United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R03-92/155
September 1992
&EPA Superfund
Record of Decision:
Commodore Semiconductor
Group, PA
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R03-92/155
3. Recipient's Accession No.
4. Title and Subtitle
SUPERFUND RECORD OF DECISION
Commodore Semiconductor Group, PA
First Remedial Action - Final
5. Report Date
09/29/92
6.
7. Author)*)
8. Performing Organization RepL No.
9. Performing Organization Name and Address
10. Project/Tuk/Work Unit No.
11. Contract(C) or Grant(G) No.
(C)
(G)
12. Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/000
14.
15. Supplementary Note*
PB93-963920
18. Abstract (Limit: 200 words)
The 14-acre Commodore Semiconductor Group (CSG) site is a manufacturing facility in
Norristown, Montgomery County, Pennsylvania. Land use in the area is residential,
commercial, and industrial with a wetland area located within 1 mile from the site.
The site overlies a Class IIA aquifer that is used as a source of drinking water. From
1969 to present, the owners, including CGS, used the site to manufacture semiconductor
chips. A concrete underground storage tank was installed adjacent to the southeast
side of the building to store a waste solution known to contain TCE and other solvents
generated from the manufacturing process. The concrete tank was reported to have
leaked in 1974. As a result, an unlined steel tank was installed next to the concrete
tank. Use of the concrete tank was discontinued. In 1978, a local water supplier
detected TCE in two of its wells adjacent to the site. The state identified the CSG
site as a possible TCE contaminant source. Subsequently, in 1979, the underground
storage tanks were excavated and replaced with a waste solvent collection system. In
1981, CSG also eliminated use of TCE in their manufacturing process. From 1981 to
1984, to address the TCE contamination, CSG pumped and spray irrigated water from a
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - Commodore Semiconductor Group, PA
First Remedial Action - Final
Contaminated Medium: gw
Key Contaminants: VOCs (PCE, TCE)
b. IdentrflenVOpen-Ended Terms
c. COSATI Reid/Group
18. Availability Statement
19. Security Class (This Report)
None
20. Security Class (This Psge)
None
21. No. of Page*
110
22. Price
(See ANSI-239.18)
See Instructions on Reverse
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R03-92/155
Commodore Semiconductor Group, PA - • ~
First Remedial Action - Final
Abstract (Continued)
public supply well, purchased and installed an air stripper for treating contaminated
ground water, implemented a residential sampling program, and installed carbon filter
systems at affected residences. . In 1984, further state and EPA investigations confirmed
contaminants onsite in ground water and drinking water. This ROD addresses the
contamination of onsite ground'water and drinking water. The primary contaminants of
concern affecting the ground water are VOCs, including PCE and TCE.
The selected remedial action for this site includes extending the public water supply
lines and connecting affected residences located in areas south of the CSG facility;
abandoning contaminated wells; continued maintenance of existing residential carbon
units, with disposal or recycling of the spent carbon filters as determined during the
remedial design phase; installing additional ground water extraction wells, air
strippers, and vapor phase carbon units, to treat the contaminated ground water onsite
with discharge to a public water system or reuse by the CSG facility, with overflow
discharge offsite to a POTW; sampling ground water and treated water; and implementing
institutional controls, including ground water well restrictions. The estimated present
worth cost for this remedial action is $5,573,700, which includes an annual O&N cost of
$446,500 for years 0-2, and $404,300 for years 3-30.
PERFORMANCE STANDARDS OR GOALS:
Ground water clean-up goals are based on background levels as established by SDWA MCLs or
health-based levels, whichever are more stringent. Chemical-specific ground water goals
include 1,2 dichlorobenzene 75 ug/1; 1,2-DCA 810 ug/1; tetrachloroethene 5 ug/1; TCA
200 ug/1; trichloroethene 5 ug/1; and vinyl chloride 2 ug/1.
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RECORD OF DECISION
COMMODORE SEMICONDUCTOR GROUP SUPERFUND SITE
DECLARATION
SITE NAME AND LOCATION
/
Commodore Semiconductor Group Superfund Site
Lower Providence Township, Pennsylvania
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for
the Commodore Semiconductor Group Superfund Site ("the Site"),
located in Lower Providence Township, Montgomery County,
Pennsylvania. The remedial action was selected 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 is based on
the Administrative Record for this Site.
The Commonwealth of Pennsylvania has concurred on this remedy.
ASSESSMENT OF THE SITE
Pursuant to duly delegated authority, I hereby determine pursuant
to Section 106 of CERCLA, 42 U.S.C. §9606, that 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 the public health, welfare, or the
environment.
DESCRIPTION OF THE SELECTED REMEDY
« —-
«
The selected remedy for the Site will restore contaminated
groundwater to its beneficial use by cleaning both the shallow
and deep aquifers to background levels as established by EPA or
to Maximum Contaminant Levels ("MCLs") established under the
federal Safe Drinking Water Act ("SDWA"), or to health-based
levels identified in the ROD, whichever is lower. The remedy
will also protect the public from exposure to contaminated
groundwater. The selected remedy as described below is the only
planned action for the Site.
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ORIGINAL
(Red)
Because this remedy will result: in hazardous substances remaining
onsite above health-based levels, a review by EPA will be
conducted within five years after initiation of remedial action
to ensure that the remedy continues to provide adequate
protection of human health and the environment.
SEP 29 1992
Edwin B. Erickson
Regional Administrator
Region III
Date
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RECORD OF DECISION ORIGINAL
(Red)
COMMODORE SEMICONDUCTOR GROUP SUPERFUNO SITE
TABLE OF CONTENTS
I. SITE NAME, LOCATION AND DESCRIPTION 1
II. SITE HISTORY AND ENFORCEMENT ACTIVITIES 1
III. HIGHLIGHTS OF COMMUNITY PARTICIPATION 4
IV. SCOPE AND ROLE OF THE ACTION 4
V. SUMMARY OF SITE CHARACTERISTICS AND EXTENT OF
CONTAMINATION 5
VI. SUMMARY OF SITE RISKS 9
VII. DESCRIPTION OF ALTERNATIVES 15
VIII. SUMMARY OF COMPARATIVE ANALYSIS OF ALTERNATIVES ... 29
IX. THE SELECTED REMEDY 35
X. STATUTORY DETERMINATIONS 41
XI. DOCUMENTATION OF SIGNIFICANT CHANGES 46
APPENDIX A FIGURES
APPENDIX B TABLES
APPENDIX C RESPONSIVENESS SUMMARY
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DECISION SUMMARY ORIGINAL
I. SITE NAME, LOCATION AND DESCRIPTION
The Commodore Semiconductor Group ("CSG") Site (the "Site"
or the "CSG Site") is located in the Valley Forge Corporate
Center ("VFCC") in Lower Providence Township, Montgomery County,
Pennsylvania. The CSG facility is located at 950 Rittenhouse
Road in Norristown, Pennsylvania. The Site is located
approximately one mile north of the Schuylkill River. It is
bordered on the northwest by Rittenhouse Road, on the northeast
by Van Buren Avenue and on the southeast by Adams Avenue. The
General Washington Country Club golf course occupies all the
property immediately west of the facility on Rittenhouse Road
with the remainder of the surrounding property being occupied by
industrial and commercial facilities. The Transcontinental Gas
company ("Transco") Pipeline which includes three natural gas
pipes transverses the CSG property. Private residences are
located approximately one-half mile from the Site in all
directions. (See Figure 1, Location of the CSG Site)
Groundwater is -the only source of potable water in the area
and residents near the Site are dependent on public or private
wells. EPA has classified this aquifer as a Class IIA aquifer, a
current source of drinking water.
Regional surface drainage in the vicinity of the Site is
toward the Schuykill River via tributary streams. Local surface
drainage in the vicinity of the Site is to the south or west,
while actual Site runoff is collected and discharged through the
VFCC storm water system to Lamb Run, a small tributary of the
Schuylkill River. A small portion of the stormwater detention
basin at the Site contains tall grasses and cattails and,
therefore, is considered a wetland area. No other wetland areas
have been identified within one-mile radius of the Site.
There are no known endangered species or critical habitats
within the immediate vicinity of the Site.
II. SITE HISTORY AND ENFORCEMENT ACTIVITIES
^
On December*3l7 1969, the real property at 950 Rittenhouse
Road, Norristown, Pennsylvania was transferred from Valley Forge
Industrial Park, a Pennsylvania corporation, to Allen-Bradley
Company, Inc. ("Allen-Bradley"), a Wisconsin corporation.
The 14-acre CSG facility was originally developed in 1970-71
to meet the specifications of MOS Technology, Inc. ("MOS"), a
Delaware corporation, which became the initial lessee of the
property. MOS leased the property from Allen-Bradley from
November 1, 1970 until March 6, 1976. During that time, MOS was
involved in the processing of semiconductor chips. Allen-Bradley
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ultimately sold the property to MOS on March 6, 1976.
At the time the CSG property was transferred to MOS by
Allen-Bradley, the MOS stock was owned by Commodore Business
Machines, inc. ("Commodore"). Commodore obtained this stock
pursuant to a Stock Acquisition Agreement dated November 2, 1976.
Through its acquisition of the MOS stock, Commodore
established itself as an owner/operator of the CSG Site.
Commodore Semiconductor Group or CSG is not a division of
Commodore, but is rather a name used by Commodore to describe its
operations at the Norristown facility.
The CSG facility was originally built by Robert E. Lamb,
Inc., the developer of the Valley Forge Corporate Center for MOS
for manufacturing semiconductor chips. At the time the
manufacturing building on site was constructed, a 250-gallon
underground concrete storage tank was installed adjacent to the
southeast side of the building. The concrete tank was used by
MOS to store a waste solution known to contain trichloroethene
("TCE") and other solvents. According to information obtained
from Commodore in response to a CERCLA §104(e) information
request from the Agency, the concrete tank leaked in 1974. As a
result, in 1975, MOS discontinued the use of the concrete tank
and installed an unlined steel tank in the ground adjacent to the
concrete one.
In 1978, the Audubon Water Company ("AWC"), suppliers of
water to the Village of Audubon and Lower Providence Township,
detected TCE in two of its wells located near the CSG Site.
After some investigation, the Pennsylvania Department of
Environmental Resources ("FADER11) identified the CSG facility as
a possible TCE source. In the fall of 1979, the underground
tanks were excavated. Sampling, which was only for TCE and
tetrachloroethene ("PCE"), conducted during the excavation
revealed high levels of TCE and PCE in the soil directly below
the underground storage tanks and in the surrounding groundwater.
Commodore replaced the tanks with a waste solvent collection
system consisting of a tank within a lined vault. In 1981,
Commodore discontinued the use of TCE in its manufacturing
process. At the-same time, the company installed groundwater
monitoring wells"and" began a sampling program.
Measures to reduce TCE contamination at the Site started in
early January 1981. From 1981 to 1983, Commodore pumped and
spray irrigated water from Audubon Water Company's public supply
well, VFCC-4. Spray irrigation is a practice consisting of
spraying contaminated water on a field and allowing volatile
organic compounds ("VOCs") to evaporate into the air. Commodore
had informal state approval for the spray irrigation system, but
did not operate the system under a PADER permit.
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In February 1984, Commodore purchased and installed an air
stripper on VFCC-4 to be used in the treatment of contaminated
groundwater. In 1984, Commodore began a residential sampling
program and installed whole-house carbon filter systems on
residences with at least l part per billion ("ppb") of VOCs
detected. A total of 23 residences were supplied with these
filters. Commodore also began construction of a 100,000 square
foot building expansion with a french drain groundwater
collection system under the entire expansion. Construction was
completed in 1985. The groundwater from the drain is piped to an
air stripper, then discharged to the VFCC stormwater runoff
system. As a result of the facility expansion in 1985, the
property was regraded, a stormwater detention basin was
constructed, and the parking area of the facility was
expanded.
In February 1984, EPA performed a Site Inspection ("SI11) at
the CSG Site. A Preliminary Assessment ("PA") and another SI
were subsequently completed on December 5 and 12, 1986,
respectively. Sampling results revealed the presence of TCE in
nearby residential wells. TCE and TCE-related compounds were
also found in the groundwater, surface water, and soil samples
taken from the Site. The Site was proposed for inclusion on the
National Priorities List ("NPL") in January 1987. The Site
scored 42.35 under EPA's Hazard Ranking System and was included
on the final NPL on October 4, 1989 (54 Fed. Reg. 41000-41015).
Commodore Business Machines, Inc., ("Commodore11), the
current owner/operator of the facility at 950 Rittenhouse Road,
has been identified by EPA as a Potentially Responsible Party
(nPRPM) for contamination at the CSG Site. Commodore conducted a
Remedial Investigation/Feasibility Study ("RI/FS") at the Site
pursuant to the terms of an Administrative Order By Consent
(Docket No. III-88-09-DC) signed by EPA on July 29, 1988. The
purpose of the RI/FS was to characterize the type and extent of
contamination at the Site, to quantify any existing or potential
human health risks, to evaluate potential environmental risks,
and to develop alternatives to remediate the contamination.
RI/FS Reports were submitted to EPA by Commodore in February 1992
and July 1992.
«
Allen-Bradley Company, Inc. ("Allen-Bradley") owned the CSG
Site during the time hazardous substances were released into the
environment. Allen-Bradley has been identified as a PRP for
contamination at the CSG Site and was sent a General Notice
letter on February 27, 1992.
EPA solicited comment on a draft Feasibility Study for the
CSG Site from the Delaware River Basin Commission on March 5,
1992. On July 30, 1992, EPA sent notice of impending remedial
design/remedial action ("RD/RA") negotiations to the Department
of Interior ("DOI") and the National Oceanic and Atmospheric
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Administration ("NOAA").
III. HIGHLIGHTS OF COMMUNITY PARTICIPATION
A Community Relations Plan for the CSG Site was finalized in
February 1989. This document lists contacts and interested
parties throughout government and the local community. It also
establishes communication procedures to ensure timely
dissemination of pertinent information. A draft RI/FS report and
the Proposed Plan for the CSG Site were released to the public on
July 21, 1992, in accordance with Sections 113(k)(2)(B), 117(a),
and 121(f)(l) (G) of CERCLA, 42 U.S.C. §§9613(k) (2) (B) , 9617(a),
and 9621(f)(1)(G). These and other related documents were made
available in both the Administrative Record located at the U.S.
EPA Region III Offices, 841 Chestnut Building, Philadelphia,
Pennsylvania, 19107, and at the Site Repositories, Lower
Providence Community Library, 2765 Egypt Road, Audubon,
Pennsylvania, 19405, and Montgomery County Planning Commission
Courthouse, One Montgomery Plaza, Norristown, Pennsylvania,
19404.
Due to a request for an extension, the comment period was
extended to 60 days, closing on September 19, 1992. In addition,
a public meeting was held on August 6, 1992 to discuss the
results of the Ri/FS and the preferred alternative as presented
in the Proposed Plan for the Site. Notice of the Proposed Plan
and public meeting was published in a major local newspaper of
general circulation, The Times Herald. Norristown, Pennsylvania.
Additionally, the Proposed Plan and the Notice of the Comment
Period Extension were mailed to many residences in the nearby
vicinity of the Site.
All significant comments on the Proposed Plan which were
received by EPA prior to the end of the public comment period,
including those expressed orally at the public meeting, are
addressed in the Responsiveness Summary which is attached to this
Record of Decision.
IV. SCOPB AMP ROTrTt Of TUB ACTION
This Record*of^.Decision ("ROD") mandates remediation of
contaminated groundwater and addresses the drinking water sources
(public supply wells and residential wells) affected by
contamination at the CSG Site. This ROD is the only planned
response action for the Site.
EPA has classified the affected aquifer at the CSG Site as a
Class IIA aquifer, a current source of drinking water, in
accordance with the EPA document "Guidelines for Groundwater
Classification" (Final Draft, December 1986). Ingestion of, and
contact with, contaminated groundwater poses the primary risk to
human health being addressed by this ROD. The concentrations of
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contaminants in the groundwater at the Site are above Maximum j
Contaminant Levels ("MCLs") which are enforceable, health-based
drinking water standards established under the Safe Drinking
Water Act ("SDWA"), 42 U.S.C. §§300f to 300J-26.
This Class IIA aquifer is located in a Groundwater Protected
Area of Southeastern Pennsylvania as designated by the Delaware
River Basin Commission. As such it is the intent of the U.S. EPA
to beneficially reuse the contaminated groundwater to the maximum
extent practicable via a treatment system meeting federal and
Commonwealth of Pennsylvania regulations for primary and
secondary treatment requirements.
The purpose of the selected response action is to prevent
current or future exposure to contaminated groundwater, to
protect uncontaminated groundwater for current and future use,
and to restore contaminated groundwater to MCLs or to background
concentrations, if background for Site-related contaminants is
lower than the MCLs. Pumping and treating groundwater is the
most expeditious way to reduce the contaminant levels that have
been detected.
V. SUMMARY OP SITE CHARACTERISTICS AND EXTENT OF CONTAMINATION
A. SITE CHARACTERISTICS
1. Geology
The Site is underlain by the middle member of the Triassic-
age Stockton formation. The Stockton formation is characterized
by siltstone, fine-grained and medium-grained sandstone, red
shale, very fine-grained red sandstone, and a few beds of coarse-
grained sandstone and conglomerate. The strata have a regional
dip of five to eighteen degrees to the northwest. Fractures
within the bedrock appear to be vertical, and for the most part,
evenly distributed.
The unconsolidated overburden deposits consist of
predominantly red-brown silt and clay. Overburden thickness
ranges from six feet to 22.5 feet. The soil/bedrock interface is
gradational. Soil gradually grades into consolidated material
where relict bedding* is visible, and then into weathered bedrock.
2. Hydroaeolocry
The Site stratigraphy is complex with many lithologic
variations and discontinuous units. This creates complex
hydrogeologic conditions. Two units that are not isolated
hydraulically were identified beneath the Site: a shallow
(perched), water-bearing zone in soil and shallow bedrock and a
deeper bedrock unit. The saturated thickness of the shallow zone
varies seasonally and is dependent upon precipitation. The
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bedrock water-bearing zone does not appear to respond to
precipitation. This is due to the presence of siltsone and shale
units that act as semiconfining units by retarding the downward
migration of groundwater. Although the water levels in the
bedrock water-bearing zone do not appear to respond to
precipitation, the shallow zone, which is a low yield zone,
provides water to the deeper zone. Water levels in the bedrock
water-bearing zone do fluctuate as a result of pumping of nearby
water supply wells. The shallow and deep aquifers are not
isolated hydraulically and the shallow water provides recharge to
the deeper zone.
Groundwater mounding exists in the subsurface soils around
the vicinity of the former underground concrete storage tank
which were located on Site. The mounding exists as a result of
recharge from the porous and permeable material used as fill
after the tanks were removed. Groundwater flow in this shallow
zone is directed away from the recharge area in all directions.
Groundwater in this shallow zone which flows to the south-
southeast may also be intercepted by the Transco pipeline. The
pipeline is approximately 75 feet from the former underground
storage tanks. The permeable fill surrounding the pipeline
probably provides a pathway for groundwater flow and migration of
contaminants to the southwest.
Groundwater movement through the heterogeneous anisotropic
bedrock water-bearing zone occurs through a combination of
primary and secondary porosity. Groundwater movement and hence
migration of the site-related contaminants is influenced by the
pumping of the bedrock public water supply wells: VFCC-2, VFCC-
3, VFCC-4, Aud-3, and Aud-5, as well as the gravel bed of the
Transco pipeline. The regional groundwater flow is to the
southeast; however, groundwater in the vicinity of the Site
appears to be moving south-southwest as well.
3. Surface Water
The Site is located in gently rolling terrain in the
Schuylkill River Drainage Basin. Regional surface water drainage
near the Site is directed to the south toward the Schuylkill
River via tributary^systems. Since the CSG facility expansion in
1985, roughly 50"percent of the regraded and expanded parking
area located on the southern side of the property directs runoff
to a man-made detention basin measuring approximately 100 feet by
160 feet by 190 feet. The remainder of runoff is directed to a
drainage ditch. The drainage ditch is dry except for periods of
heavy or constant rainfall. The drainage ditch empties into the
intermittent portion of Lamb Run, a small tributary to the
Schuylkill River.
4. Meteorology
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(Red;
The Site is located in Montgomery County, Pennsylvania.
