United States Office of
Environmental Protection Emergency and
Agency Remedial Response .
EPA/ROD/R03-93/177
March 1993
SEPA Superfund
Record of Decision:
William Dick Lagoons, PA
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R03-93/177
3. Recipient* * Accession No.
Title and Subtitle
SUPERFUND RECORD OF DECISION
William Dick Lagoons, PA
Second Remedial Action - Final
5. Report Date
03/31/93
7. Authors)
8. Performing Organization Rept No.
9. Performing Organization Nam* and Address
10 Pro)** Tatk/Work Unit No.
11. Contract(C)orGrant(G)No.
(C)
(G)
12. Sponsoring Organization Nam* and Address
U.S. Environmental Protection Agency
401 M Street, S.w.
Washington, D.C. 20460
13. Type of Report a Period Covered
800/800
14.
15. Supplementary Notes
PB94-963906
16. Abstract (Limit: 200 words)
The 4.4-acre William Dick Lagoons site is an inactive waste disposal site located in
West Cain Township, Chester County, Pennsylvania. Land use in the area is
predominantly residential, with a sparse population density. The majority of residents
in the vicinity of the site use private wells as their drinking water supply. The site
is located near Birch Run, a tributary of the West Branch of Brandywine- Creek, which is
used as a water source for populations as far as Wilmington, Delaware. From the late
1950s until 1970, Mr. William Dick used a series of onsite lagoons for the disposal of
minor amounts of chemical residuals and final rinse waters from the interior cleaning
of tank trailers owned by Chemical Leaman Tank Lines, Incorporated (CLTL). These tank
trailers were used to transport various chemical products using petroleum, latex, and
resins. In 1971, Mr. Dick, CLTL, and the State reached an agreement to .close the
lagoons after a violation of the Clean Streams Law and a vandal-inflicted breach in one
of the berms resulted in the discharge of approximately 300,000 gallons of wastewater
into a nearby creek, the death of 2,600 fish, and the closure of public water supplies
in the vicinity. Any residual remaining in the bottom of the lagoons after drainage
was buried by pushing the earthen berms into the lagoons, filling them with soil, and
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - William Dick Lagoons, PA
Second Remedial Action - Final
Contaminated Medium: soil
Key Contaminants: VOCs (PCE, TCE), other organics (PAHs, pesticides), metals (arsenic,
chromium)
b. Identifiers/Open-Ended Ti
c. COSATI Reid/Group
18. Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Pags)
None
21. No. of Pages
82
22. Price
(See ANSt-Z39.1B)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTO-35)
Department of Commerce
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EPA/ROD/R03-93/177
William Dick Lagoons, PA
Second Remedial Action - Final
Abstract (Continued)
planting a vegetative cover on the surface. In 1988, EPA sampled the former lagoon site
and collected well water samples from several surrounding residences. These
investigations revealed elevated levels of numerous organic compounds in the soil. In
1987, EPA required CLTL to install a fence around the site and point of entry. A 1991 ROD
addressed final remedy for OU1 for the provision of an alternate water supply to more than
50 residences impacted by the site, carbon filtration units on homes where TCE
concentrations were above 5 ug/1, and also provided for an interim remedy for OU2
consisting of pumping and treatment of ground water and a hydrogeologic study. In 1992,
CLTL also performed a soil vapor extraction/bioremediation treatability study to
determine the feasibility of using this technology to remove contaminants from the onsite
soil. This ROD addresses the 2.2 acres covered by the lagoons and the remaining 2.2
acres, which served as a burrow area for soil used to construct the compacted earthen
ridges or berros around the perimeter of the lagoons, as OU3. The primary contaminants of
concern affecting the soil are VOCs, including PCE and TCE; other organics, including PAHs
and pesticides; and metals, including arsenic and chromium.
The selected remedial action for this site includes determining the extent of soil
contamination; excavating and treating approximately 24,000 yd^ of contaminated soil
onsite using thermal desorption; treating air emissions from the thermal desorption
process using a control system consisting of a fabric filter for particulate removal, a
wet scrubber for acidic gas conversion, and a carbon adsorption system for capturing the
contaminants; managing and disposing of treatment residuals offsite; backfilling the
treated soil in excavated areas; placing either a vegetative soil cover or multi-layer cap
over the excavated areas; and implementing institutional controls, including deed
restrictions. The estimated present worth cost for this remedial action ranges from
$7,800,000 to $9,300,000, which includes an estimated annual OSM cost of $20,000 for 30
years.
PERFORMANCE STANDARDS OR GOALS:
Chemical-specific soil cleanup goals are based on either RCRA LDRs or a health-based risk
level of 10~6 or less and include acenaphthene 31 mg/kg; anthracene 94 mg/kg;
benzo(a)pyrene 7,300 mg/kg; bis(2-ethylhexyl)phthalate 266 mg/kg; chlorobenzene 5.7 mg/kg;
chloroform 280 mg/kg; 4,4-DDE 7,250 mg/kg; 2,4-dichlorophenol 230 mg/kg; fluorene 49
mg/kg; fluoroanthrene 250 mg/kg; naphthalene 3,100 mg/kg; phenanthrene 94 mg/kg; PCE 1.2
mg/kg; 1,2,4-trichlorobenzene 61 mg/kg; and TCE 0.42 mg/kg.
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RECORD OP DECISION
WILLIAM OZCX LAGOONS SITE
DECLARATION
SITE MAMS AND LOCATION
William Dick Lagoons Site
West Cain Township, Chester County, Pennsylvania
STATEMENT OF BASIS AND* PURPOSE
This decision document presents the selected remedial action for
Operable Unit 3 of the William Dick Lagoons Site ("Site"), in
West Cain Township, Pennsylvania, which was chosen in accordance
with the Comprehensive Environmental Response, Compensation, and
Liability Act of 1980 (CERCLA), as amended by the Superfund
Amendments and Reauthorization Act of 1986 (SARA), and, to the
extent practicable, the National Oil and Hazardous Substances
Pollution Contingency Plan (NCP). This decision document
explains the factual and legal basis for selecting the remedy for
Operable Unit 3 at this Site. This decision is based on the
Administrative Record for this site.
The Commonwealth of Pennsylvania has evaluated and commented on
the alternatives presented in this Record of Decision and has
initially agreed with the technical remedy selected. The
official position of the Commonwealth of Pennsylvania will be
documented in the Administrative Record for this Site upon
receipt.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this
Site, 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 REMEDY
The remedy described in this Record of Decision is for Operable
Unit 3 at the Site. This remedy addresses the principal threat
at the Site.
Operable Unit 1 at this Site involves providing a water line to
protect residents from contaminated private veil water, operable
Unit 2 involves an interim remediation of the groundwater which
includes measures to.pump and treat the groundwater and further
investigation of the hydrogeology. A Record of Decision for
Operable Unit One and the interim groundwater remediation measure
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58
for Operable Unit Two was issued on June 28, 1991. A decision on
the final groundwater remediation is intended for this Site at a
later date.
The remedy selected for Operable Unit 3 will reduce the
concentrations of hazardous substances in the Site soils so that
leaching of contaminants into the groundwater will be minimized.
Reduction of the volatile organic compounds and semi-volatile
organic compounds in the soils is necessary in order the
groundwater will not continue to be impacted above acceptable
levels. In addition, the installation of a vegetative soil cover
or multi-layer cap will prevent the surrounding community from
exposure to Site-related contaminants through inhalation,
ingestion, and dermal contact.
The selected remedy includes the following major components:
1. Determination of extent of soil contamination.
2. Excavation of contaminated soils and treatment of
contaminated soils in an on-site thermal desorption
unit.
3. Treatment of air emissions from the thermal desorption
unit.
4. Management and off-site disposal of treatment residuals
and wastewaters.
5. Backfilling of treated soils in the excavated areas and
placement of a vegetative soil cover or multi-layer cap
over such areas.
6. Operation and maintenance ("O&M") of the vegetative
soil cover or multi-layer cap.
7. Institutional controls in the fora of deed
restrictions.
DECLARATION OF STATUTORY DBTBRMIMATIOITS
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 technologies to the
maximum extent practicable, and satisfies the statutory
preference for remedies that employ treatments that reduce
toxicity, mobility, or volume as a principal element.
Subsequent actions are planned to more fully address the threats
posed by the groundwater at this Site.
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Because this remedy may result in hazardous substances remaining
on-site above health-based levels, a review will be conducted
within five years after the start of this remedial action to
ensure that the remedy continues to provide adequate protection
of human health and the environment.
Stanley LT Laskowski Date
Acting Regional Administrator
Region III
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WILLIAM DICK LAGOONS SITE
RECORD OF DECISION
OPERABLE UNIT 3
SOURCE OF CONTAMINATION
TABLE OF CONTENTS
I. Site Name, Location, and Description i
II. Site History and Enforcement Activity ... i
III. Highlights of Community Participation 7
IV. Scope and Role of Operable Unit 3 8
V. Summary of Site Characteristics 9
VI. Summary of Site Risks 12
VII. Description of Alternatives 21
Alternative 1: NO ACTION 23
Alternative 2: CAPPING 24
Alternative 3: SOIL VAPOR EXTRACTION/BIOREMEDIATION
WITH MULTI-LAYER CAP 25
Alternative 4: THERMAL DESORPTION WITH VEGETATIVE SOIL
COVER OR MULTI-LAYER CAP 27
Alternative 5: INCINERATION WITH VEGETATIVE SOIL
COVER 30
VIII. Summary of the Comparative Analysis of Alternatives . . 31
A. Overall Protection 31
B. Compliance with Applicable or Relevant and
Appropriate Requirements (ARARs) 31
C. Long-Term Effectiveness and Permanence: 37
D. Reduction of toxicity, mobility, or volume of the
contaminants through treatment: 38
E. Short Term Effectiveness: . 39
F. Implementability 39
G. Cost 40
H. State Acceptance: <40
I. Community Acceptance: 40
IX. Selected Remedy and Performance Standards ....... 41
X. Statutory Determinations 49
A. Protection of Human Health and the Environment ... 49
B. Compliance with ARARs 50
l. Chemical-Specific ARARs 50
2. Location-Specific ARARs 50
3. Action-Specific ARARs 50
C. Cost-Effectiveness 53
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D. Utilization of Permanent Solutions and
Alternative Treatment Technologies or Resource
Recovery Technologies to the Maximum Extent
Practicable 54
E. Preference for Treatment as a Principle Element ... 54
XI. Documentation of Significant Changes 54
APPENDIX A- RESPONSIVENESS SUMMARY
APPENDIX B- ADMINISTRATIVE RECORD INDEX
APPENDIX C- AIR EMISSIONS MODELS AND RISK ASSESSMENT FOR
EXCAVATION
APPENDIX D.- RISK ASSESSMENT DATA
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I. Sit* Name, Location and Description
The William Dick Lagoons Site is located in West Cain
Township, Chester County, Pennsylvania approximately 3.5 miles
.south-southeast of the Village of Honey Brook. The 4.4 acre site
is located within a larger 105-acre parcel of land and is
situated in a rural wooded setting on the crest of a small ridge
known as the Baron Hills. It is accessible via Telegraph Road,
at approximately 2,500 feet west of Sandy Hill Road (see Figure
1). The nearest residence is located, roughly 300 feet to the
north and approximately thirty homes are within 1000 feet of the
Site. Figures 1 and 5 provide a perspective of the site setting
relative to proximal residencies.
•; The site currently appears as a sparsely vegetated field
behind several residences located on the south side of Telegraph
Read. The site is obscured from view by both the surrounding
trees and its position at the crest of a hill. Land use
surrounding the site is primarily residential, with a generally
sparse population density. Housing development in West Cain
Township is progressing relatively quickly and several new homes
have been built since the commencement of site remedial
investigative activities. The majority of the residences are
single family dwellings with private wells and onsite septic
systems. Several trailer parks and a campground exist within the
vicinity of the site and two separate automobile junkyards are
located just north of the site.
Much of the area extending outward from the near-site
residences is actively farmed. Important crops include corn,
wheat, oats, soy beans and hay. Dairy cattle are also raised
within the surrounding countryside.
Two other Superfund sites are located within five miles of
the site. The Blosenski Landfill is located approximately 1.7
miles to the southeast and the Welsh Road Landfill is roughly 5
miles to the northwest.
II. site History and Enforcement Activities
Waste disposal activities at the site were conducted by its
former owner, Mr. William Dick, in the late 1950s through May
1970. Originally, the Site consisted of three unlined earthen
lagoons or ponds that were used for the disposal of wastewater.
The lagoons covered approximately 2.2 acres of the 4.4 acre Site;
the remaining 2.2 acres served as a borrow area for soil used to
construct the compacted earthen ridges or barns around the
perimeter of the lagoons (see Figure 2).
The lagoons were used to dispose of final rinse waters from
the interior cleaning of tank trailers owned by Chemical Leaman
Tank Lines, Incorporated ("CLTL"). Trichloroethylene (TCE) was
used to clean out the tank trailers. In addition, minor amounts
of residual chemical products were occasionally disposed of in
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the lagoons. The tank trailers were used for transporting
petroleum products, latex, and resins. Following the rinsing and
cleaning of the tank trailers at CLTL's Downingtown, Pennsylvania
facility, the rinse water was delivered to the lagoons by tanker
approximately every three days for disposal. The information
currently available to EPA indicates that all disposal activities
at the Site were completed prior to the effective date of the
regulations implementing the Resource Conservation and Recovery
Act, November 19, 1980.
On April 26, 1970, 37 wild geese were shot at the site by
the district game protector for humane reasons. The birds'
feathers were coated with waste after the birds descended onto
the lagoons. In May 1970, the Pennsylvania Department of Health
(PADH) notified Mr. William Dick that the discharge from the
lagoons to underground waters was a violation of the Clean
Streams Law, the Act of June 22, 1937, P.L. 1987, as amended and
ordered the lagoons closed. On June 7, 1970, vandals allegedly
caused a breach in the berm of the second lagoon, resulting in
the release of an estimated 300,000 gallons of wastewater that
moved into Birch Run, a tributary of the West Branch of
Brandywine Creek. The discharge caused the death of more than
2,600 fish and the closure of public water supplies which used
the creek as a water source as far downstream as Wilmington,
Delaware. Mr. William Dick was notified by PADH that the
discharge into the into Birch Run violated the Clean Streams Law.
A complaint was filed by the Commonwealth of Pennsylvania in the
Court of Common Pleas, Dauphin County, Pennsylvania (Number 3072
Equity Docket, No.345 C.D. 1970)
In early 1971, per the agreement reached with PADH
under the aforementioned complaint, CLTL and William Dick began
work to close the lagoons. This activity included the addition
of alum to -the lagoon wastewater, and spray irrigation of the
ntreated" wastewater into the woods adjacent to the lagoons.
Settled residue remaining in the bottom of the lagoons was buried
by pushing the earthen b«rms into the lagoons. The lagoons were
completely filled in with soil and a vegetative cover planted on
the surface.
In April 1985, under the authority of the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA)
of 1980, an EPA contractor performed a sit* sampling inspection
of the former lagoon sit* and collected well water samples from
several surrounding residences. This inspection was conducted in
response to a 1981 CERCLA notification to EPA by CLTL which
indicated that the former lagoons may contain hazardous
substances. During the inspection, elevated levels of numerous
organic compounds were detected in the soil samples collected
from the former lagoon area. A few site-related compounds also
were found in two residential wells.
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In May 1987, additional sampling of 28 residential veils by
EPA's Technical Assistance Team (TAT) found TCE to be the most
prevalent organic compound, at the highest concentration, in
groundwater. This, volatile organic compound (VOC), a suspected
carcinogen and common industrial solvent, was detected in two
spring-fed water supplies and five wells. Following the
completion of these follow-up evaluations, the Site was listed in
July 1987 on the National Priorities List (NPL) of hazardous
waste sites eligible for cleanup under Superfund.
On July 20, 1987, EPA informed CLTL of its potential
responsibility regarding contamination at the site by issuing a
special notice letter. On January 27, 1988, EPA and CLTL entered
into an Administrative Order on Consent ("1988 Removal Order")
which required CLTL to install a fence around the site, conduct
at least yearly monitoring of residential wells (more frequent
monitoring in some cases), and install point-of-entry treatment
systems for home well water exceeding Maximum contaminant Levels
(MCLs). The fence was installed at the site in February 1988.
The sampling and treatment unit requirements of the Consent Order
will continue to be in effect until the waterline is constructed
and is operating at the affected and potentially affected
residences. At that time, the treatment units will be removed
from the residences and CLTL will discontinue the residential
well monitoring.
CLTL has supplied bottled water to all homes (approximately
34) in which TCE levels between 0 to 5 parts per billion (ppb)
were detected in residential wells. The company has supplied
bottled water under its own initiative; CLTL is not required to
do so by EPA. To date, CLTL has installed point-of-entry carbon
filtration units in the twelve homes where TCE concentrations in
well water exceed EPA's MCL of 5 ppb.
On September 14, 1988, CLTL and EPA signed a second
Administrative Order on Consent, requiring that a Remedial
Investigation/Feasibility Study (RI/FS) be conducted. CLTL .
obtained the services of Environmental Resources Management
("ERM") for this work. The RI began in December 1988 and
progressed throughout the Spring and Summer of 1989. Based upon
data gaps identified by both EPA and ERM, a second shorter phase
of RI work was initiated in October 1989. An interim RI report
was submitted to EPA in December 1989. After EPA comments, a
more detailed draft RI report, along with a draft FS report and
Risk Assessment (RA), ware submitted for EPA review on March 8,
1990. Following receipt of EPA comments, a Preliminary Final
RI/RA/FS was submitted by CLTL on September 6, 1990.
On September 24, 1990, EPA informed the Rohm & Haas Company
of Philadelphia, Pennsylvania of its potential responsibility
regarding contamination at the site by issuing a general notice
letter . This notification was based on information received on
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the company's past involvement at the site through interviews
with former CLTL employees. Specifically, CLTL hauled Rohm & Haas
product to Rohm & Haas' customers and then cleaned product
residue from CLTL's tanker trucks and hauled it to the William
Dick Lagoons Site.
On June 28, 1991, EPA issued a Record of Decision for
Operable Units One and Two at the Site. The major components of
the remedies selected included (1) with respect to an alternative
water supply, providing an extension of the City of Coatesville
Authority water line to at least 50 homes impacted or potentially
impacted by the Site and, (2) with respect to the interim action
for groundwater clean-up, performing a hydrogeological study
aimed at determining the proper design of a groundwater
remediation system, and pumping and treating the contaminated
ground water to remove site-related contaminants for a limited
time frame.
