SDMS Document 113239 USEPA WORK ASSIGNMENT NUMBER 066-2L6X USEPA CONTRACT NUMBER 68-W8-0110 EBASCO SERVICES INCORPORATED FOCUSED FEASIBILITY STUDY BASELINE RISK ASSESSMENT GCL TIE & TREATING SITE SIDNEY, NEW YORK APRIL 1994 NOTICE THE INFORMATION PROVIDED IN THIS DOCUMENT HAS BEEN FUNDED BY THE UNITED STATES ENVIRONMENTAL PROTECTION AGENCY (USEPA) UNDER ARCS II CONTRACT NO. 68-W8-0110 TO EBASCO SERVICES INCORPORATED (EBASCO). THIS DOCUMENT HAS BEEN FORMALLY RELEASED BY EBASCO TO USEPA. THIS DOCUMENT DOES NOT REPRESENT, HOWEVER, THE USEPA POSITION OR POLICY, AND HAS NOT BEEN FORMALLY RELEASED BY THE USEPA. D0065.LYN 400318
Report: Focused Feasibility Study, Baseline Risk Assessment, GCL
Tie & Treating Site, Sidney, New YorkEBASCO SERVICES
INCORPORATED
GCL TIE & TREATING SITE SIDNEY, NEW YORK
APRIL 1994
NOTICE
THE INFORMATION PROVIDED IN THIS DOCUMENT HAS BEEN FUNDED BY THE
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY (USEPA) UNDER ARCS II
CONTRACT NO. 68-W8-0110 TO EBASCO SERVICES INCORPORATED (EBASCO).
THIS DOCUMENT HAS BEEN FORMALLY RELEASED BY EBASCO TO USEPA. THIS
DOCUMENT DOES NOT REPRESENT, HOWEVER, THE USEPA POSITION OR POLICY,
AND HAS NOT BEEN FORMALLY RELEASED BY THE USEPA.
D0065.LYN 400318
EBASCO April 15, 1994 ARCS 11-94-66-090
Mr. Carlos Ramos Work Assignment Manager US Environmental
Protection Agency 26 Federal Plaza New York, NY 10278
SUBJECT: ARCS H PROGRAM - EPA CONTRACT NO. 68-W8-0110 WORK
ASSIGNMENT NO. 066-2L6X - GCL TIE & TREATING SUBMITTAL OF FINAL
FFS RISK ASSESSMENT
Dear Mr. Ramos:
Ebasco is pleased to submit 10 copies of the Final Focused
Feasibility Risk Assessment under the subject work assignment. All
EPA and New York State comments have been addressed and
incorporated into the final documents. A detailed accounting of
comments and responses is being provided under a separate cover
letter.
Please do not hesitate to contact me at (201) 460-6434 or the Site
Manager, Mr. Howard Lazarus at (201) 460-6062 if you have any
questions or need additional assistance concerning this
matter.
Very truly yours,
Dev R. Sachdev, Ph.D., P.E. ARCS n Program Manager
cc: M S Alvi K Moncino D Butler H Lazarus MKuo L Voyce Project File
(1.9.3)
(EPA) (w/o attachment) (EPA) (w/o attachment) (EPA) (w/o
attachment)
400319
E B A S C O E N V I R O N M E N T A L A Division ofEbasn services
incorporated
160 CHUBB AVENUE • LYNDHURST, N.J. 07071-3586 • (201)
460-6500
USEPA WORK ASSIGNMENT NUMBER: 066-2L6X USEPA CONTRACT NUMBER:
68-W8-0110
EBASCO SERVICES INCORPORATED
GCL TIE & TREATING SITE SIDNEY, NEW YORK
APRIL 1994
Prepare^ By: ^ Approved By:
loward Lazar\s^_yy ^ Dev Sachdev, P.E., Ph.D. Site Manager ARCS n
Program Manager Ebasco Services Incorporated Ebasco Services
Incorporated
Reviewed By:
Ming Kuo, Ph.D., P.E. Technical Support Manager Ebasco Services
Incorporated 400320
D0065iYN
RISK ASSESSMENT SUMMARY
The GCL Tie & Treating site is an inactive wood processing and
treating facility located in Sidney, Delaware County, New York.
Timber was cut and treated with creosote on site in the fabrication
of wood products, predominantly railroad ties. Contaminants have
been released to the environment through direct contact with the
surface soil as a result of open drip-drying of treated products,
disposal of end cuts and scrap as fill material, and at least one
documented spill.
This Focused Feasibility Study Baseline Risk Assessment addresses
the potential human health impacts associated with contaminated
soils on the western portion of the GCL site. At the direction of
EPA, the scope is limited to exposure to contaminated soils via
dermal contact, ingestion, and inhalation of particulates.
Potential receptors are young child and adult off-site residents,
older child and adult trespassers, off-site workers, and future
on-site workers. Site land use is expected to remain
industrial/commercial. Data used to evaluate the risk posed by the
site were obtained from sampling performed by EPA as part of a 1990
USEPA Removal Action and a Subsurface Sampling Investigation
conducted in 1993 by Ebasco at the direction of EPA.
Results of this Risk Assessment indicate potential carcinogenic
risks above EPA target levels to all receptors included in the
analysis, through incidental ingestion of contaminated soil, should
no cleanup be performed. Inhalation risks are within or below, and
dermal contact risks are below target levels. No noncarcinogenic
effects are predicted for the site, as all receptor Hazard Index
values are below 1.0.
Chemicals contributing to excess risks include carcinogenic
polycyclic aromatic hydrocarbons
(PAHs), the main constituents of creosote, as well as arsenic and
chromium.
This Risk Assessment was performed in accordance with "Risk
Assessment Guidance for
Superfund" (USEPA, 1989b), Guidance for Conducting Remedial
Investigation and Feasibility
Studies under CERCLA (USEPA, 1988a) and Superfund Accelerated
Cleanup Model (SACM)
Guidance (USEPA, 1992d).
400321 D0065.LYN
i r- m O -n O O z H m z H w
400322
3.0 SELECTION OF CHEMICALS OF CONCERN 9
3.1 Database Selection 9
3.2 Selection Criteria 10
3.4 Chemicals of Concern 10
4.0 IDENTinCATION OF EXPOSURE PATHWAYS 13 4.1 Contaminant Source
Analysis 14 4.2 Receptor Analysis 14
4.3 Exposure Pathway Analysis 15
5.0 HAZARD IDENTIFICATION 19
5.2 Health Effects Criteria for Potential Carcinogens 20
5.3 Toxicological Assessment 22
6.1 Health-Based Applicable or Relevant and
Appropriate Requirements (ARARs) and To Be Considered (TBC)
Criteria 22
6.2 Estimation of Exposure Point Concentrations 26
D0065I.YN . i - f, . ? 11 400323
TABLE OF CONTENTS (Cont'd)
Section Title Page No.
7.0 QUANTITATIVE RISK CHARACTERIZATION 43
7.1 Quantitative Risk Assessment Methods 43
8.0 RESULTS OF RISK CALCULATIONS 45
8.1 Reasonable Maximum Case 45
8.2 Average Case 46
9.0 COMBINING RISK LEVELS AND HAZARD INDEX VALUES 46 ACROSS
PATHWAYS
10.0 QUALITATIVE DISCUSSION OF RISKS NOT QUANTITATIVELY 46
EVALUATED IN THE RISK ASSESSMENT
11.0 POTENTIAL PUBLIC WELFARE IMPACTS 50
12.0 UNCERTAINTY IN THE RISK ASSESSMENT 50
12.1 Uncertainties Associated with Sampling and
Analytical Procedures 50
Intake Assessment Methods 54
12.3 Uncertainties Associated with Toxicologic
Models and Parameter Estimates 55
13.0 RISK ASSESSMENT SUMMARY 56 13.1 Human Health Risk Assessment
Summary 56
REFERENCES R-1
Chemical Data Summary Toxicological Profiles Human Health Risk
Assessment Spreadsheets
.ih^^m^jt iii 400324
LIST OF TABLES AND FIGURES
1
2
3
5-16
17-19
20
21
TABLES
Chemicals of Potential Concem - ARARs/TBCs and Levels
of Detection in Soil
Risk Levels and Hazard Index Values Summary Across
Exposure Pathways - Present/Future Use Scenarios
Sources of Uncertainty in the Risk Assessment
Summary of Potential Risks
2
3
16
17
1.0 INTRODUCTION
1.1 Scope
This Focused Feasibility Study Baseline Risk Assessment (FFSBRA)
addresses the potential human health impacts associated with
contaminated soils on the western portion of the GCL Tie &
Treating site, located in Delaware County, New York. The GCL
property encompasses an area of approximately 26 acres. This FFSBRA
is designed to focus on the potential health impacts of surface and
subsurface soil contamination only. The procedures used in this
risk assessment are consistent with USEPA guidelines for risk
assessments in general, and Superfund sites in particular,
including the "Risk Assessment Guidance for Superfund" (RAGS, 1989)
and Guidance for Conducting Remedial Investigation and Feasibility
Studies under CERCLA (USEPA, 1988a).
1.2 Site Location
The GCL Tie & Treating site (GCL) is a 60 acre property located
at 42n7'N and 75^25^ in a
commercial/industrial section of the Village of Sidney, Delaware
County, New York. The site
is bordered to the north by a rail line owned by the Delaware and
Hudson Railroad. A
warehouse and the Sidney Municipal Airport are located to the north
of the rail line. Route 8
forms the eastern border of the property, with the principal
residential and commercial sections
of the Village of Sidney to the east. Delaware Avenue (also
indicated as Gifford Road on the
Site Location Map, see Figure 1) runs along the southern border of
the site in a northeast to
southwest direction. A drainage ditch and woodlands area lie on the
northern side of the road,
while a large shopping center, containing a supermarket, retail
stores, motel, restaurants, and
other small businesses, is located on the southern side of Delaware
Avenue. The western edge
of the property abuts an impoundment and wetlands area. Figure 1
provides a Site Location
Map, and Figure 2 presents a Site Plan.
