EPA/540/4-90/009
September 1990
NATIONAL PRIORITIES LIST SITES:
Delaware
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
Office of Emergency & Remedial Response
Office of Program Management
Washington, D.C. 20460
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If you wish to purchase copies of any additional State volumes or the National
Overview volume, Superfund: Focusing on the Nation at Large, contact:
National Technical Information Service (NTIS)
U.S. Department of Commerce
5285 Port Royal Road
Springfield, VA 22161
(703) 487-4600
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PAGE
INTRODUCTION:
A Brief Overview. ; iii
SUPERFUND:
How Does the Program Work to Clean Up Sites vii
How To:
Using the State Volume xvii
NPL SITES:
A State Overview xxi
THE NPL PROGRESS REPORT xxiii
NPL: Site Fact Sheets 1
, '**'
GLOSSARY:
Terms Used in the Fact Sheets G-l
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11
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WHY THE SUPERFUND
PROGRAM?
A, s the 1970s came to a
close, a series of head-
line stories gave
Americans a look at the
dangers of dumping indus-
trial and urban wastes on the
land. First there was New
York's Love Canal. Hazard-
ous waste buried there over a
25-year period contaminated
streams and soil, and endan-
gered the health of nearby
residents. The result: evacu-
ation of several hundred
people. Then the leaking
barrels at the Valley of the
Drums in Kentucky attracted
public attention, as did the
dioxin tainted larid and water
in Times Beach, Missouri.
In all these cases, human
health and the environment
were threatened, lives were
disrupted, property values
depreciated. It became in-
creasingly clear that there
were large numbers of serious
hazardous waste problems
that were falling through the
cracks of existing environ-
mental laws. The magnitude
of these emerging problems
moved Congress to enact the
Comprehensive Environ-
mental Response, Compensa-
tion, and Liability Act in 1980.
CERCLA commonly
known as the Superfund
was the first Federal law
established to deal with the
dangers posed by the
Nation's hazardous waste
sites. ,
After Discovery, the Problem
Intensified
Few realized the size of the
problem until EPA began the
process of site discovery and
site evaluation. Not hun-
dreds, but thousands of
potential hazardous waste
sites existed, and they pre-
sented the Nation with some
of the most complex pollution
problems it had ever faced.
In the 10 years since the
Superfund program began,
hazardous waste has surfaced
as a major environmental
concern in every part of the
United States. It wasn't just
the land that was contami-
nated by past disposal prac-
tices. Chemicals in the soil
were spreading into the
groundwater (a source of
drinking water for many) and
into, streams, lakes, bays, and
wetlands. Toxic vapors
contaminated the air at some
sites, while at others improp-
erly disposed or stored
wastes threatened the health
of the surrounding commu-
nity and the environment.
EPA Identified More than
1,200 Serious Sites
EPA has identified 1,236
hazardous waste sites as the
most serious in the Nation.
These sites comprise the
"National Priorities List":
sites targeted for cleanup
under the Superfund: But site
discoveries continue/ and
EPA estimates that, while
some will be deleted after
lengthy cleanups, this list,
commonly called the NPL,
will continue to grow by ap-
proximately 100 sites per
year, reaching 2,100 sites by
the year 2000.
THE NATIONAL
CLEANUP EFFORT IS
MUCH MORE THAN
THE NPL
From the beginning of the
program, Congress recog-
nized that the Federal govern-
ment could not and should
not address all environmental
problems stemming from past
disposal practices. Therefore,
the EPA was directed to set
priorities and establish a list
of sites to target. Sites on the
NPL (1,236) are thus a rela-
111
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\
lively small subset of a larger
inventory of potential hazard-
ous waste sites, but they do
comprise the most complex
and environmentally compel-
ling cases. EPA has logged
more than 32,000 sites on its
National hazardous waste
inventory, and assesses each
site within one year of being
logged. In fact, over 90 per-
cent of the sites on the inven-
tory have been assessed. Of
the assessed sites, 55 percent
have been found to require no
further Federal action because
they did not pose significant
human health or environ-
mental risks. The remaining
sites are undergoing further
assessment to determine if
long-term Federal cleanup
activities are appropriate.
EPA IS MAKING
PROGRESS ON SITE
CLEANUP
The goal of the Superfund
program is to tackle immedi-
ate dangers first, and then
move through the progressive
steps necessary to eliminate
any long-term risks to public
health and the environment.
The Superfund responds
immediately to sites posing
imminent threats to human
health and the environment
at both NPL sites and sites
notontheNPL. The purpose
is to stabilize, prevent, or
temper the effects of a haz-
ardous release, or the threat
of one. These might include
tire fires or transportation
accidents involving the spill
of hazardous chemicals.
Because they reduce the
threat a site poses to human
health and the environment,
immediate cleanup actions
are an integral part of the
Superfund program.
Immediate response to immi-
nent threats is one of the
Superfund's most noted
achievements. Where immi-
nent threats to the public or
environment were evident,
EPA has completed or moni-
tored emergency actions that
attacked the most serious
threats to toxic exposure in
more than 1,800 cases.
The ultimate goal for a haz-
ardous waste site on the NPL
is a permanent solution to an
environmental problem that
presents a serious (but not an
imminent) threat to the public
or environment. This often
requires a long-term effort. In
the last four years, EPA has
aggressively accelerated its
efforts to perform these long-
term cleanups of NPL sites.
More cleanups were started
in 1987, when the Superfund
law was amended, than in
any previous year. And in
1989 more sites than ever
reached the construction
stage of the Superfund
cleanup process. Indeed
construction starts increased
by over 200 percent between
late 1986 and 1989! Of the
sites currently on the NPL,
more than 500 nearly half
have had construction
cleanup activity. In addition,
over 500 more sites are pres-
ently in the investigation
stage to determine the extent
of site contamination, and to
identify appropriate cleanup
remedies. Many other sites
with cleanup remedies se-
lected are poised for the start
of cleanup construction activ-
ity. Measuring success by
"progress through the
cleanup pipeline," EPA is
clearly gaining momentum.
EPA MAKES SURE
CLEANUP WORKS
EPA has gained enough
experience in cleanup con-
struction to understand that
environmental protection
does not end when the rem-
edy is in place. Many com-
plex technologies like
those designed to clean up
groundwater must operate
for many years in order to
accomplish their objectives.
EPA's hazardous waste site
managers are committed to
proper operation and mainte-
nance of every remedy con-
structed. No matter who has
been delegated responsibility
for monitoring the cleanup
work, the EPA will assure
that the remedy is carefully
followed and that it continues
to do its job.
Likewise, EPA does not
abandon a site even after the
cleanup work is done. Every
IV
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five years the Agency reviews
each site where residues from
hazardous waste cleanup still
remain to ensure that public
and environmental health are
still being safeguarded. EPA
will correct any deficiencies
discovered and report to the
public annually on all five-
year reviews conducted that
year.
CITIZENS HELP SHAPE
DECISIONS
Superfund activities also
depend upon local citizen
participation. EPA's job is to
analyze the hazards and
deploy the experts, but the
Agency needs citizen input as
it makes choices for affected
communities.
Because the people in a
community with a Superfund
site will be those most di-
rectly affected by hazardous
waste problems and cleanup
processes, EPA encourages
citizens to get involved in
cleanup decisions. Public in-
volvement and comment does
influence EPA cleanup plans
by providing valuable infor-
mation about site conditions,
community concerns and
preferences.
This State volume and the
companion National Over-
view volume provide general
Superfund background
information and descriptions
of activities at each State NPL
site. These volumes are
intended to clearly describe
what the problems are, what
EPA and others participating
in site cleanups are doing,
and how we as a Nation can
move ahead in solving these
serious problems.
USING THE STATE AND
NATIONAL VOLUMES
IN TANDEM
To understand the big picture
on hazardous waste cleanup,
citizens need to hear about
both environmental progress
across the country and the
cleanup accomplishments
closer to home. The public
should understand the chal-
lenges involved in hazardous
waste cleanup and the deci-
sions we must make as a
Nation in finding the best
solutions.
The National Overview
volume Superfund: Focus-
ing on the Nation at Large
accompanies this State vol-
ume. The National Overview
contains important informa-
tion to help you understand
the magnitude and challenges
facing the Superfund pro-
gram as well as an overview
of the National cleanup effort.
The sections describe the
nature of the hazardous
waste problem nationwide,
threats and contaminants at
NPL sites and their potential
effects on human health and
the environment, the Super-
fund program's successes in
cleaning up the Nation's
serious hazardous waste sites,
and the vital roles of the
various participants in the
cleanup process.
This State volume compiles
site summary fact sheets on
each State site being cleaned
up under the Superfund
program. These sites repre-
sent the most serious hazard-
ous waste problems in the
Nation, and require the most
complicated and costly site
solutions yet encountered.
Each State book gives a
"snapshot" of the conditions
and cleanup progress that has
been made at each NPL site in
the State through the first half
of 1990. Conditions change as
our cleanup efforts continue,
so these site summaries will
be updated periodically to
include new information on
progress being made.
To help you understand the
cleanup accomplishments
made at these sites, this State
volume includes a description
of the process for site discov-
ery, threat evaluation arid
long-term cleanup of Super-
fund sites. This description
How Does the Program
Work to Clean Up Sites?
will serve as a good reference
point from which to review
the cleanup status at specific
sites. A glossary also is
included at the back of the
book that defines key terms
used in the site fact sheets as
they apply to hazardous
waste management.
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he diverse problems posed by the Nation's hazardous
IT; ; waste sites have provided EPA with the challenge to
k , establish a consistent approach for evaluating and
cleaning up the Nation's most serious sites. To do this, EPA
had to step beyond its traditional role as a regulatory agency
to develop processes and guidelines for each step in these
technically complex site cleanups. EPA has established proce-
dures to coordinate the efforts of its Washington, D.C. Head-
quarters program offices and its front-line staff in 10 Regional
Offices with the State governments, contractors, and private
parties who are participating in site cleanup. An important
part of the process is that any time during cleanup, work can
be led by EPA or the State or, under their monitoring, by
private parties who are potentially responsible for site con-
tamination.
The process for discovery of the site, evaluation of threat, and
long-term cleanup of Superfund sites is summarized in the
following pages. The phases of each of these steps are high-
lighted within the description. The flow diagram below pro-
vides a summary of this three step process.
STEP1
Discover site
and determine
whether an
emergency
exists *
STEP 2
Evaluate whether
a site is a serious
threat to public
health or
environment
STEP 3
Perform long-term
cleanup actions on
the most serious
hazardous waste
sites in the Nation
* Emergency actions are performed whenever needed in this three-step process
FIGURE 1
Although this State book provides a current "snapshot" of site progress made only by emer-
gency actions and long-term cleanup actions at Superfund sites, it is important to understand
the discovery and evaluation process that leads up to identifying and cleaning up these most
serious uncontrolled or abandoned hazardous waste sites in the Nation. This discovery and
evaluation process is the starting point for this summary description.
VII
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STEP 1: SITE DISCOVERY AND EMERGENCY
EVALUATION
Site discovery occurs in a number of ways. Information
comes from concerned citizens people may notice an odd
taste or foul odor in their drinking water, or see half-buried
leaking barrels; a hunter may come across a field, where waste
was dumped illegally. Or there may be an explosion or fire
which alerts the State or local authorities to a problem. Rou-
tine investigations by State and local governments, and re-
quired reporting and inspection of facilities that generate,
treat, store, or dispose of hazardous waste also help keep EPA
informed about either actual or potential threats of hazardous
substance releases. All reported sites or spills are recorded in
the Superfund inventory (CERCLIS) for further investigation
to determine whether they will require cleanup.
As soon as a potential hazardous waste site is reported, EPA
determines whether there is an emergency requiring an imme-
diate cleanup action. If there is, they act as quickly as possible
to remove or stabilize the imminent threat. These short-term
emergency actions range from building a fence around the
contaminated area to keep people away or temporarily relo-
cating residents until the danger is addressed, to providing
bottled water to residents while their local drinking water
supply is being cleaned up, or physically removing wastes for
safe disposal.
However, emergency actions can happen at any time an imminent
threat or emergency warrants them for example, if leaking
barrels are found when cleanup crews start digging in the
ground or if samples of contaminated soils or air show that
there may be a threat of fire or explosion, an immediate action
is taken.
