfill
and are monitored on a regular basis by Sussex County as part of the requirements of an
agreement between the County and DNREC. In addition, some domestic wells in close proximity
to the landfill are monitored. During 1992, Sussex County, under an EPA Administrative Order,
conducted an investigation at the site which included installing several additional monitoring
wells, and sampling groundwater, surface water, air, soil, and sediments. This investigation
confirmed that the groundwater is contaminated primarily with several VOCs and that
contaminated groundwater is the primary concern at this site. The Human Health Risk
Assessment conducted by EPA determined that current and potential future risk levels posed by
the very low levels of VOCs in the groundwater are within or slightly above EPA's acceptable
risk range. Because of the low levels of contamination, the low risk levels, and the actions being
taken by the State and the County, EPA determined that no further actions are needed at the site.
Site Facts: Sussex County and the DNREC entered into an agreement in 1988 to establish a
groundwater management program near the landfill which includes the future construction of a
water line. In 1991, an Administrative Order for the site investigation conducted by the County,
was signed by Sussex County and the EPA.
Environmental Progress
By closing the Sussex County Landfill No.5 and installing a carbon treatment system, the State
has reduced threats to human health and the environment posed by the site. An alternate water
supply has been provided to one residence with a contaminated water supply, and additional
homes downgradient of the landfill are scheduled to be connected as well.
August 1995 2 SUSSEX COUNTY LANDFILL NO. 5
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Site Repository
Laurel Public Library, 6.E. Fourth Street, Laurel, DE 19956, (302) 875-3184
U.S. EPA, Region 3, Docket Room 9th Floor, 841 Chestnut Bldg., Philadelphia, PA 19107,
(215) 597-3037
SUSSEX COUNTY LANDFILL NO. 5
August 1995
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TYBOUTS CORNER W E^A REpION 3
New Castle County
10 miles south of Wilmington
DELAWARE
EPA ID# DED000606079
Site Description
Tybouts Corner Landfill Site is located approximately 10 miles south of Wilmington and 4 miles
west of the Delaware River, which is close to the confluence of Pigeon Run Creek and Red Lion
Creek. The landfill consists of two noncontiguous sections: a west landfill that is about 4 acres
and the main landfill that is about 47 acres. The fill currently ranges from 5 to 40 feet thick.
The site was used by the New Castle County Department of Public Works as a municipal sanitary
landfill that also accepted industrial wastes from December 1968 until July 1971. The industrial
wastes contained volatile organic compounds (VOCs) and various other organic and inorganic
chemicals. The first reported occurrence of contamination from the Tybouts Site was a domestic
water well in May of 1976. A second private well was found to be contaminated in 1983. There
are only two water supply wells reported to be contaminated from the site.
Site Responsibility: The site is being addressed through
Federal and potentially responsible
parties' actions.
Final Date: 09/08/83
Threats and Contaminants
Local drinking water wells and soils are contaminated with VOCs and other organic
compounds from former disposal practices. The contaminants of concern include the
VOCs, 1,2-dichloroethane, trichloroethylene, benzene and various other organic and
inorganic chemicals. Ingesting or coming into direct contact with contaminated
groundwater or soil may threaten the health of the people in the area.
Cleanup Approach
This site is being addressed in two stages: immediate actions and a long-term remedial phase
focusing on source control and groundwater cleanup.
August 1995
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Response Action Status
Immediate Actions: The EPA installed a fence in 1982. Between 1984 and 1986,
the EPA extended the public water lines to provide service to all 42 residences and
facilities surrounding the landfill. The EPA repaired and reconstructed the security
fence around the site and posted warning signs in 1987. A new fence was installed around the
main landfill in the Spring of 1993.
Source Control and Groundwater Cleanup: In 1986 EPA selected a cleanup
remedy calling for excavation and consolidation of the west landfill to the main
landfill; installation at a multi-layered cap to minimize infiltration of rainfall;
installation of a subsurface drain to minimize lateral migration of groundwater and another
subsurface drain to collect leachate; and a pump and treat system for the contaminated
groundwater and leachate. The selected remedy was modified in May 1992 to replace one of the
subsurface drains with a slurry wall and the other subsurface drain with interceptor wells.
