PB98-964023
EPA 541-R98-103
November 1998
EPA Superfund
Record of Decision:
Stauffer Chemical Co.
(Tarpon Springs) OU 1
Tarpon Springs, FL
7/2/1998
-------
5 9 0001
Record of Decision
The Decision Summary
Operable Unit 1
Stauffer Chemical Tarpon Springs Site
Tarpon Springs, Pinellas County, Florida
Prepared By:
U.S. Environmental Protection Agency
Region 4
Atlanta, Georgia
-------
5 9 0009
RECORD OF DECISION
DECLARATION
SITE NAME AND LOCATION
Stauffer Chemical Tarpon Springs Site
Tarpon Springs, Pinellas County. Florida
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for Operable Unit 1 at the Stauffer
Chemical Tarpon Springs Site in Tarpon Springs, Pinellas County, Florida, which was chosen in
accordance with the Comprehensive Environmental Response Compensation and Liability Act of
1980 (CERCLA), as amended by the Superfimd Amendments Reauthorization Act of 1986
(SARA), 42 U.S.C. § 9601 et seq.. and the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP), 40 CFR Part 300. This decision is based on the Administrative Record
file for this site.
The State of Florida, as represented by the Department of Environmental Protection (FDEP), has
been the support agency during the Remedial Investigation/Feasibility Study process for the
Stauffer site. In accordance with 40 CFR § 300.430, FDEP, as the support agency, has provided
input during this process. Based upon comments received from FDEP, it is expected that
concurrence will be forthcoming; however, a formal letter of concurrence has not yet been
received.
ASSESSMENT OF THE SITE
Actual or threatened releases of hazardous substances from this site, if not addressed by
implementing the response action selected in the Record of Decision (ROD), may present an
imminent and substantial endangerment to public health, welfare, or the environment.
DESCRIPTION OF THE REMEDY
This is the first of two operable units planned for the Site. This operable unit addresses the source
of the soil and groundwater contamination by treating and containing the source material. The
second operable unit will address the contaminated groundwater in the surficial aquifer. The
diesel fuel product identified during the groundwater investigation will be addressed under the
State of Florida's Underground Storage Tank Program.
-------
5 9 0003
The major components of the selected remedy include:
• Limited excavation of radiologically and chemically contaminated material/soil which
exceed Residential Cleanup Standards.
• Consolidation of contaminated material/soil in the main pond area, slag area, and/or other
areas on-site. Top Cover Caps which meet the Florida Administrative Code § 62-
701.050 will be placed over the Consolidation Areas. The movement of contaminated
soil/waste will be limited to minimize the generation of fugitive dust and to prevent the
creation of additional threats to human health and the environment.
• Institutional Controls must be placed on the site. Institutional controls must include deed
restrictions, land use ordinances, physical barriers, and water supply well permitting
prohibitions. These restrictions will limit access to the site and prohibit the disturbance of
the remedy.
• In-situ Solidification/Stabilization of pond material and contaminated soil below the water
table will be required in the consolidation areas on-site. The consolidation areas will be
delineated in the Remedial Design Report.
The total present worth cost for the selected remedy as presented in the Feasibility Study is
$9,356,000. The construction of multiple consolidation areas may increase the present worth cost
of this remedy.
STATUTORY DETERMINATION
The selected remedy is protective of human health and the environment, is cost effective, and it
complies with Federal and State requirements that are legally applicable or relevant and
appropriate to the remedial action. This remedy utilizes permanent solutions and alternative
treatment (or resource recovery) technologies to maximum extent practicable and satisfies the
statutory preference for remedies that employ treatment that reduces the toxicity, mobility, or
volume as a principal element.
Because this remedy will result in hazardous source material remaining on-site above health-based
levels, a review will be conducted within five years after the commencement of remedial action
and every five years thereafter to ensure the remedy continues to provide adequate protection of
human health and the environment.
RICHARD D. GREEN DATE
WASTE DIVISION
DIRECTOR
-------
i; 9 OC
w> X
TABLE OF CONTENTS
1.0 SITE LOCATION AND DESCRIPTION 1
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES 1
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION 6
4.0 SCOPE AND ROLE OF ACTION 6
5.0 SUMMARY OF SITE CHARACTERISTICS 6
5.1 Physiography and Topography 6
5.2 Geology 7
5.3 Hvdroeeology 7
5.4 Surface Water and Drainage 9
5.5 Spjl 9
5.6 Summary of Site Contaminants 10
5.6.1 Substances Detected in Soil 10
5.6.2 Substances Detected in Surface Water and Sediment 11
5.6.3 Air Monitoring 12
6.0 SUMMARY OF SITE RISKS , 22
6.1 Risk Assessment Overview - Chemical 22
6.2 Human Health Risk 24
6.2.1 Chemical 24
6.2.2 Radiological Overview and Assumptions 25
6.3 Summary of Exposure Scenarios 26
6.3.1 Summary of the Chemical Exposure Scenarios 27
6.3.2 Summary of Radiological Exposure Scenarios 28
6.4 Ecological Risks 33
6.5 Cleanup Levels 35
7.0 DESCRIPTION OF REMEDIAL ACTION ALTERNATIVES 36
8.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES 42
8.1 Comparative Analysis - Nine Criteria 42
8.2 Threshold Criteria 43
8.2.1 Overall Protectiveness of Human Health and the Environment 43
8.2.2 Compliance with ARARs 43
8.3 Primary Balancing Criteria 48
8.3.1 Lone-Term Effectiveness and Permanence 48
8.3.2 Reduction in Toxicitv. Mobility, or Volume Throueh Treatment 48
8.3.3 Short-Term Effectiveness 48
8.3.4 Implementabilitv 48
8.3.5 Cost 49
-------
r c\ o i~~-
59 U u
8.4 Modifying Criteria % 49
8.4.1 State Acceptance 49
8.4.2 Community Acceptance 49
9.0 SUMMARY OF SELECTED REMEDY 56
9.1 Major Components of the Selected Alternative 56
9.2 Performance Standards 57
9.2.1 Performance Standards - Cap 57
9.2.2 Performance Standards - Solidification 57
9.2.3 Performance Standards - Design 57
9.3 Compliance Testing 59
10.0 STATUTORY DETERMINATION 59
10.1 Protection of Human Health and the Environment 59
10.2 Attainment of Applicable or Relevant and Appropriate Requirements (ARARs) 59
10.3 Cost Effectiveness 60
10.4 Utilization of Permanent Solution to the Maximum extent Practicable 60
10.5 Preference for Treatment as a Principal Element 61
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES 61
-------
5 9 0006
LIST OF TABLES
Table 5-1 Surface Soil Samples 16-17
Table 5-2 Sediment Samples 18
Table 5-3 Surface Water Samples 19
Table 5-4 Pond Material Samples 20-21
Table 6-1 Summary of Contaminants of Concern 23
Table 6-2 Contaminants of Concern that Pose a Carcinogenic Risk 29
Table 6-3 Contaminants of Concern with Hazard Quotient Greater than
.01 for Pathways with a Hazard Index Exceeding 1.0 30
Table 6-4 Comparison of Maximum Detected Concentrations
of Lead to ARARs 30
Table 6-5 Scenarios Analyzed for the Radiological Risk Analysis 31
Table 6-6 Estimated Radiological Risk Considering Major Pathways 32
Table 6-7 Ecological Summary of the Contaminants of Concern 34
Table 6-X Cleanup Standards: Remedial Goals 36
Table 7-1 Response Actions and Associated Remedial Technologies 37
Table 8-1 Locations Specific ARARs 45
Table 8-2 Action Specific ARARs 46
Table 8-3 Chemical-Specific ARARs 47
Table 8-4 Summary of Remedial Action Alternatives 50-54
Table 8-5 Cost Comparison of Remedial Action Alternatives 55
Table 9-1 Performance Standards - Remedial Goals 58
-------
5 9 . 0007
LIST OF FIGURES
Figure 1-1 Site Location Map 2
Figure 2-1 1993 Soil Sampling Results 3
Figure 2-2 1993 Pond and Road Sampling Results 4
Figure 5-1 Surface Water Analytical Results 13
Figure 5-2 Sediment Analytical Results 14
Figure 5-3 Sediment Core Analytical Results 15
APPENDIX A - RESPONSIVENESS SUMMARY
-------
5 9 0008
1.0 SITE LOCATION AND DESCRIPTION
The Stauffer Chemical Tarpon Springs Superfund Site (Site) is located on Anclote Road in
Tarpon Springs, Pinellas County, Florida. The location of the Site, taken from the U.S.
Geological Survey (USGS) Topographic Map prepared in 1987, is presented in Figure 1-1 (not to
scale). The Site is situated along the Anclote River, which flows into the Gulf of Mexico
approximately two miles downstream of the Site. The town of Tarpon Springs is located
approximately 2 miles southeast of the Site. The Site comprises an area of approximately 130
acres and includes the former phosphate processing area, elemental phosphorus production
facilities, and office/administrative buildings. While operating, the plant utilized a system of
seventeen waste ponds on-Site. Currently, these unlined ponds contain waste and no water.
Land use in the surrounding area includes light industrial, commercial, and residential. Also, there
are some undeveloped areas near the Site. The Site is generally flat with an average elevation of
10 ft above sea level.
The most significant surface water bodies near the Tarpon Springs Site are the Anclote River
which is located along the Site's southern and western boundaries and the Gulf of Mexico which is
approximately 2 miles from the Site. Pinelias County and the Site are underlain by two primary
aquifers, the surficial aquifer and the Floridan aquifer. The depth to the surficial aquifer
groundwater is relatively shallow. The thin nature of the surficial aquifer limits its usefulness as a
drinking water supply; however, the aquifer provides water for irrigation purposes. The surficial
aquifer is separated from the Floridan aquifer by a semi-confining, relatively continuous bed of
clay to sandy clay. The Floridan aquifer, consisting of a thick sequence of carbonate (limestone)
rocks which are hydraulically connected, provides most of the public water supply for Pinellas
County. There are no active residential, or commercial wells either on-Site or between the Site
and the Anclote River; therefore, there are no groundwater users on-Site or downgradient of the
Site.
2.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
The Stauffer Chemical Company Tarpon Springs Plant (the "Plant") produced elemental
phosphorus using phosphate ore mined from deposits in Florida. The Plant was originally
constructed and operated by the Victor Chemical Company, which began production in 1947.
Stauffer Chemical Company obtained the Plant from Victor Chemical in 1960 and operated it until
shutdown of operations in 1981. In 1983, the decision was made to decommission and dismantle
the Plant permanently. Most of the Plant's former process buildings have since been dismantled.
In 1987, the Stauffer Management Company (SMC) was formed as a result of a divestiture of the
Stauffer Chemical Company.
In the February 1992 Federal Registry Notice, the Stauffer Chemical/Tarpon Springs Site was
proposed for listing on the National Priorities List (NPL) by the United States Environmental
Protection Agency (U.S. EPA). On July 28, 1992, SMC voluntarily entered into an
Page 1 of 61
-------
5 9 0009
• —, -» • j !
^;V>C.- 'IBS: ^i:
':•:• • • ~ •. •-"•.' ••'•.
iChOOl**^ ^^4**^mm*.r4
r=n "^Ti**"
2 '•: .. . ITS
• •(£=. o':.!1-*1
• !* •. /Llr*
w..o r*.« lfe^=^^^| C' f/"P^
^^ Sana ft:>^Zr •>-'' sPsr-V '•**•/ / R'
^>*«^_ ^^T^ _ -r. />^' 'CX >WiiiJ- / B
SOUIM: U.S.GS. Oiwdrangte. Tarpon Springf. Florid* 1973. mxoravfacd 1B6T
FIGURE 1-1 GEOGRAPHIC LOCATION MAP, SMC TARPON SPRINGS, FLORIDA
Figure 1-1
-------
"2 «
« c
cn M
CD
C!'
O
-------
•Mil
I I. «..-. tti.
•t»*l
it i
»«•*.«*»»
0 r»M.>«4«
-------
5 9 00".2
Administrative Order on Consent (Consent Order) with U.S. EPA Region 4 (EPA), which
requires the performance of a Remedial Investigation and Feasibility Study (RI/FS). The RI and
FS final reports were completed and approved in March of 1996.
Several field investigations by various consultants were conducted at the Site. These
investigations began with sampling of on-Site groundwater wells in 1974. Beginning in 1987,
additional, multi-media investigations were conducted by various parties. To the extent possible,
the studies were utilized in the Remedial Investigation
In addition to the RI field activities, a Contamination Assessment (CA) investigation was
conducted at the Site in 1993. The CA was performed for the Florida Department of
Environmental Protection (FDEP) in response to reported soil and groundwater contamination in
the vicinity of two former above ground fuel oil storage tanks removed in August 1992. The
cleanup of these areas in a coordinated approach with this operable unit will proceed under the
State of Florida's Underground Storage Tanks Program.
Black & Veatch Waste Science and Technology Corporation (BVWST), under contract with
EPA), prepared the Final Baseline Risk Assessment (dated May 18, 1994) for the Site. EPA
issued Addendum I (dated June 10, 1994) to revise the Final Baseline Risk Assessment
acknowledging the conservative nature of the assumption that all Phosphorus present was
considered to be the most toxic Phosphorus (Elemental Phosphorus). In response to this
addendum, additional samples were collected and analyzed by Roy F. Weston Incorporated, the
SMC's consultant in September of 1996. The purpose of this sampling event was to confirm
presence or absence of Elemental Phosphorus in Site media. EPA was present to oversee this
sampling event. Based on the results of the Phosphorus Sampling Program conducted by
WESTON, EPA issued Addendum II - Elemental Phosphorus and Diesel (February 2, 1996).
