United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R03-91/121
September 1991
Superfund
Record of Decision
Sealand Limited, DE
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50272-101
REPORT DOCUMENTATION i. REPORT NO. 2.
PAGE EPA/ROD/R03-91/121
4. TrUe and SuMMe
SUPERFUND RECORD OF DECISION
Sea land Limited, DE
First Remedial Action - Final
7. AlflhorW
9, MBrfoiniinQ OFQsinlzktion ratine And Adoicss
12. Sponsoring Organization (tone «nd Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
3. Redpienfs Accession No.
5. Report Date
09/30/91
&
8. Performing Organization Rept No.
ia Proiect/Tssk/Work Unit No.
11. Contmct(O or Gr«nt(G) No.
(C)
(G)
13. Type of Report & Period Covered
800/000
14.
15. Suppleinentiry Notes
16. Abstract (Umrt: 200 words)
The 2-acre Sealand Limited site, a former coal tar treatment and recycling facility,
is located in Mt. Pleasant, New Castle County, Delaware. Land use in the area is
primarily industrial and commercial. Current site features include a concrete slab,
a one-story building, an abandoned rail spur, a gravel road, and miscellaneous
debris. Ground water underlying the site is used as a source of drinking water.
From 1971 until 1976, Adams Laboratory used the site for animal fat rendering
activities. The property was subsequently sold to Conrail, which cleaned up the
property to meet State standards in 1979. From 1982 to 1983-, Conrail leased the
property to Sealand. Sealand allegedly conducted treatment, processing, and
recycling of coal to tar and off- specification creosote wastes onsite until
abandoning the site in 1983. A 1983 State investigation discovered 21 steel tanks
or hoppers; a 10,000-gallon wooden storage tank and 300 55-gallon steel drums, which
were leaking liquids onsite; a boiler house; and various mixing chambers and
pressure vessels on the abandoned site. Additional studies by EPA and the State
identified organics including PAHs, creosols, and solvents in the onsite soil,
drums, and tanks. Subsequently in 1983, EPA conducted an emergency removal action
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - Sealand Limited,
First Remedial Action - Final
Contaminated Medium: None
Key Contaminants: None
b. Icfentrffcrs/Open-ErKM Terms
DE
c. COSATI Reid/Group
18. Avsilabifty Statement
19. Security Class (This Report)
None
20. Security Class (This Page)
None
21. No. of Pages
32
22. Price
(SeeANSI-Z39.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R03-91/121
Sealand Limited, DE
First Remedial Action -. Final
Abstract (Continued)
at the site and removed offsite 240,000 gallons of organic wastes from within the
wooden and steel tanks, and 320 drums. Additionally, EPA disposed of 122 cubic yards
of solid waste, including 30 cubic yards of wooden tank debris and approximately 50 to
92 cubic yards of sludge and contaminated material offsite. The owner voluntarily
removed 239 drums of off-specification product. In addition, the storage tanks were
cleaned and moved, and the tank and drum storage area was capped with clay. This
Record of Decision (ROD) addresses onsite soil as the first and final operable unit
(OU1). All hazardous materials contained in abandoned onsite tanks and drums were
disposed of offsite during the EPA removal action, and any remaining soil contaminants
pose low risks for humans at the site. Based on this rationale, there are no primary
contaminants of concern affecting this site.
The selected remedial action for this site is no action. There are no costs associated
with this no action remedy.
PERFORMANCE STANDARDS OR GOALS: Not applicable.
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United States Environmental Protection Agency - Region III
Superfund Program . __
Record of Decision
Sealand Limited Site
Mt. Pleasant, Delaware
September 1991
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Table of Contents
DECLARATION l
DECISION SUMMARY
1. Site Name, Location, and Description 2
2. Site History and Enforcement Activities .... 2
3. Highlights of Community Participation 4
4. Scope and Role of the Response Action
Within Site Strategy . 4
5. Summary of Site Characteristics 5
6. Summary of Site Risks 8
7. Description of the No Action Alternative .... 12
8. Documentation of No Significant Change 13
RESPONSIVENESS SUMMARY . 14
Figures and Tables follow text
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RECORD OF DECISION
SEALAND LIMITED SITE
' DECLARATION
SITE NAME AND LOCATION
Sealand Limited Site
Mt. Pleasant, Delaware
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for the
Sealand Limited Site, in Mt. Pleasant, Delaware, which was chosen in
accordance with the requirements of the Comprehensive Environmental
Response, Compensation, and Liability Act of 1980 (CERCLA), as
amended by the Superfund Amendments and Reauthorization Act of 1986
(SARA) and, to the extent practicable, the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP). This
decision document explains the factual and legal basis for selecting
the remedy for this Site.
The Delaware Department of Natural Resources and Environmental
Control has not yet concurred with the selected remedy. The
information supporting this remedial action decision is contained in
the Administrative Record for this Site.
DESCRIPTION OF THE SELECTED REMEDY
The selected remedy for the Sealand Limited Site is No Action.
Under this alternative, no further action will be taken at the site.
Although not required by EPA policy or guidance, a review of the
condition of the Site will be conducted in five years to verify that
no unacceptable hazards are posed by conditions which then exist at
the Site.
DECLARATION STATEMENT
Emergency removal activities that were taken at the Site were
sufficient to mitigate threats posed by the Site to human health and
the environment. Therefore, no further action is necessary to
ensure protection of human health and the environment.
Edwin B. Erickson Date
Regional Administrator
Region III
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DECISION SUMMARY
1. Site Name. Location, and Description
The Sealand Limited, Inc. Site (Site) is located in Mt.
Pleasant, New Castle County, Delaware, several hundred feet east of
the intersection of Routes 896 and 71/301 (Figure 1). The
Chesapeake and Delaware Canal is approximately 2 miles north of the
Site. The Site property is approximately 2 acres in size and is
currently owned by the Consolidated Railroad Corporation (Conrail).
The Site is rectangular in shape and is bordered on the west by an
active Conrail track and on the north and east by a 15-acre parcel
of land owned by Tilcon Minerals, Inc. On the south, the Site is
bordered by Routes 71/301. Private residences and light industrial
and commercial establishments are also located to the south and west
of the Site.
The Site is presently inactive and unoccupied following an U.S.
Environmental Protection Agency (EPA) Emergency Removal Action
conducted in late 1983 and early 1984. Current Site features
include a concrete slab, a one-story building, an abandoned rail
spur, a gravel road, and miscellaneous debris. A one to three foot
thick clay cap which was placed over the process area following the
removal action is intact and well vegetated. Shallow ground water
flows in a north- northeasterly direction, toward Joy Run, a stream
located 1000 feet north of the Site. Ground water is used as a
source for domestic water supplies. The nearest residences are less
than 500 feet from the site.