EPA deferred the decision regarding soil remediation (OU 3)
until a Soil Vapor Extraction/Bioremediation (SVE/BIO)
treatability study and Focused Feasibility Study was performed at
the Site by CLTL.
After EPA issued the June 1991 ROD, CLTL entered into
negotiations with EPA to implement the clean-up activities
described in the ROD. These negotiations continued, without
resolution, until March 1992. On June 30, 1992,, EPA issued an
Administrative Order requiring the PRPs to undertake the remedies
respecting alternate water supplies and interim groundwater
studies and remediation defined in the ROD. The PRPs did not
agree to comply with all of the terms of the order.
Consequently, EPA hired a contractor to perform the design work
for the water line, ground water investigation and interim
groundwater remediation. Currently, EPA is reviewing the
contractor's work plan for the pre-design groundwater
investigation. The pre-design groundwater investigation needs to
be performed prior to the completion of the design of the water
line and groundwater pump and treat system.
In June 1991, EPA verbally approved CLTL's performance of a
SVE/BIO treatability at the Site. In August 1991, EPA confirmed
this approval in writing. The SVE/BIO treatability study was
performed pursuant to Section 6.2.2 of the Final Remedial Site
Operations Plan (RISOP) prepared by CLTL in November 1988. This
RISOP was incorporated into the September 1988 RI/FS Consent
Order between EPA and CLTL, as described in Section VIII (C) of
this Order. CLTL submitted its workplan for the treatability
study in February 1992. This workplan was disapproved by EPA in
April 1992. CLTL submitted a revised workplan in June 1992.
This workplan was subsequently disapproved by EPA. A second
revision was submitted to EPA in August 1992. EPA verbally
approved of this workplan in August 1992. Written approval was
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provided in September 1992.
CLTL (through its contractor) performed a SVE/BIO
treatability study in former Lagoon #1 at the Site from August
1992 to November l"992 and submitted a Focused Feasibility Study
which evaluated alternatives for remediating the soils at the
Site. The purpose of this study was to determine the feasibility
of using this technology to remove contamination from the soils
on the Site.
In addition to this work, CLTL (through its contractor) also
used several mathematical models to calculate the level of
contamination that can remain in the soil without releasing
contaminants to groundwater above levels acceptable to EPA.
These soil clean-up levels were developed using a combination of
the fate and transport mathematical models, HELP and PRZM, as
well as a groundwater mixing zone model. Compounds which have
been identified in the groundwater were used in the model. The
groundwater concentration input data into this model was based on
Maximum Contaminant Levels ("MCLs") and health-based drinking
water concentrations. Health-based drinking water concentrations
were established based on a carcinogenic risk of 10E-05 or 10E-
04. A cancer risk of 10E-05 means that one additional person per
100,000 has a chance of contracting cancer given the relevant
exposure scenario. The NCP directs hazardous substance responses
for Sites presenting risks outside the established acceptable
carcinogenic risk range for Superfund Sites of between 10E-06 (l
additional chance in one million) and 10E-04 (one additional
chance in 10,000). EPA used a carcinogenic risk of either 10E-04
or 10E-05 as the basis for the health-based drinking water
concentrations for chemicals without an MCL at this Site rather
than use the more conservative 10E-06 carcinogenic risk values
since the 10E-06 carcinogenic value for some compounds are below
the contract required quantitation limit for the drinking water
analytical technique, EPA Method 524.2. The contract required
quantitation limit is the detection level required for a
particular analytical method under EPA's Contract Laboratory
Program (CLP). Use of either 10E-04 or 10E-05 carcinogenic risk
is protective of human health since it falls within the EPA's
acceptable risk range of 10E-06 to 10E-04.
For those chemicals without an MCL or with a health-based
drinking water concentration greater that 10 ppb, a groundwater
concentration of 10 ppb was used. The use of 10 ppb was based on
the contract required quantitation limits as established under
the Contract Laboratory Program (CLP) Statement of Work for
Organics Analysis (CLP Document Number OLM01.1). The 10 ppb
level was established in the focused feasibility study by CLTL in
an attempt to conform to PADER's groundwater protection strategy,
which, although not an applicable or relevant and appropriate
regulation for this ROD, is a "To Be Considered" policy. Soil
clean-up levels calculated on the assumption that a vegetative
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soil cover would be placed over the site after soil treatment are
listed in Table 1.
A vegetative soil cover is defined in this ROD as a layer of
soil which will support the germination and propagation of
vegetation and will provide dermal protection from the treated
soils. The vegetated soil cover will not restrict the
infiltration of rainwater or surface water through the soils.
According to the model, some of the compounds listed in
Table 1 will degrade prior to reaching the groundwater and,
therefore, no soil clean-up level was provided. However, if the
contaminated soils are treated and placed back on-site, certain
contaminants (i.e., those compounds related to F001-F005 wastes)
will have to meet the treatment standards established by the Land
Disposal Restrictions (LOR) listed at 40 CFR $268.43. The LOR
levels for the relevant compounds are listed in Table l. For the
remaining compounds which are not F001-F005 wastes but do,
according to the model, degrade before reaching the groundwater,
EPA believes that it is appropriate to establish soil clean-up
levels based on direct contact risks. These levels are also
noted in Table 1. The groundwater concentrations used in the
fate and transport models- to calculate the soil clean-up levels
are listed in Table 1 and are based on either MCLs, health-based
concentrations under a drinking water exposure scenario or 10 ppb
as described above.
Some of the soil clean-up levels that were calculated by the
model exceeded the concentrations for a direct contact risk. The
soil concentrations that need to be met so that the direct
contact risk is acceptable to EPA are provided in Table 2.
Attainment of the direct contact risk levels listed in this table
are not required for this ROD, because placement of a cover or
cap over the soils and implementation of institutional controls
will prevent exposure to the soils through direct contact.
However, if the values listed in Table 2 can be met during remedy
implementation, deed restrictions on the property may be
eliminated.
CLTL also calculated contamination levels that can remain in
the soil with various types of caps proposed to be placed over
the site to reduce infiltration of rain water. These soil clean-
up values are described and summarized in the Appendix C of the
Focused Feasibility Study, dated November 16, 1992. This
document is located in the Administrative Record (AR300569-
AR300597). The soil clean-up levels in this Appendix do not take
MCLs or health-based drinking water concentrations into account,
therefore, these values are considered preliminary by EPA.
The results of the SVE/BIO treatability study indicate that
significant quantities of VOCs can be removed from the soils
through SVE/BIO. Approximately 610 pounds of VOCs were removed
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during six weeks of continuous operation. Good subsurface air
flow conditions were observed during the treatability study.
After the six week treatability study, it could not be
conclusively demonstrated that bioremediation ("BIO") could be
effective in reducing the levels of VOCs and Semi-volatile
organic compounds (SVOCs) in the soils at the William Dick
Lagoons Site. During the RI and the treatability study, soil
samples were taken in the former lagoon area. Thin layers of a
black, sticky, fibrous (i.e., tar-like) substance were found at
depths ranging from 2 to 6 feet in former Lagoon #l. Analysis of
this layer showed that it contained the VOCs and SVOCs found in
the soil. The impact of this layer on the operation of the
SVE/BIO system was not analyzed during the treatability study.
According to CLTL, an additional 6-12 month pilot study would be
necessary during the remedial design to determine how this layer
would affect SVE/BIO remediation. If this layer can not be
remediated with SVE/BIO, CLTL proposed to excavate this material
and treat it by either thermal desorption or incineration.
In addition to the thin layers of a black, sticky, fibrous
substance, other materials were identified in the three former
lagoons. These materials were classified as "spongy", "rubber-
like", "dry, matted and latex-like" and were observed at depths
ranging from 2 to 14 feet in all three lagoons. These materials
could also impact a full-scale SVE/BIO remediation.
III. Highlights of Community Participation
.In accordance with CERCLA Sections 113(k)(2)(B)(i-v) and
117, EPA instituted several measures to contact and correspond
with residents in the community surrounding the William Dick
Lagoons Site concerning Operable Unit 3. Following is a listing
of the community relations efforts conducted by EPA:
June 1991- issued the Record of Decision for OU l and OU 2
to persons on the site nailing list site and government
officials. This ROD discussed why the decision on
remediating the soils at the site would be deferred.
July 1991- held a public meeting with interested individuals
to describe the components of the Record of Decision for OU
l and OU 2.
August 1992- issued a fact sheet to persons on the site
mailing list and government officials describing the Soil
Vapor Extraction/ Bioremediation treatability study.
January 1993 - issued the Proposed Plan for the site
respecting OU 3 via press release, newspaper publication,
and direct mailing to all individuals on the site mailing
list; announced public meeting in February.
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February 1993 - held public meeting with approximately 50
interested individuals to explain EPA's rationale for the
proposed remedial alternatives presented in the January 25,
1993 Proposed Plan and to solicit comments on this Proposed
Plan during the 30 day public comment period which was held
from January 25, 1993 to February 24, 1993.
In addition, EPA has updated the information repository and
administrative record, available for public review at the West
Cain Township Building, with the reports relating to the Soil
Vapor Extraction/ Bioremediation Treatability Study and the
Focused Feasibility Study for OU 3. The index to the
administrative record for OU 3 is attached to this Record of
Decision in Appendix B.
A response to the comments received during the public
comment period, including the public meeting, is included in the
Responsiveness Summary, which is part of this Record of Decision
and is attached in Appendix A.
IV. SCOPE AHD ROLE Of OPERABLE UNIT 3
Based'on the results of the Preliminary Final RI/FS, EPA has
decided that remediation of the entire site can best be
approached by considering the site as consisting of three
separate "units'*. These units are:
(l) Residential Water Use fi.e.. Alternate Water Supply)- which
involves a remedy to protect residents from contaminated
private well water
(2) Groundwater- which involves a remedy to remediate all or
portions of the contaminated groundwater aquifer
(3) Source Control- which involves a remedy to clean up
contaminated soils at the Site (contaminated soil is the
media considered to be the "principal threat" at the Site
per the definition of principal threat in the NCP 40 CFR
Section 300.430(a)(1)(iii)).
A ROD was issued for Operable Unit 1 and for an interim
action on Operable Unit 2 in June 1991.
Operable Unit 3 (Source Control) is being addressed by this
ROD. The goal of this remedy is to clean soils to contaminant
levels which, along with the installation of a vegetative soil
cover or multi-layer cap (as defined in Section VII. of this
ROD), are sufficient to ensure that any residual contaminants
migrating or leaching to the groundwater will not exceed risk-
based levels or Federal standards for drinking water. In
addition, the vegetative soil cover or multi-layer cap will
ensure against erosion and direct contact by the surrounding
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community and trespassers with site soils.
Reducing the source of contamination impacting the
groundwater at the site will allow an effective final remedy for
groundwater clean-up to be designed. The final remedy for the
groundwater remediation (OU 2) will be outlined in a future ROD.
V. SUMMARY OF SITE CHARACTERISTICS
The purpose of the remedy under OU 3 is to address the soil
contamination on-site so that it does not continue to impact
groundwater above acceptable levels and so that any risks
associated with direct contact with the soil are minimized.
Therefore, this section of the ROD summarizes the site
characteristics related to soils and groundwater as determined
during the RI and the Soil Vapor Extraction/Bioremediation
Treatability Study performed in Fall 1992. A detailed discussion
of all site conditions can be found in the Preliminary Final RI
(September 1990) and the Focused Feasibility Study (November
1992). The groundwater and soil findings are summarized below:
Geology and Qroundvater:
• The site is located in the Honeybrook Uplift in an outcrop
belt of a geological structure known as the Chickies
Formation. It is situated on the crest of the Baron Hills
Anticline in a fault block bounded by two normal faults to
the north and south. (The Chickies is a white to light grey
quartzite with interbedded phyllitic beds.) The site is
located on a groundwater divide. The bedrock beneath the
lagoons is highly weathered and forms a thick saprolite up
to 100 feet thick. Although laboratory analysis indicates
that the saprolite material is of low permeability,
contaminants have migrated to the groundwater table
(approximately 50 feet below the surface) through joints and
fractures in the saprolite.
• Groundwater at the site, as determined by monitoring well
sampling, is contaminated primarily by VOCs and, to a lesser
extent in frequency and concentration, semi-volatile organic
compounds (SVOCs). TCE is the predominant VOC (average
concentration • 1200 ppb, maximum concentration * 16,000
ppb) and phenol is the predominant semi-VOC (average * 800
ppb, maximum * 14,000 ppb). Other compounds found less
frequently and/or in lover concentrations include
chloroform, benzene, acetone, 2-methylphenol, 4-
. methylphenol, isophorone and other organic compounds. Vinyl
chloride was detected on only one occasion in one monitoring
well during post-RI/FS sampling. Table 3 lists the maximum
and average groundwater concentrations in onsite monitoring
wells.
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The highest groundwater concentrations of organic chemicals
are found in two of the thirteen monitoring wells installed
at the site, wells MW-5D and MW-7D. The seven deeper
monitoring wells (MW-1D, MW-3D, MW-5D, MW-7D, MW-9D, MW-llD
and MW-20D) (110 to 397 feet deep) are generally more
contaminated than the six shallow wells (MW-2S, MW-4S, MW-
6S, MW-8S, MW-lOS, MW-12S) (70 to 80 feet deep). All wells
were installed in bedrock (See Figure 4). At well MW-20,
the southwest corner of the site, groundwater was found to
be contaminated down to a depth of 397 feet.
The groundwater surrounding the Site, which is utilized by
residents, is also characterized by low-level TCE
concentrations. Of the approximately 130 residential wells
sampled (See Figure 5), roughly 30 to 40 appear to have some
site-related contamination. Of these 30 to 40, eleven have
concentrations of TCE in the 5 to 15 ppb range (the MCL is 5
ppb) and one well contains TCE at levels from 20 to 280 ppb,
dependent on the sampling season. Residential wells within
a radius of the site are sampled at least once a year; those
homes found to have a detectable level of TCE are sampled
twice a year. The radius was established by CLTL and EPA
under the Removal Order. Due to the number of homes within
the radius of the site (1 mile south, 1/2 mile north) the
sampling schedule is set up so that samples are collected
from 20 to 25 home wells every quarter of the year.
The results of the RI and four years of residential well
sampling data indicate that TCE levels have not changed
significantly at the edge of the contaminant plume where
residential wells are generally located. Based on this
information, the boundary of the groundwater area affected
by site-related contaminants has been relatively well-
defined (See Figure 6), although additional characterization
work is needed.
The regional groundwater flow at the Site appears to be •
toward the southeast. Three significant bedrock fracture
features (two of which are faults) are believed to exist in
the vicinity of the site. Each appears to provide pathways
for contaminant migration to vary froa the overall
southeasterly flow direction and two may serve to partially
block the) flow of groundwater beyond the fractures.
However, it seems that intersecting smaller fractures act as
conduits for groundwater contamination to migrate beyond the
three larger fractures, resulting in a rather complex flow
pattern.
Additional groundwater monitoring wells are needed and
further studies are necessary to confirm the theory that
groundwater flow is controlled by site geologic fractures,
to determine the extent of groundwater flow to the north,
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and to determine the severity of contamination in the area
generally south of the site.
soil:
Soils in the former lagoon area are contaminated by volatile
organic compounds (VOCs), principally trichloroethene (TCE),
which was used at one time to clean out chemical, tank
trailers disposing material at the site, and semi-VOCs,
which appear to be primarily associated with fuel oil
residues. Other than TCE, compounds found at significant
levels in site soils are 2-butanone, toluene, styrene,
xylenes, ethylbenzene, chlorobenzene, and tetrachloroethene
(all VOCs); and several semi-VOCs, especially phenol, 1,2,4-
trichlorobenzene, naphthalene and bis(2-ethylhexyl)
phthalate. The pesticide ODE was also found in
concentrations suggesting that it was disposed of at the
site. Table 4 presents a listing of average and maximum
concentrations of soil contaminants.
Soils are heavily contaminated from a depth of about one
foot below the surface down to approximately 20 feet,
depending on site location. Former lagoon #1 is most
heavily contaminated, with concentrations decreasing as one
moves across the site to former lagoon #2 and lagoon £3.
(See Figures 2 and 7) Because groundwater is contaminated,
and the water table lies at approximately 50 feet below the
site, low-level subsurface soil contamination exists as deep
as 50 feet although a significant drop-off in levels occurs
after approximately 20 feet (See Figure 8 and 9).
Contamination of soils at and below the surface appears to
be confined to the area of the three former lagoons.
As a result of the reported occasional burning of floating
oils on the surface of the lagoons, the RI included an
analyses for dioxins in the soil (dioxins can be created
from the burning of chlorinated phenols and hydrocarbons).
Although dioxins were detected in the parts per trillion
(ppt) range (See Table 5), the levels do not present an
unacceptable risk and will not require remediation. EPA
generally considers the potential need for remediation of
dioxins when levels are found to exist in the ppb range or
higher.
Based on the results of RCRA Subtitle C 40 CFR §261.24
Toxicity Characteristic Leaching Procedure (TCLP) analyses
of three of six soil boring samples, the soil/waste mixture
at the site would be classified as characteristic hazardous
waste under RCRA. In addition, based on EPA's understanding
of the nature of the operations leading to the generation of
waste materials disposed of at the site, EPA Region III has
determined that the soil/waste mixture also would be
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classified as a land disposal restricted hazardous waste
under the RCRA program (See CFR Part 268). The waste
disposed at the site contains F001-F005 waata.
• The former spray irrigation and berm borrow areas (See
Figure 7) only have minor levels of organic contamination
which is not expected to present a direct contact risk. (See
Table 6 for spray irrigation area sampling results.)
• Activities at the site does not appear to have caused
inorganic contamination of site soils, although levels were
occasionally above background concentrations. This finding
is in agreement with EPA's understanding that only organic
chemical rinsewaters and wastes were disposed of at the
site.
• During the RI and the Soil Vapor Extraction/ Bioremediation
treatability study, soil samples were taken in the former
lagoon area. Thin layers of a black, sticky, fibrous
substance were found at depths ranging from 2 to 6 feet in
former Lagoon /I. Analysis of this layer showed that it
contained the vocs and SVOCs found in the soil. In addition
to the thin layers of a black, sticky, fibrous substance,
other materials were identified in the three former lagoons.