Also, EPA presented Addendum IIA - Elemental Phosphorus in Surface Water and Sediment on
February 22, 1995. Based on the confirmed absence or presence of Elemental Phosphorus in
discrete samples collect in each Site media, the risk assessment was revised to re-evaluated risk
levels in Site media. As a result of this additional work, the Final Revised Baseline Risk
Assessment was issued by EPA on July 21, 1995.
The Feasibility Study (FS) was prepared by WESTON in accordance with the Consent Order.
EPA reviewed and approved this FS. As part of the FS, an assessment of the environmental
impact created by the Site was performed through a comparison of the concentration of
contaminants at the Site with federal and state Applicable or Relevant and Appropriate
Requirements (ARARs) and Site-specific criteria developed in the Baseline Risk Assessment.
Page 5 of 61
-------
5 9 0013
3.0 HIGHLIGHTS OF COMMUNITY PARTICIPATION
All basic requirements for public participation under CERCLA Sections 113(k)(2)(B)(I-V) and
117 were met in the remedy selection process. The first fact sheet on the Site was distributed in
February 1993. Since that time, a community relations plan was developed and implemented at
the Site. An information repository was established in March 1993, at the Craig Park Branch of
the Pinellas County Public Library, Spring Street, Tarpon Springs, Florida. The Remedial
Investigation (December 1993), the Revised Final Baseline Risk Assessment (July 1995),
Feasibility Study (January 1996) and the Proposed Plan (March 1996) were released to the public
and continue to be available for public review. These documents have been incorporated in the
Administrative Record for the Site. A copy of the Administrative Record, upon which the remedy
is based, is available to the public at the information repository. In addition, the Administrative
Record and the Site files are available for review at the EPA Region 4 offices in Atlanta, Georgia.
Notices of the availability of these documents were published in the Tampa Tribune and the St.
Petersburg Times on May 26, 27, and 29 of 1996.
On May 29, 1996, EPA presented its preferred remedy for the Stauffer Chemical Tarpon Springs
Superfund Site during a public meeting at the Gulfside Elementary School, Holiday, Florida. At
this meeting, representatives of EPA answered questions about the sampling at the Site and the
remedial alternatives under consideration.
A 90-day public comment period was held from May 29, 1996, through August 29. 1996. At the
request of the public, this comment period was extended for an additional 30 days. The public
comment period concluded on September 30, 1996. EPA's response to comments which were
received during the comment period are contained in Appendix A of the Record of Decision.
4.0 SCOPE AND ROLE OF ACTION
The ROD selects the remedy for the first of two operable units. This ROD addresses the cleanup
of heavy metals and radiation in soil and waste at the Site. Contaminants pose a risk to human
health and to environmental receptors. The purpose of this proposed action is to prevent current
or future exposure to contamination and to control the source of contamination. Groundwater
will be addressed in a subsequent operable unit.
5.0 SUMMARY OF SITE CHARACTERISTICS
5.1 Physiography and Topography
The terrain at and surrounding the Site is generally flat with an average elevation of 10 feet above
sea level. There is a slight slope to the south toward the Anclote River. The Site is sparsely
wooded in the north and northeastern areas, but is clear of vegetation throughout the main Plant
area. The Site is located in the Gulf Coastal Lowlands physiographic region within the Gulf and
Page 6 of 61
-------
5 9 0014
Atlantic Coastal Plain physiographic province. The Gulf Coastal Lowlands generally contain
numerous wetlands which are interspersed with pine-palmetto flatwoods.
5.2 Geology
The Site is located in the Gulf Coastal Lowlands Physiographic Province. The Gulf Coastal
Lowlands are characterized by three sedimentary sequences: (1) unconsolidated fine sand with
interbeds of clay and marl; (2) fossilferous limestone and dolomite; and (3) gypsiferous limestone
and dolomite. The primary sedimentary units underlying Pinellas County comprise a thick,
continuous sequence of shallow-water platform carbonate rocks ranging in thickness from 10,000
to 12,000 feet.
The carbonate rocks underlying Pinellas County form a peninsula which separates Tampa Bay
from the Gulf of Mexico. These rocks lie on the southwest flank of the Peninsula Arch. The
Peninsular Arch is the dominant subsurface structure in southwest Florida whose axis trends in a
northwest direction. In northern Pinellas County, these highly fractured units demonstrate a
preferred fracture orientation of N 54° W to N 35° W.
Two distinct stratigraphic units exposed in Pinellas County: A thin veneer of fine sand with clay.
marl, and phosphorite interbeds (surficial sand) and a thicker, highly variable calcareous sand to
sandy clay with black phosphate nodules and chert (Hawthorn Formation). The Pleistocene
surficial sand is located throughout the county except for in the south-central region. These
deposits range in thickness from 5 to 50 feet and rest unconformably upon the underlying Tampa
formation. The late Miocene Hawthorn formation is exposed in the south-central region and
attains thicknesses of approximately 50 to 90 feet.
A thick sequence of carbonate strata unconformably underlies the surficial sediment. These strata
are listed in descending order from youngest to oldest: the early Miocene Tampa formation - a
poorly to semi-cemented, sandy limestone which thickens from 100 feet in the north to 250 feet in
the south, the Suwanee formation; a white, fossiliferous, sandy limestone attains a maximum
thickness of approximately 180 feet, and a series of Eocene limestones and dolomites which may
achieve thicknesses of 3,000 feet including the Ocala formation - a fossiliferous, chalky limestone
unit exhibiting some dolomitization; Avon Park formation - a limestone and dolomite unit
containing intergranular evaporates; and the Lake City and Oldsmar formations - a chalky
limestone with intergranular gypsum and anhydrite deposits.
5.3 Hvdrogeology
Pinellas County is underlain by two primary aquifers, the surficial aquifer, and the Floridan
aquifer. The surficial aquifer is a thin veneer of predominantly fine sand whose pore waters are
influenced by atmospheric pressures. The water table rises and falls within the surficial aquifer in
response to infiltration via precipitation, tidal changes, and variations in atmospheric pressures.
Page 7 of 61
-------
5 9 0015
In eastern Pinellas, the depth to groundwater is relatively shallow and the saturated thicknesses
range from 5 to 35 feet while averaging 15 feet. The thin nature of the surficial aquifer limits its
usefulness as a drinking water supply; however, the aquifer adequately provides water for
irrigation purposes. Hydrogeologists have measured mean horizontal conductivity (Kh), vertical
conductivity (Kv), and storativity (S) values of 23 ft/day, 9 ft/day, and 0.3, respectively, for the
surficial aquifer.
Underlying the surficial aquifer is a semi-confining, relatively continuous bed of clay to sandy clay.
The clay unit behaves as a semi-confining unit separating the surficial aquifer from the Floridan
Aquifer. Laboratory measurements indicate the vertical hydraulic conductivity of the clay ranges
from 2.9 x 10^ to 5.6 x 10° ft/day (1.0 x 10'7 to 2 x 10* cm/sec) with an average of 2.3 x 10°
ft/day (8.1 x 10'7 cm/sec). In south-central Pinellas, the calcareous sand and sandy clay of the
Hawthorn formation overlie the Floridan aquifer creating semi-confined to confined aquifer
conditions.
The Floridan aquifer consists of a thick sequence of carbonate rocks which are hydraulically
connected. The aquifer system is heterogeneous and groundwater flow is principally through a
series of interconnected fractures and solution channels. A considerable amount of water is
stored, and to a lesser degree transmitted, through the pore matrix of limestone units.
Groundwater flow in the upper Floridan aquifer typically occurs under leaky-confined to confined
conditions. In Pinellas County, the Floridan aquifer system encompasses the limestone units of
the Tampa, Suwannee, Ocala, and Avon Park formations.
Locally, the top of the aquifer system is defined as the first competent sequence of limestone
containing small percentages of clay, marl, and sand. This lithologic distinction coincides with the
highly porous Tampa limestone. Conversely, the base of the aquifer is generally considered to
occur at the first limestone or dolomite unit containing thin, continuous beds of gypsum. Locally,
the base of the aquifer occurs at the formational contact separating the Avon Park and Lake City
limestones.
Groundwater flow through the Floridan aquifer is by the way of a series of permeable units which
typically do not coincide with formational boundaries. These permeable units consist of
interconnected fractures and solution channels which are partly separated by dense carbonate
beds containing clay seams of lower permeability. These less permeable units behave as
semiconfining beds. Hydrogeologists have subdivided the Floridan aquifer into four
hydrostratigraphic units separated by three semiconfining units. The shallowest of these
hydrostratigraphic units are located approximately 10 to 140 feet below MSL (Tampa limestone)
and approximately 250 to 330 feet below MSL (Suwannee limestone). Most production wells
providing public water supply for Pinellas County are open exclusively to the upper
hydrostratigraphic units. Aquifer tests performed on this unit yielded an average hydraulic
conductivity value of 145 ft/day (5.1 x 10'2 cm/sec) and a storativity value of 7.7 x 10"4. The
deeper hydrostratigraphic units are predominantly saline within the study area and, thus, not
considered important water sources.
Page 8 of 61
-------
5 9 0016
The average annual water budget for Pinellas County consists of 53 inches of precipitation of
which 39 inches (74%) is attributed to Evapotranspiration, 6 inches (11%) is attributed to surface
water runoff, 6 inches as (11%) is attributed to ground water recharge and 2 inches (4%) is
attributed to leakage to the Floridan Aquifer. Predicted groundwater recharge rates in Pinellas
County vary from 6 to 11 in/yr.
5.4 Surface Water and Drainage
Florida has created several water management districts. The individual districts have the
regulatory responsibility for the management, retrieval and storage of any surface water and
groundwater within the established boundaries. Pinellas County is located within the
Southwestern Florida Water Management District (SWFWMD).
The most significant surface water features near the Tarpon Springs Site are the Anclote River, a
recreational, Fish and Wildlife Class Ill-marine surface water body, located on the southern Site
boundary and the Gulf of Mexico, located approximately two miles west of the Site. Class Ill-
marine surface waters are defined as suitable for fishing and swimming. The Anclote River
extends from south-central Pasco County, south into Pinellas County and then westward to the
Gulf of Mexico. The Pinellas County Aquatic Preserve is approximately one mile downstream of
the Site along this river. Upstream from the Site are the Port of Tarpon sewage treatment Plant,
and the City of Tarpon Springs. Tidal movement can reverse river flow. The primary uses of this
river include recreation and maintenance and propagation of wildlife. Stormwater runoff from the
Site drains directly into the Anclote River.
5.5 Soil
According to the soil survey of Pinellas County, Florida (USDA-SCS, 1972), the primary soil
underlying the Tarpon Springs area are of the Ashtabula St. Lucie Association. The deep sandy
soil are relatively flat-lying and classified as extremely well drained. There are lesser percentages
of Astar association consisting of poorly drained sandy soil overlain by organic-rich material, and
the Ashtabbula-Adamsville Association, consisting of gently sloping, deep sandy soil. The study
area is underlain predominately by Made Land soil (Ma) which consist of mixed sand, clay, hard
rock, shells and shell fragments. The thickness of the Made Land soil typically ranges from 2 to 8
feet below ground surface. Adjacent to the Made Land Series to the north and east of the Site lie
the Ashtabula (AfB) soil consisting of excessively drained, fine sands. Ashtabula soil (AfB) series
predominantly underlies the Made Land soil throughout the Site.
Page 9 of 61
-------
5 9 0017
5.6 Summary of Site Contaminants
5.6.1 Substances Detected in Soil
Soil samples were collected at many different times during the Site investigation process. Initially,
soil samples were collected by NUS (a company under contract with EPA to conduct the Site
Inspection) for purposes of ranking the Site and placing it on the National Priorities List.. For the
Expanded Site Investigation Report in 1989, four surface soil samples and twenty-two subsurface
soil samples were collected and analyzed. Concurrent with sampling conducted by EPA, SMC
utilized the services of Roy F. Weston to sample surface soil. AJso in 1990, Weston collected 47
discrete samples of the surface soil and 47 samples of the subsurface soil. In addition to Weston's
discrete soil samples, eight composite surface soil samples were collected in the northeast part of
the Site. In 1990 Weston also collected an additional 35 subsurface samples. All of this
information was compiled into the Past Work Document which has become Volume II of the
Final Remedial Investigation Report. Pond material was analyzed to determine the maximum
degree of contamination. Seventeen samples were collected by Weston in the pond areas on-Site.
The purpose of the Final Remedial Investigation Report (RI) was to confirm the past work and to
further define the extent of contamination at the Site. As pan of the RI, twenty-one surface and
seven subsurface soil samples were collected to confirm the past work performed on-Site. The
analytical results were consistent with the results from earlier sampling work.
Subsurface Soil
All subsurface soil samples (collected in 1993) were analyzed for Target Analyte List (TAL)
metals, cyanide, fluoride, and total phosphorus. In addition to these parameters, two samples
were analyzed for Target Compound List (TCL) volatiles, semi-volatiles, pesticides, and PCBs.
Radiological parameters were also tested.
Few TCL contaminants were detected in the subsurface soil sample locations. The only two TCL
volatiles detected were acetone and methylene chloride. The only TCL semi-volatile was di-n-
butyl phthalate. No TCL pesticides or PCBs were detected.
