United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R04-90/077
September 1990
&EPA Super-fund
Record of Decision
Cabot/Koppers, FL
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50772-101
REPORT DOCUMENTATION i. REPORT NO. *•
PAGE EPA/ROD/R04-90/077
4. TtBe and SubtiOe
SUPERFUND RECORD OF DECISION
Cabot/Koppers, FL
-st Remedial Action - Final
7. ;•)
«. Performing Oroelnlatfon Neme end Addreee
4
»
12. aponeorlng Orfleniietlon Neme end Adi>eee
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
X Recipient1 e Acceeeion No.
S. Report 0»te
09/27/90
«.
0. Performing Orgenlation Rept No.
10. Pro|»clrt*ek/Work Unit No.
11. Contract(C) or G/«nt(G) No.
(C)
(G)
IX Type ol Report 4 Period Covered
800/000
14.
IS. Supplementary No lee
if. Abe«ec< (Umll:
The 99-acre Cabot/Koppers site is a pine tar and charcoal generation facility in
Gainesville, Alachua County, Florida. The site is underlain by shallow and intermediate
ao^iifers. Land in the site vicinity is used for commercial and residential purposes.
The site is comprised of 2 distinct areas, the inactive Cabot Carbon property to the
southeast, and the industrial zoned and currently operating Koppers area to the west.
North Main Street borders the entire site to the west as does a drainage ditch, which
drr s into nearby Springstead and Hogtown creeks. Pine tar and charcoal generation
op ;ions began at the Cabot Carbon facility in the-early 1900s and generated a large
number of blended solvents as by-products. Resultant wastewaters were treated onsite in
a lagoon. The Koppers portion of the sice has been operated since 1916 as a wood
preserving operation, primarily for utility poles and timbers. The main processing
facilities at the Koppers area include a tank farm, a former cooling water pond,
cylinder drip track's, a wastewater management system comprised of a north and south
lagoon, a wood shavings pile, and drying kilns. Between 1980 and 1989, various site
investigations by the State, EPA and private parties identified soil contamination in
the three lagoons, the inactive cooling pond, the drip tracks, and a wood shavings pile.
(See Attached Page)
17. Oocumnt Aiwlyci* & 0**criptoi*
Record of Decision - Cabot/Koppers, FL
First Remedial. Action - Final
Contaminated Media: soil, gw
Key Contaminants: VOCs (benzene), other organics (oils, PAHs,
(arsenic, chromium)
Ix ld*nllll*r«/Op»n.End*d Terms
phenols), metals
e. COSATI FWktC/oup
1*. AveUtbUlly SUMmem
19. Security Clece (Thie Report)
None
20. Security Cleee (Thie P«g«)
None
21. No. olPigee
136
22. Price
(See ANSt-ZJMB)
SM Inttructiont an Rtvtn*
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-1S)
Department ol Commerce
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EPA/ROD/R04-90/077
Cabot/Koppers, FL
First Remedial Action - Final
Abstract (Continued)
Ground water contamination also was identified in both the onsite shallow and
intermediate aquifers. In addition, in 1986 the State identified organics and heavy
metal contamination in offsite soil west of the site. This Record of Decision (ROD)
addresses contaminated onsite soil and ground water. The primary contaminants of concern
affecting the soil and ground water are VOCs including benzene; other organics including
oils, phenols, and PAHs; and metals including arsenic and chromium.
The selected remedial action for this site includes excavating 6,400 cubic yards of
onsite contaminated soil from the north and south Koppers lagoon areas, treating the soil
using soil washing and bioremediation if necessary, followed by solidifying/stabilizing
the residual material and disposing of these residuals onsite; treating soil from the
cooling pond and drip track areas by in-situ bioremediation; lining the North Main Street
ditch to prevent further discharge of leachate (if the ditch is to remain intact);
pumping and treatment of ground water followed by offsite discharge to a publicly owned
treatment works (POTW); operating and maintaining the North Main Street lift station as
needed until the ground water remediation system renders it superfluous; monitoring
ground water and surface water; and implementing institutional controls including land
use restrictions. The estimated present worth cost for this remedial action is
$4,192,000, which includes an annual O&M cost of $388,000.
PERFORMANCE STANDARDS OR GOALS: Chemical-specific soil cleanup goals were developed •
based on ground water protection and include carcinogenic PAHs 0.59 mg/kg, phenol
4.28 mg/kg, arsenic 27 mg/kg, and chromium 92.7 mg/kg. Chemical-specific ground water
cleanup goals include carcinogenic PAHs 0.003 ug/1 (health-based), phenol 2,630 ug/1,
arsenic 50 ug/1, chromium 50 ug/1 (MCL), and benzene 1 ug/1 (State).' Total
noncarcinogenic risk will result in a HI < 1.0.
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RECORD OF DECISION
DECLARATION
SITE NAME AND LOCATION
Cabot Carbon/Koppers Site
Gainesville, Alachua County, Florida
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action
for the Cabot Carbon/Koppers Site, in Gainesville, Florida,
developed with CERCLA, as amended by SARA and, to the extent
practicable, the National Contingency Plan. This decision is
bases on the Administrative Record for this site.
The State of Florida concurs with the selected remedy.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from
this site, if not addressed by implementing the response
action selected in this ROD, may present an imminent and
substantial endangerment to public health, welfare and the
environment.
DESCRIPTION OF THE RE>tEDY
The remedial action is proposed as both the first, and the .
final remedial action for the site. The function of this
remedy is to treat, where feasible, contamination down to
health based levels and to prevent exposure to those
contaminants in areas where treatment is infeasible.
The major components of the selected remedy are as follows:
o Excavation of contaminated soils from the former
North and South Lagoons on the Koppers facility;
o Soils washing of the soils.from the former North and
South Lagoons, bioremediation and, if appropriate,
solidification/stabilization of residual materials,
and deposition of treated soils back onsite;
o In situ bioremediation and institutional controls for
process areas on Koppers facility, including the
former Cooling Pond and Drip Track Areas;
o Institutional Controls for the former Cabot Carbon
facility;
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o Extraction of contaminated groundwater from shallow
aquifer, pretreatment if necessary, and discharge
into Gainesville Treatment Utility (GRU) system. A
plan for satisfying NPDES requirements will be
developed in the Remedial Design, as a contingency
against GRU not allowing this discharge;
o Provision for lining of North Main Street Ditch to
prevent further discharge of leachate into the Ditch
and Springstead and Hogtown Creeks; to be implemented
if Ditch is, in the long term, to remain intact;
o Continued Operation and Maintenance of the North Main
Street lift station until implementation of
groundwater remediation system renders it
superfluous; —
o Confirmatory sampling of the intermediate aquifer,
Springstead Creek, old Cabot lagoons area, and
Wetlands/lagoon area.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with Federal and State requirements that
are legally applicable or relevant and appropriate to the
remedial action, and is cost-effective.
This remedy utilizes permanent solutions and alternative
treatment technologies to the maximum extent practicable for
this site. Four source areas are undergoing treatment
technologies that will reduce the volume, toxicity and
mobility of contaminants. For these source areas, this remedy
satisfies the statutory preference for treatment as a
principal element of the remedy. However, existing structures
located on several of the source areas prevent effective
treatment technologies from being implemented. For these
source areas, this remedy does not satisfy the statutory
preference for treatment as a principal element of the remedy.
For the groundwater remedy, this remedy does satisfy the
statutory preference for treatment as a principal element of
the remedy.
Because this remedy will result in hazardous substances
remaining onaite above health-based levels, a review will be
conducted within five years after commencement of the remedial
action to ensure that the remedy continues to provide adequate
protection of human health and the environment.
Date Greer C. Tidwell
Regional Administrator
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RECORD OF DECISION
SUMMARY OF REMEDIAL
ALTERNATIVE SELECTION
CABOT CARBON/XOPPERS SITE
GAINESVILLE, ALACHUA
COUNTY, FLORIDA
PREPARED BY:
O.S. ENVIRONMENTAL PROTECTION AGENCY
REGION IV
ATLANTA, GEORGIA
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TABLE OF CONTENTS
1.0 Introduction 1-1
2.0 Site Name, Location and Description . 1-1
2.1 Area Land Use 1-1
2 .2 Regional Geology 1-2
2.2.1 Regional Geologic Setting 1-2
2.2.2 Site Specific Geology 1-3
2.2.3 Soil Types 1-3
2.2.4 Surface Water 1-4
2.2.5 Climate 1-4
2.2.6 Local Habitat 1-4
2.2.7 Protected Species 1-5
3 .0 Site History and Enforcement Activities 1-6
3 .1 Cabot Carbon Operations 1-6
3 . 2 Koppers Operations 1-8
4.0 Community Relations * 1-10
4.1 Community Profile 1-10
4.2 History of Community Concern 1-11
4 .3 Key Issues and Community Concerns 1-15
4.3.1 Proposed Widening of North Main Street 1-15
4.3.2 Ground, Drinking and Surface Water 1-15
4.3.3 North Main Street Ditch 1-16
4.3.4 Schedules 1-16
4.3.5 Proposed Developed _._ 1-16
4.3.6 Health Effects '.". 1-16
4.3.7 Airborne Toxins 1-17
4.3.8 EPA Commurdcations 1-17
5.0 Summary of Site Characteristics 1-17
5.1 Investigative History ^ 1-17
5.1.1 Explanation «? 1-17
5.1.2 EPA 1980 1-17
5.1.3 EPA 1983 1-19
5.1.4 University of Florida 1-22
5.1.5 Koppers 1984 1-22
5.1.6 Koppers 1986 1-23
5.1.7 FDER 1986 ' 1-26
5.1.8 IT - RI - 1987 1-26
5.2 Supplemental RI - 1989 1-31
5.2.1 Explanation 1-31
5.2.2 Indicator Chemical Selection 1-31
5.3 Groundwater 1-32
5.3.1 Aquifer Characterizatuions 1-32
5.3.2 Groundwater Quality Assessment 1-33
5.3.3 Soil/Source Characterization 1-35
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5.4 Surface Water and Sediment Assessment 1-36
5.4.1 Surface Water 1-36
5.4.2 Sediment Investigation 1-36
5.4.3 Air Investigation 1-36
6.0 Risk Assessment
6 .1 Introduction 1-36
6.2 Indicator Chemical Selection 1-37
6 . 3 Exposure Assessment 1-37
6.3.1 Definition 1-37
6.3.2 Onsite Exposure Pathways
To Workers 1-38
6.3.2.1 Direct Contact 1-38
6.3.2.2 Incidental Ingestion 1-38
6.3.2.3 Inhalation 1-38
6.3.3 Potential Onsite Exposure to
the General Public 1-39
6.3.3.1 Direct Contact 1-39
6.3.3.2 Inhalation 1-39
6.3.4 Potential Offsite Exposures to
the General Public 1-40
6.3.4.1 Direct Contact ...... 1-40
6.3.4.2 Direct Ingestion of Aquatic Organisms... 1-40
6.3.4.3 Inhalation l-Al
6.3.4.4 Groundwater 1
6.3.5 Environmental Receptors Exposure Pathways..1-
6.3.5.1 Terrestrial Exposure 1-41
6.3.5.2 Aquatic Exposure 1-42
6.3.6 Summary. . 1-42
6.4 Toxicity Assessment 1-42
6.4.1 Reference Doses 1-42
6.4.2 Chronic Hazard Index (HI) 1-42
6.4.3 Weight-of-Evidence Categories 1-42
6.4.4 Carcinogenic Potency Factor 1-42
6.5 Risk Characterization 1-43
6.5.1 Introduction 1-44
6.5.2 Risk Results 1-44
6.5.3 Environmental Risks 1-45
6 . 6 Feasibility Study Risk Results 1-46
6.6.1 Explanation 1-46
6.6.2 Risk Analysis For FOOT Workers During
Soil Excavation 1-46
6.6.3 Risk Analysis for Offsite Disposal of
Soils From North Main Street Ditch 1-46
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7 .0 Cleanup Criteria 1-47
7 .1 Explanation. . . 1-47
7.2 Groundwater Cleanup Criteria . .1-47
7 . 3 Soils Cleanup Criteria 1-48
7 .4 Surface Water Cleanup Criteria 1-49
8.0 Summary of Alternatives 1-49
8 .1 Areas to be Remediated 1-49
8.2 Summary of Remedial Alternatives 1-50
8.2.1 No-Action 1-50
8.2.2 Limited Action - Water Use Restrictions.... 1-50
8.2.3 Groundwater Extraction and Treatment 1-50
8.2.4 Groundwater Containment, Treatment
and Disposal 1-51
8.2.5 Onsite Landfill 1-51
8.2.6 Asphalt Capping 1-52
8.2.7 Removal and Offsite Disposal 1-52
8.2.8 Excavation and Onsite Treatment .1-52
8.2.9 In Situ Solidification/Stabilization 1-52
8.2.10 Source Containment 1-52
8.2.11 Source Treatment and Containment 1-52
8.2.12 In Situ Biodegradation 1-53
8.2 .13 Soils Washing 1-53
8.2.14 Incineration. 1-53
8 . 3 Screening of Remedial Alternatives 1-53
8.3.1 Screening Criteria 1-53
8.3.1.1 Effectiveness 1-53
8.3.1.2 Implementability 1-53
8.3.1.3 Cost 1-54
8.3.2 Alternative Screened Out 1-54
9.0 Summary of Comparative Analysis of Alternatives 1-54
9 .1 Glossary of Evaluation Criteria 1-55
9.2 Overall Protection of Human Health
And the Environment 1-55
9.3 Compliance with ARARs 1-55
9 .4 Long-Term Effectiveness 1-56
9.5 Reduction of Toxicity, Mobility/ or Volume 1-56
9.6 Short-TermEffectiveness. 1-56
9.7 Implementability 1-56
9.8 Coat 1-57
9. 9 State Acceptance 1-57
9 .10 Community Acceptance 1-57
10.0 Selected Remedy 1-57
11.0 Statutory Determinations 1-59
11.1 Introduction 1-59
11.2 Protection of Human Health and the Environment.... 1-60
11.3 Attainment of ARAKs 1-60
11.4 Cost Effectiveness 1-61
11.5 Utilization of Permanent Solutions and Alternative
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Treatment Technologies to the Maximum Extent
Practicable .. . r; r. 7~. ...... 1
11.6 Preference for Treatment as a Principle Element....!-
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RECORD OP DECISION
CABOT CAKBON/KOPPERS SITE
GAINESVILLE, FLORIDA
1.0 INTRODUCTION
The Cabot Carbon/Koppers Site (CC/K) was proposed for the
National Priorities List (NPL) in October, 1981 and finalized in
August 1983. A map of the site can be found on Figure 1.2-1.
In 1983, EPA issued a Cooperative Agreement grant to the Florida
Department of Environmental Regulation for the performance of a
Remedial Investigation and Feasibility Study (RI/FS). During
the implementation of the RI, the Florida Department of
Transportation (FDOT) announced that they were going to widen
North" Main Street, which runs along the eastern border of the
site, from two lanes to four lanes. This elicited a flurry of
public opposition because the public was concerned that widening
the road would cause exposure to contaminants that the road
overlay. FDOT later decided to put the project on hold until
EPA had selected a remedial action.
In 1987, the initial RI was completed. The EPA and FDER decided
that additional data gathering activities were necessary before
a comprehensive FS could be written. However, the Cooperative
Agreement fund was depleted. The lead was then switched back to
EPA, which then started negotiations with two major potentially
responsible parties (PRPs) (Cabot Carbon Corporation and Beazer
Inc. (formerly Koppers)) for the supplemental RI and the FS.
The Consent Order between EPA and the PRPs for this work was
signed in October 1988. The RI was approved in September 1989,
the Risk Assessment (RA) was approved in February 1990 and the
Feasibility Study in May 1990. . The public comment period
started August 8, 1990, and finished September 7, 1990. The
public meeting to describe the preferred alternative was held
August 14, 1990.
2.0 SITS NAME. LOCATION AND DESCRIPTION
2.1 Area Land Use
The site La located within the northern part of the city limits
of Gainesville,'Florida. The Koppers half of the site is zoned
industrial; it is the only parcel of land zoned industrial, and
is currently operating, in that area. The closest area zoned
industrial is the Gainesville Industrial Area, which is several
miles to the north. The former Cabot Carbon property, along
with the marshy area to the north of the old Cabot facility and
property east and south of the site are zoned commercial. The
land to the immediate west of the site is zoned single family
1-1
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SITE BOUNDARY
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NORTH MAIN
STREET DITCH
CABOT CARBON
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Figure 1.2-1
SITE PLAN
SOURCC:
CABOT CARBON/KCPPE?S
Remedial lnvestiga::cr
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and multiple family residence. To the north-northwest of the
site are scattered small businesses and a trailer park. To t>
west and northwest of the site, the adjacent property is
residential, consisting primarily of single family housing.
Commercial facilities border the site
to the south and east along NW 23rd Avenue and North Main
Street. To the northeast, the adjacent land is primarily
undeveloped and heavily vegetated.
The Gainesville Regional Utilities (-GRU) northern well field and
treatment facility is located approximately 2.5 miles northeast
of the site area. The facility, which is the municipal supply
for the city of Gainesville, draws water from the Floridan
aquifer.
The site area is relatively flat, ranging in elevation from 165
to 185 feet above mean sea level (ft-msl). Low, swampy areas
are prevalent in the northeastern quadrant of the site and to
the east and northeast of the site in the undeveloped land
segments. The primary surface water drainage in the area is
Springstead Creek, which parallels the northern boundary of the
site. Springstead Creek flows into Hogtown Creek. The North
Main Street ditch, which flows into Springstead Creek, bounds
the site along the eastern and northeastern perimeters. A
secondary drainage ditch runs northeast through the KII property
and discharges into Springstead Creek, a tributary of Hogtown
Creek.
2.2 REGIONAL GEOLOGY
2.2.1 Regional Geologic Setting
Alachua County is underlain by several hundred feet of
unconsolidated to semiconsolidated marine and nonmarine deposits
of sand, clay, marl, gravel, limestone, dolomite, and do1oraltic
limestone. The oldest formation bearing fresh water in the area
is the Lake City Limestone of Eocene Age. This unit is overlain
by the younger Avon Park Limestone and Ocala Group (both of
Eocene Age), the Miocene-Age Hawthorn Formation, and
Plio-Pleistocene terrace deposits.
The principal geologic structure in central peninsular Florida
is the Ocala Uplift, an anticlinal fold or arch whose crest
traverses southwest of Alachua County. The Ocala Group, an
extensive sequence of limestones and dolomites, is exposed at
the ground surface approximately 5 miles southwest of the Cabot
Carbon/Koppers site. From this area of limestone exposures, the
ground surface rises to the northeast as the Ocala Group is
overlain by the Hawthorn Formation and Plio-Pleistocene terrace
deposits in the vicinity of the Cabot Carbon/Koppers site.
1-2
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There are three aquifer systems in Alachua County: (1) the
water-table aquifer, (2) the secondary artesian aquifer, and
(3) the Floridan aquifer. The water-table aquifer is composed
of Plio-Pleistocene sands and clayey sands. The secondary
artesian aquifer is limited vertically and laterally in extent
and consists primarily of a few limestone and sand units within
the clays of the Hawthorn Formulation. The Floridan aquifer is
comprised of several hundred feet of limestone and underlies the
entire county. This aquifer is the most productive because it
transmits and stores water more easily. The aquifer is confined
where it is overlain by the Hawthorn Formation; it is
unconfirmed where the Ocala Limestone is near the surface. In
the immediate vicinity of the site, it is projected that the
depth to the top of the Floridan aquifer is approximately 200 to
250 ft.
2.2.2 Site Specific Geology
Based upon the subsurface data available from the previous site
investigations, two cross sections have been constructed to
illustrate geologic conditions at the Cabot Carbon/Koppers site
(see Figures 2.2-2 and 2.2-3). The surficial Pliocene and
Pleistocene sediments that underlie the site consist of
fine-to-medium sand, silt, and clay. This unit is approximately
25 to 30 ft in thickness and exhibits increased clay content
with depth. Underlying these surficial deposits is the Hawthorn
Formation, which consists of a dense, light green, marine clay
in the upper 10 ft, becoming interbedded with sandy clay
stringers and phosphatic limestone. The surface of this unit
appears to be dipping toward the northeast. A limestone unit,
as determined from gamma logging, was encountered at a depth of
60 to 65 ft grading from thin seams of interbedded clay, sand,
and limestone into massively bedded fossiliferous limestone (IT,
1987).
2.2.3 Soil Types
The soils that make up the Cabot Carbon/Koppers site belong to
the Millhopper-Urban Land Complex and the Wauchula-Urban Land
Complex (Thomas et al.. 1985). The term "complex" indicates
that each mapping unit La an undifferentiated mix of the two
soil types; in these cases, the individual soil series of the
Urban Land.
The Millhopper Complex covers the majority of the Cabot Carbon
property and the eastern two thirds of the KII property. This
complex is characteristically drier than the Wauchula Complex
with the water table expected to be below 60 inches for most of
the year. Permeability is rapid in the surface and subsurface
layers and alow in the subsoil layer.
1-3
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Figure 2.2 2
GEOLOGIC PROFILE A-A1
BOUHCIt II. !»*>. HUNItfWSt. !»••
CABOT CARBON/HOPPERS
Remedial Investigation
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CABOT CARBON/KOPPERS
Remedial Invasllgclion
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The Wauchula Complex covers up approximately one third of the
area. This complex is wetter than the Millhopper Complex, where
the water table usually is within 40 inches of the surface.
Permeability is rapid in the sand surface and subsurface layers
and slow to moderately slow in the loamy subsoil.
2.2.4 Surface Water
The Cabot Carbon/Koppers site lies within the Hogtown Creek
drainage basin, which covers an area of 15.6 square miles
(mi2). The contact between the upland plateau and the
transitional physiographic regions occurs at the scarp carved by
erosion associated with Hogtown Creek drainage. Hogtown Creek
drains southward across the transition zone into the western
plains region, where it ultimately discharges directly to the
Floridan aquifer by way of Haile Sink, approximately 10 miles
downstream of the site area.
The Cabot Carbon/Koppers site has two drainage ditches which
discharge to the Hogtown Creek system. The North Main Street
ditch extends to the north along the eastern boundary of the
site and discharges into Springstead Creek, which parallels the
site's northern boundary. The second site drainage ditch
transverses the KII property and also discharges into
Springatead Creek at the northern property boundary.
Springstead Creek discharges into Hogtown Creek north of the
site.
2.2.5 Climate
The climate in north-central Florida is humid and subtropical.
Slimmer temperatures are fairly uniform; afternoon temperatures
generally reach 90°F. Winter temperatures vary from day to
day and frost and freezing temperatures normally occur several
times a year. Mean annual precipitation ia approximately 53
inches; with over half of that coming in the months of June
through September. During this time of year, precipitation
usually occurs during thunderstorms that can drop 2 to 3 inches
of rain in several hours.
2.2.6 Local Habitat
Locally, the most significant feature influencing species
composition on the Cabot Carbon/Koppers site is past and present
land use management. As described previously, the site consists
of approximately 99 acres of industrial and commercial
activities, which limit or exclude the occurrence of natural
resources. Retail commercial establishments occur on the former
Cabot Carbon property within the southeastern portion of the
site; consisting of support buildings, roadways, parking lots,
1-4
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and isolated landscaped areas. The KII facility dominates the
western portion of the site supporting industrial-related
buildings and structures, railroad siding/ and nonvegetated open
areas.
Within these two developed portions of the site, features
exhibiting more natural conditions, although altered, include
forested land (13 acres), an old field/rural community (7
acres), and wetlands (2 acres). These communities are found on
Millhopper and Wachula soils and introduced fill material.
Under natural conditions, Millhopper and Wachula soils exhibit
moderate to poor drainage. Drainage of surface water has been
enhanced by man made ditches, which convey surface and shallow
groundwater to the north to Springstead Creek. Drainage
patterns influence plant community composition and have resulted
in the limited occurrence of onsite wetlands.
Within the northeast undeveloped portion of the site, a forested
area covering approximately 30 acres represents second growth
conditions and supports both wetland and upland species. A
review of historic aerial photos indicates that much of this
area had been marsh and swampland, but effective drainage has.
allowed upland species to colonize.
2.2.7 Protected Species
No federally protected species were observed on or in the
vicinity of the Cabot Carbon/Koppers site during site
investigations. Based on a review of habitat requirements,
known ranges of protected species, and an assessment of onsite
resources, no federally protected species are expected to use
site resources to a significant degree.
State of Florida-listed species potentially occurring on or in
the vicinity of this site include little blue heron (Egxetta
caerulea), snowy egret (E^. thula), tricolored heron (E.
tricolor), which are species of special concern, and
Southeastern American Kestrel (Falcon sparverious paulus);
designated as threatened.
Wetland habitats onsite may provide resources available to
wading birds, but because of the limited size of wetlands,
utilization by wading birds is expected to be minjjmal. No
nesting activity or sign of past use by wading birds was
observed or ia expected.
In Florida, the preferred habitat of the Southeastern American
Kestrel includes pine forests and clearings where dead trees are
present, providing sites for roosting, nesting, and hunting.
1-5
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Additional habitats used include open areas of river bottoms,
coastal regions, suburban areas, and cities. An American
kestrel (Falcon sparverius) was observed during assessment of
site resources.
Kestrels feed primarily on large insects, although small
rodents, reptiles, and birds are also important prey. Because
of its position in the food chain, potential exists for the
accumulation and concentration of chemicals. Kestrels are
territorial and occur in naturally low densities. For this
reason, the Cabot Carbon/Koppers site does not represent a
resource for a significant number of kestrels. As such,
conditions found onsite should not represent a significant
factor to the status of the Southeastern American Kestrel.
3.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
3.1 Cabot Carbon Operations
The facility thar existed on the former Cabot Carbon property
has been in operation since the early 1900s. The various names
it operated under, as shown on the Sanborn maps kept at UF,
were: the Williamson Chemical Company; the Florida Industrial
Corporation; and the Retort Chemical Co. The Cabot Carbon
Company bought the operation in the mid 1940s and continued to
operate the pine tar and charcoal generation facility in the
southeast quadrant area. The processing, which consisted of the
destructive distillation of pine stumps, resulted in the
generation of a large number of liquid products that in the past
had been marketed collectively as blended solvents. It was
estimated that the distillation of one ton of softwood produced:
0 Pine Oil [35 to 40 gallons (gal)],
0 Turpentine (4 to 6 gal),
0 Pine tar (20 to 30 gal),
0 Charcoal [350 to 400 pounds (lb), and
° Pyroligneous acid.
The Cabot Carbon process generated an estimated 6,000 gal of
crude wood oil and pitch per day. This destructive process is
no longer used by the forest products industry because the major
products, turpentine and pine oil, can be obtained in better
quality and at a lower cost from other processes such as
extraction.
The general layout of the Cabot Carbon facilities is presented
in Figure 1.2-3. As shown, the facilities included a series of
retorts, briquette processing and storage facilities, a machine
shop, a barreling shed, office and garage areas, and a series of
storage bins and tanks. Railroad sidings serviced the retort
1-6
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— — NV¥ 23«0 AVf NUB — — —
200 '00
SCALE IN FEE-
Flgur* 1.2-3
PLAN OF CABOT CARBON SITE DURING
GAINESVILLE OPERATIONS
SOUMCE
-------
areas and the briquette processing and storage facilities. The
plant facilities also included a boiler house, locker room, pump
house and showers. It was projected that the site was serviced
by a series of three groundwater wells located in the vicinity
of the pump house. The exact location, size, and depth of these
wells are unknown. The site also contained three small settling
ponds of earthen construction that were located within the
property. The overflow from these ponds was generally directed
to a drainage ditch that flowed in an easterly direction across
the northern boundary of the site.
For the destructive distillation process, only resinous
softwoods,, especially longleaf and slash pine, were used due to
the value of the products obtained from the resin content.
Stumpwood from logged-off areas and pitchy portions of fallen
trees were the preferred materials. For the Cabot Carbon
operations, a series of retorts were used in the destructive
distillation process. The retorts were built in sections of
two, with three condensers from each retort built along the
outside wall. The heat source was oil. The carts or buggies,
which held almost 5 cords of wood, were sealed in the retort,
and steam was used to sweat out or purge any noncondensable
explosive gas mixtures. The actual firing resulted in
temperatures between 750 to 800 degrees Fahrenheit (°F), which
were maintained for 15 hours for complete distillation. The
residue was charcoal that had been reduced to 20 percent by
weight and 30 percent by volume. The charcoal was cooled for
approximately 24 hours in special air-tight sheet iron buildings
and then stockpiled onsite.
The products from the retorts were usually light and heavy pine
oils, pitch, and a composite of several light solvent oils.