Temperatures in Montgomery County ranged from a mean monthly Low
of 19 degrees Fahrenheit in January to a mean monthly high of 86
degrees Fahrenheit in July for the years 1981 to 1986.
Seasonally, the greatest amount of precipitation occurs in the
spring and the least amount occurs during the winter months.
Average annual precipitation over the years 1980 to 1990 was
slightly less than 44 inches.
5. Natural Resources
The Site and surrounding area ecology consist of an
industrial/corporate park with grass-covered lawns, few trees,
and some intermittent drainage areas connected to an intermittent
stream. Within the industrial park are some open lots with wild
grass and shrubs. In addition to the corporate park ecology are
residential communities, vacant lots, and a golf course.
Within the corporate park, the vacant lots support the most
diverse ecology. This ecology includes birds, rabbits,
squirrels, rats and mice in addition to the grasses and shrubs.
Though larger animals such as raccoons and deer may possibly
wander through, there is not enough vacant area to support a
reasonable habitat for larger animals. Areas exterior to the
corporate park also would provide minimal habitat and shelter for
wildlife beyond the size of a raccoon.
No known threatened or endangered plant or animal species
have been identified at the Site. The wildlife that are found
are very limited because of the human population and human
culture alterations in the Site vicinity. A limited area of
wetlands exists in a portion of the stormwater detention basin
identified above. Areas do get wet during rainy periods;
however, these quickly dry. Most areas of ponding water are
manmade and these areas do not contain threatened plant or animal
species.
B. NATURE AND EXTENT OF CONTAMINATION
The nature and extent of contamination at the Site was
characterized through a soil gas survey; sampling of soils,
groundwater monitoring wells, residential drinking water wells,
public water supply wells, and golf course irrigation wells; and,
sampling of surface water.
1. Soils
Soil gas testing revealed detectable levels in separate,
discrete locations of the following four volatile organic
compounds ("VOCs"): 1,2-Dichloroethene ("1,2-DCE"),
Trichloroethane ("TCA"), Trichloroethene("TCE"), and
Tetrachloroethene ("PCE").
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Ten soil samples were taken and analyzed (See Figure 2 for
the location of the soil borings). The four borings located
within the boundaries of the CSG property were situated near
suspected areas of elevated VOC concentrations. These borings
were labeled: S-5, which was drilled near the former underground
concrete storage tank, and S-6, S-8 and S-10, which were drilled
along the trace of the Transco pipeline where elevated soil gas
concentrations had been detected.
All ten soil borings were analyzed for the complete target
compound list ("TCL"). Soil borings S-5 and S-8 were
additionally analyzed for the target analyte list ("TAL"). The
following five VOCs were found at detectable levels at the Site:
Carbon Tetrachloride, 1,2-Dichloroethene, Trichloroethene,
1,1,2,2- Tetrachloroethane, and 1,2-Dichlorobenzene. The highest
detected concentration of any of these compounds was for
Trichloroethene at 16 parts per billion ("ppb") from soil boring
S-8, at a 1.2 - 1.5 foot depth. For the remaining TCL
substances, only 1,2,4-trichlorobenzene, a base neutral
extractable compound was detected at a depth of 11 feet.
Several TAL metals were detected in the two TCL/TAL samples
including: aluminum, arsenic, barium, beryllium, chromium,
copper, iron, lead, magnesium manganese, potassium, silver,
vanadium and zinc. The levels detected do not exceed levels
which can occur naturally in soils.
Each soil boring was completed as either a vapor probe or a
piezometer for the purpose of monitoring conditions in the
overburden. Depth-to-water measurements and Organic Vapor
Analyzer ("OVA") readings were taken monthly beginning in June
1990 and ending March 1991. See Table 1 for water level
measurements and Table 2 for OVA readings.
2. Surface Water
Groundwater level measurements taken in the overburden
piezometers indicate that groundwater at the Site potentially
discharges to Lamb Run, a small tributary to the Schuykill River.
Five surface water samples were taken from the intermittent
stream that parallels Rittenhouse Road, just south of the CSG
facility, and were analyzed for VOCs. Sediment samples were not
collected because the base of Lamb Run consisted primarily of
gravel or bedrock at the sampling locations.
The following three VOCs were detected in the surface water:
1,2 DCE, PCE, and TCE. Figure 3 provides the locations of the
samples and a summary of the analytical results. All
concentrations were more than 10 times lower than the Fresh Water
Acute Water Quality Criteria for aquatic life (25 Pa. Code
Section 16.51, Table 1) . Of the three compounds detected, only
PCE has a chronic limit established by the above cited
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ORIGINAL
(Red)
regulations (840 ppb). None of the levels detected exceed MCLs
established under the SDWA. At the levels detected, natural
attenuation will most likely remove the volatile organics.
3. Groundvater
Groundwater was sampled both upgradient and downgradient of
the facility. (See Figure 4 for groundwater sampling locations).
The results of the groundwater investigations are summarized in
Table 3. The highest VOC concentrations detected were in the
shallow groundwater near the former underground concrete tank and
the unlined steel tank. The VOCs detected in those areas were
TCE, TCA, 1,1-DCE, 1,2-DCE, 1,1-DCA, PCE, and chloroform. Vinyl
chloride was detected at only three locations in the shallow
aquifer: once at 2 ppb in the french drain, once at well MOS-13
at 2.2 ppb, and once at well MOS-15 at 8.1 ppb. Groundwater in
the bedrock wells was found to have the same chemicals found in
the shallow aquifer.
The concentrations of the contaminants in the deep bedrock
aquifer (the drinking water aquifer) were generally lower than
those in the shallow aquifer. The exception is vinyl chloride
which was detected twice in the deep aquifer at MW-l, at 12 ppb
and 14 ppb. The Site-related contaminants detected in the deep
bedrock aquifer exceed MCLs. Figure 5 represents the potential
areal extent of the Site-related plume and also represents the
approximate areal extent where MCLs are exceeded in the bedrock
aquifer. Table 4 summarizes the wells with major MCL
exceedances.
VI. SUMMARY OF SITE RISKS
This section of the ROD summarizes the results of the
baseline risk assessment which was conducted as part of the
RI/FS. The risk assessment for the CSG Site characterizes the
current and potential threats to human health and the environment
based on reasonable maximum exposures to contaminants in the
groundwater, soil and subsurface soil, the migration of
contaminants to surface water, and exposure to contaminants in
the air if no remedial action were taken.
«
The risk assessment consisted of identification of
contaminants of concern, a toxicity assessment, an exposure
assessment, and risk characterization. The first task in the
risk assessment was the selection of Site-related contaminants
for which risks were assessed. In the data evaluation, sampling
data were reviewed by medium. The list was based on chemical
toxicity characteristics, the occurrence and distribution of the
chemical in the medium, potential exposure routes, and
contaminant migration characteristics.
A. EXPOSURE ASSESSMENT
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10
Exposure pathways were identified for groundwater, surface
water, soils, and air at the Site. The human health risk
assessment was conducted only for exposure to groundwater and
outdoor air. Exposures to soil and surface water were not
evaluated because the concentrations of contaminants detected in
these media were low, the duration of the exposure short, and/or
the concentrations were below health-based screening criteria.
Comparisons of potential chemicals of concern detected in soils
and surface waters to risk-based concentrations are listed in
Tables 5 and 6, respectively.
Current land use in the vicinity of the Site is residential
and industrial park. Future land use in the vicinity of the Site
is also expected to be residential and industrial park. The
George Washington Country Club golf course ("GWCC") is
immediately west of the Site. Though GWCC is currently used for
recreation, it is zoned for residential use. Therefore, a
probable future use of GWCC is residential use.
Groundwater beneath the Site is classified as a Class IIA
aquifer, a current source of drinking water. Contaminants from
the Site migrate towards public supply wells and private drinking
water wells through the groundwater flow system.
Based on current and potential future land uses at the Site,
seven populations were evaluated in the risk assessment:
Residents who currently obtain water from private wells;
• Residents who currently-obtain water from public supply
wells;
Hypothetical future residents of GWCC;
Current members and recreational users of GWCC;
Current workers of GWCC;
• Current workers at Valley Forge Corporate Center ("VFCC");
and
• Future workers at VFCC.
These are the populations that are the most probable current
and future receptors of contamination from the Site, and
represent the populations with maximum potential for exposure to
Site-related contaminants. Chemicals of potential concern in the
groundwater using the exposure scenarios identified above are
listed in Tables 7 through 12.
Use of an exposure scenario based on future residential use
is consistent with EPA policy described in "EPA Risk Assessment
Guidance for Superfund" (December 1989). This policy requires
consideration of hypothetical residential use. In addition, the
National Contingency Plan ("HCP"), 40 C.F.R. Part 300, requires
that groundwater which is suitable for use as a water supply be
protected and restored to its beneficial use.
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ORIGINAL
(Red)
11
Potential exposure routes considered for the purpose of
evaluating CSG Site risks included: ingestion of contaminated
groundwater, inhalation of volatiles from tap water, dermal
absorption, and inhalation of volatiles in outdoor air due to the
existing air stripping emissions. The potential exposure routes
chosen for each of the exposed populations are listed in Table
13.
The next step in the exposure assessment process involved
the quantification of the magnitude, frequency, and duration of
exposure for the populations and exposure routes selected for
evaluation.
The contaminant intake equations and intake parameters were
derived from standard literature sources and data from EPA
guidance documents. The exposure assumptions used to calculate
chemical intakes were selected based on the reasonable maximum
exposure ("RME") which is defined as the highest exposure that is
reasonably expected to occur at a Site.
The Risk Assessment compiled a list of contaminants of
concern from the results of the various sampling activities at
the Site. These contaminants of concern were selected based on
concentrations at the Site, toxicity, physical/chemical
properties that affect transport/movement in air and groundwater,
and prevalence/persistence in these media. These contaminants of
concern were used in the Risk Assessment to evaluate potential
health risks at the Site.
The contaminants of potential concern in the groundwater
that were evaluated in the Risk Assessment were VOCs. These
chemicals are listed below with their respective maximum
contaminant level (MCL) or in the absence of an MCL, a health-
based calculation. The contaminants of potential concern were
selected for evaluation at a receptor location if they were
detected in the groundwater of a well or cluster of wells to
which a receptor might potentially be exposed. If a chemical was
detected in a grouping of wells to which there might be exposure,
the chemical was evaluated for potential risk.
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ORIGINAL
i2(Red)
MCL in parts per billion
(ppbl
Bromodichloromethane 100
Chloroform 100
1,2 Dichlorobenzene 75
1,4 Dichlorobenzene 600
1,1 Dichloroethane 810*
1,1 Oichloroethene 7
1,2 Dichloroethene 70
Tetrachloroethene 5
1,1,1 Trichloroethane 200
Trichloroethene 5
Vinyl Chloride 2
*Non-carcinogenic health-based concentration.
B. Toxicity Assessment and Risk Characterization
Projected intakes for each risk scenario and each
contaminant were compared to acceptable intake levels for
carcinogenic and noncarcinogenic effects. With respect to
projected intake levels for noncarcinogenic compounds, a
comparison was made to reference doses ("RfDs"). RfDs have been
developed by EPA for chronic (lifetime) and/or subchronic (less
than lifetime) exposures to chemicals. RfDs define intake levels
that are unlikely to cause appreciable risk of deleterious
effects. The chronic RfD for a chemical is an estimate of a
lifetime daily exposure level for the human population, including
sensitive subpopulations, that is likely to be without an
appreciable risk of deleterious effects. The potential for non-
cancer health effects is evaluated by comparing an exposure level
over a specified time period with the RfD derived by EPA for a
similar exposure period. The ratio of exposure to toxicity is
called the hazard quotient. Chronic and Subchronic RfDs for
noncarcinogenic health effects are listed in Tables 14 and 15,
respectively.
The non-cancer hazard quotient assumes that there is a
threshold level ff exposure below which it is unlikely for even
the most sensitive populations to experience adverse health
effects. If the exposure level exceeds that threshold (the
hazard quotient exceeds a value greater than 1.0) there may be
concern for potential non-cancer effects. If the hazard quotient
does not exceed one, there is not a concern for a non-
carcinogenic public health threat. The greater the value of the
hazard quotient, the greater the level of concern for potential
adverse health impacts.
To assess the overall potential for non-cancer effects posed
by multiple chemicals, a hazard index ("HI") is derived by adding
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13
the individual hazard quotients for each chemical of concern.
This approach assumes additivity of critical effects of multiple
chemicals. EPA considers any HI exceeding one to be an
unacceptable risk to human health.
For carcinogens, risks are estimated as the incremental
probability of an individual developing cancer over a lifetime as
a result of exposure to a potential human carcinogen. The
toxicity values that are used in the evaluation of carcinogenic
risk are cancer slope factors ("CSFs") that have been developed
by EPA. A CSF generally is derived from animal studies of
chemical toxicity. The high doses administered to laboratory
animals are extrapolated to the low doses generally received by
humans in a linear relationship.
The value used in reporting the CSF is the upper 95 percent
confidence limit value on the probability of response per unit
intake of a contaminant over a lifetime (70 years). The CSF is
multiplied by the predicted intake to result in a unitless
expression of an individual's likelihood of developing cancer as
a result of the defined exposure. An incremental cancer risk of
1 x E-6 (also abbreviated as 1 x 10*6) indicates that the exposed
receptor has an additional risk of one in one million of
developing cancer. Again, the risks associated with multiple
chemicals should be added together. The carcinogenic chemicals
addressed in this evaluation and their EPA and International
Agency for Research on Cancer ("IARC") carcinogenicity
classifications are presented in Table 16. An explanation of the
EPA and IARC carcinogenicity classification systems is presented
in Table 17. The cancer slopes for the carcinogenic contaminants
detected at the CSG Site are listed in Table 18.
The hazard quotients and indices for the residential
scenarios are presented in Tables 19 through 24. The hazard
quotients and indices for the GWCC member are present in Tables
25 and 26. Hazard quotients and indices for the worker scenarios
are presented in Tables 27 through 29.
The lifetime carcinogenic risk and risk distributions by
chemical and pathway for each exposure scenario are.presented in
Tables 30 through* 43.. The risks and distributions for the
residential scenarios are presented in Tables 30 through 35. The
carcinogenic risks and risk distributions for the GWCC member are
presented in Tables 36 and 37. The carcinogenic risks and
distributions for the worker scenarios are presented in Tables 38
through 43.
Table 44 summarizes the total risks from all exposure
pathways to contaminants in the groundwater at the CSG Site.
The total lifetime carcinogenic risk for the private
residential well scenario is 2.0E-05, with groundwater ingestion
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ORIGINAL
(Red)
14
representing the highest risk pathway (61%) and 1,1-DCE the
highest risk chemical. The risk from inhalation of outdoor air
is 4.5E-09 and accounts for .02 % of the total risk. The hazard
indices were less than 1.0, which represents an acceptable risk
level.
The risk from exposure to untreated public water (public
residential well scenario) is 4.0E-05 with 55% of the total risk
attributed to ingestion of groundwater, and 1,1-DCE
representing 61% of the total risk. The risk associated with the
inhalation of outdoor air is 8.1E-09. The hazard index for the
adult receptor was less than 1.0 which represents an acceptable
risk level. For the child receptor, the hazard index was 1.2,
which represents an unacceptable risk.
The lifetime carcinogenic risk for the hypothetical GWCC
future resident is 1.4E-04. As with the other residential
scenarios, ingestion of groundwater and exposure to 1,1-DCE
represents the majority of the risk. The risk associated with
inhalation of outdooor air is 8.7E-07 and is 0.64% of the total
risk. The hazard indices were 1.0 or less which represent an
acceptable risk level.
The carcinogenic risk posed to the GWCC member is 9.9E-07.
Exposure to chloroform through inhalation while showering
represents 86% of the total risk. The risk from inhalation of
outdoor air is the lowest risk pathway (7.8E-10) and accounts for
0.08% of the total risk. The hazard index was less than 1.0
which represents an acceptable risk level.
The total risk for the GWCC worker is 1.5E-07. Ingestion of
water represents 97% of the total risk. Exposure to
bromodichloromethene accounts for 47% of the total risk.
The hazard index was less than 1.0 which represents an acceptable
risk level.
The carcinogenic risks posed to the current and future VFCC
workers are l.OE-05 and 4.9E-05, respectively. Groundwater
ingestion accounts for 99% of the risk in the current worker
scenario and 64% of the risk to the future worker. Inhalation of
outdoor air poses, little risk to the VFCC current worker (1.3E-O8
and VFCC future worker (6.5E-07). The hazard indices were less
than 1.0 which represent an acceptable risk level.
C. ENVIRONMENTAL RISKS
No known threatened or endangered plant or animal species
have been identified in the immediate vicinity of the Site. The
wildlife that is found is very limited because of the human
population and human culture alterations in the Site vicinity.
Under current conditions, the compounds detected in surface water
(due to discharge from the shallow aquifer) are below the
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15
threshold level for chronic or acute effects to aquatic
organisms. Additionally, no risks are anticipated for
terrestrial vertebrates that may come into contact with Lamb Run.
D. UNCERTAINTY ANALYSIS
Throughout the risk assessment process, uncertainties
associated with evaluation of chemical toxicity and potential
exposures arise. For example, uncertainties arise in derivation
of toxicity values for reference doses (RfDs) and carcinogenic
slope factors (CSFs), estimation of exposure point
concentrations, fate and transport modeling, exposure
assumptions, and ecological toxicity data.
Risks from exposure to vinyl chloride, a breakdown product
of TCE, were evaluated in the uncertainty analysis because vinyl
chloride has not been detected in any wells to which there is
current exposure but may be found at detectable concentrations in
the future. Risks from vinyl chloride were evaluated using a
concentration of one-half the required detection limit (1 ppb) in
the following two future use scenarios: Future GWCC Residential
Well and Future VFCC Worker. The risk would be 1.7E-04 and
5.6-05, respectively.
E. CONCLUSION ^'
Actual or threatened releases of hazardous substances from
the CSG Site, if not addressed.by implementing the response
action selected in this ROD, may present an imminent and
substantial endangerment to public health, welfare, and the
environment.
VII. DESCRIPTION OF ALTERATIVES
A feasibility study was conducted to identify and evaluate
remedial alternatives for remediation of contaminated groundwater
at the CSG Site. Applicable remediation technologies were
initially screened in the feasibility study based on
effectiveness, implementability, and cost. The alternatives
meeting these criteria were then evaluated and compared to nine
criteria required by the National Contingency Plan ("NCPH). The
NCP requires that a "no action" or "no further action"
alternative be evaluated as a point of comparison for other
alternatives.
The alternatives evaluated and their present worth costs are
described, below. It should be noted that all costs and time
frames discussed below are estimates. This information will be
further refined during the remedial design. The alternatives
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16
describe final remedial actions for groundvater remediation. The
RI/FS Reports dated February 1992 and July 1992 discuss the
alternatives evaluated for the Site and provide supporting
information leading to the alternative selection by EPA.
ALTERNATIVE 1; No Action
This alternative involves taking no action at the Site to
remove, remediate, or contain the contaminated groundwater.
Maintenance of the existing whole-house carbon filtration systems
on the 23 residential wells would be discontinued and no
monitoring of residential wells would be required. The following
groundwater monitoring wells on the CSG property would be sampled
semi-annually: MOS-15, MOS-14, MOS-13, MOS-11, and the three well
cluster at MW-20.
Because this alternative would result in contaminated
groundwater remaining on the Site, 5-year site reviews pursuant
to Section 121(c) of CERCLA would be required to monitor the
effectiveness of this alternative. There are no capital costs
for this alternative. This alternative could be implemented
immediately.
Compliance with ARARs
Since Alternative 1 does not include groundwater remediation
as a component of the remedy, this Alternative would not meet the
chemical-specific ARARs relating to groundwater remediation and
treatment.
Additionally, Alternative 1 would not comply with the
requirements of the Pennsylvania Hazardous Waste Management
Regulations, 25 Pa. Code §§264.90-264.100 and in particular, 25
Pa. Code §§ 264.97(i) (j) and 264.100(a)(9), which require
contaminated groundwater to be remediated to background levels.
With respect to location-specific ARARs, Alternative 1 would
not comply with EPA's Ground Water Protection Strategy policy for
a Class IIA aquifer*, which is a to be considered ("TBC")
standard.