STEP 2: SITE THREAT EVALUATION
Even after any imminent dangers are taken care of, in most
cases contamination may remain at the site. For example,
residents may have been supplied with bottled water to take
care of their immediate problem of contaminated well water.
But now it's time to figure out what is contaminating the
drinking water supply and the best way to clean it up. Or
viii
-------
EPA may determine that there is no imminent danger from a
site, so now any long-term threats need to be evaluated. In
either case, a more comprehensive investigation is needed to
determine if a site poses a serious but not imminent danger,
and requires a long-term cleanup action.
Once a site is discovered and any needed emergency actions
are taken, EPA or the State collects all available background
information not only from their own files, but also from local
records and U.S. Geological Survey maps. This information is
used to identify the site and to perform a preliminary assess-
ment of its potential hazards. This is a quick review of readily
available information to answer the questions:
Are hazardous substances likely to be present?
o How are they contained?
How might contaminants spread?
How close is the nearest well, home, or natural resource
area like a wetland or animal sanctuary?
What may be harmed the land, water, air, people,
plants, or animals?
Some sites do not require further action because the prelimi-
nary assessment shows that they don't threaten public health
or the environment. But even in these cases, the sites remain
listed in the Superfund inventory for record keeping purposes
and future reference. Currently, there are more than 32,000
sites maintained in this inventory.
Inspectors go to the site to collect additional information to
evaluate its hazard potential. During this site inspection, they
look for evidence of hazardous waste, such as leaking drums
and dead or discolored vegetation. They may take some
samples of soil, well water, river water, and air. Inspectors
analyze the ways hazardous materials could be polluting the
environment such as runoff into nearby streams. They also
check to see if people (especially children) have access to the
site.
Information collected during the site inspection is used to
identify the sites posing the most serious threats to human
health and the environment. This way EPA can meet the
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IX
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i How do people find J
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requirement that Congress gave them to use Superfund mo-
nies only on the worst hazardous waste sites in the Nation.
To identify the most serious sites, EPA developed the Hazard
Ranking System (HRS). The HRS is the scoring system EPA
uses to assess the relative threat from a release or a potential
release of hazardous substances from a site to surrounding
groundwater, surface water, air, and soil. A site score is based
on the likelihood a hazardous substance will be released from
the site, the toxicity and amount of hazardous substances at
the site, and the people and sensitive environments potentially
affected by contamination at the site.
Only sites with high enough health and environmental risk
scores are proposed to be added to EPA's National Priorities
List (NPL). That's why there are 1,236 sites are on the NPL,
but there are more than 32,000 sites in the Superfund inven-
tory. Only NPL sites can have a long-term cleanup paid for
from the national hazardous waste trust fund the Super-
fund. But the Superfund can and does pay for emergency
actions performed at any site, whether or not it's on the NPL.
The public can find out whether a site that concerns them is
on the NPL by calling their Regional EPA office at the number
listed in this book.
The proposed NPL identifies sites that have been evaluated
through the scoring process as the most serious problems
among uncontrolled or abandoned hazardous waste sites in
the U.S. In addition, a site will be added to the NPL if the
Agency for Toxic Substances and Disease Registry issues a
health advisory recommending that people be moved away
from the site. Updated at least once a year, it's only after
public comments are considered that these proposed worst
sites are officially added to the NPL.
Listing on the NPL does not set the order in which sites will be
cleaned up. The order is influenced by the relative priority of
the site's health and environmental threats compared to other
sites, and such factors as State priorities, engineering capabili-
ties, and available technologies. Many States also have their
own list of sites that require cleanup; these often contain sites
not on the NPL that are scheduled to be cleaned up with State
money. And it should be said again that any emergency action
needed at a site can be performed by the Superfund whether
or not a site is on the NPL.
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STEP 3: LONG-TERM CLEANUP ACTIONS
The ultimate goal for a hazardous waste site on the NPL is a
permanent, long-term cleanup. Since every site presents a
unique set of challenges, there is no single all-purpose solu-
tion. So a five-phase "remedial response" process is used to
develop consistent and workable solutions to hazardous waste
problems across the Nation:
1. Investigate in detail the extent of the site contamination:
remedial investigation,
2. Study the range of possible cleanup remedies: feasibility
study,
3. Decide which remedy to use: Record of Decision or ROD,
4. Plan the remedy: remedial design, and
5. Carry out the remedy: remedial action.
This remedial response process is a long-term effort to provide
a permanent solution to an environmental problem that
presents a serious, but not an imminent threat to the public or
environment.
The first two phases of a long-term cleanup are a combined
remedial investigation and feasibility study (RI/FS) that
determine the nature and extent of contamination at the site,
and identify and evaluate cleanup alternatives. These studies
may be conducted by EPA or the State or, under their monitor-
ing, by private parties.
Like the initial site inspection described earlier, a remedial
investigation involves an examination of site data in order to
better define the problem. But the remedial investigation is
much more detailed and comprehensive than the initial site
inspection.
A remedial investigation can best be described as a carefully
designed field study. It includes extensive sampling and
laboratory analyses to generate more precise data on the types
and quantities of wastes present at the site, the type of soil and
water drainage patterns, and specific human health and
environmental risks. The result is information that allows
EPA to select the cleanup strategy that is best suited to a
particular site or to determine that no cleanup is needed.
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Placing a site on the NPL does not necessarily mean that
cleanup is needed. It is possible for a site to receive an HRS
score high enough to be added to the NPL, but not ultimately
require cleanup actions. Keep in mind that the purpose of the
scoring process is to provide a preliminary and conservative
assessment of potential risk. During subsequent site investiga-
tions, the EPA may find either that there is no real threat or
that the site does not pose significant human health or envi-
ronmental risks.
EPA or the State or, under their monitoring, private parties
identify and analyze specific site cleanup heeds based on the
extensive information collected during the remedial investiga-
>,-,/ T tion. This analysis of cleanup alternatives is called a feasibility
" ^ ftf-v.- study.
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Since cleanup actions must be tailored exactly to the needs of
each individual site, more than one possible cleanup alterna-
tive is always considered. After making sure that all potential
cleanup remedies fully protect human health and the environ-
ment and comply with Federal and State laws, the advantages
and disadvantages of each cleanup alternative are carefully
compared. These comparisons are made to determine their
effectiveness in the short- and long-term, their use of perma-
nent treatment solutions, and their technical feasibility and
cost.
To the maximum extent practicable, the remedy must be a
permanent solution and use treatment technologies to destroy
principal site contaminants. But remedies such as containing
the waste on site or removing the source of the problem (like
leaking barrels) are often considered effective. Often special
pilot studies are conducted to determine the effectiveness and
feasibility of using a particular technology to clean up a site.
Therefore, the combined remedial investigation and feasibility
study can take between 10 and 30 months to complete, de-
pending on the size and complexity of the problem.
'-E)oes the pttblk have ^ ^ ^ Yes. The Superfund law requires that the public be given the
; a say in the final , s .,/^ opportunity to comment on the proposed cleanup plan. Their
5 cleanup dedsionf ^ "*<* concerns are carefuUy considered before a final decision is
-, .V *"-? made.
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Xll
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The results of the remedial investigation and feasibility study,
which also point out the recommended cleanup choice, are
published in a report for public review and comment. EPA or
the State encourages the public to review the information and
take an active role in the final cleanup decision. Fact sheets
and announcements in local papers let the community know
where they can get copies of the study and other reference
documents concerning the site.
The public has a minimum of 30 days to comment on the
proposed cleanup plan after it is published. These comments
can either be written or given verbally at public meetings that
EPA or the State are required to hold. Neither EPA nor the
State can select the final cleanup remedy without evaluating
and providing written answers to specific community com-
ments and concerns. This "responsiveness summary" is part
of EPA's write-up of the final remedy decision, called the
Record of Decision or ROD.
The ROD is a public document that explains the cleanup
remedy chosen and the reason it was selected. Since sites
frequently are large and must be cleaned up in stages, a ROD
may be necessary for each contaminated resource or area of
the site. This may be necessary when contaminants have
spread into the soil, water and air, and affect such sensitive
areas as wetlands, or when the site is large and cleaned up in
stages. This often means that a number of remedies using
different cleanup technologies are needed to clean up a single
site.
Yes. Before a specific cleanup action is carried out, it must be
designed in detail to meet specific site needs. This stage of the
cleanup is called the remedial design. The design phase
provides the details on how the selected remedy will be
engineered and constructed.
Projects to clean up a hazardous waste site may appear to be
like any other major construction project but, in fact, the likely
presence of combinations of dangerous chemicals demands
special construction planning and procedures. Therefore, the
design of the remedy can take anywhere from 6 months to 2
years to complete. This blueprint for site cleanup includes not
only the details on every aspect of the construction work, but a
description of the types of hazardous wastes expected at the
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site, special plans for environmental protection, worker safety,
regulatory compliance, and equipment decontamination.
The time and cost for performing the site cleanup called the
remedial action are as varied as the remedies themselves.
In a few cases, the only action needed may be to remove
drums of hazardous waste and decontaminate them an
action that takes limited time and money. In most cases,
however, a remedial action may involve different and expen-
sive measures that can take a long time.
For example, cleaning polluted groundwater or dredging
% , *' > vj contaminated river bottoms can take several years of complex
"" '-l^ ;,? engineering work before contamination is reduced to safe
,,x \J ,7J\ levels. Sometimes the selected cleanup remedy described in
- ,,- V^s\*4*£ ^e ROD may need to be modified because of new contami-
s " ^ nant information discovered or difficulties that were faced
during the early cleanup activities. Taking into account these
differences, a remedial cleanup action takes an average of 18
months to complete and costs an average of $26 million per
site.
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LNPL?
the Cleaimp * ^ No. The deletion of a site from the NPL is anything but auto-
_ __i IS Complete/ is ^ -I matic. For example, cleanup of contaminated groundwater
| the Site automatically * ,'; mavtake UP to 20 years or longer. Also, in some cases the
? "deleted" ixom tEe X '" * long-term monitoring of the remedy is required to ensure that
* <*»..-, it is effective. After construction of certain remedies, opera-
tion and maintenance (e.g., maintenance of ground cover,
groundwater monitoring, etc.) or continued pumping and
treating of groundwater, may be required to ensure that the
remedy continues to prevent future health hazards or environ-
mental damage, and ultimately meets the cleanup goals
specified in the ROD. Sites in this final monitoring or opera-
tional stage of the cleanup process are designated as "con-
struction completed".
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It's not until a site cleanup meets all the goals and monitoring
requirements of the selected remedy that EPA can officially
propose the site for "deletion" from the NPL. And it's not
until public comments are taken into consideration that a site
can actually be deleted from the NPL. Deletions that have
occurred are included in the "Construction Complete" cate-
gory in the progress report found later in this book.
xiv
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Yes. Based on the belief that "the polluters should pay," after a
site is placed on the NPL, the EPA makes a thorough effort to
identify and find those responsible for causing contamination
problems at a site. Although EPA is willing to negotiate with
these private parties and encourages voluntary cleanup, it has
the authority under the Superfund law to legally force those
potentially responsible for site hazards to take specific cleanup
actions. All work performed by these parties is closely guided
and monitored by EPA, and must meet the same standards
required for actions financed through the Superfund.
Because these enforcement actions can be lengthy, EPA may
decide to use Superfund monies to make sure a site is cleaned
up without unnecessary delay. For example, if a site presents
an imminent threat to public health and the environment, or if
conditions at a site may worsen, it could be necessary to start
the cleanup right away. Those responsible for causing site
contamination are liable under the law for repaying the money
EPA spends in cleaning up the site.
Whenever possible, EPA and the Department of Justice use
their legal enforcement authorities to require responsible
parties to pay for site cleanups, thereby preserving the Super-
fund for emergency actions and sites where no responsible
parties can be identified.
forth* ,
. eoataminatiott pay?
xv
-------
xvi
-------
The Site Fact Sheets
, presented in this book
- are comprehensive
'summaries that cover a broad
range of information. The
fact sheets describe hazard-
ous waste sites on the Na-
tional Priorities List (NPL)
and their locations, as well as
the conditions leading to their
listing ("Site Description").