1.3 Site History
The GCL Tie & Treating property was owned by the Delaware and
Hudson Railroad Company between 1940 and 1979. Railcon Wood
Products/Railcon Materials, Inc. acquired the site in 1979 and sold
it to GCL Tie & Treating in 1983. GCL filed for bankruptcy in
1987 and abandoned the property in January 1988. Railcon regained
control of the property, sold aU inventory and equipment, and then
abandoned the property. Present ownership of the site is unclear
and is currently being investigated by USEPA.
400326 D0065.LYN 1
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juntoxttuTt sau.e ojp 0i/za/9i
EBASCO SERVICES INCORPOP T D
s
MILl]
UOUNO WITH A S S O R U B DEBRIS
SAW
VILLAGE OF SIDNEY. NY
DJP OI /Ba/9 i SHOPPING PLAZA ^
CREOSOTE STORAGE TANKS
U.S. ENVIRONMENTAL PROTECTION AGENCY
GCL TIE & TREATING SITE
««ieooi
Wood preserving operations began on-site as early as the 1940s. The
property was used as a
railroad tie manufacturing and treating plant since at least the
early 1960s. Logs were brought
on site, cut, and treated with creosote. The practice of drip
drying creosote soaked lumber, with
no containment safeguards resulted in numerous areas of stained
soil. A sequence of aerial
photographs taken between 1963 and 1983 indicate a gradual
expansion of site operations from
the eastern section of the property to the west. The greatest
growth occurred between 1977 and
1983, when clearing of vegetation and filling of wetland areas
occurred.
In October 1986, the site came to the attention of the New York
State Department of
Envkonmental Conservation (NYSDEC) after a spill of 9,000 to 10,000
gallons of creosote was
reported. The spill occurred at night and attempts to remediate the
area were made by GCL.
Sidney police noticed the spill the next morning and notified
NYSDEC, which instructed GCL
to excavate the contaminated soil, place it on a polyurethane
liner, and cover it pending final
disposal. Contaminated soil was to be placed in 55-gallon
containers and removed from the site.
As of November 1992, uncovered, unlined contaminated soil remained
on site.
Contamination at this site is not limited to the creosote spill.
Stained soils are present throughout
the site and are assumed to be a result of creosote dripping from
the tie-drying process. Former
GCL employees have stated that creosote contaminated material was
routinely disposed of in the
wetland area adjacent to the site. In addition, contaminated
material was added to the stockpiled
soil and unspecified amounts of material were transferred from the
waste pile and placed in the
wetlands. A large pile of sawdust and wood debris abuts the wetland
area.
In December 1989, USEPA Region II conducted a sampling program in
conjunction with their criminal investigation. Samples were
collected from soils, the waste pile, and materials in the above
ground storage tanks. In addition, a sample of creosote was
obtained from Allied Chemical, GCL's supplier of this material, and
used as a fingerprint to match the chemical analyses of on-site
samples. Results of these analyses confirmed the presence of
creosote in all samples.
In July 1990, NYSDEC boarded up the buildings and erected a fence
along the eastern edge of the GCL property. These actions were
taken to limit access and potential exposure to contaminated
materials. Before this action, access to the site and all buildings
was unrestricted. Public access to the site is still easily
obtained as there is no fence around the site perimeter and no gate
across the access road.
In addition to the creosote stained soils, seven 55-gallon drums of
muriatic (hydrochloric) acid were discovered in the abandoned
buildings. This material had a pH of 1. At one time there were at
least two underground storage tanks present on-site. One
2,000-gallon storage tank
D0065.LYN 400329
contained fuel oil for the boiler and one 1,000-gallon tank held
fuel oil for the furnace. Five
above ground tanks, presumed to have contained creosote, were also
on site.
In September 1990, NYSDEC sent USEPA a written request to conduct a
removal action at the
site pursuant to Section 104 of CERCLA. As a result of this
request, USEPA initiated a removal
action in March 1991 to undertake mitigation including fence
installation, site security, and
stabilization and disposal of hazardous substances. Under the
removal action, 14,159 gallons of
creosote were removed from the tanks and associated piping. An
additional 500 gallons of
creosote were removed from floors, tanks, and sumps. Approximately
4,000 cubic yards of soil
were screened and staged pending final disposal.
1.4 Current Conditions
The site is divided into sections, defined by USEPA as the GCL
property and non-GCL property.
The GCL property section has been partially fenced and is comprised
of the 26 acre inactive
sawmill and wood pressure treating facility known as GCL Tie &
Treating. Present ownership
of this section of the site is under investigation. The current
conditions on the GCL property are
discussed in detail below. The non-GCL section of the site has
unrestricted access and has two
active businesses present. A small sawmill operation is located
adjacent to the restricted GCL
property. The company has stockpiles of cut and uncut wood as well
as shavings in open
storage. The sawmill appears to lease the property from the
unidentified owners of the GCL
property. On the other side of the sawmill, a different company
runs a wood laminating
operation in the buildings located on the eastern end of the
property. All manufacturing and
storage is located indoors, and both interior and exterior areas
are apparently well maintained.
The GCL property section of the site underwent a removal action by
USEPA. The activities
included removal and cleaning of storage tanks and associated
piping, stockpiling of contaminated
soils, removal of drums, screening and relocation of the debris
pile, and performance of a pilot
scale composting operation. Entry to this section of the site from
the access road has been
limited by the construction of a chain link fence along the eastern
edge of the GCL property.
Soil sampling was performed along the fence line during
construction. Additional soil sampling
was performed in known hot spots, and water samples were taken from
the impoundment on the
western edge of the site.
A site visit was conducted by USEPA, NYSDEC, and Ebasco
Environmental personnel on November 5, 1992. A tour of the site was
provided by the USEPA On Scene Coordinator (OSC). During the site
walk, it was noted that the site exhibited a strong creosote aroma
and poor Surface drainage. The abandoned saw mill and
pressure-treating buildings are in poor condition. The warehouse
building that was providing shelter to the composting study and an
open shed
D0065.LYN t ^ U m 5 400330
providing cover for the EPA decontamination area had been better
maintained. The piles of
contaminated soil were partially covered. The western edge of the
property, adjacent to the
impoundment, had been filled using an assortment of end-cuts from
wood products and other
assorted materials. A second site visit was conducted by Ebasco
Environmental personnel on
July 1-2, 1993. This visit was specifically made to identify
potential exposure pathways,
sensitive populations, access points, as well as patterns and
likely routes of exposure to
contaminants on-site and potentially migrating off-site, given
current conditions at the site.
2.0 RISK ASSESSMENT METHODOLOGY
Methods used in this assessment are in accordance with the RAGS
document As outlined below,
this document presents a six-step methodology for conducting a risk
assessment:
1. Identify chemicals of potential concern (Section 3).
2. Define human exposure pathways (Section 4).
3. Assess contaminant toxicity (Section 5). 4. Estimate exposure
point concentrations (Section 6). 5. Assess human contaminant
intakes (Section 7).
6. Characterize the human health risks (Section 8).
A brief summary of this methodology is presented below.
1. Identify Chemicals of Potential Concem - Identification and
selection of site-specific "chemicals of potential concem"
(site-related contaminants whose data are of sufficient quality to
be used in a quantitative risk assessment) for soils at the GCL Tie
& Treating property were based on:
frequencies of occurrence
the historic data base of contamination at the site, and
the toxicological, physical, and chemical characteristics of the
chemicals detected
The USEPA Region II and RAGS selection criteria for an organic
compound to be retained as a chemical of potential concem for
quantitative evaluation includes meeting one or more of the
following: the compound occurred in at least 5 percent of the
samples in a given medium in a single data set; the chemical is
either a known human carcinogen (Group A) detected at any level or
the chemical is a probable human carcinogen carcinogen (Group B1
and B2) detected above 1 ug/kg in the soil; the compound was
detected above the applicable analytical detection limit;
i ^BQOk 6 400391
and toxicological data were available for the compound. Unless
specifically stated, these criteria apply to both carcinogenic and
noncarcinogenic compounds.
As with organics, an inorganic compound was selected if the
toxicological data were available for the compound; the compound
was detected above the applicable analytical detection limit; the
compound occurred in at least 5 percent of the samples in a given
medium in a single data set; the compound is either a known human
carcinogen (Group A) or the compound is a probable human carcinogen
detected above 1 ug/kg in soil. Those metals which were present at
levels not significantly higher than local background, which are
naturally occurring trace nutrients, or which were present at
levels far below levels of potential concern from a health
standpoint were eliminated. Based on these criteria, the inorganics
arsenic and chromium, both Class A carcinogens, were chosen as
chemicals of concern.
A toxicity/concentration screen was not performed for this Risk
Assessment because the contaminants detected in soil which have
toxicity criteria were limited. All chemicals detected that have
current toxicological data and met the other chemical of potential
concem criteria were included in the risk analysis (see Section
3).
2. Define Human Exposure Pathways - Prior to selecting the
chemicals of concern, all potential
human exposure pathways for the site (i.e., inhalation, ingestion
and dermal contact) were
defined. Each potential pathway was then evaluated considering
site-specific conditions to
determine if the pathway could be present at the site. The area
demography and land use
characteristics were taken into consideration when the pathways
were developed. If a pathway
between the source of contamination and a human receptor could
potentially be complete, and
was included in the scope of work for this risk assessment, it was
retained for further quantitative
or qualitative evaluation (see Section 4).