Capital Costs - $00.00
0 & M Cost/Year - $26,600
30 Year Present Worth - $299,800
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17
ALTERNATIVE 2: Installation of Private Water Lines and
Connection to the P"**lie Water Supply System and Institutional
Controls
The general components of this alternative are:
• Connecting affected and potentially affected parties into an
extension of the public water supply system;
• Continuing maintenance of carbon filtration systems at
residences previously supplied with systems;
• Abandoning of the existing residential wells when parties
are connected to the public water supply system;
• Creating a. groundwater management zone with restrictions on
installation of new wells in areas of contamination which
exceed MCLs; and
• Conducting quarterly groundwater monitoring.
The intent of this alternative is to prevent any
unacceptable present and future risk associated with exposure to
contaminated groundwater. Residences south of the CSG Site on
Rittenhouse Road and on Audubon Road between Rittenhouse Road and
Thrush Lane would be connected to the public water supply system.
Table 46 lists the affected and potentially affected residences.
The existing whole-house carbon filtration systems that have
previously been installed in residences would be maintained until
connection to the public system is complete. One additional
system would be installed in a residence located at 2705 Audubon
Road. Maintenance of whole-house carbon filtration systems would
also continue for the residences southeast of the Site which are
identified as Group 2 in the Feasibility Study.
At the conclusion of the remedy construction or at the
Site's first 5-year review, whichever takes place first, this
residential area would be re-evaluated to determine whether the
maintenance of carbon filters should be continued.
Under Alternative 2, when the affected and potentially
affected residences are connected into the public water supply
system, the residential wells would be abandoned unless the
residential well is selected as a sampling location for long-term
groundwater monitoring.
This alternative includes development of a groundwater
management zone that encompasses the area of the Site in which
the groundwater is contaminated at levels which exceed MCLs, and
a surrounding buffer zone. Restrictions on well installations
within the contaminated groundwater management zone would be
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(P,or1\
18 '
implemented as institutional controls. The estimated
implementation time for installation of additional water lines in
the community near the Site is two years.
Because this alternative would result in contaminated
groundwater remaining on the Site, 5-year site reviews pursuant
to Section 121 (c) of CERCLA. would be required to monitor the
effectiveness of this alternative.
Capital Costs - $125,500
0 & M Cost/Year (Years 1-2) - $242,600
O & M Cost/Year (Years 3-30) - $211,800
30 Year Present Worth - $2,564,800
Compliance With ARARs;
Under Alternative 2, the spent whole-house carbon filters
would be considered a RCRA hazardous waste if the toxic
characteristic leaching procedure ("TCLP") analysis performed on
the filters resulted in a VOC concentration greater than 0.5
parts per million ("ppm"). Pennsylvania's Hazardous Waste
Management Regulations, 25 Pa. Code Parts 262, 263, and 264 would
apply to the disposal of this hazardous waste.
ALTERNATIVE 31 Daep Groundvatar Extraction nn* TfTfl'frff^Tl't IMlfl
Discharge. nTd installation of Private Water Lines
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19
added to the existing onsite air stripper which currently treats
contaminated water from the french drain system located on the
CSG property. The contaminated groundwater from well RW-i, a
deep recovery well, and the contaminated groundwater from the
french drain would then be treated by this air stripper.
Groundwater from the deep recovery wells proposed to be located
in close proximity to Aud-3 and Aud-5 would be treated by an air
stripper with vapor phase carbon. The groundwater extracted from
the well proposed to be close in proximity to VFCC-2 would be
treated by a separate air stripper with vapor phase carbon.
Under Option B, the existing onsite air stripper would
continue to be used for treatment of groundwater from the french
drain and an aqueous phase carbon treatment system would be used
to treat contaminated groundwater recovered from the deep
recovery well, RW-l. Groundwater from the deep wells installed
off the CSG property (those wells proposed to be in close
proximity to Aud-3, Aud-5, and VFCC-2) would be treated as
described in Option A above.
Because this alternative would result in contaminated
groundwater remaining on the Site, 5-year site reviews pursuant
to Section 121(c) of CERCLA would be required to monitor the
effectiveness of this alternative.
For costing purposes the remediation time for this
alternative was based on 30 years (the maximum period of
performance used by EPA for costing purposes). It is anticipated,
however, that this alternative-would take more than 30 years.
Implementation time considers the time required to design
and construct the alternative. Implementation time for this
alternative is estimated to be between two and five years.
Option A Costs;
Capital Costs - $732,730
O & M/Year (Years 1-2) - $288,900
O & M/Year (Years 3-30) - $246,700
30 Year Present Worth - $3,585,300
Option B Costs: ~ ^
Capital Costs - $985,730
O & M/Year (Years 1-2) - $326,600
0 & M/Year (Years 3-30) - $282,500
30 Year Present Worth - $4,244,700
Alternatively, the Audubon Water Company water supply wells
Aud-3, Aud-5, and VFCC-2 may be utilized for groundwater
extraction. Water extracted from these wells would continue to
be treated by their existing air strippers. Vapor phase carbon
units would be installed on these existing air strippers to
control air emissions. If the Audubon Water Company supply wells
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20
and their existing air strippers can be used for remediation as
described above, then the cost for implementing Alternative 3,
Option A or Option B, is estimated as follows:
Option A Costs;
Capital Costs - $420,000
O & M/Year (Years 1-2) - $288,900
O & M/Year (Years 3-30) - $246,700
30 Year Present Worth - $3,272,500
Option B Costs;
Capital Costs - $673,000
O & M/Year (Years 1-2) - $326,600
O & M/Year (Years 3 -30) - $285,200
30 Year Present Worth - $3,932,000
Compliance with ARARs;
Under this alternative, the spent whole-house carbon filters
would be considered a RCRA hazardous waste if the toxic
characteristic leaching procedure ("TCLP") analysis performed on
the filters resulted in a VOC concentration greater than 0.5
parts per million ("ppm"). Pennsylvania's Hazardous Waste
Management Regulations, 25 Pa. Code Parts 262, 263, and 264 would
apply to the disposal of this hazardous waste.
This alternative would comply with the levels for the
contaminants of concern identified in Table 45. Also, this
alternative would meet the risk-based action levels as referenced
in the NCP as acceptable groundwater cleanup criteria.
Additionally the Pennsylvania Safe Drinking Water Act (25 Pa.
Code Chapter 109) lists secondary maximum contaminant levels as
applicable requirements for public drinking water supplies.
These requirement would be relevant and appropriate for any
water provided to the Audubon Water Company.
This alternative would not comply with the Pennsylvania
Hazardous Waste Management Regulations, 25 Pa. Code §§264.90-
264.100 and in particular, 25 Pa. Code §§ 264.97(1)(j) and
264.100(a)(9), which require that contaminated groundwater be
remediated to background levels since the contaminated shallow
aquifer is not actively remediated under Alternative 3. With
respect to location-specific ARARs, this alternative would not
comply with the EPA's Ground Water Protection Strategy Policy for
a Class IIA aquifer, which is a "To Be Considered" ("TBC")
standard, since contaminated groundwater from the shallow aquifer
will be allowed to migrate vertically to the deep bedrock aquifer
which is the drinking water aquifer.
This alternative would comply with fugitive emissions
control requirements established under the Clean Air Act, 42
U.S.C. §§7401 to 767lq, the Pennsylvania Air Quality Regulations,
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21
25 Pa. Code Chapter 127, and EPA OSWER Directive 9355.0-28
regarding control of air emissions from Superfund air strippers
at Superfund groundvater sites.
Pumping of groundwater and discharge of treated water would
be in compliance with the requirements of the Delaware River
Basin Commission (18 C.F.R. Part 430).
Any treated water discharged through a "point source" to
"waters of the United States" would comply with the Clean Water
Act, 33 U.S.C. §§1251 et sea. . the National Pollutant Discharge
Elimination System ("NPDES") regulations promulgated thereunder
at 40 C.F.R. Parts 122-124, including any state and federal
regulations promulgated pursuant to Section 402 (p) of the Clean
Water Act, 33 U.S.C. §1342 (p) ("Municipal and Industrial
Stormwater Discharges") , the Pennsylvania NPDES regulations (25
Pa. Code §92.31), and the Pennsylvania Water Quality Standards
(25 Pa. Code §§93.1-93.9).
All hazardous wastes generated during implementation of this
alternative would be handled, transported, treated, and disposed
of in compliance with 25 Pa. Code Chapter 262 Subparts A
(relating to hazardous waste determination and identification
numbers) , B (relating to manifesting requirements for off-site
shipments of spent carbon or other hazardous wastes) , and C
(relating to pretransport requirements; 25 Pa. Code Chapter 263
(relating to transporters of hazardous wastes) ; and with respect
to the operations at the Site generally, with the substantive
requirements of 25 Pa. Code Chapter 264 Subparts B-D, I (in the
event that hazardous waste generated as part of the remedy is
managed in containers), 25 Pa. Code Chapter 264 Subpart J (in the
event that hazardous waste is managed, treated or stored in
tanks). 40 C.F.R. Part 264, Subpart AA (relating to air
emissions from process vents) and 40 C.F.R. Part 268, Subpart C,
Section 268.30 and Subpart E (regarding prohibitions on land
disposal and prohibitions on storage of hazardous waste) . 40
C.F.R. Part 264, Subpart AA (relating to air emission standards
for process vents) ; 49 C.F.R. Parts 107 and 171-179 (relating to
the transportation of hazardous wastes off -site.
This alternative would comply with EPA OSWER Directive
9834.11 and CERCLA §121 (d) (3) which prohibit the disposal of
Superfund Site waste at a facility not in compliance with §3004
and §3005 of RCRA and all applicable State requirements.
ALTERNATIVE 4: shallow aad D<
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22
additional components of Alternative 4 include extracting both
shallow and deep groundwater, and treating the water using air
stripping and carbon adsorption.
Treated water from extraction may be provided to the Audubon
Water Company for use in the public water supply system or may be
utilized by the CSG facility in its operations or discharged to
the Publicly Owned Treatment Works ("POTW"). The conceptual
design developed for the approximate location of the shallow and
deep bedrock extraction wells is illustrated in Figure 7.
The primary objective of the shallow and deep groundwater
recovery on the CSG property is to provide a hydraulic control
that would minimize migration of VOCs and recover groundwater
near the source areas. The supplemental shallow groundwater
wells would recover the higher concentration VOCs before they
migrated down to the deep aquifer. By extracting from both
shallow and deep groundwater on the CSG property, the overall
volume of water extracted over the life of remediation should be
reduced as well as the overall time required for groundwater
remediation. Groundwater monitoring and 5-year site reviews
would be provided to measure the effectiveness, of the cleanup.
Under Option A, recovered water from the deep groundwater
well, RW-1, the french drain and shallow wells: MOS-11, MOS-14,
and MOS-15, would be treated by the air stripper which currently
treats groundwater from the french drain system. Vapor phase
carbon control would be added to this stripper. Groundwater from
the deep recovery wells RW-3 and RW-5 proposed to be located in
close proximity to Aud-3 and Aud-5 would be treated by an air
stripper with vapor phase carbon. The groundwater extracted from
well KW-4, proposed to be in close proximity to VFCC-2, would be
treated in a separate air stripper with vapor phase carbon.
Under Option B, an aqueous phase carbon treatment system
would be used to treat contaminated groundwater recovered from
RW-l, the french drain, MOS-11, MOS-14, MOS-15. Groundwater from
the deep wells RW-3, RW-5 and RW-4, the deep bedrock wells
proposed to be located in close proximity to Aud-3, Aud-5, and
VFCC-2, respectively would be treated as described in Option A
above.
* -—
Because this alternative would result in contaminated
groundwater remaining on the Site, 5-year site reviews pursuant
to Section 121(c) of CERCLA would be required to monitor the
effectiveness of this alternative.
For costing purposes the remediation time for this
alternative was based on 30 years (the maximum period of
performance used by EPA for costing purposes). It is
anticipated, however, that this alternative would take more than
3O years.
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Implementation time considers the time required to design
and construct the alternative. Implementation time for this
alternative is estimated between two and five years.
Option A Costs:
Capital Costs - $810,930
O & M/Year (Years 1-2) - $300,300
O & M/Year (Years 3-30) - $258,000
30 Year Present Worth - $3,790,900
Option B Costs:
Capital Costs - $1,071,230
O & M/Year (Years 1-2) - $356,100
0 & M/Year (Years 3-30) - $313,900
30 Year Present Worth - $4,680,300
Alternatively, the Audubon Water Company water supply wells
Aud-3, Aud-5, and VFCC-2 may be utilized for groundwater
extraction. Water extracted from these wells would continue to
be treated by their existing air strippers. Vapor phase carbon
units would be installed on these existing air strippers to
control air emissions. If the Audubon Water Company water supply
wells and air strippers can be used to implement the remedy, the
costs for implementing Alternative 4, Option A or Option B, is
estimated as follows.
Option A Costs;
Capital Costs - $498,200
0 & M/Year (1-2 years) - $300,300
O & M/Year (3-30 years) - $258,000
30 Year Present Worth - $3,478,200
Option B Costs:
Capital Costs - $758,500
0 & M/Year (1-2 years) - $356,100
0 & M/Year (3-30 years) - $313,900
30 Year Present Worth - $4,367,600
Compliance with ARARS;
Under this alternative, the spent whole-house carbon filters
would be considered a RCRA hazardous waste if the toxic
characteristic leaching procedure ("TCLP") analysis performed on
the filters resulted in a VOC concentration greater than 0.5
parts per million ("ppm"). Pennsylvania's Hazardous Waste
Management Regulations, 25 Pa. Code Parts 262, 263, and 264 would
apply to the disposal of this hazardous waste.
This alternative is designed to meet MCLs established under
the SDWA for the contaminants of concern identified in Table 45.
Also, this alternative would meet the risk-based action levels as
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•" -rdj
24
referenced in the NCP as acceptable groundwater cleanup criteria.
Additionally the Pennsylvania Safe Drinking Water Act (25 Pa.
Code Chapter 109) lists secondary maximum contaminant levels as
applicable requirements for public drinking water supplies.
These requirements would be relevant and appropriate for any
water provided to the Audubon Water Company.
This alternative would comply with the Pennsylvania's
Hazardous Waste Management Regulations, 25 Pa. Code §§264.90-
264.100 and in particular, 25 Pa. Code §§264.97(i)(j) and
264.100(a)(9) which require that contaminated groundwater be
remediated to background levels. With respect to location-
specific ARARs, this alternative would comply with the EPA's
Ground Water Protection Strategy Policy for a Class IIA aquifer,
which is a "To Be Considered" ("TBC") standard.
This alternative would comply with the Pennsylvania's
Hazardous Waste Management Regulations, 25 Pa. Code Chapter 264,
Subchapter F regarding groundwater monitoring requirements.
This alternative would comply with fugitive emissions
control requirements according to the federal Clean Air Act, RCRA
(40 C.F.R. Part 264, Subpart AA),the Pennsylvania Air Quality
Regulations, 25 Pa. Code Chapter 127, and EPA's OSWER Directive
9355.0-28 regarding the control of air emissions from Superfund
air strippers at Superfund groundwater sites.
Pumping of groundwater and discharging of treated water
would be in compliance with the requirements of the Delaware
River Basin Commission (18 C.F.R. Part 430).
Any treated water discharged through a "point source" to
"waters of the United States" would comply with the Clean Water
Act, 33 U.S.C. §§1251 e£ sea., the National Pollutant Discharge
Elimination System ("NPDES") regulations promulgated thereunder
at 40 C.F.R. Parts 122-124, including any state and federal
regulations promulgated pursuant to Section 402(p) of the Clean
Water Act, 33 U.S.C. §1342(p) ("Municipal and Industrial
Stormwater Discharges"), the Pennsylvania NPDES regulations (25
Pa. Code §92.31, and the Pennsylvania Water Quality Standards (25
Pa. Code §§93.1-93.9).
All hazardous wastes generated during implementation of this
alternative would be handled, transported, treated, and disposed
of in compliance with 25 Pa. Code Chapter 262 Subparts A
(relating to hazardous waste determination and identification
numbers), B (relating to manifesting requirements for off-site
shipments of spent carbon or other hazardous wastes), and C
(relating to pretransport requirements; 25 Pa. Code Chapter 263
(relating to transporters of hazardous wastes); and with respect
to the operations at the Site generally, with the substantive
requirements of 25 Pa. Code Chapter 264 Subparts B-D, I (in the
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25
event that hazardous waste generated as part of the remedy is
managed in containers), 25 Pa. Code Chapter 264 Subpart J (in the
event that hazardous waste is managed, treated or stored in
tanks). 40 C.F.R. Part 264, Subpart AA (relating to air
emissions from process vents) and 40 C.F.R. Part 268, Subpart C,
Section 268.30 and Subpart E (regarding prohibitions on land
disposal and prohibitions on storage of hazardous waste). 40
C.F.R. Part 264, Subpart AA (relating to air emission standards
for process vents); 49 C.F.R. Parts 107 and 171-179 (relating to
the transportation of hazardous wastes off-site.
This alternative would comply with the EPA OSWER Directive
9834.11 and CERCLA §121(d)(3) which prohibit the disposal of
Superfund Site waste at a facility not in compliance with §3004
and §3005 of RCRA and all applicable State requirements.
Treatment,
Connection to Public Water Supply System
This alternative fully incorporates all of the components of
Alternative 2 to provide public health protection. The additional
components of Alternative 5 include extracting both shallow and
deep groundwater, and treating the water using air stripping and
carbon adsorption.
Treated water from extraction may be provided to the Audubon
Water Company for use in the public water supply system or may be
utilized by the CSG facility in its operations or discharged to
the Publicly Owned Treatment Works ("POTW"). The conceptual
design developed for the approximate location of the shallow and
deep bedrock wells is illustrated in Figure 8.
This alternative is similar to Alternative 4 except that
deep groundwater recovery is modified such that off-property
pumping maximizes capture within the Site plume by changing the
location of one of the off-property pumping wells. Instead of
utilizing the deep well proposed to be located in close proximity
to VFCC-2 as in Alternatives 3 and 4, a new recovery well, RW-2,
would be utilized to more effectively recover the contaminated
plume. It is assumed that RW-2 would pump at the same rate that
VFCC-2 currently pumps. This pumping scenario is expected to
recover the highest rate of VOCs while maximizing the use of the
local water resources. Groundwater monitoring and 5-year site
reviews would be required to measure the effectiveness of the
cleanup.
Under Option A, recovered water from the deep groundwater
well, RW-1, the french drain, and wells MOS-11, MOS-14, and MOS-
15, would be treated by the existing french drain air stripper.
Vapor phase carbon control would be added to this stripper.
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26
Groundwater from the deep recovery wells RW-3 and RW-5 proposed
to be located in close proximity to Aud-3 and Aud-5 would be
treated by an air stripper with vapor phase carbon. The
groundwater extracted from the deep bedrock well, RW-2, would be
treated in a separate air stripper with vapor phase carbon.
Under Option B, an aqueous phase carbon treatment system
would be used to treat contaminated groundwater recovered from
RW-l, the french drain, MOS-11, MOS-14, and MOS-15. Groundwater
from the deep wells RW-3 and RW-5 (the deep bedrock wells
proposed to be located in close proximity to Aud-3 and Aud-5) ,
and RW-2 would be treated as described in Option A above.
Because this alternative would result in contaminated
groundwater remaining on the Site, 5-year site reviews pursuant
to Section 121(c) of CERCLA would be required to monitor the
effectiveness of this alternative.
For costing purposes the remediation time for this
alternative was based on 30 years (the maximum period of
performance used by EPA for costing purposes) . It is anticipated
that this alternative would take 25 years.
Implementation time considers the time required to design
and construct the alternative. Implementation time for this
alternative is estimated between two and five years.
Option A Costs;
Capital Costs - $946,910
O & M/Year (Years 1-2) - $446,500
O & M/Year (Years 3-30) - $404,300
30 Year Present Worth - $5,573,700
B Costs i
Capital Costs - $1,203,910
O & M/Year (Years 1-2) - $521,500
O & M/Year (Years 3-30) - $477,400
30 Year Present Worth - $6,657,000
Alternatively, the Audubon Water Company water supply wells
Aud-3, Aud-5 may ..be utilized for groundwater extraction. Water
extracted from these wells would continue to be treated by their
existing air stripper. Additionally the existing stripper at
VFCC-2 may be utilized to treated groundwater extracted from well
RW-2. Vapor phase carbon units would be installed on these
existing air strippers to control air emissions. If the Audubon
Water Company water supply wells and air strippers can be used to
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27
implement the remedy, the cost for implementing Alternative 5,
Option A or Option B, is estimated as follows.