These materials were classified as "spongy1*, "rubber-like",
"dry, matted and latex-like* and were observed at depths
ranging from 2 to 14 feet in all three lagoons.
VI. SUMMARY Or 8ITB RISKS
The baseline risk assessment (RA) provides the basis for
taking remedial action and indicates the exposure pathways that
need to be addressed by the remedial action The RA was performed
for the Site in accordance with EPA guidelines. It involves
assessing the toxicity or degree of hazard posed by substances
found at the site by considering the levels at which these
substances are present. The RA also entails describing the
exposure routes by which humans and the environment could come
into contact with these substances.
When estimating an individual's exposure to sit* substances,
conservative assumptions regarding such factors as length of the
exposure period, frequency of exposure, amount of skin exposed
and/or quantity of substance ingested, are purposely used to
ensure that the risk is not underestimated. After evaluation of
the site data, an assessment of toxicological information and
potential exposure is performed, followed by calculations of the
risks posed. Separate calculations are made for those substances
that can cause cancer and for those that can cause other, non-
carcinogenic health effects. Risks to both childen and adults
are presented.
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A) Contaminant Identification
The initial phase of the RA involves reviewing all RI data
and identifying the contaminants of potential concern found in
all exposure media at the site for further risk evaluation. The
exposure media include onsite soil, groundwater, surface water,
springwater, fugitive dust and air emissions, and deer which
might graze at the site. Identified contaminants are primarily
chosen based on their relatively high toxicity, mobility,
persistence and prevalence when compared to all contaminants
present at the site. The chosen contaminants also provide a
representative analysis of the potential risks at the site.
Arithmetic average and maximum concentration levels of the chosen
contaminants are utilized to develop most probable and maximum
exposure scenarios in a later phase of the RA. A listing of the
identified contaminants of concern or "indicator" contaminants
appears in Table 7. Based on RI data, the selected contaminants
represent 99% of the risk associated with each exposure scenario
for each medium. Sources of uncertainty in selecting the
indicator contaminants are discussed in the RA and in Section F,
below.
B)
The objectives of the exposure assessment are to identify
potential exposures associated with the contaminants of concern
at the site and to estimate the magnitude of these exposures.
Based on the site's environmental setting, the RA identified
five potential populations which could be exposed to site
contaminants. Actual exposure of these groups is currently
severely limited however, due to controls implemented at the site
to date. The "potential exposure pathways" for this site are:
Use of groundwater (via private well) as a residential
water supply by residents living in the area of.
estimated site-related impact. Exposure includes .
dermal contact with and ingestion of groundwater as
well as inhalation of volatile organic chemicals
released during showering and other activities.
Dermal contact with and incidental ingestion of
contaminated onsite soils by a casual trespasser.
Ingestion of venison from deer that may graze onsite.
Inhalation of volatile organic chemicals and fugitive
dust released from on-site soils, and
Recreational use of the ponds fed by spring #48 (a.k.a.
the Baldwin Campground spring) (Figure 5). Exposure
includes dermal contact with and incidental ingestion
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of water, as well as inhalation of volatiles released
from the water.
Hypothetical residential use of groundwater from the
onsite monitoring wells installed during RI field work.
The rationale for the selection of these potential exposure
pathways appears in Table 8. When calculating the risks
associated with each of these pathways, the RA considers three
age groups as potentially exposed: adults, children ages 6 to 12,
and children ages 2 to 6. Table 9 provides additional
information on exposure duration.
Actual quantification of potential exposure involves
estimating exposure point concentrations and calculating
potential intakes for each exposure pathway identified above.
Exposure point concentrations (the contaminant concentration at
the point at which the resident is exposed) were based on the
arithmetic average and maximum values for each indicator chemical
found in each medium at the site. To determine the concentration
of VOCs released from onsite soils and the pond fed by Spring
#48, and to determine the concentrations in fugitive dust
released from onsite soils, air screening models were utilized.
When estimating VOC concentrations released during showering with
private residential well water, an inhalation dose equivalent to
that experienced via ingestion of such water was assumed.
Summaries of the average and maximum exposure point
concentrations appear in Appendix 0 of this ROD.
In the calculation of potential intakes (how much and for
how long one is exposed to the exposure point concentrations),
the characteristics of the various exposure pathways must be
defined. Important parameters include the frequency, duration,
and degree of exposure as well as physiologic characteristics of
the exposed population, such as body weight and skin surface
area. Estimates of these parameters are based on EPA guidelines,
recommendations found in the current literature, and professional
judgment. The exposure assumptions used in calculating the
potential intakes appear in Table 9.
Several assumptions wars made regarding both the nature and
extent of contamination present at the site as well as the
behavior and characteristics of the populations potentially
exposed to the contamination. These assumptions include use of
the following: monitoring data to represent exposure
concentrations across a medium; screening level models to
represent exposure concentrations across a medium; single values
for exposure parameters to characterize the behavior of an entire
population over an extended period of time, and the intake
calculations for the deer ingestion scenario, which should be
considered semi-quantitative in light of the numerous assumptions
required.
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C) Toglcitv Assessment gmgq*^v
This task requires the assessment of the intrinsic
toxicological properties of the contaminants of potential
concern. Both carcinogenic and non-carcinogenic effects from the
indicator contaminants must be presented. A summary of
toxicological information on all indicator compounds assessed for
the site appears in Table 10. This table identifies those
compounds which are considered potential carcinogens and those
identified for non-carcinogenic effects. In some cases,
compounds are evaluated for both types of effect. The acronyms
used in Table 10 are defined as:
Cancer Potency Factors fCPFsl have been developed by EPA for
estimating excess lifetime cancer risks associated with exposure
to potentially carcinogenic chemicals. CPFs are multiplied by
the estimated intake of a potential carcinogen to provide a
conservative estimate of the excess lifetime cancer risk
associated with exposure at that intake level. CPFs are generally
derived from human epidemiological studies or chronic animal
bioassays.
Reference doses fRfDs) have been developed by EPA for indicating
the potential for adverse health effects from exposure to
chemicals exhibiting noncarcinogenic effects. RfDs are estimates
of daily exposure levels for humans, including sensitive
individuals that are likely to be without an appreciable risk of
adverse health effects. 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).
Carcinogenic class refers to EPA's weight-of-evidence system for
classifying chemicals suspected of being human carcinogens. The
classes appearing on Table 10 are defined as Group A - human
carcinogen; Group Bl - Probable human carcinogen based on limited
human data; Group B2 - Probable human carcinogen based on
sufficient evidence in animals but little or no evidence in
humans; Group C - Possible human carcinogen; Group D - Not
classified as to human carcinogenicity; Group E - Evidence of
noncarcinogenicity for humans.
0) Risk Characterisation
The final task of the RA is to integrate the results of the
Exposure Assessment and Toxicity Assessment to quantitatively
estimate the potential risk associated with the six exposure
pathways previously identified. Both carcinogenic and
noncarcinogenic effects are considered.
Carcinogenic risk - Carcinogenic risk is calculated by
multiplying the daily intake of each chemical, averaged over the
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years of exposure, by the appropriate CPF. Results are presented
in probabilities expressed in scientific notation. A result of
1E-04 (ixlO"4) indicates that an individual has a one in ten
thousand chance of developing cancer as a result of site-related
exposure to that chemical under the specific exposure conditions
at the site. Based on EPA policy, a risk exceeding the range of
1E-04 to 1E-06 is generally considered as exceeding the
acceptable risk level.
The risk associated with exposure to a set of chemicals is
estimated by adding the risks associated with exposure to each
chemical. Several of the exposure scenarios at the site may
involve more than one route of exposure. A summary of the
results of the calculations for each age group under each
exposure scenario, as well as a lifetime exposure scenario
(calculated by adding the risk for each age group), is presented
in Table 11. This table also provides a summation of risk
associated with simultaneous exposure under multiple scenarios.
Noncarcinoaenic Risk - Noncarcinogenic risk is determined by
calculating the Hazard Index (HI). This number is found by
dividing the daily intake by the appropriate RfD. The HI
provides an estimate of the potential for toxic effects to
develop as a result of exposure to a chemical or set of chemicals
under the assumed conditions of exposure.
A HI less than one indicates that no toxic effects are expected
to occur as a result of a given exposure, while a HI of greater
than one indicates that there is a potential for an individual to
experience adverse health effects as a result of a given
exposure. Noncarcinogenic risk associated with exposure to a set
of chemicals is conservatively estimated by adding the risks
associated with exposure to each chemical. A summary of the
results of the HZ calculations for each age group under each
exposure scenario, including a lifetime exposure scenario,
appears in Table 12. A multiple exposure summation appears in
this table.
E)
During the RX, an ecological investigation of the surrounding
site area was conducted to assess site-related impacts to the
local flora and fauna. The objectives of this work were to:
l) characterize the terrestrial and wetland communities of
the site and surrounding area,
2) identify the macroinvertebrate communities of the
downgradient tributaries,
3) assess any site-related impacts on these various
ecological communities.
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Utilizing the data obtained from the above tasks, an ecological
assessment of the site was conducted in a methodology similar to
that described above for public health impact. After completion
of the Exposure Assessment and Toxicity Assessment phases of the
total ecological assessment, it was determined that RI analytical
results of surrounding stream samples did not indicate an
exposure of aquatic ecological receptors to site-related
contaminants. In fact, the macro invert br ate community in the
streams surrounding the site were found to be diverse and
healthy.
The only terrestrial receptors experiencing site-related impact
would be those trespassing or residing directly on the 2.2 acre
former lagoon area. The chain link fence around the site and the
lack of an adequate food supply onsite acts to prevent
surrounding wildlife from coming into direct contact with site
soils. The vegetation surrounding the site appears quite
healthy, and is not measurably affected by the site. Wildlife
residing around the site is not expected to be impacted by the
site contamination based on evaluation of the RI data, lack of
access to the site, and the RA analysis of potential exposure to
grazing deer. Due to past onsite dumping activities, onsite
vegetation is quite sparse, resulting in the one measurable
effect of the site to the local ecology.
Finally, although fringe, forested wetlands exist along the
streams surrounding the site, they have been determined not to be
impacted based on both visual inspection and the analytical
results of stream surface water and sediment samples. Based on
consultation with the appropriate state and Federal agencies, no
threatened or endangered species are known to exist in the site
area, save the occasional transient species.
P) Significant Sources of Uncert
The RA for the sit* is based on conservative assumptions
regarding exposure and toxicity. In making estimates of potential
exposure and resultant intake, an effort was made to select
parameters that overestimate actual exposures, so that the
resulting estimate of potential risk also overestimates the
actual risk associated with site-related exposures. The
assumptions made for this risk assessment are:
- an individual may be exposed to any of these exposure
conditions over the course of a lifetime,
- an individual may be chronically exposed to concentrations
of contaminants approaching the values used in the RA,
- an individual may be simultaneously exposed to multiple
pathways of exposure over the period of a lifetime,
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- deliberate overestimation of toxicity indices where
questions exist about the actual toxicity or carcinogenicity
of a substance or group of substances. (One exception to
this conservative methodology is the RA's assumption that
the risk associated with exposure to more than one toxicant
is additive. In some cases, depending on the chemicals,
risk may be greater than additive.)
Several limitations of the RA should also be noted:
- analytical results from only five surface soil samples
were available to evaluate the exposure pathways associated
with dermal contact, contaminant air releases/fugitive dust
emissions, and ingestion of venison associated with deer
grazing onsite;
- the method utilized during the RI to identify the depth
interval of soil borings for sample analyses may or may not
have excluded samples with higher concentrations of
semivolatile organic compounds;
- the sampling data utilized in the RA for exposure via use
of residential well water is solely comprised of volatile
organic analytical results collected under the Consent Order
between EPA and CLTL. For this reason, exposure of
residents to other chemicals associated with site soils,
such as semivolatile compounds and tentatively identified
compounds (TICs), was not determined. Results from the one
round of sampling of residential wells for semivolatile
organic analyses were not used based on the limited data set
for these compounds;
• the use of monitoring data, single concentration values,
and screening level models (especially in the air and
grazing deer exposure scenarios) all present a measure of
uncertainty when estimating one's exposure to site
contaminants;
- the RA is based on conditions of no action at the site.
Protective measures instituted at the site, including the
installation of a fence around the site and provision of
point-of-entry carbon treatment units to homes with veil
water exceeding MCLs, results in risks considerably lower
than that predicted in this RA.
O) Conclusions of the Risk Assessment
The results of the calculations performed in the RA using the
aforementioned exposure routes indicate that the estimate of most
probable risk associated with all routes of exposure, except the
Hypothetical Residential Use of Monitoring Hell (or "Onsite")
Groundwater, is within EPA's range of acceptable risk. The
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estimate of maximum or worst case risk exceeds EPA's range for
two exposure routes; (1) the Hypothetical Residential Use of
Onsite Groundwater and (2) the more realistic and actual
Residential Use of -Offsite Groundwater.
Following is a condensed table of the lifetime carcinogenic risks
calculated for each exposure scenario:
Table 13
Exposure Route Most Probable Worst Case
Residential Use of
Offsite Groundwater , 1 x 10"5 3 x 10"**
Contact and Ingestion
of Onsite Surface 9 x 10"6 2 x 10~5
Soils
Deer Meat Ingestion 5 x 10"6 i x 10"5
Recreational Use of
Spring Water at Campground 3 x 10~8 3 x 10"8
Inhalation of Dust and
Vapor from Onsite Soils 5 x 10'6 i x 1
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directly below and adjacent to the site. It has not been
determined when and if this contaminated groundwater, at or near
to the concentration levels found below the site, could reach
residential wells. - Using a conservative approach to public
health protection, EPA assumed that groundwater contaminant
concentrations approaching the levels below the site would
ultimately reach residential wells if either the pollutant source
or contaminated groundwater is not contained or remediated.
In addition to carcinogenic risks, the RA calculated risks
to humans of contracting non-carcinogenic health effects from
substances associated with the site using the same identified
exposure routes. The results of these calculations for non-
carcinogenic health effects were below the EPA guideline of i.o
for children and adults for all exposure scenarios except both
the most probable and maximum Hypothetical Use of Onsite
Groundwater scenarios. These results suggest that exposure to
non-carcinogenic chemicals at the site is not anticipated to
result in adverse health effects under the current conditions of
exposure. As stated above, however, it implies that groundwater
contaminants found at levels directly below and adjacent to the
site could pose non-carcinogenic health effects to users.
Therefore, if groundwater contaminant concentrations at or
approaching these levels were to migrate to residences, non-
carcinogenic health effects would be expected.
For the two groundwater exposure scenarios exceeding EPA's
carcinogenic and noncarcinogenic guidelines (Residential Use of
Of fsite and Onsite Groundwater), TCE is the contaminant which
poses the greatest carcinogenic risk and chloroform and
tetrachloroethene pose the greatest noncarcinogenic risk.
Under the scenario Hypothetical Residential Use of
Monitoring Well Groundwater, it should be emphasized that no one
is currently using this water. This scenario presents the risk
which could be posed if the site were left unaddreseed and the
contaminant plume continued to spread.
From an environmental risk perspective, analyses of surface
water and sediment samples near the William Dick Lagoons Site do
not indicate that these media are currently measurably affected
by site-related contamination. Further, except for that of the
immediate area of the former lagoons, the assessment made of the
local environment did not identify any potentially adverse
effects of site~related contamination to the wellbeing of plants
and animals. Thus, it appears that the Sit* has had no
persistent adverse effect upon the surrounding ecosystem.
EPA has determined that actual or threatened releases of
hazardous substances from this site, if not addressed by
implementing the response action selected in this ROD, may
present an imminent and substantial endangerment to public
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health, welfare, or the environment.
vzi. Description of Alternatives
The draft Focused Feasibility Study (FFS) discusses the
alternatives evaluated for the soil and provides supporting
information leading to alternative selection by EPA. EPA's
comments to this draft document did not affect EPA's selection
process but may effect the design and implementation of the
remedy. Both the draft FFS and EPA's comments to the draft are
included in the Administrative Record. The index for this
administrative record is attached to this ROD in Appendix B.
CERCLA Section 121 requires that the alternative chosen in
the ROD meet several criteria. The alternative must protect
human health and the environment, be cost effective, and meet the
requirements of environmental regulations. Permanent solutions
to contamination problems should be developed wherever possible.
These solutions should reduce the volume, toxicity, or mobility
of the contaminants. Emphasis is also placed on treating the
wastes at the Site, whenever possible, and on applying innovative
technologies to clean up the contaminants.
The soil clean-up levels listed in Table 1 were used as a
basis for the comparison of alternatives for this ROD. These
levels were calculated based on the assumption that a vegetative
soil cover would be placed over the site after treatment. A
vegetative soil cover is defined in this ROD as a layer of soil
which will support the germination and propagation of vegetation
and will provide dermal protection from the treated soils. The
vegetated soil cover will not restrict the infiltration of
rainwater or surface water through the soils.
EPA's goal is to restore the site to a condition as close as
possible to the pre-disposal conditions within a reasonable cost.
Restoration of the site to a state similar to pre-disposal
conditions may be achievable if the soil clean-up levels in Table
l are met. These soil clean-up levels do not take into account
the risk of direct contact with the soils for all of the
compounds listed because the installation of a the vegetative
soil cover and implementation of institutional controls, which
are included as part of all of the alternatives listed below,
will provide acceptable protection against direct contact with
the subsurface soils. Although reducing contaminants in the soil
to levels that do not pose an unacceptable direct contact risk is
not a requirement of this ROD, if the treatment technology used
in this remedy can remediate the soils to the direct contact risk
levels provided in Table 2, the site could be used with
unrestricted access. If the direct contact risk levels are not
met by the remedy, than deed restrictions will need to b«
implemented so that the the treated soil at the site is not
excavated or uncovered.
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If the levels listed in Table 1 cannot be obtained by any of
the treatment technologies listed below, than a multi-layer cap
that will restrict- infiltration of water so that contaminants
will not leach into groundwater above an acceptable level will be
installed at the site. Therefore, for the remedy described in
this ROD, the soil clean-up levels described in Table l may be
refined during the Remedial Design by incorporating any
information generated by any future treatability studies
conducted at the Site. In addition, data generated during the
hydrogeological study, which is expected to be completed during
1993, may, be incorporated into the model to refine the soil
clean-up levels to ensure compliance with the MCLs and health-
based drinking water concentrations, as described in Section II.