2. Site History and Enforcement Activities
According to EPA records, industrial activity at the Site began
in 1971 when Adams Laboratory operated an animal fat rendering plant
on the property. Sometime prior to 1976, Adams Laboratory ceased
operations at the facility. In 1976, Conrail acquired the property.
A contractor hired by Conrail cleaned up the Site to the Delaware
Department of Natural Resources and Environmental Control's
(DNREC's) satisfaction in 1979.
In August 1982, Conrail leased the Site to Sealand Ltd. for the
stated purpose of waste oil recycling. The Site was operated by
Sealand Ltd. from August 1982 until August 1983. During that
period, the operations consisted of the treatment and/or processing
of coal tars and other similar materials referred to as No. 4 and
No. 6 oiL»,,oil/gas tar, off-spec creosote, ink oil waste, and oil
cuff (an oil and water mixture). The operators allegedly accepted
the various materials, separated the water, and transferred the
liquid materials by tank truck to Burke-Parsons-Bowlby Corporation.
Sealand Ltd. abandoned the Site in August 1983. At that time,
the Site contained 21 steel tanks or hoppers, one 10,000-gallon
wooden storage tank, approximately 300 55-gallon steel drums, a
boiler house, and various mixing chambers and pressure vessels. An
investigation of the Site conducted by the DNREC concluded that the
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wooden storage tank and numerous 55-gallon drums were leaking their
contents onto the ground surface. The observed leaking liquids were
described by DNREC representatives as black, viscous, tar-like
substances. .Laboratory analysis of samples collected in October
1983 by the DNREC and EPA from tanks, drums, and soils reported the
presence of polynuclear aromatic organic compounds, creosols,
solvents, and other organic compounds.
In December 1983, EPA initiated an Emergency Removal Action
under the Comprehensive Environmental Response, Compensation and
Liability Act (CERCLA). The action consisted of the removal of
240,000 gallons of coal tar which had been contained in the wooden
and steel tanks, 320 drums, and approximately 122 cubic yards of
solid waste. The solid waste consisted of 30 cubic yards of the
wooden tank debris and anywhere from 50 to 92 cubic yards of sludge
and contaminated material. Parboil Company voluntarily removed 239
drums of off-spec product (EPA OSC report mentions two quantities,
238 and 239) from the site in December 1983. In addition, storage
tanks were cleaned and moved, and the tank and drum storage area was
capped with clay. The extent of the capped area is shown in Figure
2.
None of the potentially contaminated soil located within the
storage tank area was removed from the Site. Soil from the
excavation of an L-shaped trench along the southern and western
boundaries of the storage tank area was also left onsite within the
subsequently capped former tank area. According to EPA records, the
trench was constructed along the railroad side of the Site to aid in
minimizing any horizontal movement of contaminants. The trench was
filled with clay, and it and soil within the storage tank area were
then covered with l foot of clay and 6 inches of topsoil. Six
groundwater monitoring wells were also installed during the
Emergency Removal Action. Available information indicates that
there were two wells existing onsite prior to the emergency action.
The removal action was concluded in June 1984.
The following is a chronology of EPA and DNREC regulatory
actions with regard to the Sealand Ltd. operations:
- August 1983: DNREC site visit following abandonment of
Sealand Ltd. operations
- September 1983: DNREC request to EPA to perform CERCLA
preliminary assessment
- September 1983: EPA performs visual site inspection
- October 1983: EPA site assessment
- November 1983 to June 1984: EPA Emergency Removal Action
- August 20, 1985: Civil Compliant filed by the United States,
U.S. v. Consolidated Rail Corporation, et al.. Civil No. 85-502
MMS, pursuant to Sections 104 and 107 of CERCLA.
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- September 2, 1986: Amended Civil Complaint filed by the
United States in U.S. v. Consolidated Rail Corporation, et al..
Civil No 85-502 MMS, pursuant to Sections 104 and 107 of
CERCLA. •— - --
- June 28, 1988: Sealand Limited Site proposed for National
Priorities List (NPL)
- December 30, 1988: EPA and Sealand Respondents - National
Industrial Services, Inc; Coopers Creek Chemical Corp.; Casie
Ecology Oil Salvage Co., Inc.; The Times Journal Company;
Parboil Company; Philadelphia Gas Works; Consolidated Rail
Corporation; Public Service Electric and Gas Company; Chem
Clear, Inc.; Koppers Co., Inc.; Globe Newspaper Company; The
Washington Post Company; Penn Fuel Gas, Inc.; USX - sign
Administrative Order on Consent for RI/FS (Docket No.
111-89-08-DC).
- January 30, 1990: EPA and Sealand Respondents enter into a
Partial Consent Decree for Response Costs (Civil No. 85-502
MMS) .
- August 30, 1990 Sealand Limited formally added to NPL
3. Highlights of community Participation
The RI/FS Report and the Proposed Plan for the Sealand, Limited
Site were released to the public for comment on July 26, 1991. In
accordance with Section 117(a) of the Comprehensive Environmental
Response, Compensation and Liability Act (CERCLA) of 1980, as
amended by the Superfund Amendments and Reauthorization Act of 1986,
these two documents were made available to the public in the
Administrative Record maintained at the EPA Docket Room in Region
III, at the Middletown Public Library, and at Townsend's, Inc. in
Mt. Pleasant, Delaware. The notice of availability of these two
documents was published in the Wilmington News Journal on July 26,
1991. A public comment period on the documents was held from July
26, 1991 to August 24, 1991. In addition, a public meeting was held
on August 6, 1991. At this meeting, representatives from EPA and
the DNREC answered questions about conditions at the site and the
remedial alternative under consideration. A response to the
comments received during this period is included in the
Responsiveness Summary, which is part of this ROD.
4. Scope and Role of the Response Action Within Site Strategy
EPA first identified the need to take action at the Site
following the abandonment of the recycling operation. EPA then
conducted the emergency removal described in the Site History
section of the Decisio" snirnnayy. Following the completion of the
removal action, the site was listed on the National Priorities List,
and an Remedial Investigation (RI) was undertaken by a group of
PRPs. Upon reviewing the RI report and the Site risk assessment,
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EPA has determined that the Site does not pose a threat to human
health and the environment, and that no further action is required.
5. Simrmarv #f- Site Characteristics
The Site is located within the Coastal Plain Physiographic
Province which is characterized as a series of unconsolidated or
partially consolidated sands, gravels, silts, and clays. These
sediments form a wedge which dips and thickens to the southeast.
According to Sundstrom and Pickett (1971), the thickness of the
coastal plain sediments is approximately 700 feet in the vicinity of
the Site. The geologic formations in the vicinity of the Site are,
from youngest to oldest: Columbia, Mt. Laurel, Marshalltown,
English town, and Merchantville Formations. The Pliestocene Columbia
Formation occurs as a thin cover over the majority of the area in
the vicinity of the Site.