Option A Costs;
Capital Costs - $641,500
O & M (0-2 years) - $446,500
O & M (3-30 years) - $404,300
30 Year Present Worth - $5,268,300
Option B Costs;
Capital Costs - $899,400
O & M/Year (0-2 years) - $521,500
O & M/Year (3-30 years) - $477,400
30 Year Present Worth - $6,352,800
Compliance with ARARS;
Under this alternative, the spent whole-house carbon filters
would be considered a RCRA hazardous waste if the toxic
characteristic leaching procedure ("TCLP") analysis performed on
the filters resulted in a VOC concentration greater than 0.5
parts per million ("ppm"). Pennsylvania's Hazardous Waste
Management Regulations, 25 Pa. Code Parts 262, 263, and 264 would
apply to the disposal of this hazardous waste.
This alternative would comply with the Pennsylvania's
Hazardous Waste Management Regulations, 25 Pa. Code §§264.90-
264.100 and in particular, 25 Pa. Code §§264.97(i)(j) and
264.lOO(a)(9) which require that contaminated groundwater be
remediated to background levels. With respect to location-
specific ARARs, this alternative would comply with the EPA's
Ground Water Protection Strategy Policy for a Class II aquifer,
which is a "To Be Considered" ("TBC") standard.
This alternative would comply with the Pennsylvania's
Hazardous Waste Management Regulations, 25 Pa. Code §264,
Subchapter F regarding groundwater monitoring requirements.
This alternative is designed to meet the MCLs established
under the SDWA for the contaminants of concern. Also, this
alternative would meet the risk-based action levels as referenced
in the NCP as acceptable groundwater cleanup criteria.
Additionally the Pennsylvania Safe Drinking Water Act (25 Pa.
Code, Chapter 109) lists secondary maximum contaminant levels as
applicable requirements for public drinking water supplies.
These requirements would be relevant and appropriate for any
water provided to the Audubon Water Company.
This alternative would comply with fugitive emissions
control requirements according to the federal Clean Air Act, RCRA
(40 C.F.R. Part 264, Subpart AA), the Pennsylvania Air Quality
Regulations, (25 Pa. Code Chapter 127), and EPA's OSWER Directive
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9355.0-28 regarding the control of air emissions from Superfund
air strippers at Superfund groundvater sites.
Pumping of groundwater and discharging of treated water
would be in compliance with the requirements of the Delaware
River Basin Commission (18 C.F.R. Part 430).
Any discharge of treated effluent to the POTW would comply
with federal Clean Water Act pretreatment regulations and any
State/federal regulations promulgated thereunder. Any discharge
of treated effluent to the Audubon Water Company would meet SMCLs
established under the Pennsylvania Safe Drinking Water Act, 25
Pa. Code, Chapter 109.
Any treated water discharged through a "point source" to
"waters of the United States" would comply with the Clean Water
Act, 33 U.S.C. §§1251 et seq.. the National Pollutant Discharge
Elimination System ("NPDES") regulations promulgated pursuant
thereto at 40 C.F.R. Parts 122-124, including any state and
federal regulations promulgated pursuant to Section 402(p) of the
Clean Water Act, 33 U.S.C. §1342(p) (Municipal and Industrial
Stormwater Discharges"), the Pennsylvania NPDES regulations (25
Pa. Code §92.31), and the Pennsylvania Water Quality Standards
(25 Pa. Code §§93.1-93.9).
All hazardous wastes generated during implementation of this
alternative would be handled, transported, treated, and disposed
of in compliance with 25 Pa. Code Chapter 262 Subparts A
(relating to hazardous waste determination and identification
numbers), B (relating to manifesting requirements for off-site
shipments of spent carbon or other hazardous wastes), and C
(relating to pretransport requirements; 25 Pa. Code Chapter 263
(relating to transporters of hazardous wastes); and with respect
to the operations at the Site generally, with the substantive
requirements of 25 Pa. Code Chapter 264 Subparts B-D, I (in the
event that hazardous waste generated as part of the remedy is
managed in containers), 25 Pa. Code Chapter 264 Subpart J (in the
event that hazardous waste is managed, treated or stored in
tanks). 40 C.F.R. Part 264, Subpart AA (relating to air
emissions from process vents) and 40 C.F.R. Part 268, Subpart C,
Section 268.30 and Subpart E (regarding prohibitions on land
disposal and prohibitions on storage of hazardous waste). 40
C.F.R. Part 264, Subpart AA (relating to air emission standards
for process vents); 49 C.F.R. Parts 107 and 171-179 (relating to
the transportation of hazardous wastes off-site.
This alternative would comply with CERCLA §121(d)(3) which
prohibits the disposal of Superfund Site waste at a facility not
in compliance with §3004 and §3005 of RCRA and all applicable
State requirements.
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29
VIII. SUMMARY OF COMPARATIVE ANALYSIS OP ALTERNATIVES
Each of the remedial alternatives described above were
evaluated using nine criteria. The resulting strengths and
weaknesses of the alternatives were then weighed to identify the
alternative providing the best balance among the nine criteria.
These nine criteria are:
Threshold Criteria
- Overall protection of human health and the environment
- Compliance with applicable or relevant and appropriate
requirements ("ARARs")
Primary Balancing Criteria
- Reduction of toxicity, mobility or volume
- Implementability
- Short-term effectiveness
- Long-term effectiveness and permanence
- Cost
Modifying Criteria
- State acceptance
- Community acceptance
A. PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
A primary requirement of the Comprehensive Environmental
Response, Compensation and Liability Act ("CERCLA") is that the
selected remedial action be protective of human health and the
environment. A remedy is protective if it eliminates, reduces,
or controls current and potential risks posed through each
exposure pathway to acceptable levels through treatment,
engineering controls, or institutional controls.
Alternative 1, the no action alternative, does not include
treatment or controls, provides no reduction in risk, and is not
protective.
*»
Alternatives 27 3, 4, and 5 are protective of human health.
Risks posed by exposure to contaminated groundwater are addressed
by connecting affected and potentially affected parties to the
existing public water supply system and by the use of whole-house
carbon filter systems until the water lines are installed. Since
Alternative 2 does not provide for treatment of contaminated
groundwater or prevent migration of contaminants to currently
unaffected areas it is not as protective of human health as
Alternatives 3, 4 and 5.
Alternatives 3, 4, and 5 include extraction and treatment of
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contaminated groundwater. These alternatives would eventually
restore contaminated groundwater to background levels or MCLs,
whichever is more stringent. By providing connection to the
existing public water supply and continuing maintenance of
existing carbon filters, human health would be protected from
exposure to contaminated groundwater while the groundwater
aquifer is being restored. Public and environmental risks from
direct contact with, and ingestion of, contaminated groundwater
would be mitigated through treatment of the groundwater plume.
Alternatives 3, 4, and 5 would achieve a greater degree of
overall protection of human health and the environment than
Alternatives 1 and 2. Alternatives 4 and 5 would achieve an even
greater degree of overall protection of human health and the
environment than Alternative 3 because Alternatives 4 and 5
actively remediate the shallow aquifer while Alternative 3 does
not.
B. COMPLIANCE WITH ARARS
Section 121(d) of CERCLA requires that remedial actions at
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 substantive environmental
protection requirements, criteria, or limitations promulgated
under federal or State laws that specifically address hazardous
substances found at the site, the remedial action to be
implemented at the site, the location of the site, or other
circumstances present at the site.
Relevant and appropriate requirements are those substantive
environmental protection requirements, criteria, or limitations
promulgated under federal or State law which, while not
applicable to the hazardous materials found at the site, the
remedial action itself, the site location or other circumstances
at the site, nevertheless address problems or situations
sufficiently similar to those encountered at the site that their
use is well-suited to the site. ARARs may relate to the
substances addressed by the remedial action (chemical-specific),
to the location of the site (location-specific), or the manner in
which the remedial action is implemented (action-specific).
In addition to applicable or relevant and appropriate
requirements, the lead and support agencies may, as appropriate,
identify other advisories, criteria, or guidance to be considered
for a particular release. The "to be considered" ("TBC")
category consists of advisories, criteria, or guidance that were
developed by EPA, other federal agencies, or states that may be
useful in developing CERCLA remedies.
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Since Alternatives 1 and 2 do not include groundwater
remediation as a component of their respective remedies, neither
alternative would meet the chemical-specific ARARs relating to
groundwater remediation and treatment.
Additionally, Alternatives 1, 2, and 3 would not comply
with the requirements of the Pennsylvania Hazardous Waste
Management Regulations, 25 Pa. Code §§264.90*264.100 and in
particular, 25 Pa. Code §§264.97(i)(j) and 264.100(a)(9), which
require contaminated groundwater to be remediated to background
levels. Alternatives 1 and 2 do not involve any treatment of
contaminated groundwater, and Alternative 3 does not comply with
these regulations since the shallow aquifer would not be actively
remediated.
With respect to location-specific ARARs, Alternatives 1, 2,
and 3 would not comply with EPA'3 Ground Water Protection
Strategy Policy for a Class IIA aquifer, which is a TBC standard.
With respect to location-specific ARARs, Alternatives 4 and
5 would comply with the EPA's Ground Water Protection Strategy
Policy for a Class IIA aquifer, which is a TBC standard.
Alternatives 4 and 5 would protect current and potential sources
of drinking water and waters having other beneficial uses.
With respect1 to location-specific ARARs, Alternatives 3, 4,
and 5 would comply with the substantive requirements of the
Delaware River Basin Commission (18 C.F.R. Part 430).
Alternatives 4 and 5, which include groundwater remediation,
would meet the chemical-specific ARARs (as set forth in Section
XI of this ROD) relating to groundwater remediation and
treatment. Alternative 3 would only meet all chemical-specific
ARARS through natural attenuation of the contaminants because the
shallow aquifer would not be actively remediated.
Alternatives 3, 4, and 5 would meet all action-specific
ARARs relating to activities performed as part of the remedy,
including federal and State air emission requirements, federal
Pretreatment Standards for discharges to a POTW, and federal and
State treatment, j3torage, and disposal requirements for any
hazardous and solid-wastes generated during the groundwater
treatment process.
C. REDUCTION OF TOXICITY. MOBILITY. OR VOLUME
This evaluation criteria addresses the degree to which a
technology or remedial alternative reduces toxicity, mobility or
volume of hazardous substances.
Alternatives 1 and 2 are remedial actions that do not use
treatment technologies. Therefore, Alternatives 1 and 2 would
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not reduce the toxicity, mobility, or volume of contaminants in
the groundwater plume at the Site. Over time, contaminant levels
in the present areas of contamination may decrease gradually
through natural attenuation, but the groundwater plume itself may
increase in area.
Alternatives 3, 4, and 5 are the only alternatives which
involve treatment and which would result in active reduction of
VOCs in the contaminated aquifer. Alternative 3, however, would
not actively reduce the level of VOCs in the shallow aquifer. A
reduction of contaminants in the shallow aquifer, under
Alternative 3, would only occur through natural attenuation.
Alternatives 4 and 5 would remove contaminants from both the
shallow and the deep aquifers which would result in the reduction
of toxicity, mobility and volume of Site contaminants in
groundwater through treatment. Specifically, a combination of
air stripping and carbon adsorption would change the physical,
chemical and/or biological characteristics of the contaminants on
Site, thereby reducing the toxicity, mobility, and volume of
these contaminants.
D. IMPT/FMENTABILITY
Implementability refers to the technical and administrative
feasibility of a remedy, from design through construction,
operation, and maintenance. It also includes coordination of
federal, State, and local governments to clean up the Site. All
alternatives evaluated are considered implementable and use
technologies that have been recommended and used at other
Superfund sites. All alternatives require groundwater monitoring
and Alternatives 3, 4, and 5 require monitoring of treated
groundwater discharge.
Alternative 1 which includes groundwater monitoring solely
on the CSG property would be the easiest alternative to
implement.
Alternative 2 can also be implemented easily, but would
require the participation of the Audubon Water Company and State
and local governments for the construction of water lines within
existing road right-of-ways. The public water supply is
regulated under the--Safe Drinking Water Act. The Audubon Water
Company is in compliance with the Safe Drinking Water Act and
operates under a State permit.
Alternatives 3, 4, and 5 would require the participation of
the Audubon Water Company and State and local governments for the
construction of water lines within existing road right-of-ways.
Because Alternatives 3, 4, and 5 involve the extraction and
treatment of groundwater, there are more implementation and
operation considerations associated with these alternatives.
Alternatives 3, 4, and 5 present minimum technical difficulties
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33
in designing and constructing the treatment systems but may
require additional groundwater investigations during the design
stage.
The components of the air stripping and carbon adsorption
systems (Alternatives 3, 4, and 5) are readily implementable
using existing technologies. The reliability of these treatment
technologies has also been established and demonstrated
successfully at other hazardous waste sites. No special
materials or equipment would be required to implement
Alternatives 3, 4, or 5. Operation and maintenance
considerations include cleaning and replacement of wells and well
pumps; maintenance of blower units; cleaning of fouled packing;
and regeneration of the vapor phase carbon units (Option A) or
the liquid phase carbon units (Option B).
E. SHORT-TERM EFFECTIVENESS
Short-term effectiveness addresses the period of time needed
to achieve protection of human health and the environment and any
adverse impacts that may be posed during the construction and
operation period until remediation goals are achieved.
None of the alternatives evaluated involve extensive
construction, excavation, or other remedial action measures that
would pose any appreciable short-term risks to the community or
to workers during construction or implementation. Workers will
be required to wear appropriate levels of protection during
installation of extraction wells to avoid direct contact with
contaminated groundwater. During installation of the treatment
systems and other Site activities, precautions mandated by the
Occupational Safety and Health Act ("OSHA") for construction
activities will be taken. Disposal of any wastes generated
during construction and operation will follow proper handling
practices and therefore should not have an adverse environmental
impact.
EPA's Weil-Head Protection Areas ("WHPAs) Model was used to
estimate the time frame for aquifer remediation. The WHPA model
is a model which models an area through which contaminants are
reasonably likely- to move toward and reach water wells or
well fields. Based o*n the model, Alternative 5 should remediate
the aquifer in the shortest time frame because the groundwater
extracted using Alternative 5 should contain a greater
concentration of contaminants. However, a more accurate
evaluation of the response of the aquifer to pumping will be
undertaken during the remedial design stage.
F. LONG-TERM EFFECTIVENESS AND PERMANENCE
Long-term effectiveness and permanence refers to the ability
of a remedy to maintain reliable protection of human health and
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34
the environment over time. This evaluation criterium includes
the consideration of residual risk and the adequacy and
reliability of controls.
Since no actions would be taken to remediate the
contaminated groundwater under Alternative l, the health risks
remaining after implementation of this alternative would be very
similar to those posed by the present use of contaminated
groundwater. Implementing Alternative 1 would result in more
than minimal residual risk from groundwater ingestion, dermal
contact, and inhalation under the future use reasonable maximum
exposure scenario, since groundwater would not be treated or
contained and ARARS would not be attained.
Alternative 2 meets the objective of eliminating the public
health risk associated with use of contaminated groundwater, but
does not involve the actual treatment or remediation of
contaminated groundwater. Therefore, it would not maintain
reliable protection of the environment over time.
With respect to environmental risk, the contaminants in the
groundwater would continue to migrate over time under
Alternatives 1 and 2. Under Alternative 3, contaminants would
continue to migrate from the shallow aquifer to the deep aquifer.
Therefore Alternatives 1, 2 and 3 would not maintain reliable
protection of the environment over time.
Alternatives 4 and 5 would provide the greatest degree of
long-term effectiveness and permanence for groundwater protection
and remediation and would result in minimal residual risk by
attaining ARARs for groundwater.
G. COST
This criterion examines the estimated costs for each
remedial alternative. For comparison, capital, annual O&M, and
present worth costs are shown in Table 47.
H. STATE ACCEPTANCE
The Pennsyl-wania Department of Environmental Resources has
concurred on EPA's selected remedy, Alternative 5, Option A.
I. COMMUNITY ACCEPTANCE
A public meeting on the Proposed Plan was held on August 6,
1992 in Eagleville, Pennsylvania. Comments received orally at
the public meeting and in writing during the public comment
period are referenced in the Responsiveness Summary attached to
this Record of Decision. Residents who live in Lower Providence
Township have not objected to the selected remedy.
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35
IX. THE SELECTED REMEDYt DESCRIPTION AMD PERFORMANCE
STANDARD(8) FOR EACH COMPONENT OP THE REMEDY
A. GENERAL DESCRIPTION OF THE SELECTED REMEDY
EPA has selected Alternative 5, Option A, as the selected
remedy for the CSG Site. This remedy will restore the
groundvater in the area of attainment to background levels or
MCLs, whichever is lower, for the contaminants of concern and
protect the public from exposure to contaminated groundwater.
The area of attainment for the cleanup is the potential extent of
the contaminant plume as depicted in Figure 5. Based on current
information, this alternative provides the best balance among the
alternatives with respect to the nine criteria EPA uses to
evaluate each alternative. The selected remedy consists of the
following components:
Construction of public water supply lines and
connections to the residences south of the CSG facility
on Rittenhouse Road and on Audubon Road between
Rittenhouse Road and Thrush Lane.
Continued maintenance of the whole-house carbon filtration
systems previously supplied to residences along Audubon Road
near Trooper Road;
• Installation, operation and maintenance of groundwater
extraction wells to remove contaminated groundwater
from beneath the Site and to prevent contaminants from
migrating further;
Installation, operation, and maintenance of air strippers
at the groundwater extraction wells to treat groundwater to
the required levels;
Installation, operation, and maintenance of vapor phase
carbon units on air strippers;
Periodic sampling of groundwater and treated water to ensure
that treatment components are effective and that groundwater
remediation*is-progressing towards the cleanup goals; and
• Creation of a groundwater management zone with restrictions
on the installation of new wells in areas of contamination
which exceed MCLs.
Each component of the selected remedy and its performance
standard(s) is described in detail in Section C, below.
B. Stratecrv if the Selected Remedy is Not Achieved
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ORIGINAL
.'Red)
36
Based on the information obtained during the Rl, and the
analysis of the remedial alternatives, EPA and the Commonwealth
of Pennsylvania believe that it may be possible to achieve the
required groundwater cleanup levels. However, the ability to
achieve required cleanup levels at all points throughout the area
of attainment or plume of contamination cannot be determined
until the extraction system has been implemented, modified as
necessary, and plume response monitored over time.
If it is determined by EPA, in consultation with PADER, that
on the basis of the system performance data, that certain
portions of the aquifer cannot be restored to background levels,
or MCLs, whichever is lower, and/or if EPA determines that it is
technically impracticable to restore the aquifer, EPA may amend
the ROD or issue an Explanation of Significant Differences in
accordance with the NCP. In such event, the likely alternative
actions will attempt to remediate the groundwater to its
beneficial use that would be used as a drinking water source. If
the aquifer cannot be restored to its beneficial use, some or all
of the following measures involving long-term management could
occur, as determined by EPA in consultation with PADER/ for an
indefinite period of time, as a modification of the existing
system:
long term gradient control may be provided by low level
pumping, as a containment measure;
chemical-specific ARARs may be waived for those portions of
the aquifer for which EPA and PADER determine that it is
technically impracticable to achieve further contaminant
reduction;
institutional controls may be provided/maintained to restrict
access to those portions of the aquifer where contaminants remain
above Performancer*Standards;
remedial technologies for groundwater restoration may be
reevaluated; and
further sampling and/or monitoring of existing and/or new
wells may be ordered.
* —-
C. PERFORMANCE STANDARDS
l) Connection to the Public Water Supply
The extension of the Audubon Water Company water supply
lines shall be constructed in compliance with local and State
requirements. Connections shall be offered and provided to the
residences listed in Table 46 and any other residence determined
by EPA during the Remedial Design to be affected or potentially
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(Red)
37
affected by the plume of contamination. All areas impacted by
the construction activities during remedy implementation and
operation and maintenance shall be restored to preexisting
conditions. When the affected and potentially affected parties
are connected into the public water supply system, each
residential well shall be abandoned in accordance with all
applicable regulations unless the residential well is selected as
a sampling location for long-term groundwater monitoring.