The alternatives evaluated in this ROD for OU 3 are
described below. The method and detail of the alternative
evaluation differs from that presented in the FFS. Specifically,
EPA arranged the separate SVE/BIO alternatives into one
alternative and the separate thermal desorption alternatives into
one alternative. The SVE/BIO alternative and the thermal
desorption alternative described in this ROD outline all of the
variations of alternatives in the FFS. In addition, although
incineration was screened out of the detailed analysis of
alternatives in the FFS, EPA has included it in its evaluation.
All of the costs and implementation times listed in this
Proposed Plan are estimates.
The alternatives evaluated for Source Control - Oerable Unit 3
Alternative 1: No Action
Alternative 2: Capping
Alternative 3: SVE/BIO with Multi-layer Cap
Alternative 4: Thermal Desorption with Vegetative Soil Cover or
Multi-layer Cap
Alternative 5: On-«ite Incineration with Vegetative Soil
Cover
COKMOM BLEKENTSs All of the alternatives which were considered,
except for the No Action alternative, contain common elements.
Prior to remedy implementation, alternatives 2 through 5 will
require a minor amount of surface soil sampling in the former
lagoon berm borrow area (Figure 2) to determine if a vegetative
soil cover is appropriate in this area to limit direct contact
with soils. Because only a limited number of surface soil
samples were obtained during the RI from the former lagoon berm
borrow area for evaluation of the direct contact exposure
scenario, additional sampling is required. The remediation
design work for Alternatives 2 through 5 will delineate those
areas of the site requiring source control activities,
specifically, the former lagoon area and those areas requiring
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only a vegetative soil cover. Based on the sampling performed,
the subsurface soil in this area may require treatment as
described in Alternatives 2 through 5. This treatment will be
performed as part of this ROD.
Because a cap or cover would be installed in Alternatives 2
through 5, long term monitoring and maintenence will be required.
The cap or cover shall (l) provide dermal protection from the
treated soils; (2) support the germination and propagation of
vegetative cover; and (3) compact veil and be stable when dry.
The cap or cover shall be maintained for 30 years.
.. Alternatives 4 and 5 require excavation of contaminated
soils. Because of the high levels of VOCs in the soils,
excavation will need to be performed under controlled conditions
to reduce the risks to workers and nearby residents. The risks
associated with the excavation will be determined during the
remedial design phase. A preliminary risk assessment for the air
emissions from excavation was performed by EPA's toxicologist.
Air emission rates were calculated by personnel in EPA's Region
III Air, Radiation, and Toxics Division. The air emission model
report and the preliminary risk assessment are attached to this
ROD in Appendix C. Results from this preliminary risk assessment
indicate that the potential carcinogenic risk to a young child
exposed to air emissions of TCE for 90 days, which is the
predicted duration of soil remediation, is 2.77E-06. This is
within the EPA's generally acceptable carcinogenic risk range of
l.OE-06 to l.OE-04. These values are preliminary and may be
refined during the remedial design. If calculations performed
during the remedial design indicate an unacceptable risk, than
the risk will be mitigated. Possible options for mitigating the
risks include continued operation of the SVE system until VOC
levels are reduced to an acceptable level, staging the excavation
so that only a small amount of soil is excavated at a time,
excavating during the winter months or containing the excavation
process under a tent-type enclosure. In addition, appropriate
monitoring will occur to ensure that any excavation emissions do
not present a health threat.
Alternative 1: No Action •
• Capital Cost: $0
• Annual Operation and Maintenance (O&M): $0
• Present Worth: $0
• Time to Implement: None
The.NCP requires that the "no action* alternative be
evaluated for each site unit in order to establish a baseline for
comparison.. Under this alternative, EPA would take no action
with respect to the contaminated soils at the former lagoons.
This approach would allow contaminants to continue to leach into
the groundwater thereby preventing an effective groundwater
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remediation program. It would also permit access to the site
which would increase the risk of direct contact with subsurface
contaminated soils. Any future use of the site property which
disturbs site soils would present an inhalation and direct
contact threat.
The no action alternative is .not protective of human health
and the environment and, therefore, will not be considered
further in this ROD.
Alternative 2: Capping
• Capital Cost: $500,000 to $850,000
• Annual O&M: $19,600 to $32,600
• Present Worth: $800,000 to $1,350,000
• Time to Implement: 14 months
This alternative involves multi-layer capping of the lagoon
area soils. A multi-layer cap is defined in this ROD as an upper
vegetative layer (topsoil) underlain by a drainage layer (sand)
over a low permeability layer fi.e.. natural soils, admixed
soils, a synthetic liner or membrane, or any combination of these
materials). The area to- be capped is expected to be
approximately 2.2 acres, although the actual extent of the cap
will be determined during design. The total area of the cap will
be somewhat larger than the area of contaminated soil to prevent
any lateral infiltration of precipitation. The cap may need to
extend over portions of the former lagoon borrow area as
determined by the sampling described in the Common Elements
section, above. The cap would be designed to conform to the
substantive performance standards outlined in the Pennsylvania
closure regulations set forth in 25 Pa. Code 265.110-.119 and the
landfill closure regulations at 265.310 which are relevant and
appropriate regulations..
Because the contaminated soil would not be removed or
treated under this alternative, the soil clean-up levels listed
in Table 1 would net be net. However, the cap would be designed
to eliminate direct contact with the soils. The cap would also
limit the amount of rainwater infiltration through the
contaminated soils so that the leaching of contaminants from the
soil to the groundwater is reduced to levels which would not
result in groundwater contamination above MCLs or health-based
levels.
The range in O&M costs reflects the use of either an
"alternative" cap or a "RCRA" cap. CLTL defined a so-called
"RCRA" cap in the focused feasibility study as an upper
vegetative layer (topsoil) underlain by a drainage layer (sand)
over a low permeability layer (i.e.. natural soils, admixed
soils, a synthetic liner, or any combination of these materials).
The "alternative" cap, as defined by CLTL in the focused
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feasibility study/ substitutes a synthetic membrane for the low .
permeability layer used in the "RCRA" cap definition, above.
Using the mathematical models that were developed during the
focused feasibility study, the specific cap structure will be
determined during the remedial design.
Institutional controls (i.e.. deed restrictions) would need
to be implemented under this alternative so that access to the
property is limited. The integrity of the cap would be
maintained to ensure adequate protection against direct contact
with the soils and infiltration of surface and rain water.
Alternative 3: SVE/BIO with a Multi-layer Cap
• Capital Cost: $1,700,000 to $4,100,000
• Annual O&M: $280,000
• Present Worth: $2,700,000 to $5,100,000
• Time to Implement: 33-35 months (+3-5 years of operation)
This alternative involves the in-situ treatment of
approximately 24,000 cubic yards of site soil via Soil Vapor
Extraction (SVE) and Bioremedition (BIO). This estimated volume
was determined during the Focused Feasibility Study by assuming
that the contaminated soil extends out: to a distance halfway
between each contaminated sample location and the closest "clean"
boring. "Clean" borings are defined as those with chemical
constituent levels below clean-up levels defined in Table 1. SVE
consists of a network of air withdrawal (or vacuum) wells
installed throughout the contaminated soils. The walls are
connected to a vacuum pump systea to provide continuous air flow
through the soil, resulting in the removal or stripping
(volatilization) of contaminants from the soil. SVE would be
used in conjunction with bioremediation. BXO is the use of
indigenous microorganisms to degrade the chemicals in the soils.
The addition of air through the soil with the SVE would stimulate
bacterial growth. The bioremediation could be enhanced with the
addition of nutrients, such as nitrogen and phosphorous. This
would be accomplished by spraying a water solution containing the
nutrients over the area to be treated. The types of chemicals
degraded depends on the types of organisms which are naturally
occurring in the soil.
During the operation of this remedy, air emissions controls
would be required to meet appropriate State and Federal hazardous
waste and air standards. Any contaminants generated by these
emissions controls would be disposed of off-site in accordance
with Resource Conservation and Recovery.Act (RCRA) requirements.
The SVE/BIO remedy would be concluded at the point in time
when no significant reduction in voc and SVOC soil concentrations
result after continuous operation. A statistically valid
confirmatory soil sampling program would be established during
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the remedial design to determine the endpoint of remediation.
Based on the results of the SVE/BIO treatability study
conducted in August 1992 and SVE studies performed at similar
sites, it is not anticipated that this technology can meet the
soil clean-up levels listed in Table 1, which were based on
installation of a vegetative soil cover over the area containing
the treated soils once the soil has been remediated. Therefore,
after completion of the SVE/BIO process, it is anticipated that a
multi-layer cap (similar to the "alternative" or "RCRA" cap, as
described in alternative 2), would have to be placed on the site.
The cap would be designed to eliminate direct contact with the
contaminants remaining in the soils The cap would also limit
the amount of rainwater infiltration through the remaining
contaminated soils so that the leach .ig of contaminants from the
soil to the groundwater is reduced to levels which do not exceed
MCLs or health based levels. A final decision on the type of
multi-layer cap would depend on the success in achieving the soil
remediation goals. For costing purposes, an "alternative" cap,
as described under alternative 2, is proposed. The cap would be
designed to conform to substantive Pennsylvania closure
regulations set forth in 25 Pa. Code 265.110-.119 and the
landfill closure regulations at 265.310 which are relevant and
appropriate regulations.
The results of the SVE/BIO treatability study indicate that
significant quantities of VOCs can be removed from the soils.
Approximately 610 pounds of VOCs were removed during the six week
continuous operation of the treatability study. Good subsurface
air flow conditions were observed during the treatability study.
Because the treatability study was only operated for six weeks,
it did not conclusively demonstrate that bioremediation could be
effective in degrading the VOCs and SVOCs in the soils.
Even though the SVE/BIO treatability study showed that this
technology removed large amounts of VOCs, it did not confirm that
the soil cleanup criteria could be net, especially with respect
to SVOCs. Because the lagoon soils are not uniform, it is
possible that the air flow during SVE/BIO remediation would
short-circuit throughout the subsurface. This short-circuiting
may result in minimal treatment of subsurface areas which have a
low permeability.
As described in the Site Characteristics section, thin
layers.of a black, sticky, fibrous substance and materials
classified as "spongy", "rubber-like", "dry, matted and latex-
like" were identified in the three former lagoons during the RI
and treatability study. The impact of these layers on the
operation of the SVE/BIO system was not analyzed during the
treatability study. According to CLTL, an additional 6-12 month
pilot study would be necessary during the remedial design to
determine how this layer would affect SVE/BIO remediation. CLTL
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proposed that if this layer could not be remediated with SVE/BIO,
this material should be excavated and treated by either thermal
desorption or incineration. EPA agrees that additional studies
would be necessary during the remedial design to determine the
impact of these materials on the SVE/BIO remediation. These
materials could adversely impact a full-scale SVE/BIO
remediation. The type of cap installed under this alternative if
thermal desorption or incineration of the tar-like material is
necessary would be determined during the remedial design.
The range in costs listed above reflect the possible need
for thermal treatment (either off-site incineration or on-site
thermal desorption) of the tar-like layer identified in former
lagoon area after operation of the SVE/BIO system. The need for
thermal treatment of the tar-like layer and the type of thermal
treatment required would be assessed during a pilot study
conducted during the remedial design.
Institutional controls (i.e., deed restrictions) would be
implemented under this alternative so that access to the property
is limited. The integrity of the cap must be maintained to
ensure adequate protection against direct contact with the soils
and infiltration of surface and rain water.
Alternative 4: Thermal Desorption with Vegetative Soil Cover or
Multi-layer Cap
• Capital Cost: $7,500,000 to $9,000,000
• Annual O&M: $20,000
• Present Worth: $7,800,000 to $9,300,000
• Time to Implement: 25 months
This alternative involves the excavation and treatment of
approximately 24,000 cubic yards of site soil via thermal
desorption. This estimated volume was determined during the
Focused Feasibility Study by assuming that the contaminated soi
extends out to a distance halfway between each contaminated
sample location and the closest "clean" boring. "Clean" borings
are defined as those with chemical constituent levels below
cleanup levels defined in Table 1. Thermal desorption generally
consists of a rotary dryer designed to accept contaminated soils
which are then heated to a sufficient temperature to volatilize
the contaminants froa the soil into the air. The rotary dryer
rotates to allow for proper mixing and the contaminated air
stream is treated in a control system consisting of a fabric
filter for particulate removal, a wet scrubber for acidic gas
conversion, and a carbon adsorption systea for capture of the
contaminants. Excavation of contaminated soil and replacement of
treated soil would be performed using conventional construction
equipment. Soils would be stockpiled onsite before loading into
the rotary dryer for treatment.
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Based on the nature of the operations leading to the
generation of the waste materials at the site, EPA Region III has
determined that the'contaminated soil, prior to treatment, either
constitutes or must be managed as a hazardous waste bearing the
hazardous waste identification numbers F001 through F005 under
State and Federal law. EPA anticipates that following treatment,
the soil will no longer "contain1* hazardous wastes and thus need
no longer be managed as a hazardous waste for purposes of Federal
law. EPA also anticipates that for State law purposes, the
levels of contaminants in the soils after treatment will be such
that the soils may be "delisted" and no longer considered a
hazardous waste under State law. (Any such "delisting"
determination will be made by EPA in accordance with the
substantive requirements of 25 Pa. Code Section 260.22, and the
applicable requirements of CERCLA and the National Contingency
Plan, 40 C.F.R. Part 300.). It is not expected that the treated
soil will constitute "contaminated soil1* for the purposes of PA's
Residual Waste Management Regulations, 25 Pa. Code Ch. 287 et.
3«q.
After completion of the thermal desorption process and
replacement of treated soils, a vegetative soil cover or multi-
layer cap will be placed on the site. The cap or cover will be
designed to eliminate direct: contact with the any contaminants
remaining in the soils. The thermal desorption system will be
designed to reduce the levels of contaminants in the soil so that
infiltration of rainwater through these soils will not leach
contaminants into the groundwater above MCLs or health based
levels, as describe in Section II. Soil levels which meet these
criteria are listed in Table 1. A final decision on the type of
cap or cover will depend on the success in achieving the soil
remediation goals. If, during the thermal desorption
treatability study, EPA determines that the soil clean-up levels
listed in Table 1 are not achievable, a multi-layer cap (as
described under Alternative 3) designed to limit the amount of
rainwater and surface water infiltration through the
contamination remaining in the soils so that the leaching of
contaminants froa the soil to the groundwater is reduced to MCLs
or health based levels, will be installed.
The success in obtaining the soil remediation goals listed
in Table 1 will be determined by performing a thermal desorption
treatability study during the remedial design. The soil clean-up
levels may need to be modified based on the results of the
thermal desorption treatability study. Any such modification
shall be made in accordance with the National Oil and Hazardous
Substance Pollution Contingency Plan ("NCP"), 40 CRF Part 300,
and applicable agency guidance.
For costing purposes for this ROD, an "alternative" cap, as
described under Alternative 2, is proposed. It is possible,
however, that thermal desorption could reduce the soil
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concentrations to a level which would require only a vegetative
soil cover, as described in Table 1. if only a vegetative soil
cover was required, the present worth cost of this remedy would
be reduced by approximately $620,000.
As in Alternative 3, air emissions from the treatment
operation would be controlled to meet appropriate State and
Federal standards. Any emission control residues generated by
the treatment system would be disposed of off-site in accordance
with federal and state waste disposal reguations. Any
wastewaters generated by any treatment component of the thermal
desorption system, including a scrubber, would be disposed of
off-site in accordance with applicable or relevent and
appropriate state and federal waste disposal regulations.
Wastewaters generated during the thermal desorption process
would be stored on-site in containers or a tank and be disposed
off-site in accordance with federal and/or state hazardous waste
storage and disposal requirements. Treated off-gases would be .
released at the site after passage through an emissions control
system and would be required to meet State and Federal air
standards. Off-site disposal of treatment residuals, if anyr
will comply with federal and/or state hazardous waste disposal
regulations. Operation of the incinerator, if required, would be
comply with the standards set forth in PA Code 264.340 through
264.353.
As stated in the Genoa Elements section above, the
excavation process will need to be controlled to reduce the risks
to workers and nearby residents posed by the emission of VOCs.
Appropriate monitoring will occur to ensure that any excavation
emissions do not pose a health threat.
Based on thermal desorption remediation performed at. similar
sites with similar contamination, EPA believes that the thermal
desorption unit will b« able to process the tar-like materials
found in the former lagoons. Because of the possibility that the
tar-like layer cannot be treated by thermal desorption, EPA
considered the possibility of off-site incineration of the tar-
like layer to meet the soil clean-up goals. The rang* in costs
listed above reflects the possible need for off-site incineration
of the tar-like layer identified in the former lagoon area. The
need for incineration of the tar-like layer will be assessed
during the remedial design. It the thermal desorption
treatability study indicates that off-site incineration of the
tar-like material is necessary, the off-site incinerator must
comply with all Federal and State applicable or relevent and
appropriate requirements for the operation of an incinerator.
Depending on the soil clean-up level that is achieved at the
Site, institutional control* (i.e., deed restrictions) may need
to be implemented so that access to the property is limited. The
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integrity of the cap or vegetative soil cover must be maintained
to ensure adequate protection against direct contact with the
soils and infiltration of surface and rain water.
Alternative 5: Onsite Incineration With Vegetative Soil Cover
Estimated Capital Cost: $19,500,000
Estimated Annual O&M: $0
Estimated Present Worth: $19,500,000
Time to implement: 28-34 months
This alternative achieves source control by excavating an
estimated 24,000 cubic yards or more of contaminated soil and
incinerating it onsite. This estimated volume was determined
during the Focused Feasibility Study by assuming that the
contaminated soil extends out to a distance halfway between each
contaminated sample location and the closest "clean" boring.
"Clean" borings are defined as those with chemical constituent
levels below cleanup levels defined in Table 1. Incineration, or
thermal destruction, uses high temperature oxidation under
controlled conditions to degrade soils containing organics into
by-products that include carbon dioxide, water vapor, inert ash,
and hydrogen chloride gas (if chlorinated organics are present in
the soil). Soils would be stockpiled onsite before loading into
the incinerator for treatment, once all soils are incinerated,
the remaining ash along with clean fill will be deposited onsite,
graded and revegetated to restore the sit* to a natural
condition.