The vadose zone at the Site is comprised of sediments of the
Columbia Formation. The Columbia Formation consists primarily of
unconsolidated brown, fine to coarse (0.1 to 1.0 mm), subround,
moderately to poorly sorted sand. Minor components include silt and
fine gravel. In some areas, the vadose zone sediments consist of
fill containing trace amounts of coal and/or cinders which may be
attributable to the adjacent rail lines. These minor constituents
caused the sediments to appear grey to dark grey. The vadose zone
was generally 4 to 5 feet thick onsite.
The aquifer beneath the Site consists of the Columbia, Mt.
Laurel, Marshalltown, and additional underlying formations. These
formations are generally hydraulically interconnected and are
usually referred to as the water table aquifer. No laterally
continuous confining layers are in evidence within the depth
encountered by onsite wells. This indicates that there are no
confining layers separating the water table aquifer from deeper
water bearing zones. However, the Marshalltown Formation,
encountered at approximately 93 feet below grade, contains
significant amounts of fine grained materials (silt and clay) which
would impede groundwater flow and is thus considered an aquitard in
this setting. Sundstrom and Pickett (1971) do not consider the
Marshalltown Formation to be an aquifer and it is not generally
mapped as such. For the purpose of the Remedial Investigation (RI),
the water table aquifer was considered to extend from the surface of
the water table to a depth of 93 feet below grade.
Grou»dwater movement at the Site has a downward component of
flow indicating that the Site is in a groundwater recharge area.
Flow is considered to move toward Joy Run northeast of the Site and
regionally to the C & D Canal approximately 2 miles north of the
Site. The nearest downgradient residential well is located on the
opposite side of Joy Run; the nearest commercial well is located
approximately 200 feet east of the site.
As part of the RI, onsite soil samples were collected in March
and June 1990 to delineate the horizontal and vertical extent of
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soil contamination. Soil samples were collected from eight
locations within the former drum and storage tank area, four other
onsite areas and one additional soil sample location adjacent to the
east side of^the concrete pad. In one boring, no sample was
collected because no sample interval of unsaturated soil was present
between the clay cap and the top of the water table.
A total of 24 soil samples were submitted for laboratory
analyses, including three field duplicate samples. Table 1
represents a statistical summary and frequency of detection for the
RI soils analytical data. The distribution of compounds detected
onsite is presented in Figure 3. All analytical data and
accompanying documentation is contained in the RI report.
Twenty-three soil samples were analyzed for volatile organic
compounds (VOCs). VOCs were found in onsite soil samples in
concentrations ranging from non-detect to 220 ug/kg (parts per
billion). Methylene chloride was found in all 23 soil samples
(5-220 ug/kg); however, this compound was found to be a laboratory
contaminant in all but one of the samples analyzed for VOC. Acetone
was found in 20 of 23 soil samples (5-220 ug/kg); however, all but
one of these contain data validation qualifiers. Benzene was found
in 1 of 23 samples (4 ug/kg). 2-Hexanone was found in 1 of 23
samples (110 ug/kg). Many of the values reported for individual
VOCs were estimated values below the detection limit established for
the compound in question. These estimated values were considered
detected in this discussion of results.
Semivolatile organic compounds were found in onsite soil
samples at concentrations ranging from non-detect to 23,000 ug/kg.
Of the 24 Target Compound List (TCL) list semivolatile organic
compounds, all 24 were found in at least one sample and 22 were
found in at least three samples. The compounds found most
frequently and at the highest concentrations include naphthalene (8
of 24 samples, with the highest concentration of 20,000 ug/kg),
2-Methylnapthalene (8 of 24 samples, up to 14,000 ug/kg),
phenanthrene (11 of 24 samples, up to 22,000 ug/kg), fluoranthene (9
of 24 samples, up to 23,000 ug/kg), pyrene (10 of 24 samples, up to
22,000 ug/kg), and other isomers of fluoranthene and pyrenes ranging
up to 20,000 ug/kg. The highest concentrations of semivolatile
organic compounds were seen in the borings that had been completed
below the clay cap. Total semivolatile organic compound
concentrations of up to 169,840 ug/kg were detected between the clay
cap and the water table.
Of tEi~19 metals analyzed, only antimony was absent from any of
the samples. Cyanide was detected in two samples at 0.59 and 1.6
mg/kg. Figure 3 shows the distribution of several metals in onsite
soil samples. Arsenic is present at concentrations ranging from
non-detect to 9.0 mg/kg. Chromium was present in all samples at
concentrations ranging from 9.6 to 58.4 mg/kg. The horizontal
distribution of chromium appears to be random. The concentrations
of chromium appear slightly lower in the deeper samples than in the
shallow samples. Lead was present in onsite soil samples in
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concentrations ranging from 6.1 to 100 mg/kg. Lead was present in
all samples. In a majority of samples the concentration of lead was
lower in the deeper samples than in the shallow samples. No
horizontal distribution pattern is evident. Mercury was present in
15 of 18 samples in concentrations ranging from non-detect to 3.9
mg/kg.
Table 2 presents a statistical summary and frequency of
detection for groundwater analytical data. The distribution of
selected compounds detected is presented in Figure 4. All
analytical data and accompanying documentation is contained in the
RI report.
Two samples showed the presence of VOCs above the level at
which they could be quantified by laboratory equipment. Methylene
chloride was detected in a sample from an offsite well at 11.0 ug/1
and acetone in a sample from an onsite well at 10.0 ug/1. Acetone
was present in the Trip Blank for April 26 at a concentration of 210
ug/1. Methylene chloride was present in the Trip Blank for April 27
at l.O ug/1. No other well water samples showed the presence of
VOCs. Therefore, it seems likely that the presence of methylene
chloride and acetone in ground water is indicative of laboratory
contamination rather than of their presence in onsite or offsite
wells.
Few semivolatile organic compounds were detected in groundwater
samples. Bis(2-ethylhexyl) phthalate was detected at an estimated
concentration of 2.0 ug/1 in one offsite well sample. Naphthalene
was detected at estimated concentrations of 4.0 ug/1 in two onsite
well samples. No other well samples showed the presence of
semivolatile organic compounds.
Twenty metals plus cyanide were analyzed in filtered and
unfiltered groundwater samples from offsite and onsite wells. The
presence of beryllium, cobalt, copper, silver, and zinc in some of
the filtered and unfiltered samples was questioned during data
validation because the level at which they were detected was below
the detection limit used during analysis. Of the 20 metals tested,
only antimony, barium, beryllium, chromium and mercury were not
present above their respective detection limits in any sample.
Cyanide was detected in filtered samples at 25.7 ug/1 and 19.5 ug/1.