Construction of the remedy began in early 1993. The west landfill and the perimeter of the main
landfill have been excavated onto the consolidation area at the main landfill. The landfill has
been regraded with several feet of overburden material placed on top at the main landfill. The
slurry wall construction was completed in late 1993. The multi-layer cap was completed in late
1994. The cap was seeded during the spring of 1995. Construction completion is scheduled for
late 1995.
Site Facts: In 1988, EPA signed a Consent Decree in which several parties agreed to
implement and partially finance the selected remedy.
Environmental Progress
With the construction of a fence around the site to limit access and the provision of a safe
drinking water source to affected residents and businesses, the EPA has made the Ty bouts Corner
Landfill site safer while long term cleanup activities are underway.
Site Repository
Delaware Department of Natural Resources and Environmental Control, 715 Grantham Lane,
New Castle, DE 19720.
August 1995 2 TYBOUTS CORNER LANDFILL
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TYLER
REFRIGERATION
PIT
DELAWARE
EPA ID# DED980705545
EPA REGION 3
Kent County
Smyrna
Site Description
From 1952 to 1969, Tyler Refrigeration, located on a 3-acre parcel of land, used solvents to
degrease and clean refrigeration equipment, and dumped the spent solvents, paint room wastes,
and sludges into two unlined disposal pits. In the 1970s, Clark Equipment Company excavated
the pit to a depth of 20 feet, filled it in, capped it with 6 inches of topsoil and clay, and planted
vegetation. The site is now occupied by Metal Masters, an active manufacturer of commercial
kitchen equipment. Public access is unrestricted, but most of the old pit's surface area has been
paved. Since 1977, trichloroethylene (TCE) and trichloroethane (TCA) have been detected in
Smyrna's municipal wells. The state identified the Tyler pit as a likely contributor to this
pollution, although there may be other sources, since TCE has not been found in on-site soils or
ground water. In 1982, EPA conducted an investigation which revealed the presence of elevated
concentrations of toluene, 1,1-dichloroethane and TCA in the soil taken around the former pit
area. In 1988, EPA tasked the state to conduct a follow up site inspection. Analyses of the
ground water in the pit area revealed elevated concentrations of TCA. About 5,000 people receive
drinking water from the Smyrna municipal wells. Sixty homes stand within 1/4 mile of the site;
the closest is located within 300 feet.
Site Responsibility:
This site is being addressed through
Federal and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date: 06/10/86
Final Date: 02/21/90
Threats and Contaminants
The groundwater near the former disposal pits is contaminated with volatile organic
compounds (VOCs), including trichloroethane. Monitoring wells also have detected
the pesticide, dieldrin, in groundwater samples down gradient of the former disposal
pits. The soils contain elevated levels of VOCs. Accidental ingestion of or direct
contact with contaminated soil or groundwater may pose a health threat.
August 1995
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Cleanup Approach
This site is being addressed in two stages: an immediate action and a long-term remedial phase
focusing on groundwater cleanup at the site.
Response Action Status
Immediate Action: To remove VOC contamination in the municipal wells, the
town improved the efficiency of its air-stripping process and added an activated
carbon filtration unit to its water treatment system. The treatment system continues to
Groundwater: The parties potentially responsible for the site contamination began
an investigation of contamination at the site in 1991. This investigation revealed that
the groundwater is contaminated with VOCs. The groundwater contamination,
however, does not appear to be related to the former disposal pits. An upgradient source on the
nearby Metal Masters property is suspected to be the cause of the groundwater contamination.
Metal Masters under state oversight is investigating the source and extent of this contamination.