EPA expects that the characterization and management of the
residual ash under the State hazardous and residual waste
regulations will be equivalent to that accorded the treated soil
in Alternative 4. It is anticipated that the ash generated as a
result of the incineration process will meet the soil clean-up
levels listed in Table 1. After the ash and clean fill are
deposited on site, a vegetative soil cover would be installed to
eliminate direct contact with the any contaminants remaining in
the soils. The incineration system will be designed to reduce
the levels of contaminants in the soil so that infiltration of
rainwater through these soils will not leach contaminants into
the groundwater above MCLs or health based levels.
wastewaters generated during the incineration process would
be stored on-site in containers or a tank and be disposed off-
site in accordance with federal and/or state hazardous waste
storage and disposal requirements. Treated off-gases would be
released at the site after passage through an emissions control
system and would be required to meet State and Federal air
standards. Off-site disposal of treatment residuals, if any,
will comply with federal and/or state hazardous waste disposal
regulations. Operation of the incinerator would be comply with
the substantive standards set forth in PA Code 264.340 through
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264.353.
As stated in the common Elements section above/ the
excavation process^will need to be controlled to reduce the risks
to workers and nearby residents posed by the emission of VOCs.
Appropriate monitoring will occur to ensure that any excavation
emissions do not pose a health threat.
vin. summary of Comparative Analysis of Alternatives
Each of the remedial alternatives for this operable unit has
been compared and evaluated with respect to the nine evaluation
criteria in the NCP, 40 CFR Part 300.430(e)(9). The nine
criteria are listed in Figure 3. The nine criteria are:
A. Overall Protection of Human Health and the Environment
Overall protection of human health and the environment
addresses whether a remedy provides adequate protection and
describes hov risks posed through each pathway are eliminated,
reduced, or controlled through treatment, engineering controls,
or institutional controls.
The "No Action" alternative is not protective of human
health and the environment because the site would be open to
public access and, therefore, the risk of exposure to VOCs via
ingestion or dermal contact of subsurface soil, if excavated or
uncovered, or inhalation of VOC vapors from the subsurface soil,
if excavated or uncovered, would not be addressed. The "No
Action" alternative would not prevent the continued leaching of
contaminants from the soil to the groundwater. Therefore, the
"No Action" alternative will not be considered further in this
Proposed Plan.
Alternatives 2 through 5 would protect human health by
reducing the leaching of contaminants from soil to groundwater.
Installation of a vegetative soil cover or multi-layer cap and
implementation of institutional controls under Alternatives 2
through 5 would provide additional protection against direct
contact with the VOCs and SVOCs in the subsurface soil.
Alternatives 3, 4 and 5 would provide more protection of
human health and the environment than Alternative 2 by not only
preventing direct contact and reducing the level of contaminants
leached to groundwater but by also reducing and controlling the
risk of exposure to source contaminants through treatment of the
soils in the former lagoons.
B. Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs)
Section 121(d) of CERCLA requires that remedial actions at
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CERCLA sites at least attain legally applicable or relevant and
appropriate federal and State standards, requirements, criteria,
and limitations which are collectively referred to as "ARARs",
unless such ARARs are waived under CERCLA Section 121(d)(4).
Applicable requirements are those cleanup standards,
standards of control, or other substantive requirements,
criteria, or limitations promulgated under federal environmental
or state environmental law or facility siting laws that
specifically address hazardous substance, pollutant, contaminant,
remedial- action, location, or other circumstance at a CERCLA
Site. Only those state standards that are identified by a state
in a timely manner and that are more stringent than federal
requirements may be applicable.
Relevant and appropriate requirements are those cleanup
standards, standards of control, and other substantive
requirements, criteria, or limitations promulgated under federal
environmental or state environmental law or facility siting laws
that, while not applicable to a hazardous substance, pollutant,
contaminant, remedial action, location or circumstance at a
CERCLA Site, address problems or situations sufficiently similar
to those encountered at the CERCLA Sit* that their use is well
suited to the particular Sit*. Only those state standards that
are identified in a timely manner and are more stringent than
federal requirements may be relevant and appropriate.
ARARs may relate to the substances addressed by the remedial
action (chemical-specific), to the location (location-specific),
or the manner in which the remedial action is implemented
(action-specific).
The Applicable and Relevant or Appropriate Requirements
for the alternatives developed in this ROD are listed below.
Alternatives 2 through 5 would meet the respective ARARs for
the Federal and State environmental laws for this action. The
ARARs for this action and the alternatives which are affected by
each alternative are described below.
EPA recognizes that under the Commonwealth of Pennsylvania's
regulations governing remediation of groundwater contaminated by
hazardous wastes, the standard for remediation is the achievement
of background levels for such hazardous wastes (sjje. 25 Pa. Code
S264.ioo(a) (9). This standard is a State ARAR for CERCLA
remedial actions requiring remediation of groundwater. Although
the remedy selected in this ROD for operable Unit 3 does not
require the remediation of groundwater contamination, EPA
recognizes that the cleanup levels selected for contaminated
soils at the site in this ROD may impact groundwater at the Site.
At such time as a final groundwater remedy is selected for the
Site, the State's groundwater remediation standard, if effective
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at that tine, will be considered an ARAR which must be net by the
remedy unless waived in accordance with Section 121(d)(4) of
CERCLA, 42 U.S.C. (d)(4).
Chemical Specific ARARs
a. The Resource Conservation and Recovery Act (RCRA)
regulations at 40 CFR Part 264 Subpart AA- Air Emission
Standards for Process Vents is relevant and appropriate
for Alternatives 3, 4, and 5 because the SVE, thermal
• desorption and incinertion have a stack vented to the
atmosphere. The total organic emissions from all
affected process vents at the Site are required to be
below 1.4 kg/hr and 2800 kg/hr or reduce, by use of a
control device total organic emissions from all
affected process vents at the facility by 95 weight
percent under this regulation.
b. The emissions from the treatment system must comply
with the special permit requirements for sources
located in or siginificantly impacting nonattainment
areas set forth at Pa. Code 5127.61-73. These
requirements are applicable to Alternatives 3, 4, and
5.
c. The emissions from the treatment system must comply
with the National Ambient Air Quality Standards (NAAQS)
as implemented under the Pa. State Implementation Plan
("SIP"). This regulation, which deals with the release
of volatile organic emissions, applies to this action
because the sit* lies in an ozone non-attainment area.
Alternatives 3, 4 and 5 must comply affected by this
ARAR.
d. The emission standards set forth in 40 CFR Part 61,
Subpart F and Subpart J which regulate vinyl chloride
and benzene emissions under the Clean Air Act, Section
112, 42 U.S.C. $7412 and are Known as National Emission
Standards for Hazardous Air Pollutants (NESHAPs) are
relevant and appropriate requirements for Alternatives
3, 4 and 5.
a. Location specifie ABAfts: There are no location specific ARARs
for this Operable Unit at the Site.
3. Action specific ARABS<
a. The requirement in 25 PA Code S127.12(a) (5) that air
emissions be reduced to the minimum obtainable levels
through the use of test available technology (BAT), as
defined in 25 PA Code Section 121.1, will apply to
Alternatives 3, 4 and 5.
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b. 25 PA Code §123.1, which prohibits the emission of
fugitive air contaminants and regulates emissions
during construction activities, is applicable to
Alternatives 3, 4 and 5.
c. 25 PA Code §123.2, which prohibits the emission of
fugitive air contaminants from crossing the facility's
property line, is applicable to Alternatives 3, 4 and
5.
d. • 25 PA Code §123.31, which prohibits the emission of
; malodorous air contaminants from crossing the property
line, is applicable to Alternatives 3, 4 and 5.
e. 25 PA Code §123.41, which prohibits the emission of
visible emissions of greater that 20% opacity, is
applicable to Alternatives 3, 4 and 5.
t. RCRA regulations 25 Pa. Code S262.ll (a) and (b) (this
section establishes standards for generators of
hazardous waste and relates to hazardous waste
determination), §262.20 (relating to manifesting
requirements for off-site shipments of spent carbon or
other hazardous wastes), and $262.30-33 (relating to
pretransport requirements) are applicable to
Alternatives 3, 4 and 5.
g. With respect to Alternative 2 and Alternative 3
(assuming the cleanup levels cannot be attained as part
of that remedial alternative), the substantive closure
requirements set forth at 25 PA. Code §§265.110-119 and
the landfill closure requirements set forth at 25 Pa.
Code §265.310 are relevant and appropriate; the
groundwater monitoring requirements at 25 Pa. Code
§§264.90-110 are relevant and appropriate. To the
extent that the treated soils in Alternative 4 or
residual ash in Alternative 5 constitute hazardous
wastes, the requirements of 25 Pa. Code Sections
264.13-15 (General Facility standards); 264.31, 37 (PPC
Plan and Emergency Procedures); 264.90, .91, .97, and
.98-.100 (Groundwater Monitoring); 264.111, .114, and
.117-.119 (Closure and Postclosure); and 264.301,
.302, .303, .305, .309, and .310 (Landfills) would be
applicable to the design, construction and maintenance
of the area into which the treated soils or residual
ash are deposited. To the extent that the treated
soils or residual ash are not hazardous wastes due to
application of the "centained-in" rule under federal
lav and delisting under State lav, they may
nevertheless constitute "contaminanted soil" for the
purposes of PA'S Residual Waste Management Regulations.
In that event, management of those wastes may be
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subject to the substantive requirements of
Pennsylvania's residual waste regulations to the extent
required under 25 Pa. Code Section 287.101(d).
h. With respect to Alternative 3, the container storage
standards set forth at 25 Pa. Code SS264.171-180 and
the substantive closure requirements set forth at 25
Pa. Code SS264.110-119 are applicable to the container
storage of contaminants collected by the air emissions
controls unless they are stored on-site in accordance
- with 25 Pa. Code $262.34; the regulations set forth at
25 Pa. Code §263.10-263.32 are applicable when the air
emission control residues are transported off-site; if
thermal desorption and/or incineration are utilized as
part of this remedy, the ARARs set forth in paragraphs
i. and j., infra, respectively, are applicable or
relevant and appropriate, as indicated; the groundwater
monitoring requirements at 25 Pa. Code 264.90-100 are
relevant and appropriate.
i. With respect to Alternative 4, the container storage
standards set forth at 25 Pa. Code SS264.171-180 and
the closure requirements set forth at 25 Pa. Code
§§264.110-119 are applicable to the container storage
of contaminants collected by the air emissions controls
unless they are stored on-site in accordance with 25
Pa. Code §262.34; the regulation set forth at 25 Pa.
Code 5263.10-263.32 are applicable when the air
emission control residues are transported off-site; 40
CFR §264, Subpart X, is applicable to the operation,
closure and post-closure care of the thermal desorption
unit; the waste pile design, operation and closure
requirements set forth at 25 Pa. Code §§264.250-.258
are applicable to the stockpile of excavated soil; the
substantive closure and post-closure requirements set
forth at 25 Pa. Code §§264.110-119 are applicable to
the stockpile of excavated soil; the container
management requirements at 25 Pa. Code §§264.171-180 or
the tank standards at 25 Pa. Code §§264.190-199 are
applicable to the on-site storage of wastewater
dependent upon how the wastewaters are stored; the
substantive closure and post-closure requirements set
forth at 25 Pa. Code §264.110-119 are applicable to the
closure of the units used to store wastewater unless
the wastewater is stored on-site in accordance with 25
Pa. Code §262.34; the regulations set forth at 25 Pa.
Code 263.10-263.32 are applicable when the wastewater
is transported off-site; if off-site incineration of
the tar-like material is necessary, the substantive
standards of 25 Pa. Code §262 relating to generators of
hazardous waste apply ot the tar-like material and the
container or tank storage standards set forth at 25 Pa.
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Code §264.171-180 and/or §264.190-.199 for storage of
the tar-like material prior to transport for off-site
incineration are applicable; the substantive
requirements of 25 Pa. Code 265.373, .375, .377, and
.381 are relevant and appropriate to the operation and
closure of the thermal desorption unit (to the extent
that such requirements are more stringent than those
imposed by 40 CFR Part 264, Subpart X).
j. With respect to Alterative 5, the container storage
standards set forth at 25 Pa. Code §§264.171-180 and
the substantive closure requirements set forth at 25
Pa. Code §§264.110-119 are applicable to the container
storage of contaminants collected by the air emissions
controls unless they are stored on-site in accordance
with 25 Pa. Code 262.34; the operation and closure
standards for incinerators set forth at 25 Pa. Code
264.340-353 are applicable; the substantive general
closure standards set forth at 25 Pa. Code 264.110-119
are applicable to the closure of the incinerator unit;
the waste pile design, operation and closure
requirements set forth at 25 Pa. Code §§264.250-258 are
applicable to the stockpile of excavated soil; the
container management requirements at 25 Pa. Code
§§264.171-180 and/or the tank standards at 25 Pa. Code
§§264.190-199 are applicable to the on-site storage of
wastewater dependent upon how the wastewaters are
stored; the substantive closure and post-closure
requirements set forth at 25 Pa. Code §264.110-119 are
applicable to the closure of the units used to store
wastewater unless the wastewater is stored on-site in
accordance with 25 Pa. Code §262.34; the regulations
set forth at 25 Pa. Code 263.10-263.32 are applicable
when the wastewater is transported off-site; the
provisions of RCRA 3004(o)(1)(B), 42 U.S.C.
§6244(0)(1)(B), and the regulations thereunder, minimum
technology requirements, apply to operation of the
incinerator.
k. DOT regulations 49 CFR Parts 107 (Hazardous Material
Program Procedures) and 171.1-172.604 apply to
Alternatives 3, 4, and 5 for the transport of hazardous
materials.
1. The land disposal restrictions as described in RCRA 40
CFR Part 268 are applicable since the remedy involves
the excavation and treatment of the soils and the re-
placement of treated soils which were "hazardous
wastes1* at the point of generation into a land disposal
unit at the Site. The untreated soils contain FOOi-
F005 hazardous wastes and, therefore, the treated soils
or residual ash must meet, at a minimum, the
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concentration levels listed in 40 CFR part 268.43.
Because the soil clean-up levels for some of the
chemicals listed in Table l are more stringent than the
LDR levels, the levels listed in Table 1 shall be met
prior to placement. For chemicals which do not have a
calculated clean-up level as described in Table 1, the
levels listed in 40 CFR Part 268.43 shall be met.
Alternatives 4 and 5 are affected by this ARAR.
m. The provision of Section 121(a)(3) of CERCLA, 42 U.S.C.
S962l(d)(3), apply to the off-site disposal of any
hazardous substance under Alternatives 3, 4, and 5.
4. To Be Considered
a. The policies set forth in PADER's "Groundwater
Protection Strategy", February 1992, and the MCLs, and
risk-based drinking water concentrations are "to be
considered" (TBC) in developing soil clean-up levels.
Soil clean-up levels were developed using a combination
of the fate and transport mathematical models, HELP and
PRZH as well as a groundwater mixing zone model. The
groundwater concentration input data into this model
was based on MCLs and risk-based drinking water
concentrations. For those chemicals without an MCL or
with a risk-based drinking water concentration greater
that 10 pppb, a groundwater concentration of 10 ppb was
used. Soil clean-up TBCs are listed in Table 1. These
levels may be refined during the Remedial Design by
incorporating data generated during the
hydrogeological study which is currently ongoing to
ensure compliance with MCLs and risk-based drinking
water concentrations. Alternatives 2, 3, 4, and 5 are
affected by this TBC.
b. The policies set forth in EPA's "Revised Procedures for
Planning and Implementing Off-Site Response Actions11,
(November 13, 1987) is a TBC for Alternatives 3, 4, and
5.
C. Lona-Term Effectiveness and Permanence
Long-term effectiveness and permamence refers to expected
residual risk and the ability of a remedy to maintain reliable
protection of human health and the environment over time once
clean-up goals have been met.
Alternatives 2 through 5 require long-term maintenance of a
vegetative soil cover or multi-layer cap. Because Alternative 5
would require only a vegetative soil cover, only routine mowing
would be required. The cap installed under Alternative 2 would
probably require the most maintenance because it would be the
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most complex cap. Not only would it require routine mowing but
inspections and, possibly repairs, to the cap would be necessary.
In addition, monitoring of surrounding wells may be necessary to
confirm that the cap is operating effectively. Although it is
not known what type of cap would be required for Alternatives 3
and 4, it is anticipated that the cap installed under Alternative
4 would be less complex than the cap for Alternative 3 and,
therefore, may require less maintenance. Alternative 4 is
expected to require a less complex cap than alternative 3 because
more contaminants will be removed from the soil under Alternative
4. It is .possible that only a vegetative soil cover would be
required for Alternative 4.
The direct contact risk will be eliminated under
Alternatives 2 through 5 because a vegetative soil cover or
multi-layer cap will be installed. The risk associated with
contaminant migration to groundwater would be virtually
eliminated under Alternative 5 because the contaminants would be
destroyed. If the cap was not installed or maintained properly,
Alternative 2 would exhibit the highest risk of contaminant
migration to groundwater because the contaminants would remain in
the soil. If operation and maintenance was not implemented
properly, the risk of contaminant migration to groundwater for
Alternatives 3 would be greater than that for Alternative 4
because more contaminants are expected to remain in the
subsurface under Alternative 3.
D. Reduction of toxicitv. mobility, or volume of the contaminants
through treatment
Reduction of toxicity, mobility, or volume through treatment
refers to the anticipated performance of the treatment
technologies a remedy may employ.
Alternatives 3, 4 and 5 are the only alternatives which
would result in a reduction of the toxicity, mobility and volume
of contaminants in the soil through treatment. Alternatives 3,
4, and 5 would reduce the level of VOCs in the soils.
Alternatives 4 and 5 would also reduce the levels of SVOCs in the
soil. Alternative 3 may reduce the levels of SVOCs in the soil,
although the treatability study did not determine the
effectiveness of this reduction. Alternative 5 destroys the
contaminants in the immediate environment. Because previous
studies have confirmed that thermal desorption can remove site-
related VOCs and SVOCs, Alternative 4 is expected to be more
effective than Alternative 3 in reducing the contaminants at the
Site. Alternatives 3 and 4 would remove contaminants from the
immediate environment, although disposal of the residual waste
(i.e. spent carbon, pure product, wastewater, etc.) or
destruction of the extracted contaminants in a safe and effective
manner would be required. Alternative 2 would not reduce the
toxicity, mobility or volume of the contaminants through
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treatment. Under Alternative 2, the contaminants will remain in
the soil and a cap will be installed over the contamination.