Cyanide was also detected a number of unfiltered samples. Figure
4 shows the distribution of several metals and cyanide in both
onsite and offsite monitoring wells. Iron is present at
concentrations ranging from non-detect to 45,000 ug/1. Manganese
was present in all samples at concentration ranging from 17.8 to
6,360 ug/1. The distribution of nickel appears to be limited to
onsite wells only. The concentrations of nickel ranged from
non-detect to 789 ug/1.
A review of the compounds detected during the soil and
groundwater investigations indicates that the chemicals of potential
concern are the semivolatile organic compounds, including
polynuclear aromatic hydrocarbons (PAHs), and two metals, nickel and
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mercury in soil. The remaining compounds in soil and all the
compounds in groundwater were detected at low frequencies and
concentrations, at isolated locations, or at concentrations within
the range of .background. PAHs tend to bind to soil material and
generally do not contaminate the groundwater.
The most likely potential receptors under current site
conditions are children exposed to shallow soils while trespassing
on the Site; under a potential future use scenario, potential
receptors are workers that may be exposed to soil during
construction activities. The exposure pathways include ingestion of
soil and dermal absorption of contaminants. The presence of the
clay cap currently restricts access to Site contaminants by
trespassers. However, construction workers would be exposed to the
relatively higher levels of contamination present in the subsurface
soil.
The nearest surface water, Joy Run, is located 1,000 to 1,500
feet north of the Site. Soil within the former tank area is capped
so there is no source of surface contamination to the stream. There
is no visible evidence of intrusive activities or disturbance to the
cap. There are currently other sources of surface runoff
contamination from a former asphalt manufacturing facility,
including several tar spills and an abandoned tank trailer, which
are between the Site and Joy Run.. A dump area (which consists
mainly of discarded highway materials) located on the banks of Joy
Run is another potential source of contaminated subsurface water.
These areas were not evaluated during the RI as they are not a part
of the Site.
6. Summary of Site Risks
The risk assessment for the Sealand Site was conducted in
accordance with EPA protocols. The risk assessment first evaluated
the chemicals found in the soil and groundwater at the Site and
determined which Site-related chemicals are a potential concern to
human health and the environment. Next, it considered whether
humans or the environment are currently exposed to these chemicals
or will be at some time in the future. In the final step, the
concentrations of the chemicals at the point of exposure were used
to estimate the potential for an adverse effect on human health or
the environment.
The chemicals of potential concern for the risk assessment
included Jill semivolatile organic compounds and two inorganics,
nickel and* mercury, in the soil. The selection of semivolatile
organics is supported by the analytical data collected during
previous investigations and the history of Site operations. The
metals are included based on their frequency of detection at
concentrations above background. In soil, the eight volatile
organic compounds detected have low frequency of detection and
distribution. The inorganic parameters, with the exception of
nickel and mercury, are within the range of background, or appear to
be isolated occurrences unrelated to activities which took place at
8
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the Site. No chemicals of potential concern were identified in
groundwater samples. The volatile and semivolatile detections were
low in frequency and concentration and the inorganic parameters are
within Site-related background concentrations.
The potential receptors, both current and future, were
evaluated. For current exposure, the most likely potential
receptors are children exposed to shallow surface soils while
trespassing on the Site on an infrequent basis. For the future use
of the Site, the potential receptors are workers that may be exposed
to soil from all depths during construction activities.
Observations during the remedial investigation and evidence of Site
use support an exposure pathway of trespassers, particularly
children.
There are low density private residential areas located to the
east of the Site. Private residences and light industrial and
commercial establishments are located to the south and west of the
Site. Bordering the Site to the north, a 15-acre parcel of land
owned by Tilcon Mineral Inc. contains miscellaneous equipment and
debris. There is no evidence of consistent use of the Site such as
dirt bike trails to suggest that children from the nearby residences
play at the site on a regular basis. There is evidence, however,
that pre-teenage children are potentially exposed while walking
along the active railroad bed. Although there is no evidence that
these children actively play on the Site, the risk assessment was
based on a worst case assumption that there is regular use of the
Site by area children.
A future use scenario was developed considering exposure by
workers during construction of a manufacturing facility. The Site
is zoned for manufacturing uses only. The zoning cannot be changed
to residential because a 60-foot frontage is required for
residential use and the Sealand property has only 57 feet of
frontage. Property to the east of the Site is also zoned for
manufacturing use. The active railroad bordering one side of the
Site significantly reduces the likelihood that the Site will be
developed for residential use.
Exposure pathways include all the various ways in which humans
may come in contact with the chemicals of potential concern, either
currently or at some time in the future. Identification of exposure
pathways is developed from a fate and transport evaluation followed
by an analysis of the likelihood that human or environmental
receptors—will contact the chemicals and the way in which any
potential contact may occur. The fate and transport evaluation
considers the properties of the chemicals of potential concern, the
media in which the chemicals are found, and the likelihood that the
chemicals will persist and/or migrate to other media.
The focus of the fate and transport study was polynuclear
aromatic hydrocarbons (PAHs) in soil because these chemicals
comprise 17 of the 26 chemicals of potential concern. PAHs, which
are mixtures of organic chemicals made up of benzene rings, are
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by-products of the incomplete combustion of organic material.
Although combustion of petroleum products represents a major source
of PAHs in the environment, combustion of any organic material
including wood,- coal,- charcoal and even garbage can result in ash
and smoke containing PAHs.
The chemical properties of individual PAH compounds, in
particular their solubility in water, depend on the number of
benzene rings. Chemicals with few benzene rings (such as
naphthalene with two rings) tend to be the most water soluble,
mobile in the groundwater and also susceptible to degradation by
bacteria. They are also less toxic than the higher weight PAHs.
PAHs with higher numbers of benzene rings (such as benzo(a)pyrene
with five rings) tend to remain strongly bound to soil particles,
especially particles high in organic content, and are highly
water-insoluble. These higher weight PAHs are also more persistent
and are degraded slowly by bacteria.
Because chemicals of potential concern were not detected in
Site ground water, the soil represents the only exposure pathway for
these chemicals. The media of concern is soil and the chemicals of
potential concern are all the semivolatile organic chemicals
detected and nickel and mercury. The exposure pathways identified
are (1) ingestion of soil and (2) dermal absorption of contaminants.
In risk assessment, it is seldom possible to measure a specific
dosage for each identified exposure pathway. As a result, it is
necessary to estimate the dose based upon a series of assumptions
such as how much soil the average person ingests. These assumptions
were developed from the most current Superfund Risk Assessment
Guidance documents. The assumptions used in calculating the exposure
for each pathway are presented in Table 3.
