United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R03-90/096
September 1990
Superfund
Record of Decision:
Coker's Sanitation Service
Landfills, DE
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REPORT DOCUMENTATION 11. REPORT NO. I ~ 3. Reclplenra Acce..lon No.
PAGE EPA/ROD/R03-90/096
4. TIDe end SubtiDe 5. Report Dete
;UPERFUND RECORD OF DECISION 09/28/90
,oker' s Sanitation Service Landfills, DE
6.
First Remedial Action - Final
7. Au1hor(a) 8. Perfonnlng Organization Rept. No.
8. Perfonnlng Orgalnlzetion Name and Addte.. 10. ProjectITeeklWork Unit No.
11. Con1rec1(CJ or aran1(G) No.
(C)
(G)
1~ Sp_orlng Organlza1lon Name end Addre.. 13. Type 01 Report & Period Covered
U.S. Environmental Protection Agency 800/000
401 M Street, S.W.
Washington, D.C. 20460 14.
15. Supplemen18ry NOlea
16. Abstract (Urnlt: 200 worda)
The Coker's Sanitation Service Landfills site is comprised of two inactive landfills,
the 10-acre- landfill #1 and the IS-acre landf i 11 #2, located approximately 0.5 miles
apa rt, in Kent County, Delaware. Landfill #1 is bordered to the north by a forested
wetland that includes a shallow stream known as the Willis Branch of the Lepisc River.
Land use in the area is primarily agricultural and residential. Each landfill contains
approximately 45,000 cubic yards of latex sludge waste in addition to the contaminated
soil/waste. From 1969 to 1977, latex rubber waste sludge was disposed of at Landfill #1
into unlined trenches, which were topped off with local soil when nearly filled with
sludge. From 1976 to 1980, latex sludge was also disposed of in lined trenches at
Landfill #2. The landfill operating permit required a leachate collection and treatment
system and a ground water monitoring system to be installed. Subsequently, the latex
sludge waste in both landfills gradually settled and compacted reducing permeability and
minimizing the amount of leachate from the site. Excess levels of styrene and
ethylbenzene were found in the waste trenches of both landfills and in the leachate
collection system of landfill #2. This Record of Decision (ROD) addresses contamination
in both landfills and in the leachate collection system at Landfill #2. The primary
(See Attached Page)
17. Documenl Anelyala L Deacriptors
Record of Decision - Coker's Sanitation Service Landfills, DE
First Remedial Action - Final
Contaminated Media: soil, sludge
Key Contaminants: VOCs (benzene); metals
b. IdentifieralOpen-Ended T arms
-
Co CooA TI ReIdIGroup
18. Av8llabllity Statemen1 18. Security Clna (Thia Report) 21. No. of Pagea
None 85
20. Sec..ity CI..a (Thia Page) n Price
None
272 (4-77)
50272-101
(See ANSl-Z39.18)
See Inetructions on Reverae
(Formet1y NTIS-35)
Depar1ment 01 Commerce
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EPA/ROD/R03-90/096
Coker's Sanitation Service Landfills, DE
7irst Remedial Action - Final
:~stract (Continued)
contaminants of concern affecting the soil and sludge are VOCs including benzene and
metals.
The selected remedial action for this site includes covering the seeps at Landfill #1;
backfilling depressed areas of Landfill #2 and sealing the Landfill #2 leachate
collection system; monitoring ground and/or surface water; and implementing
institutional controls including deed restrictions on land use and site access
restrictions. The estimated total cost for this remedial action is $653,000, with total
O&M costs of $527,257.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific goals are not applicable, since this
remedial action uses no treatment technologies. The remedial activities will reduce the
cancer risk level to less than 10-6, and the hazard index to less than 1.0.
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RECORD OF DECISION
COKER'S SANITATION SERVICE LANDFILLS
DECLARATION
Site Name and Location
Coker's Sanitation Service Landfills
Kent County, Delaware
Statement of Basis and Purpose
This decision document presents the selected remedial action
for the Coker's Sanitation Service Landfills Site (Site), located
in Kent Cr-'~ty, Delaware, which was chosen in accordance with the
:2~uiren of the Comprehensive Environmental Response,
Compensat~un, and Liability Act of 1980, (CERCLA), as amended by
the Superfund Amendments and Reauthorization Act (SARA) and, to the
extent practicable, the National oil and Hazardous Substances
Pollution Contingency Plan (NCP), 40 C.F.R. Part 300. This
decision document explains the factual and legal basis for
selecting the remedy for the Site.
The State of Delaware concurs with ~he selected remedy. The
information supporting this remedial act~on decision is contained
in the Administrative Record file for this site.
Assessment of the site
Pursuant to duly delegated authority, I hereby determine,
pursuant to Section 106 of CERCLA, 42 U.S.C. 9 9606, that actua~
or threatened releases of hazardous substances from this Site, as
discussed in the "Summary of Site Risks" on pages 4 to 8 of the
Decision Summary, if not addressed by implementing the response
action selected in this Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare,
or the environment.
Description of the Selected Remedy
The selected remedy addresses the principa~ threats posed by
the conditions at the Site by reducing the potential for human
exposure to wastes remaining at the site.
The major components of the selected remedy are as follows:
Deed restrictions
properties.
will
be
placed
on
both
landfil:
j
-------
2
The entire waste disposal areas of both landfills will
be enclosed by a chain-link security fence with a locked
gate to restrict the access of unauthorized persons and
equipment onto the landfills.
Appropriate warning signs will be placed along the fence.
Cover material will be placed along the northern slope
of Landfill #1 to eliminate exposure to leachate seeps.
Areas of Landfill #2 which have subsided due to uneven
settling of waste will be backfilled to grade and seeded.
Leachate collection wells at Landfill #2 will be sealed
with grout to reduce the potential for direct contact
with leachate.
Ground water wi-
landfills.
be
sampled
semi-annually
at
both
The landfills will be inspected semi-annually durinq
ground water sampling events.
Surface water monitoring will be conducted at the Willis
Branch adjacent to Landfill 11 at the same time as ground
water monitoring for a period of no less than five years.
A Site review will be conducted at least every f.ive years
as required under Section 121(c) of CERCLA, 42 u.s.c. 9
9621(c) .
Statutory Determinations
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that are
legally applicable or relevant and appropriate to the remedial
action, and is cost-effective. This remedy utilizes permanent
solutions and alternative treatment (or resource recovery)
technologies, to the maximum extent practicable for this Site.
However, because treatment of the principal threats of the site was
not found to be practicable, this remedy does not satisfy the
statutory preference for treatment as a principal element.
The preamble of the NCP states that trea~ment will be the
preferred means by which principal threats posed by sites will be
addressed. The preamble characterizes principal threats as "waste
that ,=annot be reliably controlled in place, such as liquids I
highly mobile materials. . and high concentrations of toxic
compounds. . . Treatment is less likely to be practicable whe~
sites have large volumes of low concentrations of material, or whe~
the waste is very difficult to handle and treat." (55 Fed. Rea.
8,703, (March 8, 1990». The waste materia]. found in the l3"d!i~:5
-------
3
--
at the site is neither liquid nor highly mobile, and can be
reliably controlled in place. The Site contains a large volume of
material (llO,OOO ydS3) that would be difficult to handle and treat
due to its clay-like physical properties and the potential risk
posed by substantial release of volatile organic compounds. EPA
and the State have therefore determined that onsite containment of
waste is an appropriate remedial action.
Because this remedy will result in hazardous substances
remaining on the Site above health-based levels, a review will be
conducted within five years after commencement of remedial action
and every five years thereafter, as required by Section 121(c) of
CERCLA, 42 U.S.C. ~ 9621(c), to ensure that the remedy continues
to provide adequate protection of human health and the environment.
~~
f?~.~-_.'
SEP. 28 10.
Edwin B. Erickson
Regional Administrator
EPA Region III
Date
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DBCISIOH SOKXARr
1.
site Name. Location. and Descriction
The Coker's Sanitation Service Landfills Site (Site) 1"s
located in Kent County, Delaware, approximately 1.3 miles
northwest of Cheswold and 5.7 miles northwest of the City of
Dover. The Site consists of two landfills located approximately
~ne-halt mile apart on opposite sides ot County Route 152 (figure
1). Coker's Landfill 11, which is on the north side of Route
152~, and Coker's Landfill #2, which is on the south side of Route
152, are both part of larger, heavily Wooded tracts of land.
Properties adjacent to both landfills are primarily used for
agricultural or light residential development. Landfill 11 is
bordered on the north by a forested wetland that includes a
shallow meand,..:'ing stream, the W.;:''';,l.s Branch of the Leipsic River
(Willis Brarlc-:h\. Agricultural 1,;",113 border the tree lines east
and west of Landfill 12. Deer and other wildlife populate this
area of Kent County.
The Site overlies two aquifers, the Columbia aquifer and the
Cheswold aquifer. The Columbia aquifer directly underlies both
landfills, and in the vicinity of the Site discharges north-
northeast toward the Willis Branch. This aquifer is not
generally used for domestic water supplies due to indigenous high
levels of iron and manganese. The Columbia and Cheswold aquifers
are separated by several feet of clay containing sand and silt
that has demonstrated some ability to transmit water. The
Cheswold aquifer is the primary SQurce of potable water in the
Dover area. A geological cross-section, which includes the Site,
the Columbia and Cheswold aquifers, and the Willis Branch,
is shown in figure 2.
The waste disposed ot in the landfills consists of process
sludge generated during'fhe manufacture ot latex rubber.
Approximately 45,000 yds ot waste sludge are present at each
landfill. Landfill'l covers about 10 acres, and Landfill "*2 is
about 15 acres in size.
2 .
Site Historv and Enforcement Activities
All waste disposed of at Landfills '1 and 2' was generated at
a latex rubber manufacturing facility now owned by Reichhold
Chemicals, Inc. The facility was previously owned by
International Latex and Chemical Corp. (1962-1967), Glen Alden,
now a part of Rapid American Corp. (1967-1968), and Standard
Brands Chemical Industries, Inc. (1968-1978).
Landfill 11 is located on the property ot Mr. John Schmidt.
Use of Landfill '1 began in 1969 under a permit issued by the
-1-
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-------
48402 O~}
FIGURE 2
Geologic Cross Section
Coker's Landfills Site
NORTH
A
COI(( ..'.
LANDfill 8tUUU" 1
I
COKER'S LANDfILL NUUBER '1
en
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-------
Delaware Water and Air Resources Commission. SUbsequent permits
(1973-1976) --vere issued by the Delaware Department ot Natural
Resources and Environmental Control (DNREC). The landfill was
closed in 1977 in accordance with Delaware Solid Waste Disposal
Regulation. ot August 1974. Durinq landtill operation, latex
waste sludqe was discharqed into unlined trenches that were 6 to
8 feet deep and 12 feet wide. Liquids were allowed to drain off
as solids settled. Trenches were used until the solids level was
within several feet of the qround surtace. Trenches were then
backfilled with soil obtained locally.
~
Landfill '2, located on property tormerly owned by Mr.
Joseph Kowinsky and currently owned by the estate ot Genevieve M.
Kowinsky, was operated from 1976 to 1980 under state permit. The
permitfrequired each 6-toot deep, 28-toot wide, 125-foot long
trench to have a synthetic liner and a leachate collection.
system. The permit also required leachate collection and
trea~ 18nt, installation of qround water monitoring wells,
re~.'.i. :.:-ly scheduled site inspections, and periodic qround water
and leachate monitoring. When the Site was closed in 1980, all
trenches were capped with two teet ot native soil. As waste
settled and no lonqer generated collectable quantities of
leachate, leachate collection was phased .out in the early 1980'8.
EPA has taken several actions pursuant to the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA)
in response to conditions at the Site. Site investiqations, .
including sampli~q of qround water (Landtill '2 only) and
leachate were conducted in 1980. Samples taken from one qround
water monitorinq well and one leachate collection pipe at
Landfill '2 were tound to contain .levated levels ot acrolein
(1278 parts per billion (ppb) and '2128 ppb, respectively);
ethylbenzene was detected in the same leachate collection pipe at
3987 ppb. In 1983, 17 ppb ethylbenzene vas detected in the same
well, and 28 ppb bis(2-chloroethyl)ether was detected in Landfill
#1 leachate seeps.
In 1985, the Site was scored usinq the Hazard ~anking
System. The Site vas proposed for inclusion on the National
Priorities Li.t (NPL) in April 1985, and was tinalized on the NPL
in July 1987.
In April ot 1986, EPA issued letters to several potentially
responsible parties (PRPs) notityinq the. ot their potential
liability tor Site response actions and invitinq them to perform
the Remedial Investiqation and Feasibility StudY-(RI/FS). The
purpose of the Remedial Investiqation (RI) is to determine the
nature and extent of contamination at a site, while the
Feasibility Study (FS) develops, screens, . and evaluates potential
clean-up actions. On December 30, 1987, three PRPs siqned an
agreement with EPA in the form ot an administrative order on
consent (docket number III-88-16-DC) to conduct the RI/FS.
-2-
.
-------
DNREC, the .support agency for Site activities, agreed with the
entry of tais order. The parties agreed, under a separate order
to remove drums containing varying quantities of latex waste'
found onsite during the RI.
3.
Hiahlights of Community Participation
The RI/FS Report and the Proposed Plan for the site were
released to the public for comment on August 22, 1990. These two
documents were made available to the public in the administrative
~ecord file maintained at the EPA Docket Room in Region III and
at the information repository at the Clayton Post Office,
Railroad Ave., Clayton, Delaware 19938. The notice of
availability of these two documents was published in the
Wilminqton News Journal and the Delaware State News on Wednesday,
August 22, 1990. A public comment period was held from August
22, 1990 to~eptember 21, 1990. In addition, a public meeting
was held on September 5, 1990. . At this meeting, ~epLesentatives
from EPA and DNREC answered questions about the Site and the
remedial alternatives under consideration. The comments received
during the public comment period, including those expressed
verbally at the public meeting, are addressed in the
Responsiveness Summary, which is part of this Record of Decision
(ROD). EPA has thus met the public participation requirements of
Sections 113(k) (2) (8) and 117(d) of CERCLA, 42 U.S.C. SS
9613(k) (2) (B) and 9617(d).
4.
Scope and Role of the Response Action
The principal concerns posed by conditions at the Site are
summarized below. The remedial action will address these
concerns by reducing the potential. for human exposure to wastes
remaining at the site. This is the only planned response action
for this Site.
5.
Summary of Site Characteristics
Both landfills contain a large volume of latex sludge that
has been compacted and has a laboratory-measured permeability
similar to that of clay. The low permeability of the waste serves
to minimize the quantitfes of leachate generated at the Site.
An estimated 45,000 yds of waste is present at each landfill,
along with a smaller volume of soil mixed with waste (15,000 yds3
at Landfill '1 and 5,000 yds3 at Landfill 12). .The primary
contaminants of concern, styrene, which is a class 82 probable
human carcinogen, and ethylbenzene, were found primarily in the
waste trenches of both landfills and in the leachate collection
system of Landfill 12. Both styrene and ethylbenzene are only
slightly soluble in water. Maximum concentrations of the
compounds and the media in which they were found are shown in
table 1. .
-3-
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.
At this tiae, all waste is contained within the cells of
either Landfill '1 (unlined) or Landfill '2 (lined). Landfills
'1 and '2 are shown in tigures 3 and 4 respectively. Ground
water in contact with waste at Landfill '1 can transport
contaminants offsite to leachate seeps located along the northern
border of the landfill. OVerland flow of runoft can then carry
leachate to the Willis Branch. Bioloqical testing showed some
evidence of leachate toxicity to aquatic organisms. Further
studies, however, indicated the leachate has no apparent impact
on the receiving stream. Although waste cells at Landfill '2 are
lined, the potential for future liner failure and subsequent
ground water contamination exists.
1 .
. Most of Kent County is non-urbanized, consisting of lands
under cultivation, open fields, wetlands and marsh, and inland
waster bodies. OVer 90 percent ot the open land, excluding marsh
areas, is in active agricultural use. Organized land use is
primarily residential. The Willis Branch, which is located to
the nocth of Landfill #1, is a tributary of the Leipsic River and
discharges into the river approximately 3,000 feet downstream of
the Site via a man-made lake named Garrison's Lake. Garrison's
Lake is used for recreational purposes. The primary drinking
water source for this area of Kent County is the Cheswold
aquifer, although the Columbia aquifer is also used for domestic
water supplies.
An environmental assessment was conducted as a part of the
RI. The results. of the qualitative har.itat assessment indicate
that the wetlands areas and the landfills support a diverse flora
and fauna that is apparently unaffected by the Site. There is no
known occurrence of any rare, threatened, or endangered species
of birds, mammals, fish, reptiles, amphibians, or plants within
the Site area. .
6.
Summary of Site R~
EPA conducted a baseline risk assessment for the Site.
Because the State regulations under which the landfills were
closed did not require deed restrictions on the properties,: EPA
evaluated onsite risk under a hypothetical residential use
scenario. Risks to offsite residents resulting from exposure to
contaminants released from Landfill '2 waste cells into the
shallow ground vater following liner failure were also evaluated.
The first step in conducting a risk assessment is to
identify contaminants of concern. A total of ten contaminants of
concern, including carcinoqens and non-carcinogens, were
identified for Landfill #1: nineteen contaminants of concern,
including carcinogens and non-carcinogens, were identified for
Landfill #2. The overall risks quantified in the risk assessment
were primarily based upon exposure to the following compounds:
benzene, cadmium, chloroform, dibutyl phthalate, manganese,
-4-
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4f1402 0
FIGURE)
Delineation of Waste Cells
Confirm j in the Soil Boring Investigation
Coker.s Landfill No.1
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FIGURE 4
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~
\
/
o
.~~.
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.--
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phenol, cresol, ethylbenzene, and styrene. Table 1 shows t" e
range in concentrations of these contaminants, the number of
samples taken, and the number of "hits" in the waste, leachate
and ground water at both landfills. All compounds considered in
the risk assessment, along with their respective Cancer Potency
Factors and Reference Doses' (RfDs) are listed in Table 2. .
Cancer potency factors (CPFs) have been developed by EPA's
carcinogenic Assessment Group for estimating excess lifetime
cancer risks associated with exposure to potentially carcinogenic
~emicals. CPFs, which are expressed in units of (mg/kq-day) 0',
are multiplied by the estimated intake of a potential carcinogen,
in mg/kq-day, to provide an upper-bound estimate of the excess
lifetime cancer risk associated with exposure at that intake
level. The term "upper bound" reflects the conservative estimate
of the risks calculated from the CPF. Use of this approach makes
underestima~ion of the actual cancer risk highly unlikely.
Cancer potency factors are derived from the rec'lts G! human
epidemiological studies or chronic animal bio~~~ays to which
"animal-to-human extrapolation and uncertainty factors have been
applied.
Reference doses (RfDs) have been developed by EPA for
indicating the potential for adverse health effects from exposure
to chemicals exhibiting noncarcinogenic effects. RfDs, which are
expressed in units of mg/kq-day, are estimates of lifetime daily
exposure levels for humans, including sensitive individuals, that
are likely to be without 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 RtDs will not
underestimate the potential for adverse noncarcinogenic effects
to occur.
After the toxicity assessment of contaminants of concern,
potential receptors, exposure media, and pathways for. exposure
are identified. Under the residential use scenario, adults and
children living onsite are the potential receptors. The exposure
media are 80il contaminated with waste disturbed during building,
and shallow ground water that is assumed to be contaminated with
leachate. The risk estimates consider the following routes of
exposure: ingestion of drinking water, inhalation of volatile
organic compounds (VOCs) volatilized during bathing or showering,
dermal contact with VOCs during bathing, ingestion of residential
, The terms "Cancer Potency Factor" and "Reference Doselt
will be comprehensively explained later in this section.
-5-
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soil, and.dermal contact with residential soil. Maximum
concentrati~n8 of contaminants found in the waste and the
leachate were used in the risk calculations. The cancer risks
and Hazard Index scores for adults and children for each
contaminant of concern in each exposure media for each exposure
pathway are given in Tables 3 to 11. Relevant exposure
assessment information, as well as all major assumptions about
exposure frequency and duration, is given in the caption for each
table.