Arsenic, lead, fluoride, and total phospK5rt»-were detected in the subsurface soil.
The radiological parameters of Gross Alpha, Gross Beta, Radium-226, Radon-222, and
Polonium-210 were ail detected in on-Site subsurface soil.
For more detailed information concerning the subsurface soil results please refer to the Final
Remedial Investigation.
Surface Soil
As part of the RI, twenty-two discrete samples were collected in the main production area,
Page 10 of 61
-------
5 9 0018
northeast property, and southern properly areas. In 1993, three discrete samples were collected at
the Gulfside Elementary School located directly across the street from the Site on Anclote
Boulevard. Ten additional surface soil samples were collected at the elementary school in
February 1996. See Table 5-1 for further detail.
All samples on the elementary school property were detected at normal levels.
Surface soil samples were tested for one or more of the following: TAL metals, Cyanide, Fluoride.
Total Phosphorus, Elemental Phosphorus, TCL volatiles. semi\ olatiles, pesticides. Gross Alpha
Radiation, Gross Beta Radiation, and Gross Gamma Radiation. Specifically for the radiological
parameters, an isotopic analysis was performed which confirmed that the radiological
contamination is detected in the form of Radium 226.
Soil within the Site is contaminated with radionuclides primarily found in the uranium decay chain,
specifically Radium 226. As noted earlier, radioactive waste material, suspected to have originated
from the Phosphate ore (radium) processing Plant, were disposed on-Site. The radioactive decay
of Radium 226 in soil causes elevated concentrations of radon gas and radon decay products.
In broad terms, the results of the assessment for surface soil were as follows:
• The main contaminants of concern for soil were radiological constituents, mostly
located in the former slag processing area, railroads, road, and parking lots. In
addition, some chemical contaminants including arsenic, antimony, beryllium,
cadmium, chromium, thallium, PAHs, and fluoride, were identified. For a complete
list of Potential Contaminants of Concern refer to Table 6-1.
• The pond material were not evaluated from a risk standpoint in the Final Baseline
Risk Assessment (BVWST, 1994). The risk assessment assumed that this material
would be treated or remediated. Radiological levels detected in the ponds exceeded
residential and commercial use standards. Refer to Table 6-1 Potential
Contaminants of Concern for a complete list of contaminants.
Contaminant detection tables for all media are presented as Table 5-1, 5-2, 5-3, and 5-4. These
tables present the sampling results from the Remedial Investigation for the media of soil and pond
material.
5.6.2 Substances Detected in Surface Water and Sediment
Surface water and sediment samples were collected from the Anclote River directly adjacent to the
Site (located directly south and south-west of the Site property boundary). Surface water and
sediment samples were collected in a two phase sampling event. The first phase focused on the
comprehensive sampling of the Anclote River's surface water and sediment. The sample locations
Page 11 of 61
-------
5 9 00", 9
were selected to include areas upstream, areas downstream, and areas adjacent to the Site. The
second phase of sample collection included a focused investigation of the sediment in the Myers
Cove area adjacent to the Site. During the RI, a total of 15 surface water and 27 sediment samples
were collected. Refer to Table 5-1, 5-2, and 5-3.
The results of the RI sampling documented that Site-related contamination was not detected in
surface water above background (normal) levels. Only mercury and cadmium were detected (once
each) above the National Oceanic and Atmospheric Administration (NOAA) Effect Range-Low
(ER-L) guideline values, at sediment locations in Meyers Cove. Both contaminants did not exceed
the NOAA Effects Range-Medium (ER-M) guideline values. For further detail, refer to the Final
Remedial Investigation Report (WESTON 1993).
5.6.3 Air Monitoring
Air monitoring results obtained during the RI field work indicated that airborne volatile organics
compounds were not problematic at the Site unless construction activities are in progress. Prior to
excavation, drilling, and sampling activities, on-Site workers tested the air quality with either a
'flame ionizination detector (FID) and/or an organic vapor analyzer (OVA). Instrument readings
were taken continuously at each drilling location for monitor wells. In addition VOCs were not
detected during air monitoring conducted to support the health and safety plan. Elemental
Phosphorus is the only contaminant of concern that may present a problem since it may ignite
spontaneously when exposed to the atmosphere. Supported by historical information and the
results of the RI field work, EPA has drawn the conclusion that airborne contaminant transport is
not a significant migration pathway at the Site. The exceptions to this statement would exist when
the pond and other contaminated areas are excavated or disturbed. This scenario may cause the
Elemental Phosphorus to be exposed to the atmosphere. During the Removal Action construction
activities on-Site, asbestos was detected at levels below the Occupational Safety and Health
Administration (OSHA) Permissible Exposure Limit. Even though the asbestos levels are below
the Permissible Exposure Limits, EPA will add asbestos to the list of Contaminants of Concern.
This decision is based on input and concerns expressed by the community. Additional samples will
be collected and analyzed for asbestos as part of the Remedial Design.
Page 12 of 61
-------
5 9 0020
SOUKC& SvuMig i-~m**nal Auocattl
AAdMt nnt Wtur Cetumn tnd S«4nMM
Simpling riuJ fepcfl. »S1
/I
SW.7
A
UJ
J.Og
OJO
0.06
•MM^^
6
3.ia
i.«
OJ2
NO
C
l.0»
j.0w
OJ2
0.04
I
• Appraoxiol* Sorfoet Wctcr
I Aflolyte fraunt in llenk
NO NolDtltctatf
• NafD*ta0c4{2cport«jVaUb
I4CT-11U IW1*»»
MARCH/APRIL 1993 SURFACE WATER ANALYTICAL
RESULTS OF SELECTED PARAUETERS
Figure 5-1
Page 13 of 57
-------
5 9
0021
5CUKC&
Anctou f+*t< Wuif Column tr.4
S*drrxm &i/nplin0 FV»«» R«£oi ISM.
50-07
" I C
IO.ll9.II
51.9 I242I2A.O
SD-n
11.70
211.0
50-10
BA9
197.0
•11
50-12
3M
39.X
»T2
50-08
NO
55.2
Legend
SD-12
NO
•OITfc
1993 SEDIMENT ANALYTICAL
RESULTS OF SELECTED PARAUETERS
Rgure 5-2
Page i< of 57
-------
5 9 0022
A/M2DU Hiowr Sreim.ni Coring
IV.alRtpeM.1ffX
IU. 17.1
0.1). 0.11
J.f.O.
17.1 3*7
Meyer's Cove
UC 14B 14A
.^9. 0.63
1.< 1^
O.IOu. 0.12v
Zinc,
nuorid*. mg/Vg
fkeipKoirvi. me/Va
Sample locelion
fxl (Report Value it
Oetocfton UmW.
JULY 1993 SEDIMENT CORE ANALYTICAL
RESULTS OF SELECTED PARAMETERS
Figure 5-3
Page 15 of 57
-------
TAIII.KM
MIKKACK .SOIL XAMI'l-KS
OlltMICAI.
OKCANICS
•ail.OKOPIUiNOI.
j-MirniYiXAi'imiAU-iNi;
2.4-DINITKOTOI.UIiNli
2.4.6-TRJCI II.OKOPIII-NOI.
i MrrriiYiJ-iii-NOt.
ACtiNAI'imiliNi;
ACKNAPimiYU-NIs
ACIiTONB
AU'llA-ClU-OklMNI:
III-N/Q A ANTllKAaiNIJ—
IIKNZO A PYRJiNIC'—
lll-N/0 II H-UORANTHI-NIi— •
III;N/O cjuiPi-RYiitXi;
IH-N/.O K|i i.uoRArrnu:Ni-—
k.-AKIIAZOIj;
aiRYSIsNIi*"*
DI-N-IIII TYI. PIIT1IALATI-:
OUII-N/OFUKAN
DUIIiN/^AJIlANTIIKACIiNIi***
lUJORANTHHNH
l.UOKI-NI:
INDUNOJ LW-CDlPYRIiNli***
LSOPIIORONH
MicriiYiJ-Nii anxjKjni-
NAPlllAIJ'Nfi
l'i:NTAOIII.OROrili;NOI.
I'HHNANTIIKI-Ni;
I'lllsNOI.
PJMMMi
I'.P-ODT
I'YRCNIC
KRWIIKNCY
OKDK'm.TS
1 / 9
2/ 9
I/ «
I/ 9
1 / 9
I/ 9
11 9
I/ It
I/ 12
J/ 9
J/ !>
61 9
61 9
S/ 9
?/ 9
6/ 9
9/ 9
1 / 9
2/9
6/ 9
2/ 9
S/ 9
I/ 9
•I/ II
/ 9
/ 9
/ 9
/ 9
/ 12
/ 12
7/ 9
KANCK
OK DKIKiM.S
|i(^K<;
>0
45 • 60
7KU
990
I3
68 • 4.100
43 • I.6IM)
42 • I.IOO
Ml - 200
5.1 - 2.1 IM»
7H . I..100
3«
100 - JMO
6-1 • I/.OO
75 - 450
KK - I.MXI
540
7 . 25
48 - 4K
2.NU
CONt.-fJVIKAllUN
II«:/K<:
Nl)
Nl>
Nl>
Nl)
Nl)
Nl)
Nl)
Nl)
Nl)
Nl)
Nl)
Nl)
Nl)
Nl)
Nl)
NO
NO
NO
NO
NO
NO
NO
NO
Nl)
NO
NO
NO
Nl)
Nl)
NO
Nl)
KM;ION in
KKSIDKNTIAI. SOU."
H«/K<: ;
19.OOO
940
5».000
19.000
470.000
780.000
490
88
12.000
780.000
J 10.000
J 10.000
670.000
85.000
.110.000
5.JOO
4.700.000
I.90O
1.900
2JO.OOO
rO
CM
O
O
ON
uO
in
•M
O
VD
H
0)
Pi
•Tliit; Ulile lunnuri/M UK ditmicils Uul wtrc ikUilcJ in al leiM one tanvle i>i lliis nicJnini. HMS Hulial lia of dicniii-il* in further evaluate J by i-a^iarii« to qifv«|iriilc
naceiiifv; viliic*. aifh is mem liitigroiiml cniKeK/alioiK. iii tirclcr lo niclcil (lie list ofilieinii-aU oT|Mlcicr ConliilciHrc Limil*.
•• Re/jiwi in vilue» were oWaiied fran Die Khl Mated C«iceistiui PAIIs tiascil wi eaili ««if NmmN relative |M*cmy In Ute |x4ciHy un>ai/uafkpuuinl KUif tie.
-------
SIWK
I.KM
IQ
H
•J
O
Hi
UI
CIIKMICAI.
INORGANICS
AMJMINUM
ANTIMONY
ARSIiNIC
IIAKJUM
III-RYIJJUM
CADMIUM
:ALCIUM
OIKOMIUM
COIIAI.T
COPPI-X
FLUORIOK
IRON
IJ-AI)
MAGNESIUM
MANCJANI3C
MERCURY
NTCKI-J.
POTASSIUM
.SI3J-NIUM
SO.VI-R
SOfNUM
niAIJJtfM
/JNC
KHKOUKNCY
OK DKTKCTS
IH/ 21
»/ 21
IJ/ 21
II / 1)
U/ 21
II / 21
18 / 21
17 / 21
lOt 21
14 / 21
I9/ 21
18 / 21
I7/ 21
17 / 21
IS/ 21
It 21
17 / 21
II / 21
12 / 21
4t 21
17 / 21
8/21
IK/ 21
KANCK
OK DKTKCTS
|iC/KC
287.000 • 6. HI 0.000
4.900 • 32.100
410. 127.000
2.000 . K0.900
160 - 1.600
)90 . J7.400
36.000 - .177.VOO.OOO
1.100 . 161.00(1
1.100 - 33JOO
I.XOO • 65.500
2.400 • 2.810.000
131.000- 44.800.000
1.600. 324.000
39.000- 3.91 0.WH)
.>W . 292.000
230. 420
1.900- II.VOOQ
in i.ooo - i .6x0.000
240- 32.500
1.200. 9.700
8.400 . 15.500.000
370 . 13.400
770 . 519.000
MKAN I>K 1 M.TKD
C:ONt>aVTKATION
|iC/KC
2.765.0)0
14.6X9
26.RH5
29.206
672
14.346
IO9.96K.I67
43.700
• 7J60
20.3KA
401.774
9.097.167
58.691
1.226.994
88.099
325
24.759
708.846
7.828
4.225
2.869.0041
4.110
120.941
MKAN IIACK<;KOUNI>
CONCKNTKATION
pC/KR
631
Nl)
NO
3.2
NO
Nl>
2240
I.J
NO
0.92
NO
455
7.5
70.6
20.A
Nl)
4
Nl>
0.32
Nl>
.15.2
Nl>
J8
KM:ION HI
KK.MOI'^ITIAL. SOIL"
liO/KC
23.000.000
3.100
360
550.000
150
3.900
3 9.000
290.CXNI
470.000
'
.19.000
2..100
I60.OOO
.19.000
.19.000
2..IINI.ODO
•TINS table xunmarizts the chemicib lhat were ddeilcd in at Icasl one sample in lltis mtilriim. This iniliil list ofdictnirals is fiirllwr evaluated by conf ivjiy; to aji|iro|riale
xcrceiring vidie*. aufi n mean bacfcpmmj r«MvenlnlioiM. in order to stletl die list of dtcinit-als of|H>4ti(iil cointni dial will l>e evaluated in die ItKA. iri iccorilance widi
(•PA Region IV guidance, the non-dcleds were not imorporntd k«o UK averigc vaiiceitfraiiorH. llowevtr.mm-iklttls arc *K hided in Hie caliulalioii of 95 (Krcei*
ttyficr Confidence Until*.