They list the types of con-
taminants that have been dis-
covered and related threats to
public and ecological health
("Threats and Contami-
nants"). "Cleanup Ap-
proach" presents an overview
of the cleanup activities
completed, underway, or
planned. The fact sheets
conclude with a brief synop-
sis of how much progress has
been made on protecting
public health and the envi-
ronment. The summaries also
pinpoint other actions, such
as legal efforts to involve pol-
luters responsible for site
contamination and commu-
nity concerns.
The following two pages
show a generic fact sheet and
briefly describes the informa-
tion under each section. The
square "icons" or symbols ac-
companying the text allow
the reader to see at a glance
which environmental re-
sources are affected and the
status of cleanup activities.
Icons in the Threats
and Contaminants
Section
Contaminated
Groundwater re-
sources in the vicinity
or underlying the site.
(Groundwater is often used
as a drinking water source.)
Contaminated Sur-
face Water and
Sediments on or near
the site. (These include lakes,
ponds, streams, and rivers.)
Contaminated Air in
the vicinity of the
site. (Pollution is
usually periodic and involves
contaminated dust particles
or hazardous gas emissions.)
Contaminated Soil
and Sludges on or
near the site.
Threatened or
contaminated Envi-
ronmentally Sensi-
tive Areas in the vicinity of
the site. (Examples include
wetlands and coastal areas,
critical habitats.)
Icons in the Response
Action Status Section
Actions
have been taken or
are underway to
eliminate immediate threats
Site Studies at the
site are planned or
underway.
Remedy Selected
indicates that site
investigations have
been concluded
and EPA has se-
lected a final cleanup remedy
for the site or part of the site.
Remedy Design
means that engi-
neers are prepar-
ing 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 are currently
underway.
Cleanup Complete
shows that all
cleanup goals have
been achieved for
the contaminated site or part
of the site.
XVll
-------
Site Responsibility
Identifies the Federal, State,
and/or potentially responsible
parties that are taking
responsibility for cleanup
actions at the site.
EPA REGION
CONGRESSIONAL DIST
County Name
SITE NAME
STATE
EPA ID* ABCOOOOOOOO
Site Description
NPL Listing
History
Dates when the site
was Proposed,
made Final, and
Deleted from the
NPL
Threats and Contaminants
Cleanup Approach
Environmental Progress
A summary of the actions to reduce the threats to nearby residents and
the surrounding environment; progress towards cleaning up the site
and goals of the cleanup plan are given here.
XVU1
-------
WHAT THE FACT SHEETS CONTAIN
Site Description
This section describes the location and history of the site. It includes
descriptions of the most recent activities and past actions at the site that have
contributed to the contamination. Population estimates, land usages, and nearby
resources give readers background on the local setting surrounding the site.
Throughout the site'description and other sections of the site summary, technical
or unfamiliar terms that are italicized are presented in the glossary at the end of
the book. Please refer to the glossary for more detailed explanation or definition
of the terms.
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
environments arising from the site contamination are also described. Specific
contaminants and contaminant groupings are italicized and explained in more
detail in the glossary.
>
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 are often 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 description.
- v.~ - ~s- ~*y- >«*»&&
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 EPA to achieve
site cleanup or other facts pertaining to community involvement with the site
cleanup process are reported here.
-4
XIX
-------
The fact sheets are arranged
in alphabetical order by site
name. Because site cleanup is
a dynamic and gradual
process, all site information is
accurate as of the date shown
on the bottom of each page.
Progress is always being
made at NPL sites, and EPA
will periodically update the
Site Fact Sheets to reflect
recent actions and publish
updated State volumes.
HOW CAN YOU USE
THIS STATE BOOK?
You can use this book to keep
informed about the sites that
concern you, particularly
ones close to home. EPA is
committed to involving the
public in the decisionmaking
process associated with
hazardous waste cleanup.
The Agency solicits input
from area residents in com-
munities affected by Super-
fund 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 differ-
ent 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
EPA intends to dean up the
site. You must understand
the cleanup alternatives being
proposed for site cleanup and
how residents may be af-
fected by each one. You also
need to have some idea of
how your community intends
to use the site in the future
and to know what the com-
munity can realistically
expect once the cleanup is
complete.
EPA wants to develop
cleanup methods that meet
community needs, but the
Agency can only 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 in-
volved, and assure that
hazardous waste cleanup at
"your" site considers your
community's concerns.
xx
-------
NPL Sites in
State of Delawa^
Delaware is the third smallest state in the nation, covering 2,045 square miles. The
State is located on the Atlantic coastal plain with the Piedmont plateau to the north, and
sloping to a near sea-level plain. Delaware's population grew by 11.1 percent in the
1980s, and currently has approximately 660,000 residents, ranking 49th in U.S.
populations. Principal State industries include chemistry, agriculture, finance, poultry,
shellfish, tourism, auto assembly, and food processing. Delaware produces a variety of
agricultural products and livestock, nylon, apparel, luggage, and railroad and aircraft
equipment.
How Many Delaware Sites
Are on the NPL?
Proposed
Final
Deleted
4
16
1
21
Where Are the NPL Sites Located?
Cong. District 01
21 sites
20--,,
"3 10 +
*
How are Sites Contaminated and What are the Principal* Chemicals ?
Groundwater: Heavy metals
(inorganics), and volatile organic
compounds (VOCs).
Soil, Solid and Liquid Waste:
Heavy metals (inorganics), volatile
organic compounds (VOCs),
creosote (orgnanics), and
polychlorinated biphenyls (PCBs).
Surface Water and Sediment:
Heavy metals (inorganics), and
volatile organic compounds (VOCs),
creosote (orgnanics), and
polychlorinated biphenyls (PCBs),
petrochemicals, and pesticides.
"Appear at 15% or more sites
V77A
GW Soil SW Sed Solid Liquid
Waste Waste
(Sludge)
Contamination Area
State Overview
XXI
continued
-------
Where are the Sites in the Superfund Cleanup Process* ?
Site
Studies
Remedy
Selected
Remedy-
Design
Cleanup
Ongoing
Construction
Complete
Initial actions have been taken at 11 sites as interim cleanup measures.
Who Do I Call with Questions?
The following pages describe each NPL site in Delaware, providing specific information
on threats and contaminants, cleanup activities, and environmental progress. Should
you have questions, please call one of the offices listed below:
Delaware Superfund Office
EPA Region III Superfund Office
EPA Public Information Center
EPA Superfund Hotline
EPA Region III Superfund Public
Relations Office
(302) 736-3672
(215)597-8132
(202) 475-7751
(800) 424-9346
(215)597-9905
* Cleanup status reflects phase of site activities rather than administrative accomplishments.
State Overview
XXII
_
-------
The NPL Progress Report
The following Progress Report lists the State sites currently on or deleted from the NPL,
and briefly summarizes the status of activities for each site at the time this report was
prepared. The steps in the Superfund cleanup process are arrayed across the top of the
chart, and each site's progress through these steps is represented by an arrow K) which
indicates the current stage of cleanup at the site.
Large and complex sites are often organized into several cleanup stages. For example,
separate cleanup efforts may be required to address the source of the contamination,
hazardous substances in the groundwater, and surface water pollution, or to clean up
different areas of a large site. In such cases, the chart portrays cleanup progress at the
site's most advanced stage, reflecting the status of site activities rather than administrative
accomplishments.
»- An arrow in the "Initial Response" category indicates that an emergency cleanup or
initial action has been completed or is currently underway. Emergency or initial actions
are taken as an interim measure to provide immediete relief from exposure to
hazardous site conditions or to stabilize a site to prevent further contamination.
*- An arrow in the "Site Studies" category indicates that an investigation to determine the
nature and extent of the contamination at the site is currently ongoing or planned to
begin in 1991.
*' An arrow in the "Remedy Selection" category means that the EPA has selected the
final cleanup strategy for the site. At the few sites where the EPA has determined that
initial response actions have eliminated site contamination, or that any remaining
contamination will be naturally dispersed without further cleanup activities, a "No
Action" remedy is selected. In these cases, the arrows in the Progress Report are
discontinued at the "Remedy Selection" step and resume in the final "Construction
Complete" category.
* An arrow at the "Remedial Design" stage indicates that engineers are currently
designing the technical specifications for the selected cleanup remedies and
technologies.
*- An arrow marking the "Cleanup Ongoing" category means that final cleanup actions
have been started at the site and are currently underway.
* A arrow in the "Construction Complete" category is used on/y when all phases of the
site cleanup plan have been performed and the EPA has determined that no additional
construction actions are required at the site. Some sites in this category may currently
be undergoing long-term pumping and treating of groundwater, operation and
maintenance or monitoring to ensure that the completed cleanup actions continue to
protect human health and the environment.
The sites are listed in alphabetical order. Further information on the activities and progress
at each site is given in the site "Fact Sheets" published in this volume.
XXlll
-------
Page
1
3
5
7
9
11
13
15
17
19
21
23
25
27
29
31
33
35
CU -VHVIW ~m ^r -mm mi ^MM ^^«»^^«*^* V*fe£^
Site Name
ARMY CREEK LANDFILL
CHEM-SOLV, INC.
COKER'S SANITATION SERVICE
DELAWARE CITY PVC PLANT
DELAWARE SAND & GRAVEL
DOVER AIR FORCE BASE
DOVER GAS LIGHT CO
E.I. DU PONT, NEWPORT
HALBY CHEMICAL
HARVEY & KNOTT DRUM SITE
KENT CTY LANDFILL
KOPPERS COMPANY FACILITIES
NCR CORP, MILLSBORO
NEW CASTLE SPILL
NEW CASTLE STEEL PLANT
SEALAND LTD.
STANDARD CHLORINE COMPANY
SUSSEX COUNTY LANDFILL #5
**i* ifci* **r i»^jkt0^*»-
County
NEWCASTLE
KENT
KENT
NEWCASTLE
NEWCASTLE
KENT
KENT
NEWCASTLE
NEW CASTLE
NEW CASTLE
KENT
NEWCASTLE
SUSSEX
NEW CASTLE
NEW CASTLE
NEWCASTLE
NEWCASTLE
SUSSEX
I JUU ItJUL!
NPL
Final
Prop.
Final
Final
Final
Final
Final
Final
Final
Final
Prop.
Prop.
Final
Final
Deleted
Prop.
Final
Final
\f V7l»CU.«^ VA ASCJUXWClAG
Initial Site Remedy Remedy Cleanup Construction
Date Response Studies Selected Design Ongoing Complete
09/08/83 ++-+ +
06/10/88 "K *>*
07/01/87 "^ *-
09/01/83 * *- + + +
09/01/83 "K + my
03/13/89 + *>-
10/04/89 +
02/16/90 +
06/01/86 »>
09/01/83 «* * + my +
06/16/88 ^
10/26/89 ^
07/01/87 +
09/08/83 ' *- ^
03/17/89 *> +- +-
06/16/88 +~ +
07/01/87 * . .^ -
10/06/89 " ^
XXIV
-------
Page Site Name
County
NPL Date
Initial Site Remedy Remedy Cleanup Construction
Response Studies Selected Design Ongoing Complete
37 TYBOUTS CORNER LANDFILL
39 TYLER REFRIGERATION PIT
41 WILDCAT LANDFILL
NEWCASTLE
KENT
KENT
Final 09/01/83
Final 02/21/90
Final 09/01/83
XXV
-------
-------
-------
-------
ARMY CREEK
LANDFILL
DELAWARE
EPA ID# DED980494496
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
2 miles southwest of New Castle
Alias:
Llangollen Landfill
Site Description
The Army Creek Landfill site occupies 47 acres of a 64-acre parcel. 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 was previously
used as a sand and gravel quarry. Approximately 30% of the waste lies below the
seasonal high water table. Army Creek, which forms the southern and eastern border
of the site, flows into the Delaware River about 1 mile east of the site. Groundwater
contamination was discovered in a nearby residential well in 1972. After studies were
conducted by the County/which identified alcohols and acidic compounds in leachate,
wells were installed to prevent the movement of groundwater toward public water
supply wells. The water pumped out of these wells is discharged untreated to Army
Creek and Army Pond. About 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
County and Federal actions.
NPL LISTING HISTORY
Proposed Date: 10/01/81
Final Date: 09/08/83
n\
Threats and Contaminants
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 contamination from cadmium, chromium,
mercury, iron, and zinc. People working or trespassing on the site could
be exposed to contaminants in the soil by touching or accidentally eating
it, by breathing contaminants in the air, or by drinking contaminated
groundwater. Methane escaping from the landfill could cause injuries if
an explosion occurred.