. 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., 1X10'6 or 1E-6). An excess lifetime cancer risk of 1X10'6
indica~es 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 ?O-year lifetime
under the specific exposure ~,' 1d.itions at a site.
Potential concern for noncarcinogenic effects of a single
contaminant in a single medium is expressed as the hazard
quotient (HQ) (or the ratio of the estimated intake derived fro.
the contaminant concentration in a given medium to the
contaminant's reference dose). By adding the HQs for all
contaminants within a medium or across all media to which a given
population may reasonably be exposed, the Hazard Index (HI) can
be generated. The HI provides a useful reference point for
gauging the potential siqnificance of multiple contaminant
exposures within a single medium or across media.
The total cancer risks and Hazard Index scores for all
contaminants of concern in all exposure media for all exposure
pathways for adults and children are shown in Tables 12 and 13.
The cancer risk for a child associated with the residential use
SCE ,rio at Landfill '1 is 1 x 10"4, which is the upper bound
rea..;n of EPA' s acceptable risk range of 1 x 10'4 to 1 X 10"6. The
Hazard Index for a child is 3.26, which exceeds EPA's preferred
guideline of 1.0. The cancer risks for adults and childre~
associated with residential use of Landfill '2 were 6 x 10"' and
5 x 10"3, respectively; the Hazard Index scores were 48 and 156.
These level. exceed the upper boundary of EPA's acceptable range.
Given the above, actual or threatened releases of hazardous
substances trom this Site, if not addressed by implementing the
response action selected in this ROD, may presen~ an imminent and
substantial endangerment to public health, welfare, or the
environment as set forth in Section 106 of CERCLA, 42 U.S.C ~
9606.
7.
Descriotion of Alternatives
Alternative 1 -- No Action.
Section 300.430(e) (6) of the
-6-
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National Oil and Hazardous Substances Pollution Contingency Plan
(NCP), 55 ~. ~. 8,849 (March 8, 1990) (to be codified at 40
C.F.R. S 300.430(e)(6», requires that the "no action"
alternative be evaluated at every site to establish a baseline
for comparison to other alternatives. Under this alternative no
. '
act~on would be taken to address current or future exposure to
contaminants remaining at the site. A review would be conducted
every five years as required under Section 121(c) of CERCLA, 42
U.S.C. S 9621(c). This alternative does not address any
contaminated media, nor does it result in the reduction of any
risks associated with the Site.
Capital Cost: $
Operation' Maintenance Cost: $
Net Present Worth: $
o
o
o
Alternative.2 -- Monitoring. This alternative includes Site
inspection, ground water sampling, and leachate sampling from the
area o! the seeps (Landfill 11 only) on a semi-annual basis.
Monitoring wells installed during the RI/FS or other suitable
onsite wells would be used for ground water monitoring. A five
year review would be conducted to assess the Site's physical
condition and ground water data. The primary purpose of the
monitoring program is to detect any deterioration of site
conditions. This alternative does not address any contamination
found at the Site. Implementation of this alternative would not
result in any significant reduction in risks associated with the
Site.
capital Cost: $
Operation & Maintenance Cost: $
Net Present Worth: $
o
653,000
653,000
Alternative 3 -- Limited Action. This alternative includes a.
si~e fence, placement of cover material over the seeps at
Landfill 11, backfilling and seeding depressed areas of Landfill
#2, sealing the Landfill '2 leachate collection system with
grout, placement of deed restrictions on'both land~ill
properties, site inspection, monitoring, and a review at least
once every five years.
Placement of cover material over the seeps at Landfill II
would eliminate the potential for direct exposure to the
leachate, and reduce potential erosion of the slope along the
northern border of the landfill. Backfilling depressed areas of
Landfill 12 would eliminate standing water on the landfill
surface, provide protection from erosion, and further stabilize
the Site. Sealing leachate collection pipes at Landfill '2 would
eliminate the potential for contact with leachate from this
landfill. Deed restrictions on both properties would eliminate
the possibility of future use of the land in a manner that would
result in unacceptable exposures to the constituents in the
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waste, or.d~sturbance of the closed landfills. Fencinq the site
and posting the appropriate warninq siqns would restrict access
of unauthorized persons and equipment to the landfills.
In addition to these components, this alternative includes
semi-annual Site inspections and qround water monitorinq (both
landfills) and surface water monitorinq (Landfill '1 only)'-
Should qround water monitorinq detect any unacceptable levels of
contamination, DNREC, in conjunction with Kent County, would
develop and implement a Ground Water Manaqement Zone (GWMZ) in
~he vicinity of the Site. A GWM2 is an area of restricted qround
water use developed under state authorities and implemented by
the county. Should the shallow aquifer contain levels of
contamination that may present a threat to human health, any
drinkiriq water wells within the GWMZ drawinq from this aquifer
would be replaced by deeper wells in the Cheswold aquifer.
Should surface water monitorinq detect any site-related chanqes
in the quality of the Willis Branch, ~ore detailed environmental
studie-- would be performed to deten:,i.ne whether further action is
warranted at the Site. Under the limited action alternative, a
review of the remedial action will be conducted at least once
every five years, as required under CERCLA.
This alternative would eliminate the possibility of
residential development at both landfills. Carcinoqenic risk due
to exposure to ~aste and inqestion of leachate under a
residential use scenario was calcul~ted to be 1 f 10.' for
children at Landfill '1, and 5 x 10' and 6 x 10' for children
and adults, respectively, at Landfill '2. The Hazard Index score
for children at Landfill 11 was 3.26; the Hazard Index scores for
adults and children at Landfill .~ were 48 and 156, respectively.
This alternative would reduce cancer risk levels to below 1 x
10'6 and Hazard Index scores to below 1.0. Common construction
materials and methods would be used to implement this
alternative. .Institutional. controls (deed restrictions and the
potential for a GWMZ), which would eliminate the possibility of
future devel?pment at the Sit., would reduce total site risk to
below 1 x 10 .
No cheaical- or location-specific ARARs2 are violated by the
Site in it. current condition. All onsite activities.would be
carr ied out in accordance with the Occupational Safety and Heal,th
Administration (OSHA) requirements for workers at remedial action
sites (29 C.P.R. Part 1910). Remedial actions are not expected
to disturb the wetlands located to the west of Landfill '2.
2ARARs are applicable or relevant and appropriate
requirements of other Federal and State environmental statutes,
such as the Safe Drinkinq Water Act, which EPA must take into
consideration when selectinq remedial actions for Superfund
sites.
-8-
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However, construction activities along the northern slope of
Landfill t~ are likely to cause minor disturbances along the
periphery ot the wetlands located along the Willis Branch. These
disturbances should be kept to a minimum, and construction plans
should be reviewed and approved by the U.S. Army Corps of
Engineers and DNREc. Before any remedial actions are conducted
at the Site, the Delaware Department of State would be contacted
to ensure adherence to the National Historic Preservation Act of
1966. The expected time frame for implementation of this
alternative is approximately two months. Implementation would
~egin following approval of a Remedial Action Work Plan.
Capital Cost: $
Operation' Maintenance Cost: $
Net Present Worth: $
555,000
685,000
1,240,000
Alternative.4 -- Soil Cap. This alternative includes all
components of Alternative 3 - Limited Action (site fence,
leachate cover, backfilling and regrading, leachate system'
closure, deed restrictions) plus regrading both landfills and
importing additional top soil to improve drainage and to provide
additional protection against erosion. This alternative would
also include semi-annual Site inspection, ground water and
surface water monitoring, and Site review every five years as
described for Alternative 3.
Both landfills would be regraded using conventional earth
moving equipment and existing cover soil to establish -improved.
drainage patterns. Up to 6" of imported top soil would be placed
over each landfill, followed by seeding to provide a vegetative
Cover and erosion control. Drain~ge swales with erosion controls
would be installed to prevent erosion of the soil cap. The
northern slope of Landfill '1 would be regraded to facilitate
placement of the cover material for the seeps.
Placing a cover over leachate seeps at Landfill '1 and
closing the leachate collection system at Landfill '2 under this
alternative minimizes the potential for direct contact with
leachate. Deed restrictions on both properties would eliminate
the possibility of future use of the land in a manner that would
result in unacceptable exposures to the waste or constituents of
the waste or disturbance of the closed landfills. Fencing the
site and posting the appropriate warning signs would restrict
access of unauthorized persons and equipment to the landfills.
The deed restrictions Coupled with the establishment ot a GWMZ,
as described under Alternative 3, would reduce site-related risks
to acceptable levels (i.e., cancer risk below 1 x 10'6 and.
Hazard Index of less than 1.0). Establishment of drainage
patterns and placement of a vegetative cover would enhance the
long-term stability of both landfills.
All engineering controls would be easy to implement using
-9-
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convention~~ construction methods and materials. The estimated
time traae tor implementation of this alternative is three months
following the approval of Remedial Action Work Plans.
No ch..ical- or location-specific ARARs are violated by the
Site in its current condition. All onsite activities would be
carried out in accordance with the Occupational Safety and Health
Administration (OSHA) requirements for workers at remedial action
sites. Remedial actions are not expected to disturb the
wetlands located to the west of Landfill '2. However,
~onstruction activities along the northern slope of Landfill 11
are likely to cause minor disturbances along the periphery of the
wetlands located along the Willis Branch. These disturbances
should be kept to a minimum, and construction plans should be
reviewed and approved by the U.S. Army Corps of Engineers and
DNREC. Before any remedial actions are conducted at the Site,
the Delaware Department of State would be contacted to ensure
adherence to the National Historic Preservation Act of 1966.
Capital Cost: $
Operation' Maintenance Cost: $
Net Present Worth: $
1,706,000
778,000
2,484,000
",
Alternative 5 -- Multi-layer Cap (both landtills) and Subdrain
(Landfill '1 only). The primary components of this alternative
are multi-layer caps at both landfills and shallow ground water
controls at Land~ill '1. The purpose of the multi-layer caps is
to reduce infiltration of precipitation into the waste to a
minimum. The subdrain at Landfill '1 would intercept local
ground water flow and lower the water table to a level below the
bottom of the waste cells. In addition, this alternative
includes Site fencing, deed restrictions, Site inspect,ion, Site
maintenance, ground water monitoring, and a review every five
years.
In order to iapl..ent this alternative, the surfaces of both
landfills would be regraded to provide a smooth s~rade for
placement ot the cap and to provide an adequate grade for'
establishinq .urtac. drainage. A multi-layer, RCRA-type cap
would be placed over the entire landfill areas. Surtace water
control featur.., such a. diversion ditches and erosion control
matting, would be placed aa needed. At Landfill '1, a subdrain
would be placed along the upqradient sides of the Landtill. This
subdrain would extend to sutficient depth (10 - _14') to lower the
local water table to below the bottoa of the waste cells.
Intercepted ground water would be discharged by gravity drain to
the Willis Branch.
The mUlti-layer c~; at both landfills would reduce the
amount of precipitation-reaching the waste, thereby limiting the
potential for leachate generation. The subdrain at Landfill #1
-10-
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would prevent ground water contact with the waste further
reducing. the potential for leachate generation. This alternative
would virtually eliminate the migration of low levels of
contaminants into the ground water. Because additional leachate
would no longer be generated and the potential for ground water
contamination would be minimized, nearly all risks associated
with exposure to ground water and leachate would be eliminated.
Deed restrictions would prevent future disturbance of the caps,
ground water monitoring would allow detection of any failure in
the remedy, and regular site inspection and maintenance would
provide long-term assurance of the effectiveness of the remedy.
The engineering aspects of this alternative would be fairly
easy to implement using conventional construction materials and
methods. The estimated time frame for implementation is six
months following approval of the Remedial Action Work Plan.
No che~ical- or location-specific ARARs are violated by the
Site in its current condition. All onsite activities would be
carried out in accordance with the Occupational Safety and Health
Administration (OSHA) regulations for workers at remedial action
sites. Remedial actions are not expected to disturb the wetlands
located to the west of Landfill #2. However, construction
activities at Landfill #1 are likely to cause minor disturbances
along the periphery of the wetlands located along the Willis
Branch. Possible disturbances could include increased sediment
yield, clearing of some trees and bushes, and damage resulting
from equipment access. These disturbances should be kept to a
minimum, and construction plans would be reviewed and approved by
the U.S. Army Corps of Engineers and DNREC. Ground water
discharged from the subdrain to the Wil~is Branch will have to
comply with Delaware Surface Water Quality Standards of 1990.
Because the ground water upgradient of the landfill is not
contaminated, treatment of the. ground water to remove hazardous
constituents would not be necessary. However, treatment may
still be necessary due to the indigenous high levels of iron in
the shallow aquifer. Discharge limitations would be developed
based on Delaware Surface Water Quality Standards ot 1990. This
alternative would comply with all chemical-specific ARARs.
Before any remedial actions are conducted at the Site, the
Delaware Department of State would be contacted to ensure
adherence to the National Historic Preservation Act of 1966.
Capital Cost: $
Operation' Maintenance Cost: $
Net Present Worth: $
4,343,000
921,000
5,264,000
Alternative 6 -- Volatile Organic Compound (VOC) Stripping by
Aeration. This alternative involves removal of VOCs from the
waste by aeration, first by aggressive agitation within an
enclosed space, and second by further aeration outside the
shelter. After aeration, the treated material would be
-11-
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stabilized,_~it necessary, and disposed ot onsite. This
alternative also includes a Site fence; a Site maintenance
program, deed restrictions on future ground water and land use
. . ,
ground water and leachate mon1tor1ng, and a Site review every
five years.
In order to implement this alternative, an enclosed shelter
containing air exchange features to control VOC release to the
surrounding air would be constructed at Landfill fl. The
material in Landfill #2 would be excavated and transported to
~ndtill #1 for treatment and disposal. Empty Landtill '2 waste
cells would be backtilled and graded. The same treatment process
wou~ be applied to the material i~ Landfill #1. Approximately
45,000.yds of waste and 15,000 ~ds ot soil mixed with ,aste
from Landfill f1, and 45,000 yds of waste and 5,000 yds of soil
mixed with waste from Landfill '2 would be treated under this
alternative~ The primary method for reducing the concentration
of contaminants of concern is permanent removal of VOCs by
aeration. Although no treatability testing has been conducted, a
landfarming equation modified by an aeration factor was used to
predict the effectiveness ot this treatment method. An estimated
95' (two orders ot magnitude) reduction in concentrations of
total VOCs was predicted. .
This alternative would address the waste in the landfills,
the potential source ot offsite contamination. Since all waste
would be removed from Landfill '2, and since the waste residuals
resulting from the treatment of the material from both landfills
will contain substantially reduced levels ot contaminants and
would be landfilled in accordance with Delaware Solid Waste
Disposal Regulations of March 1990 or RCRA Subtitle C (hazardous
waste management), virtually all risk evaluated for the Site
would be eliminated. Treatment of all waste material from both
landfills would be expected to take one year to eighteen m9nths. .
Materials required for this alternative are available. However,
potential implementation problems include protection ot workers'
health, air monitoring requirements, and potential for slowdown
of the process due to variability in VOC emissions:
No chemical- or location-specific ARARs are violated by the
Site in it. current condition. All onsite activities would be
carried out in accordance with the Occupational Safety and Health
Administration (OSHA) regulations for workers at remedial action
sites. Because there are no air quality ARARs for the
contaminants ot concern, a site-specific air quaJity monitoring
program, developed using health-based exposure levels, would be
included as a part of the health and safety plan developed for
remedial action. Although the waste present at the site is not
now considered a hazardous waste or hazardous substance under
RCRA, treated waste would be subject to reclassification based
upon Toxicity Characteristic Leaching Procedure (TCLP) testing
prior to disposal. If the treated waste were reclassified as a
-12-
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hazardous waste, subsequent disposal of the waste would comply
with RCRA ~Ubtitle C (hazardous waste management). It the
treated waate was not reclassified, disposal would comply with
Delaware Solid Waste Disposal Requlations of March, 1990.
Remedial actions are not expected to disturb the wetlands
located to the west of Landfill '2. However, construction.
activities at Landfill 11 are likely to cause minor disturbances
along the periphery of the wetlands located along the Willis
Branch. These disturbances should be kept to a minimum. If
disturbance of the wetlands is unavoidable, mitigation measures
should be implemented, and construction plans should be reviewed
and approved by the U.S. Army corps of Engineers and DNREC.
Before any remedial actions are conducted at the Site, the
Delaware Department of State would be contacted to ensure
adherence to the National Historic Preservation Act of 1966.
Capital Cost: $
Operation' Maintenance Cost: $
Net Present Worth: $
16,281,000
427,000
16,708,000
Alternative 7 -- Onsite Incineration. This alternative would
involve excavation of all waste from Landfills '1 and '2,
incineration of waste material from both landfills at Landfill
#1, stabilization of incinerator ash and pollution control system
waste, and onsi~e containment of stabilized materials at Landfill
#1. Landfill'2 cells would be backfilled with clean fill and
revegetated.
In order to implement this alternative, approximately 10
acres would be cleared at Landfill '1 for incinerator staging and
general support activities. Surface water control features,
including a diversion ditch and sedirent catch basin, would be
developed. Approximately 60,000 yds of waste material would .be
exc ~ted from Landfill '1. Approximately 50,000 yds3 of .
adc~~ional waste would be excavated from Landfill #2 and
trapsported to Landfill '1 for treatment. A total of 110,000
yds of material would be incinerated. An estimated 79,000 yds3
of ash and scrubber waste, along with soil mixed with small:
quantities of waste excavated at Landfill '1, would be stabilized
and contained onsite. A Site monitoring and maintenance plan
would be iaplemented and a Site review would be conducted every
five years.
This alternative would address the waste material itself,
the potential source of offsite contamination. The incinerator
would destroy 99.99' of the VOCs in the waste. Residual
materials remaining onsite would pose very little threat to human
health and the environment (estimated at 0.1' of the current
risk). Excavation and incineration of waste materials and
closure of the landfills may take as long as seven years from the
start of remediation.
-13-
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No ch..ical- or location-specific ARARs are violated at the
Site. Incinerator operations would comply with RCRA incineration
operation regulations (40 C.P.R. ~art 264~ Subpart 0,), including
performance standards, and operatlng, monltoring, and inspection
requirements. Water quality requirements for discharge of waste
water following treatment of scrubber ash blowdown would be
subject to state and federal National Pollution Discharge
Elimination System (NPDES) rules (40 C.P.R. Parts 122 through
124, except, in accordance with Section 121(e) of CERCLA, 42
q.s.C. S 9621(e), for permitting requirements). Although the
waste present at the site i. not now considered a hazardous waste
or a hazardous substance under RCRA, treated waste would be
subject to reclassification based upon Toxicity Characteristic
Leaching Procedure (TCLP) testing prior to disposal. If the
treated waste were reclassified as a hazardous waste, subsequent
disposal of ,the waste would comply with RCRA Subtitle C
(hazardous waste management). If the treated waste was nc~.
reclassified, dispos~l would comply with Delaware's Solid W, .~e
Disposal Regulations of March 1990.
During Site work, Clean Air Act (CAA), 42 U.S.C. S 7401 et
seq., and Delaware Regulations Governing the Control of Air
Pollution would have to be met. Compliance with National Ambient
Air Quality Standards (NAAQS) for particulate matter (40 C.F.R.
Part 50) would also be required. In addition, because excavation
and handling of the waste would allow VOCs to be released into
the atmosphere, a site-specific air quality monitoring plan would
be developed to ensure the health of workers and nearby residents
is not threatened by Site activities. All onsite activities
would be carried out in accordance with the occupational Safety
and Health Administration (OSHA) regulations for workers at
remedial action sites.