Further fractional distillation of the solvent oils yielded
turpentine, dipentene, pine oil, and small amounts of other
hydrocarbons. The crude oils and pitch mixtures were stored for
refining, with one retort charge producing about 1,100 gal of
crude wood oil. A summary of the primary constituents of pine
oil and turpentine mixtures is presented in Table 1.2-1. The
available literature indicates that pine oil, pine tar, and
terpentine are not pure compounds but contain a mixture of
chemical constituents. It should be noted that the list of
constituents on Table 1.2-1 is not necessarily exclusive to the
pine tar industry.
Minor products of the process, such as tar and tar oils,
pyroligneous acid (acid water), and charcoal, were also
obtained. The wood tars were of two types: soluble tars and
settled tars. The soluble tars are those in the pyroligneous
acid solutions, and they are separated as tars in the refining
process. The settled tars are insoluble in, and heavier than,
the aqueous pyroligneous acid and, thus, can be mechanically
separated. The settled tars can be fractioned into: (1) light
1-7
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Table 1.2-1. Constituents of Pine Oil and Turpentine Mixtures
Constituent Soecific Cn
Alpha- terpir.eol
Beta- terp ir.eol
Ga.T-ta- terpir.ec 1
!sabcr~ecl
3orr.ec I
Alpha-fer.chol C ?2:
Car.pr.or • ' 0.93:3
Terp ir.er. • 1 -ol 0.?'.".
Terpinen---ol ' 0 ?239
Sihydrorerpir.eol NA
Methyl charicol , NA
Anethole 0.965^
l.i»-Cineole 0.899'
1.8-Cineole 0.9257
Char.phene 0.8i-6
Dipentene 0.8^02
Lioonane . 0.8^02
Terpinol«n« 0.8623
Alpha-plnene. 0.8582
Beca-plneh* 0.8694
Rho-cynene . 0.8573
Fenchyl alcohol NA
Paraaenthane ' l NA
Noce: NA - nor available
Source: Huncer/ESE. 1989
-------
oils (specific gravities less than 1.0) with boiling points up
to 200 degrees Celsius (°C), containing aldehydes, ketone~7
acids, and esters; (2) heavy oils (specific gravities greater
than 1.0) with boiling points over 200°C, containing many
phenolic components; and (3) pitch. The heavy oil fraction
contains phenols, especially cresols, and is known as wood tar
and wood creosote. Pyroligneous acid is the dilute aqueous
solution obtained by cooling the vapors from the retort or
oven. This acid contains acetic acid, methanol, acetone, and
minor quantities of numerous other organic compounds.
During the site operations, wastewater containing residual
pyroligneous constituents and pine tar was discharged to a
concrete-lined, acid water pond, where pine tar was allowed to
settle for product recovery. This settling pond, which was
located within the northern portion of the plant area (see
Figure 1.2-3), was approximately 27 feet (ft) by 90-ft in plan
dimension and consisted of a series of shallow, concrete basins
separated by partitions with connecting spillways. The
spillways were constructed with baffles designed to confine the
floating pine-oil fractions. The settled pine tars were
periodically recovered as product and pumped to adjacent storage
facilities. The pond overflowed intermittently to an onsite
drainage ditch that discharged to a second ditch paralleling
North Main Street (the North Main Street ditch) and ultimately
discharged to Hogtown Creek. During later years of operation,
the three previously referenced, unlined earthen impoundments
were constructed to the north and downstream of the
concrete-lined pond to increase set line capacity. The general
location and configuration of these ponds is shown on Figure
1.2-3.
In 1967, the site area was sold to Raymond Tassinari, a local
private investor, and in October of that year the impoundment
walls were breached, and the contents discharged to a surface
ditch and eventually to Hogtown Creek. Approximately 10 years
later, the property was sold to Harry S. Hamilton, who proceeded
in developing the property into the existing shopping center.
Cleanup operations were performed in 1979 to remove some
contaminated sediments from the ditch; however, there is no
documented evidence of the extent of source remediation
activities.
3.2 Koppera Operations
The facility on the Koppers site has been an active plant since
1916 and has been used primarily to preserve wood utility poles
and timbers. The plant initially was operated by the American
Lumber and Treating Company, which used a creosote impregnation
process. Koppers purchased the plant operations in 1954 while
leasing the property from the Seaboard Coastline Railroad. In
1984, Koppers purchased the property.
1-8
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As of June 30, 1988, BNS Acquisitions, Inc., a Delware
Corporation and a wholly-owned subsidiary of Beazer PLC,
indirectly acquired more than 90 percent of the outstanding
common stock of Koppers. On November 14, 1988, BNS Acquisitions
acquired indirectly the balance of common shares. On January
20, 1989, the name of Koppers was changed to Beazer Materials
and Services, Inc. On December 28, 1988, Koppers (now BMS) sold
the assets of its Tar and Treated Wood Sector, including its
Gainesville, Florida facility, to a management buy out group
known as Koppers Industries, Inc. As agreed between the
parties, BMS has retained responsibility to satisfy the
obligations under the Administrative Order on Consent Docket No.
89-06-C, dated October 26, 1988 in conjunction with the Cabot
Carbon Company.
In later years, the Koppers facility operations were modified to
include two additional processes, one using CCA salts and the
other using PCP. Wolman salts were mixed at the site beginning
in 1936. The current CCA plant was constructed in the late
1960s. It is reported that PCP was used at the site beginning
in 1969. A brief discussion of the type of compounds associated
with these wood preserving processes is presented next.
° Creosote is not a pure compound, but a mixture
of compounds that are distilled from coal tar at
200 to 400°C. Some of the more common chemical
compounds associated with creosote are listed in
Table 1.2-2.
° PCP is prepared by the chlorination of phenol in
the presence of a catalyst and containing a
mixture of chemical constituents. Several of the
compounds associated with the PCP wood-preserving
process are listed in Table 1.2-3.
° The CCA wood-preserving process is normally
prepared by mixing portions of arsenic acid,
sodium dichromate, and copper sulfate.
It should be noted that the lists of constituents on Tables
1.2-2 and 1.2-3 are not necessarily exclusive to the
wood-preserving industry.
At the present time, only the creosote and CCA treatment
processes are in use at the site.
The main processing facilities are located within the southeast
corner of the property. This area includes the tank farm, a
former cooling water pond, the cylinder drip tracks, the
treating cylinders' wastewater system, and the drying kilns.
The general layout of the main plant area is presented in Figure
1-9
-------
wccc S-AVINGS
ABSi
a
r
OPV KILN __
STBUC'UPE
i --
-r^r
PROJECTED
LIMITS CP
FORMER SOUTH
LAGOCN
DRAINAGE
DITCH
CCA PUkNT
_ OIL Cf
PLANT
CCA STORAGE M
..j TANKS
- CREOSOTE
" TANKS
cot
80ILE0
HOUSE
MAINTENANCE aUILOlNGr
"CP.A STORAGE
EFFLUENT
STORAGE
TANKS
o ---- r
\ \'
\M
\ K
PROJECTED LIMITS
OF DORMER
COOLING PONO
. 23fO AVENUE
1
'im.ii 31
Figure 1.2-4
MAIN Kll FACILITIES
NUNTIMCSK, IM*.
CABOT CARBON/KOPPERS
Remedial Investigation
-------
C-CCKS: i v?.v ;
06 ••• :
Tib'.e 1 2-2 Tor.stitue- :s cf Creosote
Major constituents reported preser.; ih whole creosote
Naphthalene
I -Methylr.aphtr.aler.e
l-Merhvlr.apthaler.e
2i;her.yl
Disc thy Ir.aph t- a 1 eres
Acer.aphtr.er.e
uiber.iofurar.
- F'.uorer.e
? . 1 "• • 2 i r. v ; r : a r. t r. r a •: e T. e
Metnylfluorer.e
Pher.ar.threr.e
A r. t r. r a i e r. c
Acrid:r.e
Carbazcl
Me try lpr.er.ar.threr.es
2 • Pher.vlr.apht.-.aler.e
Me thy 1 ar. thr ac er.e s
Pyrere
Ser.zof luorer.es
Chrysene
9 , 1C • Ser.zopher.ar.threr.e
Hazardous cor.scituer.ts present ir. s^all quantities less thar. 1 perre
in creosote:
3enzo( a)pyrer.e
Ber.z (a)anthracene
Benzo( b) f luorar.thene
DibenzCa.hJanchracene
Idenot!l 2 . 3-cd;pyrer.e
Source: IT. 1987.
-------
3. -orrpcsitior. of Corrrercial PC? Formerly Available
(Prior :a 19--
Compound
Dowcide
EC-7
Dovicide
: ~ e
85-9
Trirhloropher.ol
Hizhe'r chlcrcpherols
Causric insolubles •..•sax1
:.].". £-7e:rachlorodiber.=o-
p-dioxins
?er.;achlorodiber.zo • p -dicxir.s
Hexachlorodibenzo-p-dioxir.s
HepzachLorodiben;o-p-dioxir.s
P?-
Gc:ach lorodiber.ro -p-dioxins
Te:rachlorodibenzofurans
Pencachlorodibenzofurans
Hexachlorodibenzo£urans
Hepcachlorodibenzofurans
Occachlorodibenzofurans
<0 .
an
^ j v. r.....
2 . 510 ppm
40 pp^
3.4 >0.4 ppm Dececced 9G pp-
1.8 ±0.3 ppm Dececced 400 pprr.
<1 ppm . Dececced. 260 ppr:
Sore: •- - noc detected.
ppm - parts per million.
Source: IT. 1987.
-------
1.2-4. The central and northern portions of the site area have
been cleared and graded and are used primarily as storage areas.
This area contains a network of railroad sidings and dirt access
roads. The main plant access is from the south off of NW 23rd
Avenue. The unpaved main access road bisects the site area in a
north-south direction. A drainage channel crosses the entire
site from the southwest to the northeast corners and discharges
into Springstead Creek.
In the past, two lagoon areas were used to manage wastewaters
generated by the treating process. The south lagoon was located
to the west of the.plant access road immediately south of the
current office building. The north lagoon was located
approximately 1,500 ft to the north. The north lagoon was
operated from 1956 until the 1970s. The operating period on the
south lagoon is not known. Both lagoon areas have been closed
and graded and are currently utilized for pole storage.
The exact year of closure for either lagoon is not known.
Detailed information pertaining to the method of closure (i.e.,
drainage, sludge removal, backfill, etc.) is not available.
4.0 COMMUNITY RELATIONS
4.1 Community Profile
The site is located in an urban neighborhood in the Northwest
section of Gainesville, Florida, a growing inland city, seventy
miles southwest of Jacksonville, Florida. Residential areas
border the site to the west and northwest, with commercial
properties to the south. There are several schools within a
one-mile radius of the site, as well as three parks and one
community center.
Gainesville's 1987 population was 85,469, and is projected to
reach 92,400 by the year 2,000. Gainesville has a young
population, due mostly to the presence of the University of
Florida and the Santa Fe Community College, which have a
combined full-time and part-time enrollment of approximately
43,000 students.
The University of Florida contributes significantly to community
life in Gainesville. With 10,000 employees, it is by far the
largest single employer in Gainesville and Alachua County, which
haa an unemployment rate of 3.3 percent. Approximately 37
percent of Alachua County's work force is employed by the
government, 23 percent by the service industry, and 22 percent
by the trade industry. The remainder work in manufacturing;
construction; finance, insurance and real estate; and
transportation, communications and utilities. The University
contributes also to the health care available to area
1-10
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residents. Shands Hospital, a private, non-profit teaching
hospital associated with the University's J. Hills Miller Health
Center, is one of four major hospitals in the city. City and
county officials and citizens readily acknowledge the
University's other contributions to the cultural and
intellectual life of the community, through fine and performing
arts and the athletics program. The variety of residents and
officials who were interviewed for this report spoke proudly of
the city's resources and accomplishments, and for the most part
expressed a desire to continue its growth.
The City of Gainesville is governed by a five-member commission.
The commissioners are elected for three-year staggered terms,
and each year select one of their own to serve as
Mayor-Commissioner. Alachua County also has a Board of
-Gommxss-ioners,—whose five members are elected to four-year
terms, with one member serving as the chairperson. These two
commissions work together on various issues, most notably on the
Metropolitan Transportation Planning Organization (MTPO), which
schedules regular monthly meetings. The MTPO comprises the
members of both the City and County Commissions, and is the
primary local government entity holding jurisdiction over the N.
Main Street widening proposal. Non-transportation planning and
zoning actions for the city are accomplished by the Gainesville
Planning Board, and for the county by the Alachua County
Planning and Development Commission. The city and county
governments demonstrate good organization, as evidenced by their
ready information referrals.
Gainesville Regional Utilities (GRU), owned by the City of
Gainesville, owns and operates the electric, water, and
wastewater systems. Most of the electricity is provided by
GRU's Kelly and Deerhaven Stations, with the remainder supplied
by a nuclear power unit owned by the Florida Power Corporation.
GRU's Murphree Treatment Plant provides the county's commercial
and residential customers with water, utilizing a distribution
capacity of 64 million gallons per day (mgd). The Murphree
plant draws most of its water from eight deep wells, which tap
into the Floridan aquifer. GRU plans to sink more wells into
Murphree's well field within the next two years. Other water
sources include three reservoirs, and officials and citizens
report that there are a number of private wells in the site
vicinity. Wastewater is treated at two major facilities. One
of these, the Kanapaha Treatment Plant, has a current capacity
of 10 mgd, which city officials expect to expand to 14 mgd in
1991.
Gainesville's citizens participate actively in community
affairs, as evidenced by the number of attendees at city and
county commission meetings, and has a wide variety of
informational resources at its disposal. Several civic and
environmental groups are active in the community. In addition,
1-11
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a number of citizen advisory boards and committees, appointed by
the city and county commissions, provide recommendations on
policies and directions and solicit citizen input on important
issues.
4.2 History of Community Concern
.The site has sparked the community's interest for many years.
Although previous studies conducted by the University of Florida
in 1961 and 1962 concluded that the operating wood treatment
facilities were having a detrimental effect on Hogtown Creek,
the community as a whole reportedly did not become active until
a discharge incident in 1967. At that time, the new owner of
the Cabot Carbon property broke the lagoon impoundment walls and
allowed the contents to drain into Hogtown Creek; local citizens
began to complain about the site. The City of Gainesville fined
the owner $100 for causing the pollution, and assessed another
charge to cover the City's cost for performing part of the
corrective action. The corrective action consisted of:
removing material two feet west and one foot deep from west bank
of North Main Street Ditch (starting at discharge pipe for
overflow pond and going 55 feet north); and disposal of this
soil in Southwest Landfill in Archer, Florida.
Reports indicate that problems and interest in the site remained
dormant until 1977, when a new owner began developing the site
into the shopping center that now exists there. During
construction, the owner allowed lagoon wastes to drain into
Hogtown Creek. The County, as well as FDER, received several
complaints from citizens about the look and smell of the creek.
In October 1977, FDER conducted a biological survey of the upper
2.8 miles of Hogtown Creek, showing the creek to be devoid of
life (except for bacteria) from the point of drainage discharge
to 1.1 miles downstream. The owner agreed to implement measures
to prevent further contamination from the development.
Local and state agencies continued, however, to receive
complaints about the site, and local newspaper published
articles and editorials about it. This community attention
continued, during the next few years, as EPA and FDER conducted
preliminary studies and investigations of the site in 1979
through 1981. Citizens, media, and environmental groups
reportedly began calling and writing to both EPA and FDER during
this time to find out about study results and express their
concerns about the site.
Community interest increased dramatically in 1983 through 1985.
During this time, the site was placed on the NPL, FDER and EPA
entered into a Cooperative Agreement giving FDER management lead
at the site, and the Florida Department of Transportation (DOT)
proposed to widen N. Main Street between 23rd and 39th Avenues,
1-12
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a section of the road that traverses the site. Some
interviewees reported that the site had not concerned them until
this time. Although part of the community's concern arose
because the NPL listing heightened the public's awareness of the
site, part of the concern also resulted from the road-widening
proposal. A number of citizens and civic and environmental
groups contacted FDER, EPA, and city and county officials with
questions and concerns about the pollution coming from the site
and the environmental impact of widening the road.
Gainesville citizens called for a public meeting that was held
on June 28, 1984, to discuss the history of the site, the
industrial processes used there, possible air problems at the
site, Superfund and RCRA procedures and regulations, and FDER's
proposed interim measure for the site (Project Jumpstart). The
meeting was moderated by the Chairperson of the Board of County
Ccmmissioners, and panelists included personnel from the County
and FDER.
Community attention to the site continued as plans were
developed to widen N. Main Street. FDER and DOT had agreed in
late 1985 that construction should wait until FDER completed
its,RI/FS, but citizens and civic and environmental groups
perceived a change in that policy by FDER and DOT in 1986, and
protested the projects resumption. Those protesting asserted
that FDER's RI data were not conclusive enough to allow DOT to
proceed with road construction and the possible movement of
contaminated material.
A number of articles and editorials appeared in the Gainesville
Sun and the Independent Florida Alligator in 1985, protesting
the road construction and assailing FDER for what many citizens
perceived to be a lack of caution based on incomplete test
results.
Citizens called for another public meeting to be held on May 1,
1986, and several civic and environmental organizations wrote
letters to EPA officials requesting their input and advice prior
to the meeting. It was reported that in the May 1986 meeting,
attendees were angry and upset about site proceedings. Many
felt that their environmental concerns were being ignored, and
they were afraid that widening the road would supercede cleaning
up pollution at the site. Some apparently thought remediation
will proceed without taking the road into consideration.
Although DOT has de-obligated funds for the road-widening
project, it La still a high priority of Gainesville's MTPO,
according to local officials, and is a subject of great debate
within the community.
The community has two opposing views regarding road construction
through the site. Some citizens do not believe the site poses a
great threat to the community or the environment, and feel that
the road construction should proceed without further delay.
1-13
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Some of these believe that no cleanup action should be taken,
and cite the fact that Hogtown Creek seems to have cleansed
itself five miles downstream of the site as proof that the
contamination is not serious. Several also believe that even if
the site warrants a permanent cleanup, it will take so many
years that the traffic on N. Main Street will have become a
bigger hazard that the site itself. The current two lanes
become quite congested, and interviewees noted that a lack of
traffic signals compounds the problem.
Other citizens and officials voiced the opposing view,
maintaining that previous studies have not demonstrated the
extent of contamination at the site. They stated that if people
are unaware of any dangers there, it is because the studies
conducted so far have neglected to test the site properly and
thoroughly. They cite maps showing retorts, pine tar—pi-t-s-,—and-
other process facilities in the vicinity of the existing
shopping center and the North Main Street Ditch, as well as
incidents such as a floor tile buckling problem at the
Winn-Dixie on the site, as arguments for further testing in
these specific areas, which they feel have not been addressed so
far.
The Winn-Dixie incident is a frequent topic of discussion in the
community, and members of the community disagree about whether
the tile problem was site-related. A consultant hired by the
store to study the problem concluded that site contamination
under the foundation was causing the tiles to buckle.
Reportedly, Winn-Dixie representatives and FDER disagreed with
that conclusion, attributing the trouble to a faulty foundation
and bad glue. Many citizens expressed dismay at that, and some
believe that there was a deliberate attempt by FDER and
Winn-Dixie to downplay the incident to avoid adverse publicity.
They are concerned that contaminants at the site may affect
other business there, and have given FDER and EPA specific
recommendations about where they believe further testing is
needed.
Some felt that road construction could probably begin after a
thorough RI/FS La completed, but others said that the road
project should be postponed until the site is completely cleaned
up. Many of the citizens who want road construction to proceed,
as well aa a few who do not, expressed the belief that some
citizens are using the Cabot Carbon/Koppers site merely as a
means to prevent commercial growth in the area. At this time,
questions of Superfund liability for the City, County, and
businesses on or adjacent to the site have brought the road
project to a standstill. The decision about whether or not to
ask DOT to release funds ^for and begin the project rests with
city and county officials.
1-14
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Currently, many citizens and environmental groups were most
concerned that the supplemental RI/FS address the concerns that
they have brought to the attention of EPA and FDER officials.
EPA and DOT agreed that road construction should wait until the
RI/FS is completed. Meanwhile, those interviewed said that they
will continue to press their concerns about the site, to ensure
that contamination is thoroughly quantified.
As a part of its community relations process, EPA has held a
number of informal meetings with concerned local citizens during
the 1983/90 to discuss various issues and listen to their
concerns. EPA plans to continue this pattern. Also, the formal
public comment period for the RI/FS was held from August 6 to
September 7, 1990; with the public meeting held on August 14,
1990. The results are discuss in detail in the—Responsiveness-
Summary, an appendix to this ROD.
4.3 Key Issues and Community Concerns
4.3.i Proposed Widening of North Main Street
Probably the most volatile issue is the proposed widening of
North Main Street. There appear to be two major schools of
thought concerning the proposed project. The first is composed
of citizens and environmental groups who are concerned that
there is an unknown major source of contamination where the
suspected "lagoon" under North Main Street was located. They
are worried that the construction activities associated with
road widening would disturb this source and cause them to
migrate in unexpected ways. The second is concerned that there
has already been a long delay in the road project and that EPA's
remedial process may cause additional delay and a continual
worsening of the traffic congestion along North Main Street.
They want EPA to make a decision on the appropriate remedial
action so that FOOT can make a decision on its project.
4.3.2 Ground. Drinking and Surface Water Quality
Citizens and local officials are concerned that the contaminated
ground water in the surficial aquifer will reach the Floridan
Aquifer, which La the main water supply for Gainesville and much
of Florida. Some people believe there is a link between the two
aquifers because of the numerous sinkholes in the area.
Gainesville's Murphree well fields, which tap into the Floridan
aquifer, are 2.3 miles northeast of the site. The city plans to
add new wells during the next two years to expand its services,
and there are no other well fields identified at this time.
City officials noted that it is important for them, as well as
for others who draw from the Floridan, to know the possibilities
of contamination before they expand their current water system.
1-15
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Citizens and officials also expressed concern about the possible
contamination of private drinking wells in the area. There was
concern that the supplemental RI/FS containing a survey of all
private wells within a one-half mile radius of the site is not
complete. Some interviewees asked that every private well in
the near vicinity be tested, as well.
Many residents expressed concern about damage to Hogtown Creek.
Early studies have noted detrimental effects to the creek up to
five miles downstream of the site, and many residents living
near the creek reportedly believe frustrated that damage is
still evident.
4.3.3 North Main Street Ditch
Many people are concerned about the leachate discharging into
the North Main Street Ditch. They are concerned that it appears
to be a public health threat and request that access to it be
limited.
4.3.4 Schedules
Most interested citizens wanted to know the schedule EPA has set
for the site. Most stated that site officials have not met past
schedules, and expressed the hope that EPA, as lead for the
site, will be more accurate in estimating the remediation
schedule, and adhere to announced dates.
4.3.5 Proposed Development
Many business persona in the site vicinity are reportedly
concerned about having their property values drop. Some are
concerned that the value will- drop specifically because their
property is part of a Superfund site, but most are concerned
that property value will drop as a result of delaying the
road-widening project. City officials report only one formal
request to develop a parcel of the land during .the last two
years, but could not say whether the low interest in developing
the area was a direct result of the Superfund site, or whether
it was indirectly related to the site because of the traffic
problems on N. Main Street. Many interviewees, business and
non-business, are allowed to conduct business in the area, but
the road construction has been effectively halted.
4.3.6 Health Effects
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Several individuals expressed concerns about health problems
that they believe could be related to site contamination. This
concern was raised at the June 1984 public meeting, where the
panel suggested that citizens, local doctors, and state and
county health officials contact the Centers for Disease Control
(CDC) in Atlanta to request a health study. A local official
stated that the CDC had not been contacted.
4.3.7 Airborne Toxins
A few citizens and local officials expressed concern about the
possible release of toxins into the air during site cleanup
activities. They want EPA to take proper precautions during
cleanup so that nearby residents and others doing business in
the area will not be affected by any airborne toxins.
4.3.8 EPA Communication
Some key local officials and citizens were concerned that EPA
officials have been slow to respond to their questions about the
site. They expressed the desire to help EPA facilitate site
remediation activities, but said that they need faster and more
direct responses from EPA. They cited letters requesting
meetings and/or advice related to site status, and reported that
they had yet to receive any direct answers to their querries.
5.0 SUMMARY OF SITE CHARACTERISTICS
5.1 Investigative History
5.1.1 Explanation
There have been a number of investigations of this site
conducted in the past ten years. The majority of this section
of the ROD will focus on the findings of the 1989 Supplemental
RI as the most complete and thorough investigation. The rest of
the investigations are summarized in a brief fashion.
5.1.2 EPA 1980
There were two investigations conducted by EPA in 1980. The -
results are summarized below:
The groundwater quality within the shallow aquifer at the site
initially was evaluated during the EPA investigation conducted
in 1980. This initial study consisted of the installation and
sampling of 24 temporary shallow wells in and around the
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periphery of the old Cabot Carbon Site. Five of the wells were
located within the vicinity of the former wastewater lagoons. A
maximum total phenol concentration of 50 micrograms per liter
(ug/L) was detected in this area. The results of this study
indicated that there were little shallow groundwater quality
effects within the undeveloped areas to the east of the North
Main Street ditch. Of the 19 monitoring wells in that area,
only one indicated a total phenol level equal to, or greater
than, the analytical detection limit.
The water quality of the Floridan aquifer downgradient of the
site area was evaluated during the 1980 EPA investigation
through the analysis of a composite sample from the City of
Gainesville's north well field. The only organic compound
identified during the analysis was acetone, which was discounted
due to its use as a field cleaning agent.
Soil quality at the Cabot Carbon site was initially evaluated
during the 1980 EPA investigation. This investigation consisted
of the collection of two composite soil samples from two
locations near the existing stormwater retention basin. The
sample taken from CC-036 was. a composite of soil collected from
the perimeter of the basin, and the sample taken from CC-037 was
a composite of soil taken from an area immediately to the north.
Location CC-036 had 38 organic compounds identified; 2 were
volatile organics, and 36 were extractable organics including
naphthalene, phenanthrene, anthracene, and pyrene. A total of
26 organic compounds were identified in CC-037, nine of which
were pesticides unassociated with the Cabot Carbon operations.
The surface water quality of Hogtown Creek and the North Main
Street ditch was evaluated during the EPA investigation. This
investigation included the sampling for phenol analysis from six
stations along Hogtown Creek and its tributaries.
The results of the investigation indicated that concentrations
in the surface waters were less than the detection limit (5
ug/L) at control station CC-001 (North Main Street ditch
upstream of Cabot Carbon operations) and at CC-003 (downstream
tributary to the ditch). However, phenol concentrations in the
ditch adjacent to and immediately downstream of the Cabot Carbon
aite were elevated, measuring up to 1,500 ug/L and 1,015 ug/L at
CC-002 and CC-004, respectively. The results also indicated
that phenol concentrations within the ditch decreased with
increasing distance downstream of the Cabot Carbon site (i.e.,
at downstream station CC-006, the phenol concentrations had
decreased to 70 ug/L). .
Macroinvertebrate studies conducted during the other EPA
investigation revealed a change in fauna between the sampling
stations located downstream of the former Cabot Carbon site.
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Stream recovery, regarding a diversified macroinverteorate
community, did not occur until approximately 5 miles downstream
of the site, where Hogtown Creek flows through two wetland
areas. Static toxicity tests were performed on the stream water
form station CC-004. The test results indicated a lethal
concentration for 50 percent of the exposed group (LC5Q) of 44
percent for the fathead minnow.
During November 1980, a second surface water investigation was
performed for the North Main Street ditch. The investigation
included obtaining surface water samples from four of the EPA
stations established during the previous investigation (CC-001,
CC-002, CC-003, and CC-004). The samples were analyzed for
total phenols concentrations.
The results indicate that total phenols concentrations for the
upgradient station, CC-001, and the station on the downstream
tributary were below the detection limits of 20 ug/L. However,
the station adjacent to the Cabot Carbon site, CC-002, and the
downstream station, CC-004, showed elevated phenols
concentrations of 4,100 ug/L and 3,450 ug/L. These
concentrations were higher than those documented during the
previous EPA investigation of December 1979. This difference is
attributed to the significantly higher rainfall amounts recorded
immediately prior to the 1979 sampling event.
The sediments in the Hogtown Creek/North Main Street drainage
system were evaluated. This investigation included the analysis
of three sediment samples obtained from the North Main Street
ditch at locations both adjacent to and downstream of the former
Cabot Carbon operations. Organic compounds were identified in
all three samples, with the highest concentrations associated
with the sampling station adjacent to the former plant site.
The organic compound.: encountered included C^ alkyl
phenanthrene, acenapnthene, flouorene, and anthracene.