In order to estimate the excess lifetime cancer risk associated
with exposure to potentially carcinogenic chemicals, cancer potency
factors (CPFs) have been developed by EPA's Carcinogenic Review and
Verification Endeavor (CRAVE) Workgroup. CPFs are expressed in
units of (mg/kg-day) ~l and are multiplied by the estimated intake of
a potential carcinogen (expressed in mg/kg-day). This calculation
provides an upper-bound estimate of the excess lifetime cancer risk
associated with exposure at that intake level. Cancer potency
factors are derived from the results of human epidemiological
studies or chronic animal experiments to which animal-to-human
extrapolation and uncertainty factors have been applied.
The .jsarcinogenicity of some PAHs has been known to the
scientific community since the late 1800's and a large database has
been developed regarding the mechanism of action of those PAHs which
are or appear to be carcinogens. In this regard, the EPA has
performed a study which is based on a biological model of cancer and
calculates a best estimate of the CPF for the most well known
10
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carcinogenic PAH, benzo(a)pyrene1. In addition, this study
developed CPFs for other carcinogenic PAHs, and based these values
on a comparison of their toxicities to the toxicity of
benzo(a)pyrene~. This.approach is in accordance with EPA's policy of
utilizing best science to develop risk estimates. Region III has
adopted this practice to support the risk assessment for this Site.
Excess lifetime cancer risks are determined by multiplying the
intake level with the cancer potency factor. These risks are
probabilities that are generally expressed in scientific notation
(e.g., 1 x 10~6 or 1E-6). An excess lifetime cancer risk of l x 10~6
indicates that, as a plausible upper bound, an individual has a one
in one million chance of developing cancer as a result of site-
related exposure to a carcinogen over a 70-year lifetime under the
specific exposure conditions at a site.
The cancer risk associated with each contaminant of concern in
each exposure pathway for both current and future use scenarios are
shown in Tables 4 and 5. For the sum of the current exposure
scenarios, the cancer risk associated with trespassing on the Site
is 3 x 10~7. Under the future use scenario, the cancer risk is 1
x 10~7. These risk levels are below the 1 x 10~4 to 1 x 10"6 risk
range that EPA believes to represent acceptable risk. Therefore,
the Site does not pose an unacceptable cancer risk to exposed
individuals.
Reference doses (RfDs) have been developed by EPA for
indicating the potential for adverse health effects from exposure to
chemicals exhibiting noncarcinogenic effects. RfOs, which are
expressed in units of mg/kg-day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals, that
are not likely to result in an appreciable risk of adverse health
effects. Estimated intakes of chemicals from environmental media
(e.g., the amount of a chemical ingested from contaminated drinking
water) can be compared to the RfD. RfDs are derived from human
epidemiological studies or animal studies to which uncertainty
factors have been applied (e.g., to account for the use of animal
data to predict effects on humans). These uncertainty factors help
ensure that the RfDs will not underestimate the potential for
adverse noncarcinogenic effects to occur.
The numerical value used to evaluate noncarcinogenic risk is
the Hazard Index (HI). The HI is the ratio of the exposure dose to
the RfD and is calculated by dividing dose (chronic daily intake or
GDI) by tbs RfD. The HI is not strictly an estimate of the risk,
but a number which compares GDI to a level considered to have
limited potential for lifetime health effects. Hence, HI values
greater than 1 indicate that exposure exceeded the acceptable daily
1 Comparative potency approach for estimating the cancer
risk associated with exposure to mixtures of polycyclic aromatic
hydrocarbons (1988), Interim Final Report, Contract No. 68-02-
4403, ICF-Clement Assoc., Fairfax, VA.
11
-------
level while HI values less than 1 show that exposure is lower.
Similar to cancer risks, the HI values for each chemical are
added together_£o assess the overall potential for noncarcinogenic
effects. This approach was developed by EPA based on the assumption
that simultaneous exposures to numerous chemical compounds can
result in an adverse health effect. Tables 6 and 7 present the HI
associated with each chemical and pathway for the current and future
use scenarios. The maximum HI values for all chemicals for
ingestion and dermal contact added together, 0.007 for current use
and 0.006 for future use, are more than 2 orders of magnitude below
the trigger HI value of 1. Therefore, potential noncarcinogenic
health effects for all pathways under current and future use
conditions are expected to be negligible.
Areas that represent some uncertainty in the risk assessment
include carcinogenic and non-carcinogenic effects of chemicals in
mixtures and the presence of any unknown chemicals. There is very
little information on the toxicological effects of mixtures. In
some cases, the presence of several chemicals together may result in
an enhancement of the overall toxicity (synergistic) effects. Other
chemicals mixed together may result in fewer toxic effects
(antagonism). Lastly, the chemical analyses were for specific
parameters. The chemicals evaluated are those that have been
identified as the most important chemicals in air, soil, and water.
The possibility exists that other chemicals are present that were
not detected. However, the chemicals which were found onsite are
reflective of the activities which took place during Site
operations; it does not appear likely that other sources of
contamination exist at this time.
The environmental risk assessment conducted for the Site
concluded that there are no complete exposure pathways. The
contaminated soils are capped and there are no chemicals of
potential concern in the groundwater. The nearest environmental
receptor of concern, Joy Run, is potentially impacted by multiple
sources of contamination (not related to Site activities) including
tar spills, numerous piles of asphalt and highway debris between the
Site and the creek, and road bed materials dumped along the creek
banks.
7. Description of the No-Action Alternative
Under the Super fund Program, studies are conducted at NPL sites
to characterize the nature and extent of contamination and to
determine the most feasible cleanup approaches. During the course
of the removal action that took place at this site, EPA disposed of
hazardous materials contained in tanks and drums abandoned onsite.
Leakage or spillage which took place prior to the removal action
during Sealand's short tenancy at the Site accounts for any
contaminants currently onsite. The levels of contaminants present
beneath the site cap do not pose an unacceptable risk to human
health or the environment.
12
-------
Long-term management controls relative to maintenance of the
clay cap are not considered necessary since even under a worst case
scenario of cap erosion or loss of integrity and subsequent human
exposure, a significant health threat would not result. Remaining
soil contaminant levels are within EPA's acceptable health risk
range, even considering a lifetime of residential exposure.
However, EPA will conduct a five-year review to verify that the
selected remedy remains . protective of human health and the
environment.
EPA's selection of the No Action alternative under CERCLA is
not to be construed as a recommendation or indication that the State
of Delaware should not seek to undertake additional cleanup of the
Site pursuant to its authorities under State law. EPA considers
action to be warranted at a site when the calculated cancer risk
exceeds one in ten thousand. At the Sealand Site, an individual
would have less than one in one million chances of developing cancer
as a result of exposure to site contamination. Therefore, in
accordance with the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP), no action is warranted. However, the State
may have requirements that differ from EPA's, under which it may
chose to take further action.