Remedial actions are not expected to disturb the wetlands
located to the west of Landfill '2. However, construction
activities at Landfill '1 are likely to cause minor disturbances
along the periphery of the wetlands located along the Willis
Branch. It disturbance ot the wetlands is unavoidable, adequate
mitigation measures should be implemented, and construction
plans should be reviewed and approved by the u.S. Army. Corps of
Engineers and DNREC. Betore any remedial actions are conducted
at the Site, the Delaware Department of State would be contacted
to ensure adherence to the National Historic Preservation Act of
1966.
Capital Cost: $
Operation' Maintenance Cost: $
Net Present Worth: $
82,571,000
427,000
82,998,000
8.
Summary of ComDarative Analysis of Alternatives
-14-
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The following section provides a briet comparison ot each of
the altern&tives developed for this Site to each ot the nine
evaluation criteria identified in the National Contingency Plan
(NCP). The nine criteria are summarized in Table 14. The tirst
two criteria, overall protectiveness and compliance with ARARs,
are considered threshold criteria which any selected alternative
must meet. The next five criteria, long-term effectiveness and
permanence, reduction of toxicity, mobility, or volume, short-
term effectiveness, implementability, and cost, are considered
the primary balancing criteria. The final two criteria, state
and community acceptance, are referred to as modifying criteria,
which are evaluated fOllowing the comment period for the RI/FS
and the Proposed Plan.
Overall Protection of Human Health and the Environment
No Action: This alternative would not result in any
reduction in overall risk posed by the Site. By not preventing
contact "':~.t.h onsite contaminants and not preventing future
residential use, this alternative is not protective of human
health and the environment. Since this alternative does not meet
the threshold criteria, it will not be carried through for
analysis against the remaining criteria.
Monitoring: Although this alternative would detect changes
in Site conditions, it would not restrict access to Site waste
and allows future residential use of the Site. Therefore, it
would not result in any reduction in overall risk. This.
alternative is also not protective of human health and the
environment and will not be retained for further analysis against
the remaining criteria.
Limited Action: By covering leachate seeps and closing the
leachate collection system, this alternative would prevent direct
contact with the leachate at the Site. Deed restrictions would
prevent future residential use of the property. Monitoring would
detect any changes in ground water quality, and if necessary, a
Ground Water Management Zone can be developed and replaceme~t
wells installed. The site fence would restrict access of .
unauthorized persons to the Site. This alternative virtually
eliminates the possibility of exposure to waste and leachate and
drives the cancer risk and Hazard Index score below 1 x 10.6 and
1.0, respectively. This alternative is protective ot human
health and the environment. .
Soil Cap: In addition to the protection described under the
Limited Action alternative, this alternative would further.
enhance the long-term stability of the Site and maintain cell cap
integrity. This alternative is protective of human health and
the environment.
Multi-Laver CaD (both landfills) and Subdrain (Landfill #1
-15-
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~: Tbia.alternative would reduce the amount of leachate
generated by both landfills by use of engineering controls and
would further reduce the potential for contact with the wa~te
using institutional controls. The carcinoqenic risk and Hazard
Index score under this alternative would be well below 1 x 10'6
and 1.0, respectively; therefore, this alternative is protective
of human health and the environment. .
VOC Striccinq: By removing waste from Landfill '2, all
risks associated with that portion of the Site would be
eJiminated. All waste fro. both landfills would be treated,
reducing by 95' the amount of VOCs found in the waste. Treated
waste would be disposed of at Landfill '1 in accordance with the
requirements for an industrial landfill. During implementation,
a signtficant amount of VOCs would be released into the
atmosphere, causing potential problems for site workers and
nearby residents. After implementation, this alternative would
reduce the carcinoqenic risks and Hazard ~ndex scores to below
1 x '0'6 and 1.0, respec~ively, and is the~~fore protective.
Onsite Incineration: Removal of waste from Landfill '2 for
treatment at Landfill '1 would eliminate all risks posed by
Landfill #2. Destruction of 99.99' of the VOCs in the waste and
subsequent disposal of stabilized ash as required for an
industrial landfill would reduce the carcinoqenic risks and
Hazard Index scores to below 1 x 10" and 1.0, respectively, and
is therefore protective.
Comcliance with ARARs
Site media do not currently e~ceed any chemical-specific
ARARs, nor do they violate any location-specific ARARs. Onsite
activities for all alternatives would be carried out in
acc~rdance with the Occupational Safety and Health Administration
(as ,) requirements for workers at remedial action sites (29
C.r..R. Part 1910). Remedial actions are not expected to disturb
the wetlands located to the west of Landfill '2. However,
construction activities along the northern slope of Landfill #1
are likely to cause minor disturbances along the periphery of the
wetlands located along the Willis Branch. These disturbances
will be kept to a minimum, and construction plans will' be
reviewed and approved by the U.S. Army Corps of Engineers and
DNREC. Before any remedial actions are conducted at the Site,
the Delaware Department of State will be contacted to ensure
adherence to the National Historic Preservation Act of 1966.
Action-specific ARARs have been identified for both
treatment alternatives (VOC Stripping and Incineration).
Excavation and treatment of waste could result in release of
above health based standards. Although the waste present at
site is not now considered a hazardous waste or a hazardous
substance under RCRA, treated waste would be subject to
VOCs
the
-16-
-------
reclassification based upon Toxicity Characteristic Leaching
Procedure (~LP) testing prior to disposal. If the treated waste
were recla8.ified as a hazardous waste, subsequent disposal of
the waste would comply with RCRA Subtitle C (hazardous waste
management). If the treated waste was not reclassified, disposal
would comply with Delaware's Solid Waste Disposal Regulations for
industrial landfills (March, 1990).
Long-term Effectiveness and Permanence
, Limited Action: Deterioration of the current capping system
is not likely to occur due to the relatively flat topographical
profile of the landfills. Locked security fences will limit
access to the Site to authorized persons and therefore will limit
potential disturbance of the caps. This alternative is rated as
moderate in long-term effectiveness and permanence as compared to
the other alternatives.
$oil Cap: 2his alterr.ative further reduces the potential
for erosion damage, and was rated as moderate with respect to the
long-term effectiveness and permanence criteria.
Multi-Laver Cap and Subdrain: This alternative would
provide the most secure source control through containment.
alternative is rated high in long-term effectiveness and
permanence.
This
VOC Strippina: Treated waste contained onsite under this
alternative would contain very low levels of VOCs. Wastes would
be disposed of in accordance with Delaware Solid Waste Disposal
Regulations of March 1990 or RCRA Subtitle C (hazardous waste
management), which provide for long-term site maintenance and
monitoring. Long-term effectiveness and permanence of this
alternative is rated as high.
Onsite Incineration: All organics would be destroyed under
this alternative. Residual ash and waste would be disposed of
onsite in accordance with applicable sections of the Delawa~e
Solid Waste Disposal Requlations of March 1990 or RCRA Subtitle C
(hazardous waste management), which provide for long-term site
maintenance and monitoring. Long-term effectiveness and
permanence of this alternative is rated as high.
Reduction of Toxicity. MObility. and Volume (TMV)
Limited Action, Soil cap, and MUlti-layer Cap and Subdrain:
Because treatment is not employed as a part of any of these three
alternatives, none achieve any reduction in toxicity, mobility or
volume.
VOC Stripping: Although the volume of the waste would be
the same before and after treatment, the VOC content would be
-17-
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reduced by an estimated 95', thereby reducing the toxicity of the
waste. Should treated waste require stabilization prior to
disposal, 80bility of the residual contaminants would be reduced.
The overall rating for reduction of TMV is moderate.
Onsite IncineratlQn: Because 99.99' of organic contaminants
in the waste would be destroyed, the toxicity of the waste would
be reduced significantly. Because of the high ash content of the
waste, volume would not be reduced significantly. Should ash
residue require stabilization prior to disposal, mobility would
~e decreased as well. The overall rating for reduction of THY is
high.
Short-~erm Effectiveness
Limited Action: Because this alternative involves very
limited site activities that would result in only limited
disturbance of the Site or waste during the two-month time frame
required for implementation, its short-term ef~ect~veness is
rated as high.
Soil Cap: During implementation of this alternative, the
entire Site would be disturbed for regrading. However, no wast.
would be disturbed during the three-month time frame needed for
implementation. Short-term effectiveness is therefore rated as
high.
MUlti-Layer CaD and Subdrain: The Site surface would be
disturbed during placement of the multi-layer caps and Landfill
#1 subdrain. However, there would be relatively little potential
for disturbance of the waste during site activities. This
alternative would take approximately six months to implement:
however, the time for implementation would be considerably
shorter than for either treatment alternative. Short-term
effectiveness is rated as moderate.
VOC StriDDinq: All waste at both landfills would be
disturbed during iapleaentation of this remedy, resulting in the
potential for significant Voc emissions. The time necessary for
implem~ntation of thi. remedy is twelve to eighteen months. Due
to short-tara risk from VOC emissions, short-term effectiveness
is rated a. low.
Onsite Incinerat~: This alternative requires excavation
and handling of all waste onsite, resulting in the potential for
significant VOC emissions and the subsequent threat to site
workers and nearby residences during site activities. This
alternative would require an estimated seven years for
implem~ntation. Due to risk associated with VOC emissions and
the long time frame required for implementation, short-term
effectiveness is rated as low.
-18-
I
I
J
-------
IJDclementability
Limited Action, Soil Cap: Both of these alternatives are
easily implemented because they require relatively simple
actions. Implementability of these alternatives is rated as
high.
MUlti-Layer CaD and Subdrain: Construction of caps at both
landfills and a subdrain at Landfill *1 would be relatively easy,
using conventional construction materials and methods. When
compared to the alternatives Limited Action or Soil Cap, this
~lternative rates moderate in terms of implementability.
VOC StriDDing: The equipment required for this alternative
is readily available. However, this operation is not routinely
performed, and control of VOC emissions could be difficult.
Therefore, this alternative rates low for implementability.
Onsite IncineratiOD. The 'availability and capacity of
mobils incinerators is ~~:lited. VOC emission control during site
activities, although possible, could be difficult. Because the
types of incinerators in use today (rotary kiln, fluidized bed,
.and infrared thermal treatment) all require relatively small
sized feed particles (one to two inches) to function efficiently,
the wastes' wet clay-like properties will necessitate substantial
pre-feed handling of the waste materials. Because the moisture
content of the waste material is high (average for waste samples
at both landfills is 40%, compared to 10 to 20% generally seen in
soils), longer residence time (and greater amounts of auxiliary
fuel) would be needed to incinerate the sludge material than
would be needed to incinerate a comparable quantity of soil.
Although it may be theoretically ~ossible to incinerate the waste
material, the physical characteristics of the waste would render
such an operation highly inefficient. Therefore, this
alternative rates low with respect to implementability.
Cost
All cost figures assume 30 years of operation, maintenance,
and monitoring.
Limited Action
Capital Cost: $
Operation & Maintenance Cost: $
Net Present Worth: $
555,000
685',000
1,240,000
Soil Cap
Capital Cost:
$
1,706,000
-19-
-------
.
Operation & Maintenance Cost:
~et Present Worth:
$
$
778,000
2,484,000
Multi-Laver Cap & Subdrain (Landfill #1 only)
Capital Cost:
Operation & Maintenance Cost:
Net Present Worth:
VOC Stripping
Capital Cost:
Operation & Maintenance Cost:
Net Present Worth:
Onsite Incineration
Capital Cost:
Operation & Maintenance Cost:
Net Present Worth:
State Acceptance
$
$
$
4,343,000
921,000
5,264,000
$ 16,281,000
$. 427,000
$ 16,708,000
$ 82,571,000
$ 427,000
$ 82,998,000
The State of Delaware has concurred with the preferred
remedy.
Community Acceptance
In order to facilitate public involvement in the decision
making process, EPA held a public meeting on September 5, 1990,
at the Cheswold Fire Hall to discuss the RI/FS and the Proposed
Plan. This meeting was attended LY local residents, local
officials, and members of the local news media. A summary of the
issues raised at the public meeting and in letters received
during the public comment period and EPAls responses are provided
in .~he Responsiveness Summary section of this ROD.
In general, the local citizens did not favor EPAls preferred
alternative. The citizens expressed a desire for an alternative
that would result in total removal of all waste from both
landfills. An alternative that called for complete excavation of
waste for ottsite disposal was considered during the preliminary
screening step of the feasibility study, but this alternative did
not satisfy the preliminary screening criteria: -effectiveness,
implementability, and cost-effectiveness. EPA believes that the
preferred alternative, the primary component of ~hich is deed
restrictions, is consistent with the NCP, 55 Fed. Reg. 8,846
(March 8, 1990) (to be codified at 40 C.F.R. S
300.430(a) (1) (iii) (D», which states, "EPA expects to use
institutional controls such as . . . deed restrictions. . . as
appropriate for short- and long-term management to prevent or
limit exposure to hazardous substances, pollutants, or
-20-
-------
contaainants. . . . The Use of institutional Controls shall not
substitut~:ror active response measures. . . as the sole remedy
unless such active measures are determined not to be practicable,
based on the balancing of trade-offs among alternatives that is
conducted during the selection of remedy."
9.
Selected Remedy
The selected remedy for the Site is Alternative J - Limited
Action. The selected remedy includes the fOllowing components:
Deed restrictions will be placed on each landfill
property to limit the future uses of the property. The
restrictions would prohibit any type of activity that
could disturb the landfill surfaces or the underlying
waste, or in any way increase the risk of exposure to
Site contaminants.
The entire waste dispu~~l areas of both landfills will
be enclosed by a chain-link security fence with a
locked gate to restrict the access of unauthorized
persons and equipment onto the landfills. Appropriate
warning signs will be placed along the fence.
Cover material will be placed along the northern slope
of Landfill '1 to Cover exposed leachate seeps. The
Cover will be graded to conform with existing drainage
patterns. This cover will reduce the potential for
direct contact with the leachate, and will reduce
potential erosion from surface water runoff along the
fairly steep slope.
Areas of Landfill '2 which have subsided due to uneven
settling of waste will be backfilled to grade and
seeded.
Leachate collection wells at Landfill '2 will be sealed
with grout to reduce the potential for direct contact
with leachate.
Ground water will be sampled semi-annually at both
landfills. Should monitoring detect any significant
chanqes in ground water quality, the State of Delaware
and Kent County will establish a GWMZ in the vicinity
of the Site to prevent the use of shallow ground water.
Any wells affected by the ground water-contamination
will be replaced with deeper wells. .
The landfills will be inspected semi-annually during
ground water sampling events.
~urface water monitoring will be conducted at the
-21-
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~
-Willis Branch adjacent to Landfill '1 at the same time
.. ground water monitorinq for a periOd of no less than
five years. Should any chanqes be detected in the
quality of the Willis Branch, more extensive testing
includinq bioassays, will be conducted to determine'
whether further remedial actions are necessary.
A review of this remedial action, including site
inspection reports and qround water and surface water
data, will be conducted no less often than each five
years after the initiation of this alternative as
required under Section 121(c) of CERCLA, 42 U.S.C.
S 9621(c), for sites where hazardous substances,
POllutants, or contaminants remain at the site.
The qoal of the remedial action is to reduce the potential
for future aontact with the waste or with site contaminants,
thereby reducing risk to within EPA quidelines. The cancer risks
associated with no action at both landfills is at or above EPA's
quideline of 1 x 10.4; after implementatio~ of the selected
remedy, cancer risks will be below 1 x 10.. The Hazard Index
scores associated with no action at both landfills is above EPA's
quideline of 1.0; after implementation of the selected remedy,
the Hazard Index scores will be below 1.0. The cost summary for
the Limited Action alternative is shown in Table 15. Some
changes may be made to the remedy as a result of the remedial
design and construction process. However, any potential changes
are not expected' to reduce the effectiveness of the selected
remedy.
10.
Statutory Determinations
Under its leqal authorities, EPA's primary responsibility at
Superfund sites is to undertake remedial actions that achieve
adequate protection of human health and the environment. In
addition, Section 121 of CERCLA, 42 U.S.C S 9621, establishes
several other statutory 'requirements and preferences. These
specify that when complete, the selected remedial action fer this
Site must comply with applicable or relevant and appropriate
~nvironmental standards established under Federal and. State
environmental laws unless a statutory waiver is justitied. The
selected r..edy also must be cost-effective and utilize permanent
solutions and alternative treatment technologies, or resource
recovery technoloqies to the maximum extent practicable.
Finally, the statute includes a preterence for remedies that
employ treatment that permanently and siqnificantly reduces the
volume, toxicity, or mobility of hazardous wastes as their
principal element. The followinq sections discuss how the
selected remedy meets these statutory requirements.
-22-
-------
Protection ot Human Health and the Environment.
By preventing future uncontrolled use ot the landfill pro-
perties, the selected remedy is protective of human health and
the environment. Deed restrictions on both properties will
prevent future residential development of the Site. Under a
scenario of future residential development, EPA found
unacceptable health risk. If no action were taken, the cancer
risk and Hazard Index score for children at Landfill '1 would be
1 x 10-4 and 3.26, respectively, For Landfill #2, if no action
were taken, the cancer risks for adults and children would be 6 x
~0.3 and 5 x 10.3, respectively; the Hazard Index scores would be
48 ~d 156, respectively. After implementation of the selected
remedy, the cancer risks will be less than 1 x 10.6 and the
Hazard "Index scores will be below 1.0 at both landfills.
Placement of a leachate cover at Landfill #1, closure of the
leachate collection system at Landfill '2, and backfilling
depressed areas of Landfill #2 will impro~e the long-term
stability of the Site. Ground water monitoring, surface water
monitoring, and site inspections will detect any deterioration in
site conditions. There are no short-term risks associated with
the selected remedy. In addition, no cross-media impacts (e.g.,
release of contaminants in the waste into the air) are expected.
Comoliance with Aoolicable or Relevant and Aoorooriate
Reauirements.
No chemical- or location-specific ARARs are violated by the
Site in its current condition. All onsite activities will be
carried out in accordance with the Occupational Safety and Health
Administration (OSHA) requirements for workers at remedial action
sites (29 C.F.R. Part 1910). Remedial actions are not expected
to disturb the wetlands located to the west at Landfill #2.
How' er, construction activities along the northern slope of
Lar.~_ill #1 are likely to cause minor disturbances along the
periphery of the wetlands located along the Willis Branch. These
disturbances will be kept to a minimum, and construction plans
will be reviewed and approved by the U.S. Army Corps ot Eng-ineers
and DNREC. Before any remedial actions are conducted at the
Site, the Delaware Department of State will be contacted to
ensure adherence to the National Historic Preservation Act of
1966.
Cost-Effectiveness.
The selected remedy is cost-effective because it has been
determined to provide overall effectiveness proportional to its
costs (Net Present Worth being $1,240,000). The soil capping
alternative, although twice as costly as the selected remedy,
does not offer a higher degree of protection. While both
treatment alternatives would substantially reduce the
-23-
-------
.
treatment residuals, both alternatives would still require onsite
disposal and lonq-term site maintenance, and cost more than ten
times as 8Uch as the selected remedy, Without;rovidinq any
further reduction of cancer risk below 1 x 10' .
Utiliza~ion Qf PermAQent Solutions and ~1terna~1ve T~a~ment
(or Resource Recoverv) Technoloaies to the Maximum E e t
Practicable (MEP).
EPA and DNREC have determined that the selected remedy
represents the maximum extent to which permanent solutions and
treatment technologies can be utilized in a cost-effective manner
for....the Coker's Sanitation Service Landfills Site. Of those
alternatives that are protective of human health and the
environment and comply with ARARs, EPA and the state have
determined that this selected remedy provides the best balance' of
trade-offs in terms of nine evaluation criteria and also .
considerinq the statutory preference for treatment as a principal
e 1 <~ll1~nt .
The selected remedy does not offer the deqree of permanence
either of the treatment alternatives would offer. However, the
landfills are at this time in a stable condition, and if they
remain undisturbed, should pose no siqnificant threat to human
health and the environment. In addition, neither treatment
option would siqnificantly reduce the volume of the waste
material, and treatment residuals would have to be manaqed
onsite. Unlike the treatment alternatives, the selected remedy
poses no short-term threat to site workers or nearby residents.