3. Assess Contaminant Toxicity - All contaminants detected in site
matrices were reviewed for their toxicity to humans. Data on
contaminant toxicity was obtained from EPA's Integrated Risk
Information System (IRIS), from the Health Effects Assessment
Sununary Tables (HEAST) and from the scientific literature. On the
basis of these data, contaminants were separated into two groups,
those exhibiting carcinogenic effects (carcinogens) and those
exhibiting noncarcinogenic effects (noncarcinogens), based largely
on EPA classifications (see Section 5). Although all contaminants
were reviewed for toxicological effects, only those chemicals with
EPA promulgated toxicity criteria were considered for quantitative
evaluation. Those not having toxicity criteria were evaluated
qualitatively.
4. Estimate Exposure Point Concentrations - Estimation of exposure
point chemical
concentrations for the reasonable maximum case were based on the
upper 95% confidence limit
D0065.LYN t u r n 7 4003. 2
(95% UCL) of the arithmetic mean of the log-transformed data, or
the maximum detected
concentration if it was less than the 95% UCL, in accordance with
EPA (USEPA, 1992)
guidance. For the average case scenarios, the 95% UCL (or the
maximum concentration, if it
was less than the 95% UCL) was also used as the exposure point
concentration, in combination
with exposure parameters reflecting average case scenarios.
Particulate emissions used to
estimate soil dust contaminant concentrations were calculated using
the Cowherd Model (USEPA,
1985b).
5. Assess Human Contaminant Intakes - A quantitative assessment of
human contaminant
intakes associated with each potential exposure pathway was then
developed. Human exposure
levels and chronic and subchronic contaminant intakes were
estimated for each contaminant and
matrix through the use of exposure scenarios. Exposure scenarios
are reasonable sets of human
exposure pathways that help to define the intake levels of
contaminants in site media. The
"reasonable maximum exposure" (RME) scenario employed the exposure
point concentration and
reasonable maximum exposure circumstances. Average case exposure
scenarios for those RME
scenarios exceeding a 1 x 10" carcinogenic risk, and/or a Hazard
Index of 1.0 were also
developed in this Risk Assessment Adult and young child off-site
residents, adult and older
child site trespassers, and adult on and off-site worker potential
exposure parameters were
included in this evaluation.
6. Characterize Human Health Risks - The final step in this risk
assessment was the health risk characterization. For
noncarcinogens, exposure pathways were evaluated by comparing
site-specific Chronic Daily Intake (CDI) rates to acceptable
Reference Doses (RfDs) for each soil exposure pathway and each
chemical of potential concem. The RfD values used were obtained
from IRIS (February 1994 sessions) and HEAST (1993).
Potential noncarcinogenic effects are evaluated as the ratio of the
Chronic Daily Intake (CDI) to the Reference Dose (RfD). The sum of
all of the CDLRfD ratios for the selected chemicals of concem is
called the Hazard Index (HI) and is calculated as shown
below:
n
(1) HI = E ^ ^ i=I RfDi
Where: HI = Hazard index CDIj = Chronic daily intake for chemical i
(mg/kg/day), RfDj = Reference dose for chemical i (mg/kg/day), and
n = Number of indicator compounds (i.e. compounds of concem) in the
medium
under consideration.
D0065. ^.gGOl 8 400333
A hazard index less than 1.0 is unlikely to be associated with
health risks and is therefore less
likely to be of concem than a hazard index greater than 1.0.
However, a conclusion should not
be categorically drawn that all hazard indices less than one are
"acceptable" and all His greater
than 1.0 indicate that health risks will occur. This is a
consequence of the uncertainties inherent
in the derivation of the RfD in the exposure assessment and the
uncertainties associated with
adding the individual terms in the Hazard Index calculation.
Potential excess lifetime cancer risk due to exposure to a specific
carcinogenic compound is
calculated by multiplying the compound specific CDI by its slope
factor (SF) as follows:
(2) Excess lifetime cancer risk = CDI x SF
Where:
CDI = Chronic daily intake of the chemical (mg/kg/day), and SF =
Slope factor for the chemical (mg/kg/day)"'
This linear equation is valid for excess lifetime cancer risks less
than 10" (one in one hundred).
Above this level, individual excess lifetime cancer risks should be
calculated using the equation:
(3) Excess lifetime cancer risk = 1 - exp(-CDI x SF)
Slope Factors are defined by USEPA's Carcinogen Risk Assessment
Verification Endeavor
(CRAVE) and obtained from IRIS and HEAST. For the purposes of this
assessment, cancer risks
for exposure to multiple carcinogenic contaminants were assumed to
be additive.
A discussion of the soil pathways identified for evaluation as a
potential health risk and the specific chemical constituents of
concem within each soil exposure pathway is provided in Section 7.
Potential sources and areas of uncertainty in the risk assessment
are discussed in Section 12.
3.0 SELECTION OF CHEMICALS OF CONCERN
3.1 Database Selection
The soil sample results of the EPA Removal Action and Focused
Feasibility Study were used to
create the data base for this Risk Assessment The analytical
results of the samples taken from
soil were used to evaluate the potential risks from exposure to
chemicals detected at the site.
D0065.LYN i ^ ( m ' ^''0334
3.2 Selection Criteria
The primary considerations for selection of chemicals of concern
were: 1) frequency of
detection; 2) detections of probable carcinogens above 1 ug/kg and
known human carcinogens
regardless of the concentration; and 3) the availability of
toxicological data. All chemicals
occurring at a frequency of detection of greater than or equal to 5
percent which have
toxicological criteria were carried through the evaluation, with
the exception of inorganics which
are required trace nutrients or which were found at levels not
significantly higher than local
background. Regardless of concentrations and/or frequencies of
detection, site contaminants not
having current toxicological data were not included for
quantitative analysis in the Risk
Assessment.
3.3 Chemicals of Potential Concem Selection Summary
On the basis of the factors described above, chemicals of potential
concem were selected for the
GCL Tie & Treating site. Chemicals of concem for this Risk
Assessment are summarized in
Table 1. Data for these compounds, presenting the frequency of
detection, concentration ranges,
arithmetic and geometric means, and the 95% Upper Confidence Limit
(UCL), are included in
Appendix A.
3.4 Chemicals of Concem
The compounds which have been chosen as the chemicals of concem
(COCs) in soil meet the
foregoing criteria for carcinogenic and noncarcinogenic indicators
and are discussed below.
Table 1 is the hst of COCs for soil at the site. Table 2 provides
the typical composition of
creosote and an analysis of the creosote used at GCL Tie &
Treating.
Carcinogenic COCs selected for incidental soil ingestion and/or
inhalation pathways include
methylene chloride, chloroform, tetrachloroethene, carcinogenic
polycyclic aromatic hydrocarbons
(PAHs); including benzo(a)anthracene, benzo(b)fluoranthene,
benzo(k)fluoranthene,
benzo(a)pyrene, chrysene, indeno(l,2,3-cd)pyrene, fluorene, and
dibenz(a,h)anthracene. The
PAHs are the major contributors to the carcinogenic risks at this
site.
Other carcinogenic COCs include bis(2-ethylhexyl phthalate),
heptachlor, heptachlor epoxide, DDE, DDT, alpha chlordane, Aroclor
1248, arsenic, and hexavalent chromium.
Do^^OOi 10 400395
Methylene Chloride
DDT Heptachlor
Heptachlor Expoxide
COMPOUND OR COMPONENTS
Naphthalene Methyl Naphthalene
TOTAL 100.0 100.0
* Lorenz and Gjovik, 1972. ** Analysis of standard supplied to GCL
by Allied Chemical.
9m}in 12 400337
Noncarcmogenic COCs (some of which also have carcinogenic
properties and are included previously) for ingestion and/or
inhalation of on-site soil include methylene chloride, chloroform,
tetrachloroethene, toluene, ethylbenzene, xylenes, benzo(a)pyrene,
fluorene, naphthalene, bis(2- ethylhexyl)phthalate,
di-n-octyl-phthalate, acenaphthylene, anthracene, fluoranthene,
fluorene, pyrene, phenol, 2,4-dimethylphenol, 4-chloroaniline,
aniline, hepthachlor, heptachlor epoxide, DDT and
alpha-chlordane.
The only COC assessed for exposure via dermal contact for this site
is Aroclor 1248 (PCBs), as this is the only COC for which EPA
guidance allows quantitative evaluation. The potential effects of
dermal exposure to other COCs, including PAHs, are described in
toxicological profiles in Appendix B.
4.0 IDENTIFICATION OF EXPOSURE PATHWAYS
The purpose of this section is to identify the most significant
potential pathways through which
individuals may be exposed to the contaminants of concem in various
media at and in the
vicinity of the GCL Tie & Treating site. It is based on the
Exposure Pathways Analysis Report
submitted to USEPA in July 1993. The analyzed exposure pathways
were developed based upon
data gathered during the Removal Action, Subsurface Soil
Investigation (SSI) and from a site
visit by Ebasco Environmental personnel in July 1993. Hydrology,
geology and current land use
information from the Removal Action and SSI was used. In
identifying these pathways both
current and potential future land use of the site and surrounding
area will be considered.
As defined in the Risk Assessment Guidance for Superfund (RAGS,
1989), an exposiu-e pathway is composed of the following
elements:
• A source and mechanism of chemical release to the
environment
• An environmental transport medium (e.g., soil) for the released
chemical
• A point of potential contact by humans or animals with the
contaminated medium
and
• A route of exposure (e.g., ingestion, inhalation, and dermal
contact)
In this RA pathways are identified for the No Action alternative,
assuming no site remediation has occurred. The calculated risks
include contaminant concentrations found in site soil prior to the
EPA Removal Action, as well as later SSI soil sampling results.