March 1990
NPL HAZARDOUS WASTE SITES
1
continued
-------
ARMY CREEK LANDFILL
Cleanup Approach
This site is being addressed in three stages: emergency actions and two long-term
remedial phases focusing on source control and cleanup of the entire site.
Response Action Status
X" Emergency Actions: Tires on the site caught fire and threatened to ignite
nearby hazardous wastes. The fire was extinguished by the 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 contamination plume from reaching the source of the
drinking water supply. Pumping has separated contamination from the water supply
and eliminated further migration of the plume into the drinking water source.
Source Control: Control of the source of contamination of the site will
include: (1) installation of a multi-layer cap over the landfill; (2) installation of
the downgradient recovery well network; and (3) evaluation of the cap
system and the groundwater recovery network for the next 5 years by
monitoring well water levels and by pumping water and checking the water quality.
After 5 years, an evaluation will be carried out to determine if installation of upgradient
controls are necessary. At the same time, it also will be decided whether monitoring of
well water levels, pumping rates, and water quality should continue. The EPA is in the
process of designing the technical specifications for the selected remedy, which is
planned for completion in 1990.
Entire Site: A detailed study of the nature and extent of contamination and
treatment alternatives for the water being pumped from the groundwater
recovery wells began in 1989. This study is scheduled for completion in
1990, resulting in a final selection of a groundwater treatment remedy for recovery
wells.
JEnwiSif ISIWf
-------
CHEM-SOLV, INC.
DELAWARE
EPA ID# DED980714141
REGION 3
CONGRESSIONAL DIST. 01
Kent County
Cheswold
Site Description
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 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 at the upper Columbia Aquifer, which is adjacent to the site,
where high concentrations of volatile organic chemicals (VOCs) were found in both the
upper and lower zones 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.
Site Responsibility: This site is being addressed through
a combination of State, Federal, and
potentially responsible parties'
actions.
IMPL LISTING HISTORY
Proposed Date: 06/10/88
Threats and Contaminants
zn
The groundwater, soil, and one residential well is contaminated with
VOCs from site waste disposal practices. The primary threat to human
health is drinking the contaminated groundwater. However, at this time,
the levels of contaminants reported in residential wells are within
acceptable drinking water standards. There is little potential for exposure
to any contamination from on-site soil because it was excavated and air-
stripped in 1985.
March 1990
NPL HAZARDOUS WASTE SITES
3
continued
-------
CHEM-SOLV, INC.
Cleanup Approach
This site is being addressed in two stages: immediate actions and a long-term remedial
phase focusing on cleanup of the entire site.
Response Action Status
Ix* Immediate Actions: In 1985, the State excavated contaminated soil and
began using a process that passes air through the soil to remove VOCs.
_^ Also, in 1985, the State started to recover and treat the VOCs in the upper ,
Columbia Aquifer using an air stripping system. The air stripping process used by the
State reduced contamination to levels that permitted the soil to be returned to the
excavated area.
Entire Site: A group of parties potentially responsible for the site
contamination currently is conducting an investigation into the nature and
extent of the contamination at the site. The investigation will define the
contaminants and recommend alternatives for the final cleanup. The investigation is
planned to be completed in 1992.
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
Orcferwas signed by the potentially responsible parties, the EPA, and the State
requiring the potentially responsible parties to conduct an investigation into the
contamination at the site.
Environmental Progress
By removing VOCs from the soil and from the Upper Columbia Aquifer, the State has
eliminated immediate threats and reduced the potential for exposure to hazardous
materials. These actions have made the Chem-Solv, Inc. site safer while the potentially
responsible parties complete their investigation and begin final cleanup activities.
-------
COKER'S SANIT.
SERVICE
DELAWARE
EPA ID# DED980704860
ON
REGION 3
CONGRESSIONAL DIST. 01
Kent County
Cheswold
Aliases:
Reichold Chem Inc. #1 .
Coker's Landfill #1 & #2
Site Description ' --
The two Coker's Sanitation Service landfills cover 25 acres near Cheswold. Coker's
Landfill #1 covers 10 acres and Coker's Landfill #2 covers the remaining 15 acres. They
were formerly landfills used for disposal of latex rubber waste sludges from what js
now the Reichold Chemicals, Inc. plant. Coker's Landfill #1, operated from 1962 until
1976, consists of an unknown number of unlined trenches. Coker's Landfill #2 was
used under a State solid waste disposal permit from 1976 to 1980 and consists-of 51
lined trenches, a leachate collection and monitoring system, and a groundwater
monitoring system. The landfills overlie two groundwater systems: the Columbia
Aquifer, which is a water table aqu/ferand 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 and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date: 04/01/85
, Final Date: 07/01/87
Threats and Contaminants
On-site groundwater, sludge, leachate, and soil contamination consists of
heavy metals including iron, volatile organic compounds (VOCs) including
ethylbenzene and toluene, and acrolein from the latex rubber wastes.
Off-site monitoring wells have shown the presence of acrolein and
ethylbenzene. Potential risks to health are direct contact with
contaminated substances on site or accidental ingestion of groundwater
or leachate. However, considering the remote, rural, partially restricted
nature of the site, the potential for public contact with contaminants on or
near the site appears to be slight. There is a potential for contaminants to
move off site to the nearby surface water and to the water table aquifer
and the regional aquifer, both of which supply city water. Area wetlands
are also potentially threatened, since drainage from Coker's Landfill #1
runs through a wetlands area to the Willis Branch of the Leipsic River and
Coker's Landfill #2 is partially bordered by wetlands.
March 1990
NPL HAZARDOUS WASTE SITES
5
continued
-------
COKER'S SANITATION SERVICE
Cleanup Approach
The site is being addressed in two stages: an immediate action and a long-term
remedial phase focusing on cleanup of the entire site.
Response Action Status
Immediate Action: 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 were excavated,,
overpacked, and incinerated, and the area was fenced for protective purposes.
Entire Site: The soil and groundwater cleanup are the primary focus of site
cleanup. The total number of buried drums, their content and effect on the
soil and groundwater remain unknown. The parties potentially responsible
for site contamination are conducting an investigation of the drums and the entire site
to help determine the extent of contamination remaining at the site and to identify
alternative technologies for the cleanup. This work is scheduled to be completed in the
summer of 1990.
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 alternative
technologies for the cleanup.
Environmental Progress
Fencing the area of Coker's Landfills #1 and #2 and the removal of contaminated drums
have made the site safer while it awaits the results of the investigation and the
selection of a final cleanup remedy for the entire site.
-------
DELAWARE CITY
PVC PLANT
DELAWARE
EPA ID# DED980551667
Site Description
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
2 miles west of Delaware City
The 550-acre Delaware,City PVC Plant site was built in 1966 and serves as a polyvinyl
chloride (PVC) production facility.. From 1967 to 1970, earthen lagoons were used to
dump waste PVC. Until the wastewater treatment plant was built in 1970, a bermed
area was used to settle PVC sludges before the wastewater was discharged. Another
area was used to bury sludges from the treatment plant and was then capped. The
Columbia Formation aquifer, which has been found to be contaminated, is used locally
as a domestic water supply, and is an important source of drinking water in the area.
There are approximately 400 people living within 1 mile of the site. There are also four
residences and two manufacturing operations on the site. A water service company
that has wells within 3 miles of the site serves an estimated 100,000 people.
Site Responsibility:
This site is being addressed through
Federal and potentially responsible
parties'actions.
NPL LISTING HISTORY
Proposed Date: 10/01/81
Final Date: 09/01/83
Threats and Contaminants
The groundwater is contaminated with volatile organic compounds (VOCs)
from the waste disposal pits. The soil is contaminated with VOCs and
vinyl chloride. Contaminated groundwater in the drinking supply poses a
health threat, and on-site workers also may be exposed to contaminants
by conning into direct contact with the soils. In addition, nearby workers
and residents may be exposed to VOCs released to the air during the
groundwater cleanup process.
Cleanup Approach
This site is being addressed in four stages: immediate actions and three long-term
remedial phases focusing on the lagoon areas, groundwater treatment, and the PVC
storage area and sludge pits.
March 1990
NPL HAZARDOUS WASTE SITES
7
continued
-------
DELEWARE CITY PVC PLANT
Response Action Status
Immediate Actions: Alternate water supplies were provided to users of
on-site residential wells and off-site water supply wells to eliminate the
threat from contaminated groundwater.
Lagoon Areas: The remedies selected for cleanup of the lagoon area
include: (1) excavating sludge and contaminated soils and disposing of
residuals off-site; (2) installing a double synthetic liner in a pond, off-grade
batch pits, and aeration basins; and (3) monitoring groundwater
contamination by using test wells. The parties potentially responsible for the site
contamination have prepared the technical specifications and design for the selected
cleanup. Cleanup at the lagoon areas has started and is expected to be completed by
the end of 1990.
Groundwater: The remedies selected for groundwater contamination
include: (1) installing groundwater recovery wells at the northern and
southern edges of the contaminated plume; (2) reusing groundwater
collected in plant operations or routing it through the plant's wastewater
treatment unit; (3) installing additional monitoring wells to evaluate the recovery
system; and (4) providing an alternate source of water for residents using any existing
contaminated water-supply wells. The potentially responsible parties have designed
the technical specifications for the cleanup remedy; the cleanup is scheduled to start in
1990.
Former PVC Storage Area and Sludge Pits: The remedies selected for
cleaning up these sites include: (1.) covering and capping the areas; (2)
covering the existing synthetic membrane with a drainage layer and a
mm^ second membrane; and (3) establishing a vegetative cover on topsoil. The
potentially responsible parties are currently completing an engineering design to
construct the cap for the PVC storage areas and sludge pits.
Site Facts: In 1984, The EPA and the State entered into a Consent Order with the
potentially responsible parties to perform a site investigation and all necessary cleanup
actions to eliminate contamination at the site. In 1987, a second agreement was
reached by the EPA and the potentially responsible parties that specified the cleanup
responsibilities for each participating party.
Environmental Progress
The provision of an alternate water supply to residents and area businesses and the
start of cleanup activities at the lagoon areas of the Delaware City PVC Plant site have
eliminated the potential for exposure to contaminated groundwater. Contamination
levels at the Delaware City PVC Plant are being reduced as cleanup activities continue
and groundwater and additional disposal areas are addressed.
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DELAWARE SAN
& GRAVEL
DELAWARE
EPA ID# DED000605972
REGION 3
CONGRESSIONAL DIST. Q1
New Castle County
2 miles southwest of the City of New Castle
Alias:
Delaware Sand & Gravel Company Landfill
Site Description
The 27-acre Delaware Sand & Gravel 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 and construction wastes and
approximately 7,000 drums containing liquids and sludges from perfume, plastics,
paint, and petroleum refining processes. The Drum Disposal area is believed to be the
major source of organic contamination of the groundwater. In 1984, approximately 600
drums were removed from the surface of the Drum Disposal area, and it was then
covered with soil and a vegetative cover. The Ridge area consists of contaminated soil
and drums, storage tanks, and debris scattered on the surface. The Inert Disposal area '<
contains various domestic wastes, cars, trucks, and storage tanks scattered on the
surface. The Grantham South area is believed to contain inert wastes and chemical
wastes. Approximately 2,000 people live within 1 mile of the site. The site is located in
a sparsely populated and lightly industrialized area. Properties adjoining the site include
two residences, a health club and ball field, and a maintenance garage. The nearest
residence is about 30 feet from the edge of the landfill. The Llangollen Estates housing
development is about 1/2 mile southwest of the site. Underlying the landfill is the
Potomac Aquifer, which is accessed about 1 1/4 miles south of the site and is used as
a public water source.
Site Responsibility: jh\s sjte js being addressed through
Federal, State, and County actions.
NPL LISTING HISTORY
Proposed Date: 10/01/81
Final Date: 09/01/83
Threats and Contaminants
The groundwater is contaminated with volatile organic compounds (VOCs)
and lead from former disposal practices. Heavy metals including arsenic,"
cadmium, chromium, and mercury have also been detected in off-site
groundwater. The soil is contaminated with VOCs, polychlorinated
biphenyls {PCBs}, and heavy metals. Specific contaminants detected in
Army Creek include cadmium, chromium, mercury, iron, and zinc. The
greatest threat to health is accidental ingestion of groundwater that has
become contaminated by site releases and which is used as the drinking ;
water supply for 5,000 people. Workers, trespassers, and nearby,
residents may be exposed to contaminants in soil and air.