8. Documentation of No Significant Change
The Proposed Plan for the Sealand Site was released for public
comment on July 26, 1991. The public comment period closed on
August 24, 1991. EPA reviewed all written comments submitted during
the public comment period. A summary of the comments received
during the public comment period is included in the Responsiveness
Summary section of this Record of Decision. Based on these
comments, it was determined that no significant change to EPA's
proposed remedy, as originally identified in the Proposed Plan, was
necessary.
13
-------
RESPONSIVENESS SUMMARY
1. Overview
On August 6, 1991, EPA held a public meeting to present the
findings of the remedial investigation and to solicit comments on
the Proposed Plan issued on July 26, 1991. Residents did express
some concern over the potential for future ground water
contamination, in particular, contamination that would potentially
reach their private wells in the time prior to the five year review.
EPA explained that the contaminants of concern are relatively
insoluble in water, and that no ground water contamination has been
confirmed in onsite wells. This suggests that domestic water
supplies are not threatened by the site.
The state has maintained that the Site does pose a potential
threat to local ground water supplies, and has reserved its right to
take some action at the Site under its Hazardous Substances Control
Act. The potentially responsible parties questioned the State's
position relative to ground water issues. The full text of the
State's response is given in Section 3 of this Responsiveness
Summary.
2. Background on Community Involvement
During community interviews and public meeting held throughout
EPA's remedial response activities, the local populace indicated a
relatively low level of interest in the Site. Those most interested
were residents who lived close to the Site, or in a new development
located approximately 1/2 mile from the Site. Most residents were
primarily concerned about the quality of local ground water,
although some were also concerned about their property values.
Workers at Townsend's, Inc., a granary located approximately 200
feet from the Site, were interested in following EPA's activities at
the Site, as they have been since the time Sea land Limited began its
operation. Townsend's employees frequently complained to local
health officials about odors released during Site operations.
The Sealand Site property is bounded by an active railroad
spur, a highway, and a parcel of property owned by Tilcon, Inc.,
which is littered with road paving materials and a tar spill. Local
businesses^-which include the granary, a small shopping plaza, and
Summit Airfield, are apparently unaffected by the Site. Once the
Site has been delisted, its affect on local property values should
be negligible. No short- or long-term health risks have been
identified respective to exposure to the Site.
14
-------
3. Summary of Public Comments and Lead Agency Response
Oral Comments Received During the Public Meeting
Comment: The primary concern expressed during the public
meeting involved the potential for future ground water contamination
at the site. At least one resident stated that because EPA would
not be re-sampling ground water wells for five years, residents
could potentially be consuming contaminated ground water for a
number of years before this was recognized.
EPA Response: The primary contaminants of concern at the Site,
polynuclear aromatic hydrocarbons (PAHs), are relatively insoluble
in water and tend to adhere to soil particles. During the RI, the
only PAH detected in ground water was naphthalene, which was
detected in two onsite wells at the estimated concentration of 4
parts per billion, two orders of magnitude below levels of
regulatory concern. Even using the most sensitive analytical method
available at the current time, none of the potentially carci/nogenic
PAHs were detected in ground water onsite.
The clay cap present at the Site reduces the infiltration of
precipitation through the contaminated soil. In addition, if
contaminants were to enter the ground water, the concentration of
these contaminants would be reduced as contaminants moved offsite
and became diluted. As the nearest downgradient resident is located
over 1/4 mile from the site, it does not appear that residential
wells are threatened at this time, or will be in the future. If
data collected at the time of the five year review suggest
differently, EPA will take appropriate action at that time.
Written Comments Received Purina the Public Comment Period
Comment: EPA received a letter from BCM Engineers, the PRP's
consultant, concerning a statement in the Proposed Plan reflective
of the State's position relative to the potential for future ground
water contamination at the Site. Specifically, BCM questions the
State's position that the potential for future ground water
contamination exists when the known behavior of PNAs and the
historical Site sampling data indicate the contrary.
EPA Response: EPA requested that DNREC provide a response to
this comment. A September 9, 1991 letter from the State Project
Manager to the RPM states as follows:
"The^State concurs that laboratory evidence reveals no
contamination of groundwater has occurred up to now.
However, due to the shallow water table aquifer and its
contact with contaminated soils, it is likely the
contaminants presently retained in the soils will
eventually leach into the groundwater. ([T]he soil boring
logs from S-04, S-05, S-06, S-07, S-08, S-10 and S-ll
indicate the presence of the water table aquifer in the
contaminated soils.) The presence of the clay cap will aid
15
-------
in preventing infiltration of water into the contaminated
batch thus minimizing the risks of the contaminants being
introduced in this manner.
"We maintain that long term contact of the groundwater
with the contaminated soils will likely result in
contamination of the groundwater. Consequently it is
imperative the remediation of the contaminated soils be
conducted in a timely manner. Furthermore, it is our
opinion that removal of the pollution source occur now
before it migrates into the groundwater of the surrounding
area is a better alternative than to study the site later
and recommend a clean up after the problem has become
larger in magnitude and scope.11 ,
EPA does not agree with DNREC's assessment of the Site. Based
upon the information available at this time, EPA believes the Site
does not pose a threat to human health or the environment, nor does
it pose a threat to ground water resources in the vicinity of the
site. EPA does not, however, question the State's authority to take
action at this Site in accordance with State law to address what it
believes is a threat.
16
-------
Attachment
The Community Relations activities conducted at the Sealand
Limited Site to. date have included the following:
• January 23, 1990: Public meeting held following approval of
the RI/FS work plan to inform the public of investigatory
activities planned for the Site. Fact sheet issued.
• January 1991: EPA conducted community interviews to update
community relations plan.
• March, 1991: Fact sheet issued providing an update on site
activities.
• July 26, 1991: EPA issued Proposed Plan describing EPA's
preferred remedy.
• August 6, 1991: EPA and DNREC hold public meeting to present
the findings of the RI and to solicit public comment on the
preferred alternative identified in the Proposed Plan.
17
-------
SEALAND LTD. SITE
«t. Pteaaant. OE
BCM PfOfKt NO. 00-401A-03
2000 ft
Figure i
POOR QUALrft* l£2S2
ORIGINAL
Seatand Site
-------
BCM
SEALAND LTD. SITE
Mt. Pleasant DE
Adjacent
Property Lines
Sealand
Property_Une
Sealand
Property Line
^x
^ Adjacent
Property Lines
BCM Protect No. 00-6018-03
80 Ft
A
NORTH
Figure 2
Approximate Location of
Clay-Capped Area
Sealand Site
-------
BCM
SEALANO LTD. SITE
Mt PliuaiL DC
LEGEND
S-05 f) Soi Boring toorioft
. and 10 Number
^B«*oround3oiBa«6Jig-
Locflfion
-
TVO«
TSV*
m
At
Cr
•»
Nf
2.0'-4.0'
'1.714
MO.S
2.2(8)
18.:
56.5
0.12
43
120
2S.OCU)
2.1(8)
12.4
9.8
O.U(U)
S-14 0-1.0*
TVO
TSV
mi
At
Cr
*»
Hf
H8
TVO"
TSV*
TPH
At
:Cr
n
• NT
• NT
NT .