This RA also assumes that no additional restrictions to site access
or use exist The goal is to determine whether it .is
D0065I,' vfi^'OOl 13 400338
feasible for individuals to enter the site areas or engage in
activities resulting in exposure to site-
related contaminants.
There are three general routes through which individuals could
potentially be exposed to chemical
contamination in soil at the GCL Tie & Treating site;
ingestion, inhalation and dermal contact.
The following subsections describe the possible sources, receptors
and exposure pathways
relevant to soil considering both current and potential future land
use. An identified pathway
does not imply that exposm-es are actually occurring, only that the
potential exists for the
pathway to be complete.
4.1 Contaminant Source Analysis
Based upon observations and limited data, the major source area for
the principal contaminant, creosote, is the westem portion, or GCL
property section, of the site. Due to past practices of open
drying, the documented spill, and nature of the wetlands fill
material, the entire area of approximately 26 acres must be
considered to have some degree of contamination. The area of
greatest contamination, with soil concentrations over 50,000 mg/kg
of PAHs, is located in the former tank area, north of the large
primary building containing the pressure tanks. Contamination may
be released to the air, wetlands, surface water sediments or
groundwater pathways from the contaminated soils through
solubilization of creosote components, volatilization of some
components, migration of nonaqueous phase liquids, and physical
transport of contaminated soil particles. Only soil pathways are to
be considered in this FFS; other media- specific pathways will be
evaluated in the RI/FS for the site.
GCL Tie & Treating and other industries used a variety of
chemicals over a period of many
years, for various purposes. Accidental spills, discharges, storage
tanks, drip areas, dump areas
and other processes are all considered potential contaminant
sources. The resulting soil
contamination is considered a source of contamination to
groundwater, which will be addressed
in a subsequent investigation.
4.2 Receptor Analysis
Six potential receptor populations were identified for exposure to
GCL Tie & Treating site-related
contaminants in soil in present/future use scenarios. Off-site
adult and young child residents;
adult and older child trespassers; and on and off-site worker
potential exposure pathways were
included in this risk evaluation.
eSBM^ 14 400339
4.3 Exposure Pathway Analysis
There are three general routes through which individuals could
potentially be exposed to chemical contamination in soil and other
environmental media at the GCL Tie & Treating site; inhalation,
ingestion, and dermal contact. An identified pathway does not imply
that exposures are actually occurring, only that the potential
exists for the pathway to be complete. Several media-specific
pathways for contaminant migration and exposure exist. These
include inhalation and ingestion of contaminants in airborne soil,
surface water mnoff and groundwater, and direct dermal contact with
water, soil or sediment. Figures 3 and 4 illustrate the potential
current and future exposure pathways for this site.
Pathways Assessed in the FFS Risk Assessment
There is potential exposure resulting from windborne contamination.
The soil mounds on site are largely covered. However, additional
creosote contaminated soil on-site is still exposed to the
environment, potentially venting the volatile components of
creosote to the atmosphere. According to a NYSDEC official, there
have been complaints from the surrounding businesses of the odors
emanating from the facility during the summer months (Site
Assessment Sampling Report, D. Perera, undated). The exposed soil
is also subject to windborne movement of contaminated soil
particles. The proximity of both working and residential
communities represent significant receptors for the airborne
volatile and soil contaminants via inhalation and ingestion. Site
trespassers may also be exposed to site windborne contaminants. As
directed by USEPA, the inhalation pathway risk analysis is limited
to inhalation of particulates.
Exposure through direct contact with creosote contaminated soils
and materials is also a potential
pathway of concem for site trespassers and future on-site workers.
Employees on adjacent sites,
as well as other trespassers, may be exposed in areas where wood
treating operations previously
occurred. In addition, employees from surrounding industries use
the numerous footpaths through
and around the site to gain access to the shopping center across
Delaware Avenue from the site.
This potential exposure route has been partially mitigated by
erection of additional fencing during
the EPA removal action.
Pathways to be addressed in the RIIFS Risk Assessment
The following pathways will not be addressed in the FFS Risk
Assessment, but during the RI/FS
and are included only to provide a full characterization of
potential exposure pathways for this
site:
FIGURE 3
Current Use Receptors Current Use Receptors
Primary Source Secondary Source
5*5 nGURE4
GCL TIE & TREATING SITE RISK ASSESSMENT FUTURE USE SOIL
EXPOSURE PATHWAYS
Future Use Receptors
Site Trespassers
Child Adult
Industrial and ->
Commercial Activities
Spill/Discharge -> Soil
O CD
D0065.LYN 17
There is potential contaminant migration via surface water runoff.
The GCL site is located in
a low-lying area that receives a large amount of water during
storms. The ground quickly
becomes saturated, generating surface runoff. In areas where the
rainwater forms pools, the water
has been observed as dark brown in color. In addition, a dark
colored leachate with a noticeable
oily sheen has been observed emanating from the base of the soil
mounds. The runoff from the
western portion of the site drains into the adjacent wetlands area,
posing a threat to the biotic
communities. The ranoff on the eastern portion of the site is
channeled through a drainage
network toward the main section of the Village of Sidney,
potentially exposing the population
to dermal contact and possible inhalation hazards. Sediment in the
wetlands and drainage
network may also be impacted. Both the drainage network and the
effluent from the wetlands
impoundment empty into the Susquehanna River. This poses a
potential threat to the river's use
for recreation and as a fishery.
There is also potential migration through groundwater
contamination. Leaching from the
contaminated soils through the overburden poses a threat to
existing drinking water wells. There
are also several springs in the area where ingestion, inhalation,
and dermal contact represent
hazards. The presence of free creosote product at the surface and
potentially in the subsurface
increases the potential for contamination of the bedrock aquifer
with dense nonaqueous phase
liquids (DNAPLs).
Present Use Exposure Pathways
At the GCL Tie & Treating site chemical contaminants exist in
surface, and potentially in
subsurface soils. Ingestion and inhalation of particulates by
off-site workers and local residents
(adult/young child) and ingestion, inhalation and dermal contact by
older child and adult
trespassers will be considered completed present use pathways in
the FFS Risk Assessment.
Reasonable Maximum Exposure (RME) scenarios will be analyzed, and
Average Case (central
tendency) scenarios will be considered should the calculated
potential carcinogenic risks exceed
1x10" , or if the Hazard Index is greater than 1.0.
Future Use Exposure Pathways
The present use exposure scenarios via all pathways previously
identified will be assumed to extend indefinitely into the future
in the exposure analysis. It is expected that site use will remain
the same or be used for similar industrial activities for an
indefinite period of time. Local land use pattems (mixed
residential/commercial/industrial) are not expected to
change.
Current conditions at the site indicate that soil ingestion,
inhalation, and dermal contact for
industrial/commercial receptors should be considered completed
future use pathways. Future on-
Doo65iyN 18 400^43
site workers are assumed to be exposed to contaminants via dermal
contact, in addition to the
other present use pathways. RME, and, if calculated risks exceed
1x10" or the HI exceeds 1.0,
Average Case scenarios will be analyzed.
Figures 3 and 4 summarize the current and future soil exposure
pathways, illustrating potential contaminant pathways from their
sources to these six receptors.
5.0 HAZARD IDENTIHCATION
For chemicals that exhibit noncarcinogenic (e.g., systemic)
effects, many authorities consider
organisms to have repair and detoxification capabilities that must
be exceeded by some critical
concentration (threshold) before the health effect is manifested.
For example, an organ can have
a large number of cells performing the same or similar functions
that must be significantly
depleted before an effect on the organ is seen. This threshold view
holds that a range of
exposures from just above zero to some finite value can be
tolerated by the organism without an
appreciable risk of adverse effects.
Health criteria for chemicals exhibiting noncarcinogenic effects
for use in risk assessment are generally USEPA reference doses
(RfDs) or reference concentrations (RfCs) developed by the RfD Work
Group. The RfD is an estimate of a daily exposure level for humans
that is likely to be without an appreciable risk of deleterious
effects during a lifetime. For those chemicals for which the USEPA
has not derived verified RfDs, health criteria used in a risk
assessment may be derived from information provided in the USEPA
Health Effects Assessment Summary Tables (HEAST), IRIS, Office of
Drinking Water Health Advisories (HAs), Office of Drinking Water
Maximum Contaminant Level Goals (MCLGs), or National Ambient Air
Quality Standards (NAAQS). The RfD is expressed in units of mg
chemical/kg body weight-day. In general, the RfD is an estimate of
an average daily exposure to an individual (including sensitive
individuals) below which there will not be an appreciable risk of
adverse health effects during a lifetime. The RfD is derived using
conservative safety factors (e.g., to adjust from animals to humans
and to protect sensitive subpopulations) to ensure that it is
unlikely to underestimate the potential for adverse noncarcinogenic
effects to occur. A RfC is an estimate of the daily exposure that
is likely to be without deleterious effects via inhalation. The
purpose of the RfD/RfC is to provide a benchmark against which
estimated doses (e.g., those projected from human exposure to
various environmental conditions) might be compared. Doses that are
significantly higher than the RfD/RfC may indicate that an
inadequate margin of safety could exist for exposure to that
substance and that an adverse health effect could occur.
400344
5.2 Health Effects Criteria for Potential Carcinogens
For chemicals that exhibit carcinogenic effects, USEPA as well as
other scientific authorities recognize that one or more molecular
events can evoke changes in a single cell or a small number of
cells that can lead to malignancy. This is the non-threshold theory
of carcinogenesis, which purports that any level of exposure to a
carcinogen can result in some finite possibility of causing cancer.