5.1.3 EPA 1993
During this second EPA investigation, shallow groundwater was
obtained from three wells on the then-Koppers property> from
three walla located around the former Cabot Carbon facilities,
and from a background well located to the south of NW 23rd
Avenue. The results of the analysis indicated that of the three
wells sampled oh the Koppers property, only one contained
constituents associated with the creosote and/or PCP
wood-preserving process (naphthalene at 3,500 ug/L). This well,
M-l, was located immediately downgradient of the former north
lagoon.
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The results of the investigation also indicated that all three
wells around the former Cabot Carbon property contained organic
chemical constituents. Well A-l, which was located on the
border between the then-Koppers site and the former Cabot
Carbon plant site, contained constituents ranging in
concentration from 1 ug/L (fluorene, a coal tar derivative) to
370 ug/L [bis-(2-ethylhexyl) phthalate, a plasticizer]. The
constituents encountered in Well A-3, which was located at the
corner of North Main Street and 28th Place, included
2,4-demethylphenol (3,000 ug/L), toluene (1,500 ug/L), total
xylene (600 ug/L), and copper (7,300 ug/L). In addition, two
unidentified terpenes (associated with the destructive
distillation process) were detected at an estimated combined
concentration of 1,000 ug/L. Well A-4, which was located within
the northern portion of the site adjacent to Hogtown Creek,
contained organic compounds derived from coal tar. The
compounds identified include naphthalene (estimated at 7 ug/L),
acenaphthene (estimated at 5 ug/L), and fluorene (estimated at
5ug/L).
A subsurface soil sample was obtained from a proposed well
location in the vicinity of the former Cabot Carbon wastewater
lagoons. Odors emanating from the hole were so strong that the
well was not installed; however, a subsurface soil sample was
obtained from a depth of 9 to 45 inches. The sample, consisted
of a black "tar" granular material that contained extremely high
concentrations of the coal tar derivatives naphthalene and
phenanthrene [both estimated at 100.0 milligrams per kilogram
(mg/kg)]. In addition, PCP was detected at an estimated
concentration of 300.0 mg/kg. Other compounds detected at
extremely high concentrations were phenol (estimated at 800.0
mg/kg); 2,4-dimethylphenol (930.0 mg/kg); benzene (estimated at
11.0 mg/kg); toluene (estimated at 400.0 mg/kg); ethylbenzene
(estimated at 100.0 mg/kg); total xylene (estimated at 270.0
mg/kg); and copper (2,800 mg/kg). Also, two isomers of an
unidentified terpene (estimated at 600.0 mg/kg) were found.
This investigation also included surface water and
raacroinvertebrate sampling from two stations along the North
Main Street ditch. One station, CC-001, was located adjacent to
the Cabot Carbon facilities, and the second,m CC-004, was
located downstream just before the confluence with the KII
drainage ditch.
The analytical results indicated that the sample from CC-001
contained various organic compounds including the insecticides
alph-benze hexachloride (0.017 ug/L), beta-benzene hexachloride
(0.026 ug/L), and delta-benzene hexachloride (0.045 ug/L),
di-n-octylphthalate (11.0 ug/L) (both plasticizers), toluene
(9.1 ug/L), and two unidentified compounds (estimated
concentrations of 40 ug/L) were detected. The downstream sample
from CC-004 also contained chemical compounds associated with
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the destructive distillation process, including terpene at 70
ug/L, and from the creosote wood preserving process, including
naphthalene at 30 ug/L and acenaphthalene at 4 ug/L. Other
compounds detected included phenol (120 ug/L);
2,4-dimethylphenol (180 ug/L); benzene (3 ug/L); toluene (17
ug/L); xylene (7.8 ug/L); ethyl benzene (5 ug/L); and
tetrachloroethane (3 ug/L).
The findings of the macroinvertebrate sampling were in general
agreement with the 1979 EPA investigation, which confirmed
toxicological impact to the stream biota almost 5 miles
downstream. Static toxicity test performed on the stream water
indicated LCenS of 18.5 percent for the fathead minnow and 34
percent for the water flea.
The initial surface water investigation was performed on the KII
drainage ditch by EPA. This investigation consisted of the
analysis of one surface water sample obtained from the ditch at
the northern (downstream) perimeter of the then-Koppers
property. The analysis indicated presumptive evidence of
compounds associated with coal tar (i.e., dimethylpyridine,
trimethylpyridine, dihydroindole, methylquenoline, carbazole,
and methylquinolinol). All of these compounds were detected at
estimated concentrations of 10 ug/L.
The macroinvertebrate study performed in conjunction with this
investigation indicated three species of midges (Diptera) were
present at the sampling station. Results of 24-hour static
toxicity test indicated no mortality for either the fathead
minnow or the water flea.
The sediments in the Hogtown Creek/North Main Street drainage
system were evaluated. The upstream sample (CC-001S) was
collected from the North Main Street ditch immediately east of
the former Cabot Carbon plant site. The sample contained
various detectable constituents, with estimated concentration
values ranging from 500 ug/kg of phenanthrene to 800 ug/kg
fluoranthene. In addition, polychlorinated biphenyl (PCB) was
found at a concentration of 170 ug/kg. The downstream sample
was taken from Springstead Creek Just before the confluence with
the KII drainage ditch. There was presumptive evidence of
various detectable constituents in the sediment, ranging in
concentration from an estimated value of 5,000 ug/kg of
methylnaphthalene to 10,000 ug/kg of C4 alkyl phenanthrene.
In addition, garama-chlordane (2.9 ug/kg) and alphachlordane (3.2
ug/kg) were also detected in the sample.
The sediments in the KII drainage ditch were initially evaluated
during investigation. This investigation analyzed samples from
two locations along the ditch. The upstream sample, K-l,
contained several of the extractable organic compounds
associated with the creosote wood-preserving process. The
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estimated concentrations ranged from 600 ug/kg of anthracene to
7,500 ug/kg of fluoranthene. The other constituents identified
were PCS (960 ug/kg)/ gamma-chlordane, and alpha-chlordane. The
downstream sediment sample, K-2, generally showed an increase in
extractable organic compound concentrations, with 1,000 ug/kg
anthracene and 42,000 ug/kg fluoranthene. In addition, PCP was
detected at a concentration of 10,000 ug/kg. The metals
analysis at K-2 also showed elevated concentrations of arsenic
(26 mg/kg), chromium (32 mg/kg), and copper (28 mg/kg).
5.1.4 University of Florida
The Cabot Carbon site was evaluated further during the 1982
University of Florida investigation performed under the
direction of Dr. John Zoltek. This investigation consisted of
the. installation and sampling of 11 monitoring wells in and
around the former plant area.'
The results of this investigation confirmed that the groundwater
flow in the site area is to the east-northeast. The three major
classes of compounds were phenols, terpenes and condensed
aromatics. The highest concentration of phenols were
encountered in the wells either in or downgradient of the former
lagoon area. The phenolic compounds detected included
sigma-cresol (5,238 ug/L), rho-cresol (11,120 ug/L), dimethyl
phenol (9,428 ug/L), methoxy phenol (3,277 ug/L), and alkyl
phenol (562 ug/L). Compounds such as limonen, alpha-terpineol,
borneol, and D-caraphor, which are associated with destructive
distillation processes, also were encountered at maximum
concentrations in the downgradient wells. Naphthalene compounds
were detected at highest concentrations in the wells upgradient
of the former lagoon area, indicating potential offsite
influences.
5.1.5 Koppers 1984
The groundwater within the then-Koppers site initially was
evaluated by Koppers in an investigation summarized in their
1984 report. The investigation included the installation of ten
monitoring wells within the northern portion of the property.
Nine of the wells monitored the upper 8 ft of the aquifer, and 1
well monitored a deeper interval immediately above the clay
layer (Hawthorn"Formation). Three rounds of sampling were
conducted durign 1983 (July 28, September 6, and October 12),
with analyses including total phenols, TOC, COD, naphthalene,
and polynuclear aromatic hydrocarbons (PAHs).
The results consistently indicate detectable concentrations of
phenols [approximately 4.0 milligrams per liter (mg/L)] in M-l,
immediately downgradient of the former north lagoon area. The
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wells downgradient of M-l displayed phenols concentrations
generally at or near the detection limit, with the exception of
M-9 (0.23 mg/L) in the first sampling round. The analytical
results also show that TOG, COD, and naphthalene values follow
the same general pattern as the total phenols concentrations,
with the highest concentrations (77..0 mg/L for TOG, 200.0 mg/L
for naphthalene) found immediately downgradient of the former
north lagoon. However, the concentrations of total PAHs (less
naphthalene) are elevated in the wells along the KII drainage
ditch, indicating that the ditch may serve as a source area.
Koppers performed an invstone and Ocala Group (both of Eocene
Age), the Miocene-Age Hawthorn Formation, and Plio-Pleistocene
terrace deposits.
The "principal geologic structure in central peninsul-ar—F±or±da-
is the Ocala Uplift, an anticlinal fold or arch whose crest
traverses southwest of Alachua County. The up warping of this
structural feature brought the Ocala Group, an extensive
sequence of limestones and dolomites, to the surface
approximately 5 miles southwest of the Cabot Carbon/Koppers
site. From this area of limestone exposures, the ground surface
rises to the northeast as .the Ocala Group is overlain by the
Hawthorn Formation and Plio-Pleistocene terrace deposits in the
vicinity of the Cabot Carbon/Koppers site.
There are three aquifer systems in Alachua County: (1) the
water-table aquifer, (2) the secondary artesian aquifer, and
(3) the Floridan aquifer. The water-table aquifer is composed
of Plio-Pleistocene sands and clayey sands. The secondary
artesian aquifer La limited vertically and laterally in extent
The results of the analysis for phenols were similar to those of
the previous investigation. Relatively low concentrations were
recorded at the upstream and downstream stations, S-l and S-2,
respectively. The most elevated phenols concentrations occurred
at intermediate sampling points along the ditch (0.043 mg/L at
S-4 and 0.041 mg/L at S-5). PCP exhibited a similar trend to
phenols. Concentrations of PCP in the ditch as it enters and
leaves the site were 0.004 mg/L at S-l and less than 0.003 mg/L
at S-2. The highest concentration (0.38 mg/L) was recorded at
station S-4. Total chromium was not detected at S-l, S-2, or
S-3 (North Main Street ditch). An elevated total chromium
concentration (0.890 mg/L) was recorded at the intermediate
station S-4. The arsenic concentrations showed an overall
increase from 010028 mg/L at the upstream station, S-l, to 0.078
mg/L at the downstream station, S-2. Sampling station S-4
displayed an elevated arsenic concentration of 0.73 mg/L.
Arsenic was not detected in the North Main Street ditch.
5.1.6 Koppers 1985
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The groundwater quality at the then-Koppers site was further
evaluated in the 1985 Koppers investigation. This investigation
included the installation of wells to monitor the upper portion
of the aquifer/ with the remaining 14 screened in an interval
immediately above the Hawthorne (clay) Formation. The
monitoring wells were sampled in the three rounds (August 6,
August 27, and September 12, 1984). The analyses performed on
the samples included TOC; COD; phenols; PCP; and copper,
chromium, and arsenic.
The results of the investigation indicate that phenols
concentrations in the shallow wells are slightly above the
background levels and at or just above analytical detection
limits. The most elevated phenols concentrations (8.5 to 12.0
mg/L) occurred in the tank farm area adjacent to the former
cooling pond. The majority of the samples from the deeper wells
exhibited elevated phenol levels. The highest concentration
(17.0 to 19.0 mg/L) from these deeper wells was encountered in
M-25B, located immediately downgradient of the main process
facilities. Well M-3B (downgradient of the former north lagoon
displayed the second highest phenol levels (3.1 to 3.4 mg/L)j.
The analytical results also indicate that the trends in the
concentration of PCP are similar to the phenols trend. Elevated
PCP levels were found in the shallow wells located in and near
the potential source areas; the deep monitoring wells indicate
more widespread presence of PCP immediately above the Hawthorne
Formation. The most elevated levels at the site were detected
in the treatment area and the former south lagoon. Elevated
levels were also detected downgradient of the former north
lagoon.
The majority of.the wells on the site displayed detectable
arsenic concentrations. In general, wells downgradient of the
CCA treatment and drip track areas exhibited arsenic levels in
excess of drinking water standards (0.05 rag/L). The highest
arsenic concentrations at the site were found in M-21A and M-32A
(maximum 3.9 and 1.6 mg/L, respectively). Wells M-19, M-21B,
and M-32B, which are also downgradient of the CCA treatment
area, also displayed arsenic concentrations in excess of the
drinking water standards. Elevated arsenic concentrations (0.12
mg/L) also were detected in the former cooling pond area in Well
M-30A. Arsenic was undetected (<0.001 mg/L) in the upgradient
Wells 27A and 27B.
The distribution of total chromium concentrations essentially
paralleled the distribution of arsenic concentrations. However,
total chromium did not exceed the drinking water standards (0.05
mg/L) in the deep wells at the site. Total chromium
concentrations in excess of the drinking water standards were
detected in shallow wells in and downgradient of the CCA
treatment area, with maximum levels on the order of 0.13, 0.12,
and 0.13 mg/L recorded in M-19, M-22, and M-32A, respectively.
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Well M-30A, located near the cooling pond, also showed an
elevated concentration of total chromium (0.11 mg/L). Total
chromium was undetected (<0.007 mg/L) in the two upgradient
wells.
The PAH distribution at the site was similar to the phenols
distribution. Elevated PAH concentrations were found in and
downgradient of the CCA treatment area and downgradient of the
former north lagoon area. PAH concentrations were also
generally higher in the deep wells at the site. The highest PAH
concentration was noted in M-24 (17.0 mg/L), located in the tank
farm area. Well M-21B, downgradient of the former south lagoon
area, also displayed an elevated PAH concentration (10.5 mg/L).
PAH compounds were undetected in the upgradient Well 27A and
detected at 0.0003 mg/L in the upgradient Well 27B.
The investigation noted elevated naphthalene concentrations
throughout the site. The most elevated concentrations were
found in and downgradient of the treatment area and the former
south and north lagoon areas, with the highest concentrations
generally occurring in the deeper wells. Well M-25B, along the
eastern boundary of the site, had the highest concentration
(15.0 mg/L), followed by M-24 in the tank farm area (13.0 mg/L).
Naphthalene was undetected (<0.006 mg/L) in the two upgradient
wells.
During this investigation, a total of 20 soil borings were
drilled and sampled to. evaluate soil conditions within potential
.source areas. A total of 14 samples were analyzed for PCP and
total extractable oils analysis, plus copper, chromium, and
arsenic where appropriate.
The three borings drilled in the former north lagoon area all
displayed visible oil. The analytical results indicated PCP
concentrations of 8.6 mg/kg and 1,040 mg/kg total oils. The
five borings drilled within the former south lagoon area also
displayed visible oil. The analytical results indicated PCP
concentrations of 20.0 mg/kg and 62,400 mg/kg total oils
content.
The two borings drilled within the former cooling pond area
displayed visible oil to depths of 5 ft. Analytical results
indicated a PCP concentration of 4.2 mg/kg and 1,500 rag/kg total
oils. The boring drilled within the nearby tank farm area
showed visible evidence of oil to 12 ft with 1,590 mg/kg total
oils/ but no detectable PCP.
In the drip track areas, borings were drilled within the CCA,
creosote, and PCP areas. The analysis in the CCA area indicated
low concentrations of PCP (below detection limit) and total oils
(33.4 mg/kg). Arsenic concentrations ranged from 1.8 to 5.6
mg/kg, chromium ranged from 1.5 to 6.4 mg/kg, and copper ranged
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from less than 0.008 to 2 mg/kg. In the creosbte/PCP area,
concentrations of PCP were undetected with total oils showing a
maximum concentration of 33.4 mg/kg.
A second Koppers surface water investigation of the ditch was
conducted in 1985. This investigation consisted of 5 sampling
stations S-l through S-5, with analysis for phenols, PCP,
copper, and total chromium. Four of the sampling stations were
located along the ditch within the property limits, with the
fifth located just upstream of the confluence.
5.1.7 FDER 1986
The 1986 FDER study addressed the potential environmental issues
associated with the widening of North Main Street in the
vicinity of the site. A total of seven sediment samples were
obtained from the ditch area. Six of the samples were obtained
upstream and one downstream of Project Jumpstart. The samples
were analyzed for the 129 priority pollutants. The analytical
results indicated the presence of three classes of compounds:
acid extractables organics (2,4-dimethylphenol), base neutral
organics (PAHs), and heavy metals.
Samples from the three upstream stations (S-l, S-2, and S-3),
which were taken from the vicinity of the intersection of North
Main Street and NE 28th Avenue, had higher concentration of
2,4-dimethylphenol [830 mg/kg (maximum)] and the PAHs than the
downgradient stations. The primary base neutral organics
contributing to the total were naphthalene (225 rag/kg),
phenanthrene (63 mg/kg), acenaphthene (30 mg/kg), and
acenaphthylene (35 rag/kg). There was no similar pattern
discernible for metals. The maximum concentrations of
arsenic, chromium, and copper were noted at 29.9 mg/kg, 5.0
mg/kg, and 22.4 mg/kg, respectively.
5.1.7 IT - First Remedial Investigation - 1987
The groundwater quality within the surficial aquifer was
evaluated further, for both the combined Cabot Carbon/Koppers
site areas, in the summary IT Corporation report presented in
1987. This investigation included the installation of 24
additional wells that were selectively screened in either the
upper or lower portion of the shallow aquifer.
Groundwater elevation data indicated that groundwater flow in
the surficial aquifer is northeast with an easterly trend near
North Main Street. Analyses were performed for metals (CCA),
total phenols and acid-extractable phenol and phenolic
compounds, and volatile and semivolatile organics. The
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analytical results from this study, along with the data from the
1984/85 Koppers investigations, are summarized in the following
paragraphs.
The elevated arsenic concentrations appear to be centered in the
area of the former south lagoon and CCA drip track area, with
little indication of extensive lateral migration. The maximum
detected concentration was 3.9 mg/L at M-21A. The chromium
concentration plots are much less distinct than those for
arsenic, with the highest values (0.47 mg/L at ITW-20) located
to the north of the site and Springstead Creek. Two other areas
of elevated concentrations were observed approximately 400 to
500 ft east of the CCA retort (0.28 mg/L at ITW-7) and along the
northeast boundary of the then-Koppers property (0.14 mg/L at
ITW-24). The copper concentration plots resemble those for
chromium, except that there were no elevated copper
concentrations along the northeast corner of the Koppers
property. The highest copper concentrations were found in the
vicinity of the former Cabot Carbon lagoon system (0.318 mg/L at
ITW-8 and 0.334 mg/L at ITW-9).
The concentrations of phenols in the upper zone show elevated
concentrations to the northeast (downgradient) of the former
Cabot Carbon lagoon adjacent to North Main Street. The highest
concentration in this area was 90.0 mg/L. in ITW-14. In the
lower zone/ the maximum concentrations were encountered in the
immediate vicinity of the lagoons, with a maximum of 144.0 mg/L
recorded in ITW-10.
PCP concentrations in both the upper and lower zones indicate
elevated concentrations on the then-Koppers property near the
PCP drip tracks and the former south lagoon. The maximum
concentration in the upper zone was 23.0 mg/L at M-24 and 12.0
mg/L in the lower zone at M-25B.
The highest total volatile concentrations were found
downgradient of the former Cabot Carbon lagoon system with peak
concentrations of 1.3 mg/L at ITW-15 and 1.26 mg/L at ITW-10.
The main contributors to the total volatile concentrations were
benzene, ethylene benzene, methylene chloride, and toluene.
The highest concentrations of total semivolatiles at the site
were located:
1. Along the southern portion of the boundary between the
former Cabot Carbon and the then-Koppers properties
(2.668 mg/L at ITW-5),
2. In an area downgradient of the drip pads on the
then-Koppers property (3.763 mg/L at ITW-21), and
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3. In an area upgradient of the former Cabot Carbon
wastewater lagoons (2.202 mg/L at ITW-6).
The main contributors to the total semivolatiles concentrations
were acenapthene, acenapthalene, anthracene, bis-(2-ehtylhexyl)
phthalate, fluorene, naphthalene, phenanthrene, and pyrene.
The 1987 RI also evaluated the water quality within the
intermediate aquifer. This investigation consisted of the
installation of three monitoring wells (ITF-1, ITF-2, ITF-3) and
one round of sampling and analysis. The location of the three
wells is presented in Figure 1.3-2.
The analytical results from the three wells indicated very low
levels of phenols (0.01 and 0.02 mg/L), arsenic (<0.001 to 0.009
mg/L), and copper (0.021 to 0.042 mg/L). No volatile or
semivolatile organics were detected.
Soil samples were collected from a number of soil borings as
well, as during monitor well installation, to depths up to ten
feet. Metals were detected at relatively low levels within the
Cabot Carbon site area, with the exception of copper. The
highest concentrations of copper were recorded in the vicinity
of the former lagoon areas (72 mg/kg"at ITB-6). The arsenic
concentrations in the soils were all generally less than 10.0
mg/kg, with the maximum concentration of 16 mg/kg recorded to
the northeast of the lagoon area at ITB-9.
Phenolic compounds were detected in the soils within a number of
the borings in and around the former lagoon area. In this area,
2,4-dimethylphenol was detected at concentrations of 20.0 mg/kg
(ITB-6) and 8.9 mg/kg (ITW-10). Acid extractable phenols were
detected at concentrations of 9.5 mg/kg (ITB-6) and 8.98 mg/kg
(ITW-10). PCP was not detected in any of the soil samples
analyzed from the Cabot Carbon property.
Low concentrations of volatile organics were encountered in most
of the borings on the site. The volatiles most commonly
detected were benzene, ethylene benzene, methylene chloride, and
toluene. The highest collective volatile concentrations were
within the former lagoon area (12.18 mg/kg at ITB-6, 2 to 6 ft
in ITW-13 (4.17 mg/kg).
The semivolatile organic compounds were detected in a number of
the borings drilled within and downgradient of the former Cabot
Carbon facilities. One of the highest collective semivolatile
concentrations (105 mg/kg) was recorded in ITB-9, located to the
northeast of the lagoon area. The primary contributors at this
location were phenanthrene (36 mg/kg), chrysene (26 mg/kg),
benzo(a)anthracene (11 mg/kg), and 3,4-benzofluoranthene (10
mg/kg). The soils encountered in ITW-13, the well installation
north of the automobile dealership along North Main Street, also
1-28
-------
exhibited an elevated concentration of total semivolatile
organics (53.6 mg/kg). The main"contributors were phenanthrene
(17 mg/kg), naphthalene (11 mg/kg), acenaphthylene (8.2 mg/kg),
and acenaphthene (5.4 mg/kg).
During the IT Corporation investigation, selected soils samples
from the groundwater monitoring wells were submitted for
chemical analysis. In addition, four exploration borings were
drilled and sampled in and around the then-Koppers primary plant
facilities within the southern portion of the property. The
samples were analyzed for selected metals, phenolic compounds,
volatiles, and semivolatile organics.
The results of the analysis indicated the highest arsenic
concentrations occur within the former south lagoon area (ITB-15
at 79.0 mg/kg) and in the northeast corner of the property
(ITW-24 at 62.0 mg/kg). The former south lagoon area also
appears to represent the highest concentrations of chromium (115
mg/kg) and copper (11 mg/kg) on the site.
PCP was detected only in the borings located along the eastern
boundary of the site (ITW-21-at 9.2 mg/kg and ITW-24 at 2.1
mg/kg). Other phenolic compounds were not detected.
Low concentrations of volatile organics were encountered in most
of the borings on the site. The volatiles most commonly
detected were benzene, ehtylene benzene, methylene chloride, and
.toluene.
Semivolatile organic compounds were detected primarily along the
northeastern boundary of the Koppers property and within the
former south lagoon area. One of the highest concentrations of
total semivolatile organics was detected at ITW-21 (119 mg/kg)
located to the north of the main plant facilities along the
eastern Koppers boundary. The main semivolatile contributors to
the total were fluoranthene (23.1 mg/kg); 3,4-benzofluornathene
(18.4 mg/kg); pyrene (15,2 mg/kf); chrysene (13.6 mg/kg); and
benzo(a) anthracene. (12.0 mg/kg). Elevated concentrations (43
mg/kg) of semivolatiles were also detected in the northeast
corner of the Koppera property in ITW-24. In the former south
lagoon area (ITB-15), total semivolatile organics were detected
at a concentration of 18.7 mg/kg.
During the IT investigation, six additional surface water
samples were taken for laboratory analysis. Sample locations
ITS-1 and ITS-2 were located in the North Main Street ditch
adjacent to the former Cabot Carbon site area. ITS-3 was
located in Springstead Creek north of Project Jumpstart. ITS-4
and ITS-5 were located along the westerly flowing portion of the
ditch to the north of the site. ITS-9 was taken in a feeder
ditch near the intersection of North Main Terrace and Northeast
35th Avenue, approximately two blocks downstream of the site
area. Analyses were performed for copper, chromium,
1-29
-------
and arsenic; total phenols and acid-extractable phenol and
phenolic compounds; and volatile and semivolatile constituents.
All samples indicated low concentrations of copper, chromium,
and arsenic (<0.016 mg/L). All samples along the North Main
Street ditch showed comparable (1.0 mg/L) levels of phenolic
compounds. Volatiles were relatively low (generally less than
0.10 mg/L) along the ditch, with the highest recorded at ITS-2
(<0.125 mg/L). The primary volatile organic constituents to the
total were benzene, ethyl benzene, and toluene. Semivolatile
organic? were not detected in the upstream sample from ITS-1.
The highest concentration of semivolatile organics was
encountered at ITS-4 (<1.14 mg/L) along the northern boundary of
the site. The primary semivolatile contributor at ITS-4 was
napthalene (1.1 mq/L.L. Phenolic compounds, volatiles, and
semivolatile organics were not detected in either of the feeder
ditches, ITS-3 and ITS-9.
During the IT investigation, two additional surface water
samples, ITS-6 and ITS-7, from the drainage ditch flowing into
Springstead Creek from the Koppers facility were taken. The
analyses performed included copper, chromium, and arsenic; total
phenols and acid-extractable phenol and phenolic compounds; and
volatile and semivolatile constituents.
The results of the analysis essentially substantiated the
previous investigations. Very low metals (<0.166 mg/L) and
phenols concentrations (<0.01 rag/L) were measured. In addition,
volatile and semivolatile organics were not detected in either
of the samples. Field data obtained during the time of the
sampling did show a dissolved oxygen decrease from 4.65 mg/L at
the upstream station (ITS-6) to 2.09 mg/L at the downstream
station (ITS-7). Temperature and pH did not appear to change
appreciably.
During the IT investigation, sediment samples were taken at the
five surface water sampling locations described previously. The
samples were analyzed for chromium, copper and arsenic, phenolic
compounds; and volatile and semivolatile constituents.
The results of the analysis indicated that concentrations of
metals along the North Main Street ditch were relatively low,
with the highest recorded in the tributary stream at ITS-3 (0.62
mg/kg arsenic, 7.5 mg/kg chromium, and 4.0 rag/kg copper).
Phenolic compounds were undetected at all sampling locations,
with the exception of low levels (3.5 mg/kg) encountered at
ITS-4. The highest concentration of total volatile organics
along the ditch was encountered at ITS-2 (<1.59 mg/kg), which
included ethyl benzene at 0.92 mg/kg and toluene at 0.57 mg/kg.
The analysis for semivolatile organics indicated the highest
1-30
-------
values at ITS-2 (24.1 mg/kg total). The concentration at ITS-1
was the next highest (5.9 mg/kg total), and the total values at
ITS-3, ITS-4, and ITS-5 were approximately 1.0 mg/kg. The main
semivolatiles contributing to the total were acenaphthene,
acenaphthylene, naphthalene, phenanthrene, and pyrene.
During the IT investigation, sediment samples were taken from
two locations along the drainage ditch from the Koppers
property. The samples were analyzed for selected metals,
phenolic compounds, volatiles, and semivolatile organics.
The results of the analyses indicated metals concentrations
ranging from 3.8 to 8.4 mg/kg for arsenic, 4.2 to 6.7 mg/kg for
chromium, and 4.0 to 34.0 mg/kg for copper. Phenolic compounds
were not detected in either of the two samples. Total
volatiles, consisting primarily of methylene chloride, were also
detected at low. concentrations 'In the samples (0.03 mg/kg at
ITS-6 and 0.07 mg/kg at ITS-7). Semivolatile organics were
detected at relatively high levels, with total concentrations of
56.9 mg/kg at ITS-6 and 46.8 mg/kg at ITS-7. The primary
sem'ivolatiles contributing to the total were chrysene (4.7 and
4.9 mg/kg); fluoranthene (6.5 and 5.1 mg/kg);
3,4-benzofluoranthene (9.9 and 9.2 mg/kg); and pyrene (13.0 and
9.3 mg/kg).