4.4(8)
41.7
113
0.32UI)
i
JJ.7--4 0-
MB1
8.984
43
1.7(17
13.1
6.6
Hi
TSV*
TPH
At
Cr
Pb
Hf
3.4
IS. 2'
80.620
72
7.4(1)
13.2 .
«J.2(J>
0.18
3.4^5. 2" Out
1*24.670
61
6.7(1)
16.3
51.8(J)
0.11
f
I
NotK No samoHi
mttfval avariabte.
J.A4
TSV*
mi
At
Cr
P»
HI
2.S--4 «•
6.990
1.600
2.3(8U
23.7
33.KJ)
0.12
Is4
t t'-t.a-
NO
12.464
2.500
2.6(U
11.8
9.9
0.13
I
« J.O--4.0'
1 TVQ* HV
TSV* 15.632
!mi 250
'• As 2.2(1)
I Cr 34.4
;P» 21. S
'Hf 0.18
LJLH
TSV*
mi
At
Cr
ft
H«
161.840
2.700
7.8tAjm hydrombui»
B. Htpomdv-alMalMatMni
rviebon limit but
twffwmsfumtm
Iffllt
In*
H pg/kg; U ettare in mgtkg
°-*°-
no
1.238
140
2.1(8)
58.4
19.7
0.13
NO
211
2S(U)
Q.7(U)
20.0
6,1
0.12
.04
|W«
TSV*
mi
As
Cr
•ft
"I
NO
1.041
240
0.9(8)
22.7
16.0
0.19
2.619
26
1.4(8)
22.5
6.9
0.14
Q'-l.g' O'-l.g Qua
2.5'-« 2'
4.418
2.700
1.0(1)
33.1
26.0
0.15
9.070
2.800
1.1(8)
20.0
25.1
0.1KU)
2.060
2S(U>
4.8
16.9
29.1
0.14
°'-*•"•
NO
NO
25(U)
1.6(8)
13.6
7.4
O.KU)
M)
NO
2S(U)
2.7
9.6
20.6
O.tt(U)
1
0--2.0'
U
NO
10.59*
3.000
S.7U)
-25.
85.3U)
0.1 3(U)
NO
149
«
!.2(8O
U.6
7.5
O.IHU)
1
BCM Pro-act ND. 00401*03
0 SO Ft
A
NORTH
Figure 3
Soil Quality Characteristics Map
Seaiand Site
-------
SEALANO LTD. SITE
Mt. Plea«ant. DE
UnfoUnttarad cample data
Q- Vatoquwtowdbydi
Ffcporvd value is In* tan tf»
contact deiacbDnlim* but
gnMtartfian tie •tuiunomion
inut
U- Compound not detected. V«kM
tottd U samptt auantiutian
vakw ii t«timat»d
fltportvd vaiut it estimated
Estimatad value below
detection omit
I it jf.o w.o i
! C»UI«> «T II.f
•Value* in mg/t ay otttera m ug/l
MW-4 • Monitoring Wei
Location and
10 Number
MW-l^Backgreund
MonjBrtno Wef
Location
BCM Project No. OO-M18-03
0 300 Ft
NOfrm
Ol !AI IT^roundwater Quality Characteristics
ORIGINAL
-------
Tabl«l Pigvt
TABLE 1
FREQUENT OF DETECTION FOR SOIL SAMPLES AND
COMPARISON TO BACKGROUND CONCENTRATIONS
SEALANO LIMITED SITE
MT. PLEASANT. DELAWARE
x SITE SPECIFIC
Data, Summary
Fra^uancy of Arithinote Background
Oattction* Rang* AMrag* •• 0-2n 2-4ft
Volatile Organic*, ug/kg
7/18 4-71 184 4 9
Benzan* 1/18 <1 - 4 14 <1 <8
2-Haxanono 1/18 <2 • 110 4.9 <2 <12
Toluene 1/18 9600 526 300 <360
V19 OSO-2BOO 384 130 <380
12/19 <380>5800 622 310 <390
DkrwOiyl pMtaM» 1/19 <380 - 86 •> 269. <430 <360
I MhM* o*»ar ft* total number of tampta Mean.
I oonoavttratfon wajsaaontatad balow ttw Ojuaiilllailon Omit
Data qu*ctton*d by data vaMaflon waa oonddand to ba batow datacflen.
EPA aplit aampkM ««• not bwhidad aa pan of «tfa aummaiy.
Compiidby; BCM Engir^ra k& (BCU Pre)aet No. 00401843).
-------
Tabl* 1 Pag*2
TABLE 1
FREQUENCY OF DETECTION FOR SOO. SAMPLES AM)
COMPARISON TO BACKGBOUNO SAMPLES
SEALAND UMTTED SfTE
MT. PLEASANT. DELAWARE
s SJTESPEOFC REGIONAL
DttaSumma/y
• b •
Frequency of ArtlnmaBo Northern Ottawa Southern NJ
Duarton* Ranga Avaraaa *• Background Daiawan) MO-Delaware Geometric
0-211 2-* n Mean so MMn
Metal*, mg/kg
Aluminum 19/19 4.990 • 18,600 10.441 10400 10.700 30000 - - 70000.000
Antimony 4/10 <44 • 74 34 <44 <44 <1 <1
Araento 18/19 «a war»i not Indudadaa part ofMammmary.
a Shae««»lBo««i^i9B* EtemartCanwnWtorMlnSoteandotf
b Logan, T.O. and Ryan. JX 1«7. Land Appfcaflon o« Shidge. Lwrfa PuMahan. Chalaaa. ML
e Pannaytvanla Sam UnloarXty. 1900. Cmarta and RMommandaaona tor Land Opcflrtllon ot Sfadpaa m fta Noittaagt
BuOMin 881. Match 1986.
d USEPA.19B6. Wtor QuaBty A«M«imint A SomaninQProcadura tor Torie and Conventional
Po8ulBnt> In Surfaea and Qiound WMar - Part 1. EPA/800/648/003L Saptambar IfiOSFMaad.
a USEPA. 1904. Haaflh Aiaatamant Dacumant for >norB«nloAfianlc.EPA«0/8-e»oaiF. March 1904.