Generally, regulatory agencies assume the non-threshold hypothesis
for carcinogens in the absence of information concerning the
mechanisms of carcinogenic action for the chemical. USEPA's
Carcinogen Risk Assessment Verification Endeavor (CRAVE) has
developed slope factors (i.e., dose-response values) for estimating
excess lifetime cancer risks associated with various levels of
lifetime exposure to potential human carcinogens. The slope factor
estimate [in units of (mg/kg body weight-day)"*] is a number which,
when multiplied by the lifetime average daily dose of a potential
carcinogen (in mg/kg body weight-day), yields the upper-bound
lifetime excess cancer risk associated with exposure at that dose.
Upper-bound is a term used by USEPA to reflect the conservative
nature of the slope factors; risks estimated using slope factors
are considered unlikely to underestimate actual risks but they may
overestimate actual risks for a given exposure. Excess lifetime
cancer risks are generally expressed in scientific notation and are
probabilities. An excess lifetime cancer risk of 1x10" (one in one
million), for example, represents the incremental probability that
an individual will develop cancer as a result of exposure to a
carcinogenic chemical over a 70-year lifetime under specified
exposure conditions.
In practice, slope factor estimates are derived from the results of
human epidemiology studies or chronic animal bioassays. The animal
studies must usually be conducted using relatively high doses in
order to detect possible adverse effects. Since humans are expected
to be exposed at lower doses than those used in the animal studies,
the data are adjusted by using mathematical models. The data from
animal studies are typically fitted to the linearized multistage
model to obtain a dose-response curve.
The 95th percentile upper confidence limit slope of the
dose-response curve, subject to various adjustments and an
inter-species scaling factor is applied to conservatively derive
the slope factor estimate for humans. Dose-response data derived
from human epidemiological studies are fitted to dose-time-response
curves on an ad-hoc basis. These models provide rough, but
reasonable, estimates of the upper limits on lifetime risk. Slope
factor estimates based on human epidemiological data are also
derived using very conservative assumptions and, as such, they too
are considered unlikely to underestimate risks.
^ . i - 20 ^^^3^5
Therefore, while the actual risks associated with exposures to
potential carcinogens are unlikely to be higher than the risks
calculated using a slope factor estimate, they could be
considerably lower (if exposure estimates are conservative).
In addition, there are varying degrees of confidence in the weight
of evidence for carcinogenicity
of a given chemical. USEPA (1989) has proposed a system for
characterizing the overall weight
of evidence for a chemical's carcinogenicity based on the
availability of animal, human and other
supportive data. The weight-of-evidence classification is an
attempt to determine the likelihood
that an agent is a human carcinogen and thus qualitatively affects
the estimation of potential
health risks. Three major factors are considered in characterizing
the overall weight of evidence
for carcinogenicity: 1) the quality of evidence from human studies,
2) the quality of evidence
from animal studies which are combined into a characterization of
the overall weight of evidence
for human carcinogenicity, and 3) other supportive information
which is assessed to determine
whether the overall weight of evidence should be modified. USEPA's
final classification of the
overall weight of evidence has the following five categories:
Group A - Human Carcinogen
This category indicates that there is sufficient evidence from
human epidemiological
studies to support a causal association between an agent and
cancer.
Group B - Probable Human Carcinogen
This category generally indicates that there is at least limited
evidence from epidemiological studies of carcinogenicity to humans
(Group Bl) or that, in the absence of adequate data in humans,
there is sufficient evidence of carcinogenicity in animals (Group
B2).
Group C - Possible Human Carcinogen
This category indicates that there is limited evidence of
carcinogenicity in animals in the
absence of data on humans.
Group D - Not Classified
This category indicates that the evidence of carcinogenicity in
animals is inadequate.
400346 D0065.LYN ,, , 2 1
Group E - No Evidence of Carcinogenicity in Humans
This category indicates that there is no evidence for
carcinogenicity in at least two adequate animal tests in different
species or in both epidemiological and animal studies.
Slope factors are developed based on epidemiological or animal
bioassay data for a specific route
of exposure, either oral or inhalation. For some chemicals, such as
chloroform, sufficient data
are available to develop route-specific slope factors for
inhalation and ingestion exposure routes.
5.3 Toxicological Assessment
Table 3 summarizes the chronic oral and inhalation reference doses
and reference concentrations
(RfDs/RfCs) and slope factors (SFs) used to analyze noncarcinogenic
effects and carcinogenic
risks of the COCs. These criteria were the most current data,
obtained from February 1994
sessions of the Integrated Risk Information System (IRIS) and 1993
Health Effects Assessment
Summary Tables (HEAST). For carcinogenic PAHs, toxic equivalency
factors (TEFs), as related
to benzo(a)pyrene are also included. These TEFs were obtained
through communications with
EPA Region II Risk Assessment staff. Chronic toxicity indices were
used for residential
exposure. Toxicological profiles are included in Appendix B for
those chemicals detected on-
site, for which information is available.
6.0 HEALTH RISK CHARACTERIZATION
According to guidelines for preparing risk assessments for RI/FS
purposes, the potential adverse
effects on human health should be assessed where possible by
comparing chemical concentrations
found in environmental media at or near the site and at receptor
locations with numerical
Applicable or Relevant and Appropriate requirements (ARARs) or
other guidance that has been
developed for the protection of human health or the envu-onment.
Thus this section presents a
comparison to available ARARs and "To Be Considered" criteria
(TBCs). Exposure point
concentration estimates, modeling, chemical-specific methods of
evaluation and exposure
frequency parameters are also presented.
6.1 Health-Based Applicable or Relevant and Appropriate
Requirements (ARARs) and To
Be Considered (TBC) Criteria
ARARs or other guidance are first identified for the chemicals of
potential concem. Where chemical-specific ARARs are available for
an environmental medium, they are compared with average and maximum
concentrations observed in that medium at points of potential
exposure. USEPA interim guidance on ARARs (USEPA, 1987) defines
them as follows:
D0065.LYN 2 2
TOXICITY DATA FOR NONCARCINOGENIC AND CARCINOGENIC RISK
EVALUATION
Sheet 1 of 2
(mg/Kg-day) (mg/Cu.m) (mg/Kg-day)
Carcinogen Slope Factor
SF Weight Unit Risk SF Weight (Oral) of (Inhalation) inhalation)
of
(mg/Kd-day)-l Evidence (ug/Cu.m)-l (mg/Kg-day)-I Evidence
7.5E-03
6.1E-03
5.2E-02
TOXICITY DATA FOR NONCARCINOGENIC AND CARCINOGENIC RISK
EVALUATION
Sheet 2 of 2
(mg/Kg/day) mg/Cu.m) (mg/Kg-day)
Carcinogen Slor>e Factor
SF Weight Unit Risk SF Weight (Oral) of (Inhalation) (Inhalation)
of
(mg/Kg-day)-l Evidence (ug/Cu.m)-l (mg/Kg-day)- Evidence
1 1 7.3E+00
Group A: Human Carcinogen. Sufficient evidence from epidemiologic
studies to support a casual association between exposure and
cancer. Group Bl: Probable Human Carcinogen. Limited evidence of
carcinogenicity in human from epidemiological studies. Group B2:
Probable Human Carcinogen. Sufficient evidence of carcinogenicity
in animals. Inadequate evidence of carcinogenicity in humans. Group
C: Possible Human Carcinogen. Limited evidence of carcinogenicity
in animals. Group D: Not classified. Inadequate evidence of
carcinogenicity in animals. Note: - No data/Not available.
Dq YN
"Applicable requirements" means those cleanup standards, standards
of control, and other substantive environmental protection
requirements, criteria, or limitations promulgated under Federal or
State law that specifically address a hazardous substance,
pollutant, contaminant, remedial action, location, or other
circumstance at a CERCLA site. "Applicability" implies that the
remedial action or the circumstances at the site satisfy all of the
jurisdictional prerequisites of a requirement.
"Relevant and appropriate requirements" mean those cleanup
standards, standards of control, and
other substantive environmental protection requirements, criteria,
or limitations promulgated under
Federal or State law that, while not "applicable" to a hazardous
substance, pollutant, contaminant,
remedial action, location, or other circumstance at a CERCLA site,
address problems or situations
sufficiently similar to those encountered at the CERCLA site that
their use is well suited to a
particular site.
The relevance and appropriateness of a requirement can be judged by
comparing a number of
factors, including the characteristics of the remedial action, the
hazardous substances in question,
or the physical circumstances of the site, with those addressed in
the requirement. It is also
helpful to look at the objective and origin of the requirement For
example, while RCRA
regulations are not applicable to closing undisturbed hazardous
waste in place, the RCRA
regulation for closure by capping may be deemed relevant and
appropriate.
A requirement that is judged to be relevant and appropriate must be
complied with to the same
degree as if it were appUcable. However, there is more discretion
in this determination: it is
possible for only part of a requirement to be considered relevant
and appropriate, the rest being
dismissed if judged not to be relevant and appropriate in a given
case.
Non-promulgated advisories or guidance documents issued by federal
or state governments do not have the status of potential ARARs.
However, these "To Be Considered" (TBCs) criteria may be examined
in determining the necessary level of cleanup for protection of
health or the environment.
Only those ARARs, advisories, guidance or TBCs that are
chemical-specific requirements [i.e., those requirements which "set
health or risk-based concentration limits or ranges in various
environmental media for specific hazardous substances, pollutants,
or contaminants" (USEPA, 1987)], as opposed to ARARs/TBCs which are
classified as action-specific or locational requirements, are used
in this Risk Assessment. For soils, only TBCs from the NYSDEC
Technical and Administrative Guidance Memorandum (TAGM)
HWR-94-4046: Determination of Soil Cleanup Objectives and Cleanup
Levels are available.
v^ 9. 400350
The classes of ambient or chemical-specific health-based ARARs/TBCs
that are considered
pertinent to the Risk Assessment for the site are discussed
below.