5.2 Supplemental RI - 1989
5.2.1 Explanation
The purpose of the Supplement RI was to fill in the data gaps
identified in the 1987 RI. The 1989 RI investigations can be
divided into the following groups:
° groundwater investigation
° surface and subsurface soil investigation
° surface water and sediment investigation
° air investigation
This section of the ROD is broken down into the same subgroups.
5.2.2 Indicator Chemical Selection
Indicator chemicals were selected for this investigation based
on constituents detected during previous investigations. They
are as follows:
1. Air Analysis
Arsenic
Chromium
1-31
-------
Copper
Base-Neutral/acid extractable organics
2. Water Analysis
TOC/oil and grease
Carbon
Chromium
Base-neutral/acid extractable organics
Purgeable organics
Volatile organics (VOCs)
3. Soil/Sediment Analysis
Moisture
TOC/oil and grease
Arsenic
Copper
Chromium
Base-neutral/acid extractable organics
Because of the difficulty of distinguishing between naturally
occuring pine tar constituents versus industrial contaminants
found in coal tars (phenols, creosotes, volatile organics),
non-HSL indicator chemicals were also investigated in an attempt
to distinguish between potential industrial sources.
Preliminary candidate chemicals included pinene and other
turpentine derivatives, terpineol, and phenolate. In order to
identify these compounds, an automated unknown library search
for ten, or less, of the highest peaks in the semivolatile
analyses was conducted for each sample.
5.3 Groundwater
5.3.1 Acruifer Characterization
The groundwater flow directions observed during this
investigation correspond closely to those of previous
investigations. The monitoring data indicate that the sitewide
groundwater flow direction within the unconfined shallow aquifer
is to the northeast with a northerly flow component in the
northern portion of the site. The average hydraulic gradient is
approximately 0.010 foot/foot (ft/ft). However, the hydraulic
gradient varied across the site area. In the northwest portion
of the site the groundwater flow direction was northeast under a
relatively steep gradient of 0.020 ft/ft, whereas the
groundwater flow direction in the southern portion of the site
was to the northeast under a more gentle gradient of 0.007
ft/ft. Influence from the North Main Street ditch and the
low-lying area in the northern portion of the Cabot Carbon site
is evident. This groundwater flow direction is consistent with
1-32
-------
the geologic orientation of the underlying confining Hawthorn
Formation, which also dips to the northeast.
Groundwater elevations were compared to surface water elevations
and found to be equal to or above surface water elevations for
all but the northern portion of the- drainage ditch located on
the KII property. This indicates that shallow groundwater is
discharging into the area's surface water/drainage systems.
Additional groundwater elevation data recorded from the three
intermediate aquifer monitoring wells indicate that the flow
direction follows the regional north-northeast flow direction of
this aquifer. The average groundwater velocity in the
intermediate aquifer is 0.45 ft/day.
A comparison of the potentiometric conditions of the unconfined
and intermediate aquifers indicates that water levels in wells
screened in the intermediate aquifer are approximately 25 ft
lower than those of the unconfined aquifer. This suggests that
a potential downward component of groundwater flow is present at
the site. However, the permeability of the clay in the too of
the Hawthorn Formation ranges from an order of 10~6 to 10~8
cm/sec. Since there is 30 to 35 ft of dense clay between the
two aquifers, as reported in the initial RI (1987), it is
projected that there is little, if any, interconnection between
the unconfined and intermediate aquifer zones.
5.3.2 Groundwater Quality Assessment
The groundwater quality assessment included the analyses of
samples from the shallow, unconfined aquifer and the underlying
intermediate aquifer. Of the 25 wells sampled during the
assessment, 22 wells were screened within the shallow aquifer
and 3 within the intermediate aquifer. The locations of the
wells sampled are presented on Figure 3.4-1. A summary table of
constituents found in the shallow aquifer can be found in Table
4.2-1. Maximum concentrations can be found in Table 4.2-4.
A number of constituents were detected in the groundwater at the
site, including PAH compounds, phenols, volatile organics,
chromium, and various pine oil derivatives. A summary of the
analytical results of this groundwater quality assessment is
presented in Table 4.2-4. This summary includes a comparison of
the background concentrations of the maximum contaminant
concentrations detected in both the shallow and intermediate
aquifers.
Carcinogenic and noncarcinogenic PAH compounds were detected in
the shallow groundwater at elevated concentrations within and
downgradient of the site area. The compounds include
1-33
-------
SCALE IN PEST
Figure 3.4.1
GROUNOWATER SAMPLING STATIONS
.I
CABOT CARBON/KOPPERS
Remedial Invtstigation
3-16
-------
(<«Hi inrm IIU 1 IIU I H 1 N '•
Oil Mil ffnat. ^/l. 1 1 0 / 09
lj.it. (b)ll»xaixr. MR/I- '
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SI /h I.IHI 7. (Ill '•! \U> HI- |h II '•* IIU '-I' I.'4I> .'./III
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If >/1 <•/«''
Tle /i.2-4. ttixliBn GoiccaUraliiiis o( Ci<
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Hiuraiilitsie. /J&/L '•- - 4.-i>lllvll»-xvM U). ««l. '> .4 >l«l
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1 IU •>
nu s
nu :M (••«. 6 <.*-*
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Tattle 4.2-4. ttixliUB Concentrations of (.YoufcjaUT (*»i-.i itn-nt
. rip- .' <>i .')
I
Ol
Constituent
LUcnoun Search
Cyclnpattamie, Mfl/L
Ill-Iulene. Hffl-
911 Cmltazole. ^if/l.
Al|iwi lerptiipol , Pf'/l-
fyCIItVI
Dim'diyl -lin-nol . /if/l.
Kdrylmelliyl jiniol . ^/l
Alkyl |<*a»l. ^/l.
Klliyl benzene. ^g/L
Dinettiyl b«uene. ^/l.
Dlheicofuraii. pg/L
Ktl«nl. 2-(2 Buloxy
eiJiuxy). /Jfe/l.
SJn| low A<|iii (i-l
Barkgroiad Kixinun
Conceittrat lone."* (^11111(1,41 i*•* ITK-I
. .
•
40 nv-'i
» 0 IIV 1
-| 1') »/ IIV »
Mule:
*nVM. ITU-2. aul ITU 4 viere us«l for
* I'lV 1 v«s iiswl for U^k
-------
naphthalene, phenanthrene, fluorene, acenaphthene, and
anthracene. The compounds were generally detected at their
highest concentrations in the wells along the KII eastern
boundary, ITW-5 and ITW-21. PAH compounds were not detected in
the upgradient shallow wells, ITW-1 and ITW-2, or in any of the
deeper wells within the intermediate aquifer.
Phenolic compounds were also detected in the shallow groundwater
at elevated concentrations within and downgradient of the site.
The highest concentrations of phenol and 2,4-dimethylphenol were
detected along the eastern boundary of the site, on both sides
of the Ditch. 2,4-Dimethylphenol was also detected in
relatively low concentrations within the western portion of the
site in the wells downgradient of the former Koppers lagoons and
the main KII process area. PCP was detected in only two of the
wells sampled (ITW-5 and M-17), which were located downgradient
of the KII process area. The more mobile 2,4-dimethylphenol was
the only phenolic compound detected in wells ESE-001 and
ESE-002. 2,4-Dimethylphenol was also the only phenolic compound
detected in the underlying intermediate aquifer.
Concentrations of total VOCs were detected in the majority of
the wells sampled during this investigation. Maximum
concentrations were detected in the wells on the former Cabot
Carbon facility. Elevated levels were also detected in other
areas of the site, which include the northern and southern site
boundaries and along the eastern boundary of the KII property.
Total VOCs were also detected in the intermediate aquifer
(ITF-3) at a concentration of 168.ug/L.
Chromium was detected in relatively high concentrations in the
shallow upgradient wells, ITW-1 and ITW-2. These high
concentrations are consistent with the results of the initial
1987 RI indicating an elevated background condition within the
shallow groundwater. The upgradient concentrations were
generally higher than the.levels detected in the majority of the
onsite and downgradient wells. Chromium was also detected in
the intermediate aquifer (ITF-3) at a concentration of 0.019
rag/L. Bis-(2-ethylhexyl) phthalate was also detected at
relatively high concentrations (60 and 300 ug/L) in the shallow
background wells. The highest concentration detected in the
onsite or downgradient shallow wells was 31 ug/L recorded in
ESE-002. In the underlying intermediate aquifer,
bis-(2-ethylhexyl) phthalate was detected at similar
concentrations in each of the three deep wells.
Tentatively identified compounds detected in the unknown search
included a number of pine oil derivatives, which include
camphor, alphaterpineol, and alph- and gamma-terpinenes. These
sompounds were found almost exclusively in and downgradient of
the former Cabot Carbon lagoons area. These compounds were not
detected in the wells within the underlying intermediate
aquifer.
1-34
-------
5.3.3 Soil/Source Characterization
A number of potential source areas at the Cabot Carbon/Koppers
site were designated during the previous investigations,
including:
1. Former north and south lagoons,
2. Former cooling pond,
3. Wood-shaving area,
4. CCA'drip track area,
5. Creosote and PCP drip track area,
6. Former Cabot Carbon wastewater lagoons, and
•7. Eastern site boundary along the North Main Street
ditch. —
Each of these areas was individually evaluated during this
current supplemental investigation to more accurately define the
soil quality at each location. The investigation program
included.the drilling, logging, and sampling of 64 soil
borings. The soil samples were screened in the field both
visually and with a PIO. A total of 192 selected samples were
transmitted to the laboratory for analysis.
A summary of the analytical results of this soils investigation
showing, within each source area, the maximum concentration of
indicator parameters are presented in Table 4.3-1.
Elevated concentrations of arsenic, copper, and chromium were
detected in soils on the Koppers property at the former south
lagoon area, the CCA drip track area, and the main plant area.
Arsenic, copper, and chromium were detected, at much lower
levels, in the area of the former Cabot Carbon wastewater
lagoons and along the North Main Street ditch and generally
reflect the site's background conditions.
During this investigation, phenolic compounds were detected in
soil samples from both the former Cabot Carbon and KII
properties. PCP was detected only at the former north and south
lagoons, the PCP drip track area, and the former cooling pond
area. Phenol was detected in low concentrations only at the
former cooling pond area and the former Cabot Carbon wastewater
lagoons. 2,4-dimethylphenol was detected only in the soils at
the former Cabot Carbon wastewater lagoons.
The highest concentrations of PAH compounds were detected on the
KII property at the former north and south lagoons, the former
cooling pond/plant area/ and the PCP drip track areas.
Relatively low concentration of PAH compounds (naphthalene and
phenanthrene) were also detected in the soils at the former
Cabot Carbon wastewater lagoon area.
1-35
-------
T;4,le4.3 1. Hiximin (iarrnl ra( i<«vs ol Soil GUM
Cuitst itxkiit
Arsenic
Copier
Qinnlin
Oil and Crease
AceivqJitiitiie
Ac« tq4 u 1 ly Uiie
Anthracene
B<5Ko(A)aiillirar«ie
Btaro(B)lhtfinfliii*i*?
f. Beifo(K)l h«>r(G,H. 1 )|M»ryleiie
Bis (2.etliyll»exyl)
[Jxhalate
DlbeiE(A.II)antiirar«ne
livknr>(l ,2.3-rD)p»yretie
fta>c.^hloroj4»fmol
2.4 OiidtrotohMie
2-Uilurcrv^iiilwiln£
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Hn-iiol
Hull-: • i»l ik-iii'iiil
.'-.,•,-;•: UOU,T/I;;K. i-w;
North
Uv».
23.1
10 3
12.9
7.3SO
3.900
6S
4.900
730
620
600
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1.100
3.S(X)
4.SOO
6.200
9. bOO
4.300
2SO
0 88
160
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1 "*''""
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1. VI)
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12
0.92
2.1
12
2.0
87
71
• «)'l'l 1 /Ml '.
I"/ I'l/tt'l
ill* 'ill.-. (mv/V|'.)
('•tliiV, OA Ih i|> Ml'Driji U»l t'.d«ii NI>I ill Kiin
l^«tl I'l.nk I'l.kk 'lliviiif-;; ' Lij', m, SlH-*'!
I't 6 I7'> 9 /,8 «» V, | 71 0.676
6S 6 816 4|. / » 7». 'til |V,
116 7'IM 70 S S./S II |/.|
I.'>2O 4, I'll /, ,/UII /Oi l'i.?OI» |<).(M«)
'•U» 7 4 41 <(l 0.7<. 6. 1
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88O 1.8il> fit) 0 76 .
7 2O / l/dl O.17 I./
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l'i() It H'. 061 18
170 / 4 V, Oil 78
7 U) II 110 0 »/ 4.1
1 . WX) 7'» MXI \ U «M
SH) ViO 0 7H /I
4. (XXI 410 0 ()'. l'\ 76
7. (XX) 87 SO 1.1(1 47 17
/HO 76 87 1.70 /.()
SI / .4 '• S 0 IS
1.7 1.4 14 II 3 /
78
y, S 7 II
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0.4S • -- •-/
0 HI 10
H'l
-------
5.4 Surface Water and Sediment Assessment
5.4.1 Surface Water
Surface water samples were taken from six designated locations.
The sample locations are shown on Figure 3.6.1 and the sample
results are shown in Table 4.4-1.
5.4.2 Sediment Investigation
Sediment samples were taken from'designated locations along the
North Main Street ditch, the KII drainage ditch, and the marshy
area forming the northeast quadrant of the site, as shown on
Figure 3.6-2. The sample results are shown in Tables 4.5-1.2
and 3.
5.4.3 Air Investigation
The investigation involved the collection of respirable-sized
airborne particulate matter and vapor at three stations. Each
station was equipped with two high-volume samplers to obtain
analytical samples for metals and semivolatile organics in
accordance with the appropriate methodology. Twenty-four hour
integrated samples were collected on a daily basis for 7
consecutive days (extending from noon on November 30, 1988 to
noon on December 7, 1988). Due to mechanical problems, the
samplers at Station 2 were not functioning on the first and
fourth day of the program and, thus, analytical results are not
available. The constituents found in the air are detailed in
Table 4.6.3.
6.0 RISK ASSESSMENT
6.1 Introduction
A formal Risk Assessment (RA) Report was performed as part of
the 1989/90 RI/FS. The RA evaluated and selected appropriate
indicator chemicals, evaluated potential exposure pathways and
contaminant concentrations that were selected as the most
sensitive to exposed populations, and, based on those factors,
calculated risks posed by contamination at the site.
Because of the complexity of current and future land use at the
site, there were a number of different exposure scenarios
developed in the RA. Additional scenarios were evaluated in the
FS and will be explained further in Section 7 of this ROD.
1-36
-------
.;••;*« ;»9e
SCO 250
KEY
CSURfACE WATER
SAMPLING LOCATION
Figure 3.5-1
SURFACE WATER SAMPUNG LOCATIONS
tOUHCt NUNTtN/fU. 1M*.
CABOT CARBON/HOPPERS
R«m«dlcl lnv««tig*tion
3-:
-------
Table -• --1 Maxi.Tu.T Cor.cer.trar ions of Surface Water Cor.st it uer.;:
North -air. Street Ditch
Constituent
3il and Grease
Carbon. 7CC
Chrc~iu.7.. Tst.al
VX Total
Acenaprhene
3 ' s • i 2 • e t ""•' h e x v ~ — n a ' a " e
Naphthalene
Pher.ol -
2 . - • di.T.eth.vlpher.c '.
Fluorene
'-'-.kr.o-T : Search
H • Indene
Cycloper.tar.or.e
Cyclopentar.one . al^vl
Ethar.or.e
Phensl. ir.er-.yl
Phenol . dimethyl
Phenol, phenyl ethyl
Phenol, ethyl methyl
Phenol., alkyl
Benzene, dimethyl
Caaphor
1.8-Cineole
2-Pentanone, 4-hydroxy •£• methyl
0-Fenchyl alcohol
Alpha cerpinol
Endo-borneol
Concentration
2 r.z 1
, ^ •> •
-- •=• "5- -
0.012- rg '_
:"• U5'r
" • 2 ug.-. L
2 •• ' u ~ ' L
13 .. - ••
* - ** «. •*
2:0 ug/L
-jC ug.'L
2.C ug.. L
-" ug L
100 ug/L
100 ug/L
35 ug/L
6-0 ug/L
120 ug/L
35 ug/L
'- Ug/L
690 ug/L
1-.0 ug/L
1.300 ug/L
93 ug/L
150 ug/L
330 Ug/L
170 ug/L
64 u/L
Stiticn
s-.'-c::
5'.' • I '. :
S '-' • 0 ? 2
sv - : : :
. S'»'-05'2 "
S'.'-GCl
sv-.;:-
sv-002. s-.'-c-:-
s •-•-:;»
5'-'- I Ji
S--..V-
S'W-002. S'-'-OC- 5'.'-. -
SV-GG
SV-'OG]
SV-QC-
S'.'-CC1-
S'.'-OG-
SU-OC2
SW-00-
S--002
SWrOO-
SW-OC5
SW-006
SW-00-
SU-004
SW-005
Noce: mg/L'- milligrams per liter
Ug/L - micrograms per liter.
Source: Huncer/ESE. 1939.
-------
SEDIMENT
SAMPLING
LOCATION
Flgurf 3.5-2
SEDIMENT SAMPUNG STATIONS
CABOT CARBON/KOPPEPS
lnv«ttlg*tlon
-------
Ta'-'.e i.:-l Sedirer.r "ors:i:'-er.:s. North Main Scree- Ditch
SZ-OC2 SE-cc3
S£-OG- SI-
Hexddecyr.e
Hexaneiioic acid.
dioczv. es:er
carboxaldehyce isorer
Pher.ar.chrer.e . diirethyl
isotr.er
Pher.anchrene . crisierhvl
isorcer
Phenanchrene. cecra-
mechyl Isomer
Phenanchrene, occa-
hydromechy-1 isoraer
Anthracene mechvl tsomer
9 S
33 27. 220
9.8
7.9
59
15
6. 3
0."
0.5:
0.9.
0.63
1.9
0.37
6.1
-------
Table 4.5-1 Sedi.rer.: Cons:iruenrs. North Main Streec Dirch
(ir. eg/kg.' •. Cor.cinued. Page 2 of 2)
Cor.sriruen:
SE-OC1 SE-OC2 SE-OC2 SE-00-
I'r.V.rc-T Search
Eihar.or.e (hydroxy.
xe rhoxy . di.T.e :hy 1
Lsocer,.
1.2- Ser.zer.edicarbc •
av'.ic acid ester
Hepzadecar.e Lsoxer
6 5
Soce: •- - No: de:ec:ed.
Source- Hun:er.'ESE. -I?:?
-------
r.s: ;-'-lerrs . KII Drainage 'Di:ch
S " •"• C 6
Til and Grease 1.3?" Z ;"5.0
•. I 5 e ~ . i
?yrer.e
•Zhryser.e
r'.ucrar.ther.e
"^ ^ — 7 a * ^ *.* a
c:
3-Hexadecyr.e 1.1
Sulfur ' 32.'--
Benzene isomer • 25 0
Decanedioic acid escer 0.63
Naphcho furan isoraer •• 0.46
Phen«nchrenecarbox-alde. -• 0.66
hyde isome-r
9H-Fluorene. -• 0.83 3.3
9 ir.echylene
Decer.e. dimechvl isomer -• 14
-------
_c-cc:<=:
d
Table * . 5 - 2 Sedirrer.t Constituents. KII Drainage Ditch ( ir. T.g.kc'
(Continued. Page 2 of 2)
Cons tit-en:
Si-cos SE-CC:
•UwO
SI-OC3 SE-C1
L'r.V.r.cv- Search
2-Cvclopropen-1-one.
2'. 3 -cipheny I
Eer.is fl-oranther.e
isoser
3enzo fluorene isorrer
1.2-Benzenedicar-
boxylic acid ester
Hexaneiiioic acid ester
Methyl diol isor.er
Methyl pyrer.e isorser
Cyc lopentapher.anthrene
isomer
1.5
o. •=
0.53
Note: •- - Soc detected.
Source: Huncer/ESE. 1989.
-------
C-CCKX: i.-v :
0?, 19.-89
Sediaer:
rir-ar-.rs. Norreas: yjarsh .Area
Cons: jr. XT.: (^ 'KJJ.I
Oil and Crease
.Arsenic (zocai)
Ccpper ' so rail-
•2-r:jri--r. ''co:al''
3is • • 2 -eirylhexyl } ph^Iase
Sis- i-chlisoprotr.'l, ener
SE-011 SE-C12A
6,'SSO 251
2.-0 --
".91
9.53
1.2
..
SE-C12S SE-C13 SE-01^A
123 311 531
..
..
1.06 --
1.6 '1.3 1.2
..
SE-0148
1:0
0.35'
• -
8 33
1.5
--
SE-012
-35
C 9-
• ' 1.6
-•
0.5
A SE-01:3
-_-
"*
--
Ter.r^Tivelv Idgr.tified
carborai denvde isane r
ur. bercene Lscner
Lsoner
Hwnar.vrenecarboric
acid Lsoraer
occ^r.tiro criaerfT/l Lsoner
Hexandicic acid escar
Q.'clopropane, occvi
Terradec.nc
Hexadec.-ne
C.Tclopropane .Lsoraer
Qodecanodiol
Ocudecene
Kepcadecanol
Lbkrtvn decyne
Hexanedioic acid,
diocryl escer
Oocosane
Mediyl cyclopttvuf
Lsoaer-
UrioTDwi decmol
Qczacosana Ljoner
Occacosane
110
120
-.
..
..
..
. .
0 . '0
C.2S •-
0.16 -•
1.0 . 1.9 O.a5
0.78 --
1.1 --
0.35
0.52
. .
. . . .
. . • . . . .
--
..
• -
..
...
..
0.78
0.43
0.64
-•
2.3
..
--
0.2^
0.49
--
..
0.95
..
.--
4.9 1.9
..
0.93
..
1.4 0.35
i.o-
4.3
0.56
0.26
1.9
,0.84
0.19
0.13
i-138
-------
C-CCKRI.->/-•,
06/12.
Table -.5-3. SedlTer.- Cor5r.3jer.i3. ?cr±easi ^«rsh Araa (Cor.cirued. Page 2 of 2)
SE-011 SE-012A SE-012S SE-013 SE-01^A SE-C1-3 SE-C15A SE
Decarcl Lscrer
yterrr.'lr.rlcxTexane Lscrer •- •• -- •• •• •- 0.56
i*-i£r«r.ihren6carbc\vlic . •• •• -- 1.1
• •
acid esier
sic acid -- -- O.SS --
5 - microcrars.
•- - below deiec^able li.TJ.is.
Source: HLr.^r/'ESE. 1?59.
-------
6.2 Indicator Chemical Selection
The media of concern at this site are the soil, groundwater,
surface water, sediment and air. Due to the number of
constituents detected in these media, it was necessary to select
a limited number of "indicator chemicals" on which to base the
risk assessment. Compounds selected are the focus of the
toxicity assessment exposure analysis, risk characterization and
development of health based action levels.
All of the historical data was used to select the indicator
chemicals; however, the risk calculations were based primarily
on the analytical data collected for the supplemental RI. The
selection process followed the one outlined in the Superfund
Public Health Evaluation Manual. (1986).
It can be divided into the following four steps:
1. Determination of chemical concentrations and frequency
of detection;
2. Identification of toxicity characteristics of detected
chemicals;
3. Calculation of chemical toxicity (CT) and indicator
score (IS) values; and
4. Selection of final indicator chemical.
Using this process, the following indicator chemicals were
selected for the CC/K site:
0 Arsenic
° Benzene
• uenzene
0 Chromium (VI)
0 Napthalene
0 Potentially Carcinogenic
Polynuclear Aromatic
Hydrocarbons (PAHs)
° Noncarcinogenic PAHs
° Pentachlorophenol (PCP)
0 Phenol
6.3 Exposure Assessment
6.3.1 Definition
1-37
-------
I 11 ffl '. •'. I I
III./ I'l. H-i
Si. ii 1. 1, A m./
/I
OK. I JO 0 ?l ) -tf I Ut n
O OH
o oil
ii ir>
it /•*•
o 01*
o ir, ii n; ii in*
o nib o IIH o (fn o an o ur. o IM»* n nih
out; out) oai> o ml o mi on/i* oui/
o OM o u.s o iw» o 0/9 o IM o IMS n ii,/
Mxc: • - brlw <*-l««-l**>l« llmJU
•tllf^r*! txmrcntrMlcn »trcc: IUit*r/rSE. I I .M • I •*•!• ii •>/
II IIS
II '.!• O /"I
Ii ur.* ii ml
u ui'.* n m/
• ii ir/ Ii ir>
o II
o ir,*
.n (.'
n 11
n I*.
ii /•»• ii i
u m/ u ml* o ml n m/ n uil* u m/
o m/ o ml n ml (Mir/ our,* o m/ o ml o ml o ml null
u ui I null noil on// u ui', o in? ii ins n n,".* oii//nir/l
-------
An exposure pathway is the course a chemical agent takes from a
source to an exposed population or individual (receptor). For
the exposure pathway to be complete, the following four
components must be present:
1. A source or release from a source
2. A likely environmental migration pathway
3. An exposure point where receptors may come into contact
with the chemical agent
4. A route by which potential receptors would result in an
intake of the chemical agent.
A screening of current potential exposure pathways was
conducted; the RA focused only on the significant completed
exposure pathways.
6.3.2 Onsite Exposure Pathways to Workers
6.3.2.1 Direct Contact
An important potential exposure pathway is direct contact of
contaminated soil to uncovered skin surfaces. On the Koppers
facility, potential worker exposure exists in two areas: the
drip track areas; and the former lagoon and cooling pond areas.
The majority of the contamination in the former lagoon and
cooling pond areas is in the subsurface soils. Workers in the
drip track areas are protected from direct contact by the
Federal Insecticide, Fungicide and Rodenticide Act (FIFRA)
labeling which requires them to wear long pants, long-sleeved
shirts and gloves as well as additional protective equipment.
FIFRA contains a number of other requirements concerning worker
safety and training that effectively prevents direct contact.
OSHA regulations also provide protection to workers in both the
drip track and former lagoon and cooling pond areas.
6.3.2.2 Incidental Ingeation
The same FIFRA and OSHA regulations that effectively prevent the
completion of the exposure pathway for direct contact also
prevent the completion of the exposure pathway for incidental
ingestion.
6.3.2.3 Inhalation .
A3 part of the supplemental RI, air samples were taken from
three different areas on the Koppers site. All of sample
results were well below the OSHA limits for worker exposure.
Therefore, this pathway was not carried any further in the RA.
1-38
-------
6.3.3 Potential Onsite Exposure
Pathways to the General Public
6.3.3.1 Direct Contact
Because a portion of the Koppers facility is fenced and has a
locked gate, direct contact of the general public to source
areas on the Koppers facility under the current land use
scenerio is expected to be infrequent. This pathway was not
carried any further in the RA. However, public access to the
soils in the former Carbon lagoons is unrestricted, this pathway
was carried through the RA. The exposure concentrations
selected were the highest observed surface soil concentrations
observed in either the IT RI or the Hunter/ESE RI.
The direct contact scenario was based on a child visiting the
site to-play 36 days per year for six years. In addition, it
was assumed that 50 percent of the time onsite would be in the
contaminated area. The dermal absorption rates were 10 percent
for semivolatile organic compounds, 25 percent for volatile
organic compounds, 15 percent for chromium and 1 percent for
other metals. The exposed skin surface area and body weight was
assumed to be 2350 cm2 and 35 kg, respectively. A soil
ingestion rate of 100 mg per day was used for the ingestion
pathway. .
6.3.3.2 Inhalation
Because site access is restricted for the Koppers site, this was
not considered a completed pathway. The former Cabot Carbon
lagoons are covered with moderate vegetation, a concrete
foundation and a stormwater retention pond. For these reasons,
the generation of dust is greatly inhibited. Therefore, this
was also not considered a completed pathway.
1-39
-------
6.3.4 Potential Offsite Exposure Pathways to the General
Public
6.3.4.1 Direct Contact
There are two significant offsite exposure points for the
general public: the North Main Street Ditch and the KII drainage
ditch. Because both of these areas have unrestricted access,
they were both retained as complete pathways for exposure to
contaminated.surface water and sediment. In addition to dermal
contact, it was determined that children playing in the ditches
could also incidentally ingest small quantities of contaminated
sediment or surface water.