The selected remedy is the easiest of the protective alternatives
to implement, and offers the greatest reduction in risk in
proportion to cost, of all alternatives considered.
The containment options under consideration all prevent
fut~re disturbances of the landfills by providinq for deed
res~rictions. Althouqh the treatment alternatives involve
removal of all waste fro. Landfill '2 for treatment and disposal
at Landfill #1, deed restrictions will still be required at
Landfill '1. The treatment alternatives were the only -
alternatives which offered any reduction in toxicity,. mobility,
or volume; however, because of the potential for VOC emissions
above health-based levels, anticipated difficulty in handling the
waste material, and the time required for implementation, these
alternative. were rated considerably lower in short-term
effectiveness than containment options. Onsite incineration
would be very difficult to implement efficiently due to the
physical characteristics of the waste.
The selected remedy does not employ any treatment or
resource recovery technoloqies. The waste contained onsite is a
dense, clay-like material with a low permeability. The material
would require substantial handlinq prior to and during treatment.
-24-
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Handling of. the waste material would cause significant release of
VOCs into ~e atmosphere which would be difficUlt to control.
These VOCs may pOse a health threat to site workers and nearby
residents. In addition, the high moisture content of the waste
and the necessity of creating a small, uniform size feed from a
thick, clay-like material would make efficient incinerator
operation difficult if not impossible. Upon evaluating the
remedial alternatives developed for this Site, EPA has determined
that treatment is not practicable under the circumstances
associated with this Site.
Preference for Treatment as a PrinciDal Element.
The selected remedy does not satisfy the statutory
preference for treatment as a principal element. As stated in
the preamble of the NCP, EPA expects that treatment will be the
preferred means by which principal threats posed by the Site will
be addressed. The preamble characterizes princ;Ycll threats as
"wast~ that cannot be reli~Oly controlled in plac3, such as
liquids, highly mobile materials. . . and high concentrations of
toxic compounds. . . . Treatment is less likely to be
practicable when sites have large volumes of low concentrations
of material, or when the waste is very difficult to handle and
treat... (55~. E&g. 8,703 (March 8, 1990». The waste
material found at this Site is neither liquid nor highly mobile,
and can be reliably controlled in place. Concentrations of
contaminants are similar in all waste trenches at both lapdfills.
The Site contains a large volume of material (110,000 yds of
waste) that would be very difficult to handle and treat due its
high moisture content and clay-like physical properties as well
as the potential risk posed by VOC emissions. EPA and the state
have therefore determined onsite containment of waste is an
appropriate remedial action.
11.
Documentation of Siqnificant Chanqes
The preferred alternative described in the Proposed Plan was
the selected remedy, Limited Action. This alternative was
described in the Proposed Plan as follows:
This alternative calls for installation of a cov~ over any
leachate seeps present at landfill '1, closure of the
landfill '2 leachate collection system with grout, regrading
(backfilling and seeding) depressed areas on the surface of
landfill '2, and deed restrictions on both landfills. This
alternative includes Site inspections, ground water
monitoring at both landfills, and surface water monitoring
at landfill II. Should ground water monitoring detect any
developing plume in the Cheswold aquifer, the state could
develop a Ground Water Management Zone (an area of
restricted ground water use established under state
authority) in the vicinity of the Site to control use of
-25-
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local ground water. It surtace water monitorinq detects any
chang.. in the water quality ot the Willis Branch, in depth
biological testinq of surface water and leachate would be
pertoraed.
The Proposed Plan was released tor public comment on August
22, 1990. EPA reviewed all written and verbal comments submitted
durinq the public comment period. Upon review of these comments,
EPA determined that no significant chanqes to the remedy, as it
was oriqinally proposed in the Proposed Plan, were necessary.
However, in response to public comment, EPA has amended the
remedy to include secure fences and posted warninq signs at both
landfills.
\
-26-
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Table 1
Data summary for Landfill '1: contaminants of concern, number of
samples taken, number of hits, and ranges of concentrations of
contaminants for waste, leachate, and ground water. Maximum
contaminant levels (HCLa) set under the Safe Drinking Water Act
are given along with ground water data. All values given in
parts per billion.
No. of No. of
Media Contaminant samDles hill
Waste Benzene 8 0
Chloroform 8 1
Ethylbenzene 8 8
Styrene 8 6
Cresol 8 0
Dibutyl Pthalate 8 2
Phenol 8 0
... - . 6 ~
'_<'\C 'iUum
MaHganese 6 6
Leachate Benzene 2 2
Chloroform 2 0
Ethylbenzene 2 2
Styrene 2 1
Cresol 2 0
Dibutyl Pthalate 2 0
Phenol 2 0
Cadmium 2 0
Manganese 2 2
Ground Benzene 7 1
water Chloroform 7 0
Ethylbenzene 7 1
Styrene 7 0
Cresol 7 0
Dibutyl Pthalate 7 1
Phenol 7 0
Cadmium 7 1
Manganese 7 7
Ranae
MCL
n.d. - 1100000J
61000J - 2300000
n.d. - 5000000
n.d. - 2100J
n. d. - ~ ~ t.
15J - 33J
1J - 2J
4J - 77
n.d. - 11
---
673 - 696
n . d . - 1J
5
n.d. - 4J
700
---
.
n.d. - 2B
n.d. -' 5.6
20J - 297J
10
n.d.: Not detected
J: Indicates data was quantitatively estimated -
B: Indicates similar concentration was found in a
blank sample.
laboratory
-------
Table 1 - continued
Data summary for Landfill t2: contaminants of concern, number of
samples taken, number of hits, and ranqes ot concentrations of
contaminants for waste, leachate, and qround water. Maximum
contaminant levels CMCLs) set under the Safe Drinkinq Water Act
are given alonq with qround water data. All values qiven in
parts per billion.
No. ot No. ot
~dia contaminant samDles h1ta
Waste Benzene 8 2
,. Chloroform 8 1
Ethylbenzene 8 8
Styrene 8 8
Cresol 8 5
Dibutyl Pthalate 8 8
Phenol 8 7
Cadmium 8 1
Manqanese 8 8
Leachate Benzene 3 1
Chlorotorm 3 0
Ethylbenzene 3 3
styrer.e 3 2
Cresol 3 3
Dibutyl Pthalate 3 2
Phenol 3 3
Cadmium 3 0
Manqanese 3 3
Ground Benzene 8 0
water Chloroform 8 0
Ethylbenzene 8 1
styrene 8 0
Cresol 8 0
Dibutyl Pthalate 8 0
Pbenol 8 1
CacSaiu. 8 0
Manganese 8 8
Range
27 - 44J
n.d. - lOB
24000 - 1900000J
21000 - 5500000
n.d. - 4000
4000J - 120000J
n.d. - 38000J
n.d. - 1.7
9780J - 15600J
~
n.d. - 10J
1100 - 28000J
n.d. - 5000J
160J - 2800J
n.d. - 55 OJ
1000J - 12000J
127J - 519J
5
n.d. - 5
700
n.d. - 11J
10
12J - 359J
n.d.: Not detected
J: Indicates data was quantitatively estimated -
B: Indicates similar concentration was found in a
blank sample.
laboratory
-------
I.b II ~ Cehtt Sui 1.1 Ii.. tlldl illS i tl. C.. tll i... II 01 "".... "t """ do.... iOd "rc i "'m.;
810'" .
f:': liJ~aa~
~H:';~~ ~o .
Sar:~1 aad cOlpvuads
3~a !~D~
.ButY; ~eazYl pb:balate
(h!vroforl
Di-a-butYl pbtbalate
ftby lbeueae
Saalaaese aad cOlpound.
StHeae
~rl~OlcroetbYleae iTCl1
hiene {auedl
.~UD'rLL '0. Z
Alalaal
&DtlIODY aDd cOlpoald.
Barial aad cOlpoald.
Beueae
Beuolc acid
Beuyl alcobol
Berylliul aad cOlpoand.
Batyl bealYl patAalate
Carboa jilultide
Cruolil- J
(relc 1 (v- )
Di-a-ba:,l patbalate
hbYlbeuue
Saal:-!.e aDd cOlpoald.
Pbeao 1
Stnue
Tolueae
1.2.3-Triciloropro....
hleu (Iind)
;.j:~~"~
:Jral r~baled
~Oral ifD: rnbal~j !f~: Petea.:, Petea.:,
:(I,/i'/d) !I,/i'id) 'actor: , actor:
(lilli/ii, j') (it: I,:ii:j::
5 JOI-J2 1.401-04
Z .901-02 2.901-02
2.001-01
1.001-112 6.101-03 8.101-02
1. 001-01
1. 001-01
2.JOI-01 3.001-04
2.001-01 3.001-02
1.101-02 1.101-02
2.JOI+00 4.011-01
2.901+00
4. 001-04
5.001-02
1. 401-04
4. 001+00
3.001-01
5.001-03
2.001-01
1.001-01
5.001-02
5.001-02
1.001-01
1. 001-01
2.'11-01
4. 081-12
2.081-'1
J. 1t'-11
'.HI-U
2. tI.+OI
2.901-02
2.901-02
4. 301+ 00
8.401+00
1.001-01
3.001-04
2.0U-U
1. 501+ 00
3.001-02
1.001-01
4. 001-01
-------
TaUe 3 Coter. S&ai~tiol L.ldfill Site. I.til.ttd d.il, iat.tel of cOlt.li..lt. of coacern. wppe ~ :vU~ ~
lit'till 'ICI!~ CIIC,r riltl. lad halard indele. I..ociated litb iDfe.tioD of drill ii' later by adu:~s
Iitilit'. IJIIII I bot, leicht of 10 I'. 30 years of exposure d~rinl a 70-year lifetlte. and la,e&ti~n:f :
liters of tl' lat,r per da,.
:D8[UriG WATH
r~a!lc!~1 ! Mon -.:aacer;
h~i!!!~ ~ I ! e t ae ChroDlc apper Bound
~ intake ratite Lifulle ~uard Index
...,jnc.
Fd :iJtin t (il,ll) 1,/I,/d II/I,/d CUcer hli (Intale/RfD)
iaMDrI~~ 80. 1: 'DOL r
Barluraad cOlpound. 7.501+01 9.181-04 2.141-03 4.231-02
Stuese : 2.001+00 2.451-05 5.711-05 1.101-01
Batyl bell,l phthalate
Chiorofon
Di-n-butyi phthalati
it; y lbeuese 1.101+01 4:JW - 0 4 2.201-03 2.201-02
~al,alese and cOlpound. 6.961+02 ~.521-03 1.991-02 9.941-02
Styreae 1. 101+01 1.351-04 3.141-04 4. 041-01 1. 511-03
Tricbloroetbylele (TCI) 3.001+00 3.111-05 8.571-05 4.041-87
h lea. (Iiud) 3.001+00 3.871-05 8.571-05 4.291-05
Su: 5.111-01 1.&11-01
LAIDrILL 10. 2: ADOLT
"
Alaluul 2.941+03 3.&01-02 8.481-02 2.901-02
Aatlloa, lid ~olpoald. 1. 511+02 1. 851- 03 4. 311-U 1. 081+01
Bariwl aid cOlpoQlds 2.941+02 3. 601-03 - 8.411-03 1. 681-0 1
BeueDe I 1.001+01 1.221-04 2. 811-04 3.551-01
I
Beuoic acid I 9.201+03 1.131-81 2.131-01 &.511-02
I
Beu,l alco.ol I 2.411+13 i4l-02 1.111-02 2. 291-0 1
I
Ser,llial aid cOlpogld. I 1.311+11 1.511-85 t 711-05 1.141-05 1.431-03
I
Sat,l bela,l p~t~lllt. I
I
Carbol dilulfid. I 1.111+12 2. 081-03 4.111-13 4.111-02
I
Cruol(I-) I 2.111+U J.UI-U 1.081-1% - 1.111+00
'
Cruol( 0-) ' 1. 111+'2 1.111-13 4. 511-OS 1.141-02
I
Di-.-bl"l "tUlatt I 5.511+12 1.731-03 1.511-02 1.5n-0l
I
h~, lIMn... I 2.HI+14 J. UI-Ol 1.011-11 8.001+08
I
81111Ie.. 114 E"'I~'" I 5.111+12 1.311-03 1. 481-02 1.411-02
I
Phlol I 1. 211+14 1.471-01 J. 431-01 8.511+00
I
Styru. I S.III+U 1.121-02 1. UI-11 1.141-03 7.141-01
I.
To hea. I 1.281+81 1.411-04 3. UI-14 1.141-03
'
1.2.3-Tric~loropropale ' 2.181+11 3.551-04 8.211-04 3.551-15 1. 311-0 1
I
IJ leu. (Iiled) I 1. 181+02 1.351-03 3.141-03 1.571-03
'
Sal: 1.141-13 3.071+01
-------
hUt 4 Coters Sili~lt10' ~.Idtill Site. I.~ill~td dail, intaiel ot cOlt.li.a.t. ot CODcer~, ap~r ~cunJ
111.,110 ...... ,tic., '1.1.. I.. II"', 1...... "'0,1".. .ill 1.,"'10. 01 "I.li.. "'.r b, 'I:::",
1.11111.. ....... bod, ..1.11 01 11 I.. 5 ,..r. 01 '"'O.or. .orl" . 70-,..r 111..i... II' 10""", ,f :
litera ot ~riltll1 liter per da,.
:DIIIIIIG WA~n
: ':an.:er) : MOIl-cancH;
Albient LifHlle Ch rOIllC Opper Bollnd
Co~c. rUne La tare Lifeti.. ~uud rodu
Po llu tan t (i/IIl) II/illd I,/it/d Cucer h.1 (InuU/ifD!
tUDfrU 10. I: C8ILD
Barlill aad cOlpouad. 7.501+01 6.301-04 8.821-03 1.761-01
Beueae 2.001+00 1.681-05 2.351-04 4.811-07
But,l beazYI phthalate
Chlnoton
Di-Q';utyl pathalate
Ithy lbeu~e 1.101+01 6. HI-i)4 9.061-03 9.061-02
!allaDese aDd cOlpounds 6.961+02 5.851-03 8.191-02 4.091-01
StHne 1.101+01 9.241-05 1. 291-03 2.171-08 &.411-03
Tric~loroetbYleDe fTCI) 3.001+00 2.521-05 3.531-04 2.771-07
h lete r liled) 3.001+00 2.521-05 3.531-04 1.781-04
Saa: 3.541-01 6.831-~1
LAlD'I~L 10. 2: CHILD
Halloal 2.941+03 2.411-02 3.461-01 1.191-01
&DtltOD' aad ~olpoaadl 1. 511+02 1.271-03 1. 781- 02 4.441+01
Barlul and ~o.pounds 2.941+02 2.411-03 3.461-02 6.$21-01
Beune 1. 001+01 8.401-05 1.111-03 2.441-08
Beuoic acid 9.201+03 7.731-02 1.011+00 2.711-01
6euy 1 a leobo I 2.401+03 2.021-02 2. 821-01 9.411-01
6erylliul aid cOlpoald. 1.311+10 1.091-05 1.531-04 4.701-05 - 3.0&1-02
Bat,l btlz,l P~tillate
Carbol di.altide 1.111+82 1.431-03 2.001-02 2.001-01
CruoUI-J 2.111+13 2.351-02 3.2U-Ol 6.5"+00
Cruoi( 0-) 1.111+82 1.341-03 1.881-02 3.76(.01
Dl-~-bat,l pit~llr&t 5.5'1+82 4.621-03 6.471-02 6.4;1-01
!th, 1 beuut 2.111+14 2.351-01 3.291+00 3.291+01
Saa,aDese aid CD tL 1, S.III+12 4.361-03 6.111-02 3.051-01
P~!!Iol 1.2'1+'. 1.011-01 1.411+00 3.531+01
$tnue 5.'11+13 ..201-02 5.881-01 1. 251-03- 2.941+00
Tollleae 1. 2'1+01 1.011-04 1.411-03 4.711-03
1.2.3-Tricaloropr~pal' 2.9U+Ol 2.441-04 3.411-03 2.441-05 5. UI-01
bleDe ~Iued) 1.101+02 9.241-04 1.291-02 6.411-03
$111: 1. 331-03 1.261+02
-------
.
TJUe 5 Coter. .SuHlhol wdfill Site. "tilat~ dlily lUJiel ot COItUiluU of CODCer!. uppu ~OUQ:
lifetile 'I~' ClICef riltl. IDd bazlrd lndelel a810Ciated lith ilcideltJl loil i&(estiol b, adu,:s
!Itiaatel J''''' 1 bod, 'ei,~t of 10 i,. 30 ,ears of elpOIUr! duria, a 10-rear lifetile. ana in,estiCQ jf ~:
I' ot relidtt'111 loil per dl'.
?j~:J:aDt
LAlor ILL ~O. 1: AOaL!
Bariul and CO'POUIOI
Beuue
Butyl benz,l pbthalate
Chivrcfon
Dl-n-bDt;L pht~. late
I:n,lbeuue
BI1I18ele lid cOlpoaldl
Styrue
~ric~loroet~,leD' (TCII
If leae ! Ilud)
LAIDrILL 10. 2: ADaLT
!lalaD.
Antilon, and ~olpoaDdl
BlrlDI and COlpoDld.
Beune
Beuo ic ae ld
Bfu,l Ilcoiol
Berylliul aad cOIpoald.
Batyl bell' 1 pitblll~
Carbol di.altide
CruoHI- )
Cruol( 0-)
Di-I-hQtJl pitWN
hbrlM..e,.
Ban,IDe.e 114 EIII.LtAI
P~no 1
Styr"e
Tolaeu
1.2.J-Tric~loroproPJle
hlue (,iud)
'sor~ rIGIST;ul
hOiut
Con~.
1II/t'I
2.001+02
1.101.1)3
2.101+00
2.301+03
3.401+03
1.201+02
4.411+01
1. 481+01
I
I
I
I
I
I
I
I
I
I
I
I
I
I
,
,
I
I
I
I
I
I
1.5'1+11
1.111-11
.."1+11
1.281+12
1.I8I+U
J .111+11
5.511+13
%.481-11
4.401-01
, j:a!!~!!' i
~ifet~1f
rntalt
I,/k,/d
1.351-05
4.041-04
7.711-01
8.451-04
1.251-03
4.411-05
1.121-05
5.141-0'
3.411-05
4. 041-0'
1. 471-0'
4.411-05
'.981-04
1.401-05
2.021-03
8.821-08
1. &21-07
lion-cancer: .
Cbronlc
hUh
I,/k,/d
1.111-04
~.431-04
1.801-06
1.971-03
2.911-03
1. 031-04
Su:
3.171-05
1.%01-05
8.141-05
I. UI-O'
3.UI-0'
1.031-04
1. 631-03
3.211-05
4.111-13
2.011-07
3.711-01
SII.:
Opper BaaDd
Lif!t~1e
Cucer list
2.461-08
3. 751-05
3.991-05
4.111-01
I. 111-05'
6.111-05
hurd In.ju
( loule/itD)
8.511-04
9.431-02
1. 801-05
1. HI-OZ
1.411-02
5.141- 05
1. 211-01
4.111-85
. 4.071-14
,. UI-07
6.111-05
1.031-03
1. .n-oz
8.141-04
2.311-02
1.111-07
1.891-07
4.221-02
-------
hbl~ 6 . Cohn ~..it1tioll. Ludfill Site. Ist:uted .jaily intates of cODtUiullts jf COl1ce~l1. .iĄpe~ :-:~::
1i:~tlte eICef~ cl1cer rlltS. al1d ~az~rd il1~eles associated 'lt~ illcideltal ill,eltloD ~f sOli by ca1idr~~
hHutei .... a bod, lu,at o. 1. I,. ~ years of exposure '3UrlD( a TO-year llfetlte. lIId inclj!::.::
::,el~ioll of ZII IC of residelltial 50.1 ~er day.
?:.i ~'Jt3llt
~UDrLL ~O. ~: (BLD
Bar:JI aad COlPOUII~S
Ben:e!!!
Buty: bell:11 pbtbalate
':hlonforl
Ol-o.batyl po,~a:a>e
luy i ben:!!!!