March 1990
NPL HAZARDOUS WASTE SITES
9
continued
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DELAWARE SAND & GRAVEL
Cleanup Approach
This site is being addressed in two stages: immediate actions and a long-term remedial
phase focusing on contamination at the entire site.
Response Action Status
Immediate Actions: To reduce the threat of groundwater contamination,
New Castle County installed a recovery system downgradientof the site to
prevent contaminated water from reaching the nearby private well field. In
1984, the EPA removed approximately 600 drums from the Drum Disposal area. Drum
staging pads, consisting of a compacted clay base for the pads and a clay dike around
them to prevent contaminants from .escaping, were constructed. Drums were
removed and placed in the staging cells. Air monitoring was conducted in the work
area and at the site perimeter to determine the impact of site activities on ambient air.
The flammable solids and PCB materials were bulked, drummed, and safely disposed.
A drum shredder was used to process non-flammable solids for disposal. Shredded
material was placed in box trailers and shipped to disposal facilities. Work areas of the
site were regraded, hydroseeded, and spread with mulch.
Entire Site: The selected actions for remaining cleanup activities include:
(1) excavation and on-site treatment of approximately 36,000 tons of
contaminated soil and wastes from the Drum Disposal and Ridge areas; (2)
on- or off-site disposal of residual ash; (3) reshaping of the excavated area
and establishment of a vegetative cover; (4) removal and off-site disposal of
all surface debris from the Inert area; {5} capping of buried waste materials; (6)
construction of a cap over the Grantham South area; and (7) a groundwater pump and
treatment system with discharge to Army Creek and continued groundwater
monitoring. The groundwater recovery system is being coordinated with activity at the
neighboring Army Creek Landfill Superfund site. Continued monitoring in the area
indicates that the groundwater recovery system has been effective in controlling
groundwater contaminant migration.
Site Facts: In 1976, the State issued an enforcement action requiring the potentially
responsible pa/t/esfor the site contamination to discontinue disposal activities.
Environmental Progress
Numerous cleanup activities have been completed at the Delaware Sand & Gravel site,
including removing contaminated materials; air monitoring; and regrading,
hydroseeding, and spreading mulch over the site. The groundwater recovery system is
successfully controlling the spread of contamination from the site while final cleanup
actions are completed.
10
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DOVER AIR FORCE
BASE
DELAWARE
EPA ID# DE8570024010
REGION 3
CONGRESSIONAL DIST. 01
Kent County
Dover
Site Description
The 3,700-acre Dover Air Force Base (AFB) site is the base of operation for the 436th
Military Airlift Wing. The base contains 13 areas on site that were used for disposing
industrial waste. An estimated 23,000 cubic feet of waste were disposed of from 1951
to 1970. The base's operation generated numerous wastes, some in drums, including
paints, solvents, and oil. These wastes were disposed of in various on-base locations
including the 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
1 mile, and the site is located in a commercial and residential area that is densely
populated. The base well system serves about 3,000 people and is routinely monitored
by the Air Force.
Site Responsibility: This site is being addressed through
Federal actions.
NPL LISTING HISTORY
Proposed Date: 10/01/84
Final Date: 03/13/89
Threats and Contaminants
Specific contaminants detected in on-site groundwater include 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) and carbon tetrachloride. VOCs have
also been detected in 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 potable purposes 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 is also a concern. A nearby freshwater wetlands is threatened by
site contamination.
March 1990
NPL HAZARDOUS WASTE SITES
11
continued
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DOVER AIR FORCE BASE
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: The Air Force has cleaned the industrial waste basins and a
drum site and has provided an alternate water supply to affected residents.
Entire Site: The Air Force currently is conducting an investigation into the
nature and extent of the contamination at the site. The investigation will
define the contaminants and will recommend alternatives for the final
cleanup. The investigation is planned to be completed in 1990. As an early action, the
Air Force will suggest source controls and interim removal of contamination floating on
the water table, as well as the removal of contaminated soils.
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 is also participating in the Installation
Restoration Program (IRP), which is a federally funded Department of Defense (DOD)
mechanism to identify, investigate, and control hazardous waste on military or DOD
Installations.
Environmental Progress
By cleaning the industrial waste basins and drum sites and providing an alternate water
supply to residents and workers at the base, the Air Force has reduced the risk of
immediate threats at the Dover AFB site while it awaits further investigation and
cleanup activities.
12
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DOVER GAS LIGH
COMPANY
DELAWARE
EPA ID# DED980693550
REGION 3
CONGRESSIONAL DIST: 01
Kent County
Dover
Site Description
The 1-acre Dover Gas Light Company site operated as a coal gasification plant from
1859 to 1948 and produced gas for street lamps from coal. When the plant was closed
in 1948, the structures, except for a brick garage, were demolished. Some steel and
scrap iron were removed, but tanks and other process equipment containing coal oil,
coal tar, coke, and possibly acid were buried on site. In 1984, remains of a coal
gasification plant were found buried on the site. The site is currently used as a
museum. Approximately 10,000 people are within 1 mile of the site and an estimated
454,000 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 1 mile of the site. The closest
supply well, 1,000 feet from the the site/draws from the Cheswold aquifer, part of
Dover's municipal water system. Also nearby are a cemetery, an historic church, and a
State museum.
site Responsibility: This site is being addressed through
Federal and potentially responsible
parties' actions. :
NPL. LISTING HISTORY
Proposed Date: 01/22/87
Final Date: 10/04/89
Threats and Contaminants
Specific contaminants detected in the groundwater and soil include
volatile organic compounds (VOCs), lead, and polycyclic aromatic
hydrocarbons (PAHs) from former site activities. Possible health threats
include drinking or touching the contaminated groundwater or soil.
Contaminated groundwater may threaten nearby water supplies;
however, a 1988 sampling of two wells closest to the site did not show
signs of contamination.
Cleanup Approach
This site is being addressed in a single long-term remedial phase focusing on
contamination at the entire site.
March 1990
NPL HAZARDOUS WASTE SITES
13
continued
-------
DOVER GAS LIGHT COMPANY
Response Action Status
Entire Site: The parties potentially responsible for the site contamination
currently are conducting an investigation into the groundwater
( w contamination at the site. The investigation will define the contaminants
and will recommend alternatives for final groundwater cleanup. The investigation is
planned to be completed in 1991, after which the potentially responsible parties, under
EPA supervision, will begin cleanup of the site using the cleanup technologies selected.
Environmental Progress
After listing the Dover Gas Light Company site on the NPL, the EPA determined that
site conditions did not currently threaten nearby residents or the environment while the
potentially responsible parties, under EPA supervision, are conducting investigations
and cleanup activities at the site.
14
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E.I. DU PONT,
NEWPORT
DELAWARE
EPA ID# DED980555122
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
Along the Christiana River in Newport
Aliases:
Newport Pigments
Du Pont Newport Pigments Plant
Site Description
The E.I. Du Pont, Newport site is a pigment manufacturing facility consisting of two
industrial landfills: the 7-acre North Disposal Area and the 15-acre South Disposal Area.
From 1902 to 1929, the plant manufactured lithopone, a white inorganic pigment. In
1929, Du Pont purchased the plant and continued to produce lithopone along with other
organic and inorganic pigments. As part of the plant operations, the waste was
disposed of in the landfills. Ciba-Geigy purchased the pigment plant in 1984 while Du
Pont retained a magnetic tape manufacturing facility. Approximately 21,000 people
reside within a 3-mile radius of the site. Also within 3 miles of the site are 3 public
water supply wells that serve approximately 150,000 people. There are a number of
private supply wells within 1/2 mile of the site. Fifteen residential wells and the three
public water supply wells are threatened by groundwater contamination. The site is
within a 100-year floodplain, with wetlands and the Christiana River located nearby.
The Christiana River is used for recreational purposes.
Site Responsibility:
This site is being addressed through
Federal and potentially responsible
parties'actions.
NPL LISTING HISTORY
Proposed Date: 01/22/87
Final Date: 02/16/90
L\
Threats and Contaminants
Heavy metals and chlorinated solvents from past 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 sediments and surface water. Groundwater
contamination poses health risks to individuals who drink it. The
groundwater may also migrate and eventually affect the private wells in
the area and the Christiana River. Nearby wetlands may be threatened by
site flooding.
March 1990
NPL HAZARDOUS WASTE SITES
15
continued
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E.I. DU PONT, NEWPORT
Cleanup Approach
This site is being addressed in a single long-term remedial phasefocusing on cleanup
of the entire site.
Response Action Status
Entire Site: The parties potentially responsible for the site contamination'
started an investigation in 1988 to determine the extent of the
contamination and to identify alternative cleanup technologies. The
investigation is scheduled to be completed in 1991. After completion of the studies,
the potentially responsible parties, under EPA supervision, -will begin cleanup of
contaminants at the site. .
Site Facts: Du Pont entered into an Administrative Order with the EPA in 1988, under
which Du Pont agreed to perform a study to determine the nature and extent of the
contamination and to identify alternative cleanup technologies.
Environmental Progress
After adding this site to the NPL, the EPA performed a preliminary evaluation at the E.I.
Du Pont, Newport site and determined that it did not currently pose an immediate
threat to public health and the environment while further investigations continue and
cleanup technologies are being developed. ,.
16
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HALBY CHEMICAL
DELAWARE
EPA ID# DED980830954
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
Wilmington
Site Description
The 13-acre Halby Chemical site operated as a chemical manufacturing facility from
1948 to 1977: Wastewater from the production of chemicals at the plant was
discharged into a 1 1/2-acre unlined lagoon and then discharged into the Lobdell Canal.
Currently, the lagoon receives intertidal flow through an interstate highway drainage
.ditch. Drums from a storage area were also found to be leaking. Preliminary sampling
results indicate significant contamination of lagoon sediment in the vicinity of the
former process buildings. There is also significant soil contamination underlying the
backfilled portions of the waste lagoon. Approximately 1,800 people live within 1 mile
of the site. Area residents receive water from the Artesian Water Company which
draws water from several uncontaminated wells. There is only one known residential
well and one public well within 3 miles of the site.
Site Responsibility: This site is being addressed through
Federal actions.
NPL LISTING HISTORY
Proposed Date: 09/01/85
Final Date: 06/01/86
Threats and Contaminants
The groundwater is contaminated with cyanide, volatile organic
compounds (VOCs), and heavy metals including iron and manganese from
chemical process wastes. Sampling of the lagoon sediments revealed
high levels of carbon disulfide, zinc, arsenic, and lead. The surface water
is contaminated with arsenic and heavy metals including lead, cadmium,
and mercury. Cyanide was detected in the soil. Potential health threats
include ingestion of and direct contact with groundwater, surface water,
and soil. Worker contact with contaminated soil on site is minimal
because access to the drum area is restricted and the work areas are
away from contaminated areas on site.
March 1990
NPL HAZARDOUS WASTE SITES
17
continued
-------
HALBY CHEMICAL
Cleanup Approach
This site is being addressed in a single long-term remedial phase focusing on
contamination at the entire site.
Response Action Status
Entire Site: The EPA is conducting an investigation into the contamination
at the site. The investigation will define the contaminants and recommend
alternatives for the final cleanup. This investigation is scheduled for
completion in 1990, at which time the EPA will select appropriate cleanup technologies.
Environmental Progress?
After adding the Halby Chemical site to the NPL, the EPA performed preliminary
investigations and determined that conditions at the site did not pose an immediate
threat to public health or to its surroundings while further investigations are under way.
18
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HARVEY & KNOTT
DRUM SITE
DELAWARE
EPA ID# DED980713093
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
About 5 miles from Kirkwood
Site Description
The Harvey & Knott Drum 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 remain on site. A security fence,
enclosing about 2 1/2 acres, was erected around the most visible areas of
contamination. The enclosed area includes 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
Federal and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date: 07/01/82
Final Date: 09/01/83
Threats and Contaminants
Specific contaminants detected in the groundwater include volatile
organic compounds (VOCs) including ethylbenzene and toluene and heavy
metals including arsenic, cadmium, and lead. Heavy metals were detected
in on-site sediments and surface water. Specific contaminants detected
in soils and sediments include VOCs, heavy metals, and polychlorinated
biphenyls (PCBs). Potential health threats include ingestion, inhalation,
and direct contact with contaminated groundwater. Trespassers and
workers may be exposed to contaminants in on-site soil and waste
through accidental ingestion, direct contact, and inhalation at levels that
pose health concerns. Contaminated surface soils beyond the west
property boundary pose similar concerns for persons entering that area.