The exposure concentrations for surface water used for the North
Main Street Ditch were the maximum observed values downgradient
of the source areas and were taken from either the Hunter/ESE RI
or IT RI. For sediment concentrations, the highest
concentration from ESE location SE-004 and ITS-2 was used.
These levels appeared to most closely represent the levels as
observed during several sampling events. For the KII ditch, the
highest observed concentration from the Hunter/ESE and the
Koppers 1985 investigations were chosen. Due to the small
number of detections, no surface water concentrations were
calculated.
The direct contact exposure scenario assumes that a child (age 7
to 13 years) plays in or near Springstead Creek 2 times per
week, averaging 30 minutes per event, for the 39 weeks that
school is in session and 4 times per week averaging 1.5 hours
per event for 13 weeks during the summer. It was also assumed
that a child would spend 50 percent of this time playing in the
area along the creek banks. The exposure frequency for the
North Main Street Ditch were assumed to be 10 times per year for
2 hours per day. The skin surface area, body weight and
absorption rates for dermal contact with sediments are the same
as for the onsite direct contact with soil scenario.
The surface water absorption rate was based on the dermal
permeability constant (Kp) for each constituent. The sediment
ingestion rata waa assumed to be lOOmg per day and the surface
water ingestion rate was assumed to be 10 milliliters per event.
6.3.4.2 Direct Inoeation of Ao^iatic Organisms
The intermittent flow and small size of the North Main Street
Ditch, the KII drainage ditch and Springstead Creek, combined
with their location in an industrial/high traffic area, make it
highly unlikely that edible size fish would be caught near the
site. This was not considered a complete exposure pathway.
1-40
-------
6.3.4.3 Inhalation
Due to the presence of moderately volatile constituents in the
surface water and sediments of the two drainage ditches, this
was retained as a completed exposure pathway.
The exposure frequency is the same as for the direct contact
scenario for a child playing at the North Main Street Ditch,
except it is assumed that the exposure is occuring 100 percent
of the time that the child is in the area. The breathing rate
is assumed to be 2.1 mj/hr.
6.3.4.4 Groundwater
There are currently no users of the shallow aquifer. In order
to assess the potential risk of any future use, two hypothetical
groundwater wells were selected. Because the indicator
chemicals on the northern boundary of the site are different
from the indicator chemicals on the eastern boundary of the
site, a hypothetical well was located at both these points.
The general procedure for estimating the potential .current and
future groundwater exposure concentrations was as follows:.
o Determination of plume characteristics;
o Determination of equilibrium conditions between
groundwater and soil at source areas;
o Calculation of expected time of travel from source to
receptor; and
o Calculation of anticipated future exposure
concentrations from dilution of source concentrations.
The groundwater exposure assumptions were for the daily
consumption of 2 liters of water by a 70 kg person.
6.3.5 Environmental Receptors Exposure Pathways
6.3.5.1 Terrestrial Exposure
Organisms that live in, on, or above the land may be exposed to
surficial soils (both dermally and by ingestion) and surface
water (primarily as drinking water)1. Some terrestrial
organisms also may consume affected plants or animals from
either terrestrial or aquatic habitats; resulting in
bioaccumulation of contaminants. A qualitative evaluation of
these pathways was performed for various types of organisms
found at the site.
1-41
-------
6.3.5.2 Aquatic Exposure
Aquatic biota may be exposed to constituents via water,
sediment, or food. Organisms may be exposed via transfer from
water across thin body membranes such as gills. This is the
process of bioconcentration. This exposure pathway is limited
by the chemicals' solubilities. Chemicals with low solubilities
may adsorb preferentially to sediment particles. These may be
ingested by organisms, and some portion of the chemical may be
transferred to the organism via the gut. The assimilation
efficiency depends on numerous variables such as
bioavailability, lipid (fat) content of the organism, gut
clearance time, etc. Finally, organisms may ingest affected
prey. Bioaccumulation from food is dependent upon numerous
factors, including the degree to which the chemical transfers to
and remains in living tissue, the physiological rate constants
governing uptake and depuration in the various organisms, the
encounter rate of and concentration in affected prey,
temperature, and other factors.
6.3.6 Summary
As a result of the exposure pathway screening, the preliminary
list has been reduced to the following five potentially complete
exposure pathways:
1. - Exposure by direct contact to onsite surface soils in
old Cabot Carbon lagoons area,
2. Incidental ingestion of onsite surface soils in old
Cabot Carbon lagoons area,
3. Inhalation of vapors in offsite ambient air,
4. Ingestion of groundwater, and
5. Exposure of receptors, both human and environmental, to
affected surface water and sediements.
The RA addresses these five potential exposure pathways
associated with the inactive onsite potential reception areas
and the potential offsite.
The exposure point concentrations for these completed exposure
pathways ware than compiled.
6.4 Toxicitv Assessment
6.4.1 Reference Doses
Reference doses (Rfds), also referred to as the acceptable daily
intakes (ADIs), have been developed by EPA for indicating the
potential for adverse health effects from exposure to chemicals
1-42
-------
exhibiting noncarcinogehic effects. RfDs, which are expressed
in units of mg/kg-days, are estimates of lifetime daily exposure
levels for humans, including sensitive individuals. Estimated
intakes of chemicals from environmental media (e.g., the amount
of a chemical ingested from contaminated drinking water) can be
compared to the RfD. RfDs are derived from human
epidemiological studies or animal studies to which uncertainty
factors have been applied (e.g., to account for the use of
animal data to predict effects on humans). These uncertainty
factors help insure that the RfDs will not underestimate the
potential for adverse noncarcinogenic effects to occur. The
RfDs for the site contaminants of concern are contained in Table
8.3.1.
6.4.2 Chronic Hazard Index (HH
The chronic HI is a ratio of the lifetime average daily exposure
of a noncarcinogenic chemical to the acceptable intake exposure
level. If this ratio is greater than unity.(>l), then the
lifetime average daily exposure has exceeded the acceptable
intake exposure level, indicating that potential health
hazardous exist (EPA, 1986a).
6.4.3 Weiqht-of-Evidence Categories
The weight-of-evidence categories for potential carcinogens
qualify the level of evidence that supports designating a
chemical as a human carcinogen. Table Three contains a more
detailed explanation of the categories.
«
6.4.4 Carcinogenic Potency Factor
The carcinogenic potency factor (CPF) is used for estimating the
lifetime (70 years) probability of a human contracting cancer
caused by exposure to known or suspected human carcinogens.
This factor is the slope of the cancer risk dose-response curve
and is generally reported in (rag/kg/day)"1. This slope is
determined through an assumed low-dosage linear relationship and
extrapolation from high to low dose responses determined from
human epidemiological studies or animal bioassays. The value
used in reporting the slope factor is an upper 95-percent
confidence limit on the probability of response per unit intake
of a chemical over a lifetime, converting estimated intakes
directly to incremental risk (EPA, 1986a). Use of this approach
makes underestimation of the actual cancer risk highly
unlikeley. The CPPs for the site contaminants of concern can be
found in Table 8.3.1
6.5. Risk Characterization
1-43
-------
TABLE THREE
EPA Weight of Evidence Categories
A Human Carcinogen
Bl or B2 Probable Human Carcinogen
Bl indicates human data available, B2 indicates
sufficient animal and inadequate or no evidence
in humans _
Possible Human Carcinogen
Not Classifiable as to Human Carcinogenicity
Evidence of Noncarcinogenicity in Humans
-------
C-CCKRI.l, 3V 2
11/30/35
Table 8.3-1. Quar.cicaci*.* Evaluation of Indicator Qrenicals at cte Gaboc
Carbon/Koppers Sice
Constituent
Arsenic
Ghromi'jE <>T)*
Chroniun (III)
EPA Potential
yfeiAc-of- Care'-czsrs f~*/\cg/d^/\~' Soncarcinoeers •'-x./Vz/dav'1
Evidence GT .AD!
Category Oral ImaLition Oral Irrau-acijn
A 1.75 50
A -- 41 O.OC5
D •- . i.o o.xr.
Potentially 32
Carcinogenic ?AHs
Ncrcarcircgenic ?AHs D
Phenol D
prp 32
Naphthalene
11.5
6.11
1.00
0.006
0.6
O.M.-
. 0.006'
o.::
O.-»L
Soce: ADI - acceptable daily Lncake.
CPF - cancer pocenc/ factor.
mg/V^/day - milligrams per Vdlograo per day.
.. - does roc apply co specific ccntaninanc.
*Of *• cocal d-q^raiin dvcacrad ac t±» sce, che acre pocendally ccodc hecavalenc form
[Cr(VI) ] uu usad in this RA for conservacive purpooea (co procecc tmnn healch) , ev^n
Cr(III) is ch« sere stable and less toxic fora of chroniua in Che envrLroroenc .
Source: tixicer/ESE, 1989.
n..
-------
6.5.1 Introduction
Excess lifetime cancer risks are determined by multiplying the
intake level with the CPF. These risks are probabilities that
are generally expressed in scientific notation (e.g. 1X10 ).
An excess lifetime cancer risk of 1X10"5 indicates that, as a
plausable upper bound, an individual has a one in a million
chance of developing cancer as a result of a site-related
exposure to a carcinogen over a 70-year lifetime under the
specific exposure conditions at the site. The Agency considers
individual excess cancer risks in the range of 10~4 to 10~°
as protective; however, the 10~5 risk level is generally used
as the point of departure for the setting of cleanup criteria at
Superfund sites.
Potential concern for noncarcinogenic effects of a single
contaminant in a single medium is expressed as the hazard
quotient (HQ) (or the ratio of the estimated intake derived from
the contaminant concentration in a given medium to the
contaminant's reference dose). By adding the HQs for all
contaminants within a medium or across.all media to which a
given population may reasonably be exposed, the Hazard Index
(HI) can be generated. The HI provides a useful reference point
for gauging the potential significance of multiple contaminant
exposures within a single medium or across media.
This risk characterization was performed in a two stage
process. The first stage was performed using the highest
concentration to calculate the risk. If this risk exceeded the
10~6 risk range, then a second calculation was made using
representative concentrations. Because the target organ for
arsenic (a carcinogen) is different from the target organs of
the other carcinogens, the risk for arsenic was calculated
separately. The risks to human health are discussed
independently for potentially carcinogenic and noncarcinogenic
constituents.
6.5.2 Risk Results
The results of the risk characterization indicate that
unacceptable cancer risk levels are associated with the
ingestion of shallow groundwater from the northern and eastern
hyporhetical wells for both the current and future use
scenarios. In addition, the representative concentration His
exceed unity for the northern well (current and future
scenarios) and for the future scenario for the eastern well.
The risk characterization information is summarized in Tables
9.2.6 through 9.2.9.
The cumulative risk for the northern hypothetical well resulting
from the representative exposure point concentrations was
9.9X10"J for the current scenario and 1.8X10"2 for the
1-44
-------
M
O
<: IICKHI 1/911. i
1 I/ Ui/89
Tahiti 9.2-6. Risk Characterization Assoc i.ii t-d wilh I'oi <:nl i al Sli.illuw <.'i <>imK/l x
7.51 x
1 . 44 x 10 8 . 66 x
2.86 x
4 00 x
POTENTIALLY 1 .79 x 10*
PCP
TOTAL III (Ulthout Background
Chromium)
1.47 x 10°
H<'|H fscul al i ve
May) Cancer Risk III
10 4 9 15 x 10 4
10s 1.00 x 104
1.0 J 3.24 x 10 '
IO1 7.08 x IOX
I04 2.41 x IO1
10 J 1 II x 10°
10 J 1 .97 x I02
IOJ 7.51 x I01
10 J 1 44 x 10 2
10 * 8.29 x IO6
10 '. I . 16 x IO4
8. 15 x IO4
9.93 x 10 3
1 14 x 10°
Hole:
III - hazard index.
B/Jay - reilliftiams per kilogram per day
( ) - uumbd «>l yeais l«>i luiuie coin ml r.ii i mi I o arrive al hypot h«-i i« a I w» I I
lluiiifi/r.SK. I'MI'i
-------
c-ccKRi.2.?v.•_:
11,3c.-s?
Table 9.2-7. Risk Characterization Associated with Shallow Grour.c'vatar
Uses ac the Northern Hypothetical Veil (Future Scenario;
Constituent
Representative Future
Dose
(ag/kg/day)
Cancer Risk
Arsenic
Background arsenic
Chromium (VI)
Background chromiua (VI)
Total potentially
carcinogenic ?AHs
Total noncarcir.ogenic PAHs
Naphthalene
PC?-
Phenol
Benzene
Background benzene
8.29 x 10'3
5.71 x 13's
a. 00 x 10°
-3
3.3- x 10
2.57 x 10'
6.91 x 100
9.37 x 10
•2
-•2
2.36 x.!0-
*.00 x 1C'
TOTAL CANCER RISK FROM ARSENIC
C-'ithout Background)
TOTAL CANCER RISK FROM POTENTIALLY
CARCINOGENIC PAHs AND PCP
TOTAL HI (Vithout Background Chromiua;
L.i5 x 10'2
1.00 x 10a
2.96 x 10'
I.i9 x 10'*
3.29 x 1Q-6
I. 16 x I0's
L.45 x 10'2
1.79 x 10'2
.00 x 1C';
.08 x lj';
1 1 « v • 0J
^ . k J A fc J
(99}
2.2s"x 10V
• ' (37)
:.33 x .::
x lj."
Sote: HI - hazard Index.
ag/kg/A»y - ailligraas per kilograa per day.
( ) • nuaber of years far future concentration co arrive a:
hypothetical well.
*HI Ln 70 years (includes the worst -case assuoption that total
noncAtcinogenic PAHa will be observed in 70 years).
Sourct: Huncer/ESE. 1989.
-------
C-CCKKI. 1/9H.2
11/'JO/89
Table 9.2-8.
Risk Characterization Associated with Potential Shallow Crouiuluater Uses at the Eastern
Hypothetical Uell (Current Scenario)
Upper Round
Dose
Constituent
Arsenic
Background arsenic
Chroalua (VI)
Background chroalua
(VI)
Total noncarclnogenlc
PAIIs
"*> Naphthalene
[^ Phenol
in
pep •
Benzene
Background benzene
(ag/kg/day) Cancer Risk
2
5
5
3
1
4
3
2
3
4
85
71
71
54
14
00
14
77
71
00
x
x
X
X
X
X
X
X
X
X
10
10
10
10
10
10
10
10
10
10
4 4.99 x 10 4
* 1.00 x 104
1
3
J
J
1
J 2.77 x 101
1 1.08 x 104
J 1. 16 x |04
H«-i>res»-nt at 1 vt»
Duse
HI (ag/kg/day) Cancer Risk
1
5
1 .14 x 10° 2
7.08 x 10* 3
I .90 x 10 ' 1
9 76 x 10J 1
5.23 x 101 1
2
1
4
48
71
76
54
1<>
66
43
/;
bS
00
x
x
X
X
X
X
X
X
X
X
10 4 2.59 x 10 4
10s 1.00 x 104
10 J
I01
10 J
10
10
10 2.77 x 10J
10 4.50 x 10s
10 1.16 x 10 4
III
5.52 x 10 '
7.08 x 10*
1.90 x 10'
4.05 x 10J
2.38 x 101
TOTAL CANCER RISK FROM ARSENIC
(Without Background)
TOTAL CANCER RISK FROM PCP 2.77
TOTAL HI (Without Background Chroaiua)
3.99 x 10"
10
1.59 x 10
2. 11 x 10
1.15 x 10°
4 32 x . 10
Note: HI - hazard Index.
ag/kg/day - allligians per kilogram per duy
So.irce: Hunter/ESE. 19H9
-------
C-CCXR: : v: i:
Table 9.2-9. Risk Characterisation Associated with Potential Shallow
Groundwater Uses at the Eastern,'Hypothetical Veil (Future
Scenario)
Constituent
Dose
(as/kg/day)
Representative
Cancer Risk
Arsenic
Background arsenic
Chromium (VI)
Background chromium (VI)
Total noncarcinogenic PAHs
Naphthalene
Phenol
PC?
Benzene
Background benzene
TOTAL CANCER RISK FROM ARSENIC
(Vithout Background)
TOTAL CANCER RISK FROM PC?
TOTAL HI (Vithouc Background Chromiua)
2.85 x 10'*
5.71 x 10'3
5.71 x 10'3
3.54 x 10'3
1.14 x 10'1
3,89 x 10'2
3.1- x 10"
2.77. x 10°
3.71 x 10°
4.00 x 10°
4.99 x
1.00 x
2.77 x 10°
1.08 x 10-
1.16 x IQ"
3.99 x 10'*
2.77 x 10°
7.08 x i;-
1.90 x i:'
•9.49 x 1G'
5.23 x ir
Note: HI -hazard index.
ag/kg/day - milligraos per kilogram per day.
( ) • number of years for future concentration to arrive
hypothetical well.
*HI tn 70 years (includes the worst-case assumption that naphthalene
will be observed in 70 years).
Sourca: Huncer/ESE. 1989.
9-25
-------
future scenario. The main contributors to thexrancer risk
levels are arsenic, carcinogenic PAHs and PCP. In addition, the
cumulative HI exceeds unity for the representative
concentrations, for the northern hypothetical well for both
current and future scenarios. The His for the current and
future scenarios are 1.1 and 1.5 respectively. Chromium and
noncarcinogenic PAHs are the main contributors to the HI.
The cancer risk levels for the eastern hypothetical well exceed
the 10~4 risk level for arsenic and PCP for both the current
and future scenarios. The highest risk levels are associated
with the future scenario, with a risk level of 4X10"4 for
arsenic and 2X10~J for PCP. The main contributors to the HI
are chromium, noncarcinogenic PAHs and phenols.
The risk characterization for the exposure scenarios for direct
contact with soils at the Cabot lagoons area and the surface
water and sediments in the North Main Street Ditch indicate that
the cancer risk levels and the noncarcinogenic PAHs are below
acceptable levels.
The risk levels associated with direct contact with surface
water in Springstead Creek are in the 10~° range due to
arsenic (1.3X10*6) and carcinogenic PAHs and PCP (5.01X"6).
The risk levels associated with sediment contact in this creek
are also fall within the risk range due to arsenic (2.0X10"6)
and carcinogenic PAHs (2.6X10"5). The His for contact with
the surface water and sediments in Springstead Creek are all
below unity. The risk levels for these scenarios are summarized
in Tables 9.2.2-3.
6.5.3 Environmental Risks
The environmental exposure pathway of the most potential
significance is the exposure of aquatic life in the Springstead
Creek and the Norht Main Street Ditch to contaminants ,in the
surface water and sediments. The ecological assessment
concluded .that in general, although acute responses are unlikely
based on ecotoxicity benchmark concentrations arid the upper
bound exposures point concentrations, the potential exists for
adverse chronic effects to individuals inhabiting these
locations.
An estimate of the environmental risk to aquatic organisms was
obtained by comparing the estimated environmental concentrations
(EEC) with the toxicity of the chemicals using selected
ecotoxicity benchmarks. The resulting toxicity qoutients can be
used to evaluate the potential for an adverse effect. The
toxicity qoutients indicate that aquatic organisms may be
adversely impacted due to arsenic in Springstead Creek, chromium
in the North Main Street Ditch and PCP and PAHs in both Ditch
and creek.
1-45
-------
11/30 S?
Table 9.2-2. Risk Characterisation of Potential Hunan Exposure to Surface '^=er Lr.
Springscead Creek
Consti=L«r.t
.•Arsenic
Total Poten-
tially Carcino-
genic PAHs
Total Soncar-
cino genie
PAHs
^.thaler* '
Phenol
PC?
Exposure
Pathway
Decaal Absorption
Incidental Ir^estlon
SLSIUIAL
Oezaal Absorption
Incidental Lrgestion
SL3TCTAL
r»m»i Absorption
Incidental Irgesclcn
SUBTOTAL
Decatl Absorption
Incidental Lr^esticn
StSTCTAL
Decaal Absorption
Incidental Lrgtsc.cn
SUBTOTAL
^•rmal Absorption
Incidental Lngestion
SLSIDtAL
TOTAL CA^GR RISK FSCM
TDIM. CANCER RISC HOI
•v,
Dosa
5.75 x 10'* '
6.79 x 10"
3.68 x 10"*
-.36 x KTJ
6.50 x l
-------
T.J>le 9.2-3. KliJt Qtarairlci iz:ii Kit of iVtU'iit i.il Ikiuui KX|«>;,ui«- (<> .lM»liiii'ii(a in Sfii
' I I/10/89
UM.I K....I K,.n,vs,,,i,.lv,.
Cxpa&ure (Xise ('.uici
Gutttlituuri. Padway (n^/V^/iliy) Risk . Ill
Arsenic Denaul Absorption 5 14 x IO7 9 (O x IO7
incldaiuil Ingestlon 2.20 x 10* 1.H6 8 1<>*
SUBTOTAL 4./6 x 10*
atrtnltn (VI) Derail Absorption 3 06 x IO4 6.12 x IO2
IiE-'iikatlal li^stion 8.74 x 10* J,7b x ]02
SlBTUtAJ. 7.87 x IO2
Tot.il IViioiilally IV nail Alt^oiptian 4.39 x 10* b.OS x XIs
Cticiiiu^iilc li»:l«Viiial li|^>tl«t 1.87 x 10 2.'"1 x 1"
I'AIti SHJIUIAI. 7 .H) x 10S
Tol.8i x |0
I'AltT SlWlUrAl. ~ I.% x IO2
TOTAL CANCER RISK 1HTH AKilWIC 4.76 x 10*
1UIAL CAWJK RISC H*H JUIlNriAlJ^ 7.20 x 10s
CAKC1NX1NIC PAIls
TDIAL 111 9.81 x IO2
|k»;x.- (aikor
(inyV^/tlay) Kl:.k III
2.11 k IO7 3.73 x IO7
9.11 x IO7 I.b9 x 10*
1.% x IO6
8.01 x 10* • 1.61 x 10-*
2.?8 x 10* 4.S6 x 10*
2.07 x )02
1 61 x 10* 1 85 x IO6
6 .«'> x IO7 /.92 x 10*
2.64 x IO6
I.'X, x 10s 3.21 x 10 J
8.28 x 10* | m x |0J
4.61 x IO1
1.% x 10*
2.64 x IO6
2. VI x IO2
Not*;:
III - Hazard
- milligram; |»--i kilo&iun JMJI djy.
-------
The environmental assessment predicts that, while temporal
"Changes may~occure in the aquatic system, future impacts that
may occur at the site will not be observable for the following
reasons:
o The aquatic areas consist of man-made ditches that do
not always contain sufficient amounts of water needed
to support aquatic organisms during all developmental
stages:
o These areas are small relative to the contiguous
aquatic habitat in areas further from the site, which
suggests that for populations inhabiting these areas,
only a small number of individuals within the
population would be potentially exposed to any of the
site contaminants.
Therefore, although the risk of potential adverse effects to
individuals inhabiting these locations exists, it is unlikely to
subsequently produce a potential measurable effect on the
population as a whole. This is especially true because the
potentially effected areas are not major sites for reproduction.
6.6 Feasibility Study Risk Results
6.6.1 Explanation
Another evaluation of risk was performed in the FS. This
additional work focused on the risk concerning the subsurface
soils in the general area of the North Main Street Ditch. The
reason that this was done was because the Florida Department of
Transportation may, at some future date, do some excavation work
in the widening of North Main Street.
6.6.2 Risk Analysis for FOOT Workers During Soil Excavation
For this scenario, both maximum and representative soil
concentrations were used. Exposure assumptions were based on
FOOT's estimation of on how long the road widening would take.
Based on these assumptions, the HI and potential risks
associated with short term worst case worker exposure are within
EPA acceptable limits. The results can be found in Table A-2.
6.6.3 Risk Analysis for Offsite Disposal of Soils from North
Main Street Ditch
The risk posed by offsite disposal of soils excavated during the
widening of North Main Street was assessed. A worst case
scenario was developed where the soils would be deposited in a
residential area and potential exposure to children would
result. Risk ranges and HI again indicated that the risks were
within acceptable EPA limits. The results can be found in Table
A-3.
1-46
-------
lAftlf *•]. IfSIMHIlAi MMAl AM) OUL flKKUH 10 MBIM Mil illitl flCAVAIID SOUS: NA1INUN SOU CONUMItAI IOMS
Potential
<«4>o*ura laval(c) Naiard Indei Carcinogenic liak
(all .
Conellluenl Concentre! len frerael Oral HOtd) CPHe) 0«r**l Oral D«r*el Oral
total lolal Potential
• 1 Carcinogenic • lek
>
Potential Carclnogene
Araenlc
•aruena
Carcinogenic PANa
Pent achl orophenol
Honcarclnogena
Acenaphlhana
Atenephlhylene
Anthracene
•eruoleM )perylene
Chroalua
t luoranthene
flue* ana
naphthalene
•henenlkrane
Phenol
Pyrane
6 264 01
4.204 02
9 404.00 (to)
i. 004 01
S 404.00
B. 204 .00
S 004 01
S 004 01
1.714.01
1 104.00
1. tOt «00
2.604.01
1 . 70t«01
i. oot oi
J. 10t. 00
.oot -oa
.aot oa
.OOt 06
.244 07
.721 W
.twos
.S24 06
.124 06
.29C -04
.ill 04
. S44 06
.11404
.1710$
.»2f 06
. i** oi
• 6i* oa
i.70409
1 Mt 06
6.d9f 08
i.TVt 06
• .704 06
i. lot 07
1.164 07
l.ftltOS
1.10406
1.14406
2 7V4 OS
I.A2t OS
s.)6c or
1.12406
.004 02
OOt 02
.004 01
.004 02
004 01
.004 02
.004 02
.OOt OS
.004 02
.00401
.OOt 02
1.A4.00
2.004 02
1 1S4«01
1.004.00
4
1
1
1
2
1
1
S
2
4
J
.441 04
.iat 01
.40406
.404 OS
.SOt 02
.644 04
.104-04
.264 02
.144 01
.204 06
.21404
9.6S4 OS
2.91404
I.TVt 06
1.7V40S
1.671 01
1.404-05
2.9S4 Oi
6.971 01
4.S64O4
• .944 07
1.114 04
7.104 OB 1.S14 07
1.971 09 l.6at 10
7. 014 OS 1. SOt OS
1.244 07 6. 50(08
..
. .
. .
. .
..
. .
. .
. .
..
-•
S. SOt 04
1.671 01
1.024 OS
1.024 04
2.9M 02
1.004 04
1.6&404
1.971 02
2.604 01
i. 094 06
6.12404
2.224
2.144
I.SOt
1.014
--
-.
-.
--
--
--
-•
• •
07
09
Oi
07
IOIAI:
6.1S4 02 1.174 02 7.0S4 OS 1.S14 OS | 7.S24 02
Hot*: • - all (oil concantratlona, aicapl polanllaity carclnoganlc f»K«. ara tha m»*\mm datactad concentration or 1/2 lha
raporlad dalacllon ll»ll If Ik* chaaical waa not daiaciad (i«/k|l
b • IM aoll concantration for potanilally carclno»anlc t>AHa la a total ol tha aaaiaui dttactad conctntratlon and 1/2 tha
raporlad datactlon ll*ll for thoaa «t tha aavan pot ant I ally carcinogenic .?A«a not daiaclad U«/kal
e • a«po«4jra trvala ara darlvvd u*lng lha forvulaa praaantad In labla A-1 (Ma/ka/dayi
d - riak rafaranca otoaa la«/k«/dayl
a - carclnoecnlc potancy factor Haa/kg/tfey) II
f • lha potanllal carclnoa«nlc rlak poaad by araanlc U not Inducted In lha total potential carcinogenic riak clnca aiaanlc
ha* a diffaranl lara«t or»an.
-------
7.0 rr.RANUP CRITERIA
7.1 Introduction
There are 3 sets of cleanup criteria for this site: soil,
surface water and groundwater. The remainder of this chapter
further explains the development and selection of the cleanup
criteria.
7.2 Groundwater Cleanup Criteria
Separate health based groundwater cleanup criteria were
initially developed for the surficial aquifer at the north and
east hypothetical well locations based on the assumptions
developed during the risk assessment. The more stringent
criteria for each indicator chemical was then selected to
comprise the list of cleanup criteria to be applied at the
site. In determining the individual cleanup criteria, the
additive risk posed by the simultaneous exposure to multiple
contaminants was incorporated. The cleanup goals for PAHs are
based on health based levels. Because carcinogenic PAHs are
evaluated as a separate class, the cleanup goals did not change
from the preliminary to the final•evaluation.
Potential exposure to the noncarcinogens naphthalene, phenol,
and noncarcinogenic PAHs may occur at the northern site
boundary. The noncarcinogenic PAHs are the source of virtually
all the potential endangerment at this boundary. Reduction of
all eight noncarcinogenic constituents (excluding chromium) to
the preliminary remedial action objectives presented in Table
1.1-4 will result in a total HI of 1.0, based on the assumption
that each noncarcinogen (excluding chromium) contributes
one-eighth of the overall HI of 1.