Bll1,alleSe aDd ~olpoullds
Styrelle
Tri~Dioroetb1leDe (TCI)
hlelle (Iiled:
LAJD':~~ JO. 2: CHILD
&!UI;!!UI
&11,.10111 alld cOlpoaDds
Bar:uI alld ~olpoUQds
SeueD!
Beu" Jcid
Bn:;. Hcohol
Ber1~11al alld cOlpoaDdl
8atyl belJyl phthalate
Car~. disalfide
Cresolrl- )
Cresa l( 0-)
Oi-lI-bQt,l p~tkalatf
hbJ lbeul..
BIlI,allele lid t.II.II4.
PUIO I
Styrue
TolQne
1.2.3-TricbloropropaDe
h lell (liIed)
! SOrL :'GISTIOJ
!tOlen,
Cuoc.
II/ I'
2.001-02
1. ;Ji-u3
2.101.00
2.301+03
3.401+03
1.201+02
4.401+01
1. 401+01
1.501+01
1.111-01
4.881+00
1.211+0%
1.IU+U
1.111+11
5.501+03
2. 401-01
4.401-01
.=allcer \
~lfH:Je
I n 'lie
1(/.lld
1.681-04
1.241-04
1.761-06
1.9JI-~3
2.861-03
1.011-04
3.701-05
1.111-05
7.111-05
1.241-08
3.3i1-06
1. 011-04
1.601-03
3.191-05
4.621-03
2.021-07
3.701-07
:NoD-caDce~:
Chr~Dlc
Intate
I'/.'/d
2.351-03
1.291-02
2.411-05
2.711-u2
4.001-02
1.411-03
Su:
5.111-04
1.151-04
1.1ZI-U
1.291-01
4.711-05
1. 411-03
2.241-02
4.471-04
6.471-02
2. 821-06
5.181-05
Sa:
Oppe ~ 30~Dd
Llfet~.e
CaDcer hu
5.641-C6
8.571-05
9.141-05
1.071-06
1.391-0.
1. 401-04
~Hard :ndex
(IDteUe: ifD'
1.181-02
1 291-00
2.411-04
:.ill-01
2.001-01
7.061-04
1.781+00
5.411-04
5.591-03
1.Z9I-05
9.411-04
1.411.~2
2.241-01
1.121-02
3.241-01
9.411-01
2.591-06
5.791-01
-------
TI~l._J Coten Suituiol Ludfill Site. htillted diil, illhiu ~f ~OlltUlI1UU)f ~~QCPj ._-~. -
lifeU.. IJCIII euctr' ria... ud ~uard !Ddnes u.ociated I1tb derul COQUct Iltb rellduta! 50;;' ;; h,-. .
3dulu. IIUlitf. unn i bod, iUeD. .j! '0 I-e, 30 Jears of exPosure d;,;rilll a 10-year ~ifetll!. :~s:
~i~e!!lIce of %.11 &l/CIZ, alld derlal aD5~!p,:~~ ~f :~.
;i;!A~ ~~M~AC~ .;~3 5CIL
:Cncer\ 'Mol-cucer)
hblut ~ifeti" Chrolic Opper Bould
COliC. I II ute but. Liteti.. hurd llldn
?;l ;'..tant 11,/lel le/le/d le/ie/d Cu~.r Riu (hute;UD\
~AMD':~~ MO~ 1: ADOLT
Barlul 31d ~OIPOUllds,
Beuue
ButYl belli!l phth~late 2. ~01.02 3.081-05 1.181-0$ 3.591-04
Cbluroforl 1.101+03 1. 691-1)4 3.9$1-04 1. 031-u6 3.3$1-02
Di-s-bat,l p~thllite 2.101+00 3.231-01 1.541-01 1.541-06
Ith,lbeuue 2.301+03 3.541-04 1.211-04 8.2i1-113
Bll1,llele aid cOlpauadl
S t yre.. 3.401+03 5.231-04 1.221-03 1. 511-05 6.101-)3
T!iciioroeth,lelle (TCI)
hlue (Iued) 1.201+0% 1. 851- 05 4. 311-05 2.151-05
Su: 1.&71-05 5.431-02
LUDrI~L 10. 2: 'DOLT
Uall!lGl
AntilODY IDd co.pauldl
Barial llld ~olpauld. I
I
8eue ie I 4.401+11 1.111-0' 1. 511- 05 1.111-07
I
8eU01C Icid I
I
Beu,l Ilco.ol I 1. 4'1+11 % .151-0' 5.031-0' 1. &81-05
I
8eryiliu ud COl,ocU' I
I
But,l belJ,l ,~~1a" I '.511+'1 1. 411-05 3. 411-05 1.1H-04
I
Carbol dl.llfl.. I 1.111.81 1. 691-08 3.951-01 3.951-07
I
CruoUI-) . I 4.881+88 &.161-07 1.441-01 2.811-05
I
Cruol(o-) I
I
Di-II-but,l ~~ ' 1.28.+82 1. 151-05 4.311-05 4.311-04
I
itbJ I beune I 1.11.+13 2.921-04 8.121-04 6. IZI-U
I
KID'lle.e lid cOifOll4. I
I
P~tlol I 3.111+81 5.151-06 1.311-05 3.411-04
I
5tHtle I 5.501+03 1.461-04 1. ul-n 2.541-15 9.111-03
I
Toiliell 2.401-01 3.181-01 1.621-08 2.171-07
1.2.3-Yricbloro,roPliI
h ine (Iued) 4.401-01 6.771-08 1. 511-07 1.901-08
SUI: 2.561-05 1.711-02
-------
Table 8 C4tff!: Saitatiol Landfill Site. htiuted daily intakes of COUUllllllt. of cOlicern. upper CIi'lI:.
lifetite elClt. clIcer rilli. iDd ~i3ard indexes aSlociated 11th derlal coatact iit~ resideDtial 50~1 ~1
:bildr!5. 18~1.ates aSIUle a bvdy i~li~t jf 17 ie, 5 years of exposure duriD, a 70-year Llfetile. :~::
1j:~~~:~e v! %.11 11/:1%, and 1HU: :tsvr,:l;u "f :1.
:&;!A: ::H~A:7 .;73 ;J;~
'~:auce!'~ [Ion-cueer)
hbieH ~lfHile Chronic Jpper DOllnd
C..iQc. :iltaie Intake Litetile hurd index
?:.::~t!nt :I,/ie. 1,/i,/d I,/i'/oj CaDcer iisk Ilntake/ifD)
~UD' r ~L ~Q 1: C~iLD
Barlul !Dd :?Ip~unas
Be~!~lle
Butyl benzYl phtba:!te 2.001.02 1.221-05 1.711-04 8531-04
Chl~rojfojrl 1 l:)l+J~ 6.701-05 9.~81-04 4.091-07 9.381-02
~i-n-bgtyi phtbalate 2.101+00 1.281-07 1.791-01 1.791-05
Itby 1 beanne 2.301+03 1.401-04 1.911-03 1.961-02
San,alese and c~lpoundl
Styrene 3.401+03 2.011-04 2.901-03 6. 211-06 1.451-n
Tricbloroetbylene (Tel)
h lene : IlIed) 1.201+02 ~. 311-06 1. 021- 04 5.121-05
Sat: 6.6%1-06 1.291-01
~UDr:~~ ~C. 2::Hr~D
HIIllnu.
Antilony and cOlpoands
Baria. and co,poGnd.
Beune 4.401+01 2.611-01 3.751-05 7.711-08
BeU01C acid
Buul alcolol 1. 481+11 8.531-07 1.111-05 3.981-05
Be n 11 hi ud cOlpoudl I
I
ktyl belnl p.~..l1w I 1.511+81 5.711-06 8.101-05 4.051-04
I
CarboD dil;lf1d. I 1. 111-11 6.701-09 9.381-0' 9. 3U-07
I
CresoUI-) I 4.111+01 2.441-07 3.411-01 6.821-05
I
Cresol(o-) I
I
Di-D-batyl p.~ I 1.211+12 7.311-06 1.021-04 1.021-03
I
Ita, 1 beuue I 1.181+13 1.161-04 1.621-03 1.621-02
I
lal,.lese aid COt~1 I
I
Phuol I J.IOI+Ol 2.321-06 3. 241-05 8.101-04
I
Styrue I 5.501+03 3.351-04 4.111-03 1. 011-05 2.351-02
,
Tol;ue 2. 401-01 1. 461- 08 2.051-07 6.821-07
1.2.3-Trichloropropale
hlue Ililed) 4.401-01 2.681-08 3.751-07 1.881-07
Sgl: 1.011-05 4.201-02
-------
TI~lt 9 Cote,. S&aita~101 ~dfill Site. I.tillted dlil, iatlte. of cOlttllltitl of cOlcerm. apper bou~u
lift'i.. t1C8li Clletr riata, lid bllird Lldeael Illocilted lith ililiitiol of fOC. fOll'iliaed frol :ap
laCtr by a4I1\1 IIrl., .~olerill. Iitilites Illate a bod, .ei,ht of 10 t" 30 ,eafl of eapolare daria, !
?O-,elr 1 ifl.1I8 , i.~alltiol of 20 II/d. .boler telperlture of (SoC. droplet dialeter of 1 II. drop ~lle jf
2 .. 'holer .tall folate ot 2940 liters. .Doler later folate ot 100 liters. and sholer duration vi ~~ Il~
II~olure III .a~i<t6 b, tbe lodel jf 'o.~er aad Chro.to..&i (198&1.
,rIBALATrOI CaRING 3BOWlliIG
ICucer) (Ion-cucer)
~ifetiH C~rl)llc Opper Boud
.. latlte lauie LifeU.. hurd ladu
p.jlliaut ../i'ld l,fi,ld Cuc:tr lilt (ratih/lfDI
~UD'r~~ .0.. 1: aDOL T
Barlul and cOlpound,
BtnZtIl! 5.351-05 1.251-04 1.551-06
Bat, 1 benz,l pbthalate
Chloroforl
Di-D-ble,l p~Cilllte
hh lbeuue 1.851-03 4.311-03 4.311-1%
111I1Iele aid cOlpoalda
Styrue 2.611-04 '.211-04 1.111-0' 3.111-03
Tric~loroet~,lele (TCII . .101-05 1.561-04 1. 141-0'
blue (und) 1.221-05 1.111-04 4.211-14
Su: 1.071-05 4.171-02
LA.DrILL 10. 2: aDOLT
UlIIlnul
antilOG' lIId cOlpoalda I
,
Bu:: ld cOlpondl I
I
!elli~e ' 2.111-'4 1.251-0( 1.111-"
I
8eUOlC: acid I
I
leu, 1 ilco~o 1 I
I
8e"lliu ud COltOUU I
I
ke,l bel171 pUua" '
I
Clrbol dialill.. I ..m-u 1. 011-02 1.111-01
'
Cruol(I-) . I 1.'11-14 . .121-04 1.1%1-03
I
Cruol(o-) I 2.UI-15 5.211-05 1.041-03
I
Di-.-b8\11 ..~ I 1. 211-15 %.111-05 tlTl-14
I
It~11btll'" " .121-'1 1.511+00 1. 511+'1
I
111,lle.e aid COIfOIl.. I
I
P~..o1 I 1.411-14 1.131-03 1.111-02
I
Strrue I 1.211-11 %.121-01 3.131-03 1.411+0'
I
TolaeH I 3.041-04 1.011-0( 4.1%1-04
I
1,2,3-Tric:~10roproPlJe I 1.011-04 1.421-03 I. 011-05 2.311-01
I
blue (Iiud) I 2.151-03 1.181-03 1.541-02
I
I - -
I
Sa.: 3.101-03 1.711.01
-------
tall. 10 CoI", S"itUl" L..dlil1 Si t.. 'lti.U.d d.H, ill.l.. 01 ''''''i..... 01 '''"". '''or j.:",
lil.,iJe tI,... '''''r ri.I,. 'od I...'d iod.... ...oci.t.d 'ill iol.l'.io. 01 lOC. ,ol.,ilil.d I,:. ;"
liter b, c1l1~rtl dari., bltiil,. Isti.ates a.sule a bod; leicbt of 17 t" 5 1ear. of exposure dur:u( ;
TO-year lif.tlJe, ilialatioa af 15 I'/d. batb telperature of 45oC. eDcloled 'olale of 2940 liters. "!:~
.ater ,ola.. of 100 liters, batb deptb of :0 CI, aDd batb duratioll of 20 1111. Elposure las est:.ate~ ~1 ::~
lode: of 'o.t4r aad Chr~stol8ii (1966:.
. iMBA:Ar:;N DaRiNG 3ArRiNG
(Callcerl (Moa-,:ancer)
~ifetile Chroaic Opper Sound
Illtate r a tale Litetlle Huard ladu
P~llutaat .'/te/d I,/i,/d Cucer iist (IDtale/ifDi
LUDFr L~ 10 1: CHILD
Baria. 3~d Co'pouays
Beuue 8 361-06 1. 171-J)4 2.431-u7
1~:,1 be::y! phthalate
:,11 :ardor.
ui-a-but11 pbthalate
ItbYlbeueae 2.821-04 3.941-03 3. 141-02
lal,alese aad COlPOUldl
Stnue 4. 061-05 5.681-04 1. 221-06 2.841-03
Tricbloroeth11ele ITCI) 1.011-05 1. 411-04 1. 711-07
h leu (uno) 1.101-05 1.541-04 3.851-04
--
/ Sal: 1. 631-06 4.251-02
LUDrI ~~ 10. 2; CHILD
Alai au. '
,
AatllODY aDd cOlpou.ds '
,
Barial aad co.poaad. I
,
~ueu I 4.181-85 5.851-04 1.211-01
'
~uoic acid I
,
~uY 1 alcoiol I
r
BerylliRl aid cOlpoald. I
I
Batyl bel111 pitill.\t I
I
Carbol di.alfld. I T. UI-If 1.031-02 1. UI-Ol
I
CreaoHI-) I 5.831-85 7.051-04 7.UI-03
I
CreaoH 0-) I Z. 881-88 4.031-05 ,. '51-~4
I
Di-a-batyl p.tia1lll I 1.511-88 2.221-05 Z. 221-04
I
Itb, lbeu... I 1.IZI-11 1.431+00 1.431+'1
I
Saacaae.e aid cOlfOlld. I
I
Pinol I '.571-85 1.341-03 6.701-0%
I
Styrne I 1. '41-82 2.581-01 5.531-04 1.211+81
I
TolDne I 4.181-05 6.551-04 4.UI-04
I
1.2.J-Trichloroprop.le '.031-05 1. 211-03 9.031-0' 2.111-81
hlue IliJed) 4. 031-04 5.651-03 1. 411-0%
S8I: 5.631-04 1.601+01
-------
.
Table 11 CotuI.Sult1UOI wldfill Site. I8tiuted dl~h iUlt81 ot eOltuiult. ot cOlcen. aPPtr bOwQ.j
liteci.. .ICIII Clletr ri.t.~ lid bazlrd iadexe. al80clated lith deraal Ib.orptiol ot cOltlliDlltl iD tip
liter b, e~il"" 41riIC blt~lD', I.tllate. a..ale a bod, lel,ht ot 17 k,. 5 ,elr. ot 8xpolare dQriac i 70.
,elr liteti.., I" of bod, larface illersed. bath telperatare ot 45oC. eaclosed ,olute ot 2940 liters. bat~
-ater 'olall of lOt literl. bath deptb ot 20 CI. aDd bati duratioD of 20 liD. IJposure la. e8tllated b, :~e
Ivael ot 'olter lid C\ro.tolsii (1986).
Poll'HĄt
LAtDraL MO: 1: CIILD
Barlal aDd cOlpoaDd.~
BeueDe
Bat,l bealJI phthalate
CHorotor!
Di-I-blt,l p~tiliite
8th I beune
111111888 aad cOlpoaldl
Stnue
Tricaloroeti,18De ITCII
h leDe I liled )
~jID'ILL 10. 2: CllLD
&!uual
<ilOl' aId cOlpoaadl
Barlal IDd cOlpoaldl
Beue..
Beuoie leid
Bel.,l aleoiol
""111u ud cOIf0Q4.
kt11 beu11 ..~U
Carbol di.llf1..
Creaolll-}
Cruol(o-}
Di-I-blt,l ,,~
Ita, lbeu...
IIIC118.8 lid e0lf0ll41
Pinol
S t neal
Toiaul
1.2.3-TriciloropropIII
hie.. (Iiled)
;Dli!j~ IITAli ~ORIIG BArlING
&,er.,. Octalol:
: Batillter Wlter
:ColceltrltioD Pilt. Cotft.
(a,/l) 1101'
7.501+01
1.121.00
'.751+11
. .111;0%
1.141+00
2.111+00
2.831+00
I
I
I
I
I
I
.
I
I
I
I
I
I
I
I
I
. I
I
I
I
I
I
I
I
I
I
I
I
I
I
2.941+03
1.511+02
2.141+82
1.111+11
I.%II+U
%.411+U
1. 311+"
I.UI+12
%.IU+U
1.111+'2
5.511+12
%.411+84
5.111+12
1.211+'.
..381+13
1.141+'1
2.111+11
1.151+01
1.321+02
9.331+01
3.981+05
1.411+03
1.411+03
2.401+02
1.821+03
1.321+1%
1.001+02
'.331+01
1.331+01
1.411+03
2.881+01
1. 411+03
5.371+02
2.011+02
1.821+03
(Cucer)
Lifetiae
lAtlh
II/k,/d
3.831-06
1.111-03
2.301-04
1.011-05
S. 011-'5
1. 911-05
2.451-04
..UI-U
2.521-04
1. 311-OZ
5.841-03
1.058-01
9..&1-05
1.771-05
2.911-03
(Iol-cllcerj
C~roDic
Iitah
../k,/d
5.361-05
2.211-82
3.221-U
1. 511-04
1.131-13
Su:
2.IU-04
3. 441-03
1.111-02
3.531-03
1.141-01
1.111-02
1. .&1+"
1.321-03
1.231-13
4.151-02
Su:
Opper DoaDd
Lifetil8
Cllcer h8i
1.111-07
1.911-06
1. 191-07
7.131-06
5.551-07
3.141-03
8.771-01
3.151-03
Baurd Index
([otaieiig.
2.211-11 :
1. 111-8 :
5.611-04 :
2.421.'):
3.441-02
1.241'+00 :
7.011-02 :
1.841+00 .
2.051+00
7.321+00 .
4.421-0~
2. 051-01
2.081-0:
:. :81.):
-------
T.bl. 12 Cot... SoIil.li.. ...dlill Sil.. So...f OPP<' ..o.d lil.li.. ..,... ,..,., ri.., ..d b...rd ;"...,
..,... rorIIi.1 '!JO"', lid """ ".I..i...I. I., .d.II.. S....li., ....... ,..1 .11 """""" '"
DOI-clreilOCllie tfft~t. Ire Idditi'e.
:21515 CCaSIllD ACROSS
:CBlaICALS AID iIP0SDii iOO~IS :
~:; ta I
?: , : ~ : au t
JpPH BouDd
~lfetlle
: :aDcer Bin
.