6.1.1 Soil Contamination Compared with ARARs and TBCs
Chemical-specific TBCs for chemicals of concem and the contaminant
concentrations detected
are presented in Table 4. Both health-based cleanup levels and the
recommended soil cleanup
objective, which may or may not be health-based are included. The
range of detected values,
arithmetic means and frequency of detection are summarized in
Appendix A. A comparison of
these values reveals soil contamination at levels exceeding TBC
criteria.
6.2 Estimation of Exposure Point Concentrations
Estimates of exposure point concentrations are needed as part of
the quantitative risk evaluations since these estimates are used
along with the exposure scenarios to estimate chronic daily intake
and subsequent human health risks.
Estimation of exposure point concentrations for all ingestion,
dermal contact and soil inhalation
pathways are based on measured concentrations of the COCs. The
representative exposure point
concentration was taken as the 95% UCL of the arithmetic mean of
the log transformed data (or
the maximum measured concentration if the 95% UCL exceeds the
maximum) of the compound
for the matrix in question using the reasonable maximum exposure
case. The 95% UCL was calculated using current USEPA criteria
(USEPA, 1992) from the average, variance and standard error of the
natural log transformed data using the following equation:
95% UCL = EXP [x + 0.5S^ + HSJ
where x is the mean of the natviral log transformed data, S is the
variance on the transformed data, S(, is the standard error on the
transformed data and H is the t-value for the transformed data.
(The latter value differs from the tabulated t-values because of
the natural log transformation of the data.) This calculation
includes all analyses for a given compound in a given matrix with
the non-detect analyses evaluated at one-half of the sample
specific quantitation limit. This is considered a reasonable and
conservative, representative concentration for non-detect
results.
For the average case scenarios, the 95% UCL (or the maximum
concentration, if it was less than the 95% UCL) was used as the
exposure point concentration.
''W)wiM~w» 26
• O
GCL TIE AND I'REATING SITE CHEMICALS OF POIENTIAL CONCERN
ARARSATBCS AND LEVELS OF DETECTION IN SOIL
Maximum Concentration Detected (mg/kg)
2.00E-01 4.10E+00 4.80E-01 1.20E-01 6.80E-K)0 3.50E+00 4.10E+02
1.67E+04 1.36E+04 4.40E+03 7.06E+03 2.11E+03 1.40E+04 4.74E+02
5.54E+04 3.68E+04 4.54E+04
NY State Health-Based Criteria** (mg/kg)
9.30E+01 8.00E+03 1.14E+02 1.40E+01 2.00E+05 2.00E+04
NA 2.00E+04 2.24E-01 6.10E-02
NA NA NA
NY State Soil Cleanup Objective**
(mg/kg)
l.OOE-01 5.50E-H00 3.00E-01 1.40E+00 1.20E+00 1.50E+00 4.10E+01
5.00E+01 2.24E-01 6.10E-02 l.lOE+00 l.lOE+00 4.00E-01 1.43E-02
5.00E+01 5.00E+01 5.00E+01
to 1 ^
D0065.LYN 27
TABLE 4
ARARSA'BCS AND LEVELS OF DETECTION IN SOIL
Sheet 2 of 2
Maximum Concentration Detected (mg/kg)
5.50E-01 6.79E+04 2.64E+03 1.67E+03 2.80E+01 2.30E-01 1.66E+02
2.20E-02 2.40E-02 5.00E-03 4.80E-02 2.10E-04 1.60E-01 9.70E+00
1.15E-K)2* 1.15E+02*
NY State Health-Based Criteria** (mg/kg)
5.00E+01 3.00E+02 5.00E+04
NA 2.00+02
2.00E+03 1.23E+02 1.60E-01 7.70E-02 2.10E+00 2.10E+00 5.40E-01
l.OOE+00
NA NA NA
(mg/kg)
5.00E+01 1.30E+01 3.00E-02
NA 2.20E-01 5.00E+01 l.OOE-01 l.OOE-01 2.00E-02 2.10E+00 2.10E+00
5.40E-01 l.OOE+00 10 or SB 10 or SB 10 or SB
o * - Chromium sampling was unspeciated, maximum provided is total
chromium. ** - NYSDEC Technical and Administrative Guidance
Memorandum:
Determination of Soil Cleanup Objectives and Cleanup Levels,
Revised 1/24/94. NA - Not Available SB - Site Background
D0065.LYN 28
6.3 Exposure Point Concentration Modeling
Estimation of exposure point concentrations for all ingestion and
dermal contact pathways are based on measured concentrations of the
contaminants of concern. In accordance with RAGS (1989), the
exposure point concentration was taken as the 95% UCL of the
arithmetic mean of the log-transformed data of all the analyses for
the matrix in question in a given area, for the reasonable maximum
case. For those compounds where the maximum detected value was less
than the 95% UCL, the maximum detected value was used. As required
by EPA guidance, the average case exposure point concentrations are
the same as the RME exposure point concentrations.
Exposure point concentrations for soil particulate inhalation
scenarios were estimated using
chemical concentrations in soil and a standard default measurement
of suspended soil particles
in air. The models and other methods which were used to estimate
the exposure point
concentration are discussed in detail below.
Cowherd Model
A predictive emission factor model was used to estimate respirable
particulate emissions. The
Cowherd model uses surface and meteorological data to determine the
concentration of
particulates suspended by wind erosion. These calculated emissions
are then used to develop
ambient soil bome contaminant concentrations and the resulting
potential exposure via inhalation.
This model is referenced in "Rapid Assessment of Exposure to
Particulates Emissions from
Surface Contamination Sites" (USEPA, 1985b).
A combination of default factors and site-related values were used
in applying this model to the
GCL property risk assessment.
6.4 Estimation of Pathway-Specific Parameters
In this section, parameters are defined for each of the exposure
pathways presented in Section 3.0 for both the reasonable maximum
and average case scenarios. Average case scenarios were developed
for those RME scenarios that exceeded a 1 x 10" carcinogenic risk
or Hazard Index of 1.0. These parameters are specific to each
exposure scenario and will be used along with the exposure point
concentrations previously defined to determine daily chronic or
subchronic intake rates for each of the indicator contaminants. One
set of parameters is defined for each exposure pathway for the
reasonable maximum and average exposure case. As discussed in
Section 4, exposure pathways were defined for soil for several
populations under present use and potential future use scenarios.
Parameters specific to each exposure pathway were developed for
each
^ * . « ,Q 4003?4
population as appropriate for present use and futirre use scenarios
under reasonable maximum, and when necessary, average case exposure
conditions. The present and futvu-e use scenario parameters used in
this risk assessment are defined in detail in Tables 5 through
16.
For the evaluation of present-use risks to human health,
present-use conditions are assumed to
continue indefinitely into the future. The future-use conditions
are evaluated assuming that the
site wUl be used for commercial or industrial purposes.
General Exposure Parameters
Age-specific exposure parameter distributions were developed for
each exposed population to account for variation in exposure over
an individual's lifetime for each exposure scenario. The parameters
used in this FFS Risk Assessment were included in the July 1993 GCL
Tie & Treating Exposure Pathways Analysis Report and approved
by USEPA. These distributions were largely based on data contained
in the Risk Assessment Guidance for Superfund (RAGS, 1989). Three
age groups were specified ages 0-6 (young children), ages 6-12
(older children) and ages 18-70 years (adults). For carcinogens
only, a six-year exposure rate was assumed for children (USEPA
Region II criteria).
Residential exposure durations were considered to be the years
spent at one residence based on
maximum and average case estimates (USEPA, 1989). Noncarcinogenic
hazard index values
were calculated for each group, but were not considered to have
additive effects over a lifetime.
Frequencies of exposure to contaminants for the various populations
were developed based on
RAGS (1989) and site-specific information.
The number of days per year that an individual might be exposed to
site contamination varied
depending upon age, vocation and exposure route. Resident exposures
are assumed to occur on
a daily basis, with 15 days per year spent away from home.
Three body weight groups were specified for the receptors, adults
(18-70 years) at 70 kg, older children (6-12 years) at 35 kg, and
young children (0-6 years) at 15 kg, in accordance with RAGS and
other risk assessment guidance.
Soil Exposure Pathway Parameters
In this baseline Risk Assessment only soil contamination was
evaluated. In the current and
future-use scenarios, residents, trespassers and workers were
assumed to be exposed to site soils.