Wetlands may also be threatened.
March 1990
NPL HAZARDOUS WASTE SITES
19
continued
-------
HARVEY & KNOTT DRUM SITE
Cleanup Approach
The site is being addressed in three stages: immediate actions and two long-term
remedial phases focusing on drum removal and groundwater pumping and treatment.
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 was constructed, 500
empty drums were crushed and staged, and 200 partially filled drums were staged.
Drum removal: The final selection of cleanup technologies to address
contaminated drums includes: (1) the removal of surface and subsurface
drums; (2) extraction and on-site treatment of surface water; (3) excavation
of sediments, soil, and bulk wastes with off-site disposal at an approved
facility; (4) disposal of sludges, drums, and other debris at an off-site facility; (5)
extraction and treatment of groundwater using effluent to flush contaminants from on-
site surface and subsurface soils; and (6) preparation of the site for a flushing pipe
network entailing grading, covering with clean soil, and revegetation. Cleanup activities
are presently under way.
Groundwater Pumping and Treatment: The EPA currently is conducting
an investigation into the nature and extent of the groundwater
contamination at the site. The investigation will define the contaminants of
concern and will recommend alternatives for the final groundwater cleanup.
The investigation is planned to be completed in 1991.
Site Facts: In 1977, a Consent Decree was entered into between EPA and a party
potentially responsible for the contamination for the party to conduct an investigation
into the nature and extent of contamination at the site. In 1988, a Consent Decree was
entered between EPA and another potentially responsible party. In 1988, EPA filed suit
against a responsible party to recover costs.
Environmental Progress
By providing an emergency drinking water supply to affected residents, installing a
security fence around the site, and removing all the surface and subsurface leaking
drums, the EPA has significantly reduced the potential for exposure to hazardous
materials at the Harvey & Knott Drum site. Cleanup of the groundwater and further
measures to remove contaminated drums, soils, sediments, and surface water from
the site currently are being addressed.
20
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KENT CITY
LANDFILL
DELAWARE
EPA ID# DED980705727
REGION 3
CONGRESSIONAL DIST. 01
Kent County
About 2 miles north of Houston
Site Description
The 129-acre Kent City Landfill site was operated by the County from 1969 to 1980.
Among the wastes accepted were residential trash, pesticides, sludges from poultry
processing plants, oil sludges, hospital wastes, waste polymers, and solvents. The
landfill holds an estimated 2 million cubic yards of waste and fill materials. The wastes
were deposited in unlined trenches. In 1980, the County covered the landfill with 3 to
5 feet of sandy soil and planted grass and other vegetation. In 1986, the EPA found
contaminants in a monitoring well that is in the water table aquifer underlying the site.
The EPA also found contaminated leachate seeping from the landfill/Approximately
1,300 people use private wells within 3 miles of the site. About 1,200 acres of .,
cropland within 3 miles of the site are irrigated by well water, and surface water near
the site is used for recreational purposes.
Site Responsibility:
This site is being addressed through
a combination of Federal, County,
and potentially responsible parties'
actions.
NPL LISTING HISTORY
Proposed Date: 06/16/88
Threats and Contaminants
The groundwater is contaminated with creosotes and heavy metals
including chromium, arsenic, and manganese from former disposal
practices at the site. The soil is contaminated with heavy metals including
iron, manganese, barium, and cobalt. People who trespass on the
unfenced site and who accidentally touch or swallow contaminated
groundwater or leachate may be at risk.
Cleanup Approach
This site is being addressed in a single long-term remedial phase focusing on cleanup
of the entire site.
March 1990
NPL HAZARDOUS WASTE SITES
21
continued
-------
KENT CITY LANDFILL
Response Action Status
Entire Site: The parties potentially responsible for the site contamination
will conduct a study to determine the nature and extent of contamination.
This study, planned for 1991, will recommend alternatives for the final
cleanup. After completion of the study, the potentially responsible parties, under EPA
supervision, will perform cleanup activities to reduce groundwater and soil
contamination to acceptable levels.
Environmental Progress
After adding this site to the NPL, the EPA performed a preliminary investigation and
determined that contamination at the Kent City Landfill site does not currently pose an
immediate threat to the public or the environment while waiting for investigation and
cleanup activities to begin.
22
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KOPPERS COMR
FACILITIES
DELAWARE
EPA ID# DED980552244
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
Newport
Site Description
The 317-acre Koppers Company Facilities 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 fuel
oil and pentachlorophenol (PCP). A pond filled with water and used for fire protection,
and a sump where effluent from the treatment process was collected, were in the
treatment area. In 1971, Koppers sold the site to Du Pont: As part of the sales
agreement, Koppers removed chemicals in the process tanks. Du Pont removed all
structures from the site; the site currently is vacant. 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 blends
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.
Site Responsibility: This site is being addressed through
Federal actions.
NPL LISTING HISTORY
Proposed Date: 10/26/89
L\
Threats and Contaminants
Soil and nearby creek and pond sediments are contaminated with
polycydic aromatic hydrocarbons (PAHs) from the wood preserving
treatment processes. Potential health threats to people include accidental
ingestion of and direct contact with contaminated soil and sediments.
Wetlands may also be threatened.
March 1990
NPL HAZARDOUS WASTE SITES
23
continued
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HOPPERS COMPANY FACILITIES SITE
Cleanup Approach
This site is being addressed in a single long-term remedial phase focusing on cleanup
of the entire site.
Response Action Status
Entire Site: The EPA is planning to conduct an investigation to determine
the nature and extent of contamination at the site. This investigation is
scheduled to begin in 1990. Alternative cleanup technologies will be
selected and cleanup activities will begin soon thereafter.
Environmental Progress
At the time this summary was written, this site had just obtained NPL status and it was
too early to discuss environmental progress. The EPA will be performing a study to
assess the need for any intermediate actions required to make the site safer while
waiting for cleanup actions to begin. Results of this assessment will be described in
our next edition.
24
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NCR PLANT,
MILLSBORO
DELAWARE
EPA ID# DED043958388
REGION 3
CONGRESSIONAL DIST. 01
Sussex County
1/2 mi southeast of Millsboro
Alias:
First Freedom Center
Site Description
NCR Corp. manufactured sales terminals from 1974 until 1981 at this 63-acre site 1/2
mile southeast of Millsboro. Between 1967 and 1974, the company ran electroplating
processes that produced a chromium-bearing waste. Workers treated this waste on
site, and disposed of resulting sludges in an unlined pit. NCR subsequently excavated
this material. Two of three concrete-lined storage lagoons on site contained toxic
materials that were later drained and removed. In 1981, the First National Bank of
Maryland bought the property, now known as First Freedom Center.' NCR assumed all
environmental responsibilities in. the deed of sale. The State required NCR to monitor
groundwater after the site was closed. Monitoring results showed that groundwater
under the property was contaminated with volatile organic compounds (VOCs) and
metals. The contaminated groundwater is entering Iron Branch Creek, which flows into
a recreational stream called Indian River. Riverview is located close to the site and is a
community of about 30 small houses that draw drinking water supplies from
groundwater wells. About 4,700 people depend on public and private wells within 3
miles of the site as a source of drinking water. The nearest well is 10 feet away from
the site, and the nearest people are 150 feet away. An estimated 1,000 people live
within 1 mile; 4,164 are within 3 miles of the site.
Site Responsibility:
This site is being addressed through
a combination of State, Federal, and
potentially responsible parites'
actions.
IMPL LISTING HISTORY
Proposed Date: 04/01/85
Final Date: 07/01/87
Threats and Contaminants
The groundwater and sludge are contaminated with VOCs including
trichloroethylene (TCE) and total and hexavalent chromium. A plume of
solvent waste has reached Iron Branch Creek, but no domestic supply
wells are affected.
March 1990
NPL HAZARDOUS WASTE SITES
continued
25
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NCR PLANT, MILLSBORO
Cleanup Approach
The site is being addressed in a single long-term remedial phase directed at cleanup of
the entire site.
Response Action Status
Entire Site: NCR excavated chromium-bearing sludge from an unlined pit
and drained and removed toxic materials from two concrete-lined storage
lagoons. NCR continued to monitor groundwater after site closure, and
installed 22 wells for that purpose. In 1988 an air stripper and a recovery well were put
into operation in an effort to prevent off-site migration of contaminants. Under State
supervision, NCR is conducting an intensive study of groundwater contamination at the
site. This investigation, which will explore the nature and extent of pollution and will
recommend the best strategies for final cleanup, is expected to be completed in late
1990.
Site Facts: A Consent Order tor NCR to undertake initial response measures, and a
study to determine the nature and extent of contamination and to identify alternatives
for cleanup was signed in 1988. The State ordered NCR to undertake an EPA-approved
site closure in 1981.
Environmental Progress
The removal of contaminated sludge and the installation of monitoring wells to chart
contaminant levels, as well as the construction of an air stripper and recovery well,
have reduced the potential for exposure to hazardous materials at the NCR plant site
while further cleanup activities are taking place.
26
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NEW CASTLE SPILL
DELAWARE
EPA ID# DED058980442
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
New Castle
Aliases:
Witco Chem. Co.
Tris Spill Site
Site Description
Since 1954 the Witco Chemical Company processed materials used in the production
of plastic foam on this 6-acre site in New Castle. 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 are now served by another source for their water supply.
Site Responsibility:
This site is being addressed through
a combination of State, Federal, and
potentially responsible parties'
actions.
IMPL LISTING HISTORY
Proposed Date: 12/12/82
Final Date: 09/08/83
Threats and Contaminants
7JA
Trichloroethylene (TCE) is found in the groundwater, but is believed to be
from an off site source now under investigation. The groundwater also is
contaminated with volatile organic compounds (VOCs) including acetone
and xyiene. 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, polychlorinated biphenyls (RGBs), TCE,
creosote, and phthalates from plastics production. Drinking contaminated
groundwater from the aquifer would normally pose a health threat to
people. However, a new water supply has been provided to residents
found to be at risk. Wetlands are adjacent to the site and are threatened
by runoff of surface contamination. The site is unrestricted and may pose
a threat to residents who come in direct contact with contaminated areas.
March 1990
NPL HAZARDOUS WASTE SITES
27
continued
-------
NEW CASTLE SPILL
Cleanup Approach
The site is being addressed in a single long-term remedial phase focusing on cleanup of
the entire site.
Response Action Status
Entire Site: From 1977 to 1978, the NCBW&L, under DNREC's
instruction, pumped the groundwater from the shallow aquifer into the
nearby wetlands to prevent migration of Tris into aquifers beneath the site.
, . The final decision from the EPA requires quarterly monitoring of the
shallow aquifer groundwater for Tris until the accepted safe level is reached in an
estimated 4-5 years, and annual monitoring of the deeper groundwater aquifer,
surface water, and sediments of the wetland. Institutional,controls will be developed to
restrict well development in the shallow aquifer. A 5-year effectiveness .review would
re-evaluate the effectiveness of this remedy. ' . ,
Environmental Progress
By using an alternative municipal water source and by pumping and treating the
contaminated groundwater, the potential for exposure to hazardous materials at the
New Castle Spill site has been reduced. Groundwater and surface water monitoring is
presently underway at the site to ensure continued environmental progress.
28
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NEW CASTLE STE
PLANT
DELAWARE
EPA ID# DED980705255
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
Near the Delaware River in the
City of New Castle
Alias:
Deemer Steel Company
Site Description
For 80 years, Deemer Steel used the 3-acre New Castle Steel Plant landfill to dispose
of its process wastes. Until the plant closed in 1987, workers dumped foundry sands,
slag, coke, iron oxide scale, baghouse dust, and metal scrap into two disposal areas
separated by a drainage channel that runs to the Delaware River. Regulations in 1980
indicated that the baghouse dust was a hazardous waste because of unacceptable
levels of cadmium, chromium, and lead. The site was placed on the NPL in 1982
because of potential groundwater contamination. The EPA subsequently changed the
regulation and the baghouse dust was no longer considered a hazardous waste.