•• Region n value* were obtained from die RM lined Concentration Table, fourth Qualcr. 1993 (XX^ndcr 15.1993).
For nonvarcinogcm. the large! IIQ wa* adjusted from 1.0 to 0.1 in accordance wHti I-I'A Region IV giiiilun e.
••• The TIT a|«^roarh will be wed to evahiate risk from rarchmgcnif PAIIx based on cadi cwnHnuNts relative |xi»tiicy In Hie (xrtcm-y orbcn/n(a)|>yreiM;.
Siwe die maximum conrenlration of lxiuo(a)pyrenc exceeds its Region III screciing value, all delected circimigeiiif PAIK will be retained ax
COPC* in aurface toil.
.Sample SS93-2 wa* used •< die background sanf tic.
VO
CD
CD
hO
-------
TAIII.K 5-2
.SKDIMKNI XA.MVl.KS
C1IKMICAL
INOKCANICS
ALUMINUM
ARSI-NIC
DARniM
lU-RYIJJUM
CADMIUM
CALCIUM
CHROMIUM
COPPER
FLUORIDE
IRON
LEAD
MAONIuSIUM
MANOANRSli
MI-ROIRY
NICKH.
PHOSPHORUS
POTASSIUM
SI-U-NIUM
SODIUM
ZINC
OKCANICS
AcirroNii
IttmianrYIJIIiXYDrimiALATK
MI-THYU-Ni; CIILORIDIi
pitNTACiiijOROpm-NOL
pin-Noi.
PYRKNii
TOI.UP.NU
KRKOIIKNCY
OK DETECTION
12 / 27
12 / 2?
12 / 27
J / 27
2 / 27
12 / 27
12 / 27
II / 27
2« / 27
12 / 27
12 / 27
12 / 27
12 / 27
) / 27
2 / 27
27 / 27
II / 27
2 / 27
12 / 27
12 / 27
1 / 2
1 / 2
1 / 2
1 / 2
2/2
. 1/2
. 2/2
KANCK
OK MK.mrrs
nC/KR
358.000 . 4.2VO.O(K)
•470 - ).400
900 • 6JOO
260 . 290
950 . 1.400
1. (150.000 . 29.000.0OO
1.700 . 15.400
3.200 . 20.900
J.I 00 . 44.300
370.000 • 4.340.000
1.400 • 16.400
357.000 - 2,310.000
1.400 . 19.4011
98 • 5X0
5.900 - 5.900
.17.200 - 2.560.000
204.000 - 828.000
260 . 420
1.740.000 . 9.780.0OO
4.KOO • 32.100
15
260
4
100
M • AR
6K.000
51 - 62
MK.AN OKTK.CI Kl>
rONC.'KNI RATION
|iC/K<:
1.954.750
1.763
3.330
277
1.175
11.295.833
7.325
9.025
12.872
2.105.667
6.025
1.280.167
R.I 50
286
5.900
639.993
493.364
340
5.300.000
15.300
15
260
4
KM)
67
68.000
57
MKAN IIA<:K<:KOIINI>
CONCKNTKATION
fic/K<:
Nl)
Nl>
Nl)
Nl)
NO
ND
Nl)
NO
.1
Nl)
ND
Nl)
Nl)
Nl)
ND
117
Nl)
Nl)
NO
Nl)
Nl>
44
2
Nl)
Nl>
Nl>
32
KKKION III
RKSIDKNTIAI.SOII.**
pOKO
23.000.000
360
550.000
150
3.900
39.000
290.000
470.000
39.000
2..100
160.000
39.000
2.300.000
7KU.OOO
46.001)
R.VOOO
5.100
4.700.000
230.000
1.600. 000
•tf
p»
U)
H
OB
in
•4
•This ItMc «mmriKS (he chanictli Hat wtre dcfcdcd in U lci<4 one snnfile in Otis medium. TIHs Mulial list ofthctnicils is HirOier cvahiiletl by confiviilRlo ip|irofvialc
tcrcaiinit vjhiei. wch is mem background conrcitfnlians. in order lo select Uie list ofclicmiHls of |K>crcct«
lljijKT ConTioVncc Unrtt.
•* Repon 10 v.Iucs were oUiined from Che Risk IU«d Concertnlion TiMe. l-.mrHi Quuier. 199.1 (er 15.1993).
For noncircinogcm. Iht target IIQ wis idjusleJ from 1.0 to 0.1 in accordance wrtJi lil'A Region IV pii Ja
I. SD-2. and SO-) wtre utcd H btdcerand xamjiles.
cn
VO
O
O
-------
TAJfl!Ts-J
NUUKACt: \VA I KM .NAIMM.KS
CM
CD
CD
OS
LO
CIIKMICAL
INOKCANH:
ALUMINUM
AR-SliNIC
IIAK1IIM
CAIX1UM
COPPFJI
II.UORJDI;
IKON
IJ-AD
MAtiNI-SIIJM
MIIKCIIKY
I'llOSPMOKUS
I-OTASSHIM
SI-U-NHJM
SODIUM
TtlAUJIIM
OMCANIC
ACIiTONK
TOMII-N1-
KHKOUKNCY
OK I>K TM.TION
15 / 15
« / 15
15 / 15
15 / 15
II / 15
15 / 15
15 / 15
6/15
15 / 15
II / 15
4 / 15
15 / IS
1 / 15
15 / 15
1 / 15
1 / 2
1 / 2
KANCK
ot DKIKCI.S
i.<:/i.
ji - m
1 - 6
6-11
206.IKX) . 1IK.OOO
.1 - 15
0 IV . 1
17 . 1.15
1 . )
72J.OOO . I..IOO.WW
O.I) - 1
0.05 • 0.06
31 1.CIKI>
CON< KNIKAIION
|i(^l.
5)
I
11
J.IS.WJ
9
0.51
6.1
2
914.601)
O.J!>
0.06
J79.A.11
7
K.Otll.t.t.t
17
24
«>
MKAN IIA< kCKOIJNI)
«)N( KNIKATION
Itl'Jl.
9*
2
»
I24.KOU
1.1
0.42
I6»
.1
JJ0.667
0.27
0.09
152.067
2J
4.260.000
19
15
4*
Awgc ••
ttCJt.
.
0.14
"
0.15
6
2OH.OOO
• Itii* table tuniiuri/cv Uic dwnicih Uul wne dtlcclcd in M lead one saiiftlc iii itiis mtawun. lltis iiiilul li\l of tlmiiii»ls is liiillicr c\-aNiaicd by con^iirii« la
MTcaiiiv; vilucii. Mill •< niciii bitipuwnl ium-a«nlhiitk n milcr lo itcltil ilic litt of iliciiiiuls ul'|H4ciiililx<'>ilcfii (ii|xljlcil t)uttittfi. 1992).
The v»be* titled re|«cvci« lumau health. fumuni|i«i«i of organism iwainclcrti.
Sample* SW-I. SW-2. tnd SW-J wa e used IK bwkpound «»n J«».
Page 19 of 57
-------
5 9 0027
TABLE S 4
POND MATERUtSAMPI.es
CHEMICAL
INORGANICS
ALUMINUM
ANTIMONY
ARSENIC
BARIUM
BERYLLIUM
CADMIUM
CALCIUM
CHROMIUM
COBALT
COWER
FLUORIDE
IRON
W>
'.GNESIUM
MANGANESE
MERCURY
NICKEL
ELEMENTAL PHOSPHORUS
POTASSIUM
SELENIUM
SILVER
SODIUM
THALLIUM
ZINC
FREQUENCY
ororrccnoN
J / }
) / i
3/3
3/3
J / 3
3/3
3 / 3
3 / 3
3/3
3 / 3
3/3
3/3
3/3
3 /
3 /
3 /
3 /
3 /
3 /
3 /
J /
3 /
3/3
3/3
RANGE
OFDCTTCR
|iC/K'C
•
4.510.000 - 6.060.000
27.000 . 33.000
19.800 ' 203.000
46.100 • 1)4.000
710 - 2.000
I3JOO . 36.300
167.000.000 - 370.000.000
30.000 • 226.000
UOO . 4.200
9.900 - 1.040.000
193.000 • 2.230.000
4.290.000 • 9.760.000
126.000 . 900.000
1.030.000 - 3.030.000
38.400 . 113.000
130 • 2.200
9.300 . 14.000
2l.lOO.ono . 69.iuo.ooo
933.000 - 4.820.000
6.600 . 33.100
4.500 • 19.300
2.I70.IKX) • I4.IOO.OUU
6.90V • 36.200
297.000 - 7)8.000
MEANDLTCCTCD
CONCr/ORATION
liG/KC
3.130.000
43.467
83.300
74.133
1.237
28.800
274.666.667
104.800
2.833
376.867
1.41 8 J33
7.116.667
386.000
2.630.000
80.400
887
17.000
42.400.000
2.3 34.333
23.433
11.900
6.463.333
23.933
J4IJ33
HtCIONd
RCSOTEmiALSOIL"
MC/k'G
23.000.UOO
J.I 00
360
550.000
1)0
J.900
39.01)0
2W.OOO
470.000
39.000
2JOO
160.000
39.000
39.000
2.300.0W
Page 20 of 57
-------
5 9 0028
TAIIl.E S 4
POND MATERIAL SAMPLES
CHEMICAL
ORGANIC*
ACETONE
BENZOfAlAMTHRACENE"*
BENZO(B]FUK)RANnHKNE—
BENZO(O.H.nPERYl£ME
BENZOfKJFLUORANTHENE"*
Bisfj-eHnrtKEXYL)«n«Ai>ni
CHRYSENE*"
DI-N-BUrn. PHIMALATC
KLUORANTHENE
INDENOf 1 .2 J-CDJPYRENE—
MKTIfYLENE CHLORIDE
PHENAXTHRENE
PYRENE
FRCQUCNCV
1 / 1
1 / 1
2 / 1
2 / 1
I / 1
1 / J
2/3
J / 1
1 / 1
2 / J
2/1
I / 1
1 / I
RANGE
110
2.KOO
1 tO • 3.200
91 . 1.300
32 ' I.I 00
2.200
61 . 4.100
110 . 670
1.900
120 - I.SOO
3 . 27
2.000
1.100
MEANDE1TCTCD
110
2.100
2.«IO
797
374
2.200
2.4 11
300
1.900
960
16
2.000
1.JOO
REGION OJ
78U.IXKJ
SR
88
88
46.00(1
88
780.000
J 10.000
l«
v.vooo
2JO.OOO
*Thi« (*le tunnurun ihc rttenuoli Out wen ddctled in «tn« oot iBiylc in (hit medium. Thii iniliil lid ofihenitilf ii furtha nnluKcd by
tcrcmiog vihin. writ u mem bKkjround coocentmiom, in ordv lo ictcct (he li« orchanirtli ofpotaliil conccni th* will be cviluMcd iii (hr IIRA In *c(ord vwc with
EPA Region (V fuidme. (he non-detccti were not incerpomed into the iven(e canccntnlion*. However, oon-drtnti ire included in (he cilculMiun of 9.< pa-cat
Upper Confidante LimiU
•• Reyion (D v»!uo wve otxiincd front (he Riik Ducd CoocaKnlioo Trf>ie. FourUi Quvtcr 1991 (October 13.1WJ).
For noncrtinofOK. (he t»|« IIQ wn »Jju* ed from 1.0 lo 0.1 in accordance with i-TA Region IV jpiid»irc,
••• Tlie THF «pciro*di will be uied In evilnne ri* from cvrinoseiitc PAlli bu«d on nch rompoutirfi rrlaivt po«niey lo die p.Wn«y ol'hai/odVfnie
Tlte RefiiM 01 Mrccriiig vtlitr far ImKiXaiiiyreiir it V* ufttft. All drtecled wcnwymic PAlU will be reiiincd it COPC. iii Uie pond ntaierial.
Page 21 of 57
-------
5 9 0029
6.0 SUMMARY OF SITE RISKS
CERCLA directs EPA to conduct a baseline risk assessment to determine whether a Superfund
Site poses a current or potential threat to human health and the environment in the absence of any
remedial action. The baseline risk assessment provides the basis for determining whether or not
remedial action is necessary. This risk assessment also provides the justification for performing the
remedial action. Based upon this analysis, it was determined that the Site does pose a current or
potential risk.
Site risks are summarized in the Revised Final Baseline Risk Assessment - Part A and B (B VWST-
July 21, 1995), which was submitted as part of the Remedial Investigation, consist of three major
sections: Risk Assessment - Chemical, Risk Assessment - Radiological, and the Baseline
Ecological Risk Assessment. Chemical risks and radiological risks are discussed separately due to
the complex nature of contamination at this Site. Following the discussion of each risk category,
the risks posed by the aggregate categories will be summarized.
The major risks currently associated with the Site are inhalation, ingestion, and dermal contact
with contaminated soil and slag. Actual or threatened releases of hazardous substances from the
Site, if not addressed may present an imminent and substantial endangerment to human health,
welfare, or the environment.
6.1 Risk Assessment Overview - Chemical
The chemical health threat at the Site is from heavy metal contamination. The major chemicals of
concern are arsenic which is a known carcinogen and elemental phosphorus which is reactive when
exposed to the air. See Table 6-1 for the list of Contaminants of Concern for the Stauffer
Chemical/Tarpon Springs Site. Based on additional sampling results, and comments on the
proposed plan asbestos and arsenic have been added to the list.