LA_D':LL WOo :: ADOLT
r'Jtal
Bazard rndu :
~ r D tate / if D) :
2 26i-06
4.291-02 :
BarlGI aDd cOlpounds
BeueDe
Butyl benzYL Pbtbalate
Cb ~croforl
Ji-5-~utyl ~c~L~late
!tby i benleDe
!al,anese aAd cOlpounds
Styrue
Triciloroetbylele (TCII
Iyl!1Ie (Iiledl
3.151-06
6.001-05
1. 541-06
1.101-03 :
1. 211-01 :
2.301-05 :
9.031-02 :
9.941-02 :
2.331-02 :
5.301-04 :
6.691-05
3.781-01
LAID'iLL 10. 2: ADOLT
AluilnGI 2.901-02 :
AAtilODY aDd COlpoGDds 1.081+01 :
Barlal aDd cOlpoGAds 1. 681-01 :
StDzeDe 1.191-05 I
I
~uo lC ae id 6.511-02 :
BeDn. .licoaol 2.211-01 :
Beryillal a.d cOlpcald. 1.141-05 7.431-03 :
Batyl beDlyl pitballtt 5.211-04 :
Carbo. disalfide I 1.581-01 :
I
Cresol( 1-) I 1.&11+00 :
I
Cresol(o-) I 9.251-02 :
I
Di-n-batYl pit~l88e I 1.591-01 :
_I
It~,lbeue.. 1 2.371+01 :
I
!aD,IDese lid c~ I 7.411-02 :
I
I 8.&61+00 :
Pbuo I I
Styrne , 5.54I-U 2.151+01 :
I
Tolaeae 1. &21-03 :
l,2,J-TriciloroproPlle '.531-05 3.751-01 :
Iy leu (Iiled) 1.701-02 :
5.721-03 4. 331+0 1
-------
Tlbll 13 Cottn ka1t1Uol I.udfill Site. 51111 of IIp,.r bond lifetiM nee.. cucer ri.iI ud hurd iodues
.cro.. roetel .t ll)OI;r. IIG Icr011 cOAtlllDlltl for c~i1dreD. 5Qllitiol 1.111111 t~lt III ClrClAOlellC lod
101-clrcitoCII1c Ifflct. Ir. IGditi,..
:8151$ COBBIIID ACROSS
:CIIBIC'~S "D IIPOSORI BOOTIS :
Totd
, JHer BooDd
~ifetile
: Cueer ii.t
Pollutu:
! ~ :11
hura lldu :
(luue/8fD) :
I
,
~"D'[L~ '0. 1; :SI~D
8.411-07
8.rilll lid COlPOUDdl
Beueae
SlIt,l bela,l pbthalate
Chlorotor. ~
Di-D-bat,l phtbalate
h~,1beuoe
1.1(.le.e IDd eOlpoQAd.
5tH'"
Tric~loro.t~,lele (TCI)
I,lete (li18d)
7.271-06
1.211-04
5.171-01
1. 761-01 :
1.521-02 :
1.671+00 :
3.191-04 :
7.051-01 :
4.011-01 :
2.UI-Ol :
2. 041-03 :
1.301-04
3.211+0'
LJIDr1LL 10. 2: CllLD
Ulllisal 1.1n-01 :
'ItilOl' lid COlPOliidl ., 4.441+01.:
I
Barin ud cOlpollAds I 6.121-01 1
'
Beueae I 5.511-01
I
Beuoic acid I 2. 711-01 :
I
Beu11 Ilco~ol I 1.421-81 :
I
Ier,ll!1J .Id cOIfOIId. ' 4.111-15 3.011-82 :
I
Sat,l belJ,l p~t~.l.tf I 1.211-83 :
I
Carbol d1.11f141 I 3. 311-'1 :
I
CreaoHI-) I 1. UI... :
I
Creao l( 0-) I 4.411-81 :
I
Di-'-NUI "\WI. I 2.501+11 :
I
It~,lbelJ." - I 4.111+81 :
I
hl(ue.. u4 1l1li1 It I 3.051-81 :
I
P~8IO 1 I 3.141+01 :
I
St,re.. I 5.111-U 1.201+01 :
I
To la... I 1.571-03 :
I
1.2.3-Tric~10ropropu. I 4.221-'5 1.841-01 :
I
IJ 181e (li18d) I 4.131-12 :
I
I
I
5.221-03 1.511+02
-------
TABLE 14
The nine criteria tor the evaluation ot remedial alternatives are
summarized below.
OVera~on ot Hu8an H.aill an~e 2nUron.8.nt: whether
each alternative provides adequate protection ot hu.an health and
the environment and describe. how ri.ks pO.ed through each
expo.ure pathway are eli.inated, reduced or Controlled throuqh
treat.ent, engineering controls, or institutional Control..
Comc1iance with ARAR.: whether each alternative will .eet a11 ot
the Applicable or .ele~&Dt &Ad Appropriate .equir..eAt. CARAR.)
ot rederal and State environaental lava and/or ju.titi.. invoking
a waiv.r; whether a r..edy compli.. withadvi80rie., criteria and
quidance that EPA and PACER have agreed to tollow.
Lcnq-t.nI !!1'.' ,~.' .~... and Perman.nc,: the eility ot a re.edy
to maintain r8~i~Dle protoction ot huaAn health and the
environaent over tiae, once clean-up 90al. have been .et.
Reduction ot Toxicitv. Mobl1jtv. or Volu.e throu~h Treat.ent:
addr..... the .tatutory preterenc. tor .electing r88edia1 action.
that employ treatment technoloqie. that pen.nentl '! and
.igniticantly reduce the toxicity, .obility or vol~ ot
hazardou8 .ubstanc... .
Short-ter8 Ettectivene..: the period ot ti8e needed to achieve
protection and any adver.e iapact. on huaan health and the
environaent that ..y be po.ed durinq the con8truction and
i.ple.entation period, until clean-up ioal. are achieved.
Imclementab~: the technical and adaini.trative tea.ibility of
a reaedy, includinq the availability ot ..terial. and .ervice.
needed to iapl...nt a particular option.
~: e.ti.ated capital, operation' ..intenance (O'M), and net
pre.ent worth co.t..
State/SucDO~ Aaenev Aeee~t.ncel whether the .tate concur. with,
oppo.e., or baa no C0888nt reiarding the preterred alternatl~e.
Communitv ~.atanee: the public'. iener.l re.pon.e to the
alternativ.. Vbleb vill be a..e..ed in the "cord of Deci.ioA
tollowing a review ot the public co..ent. received on the
admini.trative record and the propo.ed plan.
-------
".
Tabl. 15
Cost Summary for the Selected Remedy, Limited Action
Landtill '1
Leachate Cover
Site Fence
Indirect Cost (25\>
!,.
Desiqn and Other Cost
Total Capital Cost
Capital Plus 30\ Continqency
Landfill '2
Backfill Cells, Seal Wells
Site Fence
Indirect Cost
Design, Other Cost
Total Capital Cost
Capital Plus 30\ Continqency
O&M includinq site inspection and
semi-annual qroundwater and surface
monitorinq .
Total Cost
~
$10,000
$60,000
$17,500
580.000
$167,500
$217,500
$85,900
$57,200
$35,775
580.000
$258,875
$336,538
$527.257
$1,081,295
-------
RBSPONSIVBH'BSS StJXKARY
The following discussion summarizes the comments raised
during the public comment period for the Proposed Plan for the
Coker's Sanitation service Landfills Site (Coker's site). This
responsiveness summary is divided into two sections. The' first
section describes the comments received at the public hearing that
was held to present the Proposed Plan. The second section
summarizes the written comments received during the public comment
p'eriod.
OVERVIEW
Prior to the public comment period, EPA published its
preferred alternative for the Coker's Site, located in Kent County,
Delaware. BPA's preferred alte~native involves covering Landfill
#1 leachate seeps, grou~-:':"l1'~ Landfill #2 leachate collection pipes,
implementing deed restri~;tions, and inspe~ting and monitoring the
landfills. EPA's recommended alternative minimizes the potential
for exposure to site contaminants.
BACKGROUND
Community interest and concern about the Coker's site has
been relatively low over the past several years, with more interest
focused on the nearby Chem-Solv site. The Greater Cheswold
Environmental Safety Committee, the citizens' group that formed
immediately after the 1984 explosion at the Chem-Solv site, has
focused the community on local environmental and publ ic health
issues. Several citizens are corcerned about the safety of the
local aquifers and their ground water.
To obtain public input on the Remedial Investigation/
Fea ~ility Study (RIfFS) reports, the Proposed Plan, and the
ad:.:l.nistrative record file for the Coker's site, EPA opened a
public comment period from August 22, 1990 to September 21, 1990.
EPA's community relations efforts include on-site community
interv iews held in June 1990 to keep citizens and off ic ial s
informed of developments and activities regarding the Coker's site
and to identify current community issues and concerns; a public
meeting notice that appeared in the Delaware State News and
Wilminaton News Journal on August 22, 1990, _announcing EPA IS
Proposed Plan and public comment period: and a public meeting that
was held on September 5, 1990 to present the Proposed Plan. A
Proposed Plan Fact Sheet was distributed at the meeting, whic~
approximately 60 people attended. EPA also placed the RIIFS
reports, the Proposed Plan fact sheet, and other relevant documents
in the administrative record file at the EPA Docket Room in Regic~
III and at the information repository located at the Clayton Pos~
1
-------
Otfice, Railroad Ave., Clayton, Delaware 19938.
SECTION IeA):
SUMMARy OF MAJOR ISSUES AND CONCERNS RAISED AT THE
PUBLIC MEETING
This section provides a summary of commentors' major issues
and concerns, and expressly acknowledqes and responds to' those
raised by the local community. The major issues and concerns on
the proposed remedy for the Coker's site raised at the September
5, 1990 public meetinq:
A.
The Proposed Remedy and the Remedy Selection Process
Implementation of Remedy
B.
C.
Leachate Seeps
Ground Water
D.
E.
Health and Environmental Risks
F.
Liners
G..
Miscellaneous.
A summary of the comments and EPA's response to them is provided
below.
A.
The Proposed Remedy and the RemedY Selection Process
A meetinq attendee asked how EPA' s preferred al ternati ve
would preyent potential contamination from occurring in tt~
Cheswold aquifer.
EPA Resconse. The contamination that EPA modeled in the
RI/FS is in the Columbia aquifer, not the Ch~swold aquifer.
All of EPA' s past investigations reveal that there is no
potential for contamination in the Cheswold aquiferi EPA
will conduct monitoring in the future to detect any change
in these tindings.
A citizen inquired about the cover that EPA would install
over the leachate seeps, as described in Alternative 3. The
ci tizen wanted to know the type ot cover that EPA would
install and how effective it will be. -
EPA Resconse. EPA will determine the type of cover during
the remedial design phase. The over will be designed with
the intent of preventing human contact with the seeps.
A meetinq attendee commented that EPA is determined to selec~
2
-------
one alternative, whether there is public input or not and
is not concerned with the problems that the community is
raising. The attendee also recommended that EPA inform the
community of places where they can get site information.
EPA Response. The investigations conducted as part of the
RI found that there is little contamination on the land
immediately in contact with the landfill. To provide the
public with site-related information, EPA has established an
information repository at the Clayton Post Office. The
repository contains the complete text of the RI report, as
well as other site-related documents in the administrative
record file. Comments received from the public will be taken
into account in selecting the remedial alternative for this
Site.
A local official commented that the two landfills are
different and, therefore, probably have dif~erent needs. He
asked if EPA must propo::;e the same alternative fc;r both
landfills, and commented that he prefers Alternative 3 for
Landfill 11 but not for Landfill '2.
EPA Response. The same alternative need not be proposed for
both landfills. It is possible that EPA would take a
different approach at Landfill '1 than at Landfill 12.
An attendee asked what EPA would do if the Agency finds
something at the Site that presents a health hazard to the
community.
EPA Response. There are two parts to the Superfund program:
the removal program and the remedial program. The removal
program enables EPA to take immediate site action when a
situation presents immediate threats to human health and the
environment. For sites that do not present immediate threats
to human health and the environment, EPA takes action under
the remedial program, which begins with a RI/FS, as the
Agency has done at the Coker's site.
A citizen inquired what EPA would do with the waste if it is
removed from the Site.
EPA Response. Removing waste from the site would present
potential short-term health risks by excavating the waste,
agitating it, and releasing contaminants as the waste is
handled. In this case, EPA would need to find a plac~ :0
dispose of approximately 110,000 cubic yards of materic 3.
Basically, this would result in cleaning up one dump site and
creating another. Such action, therefore, is not generally
considered to be an acceptable alternative.
A
commentor
stated
that,
if
monitoring
wells
detecte~
3
-------
-.
contamination in the Columbia aquifer, new deeper wells
woul~ probably need to be drilled into other ~quifers, which
would not address the cause or the problem. He added that
the problem at the Coker's site will remain unresolvej until
EPA finds a way to remove the waste or to control it to
prevent further contamination.
r.
EPA Response. For hazardous waste sites where EPA determines
that treatment is impractiCable, the Agency considers
containment options. EPA evaluated several treatment
alternatives for the Coker's site and found that it would be
difficult to treat the waste to a point where it would be
significantly less harmful than in its present condition in
a cost-effective manner that also would not pose undue short-
term risks to site workers and local residents. EPA,
trerefore, recommends a containment option for the Coker's
site,'.rather than treatment. EPA recommends a containment
option rather than removal of the waste from the site for t~e
reasons stated above in the previous response.
A meeting attendee commented that the consensus ot community
opinion shows dissatisfaction with Alternative 3, and he
asked how much input the community is going to have in the
final decision before EPA selects an alternative. The
attendee also asked whether EPA would rule out Alternative
3 if everyone assembled tonight voted against it.
EPA ResDonse. Community input is important to EPA and no
decision on the final remedy selection will be made until all
comments and questions are addressed. The objective of the
decision-making process is to determine which potential
remedial alternative best addresses site problems, not to
simply rule out which alternative is not going to solve the
problem. The final decision will be made based upon EPA's
nine criteria, one of which is community acceptance.
A citizen commented that she does not like Alternative 3, nor
Alternatives 6 and 7. She and several attendees commented
that the only alternative EPA should select is to completely
remove the waste. .
EPA ResDonse. Durinq the feasibility study, removal of all
wast. .aterials for offsite disposal was one of the options
considered. However, this alternative was screened out early
in the study because it did not compare favorably to the
preliminary screeninq criteria: - effectiveness,
implementability, and cost. While complete removal of waste
material would essentially render the land areas of Landfills
'1 and 12 clean. ~ significant volume of waste material would
have to be hand j in an appropriate manner at another site.
Offsite disposa- of waste without treatment is EPA's least
preferred manner of handling a Superfund site.
4
-------
A meeting attendee asked what the community can do to stop
EPA from, selecting Alternative 3 as the remedy for the
Coker's s1te. She also asked whether EPA will respond to the
community's input and who, specifically, will make the
ultimate decision regarding the selected alternative..
EPA Response. EPA 1 istens ~o the community's input and
addresses their comments, questions, and concerns in the
Responsiveness Summary portion of the Record of Decision
(ROD). Written comments can be submitted to the addresses
provided in the Proposed Plan and fact sheet, postmarked no
later than September 21, 1990. EPA will consider all of the
public's comments and the information in the administrative
record in making a decision about the remedy for the Coker's
site. Edwin B. Erickson, the Regional Administrator of EPA
Region III, is responsible for signing the ROD, which will
be EPA's choic:: of the remedy fOl' the Site.
A citizen asked whether EPA would provide for a community
appeal process if, once the final alternative is decided, the
community does not agree with EPA's decision.
EPA Response. There is no provision for appealing the final
remedy selected by EPA. The community's opportunity to
provide comment and to make suggestions is limited to the
public comment period. The public comment period for the
Coker's site ends on September 21, 1990, and EPA will
consider all of the concerns expressed during this period.
An attendee asked, if the community is dissatisfied with
EPA's decision, whether the community should contact the U.S.
Senators or go to higher levels in the U.S. government for
support.
EPA Response.
EPA cannot suggest to you who you should call.
A media representative asked EPA to explain ~he steps that
will take place between now and the final remedy decision.
EPA Rest>onse. The public comment period will. close on
September 21, 1990. At that time, EPA will begin preparing
the ROD, part of which includes the preparation of the
Responsiveness Summary. The completed ROD will be reviewed
by EPA Region III staff and, ultimately, be signed by the
Regional Administrator who makes the final decision regarding
the remedy selected for the site. EPA plans to have the ROD
issued within approximately one month.
A citizen asked how the community will be informed of the
final decision regarding the remedy selected for the Site.
5
-------
..
EPA R~s~onset E~~ will place advertisements in the local
newspaper and notify everyone on the mailinq list of area
residents. If anyone requests a meetinq to discuss the ROD
further, EPA will provide a meetinq. When the remedy reaches
the implementation phase, EPA will arranqe a meetinq to
describe the work that will be conducted and the specific
work plan.
B.
Imclementation of Remedy
I:
A representative of the Greater Cheswold Environmental Safety
Committee commented that the lonq-term effectiveness of the
remedy depends on the lonq-term site inspection and
monitorinq program, and asked about EPA's commitment to the
monitorinq program. The representative expressed specific
conce~ns that Federal, State, or County budqet cuts could
affect the monitorinq proqram, suqqestinq that EPA' s proposed
30-year monitorinq proqram may not be guaranteed but, rather,
may qo on for only 10 or 15 years.
EPA Response. EPA plans to offer several potentially
responsible parties the opportunity to implement the remedial
action under the terms of a consent decree which would be
entered in court. Should the parties fail to conduct
scheduled monitorinq activities, EPA could fine the parties.
If the parties do not aqree to conduct the remedial action,
the responsibility for lonq-term site monitorinq would fall
upon the State. In either event, EPA and the State are
committed to fully implement the remedial action.
A representative of the Greater Cheswold Environmental Safety
Committee expressed concern that EPA's preferred alternative
does not reduce toxicity, mobility, or volume of the waste.
EPA Resconse. The specific criterion, "reduction of
toxicity, mobility, and volume," refers to reduction of the
waste throuqh treatment. Based on EPA' s evaluation of
treatment alternatives, the Aqency has found that there is
no treatment technoloqy available today that will effectively
destroy the Coker's waste in a cost-effective. manner and
without creatinq a potential for short-term health risks to
the .ite workers and to local residents. It is EPA's policy
to ex..ine containment options for sites,' such as Coker's,
where treatment is not practical at this time.
A representative of the Greater Cheswold Environmental Safety
Committee requested more information about the five-year
reviews that will be conducted at the Site, as required by
the Superfund Amendments and Reauthorization Act (SARA).
EPA Resconse.
A five-year review is necessary at sites where
6
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hazaidous substances, pollutants, or contaminants remain.
No less often than each five years after the initiation of
remedial action, EPA is required to return to the site to
determine whether or not the remedy is still protective. For
the Coker's site, such a review would be conducted every five
years.
C.
Leachate Seeps
A representative of the Greater Cheswold Environmental Safety
Committee wanted to know the depth of the leachate seeps that
are in Landfill #1, along the northeast corner.
EPA Response. The amount of leachate present varies
according to how high the, ground water tar."" is at a certain
time and whether or not there has been re,.,"-:':-; precipitation.
EPA has not observed any actual streams of leachate flowing
from the Site. Leachate seeps form along the relatively
steep bank which borders the landfill: however, these seeps
dissipate into a marshy area before reaching the Willis
Branch.
A meeting attendee inquired whether Landfill #2 is sealed
and not leaking.
EPA Response. EPA has not detected anything in the ground
water that indicates that the cells are leaking. When the
cells were originally constructed, the waste was not in a
totally settled condition an~, therefore, wastewater leached
out. The leachate was collected on a regular basis
throughout the 1980s and treated in the Reichhold Chemicals,
Inc. plant. The leachate collection was phased ou.t when
smaller and smaller amounts of leachate were generated at the
site. In fact, EPA had a difficult time finding any
leachate to test at Landfill '2 during the RI.
An attendee asked whether any leachate is leaking and asked
specifically about the toluene and ethylbenzene found in one
well in the Columbia aquifer.
EPA Response. The leachate collection systems within the
landfill cells are generally dry, which suggests the waste
is not generating appreciable quantities _of leachate. The
toluene and ethylbenzene present in the shallow well may have
~ome from a small tear in a liner, or may be an artifact 0:
past waste disposal practices (old reports indicate that :~
some instances, waste was dumped onto the ground and the~
bulldozed into the waste cells). However, the levels prese~~
are well below the proposed maximum contaminant levels (MCLs
set under the Safe Drinking Water Act (700 parts per billi:~
7
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(ppb) -~ethylbenzene and 2,000 ppb toluene).
A citizen asked whether it is possible that the site has some
leaks and that the sealed systems could be leaking now.