E. Short Term Effectiveness
Short term effectiveness refers to the period of time needed
to complete the remedy and any adverse impacts on human health
and the environment that may be posed during the construction and
implementation of the remedy until clean-up levels are achieved.
Alternative 4 could be implemented within 25 months of the
ROD. This time frame includes a 6-month treatability study.
Alternative 2 would take the shortest amount of time to implement
(19 months). Alternative 3 would take the longest time to
implement because a 6 to 12 month treatability study would be
required prior to remedy implementation and an SVE/BIO operation
and maintenance period of 3 years, or possibly more, is expected.
Alternative 5 is expected to take 21 months to implement.
Alternative 2 would be the alternative least likely to
impact the community, workers and the environment during
construction and implementation because removal of hazardous
substances would not occur. The short term risks associated with
Alternatives 4 and 5 would be greater than Alternative 3 because
these alternatives would involve the excavation of soils. If the
excavation is implemented under controlled conditions and if
worker safety procedures are properly adhered to, these risks
would be minimal.
F. Implementability
Implementability is the technical and adminstrative
feasibility of a remedy, including the availability of materials
and services needed to implement a particular option.
Alternatives 3, 4 and 5 would require initial testing of the
treatment system operation and periodic sampling to ensure
efficient operation of the treatment system.
Alternative 2 is the most easily implemented alternative
because no treatment is required. The treatment technologies
used in Alternatives 4 and 5 are well established and have.been
proven reliable at similar sites.
Although the soil vapor extraction portion of Alternative 3
has been proven at this Site and other Sites to remove
significant quantities of VOCs, the heterogeneity of the soils at
this Site could limit its effectiveness. "Tar-like", "spongy",
and "latex" layers have been identified at various depths in the
former lagoons. These layers could limit air flow through the
soil. If additional studies show that these layers do reduce the
effectiveness of the technology, these layers may need to be
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excavated and treated using a different technology, such as
thermal desorption or incineration. Due to time constraints on
the treatability study, bioremediation was not proven effective
in the removal of SVOCs. These factors could delay and increase
the difficulty in implementation of the remedy.
Services and materials are readily available for all
alternatives.
Cost includes estimated capital and operation and
maintenance costs as well as present worth costs.
This criteria examines the capital, annual O&M, and present
worth costs for each alternative. These costs are presented in
the Description of Alternatives section, above. The present
worth cost for Alternative 4 is $7,300,000 to $9,000,000. The
range provided takes into account the possibility of incineration
of the tar-like layer. The lowest cost alternative is
Alternative 2 at $800,000 to $1,350,000. The range takes into
account the possibility of several types of caps. The present
worth cost estimate for Alternative 3 is $2,700,000 to
$5,100,000. The range provided takes into account the
possibility of thermal desorption or incineration of the tar-like
layer. The costs for Alternative 3 are based on a 3-year pilot
operation. If an additional two years is necessary for
operation, the present worth costs would be increased to
$3,100,000 to $5,500,000. The highest cost is for Alternative 5
at $19,500,000.
Because the costs generated are only estimates. (-30% to
+50%) and are dependent on the type of cap required and the
effectiveness of the technology used (which will be determined
during the design phase), the difference in costs between
Alternative 4 and Alternative 3 may not be significant.
F. State Acceptance
The Commonwealth of Pennsylvania has evaluated and commented
on the alternatives presented in this ROD and has initially
agreed with the technical remedy selected. The official position
of the Commonwealth of Pennsylvania will be documented in the
Adminstrative Record for this Site upon receipt.
G. Community Acceptance
Comments received from the public are specifically addressed
in the Responsiveness Summary which is attached to this ROD in
Appendix A.
Comments received from some community members, including 15
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homeowners near the William Dick Lagoons Site and a local
remediation contractor, indicate a preference for incineration.
The 15 homeowners believe that only incineration can restore the
the site to a condition close to its pre-disposal condition. EPA
believes that thermal desorption provides acceptable protection
of human health and the environment without the additional cost
required by incineration.
One potentially responsible party (PRP) indicated a
preference for use of soil vapor extraction/bioremediation in
conjuction with thermal desorption. The PRP proposed excavating
the soils to remove the tar-like materials. The tar-like
materials would be treated by thermal desorption and the
excavated soils would be treated above ground by SVE/BIO. The
remaining contaminated soils in the subsurface would be treated
in-situ by SVE/BIO. Given the random locations of the tar-like
layers in the former lagoons, EPA believes that the technique
used in this proposal may not indentify all of the
heterogeneities in the subsurface. Therefore, this proposal may
not adequately treat the soils so that only a vegetative soil
cover is required over the treated material. In addition, this
proposal may not treat the SVOCs to levels which will not impact
groundwater above MCLs or health based levels. It is anticipated
that this proposal will require a more complex cap (i.e., a
multi-layer cap) than a vegatative soil cover. Therefore, the
site will not be returned to a condition close to its pre-
disposal condition.
IX. Selected Remedy and Performance standards
A. General Description of the Selected Remedy
Based upon consideration of the requirements of CERCLA, the
detailed analysis of the alternatives using the nine criteria and
public comments, EPA has determined that Alternative 4 (Thermal
Desorption with a Vegetative Soil Cover or Multi-layer Cap) is
the most appropriate remedy for the William Dick Lagoons Site.
This remedy was selected to reduce the chemical
concentrations in the soils so that leaching of contaminants into
the groundwater will be minimized. Reduction of the source of
contamination in the soils is necessary so that it does not
continue to impact groundwater above MCLs or health based levels.
The soil clean-up goals are listed in Table 1 and were
calculated based on mathematical models developed during the
Focused Feasibility Study. This alternative will also prevent
exposure to the site-related chemicals through inhalation,
ingestion, and dermal contact through the installation of a
vegetative soil cover or multi-layer cap over the treated soils.
Based on current information, Alternative 4 provides the best
balance among the alternatives with respect to the nine criteria
EPA uses to evaluate each alternative.
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Under this alternative, prior to remedy implementation, a
minor amount of surface soil sampling will be performed in the
former lagoon berm borrow area (Figure 2) to determine if a
vegetative soil cover is appropriate in this area to limit direct
contact with soils. Because only a limited number of surface
soil samples were obtained during the RI from the former lagoon
borrow area for evaluation of the direct contact exposure
scenario, additional sampling is required. The remediation
design work for this alternative will delineate those areas of
the site requiring source control activities, specifically the
former lagoon area, and those areas requiring a vegetative soil
cover.
This alternative involves the excavation and treatment of
approximately 24,000 cubic yards of site soil via thermal
desorption. This estimated volume was determined during the
Focused Feasibility Study by assuming that the contaminated soi
extends out to a distance halfway between each contaminated
sample location and the closest "clean" boring. "Clean" borings
are defined as those with chemical constituent levels below
cleanup levels defined in Table 1.
Because of the high levels of VOCs in the soils, excavation
shall be performed under controlled conditions to reduce the
risks to workers and nearby residents. The risks associated with
the excavation shall be determined during the remedial design
phase. A preliminary risk assessment for the air emissions from
excavation was performed by EPA's toxicologist. Air emission
rates were calculated by personnel in EPA's Region III Air,
Radiation, and Toxics Division. The air emission model report
and the preliminary risk assessment are attached to this ROD in
Appendix C. Results from this preliminary risk assessment
indicate that the potential carcinogenic risk to a young child
exposed to air emissions of TCE for 90 days, which is the
predicted duration of soil remediation, is 2.77E-06. This is
within the EPA's generally acceptable carcinogenic risk range of
l.OE-06 to l.OE-04. These values are preliminary and may be
refined during the remedial design, if calculations performed
during the remedial design indicate an unacceptable risk, than
the risk will b« mitigated. Possible options for mitigating the
risks include continued operation of the SVE system until VOC
levels arc reduced to an levels which do not: pose a risk through
inhalationfor excavation, staging the excavation so that only a
small amount of coil is excavated at a time, excavating during
the winter months or containing the excavation process under a
tent-type enclosure. In addition, appropriate air monitoring
will be performed on-site to ensure that any excavation emissions
do not present a health threat.
Thermal desorption generally consists of a rotary dryer
designed to accept contaminated soils which are then heated to a
sufficient temperature to volatilize the contaminants from the
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soil into the air. The rotary dryer rotates to allow for proper
mixing and the contaminated air stream is treated in a control
system consisting of a fabric filter for particulate removal, a
wet scrubber for acidic gas conversion, and a carbon adsorption
system for capture of the contaminants. Excavation of
contaminated soil and replacement of treated soil would be
performed using conventional construction equipment. Soils would
be stockpiled onsite before loading into the rotary dryer for
treatment.
Based on the nature of the operations leading to the
generation of the waste materials at the site, EPA Region III has
determined that the contaminated soil, prior to treatment,
constitutes a hazardous waste bearing the hazardous waste
identification numbers F001 through F005 under State and Federal
law. EPA anticipates that following treatment, the soil will no
longer "contain" hazardous wastes and thus will cease to be a
hazardous waste for purposes of Federal law. EPA also
anticipates that for State law purposes, the levels of
contaminants in the soils will be such that the soils may be
"delisted" and no longer considered a State hazardous waste.
(Any such "delisting" determination will be made by EPA in
accordance with the substantive requirements of 25 Pa. Code
Section 260.22, and the applicable requirements of CERCLA and the
National Contingency Plan, 40 C.F.R. Part 300.) Nonetheless, the
treated soils may still constitute "residual waste" under
Pennsylvania law, and be subject to the substantive requirements
of Pennsylvania's residual waste regulations to the extent
required under 25 Pa. Code Section 287.101(d).
After completion of the thermal desorption process, a
vegetative soil cover or multi-layer cap will be placed on the
site. The cap or cover will be designed to eliminate direct
contact with the any contaminants remaining in the soils. The
thermal desorption system will be designed to reduce the levels
of contaminants in the soil so that infiltration of rainwater
through these soils will not leach contaminants into the
groundwater above MCLs or health based levels, as describe in
Section II. Soil levels which meet these criteria are listed in
Table 1. A final decision on the type of cover or cap will
depend on the success in achieving the soil remediation goals.
The success in obtaining the soil remediation goals listed in
Table 1 will be determined by performing a thermal desorption
treatability study during the remedial design. The soil clean-up
levels may need to be modified based on the results of the
thermal desorption treatability study.
The soil clean-up levels, listed .in Table 1, were developed
using a combination of the fate and transport mathematical
models, HELP and PRZM, as well as a groundwater mixing zone
model. Compounds which have been identified in the groundwater
were used in the model. The groundwater concentration input data
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into this model was based on Maximum Contaminant Levels ("MCLs")
and health-based drinking water concentrations. Health-based
drinking water concentrations were established based on a
carcinogenic risk of 10E-05 or 10E-04. A cancer risk of 10E-05
means that one additional person per 100,000 has a chance of
contracting cancer given the relevant exposure scenario. The NCP
directs hazardous substance responses for Sites presenting risks
outside the established acceptable carcinogenic risk range for
Superfund Sites of between 10E-06 (l additional chance in one
million) and 10E-04 (one additional chance in 10,000). EPA used
a carcinogenic risk of either 10E-04 or 10E-05 as the basis for
the health-based drinking water concentrations for chemicals
without an MCL at this Site rather than use the more conservative
10E-06 carcinogenic risk values since the 10E-06 carcinogenic
value for some compounds are below the contract required
quantitation limit for the drinking water analytical technique,
EPA Method 524.2. The contract required quantitation limit is
the detection level required for a particular analytical method
under EPA's Contract Laboratory Program (CLP). Use of either
10E-04 or 10E-05 carcinogenic risk is protective of human health
since it falls within the EPA's acceptable risk range of 10E-06
to 10E-04.
For those chemicals without an MCL or with a health-based
drinking water concentration greater that 10 ppb, a groundwater
concentration of 10 ppb was used. The use of 10 ppb was based on
the contract required quantitation limits as established under
the Contract Laboratory Program (CLP) Statement of Work for
Organics Analysis (CLP Document Number OLM01.1). The 10 ppb
level was established in the focused feasibility study by CLTL in
an attempt to conform to PADER's groundwater protection strategy,
which, although not an applicable or relevant and appropriate
regulation for this ROD, is a "To Be Considered1* policy. Soil
clean-up levels calculated assuming that a vegetative soil cover
would be placed over the Site after soil treatment are listed in
Table 1.
According to the model, some of the compounds listed in
Table l will degrade prior to reaching the groundwater and,
therefore, no soil clean-up level was provided. However, if the
contaminated soils are treated and placed back on-site, certain
contaminants fi.e.. those compounds related to F001-F005 wastes)
which degrade before reaching the groundwater (as calculated by
the model) nonetheless will have to meet the treatment standards
established by the Land Disposal Restrictions (LDR) listed at 40
CFR S268.43. The LDR levels for the relevant compounds are
listed in Table 1. Finally, for the remaining compounds which
are not F001-F005 wastes but do, according to the model, degrade
before reaching the groundwater, EPA believes that it is
appropriate to establish soil clean-up levels based on direct
contact risks. These levels are also noted in Table 1. The
groundwater concentrations used in the fate and transport models
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to calculate the soil clean-up levels are listed in Table 1 and
are based on either MCLs, health-based concentrations under a
drinking water exposure scenario or 10 ppb as described above.
Some of the soil clean-up levels that were calculated by the
model exceeded the concentrations for a direct contact risk. The
soil concentrations that need to be met so that the direct
contact risk is acceptable to EPA are provided in Table 2.
Attainment of the direct contact risk levels listed in this table
are not required for this ROD, because placement of a vegetative
soil cover or multi-layer cap over the soils and implementation
of institutional controls will prevent exposure to the soils
through direct contact. However, if the values listed in Table 2
can be met during remedy implementation, deed restrictions on the
property may be eliminated.
If, during the thermal desorption treatability study, EPA
determines that the soil clean-up levels listed in Table 1 are
not achievable, a multi-layer cap will be designed to limit the
amount of rainwater and surface water infiltration through the
contamination remaining in the soils so that the leaching of
contaminants from the soil to the groundwater is reduced to MCLs
or health based levels. A multi-layer cap is defined in this ROD
as an upper vegetative layer (topsoil) underlain by a drainage
layer (sand) over a low permeability layer (i.e. natural soils,
admixed soils, a synthetic liner, or any combination of these
materials). The final cap design will be determined during the
remedial design. Because a cover or cap will be installed under
the Selected Remedy, long term monitoring and maintenence for the
operation and maintenence of the cover or cap will be required.
In addition, the treatability study to be performed during
the remedial design will determine if the heterogeneities in the
soil (i.e.. the tar-like, fibrous, sticky, latex materials, etc.)
requires additional treatment to meet the soil clean-up goals.
Depending on the soil clean-up level that is achieved at the
Site, institutional controls, in the form of deed restrictions,
may need to be implemented under so that access to the property
is limited. The integrity of the cap or vegetative soil cover
must be maintained to ensure adequate protection against direct
contact with the soils and infiltration of surface and rain
water.
B. Performance Standards
Determination of Extent of Soil Contamination: Prior to the
design of the thermal desorption unit, additional soil sampling
shall be performed in the former lagoon berm area, as well as the
former lagoon area, to define the extent of soil contamination.
Soil contamination shall be defined as levels of contamination
which exceed the levels listed in Table 1. The number,
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location, and depth of these sampling points shall be subject to
approval by EPA.
Excavation and Operation of the Thermal Oesorption Unit: All
soils containing chemicals above the concentrations listed in
Table l shall be excavated, stockpiled, and remediated on-site by
a thermal desorption treatment system. The soils shall be
remediated to the concentration levels listed in Table 1. These
levels may be refined during the Remedial Design by incorporating
data generated during the hydrogeological study which is
currently ongoing to ensure compliance with MCLs and health-based
drinking water concentrations.
The thermal desorption unit shall comply with the regulations
outlined in 40 CFR $264, Subpart X- Miscellaneous Units and the
provisions of RCRA 3004(o) (42 U.S.C. S6244(o). The design,
operation and closure and post-closure of the waste piles
generated during the stockpiling of excavated soil shall comply
with the substantive regulations set forth in 25 Pa. Code
§§264.250-258, 25 Pa. Code §§264.110-119 and 25 Pa. Code
§264.310. If off-site incineration of the tar-like material is
necessary, such material shall be transported to and managed at
an incinerator which satisfies applicable federal and state
requirements for incinerators. The operation and closure of the
thermal desorption unit shall comply with the substantive
requirements of 25 Pa. Code 265.373, .375, .377, and .381 (to the
extent that such requirements are more stringent than those
imposed by 40 CRF Part 264, Supart X).
Prior to excavation, a risk assessment shall be performed to
determine the risk associated with air emissions from the
excavation process. Emissions from the excavation process shall
not exceed a carcinogenic risk of 1 x 10~4. If this level is
exceeded, emission control measures shall be implemented to
reduce emissions below this level. The emission control measures
shall be subject to approval by EPA. In addition, an EPA-
approved air monitoring program for the excavation of soils shall
be established prior to remedial action.
Treatment of Air Emissions from the Thermal Desorption Unit:
contaminants in the effluent air from the thermal desorption unit
shall be removed with a treatment unit, the specifications of
which shall be determined during the remedial design and subject
to EPA and FADER approval. The treatment unit(s) shall comply
with the following ARARs which are performance standards: the
Resource Conservation and Recovery Act (RCRA) regulations 40 CFR
Part 264 Subpart AA- Air Emission Standards for Process Vents;
the special permit requirements for sources locating in or
siginificantly impacting nonattainment areas set forth at Pa.
Code §127.61-73; the National Ambient Air Quality Standards
(NAAQS) under the Clean Air Act (40 CFR SS 50.1-3, 50.9, Appendix
D, and Appendix H); 40 CFR Part 61, Subpart F and Subpart J which
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are requirements which regulate vinyl chloride and benzene
emissions under the Clean Air Act, Section 112, 42 U.S.C. §7412
and are known as National Emission Standards for Hazardous Air
Pollutants (NESHAPs); the requirement in 25 PA Code S127.12(a)(5)
that air emission be reduced to the minimum obtainable levels
through the use of best available technology (BAT), as defined in
25 PA Code Section 121.1; 25 PA Code 5123.1, which prohibits the
emission of fugitive air contaminants and regulates emissions
during construction activities; 25 PA Code $123.2, which
prohibits the emission of fugitive air contaminants from crossing
the facility's property line; 25 PA Code 5123.31, which prohibits
the emission of malodorous air contaminants from crossing the
property line; 25 PA Code 5123.41, which prohibits the emission
of visible emissions of greater that 20% opacity.