Simultaneous hypothetical exposure to noncarcinogens at the
eastern site boundary is based on the upper bound worst-case
exposure scenario, which assumes that the highest observed
concentration of phenol. The majority of the potential future
risk, excluding chromium, is contributed by phenol and
naphthalene. Noncarcinogenic PAHs were not detected above
quantification limits at the eastern site boundary in either of
the previously conducted RIs. Additionally, the environmental
fate-and-tranaport analyses conducted in the RA indicate that
noncarcinogenic PAHs observed elsewhere onsite are expected to
remain the same or decrease in concentration with time.
Reduction of all six noncarcinogenic constituents (excluding
chromium) to the preliminary remedial action objectives
presented in Table 1.1-4 will result in a total HI of 1.0, based
on the assumption that each noncarcinogen (excluding chromium)
contributes one sixth of the overall HI of 1. Therefore, the
1-47
-------
values presented in Table 1.1-4 are selected as the preliminary
remedial action objectives for phenol and noncarcinogenic PAHs
at the eastern site boundary.
If chromium is included along with the noncarcinogenic
constituents in the simultaneous hypothetical exposure
scenarios, the overall His become 1.28. This value slightly
exceeds unity due to the conservative assumption (to protect
public health) that all the chromium present in groundwater is
in the more potentially toxic hexavalent form. However, this
approach is very conservative because in the natural environment
both hexavalent and trivalent are present, with trivalent being
the most stable form. Therefore, the actual overall HI is most
likely to be closer to unity for both hypothetical exposure
scenarios, as the more stable trivalent form of chromium is less
toxic and is expected to be present -at the site.
In addition to the indicator chemicals mentioned previously, one
additional chemical was added: benzene. Although no specific
onsite source of benzene was found during previous
investigations, the pattern of groundwater contamination
indicates that there is a source of benzene on the site. The
cleanup criteria of 1 ug/1 is based on the state ARAR.
A conservative approach was utilized in this study to ensure
that the target risk will not be exceeded if the remedial action
objectives are attained. As the relative proportion of the
constituents will change throughout remediation, the
concentrations of certain constituents may become negligible by
default. Because of this change, a reassessment of the remedial
action objectives may be warranted in the future. The final
cleanup criteria can be found in Table One.
7.3 Soils Cleanup Criteria
The initial soils cleanup criteria were developed based on
protection to groundwater. They were back calculated from the
groundwater cleanup criteria such that the presence of site
constituent concentrations at or below the soil cleanup criteria
would not result in groundwater concentrations higher than the
cleanup criteria. These calculations take into account both
retardation (Kd) and dilution factors and is described in more
detail in Appendix B of the FS.
The soil cleanup criteria determined to be protective of
groundwater were then subjected to the human health risk
assessment process. The risk calculations were based on.
ingeation as the worst case exposure. The assumption was that
the site could be used as a residential area in the future so
appropriate cleanup criteria should be protective of that
potential use. The site is bordered to the immediate west by
single and multi-family use housing, which is zoned
1-48
-------
- .
5/09/90
Table 1.1-4. Croundvater Remedial Action 6b'jectiv«« G*g/L) for ch«
Cabot Carbbn/Koppers Site
Sit*
Constituent
Total Potentially
Carcinogenic PAtfs
Non-Careinoeenie PAflj
Anthracene
Phenanthrene
Acenaphthylene
Acenaphthene
Fluorene
Pyrene
Naphthalene
Phenol* '
Phenol**
Pentachlorophenol
Metals
Chromium
Arsenic
Northern*
Boundary
0.003
1.310
130
130
260
130
-UO-
13
2.630
0.1
50-"-+.
50
Lajitarn
Boundary
0.003
1.750
175 •
175
350
23
3.500
0.1
50-*-*
50
* The remedial acrion objectives for the northern boundary are selected as the
sitewide groundvater remedial action objectives.
> S'oc present at the east boundary.
**Based on apportioning an equal fraction of the target HI(I) to each
noncarcinogen identified at the eastern and northern boundary (excluding
chromium).
I-"The proposed MCL of 120 Mg/1. when finalized, will replace 50 MS/L «* che
remedial action objective.
Source: ESS, 1990.
1-30
-------
TABLE ONE
Groundwater Cleanup Criteria
Site Contaminant Cleanup Criteria
fug/1)
Anthracene 1310
Phenanthrene 130
Acenaphthylene " 130
Acenapthene 260
Fluorene 323
Pyrene 130
Napthalene . 18
Potentially Carcinogenic
PAHs . 0.003
Phenol . 2,630
Pentachlorophenol 0.1
Arsenic . 50
Chromium .50
Benzene ' 1
-------
residential. It is possible that the plant could relocate and
that land use may change.
Based on the results of this future land use scenerio, cleanup.
goals for three of the indicator chemicals, naphthalene, pyrene,
and flourine, were lowered in order for the risk to be within
acceptable EPA risk ranges. Final cleanup criteria are
identified in Table Two.
7.4 Surface Water Cleanup Criteria
Surface water cleanup criteria of 1 ug/L was selected for
phenols in Springstead Creek. This criteria is based on
Florida's Ambient Water Quality Criteria for the protection of
aquatic life. The selected compliance*.point for the surface
water standard to be met can be seen in Figure 4.1-1. The
Agency is to meet the phenol criteria at this compliance point
without the continued use of Project Jumpstart. Because the
surface water contamination is a result of leachate from the
groundwater, surface water criteria cannot be met without the
continued operation of a groundwater remediation system.
8.0 SUMMARY OF ALTERNATIVES
8.1 Areas to Be Remediated
The source areas selected for remediation are selected based on
comparison of levels of contamination in the soils to the soils
cleanup criteria and include the North Lagoon, the South Lagoon,
the Cooling Pond and the drip track areas. These areas are
located on the Koppers facility. The levels of contamination in
the other source areas investigated; the Wood Shavings area, the
old Cabot Carbon Lagoons, and the wetlands/lagoon area near
North Main Street, were also compared to the soils cleanup
criteria. While downgradient groundwater quality data near the
old Cabot lagoona and the wetlands/lagoon area near North Main
Street suggest that these areas may be acting as a source,
recent RI soil data indicated that soils in these lagoon areas
were below soil cleanup criteria. Likewise, contamination above
the groundwater cleanup criteria attributable to the onsite
source areas was found in the shallow aquifer both onsite and
immediately downgradient of the site east of North Main Street.
Volatile organic contamination, along with phenols (below
cleanup criteria), was observed in one intermediate aquifer well
centrally located onsite. Contamination in this aquifer may not
be related to the site and appears to be limited in extent.
Phenol, contamination was found in the surface water in the North
Main Street Ditch; which drains into Springstead Creek,
(legally a waters of the State).
An initial screening of technologies was done.
1-49
-------
TABLE TWO
Soil Cleanup Criteria
Site Contaminant Cleanup Criteria
(mo/kg)
Anthracene 7,700
t
Phenanthrene 770
Acenaphthylene 72.3
Acenapthene ' 389
Fluorene 323
Pyrene 673
Napthalene ' 211
Potentially Carcinogenic
PAHs 0.59
Phenol 4.28
Pentachlorophenol 2.92
Arsenic 27
Chromium 92.7
-------
SURFACE WATS3
CCMPUANCS MONfTORlNG
STAuON
FIGURE 4.1-1
SURFACE WATER COMPLIANCE
MONITORING STATION
CABOT CARBON/XOPPERS
Feasibility Study
4-9
-------
8.2 Summary of Remedial Alternatives
The alternatives evaluated in this chapter can be divided into
.two main groups: the source control alternatives; and the
management of migration alternatives. The results can be
loosely lumped into six categories: no-action; institutional
controls; containment; removal; treatment or disposal. Table
2.3-5 contains the technologies that passed the initial
technology screening.
From this list, a number of remedial alternatives were
developed. That list can be found in Table 3.2-1. A table
containing a summary of the remedial alternative costs can be
found in Table—3r2~-2~:—Fo~±Towing is a summary of the developed
remedial alternatives.
8.2.1 No Action—Monitoring (Alternative
The no action alternative involves only the long-term monitoring
of five monitoring wells on the site. No action is taken with
regard to the source areas. Sampling frequency is quarterly for
the first year and semiannually thereafter.
8.2.2 Limited Action—Water Use Restrictions (Alternative IB)
Water use restrictions will be implemented for the shallow and
intermediate aquifers on both the site and properties that may
be potentially affected downgradient of the Cabot Carbon/Koppers
site. The water use restrictions will prohibit the use of any
residential or other shallow aquifer well identified in the
affected area (i.e., one-half mile downgradient) as a potable
water, source. Additional restrictions may be imposed on future
well construction in the affected area.
This limited action alternative also involves the long-term
monitoring of five monitoring wells on the site. Sampling
frequency is assumed to be quarterly for the first year and
semi-annually thereafter.
8.2.3 Groundvater Extraction and Treatment (Alternative 2)
This alternative consists of groundwater extraction, and
treatment at the publically owned treatment works (POTW.)
operated by the Gainesville Regional Utility (GRU). A
groundwater extraction system will recover affected -
groundwater. System design will initially consider the use of
various extraction systems, such as extraction wells or linear
drainage technologies. The design phase will also consider
1-50
-------
Tafila 2.3-5.
iy of 'rocou Cptiona tatai.nod for fgrttwr Arwly«<*
lt«porw* Action
Tachnology
Typo
•rocna Opt (or
M taprwantativ*
•roe«a Option*
•Itratlon
MO action
Li«it«d Action
ColltctiOM
So»jret
MO »etion
Caotatnaont
Don*
Institutional
Slurry wall
Trtatiiwnt
Onotta Landfill
Traata«nt
Hen it or Ing
wotor uao lt*tricH«>
-------
T89C52SI
2/18/90
Table 3.2-1. Suaaary of Reaedial Alternatives (Page 1 of 2)
Alternative
Nuaber
description
?roce»» Opeton*
1A.
Migration
Marayataent
IB'
No Action
Liaited Action
Ground-water Extraction
and Treataent
Groundvater Containment,
Extraction, and Treataent
Long-Tera Monitoring
Long-lira Monitoring, '.Water
Us* Restrictions
Extraction '.'alls. Air
Stripping. Traataant at PC"
Water Us* Restrictions
Slurry Wall (Site).
Extraction Wells. Air
Stripping. Treataenc at PCI
Water Us* Restrictions
Source Control
8
9
10
11
Onsite Landfill
Asphalt Capping
Source Removal and
Offsite Disposal
Solidification/
Stabilization
la Slru Solidification/
Stabilization
Sourc* Containaent
Source Treatment and
Containaent
Sttu Biodagradation
Excavation. RCRA Landfill.
Backfill.
Asphalt Cap
Excavation. RCRA Landfill.
Backfill
Excavation, Solidification/
Stabilization. Backfill
la Steu Solidification/ .
Stabilization
Asphalt Cap. Slurry Wall
Asphalt Cap. la
Solidification/Stabilization.
Slurry Wall (source areas;
la Situ Biod*gradation
3-6
-------
Table 3.2-1. Suamury of Reaedlal Alternative. (pag. 2 of
2/18/90
2)
Alternative
Suober
Process Options
12
13
Soil Washing
Incinericion
Excavation, Soil Washing.
Backfill
Excavation, Incineration,
Backfill.
Note: Inclusion of monitoring in both the no action and liaic.d action
elc.rnative, i, consistent with current guidance (EPA &£ I..
Source: ESE. 1990.
3-7
-------
Table 3.2-2. Sui
Alternative,
1A
Manafement of Hi)
IB
2
1
Source Control
4
5
6
7
6
9
10
11
12
13
•mary of Alternative Costs
Description
No Action
iritlfiO
Limited Action
Croundwater Extraction and
Treatment
Croundwater Containment,
Extraction, and Treatment
Ons ite Landfill
Asphalt Capping
Source Removal and
Onaite/Offalte Diapoaal
Solidification/
Stabilization
la SlIU Solidification/
Stabilization
Source Containment
Source Treatment and
Containment
1JQ 5ltU Rlodegradation
Soil Uaahlng
Incineration
- - -
Capital Cost
(S)
0
17. 000
243.000
5.775.000
1.090.000
140.000
6.751.000
1.838.000
1.546.000
1.392.000
2,916.000
533.000
1.578.000
4.408,735
- - -
Annual
0&H Cost
(S)
33.000
31.000
105.000
53,000
25.300
46.000
4 1 . 000
33.000
41.000
48.000
53.000
130.000
120.0QO
45.lj>6
T89052B1
2/18/90
Present Worth
($)
507.000
559.000
1.865,000 -
-
6.349.000
2.567.000
881.000
7.269.000
2.469.000
2.205.000
2.168.000
3,764.000
1.130.000
2.128.000
4.453.891
-- — :-
Source: ESE. 1990
-------
multiple extraction system configurations, and evaluate the
relative effectiveness of the various configurations. The
function of the North Main Street Ditch and existing lift
station will also be considered in the design of the groundwater
recovery system.
It may be necessary to pretreat extracted groundwater prior to
discharge to the lift station directing water to the POTW.
Discharge criteria will be developed during design with GRU and
treatability studies will be performed as necessary to design
any needed pretreatment system.
8.2.4 Groundwater Containment. Extraction. Treatment, and
Disposal (Alternative 3^
This alternative consists of construction of a circumferential
slurry wall; construction of an upgradient subsurface drainage
trench, groundwater extraction, and treatment at a POTW operated
by GRU. The 31-ft deep slurry wall will encompass an area of
approximately 130 acres. The extraction rate is based on an
estimate of the annual recharge of groundwater by infiltration
of 5.1 inches per year and an infiltration factor of 0.8 into
the area within the confines of the slurry wall. The purpose of
the upgradient subsurface drain is to.divert groundwater flow to
reduce hydraulic loading on the slurry wall. Aquifer testing
and groundwater modeling would be necessary to more accurately
estimate the extraction rate. Within the slurry wall, at the
estimated extraction rate of 27 gpm, approximately 39,000 gpd
will be extracted to offset recharge and to maintain the
groundwater level within the confines of the slurry wall.
Extraction rate and recharge/infiltration calculations are
included in Appendix C.
The concentrations of contaminants in the extracted groundwater
are estimated in the same manner as described in Section 8.2.3.
Again, pretreatraent may be required to reduce contaminants to
concentrations below GRU pretreatment standards. Due to the
finite mass of contaminants within the confines of the slurry
wall, operation of the pretreatment system may not be necessary
over the total 30 year life of the alternative. Treated
wastewater will be discharged to a lift station to be
constructed onsite. Groundwater monitoring will be conducted
quarterly for 1 year and semi-annually thereafter as described
in Alternative 1A.
8.2.5 Onaite Landfill (Alternative 4^
The alternative consists of excavation of the source areas and
placement of the soil (12,000 yd3) in an onsite landfill.
1-51
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8.2.6 Asphalt Capping (Alternative 5^
This alternative includes construction of a 4-inch thick asphalt
cap over the source areas. Regular maintenance and sealing of
the asphalt pavement is necessary to ensure the integrity of the
cap.
8.2.7 Removal and Offsite Disposal (Alternative 6}
It is assumed that approximately 12,000 yd"* of soil would be
excavated and transported to a RCRA-permitted disposal facility
under this alternative. Excavation, loading, and hauling will
be conducted in a manner that minimizes generation of dust from
the soil and particulates. An out-of-state disposal facility
was selected for costing purposes
8.2.8 Excavation and. Onsite Treatment (Alternative 7^
This alternative involves the excavation and
solidification/stabilization of soil in the source areas to an
assumed 4'foot depth. The soil would be treated by a
silicate-based process. Treated soil would be used as backfill
onsite.
8.2.9 In Situ Solidification/Stabilization (Alternative 3}
This alternative involves the in situ
solidification/stabilization of soil by a silicate-based process
in the source areas to an assumed 4 foot depth.
8.2.10 Source Containment (Alternative 9^
This alternative includes construction .of circumferential slurry
walls to provide containment of source area soils. A
4-inch-thick asphalt cap will then be constructed over the
source areas. Regular maintenance and sealing of the asphalt
pavement is necessary to ensure the integrity of the cap.
8.2.11 Source Treatment and Containment (Alternative 10)
The source areas will be treated by in situ
stabilization/solidification. The source areas will then be
surrounded with circumferential slurry walls and capped with a
4-inch-thick asphalt cap. Regular maintenance and sealing of
the asphalt pavement is necessary to ensure the integrity of the
cap. .
1-52
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8.2.12 In Situ Biodeoradation (Alternative 11)
This alternative involves the in situ biological treatment of
soil and groundwater in the source areas and the active
wood-preserving area. The in situ biodegradation process uses '
indigenous microorganisms to degrade organics. Affected
groundwater is extracted and treated, nutrients are added as
required, and the water is percolated onto the source areas.
8.2.13 Soil Washing (Alternative 12^
This alternative involves soil excavation in the source areas to
an assumed 4-ft depth, physical/chemical removal of constituents
by soil washing, treatment of wash solution at the POTW, and
dewatering of washed soils that will be used as backfill.
8.2.14 Incineration (Alternative 13)
This alternative involves soil excavation in the source areas to
an assumed 4-ft depth. Soil is incinerated onsite in a
transportable incinerator achieving the substantive requirements
of RCRA for incineration of hazardous waste. Soil is loaded
into the incinerator feed hopper and fed to the incinerator at a
rate of between 1 and 5 tons per hour (tons/hr). The ash formed
during incineration is sampled before being used as backfill in
excavated areas.
8,3 Screening of Remedial Alternatives
8.3.1 SCREENING CRITERIA
8.3.1.1 Effectiveneaa
Alternatives were evaluated for their effectiveness in
protecting human health and the environment. Protectiveness was
evaluated over the short-term'(construction and implementation
period) and long-term (after the remedial action is complete).
The effectiveness evaluation also consiFDERed the degree to
which mobility, toxicity, or volume (MTV) would be reduced.
8.3.1.2 Implementability
This criterion includes both technical and administrative
feasibility of implementing the combination of process options
at the site. Technical feasibility is the relative ability to
construct, operate, and maintain an alternative as well as any
replacement necessary over the life of an alternative.
Administration feasibility is the ability to obtain approvals
from appropriate agencies as well as the availability of
1-53
-------
specific equipment, technical expertise, and management
expertise to implement or meet specific requirements of the
alternative.
8.3.1.3
Capital and operation and maintenance (O&M) costs were developed
for alternatives that pass effectiveness and implementability
screening criteria. Cost estimates were based on cost curves,
generic unit costs, vendor information, and prior similar
estimates. The cost estimate accuracy is dependent on the level
of detail or uncertainty of an alternative. Present worth costs
in January 1989 dollars were evaluated on a 30-year basis for
each alternative.
8.3.2 Alternatives Screened Out
Alternative 3 was screened out because the cost was
significantly more than alternative 2 without providing a
significantly higher level of protectiveness. The same
reasoning applies to alternative 4 as compared to alternative 2,
Alternative 6 was not retained because the effectiveness of
landfill containment to immobilize contaminants at this site is
questionable. Alternative 13 was not retained because it did
not provide significantly more protectiveness than the other
treatment-alternatives but it had a significantly higher cost.
The remainder of the alternatives were retained for detailed
analysis.
9.0 SUMMARY OP COMPARATIVE ANALYSIS OP ALTERNATIVES
9.1 Glossary of Evaluation Criteria
This section provides the basis for determing which alternative
provides the best balance of the evaluation criteria. EPA has
nine criteria for judging the best alternative for providing for
protection of human health and the environment. These criteria
are as follows t
Overall Protection of Human Health and the Environment -
addresses whether or not a remedy provides adequate protection
and describes how risks posed through each pathway are
eliminated, reduced, or controlled through treatment,
engineering controls, or institutional controls.
1-54
-------
\ •
Compliance with ARARs - addresses whether or not a remedy will
meet all of the applicable or relevant and appropriate
requirements of other Federal and State environmental statutes
and/or provides grounds for invoking a waiver.
Loncr-Term Effectiveness - refers to the magnitude of residual
risk and the ability of a remedy to maintain reliable protection
of human health and the environment over time once cleanup goals
have been met.
Reduction of Toxicitv, Mobility, or Volume - is the anticipated
performance of the treatment technologies that may be employed
in a remedy.
Short-Term Effectiveness - refers to the speed with which the
remedy achieves protection, as well as the remedy's potential to
create adverse impacts on human health and the environment that
may result during the construction and implementation period.
Implementabilitv - is the technical and administrative
feasibility of a remedy, including the availability of materials
and services needed to implement the chosen solution.
Cost - includes capital and operation and maintenance costs.
State Acceptance - indicates whether the State concurs with,
opposes, or has no comment on the preferred alternative.
Community Acceptance - will be assessed in the Responsiveness
Summary in the Appendix A of the Record of Decision after
reviewing the public comments received on the Feasibility Study
and the Proposed Plan.
9.2 Overall Protection of Human Health and the Environment
All of the alternatives, with the exception of the "no action"
alternative, would be protective of human health and the
environment by eliminating, reducing or controlling exposure to
the contaminants on the site. Because the "no-action"
alternative does not meet this criteria, it will not be
considered further in this section.
Alternatives IB, 5, 9 will be protective by minimizing direct
contact with the contaminants of concern. Alternatives 2, 7, 8,
10, 11 and 12 would be protective because contaminants would be
treated and removed from the environment.
9.3 Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs)
1-55
-------
Alternative IB would-not-coraply with ARARs because it would
leave groundwater contamination above standards in place.
Alternatives 7 and 12 would require a Treatability Variance in
order to meet ARARs because the contamination in the source
areas is the result of the deposition of K001 wastes and by
excavating it, the Land Ban requirements would be triggered.
.The treatments contemplated in Alternatives 7 and 12 are not the
BOAT for K001 wastes; thus are not in compliance with the Land
Disposal Restrictions. Alternatives 2, 5, 8, 9, 10 and 11 meet
all potential Federal and State ARARs.
9.4 Long-Term Effectiveness
Alternatives 2, 7_and 12 provide the best long-term
effectiveness because they involve the treatment and removal of
contaminants from the site. Alternatives 8, 9, 10 and 11
provide proportionately less long-term effectiveness because
there have been few in situ technologies implemented in the
field for the purpose of cleaning up both organic and metal .
contaminated soil; thus, there is little data to support their
effectiveness. Alternative 5 and IB have the least long-term
effectiveness because they potentially allow continuing
contamination to the groundwater.
9.5 Reduction of Toxicitv, Mobility or Volume
All of the alternatives, with the exception of alternative IB,
should meet this criteria. Alternative IB, by providing only
for maintaining and institutional controls, does not reduce the
toxicity, mobility, or volume of the contamination.
9.6 Short-Term Effectiveness
Alternatives IB, 5, 9 and 10 provide the best short-term
effectiveness because they can be implemented in a short period
of time and essentially prevent exposure to contaminants.
Alternative 2, 7, 8, 11 and 12 all involve long-term treatment
technologies that would require a number of years to implement.
9 . 7 ImplementAbility
Alternatives IB, 2, 5 and 9 are readily implementable because
they involve well known technologies. Alternatives 7, 8, 10, 11
and 12 should also be readily implementable; however, they will
require bench and/or pilot scale studies to be performed before
full scale implementation. Alternative 2 will require the
cooperation of GRU for implementation.
1-56
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9.8
Cost effectiveness is determined by comparing the costs of all
the alternatives being considered with their overall
effectiveness to determining whether the costs are proportional
to the effectiveness achieved. Using this criteria,
alternatives 2 and 12 are .the most cost effective because they
provide the most permanent and effective long-term protection to
human health and the environment.
9.9 State Acceptance
The State of Florida, as represented by the Florida Department
of Environmental Regulation, concurs with alternatives chosen in
Section 10 of this ROD.
9.10 Community Acceptance
As stated at the public meeting held on August 14, 1990, the
public indicated that they concurred with the active remedial
alternatives that EPA was proposing. However, it was strongly
felt that EPA had not thoroughly investigated all of the source
areas; especially the potential wetlands/lagoon area. They
indicated that EPA should more thoroughly investigate and, if
necessary, remediate these other potential source areas.
10.0 SBT.ECTBD REMEDY
All of the alternatives carried through to the detailed analysis
stage were evaluated using these nine criteria. Based on this
evaluation, EPA selected Alternative 2 as the preferred
alternative to address contamination in the groundwater and a
combination of Alternatives 7, 11 and 12 as the preferred
alternative for addressing contamination in source areas. These
alternatives will require extensive treatability studies during
design before implementation of the remedy.
Alternative 2 would result in the extraction of contaminated
groundwater -from the ground and disposal into the POTW.
Treatability studies will have to be done during the design in
order to insure that levels of contaminants in the discharged
water are acceptable to GRU; if not, then it will have to be
pretreated before being discharged. The groundwater recovery
system will be designed to insure collection o-f all contaminated
groundwater as well as to prevent continued discharge of
leachate to the North Main Street ditch and Springstead Creek.
The system will include the installation of recovery systems
both immediately west and east of North Main Street. Tentative
compliance points are identified in Figure 4.1-2. Specific
groundwater monitoring locations will be selected in the RD.
.1-57
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1
a
* 0 0 i
8 qq a
d
Q
04
=^ a
r
,1
o
CU
S
Q
FORMER
I NORTH
LAGOON
v,-
i FORMER
1 SOUTH
| LAGOON
'TIBH;
yw»/
COMPUANCI MO«rro«NG ZONE
FOR SOUACf CONTROL REMEDIATION
COMPUANCC MONITORING ZONE
FOR MANAGEMENT Of MIGAATON
EXTRACTION SYSTEM
500-
FIGURE 4.1-2
GROUND WATER COMPL
MONITORING AREAS
CABOT CARBONvKOPPERS
Feasibility StuoV
4-10
-------
EPA and FOOT will work closely to integrate any.-road widening
activity with the groundwater extraction system. If the final
decision on the North Main Street widening\project involves
leaving the North Main Street ditch intact, then the ditch will
be lined to insure no further contamination will leach into the
ditch.
EPA selects Alternative 12 as one of a combination of
alternatives to address the contamination of two of the source
areas. For the North Lagoon and South Lagoon, the combination
of soil washing with the solidification/stabilization and
bioremediation of residual soils containing unacceptable levels
of metals and/or organics would provide the best combination of
effectiveness, implementability, and cost for the majority of
the source areas. The combination of alternatives would treat
both the organic and inorganic chemicals in the soils. The
ready accessibility of the source areas and the large amount of
empty land available make excavation and treatment
implementable. Based on an assumption of excavation to the
shallow -groundwater table (4 feet below surface), the total
amount of soil to be treated from the 2 lagoons is approximately
6,400 cubic yards. Comparisons of soil concentrations and soil
remedial action objectives indicate that soils will have to be
excavated to levels deeper than the groundwater table in the
North and South Lagoons in order to address all soils exceeding
cleanup criteria.
This combination of alternatives will comply with Land Disposal
Restrictions (LDRs) through a Treatability Variance under 40 CFR
268.44. This Variance will result in the use of soils washing,
combined with solidification/stabilization and bioremediation of
residuals, to attain the Agency's "treatment goals" for the
contaminated soil to be excavated at the site.
EPA proposes Alternative 11 for addressing source contamination
in the cooling pond area and the drip track areas. In situ
bioremediation is selected because low hanging pipes and
buildings required for plant operation, make excavation of
contaminated soils technically infeasible. The soils in these .
areas are contaminated with both metals and organics. While in
situ bioremediation is feasible for treating organic
contaminants, ita effectiveness for reducing metals
concentrations to the cleanup criteria has not been
demonstrated. Long term institutional controls will be
implemented to assure that unacceptable exposure to metals does
not occur in the future due to changing land use.
Comparison of the remedial action objectives for soils with
existing soils data suggests that the Wood Shavings area, the
Cabot Carbon lagoon area and the wetland/lagoon area near North
Main Street may not require remedial action. Additional
sampling will be performed during design to confirm that this is
the case. Remediation of these areas will be performed as part
of the site cleanup, if necessary.
1-58
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Because of the shopping center that currently exists on the
property that the Cabot Carbon facility used to occupy, it is
impossible from both a technical and a cost-effective standpoint
to directly remediate this source area. Long term institutional
controls will be implemented to assure that unacceptable
exposure to .contaminants does not occur in the future due to
changing land use.