EPA Region 4 does not consider direct exposure to subsurface soil to be a standard scenario that
should be evaluated in the baseline risk assessment for protection of human health and the
environment. Therefore, chemicals of potential concern were not selected for subsurface soil;
however, this medium will be evaluated for the protection of groundwater.
Page 22 of 61
-------
5 9 0030
Table 6-1 Summary of Potential Contaminants of Concern
j CHEMICAL
Aluminum
Antimony
Arsenic
Barium
Beryllium
Cadmium
Chromium
1 Cobalt
Copper
Fluoride
Lead
Manganese
Mercury
Nickel
Elemental Phosphorus
Selenium
Thallium
Zinc
2-MethyInaphthalene
Acenaphthylene
Acetone
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(g,h,i)perylene
Benzo(k)fluoranthene
Chrysene
Dibenzofuran
| Dibenz(a,h)anthracene
1 Indeno(l,2,3-cd)pyrene
| Phenanthrene
SOIL
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
SURFACE
WATER
X
X
X
X
SEDIMENT
X
X
X
POND MATERIAL
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Page 23 of 61
-------
5 9 0031
6.2 Human Health Risk
6.2.1 Chemical
The Baseline Risk Assessment characterized potential current and future risks to human health and
the environment from exposure to chemicals found on-Site.
The conceptual Site model for the Stauffer Chemical Site incorporates information on the potential
chemical sources, affected media, release mechanisms, routes of migration, and known or potential
human receptors. The purpose of the conceptual Site model is to provide a framework with which
to identify potential exposure pathways occurring at the Site. Information presented in the RI,
local land and water uses, and potential receptors was used to identify potential exposure pathways
at the Site.
An exposure pathway consists of four elements: 1) a source and mechanism of chemical release; 2)
a retention or transport medium (or media in cases involving media transfer of chemicals); 3) a
point of potential human contact with the contaminated medium; and 4) an exposure route (i.e.,
ingestion) at the contact point. When all of these elements are present, the pathway is considered
complete. The assessment of pathways by which human receptors may be exposed to
contaminants includes an examination of existing migration pathways (i.e., soil and air) and
exposure routes (i.e., inhalation ingestion, and dermal absorption), as well as those that may be
reasonably expected in the future.
After the sources of contaminants are identified, the next step in the development of the conceptual
model is to determine mechanisms of release to environmental media. The primary release
mechanisms are infiltration, runoff, and tidal action from the disposal ponds, and spills leaching
from the former Plant operating equipment. The secondary source of chemicals is surface and
subsurface soil. Secondary release mechanisms include infiltration and surface runoff.
Contaminated groundwater and surface soil are believed to be the major sources of potential
exposure for human receptors, followed by surface water, sediment, and air. The following
paragraphs describe the pathways by which human receptors can be exposed to contaminated
media.
Surface soil samples were collected from the main production, northeast property, and southeast
property areas of the Site. A current or future maintenance worker may be exposed to
contaminants in surface soil. Another potential future use may involve developing the Site for
residential use. Therefore, a future resident will be evaluated for exposure to on-Site surface soil.
For more detail please refer to the Final Revised Baseline Risk Assessment.
Page 24 of 61
-------
5 9 0032
Surface water and sediment samples were collected at several locations along the Anclote River.
A current or future resident may occasionally be exposed to surface water and sediment. Nearby
residents or future on-Site residents may be exposed to chemicals in surface water and sediment
via two exposure routes - fishing and/or swimming (or wading) in the Anclote River.
6.2.2 Radiological Overview and Assumptions
Since phosphate ore contains naturally occurring radioactive material (NORM), the slag material
has appreciable amounts of measurable radioactivity which has been technically enhanced. The
phosphate ore production activity apparently concentrated the radiation in the slag and disposed of
the slag in the processing area of the Site. The Baseline Risk Assessment identified the major
potential risks associated with the NORM components of the slag material.
The identification of potential pathways for radiological risk analysis is similar to that used for
chemical risk analysis. However, several major differences do exist and need to be considered.
First, radionuclide intake through the skin is a minimal pathway and need not be analyzed (i.e.,
dermal contact will not be a considered pathway). Second, the presence of Ra-226 in the soil at
the Site indicates that Rn-222 emanation will occur and provide a potential pathway. Third, the
NORM radioactivity in the soil from the processing produces an ambient radiation field that
exceeds background levels.
The following assumptions were made to assess the major pathways of exposure.
1. Consistent with the risk analysis performed for the chemical hazards on the Tarpon Springs
Site, the potential receptors are designated as listed below:
a. On-Site Worker (current and future)
b. Off-Site Adult Resident (current)
c. Off-Site Child Resident (current)
d. On-Site Adult Resident (future)
e. On-Site Child Resident (future)
2. Some monitoring results identify the presence of the nuclides K-40 and Cs-137 in relatively
small concentrations. These nuclides were not considered as part of this analysis. Cs-137
is a fission product that is found worldwide in environmental samples. Processing at the
Tarpon Springs Site should not have enhanced the concentration of this isotope to
significant levels greater than those found elsewhere in Florida. K-40 is a naturally
occurring radioisotope that is part of elemental potassium. Its presence in concentrations
above normal (background) are of negligible radiological concern because the amount of
potassium in the human body at any given time is under control (i.e., the body regulates
how much K-40 is present in tissues at any time).
Page 25 of 61
-------
5 9 0033
3. To the extent possible, parameters were used to be consistent with the chemical risk
analysis. This includes water consumption rate, exposure fractions, exposure durations,
and soil/sediment ingestion rates. Alternate parameters from recognized standards were
used in specific pathways as needed and are described in the discussion of each model.
4. Because the radiological data from the various sources are in relative agreement with each
other (i.e., the mean and average do not vary by orders of magnitude), the maximum
reported concentration for an environmental sample will be utilized in all calculations. This
approach provides a bounding value for the risk associated with the pathways.
5. Consistent with the discussion presented for the chemical risk analysis, fugitive dust is not
considered to be a pathway for exposure.
6. Consistent with the discussion presented for the chemical risk analysis (B&V 1994), off-
Site drinking water is solely from the local city water supply. Therefore, no current
ingestion of groundwater is assumed to take place. However, an analysis is performed for
future on-Site residents who may use wells on the Tarpon Springs Site for drinking water
purposes.
7. Consistent with the discussion presented for chemical risk analysis, current off-Site child
residents are assumed not to be exposed to sediment.
8. No isotopic data were present for surface water; therefore, scenarios using surface water
were not analyzed.
9. For purposes of analysis of soil data, the activity of Ac-227 is assumed to be equal to that
of Th-227, since these would most likely be in secular equilibrium. Similarly, the activity of
Pb-210 is assumed to be equal to that ofRa-226, and the activity of Th-228 is assumed to
be equal to that of Pb-212. These assumptions are necessary because published risk factors
do not include long-lived progeny. Therefore, it is necessary to consider the activities of
parent isotope and long-lived progeny separately with regard to activity and risk.
10. Risk values are taken from "Health Effects Assessment Summary Tables (FY1992)" (EPA
1992) except as noted for the scenario involving irradiation by roadbed material.
6.3 Summary of Exposure Scenarios
This section discusses the rationale for selection of exposure pathways and routes of concern for
both the current and future exposure scenarios.
Table 6-2 and 6-3 represent the carcinogenic and non-carcinogenic risk posed by chemical
contaminants of concern for significant pathways. Table 6-4 represent a comparison of the
maximum detection concentration of lead and the EPA Interim Soil cleanup level for residential
Page 26 of 61
-------
5 9 OC34
soil.
6.3.1 Summary of the Chemical Exposure Scenarios
Current/Future Maintenance Worker
On-Site maintenance workers were assumed to be exposed to Site-related contaminants in surface
soil or fugitive dust emissions during landscaping, mowing, or other outdoor activities. The routes
of exposure considered for the on-Site maintenance worker were incidental ingestion and dermal
contact with contaminants in surface soil and inhalation of fugitive dust. It was assumed that if the
Site remains commercial/industrial in the future, a maintenance worker would still have the
greatest potential for exposure to Site contaminants. Therefore, the future worker scenario is the
same as the current worker scenario.
The air pathway was qualitatively evaluated as an exposure pathway for paniculate emissions from
surface soil. With the exception of the slag processing area, the majority of the Site is either
vegetated or covered by impervious material. Inorganic chemicals present in surface soil in the
slag processing area may adsorb to soil particles which could then potentially be transported via
wind erosion. Although surface soil in the slag processing area are relatively homogeneous, the
surface is not elevated and the soil is compact.
The closest residential areas and Gulfside Elementary School are north of the Site. The grassy area
just east of the slag processing area represents the most critical (closest) area of concern for a
maintenance worker. Based on the location of these receptors (maintenance worker, pupils at
school, and nearby residents), winds from the south and west would provide the most critical wind
conditions. Also, in order for wind erosion to occur from limited reservoir surfaces, wind speeds
of approximately 22 miles per hour would be required. Since the average annual wind speed in the
Tarpon Springs area is only 10 to 15 miles per hour in the afternoon and 5 to 10 miles per hour at
night, and the prevailing winds in the Tarpon Springs area are from the north and east, it is
assumed that exposure via inhalation of fugitive dust does not present a significant exposure
pathway. Therefore, the air pathway was not quantitatively evaluated as an exposure pathway for
particulate emissions.
The maintenance worker was quantitatively evaluated for exposure to surface soil via incidental
ingestion and dermal contact.
Current Off-Site Resident
The Anclote River is classified as a Fish and Wildlife Class Ill-marine surface water body. Class
Ill-marine surface waters are defined as suitable for fishing and swimming. Stormwater runoff and
groundwater discharge flow directly into the Anclote River; therefore, it is assumed that nearby
residents may be exposed to Site-related contaminants during recreational and fishing activities.
Page 27 of 61
-------
5 9 0035
Direct contact with surface water and sediment was evaluated for an adult resident (age 7 to 30).
Potential exposure routes included incidental ingestion and dermal contact with surface water and
sediment. It was assumed that children under the age of seven would be under parental
supervision and any direct exposure to the river would be negligible. An additional pathway that
was evaluated for the off-Site resident (child and adult) included ingestion of contaminated fish
that are caught in the Anclote River.
Future Resident
Based on surrounding land use, it was assumed that residential development might occur on-Site in
the future. Potential pathways through surface soil exposure included in incidental ingestion and
dermal contact. Sediment and surface water exposure, were identical to that discussed in the
current use scenario. These pathways included incidental ingestion and dermal contact using the
adult (age 7-30 years) as the likely exposure receptor, and ingestion of locally caught fish (age 1-
30 years). Ground water was evaluated due to the hypothetical possibility of future contamination
of off-Site private drinking wells or the installation of a residential well on-Site. The potential
exposure pathways involved the ingestion of drinking water.
6.3.2 Summary of Radiological Exposure Scenarios
The scenarios considered for potential intakes to radioactive material are summarized in Table 6-5
and 6-6, along with the radiological data used for the risk assessment.
Table 6-5 presents the analytical results of Samples collected during the Remedial Investigation as
it relates to the assumptions used in the risk assessment and potential receptor scenarios.
Table 6-6 presents the estimated individual radiological pathway and cumulative radiological
pathways exposure risk scenarios. The potential receptors are listed in the first row. Exposure
scenarios are presented in the first column.
Page 28 of 61
-------
5 9 00
• f
J 0
Table 6-2
Contaminants of Concern that Pose a Carcinogenic Risk
Greater Than 10"* for Pathways That Exceed 1Q-*
Exposure
Medium/
Pathway
Surface Soil
Surface Water
Sediment
Current/Future
Maintenance
Worker
NONE
NE*
NE*
Current
Off-Site
Resident
NE*
NONE
NONE
Future
On-Site
Resident
Benzo(a)anthracene 2x10"*
Benzo(a)pyrene 2 x 10"5
Benzo(b)fluoranthene 5x10"*
Dibenzo(a,b)anthracene 4 x 10"*
Indeno(l,2.3-cd)pyrene 2 x 10*
Arsenic 3 x 10"4
Beryllium 6 x 10"*
NONE
NONE
Note that NE means that the pathway was not evaluated for this receptor.
Page 29 of 61
-------
Table 6-3
Contaminants of Concern with a Hazard Quotient Greater Than 0.1 for
Pathways with a Hazard Index Exceeding 1.0
Exposure
Medium/
Pathway
Surface Soil
Surface Water
Sediment
Current/Future
Maintenance Worker
Arsenic 4 x 10"'
Thallium 1 x 10'1
NE
NA
Current Off-Site
Resident Adult
NE
Arsenic 2 x 10*'
Mercury.... 4
NA
Future On-Site
Resident Adult
Arsenic 6x 10"1
Thallium....! x 10'1
Arsenic 2x 10"'
Mercury 4
NA
Future On-Site
Resident Child
Fluoride .6x10''
Antimony.. 6 x 10"'
Arsenic 6
Cadmium.. 7 x 10'1
Thallium...!
Arsenic 2x 10"1
Mercury 4
NA
Notes:
**
NE means that the pathway was not evaluated for this receptor.
NA means that all hazard indices were less than 1.0 for sediment.