Although metals associated with the site have entered soils, sediments, surface water,
and groundwater, the EPA has determined that contamination levels at the site are not
threatening and do not necessitate a need for cleanup actions.
Site Responsibility:
This site was addressed through a
combination of Federal, State, and
potentially responsible parties'
actions.
NPL LISTING HISTORY
Proposed Date: 12/01/82
Final Date: 09/01/83
Deletion 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 are low and do not pose threats to nearby residents
or the environment.
March 1990
NPL HAZARDOUS WASTE SITES
continued
29
-------
NEW CASTLE STEEL PLANT
Cleanup Approach
This site was addressed in a long-term remedial phase focusing on cleanup of the
entire site.
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 have determined that this site constitutes no significant threat to
human health and the environment. The selected remedy is "no action", indicating
that no further actions are required to clean up the site.
Environmental Progress
Because the site studies indicate that site contamination has attenuated and no longer
poses a risk to the public or the environment, the EPA, in conjunction with the State,
deleted the New Castle Steel Plant from the N PL in 1989.
30
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SEALAND LTD.
DELAWARE
EPA ID# DED981035520
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
Mount Pleasant
Site Description
Operations at the 2-acre Sealand Ltd. 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 properly remained unused until it was rented by the Sealand Limited and Oil
Industry in 1982 to operate a waste oil recycling plant. The operation accepted coal tar,
gas tar, and ink oil wastes, allegedly for recycling, but instead 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 tanks, drums, and 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. Soils on the site are permeable and groundwater is shallow,
conditions that ease the movement of contaminants into groundwater. The area 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 and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date; 06/16/88
Threats and Contaminants
The groundwater is contaminated with acenapthalene. The soil is
contaminated with PAHs, creosotes, solvents, and other toxic compounds
from the former recycling operation. Possible health threats include
consuming or coming in direct contact with the contaminated materials at
the site.
March 1990
NPL HAZARDOUS WASTE SITES
31
continued
-------
SEALAND LTD.
Cleanup Approach
The site is being addressed in two stages: emergency actions and a long-term
remedial phase focusing on cleanup of the entire site.
Response Action Status
Emergency Actions: In 1983, in response to the 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: The parties potentially responsible for the site contamination
are conducting an intensive study of the nature and extent of site
contamination, scheduled for completion in early 1991 . Once the study has
been completed, the EPA will select the final remedy for the site.
Environmental Progress
By removing contaminated materials from the Sealand Ltd. site, the EPA has eliminated
immediate dangers to area residents and the environment while the potentially
responsible parties, under EPA monitoring, complete site investigations and begin
further cleanup activities.
32
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STANDARD CHL
COMPANY
DELAWARE
EPA ID# DED041212473
Site Description
NE
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
Delaware City
The 46-acre Standard Chlorine Company site manufactures chlorinated benzenes, and
was listed on the NPL due to a 1980 benzene spill from 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 1 mile of the site.
Site Responsibility:
This site is being addressed through
a combination of Federal, State, and
potentially responsible parties'
actions.
NPL LISTING HISTORY
Proposed Date: 09/01/85
Final Date: 07/01/87
Threats and Contaminants
Chlorobenzenes from spilled material have been found in the
groundwater, soil, and surface water. People may be exposed to the
chemicals by touching contaminated soil, drinking contaminated water, or
accidentally ingesting contaminated soil. Wetlands near the site may also
be threatened by contamination emanating from the spill areas.
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.
March 1990
NPL HAZARDOUS WASTE SITES
33
continued
-------
STANDARD CHLORINE COMPANY
Response Action Status
ix" Emergency Actions: The EPA took the following emergency actions in
response to the January 1986 spill: (1) excavating a drainage ditch; (2)
building a filter fence along the mouth of the wetland coves; (3)
constructing an earthen dike and pre-excavation sampling to isolate the upper portions
of the wetland from contaminants; (4) excavating contaminated sediments upstream of
the dike; (5) building a basin to trap contaminated sediments in tidal areas of the cove
(between the dike and the filter fence).
Entire Site: Under State order, the parties potentially responsible for the
site contamination are conducting an intensive study of the impact the spill
, has had on local groundwater quality. The investigation will explore the
nature and extent of the groundwater contamination and will identify the best
strategies for cleanup. The study is scheduled for completion in late 1991.
Environmental Progress
Emergency actions undertaken by the EPA, including excavating a drainage ditch,
building a filter fencet constructing an earthen dike to protect nearby wetlands,
excavating contaminated sediments, and building a trap basin greatly reduced
contamination possibilities at the site. After a study is completed by the potentially
responsible parties, final cleanup actions will begin at the Standard Chlorine Company
site.
A
34
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SUSSEX COUNTY
LANDFILL #5
DELAWARE
EPA ID# DED980494637
REGION 3
CONGRESSIONAL DIST. 01
Sussex County
Laurel
Site Description
The inactive 37 1/2-acre Sussex County Landfill #5 operated from 1970 until 1979 It
accepted municipal wastes and, according to a 1978 Congressional report, an unknown
quantity of various volatile organic compounds (VOCs). Wastes were deposited in the
ground below the water table, threatening groundwater. In 1986, the EPA detected
several organic chemicals and solvents in five on-site monitoring wells. The landfill
overlies the Columbia Formation, which is connected to and recharges the Manokin
Aquifer. Together, the two 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.
Site Responsibility:
This site is being addressed through
a combination of Federal, State, and
potentially responsible parties'
actions.
NPL LISTING HISTORY
Proposed Date: 06/16/88
Final Date: 10/06/89
Threats and Contaminants
Five groundwater monitoring wells showed 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. Bioaccumulation of contaminants in
locally raised livestock and crops is a 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.
March 1990
NPL HAZARDOUS WASTE SITES
continued
35
-------
SUSSEX COUNTY LANDFILL #5
Response Action Status
Entire Site: The landfill was closed by the Delaware Department of Natural
Resources (DNREC) in 1979. The DNREC installed monitoring wells on the
, ^ site as a part of the closure plan. In 1984, DNREC conducted a preliminary
assessment which indicated that a leachate plume extended 400 to 500 feet
downgradientof 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. An intensive
Investigation of the site is scheduled to begin in 1990. The EPA will investigate the
nature and extent of groundwater contamination and will recommend cleanup
strategies for the site. The study is expected to be completed in 1993.
Site Facts: The County and DNREC have entered into an agreement to establish a
groundwater management program near the landfill. The County will monitor on-site
wells and adjacent domestic wells regularly.
Environmental Progress
The EPA evaluated the Sussex County Landfill and determined that the site does not
currently pose an immediate threat to nearby residents. By closing the landfill, the
State has eliminated the possibility of further contamination at the site while
investigations and cleanup activities are pursued.
36
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TYBOUTS CORNER
LANDFILL
DELAWARE
EPA JD# DED000606079
REGION 3
CONGRESSIONAL DIST. 01
New Castle County
10 miles south of Wilmington
Site Description
Tybouts Corner Landfill was constructed in a sand and gravel pit located in northern
Delaware, 10 miles south of Wilmington and 4 miles west of the Delaware River. The
main landfill area is about 47 acres and is located near the confluence of Pigeon Run
Creek and Red Lion Creek. The fill ranges from 5 to 40 feet thick. Between 1968 and
1971, this privately owned landfill accepted both municipal and industrial wastes,
including volatile organic compounds (VOCs) and various other organic and inorganic
chemicals. Tybout's Corner was built without a clay liner or other impervious material
below the fill, and no clay cap was placed on top of the fill after it was abandoned. EPA
studies have revealed that two shallow aquifers beneath the site are contaminated with
the above-mentioned chemicals. About 42 homes and facilities surround the entire
landfill property and most of these have wells that draw from the aquifers contaminated
by the site. Some of these residences are less than/100 feet from the landfill. In
addition, the landfill is located in an area of extensive groundwater development, both
for municipal supplies and large industrial facilities. The possibility for contaminating
the upper hydrologic zone of the Potomac Formation, an important regional aquifer
exists. .--',
Site Responsibility:
This site is being addressed through
Federal and potentially responsible
parties' actions.
NPL LISTING HISTORY
Proposed Date: 10/01/81
Final Date: 09/01/83
Threats and Contaminants
Local drinking water wells and soils are contaminated with VOCs and
other organic compounds from former disposal practices. Surface water
is contaminated with hazardous organic and inorganic substances.
Drinking and coming into contact with contaminated water may threaten
the health of people in the area.
March 1990
NPL HAZARDOUS WASTE SITES
continued
-------
TYBOUTS CORNER LANDFILL
Cleanup Approach
This site is being addressed in two stages: immediate actions and a long-term remedial
phase divided into two segments: source control and groundwater cleanup.
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 site security fence around the site and posted warning signs in 1987.
Source Control and Groundwater Cleanup: The selected remedies
chosen for this site in 1986 organized the work into two phases. Phase 1:
Source Control includes: (1) excavation of all municipal and industrial
wastes, as well as contaminated subsoils in the west fill and consolidation
with the main fill; (2) capping of the consolidated main fill area with a multi-layered cap
to prevent rainwater from washing away contaminants; (3) installation of a subsurface
drain or trench system; (4) implementation of a health and safety plan; and (5)
establishment of a monitoring program. Phase 2: Groundwater Cleanup will consist of
the following steps: workers will pump and treat, or otherwise dispose of, the area of
contaminated groundwater off site in the upper hydrologic zone of the Potomac
Formation. If disposal is called for, it will occur either on site or off site at a local
sewage treatment plant. Restrictions to prevent use of contaminated groundwater will
be applied. The EPA began designing the remedy in spring of 1988, and the parties
potentially responsible for site contamination took over responsibility for the design in
the spring of 1989. Cleanup activities are scheduled to begin in 1991.
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
Tybouts Corner Landfill site much safer while it is undergoing further cleanup activities.
38
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TYLER
REFRIGERATION
PIT
DELAWARE
EPA ID# DED980705545
REGION 3
CONGRESSIONAL DIST. 01
Kent County
Smyrna
Site Description
From 1952 to 1969, Tyler Refrigeration, located on a 3-acre parcel of land used
so vents to degreaseand clean refrigeration equipment, and dumped the'spent
S? fSSj pa1 T°°m wastes' and sludges into a 500 cubic yard unlined disposal pit 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 In
1982, the EPA detected elevated levels of three solvents in the soils Since 1977
trichloroethylene (TCE) has been detected in Smyrna's municipal wells The State'
believes that the Tyler pit is. a likely contributor to this pollution, although there may be
other sources. About 6,700 people within 3 miles of the site get their drinking water
from wells both municipal and private. Approximately 4,700 people rely on the public
water supplies; 60 homes stand within 1/4 mile of the site, with the closest being
within 300 feet. Several private wells are reported in the vicinity of the site but none
are downgmdient of the site. '
Site Responsibility:
This site is being addressed through
a combination of Federal, State, and
potentially responsible parties'
actions.
NPL LISTING HISTORY
Proposed Date: 06/01/86
Final Date: 02/21/90
A A
Threats and Contaminants
The groundwater is contaminated with volatile organic compounds (VOCs)
including TCE from former process wastes. The soil contains elevated
levels of VOCs, including toluene, dichloroethane, and TCE. Ingestion of
contaminated groundwater from the existing private wells may pose a
health threat; however, none of the wells are downgradient of the site
March 1990
NPL HAZARDOUS WASTE SITES
39
continued
-------
TYLER REFRIGERATION PIT
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 TCE 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 operate.
Groundwater: In 1990, the parties potentially responsible for the site
contamination will begin an intensive study of the groundwater
contamination at this site. This investigation will reveal the nature and
extent of the pollution and pinpoint the best cleanup strategies. It is
scheduled for completion in 1992; once completed, the EPA will select the final
remedies for cleanup of the groundwater and other contaminated areas at the Tyler
site.
Site Facts: A Consent Orcterwas signed by Clark Equipment Company in 1989 to
perform the site investigation and is awaiting signature by the EPA. The EPA is
currently negotiating Consent Orders with other potentially responsible parties.
Environmental Progress
By improving the air-stripping process and adding an activated carbon filtration unit to
its water treatment system, the town of Smyrna has eliminated TCE contamination
from municipal wells, making the public water supply safe while investigations
continue at the site.