EPA Response. Since it is impossible to physically examine
the integrity of the liners without removing the waste, it
is impossible to say for certain that the liners are not
leaking. However, ground water monitoring data suggests that
this is not occurring to any significant extent. It is
expected that, over time, the liners at Landfill '2 will
fail.
D.
Ground Water
A cit{~en commented that most people in the area use shallow
weL'.. and asked if these wells would be affected by the
Coke~'s site contamination.
EPA Response. The areas where shallow ground water could be
affected are directly downgradient of the site, located
between Landfill '2 and the Willis Branch. CUrrently, there
are no wells located in that area.
A commentor wanted to know whether the ground water of the
Cheswold aquifer, which flows to the Willis Branch, continues
up to county Route 29.
EPA Response. EPA's ground water investigation was limited
to the immediate vicinity qf the two landfills. In this
area, both the Columbia and the Cheswold aquifers were found
to flow north-northeast toward the Willis Branch, although
in most other areas, both aquifers flow in the opposite
direction. EPA did not determine the direction of ground
water flow on the opposite side of the Willis Branch.
However, any potential threat to wells along Route 29 would
first be detected onsite.
A meeting attendee asked whether the people 11,.ving along
County Route 29 would eventually have contaminated ground
water it 80me contaminants leaked into the Cheswold aquifer.
EPA Response. EPA's ground water models did not predict any
significant human health risk associated- with use of the
Cheswold aquifer at a location 1200 feet from the site even
af~er assuming complete liner failure at Landfill '2. EPA
does not expect any health threats to exist from use of wells
located even further from Landfill '2.
A citizen wanted to know how many wells are located in the
Cheswold aquifer at Landfills '1 and '2 and asked if any 0:
8
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thea.-wells contain contaminants.
the wells were placed.
He also asked about where
EPA ResDonse. There are three wells in the deep aquifer at
each landfill, none of which reveal contamination. The wells
are both upgradient and downgradient wells, located above the
landfills and below the landfill in the direction of ground
water flow.
A citizen asked whether the Cheswold
further south than the Willis Branch.
aquifer
continues
EPA ResDonse.
Yes, it does.
A representative of the Greater Cheswold Environmental Safety
Committee commented that, from the RI/FS report, it appears
that the ground water is flowing back and forth h~~~een the
Cheswold aquifer and the Columbia aquifer. Sh, I"!xpressed
concern about the nearby shallow wells since the RI/FS report
states that EPA's preferred alternative does not reduce the
mobility, toxicity, or the volume of the waste constituents.
EPA ResDonse. It does appear that the clay-silt bed between
the two aquifers is somewhat permeable. This has been taken
into consideration in determining whether there is a
significant threat of contamination of the Cheswold aquifer.
The modeling effort, which assumed that there was no
confining layer between the two aquifers, found that the
levels of styrene in the Cheswold aquifer would be below
detection limits.
A citizen commented that EPA's preferred alternative does
nothing to allay his fears regarding the ground water'
contamination, as he does not find the preferred alternative
to be a preventive one. He also requested EPA to explain the
possible development of a ground water management zone in the
event that the ground water in the Cheswold area becomes
contaminated.
EPA ResDonse. A ground water management zone is an area that
is defined, and actually implemented, by the County in
conjunction with the State. It is an area in which
regulating authorities agree that no wells of certain depths
will be drilled. In this case, no wells would be drilled in
the vicinity of the site or in the Columbia aquifer. It is
true that EPA's alternative does not attempt to prevent any
leakage of Landfill '2 liners. However, it should be noted
that even at Landfill #1, which is unlined and where waste
is in direct contact with the Columbia aquifer, the fe-..,'
contaminants which were detected do not pose a significan~
health threat.
9
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A .e~~inq attendee asked how the qround water manaqement zone
would affect landowners if their respective wells are
contaminated. In addition, he asked who would take
responsibility for drillinq new wells and who would pay for
and .onitor wells.
EPA Response. Any contamination plume which may develop in
the future would move from the landfills toward the Willis
Branch and, therefore, would affect qround water between the
landfills and the creek only. (EPA' s model predicted no
detectable levels of contamination would be detected in the
Cheswold aquifer.) If, however, new wells had to be drilled,
it would be a State responsibility. The State, however,
would attempt to find a potentially responsible party (PRP)
to replace the wells, but would replace these wells itself
if a PRP would not aqree to do so.
A citizen ;- .-;;::ed whether there is any chance that the wells
in the Ches~~ld aquifer could become contaminated by seepage
or leachate from .the site.
EPA Resconse. The Cheswold aquifer is the lower aquifer
underlyinq the site, and, at this time, there is no evidence
of any contamination movinq into it. Modelinq conducted
durinq the feasibility study indicates the Cheswold aquifer
will not become contaminated in the future.
A citizen . commented that a qround water monitoring system
would detect a problem after it has occurred, providing no
chance for preventive action.
EPA Resconse. It is true that monitorinq will not prevent
any potential future ground water contamination. However,
wells located onsite will allow EPA to detect. any ground
water contamination before it becomes a threat to offsite
users. Based upon the scientific evidence available to EPA,
the landfills do not appear to pose a siqnificant threat to
offsite users of shallow or deep ground water, and w~ll not
pose a threat in the future. If, at the time of a review,
it is determined that this is not the case, EPA will take
further action to mitigate the threats posed by the Site.
Several attendees wanted to know the direction in which the
ground water is movinq.
EPA Resconse. In the area of the Site, the ground water is
flowinq north northeast toward the Willis Branch.
A citizen requested the name and address of the responsible
party that conducted the study on the Willis Branch, which
had concluded that the creek was not polluted. The citizen
also wanted to know what could cause the bubbles that have
10
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been .seen and the apparent lifeless condition of the Willis
Branch.
EPA ResDonse. The PRP consultant was Environmental Resources
Management (ERM) from Exton, Pennsylvania. Their work was
conducted under EPA oversight. EPA found no evidence of
contamination from the Site in the Willis Branch.' The
bubbles in the Willis Branch could be caused by anaerobic
decomposition by bacteria, which releases hydrogen sulfide
gas. This is common in swamp environments.
A citizen commented that there is nothing living in the
Willis Branch that could deteriorate.
EPA ResDonse. This is incorrect. Although no fish studies
were conducted on the Willis Branch, a benthic invertebrate
(Le.,' worms and larvae living in sediment) survey w:}s
conducted. Areas adjacent to and downstream of Landfill ~1
were actually found to have a greater number and diversity
of species, including some Pollution-in'tolerant species, than
locations upstream, although this is believed to be related
to differences in habitat (i.e., stream width and depth) than
environmental conditions. Additional organic matter can be
contributed to the stream through leaf litter from
overhanging trees and from overland flow of precipitation.
An attendee inquired whether the City of Dover draws water
from the Cheswold aquifer and, if so, have they been alerted
to the possible contamination from the landfills.
EPA Response. Yes, the City of Dover draws water from the
Cheswold aquifer. However, since there is no current ground
water problem, and because the ground water in the aquifers
in the area of the Coker's site flows toward the Willis
Branch, it is believed that any potential future
contamination would not affect the city.
A citizen expressed surprise that EPA had not tested the
wells of residents living in the immediate area of the
Coker's site.
EPA ResDonse. EPA tested the wells of the residents living
on the landfill property and found no elevated levels of
contaminants. Since no significant levels of contamination
were found on site (where the highest contaminant levels
would be expected), it was determined that no further well
testing was needed. The state has agreed to sample several
additional residential wells during the week of September 24,
1990.
A citizen asked whether he should install a deeper well O~
his property for safety reasons.
11
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EPA ResDonse. There is no need to drill a deeper well at
this time for reasons related to the Coker's site.
A meeting attendee asked when EPA began monitoring the ground
water.
EPA ResDonse. EPA began monitoring the ground water at
Landfill 11 when the Agency conducted the remedial
investigation. Monitoring the ground water at Landfill '2
began with the commencement of landfilling operations in
1976.
E.
Health and Environmental Risks
A ciuizen asked for an explanation
statements regardinJ cancer risks.
EPA ResDonse. EPA's calculation of cancer risks posed by
contaminants is based on an extremely conservative exposure
scenario. In developing these figures, EPA used the worat
case exposure scenario of total liner failure and a
hypothetical person who lives on the property line with a
well in the overburden (shallow) aquifer. The calculated
cancer risk, based on this scenario, just barely exceeds
EPA's established guideline, which is a one in 10,000 cancer
risk. This means that, using the highest amount of exposure'
possible to site-related contaminants, the site poses a risk
of one additional case of cancer per 10,000 exposed people.
of
EPA's
earlier
An attendee asked if the nearby site residents are in dange~
of breathing and drinking the pollutants and whether or no~
the pollutants have settled in the Willis Branch. .
EPA ResDonse. EPA has not detected any contamination in the
air, has found only very low levels of organics in the
shallow ground water (which, at current levels, do not pose
any significant health threat), and has not found any
evidence of contamination in the Willis Branch.
A citizen asked EPA to explain both why no fish, crayfish,
or water frogs live in the Willis Branch arid, based on this,
how EPA can claim that the water is not contaminated.
EPA ResDonse. EPA conducted an environmental assessment and
a human health risk assessment during site investigations.
In assessing the water qual ity of. the Willis Branch, EPA
found that the water and the sediments do not contain any
concentration of any substances from the Site that woul::
cause a problem for either human health or the environment.
EPA does not know why the Willis Branch is degraded. It ma:"
12
-------
be due to sUbstances that came from the Site in the past or
it may be the result of some source upstream of the Site.
Several citizens who live near the landfills complained of
animal health problems. One farmer lost four cows to acute
leukemia in a period of two years; another lost eight or nine
cats to strange leukemias and cancer in the last two or three
years; and another, over a ten-year period, lost animals to
illness, unusual cancers, leukemia, and different types of
tumors. These citizens requested that their water be tested
and, if necessary, their wells replaced by the State, the
County, or the PRPs.
EPA ResDonse. Bovine and feline leukemias are caused by
viruses, which leads EPA to believe the site had no impact
on the animals' ill health. The State has agreed to have the
concerned citizens' wells tested.
A meeting attendee asked whether EPA has e'.aluated the
possibility that site residents may contract other
health-related illnesses beside cancer, such as respiratory
illnesses or allergies.
EPA ResDonse. In addition to assessing human health risks
posed by carcinogens, EPA also evaluated risks posed by non-
carcinogens, such as ethylbenzene. EPA did not find any
elevated health risk associated with any current or future
scenario except future residential use of the Sites. Offsite
residents are not expected to experience any adverse health
problems as a result of exposure to site-related
contaminants.
A representative of the Greater Cheswold Environme~tal
Committee and other citizens requested that EPA, und~r the
Superfund program, test the wells of those residents living
in the immediate area of the Coker's site, specifically those
people who reported animal health problems.
EPA Response. The State has indicated that they will sample
the wells of residents who have had animal problems.
A citizen asked whether there is a toxic waste threat, or any
kind of hazard, to the community's health .or to the land.
EPA ResDonse. There are substances on site that are
hazardous substances as defined under CERCLA. EPA believes
that future residential development of the Site would result
in an unacceptable health risk to adults and children living
onsite as a result of exposure to these substances. Offsite
residents are not at any unacceptable risk of experienci~g
adverse health effects because of the Site.
13
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~
A com8entor stated that veqetation and animals existed on the
sit8~roperty before the property became a dumpinq site but
that, since the dumpinq beqan, everythinq in the site area
has died. She added that, only within the last five years
sign. of veqetation qrowth have appeared. Based on her o~
observations, the commentor questioned EPA's statement that
the Site presents no threat to human health and the
environment.
,.
EPA Resconse. It is difficult for EPA to comment on
activities that took place twenty years aqo and of which EPA
has no records. It is likely that clearinq and trenching
activities caused disturbance of the topsoil and therefore
hindered veqetative qrowth. EPA can only address site
~onditions which exist now or may exist in the future. At
this time, the Site does not pose any threats to human health
or the environment; if EPA implements the preferred
alternative, EPA does not e~~6ct the Site to pose any threat
in the future.
A media representative asked about the air pollution risks
involved if EPA conducts a removal at the site, and asked how
far downwind the air pollution problem would pose a risk.
EPA Resconse. The risks would depend on how people would be
exposed. The risks to a person without any kind of
respirator apparatus standinq on the property line durinq
excavation activities could be significant. The qeographic
extent of the risks would depend on the weather conditions,
wind turbulence, temperature, and cloud cover. Under some
condi tions, particularly in. the morninq and evening, the
plume could remain concentrated for the better part of a
mile. It is possible that substantial exposures could occur
durinq the excavation activities.
F.
Liners
A representative of the Greater Cheswold Environmental Safety
Committee asked about the likelihood of the lin&r failinq in
Landfill '2.
EPA R8.-ponse. EPA has assumed varyinq deqrees of liner
failure in the assessment of risk associated with Landfill
'2. Even under a scenario that assumed all liners would fail
completely at the same time (loot liner failure), EPA did not
find an unacceptable health risk associated with use of
shallow qround water.
The representative
inquiry reqardinq
tomorrow.
followed the above
whether or not the
question with an
liner could fail
14
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.
EPA ResDonse. EPA believes a certain percentage of liner
failure can be expected per year, based upon evaluation of
similar liners in similar situations.
An attendee asked whether EPA has visually examined the
liner.
EPA Response. EPA does not believe it would be prudent or
practical to actually dig up and inspect the 50 waste cell
liners. Such activities would carry a high risk of damaging
the liners and would be time consuming (each liner is
approximately 21,000 cubic feet in size). EPA has instead
considered a worst case scenario, under which all liners
would fail completely and simultaneously, and another
scenario, which assumes percentage of liner failure based
upon historical performance of similar types of liners.
A local official asked whether EPA would still recor.unend
Alternative 3 in the event of a total liner failure.
EPA Response. Yes. The preferred alternative was chosen
with consideration of the 100 percent liner failure scenario.
G.
Miscellaneous
A representative of the Greater Cheswold Environmental Safety
Committee expressed concern about the deed restrictions for
the Coker's property. She wanted to know 1) whether EPA
contacted the County government and, if so, whether the
County government was willing to implement deed restrictions
for the Coker's property; 2) on how much of the property
would the County government place deed restrictions; and 3)
whether the deed restrictions would apply to the landfills
alone or to a larger portion of property.
EPA ResDonse. The purpose of placing deed restrictions on
the property would be to prevent future resid~ntial
development of the Site. The determination of the specific
deed restrictions and their placement would be ~ade during
the remedial design or remedial action, at which time EPA
would coordinate its efforts with the County or other
appropriate parties.
A meeting attendee asked what is the PRPs' responsibility in
cleaning up the landfill.
EPA Response. In the past, EPA offered several PRPs the
opportunity to conduct the RI/FS under an administrative
order with EPA. EPA will offer the PRPs the opportunity t~
implement the remedial action after the Agency signs the
15
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. -- ------.
Reco~~ ot Decision.
A citizen asked whether EPA obtained the records of Reichhold
Chemical, Inc. to determine how much waste was qenerated by
the company. If so, the citizen wanted to know whether EPA
had compared this amount to the amount of waste in the
landfills and whether future comparative analyses would be
made if one had not already been made.
EPA Response. Yes. EPA has obtained ReiChhold's records,
but the Aqency has not used the records to compare the amount
ot waste in the landtills to the amount ot waste qenerated
by the company. This analysis is not one that EPA will make.
A meetinq attendee asked if his site property will depreciate
in va~ue because of the problems at the Coker's site.
tEA. Response. It is possible. ".d.3':orically, properties'
adjacent to Superfund sites have had ~heir values adversely
impacted. .
A citizen wanted to know whether EPA had tound any heavy
metals, such as zinc or chromate, in the landfill.
EPA Respo~ EPA found elevated levels ot iron in the
leachate at Landfill 11, but cannot attribute that finding
to the waste. The shallow aquifer has a naturally high
concentration of iron that cannot be attributed to the
landfill.
An attendee commented that zinc is used in the manufacturing
of latex.
EPA Response. EPA has not found any elevated levels of zinc
in the landtills.
A citizen asked what is beinq done with the latex waste that
the PRPs are qenerating.,
EPA Response. Waste qenerated by the manufacturinq plant is
an indu.trial waste, not a hazardous waste. Its disposal is
regulated by Delaware Solid Waste Disposal Regulations. (Had
the va.te at Coker's landfills been handled in accordance
with current state law, no further action by EPA would be
required. )
A meeting attendee inquired whether any of the PRPs have
records of how much waste they generated at the landfills.
If so, the attendee wanted to know if their records account
for all of the waste that was disposed of at the site.
EPA ResDonse.
EPA has volumetric estimates of the quantiti
16
-------
of waste that is at the Site. It is the Agency's
understanding that the landfills were intended to hold all
of the waste that the companies generated during the period
of time that the landfills were active.
A citizen asked whether hazardous waste must be registered
and if the waste at the site is hazardous.
EPA Response. Yes, hazardous wastes must be registered.
Waste that is generated by the latex manufacturing facility
today does not qualify as a hazardous waste under the
Resource Conservation and Recovery Act (RCRA) but is, rather,
an industrial waste. This particular waste, however,
includes constituents that allow EPA, under Superfund, to
address risks posed by the site.
A citizen described the problems at the Chem-Solv site that
the community faced a few years ago and expressed concern
over the unnecessary cleanup expense that resulted from
waiting too long to clean up the site. . He suggested that EPA
had waited too long to clean up Chem-SOlv and that EPA was
slow to clean up the Coker's site as well.
EPA Response. The Chem-Solv site is a different type of site
than the Coker's site. Unlike the Chem-SOlv site, the waste
at the Coker's site is difficult to handle and treat. For
this reason, EPA is recommending a containment, rather than
a treatment, alternative.
An attendee raised a complaint that she had tried to get her
water tested but no one from EPA responded to her requests.
EPA Response. As a general rule, the Federal government does
not test the water for the two hundred million residents of
the United States.
A citizen asked where community residents can seek help for
two problems that are not site-related: 1) finding someone
to test the individual wells for which the affected residents
have concerns and 2) determining the cause of ~he lack of
life in the Willis Branch.
EPA ResDonse. The residents that want their wells tested may
hire a private testing lab to perform water sampling. The
other concern, regarding the quality of the water in the
Willis Branch, may be handled by the Delavare Department of
Natural Resources and Environmental Control (DNREC). DNREC
had a group of individuals that deal specifically wit:-.
discharges to streams and the water quality in streams.
An attendee asked whether EPA plans to fence the site so tha:
people and animals cannot have access to it.
17
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EPA RaSDonseL EPA's Proposed Plan did not include fencing
the landfills to restrict access. In response to public
comment, however, EPA has included security fences and the
posting of warning signs in the selected remedy.
A commentor requested that the information repository be
established at the Cheswold Post Office.
':
EPA ResDonse. An information repository ~an be placed
immediately at the Cheswold Post Office and any additional
location that the community suggests.
II.
SECTION I(B):
~
COMPREHENSIVE RESPONSE TO COMPLEX COMKENTS RAISED
AT THE PUBLIC MEETING
This section provides a comprehensive respc;-::;e to the more
complex comments on the Coker's site received at the public hearing
held September 5, 1990. Some of the information presented in this
section elaborates with technical detail on answers covered in Part
I of this Responsiveness Summary. Concerns and questions presented
in this section can be grouped in two categories:
A.
Health and Environmental Risks
B.
Liners..
A summary of the comments and EPA's response to them is provided
below.
A.
Health and Environmental R~
A citizen asked for an explanation
statements regarding cancer risks.
of
EPA's
"earl ier
EPA ResDonse. The cancer risk for the site ~as calc~lated
based on an extremely conservative exposure scenario. The
exposure supposition that EPA made included total liner
failure and a hypothetical person who lives on the property
line with a well in the overburden (shallow) aquifer. The
hypothetical person drinks two liters of water, bathes in it,
and uses it for allot his household uses, every day over an
entire 70-year lifetime. The cancer risk, based on this
scenario, barely exceeds EPA's criterion for an acceptable
level, which is a one in 10,000 cancer risk.