2) Maintenance and Disposal of Existing Whole-House Carbon
Filtration Systems
Residences south of the Site on Rittenhouse Road and on
Audubon Road between Rittenhouse Road and Thrush Lane shall be
connected to the public water supply system. The existing whole-
house carbon filtration systems that have previously been
installed in residences to the south of the CSG property shall be
maintained in proper working order until connection to the public
system is complete. Such maintenance will ensure that
breakthrough of contaminants does not occur. The maintenance
shall include regular changing of carbon filters in accordance
with the work plan for the Remedial Design and/or at EPA's
request. One additional system shall be installed in a residence
located at 2705 Audubon Road. Maintenance of whole-house carbon
filtration systems shall also continue for the residences
southeast of the Site along Audubon Road near Trooper Road, which
are identified as Group 2 in the Feasibility Study.
At the conclusion of the remedy construction or at the Site's
first 5-year review, whichever takes place first, this
residential area shall be reevaluated by EPA and EPA will
determine whether the maintenance of whole-house carbon
filtration systems will be continued.
The management and ultimate disposition of these spent
carbon filters will be determined, subject to EPA approval,
during the remedial design. Such management may entail treatment
and/or disposal of the carbon filters. In the event these units
are a hazardous waste, the following ARARs will apply: 25 Pa.
Code Chapter 262, Subparts A (relating to hazardous waste
determination and. identification numbers), B (relating to
manifesting requirements for off-site shipments of spent carbon
or other hazardous wastes), and C (relating to pretransport
requirements; 25 Pa. Code Chapter 263 (relating to transporters
of hazardous wastes); and with respect to the operations at the
Site generally, with the substantive requirements of 25 Pa. Code
Chapter 264, Subparts B-D, I (in the event that hazardous waste
generated as part of the remedy is managed in containers), 25 Pa.
Code Chapter 264, Subpart J (in the event that hazardous waste is
managed, treated or stored in tanks). 40 C.F.R. Part 264,
Subpart AA (relating to air emissions from process vents) and 40
C.F.R. Part 268, Subpart C, Section 268.30 and Subpart E
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38
(regarding prohibitions on land disposal and prohibitions on
storage of hazardous waste). 40 C.F.R. Part 264, Subpart AA
(relating to air emission standards for process vents).
3) Groundwater Extraction and Treatment
The selected remedy includes groundwater extraction and
treatment which shall be required until such time as EPA in
consultation with FADER determine that the Performance Standard
(remediation to background levels as established by EPA during
the Remedial Design, or MCLs, whichever is lower) for each
contaminant of concern, as identified in Table 45, in the
groundwater has been achieved throughout the entire areal extent
of groundwater contamination. The details of the system are
described below:
a) Groundwater Extraction System
The groundwater shall be decontaminated through extraction
and treatment of the contaminated groundwater throughout the
entire plume of contamination. The extraction shall create
capture zones to capture contaminated groundwater throughout the
plume. Groundwater shall be extracted using multiple extraction
wells, the exact location, groundwater extraction flow rate, and
number of which shall be determined during the Remedial Design
and shall be approved by EPA in consultation with PADER.
b) Groundvatar Cleanup Levels
The well system for extracting groundwater shall be operated
until the Performance Standard for each contaminant of concern is
met and maintained throughout the entire plume of contamination
for a period of 12 consecutive quarters in accordance with
Subparagraph (e), infra. The Performance Standard for each
contaminant of concern in the groundwater shall be the MCL for
that contaminant (the federal ARAR for public drinking water
supplies under the Safe Drinking Water Act) or the background
concentration of that contaminant (the Pennsylvania ARAR under 25
Pa. Code §§264.90-264.100), whichever is lower. The background
concentration for each contaminant of concern shall be
established by EPA during the Remedial Design in accordance with
the procedures for g-roundwater monitoring outlined in 25 Pa. Code
§264.97. Establishment of background concentrations shall not
delay implementation of the remedy. In the event that a
contaminant of concern is not detected in samples taken for the
establishment of background concentrations, the method detection
limits of EPA-approved low level drinking water analytical
methods with respect to that contaminant of concern shall
constitute the background concentration of the contaminant.
c) Air stripper and vapor Phase carbon units
-------
39
The recovered groundwater shall be treated using packed
column air stripping units and, where required, vapor phase
carbon units. The Performance Standard for the air emissions
from the air stripping units shall be the requirements of the
RCRA regulations set forth at 40 C.F.R. Part 264, Subpart AA -
Air Emission Standards for Process Vents. The total organic
emissions from all affected process vents at the site are
required to be below 1.4 kg/hr and 2800 kg/yr under this
regulation. Any vinyl chloride air emissions from the
groundwater treatment units will comply with Section 112 of the
Clean Air Act, 42 U.S.C. §7412, National Emission Standard For
Hazardous Air Pollutants (NESHAPs). The relevant and appropriate
NESHAP for vinyl chloride is set forth at 40 C.F.R. Part 61,
Subpart F. The air emissions will also comply with the
Commonwealth of Pennsylvania regulations set forth at 25 Pa.
Code, Chapter 127, Subchapter A. Those regulations require that
emissions be reduced to the minimum obtainable levels through the
use of best available technology, as defined in 25 Pa. Code
§121.1.
The management and ultimate disposition of the spent carbon
from the vapor phase carbon units will be determined, subject to
EPA approval, during the remedial design. Such management may
entail treatment and/or disposal of the carbon filters. In the
event these units are a hazardous waste, the following ARARS will
apply as the Performance Standard: 25 Pa. Code Chapter 262
Subparts A (relating to hazardous waste determination and
identification numbers), B (relating to manifesting requirements
for off-site shipments of spent carbon or other hazardous
wastes), and C (relating to pretransport requirements; 25 Pa.
Code Chapter 263 (relating to transporters of hazardous wastes);
and with respect to the operations at the Site generally, with
the substantive requirements of 25 Pa. Code Chapter 264, Subparts
B-D, I (in the event that hazardous waste generated as part of
the remedy is managed in containers), 25 Pa. Code Chapter 264,
Subpart J (in the event that hazardous waste is managed, treated
or stored in tanks). 40 C.F.R. 268 Subpart C Section 268.30 and
Subpart E (regarding prohibitions on land disposal and
prohibitions on storage of hazardous waste). 40 C.F.R. Part 264,
Subpart AA (relating to air emission standards for process
vents).
4) Discharge of Treated Water
The Performance Standard for each contaminant of concern in
the effluent water from the air strippers, which may be supplied
to the Audubon Water Company Public Water System or may be used
by the CSG facility with overflow discharged to the POTW, shall
be the MCL for that contaminant as promulgated under the Safe
Drinking Water Act, 42 O.S.C. §§300f to 300J-26, and set forth at
40 C.F.R. §141.61(a). In the absence of an MCL, an EPA health-
-------
40
based concentration applies. The MCLs for the contaminants of
concern are listed in Table 45. The Pennsylvania Safe Drinking
Water Act (25 Pa. Code, Chapter 109) lists the secondary maximum
contaminant levels ("SMCLs") as applicable requirements for
public drinking water supplies. SMCLs are relevant and
appropriate for discharge of treated effluent to the Audubon
Water Company.
The appropriate analytical method for the contaminants of
concern is the "Superfund Analytical methods for Low
Concentration Water for Organics Analysis, (June 1991). The
exact point of discharge and receiver of treated water shall be
determined during the Remedial Design and shall be approved by
EPA in consultation with PADER. The discharging of water shall
comply with any applicable Clean Water Act and Commonwealth of
Pennsylvania ARARs.
e) Periodic Monitoring and System Shutdown
A long-term groundwater monitoring program shall be
implemented to evaluate the effectiveness of the groundwater
pumping and treatment system throughout the entire plume.
Numbers and locations of these monitoring wells shall be approved
by EPA during the remedial design, in consultation with the
PADER. The wells shall be sampled quarterly for the first three
years and semi-annually thereafter until the levels of
contaminants of concern in these wells have reached background
levels as established by EPA, in consultation with PADER during
the Remedial Design, or MCLs whichever is lower. Once these
required levels have been reached, the wells shall be sampled for
twelve consecutive quarters throughout the entire plume and if
contaminants remain at or below these required levels, the
operation of the extraction system shall be shut down.
Semi-annual monitoring of the groundwater shall continue for
five years after the system is shutdown. If subsequent to an
extraction system shutdown, monitoring shows that groundwater
concentrations of any contaminant of concern are above background
levels or MCLs, whichever is lower, the system shall be restarted
and continued until the required levels have once more been
attained for twelve consecutive quarters. Semi-annual monitoring
shall continue until EPA determines, in consultation with the
PADER, that contaminants have reached stable levels. The EPA-
approved analytical method will be determined in the Remedial
Design. An operation and maintenance plan for the groundwater
monitoring system shall be required, and must be approved by EPA
in consultation with the PADER.
f) Operation and Maintenance of Extraction and Treatment system
An operation and maintenance plan for the groundwater
-------
41
extraction and treatment system shall be required. The
performance of the groundwater extraction and treatment system
shall be carefully monitored on a regular basis and the system
may be modified, as warranted by the performance data collected
during operation. Samples of treated groundwater shall be
collected periodically to ensure that the treatment technologies
employed are reducing contaminant levels to required standards.
These modifications may include, for example, alternate pumping
of extraction wells or the addition or elimination of certain
extraction wells.
4) Institutional controls
Restrictions on the installation of new wells shall be
implemented in areas of the Site where MCLs are exceeded.
5) 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.
6) Five-Year Reviews
Five-year reviews shall be conducted after the remedy is
implemented to assure that the remedy continues to protect human
health and the environment. A 5-Year Review Work Plan shall be
required and shall be approved*by EPA in consultation with the
PADER.
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 sections discuss how the
selected remedy for—the CS6 Site meets these statutory
requirements.
A. PROTECTION OF HUMAN HEALTH AND THE ENVIRONMENT
The selected remedy will provide adequate protection of
human health and the environment by providing public water to
affected and potentially affected residences and maintenance of
existing whole-house carbon filtration systems, and by extracting
and treating the contaminated groundwater to achieve MCLs
-------
42
established under the SDWA or background levels, whichever is
lower.
Implementation of the selected remedy will not pose
unacceptable short-term risks or cross-media impacts. The
remedial technologies employed in the selected remedy are proven
to reduce the concentrations of volatile organic compounds to
acceptable levels.
B. COMPLIANCE WITH AND ATTAINMENT OF APPLICABLE QB RELEVANT ANH
APPROPRIATE REQUIREMENTS fARARS")
The selected remedy will comply with all applicable or
relevant and appropriate chemical-specific, location-specific,
and action-specific ARARs. Those ARARs are:
1. Chemical-Specific ARARs
The selected remedy will be designed to achieve compliance
with chemical-specific ARARs related to groundwater and ambient
air quality at the Site. The Safe Drinking Water Act specifies
MCLs for drinking water at public water supplies. The
contaminants of concern for the CSG Site and their respective
MCLs which are listed in Table 45 (for 1,1 Dichloroethane a
health-based concentration is listed) are relevant and
appropriate for this remedial action. These MCLs shall be
achieved throughout the entire contaminated groundwater plume.
These MCLs, as set forth at 40 C.F.R. §141.61(a), are listed in
Table 45.
Pennsylvania regulations set forth at 25 Pa. Code §§
109.202(1), 109.201(2), 109.203 and 109.503 establish drinking
water quality standards at least as stringent as the federal
MCLs.
The Commonwealth of Pennsylvania standards specify that all
groundwater containing hazardous substances must be remediated to
"background" quality as set forth in 25 Pa. Code §§264.90 -
264.100, and in particular, 25 Pa. Code §§264.97(i) and (j), and
264.100(a)(9). The Commonwealth of Pennsylvania also maintains
that the requirement to remediate to background is found in other
legal authorities. -This requirement that all groundwater be
remediated to background levels is a relevant and appropriate
requirement.
The method(s) by which background levels will be determined
are set forth under the description of the selected remedial
alternative. These background levels, if more stringent than
MCLs, shall be attained as part of this remedial action unless
EPA and the PADER determine that attaining such levels is
technically impracticable.
-------
'fiAL
Any vinyl chloride emissions from the groundwater treatment
system shall comply with Section 112 of the Clean Air Act, 42
U.S.C. Section 7412, National Emission Standards for Hazardous
Air Pollutants (NESHAPs). The relevant and appropriate NESHAP
for vinyl chloride is set forth at 40 C.F.R. Part 61, Subpart F.
2. Location-Specific ARARs
The substantive requirements of the Delaware River Basin
Commission (18 C.F.R. Part 430) are applicable. These
regulations establish requirements for the extraction of
groundwater within the Delaware River Basin.
3. Action—Specific ARARs
Federal Clean Air Act requirements, 42 U.S.C. §§7401 e± seq.
are applicable and must be met for the discharge of contaminants
to the air. Pennsylvania's Air Pollution Control Act is also
applicable, as are Pennsylvania's Air Pollution Control
Regulations (25 Pa. Code Chapters 121-142).
The requirements of Subpart AA (Air Emission Standards for
Process Vents) of the Federal RCRA regulations set forth at 40
CFR Part 264 are relevant and appropriate and, (depending upon
the levels of organics in the extracted groundwater and treatment
residuals) may be applicable to the air stripping operations
conducted as part of the selected remedy. These regulations
require that total organic emissions from the air stripping
process vents must be less than 1.4 kg/hr (3 Ib/hr) and 2800
fcg/yr (3.1 tons/yr).
25 Pa. Code Section 123.31 is applicable to the selected
remedial alternative and prohibits malodors detectable beyond the
CSG property line.
25 Pa. Code Section 127.12(a)(5) will apply to new point
source air emissions that result from implementation of the
selected remedial alternative. These Commonwealth of
Pennsylvania regulations require that emissions be reduced to the
minimum obtainable levels through the use of best available
technology ("BAT*") as defined in 25 Pa. Code § 121.1.
25 Pa. Code Section 127.11 will apply to the selected remedy
alternative. These Commonwealth of Pennsylvania regulations
require a plan for approval for most air stripping and soil
venting/decontamination projects designed to remove volatile
contaminants from soil, water, and other materials regardless of
emission rate.
Regulations concerning well drilling as set forth in 25 Pa.
Code Chapter 107 are applicable. These regulations are
-------
44
established pursuant to the Water Well Drillers License Act, 32
P.S.§ 645.1 et seq.
The groundwater collection and treatment operations will
constitute treatment of hazardous waste (i.e., the groundwater
containing hazardous waste), and will result in the generation of
hazardous wastes derived from the treatment of the contaminated
groundwater (i.e., spent carbon filters from the air stripping
operations and whole-house carbon filtration systems). The
remedy will be implemented consistently with the requirements of
25 Pa. Code Chapter 262 Subparts A (relating to hazardous waste
determination and identification numbers), B (relating to
manifesting requirements for off-site shipments of spent carbon
or other hazardous wastes), and C (relating to pretransport
requirements; 25 Pa. Code Chapter 263 (relating to transporters
of hazardous wastes); and with respect to the operations at the
Site generally, with the substantive requirements of 25 Pa. Code
Chapter 264, Subparts B-D, I (in the event that hazardous waste
generated as part of the remedy is managed in containers), 25 Pa.
Code, Subpart J (in the event that hazardous waste is managed,
treated or stored in tanks). 40 C.F.R. Part 264, Subpart AA
(relating to air emissions from process vents) and 40 C.F.R. Part
268, Subpart C, Section 268.30 and Subpart E (regarding
prohibitions on land disposal and prohibitions on storage of
hazardous waste). 40 C.F.R. Part 264, Subpart AA (relating to
air emission standards for process vents).
25 Pa. Code Chapter 264, Subchapter F, regarding groundwater
monitoring is applicable to the selected remedial alternative.
The discharge of treated effluent to the POTW shall comply
with the federal Clean Water Act (33 U.S.C. §§1251 e£ seq.1
pretreatment regulations for existing and new sources of
pollution as set forth at 40 C.F.R. Part 403.
Any surface water discharge of treated effluent will comply
with the substantive requirements of the Section 402 of the Clean
Water Act, 33 U.S.C. §1342, and the National Pollutant Discharge
Elimination System ("NPDES") discharge regulations set forth at
40 C.F.R. Parts 122-124, the Pennsylvania NPDES regulations (25
Pa. Code §92.31, and the Pennsylvania Water Quality Standards (25
Pa. Code §§93.1-9^J.9J .
The Pennsylvania Safe Drinking Water Act (25 Pa. Code
Chapter 109) lists the secondary maximum contaminant levels
("SMCLs") as applicable requirements for public drinking water
supplies. SMCLs are relevant and appropriate for discharge of
treated effluent to the Audubon Water Company.
The Occupational Safety and Health Act ("OSHA") regulations
codified at 29 C.F.R. Section 1910.170 are applicable for all
activities conducted during this remedial action.
-------
45
25 Pa. Code Sections 261.24 and 273.421 are applicable
regulations for the handling of residual and other waste and for
the determination of hazardous waste by the Toxic Characteristic
Leaching Procedure ("TCLP").
Transportation of any hazardous wastes off-site shall also
comply with the Department of Transportation ("DOT") Rules for
Hazardous Materials Transport (49 C.F.R. Parts 107 and 171-179).
4. To Be Considered Standards
Pennsylvania's Ground Water Quality Protection Strategy,
dated February 1992 is a to be considered standard.
EPA Directive 9355.0-28, which covers emissions from air
strippers at Superfund groundwater sites is a to be considered
standard.
Pennsylvania Bureau of Air Quality Memorandum, "Air Quality
Permitting Criteria for Remediation Projects Involving Air
Strippers and Soil Decontamination Units" is a to be considered
standard.
EPA's Ground Water Protection Strategy, dated July 1991, is
a to be considered standard.
EPA OSWER Directive 9834.11 which prohibits the disposal of
Superfund Site waste at a facility not in compliance with §3004
and §3005 of RCRA and all applicable State requirements.
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 C.F.R. Section
300.430(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 and 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
$5,573,700 if new extraction wells and treatment systems are
installed and $5,268,300 if Audubon Water Company wells and air
strippers are utilized in lieu of utilizing new extraction wells
and strippers as described under Alternative 5A.
-------
46
D. UTILIZATION OF PERMANENT SOLUTIONS AND ALTERNATIVE TREATMENT
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, or volume through treatment, State and community
acceptance, and preference for treatment as a principal element.
Under the selected remedy, treatment of both shallow and
deep bedrock groundwater using air stripping (and vapor phase
carbon where required) will provide a greater degree of reduction
of toxicity, mobility, or volume than the other alternatives
evaluated. Alternative 5, Option A will reduce contaminant
levels in groundwater and reduce the risks associated with direct
contact and ingestion of the groundwater to the maximum extent
practicable, as well as provide long-term effectiveness.
E. PREFERENCE FOR TREATMENT AS A PRINCIPAL ELEMENT
The selected remedy satisfies the statutory preference for
treatment as a principal element. Alternative 5, Option A
addresses the primary threat of future ingestion and direct
contact of contaminated groundwater through treatment using an
air stripper.
XI. DOCOMENrrATIOM OF SIGNIFICANT CHANGES
The Proposed Plan for the Commodore Semiconductor Site was
released for public comment in July 1992. The Proposed Plan
identified Alternative 5A as the preferred alternative. EPA
reviewed all written and oral comments submitted during the
comment period. Upon review of these comments, it was determined
that no significant changes to the remedy, as it was originally
identified in the Proposed Plan were necessary.
EPA has updated the cost estimates for Alternatives 3, 4,
and 5 based on the increased capital cost of installing, new
wells and air strippers with vapor phase carbon units if the
existing Audubon Water Company wells and strippers can not be
utilized.
Additionally EPA has updated the cost estimates for
Alternatives 3, 4, and 5 if the Audubon Water Company wells and
strippers are used based on the increased cost of installing,
operating and maintaining vapor phase carbon units on the
existing air strippers that may be used to implement the remedy.
-------
APPBMDXZ A FIGURES
-------
Figure i
Site Location Map
LEGEND
tonloim
hods
>
I
."' ~>
Ul' J'Uol Ul
'-I kt^wodl Ki. Dip
M'l ol i) IM IP.,ajot,
II Ihi ,.,....
-------
Figure 2
Soil Boring
-------
FIGURE J • LOCATIONS
&< RESULTS OF SURFACE
WATER SAMPLING
LEGEND
2 fi. Contours
___._ intermittent Streom
•1
•2
•3
•4
•5
ATciyljcai Resells (>n cob.'