In addition to the preferred alternatives, EPA also proposes
that the following tasks be undertaken as part of the Remedial
Design phase:
o Perform additional groundwater sampling to determine if
intermediate aquifer requires remediation.
o Sample sediment in Springstead* Creek. If contaminants
are found, the same risk assessment assumptions applied
in the North Main Street risk assessment will be used
to determine if sediments require remediation.
o Locate the Old Cabot Carbon production well and
properly plug and abandon the well.
o Determine existence of underground storage tanks .under
paved area of former Cabot Carbon property onsite and
properly abandon any existing tanks no longer in use.
o Perform additional subsurface soil sampling on both
sides of North Main Street to delineate the extent of
any subsurface soil contamination around old
wetland/lagoon area at the intersection of North Main
Street and NE 28th Avenue and east of North Main
Street.
o Perform additional soil sampling in the Cabot Carbon
old lagoons area.
Each of these additional activities is being proposed as a means
of further delineating contamination at the site prior to
implementation of the remedial action. This information is
needed for the completion of the remedial design.
11. 0 STATOTORY. DBTSRMINATIONS
11.1 Introduction
Under its legal authorities, EPA's primary responsibility at
Superfund sites La to undertake remedial actions that achieve
adequate protection of human health and the environment. In
addition, Section 121 of CERCLA establishes several other
statutory requirements and preferences. These specify that when
1-59
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complete, the selected remedial action for this site must comply
with applicable or relevant and appropriate environmental
standards established under Federal and State environmental laws
unless a statutory waiver is justified. The selected remedy
must also be cost-effective and utilize permanent solutions and
alternative treatment technologies or resource recovery
technologies to the maximum extent practicable. Finally, the
statute includes a preference for remedies that employ treatment
that permanently and significantly reduce the volume, toxicity,
or mobility of hazardous wastes as their principal element. The
following sections discuss how the selected remedy meets these
statutory requirements.
11.2 Protection of Human Health and the Environment
The selected remedy protects human health and the environment
through groundwater extraction and pretreatment, if necessary,
and disposal at the POTW for the management of migration of
contaminants, along with combination of soils washing, in situ
bioremediation, solidification/stabilization of residuals (if
necessary) and land use restrictions provides protection for the
source control remedy. This remedy provides for the permanent
treatment of contamination in areas where it is technically
feasible and land use restrictions to prevent potential future
exposure for those areas where treatment or containment
technologies are not feasible.
11.3 Attainment of the Applicable or Relevant and Appropriate
Recruirements (ARARs)
Remedial actions performed under CERCLA, as amended by SARA,
must comply with applicable or relevant and appropriate
requirements unless a statutory waiver is justified. The
proposed alternative for the CC/K site was evaluated on the
basis of the degree of compliance with those requirements. The
proposed alternative was found to meet those requirements.
The proposed alternative will comply with the Land Disposal
Restrictions (LDRs) through a treatability variance, under 40
CFR 268.44. This variance will result in the use of soils
washing with appropriate treatment of residuals, to attain the
Agency's interim "treatment levels ranges" for the contaminated
soils at the sites.
The remainder of .the ARARs are detailed in Table Four.
1-60
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TABLE FOUR
Applicable or Relevant and Appropriate Requirements
To Be Considered Requirements
Law, Regulation, policy
Standard
Application
Federal
Chemical Specific
RCRA, 40CFR 261
Definition and Identification
RCRA, 40CFR 264
Groundwater Protection
Standards
Safe Drinking Water
Act
40CFR 403, Effluent
Guidelines and Standards:
Pretreatment Standards
National Ambient Air
Quality Standards
Action Specific
RCRA, 40CFR 268
Land Disposal Restrictions
RCRA, 40CFR 264
Definition and identification of
waste material as hazardous
Standards developed for protection
of groundwater from RCRA regulated
units
Maximum Contaminant Levels (MCLs)
established for protection of
public drinking water supplies
Discharge of extracted groundwater
will be subject to pretreatment
requirements if discharged to PQTW
NAAQS for PMIO applied to fugitive
dust
Excavated waste disposed onsite
may be subject to land disposal
restrictions if placement occurs
Disposal or decontamination of
equipment, structures, and soils
-------
TABLE FOUR
(continued)
Applicable or Relevant and Appropriate Requirements
To Be Considered Requirements
RCRA, Subtitle C
OSHA, 29CFR 1910
General standards for
worker protection
-OSHA, 29CFR 1090
Regulations for workers
involved in hazardous
waste operations
40 CFR 403.5
40CFR 122.44(a),
(d), and (e)
Location Specific
Fish and Wildlife
Coordination Act
40CFR 29, Executive Order
12372, Intergovernmental
Review
Executive Order
11990
Executive Order
11980
Regulates the treatment, storage
and disposal aspects of hazardous
wastes.
Worker safety for construction and
operation of remedial action
Worker safety for construction and
operation of remedial action
Discharge requirements
Use of BAT and BCT to control
pollutants; treatment of system
effluent to comply with Federal
and state water quality standard?
set discharge limitations •--•"
Protection of fish and wildlife
when federal action result in the
control or modification of a
natural stream or body of water
State and local coordination and
review of proposed EPA assisted
projects
Protection of wetlands affected by
remedial action
Protection of flood plains
affected by remedial action
-------
TABLE FOUR
(continued)
Applicable or Relevant0 and Appropriate Requirements
To Be Considered Requirements
STATE
Chemical Specific
Section 17-30-180
F.A.C.
Action Specific
Section 17-30
GTU's Pretreatment
Standards
Location Specific
Section 17-3.402°
Adopts 40CFR 264.91-100
Adopts 40CFR Parts 260-270
Standards for discharge into GTU's
system
Groundwater classification system
To Be Considered
52FR 3748
Proposed Rulemaking
Proposed standard for the control
of volatile organics emissions
that may address air stripping
activities
-------
11.4 Cost Effectiveness
The preferred remedy for this site is a combination of several
of the remedial alternative developed in the FS. For the
management of migration remedy, the present worth cost is
$1/885,000. For soils washing at all four source areas, the
present worth cost is $2,128,000; for in-situ biodegredation,
the present worth cost is $1,130,000. Given this situation, the
present worth costs of the combined remedy can be roughly
calculated by halfing the costs of these two alternatives, then
summing them for a figure of 1,629,000. It should also be
pointed out that, in estimating these costs, the FS did not
include any fees paid to GRU for disposal into their system. An
estimate of these fees (provided by FDER) are $300,000 for the
intial hookup and $120,000/year for the yearly fees. Using
these assumptions, the estimated present worth cost of the
preferred remedy is $3,514,000. The GRU fees are not included
in this figure. This remedy provides the best balance of costs
and overall effectiveness of all the alternatives.
11.5 Utilization of Permanent Solutions and Alternative
Treatment Technologies to the Maximum Extent
Practicable
The USEPA believes this remedy is the appropriate remediation
plan for the CC/K site.
For the management of migration, the contaminated groundwater
would be removed from the shallow aquifer and discharged into
the GRU system. Any needed pretreatment would be done, prior to
discharge. The GRU's treatment plant will provide final
treatment for the contaminants in the water.
For the source areas where it is technically feasible to
excavate, the alternative of soils washing followed by
bioremediation and solidification of the residuals, will treat
the contaminated soil down to levels that are protective.
For the source areas on the Koppers facility where it is
technically infeasible to excavate, in situ bioremediation
should effectively reduce the organics contamination to levels
that are protective. In situ bioremediation will probably not
be as effective for metals contamination; however, there is no
current unacceptable risk by direct contact and the management
of migration (MOM) alternative will capture contaminants that
.leach into the groundwater. Long term land use restrictions, as
written into Koppera RCRA permit, should mitigate the potential
threat of future direct contact.
1-61
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Because the former Cabot Carbon facility is now occupied by a
shopping center, it is technically infeasible to attempt to
excavate source areas on this part of the site. However, for
the same reason, there is no current risk by direct contact with
contaminants and land use restrictions should prevent any future
direct contact threat. The MOM alternative will effectively
mitigate the current potential threat from contaminants leaching
into the groundwater.
11.6 Preference for Treatment as a Principle Element
The statutory preference for treatment was met to the greatest
extent possible given site conditions. In the source areas
where treatment was not feasible, the chosen remedy will prevent
current and future exposures and will mitigate groundwater
contamination.
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APPENDIX A
RESPONSIVENESS SUMMARY
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RESPONSIVENESS SUMMARY
CABOT CARBON/KOPPERS SUPERFUND SITE
GAINESVILLE, FLORIDA
Community Profile
The site La located in an urban neighborhood in the Northwest
section of Gainesville, Florida, a growing inland city, seventy
miles southwest of Jacksonville, Florida. Residential areas
border the site to the west and northwest, with commercial
properties to the south. There are several schools within a
one-mile radius of the site, as well as three parks and one
community center.
Gainesville's 1987 population was 85,469 and is projected to
reach 92,400 by the year 2,000. Gainesville has a young
population, due mostly to the presence of the University of
Florida and the Santa Fe Community College, which have a
combined full-time and part-time enrollment of approximately
43,000 students.
The University of Florida contributes significantly to
community life in Gainesville. With 10,000 employees, it is by
far the largest single employer in Gainesville and Alachua
County, which has an unemployment rate of 3.3 percent.
Approximately 37 percent of Alachua County's work force is
employed by the government, 23 percent by the service industry,
and 22 percent by the trade industry. The remainder work in
manufacturing; construction; finance, insurance and real
estate; and transportation, communications and utilities. The
University contributes also to the health care available to
area residents. Shands Hospital, a private, non-profit
teaching hospital associated with the University's J. Hills
Miller Health Center, is one of four major hospitals in the
city. , City and county officials and citizens readily
acknowledge the University's other contributions to the
cultural and intellectual life of the community, through fine
and performing arts and the athletics program. The variety of
residents and officials who were interviewed for this report
spoke proudly of the city's resources and accomplishments, and
for the most part expressed a desire to continue its growth.
The City of Gainesville is governed by a five-member
commission. The commissioners .are elected for three-year
staggered terms, and each year select one of their own to serve
as Mayor-Commissioner. Alachua County also has a Board of
Commissioners, whose five members are elected to four-year
terms, with one member serving as the chairperson. These two
commissions work, together on various issues, most notably on
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the Metropolitan Transportation Planning Organization (MTPO),
which schedules regular monthly meetings. The MTPO comprises
the members of both the City and County Commissions, and is the
primary local government entity holding jurisdiction over the N.
Main Street widening proposal. Non-transportation planning and
zoning actions for the city are accomplished by the Gainesville
Planning Board, and for the county by the Alachua County
Planning and Development Commission. The city and county
governments demonstrate good organization, as evidenced by their
ready information referrals.
Gainesville Regional Utilities (GRU), owned by the City of
Gainesville, owns and operates the electric, water, and
wastewater systems. Most of the electricity is provided by
GRU's Kelly and Oeerhaven Stations, with the remainder supplied
by a nuclear power unit owned by the Florida Power Corporation.
GRU's Murphree Treatment Plant provides the county's commercial
and residential customers with water, utilizing a distribution
capacity of 64 million gallons per day (mgd). The Murphree
plant draws moat of its water from eight deep wells, which tap
into the Ploridan aquifer. GRU plans to sink more wells into
Murphree's well field within the next two years. Other water
sources include three reservoirs, and officials and citizens
report that there are a number of private wells in the site
vicinity. Wastewater is treated at two major facilities. One
of these, the Kanapaha Treatment Plant, has a current capacity
of 10 mgd, which city officials expect to expand to 14 mgd in
1991.
Gainesville's citizens participate actively in community
affairs, as evidenced by the number of attendees at city and
county commission meetings, and has a wide variety of
informational resources at its disposal. Several civic and
environmental groups are active in the community. In addition,
a number of citizen advisory boards and committees, appointed by
the city and county commissions, provide recommendations on
policies and directions and solicit citizen input on important
issues. .
History of Co^^unitv Concern
The aita has sparked the community's interest for many years.
Although previous studies conducted by the University of Florida
in 1961 and 1962 concluded that the operating wood treatment
facilities were having a detrimental effect on Hogtown Creek,
the coBMunlty as a whole reportedly did not became active until
a discharge incident in 1967. At that time, the new owner of
the Cabot Carbon property broke the lagoon impoundment walls and
allowed the contents to drain into Hogtown Creek; local citizens
began to complain about the site. The City of Gainesville fined
the owner $100 for causing the pollution, and assessed another
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charge to cover the City's cost for performing part of the
corrective action.
Reports indicate that problems and interest in the site remained
dormant until 1977, when a new owner began developing the site
into the shopping center that now exists there. During
construction, the owner allowed lagoon wastes to drain into
Hogtown Creek. The County, as well as FOBR, received several
complaints from citizens about the look and smell of the creek.
In October 1977, PDBR conducted a biological survey of the upper
2.8 miles of Hogtown Creek, showing the creek to be devoid of
life (except for bacteria) from the point of drainage discharge
to 1.1 miles downstream. The owner agreed to .implement measures
to prevent further contain!nation from the development.
Local and state agencies continued, however, to receive
complaints about the site, and local newspaper published
articles and editorials about it. This community attention
continued during the next few years, as BPA and FDBR conducted
preliminary studies and investigations of the site in 1979
through 1981. Citizens, media, and environmental groups
reportedly began calling and writing to both BPA and FDBR during
this time to find out about study results and express their
concerns about the site.
Community interest increased dramatically in 1983 through 1985.
During this time, the site was placed on the NPL, FDBR and BPA
entered into a Cooperative Agreement giving FDBR management lead
at the site, and the Florida Department of Transportation (DOT)
proposed to widen N. Main Street between 23rd and 39th Avenues,
a section of the road that traverses the site. Some citizens
reported that the site had not concerned them until this time.
Although part of the community's concern arose because the NPL
listing heightened the public's awareness of the site, part of
the concern also resulted from the road-widening proposal. A
number of citizens and civic and environmental groups contacted
FDBR, BPA, and city and county officials with questions and
concerns about the pollution coming from the site and the
environmental impact of widening the road.
Gainesville citizens called for a public meeting that was held
on June 28, 1984, to discuss the history of the site, the
industrial processes used there, possible air problems at the
site, Superfund and RCRA procedures and regulations, and FDBR's
proposed inturla measure for the site (Project Jumpstart). The
meeting was Moderated by the Chairperson of the Board of County
CcflBtissionara, and panelists included personnel from the County
and FDBR. Reports from the FDBR representative indicate that
this meeting was attended by citizens that were upset about the
lack of progress at the site and the meeting apparently did not
resolve th«jr concerns.
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Community attention to the site continued as plans were
developed to widen H. Main Street. FDBR and DOT had agreed in
late 1985 that construction should wait until FDBR completed
its RI/PS. However, but citizens and civic and environmental
groups perceived a change in that policy by FDER and DOT in
1986, and protested the project's resumption. Those protesting
asserted that FDER's RI data were not conclusive enough to allow
DOT to proceed with road construction and the possible movement
of contaminated material.
A number of articles and editorials appeared in the Gainesville
Sun and the Independent Florida Alligator in 1985, protesting
the road construction and assailing PDER for what many citizens
perceived to be a lack of caution based on incomplete test
results.
•
Citizens called for another public meeting to be held on May 1,
1986, and several civic and environmental organizations wrote
letters to EPA officials requesting their input and advice prior
to the meeting. At this meeting, attendees were angry and upset
about site proceedings. Many felt that their environmental
concerns were being ignored, and they were afraid that widening
the road would supercede cleaning up pollution at the site.
Some citizens still think remediation will proceed without
taking the road into consideration. Although DOT has
de-obligated funds for the road-widening project, it is still a
high priority of Gainesville's MTPO, according to local
officials, and is a subject of great debate within the
/rtntii^ffi 11*y i ' •
The community has two opposing views regarding road construction
through the site. Some citizens do not believe the site poses a
great threat to the community or the environment, and feel that
the road construction should proceed without further delay.
Some of these believe that no cleanup action should be taken,
and cite the fact that Hogtown Creek seems to have cleansed
itself five miles downstream of the site as proof that the
contamination is not serious. Several also believe that even if
the site warrants a permanent cleanup, it will take so many
years that the traffic on M. Main Street will have became a
bigger hazard that the site itself. The current two lanes
become quite congested, and citizens noted that a lack of
traffic signals compounds the problem.
Other citizens and officials voiced the opposing view,
maintaining that previous studies have not demonstrated the
extent of contamination at the site. They stated that if people
are unaware of any dangers there, it is because the studies
conducted so far have neglected to test the site properly and
thoroughly. They cite maps showing retorts, pine tar pits, and
other process facilities in the vicinity of the existing
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shopping center, as well as incidents such as a floor tile
buckling problem at the Winn-Dixie on the site, as arguments for
further testing in these specific areas, which they feel have
not been addressed so far.
The Winn-Dixie incident is a frequent topic of discussion in the
community, and members of the community disagree about whether
the tile problem was site-related. A consultant hired by the
store to study the problem concluded that site contamination
under the foundation was causing the tiles to buckle.
Reportedly, Winn-Dixie representatives and FDBR disagreed with
that conclusion, attributing the trouble to a faulty foundation
and bad glue. Many citizens expressed dismay at that, and some
believe that there was a deliberate attempt by FDBR and
Winn-Dixie to downplay the incident to avoid adverse publicity.
They are concerned that contaminants~at the~site~may~af fect
other business there, and have given FDBR and BPA specific
recommendations about where they believe further testing is
needed.
Some citizens felt that road construction could probably begin
after a thorough RI/FS is completed, but others said that the
road project should be postponed until the site is completely
cleaned up. Many of the citizens who want road construction to
proceed, as well as a few who do not, expressed the belief that
some citizens are using the Cabot Carbon/Koppers site merely as
a meann to prevent commercial growth in the area. At this time,
questions of Superfund liability for the City, County, and
businesses on or adjacent to the site have brought the road
project to a standstill, and the decision about whether or not
to ask DOT to release funds for and begin the project rests with
city and county officials.
Currently, many citizens and environmental groups are most
concerned that the supplemental RI/FS address the concerns that
they have brought to the attention of BPA and FDBR officials.
BPA and DOT agreed at the time that road construction should
wait until the RI/FS was completed. Meanwhile, those
interviewed said that they will continue to press their concerns
about the site, to ensure that contamination is thoroughly
quantified.
Key Issues and Community Concerns
1. Proposed Widening of North Main Street
Probably the most volatile issue is the proposed widening of
North Main Street. There appear to be two major schools of
thought concerning the proposed project. The first is composed
of citizens and environmental groups who are concerned that
there is an unknown major source of contamination where the
suspected "lagoon" under North Main Street was located. They
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are worried that: the construction activities associated with
road widening would disturb this source and caused them to
migrate in unexpected ways. The second is concerned that there
has already been a long delay in the road project and that EPA'8
remedial process may cause additional day and a continual
worsening of the traffic congestion along North Main Street.
They want EPA to make a decision on the appropriate remedial
action so that FOOT can make a decision on its project.
2. Ground. Drinking and Surface Water Quality
Citizens and local officials are concerned that the contaminated
ground water in the surficial aquifer will reach the Floridan
Aquifer, which is the main water supply for Gainesville and much
of Florida. Some people believe there is a link between the two
aquifer because of the numerous sinkholes in the area.
Gainesville's Murphree well fields, which tap into the Floridan
aquifer, are 2.3 miles northeast of the site. The city plans to
add new wells during the next two years to expand its services,
and there are no other well fields identified at this time.
City officials noted that it is important for them, as well as
for others who draw from the Floridan, to know the possibilities
of contamination before they expand their current water system.
Citizens and officials also expressed concern about the possible
contamination of private drinking wells in the area. A current,
accurate inventory of private wells is unavailable at present.
Some citizens asked that every private well in the near vicinity
be tested, as well.
Many residents expressed concern about damage to Hogtown Creek.
Studies have noted detrimental effects to the creek up to five
miles downstream of the site, and many residents living near the
creek reportedly are frustrated that the damage is still
evident.
3. North Main Street Ditch
Many people are concerned about the leachate discharge into the
North Main Street Ditch. They are concerned that it appears to
be a public health threat and access to it should be limited.
4. Schedules
Most interested citizens wanted to know the schedule EPA has set
for the site. Most stated that site officials have not met past
schedules, and expressed the hope that EPA, as lead for the
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site, will be more accurate in estimating the remediation
schedule, and adhere to announced dates.
5. Proposed Development
Many business persons in the site vicinity are reportedly
concerned about having their property values drop. Some are
concerned that the value will drop specifically because their
property is part of a Superfund site, but most are concerned
that property value will drop as a result of delaying the
road-widening project. City officials report only one formal
request to develop a parcel of the land during the last two
years, but could not say whether the low interest in developing
the area was a direct result of the Superfund site, or whether
it was indirectly related to the site because of the traffic
problems on N. Main Street. Many citizens, business and
non-business, are allowed in the area without problem, but the
road construction has been effectively halted.
6. Health Effects
Several Individuals expressed concerns about health problems
that they believe could be related to site contamination. This
concern was raised at the June 1984 public meeting, where the
panel suggested that citizens, local doctors, and state and
county health officials contact the Centers for Disease Control
(CDC) Atlanta to request a health study.
7. Airborne Toxins
A few citizens and local officials expressed concern about the
possible release of toxins into the air during site cleanup
activities. They want BPA to take proper precautions during
cleanup so that nearby residents and others doing business in
the area will not be affected by any airborne toxins.
8. EPA Communication
Some key local officials and citizens were concerned that BPA
officials have been slow to respond to their questions about the
site. They expressed the desire to help BPA facilitate site
remediation activities, but said that they need faater and more
direct responses fro* BPA. They cited letters requesting
meetings and/or advice related to site status, and reported that
they had yet to receive any direct answers to their queries.
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Questions Concerning Cabot Carbon/Koppers Site Generated During
Public Comment Period
1. Organization of Responsiveness Summary
There were a number of different: areas that the public
questioned or commented on concerning this site. In general,
these questions and comments can be loosely organized into
separate categories. This questlon-and-answer section of this
Responsiveness Summary is organized Into those general
categories; which approximate the categories listed under the
Key Issues and Community Concerns section.
1. Proposed Widening of^North Main Street
Has the Agency found evidence of the lagoon that is currently
under North Main Street?
The Agency is aware of a number of different items
concerning the lagoon/wetlands area that formerly existed on
what was the northeast corner of the Cabot Carbon facility.
The Agency has in its possession aerial photographs from the
30s and 40s that show a body of water In this area. In
these photos, this body appears to be a manmade structure.
The Agency also has photos of the Site taken from an oblique
angle where this body does not seem to have well defined
boundaries and appears to contain trees; In other words, it
looks like a naturally occurring wetland. It would also
appear that, whatever it was, the majority of it existed
under what is now an auto dealership. Baaed on the
photographic exldence, the Agency cannot Conclude whether or
not this body of water was a manmade lagoon or a naturally
occuring wetland.
The Agency is aware of a number of different sampling
expeditions in this area. Although earlier studies not
supervised by BPA show high levels of some contaminants in
the soils of this area, later studies have not been able to
duplicate these levels. Sample data fro* the RI show levels
of soil contamination far below the Agency's soil cleanup
criteria. This data would appear to support the theory that
the body of water was a naturally occuring wetland that
became somewhat: contaminated when the other Cabot Carbon
settling ponds were bulldozed and their contents allowed to
drain Into the wetlands area.
As a part of the Remedial Design, BPA Intends to resample
this area to make one last effort to determine whether the
are any contaminated remains of this wetland/lagoon area.
Has the Agency seen the aerials documenting the exlstance of
the old lagoon under North Main Street?
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The Agency has copies of the aerials from the University of
Florida's library. The Agency also has photographs taken
from an oblique angle that were provided by the Cabot Carbon
Company.
Why does the Agency continue to insist, after seeing these
aerial photos, that there was no lagoon under North Main Street
The Agency does not continue to insist that there was no
lagoon at this location. EPA is well aware that a body of
water existed here and that, in some photographs, it looks
to be a manmade structure. However, in other photographs,
'it appears to be a naturally occurring wetland. No records
exist of the plant operation that would indicate the use of
that wetland as a containment lagoon.
For these reasons, EPA cannot state, for the record, that
the wetland area was a manmade structure. EPA is not,
however, disputing the strong possibility that it is. In an
effort to solve this problem, EPA is planning on
commissioning BPA's Environmental Photographic
Interpretation Center (EPIC) to develop a photoperiodical
site analysis for CC/K. As part of this analysis, EPIC will
study the existing aerial photographs to attempt to
determine the use of this area.
If this suspected lagoon did not, in fact, exist, how does EPA
explain the sharp rise in the levels of contaminants in the
groundwater in this area?
There are several potential explanations for the sharp rise
in VOC levels in the shallow aquifer in this area. The
first is that there was a containment lagoon in this area
and the VOC levels are the result of contaminants leaching
from its remains. The second is that the levels are the
result of an as yet undetermined source area on the former
Cabot Carbon property. The third is that the levels are
elevated because of a leaking underground storage tank
connected with the auto dealership. The fourth is that the
elevated levels are somehow connected with being next to a
busy road. The fifth is that the levels are resulting from
a source pellagragenic to the site itself. At this time,
EPA does not have enough data to determine the source of
these levels; EPA plans to do additional sampling in the RD
to try to determine the source.
Earlier investigations (primarily by the University of
Florida) show levels of contaminants above your soil cleanup
criteria in the North Main Street bitch area. Is the Agency
going to consider any source cleanup over there?
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As stated earlier, EPA has not been able to replicate those
levels in its investigations. It is likely that these
levels were random "hot spots" that do not require any
remediation efforts. To confirm this, EPA is going to do
some additional sampling in this area. If the additional
sampling indicates that there is a potential soils problem,
EPA will revisit this issue.
People in the area are concerned that, if FOOT widens the road
based on the current data base, FOOT may cause a release of
contaminants from this old lagoon area. What does the Agency
intend to do about this?
As part of the PS, EPA did a risk assessment for these
soils using two scenarios: short term exposure to FOOT
workers building the road; and long term residential use
exposure to children (if soil was used as fill for housing
development). In both cases, the risk fell within BPA's
acceptable risk range of 10 to 10". Thus, a release
of soil from the area should not cause a problem. What
will be problematic will be the disposal of contaminated
groundwater pumped from the shallow aquifer during
excavation activities. There have been preliminary
discussions with FDOT concerning the best way to do this,
but no final plan can be developed until it is decided how
to build the road. FDOT has made the commitment to keep
EPA involved with its plans.
What is going to happen with the soil FDOT would excavate
while building this road?
The final disposition of the soil would be FDOT'a
decision. As stated earlier, the RA done as part of the FS
indicates that no special disposition of the soil is
necessary. Final plans on disposing of this soil will have
to wait until finalizatipn of the construction plans.
Did FDOT cause a release from this old lagoon when they built
the original North Main Street? Specifically, did they cause
contamination to be spread on the property to the east of North
Main Street?
To EPA's knowledge, there are no detailed records of the
original construction of North Main Street. BPA's
investigation, done in May 1990, does not show significant
contamination in the soils east of North Main Street.
Did not EPA, in the past, tell FDOT that FOOT could not widen
the road without EPA's permission?
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EPA never prevented, or sought to prevent, the widening of
North Main Street. EPA advised FDOT that, if the widened
road interfered with the implementation of EPA's selected
remedial alternative, part of the rebuilt road may have to
be demolished and FOOT may be liable for that. EPA also
advised FDOT to wait until EPA had selected its remedy
before proceeding with the road. However, the final
decision was FDOT's.
Did not EPA require FDOT to ask for indemnification from
property owners adjacent to North Main Street in order to widen
the road?
EPA did not and has never had anything to do with the
question of third party indemnification.
Can EPA indemnify FDOT from any federal liability if, in the
course of widening the road, FDOT causes a release?
EPA does not want to discuss site specific legal issues in
this Responsiveness Summary because this is not the proper
forum for these issues to be discussed. However EPA, in
general, will not indemnify any person or organization from
liability for causing a release. EPA will not even give a
release to the PRPs that are doing the work.
If, in the course of widening the road, FDOT incurs any
additional expense due to the Superfund site, will the Superfund
make up the difference?
No. Under Superfund, EPA is only authorized to spend funds
investigating and remediating Superfund sites and, even
then, only in cases where there are no viable responsible
parties identified that can fund the work. There are no
provisions to reimburse other government agencies for
expenses incurred because of proximity to a Superfund Site.
Property owners with property to the east of North Main Street
contend that their propert was contaminated by FDOT's actions
when originally building North Main Street. Will EPA indemnify
them against any Superfund liability?
No. Again, EPA does not, in general, indemnify anyone.
Given that it is the Federal and State Government that is
determing the appropriate health based cleanup criteria, will
either entity assume liability in case these cleanup criteria
turn out to be nonprotective to human health and the
environment?
There are no provisions for the State or Federal government
to assume liability for decisions on cleanup criteria or
standards. This would be a matter of law and cannot be
properly addressed in this Responsiveness Summary.