Table 6-4
Comparison of Maximum Detected Concentrations of Lead to ARARs
Surface Soil
(mg/kg)
324
Residential Cleanup Levels
(mg/kg)
500
Page 30 of 61
-------
5
0038
Table 6-5 Scenarios Analyzed for the Radiological Risk Analysis
Scenario
Incidental Ingestion of Soil
Ingestion of Vegetation Grown on
Contaminated Soil
Direct Irradiation by Contaminated
Soil
Inhalation of Rn- Indoor
222 Exposure
Outdoor
Exposure
Incidental Ingestion of Sediment
Ingestion of Groundwater
Irradiation by Roadbed Material
Potential Receptor
1. Current/Future Worker
2. Future On-Site Adult Resident
3. Future On-Site Child Resident
1 . Future On-Site Adult Resident
2. Future On-Site Child Resident
1. Current/Future Worker
2. Future On-Site Adult Resident
3. Future On-Site Child Resident
1. Current/Future Worker
2. Future On-Site Adult Resident
3. Future On-Site Child Resident
1. Current Off-Site Adult Resident
2. Current Off-Site Child Resident
1. Current Off-Site Adult Resident
1. Future On-Site Adult Resident
2. Future On-Site Child Resident
I. Current/Future Worker
2. Future On-Site Adult Resident
3. Future On-Site Child Resident
Monitoring Data Used to
Assess Risk
Surface Soil
Ra-226: 73.8pCi/g
Pb-2IO: 73.8pCi/g
Ra-228: 29.3 pCi/g
U-238: 29.1pCi/g
U-235: 0.7 pCi/g
Ac-227: O.R pCi/g
Th-228: 0.2 pCi/p
Surface Soil
(as above)
Surface Soil
(as above)
Rn-222 Flux:
8l36pCi/nr/hr
Sediment
Ra-226: 2.4 pCi/g
Groundwater
Ra-226: 24.9pCi/l
Radiation Survey
Measurements of On-Site
Roadway
ISOuR/hr
Page 31 of 61
-------
5 9 0039
Table 6-6 Estimated Radiological Risk Considering Major Pathways
Exposure
Scenario
Current/
Future
Worker
Current
Off-Site Adult
Resident
Future
On-Site Adult
Resident
Future
On-Site Child
Resident
Current
Off-Site Child
Resident
Incidental
Injzestionof Soil
Ingcstion of
Vegetation Grown
on Contaminated
Soil
Irradiation by
Contaminated
Soil
Inhalation of
Rn-222 (Indoor
Exposure)
Inhalation of
Rn-222 (Outdoor
Exposure)
Incidental
Ingestion of
Sediment
Ingestion of
Groundwater
Irradiation by
Roadbed Material
NOTE: Shaded boxes indicate that the given exposure scenario is not applicable for the indicated
receotor.
Page 32 of 61
-------
5 9 0044
6.4 Ecological Risks
The objective of ecological risk assessment was to use available toxicological and ecological
information to estimate the probability that some undesired ecological event will occur. The
baseline ecological risk assessment (BERA) evaluated the actual and potential risks to the
environment due to releases of contaminants at the Site. The general objective of a BERA is to
provide the information necessary to assist in the decision-making process at remedial Sites.
Media of concern for ecological receptors generally include surface water, sediments, surficial soil,
and air. These are media that may have direct or indirect effects on the community and population
composition of an ecological habitat or on individual species that are pan of those communities or
populations.
Ecological chemicals of concern may often include more individual chemicals than the human
health assessment because the screening criteria for human health do not apply to ecological
receptors. As a result, different screening criteria are used to limit the chemicals evaluated in the
ecological assessment. The preliminary list of ecological chemicals of concern initially included all
chemicals detected during previous environmental sampling events. No protected species were
found at the Site This list was then evaluated as follows:
1) Chemicals were eliminated if they were not detected in RI/FS environmental samples.
2) Inorganic chemicals were eliminated if the detected concentrations did not exceed the
sample quantitation limit or the background concentration (provided that the sample
quantitation limit or the background concentration do not themselves exceed screening
levels).
3) Organic chemicals were eliminated if the detected concentrations did not exceed the sample
quantitation limit (provided that the sample quantitation limit itself does not exceed
screening levels).
4) All chemicals were eliminated if they were only tentatively identified.
5) All chemicals with a low frequency of detection (less than 5 % for each medium) were
eliminated from consideration.
6) All chemicals in ground water for which the range of detection did not exceed the Region 4
Screening Values were eliminated from consideration.
7) Chemical concentrations in sediments that did not exceed the screening values established
by Region 4 for hazardous waste Sites were eliminated.
Page 33 of 61
-------
5 9 OG43
The following is a list of contaminants which include all those exposure point concentrations which
exceed screening concentrations.
Table 6-7 Ecological Summary of the Contaminants of Concern
Contaminants of Concern for Ecological Risk
Aluminum
Arsenic
Cadmium
Copper
Iron
Mercury
Nickel
Phosphorus
Silver
Thallium
^^== — =====^IL
Acenaphthalene
Anthracene
Benzo(a)pyrene
Bis(2-ethylhexyl)phthalate
Chrysene
Dibenz(a,h)antnracene
Fluorene
Fluoranthene
Phenanthrene
Pyrene
Zinc
The overall risk to the extended community on or immediately adjacent to the Stauffer Chemical
Site is considered low to moderate. Causes for concern are that several contaminants currently
exceed screening values in both sediment and surface water. In addition several contaminants were
detected in shallow groundwater samples at relatively high concentrations and would be expected
to contribute to the overall contaminant load in the adjacent wetland and deepwater habitats.
Moderating the overall risk to the extended community is the dilution effect of the Anclote River
and the tendency of the wetlands adjacent to the Site to partition some contaminants to deeper
sediments, restricting their effect to a limited area. Based on information currently available to the
EPA contractor, the BERA was developed primarily based on chemical contaminants since
minimal information was found on the ecological impact of radiological contamination. All
available information concerning the ecological impact of chemical and radiological contamination
was considered in the decision making process. Further ecological or eco-toxicological
investigation is not warranted at the Site.
Page 34 of 61
-------
5 9 0042
.6.5 Cleanup Levels
Cleanup levels for the Site were established to ensure that any person exposed in the future will not
be exposed to unsafe levels of Site-related chemicals. Cleanup levels are either the Federal
Maximum Contaminant Limits (MCLs), other Applicable or Relevant and Appropriate
Requirements (ARARs), or risk-based concentrations. At the Site, EPA requires that soil be
remediated up to a 10* residential risk level for cancer causing contaminants and a Hazard Index
(HI) of 1 for non-carcinogenic chemicals. For the radiological contamination, a ARAR is used as
the cleanup standard. These levels are consistent with the National Contingency Plan (NCP) and
EPA requirements for cleanup levels of carcinogenic chemicals with in the 10 a to 10 "* risk range
and are protective of human health and the environment in a residential setting. This risk range of
10~* to 10** means that exposure to Site-specific contaminants as defined as in the risk assessment
would result in an estimated increase in an individual's chance of developing cancer ranging from
one in ten thousand to one in a million. For non-cancer causing risks, EPA compares the highest
dose known to be safe (not cause harmful effects) to the estimated dose from exposure to levels
found on-Site. These comparisons were used to develop cleanup levels for Contaminants of
Concern for the soil/waste at the Site. Elemental phosphorus is a CERCLA listed Hazardous
Substance.
Arsenic, a Contaminant of Concern at this Site, is a naturally occurring mineral that is considered
by EPA to be a systemic toxicant and a human carcinogen. However, there is considerable
uncertainty concerning its ability to cause cancer at low exposure levels, especially the less soluble
form that occurs in contaminated soil. The Superfund program of EPA Region 4 regulates arsenic
in soil as a systemic toxicant in deriving protective cleanup levels. As an additional precaution,
EPA also requires soil cleanup levels to fall within the protective cancer risk range of 10"4 to 10"6
for the most sensitive likely receptor even though the calculated risk may be significantly over
predictive. The co-location of arsenic with other contaminants that are to be addressed in soil
remediation will likely result in soil arsenic residuals at the more protective end of the calculated
risk range.
Page 35 of 61
-------
5 9
OC
Table 6-8
Cleanup Standards: Remedial Goals
Soil/Waste Contaminant
Arsenic
Antimony
Beryllium
Elemental Phosphorus
Thallium
Radium-226 (Lead-210)*
Total CPAHs**
Maximum Concentration
Detected (mg/kg)
127
32.3
1.6
0.854
13.4
73.8 pCi/g
—
Remedial Cleanup Goals
(mg/kg)
#
28.1
0.192
1.4.
1.4
5pCi/g
0.089
* Note that this cleanup level is measured above the background (normal) concentration.
The background (normal) concentration will be established during the Remedial
Design.
** Total CPAHs include Benzo(a)anthracene, Benzo(a)pyrene, Benzo(b)fluoranthene,
Dibenzo(a,h)anthracene, and Indeno(l,2,3-cd)pyrene.
# EPA Region 4 regulates arsenic in soil as a systemic toxicant with a reference dose
of 0.0003 mg/kg/day. The safe soil level for residential use that would not exceed
this RfD for a child was determined in the Site's risk assessment to be 21.1 mg/kg.
EPA also considers arsenic to be a carcinogen in the form that may occur in
drinking water and has included an oral slope factor in its IRIS database. The
application of the slope factor here, though not considered appropriate, would yield
a calculated safe soil level for a child at the most protective 10"* risk level of 0.46
mg/kg. The latter soil cleanup level for arsenic is likely to be achieved since soil
containing arsenic above this level also contains other contaminants that will require
remediation.
Page 36 of 61
-------
5 9 OU4Q
All Cleanup Standards have been derived from the Final Baseline Risk Assessment with the
exception of Radium-226 which has been establish in accordance with the relevant and appropriate
requirement (Federal Standards for the Cleanup of Land and Buildings Contaminated with
Residual Radioactive Material 40 CFR 192).
7.0 DESCRIPTION OF REMEDIAL ACTION ALTERNATIVES
Remedial action alternatives were formulated to address the environmental contamination at the
Site. Seven remedial action alternatives were considered for the Site through the Final Feasibility
Study Report. The alternatives in this ROD address the source of contamination at the Site
(Operable Unit 1). Alternative 6 will not be evaluated in this document since groundwater will be
addressed in a separate operable unite. The seven considered remedial action alternatives include:
• Alternative 1: No Action with Continued Monitoring
• Alternative 2: Institutional Controls
• Alternatives 3a and 3b: Consolidation and Cover (Commercial and Residential)
• Alternatives 4a and 4b: Consolidation and Capping (Commercial and Residential)
• Alternatives 5a and 5b: Consolidation, Capping, and Saturated Zone Source Control
(Commercial and Residential)
• Alternatives 7a and 7b: Consolidation, Stabilization, and Cover (Commercial and
Residential).
Page 37 of 61
-------
5 9 0045
Table 7-1
Response Actions and Associated Remedial Technologies Screening
l|| i i i • i ii ii — •a^— S
III General Response Action
Elemental Phosohorus-
Containine Material
No Action .,
Institutional Controls
II Treatment
II Site Soil
II No Action
Institutional Controls
Excavation/Consolidation
Containment
1 Treatment
Associated Remedial Technologies
Considered after the Screening Process
None
Access restrictions
Land use restrictions
Groundvvater monitoring
Conversion to phosphoric acid
Incineration
Aqueous oxidation
Low temperature air oxidation
Stabilization/Solidification
None
Access restrictions
Land use restrictions
Groundwater monitoring
Groundwater use restrictions
Excavation and Consolidation of
affected soil
Capping/Cover
Liner
Stabilization/Solidification
Volume rediirfiniL
A summary of how the alternatives address affected media and the associated technologies utilized
are presented in Table 7-2.
Alternative 1; No Action
The No Action Alternative is carried through detailed evaluation as a point of reference to the
other alternatives. For this PS, it is assumed that groundwater monitoring would be continued,
even if no further remedial action were initiated.
Alternative 2: Institutional Controls
Institutional controls provide some degree of control of future land use. As was the case under the
Page 38 of 61
-------
5 9 0046
no action alternative, groundwater and surface water monitoring would be provided and in
addition, the property fence would be maintained. In addition, deed restrictions would be placed
on the property, which would not allow it to be developed for residential use, nor for any
commercial activities requiring that personnel be assigned to the Site. Furthermore, the deed
restrictions would preclude the installation of any groundwater wells in the surficial aquifer beneath
the Site.
Alternative 3a; Consolidation and Cover (Commercial Use)
Alternative 3a, Consolidation and Cover, consists of the evacuation, consolidation, and cover of
radiological and chemical waste material on-Site. All waste material, above commercial use action
levels, would be consolidated in several different areas. By utilizing several areas the movement of
contaminated material will be minimized. In addition to radiologically and chemically identified
contaminated material, waste present in Ponds 39 and 42 along with other contaminated soil and
waste would be excavated and placed in the consolidation areas. The consolidation areas would
then be covered with a layer of soil, sufficient to reduce radiological exposure and support a
vegetative cover to prevent wind or soil erosion of this material. Any existing locations of soil
contamination, over which this soil cover would be placed, would not require excavation because
the soil would be covered in place.
Radiologically contaminated material would be consolidated and covered in several locations if
they exceed 5 pCi/g above background for surface soil. The areas above the surficial limit includes
much of the developed Plant area. Areas where the 5 pCi/g above background criterion is
exceeded are comprised of the slag processing area, roads, railroads, and parking lots.
As with the Institutional Controls Alternative, groundwater and surface water monitoring would be
continued, and the fences which currently surround the entire property would be maintained.