V2-OCE TCE PCE
6.7
9.3
* 5
.3.7
2.9
6.3
8.3
VB
?5
too 200
FtET
-------
PUBLIC VAT0 SUFftY
• MONITOMHC VHI.
• nMOATUN WILL
ntRR OOTALLID BY
PBOPOSBD MCL
W WLV M
IWO
rigure A
Ground Water
Samp I ing
Location
-------
COMMODORE
SEMICONDUCTOR
CROUP SITE
SErrcnucn. mi
»» H. C030I?
I-UDLIC »VTER SUPPLY
MONI10RINC HELL
IRRIGATION WCIJ,
RESIOENTUL WKU.
A' UCL KXCEEDED IN JULY
OR DKCCMOr.R 1990
SAMPIJNC ROUNDS
(f) riLTEII INSTMJ tU BY CSC
(I) ril.TCII INSTALLED BY
ni.reu ROMVED uv
Kt5IOENI/0»NtK
I'HOI'OSED MCI, EXCEEDED
IN JULY OH DECEMBKR
IBM fiAUPLINC ROUNDS
EXTENT or SITE-RELATED
A VOC f'LUME WHCRE
UCU HAVK BEEN
CXCEtOEO
/ESTIU/iTED EXTENT OF THE
SITE-DELATED VOC PLUUE
-------
IMl • l|.;ll Ml
Figure 6
-------
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-------
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Figure 8
GROUHDIATER EXTRACTION/COLLECTION SYSTEM FOR ALTERNATIVE 5
-------
AFPBXDXX B TABLES
-------
Table 1
Depth to Water Measurements and Saturated Thickness of the Overburden
CSG Site, 1990
DATE
30-M*r-90
OS-Jun-90
21-Jun-90
10-Jul-90
24-Jul-90
16-Ai«-90
29-AUJ-90
JO-Sep-90
28-Sep-90
26-Oct-90
08-Nov-90
13-Dec-90
31-Jan-91
22-Feb-91
Ol-Apr-91
WeULD.
EI(BGS)
TD
DTW
OWELEV
Sat Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sat. Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sit. Thick
DTW
GWELEV
Sat. Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sat Thick
DTW
GWELEV
Sat Thick
SB-1
217.05
15.00
14.25
20230
0.75
11.64
205.41
336
9.96
207.09
5.04
11.75
20530
325
1Z55
20450
2.45
14.40
20245
0.60
dry
14.80
•XP-X
020
dry
dry
dry
dry
1332
20333
1.18
13X0
20345
140
11.88
205.17
3.12
SB-2
219.42
20.90
1935
200.07
1.55
1930
200.12
140
18.98
200.44
152
1931
200.11
159
1951:
19951~
139
19.62
199.80
128
1934
199.48
0.96
20.10
19932
0.80
ss
0.90
20.00
199.42
0.90
20.17
199.25
0.73
1937
19955
l-OT
IBM
20052
2*00
1920
20022
1.70
18.49
20099
2X7
SB-3
217.06
930
dry
dry
dry
dry
'.- *>
*y
dty
dry
dry
dry
dry
*y
dry
dry
Jry
SB-S
215.77
1150
8.67
207.10
2JS3
8.75
207.02
2.75
8.06
207.71
3.44
537
20950
543
557
21020
553
620
20957
530
5.81
20954
5.69
6.10
20947
5.40
830
206.97
2.70
8.75
207.02
2.75
833
207X4
3J7
8.47
20730
3JB
850
20637
240
830
20657
2.70
553
21024
557
SB-6
215.17
9.90
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
*y
SB-7
21158
11.40
10.02
20156
138
9.78
20220
142
9.14
20244
226
9.79
202,19
141
9.41
20257
159
10.45
20153
0.95
1056
20L42
034
10-80
201.18
0.60
1030
201.18
0.60
11.05
20053
035
10JB
20156
138
952
20Z06
1.48
922
202.76
2.18
Note
821
203.77
3.19
SB-8
21236
11.40
dry
dry
dry
1130
20156
0.10
—
dry
dry
dry
dry
dry
dry
*y
*y
dry
*y
SB -9
20820
22.70
20.15
188.05
255
2023
18757
Z47
1958
18822
2.72
dry
20X7
187.73
223
2220
IS6M
050
22.13
186.07
057
2250
185.70
020
dcy
dry
dry
2flL78
187X2
152
20X7
187.73
223
20.40
18730
230
20.04
188.16
246
SB- 10
210.05
7.00
NA
NA
NA
NA
NA
dry
dry
dry
dry
dry
dry
*y
dry
520
20435
130
dry
SB- 11
20236
6.10
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
520
19746
050
dry
dry
dry
MW-19S-
226.70
21.00
NI
NI
NI
NI
NI
NI
NI
NI
NI
NI
NI
NI
14.49
2122L
651
1540
211.10
5.40
12.14
21456
835
MW-21S
211.44
1100
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
dry
939
20155
1.11
• MW-19S«ttcoapteted in December 1990
TD is at top of bedrock
DTW-Depth to Water
GWEL - Groundwater Elevaiion
Sat Thick - Saturated Thickness.
Note - Surface runoff ran into well
NI - Not installed at this date
MK01\RPT28550304\COMMT2-8.WK3
2-46
-------
Table 2
OVA Readings
CSG Site, 1990-91
6/21/90 17/10/90 18/16/90 18/29/90 19/28/90 I lQ/26/9n
Readings in parts per million (ppm).
Background values ranged from .4 to .7 ppm in the ambient air before opening the
Values have been compensated for background.
NA- Not available.
weQorsofl boring.
MK01\RPTO855
-------
COMMODORE SEMICONDUCTOR GROUP SITE
LOWER PROVIDENCE TOWNSHIP, PENNSYLVANIA
SUMMARY OF GROUNDWATER ANALYSES, 1989-1990 (5 TOTAL SAMPLING ROUNDS INCLUDED)
5 tf
* COMPOUND AVERAGE DETECTED
(I CONCENTRATION
MAXIMUM DETECTED
CONCENTRATION
NUMBER OF DETECTIONS
NUMBER OF NON-DETECTIONS
PRIMARY CONTAMINANTS OF CONCERN
VINYL CHLORIDE
I , 1 -DtCHLOROETHBNE
U-DICHLOROETHANE
1 ,2-DICHLOROETHENE
CHLOROFORM
1,2-DICHLOROETHANE
1 . 1 , 1 TRICHLOROETHANE
BROMOD1CHLOROETHANE
TRICHLOROETHENE
TETRACHLOROETHENE
1 ,2-DtCHLOROBENZENE
1 ,4-DICHLOROBENZENE
13.96
15.51
J.34
338.41
6.18
25.07
13.55
2.42
148.52
23.36
288.14
12.1
24
122
12
4100
24 •!'•'
110 *'
99
4.6
tsoo
280
1400
17
10
58
58
82
58
10
117
3
no
47
t »«
4
192
144
144
120
144
192
85
199
92
155
186
198
OTHER CONTAMINANTS
TRICHLOROFLUOROMETHANE
BROMOFORM
1 , 1 ,2,2-TETRACHLOROETH ANE
CHLOROBENZENE
1,3-DICHLOROBENZENE*
ETHYLBENZENB
TOLUENE
XYLBNB
2.50
4.7
1.2
t.t
2.6
108.36
2.35
273.44
4.4
4.7
1.4
1.1
2.6
300
4.2
620
6
1
\
2
I1'
1
5
4
5
196
201
200
201
201
168
169
168
All resulu tre listed In micrograim per liter dig/I.) or p«rU per billion (ppb). NA - Not analyzed durlnf umpllnf round. I • Compound pntent below die method limit of detection
ND - Not detected above method limit of detection. B - Compound prcttm In libontonr bltnk
U.S. ENVIRONMENTAL PROTECTION AGENCY
SOURCE: 1972 RI/FS Report. Appendii E
Table 3
Prepared by Dymmae Corporation
-------
CumiviuuuKi!. a&ivucuNUUCTUR GROUP SITE
LOWER PROVIDENCE TOWNSHIP, PENNSYLVANIA
WELLS WITH MAJOR MAXIMUM CONTAMINANT LEVEL (MCL) AND PROPOSED MCL (PMCL) EXCEEDANCE
1990 SAMPLING EVENTS (ONLY VALIDATED DATA INCLUDED)
WELL NO.
2705 Audubon
MOS • 1 1
MOS - 13
MOS • 14
MOS • 15
MOS • 18
MW- 19S
MW-19D
MW-20D
MW-2ID
f
•
MW- I
MW-1
DATE
08/03/90
07/24/90
12/31/90
07/23/90
12/20/90
07/25/90
12/17/90
07/26/90
12/18/90
07/23/90
12/20/90
01/31/91
07/10/90
07/26/90
12/18/90
07/26/90
12/18/90
07/25/90
12/20/90
07/24/90
12/20/90
CONTAMINANTS EXCEEDING MCL
TCB
(MCL - J ppb)
5.7 ppb
390 ppb
250 ppb
27 ppb
540 ppb
120 ppb
60 ppb
580 ppb
860 ppb
-
.
27 ppb
24/18 ppb
13 ppb
17 ppb
340 ppb
540/480 ppb
130/160 ppb
490 ppb
340 ppb
640 ppb
1,1-DCE
(MCL - 7 ppb)
.
14 ppb
8 ppb
-
.
.
.
43 ppb
120 ppb
-
-
.
.
.
-
17 ppb
25 / 25 ppb
-
-
16 ppb
39 ppb
1,2-DCA
(MCL - 5 ppb)
.
.
.
-
.
•
.
.
.
-
.
.
.
.
.
.
.
-
.
•
-
Vinyl Chloride
(MCL - 2 ppb)
.
•
,.i>:
3
f
1.2 ppb
.
*
.
8.1 ppb
,
.
-
.
.
-
-
-
11 Ml ppb
14 ppb
-
-
CONTAMINANTS EXCEEDING PMCL
1,2-DCB
(PMCL-
70ppb/oli
100 ppb/lnnf)
.
180 ppb
130 ppb
.
1900 ppb
4100 ppb
2500 ppb
570 ppb
510 ppb
-
-
•
.
.
•
220 ppb
220/200 ppb
2000/2000 ppb
2200 ppb
160 ppo
220 ppb
KB
(PMCL - 5 ppb)
.
JO ppb
27 ppb
35 ppb
74 ppb
.
.
.
.
5.2 ppb
•
-
.
14 ppb
It / 21 ppb
31 / 31 ppb
57 ppb
17 ppb
18 ppb
1,2-DCB
(PMCL-
600 ppb)
.
•
.
.
.
1400 ppb
760 ppb
.
-
.
.
.
.
1
.
-
'
U.S. ENVIRONMENTAL PROTECTION AGENCY
SOURCE: 1992 Rl/FS Report, Appendix E
Table A
Prepared by Dynamo Coiponllon
MCLBXC.TBI
Pi je I of 2
-------
COMMODORE SEMICONDUCTOR GROUP SITE (Continued)
WELL NO.
MW-3
VFCC - 2
VPCC - 3
VFCC - 4
AUD-3
AUD-5
OW-I
OW-2
French Dnin
DATE
07/25/90
12/21/90
07/25/90
07/27/90
12/19/90
07/27/90
12/19/90
07/27/90
07/27/90
12/19/90
07/23/90
08/03/90
08/03/90
12/20/90
CONTAMINANTS EXCEEDING MCL
TCE
(MCL - 5 ppb)
28 ppb
79 ppb
7.4 ppb
24 ppb
26 / 32 ppb
150 ppb
290 ppb
16 ppb
15 ppb
32 ppb
57 ppb
31 ppb
740 ppb
650 ppb
1,1-DCB
(MCL - 7 ppb)
-
-
.
-
-
-
8.7 ppb
.
.
-
.
9.2 ppb
16 ppb
13 ppb
1,2-DCA
(MCL - 5 ppb)
-
-
-
-
-
•
-
-
.
.
-
-
.
#
Vinyl Chloride
(MCL - 2 ppb)
.
.
.
.
.•
.
-
.
.
.
.
i .
J.2ppb
-
CONTAMINANTS EXCEEDING PMCL
1,2-DCE
(PMCL -
70 ppb/eii
100 ppb/lnni)
.
210 ppb
.
.
.
.
130 ppb
.
.
.
.
.
1500 ppb
1300 ppb
PCB
(PMCL - 5 ppb)
.
19 ppb
.
.
.
5.0 ppb
11 ppb
.
.
.
.
.
.
.
1,1-DCB
(PMCL-
600 ppb)
.
.
«
.
.
-
.
.
.
.
.
.
.
-
NOTESi t
TCE - Tfichloroelhylene(TrichloroeUi»ne) .
1,1-DCE - l,l-Dichloroethylene(l,l-Dlchloroelhene)
1,2-DCA - l,2-Dichlorocthin« f
1,2-DCE - l,2-Dichloroethylene(l,2-Dienloroelhene) '
PCE , " Telrichloroethylene(Telrachloroethene)
1 ,2-DCB » 1 ,2-Dichlorobenzene
III ppb • duplicile Mmple tnilyiei retulU
• conUmintnt wit not detected tt, or ibove the MCL or PMCL
2
Table 4 cont'd
U.S. ENVIRONMENTAL PROTECTION AGENCY
SOURCE: 1992 RJ/FS Report, Appendix E
Prepared by Dynimto Corporation
MCLEXC.TBI
P»g«2of2
-------
Table 5
Comparison of Compounds of Potential Concern in Soil
to Risk-Based Concentrations
Maximum Detected Concentration
(mg/kg)
f\ mjfm f» i n*
^JlHIUll^S
Carbon Tetrachloridc
1,2-Dichlorobenzene
1,2-Dichloroethene ,
Tetrachlorethane • '.*.
1,2,4-Trichlorobenzcne
TricUoroethene
_ *
inorganics
Aluminum
Arsenic
Barium
Beryllium
Chromium
Copper
Iron
Lead
Magnesium
Manganese
Potasnium
Silver
Vanadium
Zinc
0.0078
0.011
j.0.005
%0059
0.04
0.016
9,110
2'
75.1
1.2'
8.3
8
11,900
3.3
1,020
518
958
3
17.7
9.7
Risk-Based Concentration
fag/kg)
f
11.3
92,000
20,400
35
1340
163
2,960,000
1.02
72,000
0.42
5,100*
38,000
— d
143e
-"
5,100
\ "d
3,070
« ^7,200
204.000
'Exceeds risk-based concentration.
feBased on Cr VI, which is lower than Cr III.
'Based on lead as carcinogen, which is lower than noncarcinogcnic endpoint.
'No number listed.
MK01\RPT:Z8530303\eommodor.s«b
02/07/92
-------
Table 6
Comparison of Compounds of Potential Concern in
Surface Water to Risk-Based Concentrations
Maximum Detected Concentration
-------
Table 7
Compounds or Potential Concern in Residential Wells
Organics
Chloroform
1 ,2-Dichlorobenzcnc
1 ,4-Dichlorobenzene
1,1-Dichloroclhane
1,1-Dichloroelhenc
1,2-Dichloroethcne
Melhylene chloride
Tclrachloroclhcnc
1,1,1-Trichloroeihane
Trichloroelhene
Trichlorofluoromethanc
Frequency of
Detection
29/52
1/52
1/52
7/52
4/52
15/52
4/52
4/52
27/52
18/52
1/52
Concentration
Range
to/0
1.1-22
1.4'
17*
0.47-2.6
0.87-1.3
0.82-8.1
6.4-8.3
0.32-1.3
0.91-7.8
0.29-5.7
2.4*
Arithmetic
Mean
to/0
3.49
0.51
0.74
0.71
0.53
1.18
2.42
0.49
1.85
0.96
1.02
Standard
Deviation
to/0
5.16
0.08
1.37
0.48
0.10
1.61
1.35
0.11
1.73
1.10
0.12
Upper 95%
Concentration
-------
Table 7 cont'd
(continued)
IARC Categorization of Carcinogens (IARC, 1987)
Group 1 • Human carcinogen (sufficient evidence of carcinogenicity in humans).
Group 2A ' - Probable human carcinogen (limited evidence of carcinogenicity in humans -and sufficient evidence of carcinogenicity in
experimental animals).
t
Group 2B - Possible human carcinogen (limited evidence of carcinogenicity in humans and insufficient evidence of carcinogenicity in
experimental animals; insufficient evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity b experimental
animals; or insufficient evidence of carcinogenicity in humans and limited evidence of carcinogenicity b experimental animals,
with supporting evidence from other relevant data). . {}
J\
Group 3 - Not classifiable (substances in this category do not fall into any other category).
Group 4 - Probably not carcinogenic to humans.
MK01\RJT28550303\commodor.s6c 02/15/92
-------
Tnble 8
-------
Il
Table 9
Compounds of Potential Concern in Corporate Park Supply Wells
J
'•>
Organics
Chloroform
1,1-Dichloroeihane
1,1-Dichtoroethene
1,2-Dichlorocthenc
Tetrachloroethene
1,1,1-Trichloroethanc
Trichloroelhene
Frequency of
Detection
1/3
2/3
3/3
3/3
2/3
3/3
3/3
Concentration
Range
0*g/l)
1.8'
1.5-3.2
1.6-4.25
1.05-6.7
2.1
1.9-11
7.4-29
Arithmetic
Mean
(WJ/I)
1.15
1.43
2.74
4.09
1.30
6.40
16.95
Standard
Deviation
0*g/0
0.92
1.31
1.61
3.69
1.13
6.36
13.51
Upper 95%
Concentration
0*8/0
5.23
7.28
9.93
20.56
6.35
37.80
77.27
'Only detected value.
MK01\RPT28550303\commodor.i6
02/07/91
-------
Table 10
u
Compounds of Potential Concern in GWCC Water Supply Well
Organics
Bromodichloromethane
Chloroform ;
Trichloroeihene
Frequency of
Detection
1/2
1/2
1/2
Concentration
Range
0.16'
3.3'
0.16*
Arithmetic
Mean
0.33
1.90
0.33
Standard
Deviation
0.24
1.98
0.24
Upper 95%
Concentration
.b
.
-
'Detected only once. Concentration represents only detected value.
'Sample size is too small to calculate.
MKOI\RJT:Z85M)303\commodor s6
02/07/W
-------
Table 11
Compounds of Potential Concern in GWCC Irrigation and Monitoring Wells
Organics
Bis(2-ethylhexyl)phthatate
1,1-Dichlorocthane
1,1-Dichloroelhenc
1,2-Dichloroelhenc
Dimethylphthalate
Di-n-Bulylphthalate
Tctrachlorocthcnc
Toluene
1,1,1-Trichloroethane
Trichloroelhenc
Peslicidcs/PCBs
Not detected
Frequency of
Detection
1/1
2/4
3/4
2/4
1/1
1/1
2/4
1/4
3/4
3/4
o/i
Concentration
Range
(WJ/I)
4'
1.6-3.1
4.1-9.2
6.4-65
5*
4.5*
1.6-2.1
4.5'
5-25
4.8-57
-
Arithmetic
Mean
<«?/') .
4
1.6
4.63
17.88
5
4.5
1.54
1.5
10.73
25.85
-
Standard
Deviation
(WJ/I)
_b
0.83
3.15
31.44
_b
_b
0.92
1.15
10.07
23.87
\
' ,.
Upper 95%
Concentration
to/0
_b
2.57
8.38
54.87
_b
_b
2.62
2.86
22.57
53.94
-
£
'Delected only once. Concentration represents only detected value.
''Sample size too small to calculate.
MKOI\I»rr:2a550303\commodor.t6
02/07/92
-------
Table 12
.-: ct
oc —
O
Compounds of Potential Concern in VFCC-4 and the Deep Monitoring Wells
Organics
Chloroform
1,1-Dichlorocthanc
1,2-Dichlornclhane
1,1-Dichloroelhene
1,2-Dichloroelhenc
Melhylene chloride
Tclrachloroclhene
1,1,1-Trichloroethane
Trichloroclhcnc
Inorganics
Barium
Calcium
Magnesium
Sodium
Pesticides/PCBs
Not detected
Frequency of
Detection
1/12
6/12
1/12
10/12
12/12
2/12
12/12
12/12
12/12
1/1
1/1
1/1
1/1
-
Concentration
Range
(Mg/0
2.2*
1.9-12
2.8*
1.4-39
1.3-280
20-23
3.8-30
1.3-51
13-640
415'
55.5001
21.6001
16,500"
-
Arithmetic
Mean
0*8/0
1.35 .