^'S!^M!^^' 30 4003^5
TABLE 5
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
RME
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Oif-Site Residents - Young Children
Exposure Route
12<^^
0.83®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
400356
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
RME
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Off-Site Residents - Adults
8(3)
0.83®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
32 400357 D0065I.YN
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
AVERAGE
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Off-Site Residents - Young Children
Exposure Route Ingestion
Ingestion Rate (mg/day) 200®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
D006:
400358
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
AVERAGE
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Off-Site Residents - Adults
Ingestion
43 ^
9(2)
70®
1
100^^>
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
*.#p M ituui ' I ^ S ^ V N ' 34 40035^
TABLE 9
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
RME
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Site Trespassers - Older Children
Exposure Route
5®
0.83®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
DOO65/YN" t s k v n 1)1 35 4 U U a b
TABLE 10
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
RME
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Site Trespassers - Adults
Exposure Time (hours/day)
8(3)
0.83®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
0<Jfc i- {•*' >i A n of t I D0065iYN 3 6 4UUwVX
TABLE 11
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
AVERAGE
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Site Trespassers - Older Children
Exposure Route Ingestion
Ingestion Rate (mg/day) 200®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
D0065
4003P2
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
AVERAGE
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Site Trespassers - Adults
Ingestion
43®
g(i)
70®
1
100®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
s;%oui D0065I.YN 38 400363
TABLE 13
GCL TIE 8c TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
RME
SOIL EXPOSURE PATHWAYS FUTURE USE SCENARIO
Receptor: On-Site Workers
gO)
0.83®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
Doo65.i-'^||^y y ^ 39 4003B4
TABLE 14
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
AVERAGE
SOIL EXPOSURE PATHWAYS FUTURE USE SCENARIO
Receptor: On-Site Workers
Exposure Route Ingestion
Ingestion Rate (mg/day) 100®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991)
TABLE 15
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
RME
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Off-Site Workers
Inhalation
250®
25®
70®
1
g(3)
0.83®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991) (3) Dermal Exposure Assessment: Principles and
Applications (EPA, 1992)
D0065:
GCL TIE & TREATING SITE PARAMETERS AND ASSUMPTIONS TO CALCULATE
AVERAGE
SOIL EXPOSURE PATHWAYS CURRENT/FUTURE USE SCENARIO
Receptor: Off-Site Workers
Ingestion
250®
25®
70®
1
50®
(1) Risk Assessment Guidance for Superfund (EPA, 1989) (2) Human
Health Evaluation Manual, Supplemental Guidance, "Standard Default
Exposure
Factors" (EPA, 1991)
400367 D0065.LYN 4 2
Residents were assumed to be exposed to soil via ingestion,
inhalation and dermal contact. The
adults were assumed to be exposed for 30 years, 350 days per year,
and children were assumed
to be exposed for 6 years (carcinogenic scenario only), 350 days
per year, in the reasonable
maximum case. In the average case, adults were assumed to be
exposed for 9 years (RAGS,
1989).
For soil ingestion exposure parameters, adult residents were
assumed to consume an average of
100 mg/day. Other potential receptors' exposure parameters vary, as
shown in Tables 5 through
16.
7.0 QUANTITATIVE RISK CHARACTERIZATION
The results of the quantitative assessment of human health risks
associated with exposure
pathways and scenarios described previously, and the methods used
to perform the quantitative
analysis are presented below. Potential health risks were
calculated for baseline conditions, i.e.,
with no treatment of soil prior to contact with the receptor. The
approach taken in this section
is to combine the concentration data, exposure scenarios and
chemical intake models, and critical
toxicity values, to generate quantitative estimates of carcinogenic
and noncarcinogenic health
risks for the present and future use reasonable maximum case and
average case (when necessary)
exposure scenarios. These factors are combined using methods
defined by the EPA for exposure
and risk assessment for Superfund and other hazardous waste sites.
These methods are discussed
in detail in Section 7.1.
Section 8 provides a discussion of the risk results for the various
exposure pathways and
scenarios.
7.1 Ouantitative Risk Assessment Methods
To quantitatively assess the potential risks to human health
associated with present and future use
scenarios, chronic daily intakes (CDIs) were calculated for each
ingestion and inhalation exposure
pathway, and Dermally Absorbed Doses (DADs) were calculated for the
dermal exposure
pathway using the estimated exposure point concentrations. Formulae
for each soil exposure
pathway are summarized in each spreadsheet in Appendix C. CDIs and
DADs are expressed as
the amount of a chemical an individual would be exposed to per unit
body weight per day (e.g.,
mg/kg/day). The CDI and DAD are averaged over a lifetime for
carcinogens for adults (RAGS,
1989) and over a six year period for children. The CDI and DAD are
averaged over the annual
exposure period for noncarcinogens (RAGS, 1989).
DooeS^COUt 43
The estimated CDIs and DADs are then combined with health effects
criteria (reference doses and slope factors) to quantitatively
estimate potential human health risks. For potential carcinogens,
excess lifetime cancer risks are obtained by multiplying the
CDI/DAD for the contaminant under consideration by its slope factor
(SF). Cancer risks are assumed to be additive. Therefore, the sum
of these values is then evaluated as the potential for excess
cancer risks. The goal of developing a quantitative risk assessment
is to estimate the potential upper-bound risk at the site in the
absence of remediation.
Potential risks for noncarcinogens are presented as the ratio of
the CDI/DAD to the reference dose (RfD) (i.e., CDI/RfD). The sum of
all the ratios of chemicals under consideration for a given pathway
is called the hazard index. The hazard index is useful as a
reference point for gauging the potential noncarcinogenic effects
of environmental exposures to complex mixtures. In general, hazard
index values which are less than one are not likely to be
associated with any health risks. If the hazard index is greater
than one for the total of all chemical HI values, the compounds can
be segregated according to their critical effects (target organs)
and separate hazard index values can be derived for each effect
(USEPA 1986a). A conclusion should not be categorically drawn,
however, that all hazard index values less than one are
"acceptable" or that hazard index values greater than one are
"unacceptable". This is perhaps a consequence of the one order of
magnitude or greater uncertainty inherent in estimates of the RfD,
as discussed further in Section 11.
In accordance with USEPA's guidelines for evaluating the potential
toxicity of complex mixtures
(USEPA, 1986b), it is assumed that the toxic effects of the
site-related chemicals would be
additive. Lifetime excess cancer risks and the CDI/RfD ratios are
summed to indicate the
potential risks and effects associated with mixtures of potential
carcinogens and noncarcinogens,
respectively. In the absence of specific information on the
toxicity of the mixture to be assessed
or on similar mixtures, USEPA guidelines generally recommended
assuming that the effects of
different components in the mixtures are additive when affecting a
particular organ or system.
Synergistic or antagonistic interactions may be taken into account
if there is specific information
on particular combinations of chemicals. In this risk assessment,
it is assumed that the potential
effects of the site-related chemicals are additive, and no
synergistic or antagonistic effects exist.
The CDIs/DADs of chemicals of potential concem for potentially
exposed individuals are first calculated. To determine these
CDIs/DADs, the assumptions concerning chemical concentrations
(exposure point concentrations) and exposure conditions such as
fi-equency, duration, and time of exposure, are used together with
media intake parameters. For each exposure scenario, a reasonable
maximum case is considered. The reasonable maximum case scenario is
intended to place an upper-bound limit on the potential risks by
combining plausible maximum exposure estimates with upper-bound
health criteria. For the reasonable maximum case, the exposure
point
^ ^ £ ^ 44 4003^9
and duration of exposure.
8.0 RESULTS OF RISK CALCULATIONS
The following is a receptor-specific summary of the results of the
potential carcinogenic and
noncarcinogenic risk calculations for the reasonable maximum and
average case soil exposure
scenarios for the GCL Tie & Treating site. Reasonable maximum
exposure (RME) case potential
carcinogenic risks and Hazard Indices were calculated for all
exposure pathways approved by
EPA following review of the July 1993 GCL Tie & Treating
Exposure Pathways Analysis
Report. Average case potential risk was calculated for those RME
exposure pathways exceeding
either a Hazard Index of 1.0 or carcinogenic risk of 10" . This
includes potential carcinogenic
risk from soil ingestion for all receptors. The risk calculation
spreadsheets are included as
Appendix C.
Residents, trespassers and workers were assumed to be exposed to
soil via several pathways in
the cmrent/future use scenarios.
8.1 Reasonable Maximum Case
The carcinogenic risk of incidental ingestion of soil contaminants
for adult and young child
residents is 2.67E-04 and 6.23E-04, respectively. Adult and child
trespasser risks are similar, at
2.67E-04 for both potential receptors, adults and older children.
On-site and off-site worker
potential risks are higher, at 9.54E-04. The majority of the risk
is due to the presence of
carcinogenic PAHs, particularly benzo(b)fluoranthene,
benzo(a)pyrene, dibenz(a,h)anthracene,
benzo(a)anthracene, benzo(k)fluoranthene and
indeno(l,2,3-cd)pyrene. Arsenic also significantiy
contributes to excess risk. The HI for incidental ingestion for
adult and child residents is below
the threshold of 1.0, at 4.92E-02 and 4.59E-01, respectively. Adult
and older child trespassers
have an HI of 4.94E-02 and 1.98E-01, respectively. Worker
noncarcinogenic potential impacts
were calculated to be 1.69E-01, also below the level of
concern.
Potential carcinogenic risk from the inhalation of airborne
particulate soil contaminants for adult and child residents is
3.49E-06 and 6.11E-06, respectively. Potential risks are 3.49E-06
and 1.09E-06 for adult and older child trespassers and 2.60E-06 for
both off-site and on-site workers. The risk is largely due to the
presence of carcinogenic PAHs, particularly benzo(b)fluoranthene.
Benzo(a)pyrene, dibenz(a,h)anthracene, arsenic and chromium also
contribute to risk. The calculated HI for inhalation is 6.19E-04
for adult, and 6.07E-03 for young child residents. Trespassers His
are 8.67E-04 and 1.08E-03 for adults and older children,
respectively. On-site
J ^ - O e i 45 460170
and off-site worker potential noncarcinogenic risks were calculated
to be 6.19E-04. Like ingestion, all inhalation His are below levels
of concem.
Dermal contact risk was calculated as 1.98E-07 for adult
trespassers and 5.51E-08 for older child
trespassers. On-site worker risks from dermal contact are at
5.09E-08.
8.2 Average Case
Ingestion average case potential carcinogenic risk is 1.23E-05 for
adult, and 2.32E-04 for young
child residents. Adult and older child trespassers face an average
case potential risk of 1.23E-05
and 9.92E-05, respectively. On-site worker risks were calculated at
1.99E-04, and off-site worker
risks at 9.94E-05.