Management and Disposal of Treatment Residuals: The management
and ultimate disposal of the treatment residuals shall be
determined, subject to EPA approval, during the remedial design.
Such management may entail treatment and/or disposal of carbon
filters or contaminated water. In the event the treatment
residuals are a hazardous waste, as determined by EPA, the
following ARARS will apply as the Performance Standards. The on-
site storage of wastewater shall comply with the container
management regulations set forth in 25 Pa. Code 55264.171-180 or
the tank standards at 25 Pa. Code 55264.190-199, dependent on how
the wastewater is stored. The closure and post-closure of the
waste water storage units shall comply with the requirements set
forth at 25 Pa. Code 5264.110-119 unless the wastewater is stored
on-site in accordance with 25 Pa. Code 5262.34. The
transportation of wastewater off-site shall comply with the
requirements of 25 Pa. Code 5263.10-32. The container storage of
contaminants collected by the air emissions control system shall
comply with 25 Pa. Code SS264.171.180 and 25 Pa. Code SS264.110-
119 unless the containers are stored on-site in accordance with
25 Pa. Code S262.34. The off-site transporation of the air
emission control devices shall comply with 25 Pa. Code 5263.10-
32. The transport of hazardous materials shall comply with DOT
regulations 49 CFR Parts 107 (Hazardous Program Procedures) and
171.1-172.604. The generation of hazardous waste on-site and the
transporation of hazardous waste shall comply with 25 Pa. Code
§262.11 (a) and (b), §262.20, and 5262.30-33.
Backfilling of Treated Soils and Placement of a Vegetative Soil
cover or Multi-layer caps The treated soils shall be backfilled
into excavated areas. The backfilling of treated soils shall
comply with the Land Disposal Restriction regulations as
described in 40 CFR Part 268. The untreated soils contain
"hazardous wastes" in the F001-F005 category at the point of
generation and, therefore, the treated soils must meet, at a
minimum, the concentration levels listed in 40 CFR Part 268.43.
Because the soil clean-up levels for some of the chemicals listed
in Table 1 are more stringent than the LDR levels, the levels
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48
listed in Table 1 shall be met prior to placement. For chemicals
which do not have a calculated clean-up level as described in
Table l, the levels listed in under the F001-F005 category in 40
CFR Part 268.43 shall be met.
Once the treated soils are placed on-site, a protective,
vegetative soil cover will be placed over the backfilled area if
the treatment levels in Table 1 are attained by the thermal
desorption treatment. The vegetative soil cover shall: (1)
provide dermal protection from the treated soils; (2) support the
germination and propagation of vegetation; and (3) compact well
and not crack excessively when dry. EPA anticipates that
following treatment, the soil will no longer "contain" hazardous
wastes and thus will cease to be a hazardous waste for purposes
of Federal law. EPA also anticipates that for State law
purposes, the levels of contaminants in the soils will be such
that the soils may be "delisted" and no longer considered a State
hazardous waste. (Any such "delisting" determination will be
made by EPA in accordance with the substantive requirements of 25
Pa. Code Section 260.22, and the applicable requirements of
CERCLA and the National Contingency Plan, 40 C.F.R. Part 300.)
Nonetheless, the treated soils may still constitute "residual
waste" under Pennsylvania law, and be subject to the substantive
requirements of Pennsylvania's residual waste regulations to the
extent required under 25 Pa. Code Section 287.101(d).
If, during the design of the thermal desorption unit, it is
determined that the technology can not meet the soil clean-up
levels outlined in Table 1, technology-based criteria shall be
determined by EPA. Using the technology-based criteria as the
treatment standards for the thermal desorption unit and the
mathematical models developed in the Focused Feasibility Study, a
suitable cap will be designed to reduce the leaching of
contaminants into the groundwater to MCLs or health-based levels.
The permeability of the cap will be determined with the model
used to determine soil clean-up levels in the Focused Feasibility
Study (and subsequent revisions) prepared for this Site.
The vegetative soil cover or multi-layer cap shall be
maintained for 30 years. The vegetative soil cover or multi-
layer cap design shall include a cost/benefit analysis for
maximizing the biodiversity of the cover or cap. This analysis
shall compare the capital and operation and maintenance costs of
a conventional cap or cover (i.e. grass or similar vegetation) to
the costs associated with a cap or cover which promotes
biodiversiy on the site. This evaluation shall be used to allow
EPA to determine the vegetation on the soil cover or cap.
operation and Maintenance ("OUT*): The vegetative soil cover or
multi-layer cap shall be given routine maintenance for at least
30 years to maintain the integrity and effectiveness of the final
cover or cap, including making repairs to the cover or cap as
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49
necessary to correct cracks and the effects of settling,
subsidence, erosion, etc. Natural vegetation (grasses and weeds)
shall be maintained on the cover or cap. An O&M plan shall be
developed, based on the type of cover or cap selected by EPA, and
implemented. Because the selected alternative shall result in
contaminants remaining on-site, 5-year Site reviews under Section
121(c) of CERCLA will be required.
Institutional Controls: If the soil clean-up levels listed in
Table 2 are not achieved, deed restrictions shall be placed on
the deed to the portion of the property that comprises the
excavated and capped area. This is required to limit the use of
this land and prevent excavation or construction on the capped
and closed former lagoon area and any other area on-site which
requires soil treatment or a cap so that threats to human health
and the environment are minimized.
Worker Safety: During all Site work, Occupational Safety and
Health Administration ("OSHA") standards set forth at 29 C.F.R.
Parts 1910, 1926 and 1904 governing worker safety during
hazardous waste operations, shall be complied with.
X. Statutory Determinations
EPA's primary responsibility at Superfund sites is to select
remedial actions that are protective of human health and the
environment. Section 121 of CERCLA also requires that the
selected remedial action comply with ARARs, be cost-effective,
and utilize permanent treatment technologies to the maximum
extent practicable. The following section discuss how the
selected remedyfor the William Dick Lagoons Site meets these
statutory requirements.
A. Protection of Human Health and the Environment
The Selected Remedy protects human health and the
environment by reducing the level of contaminants in the soils at
the Site which, in turn, reduces the leaching of contaminants
into the groundwater beneath the Site. By reducing the source of
contamination to the groundwater, a groundwater remediation
system can be designed and installed to reduce the level of
contaminants in groundwater to background levels or, if
background levels are unattainable, to the maximum contaminant
levels (MCLs) established under the Safe Drinking Water Act
(SWDA).
Installation of a vegetative soil cover or multi-layer cap
over the treated soil will prevent exposure to the site-related
chemicals through inhalation, ingestion, and dermal contact.
Implementation of the selected remedy will not pose
unacceptable short-term risks or cross-media impacts. The
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50
remedial technologies employed in the selected remedy are proved
to reduce the concentrations of the organic compounds identified
on-site to acceptable levels.
B. Compliance with Applicable or Relevant and Appropriate
Requirements (ARARS)
Chemical Specific ARARs
a. The Resource Conservation and Recovery Act (RCRA)
• regulations 40 CFR Part 264 Subpart AA- Air Emission
Standards for Process Vents is relevant and appropriate
for the selected alternative because the SVE, thermal
desorption and incinertion have a stack vented to
atmosphere. The total organic emissions from all
affected process vents at the Site are required to be
below 1.4 kg/hr and 2800 kg/hr or reduce, by use of a
control device total organic emissions from all
affected process vents at the facility by 95 weight
percent under this regulation.
b. The emissions from the treatment system must comply
with the special permit requirements for sources
locating in or siginificantly impacting nonattainment
areas set forth at Pa. Code $127.61-73.
b. The emissions from the treatment system must comply
with the National Ambient Air Quality Standards (NAAQS)
under the Clean Air Act (40 CFR SS 50.1-3, 50.9,
Appendix D, and Appendix H). This regulation, which
deals with the release of volatile organic emissions,
applies to this action because the site lies in an
ozone non-attainment area.
c. 40 CFR Part 61, Subpart F and Subpart J are relavant
and appropriate requirements which regulate vinyl
chloride and benzene emissions under the Clean Air. Act,
Section 112, 42 U.S.C. S7412 and are known as National
Emission Standards for Hazardous Air Pollutants
(NESHAPs).
2. Location Specific AJUtR*: There are no location specific ARARs
for this Operable Unit at the Site.
3. Action Specifie ARARs:
a. The requirement in 25 PA Code S127.12(a)(5) that air
emission be reduced to the minimum obtainable levels
through the use of best available technology (BAT), as
defined in 25 PA Code Section 121.1, will apply to the
seltected alternative.
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51
b. 25 PA Code §123.1, which prohibits the emission of
fugitive air contaminants and regulates emissions
during construction activities, is applicable to the
selected alternative.
c. 25 PA Code §123.2, which prohibits the emission of
fugitive air contaminants from crossing the facility's
property line, is applicable to the selected
alternative.
d. . 25 PA Code §123.31, which prohibits the emission of
malodorous air contaminants from crossing the property
line, is applicable to the selected alternative.
e. 25 PA Code §123.41, which prohibits the emission of
visible emissions of greater that 20% opacity, is
applicable to the selected alternative.
f. RCRA regulations 25 Pa. Code §262.11 (a) and (b) (this
section establishes standards for generators of
hazardous waste and relates to hazardous waste
determination), §262.20 (relating to manifesting
requirements for off-site shipments of spent carbon or
other hazardous wastes), and §262.30-.34 (relating to
pretransport requirements) are applicable to the
selected alternative.
g. To the extent that the treated soils constitute
hazardous wastes, the requirements of 25 Pa. Code
Sections 264.13-15 (General Facility Standards);
264.31, 37 (PPC Plan and Emergency Procedures); 264.90,
.91, .97, and .98-.100 (Groundwater Monitoring);
264.111, .114, and .117-.119 (Closure and
Postclosure); and 264.301, .302, .303, .305, .309, and
.310 (Landfills) and regulations at 40 CFR Part 264,
Subpart N which implement the minimum technological
requirements for replacement of an existing landfill or
surface impoundment unit set forth at 42 U.S.C.
§6924(o) would be applicable to the design,
construction and maintenance of the area into which the
treated soils or residual ash are deposited. To the
extent that the treated soils or residual ash are not
hazardous wastes due to delisting, the management of
those .wastes may be subject to the substantive
requirements of Pennsylvania's residual waste
regulations to the extent required under 25 Pa. Code
Section 287.101(d).
h. The container storage standards set forth at 25 Pa.
Code §§264.171-180 and the substantive closure
requirements set forth at 25 Pa. Code §§264.110-119 are
applicable to the container storage of contaminants
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52
collected by the air emissions controls unless they are
stored on-site in accordance with 25 Pa. Code §262.34;
the regulation set forth at 25 Pa. Code §263.10-263.32
are applicable when the air emission controls are
transported off-site; 40 CFR §264, Subpart X, is
applicable to the operation, closure and post-closure
care of the thermal desorption unit; the waste pile
design, operation and closure requirements set forth at
25 Pa. Code §$264.250-258 are applicable to the
stockpile of excavated soil; the substantive closure
• and post-closure requirements set forth at 25 Pa. Code
§§264.110-119 and 25 Pa. Code §264.310 are applicable
to the stockpile of excavated soil; the container
management requirements at 25 Pa. Code §§264.171-180 or
the tank standards at 25 Pa. Code §§264.190-199 are
applicable to the on-site storage of wastewater
dependent upon how the wastewaters are stored; the
substantive closure and post-closure requirements set
forth at 25 Pa. Code §264.110-119 are applicable to the
closure of the units used to store wastewater unless
the wastewater is stored on-site in accordance with 25
Pa. Code §262.34; the regulations set forth at 25 Pa.
Code 263.10-263.32 are applicable when the wastewater
is transported off-site; the substantive standards of
25 Pa. Code §262 relating to generators of hazardous
waste apply ot the tar-like material and the container
or tank storage standards set forth at 25 Pa. Code
§264.171-180 and/or §264.190-.199 for storage of the
tar-like material prior to transport for off-site
incineration are applicable; the substantive
requirements of 25 Pa. Code 265.373, 375, .377, and
.381 are relevant and appropriate to the operation and
closure of the thermal desorption unit (to the extent
that such requirements are more stringent than those
imposed by 40 CFR Part 264, Subpart X).
i. DOT regulations 49 CFR Parts 107 (Hazardous Material
Program Procedures) and 171.1-172.604 apply to the
selected alternative for the transport of hazardous
materials.
j. The land disposal restrictions as described in 40 CFR
Part 268 are applicable since the remedy involves the
excavation and treatment of the soils and the placement
of the treated soils back onto the Site. The untreated
soils contain F001-F005 RCRA wastes and, therefore,
must meet, at a minimum, the concentration levels
listed in 40 CFR Part 268.43. Because the soil clean-
up levels for some of the chemicals listed in Table 1
are more stringent than the LOR levels, the levels
listed in Table l shall be met prior to placement. For
chemicals which do not have a calculated clean-up level
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53
as described in Table 1, the levels listed in 40 CFR
Part 268.43 shall be met.
k. The provisions of Section 121(a)(3) of CERCLA (42
U.S.C. §9621 (d)(3)) apply to the off-site disposal of
any hazardous substance under the selected alternative.
4. To Be Considered
a. The policies set forth in FADER's "Groundwater
. Protection Strategy", February 1992, and the MCLs, and
•' risk-based drinking water concentrations are "to be
considered" (TBC) in developing soil clean-up levels.
Soil clean-up levels were developed using a combination
of the fate and transport mathematical models, HELP and
PRZM as well as a groundwater mixing zone model. The
groundwater concentration input data into this model
was based on MCLs and risk-based drinking water
concentrations. For those chemicals without an MCL or
with a risk-based drinking water concentration greater
that 10 pppb, a groundwater concentration of 10 ppb was
used. Soil clean-up TBCs are listed in Table l. These
levels may be refined during the Remedial Design by
incorporating data generated during the
hydrogeological study which is currently ongoing to
ensure compliance with MCLs and risk-based drinking
water concentrations.
b. The policies set forth in EPA's "Revised Procedures for
Planning and Implementing Off-Site Response Actions",
(November 13, 1987) is a TBC for the selected
alternative.
c. cost-effectiveness
The selected remedy is cost-effective in providing overall
protection in proportion to cost, and meets all other
requirements of CERCLA. The NCP, 40 CFR Section
300.340(f)(ii)(D), requires EPA to evaluate cost-effectiveness by
comparing all the alternatives which meet the threshold
criteria - protection of human health and the environment and
compliance with ARARs - against three additional balancing
criteria: long-term effectiveness and permanence; reduction of
toxicity, mobility, or volume through treatment; and short-term
effectiveness. The selected remedy meets these criteria and
provides for overall effectiveness in proportion to its cost.
The estimated present worth cost for the selected remedy is
$7,800,000-$9,000,000. The range of costs accounts for possible
added treatment for the tar-like material and possible need for a
more complex cap (i.e. a multi-layer cap) once treatment is
complete. The type of cap and need for additional treatment will
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54
be determined during remedial design.
D. Utilization of Permanent Solutions and Alternative Treatment
Technologies or Resource Recovery Technologies to the Maximum
Extent Practicable
EPA has determined that the selected remedy represents the
maximum extent to which permanent solutions and treatment
technologies can be utilized while providing the best balance
among the other evaluation criteria. Of those alternatives
evaluated that are protective of human health and the environment
and meet ARARs, the selected remedy provides the best balance of
tradeoffs in terms of long-term and short-term effectiveness and
permanence, cost, implementability, reduction in toxicity,
mobility and volume through treatment, State and community
acceptance, and preference for treatment as a principal element.
Under the selected remedy, thermal desorption of the soils
will provide a greater degree of reduction of toxicity, mobility,
and volume than soley capping the contaminanted soils or using
soil vapor extraction and bioremediation. Thermal desorption
will provide similar long-term effectiveness and implementability
to incineration, while reducing the toxicity, mobility and volume
through treatment to acceptable levels, at a significant cost
reduction. The State is supportive of the selected remedy.
Some members of the community requested that incineration be
used at the site to restore the site to conditions as close to
the pre-disposal conditions as possible. EPA believes that
thermal desorption will reduce the risk associated with the soils
on Site at an acceptable cost and that the added cost of
incineration does not provide any additional protection benefits.
In designing the thermal desorption system, EPA will attempt to
reduce the levels in the soils to levels which would require only
a vegetative soil cover, therefore, returning the site to
conditions as close to the pre-disposal conditions as possible.
E. Preference for Treatment as a Principle Element
The selected remedy employs a treatment process which has
been demonstrated to effectively reduce VOC and SVOC
contamination at other Superfund sites. Therefore/ the statutory
preference for remedies that employ treatment as a principal
element is satisfied.
XX. Documentation of Significant Changes
The Proposed Plan for OU 3 for the William Dick Lagoons Sie
was released for public comment in January 1993. The Proposed
Plan identified Alternative 4 as the preferred alternative. EPA
reviewed all written and oral comments submitted during the
comment period. Upon review of these comments, it determined
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55
that the soil cleanup levels, as described in the Focused
Feasibility Study, needed to be modified to conform with the
health-based drinking water concentrations, Land Disposal
Restrictions, and direct contact risks.
As described in Section II. of this ROD, preliminary soil
cleanup goals were based on a mathematical model which calculated
soil levels using specified groundwater concentrations. Although
the PRP performing the focused feasibility study (FFS) did modify
the soil cleanup levels to conform with existing MCLs, as
required by EPA, the PRPs did not modify the soil cleanup levels
to conform with health-based drinking water concentrations for
compounds without MCLs or for compounds with health-based
drinking water concentrations less than 10 ppb, as required by
EPA.
EPA believes the model should incorporate health-based
drinking water standards for compounds with health-based drinking
water levels greater tha 10 ppb. Therefore, the soil clean-up
levels were modified by EPA using health-based drinking water
concentrations. Health-based drinking water concentrations were
established based on a carcinogenic risk of 10E-05 or 10E-04. A
cancer risk of 10E-05 means that one additional person per
100,000 has a chance of contracting cancer given the relevant
exposure scenario. The NCP directs hazardous substance responses
for Sites presenting risks outside the established acceptable
carcinogenic risk range for Superfund Sites of between 10E-06 (1
additional chance in one million) and 10E-04 (one additional
chance in 10,000). EPA used a carcinogenic risk of either 10E-04
or 10E-05 as the basis for the health-based drinking water
concentrations for chemicals without an MCL at this Site rather
than use the more conservative 10E-06 carcinogenic risk values
since the 10E-06 carcinogenic value for some compounds are below
the contract required quantitation limit for the drinking water
analytical technique, EPA Method 524.2. The contract required
quantitation limit is the detection level required for a
particular analytical method under EPA's Contract Laboratory
Program (CLP). Use of either 10E-04 or 10E-05 carcinogenic risk
is protective of human health since it falls within the EPA's
acceptable risk range of 10E-06 to 10E-04. (The 10 ppb level was
established during the FFS by the PRP in an attempt to conform to
PADER's groundwater protection strategy, which, although not an
applicable or relevant and appropriate regulation for this ROD,
is a "To Be Considered" policy.)