The background cancer
populations is that one
cancer. The scenario
hypothetical person (who
risk over a lifetime in human
out of every four people will get
described above results in the
already has a one in four, or 2:
18
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percent, chance of getting cancer) having a 25.01 percent
chance.
A citizen asked EPA to explain both why no fish, crayfish
or water frogs live in the willis Branch and, based on this:
how EPA can claim that the water is not contaminated.
EPA Response. EPA conducted an environmental assessment and
a human health risk assessment. In assessing the water
quality of the Willis Branch, EPA found that the water and
the sediments do not contain any concentration of any
substance from the Site that would cause a problem for either
human health or the environment. EPA does not know why the
Willis Branch is degraded. It may be due to something that
came from the site in the past or it may be the result of
some source upstream of the Site.
In conducting the human health risk assessment, EPA
determined that a number of contaminants from Landfill #1
have leached out, moved through the ground water into the
Willis Branch and, over a period of years, evaporated into
the air, possibly traveled downstream to the estuary;
however, EPA can not find them in the Willis Branch. EPA
also evaluated the wetlands along the north side of the
willis Branch and, still, found nothing.
B.
Liners
A representative of the Greater Cheswold Environmental Safety
Committee asked about the li~~elihood of the liner failing in
Landfill #2.
EPA Response. Because EPA cannot precisely predict when or
at what rate liners may fail, EPA looked at several liner
failure scenarios during the RI and during the FS, and used
extremely conservative assumptions when developing qround
water models. The failure scenario evaluated under the RI
resul ted in a risk corresponding to 1 x 10"' or a one in
10,000 excess risk of cancer. As a part of the FS, a revised
liner failure scenario, which took into account data
collected after the RI report was written, was evaluated.
The percentage liner failure was based upon studies of liner
performance in field conditions. Under this scenario, the
risk associated with use of shallow ground water was 4 x
10"6, or a four in one million excess risk of cancer.
SECTION II:
RESPONSES TO WRITTEN COMMENTS
During the public comment period, EPA received 6 letters
containing written comments. EPA received letters from U.s.
19
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2.
Senator William v. Roth and U.S. Congressman Thomas R. Carper
containinq-a petition from local residents; this same petition was'
submitted directly by the citizens to EPA Region III Regional
Administrator Edwin B. Erickson and to the EPA Community Relations
Coordinator for the Coker's site, Ms. Francesca DiCosmo. EPA also
received letters from the Greater Cheswold Environmental Safety
Committee, The Honorable Mr. Kim Gilson, Mayor of Cheswold, and
from Dr. Albert Vickers, Chairman of the PRP steering committee.
~.
Petition from Local Residents
EPA received four copies of a petition from area residents.
One copy was sent to Mr. Edwin Erickson, the Regional
Administrator; the other was sent to Ms. Francesca DiCosmo. Two
additional copies of the petition were mailed to Senator william
V. Roth and Congressman Thomas R. Carper and subsequently sent to
the Regional Administrator. EPA responded directly to SenQ,\:;.:>r Roth
and Congressman Carper. The ci tL..ens' concerns and EPA' s r-a~ponses
are summarized below.
1.
The first section of the petition's stated concerns addresses
ground watgr contamination. The letter expresses a belief
that car ~enic compounds are "leaking" from the site.
EPA ResDonse: Sampling data collected during the site
investigation does not support the belief that the landfills
are leaking waste constituents at levels that are a threat
to human health. Organic compounds of potential concern,
none of which are carcinogenic, were detected in low
concentrations in one well at each landfill. The compounds
detected, ethylbenzene, toluene, and xylenes, were found at
Landfill '2 at 5 parts per billion Cppb), 7 ppb, and 44 ppb
respectively. The proposed maximum contaminant levels CHCLs)
for these compounds under the Safe Drinking Water Act are 700
ppb ethylbenzene, 2000 ppb toluene, and 10,000 ppb xylenes.
The levels found ansite are well below the proposed HCLs and
are not considered to be a threat to human health.
The letter also states that EPA has not tested- residential
wells, and infers that the deaths of several domestic pets
and farm animals may be linked to the site.
EPA ResDonse. The contention that EPA did not test
residential wells is incorrect. Four residential wells
located in proximity to the landfills were tested on August
9, 1988. The sampling results, as shown in the RI report,
indicate no evidence of Site-related contamination in the
residential wells. In addition, the owners of the deceased
animals in question, who were present at a public meeting
held on September 5, 1990 indicated that their animals had
died of leukemia. Because both feline and bovine leukemia
20
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4.
5.
are highly contagious viral infections, EPA does not believe
the presence of the landfills adversely affected the health
of these animals. However, the State of Delaware has agreed
to sample the wells of those residents whose animals had
died.
3 .
Another section of the petition discusses human health risk.
The petition raises concern for any potential community
health risk associated with the Site and the potential for
lower property values.
EPA ResDonse. At the Coker's site, EPA found unacceptable
health risks only under an extremely conservative residential
use scenario which assumed daily exposure to maximum
concentrations of waste and ingestion of leachate over a
lifetime. (The Proposed Plan calls for deed restrictions
that would prevent any such future use of the Site.) Ground
w2~er modeling does not indicate that residents living
0:: .:.:te are at an excess risk of experiencing ill health
eff~~ts or of developing cancer as a result of exposure to
site contaminants. Onsite. ground water monitoring will
detect any contaminant plume before it could affect local
residents.
The petition goes on to state, "we possess the methodology
. . . to remove this toxic health risk."
EPA ResDonse. While it is technically possible to excavate
and remove all waste from the Site, EPA considers offsite
disposal of waste without treatment to be the least
preferable strategy for handling sites under the Superfund
law. Removal of the more than 110,000 cubic yards of waste
contained at the site would not only be costly (approximately
$84,000,000), but also could result in significant short term
risks to workers and nearby residents associated with release
of volatile organic compounds during excavation and handling
of waste. Another short-term impact on the community would
be a significant increase in truck traffic, and the risk of
a truck accident and subsequent spill. An alternative
involving removal for offsite disposal was ruled out early
in the Feasibility Study because it did not compare favorably
to EPA' s preliminary screening criteria of effectiveness,
implementability, and cost-effectiveness.
The next section of the petition addresses environmenta 1
contamination. The citizens are concerned because EPA has
stated that although the leachate from landfill 11, which
borders the Willis Branch of the Leipsic River (the Willis
Branch), has some observed toxicity to aquatic organisms,
there is no evidence of contamination of the Willis Branch.
EPA ResDonse.
Because the leachate theoretically reaches the
21
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Willi_I!' Branch, these statements may appear contradictory.
However, the leachate does not actively run from the Site to
the creek. Rather, leachate is found in seeps located along
the sloping land which borders Landfill 11 to the north.
These seeps dissipate into a flat, marshy area which borders
the willis Branch. Because the chemicals of concern are
found only in very low concentrations and are readily
released to the air, it is likely that these contaminants
vaporize before they can reach the Willis Branch. Even if
a significant flow of leachate did reach the stream, the
larger volume of the stream would quickly dilute the leachate
and further reduce the already low levels of contaminants.
Chemical and biological testing have shown no evidence of
site-related contamination in the Willis Branch.
6.
The citizens expressed concern because EPA does not knoW'
where.Reichhold Chemicals, Inc., the current owner of the
facility that produced the waste contained at the Coker's
landfills, currently disposes of its waste.
EPA Response. This waste material is considered an industrial
waste, not a hazardous waste as defined under RCRAi
therefore, its disposal is not regulated by EPA. Industrial
waste is handled under Delaware Solid Waste Disposal
Regulations. In addition, the Superfund program is only
authorized to respond to abandoned sites, not operating
facilities.
7.
The citizens expressed concern that EPA' s preferred
alternative does not call for treatment or removal of the
waste material.
EPA Response. EPA's preference, as stated in tne Nationa:.
oil and Hazardous Substances Pollution Contingency Plan
(NCP) , is to utilize permanent solutions and alternative
treatment (or resource recovery) technologies to the maximum
extent practicable. However, for this Site-, EPA and the
State believe that limited action meets all of EPA's
statutory requirements, and is protective of huma.n health and
the environment.
B.
the
Greater
Cheswold
Environmental
Safety
Letter from
Committee
A letter was sent by Mrs. Dorothy Dempsey, Chairman of the
Greater Cheswold Environmental Safety Committee to Ms. Francesca
DiCosmo, EPA's Community Relations Coordinator for the site. Mrs.
Dempsey's letter expresses dissatisfaction with EPA's preferred
alternative, stating that any threat of ground water contaminatio~
and any resultant risk to human health are unacceptable to he~
committee, and also expresses concern over potential threat to the
water supply of the City of Dover, and a preference for complete
22
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3.
4.
C.
removal ot.all waste by PRPs.
1.
Mrs. Dempsey'S letter states that the committee does not
believe the remedy "goes far enough to protect the citizens
that live in the area."
EPA Response. According to EPA's risk calculations,
implementation of the preferred alternative will result in
a risk below the lower boundary of EPA' s acceptable risk
range. This risk range is used nationwide by EPA to manage
risks and select remedial actions at Superfund sites;
therefore, the preferred alternative is as protective as, if
not more protective than, any other remedial action EPA has
selected at any other Superfund site.
2 .
Mrs. Dempsey's letter expresses concern over the potential
threat to the Cheswold aquifer, which is the primary drinking
water source not only for the Cheswold area, but also for the
City of 0c-ver.
EPA Response. Ground water modelling conducted during the
Feasibility Study indicates the landfills do not pose a
threat to the Cheswold aquifer and therefore do not pose a
threat to the drinking water supply of either the local
residents or the City of Dover. Further, an onsite ground
water monitoring program will detect any changes in water
quality before contamination moves offsite in the Cheswold
aquifer.
The letter states,
extremely complex
completely."
"[The committee's] solution to this
problem. is to remove the material
EPA ResDonse. As was explained previously in this
Responsiveness Summary, EPA did examine a complete removal
option; however, this alternative was screened out early in
the Feasibility Study because it did not pass the preliminary
screening criteria of effectiveness, implementability, and
cost-effectiveness. Please refer to EPA's response to the
citizen's petition for further discussion of this issue.
Mrs. Dempsey'S letter implies a preference
implementation of the selected remedy.
EPA ResDonse. EPA does intend to offer the PRPs the
opportunity to implement the selected remedy. If the PRPs
decline, EPA may order the PRPs to implement the remedy, or
EPA may elect. to implement the remedy and pursue cost
recovery against the PRPs.
for
PRP
Letter from the Mayor of Cheswold
23
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Ms. trancesca DiCosmo of EPA received a letter from the
Honorable Mr. Kim Gilson, Mayor of Cheswold. Kayor Gilson's letter
reiterated the concerns of the citizens present at the public
meeting held at the Cheswold Fire Hall on September 5, 1990. These
concerns, as listed in the letter, involve the following issues:
residential ground water testing and mortality of local animals;
the condition of the Willis Branch; similar treatment of both
landfills although they are quite different; securing the
properties from human and animal incursion; EPA's preferred
al ternative. Please refer to EPA' s responses to issues raised
cJ.uring the public meeting for discussion of residential well
testing, mortality of local animals, and condition of the Willis
Branch.
1.
During the public meeting, some residents expressed a concern
(repeated in Mayor Gilson's letter) over the fact that the
site is not fenced and that EPA' s Proposed Plan does not
include fencing the site.
2.
EPA Response. EPA's Proposed Plan did not include fencing
the landfills to restrict access. In response to public
comment, however, EPA has included security fences and the
posting of warning signs in the selected remedy.
Mayor Gilson's letter indicates the town council prefers a
remedy which would allow unrestricted use of the land in the
future, but does not indicate a firm preference for any of
the alternatives presented in the Proposed Plan.
I
I
i
I .
3 .
EPA ResDonse. None of the alternatives under consideration
provide for unrestricted future use of both landfill
properties. Alternatives 6 and 7 (VOC stripping and
incineration) call for consolidation of all treated waste at
Landfill '1. However, while this would allow for
unrestricted future use of Landfill '2 property, the laws
under which the treated waste would be disposed would
preclude unrestricted use of Landfill '1 property. EPA's
primary criteria for selecting remedial actions are
protection of human health and the environment and compl iance
with environmental laws. EPA's preferred' alternative
satisfies these criteria, and provides the best balance of
long-term effectiveness, reduction of toxicity, mobility and
voluae, short-term effectiveness, implementability, and cost
of all alternatives presented in the Proposed Plan.
Mayor Gilson's letter indicates a belief, predicated upon a
statement made in the Proposed Plan regarding the total
number of alternatives evaluated in the feasibility study,
that some alternatives were "not made available" to the
community.
EPA ResDonse.
There are three stages to a feasibility study:
24
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identification and screening of remedial technologies
development and screening of .remedial alternatives and
detailed evaluation of alternatives. Only alternatives 'which
pass detailed evaluation are presented in the Proposed Plan.
All of these alternatives were presented to the community.
Letter from Dr. Albert Vickers
D.
Ms. Lesley Brunker, the Remedial Project Manager for the
Coker's site, received a letter from Dr. Albert Vickers, the Coker
Steering Committee Executive. The letter, in general, indicated
concurrence with EPA's preferred alternative, with several
mOdifications. The letter also expresses concern for potential
difficulties in securing deed restrictions on the landfill
properties, and states that it is inappropriate to compare risks
evaluated during the EA and FS to EPA's residential use scenario.
1.
The letter stat~~;; that there is no mechanism under CERCLA
which allow for imposition of involuntary deed restrictions
on owners of real property.
EPA Response. When a determination is made under Section 106
of CERCLA, 42 U.S.C. S 9606, as has been made for the Coker's
site, that there may be an imminent and substantial
endangerment to the public health or welfare or the
environment because of an actual or threatened release of a
hazardous substance, Section 106 grants authority to secure
such .relief as may be necessary to abate such danger or
threat. The authority exists under CERCLA, therefore, to
impose institutional controls such as deed restrictions on
the Site property.
Deed restrictions are an inteqral component of. the
preferred remedy, in that they will prevent future use of the
property in a manner that will result in unacceptable risk
to human health and the environment. All remedies which were
considered to be protective included deed restrictions on one
or both properties. As Dr. Vickers' letter acknowledges, EPA
has left the exact nature and extent of the deed restrictions
subject to definition during the remedial design phase in
order to develop the most reasonable, yet protective,
strategy for implementation.
Section 300.510(c) (1) of the NCP, 55 ~. ~. 8,854
(March 8, 1990) (to be codified at 40 C. F .R. 9
300.510(c) (1», provides that, when appropriate, as part of
the operation and maintenance assurance provided by a state
pursuant to Section 104(c) (3) (A) of CERCLA, 42 U.S.C. 9
104 (c) (3) (A), and prior to a Superfund financed remedial
action, the state must assure that any institutional controls
implemented as part of the remedial action at a site are in
25
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3 .
4.
2..
placa~ reliable, and will remain in place after the
initiation of the operation and maintenance. In addition,
section 300.510(f) of the NCP, 55 ~. B&g. 8,855 (March 8,
1990) (to be codified at 40 C.F.R. S 300.5l0(t», provides
that, if EPA determines that an interest in real property
must be acquired in order to conduct a response action, then
as a general rule, a state must agree to acquire and hold any
property interest needed to ensure the reliability of
institutional controls restricting the use of that property.
Dr. Vickers' letter supports EPA's statement, made in the
Proposed Plan, that the residential use scenario is extremely
conservative. However, the letter objects to the comparison
af the assessment risks under this scenario to the
assessments made during the RI/FS.
EPA Response. Because the RI/FS risk assessment was
conducted in accordance with guidance that has been
superceeded, and the future use scena..io was cOl~ucted in
accordance with current EPA guidance, EPA agrees that it is
not appropriate to strictly compare results (as was done in
the Proposed Plan). The ROD is based solely upon the
residential use scenario.
Dr. Vick~rs ' letter expresses some confusion over EPA' s
proposed monitoring plan and plans for potential restrictions
on future ground water use.
EPA Response. EPA intends to monitor the Columbia and the
Cheswold aquifers to detect any changes in ground water
quality. It is expected that any contamination would first
be detected in the Columbia (shallow) aquifer. Al though
significant contamination is not anticipated, EPA has
proposed implementation of a Ground Water Management Zone
should restrictions on ground water use be deemed necessary.
The details ot the monitoring program will be defined during
the remedial design stage.
Dr. Vickers' letter suggests modifying the preferred remedy
to eliminate surtace water monitoring and to instead gauge
the potential tor impacts on the Willis Branch on changes
detected in shallow ground water. The letter suggests that
external tactors could cause changes in the water quality,
and that because shallow ground water is essentially the same
as the water that makes up the leachate seeps, ground water
monitoring could provide an "early warning system" for
potential changes in the Willis Branch.
EPA Response. EPA agrees that external factors can, an.j
likely will, result in overall changes in the quality of the
surface water. However, EPA believes that the surface wate~
sampling program can be designed to minimize the effects c:
26
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~
5.
,.
these. external factors on the evaluation of the impacts from
the landfill on the Willis Branch (i.e., sampling immediately
upqradient of, adjacent to, and downgradient of, the
landfill). It is not likely that the effects of oiling or
salting nearby roadways could be misconstrued as effects from
the leachate characterized during th~ RIjFS. Furthermore,
the concentrations of contaminants found in the leachate and
in the shallow ground water were dissimilar. No styrene was
detected in the shallow ground water, although it was
detected in the leachate, and the concentration of
ethylbenzene detected in the ground water was an order of
magnitude lower than the level detected in the leachate.
Dr. Vickers' letter suggests that covering leachate seeps at
tandfill '1, sealing the leachate collection pipes at
Landfill '2, and regrading the depressed area of Landfill #2
be eLiminated from the preferred remedy because these
components do not result in a significant reduction in risk
posed by the ~ite.
EPA ResDonse. Although EPA acknowledges that placement of
deed restrictions and establishment of a Ground Water
Management Zone, if needed, will have the greatest impact on
reducing risk associated with this Site, EPA believes the
other components (covering leachate seeps at Landfill #1,
closing the leachate collection system at Landfill '2, and
backfilling depressed areas of Landfill '2) should still be
implemented because they contribute to the overall
effectiveness of the selected remedy.
27
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SEP-28-90
THU
1 0 : ~ 6
DNREC""'OFC
OF
SECRETARY
P.02
..
I~.;i ~
. ,.. .
... '. . ,I.
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SIC-lit".....
$""''1'1: O~ OI;'.4""A~1
O!:IDA~:Me:.\jT OF N.4 ':"~ ~A L.. Rrso\..'.~C!!
& ENVI~ONMe:':A:" CO,"i~O~
at 0(":-,,, ... :",- '...
-0 1:..11 : 4:(,;'
co.." ~L_"',""".. . ttCJ
T" ..,.'..
'. )~..! -)8 "6~'
S.~tember 27, 1990
~
,"
Mr. E~w1n B. Irickson
Re&ional Adm1n1serator
U.S. EPA ReiiQn II!
!~l Chescnut Buil~in,
Ph11.de:~h1a, PA 1911~
~E:
Conc~r~ence with the ROD
Coke: Sanitation SicI LAndfill. -1 and -2
Cheswold, K.nt County, Dela~are
Dear Mr. Erickson: ,
rhrc~gh ~he coordinated effort. of EPA and DNR!C, thl Oep&~~m8r.: fei:, ~hat &~
appropriate remley has be.n sllected for the Coktr Sanitation Land!i1l. -: a~d
;;2 s1:.. !his remedy (AleernAtive .3 with modification.) i. consister.: ..,~::-.
the var1o~8 rederal and Scace resulation. and identified ARARs.
By 8 il:'\Łtu::'e of this letter I D~EC formally tXPUliU
selected remedy.
i 1:. support
for :ht
Sincere:y,
~ ~' . ~ R/~ .<
C;:"?"~ ~. / 0-
!dv1n H. Clark, II
Sec:'lcary
.; F3/ j t'o
JF32072
cc: Ph~llip G. ~etallick
N.V. R~an
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