40
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WILDCAT LANDFILL
DELAWARE
EPA ID# DED980704951
REGION 3
CONGRESSIONAL DIST. 01
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 of the84-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 site 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 Groundwater is
?°"?ted Wlth heavV metals, organics, and low levels of polychlorinated biphenyls
(POBs). Open and empty metaLdrums; tires, solid latex, and municipal trash were
scattered over the surface of the site. A 3-acre pond, which collects surface drainage
from the western half of the landfill, lies immediately west of the landfill. Monitoring of
drinking water wells in 1987 showed no contamination, but contaminant levels in
groundwater underneath and ctowngradient of the site are 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 groundwater 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 ^dressed through
Federal actions.''"
.''«- ? *i * ' " ' ' " .
NPL LISTING HISTORY
Proposed Date: 12/01/82
. Final Date: 09/01/83
II
Threats and Contaminants
The groundwater is contaminated with chlordane, methylene chloride
and xylenes. On-site leachate, surface water, soils, and sediments
contain PCBs and chlordane, a pesticide. Accidentally ingesting
contaminated groundwater, surface water, soil, sediments, contaminated
aquatic organisms or coming into direct contact with contaminated
groundwater, surface water, soil, sediments, and air may threaten the
health of people at or near the site. The State has issued a health
advisory on fish caught from the St. Jones River. The St. Jones
marshlands are threatened, and lead has been detected in snappinq
turtles on the site.
March 1990
NPL HAZARDOUS WASTE SITES
41
continued
-------
WILDCAT LANDFILL
Cleanup Approach
The site is being addressed in two long-term remedial phases focusing on source
control and pond cleanup.
Response Action Status
Source Control: Cleanup activities for this site have been separated into
two phases. The first deals with the landfill itself, and the second
addresses the 3-acre pond at the northwestern corner of the landfill. The
t-^fiH remedy selected for landfill cleanup features: (1) restricting development
of the site and preventing installation of drinking water wells on or near the site; (2)
grading, covering, and seeding on-site areas where direct risks of contact with
contaminants have been identified; (3) removing and disposing of drums; (4) replacing
two domestic wells adjacent to the site; and (5) monitoring groundwater. The
engineering design for this work was started in October 1988 and is scheduled for
completion in 1990, when cleanup activities are slated to begin, with completion
scheduled for 1992.
Pond Cleanup: The remedy for the 3-acre pond that drains the western
half of the landfill features filling in the existing pond and building a new
shallow pond southeast of the landfill. The engineering design for pond
cleanup was started in 1988 and is scheduled for completion in 1990, at
which time cleanup activities are slated to begin.
Environmental Progress
The EPA has selected the cleanup technologies for the source control and the pond
cleanup phases of the cleanup activities. The engineering designs are being completed
for both phases and the work is scheduled to begin in 1990. While these activities are
taking place, the EPA has determined that the nearby population and the environment
are not at risk.
42
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This glossary defines the italicized terms used in the site
fact sheets for the State of Delaware. The terms and
abbreviations contained in this glossary are often
defined in the context of hazardous waste management as de-
scribed in the site fact sheets, and apply specifically to work per-
formed under the Superfund program. Therefore, these terms
may have other meanings when used in a different context.
Administrative Order On Consent: A legal and enforce-
able agreement between EPA and the parties potentially
responsible for site contamination. Under the terms of
the Order, the potentially responsible parties agree to
perform or pay for site studies or cleanups. It also de-
scribes the oversight rules, responsibilities and enforce-
ment options that the government may exercise in the
event of non-compliance by potentially responsible parties. This Order is signed by
PRPs and the government; it does not require approval by a judge.
Administrative Order [Unilateral]: A legally binding document issued by EPA direct-
ing the parties potentially responsible to perform site cleanups or studies (generally,
EPA does not issue unilateral orders for site studies).
Aeration: A process that promotes breakdown of contaminants in soil or water by
exposing them to air.
Air Stripping: A process whereby volatile organic chemicals (VOCs) are removed from
contaminated material by forcing a stream of air through it in a pressurized vessel. The
contaminants are evaporated into the air stream. The air may be further treated before
it is released into the atmosphere.
Ambient Air: Any unconfined part of the atmosphere. Refers to the air that may be
inhaled by workers or residents in the vicinity of contaminated air sources.
Aquifer: An underground layer of rock, sand, or gravel capable of storing water within
cracks and pore spaces, or between grains. When water contained within an aquifer is
of sufficient quantity and quality, it can be tapped and used for drinking or other pur-
poses. The water contained in the aquifer is called groundwater.
Artesian (Well): A well made by drilling into the earth until water is reached which,
from internal pressure, flows up like a fountain.
G-l
-------
Backfill: To refill an excavated area with removed earth; or the material itself that is
used to refill an excavated area.
Berm: A ledge, wall, or a mound of earth used to prevent the migration of contami-
nants. , -;
Bioaccumulate: The process by which some contaminants or toxic chemicals gradually
collect and increase in concentration in living tissue, such as in plants, fish, or people as
they breathe contaminated air, drink contaminated water, or eat contaminated food.
Cap- A layer of material, such as day or a synthetic material, used to prevent rainwater
from penetrating and spreading contaminated materials. The surface of the cap is
generally mounded or sloped so water will drain off.
Carbon Disulfide: A degreasing agent formerly used extensively for parts washing.
This compound has both inorganic and organic properties, which increase cleaning
efficiency. However, these properties also cause chemical reactions that increase its
hazard to human health and the environment.
Closure: The process by which a landfill stops accepting wastes and is shut down
under Federal guidelines that ensure the public .and the environment is protected.
Consent Decree: A legal document, approved and issued by a judge, formalizing an
agreement between EPA and the parties potentially responsible tor site contamination.
The decree describes cleanup actions that the potentially responsible parties are re-
quired to perform and/or the costs incurred by the, government that the parties will
reimburse, as well as the roles, responsibilities, and enforcement options that the gov-
ernment may exercise in the event of non-compliance by potentially responsible parties.
If a settlement between EPA and a potentially responsible party includes cleanup ac-
tions, it must be in the form of a consent decree. A consent decree is subject to a public
comment period.
Consent Order: [see Administrative Order on Cpnsent]..
Creosotes: Chemicals used in wood preserving operations and produced by distillation
of tar, including polycyclic aromatic hydrocarbons and polynuclear aromatic hydrocar-
bons [see PAHs and PNAs]. Contaminating sediments, soils, and surface water, creo-
sotes may cause skin ulcerations and cancer with prolonged exposure.
Degrease: To remove grease from wastes, soils; or'chemicals, usually using solvents.
Downgradient: A downward hydrologic slope that causes groundwater to move
toward lower elevations. Therefore, wells dawrigradient of a contaminated groundwater
source are prone to receiving pollutants.
G-2
-------
Effluent: Wastewater, treated or untreated, that flows out of a treatment plant, sewer,
or industrial outfall. Generally refers to wastes discharged into surface waters.
Gasification (coal): The conversion of soft coal into gas for use as a fuel.
Installation Restoration Program: The specially funded program established in 1978
under which the Department of Defense has been identifying and evaluating its hazard-
ous waste sites and controlling the migration of hazardous contaminants from those
sites.
Interagency Agreement: A written agreement between EPA and a Federal agency that
has the lead for site cleanup activities (e.g. the Department of Defense), that sets forth
the roles and responsibilities of the agencies for performing and overseeing the activi-
ties. States are often parties to interagency agreements.
Lagoon: A shallow pond where sunlight, bacterialaction, and oxygen work to purify
wastewater. Lagoons are typically used for the storage of wastewaters, sludges, liquid
wastes, or spent nuclear fuel.
Landfill: A disposal facility where waste is placed in or on land.
Leachate [n]: The liquid that trickles through or drains from waste, carrying soluble
components from the waste. Leach, Leaching [v.t.]: The process by which soluble
chemical components are dissolved and carried through soil by water or some other
percolating liquid.
Long-term Remedial Phase: Distinct, often incremental, steps that are taken to solve
site pollution problems. Depending on the complexity, site cleanup activities can be
separated into a number of these phases.
Migration: The movement of oil, gas, contaminants, water, or other liquids through
porous and permeable rock.
Overpacking: Process used for isolating large volumes of waste by jacketing or encap-
sulating waste to prevent further spread or leakage of contaminating materials. Leak-
ing drums may be contained within oversized barrels as an interim measure prior to
removal and final disposal.
Pentachlorophenol (PCP): A synthetic, modified petrochemical that is used as a wood
preservative because of its toxicity to termites and fungi. It is a common component of
creosotes and can cause cancer.
Plume: A body of contaminated groundwater flowing from a specific source. The
movement of the groundwater is influenced by such factors as local groundwater flow
G-3
-------
s~, ,">''-wS
GLOSSARY
patterns, the character of the aquifer in which groundwater is contained, and the den-
sity of contaminants.
Polycyclic Aromatic Hydrocarbons or Polyaromatic Hydrocarbons (PAHs): PAHs,
such as pyrene, are a group of highly reactive organic compounds found in motor oil.
They are a common component of creosotes and can cause cancer.
Polychlorinated Biphenyls (PCBs): A group of toxic chemicals used for a variety of
purposes including electrical applications, carbonless copy paper, adhesives, hydraulic
fluids, microscope emersion oils, and caulking compounds. PCBs are also produced in
certain combustion processes. PCBs are extremely persistent in the environment be-
cause they are very stable, non-reactive, and highly heat resistant. Burning them pro-
duces even more toxins. Chronic exposure to PCBs is believed to cause liver damage. It
is also known to bioaccumulate in fatty tissues. PCB use and sale was banned in 1979
with the passage of the Toxic Substances Control Act.
Polynuclear Aromatic Hydrocarbons (PNAs): PNAs, such as naphthalene, and biphen-
yls, are a group of highly reactive organic compounds that are a common component of
creosotes, which can be carcinogenic.
Polyvinyl Chloride (PVC): A plastic made from the gaseous substance vinyl chloride.
PVC is used to make pipes, records, raincoats, and floor tiles. Health risks from high
concentrations of vinyl chloride include liver cancer and lung cancer, as well as cancer
of the lymphatic and nervous systems.
Potentially Responsible Parties (PRPs): Parties, including owners, who may have
contributed to the contamination at a Superfund site and may be liable for costs of
response actions. Parties are considered PRPs until they admit liability or a court makes
a determination of liability. This means that PRPs may sign a consent decree or admin-
istrative order on consent [see Administrative Order on Consent] to participate in site
cleanup activity without admitting liability.
Runoff: The discharge of water over land into surface water. It can carry pollutants
from the air and land into receiving waters.
Sediment: The layer of soil, sand and minerals at the bottom of surface waters, such as
streams, lakes, and rivers that absorb contaminants.
Sludge: Semi-solid residues from industrial or water treatment processes that may be
contaminated with hazardous materials.
Sumps: A pit or tank that catches liquid runoff for drainage or disposal.
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Trichloroethylene (TCE): A stable, colorless liquid with a low boiling point. TCE has
many industrial applications, including use as a solvent and as a metal degreasing
agent. TCE may be toxic to people when inhaled, ingested, or through skin contact and
can damage vital organs, especially the liver [see also Volatile Organic Compounds].
Upgradient: An upward slope; demarks areas that are higher than contaminated areas
and, therefore, are not prone to contamination by the movement of polluted ground wa-
ter.
Volatile Organic Compounds (VOCs): VOCs are made as secondary petrochemicals.
They include light alcohols, acetone, trichloroethylene, perchloroethylene, dichloroeth-
ylene, benzene, vinyl chloride, toluene, and methylene chloride. These potentially toxic
chemicals are used as solvents, degreasers, paints, thinners, and fuels. Because of their
volatile nature, they readily evaporate into the air, increasing the potential exposure to
humans. Due to their low water solubility, environmental persistence, and widespread
industrial use, they are commonly found in soil and groundwater,
Wetland: An area that is regularly saturated by surface or groundwater and, under
normal circumstances, capable of supporting vegetation typically adapted for life in
saturated soil conditions. Wetlands are critical to sustaining many species of fish and
wildlife. Wetlands generally include swamps, marshes, and bogs. Wetlands may be
either coastal or inland. Coastal wetlands have salt or brackish (a mixture of salt and
fresh) water, and most have tides, while inland wetlands are non-tidal and freshwater.
Coastal wetlands are an integral component of estuaries.
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