In addition, EPA modified the cleanup criteria for some
compounds because of requirements under the Land Disposal
Restrictions (LDRs). According to the model, some of the
compounds listed in Table 1 will degrade prior to reaching the
groundwater and, therefore, no soil clean-up level was provided.
However, if the contaminated soils are treated and placed back
on-site, certain contaminants (i.e. those compounds related to
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56
F001-F005 wastes) which degrade before reaching the groundwater
(as calculated by the model) will have to meet the treatment
standards established by the LOR listed at 40 CFR §268.43. The
LOR levels for the relevant compounds are listed in Table 1.
Finally, for the remaining compounds which are not F001-F005
wastes but do, according to the model, degrade before reaching
the groundwater, EPA believes that it is appropriate to establish
soil clean-up levels based on direct contact risks. These levels
are also noted in Table 1. The groundwater concentrations used
in the fate and transport models to calculate the soil clean-up
levels are.listed in Table 1 and are based on either MCLs,
health-based concentrations under a drinking water exposure
scenario or 10 ppb as described above.
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WILLIAM DICK LAGOONS
RECORD OP DECISION
TABLES 1 through 12
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TABLE l: SOIL CLBAH-tTP LEVELS
(Based on a vegetative Soil Cover)
Chemical
Soil Cleanup
Groundvater
concentration
Volatile Organic*
benzene*
butanone (MEK)
chlorobenzene
chloroform
1-2 , dichloroethane
1-2, dichloroethene (total)
1-2 , dichloropropane
ethylbenzene
4-methyl-2-pentanone (MIBK)
styrene
tetrachloroethane (PCE)
toluene
1,1, 1-trichloroethane
trichlorethene
xylene (total)
methylene chloride
Smivolatile Oronnlos
acenaphthenne
anthracene
benzo (a) anthracene
Levels
(mo/kg)
3.7*
362(NC)1
5.72(NC)1
2803(NC)1
0.047
0.36
0.17
1.7
0.064
3.7
1.2
282(NC)1
1
0.42
28* (NC)1
33*
31
94
920
used in
Model (ppbl
5
-
-
-
5
10
5
10
10
10
5
-
10
5
-
10
10
1.0
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benzo(b)floranthene
benzo(k)floranthene
benzo(a)pyrene (BaP)
benzo(g,h,i)perylene
benzole acid
bis(2-chloroethyl)ether(BCEE)
bis(2-ethylhexyl(phthalate(DEHP)
4-chloro-3-methylphenol
chrysene
disbenz(a,h)anthracene
1,2-dichlorobenzene
1,4-dichlorobenzene
4,4-DDE
2,4-dichlorophenol
diethyl phthalate
2,4-dimethyIphenol
fluoranthene
fluorene
indeno(1,2,3-c,d)pyren*
isophoron*
2-methylnaphthalene
2-methylphenol(o-cresol)
4-methylphenol(p-cresol)
napnthalene
nitrobenzene
740
740
7300
6050
3 10, 000s (NC)1
0.01
266
5.2
390
6600
6.2*
11
7250
230s (KC)1
0.95
0.82
250
49
4400
0.68
57s (NC)1
5.62(NC)1
3.22(HC)1
3100S(MC)1
14*
2.0*
2.0*
2.04
5.54
-
1.2s
4
10
3
3
10
10
2.5*
-
10
10
10
10
4
10
-
-
-
-
-
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phenanthrene
phenol
pyrene
1,2-4-trichlorobenzene
94
470003(HC)1
250
61
10
10
10
1 (NC) Soil Clean up value not calculated by model; according to
model compound degrades before reaching groundvater.
2 Soil Clean up value based on Land Disposal Restrictions for
F001-F005 wastes in mg/L (40 CFR 268.43).
3 Soil clean up value based on either 1 x 10"* cancer risk or a
hazard quotient » 1 under a residential direct contact
exposure scenario.
* Groundvater concentration based on a 1 x 10"5 cancer risk for a
drinking water exposure scenario.
5 Ground water concentration based on a 1 x 10*4 cancer risk for
a drinking water exposure scenario.
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Table 2
CONTACT RISK CONCENTRATIONS
Volatile oraaniea
benzene
2-butanone (MEK)
chlorobenzene
chloroform
1-2, dichloroethane
1-2, dichloroethene (total)
1-2 , dichloropropane
ethylbenzene
4-methyl-2-pentanone (KIBK)
styrene
t et r achl or oe thane ( PCE )
toluene
1,1, 1-trichloroethane
trichloroethene (TCE)
xylene (total)
Direct contact
acenaphthene
anthracene
benzo (a) anthracene
benzo (b) f loranthene
benzo (k) f loranthene
Residential
59
3900
1600
280
19
700
25
7800
3900
57
33
16000
7000
150
160,000
4700
23000
1.6
1.9
4.4
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benzo(a)pyrene(BaP)
benzo(g,h,i)perylene
benzole acid
bis(2-chloroethyl)ether (BCEE)
bis(2-ethylhexyl)phthalate(DEHP)
4- chloro-3-nethylphenol
chrysene
dibenz(a,h)anthracene
1,2-dichlorobenzene
1,4-dichlorobenzene
4,4-DDE
2,4-dichlorophenol
diethyl phthalate
2,4-dimethylphenol
fluoranthene
fluorene
indeno(1,2,3-c,d)pyrene
isophorone
2-methyInaphthalene
2-methylphenol(o-creaol)
4-methylphenol(p-creaol)
naphthalene
phenanthrene
phenol
pyrene
1,2-4-trichlorobenzene
0.23
11
310,000
1.5
120
0.21
7000
71
5
230
63000
1600
3100
3100
0.84
1800
3900
390
3100
2300
47000
2300
780
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TAIL! 3
GflOUNO WATl» QUALITY
WILLIAM DICK LAGOONS StTI
Maximum Avtrag* Av«rag« Frequency
Ma«tmum* Caneantfitlan of
VOLAT1LU
m«tftyi«n« cftlene* 36 36 3 i of ••
•eaten* 960 *80 39 A of -3
careen duulfid* 32J 17j 4 s of • 3
i.2-dicnioro*tn«ne. (total) 210 ' 53J 20 3 of -3
entereform 560 «87 39 3 of -3
1 2-dien»ero«man« 120 102J M 3 of "3
2-outanona 350 ' 207 '« . 3 ot "3
'.2-4ieniorooropan« *7j . 9J «! 1 of'3
tnemoreatnan* 16.000 '4.300 '200 9 of'3
o*nz*n« '80 170J 14 3 of 13
4.m«inyi.2-0«manone 220 1QSJ 13 3 of 13
tatraemorootnon* ' 320 2SOJ 19 2 of 13
toiuana 510 430 35 3 of 13
enioroe«ftzon« 32J 19J 2 2 of 13
total iyi«*i»a 160 127J 12 3 of ?3
SIMIVOLATILIS
0n*nol 14.000 10.300 818 3 of '3
oia (2-cntoreamyi) •tnar 24 17 2 2 of 13
2-cmoropnanoi 41 14 1 i of 13
Danzyf aieonoi 19 17 i 1 of 13
2-matnyipnanoi 300 217J il 2 of i3
4.m«tfiylpfi«nel 21 7
-------
UGOON AMD BEflM AAEASOH. OUAUTY
OICX LAGOONS SITE
Avaraga Maiimum Fraquancy of
i . i -dicnioroatnana
l.2-tficnioroatnan«. (total)
cmoroform
i.2-dicfiieroatr»ana
2-outanotrieliloropli«nol
2-cftioronapfltftalana
137
3.120
« «A
1 79
741
12.040
_ «
»:
93.000.000
5.300J
2.800J
73.SOOJ
2.400.000
64,000
200.000
217.500
5.500.000
350.000J
2.200J
7.200J
36.000J
44.000J
3.400J
31.000J
20.000J
900J
31.0004
1.300.000J
1.SOO.OOOJ
130. 000 J
1.800J
3.300J
220.000J
21 OJ
1.700J
i1 wwracriai
1 Of 27
5 af 27
4 of 27
« Of 27
1 Of 27
1 Of 27
11V» 1 «' 27
12 Of 27
2 of 24
2 of 27
8 of 27
12 of 27
12 of 27
14 of 27
4 of 27
12 of 26
10 of 27
4 of 27
10 of 27
5 of 27
6 of 27
1 Of 27
2 Of 27
3 Of 27
2 of 27
Oof 27
19 of 27
19 of 27
2 of 27
1 Of 27
3 Of 27
19 of 27
1 Of 27
1 Of 27
1 of 3
-------
GROUND WATER QUALITY
WILLIAM DICK LAGOONS SITE
Compound
METALS (dissolved) (»g/l)
aluminum
oanum •;
beryllium
calcium
cooait
copper
iron
lead
magnesium
manganese
potassium
selenium
sodium
zmc
Maximum
Caneantrf'lgn,
•
1.430
83.7
1.6
5.280
20.8
14.4
20.200
i
4.260 •
863
8.520
2.«
32.500
61.2
Average
Maximum*
1.430
83.7
1.6
S.280
20.8
144
19.800
1
4.260
863
4.260
2.4
32.500
61.2
Average
Concentration
'54
25.7
0.1
1.875
3.3
3.9
4.870
0.27
1.705
193
426
0.2
8.182
61.2
Frequency
of 0«t«etie
3 of -2
^2 v -Z
: at :Z
9 of 9
* or "2
2 3f 5
11 or :•
4 af ".
3 of *
n of .12
1 Oflfl
1 of 12
7 of 12
1 Of 1
CONVENTIONAL PARAMETERS (mg/l)
otocnomicai oxygen
demand (BOO) .
total dissolved solids (TOS)
nitrate
alkalinity (as CaCO3)
cnionae
naraness (as CaCO3)
total organic canon (TOO
91
560
3.1
20
20
64
52
PH"'
•
CQftCM!fslIIM>isl fVpOIIBd fflf • iMll flTOfll Wtl
M^MSk mar mn tt> Is* ttsA •M^BMS&AA mA •••*»> r^nnrrei
91
560
3.1
20
20
64
52
<1S
<8S
<1.3
8.2
<5
22
<&4
12 3f '2
12 of '2
12 3f -2
12 of -2
12 3f '2
12 of '2
12 3f '.2
5.6
when me) maximum
icft two or more samples
• * Out of a msflrimum of 13 wait tar erganics and 12 wotts for motats:
s^ek •••ASBJ A^^^B^B^^ ^^&« >^be) eeBi^hAA «^t^^^ekl^ ^B ^Mei^dkiai
IO IBM sample count tnose sampio n MII*UI
kdlt ffloA
• • • From pump tost on MW-20. October/November 1919.
Noto: Pesoades/PCSa not eotoctsd in any weUa.
J<- Estimated concontration
2 or 2
-------
LAGOON AND BERM AREA SOB. QUAL rrv
O.CK LAGOONS
Compound e^A™?* M«*»mum
METALS (confd) (mg/kg)
cobalt
copper
iron
lead
magnesium
mercury
nickel
potassium
silver
sodium
vanadium
zinc
1.4
tA
9
7.960
24
916
64
0.01
5.4
628
04
. 1
38
1A
3
52
4.1
40J
18.000
269J
5.080
160
2.3
1 4
3.070
1.7
644
28J
253J
5 of 6
7 of 8
27 of 27
27 of 27
18 of 18
23 Of 23
3 Of 27
t7 of 27
4 of 17
2 of 27
1 Of 17
27 of 27
23 of 23
J • estimated concentration
Page 3 of 3
-------
LAGOON AND BEAM AREA SOIL QUALITY
WILLIAM DICK LAGOONS SITE
Avaraga Maximum Frequency of
Compcund ConcantrationConeanffatlon Oafaetfon*
SEMIVOLATILCS (confd) (tig/kg)
dimatnyl pfttftafata 1i S90J i of 27
acanapfttfiylana 740 7.000J 8 of 27
acanaptnana 3.970 47.000J 13 of 27
oibafttofuran 3.570 36.000J 13 of 27
diatftyl pmftalatf 83 1.*OOJ 2 cf 27
fluorana 4.240 41.000J 13 of 27
N-nitrosodipftanylamina 734 ' 5.300J 5 of 27
ptntacnioropnanol 2 S4j i of 27
pn«nantnr«n« 16.500 280.000J 16 of 27
antftrac«n« 1.830 13.000J 16 of 27
di-n-outylphtnalata 5.910 32.000J u of 27
fluorantnanr 8.360 200.000J 16 of 27
pyr«n« 6.020 120.000J 16 of 27
butyibanzyipmhaiata 11.300 78.000J 15 of 27
banzo (a) amtiracana 1.860 . 30.000J 13 of 27
cnrysana 2.130 29.000J 16 of 27
bis(2-ttnyihaxyi)phtfiaiata 169.000 1.200.000J 22 of 27
di-n-octyipfttnaiatt 4.720 29.000J 15 of 27
banzo(b and/or k)fluor«ntMana 3.940 54,000J 15 of 27
banzo(a)pyrtnt 1.250 2S.OOOJ 11 of 27
indtno(1.2.3.e.d)pyrana 300 7.600J 5 of 27
dibanzo(a.A)antftracan« 81 2.700J 3 of 27
ban20(g.ft,i)p«ryitn« 300 8.000J 5 of 27
PEST1CIOES/PC8S big/kg)
•
haptaefilor tpoxida 6 150 1 of 27
4.4'.QOE 34.300 220.000 17 of 27
METALS (mgAg)
aluminum 8.040 15.100 27 of 27
arsanic 9.2 14J 27 of 27
barium 81 672J 27 of 27
baryllium 0.09 O.S1 1 of 6
cadmium 0.04 1.U 1 of 26
calcium ..- 2.190 11.100 6 of 6
cftromium 39 349J ' 26 of 27
Paga 2 of 3
-------
TAIL! 5
Oiom Oat* Summary
William Oicx Lftgoofl* Sit*
W«R C*J« Townsftp. C***t*r County
EMM T.ft. Ma
3*mo<* location
3*mp<* 0*t*
unit*
2.3.78-TCOO
atn*f TCOO
2.3.7.B-TCOF
am*r rco*
2.3.7J-PCOO
otn«r PCOO
2.3.7 8.PCOF
otrw PCO«
2.3.7 8-MxCDD
om«f MiCOO
2.3.7.1-HiCDF
omcfMiCO'
2.3.7 i-WoCDO
otMfMeCOO
2.3.7 8-HBCOf
om«f MoCOF
OCO3
OCO *
2.3.7.11 TCOO •dumMmi
23297
0-8«e*qrogno
10/11/89
u«/K«
o.oot
O.OS
S.9
ud/K«
0.007
23291
0-9 (2-4)
10/11/89
ufl/Kfl
o.gt
3.t
uo/K*
0.0044
23301
0>« fO-21
10/1 1'89
u«/K«
O.Tt
0.01
O.t9
0.01
0.00«
0.024
O.Of
0.27
0.03
0.09
0.37
0.42
o.oa
0.01
4.1
0.1 •
(M/Kfl
0.0241
23299
0-4 (2-*>
t 0/1 1/89
ua/Kq
0.03S
0.09S
02i
Z4
uO/Ko
0.01 45
tfw fMtfMd tf«t»ctten iMt IWM Mt MM f»port*d.
-------
wB
O.CK
aluminum
arsenic
barium
5«ryllium
eitremJum
eebtlt
iron
itatf
mercury
potassium
sodium
vanadium
zinc
VOUTILCS
SI yiVOLATILf 3
".
btnzoic aetd
«.«,,.„.,.„.„,„,„„„,,
S'«(2..enyii.,,y,,Blu(ul ?' <«oj !*•
*U • t «/• . ' 0" «
• OUJ t af |
PfSTICI06S/PCS«
MfTALS (mg/kgj
tO. 843
2.2
39
0.32
10
2.7
7.899
8.8
730
121
0.1
m + A
749
294
15.5
31
14 inn
1 *.auo
^ •
•J.*
48
O.S8
20
^ •
11.700
15
1.260
291
0.69
2.170
1.070
21
39
8 of •
8 of |
8ofS
8 of 8
8ofS
7 of 8
8 Of 8
8 of 8
8of8
8of6
1 of 8
4 Of 8
2 of 8
8of9
8of8
-------
TA8LI 7
or CB
Of EA
CAU or cofraunr
IDIf
l^-4lehIoreetjitM (tocaO
1.2mehlenbcn>en«
.41
l.lttIqrlheyl)pluhaUte
phenol
lwt«diehtorMtiitnc ItouO
ehtonbenzcnc
4-mtthjriph«nol (p^meO
2.4-dicWorophenol
-------
TABLE •
Com
water aquifer
MiriaMm «*
OMHUI
HP • n*
Air
•I fcfM* AIM
VM
OM
Vw
-------
<«
I.1M cma '0.470 out
•OfcTw
it 70 iwr Ufwiv
WATW
WIM» SflOMnnylMMf
•* tHH A/M Cra^M (f
MMI MOVtf I
•t ft
r 1m*n rr'
«»
(•I
a nun
71%
1C
(0
let
(0
(Ml
(0
0.0*
t«
(0 24 IM<
(0 3M Mr
m
m
m
(0
UMIO
» liar*
71%
1C
O.It
11* •
24 IMO
0.1*
14 0*
»f
14 Mr
•Jt
1
24
1.4*
OJ
-------
10
-------
TABLE 1t
3C-OS • IC-03
DMT Mm UcMttea
flt-07 .
5£-Oi • IE-OS
IC4S
IE-OS
3K4S - 3C-OC
N* . NA
T«Ml
arM . JfrO* 3*O« • 3»CB lf-OB
WOTCi
Vl
-------
12
3C41
8C-C8
7C-M
NA • NA
•t 1.0 fcr teutpnud
------- |