4.44
1.40
11.37
101.5
5.25
14.54
18.99
253.92
-
-
-
-
•
Standard
Deviation
0*g/l)
1.26
3.88
1.27
10.86
91.65
5.06
8.59
17.85
193.79
\-
'•«•
.
•
-
Upper 95%
Concentration
Cm/0
139
7.63
2.44
20.30
176.89
9.41
21:61
33.67
41333
,
.
.
•.
o
.-^377
»-J ,-.
n> '•-•
«A. ••:.
'Detected only once. Concentration represents only detected value.
-------
Table 13
Human Exposure Scenarios - Potential Exposure Routes
-£
Exposure Routes
Drinking water ingestion
Inhalation while showering
Dermal contact while
showering
Inhalation of outdoor air
Incidental water ingestion
while swimming
Dermal absorption while
swimming
Exposure Scenarios
Resident-Private
Well Scenario
X
X
X
X
X
X
Resident-Public
Well Scenario
X
X
X
X
X
X
GWCC Future
Resident
Scenario
X
X
X
X
X
X
GWCC
Member
Scenario
X
X
X
X
X
,x
GWCC
Worker
Scenario
X
X
VFCC Worker-
Current Use
Scenario
X
X
VFCC Worker-
Future Use
Scenario*
X
X
X
X
MKOI\RPT:285S030.1\rommodor.s«b
02/15/92
-------
Table 14
z
OS '
Reference Doses Tor Noncarcinogenic Effects
(mg/kg-day)
Compound
Bromodichlornmclhanc
Chloroform
1 ,2- Dichlorohcnrenc
1,1-Dichloroelhane
1,1-Dichloroelhcnc
1,2-Dichloroclhcne
Telrachloroelhcnc
1,1,1 -Trichloroelhane
Trichloroclhene
Vinyl chloride
Chronic Inhalulion RID
2.00E02
1.00E02
4.00E-02
1.00E01
9.00E-03
1.00E02
I.OOE-02
3.00E-OI
7.40E-03
3.71 E-03
Source or Basis
EPA, I99lb*
Oral RID
EPA, 199IH
EPA, 1991b
Oral RID
Oral RID
EPA, 199lb
Oral RID
See (ext
Chronic Oral RID
2.00E-02
I.OOE-02
9.00E-02
l.OOEOI
9.00E-03
I.OOE-02'
I.OOE-02
9.00E-02
7.40E-03
I.30E-03
Source or Basis
EPA, I99la
EPA, I99la
EPA, 199la
EPA, 1991a
EPA, 199la
EPA, 1991a
EPA, 1991 a
EPA, 1991a
EPA, 1987
See text
Dermal RID"
I.80E-02
9.00E-03
NE
9.00E-02
8.IOB-02
1.80E-02
9.00E-03
8.IOE-02
6.66E-03
1.17E-03
'Oral Rfd was used since neither an inhalation RID nor an OEL were available.
b Derived from oral RID (see Subsection 6.5.3).
'Lower of the two RIDs available for cis and trans isomcrs of 1,2-dichloroclhcnc.
ACf JIH-TLV = American Conference of Governmental Industrial Hygicnists - Time Weighted Average.
NE - No exposure through this route.
MKOI\RrT:28V5IHfl1\riimini.
-------
T.ihk- 13
Subchronic Reference Doses for Noncnrcinogcnic Effects
(mg/kg-day)
Compound
Bromodichloromelhcnc
Chloroform
1,2- Dichlornbcn/cnc
1,1 Dichloroethanc
1,1 Dichloroelhcnc
1,2-Dichloroclhcnc
Tclrachloroclhcnc
1,1,1 -Trichlorocl hanc
Trichloroclhenc
Vinyl chloride
Subchronic Inhalation RID
2.00E-02
I.WE 02
4.00iloi
i.flOE+oo
9.00E03
i.flOEOi"
I.OOE-OI
.inoEfOo
7.40E-0.1
3.7 IE 03
Source or Basis
EPA, IWIb
Oral RID
JR
EPA, l«Wlh
EPA, I99lh
Oral RIB
Oral RID
Oral RID
EPA, IWII*
Oral RID
Sec text
Subchronic Oral RID
2.00E02
I.OOE02
NE
NE
NE
NE
NE
NE •
7.4IIE-03
NE
Source or Basis
EPA, I99la
EPA, 199la
--
--
EPA, I99la
EPA, I99la
EPA, I99la
—
EPA, 1987
--
Subchronic Dermal RID*
1. ROE 02
9.00E-03
NE
NE
NE
NE
NE
NE
6.66E03
NE
'Subchronic dermal RfDs were calculated from the oral RIDs as described in Subsection 6.5.4.
NE = No exposure through this route.
b Lower of the two RIDs available for cis and trans isomcrs of 1,2-dichloroclhcnc.
MKIM\RI'I •
i •uniniinhir
l.'2/I.Y'tt
-------
g_
StI
QC *"**
O
Table 16
EPA and IARC Categorizations of the Carcinogenic Pollutants
Pollutant
Bromodichloromethane
Chloroform
1,1-Dichloroethane
1,2-Dichloroe thane
l^Dichloroethene
Methylene chloride
Tetrachloroethene
Trichloroethene
Vinyl chloride
EPA" Carcinogenicity Category
B2
B2
C
B2
C
B2
B2
B2
A
IARC* Carcinogenicity Category
2B
2B
NC
2B
NC
2B
2B
3
1
•EPA, 1991a.
"IARC, 1987.
NC = Not classified.
MK01\RPT:2aS50.in.1\commodor.s«c
02/15/92
-------
Table 17
EPA and IARC Categorizations of Carcinogens
Based on Human and Animal Evidence
. {
EPA Categorization of Carcinogens (EPA, 1986)
Animal Evidence <
Human Evidence
Sufficient
Limited
Inadequate
No data
No evidence
Sufficient
A
Bl
B2
B2
B2
Limited
A
Bl
C
C
C
Inadequate
A
Bl
D
D
D
No Data
•
A
Bl
D
D
D
No Evidence
A
Bl
D
E
E
Key:
Group A
Group Bl
Group B2
Group C
Group D
Group E
Human carcinogen (sufficient evidence from epidemiological studies).
Probable human carcinogen (at least limited evidence of carcinogenicily to humans).
Probable human carcinogen (a combination of sufficient evidence in animals and inadequate data in humans).
Possible human carcinogen (limited evidence in animals in the absence of human data). ' «
Not classified (inadequate animal and human data).
No evidence for carcinogenicity (no evidence for carcinogenicily in at least two adequate animal tests in different species, or in both
epidemiological and animal studies).
MKOl\RJT:M5S0303\commodor.s(Sc
OZ/15/92
-------
Table 17 (cont'd)
o
S: «
IARC Categorization of Carcinogens (IARC, 1987)
Group 1 - Human carcinogen (sufficient evidence of carcinogenicity in humans).
Group 2A - Probable human carcinogen (limited evidence of carcinogenicily in humans and sufficient evidence of carcinogenicity in
experimental animals).
Group 2B - Possible human carcinogen (limited evidence of carcinogenicity in humans and insufficient evidence of carcinogenicity in
experimental animals; insufficient evidence of carcinogenicity in humans and sufficient evidence of carcinogenicity in experimental
animals; or insufficient evidence of carcinogenicity in humans and limited evidence of carcinogenicity in experimental animals,
with supporting evidence from other relevant data).
Group 3 - Not classifiable (substances in this category do not fall into any other category).
Group 4 - Probably not carcinogenic to humans.
MKn'-RPTtMSSOMAcomnwxfor.sfc 6-1'0 07/10"
-------
Table 18
!•-. . • ~> -.-•(-»
Cancer Slope Factors
Compound
Bromodichloromelhaoe
Chloroform
1,1-Dichloroelhane
1,1-Dichloroelhene
Tetrachloroetbene
Trirhloroelhene
Vinyl chloride
Inhalation Slope Factor
I.ME 01*
8 IOC 02
NFA
1.75B-01*
I.ROE-03
1.70E-02
2.94B-01*
Source or Basis
EPA, 1991.
EPA, 1991a
--
EPA, 19911
EPA, 1991.
EPA, 19911
EPA, 1991*
Oral Slope Factor
I.30E-OI .
6.IOB-03
NFA
6.006-01
5.106-02
1.106-02
1.906400
Source or Basis
EPA, I99la
EPA, 199U
—
EPA, 199U
EPA, 19911
EPA, 199la
EPA, 1991«
Dermal Slope Factor*
1.44E-01
6.78E-03
NFA
6.6764)1
NE
1.22E-02
2.11B+00
* Oral slope factor used because no inhalation slope factor b available.
k Converted from inhalation concentration to CSP assuming breathing rate of 20 m'/dajr and body weight of 70 kg.
'Dermal slope factors were calculated from oral slope factors as described in Subsection 6.5.5.
NFA = No slope factor available.
NE = No exposure through this route.
MKOI\RrriW50J0.1\commodof.t6t
02/15/92
-------
Table 19
£?<£?
Private Residential Well Scenario
Child Hazard Quotients and Indices
Chronk Exposure
PARAMETERS
•ronwdl cM oromethtne
Chloroform
1,2-0«cM orob«ntene
1,1-Dlchleroethww
1,1-Olchloroethene
1,2-DleMoroethen«
Tetrvchloroethene
1,1.1-TrlchloroethMW
Trlchtoroethene
Vtny1. chloride
TOTAL
GROUNDWATER
INGEST ION
NA
6.4E-03
NA j
NA
9.2E-03
4.5E-02
NA
NA
3.7E-02
NA
INHALATION
WHILE
SHOWERING
NA
.1.TE-02
' '.fllA
NA
1.4E-02
7.«E-02
NA
NA
6.3E-02
NA
DERMAL
WHILE
SHOWERING
NA
T.7E-04
HA
HA
2.0E-04
5.4E-05
NA
NA
1.7E-03
NA
INHALATION
OT OUTDOOR
AIR
6.8E-09
|J.3E-06
4.7E09
7.9E-07
8.8E 06
8.1E-05
7.0E-05
4.1E-07
2.3E-OS
5.1E-08
INGEST ION
WHILE
SWIMMING
NA
1.4E-04
NA
NA
2.1E-04
1.0E-03
NA
NA
8.3E-04
NA
SWIMMING
DERMAL
ABSORPTION
NA
4.6E-04
NA
NA
5.51-04
1.5E-04
NA
NA
4.5E-03
NA
HAZARD
INDEX
8.8E-W
1.8E-02
4.7E-09
7.9E-07
Z.tt-02
1.21-01
7.0E-0)
4.1E-07
1.1E-01
5. IE-OB
9.8E-02 1.7E-01 Z.TE-OI T.9E-04 2.2E-0) 5.6E-0)
NA = Coufwond not detected In the nedliM.
2.7E-01
MK01\WT:MBS03M\commodor.lh6
6-117
07/IJ/72
-------
Table 20
«<' .•'.••••* ,.•!•••• > .Ul«-j:if» •'«..« .,-'«.«T/ir •"~'i-.'«H
Private Residential Well Scenario
Adult Hazard Quotients and Indices
Chronic Exposure
PARAMETERS
IrcModlchloro
Chlorofora
1.2 OlcMorotMniww
1.t-Dlchloro*th*n*
1,1-OteMoro«th«nt
1.2-OlcMorotth«n«
INHALATION DERMAL
GROUNDUATER WNUt IMKE
INGESflON SNOUERINO SMWERINC
1.1,1-Trlchlorotthww
TrichtorMthtn*
Vinyl chloride
fOTAL
HA
t.n-n
HA
HA
4.0E-OS
1.9E-02
HA
HA
1.M-02
HA
HA
2.SE-OS
HA
HA
3.4E-01
1.4E-02
HA
HA
1.4E-02
HA
HA
9.2E-OS
HA
HA
1.1E-M
3.0E-05
HA
HA
9.0E-0*
HA
INHALATION INGESTION SVINNIHC
Of OUTDOOR WHILE DERMAL
AIR SWIMMING MSORPTION
3.8E-09
3.7E-07
2.0E-09
s.w-or
3.BE-M
3.9E-OS
3.0E-K
1.8E-07
1.0E 05
2.2E-08
HAZARD
INDEX
HA
J.1E 05
IA
HA
«.(C-OS
!.tE-(M
HA
HA
t.BE-M
HA
HA
2.SE-M
HA
HA
J.OE-04
0.1E-OJ
HA
HA
2.4E-03
HA
3.K-09
S.4C-03
2.0E-09
S.4E-07
7.BE-03
S.M-02
J.OE-05
i.ac-or
I.3E-02
2.2E-08
4.2E-02
S.Af-02
LIE -OS
8.0E-05
4.71-0*
3.0E-03
6.2E-02
HA ' Compound net W VN\rommodot «hft
07/r
-------
Table 21
•
Public Residential Well Scenario
Child Hazard Quotients and Indices
Chronic Exposure
PARAMETERS
•r
-------
Table 22
Public Residential Well Scenario
Adult Hazard Quotients and Indices
Chronic Exposure
PARAMETERS
CMorofem
1,2-Dlcnlorobeniene
1.1-Dlehlor
-------
Table 23
CWCC Future Resident Scenario
Child Hazard Quotients and Indices
Chronic Exposure
PARAMETERS
Chloroform
1.1-0lchloro«th*ne
t.l-Dlchloroethene
1.2-DleMoroethene
Tetraehloroethene
1.1,1-Trlehloroethane
lrlchloro«lhen«
TOTAL
INHALATION DERMAL
CDOUNOWAIEII UHILE UHUE
INCESTION SWMRINQ SHOWERING
INHALATION INGESTION SKINNING
Of OUTDOOR UNIIE OERNAl
AIR SWIMMING ABSORPTION
NA
NA
6.5E-OZ
.HA
NA
1.K-02
2.7E-01
NA
NA
ME 01
NA
NA
9.IE OS
4.6E-01
NA
NA
1.5E-03
NA
NA
7.1E-0*
1.2E-02
9.0E M
I.0E-05
LIE OJ
4.7E-01
3.8E-M
f.OE-0)
1.0E 02
3.5E-01 5.8E 01 1.*E 02 1.7E-02
NA > Compound not detected In the meditn.
NA
NA
I.SErOS
NA
NA
4.0E-04
6.0E-03
7.8E-03
NA
NA
J.9E-03
NA
NA
2.4E-03
3.2E-02
3.BE-02
HAZARD
INDEX
9.0E-0*
1.8E-05
1.8E-01
4.7E-03
2.8E-M
3.1E-02
7.W-01
1.0E«00
MKOI\RPT: »W.«mi\rommodor ibfi
6-121
07/13/92
-------
Table 24
GWCC Future Resident Scenario
Adull Hazard Quotients and Indices
Chronic Exposure
PARAMETERS
Chloroform
t.t-OlehloTMthMW
t.l-DlcMoroetben*
l,2-Dlchloro«th«n*
Tetrachlorocthene
1.1,1-TrlchlorotthMW
Trlchloroethene
TOTAl
INHAIATIOH
GROUNDWATER MILE
INGESTION SHOUERING
NA
NA
2.BE-02
NA
NA
7.6E-OS
1.1E-01
HA
HA
2.4E-02
NA
HA
1.9E-OS
9.8E-02
DERMAL
WHILE
s HOWE Arms
HA
HA
7.8E-M
NA
NA
4.9C-04
A.5E-03
INHALATION
or OUTDOOR
AIR
3.K-04
7.8E-06
4.7E-04
2.0E-OS
t.2E-04
2.2E-05
4.JE-OJ
INGESTION
UNILE
SWIMMING
NA
HA
S.IE-M
NA
NA
e.sc-os
I.SE-OS
I.5E-01 I.2E-01 7.BE-03 7.36-03
NA * CoMpound not detected In the medlu*.
SWIMMING
DERMAL
AISORPTION
HA
HA
2. IE-OS
HA
HA
1.3E-03
1.7E-02
HAZARD
INDEX
3.K-M
7.K-06
S.«f-02
2.0E-03
f.ft-04
1.1E-02
2.4E-OI
I.7E-OS 2.1E-02 J.1E-01
«Fl:Za550303\commodor Ib5
6-P2
07/1.1 A>?
-------
Table 25
GWCC Member Scenario
Child Hazard Quotients and Indices
Subchronic Exposure
PARAMETERS
•roMdl eh I oronethwit
Chloroforn
1,2-Dlchlorobentene
t.t-OlchloroethMW
t.l-Olchloroethen*
1.2-Dlchloroethene
Tetrtchloroethent
I.t.t-Trlchloroethme
THchlorotthtne
Vinyl chloride
TOTAL
DRINKING
UATER
INCESTION
4.4E-OS
t.BE-03
NA
NA
NA
NA
NA
NA
1.2E-04
NA
INNAIAMON DERMAL
«W«lf tm,u
SWUERmo SHOWERING
1.SE-04
6.2E-03
NA
NA
NA
NA
NA
NA
4.0E-04
NA
2.4E-06
9.6E-OS
NA
NA
NA
NA
NA
NA
1. IE-OS
NA
OUTDOOR
AIR
2.0E-03 A.7E-03 LIE-04
NA ° Coipound not detected In the
1.0E-09
S.OE-07
S.JE-11
6.2E-09
1.3E-06
6.BE-07
4.2E-07
6.JE-09
rOE 06
6.0E-09
9.9E-06
INGESTION SUIHNINC
UHUE DERNAl
SUINNIH6 MSORPTION
t.IE-OS
4.7E-04
NA
NA
NA
NA
NA
HA
3.IE-OS
NA
•AZARO
INKX
3.7E-OS
1.SE-03
HA
HA
NA
NA
M
NA
1.7E-04
NA
2.4E-04
t.OE-02
S.SE-11
6.2C-09
1.3E-M
A.BE-Or
4.2E-07
6.SC-09
7.4E-04
6.0E-09
l.rE-03 1.IE-02
MKOI\RPT: JAVWIW\rommodnr IhA
6-123
07/I1/9J
-------
Table 26
GWCC Member Scenario
Adult Hazard Quotients and Indices
Subchronlc Exposure
PARAMETERS
•roModlehloroMethan*
Chloroform
1.2 • 01 eh I orotwniene
t.l-OlcMoroelhene
1,1-Dlchloroethene
1.2-DlchlorMthene
Tetrechloroethene
1(1,t-lrlchlorocthwie
Trlchlorocthem
Vinyl chloride
TOTAl
DRINKING INHALATION DERMAL
IMTH tMIU UHUE
INCCSflON SHOW AI NO SHOUCMIMC
1.91-05
7.71-04
NA
NA
NA
NA
S.IE-OS
NA
a.4E-M
3.21-05
1.SE-03
NA
NA
NA
NA
NA
NA
8.7E-OS
NA
1.JE 06
5.2E-05
NA
NA
NA
NA
NA
NA
5.7E-06
HA
4.4E-10
2.1E-07
2.4E-11
2.7E-09
5.4E-07
2.9E-07
I.8E-07
2.0E-09
3.0E-06
2.4E-09
ME-03
OUTDOOR INGECTION SWIHNINC
AIR UNILE DERMAL HAZARD
INHALATION SWIMMING AISORPTIOH INDEX
2.4E-06
1.0E04
NA
NA
NA
NA
6.6E-06
NA
1.1E-04 9.2E-04 3.4E-03
2.0E-05
8. IE -04
NA
NA
NA
NA
NA
NA
9.0E-05
NA
7.5E-05
1. IE-OS
2.4E-11
2.7E-09
5.4E-07
2.9E-07
1.8E-07
2.8E-09
2.4E-04
2.6E-09
5.VE-05 4.2E-06
NA » Co^MWid not detected In the «edlM.
" " tPT 2A550V)1\ronimcxJor Ihfi
07/1'
-------
Table 27
CWCC Worker Scenario
Adult Hazard Quotients and Indices
Chronic Exposure
PARAMETERS
•roModlctilorowthane
Chlorofom
1,2-Oichlorobeniene
1.1-OlchlorcwthMit
1,1-OlchloTMIhMw
t,2-0lchlorotthene
T«traehloroethene
1,1,1•Tr IcMoroethme
TricMoroethene
vinyl chloride
TOTAL
INHALATION
GftOUNOWAIER OF OUTDOOR
INGEST ION AIR
7.8E-05
3.ZE-03
NA
NA
NA
NA
NA
NA
2.1E-04
NA
3.7E-09
1.8E-06
2.0E-09
2.K-07
4.SE-06
2.4C-OJ
1.51-05
2.H-07
2.5E-05
2.IE-OB
HAIARO
INDEX
roe-05
3.M-03
2.0E-09
2.2E-07
4.5E-06
Z.« 05
1.5E-05
2.J8-07
2.4E-M
2.11 08
3.51 03 7.If-05 3.6E-03
NA • COTpound not detected In the Medium.