Cempiladby: BCM En0lnaani he. (BCM Prajaet No. 00401843)
-------
Tabto 2 Pegat
TABLE 2
FREQUENCY OP DETECTION FOR GROUNOWATER SAMPLES AND
COMPAHSON TO BACKGROUND CONCENTRATIONS
SEALANO UMtTED SITE
MT. PLEASANT, DELAWARE
SITE SPECIFIC
Data Summary
Matais, Flltarad. ug/l
Aluminum
Antimony
Barium
BaryUhim
Calcium
Chromium
Cobatt
CflKMMaf
•*• "••*•
tan
Magnaaium
Manganaaa
MeM
miiiali»i
Sodium
Vanadium
Zno
CyanWa
MaMa.Unffitorad.ug/1
Aluminum
Barium
BaryMum
Calcium
Cnrofnium
Cobatt
Coppar
tan
laadt
Magmafun*
Manganaaa*
MOM .
Potaaakjnv "
Soda**""
Vanadium
Zno
Cyartda
Dttaolon*(]
3/10 [21
1/10 [1J
10/10 [3]
1/10 [11
10/10 [0]
1/10 [11
2/10 [2J
2/10 [2]
8/10 [31
10/10 [2]
10/10 [4]
3/10 [11
10/10 (3)
10/10 (1)
2/10 [2]
3/10 11J
2/4 H
6/6
6/8
2/8
6/8
2/8
1/8
2/8
6/8
4/8
6/8
6/8
1/8
5/8
6/8
3/8
5/8
6/8
Rang*
<16 - 217
<21 - 24
SO- 149
<14 • 2
13400-87.000
-------
TABLE 2
TOOUENOr OF DETECTION FOR GflOUNOWATER SAMPLES AND
COMWWSON TO BACXQROUNO CONCENTRATIONS
SEALANO UMTTED SITE
MT. PLEASANT. DELAWARE
STTESPSOPIC
Otta Summary
MW1 MW2*
VoUta* Organta Compot
1/7 <3 • 2 * 2,4 <3 <3
MMXytom CNortd* 2/7 <3 • 11 i3
-------
TABLE 3
ASSUMPTIONS USED IN CALCULATING EXPOSURE
SEALAND LIMITED SITE
MT. PLEASANT, DELAWARE
INGESTION OF SOIL
Current DM
Ingestien Ratt (mg/day)
Body Wight (kg)-Child
Exposure Frequency (days/year)
Exposure Duration (years)
Reference
100 EPA, 1989c
32 EPA, 19896
100 Site Specific
4 Site Specific
Future Use
ingestton Rate (mg/day)
Body Weight (kg) • Adult
Exposure Frequency (days/year)
Exposure Duration (years)
100
70
120
1
EPA.1989C
EPA.1989C
Site Specific
Site Specific
DERMAL ABSORPTION FROM SOIL
Current Use
Skin surface area (sq. cm). Child 4.970 EPA. 1989b
Skin adherence factor (mg/sq. cm) 2.77 EPA, I986g
Absorption factor (percent) 1.8 EPA, 1988
Exposure frequency (events/year) 100 Site Specific
Exposure duration (years) 4 Site Specific
Body weight (kg)-Child 32 EPA, 1989c
Future Use
SUn surface area (sq. cm). Mutt 3.120 EPA, I989b
SUn adherence factor (mg/sq. cm) 2.77 EPA. I986g
Absorption factor (percent) 04 EPA. 1988
Exposure frequency (events/year) 120 Site Specific
Exposure duration (years) 1 Site Specific
Body weight (kg)-Adutt 70 EPA. 1989e
CompUed by. BCM Engineers Inc. (BCM Protect No. 00401843)
-------
TABLE 4
CANCER RBK ESTIMATES-CURRENT USE
SEALANOUMITEOSrTE
MT. PLEASANT. DELAWARE
Chwnfeal
CO Stop* WWgfttof Chemical
(mg/kg^ay) Factor CvManca Specific
RMc
Total Expotur*
bis(2-e>iyttM«yl)ptn
4.96-11
2.4E-10
8.1E-00
2.6E-08
7.8&00
84E-10
94C-&
t.lE-00
122
X2Z
0.014
X22
3J2
82
B2
B2
82
82
82
82
2E-10
O0048
1E-10
OE-00
3E-OI
3E-00
3E-OB
4E>M
8wno(Dpyraiw
8.1E-10 3J2
O014
122
i22
2JC48 i22
122
82
82
82
82
46-10
36-10
2E4S
7E40
7C48
16-10
2E-OT
TOTAL EXK3SURE
3frOT
Compfcdtty; BCM EngbtMA toe. (BCM PrajMt Me, 00401»43)
-------
TABLE 5
CANCSRPSK ESTIMATES-FUTURE USE
SEALANO LIMITED SITE
MT. PLEASANT. DELAWARE
Chwnfctf
GDI Stop* Wtfghtof Chemical Total Expoaura
BAo-day) Factor Evidane* Spacifie Pathway
RME Rtak
WaC-Em
*yl)pmiau
BwtzoMpyrwM
Nttraw«plwny«ainlM
4.06-11
ZSE-tO
1^E-00
2.06-08
1.3&OS
1.1E-OB
166-00
122
122
122
122
122
122
04048
82
82
82
82
82
82
82
82
1E-10
BE-10
6&00
4E-M
4E-00
1E-11
7E-OB
bte(2-ehy»wiyI)pMtalati
Z4E-10
1J
MtroMdlplwnylamlM
1.1640
Z4600
122
122
O014
122
122
122
122
82
82
82
82
82
82
82
82
16-10
86-10
1E48
TOTAL EXPOSUflft
1EXJ7
Mnknum bpowt* t> dtRntd n flM upptr bound 96 pworrt
Hvri of ft»mo« prataMc eenewmttan
BCUCnglMm to. (BCMPrejKt to. 00401*03)
-------
TABLE 6
CHRONC HAZARD INDEX ESTIMATES-CURRENT USE
SEALANO UMfTB) SITE
MT. PLEASANT. DELAWARE
CO
Chwnteri
RIO
(mg/kfrday)
Hazard MM
BwnotoAdd
Mwewy
1J&08
1.1E-OT
2J606
4.7&W
1.4tOT
AfltfWI
M*
Ruaranttwrn
Pyiww
4 •
OQ2
O004
008
03
004
0.0000004
O0004
0.001
O.00001
0*000002
0*0000000
1.4647
Ruoram
t**tt&t****rtt*t
•HM
Okvbulyt pMhaiaM
1.46-07
1.4C-07
1.4M7
1.4&07
08
O08
004
008
O1
0*000008
OiOOOOOOS
0*000007
0000001
0002
MMwy
2J&07
7.1E4B
1JS47
3J&OT
3JMT
4J.M7
4
ooa
OOM
O08
OS
O04
7-Ofror
3JM7
04
OOB
004
0.000001
ooooa
O004
0*000006
0000001
O00001
O00001
0.000001
0*000007
OjQQOQx
O1
OC08
TOTM.DVOSUK
ooor
BCMEnolnaarakie.(BCMPreiaclNo.O»«01»«3)
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