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Will the road widening have any impact on-the flow of the
shallow aquifer in the immediate area?
It La not anticipated that the road widening will have a
significant impact on the direction of flow in the shallow
aquifer. As part of its proposed remedy, EPA will have a
number of monitor and extraction wells in the immediate
vicinity. This will allow long term monitoring of the
situation.
Does EPA think that its OK for FOOT to proceed with its road
widening plans?
At this time, EPA does not oppose FDOT's road widening plan.
EPA does not expect the road widening to have a significant
impact on its rew^H^*^"" pt-arrr—Again, it~±s~hot BPA's
decision to make.
Can EPA accelerate its process so that the part of the remedy
concerning North Main Street is finished first?
EPA has committed to working with FOOT so that its
remediation plan and the North Main Street widening plans
are compatible. EPA is always interested in minimizing the
amount of time needed to complete an action; not, however,
at the expense of implementing the action correctly. EPA
will study this request during the Remedial Design phase in
order to attempt to find ways to accelerate this portion of
the remedy in technically feasible ways.
Will EPA make any effort to coordinate its remediation design
with the FDOT's road widening design?
Yes, EPA will coordinate its Remedial Design with FDOT's
road widening design and construction.
What, if any, problems does EPA foresee in the road widening
project?
There are any number of generic problems that can come up
with different construction projects happening at the same
time. EPA vill not be in the position to define specific
problems until it is well into the Remedial Design phase.
2. Ground, Drinking and Surface Water Quality
Has the contamination reached the Floridan aquifer?
There is no evidence that contamination from the site has
reached the Floridan Aquifer.
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Is the plume from the site going.to impact Gainesville's
Murphree well field?
Data from the RI indicates that the plume of contamination
is no more tfrqn a couple of hundred yards offsite. The
implementation of the groundwater extraction system will
effectively prevent any chance of this plume ever reaching
the Murphree veil field.
How far off the site has the contamination spread?
The flow of the shallow aquifer is to the north east. Data
indicates that the plume is no more that 200 yards
downgradient from the site's eastern boundary (North Main
Street).
Does the Agency have a complete listing of private wells in the
area? If not, will EPA consider doing a door to door search in
the area to identify those wells? .
The Agency does not have a complete list of private wells in
the area. It is BPA's understanding that the Florida
Department of Health and Rehabilitative Services (FHRS) has
committed to assembling such a list.
Has the Agency tested any of the private wells in the area?
The Agency has not tested any private wells in the area.
If the Agency has not tested all of the wells in the area, how
can it be confident that none are contaminated?
BPA is confident that the direction of shallow groundwater
flow and the extent of the plume of contamination have been
well defined in the RI. BPA knows that there are no private
wells in the general vicinity of this plume.
Was the Agency aware that there was an operating Floridan well
on the site?
The Agency waa not aware of an operating Floridan well on
the site.
Given that there are several pellagragehic sources of benzene,
and no sources-of benzene were identified onsite, what is the
Agency's justification for adding benzene as a cleanup criteria
for groundwater?
It is true that there are several sources of benzene that
are pellagragenic of the site. However, the Agency does
have justification for adding benzene as a cleanup criteria
for groundwater. Based on the results of the supplemental
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RI (Hunter/ESB), the VOC contamination in the shallow
monitor wells downgradient of the Cabot Carbon lagoon
areas. Benzene is a significant component of these VOCs.
In addition, earlier investigations showed indications of
benzene contamination in the soils onsite. The Agency is
also aware that there were a number of storage tanks that
existed on the Cabot Carbon facility; with no record that
they were ever removed. For these reasons, EPA has
justification for believing that there is a yet unidentified
source area for benzene onsite. For that reason, EPA is
justified in adding benzene to the site cleanup criteria for
the groundwater.
How thick and contiguous is the confining layer between the
shallow and intermediate aquifer?
*
Data from the IT RI indicates that there is thirty to thirty
five feet of dense clay between the two aquifers and that
the layer is contiguous under the site.
Is the site currently impacting Hogtown Creek?
o
The site is not currently having a significant impact on
Hogtown Creek. The lift station appears to be intercepting
the majority of the surface water contamination; and
sampling of surface water in Springstead Creek did not show
significant levels of phenol contamination.
Is it safe for children to play in Hogtown or Springstead
Creek?
EPA is not in a position to comment in general about the
safety of playing in either one of those creeks. SPA does
feel confident that these creeks are not being currently
impacted by the site. The area of highest surface
water/sediment contamination is the North Main Street Ditch
and the risk assessment performed for exposure to children
shows that the risk is well within BPA's acceptable risk
range.
3. North Main Street Ditch
How contaminated is the water in the ditch?
The only significant contaminants in the water in the ditch
are the hyphenless. The phenols are at levels that pose a
threat to aquatic life, but not at levels that pose a
problem for human health.
Is it safe to come into contact with the ditch?
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EPA is not in the position to say that it is absolutely safe
to come into contact with the ditch. EPA can only make a
judgement on the relative risk that the contaminants cause
based on the current state of knowledge concerning these
contaminants. The RA done for the ditch shows that the
levels of contaminants in the ditch are within BPA's
acceptable risk range. Each individual will have to judge
for him- or herself whether he or she is comfortable with
that judgement.
What about the odors from the.ditch?
Phenolics are well known for being very odoriferous. It
takes only a very low level of phenol to cause an odor that
humans can detect. The air pathway was analyzed in the RA
and the levels fell well within EPA^s— acceptable~risk~range~.
Why isn't access to the ditch restricted in some way?
In order to justify restricting access to the Ditch, EPA
would have to make a determination that exposure to the
contaminants posed some potential or actual short or long
term risk. Based on the known levels of contaminants, there
is no justification for making such a determination.
Does Project Jumpstart prevent phenol contamination from
reaching Springstead Creek?
Project Jumpstart was designed to handle 'the normal flow of
surface water in the North Main Street Ditch. As long as
the flow is normal, Project Jumpstart does an effective job
of preventing significant contamination from reaching
Springstead Creek. However, during storm events, the
capacity of the lift station is overwhelmed by the greatly
increased amount of water in the Ditch. Some of the phenol
contamination undoubtedly is carried into Springstead Creek
during these times.
How much longer is Project Jumpstart going to be in operation?
It is anticipated that Project Jumpstart remain in operation
at least until the implementation of the groundwater
extraction system. The groundwater extraction system should
eliminate the need for Project Jumpstart.
Is Project Jumpstart expected to be in operation concurrently
with the groundwater extraction system? If so, does EPA know
how much additional flow into GRU's system that would create?
The logistics of Project Jumpstart's shutdown and the amount
of additional flow this would cause cannot be determined at
this time. The answer to these questions will be determined
as part of the remedial design.
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Will the ditch be in existance after the road is widened?
According to PDOT's current road design, the ditch will be
filled as part of of the road widening project. In its
place will be a sealed storm drain system designed to handle
excess surface water flow.
4. Schedules
Why is -it, after eight years worth of studies, EPA still does
not have all of the source areas as well identified as the
source areas on the Koppers facility?
This site is an extremely complex site containing a number
of different"~p^t^litial "source> areas. Records that could be
used to more accurately locate any of these these areas are
few and incomplete. Complicating the situation further are
the number of site alterations that have occurred; due both
to expansion of facility's plant operations and to the
evolution of the site's use in the last twenty five years.
These factors have made it almost impossible to pinpoint all
of the source areas that may have existed on the site at one
time.
After the decision on the remedial alternative is made, how
much longer will it be before cleanup actually starts?
There are a number of mandatory processes that will have to
be undertaken before the remedial alternative can be
implemented. After the Record of Decision (ROD) is signed,
EPA must offer the PRPs the opportunity to perform the
RD/RA. This process will take approximately six months.
After this process is complete, then the Remedial Design
will have to be performed. The RD determines, in detail,
how the remedy is to be implemented. At this site, the
complexity of the chosen remedy dictates extensive bench and
pilot studies be done and this is estimated to take a
T»inTT»m« of eighteen months. A more detailed schedule for
the RD will be developed at the beginning of the RD
process. Altogether, it will be a «infi»Hta of two years
after the inmuily is chosen before the remedy will be
implemented.
How long will the cleanup take?
It will take approximately five years for the source control
remedy to be completed. The groundwater remedy is estimated
to take thirty years.
5. Proposed Development
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Is there a formal process by which property owners around a
Superfund site submit their development plans to EPA for
approval?
For property owners that signatories to the Consent Decree,
there is a provision for notifying EPA about about changes
in ownership or land use. For local property owners that
are not parties to the Consent Decree, EPA does not yet have
a strategy for allowing EPA to formally review development
plans. EPA will address this issue in the future.
Several property owners around the site have stated that their
property values have dropped significantly because of proximity
to a Superfund site. Shouldn'.t the Agency be held responsible
for that?
There are no provisions In the Superfund law for reimbursing
nearby property owners for loss of property values due to
proximately to a Superfund site. Other than advising these
property owners to seek advise from their counsel, EPA
cannot further address the issue.
Is there a mechanism in place for the private corporations that
benefitted from the pollution at the site to reimburse the
property owners and/or the surrounding community for the lost
business opportunities because of the site?
There are no mechanisms In the Superfund law to allow for
this kind of settlement as a part of the RD/RA Consent
Decree. Again, all the EPA can do is to advise all parties
concerned to seek advise from counsel.
Will EPA give "no action" letters to these property owners in
the area so that their property can be sold without liability?
EPA can give letters stating its findings from the RJ/PS and
what actions it is taking as a result of these
Investigations. These findings may include "no current
action" on particular pieces of property. However, EPA
cannot: give property owners a release of future liability
for any future proposed remedial or removal actions.
6. Health Effects
The Agency received no comments directly asking about whether an
Individual's health problems were related to the Site. Rather,
the majority of questions regarding health were concerned with
potential health problems caused by the Site and are addressed
in other parts of the Responsiveness Summary.
7. Airborne Toxics
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Citizens who live near the Koppers facility are fed up with the
odors—coming from the facility. Can't EPA do anything about
it?
The regulation of emissions from the Koppers plant is a
State function; EPA has no regulatory authority to address
the problem.
Are the odors from the Koppers facility a health hazard?
Questions concerning the emissions should be addressed to
the Florida Department of Environmental Regulation. EPA car
only address issues concerning the activities conducted
under Superfund authority in this Responsiveness Summary.
Is there a mechanism for the government to buy out communities
that are adversely affected by a point source aizT pollution
problem?
The only buyout mechanism EPA has at its disposal is the
mechanism in the Superfund law that allows EPA to relocate
people if that is the only way to prevent exposure to
hazardous levels of contaminants. There is no mechanism foi
relocating communities because of air pollution problems.
8. EPA Communication
Some feel that EPA'3 studies could have been better if EPA had
more local input into the design of those studies. Will EPA
consider doing that in the future?
EPA realizes that past community relation activities have
not alsawys been as complete as they should have been.
Although EPA is not in a position to commit to any specific
activities at this tine, EPA will comit to doing more to
involve the coaBunity in upcoming activities. EPA will
review its community relations plan prior to the
implementation of the RD and revise it as appropriate to
insure that the public is provided sufficient opportunities
for involvement. >
Will EPA keep local organizations such as FOOT and GRU informed
of ongoing progress?
EPA in-twiHa to keep GRU and FOOT fully involved in upcoming
activities.
9. Miscellaneous
How were the Agency's cleanup criteria developed?
A detailed description of the development: of the cleanup
criteria can be found in the FS and the ROD. In general,
the cleanup criteria were developed to be protective of both
human health and the groundvater.
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Do the cleanup criteria consider exposure to multiple
chemicals?
Yes, the cleanup criteria are developed to be protective
against exposure to all of the indicator chemicals.
Some feel that the Agency's soil cleanup criteria for several
of the noncarcinogenic PAHs are too high and should be lowered
to the 50-100 ppm range. Will EPA consider doing this?
The methodologies EPA used to develop its criteria are
standard methodologies that have been used at a number of
different Superfund sites. EPA stands by those criteria as
being protective, based on the current state of knowledge.
Because, residual levels of contamination will be left
onsite, EPA is mandated to perform a Five Year Review. This
review must be done within five years after the start of the
RA and is intended to assess the effectiveness of the chosen
alternative and the protectiveness of the chosen cleanup
criteria.
One commentator stated that having' one set of cleanup criteria
for the site was not technically defensible; given that the site
consisted of two separate facilities with two different
operations. What is the Agency's justification for having only
one set of criteria?
The Agency is cognizant of the fact that the varied source
areas do not all contain the same indicator chemicals.
However, as emphasized in the RI/FS, one of the major
potential exposure pathways is the shallow aquifer. Once
the contaminants have intermingled in the aquifer, there is
no practicable way to set and enforce different cleanup
criteria. As to trying to develop different cleanup
criteria for the source areas; operationally, this is very
difficult to implement and the numbers would not necessarily
be protective of human health. The cleanup criteria as
chosen by EPA is protective of human health and the
groundwater and EPA believes this approach is defensible.
In one part of the Proposed Plan, EPA stated that one of the
sources of groundwater contamination was the Cabot lagoons on
the northwest corner of the former Cabot facility; in another
part, EPA states that the level of soil contamination in this
area does not require remediation? Can the Agency explain this
seeming contradiction?
These statements are do innitially appear contradictory.
The former Cabot Carbon lagoons functioned as source areas
when they contained liquid sludges during the plant's
operation. However, after the ponds were bulldozed, their
contents were
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scattered over the northern portion of the Cabot Carbon
property and have, in effect, become too diluted to
currently act as a significant source area.
What, specifically, are the potentially carcinogenic PAHs?
The site contaminants that are potentially carcinogenic PAHs
are benzo(a)anthracene, benzo(a)fluoranthene,
benzo(k)fluoranthene, benzo(a)pyrene,chrysene,
dibenzo(a,h)anthracene, indeno(1,2,3-C,d)pyrene and
indeno(1,2,3-c,d)perylene.
In your presentation at the public meeting on August 14, you
indicated that extraction wells for the contaminated groundwater
would be placed to the east of North Main Street, but the
Proposed Plan does not specify this. Could you clarify whether
or not this is true? •
Extraction wells will be placed to intercept the plume east
of North Main Street.
It is believed by some commenters that Alternative 11, in situ
bioremediation, will alleviate the source areas on the Koppers
site. Why does the Agency not select this alternative for the
source control?
EPA has contacted a number of different sources regarding
the effectiveness of in situ bioremediation in remediating
both organic and inorganic contamination. These sources
were questioned concerning the bioremediation in cleaning up
the organica and the concurrent soils washing effect on
removing the soluble metals from the soil particles. The
sources include RPMs in other EPA Regions, and technical
experts in labs in Cincinnati, Ohio, ADA, Oklahoma and the
SITES program. None of these sources gave any encouragement
that this technology would be effective.in remediating
metals contamination.
In the Proposed Plan, EPA states that the "large amount of
empty land available make excavation and treatment
implementable." This statement has been disputed.
In making this statement, EPA is referring to what appears
to be unused space in the southwest corner of the Koppers
facility. However, EPA is not implying that the soils
washing equipment should be set up in this area. The
location of the equipment would be designated as part of the
remedial design.
There is concern that any excavation activities will greatly
increase the odor problem at the site. How does the Agency
propose to deal with that? .
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The problem will be addressed specifically in the Remedial
Design.
How does EPA justify having soil cleanup criteria for some
chemicals that are lower than levels present in some foods?
As stated earlier, EPA developed its cleanup criteria based
on standard methodologies used for Superfund remediation in
Region IV. EPA has no real expertise regarding food
products and is not in a position to comment on the
comparison.
Considering the large number of studies already done on this
site, how does EPA justify asking for additional investigation
—work-as—part-of—the—Remedial Design?
Despite the large number of studies, there are still
significant questions about several of the source areas;
especially the Cabot lagoons and the wetland/lagoon area.
Levels of contaminants higher than the cleanup criteria
appear in several locations in earlier studies and EPA
needs to confirm that these areas to not require
remediation.
Is EPA aware that Koppers is planning to install a new
containment area for their creosote tanks and associated
equipment?
Yes, EPA is now aware of this fact.
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6.2 indicator Chemical Selection
The media of concern at this site are the soil/ groundwater,
surface water, sediment and air. Due to the number of
constituents detected in these media, it was necessary to selec'
a limited number of "indicator chemicals" on which to base the
risk assessment. Compounds selected are the focus of the
toxicity assessment exposure analysis, risk characterization an<
development of health based action levels.
All of the historical data was used to select the indicator
chemicals; however, the risk calculations were based primarily
on the analytical data collected for the supplemental RI. The
selection process followed the one outlined in the Superfund
Public Health Evaluation Manual, (1986).
It can be divided into the following four steps:
1. Determination of chemical concentrations and frequency
of detection;
2. Identification of toxicity characteristics of detected
chemicals;
3. Calculation of chemical toxicity (CT) and indicator
score (IS) values; and
4. Selection of final indicator chemical.
Using this process, the following indicator chemicals were
selected for the CC/K site:
0 Arsenic
° Benzene
oeuzant*
0 Chromium (VI)
0 Napthalene
° Potentially Carcinogenic
Polynuclear Aromatic
Hydrocarbons (PAHs)
0 Noncarcinogenic PAHs
0 Pentachlorophenol (PCP)
0 Phenol
6.3 Exposure Assessment
6.3.1 Definition
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An exposure pathway is the course a chemical agent takes from a
source to an exposed population or individual (receptor). For
the exposure pathway to be complete, the following four
components must be present:
1. A source or release from a source
2. A likely environmental migration pathway
3. An exposure point where receptors may come into contact
with the chemical agent
4. A route by which potential receptors would result in an
Intake of the chemical agent.
A screening of current potential exposure pathways was
conducted; the RA focused only on the significant completed
exposure pathways.
6.3.2 Onsite Exposure Pathways to Workers
6.3.2.1 Direct Contact
An important potential exposure pathway is direct contact of
contaminated soil to uncovered skin surfaces. On the Koppers
facility, potential worker exposure exists in two areas: the
drip track areas; and the former lagoon and cooling pond areas.
The majority of the contamination in the former lagoon and
cooling pond areas is in the subsurface soils. Workers in the
drip track areas are protected from direct contact by the
Federal Insecticide, Fungicide and Rodenticide Actr—(-FIFRA)
labeling which requires them to wear long pants, long-sleeved
shirts and gloves as well as additional protective equipment.
FIFRA contains a number of other requirements concerning worker
safety and training that effectively prevents direct contact.
OSHA regulations also provide protection to workers in both the
drip track and former lagoon and cooling pond areas.
6.3.2.2 Incidental Inoestion
The same FIFRA and OSHA regulations that effectively prevent the
completion of the exposure pathway for direct contact also
prevent the completion of the exposure pathway for incidental
ingestion.
6.3.2.3 Inhalation
As part of the supplemental RI, air samples were taken from
three different areas on the Koppers site. All of sample
results were well below the OSHA limits for worker exposure.
Therefore, this pathway was not carried any further in the RA.
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6.3.3 Potential Onsite Exposure
Pathways to the General Public
6.3.3.1 Direct Contact
Because a portion of the Koppers facility is fenced and has a
locked gate, direct contact of the general public to source
areas on the Koppers facility under the current land use
scenerio is expected to be infrequent. This pathway was not
carried any further in the RA. However/ public access to the
soils in the former Carbon lagoons .is unrestricted, this pathway
was carried through the RA. The exposure concentrations
selected were the highest observed surface soil concentrations
observed in either the IT RI or the Hunter/ESE RI.
The direct contact scenario was based on a child visiting the
site to play 36 days per year for six years. In addition, it
was assumed that 50 percent of the time onsite would be in the
contaminated area. The dermal absorption rates were 10 percent
for semivolatile organic compounds, 25 percent for volatile
organic compounds, 15 percent for chromium and 1 percent for
other metals. The exposed skin surface area and body weight was
assumed to be 2350 cm2 and 35 kg, respectively. A soil
ingestion rate of 100 mg per day was used for the ingestion
pathway.
6.3.3.2 Inhalation
Because site access is restricted for the Koppers site, this was
not considered a completed pathway. The former Cabot Carbon
lagoons are covered with moderate vegetation, a concrete
foundation and a stormwater retention pond. For these reasons,
the generation of dust is greatly inhibited. Therefore, this
was also not considered a completed pathway.
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6.3.4 Potential Offsite Exposure Pathways to the General
Public
6.3.4.1 Direct: Contact
There are two significant offsite exposure points for the
general public: the North Main Street Ditch and the KII drainage
ditch. Because both of these areas have unrestricted access,
they were both retained as complete pathways for exposure to
contaminated surface water and sediment. In addition to.dermal
contact, it was determined that children playing in the ditches
could also incidentally ingest small quantities of contaminated
sediment or surface water.
The exposure concentrations for surface water used for the North
Main Street Ditch were the maximum observed values downgradient
of the source areas and were taken from either the Hunter/ESE RI
or IT RI. For sediment concentrations, the highest
concentration from ESE location SE-004 and ITS-2 was used.
These levels appeared to most closely represent the levels as
observed during several sampling events. For the KII ditch, the
highest observed concentration from the.Hunter/ESE and the
Koppers 1985 investigations were chosen. Due to the small
number of detections, no surface water concentrations were
calculated.
The direct contact exposure scenario assumes that a child (age 7
to 13 years) playa in or near Springstead Creek 2 times per
week, averaging 30 minutes per event, for the 39 weeks that
school is in session and 4 times per week averaging 1.5 hours
per event for 13 weeks during the summer. It was also assumed
that a child would spend 50 percent of this time playing in the
area along the creek banks. The exposure frequency for the
North Main Street Ditch were assumed to be 10 times per year for
2 hours per day. The skin surface area, body weight and
absorption rates for dermal contact with sediments are the same
as for the onsite' direct contact with soil scenario.
The surface water absorption rate was based on the dermal
permeability constant (Kp) for each constituent. The sediment
ingestion rate was assumed to be lOOmg per day and the surface
water ingestion rate was assumed to be 10 milliliters per event.
6.3.4.2 Direct Inoeation of Aquatic Organisms
The intermittent flow and small size of the North Main Street
Ditch, the KII drainage ditch and Springstead Creek, combined
with their location in an industrial/high traffic area, make it
highly unlikely that edible size fish would be caught near the
site. This was not considered a complete exposure pathway.
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6.3.4.3 Inhalation
Due to the presence of moderately volatile constituents in the
surface water and sediments of the two drainage ditches, this
was retained as a completed exposure pathway.
The exposure frequency is the same as for the direct contact
scenario for a child playing at the North Main Street Ditch,
except it is assumed that the exposure is occuring 100 percent
of the time that the child is in the area-. The breathing rate
is assumed to be 2.1 nrvhr.
6.3.4.4 Groundwater
There.are currently no users of the shallow aquifer. In order
to assess the potential risk of any future use, two hypothetical
groundwater wells were selected. Because the indicator
chemicals on the northern boundary of the site are different
from the indicator chemicals on the eastern boundary of the
site, a hypothetical well was located at both these points.
The general procedure for estimating the potential current ^and
future groundwater exposure concentrations was as follows:
o Determination of plume characteristics;
o Determination of equilibrium conditions between
groundwater and soil at source areas;
o Calculation of expected time of travel from source to
receptor; and
o .Calculation of anticipated future exposure
concentrations from dilution of source concentrations.
The groundwater exposure assumptions were for the daily
consumption of 2 liters of water by a 70 kg person.
6.3.5 Environmental Receptors Exposure Pathways
6.3.5.1 Terrestrial Exposure
Organisms that live in, on, or above the land may be exposed to
surficial soils (both dermally and by ingestion) and .surface
water (primarily as drinking water). Some terrestrial
organisms also may consume affected plants or animals from
either terrestrial or aquatic habitats; resulting in
bioaccumulation of contaminants. A qualitative evaluation of
these pathways was performed for various types of organisms
found at the site. •
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6.3.5.2 Aquatic Exposure
Aquatic biota may be exposed to constituents via water,
sediment, or food. Organisms may be exposed via transfer from
water across thin body membranes such as gills. This is the
process of bioconcentration. This exposure pathway is limited
by the chemicals' solubilities. Chemicals with low solubilities
may adsorb preferentially to sediment particles. These may be
ingested by organisms, and some portion of the chemical may be
transferred to the organism via the gut. The assimilation
efficiency depends on numerous variables such as
bioavailability, lipid (fat) content of the organism, gut
clearance time, etc. Finally, organisms may ingest affected
prey. Bioaccumulation from food is dependent upon numerous
factors, including the degree to which the chemical transfers to
and remains in living tissue, the physiological rate constants
governing uptake and-depuration in the various-organisms, the
encounter rate of and concentration in affected prey,
temperature, and other factors.
.6.3.6 Summary
As a result of the exposure pathway screening, the preliminary
list has been reduced to the following five potentially complete
exposure pathways:
1. Exposure by direct contact to onsite surface soils in
old Cabot Carbon lagoons area,
2. Incidental ingestion of onsite surface soils in old
Cabot Carbon lagoons area,
3. Inhalation of vapors in offsite ambient air,
4. Ingestion of groundwater, and
5. Exposure of receptors, both human and environmental, to
affected surface water and sediements.
The RA addresses these five potential exposure pathways
associated with the inactive onsite potential reception areas
and the potential offsite.
The exposure point concentrations for these completed exposure
pathways were than compiled.
6.4 Toxicity Assessment
6.4.1 Reference Doses
Reference doses (Rfds), also referred to as the acceptable daily
intakes (ADIs), have been developed by EPA for indicating the
potential for adverse health effects from exposure to chemicals
1-42
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exhibiting noncarcinogenic effects. RfDs, which are expressed
in units of mg/kg-days, are estimates of lifetime daily exposure
levels for humans/ including sensitive individuals. Estimated
intakes of chemicals from environmental media (e.g., the amount
of a chemical ingested from contaminated drinking water) can be
compared to the RfD. RfDs are derived from human
epidemiological studies or animal studies to which uncertainty
factors have been applied (e.g., to account for the use of
animal data to predict effects on humans). These uncertainty
factors help insure that the RfDs will not underestimate the
potential for adverse noncarcinogenic effects to occur. .The
RfDs for the site contaminants of concern are contained in Table
8.3.1.
6.4.2 Chronic Hazard Index (HI)
The chronic HI is a ratio of the lifetime average daily exposure
of a noncarcinogenic chemical to the acceptable intake exposure
level. If this ratio is greater than unity (>1), then the
lifetime average daily exposure has exceeded the acceptable
intake exposure level, indicating that potential health
hazardous exist (EPA, 1986a).
6.4.3 Weiqht-of-Evidence Categories
The weight-of-evidence categories for potential carcinogens
qualify the level of evidence that supports designating a
chemical as a human carcinogen. Table Three contains a more
detailed explanation of the categories.
6.4.4 Carcinogenic Potency Factor
The carcinogenic potency factor (CPF) is used for estimating the
lifetime (70 years) probability of a human contracting cancer
caused by exposure to known or suspected human carcinogens.
This factor is the slope of the cancer risk dose-response curve
and is generally reported in (rag/kg/day)" . This slope is
determined through an assumed low-dosage linear relationship and
extrapolation from high to low dose responses determined from
human epidemiological studies or animal bioassays. The value
used in reporting the slope factor is an upper 95-percent
confidence limit on the probability of response per unit intake
of a chemical over a lifetime, converting estimated intakes
directly to incremental risk (EPA, 1986a). Use of this approach
makes underestimation of the actual cancer risk highly
unlikeley. The CPFs for the site contaminants of concern can be
found in Table 8.3.1
6.5. Risk Characterization
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TABLE THREE
EPA Weight of Evidence Categories
A Human Carcinogen
Bl or B2 Probable Human Carcinogen
Bl indicates human data available, B2 indicates
sufficient animal and inadequate or no evidence
in humans .
C Possible Human Carcinogen
0 Not Classifiable as to Human Carcinogenicity
E Evidence of Noncarcinogenicity in Humans
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The problem will be addressed specifically in the Remedial
Design.
How does EPA justify having soil cleanup criteria for some
chemicals that are lower than levels present in some foods?
As stated earlier, EPA developed its cleanup criteria based
on standard methodologies used for Superfund remediation in
Region IV. EPA has no real expertise regarding food
products and is not in a position to comment on the
comparison.
Considering the large number of studies already done on this
site, how does EPA justify asking for additional investigation
-work-as—part-of—the—Remedial Design?
Despite the large number of studies, there are still
significant questions about several of the source areas;
especially the Cabot lagoons and the wetland/lagoon area.
Levels of contaminants higher than the cleanup criteria
appear in several locations in earlier studies and EPA
needs to confirm that these areas to not require
remediation.
Is EPA aware that Koppers is planning to install a new
containment area for their creosote tanks and associated
equipment?
Yes, SPA is now aware of this fact.
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