Site Facts: A Consent Order was signed in 1991, under which the potentially responsible party
agreed to perform an investigation of site contamination. In early 1995, the State of Delaware
issued a Consent Decree to Metal Masters to perform an investigation to determine the source
and extent of contamination.
Environmental Progress
By improving the air-stripping process and adding an activated carbon filtration unit to its water
treatment system, the Town of Smyrna is reducing the threat of VOC contamination from
municipal wells, making the public water supply safer while investigations to select the final
remedy are conducted at the Tyler Refrigeration Pit site.
Site Repository
Smyrna Public Library, 107 South Main Street, Smyrna, DE 19977
August 1995
TYLER REFRIGERATION PIT
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WILDCAT
LANDFILL
DELAWARE
EPA ID# DED980704951
EPA REGION 3
Kent County
21/2 miles south of Dover,
adjacent to the St. Jones River
Site Description
From 1962 until 1973, a landfill operated on 44 acres of the 84-acre Wildcat Landfill site,
situated next to the St. Jones River in Dover, 1/2 mile west of the Dover Air Force Base (AFB)
NPL site. The privately owned landfill accepted municipal and industrial waste until it was closed
under a State order for numerous violations of a State permit. Operators dumped wastes into
wetlands and frequently left them uncovered. Ground water is contaminated with heavy metals,
organics, and low levels of poly chlorinated biphenyls (PCBs). Open and empty metal drums,
tires, solid latex, and municipal trash were scattered over the surface of the site. A 3-acre pond
collected surface drainage from the western half of the landfill. Monitoring of drinking water
wells in 1987 showed no contamination, but contaminant levels in groundwater underneath and
downgradient of the site were at levels of public health concern. The St. Jones River, which
borders the site, is used for recreational fishing and boating. Two trailer parks, the Dover AFB
housing complex, and 12 residences are located within 1/2 mile of the site. Local residents rely
on ground water for drinking water supplies and are served by public or private wells. There are
24 active wells within 1/2 mile and 16 within 1,000 feet of the site.
Site Responsibility:
This site is being addressed by Federal,
State, and potentially responsible party
actions.
NPL LISTING HISTORY
Proposed Date: 12/30/82
Final Date: 09/08/83
Threats and Contaminants
The groundwater was contaminated with chlordane, a pesticide, and volatile organic
compounds (VOCs) including methylene chloride and xylene. On-site surface water,
leachate, soils, and sediments contained PCBs and chlordane. Accidentally ingesting
or coming into direct contact with contaminated groundwater, surface water, soil,
sediments, or contaminated aquatic organisms may have threatened the health of
people at or near the site. The State has issued a health advisory on fish caught from
the St. Jones River.
August 1995
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Cleanup Approach
The site has been addressed in two long-term remedial phases focusing on source control and
pond cleanup.
Response Action Status
Source Control: The remedy selected to clean up contamination from the landfill
includes: restricting development of the site and preventing installation of drinking
water wells on or near the site; grading, covering, and seeding on-site areas where
direct risks of contact with contaminants have been identified; removing and disposing of drums;
replacing two private domestic wells adjacent to the site with uncontaminated wells drilled deeper
into the aquifer; and monitoring groundwater. All construction activities were completed in 1992.
Monitoring of the groundwater continues to ensure the long-term effectiveness of the remedy.
Pond Cleanup: The remedy for the 3-acre pond that drained the western half of the
landfill consisted of filling in the existing pond and building a new shallow pond
southeast of the landfill. These activities were completed in 1992. Long-term
monitoring will ensure the remedy remains effective.
Environmental Progress
Removal of site contaminants, placement of restrictions on the use of groundwater in the area,
the replacement of contaminated wells, and pond replacement have eliminated the threat of
exposure to hazardous materials from the Wildcat Landfill site. Long-term monitoring will
ensure the remedy remains effective.
Site Repository
Delaware Department of Natural Resources & Environmental Control, Superfund Branch, 715
Grantham Lane, New Castle, DE 19720
August 1995
'WILpCAT LANDFILL
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