Notification of Site conditions would be included in the property deed to alert prospective buyers
of Site conditions and deed restrictions would be implemented. These restrictions would prohibit
future development of the covered pond areas, and would restrict the remainder of the Site to
commercial use. A final restriction would be that no surficial groundwater wells, for any purpose,
could be installed on any portion of the property.
Alternative 3b; Consolidation and Cover (Residential Use)
This alternative includes the same remediation activities and institutional controls noted for
Alternative 3a, except that remediation action levels and deed restrictions would be based on
future residential use of the Site. Compared to Alternative 3 a, this alternative would require
additional remediation of radiologically and chemically contaminated soil due to lower cleanup
goals for residential use. Based on residential cleanup goals, radiologically contaminated material
would be remediated if they exceed 5 pCi/g above background for soil, regardless of depths. The
areas requiring remediation under the residential land use scenario encompass those for the
commercial use scenario plus all soil that has radiation levels between 5 and 15 pCi/g at depths
greater than 15 cm. In addition to the areas described for commercial use, an additional area in the
Page 39 of 61
-------
5 9 0047
west central portion of the Main Plant Area would require remediation at depth to meet the 5
pCi/g above background standard.
In addition to excavating and consolidating radiological contaminated material/soil and Ponds 39
and 42, soil exceeding a chemical carcinogenic risk level of 1 x 10"06 or a hazard index of 1.0
would also be excavated and placed in one of the consolidation areas. As noted in Alternative 3a,
locations over which cover would be placed would not be excavated.
Alternnfive 4a; Consolidation and Capping (Commercial Use)
This alternative includes the same activities and institutional controls noted for Alternative 3a:
excavation and consolidation of radiologically and chemically contaminated material/soil in several
consolidation areas exceeding commercial use levels. However, under this alternative, the
consolidated material in the main pond areas would be capped, rather than covered, to further
decrease the potential migration of contaminants from the consolidated material into the surficial
aquifer. A synthetic membrane and drainage system would be included as part of the cap.
In addition to reducing contaminant migration into the surficial aquifer, based on the Soil Cover
Depth Study (WESTON, 1994a) findings, the cap would reduce gamma radiation exposure to
someone working on the cap. Under the Consolidation and Capping Alternative, institutional
controls would prevent the development of the capped area; therefore, reducing the gamma
radiation exposure. Also, the synthetic membrane of the cap would reduce the escape of radon gas
from the consolidation area.
As with the Institutional Controls Alternative, groundwater and surface water monitoring would be
continued, and the fences which currently surround the entire property would be maintained.
Notification of Site conditions would be included in the property deed to alert prospective buyers
of Site conditions and deed restrictions would be implemented. These restrictions would prohibit
future development of the covered pond areas, and would restrict the remainder of the Site to
commercial use. A final restriction would be that no surficial groundwater wells, for any purpose,
could be installed on any portion of the property.
Alternative 4b: Consolidation and Capping (Residential Use)
This alternative includes the same activities and institutional controls noted for Alternative 3b:
excavation and consolidation of radiologically and chemically contaminated material/soil found on
Site exceeding residential use levels. However, under this alternative, the consolidated material at
locations on-Site would be capped, rather than covered, to further decrease the potential migration
of contaminants from the consolidated material into the surficial aquifer. The cap would be
constructed in the same way as mentioned in Alternative 4a. Based on residential cleanup goals,
radiologically contaminated material would be remediated if they exceed 5 pCi/g above
background for soil, regardless of depths. The areas requiring remediation under the residential
Page 40 of 61
-------
5 9 OG48
land use scenario encompass those for the commercial use scenario plus all soil that has radiation
levels between 5 and 15 pCi/g at depths greater than 15 cm. In addition to the areas described for
commercial use, an additional area in the west central portion of the Main Plant Area would
require remediation at depth to meet the 5 pCi/g above background standard.
Alternative 5a: Consolidation, Capping, and Saturated Zone Source Control (Commercial
Use)
This alternative includes the same activities and institutional controls noted for Alternative 4a
(excavation, consolidation, and capping), plus a provision to further reduce contaminant migration
to the surflcial aquifer by in situ solidification, and subsequent immobilization, of contaminants
within pond material that are below the water table. In situ solidification would be performed by
injecting and mixing admixtures/binding agents into the saturated pond material to form a solid,
low permeability matrix. Contaminants would be bound in the matrix, unable to migrate into the
surficial aquifer..
As with the Institutional Controls Alternative, groundwater and surface water monitoring would be
continued, and the fences which currently surround the entire property would be maintained.
Notification of Site conditions would be included in the property deed to alert prospective buyers
of Site conditions and deed restrictions would be implemented. These restrictions would prohibit
future development of the covered pond areas, and would restrict the remainder of the Site to
commercial use. A final restriction would be that no surficial groundwater wells, for any purpose.
could be installed on any portion of the property.
Alternntive 5b: Consolidation. Capping, and Saturated Zone Source Control CResidentinl
Use)
This alternative includes the same activities and institutional controls noted for Alternative 4b
(excavation, consolidation, and capping), plus the provision identified in Alternative 5a for in situ
solidification, and subsequent immobilization, of pond material below the water table.
Based on residential cleanup goals, radiologically contaminated material would be remediated if
they exceed 5 pCi/g above background for soil, regardless of depths. The areas requiring
remediation under the residential land use scenario encompass those for the commercial use
scenario plus all soil that has radiation levels between 5 and 15 pCi/g at depths greater than 15 cm.
In addition to the areas described for commercial use, an additional area in the west central portion
of the Main Plant Area would require remediation at depth to meet the 5 pCi/g above background
standard.
Alternative 7a; Consolidation. Stabilization, and Cover (Commercial Use)
This activity is similar to Alternative 5a, where material below the water table was stabilized.
Under Alternative 7a, all material in one of several consolidation areas would be treated by
stabilization. This would include all soil, pond material, and slag material. In-situ stabilization
Page 41 of 61
-------
5 9 0049
would generally be used for material presently located within the pond area; ex-situ stabilization
would be performed on excavated material. A combination of material stabilization and placement
of a soil cover will reduce contaminant migration and shield low-level radiation.
As with the Institutional Controls Alternative, groundwater and surface water monitoring would be
continued, and the fences which currently surround the entire property would be maintained.
Notification of Site conditions would be included in the property deed to alert prospective buyers
of Site conditions and deed restrictions would be implemented. These restrictions would prohibit
future development of the covered pond areas, and would restrict the remainder of the Site to
commercial use. A final restriction would be that no surficial groundwater wells, for any purpose,
could be installed on any portion of the property.
Alternative 7b: Consolidation. Stabilization, and Cover (Residential Use)
This alternative would provide the same treatment and capping identified for Alternative 7a.
However, the extent of soil excavated/stabilized would be expanded to meet residential use
criteria.
Based on residential cleanup goals, radiologically contaminated material would be remediated if
they exceed 5 pCi/g above background for soil, regardless of depths. The areas requiring
remediation under the residential land use scenario encompass those for the commercial use
scenario plus all soil that has radiation levels between 5 and 15 pCi/g at depths greater than 15 cm.
In addition to the areas described for commercial use, an additional area in the west central portion
of the Main Plant Area would require remediation at depth to meet the 5 pCi/g above background
standard.
8.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
8.1 Comparative Analysis - Nine Criteria
This section of the ROD provides the basis for determining which alternative provides the best
balance with respect to the statutory balancing criteria in Section 121 of CERCLA, 42 USC 9621,
and in the NCP, 40 CFR 300.430. The major objective of the feasibility study (FS) was to
develop, screen, and evaluate alternatives for the remediation of the Site. A wide variety of
alternatives were identified as candidates to remediate the contamination at the Site. These were
screened based on the contaminants present and Site characteristics. After the initial screening,
the remaining alternatives/technologies were combined into potential remediation alternatives and
evaluated in detail. The selected remedial alternative emerged from the screening process using
the following nine evaluation criteria:
• Overall Protection of Human Health and the Environment
• Compliance with ARARs
• Short-Term Effectiveness
Page 42 of 61
-------
5 9 UubO
Long-Term Effectiveness and Permanence
Reduction ofToxicity, Mobility, and Volume of Contaminants
Implement ability
Cost
State Acceptance
Community Acceptance
The NCP Categorizes the nine criteria into three groups:
(1) Threshold Criteria - overall protection of human health and the environment and
compliance with ARARs (or invoking a waiver ) are threshold criteria that must be
satisfied in order for an alternative to be eligible for selection;
(2) Primary Balancing Criteria. - long-term effectiveness and permanence; reduction
of toxicity, mobility, or volume; short-term effectiveness; implementability; and
cost are the primary balancing factors used to weigh major trade-offs among
alternative hazardous waste management strategies; and
(3) Modifying Criteria - state and community acceptance are the modifying criteria
that are formally taken into account after public comments are received on the
proposed plan and incorporated into the ROD.
The following analysis is a summary of the evaluation of alternatives for remediating the Site under
each criteria. A comparison is made between each of the alternatives for achievement of a specific
criterion.
8.2 Threshold Criteria
8.2.1 Overall Protection of Human Health and the Environment
With the exception of the No Action Alternative (Alternative 1) and the Institutional Controls
Alternative (Alternative 2), all of the alternatives would provide protection for human health and
the environment to some degree. Alternatives 3, 4, 5, and 7 would limit access and exposure. By
simply consolidating and capping or covering the contamination, the contamination would still be
available to be transported off-Site through the groundwater. Therefore, only alternatives 5 and 7
provide scenarios in which the source of contamination has been controlled. Alternatives 5 and 7
would limit the migration of contaminants and contain the contaminants within the Site boundaries.
8.2.2 Compliance with ARARs
The remedial action for the Site, under Section 121(d) of CERCLA, must comply with federal and
state environmental laws that either are Applicable or Relevant and Appropriate Requirements
Page 43 of 61
-------
5 9 0051
(ARARs). Applicable requirements are those standards, criteria, or limitations promulgated under
federal or state law that specifically address a hazardous substance, pollutant, contaminant,
remedial action, location or other circumstance at a CERCLA Site. Relevant and Appropriate
Requirements are those that, while not applicable, still address problems or situations sufficiently
similar to those encounter at the She and that their use is well suited to the particular Site. To-Be-
Considered Criteria (TBCs) are non-promulgated advisories and guidance that are not legally
binding, but should be considered in determining the necessary level of cleanup for protection of
human health or the environment. While the TBCs do not have the status of ARARs, EPA's
approach is to determine if a remedial action is protective to human health and the environment
involves consideration of TBCs along with ARARs.
Location-specific ARARs are restrictions placed on the concentration of hazardous substances or
the conduct of activities solely on the basis of location . Examples of location-specific ARARs
include state and federal requirements to protect floodplains, critical habitats, and wetlands, and
solid and hazardous waste facility siting criteria. Table 8-1 summaries the potential location
specific ARARs and TBCs for the Site.
Action-specific ARARs are technology- or activity-based requirements or limitations on actions
taken with respect to hazardous wastes. These requirements are triggered by particular remedial
activities that are selected to accomplish a remedy. Since there are usually several alternative
actions for any remedial Site, various requirements can be ARARs . Table 8-2 lists potential
action-specific ARARs and TBCs for the Site.
*
Chemical-specific ARARs are specific numerical quantity restrictions on individually listed
contaminants in specific media. Examples of chemically-specific ARARs include the MCLs
specified under the Safe Drinking Water Act as well as the ambient water quality criteria that are
enumerated under the Clean Water Act. Since there are usually numerous contaminants of
potential concern for any remedial Site, various numerical quantity requirements can be ARARs.
Table 8-3 lists potential chemical-specific ARARs.
Alternatives 4, 5, and 7 met or exceed all ARARs (action-, location-, and chemical-specific).
Alternative 4 currently meets surface water ARARs, but this alternative may not provide a
permanent solution for the surface water. Alternatives 1, 2, 3, and 4 would leave the
contamination in a state where it is still available to move off-Site through the surficial aquifer.
Page 44 of 61
-------
5 9 0052
Table 8-1
Location-Specific ARARs
Applicable (A) or
Relevant &
Appropriate
(R&A)
Citation
Comments
R&A
RCRA
Disposal Subtitle D
40 CFR 258.40
Outlines top cover design criteria.
R&A
Land Disposal
Restrictions
40 CFR Part 268
Identifies hazardous wastes that are restricted
from land disposal and describes those
circumstances under which an otherwise
prohibited may be land disposed.
R&A
Endangered Species-Act
42 USC 6901, 6905,
6912, & 6925
Only applies if threatened or endangered
species or critical habitats of the endangered
species are identified near the Site.
R&A
Coastal Zone
Management Act
16USCSec.l951etseq.
It is national policy to preserve, protect, and.
when possible, restore costal land.
R&A
FDEP Solid and
Hazardous Waste
FAC 62-296.705
Regulations include closure and operations&
maintenance requirements.
R&A
FAC 62-701.050
Regulations cover the criteria for the top
cover design.
R&A
Rivers and Harbors Act
of!899(SectionlO
Permit) 33 USC Sec 403
Requires that the substantive requirements of
permits for work in affected navigable waters
be met.
R&A
Floodplain Management
Executive Order 11988,
40 CFR 6.302
Activities that occur in the floodplain should
avoid adverse effect, minimize potential harm,
and preserve natural and beneficial values.