9.0 COMBINING RISK LEVELS AND HAZARD INDEX VALUES ACROSS
PATHWAYS
Tables 17 through 19 present the combined potential carcinogenic
risk and Hazard Index for each
receptor considered to have multiple pathways of exposure under
reasonable maximum exposure
conditions, for present and future use scenarios at the GCL Tie
& Treating site. Adult and young
child residents, adult and older child tiespassers, and on and
off-site workers are all considered
to have multiple potential pathways of exposiu-e.
In the current and future use exposure scenario, off-site residents
were assumed to be exposed to soil via ingestion and inhalation. As
shown in Table 17, the combined carcinogenic potential risk is
2.70E-04 and 6.29E-04 for adult and child residents, respectively;
and the HI is 4.98E-02 for adults and 4.65E-01 for children. Table
18 illustrates the combined risk and HI for site trespassers and
Table 19 is a summary of worker potential risks and His.
10.0 QUALITATIVE DISCUSSION OF RISKS NOT QUANTITATIVELY EVALUATED
IN
THE RISK ASSESSMENT
The quantitative risk assessment of site matrices does not include
several compounds detected in the EPA Removal Action and Subsurface
Soil Investigation for several reasons. Some compounds did not meet
the frequency of detection criterion, or were not probable human
carcinogens detected above 1 ug/kg, while others lacked sufficient
toxicological data.
Contaminants are present in soil in a highly varied pattern. Some
potential source areas have minimal levels of a few contaminants in
soil.
t iV^ i^ 46 400371
TABLE 17
O
GCL TIE & TREATING SITE OFF-SITE RESIDENT RISK LEVELS AND
HAZARD INDEX VALUES
SUMMARY ACROSS EXPOSURE PATHWAYS PRESENT/FUTURE USE SCENARIOS
Present/Future Use Scenarios:
Exposure to Soil
Off-Site Resident Adults
3.49E-06 2.67E-04
6.11E-06 6.23E-04
6.19E-04 4.92E-02
6.07E-03 4.59E-01
Summation Results - Off-Site Resident Adults:
Carcinogenic Health Effects = 2.70E-04 Noncarcinogenic Health
Effects = 4.98E-02
Summation Results - Off-Site Resident Children:
Carcinogenic Health Effects = 6.29E-04 Noncarcinogenic Health
Effects = 4.65E-01
o o CO
1 TABLE 18
GCL TIE & TREATING SITE SITE TRESPASSER RISK LEVELS AND HAZARD
INDEX VALUES
SUMMARY ACROSS EXPOSURE PATHWAYS PRESENT/FUTURE USE SCENARIOS
Present/Future Use Scenarios:
Exposure to Soil
Carcinogenic Risk Levels Reasonable Maximum Exposure
3.49E-06 2.67E-04 1.98E-07
1.09E-06 2.67E-04 5.51E-08
8.67E-04 4.94E-02
1.08E-03 1.98E-01
Total Health Risk = Soil Inhalation + Soil Ingestion + Soil Dermal
Contact
Summation Results - Adult Trespassers:
CO SI V9
Carcinogenic Healtii Effects = 2.68E-04
Noncarcinogenic Health Effects = 1.99E-01
1) Inhalation 2) Ingestion
GCL TIE & TREATING SITE WORKER RISK LEVELS AND HAZARD INDEX
VALUES
SUMMARY ACROSS EXPOSURE PATHWAYS PRESENT/FUTURE USE SCENARIOS
Carcinogenic Risk Levels Reasonable Maximum Exposure
2.60E-06 9.54E-04 5.09E-08
6.19E-04 1.69E-01
6.19E-04 1.69E-01
Total Health Risk = Soil Inhalation + Soil Ingestion + Soil Dermal
Contact
Summation Results - On-Site Worker:
Summation Results - Off-Site Worker:
• M l
o Cdf * ^ J D0065 LYN
lib.
49
11.0 POTENTIAL PUBLIC WELFARE IMPACTS
Contamination at levels exceeding regulatory limits, and posing
potential carcinogenic and noncarcinogenic health impacts has been
detected in site soil. Additionally, the soil contamination may
preclude its future use as a commercial site. This may limit
redevelopment and decrease the value of the site and smrounding
properties.
12.0 UNCERTAINTY IN THE RISK ASSESSMENT
The quantitative assessment of health effects at hazardous waste
sites is inherently uncertain. This uncertainty arises from the
need to predict potential future health impacts (often quite subtie
or infrequent events) in the absence of observed health effects,
and on the basis of limited data concerning contaminant levels,
transport mechanisms, receptor behavior and the toxicologic
behavior of the chemicals present. In the face of this unavoidable
uncertainty, the general approach that has been employed in this
assessment is to first develop conservative estimates of
contaminant concentrations. Doses and health risks for each medium
were calculated for specified exposure routes and exposed
populations. For reasonable maximum case exposure, scenarios are
defined to provide additional information as to whether the
specific contaminant/pathway/receptor scenario is, in fact, likely
to be associated with adverse health effects. These reasonable
maximum case exposure scenarios, while providing a likely
assessment of contaminant exposiue and health risks, are still
uncertain, and contain a number of inherentiy conservative
assumptions which provide an additional "margin of ertor" for
interpreting the quantitative risk estimates. Sources of
uncertainty in this risk assessment are summarized in Table
20.
12.1 Uncertainties Associated with Sampling and Analytical
Procedures
A major group of factors contributing to uncertainty in the risk
analysis are the uncertainties in
exposiue point concentration estimates associated with the
sampling, analytical and modeling
procedures used to define contaminant levels in contaminated media.
In this assessment,
available data from the USEPA Removal Action and Subsiuface Soil
Investigation were used to
assess contaminant levels. This is in accordance with Superfund
Accelerated Cleanup Model
(SACM) guidelines.
An analysis of these data sets was performed, using the EPA
"Guidance for Data Useabihty in Risk Assessment," Part A. This
analysis shows that the data from the Removal Action increases the
uncertainty inherent in the calculated potential risks.
D0065.LYN 50 4 0 0 3 7 5
TABLE 20 Sheet 1 of 2
f t '
LIKELY MAGNITUDE OF UNCERTAINTY LEVEL OF BL\S INTRODUCED
Reasonable maximum case exposure
point concentrations calculated using
Highest contaminant levels used to
develop reasonable maximum case
exposure estimates when exceeded
calculation of reasonable maximum risk
Use of historical, removal action
data in risk assessment
meet risk assessment useability criteria
Likely upward bias.
Trench sampling design Moderate to high - data may not be
representative of site conditions
Particulate generation and transport
parameters instead of measured values.
Residential land use unlikely
Exposure estimates assume contaminants
are conservative over time
COCs are persistent
SUght upward bias
GCL TIE & TREATING SITE
CP - J
-a
SOURCE OF UNCERTAINTY LIKELY MAGNITUDE OF UNCERTAINTY LEVEL OF BL
.S INTRODUCED
Estimates of physiological, behavioral
residences and use of conservative parameters
Moderate upward bias
Estimates of exposure frequency and duration Moderate Moderate
upward bias
Estimates of contaminant contact rates,
intake factors
3. Toxicological Risk Characterization Methods
RfD/CDI ratios to characterize non-cancer
health effects
variable; uncertainty factors vary by orders of magnitude
RfDs are defined conservatively for most pollutants
Lack of toxicity criteria for certain
chemical detected on-site
for dermal contact
Calculated risks may be understated
SFs, Unear low-dose model to assess cancer risks Moderate to high -
most SFs are derived from
animal bioassay data
risk slopes
exposures are additive
D0065.LYN
I
52
Use of data from the Removal Action may result in elevated
contaminant concentrations being input to the risk assessment by
including pre-removal samphng results. There are also several data
quality concerns for Removal Action data. These concerns include
high detection limits, lack of a specific map for sampling
locations, uncharacterized areas of the site, and SOPs and field
records not being provided to the risk assessor.
Additional uncertainty comes from the limited analysis done on some
samples. Method Detection
Limits (MDLs) which were higher than concenfrations of concem, and
unverified data review
procedmes. Several data quaUty indicators, including data
completeness, comparability,
representativeness, precision and sampling accuracy are also
questionable for the Removal Action
data. All these factors add uncertainty to the resulting risk
estimates.
However, the Subsurface Soil Investigation (SSI) data provides an
appropriate data quality level
that mitigates some of this uncertainty. It is apparent from the
SSI data that while the Removal
Action data may increase overall concentrations, it does not
intioduce inappropriate chemicals
of concem. The SSI provides the chemical-specific data necessary to
meet the needs of the risk
assessment process.
The SSI sampling does present some additional uncertainty in terms
of site coverage and sample representativeness. The tiench
locations do not include several areas of the site. Therefore,
these areas, and the site are not fully characterized.
The determination of the contaminant concentrations which were used
in the exposure models also provides some uncertainty. Pursuant to
EPA directives, [Ebasco Environmental's March 7, 1990 meeting
regarding guidance issues from the Risk Assessment Guidance for
Superfund (RAGS, 1989)] it was determined that the contaminant
concentration used for the quantification of risk should be the 95%
UCL on the arithmetic mean of the log-transformed data for the RME
case. This value provides a conservative estimate of the reasonable
maximum risks when used with conservative exposure parameters. This
method, however, assumes that the data have a geometiic
distribution, which may contribute further to uncertainty, ff the
data for a given compound does not have a geometric distiibution,
the method used to calculate the UCL results is an inflated value
relative to the maximum value in the untransformed data.
Incorporation of these UCLs into the risk calculations would result
in an overly conservative estimate of risk which would not be
representative of the actual site conditions. Therefore, when the
95 percent UCLs on the arithmetic mean of the log-transformed data
exceeded the actual maximum contaminant concentrations detected,
the maximum contaminant concentration detected was used for the
risk calculations. Similar uncertainty exists fo