MKOI\
6-125
07/13/92
-------
rn 01
I? tt:
Table 28
VFCC Current Worker Scenario
Adult Hazard Quotients and Indices
Chronic Exposure
PAftAMEIERS
IrcModicMoroMthane
Chloroform
1,2-Dlchlorobenitne
1,1-PlchloroethMM
1.1-Dlchloroelhene
1,2-Dlchloro*thtiM
tetrachloroethene
l.l.t-TrlcbloroethMW
Trlchloroethen*
Vinyl chloride
IOTAL
INHALATION
CDOUMHMtiR Of OUIOOM
INGESflON AIR
MA
i.at-03
HA
J.11-04
4.6E-OI
6.6E-OI
2.11-01
I.Zf-OJ
J.8E-02
HA
s.ot-oe
5.81-04
1.61-08
S.4C-07
1.2E-05
9.08-05
4.0C-05
5.4f-0r
8.71-05
1.7E-07
HAIAtD
IMOEN
J.Ot-08
1.8E-OS
1.6E-08
S.1E-04
4.0E-OS
«.6E-03
2.1E-01
1.2E-OS
J.BE-02
1.7E-07
S.5E-02 2.4E-04 5.SE-02
HA • Compound not dtttctcd In tht
MS50KI3\rommodorIhh
6-
07/1'
-------
o
Table 29
VFCC Future Worker Scenario
Adult Hazard Quotients and Indices
Chronic Exposure
PARAMETERS
ChloroforB
I.t-Dlchloroethene
1,1-Dlchloroetheiw
1,2-OtcMoroethene
letrcchloroethene
1.1.1-lrlchloroetfiMW
Irichloroethene
TOIAl
INHALATION
GMUNDUAIER WHILE
INCEST IM SHOWERING
1.8E-OJ
S.21-04
9.SE-01
1.JE 01
1.IE-M
1.4E-0)
J.81-0!
5.K-01
DEMUL INHALATION
MILE Of OUIOOON
SHOUERING AIR
1.2E-03
2.K-M
*.X-OJ
a.rc-oz
7.4C-01
2.9E-04
2.6E-01
J.6C-01
4.7E-M
6./E-06
2.U-04
1.6E-04
A.K-M
r.K-05
1.7E-02
I.BE-02
A.X-06
2.9E-05
1.4E-M
4.TE-OJ
S.9E-04
1.H 05
1.3E-02
1.7E-02
HAZARD
INDEX
I.OE-03
5.BE-04
t.M-02
2.2E-01
t.9E-02
1.8E-OJ
6.BE-OI
9.3E-01
NA = CtMpound not detected In the MdiuM.
6-127
07/n/w
-------
T3- Table 30
;j&
" Private Residential Well Scenario
Lifetime Carcinogenic Risk
INHALATION DfltNAl INHALATION INCEST ION SWIMMING
GftOUNOUATER UNUE UNILE OF OUIOOM IMIIE DERMAL TOTAL
INGESIION SHOMMING SHOWERING AIM SKINNING AKORPTION HIM
PARAMETERS
•rttwdlchlorcmethww NA NA NA S.JE-12 NA NA 5.JE-I2
CMorofor* 9.1E-06 1.4E-06 2.8E-09 2.SE-10 1.4E-09 7.SE-09 1.5E-06
1.1-OlcMoroethcne 1.ZE-05 4.0E-06 3.0E-07 I.2E-09 I.8E-07 fl.Of-07 1.71-05
TetraehlorMthme NA NA NA 2.9C-10 NA NA 2.9E-10
Trichlorocthene 7.0E-07 1.3E-06 3.7E 08 6.9E-10 LIE-08 9.8E-08 2.IE-06
Vinyl ehlorldt NA NA NA 1.JE 11 NA NA 1.3t 11
TOTAL 1.2E-05 6.4E-06 J.4E 07 4.5E-09 1.9E-07 9.1E-07 2.0E-05
NA • Compound not dittcttd In th«
" r>rr:2H550Wl\c(immodi>r Ihr. 6-1""* 07/1.1'
-------
ta v\i
Table 31
Private Residential Well Scenario
Lifetime Carcinogenic Risk Distribution
PARAHEIERS
BrOTOdlchloroMthane
Chloroform
1.1-Olchioroethcfw
Tctrachtoroethtne
Trlchloroethene
Vinyl chloride
TOTAL
INHALATION OERHAL
GROUNDUATER WHILE WHILE
IHGESTION SIMMERING SIMMERING
INHALATION IHGESTION SHINNING
OF OUTDOOR WHILE OERNAL
AIR SUIMNINC AISORPTION
NA
0.44
M.67
NA
3.44
NA
NA
6.88
19.32
NA
6.21
NA
NA
0.01
1.47
NA
0.18
NA
0.00
0.00
0.02
0.00
0.00
0.00
NA
NA
0.01
0.86
0.04
3.92
NA
NA
0.05
0.48
HA
NA
60.55 32.40 1.66 0.02
HA • Compound net detected In the »edlu*.
0.92
4.44
TOTAL
0.00
7.58
82.26
0.00
10.36
0.00
100.00
MKOI\RPT2HVSOW\rnmmodnr(b6
6-129
07/13/92
-------
-
o" J? Table 32
o
Public Residential Well Scenario
Lifetime Carcinogenic Risk
INHALATION DERMAL INHALATION INCtSTIOH SHINNING
GROUNDWATER UHILC WNIIE Of OUTDOOR WHILE OEMUl TOTAL
INGESIION SHOUERING SIMMERING AIR SWIMMING ABSORPTION RISK
PARAMETERS
•r
-------
Table 33
Public Residential Well Scenario
Lifetime Carcinogenic Risk Distribution
INNMATIOM DERNAl INHALATION INGESIION SWIMMING
GROUNDUATER MILE (WILE Of (WIDOW UN lit OEMML
INGESTION SMMCRIW SIMMERING AIR SKINNING ABSORPTION TOTAl
PARAMETERS
•roMxIlchlorwiNthMW HA NA NA 0.00 NA NA 0.00
CMorofon* NA M NA 0.00 NA NA 0.00
1.1-OlcMonwthtne 41.98 14.31 1.09 0.01 0.44 2.90 40.93
TeirachlorMthm* NA NA NA 0.00 NA NA 0.00
Trlchlorotthww 12.96 23.41 0.68 0.01 0.20 1.61 39.06
Vinyl chloride NA NA NA 0.00 NA NA 0.00
TOTAL S4.94 37.72 1.76 0.02 0.84 4.71 100.00
NA • Compound not dtt«ct«d In th« Mdlu*.
MKOI\RPI':2«550303\rommndnr.lhA 6-13] 07/13/92
-------
Table 34
GWCC Future Resident Scenario
Lifetime Carcinogenic Risk
PARAMETERS
CMorofore
1,1-DlchloTMthene
Tetrachloroethene
Trlchtoroethene
TOTAL
INHALATION DERMAL INHALATION INGEST KM SHINNING
CROUNDWATER WHILE WHILE Of OUTDOOR WHILE DERMAL
INCEST ION SHOWERING SHOWER 1 NO AIR SHINNING ABSORPTION
NA
8.2E-OS
HA
5. IE -06
HA
2.SE-OS
NA
9.2E-06
NA
2. IE -06
HA
2.6E-07
1.7E-07
4.0E-07
1.2E 09
2.9E-07
HA
1.3E-06
HA
7.7E-08
HA
5.7E-06
HA
7.TE-07
TOTAL
RISK
1.71-07
T.ZE-04
l.if-09
1.6E-M
8. rt-05 J.7E-05 2.4E-06
HA • Compound not detected In the
B.7E-07
1.SE-06
6.4E-06
1.4E-04
MKOi\RPT:2a550303\commodorll>6
6-112
07/13/92
-------
3,
Table 35
CWCC Future Resident Scenario
Lifetime Carcinogenic Risk Distribution
PARAMETERS
Chloroform
1.1-OlcMotMthww
TvlrMhloreethene
Irlrhioroethene
10TAL
INNAIATION OEMUL
GROUNDUATER UHILE IMIIE
INCEST ION SHOWERING SHOUERING
INHALATION INGESTION
OF OUTDOOR WILE
AIR
NA
60.68
NA
3.75
NA
20.68
NA
A. 77
NA
1.57
NA
0.20
64.43 27.45 1.77
NA * Compound not detected In the
0.1]
0.30
0.00
0.22
0.64
SHINNING
DCKNAL
SWIMMING ABSORPTION
NA
NA
NA
0.93
A
0.06
0.98
NA
4.20
A
0.52
4.72
TOTAL
0.1]
88.36
0.00
11.51
100.00
MKOI\RPI:.Ul«(miV<>mmodorlbf>
6-133
07/l3/r>2
-------
Table 36
.-.
'' - GWCC Member Scenario
r:
Lifetime Carcinogenic Risk
INHALATION DERMAL INHALATION INGESTION SUIHNINO
GftOUNMMTEA WHILE UNUE Of OUTDOOR UHIIE OEMMl TOTAL
INCEST ION SHOWERING SHOWERING AIR SHINNING MSORPTION RISK
PARAMETERS
•roMdlcMorawthww 2.7E-08 A.2E-08 1.7E-09 6.2E-TJ 4.7E-09 2.0C-OB 1.?E-07
Chloroform 2.6E-OB 8.0E 07 T.AE-09 9.4E-1I «.«E-09 2.5E 08 8.J€-Of
T,1-DlcMorMth«nt NA M NA 4.6E-10 DA NA 4.tt-tO
Tetrachloroelhene NA NA NA l.ft-11 NA NA I.Tt-11
Trlchlore«thene 2.2E-09 8.1E-09 2.K-10 2. IE 10 4.0E-10 3.7E-09 1.K-M
Vinyl chloride NA M NA 1.SE-I2 NA NA 1.5E-I2
TOTAL 5.4E-OB B.Tf-07 S.5E-09 T.8E-10 7.7E-W J.51-08 9.«t 07
NA • Compound not detected In the nedlu*.
MK' "PT.ZMWTOIVmmmodnMhft 6-1'1'* OT/P
-------
Table 37
GWCC Member Scenario
Lifetime Carcinogenic Risk Distribution
PARAMETERS
•round I eh I oronie thaoe
Chloroform
1.1-Dlchloroethene
T«tr»cM oroethene
Trlchloroethene
Vinyl chloride
TOTAL
INHALATION DERMAL
CROUNDWATER WHILE UNIIE
INGESTION SHOWERING SHOWERING
INHALATION INGESTION SUINMINO
OF OUTDOOR WHILE DEMMl
AIR SWINNIN6 AISORPTION TOTAL
2.66
2.59
NA
NA
0.21
NA
6.26
80.47
NA
NA
0.82
NA
0.17
0.16
NA
NA
0.02
NA
5.50
87.55
0.36
NA = Compound not detected In the
0.00
0.01
0.05
0.00
0.02
0.00
0.08
0.46
0.46
2.66
2.51
NA
NA
NA
0.04
O.J7
NA
NA
0.98
5.54
12.25
86.20
0.05
0.00
1.50
0.00
100.00
MKOI\RPT:2R550W»\cnmmodor.iM
6-135
07/13/92
-------
Table 38
GWCC Worker Scenario
Lifetime Carcinogenic Risk
PARAMETERS
•romodlchloromethane
Chloroforn
1,1-Dlchloroethene
Tetrechloroethene
Trlehloroethene
Vinyl chloride
TOTAL
INHALATION
GROUNDUMER OF OUTDOOR
INGEST ION AIR
7.3E-08
7.Of-09
MA
HA
6.2E-09
NA
3.4E-12
5.2E-10
2.51-09
9.5E-11
1.1E-09
8.3E-12
TOTAL
RISK
7.3E-OS
ME-08
2.5E-09
9.SE-11
T.3E-09
8.3E-12
1.5E-07 4.3E-09 1.5E-07
NA • Coifiound not detected In the Medium.
RrT:Z«SM.103\rommodor.lb6
-------
Table 39
CWCC Worker Scenario
Lifetime Carcinogenic Risk Dlslribution
INHALATION
GROUNDUATER Of OUIOOOR
INGEST ION AIR TOTAL
PARAMETERS
BromdlchloroMthane 47.37 0.00 47.37
Chloroform 45.64 0.34 46.18
1.1-Dlchloroethene NA 1.64 1.64
Tetrechloroethene NA 0.06 0.06
Trichloroethene 4.01 0.73 4.74
Vinyl chloride NA 0.01 0.01
TOTAL 97.22 2.78 100.00
NA • Compound not detected In the Medium.
MKOI\RPT:ZB550303\commodor.lh6 6-137 07/13/92
-------
Table 40
VFCC Current Worker Scenario
Lifetime Carcinogenic Risk
INHALATION
GROMDVATER OF OUTDOOR TOTAL
INGESTIOM AIR RISK
PARAMETERS
Bromodlchloronethane HA Z.8E-11 2.K-11
Chloroform J.BE-08 1.TI-09 l.OE-08
1,1-Dlchloroethene 8.9E-06 6.8E-09 8.9E-06
Tetrachloroethene 3.7E-07 2.of-10 3.7E-07
Trlchloroethene 1.1E-06 I.9E-09 1.1E-06
Vinyl chloride NA 6.BE 11 6.8E-11
TOTAL 1.0E-OS 1.3E-08 1.0E-05
NA • Compound not detected In the medium.
MK«»^RPT:2M50303\rommodor.lb6 6-H8 07/IJ/<>2
-------
Table 41
VFCC Current Worker Scenario
Lifetime Carcinogenic Risk Distribution
INHALATION
GROUNDIMTER OF OUTDOOR
I"GESUON «m TOMl
•rmodlcMoronethwie m n nn « M
Chlorofom „ „ J-JJ <»•«»
t.l-D..htoW,hene a?1I °0% ^'2
Tetr^hloroetheoe j,i °-°T *•"
Trlehloroethene t»'« '•"? '•»
Voy, eh,or,de J0^ J;g IJ-J
"•W 0.12 100.00
«* • Compound not detected In the
MKOI\Rrr:ZM50»3\rommo(»or IM
6-139
07/13/W
-------
,\. Table 42
it:
VFCC Future Worker Scenario
Lifetime Carcinogenic Risk
INHALATION DERHAl INHALATION
CROUMHMTER UHIIE HHILE OF OUTDOOR TOTAL
INCESTION SIMMERING SNOUERINfl AIR RISK
PARAMETERS
Chloroform 3.BE-M 3.SE-07 1.0E-09 1.8E-09 3.9E-07
1.1-Olchloroethene 1.86-05 3.6E-06 4.1C-07 7.6E-06 2.2E-05
letrachlorocthtne 2.0E-06 4.7E-06 LIE 07 2.SE-09 2.1E-06
Trichloroethene LIE-OS L2E-OS 5.0E-07 S.7E-07 2.4E-05
TOTAL J.IE-OS 1.6E-05 LOE-06 6.SE-07 4.9E-05
NA * Confound not detected In the medium.
r:28J30303\commodor.lh6 6-l<
-------
Table 43
Cl
VFCC Future Worker Scenario
Lifetime Carcinogenic Risk Distribution
PARAMETERS
Chloroform
1,1-Oichloroethene
Tetrtchloroethene
Irlchtoroethene
TOTAL
GROUNDUATER
DIGESTION
0.08
37.33
4.01
22.81
INHALATION
WHILE
SHOWERING
0.71
7.44
0.10
24.09
DERMAL
WHILE
SHOWERING
0.00
0.84
0.23
1.03
INHALATION
Of OUTDOOR
AIR
0.00
0.16
0.01
1.17
64.21 32.33 2.10 1.33
NA • Coi*x>und not detected in the medium.
TOTAL
0.80
45.76
4.34
49.10
100.00
MKOt\RPT:2H55030)\rommndor.lbA
6-141
07/13/W
-------
TABLE 44
Summary of Human Health Risk Results
Scenario
Private
Residential
Well
Public
Residential
Well
GWCC Future
Resident
GWCC Member
GWCC Worker
VFCC Current
Worker
VFCC Future
Worker
Child
non-cancer
total chronic
HI
0.27
a..*'
1.0
-
-
-
-
Adult
non-cancer
total chronic
HI
0.082
0.37
0.31
-
0.0036
0.055
0.93
Adult & Child
cancer total
lifetime risk
2.0E-5
4.0E-5
1.4E-4
9.9E-7
1.5E-7
l.OE-5
4.9E-5
-------
.,/..
Table 45
Contaminant of Concern MCL in parts per billion (ppb)
Bromodichloromethane 100
Chloroform 100
1,2 Dichlorobenzene 75
1,4 Dichlorobenzene 600
1,1 Dichloroethane 810*
1 , 2 Dichloroethane 5
1,1 Dichloroethene 7
1,2 Dichloroethene 70
Tetrachloroethene 5
1,1,1 Trichloroethane 200
Trichloroethene 5
Vinyl Chloride 2
* Non-carcinogenic health-based concentration
-------
TABLE 46
Affected And Potentially Affected Residences To Be
Connected To The Public Water Supply system
Residence
1139 Rittenhouse Road
1151 Rittenhouse Road
1161 Rittenhouse Road
2660 Audubon Road
2703 Audubon Road
2705 Audubon Road
2709 Audubon Road
2711 Audubon Road
2714 Audubon^Road
2719 Audubon road
2723 Audubon Road
2729 Audubon Road
-------
Table 47
COMMODORE SEMICONDUCTOR GROUP SITE ^.5
LOWER PROVIDENCE TOWNSHIP, PENNSYLVANIA -
SUMMARY OF ALTERNATIVE COSTS FOR REMEDIAL IMPLEMENTATION^
ALTERNATIVE | CAPITAL COST
O&MCOST
(30 years)
NET PRESENT
WORTH
COSTS UTILIZING THE INSTALLATION OF NEW WELLS AND STRIPPERS'
ALTERNATIVE 1
ALTERNATIVE 2
ALTERNATIVE 3 (OPTION A)
ALTERNATIVE 3 (OPTION B)
ALTERNATIVE 4 (OPTION A)
ALTERNATIVE 4 (OPTION B) "'
ALTERNATIVE 5 (OPTION A)
ALTERNATIVE 5 (OPTION B)
NONE
125,500
732,730
985,730
810,930
1,071,230
946,910
1,203,910
LUSIJ* UTlUZlMCr THE EXJ&TlNG WAl'tk iAjmX C
ADJUSTED TO REFLECT THE COSTS FOJ
VAPOR PHASE CARBON UNITS*
ALTERNATIVE 1
ALTERNATIVE 2
ALTERNATIVE 3 (OPTION A)
ALTERNATIVE 3 (OPTION B)
ALTERNATIVE 4 (OPTION A)
ALTERNATIVE 4 (OPTION B)
ALTERNATIVE 5 (OPTION A)
ALTERNATIVE 5 (OPTION B)
NONE
125400
420,000
673,000
498,200
758,500
641,500
899,400
26,640
211,800
246,700
282,500
258,00
313,900
404,300
477,400
299,800
2,564,800
3,585,300
4,244,700
3,790,900
4,680,300
5,573,700
6,657,000
OMPANY WELLS AND STRIPPERS
R INSTALLATION OF
26,640
211,800
246,700
285,200
258,000
313,900
404,300
477,400
299,900
2,564,900
3,272,500
3,932,000
3,478,200
4,367,600
5,268,300
6,352,800
Thr i n«tircf nitcil fnr imlilliin nnrTrrlli anil Itrippr
by Dynamic Corporation. «•
The caa* repotted for tuiag (he existing well* end Krippc
obutned 6am the September 21.1992, Feoability Study Coa Evaluation Report, u prepared
to >rcounl for (be iiKillitioo of Vmpor RUJC Ccrboo Unitt
: uken from tixJufy 1992, Rl/FS Report, •» prepared by WESTON, tnd h*vx beenmdjuced
U.S. ENVIRONMENTAL PROTECTION AGENCY
Prepared by Dyounc Corponuoo
COSTSUM.TB1
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