Page 45 of 61
-------
5 9 0053
Table 8-2
Action-Specific ARARs
Applicable (A) or
Relevant &
Appropriate
(R&A)
Citation
Comments
Identification and Listing
of Hazardous Waste
40CFRPart261
Identifies those solid wastes which are subject
to regulation as hazardous waste. Defines
"hazardous waste" and "solid waste"
R&A
Generators of Hazardous
Waste
40 CFR Part 262
Establishes Standards for generators of
hazardous waste.
R&A
Transporters of
Hazardous Waste
Establishes the responsibility of generators
and transporters of hazardous waste.
Owners and Operators of
Hazardous Waste
Treatment, Storage, and
Disposal (TSD) Facilities
40 CFR 264
Establishes minimum national standards for
which define the acceptable management of
hazardous waste for owners and operators of
facilities which treat, store, or dispose of
hazardous waste.
Page 46 of 61
-------
5 9 0054
Table 8-3
Chemical-Specific ARARs
Applicable (A) or
Relevant and
Appropriate
(R&A)
Citation
R&A
To Be
Considered*
Federal Standards for the
Cleanup of Land and
Buildings Contaminated
with Residua]
Radioactive Material
40CFR192
National Oceanic and
Atmospheric
Administration (NOAA)
(Effects Range Low,
Effects Range Medium,
& Effects Range High)
Comments
Establishes soil and waste standards for
radioactive constituents at the Site.
Guidance that evaluates sediment values.
Note that additional To Be Considered requirements are found in Section 9.2 Performance
Standards.
Page 47 of 61
-------
5 9 Du55
8.3 Primary Balancing Criteria
8.3.1 Long-Term Effectiveness and Permanence
Alternatives 5 and 7 are effective and permanent, but both would require a period of time to reach
a clean and safe condition. Alternative 4, as stated above, is not a permanent source control
alternative. Under Alternative 4, the contamination remains uncontrolled and may allow a future
release to the surface water.
8.3.2 Reduction in Toxicitv. Mobility, or Volume Through Treatment
Alternative 4 would have a limited impact on the mobility of contaminants by slowing the
horizontal migration of contamination. However, the toxicity and volume would not be reduced.
Alternative 7 would be the most effective in immobilizing and shielding all the contaminants. Also,
Alternative 7 contains the toxic material by binding these contaminants into a relatively
impermeable matrix. This alternative does have one drawback - it would provide a dramatic
increase in volume.
Alternative 5 provides the best balance of the feasible alternatives. By utilizing a top cover and
solidification. Alternative 5 effectively contains the Site-related contamination. Toxic material is
rendered immobile, and the volume increase would be limited and small compared to Alternative
7's increase.
8.3.3 Short-Term Effectiveness
Alternative 1 is the only alternative that is completely ineffective in the Short-Term. Alternative 2
which restricts access and places institutional controls on the Site would be effective in the Short-
Term. Alternatives 3, 4, 5 and 7 would represent minor short-term risks related to excavation and
construction activities.
8.3.4 Implementabilitv
The implementability of an alternative is based on technical feasibility, administrative feasibility and
the availability of services and material. Alternative 2 involves only access restrictions and deed
restrictions, which are easily implemented, given a cooperative property owner. Alternative 3 and
4 are relatively easy to implement since most of the contaminated soil located in the top
cover/consolidation area. Alternative 5 and 7 would require pilot studies and would require more
additional work to complete their solidification components.
Page 48 of 61
-------
5 9 0056
8.3.5 Cost
A summary of the present worth costs which include capital as well as operations and maintenance
costs for each alternative is presented in Table 8-5.These cost were presented in the FS. The
present worth costs to attain the recommended performance standards (Section 9.2) and to meet
the requirements of the compliance testing (Section 9.3) must remain within the range which is
considered accurate (+50% or -30% of the present worth cost).
Alternative 2 is the least costly alternative, other than the No Action alternative. Of the treatment
alternatives. Alternative 5 is less expensive than Alternative 7 and affords the same level of
protection. The residential scenarios are only slight more expensive than the commercial use
scenarios, but the residential scenarios are found to be the more protective than the commercial
scenarios.
8.4 ModifVine Criteria
8.4.1 State Acceptance
The State of Florida, as represented by the Florida Department of Environmental Protection
(FDEP), has been the support agency during the Remedial Investigation/Feasibility Study (RI/FS)
process for the Site. In accordance with 40 CFR 300.430, FDEP as the support agency, has
provided input during the process by reviewing and providing comments to EPA on all major
documents in the Administrative Record. Based upon comments received from FDEP, it is
expected that written concurrence will be forthcoming; however, letter formally recommending
concurrence with EPA's selected remedy has not been received.
8.4.2 Community Acceptance
Based on written comments received during the extended comment period, it appear that the
public would prefer off-Site disposal; even though, it may be more expensive, more difficult to
implement, and riskier (may exposure them to the contamination). Atkemix Thirty-seven
Incorporated (the PRP) commented that they preferred the commercial use as opposed to the
residential use scenario. Zeneca does recommend Alternative 5. Specific response issues raised by
the community and other interested parties are summarized in Appendix A, the Responsiveness
Summary.
Page 49 of 61
-------
Table 8-4
Summary of Remedial Action Alternatives
for the Tarpon Springs Site
Alternative
Effectiveness
Implementability
1. No Action with Continued Monitoring
Under this alternative no remedial action will be
conducted at the Site.
Long-term semi-annual groundwater and surface
water monitoring will be conducted.
Inspection and maintenance of facility fence to
restrict access to Site will be conducted.
Compliance with ARARs will not be met.
Implementation of this alternative will cause
no additional environmental impact.
This alternative will not provide an effective
long-term solution for the Site.
Exposure to Site constituents will be limited
by access restrictions.
Toxicity, mobility, and volume of
contaminants are not changed in this
alternative.
• Can be readily implemented.
• No construction activities
required.
2. Institutional Controls
Incorporation of features from the No Action with
Continued Monitoring alternative with the addition
of a caretaker.
Internal fences at the slag processing area and the
main pond area.
Placement of deed restrictions prohibiting.
- installation of groundwater supply wells.
- excavation in designated areas where elemental
phosphorus is known to exist.
- development of any portion of the properly for
residential use.
- development of any portion of the property for
commercial/industrial use unless approved by
EPA.
Compliance with ARARs will not be met.
Implementation of this alternative will cause
no additional environmental impact.
This alternative will substantially reduce the
risk to human health in the long-term by:
- insuring that the surficial aquifer will not be
used in the future.
- not allowing the Site to be used for
residential use.
- greatly restricting commercial or industrial
tuture use.
Toxicity, mobility, and volume of
contaminants are not changed in this
alternative.
Page 50 of 61
• Can be readily implemented.
• No substantive construction
activities required.
cn
O
o
01
-------
Alternative
Effectiveness
Implementability
3a and b. Consolidation and Cover
Excavation and consolidation of on-Site
contaminated soil. A soil cover will be placed over
the consolidated material and the area will be
fenced to restrict access. The consolidation area
will include the entire main pond area, plus
additional ground to the north.
Includes Excavation of Pond 39 and 42.
Deed restrictions:
- prohibiting installation of groundwater supply
wells.
- restricting the property to commercial/industrial
use only rAlternattve 3a only; 3b allow
residential use),
• prohibiting excavation or development of the
consolidation area.
Long-term semi-annual groundwater and surface
water monitoring maintenance of facility fence, and
grounds keeping.
Compliance with radiological ARARs. For
Alternative 3a (Commercial Use), this ARAR
js expressed as a concentration that will result
in a dosage equivalent to Alternative 3b
(Residential use). The capping, groundwater
Quality criteria, and surface water quality
ARARs would not be met.
This alternative will substantially reduce the
risk to human health in the long-term by:
- isolating waste material from human and
ecological contact.
• insuring that the surftcial aquifer will not be
used in the future.
.- restricting the property td commercial use
(Alternative 3a only).
A reduction in the mobility of the
contaminants is achieved by excavating the
slag processing area and Ponds 39 and 42, and
by covering the consolidation area.
Toxicity and volume of contaminants are not
changed in this alternative.
• Can be readily implemented.
• Excavation and cover
construction are
conventional operations.
• Shoring and slope
stabilization may be required
if groundwater is
encountered during
excavation activities.
• In the short-term,
implementation of this
alternative can be achieved
without adverse effects on
the environment. However,
actions will be taken to limit
potential risks involved in
excavation, transport,
placement and covering of
soil/material.
cn
vo
CD
CD
Page 51 of 61
CO
-------
Alternative
Effectiveness
Implementability
4a and b. Consolidation and Capping
Incorporation of institutional controls and waste
isolation features from the Consolidation and
Cover alternative. However, this alternative
provides a cap, rather than a cover soil, over the
consolidation area.
The cap will comply with the FDEP regulations for
capping solid waste management units.
Compliance with radiological and capping
ARARs. Groundwater quality in the surticial
aquifer would improve, but the groundwater
and surface water quality criteria ARARs
would not necessarily be met.
This alternative will substantially reduce the
risk to human health in the long-term by:
- isolating waste material from human and
ecological contact.
- insuring that the surficial aquifer will not be
used in the future.
- restricting the property to commercial use
(Alternative 4a only).
A reduction in the mobility of the
contaminants is achieved oy excavating the
slag processing area and Ponds 39 and 42,
and by capping the consolidation area.
Toxicity and volume of contaminants are not
changed in this alternative.
Excavation and capping are
readily implementable
construction procedures.
Shoring and slope
stabilization may be required
if groundwater is
encountered during
excavation activities.
In the short-term,
implementation of this
alternative can be achieved
without adverse effects on
the environment. However,
actions will be taken to limit
potential risks involved in
excavation, transport,
placement, and covering of
soil/material.
cn
vo
Page 52 of 61
o
CD
cn
-------
Alternative
Effectiveness
Implement ability
Sa and b. Consolidation. Capping, and Saturated Zone Source Control
Incorporation of features from the Consolidation
and Capping alternative plus the additional
remediation of pond material below the water
table.
Before consolidation and capping, waste material
in the ponds below the water table will be
solidified in place.
Compliance with radiological and capping
ARARs. Groundwater and surface water
quality ARARs will also be met, although not
immediately.
This alternative will substantially reduce the
risk to human health and the environment in
the long-term by:
- isolating waste material from human and
ecological contact.
- preventing use of surficial aquifer until the
remedial action objectives are achieved.
- restricting the property to commercial use
(Alternative 5a only).
A reduction in the mobility of the
contaminants is achieved By excavating Ponds
39 and 42, and the slag processing area, and
capping the consolidation area. This, in
conjunction with remediating the pond
material below the water table, will prevent
further contamination of the surficial aquifer.
Toxicity and volume of contaminants are not
changed in this alternative.
The excavation/capping
portions of this alternative
can be readily implemented
for the same reasons as
outlined in the previous
alternative. In situ
solidification is a readily
available technology,
provided by several vendors,
although a pilot study will be
required before solidification
can begin.
• In the short-term,
implementation of this
alternative can be achieved
without adverse effects on
the environment. However,
actions will be taken to limit
potential risks involved in
excavation, transport,
placement, and covering of
soil/material.
cn
CD
Page 53 of 61
-------
Alternative
Effectiveness
Implementability
7a and b. Consolidation, Stabilization, and Cover
Incorporation of features from the Consolidation,
Capping and Saturated Zone Source Control
alternative (with the exception of cover instead of
capping) plus the additional
stabilization/solidification of all material in the
consolidation area.
Stabilization/solidification of all consolidation
material would include all soil, pond material, and
slag material. In situ stabilization would generally
be used for material presently tacated within the
consolidation area; ex-situ stabilization would be
performed on excavated material.
Compliance with radiological ARARs.
Groundwater and surface water quality
ARARs will also be met, although not
immediately.
This alternative will substantially reduce the
risk to human health and the environment in
the long-term by:
- isolating waste material from human and
ecological contact.
- preventing use of surficial aquifer until the
remedial action objectives are achieved.
- restricting the property to commercial use
(Alternative 7a only).
A reduction in the mobility of the
contaminants is achieved by excavating Ponds
39 and 42, and the slag processing area, and
by covering the consolidation area. This, in
conjunction with stabilizing/solidifying the
consolidation material, wilTprevent further
contamination of the surficial aquifer.
Toxicity and volume of contaminants are not
changed in this alternative.
The excavation/cover
portions of this alternative
can be readily implemented
for the same reasons as
outlined in the previous
alternatives. In situ and ex-
situ stabilization/
solidification is a readily
available technology,
provided by several vendors,
although a pilot study will be
required before stabilization/
solidification can begin.
In the short-term,
implementation of this
alternative can be achieved
without adverse effects on
the environment. However,
actions will be taken to limit
potential risks involved in
excavation, transport,
placement, and covering of
soil/material.
cn
Page 54 of 61
O
-------
5 9 0062
Table 8-5
Cost Comparison of Remedial Action Alternatives
1 -
2 -
3 -
4 -
5 -
Alternative
No Action with Continued Monitoring
Institutional Controls
Consolidation and Cover
3 a - Commercial Use
3b - Residential Use
Consolidation and Capping
4a - Commercial Use
4b - Residential Use
Consolidation, Capping, and Saturated Zone
Source Control
5a - Commercial Use
5b - Residential Use
Capital
Cost
($)
0
117,000
4,720,000
4,769,000
6,903,000
6,952,000
8,075,000
8,124,000
Annual O&M
Cost
($)
31,250
81,250
71,250
71,250
71,250
Present
Worth
Cost'
($)
540,000
1,522,000
5,952,000
6,001,000
8,135,000
8,184,000
9,307,000
9,356,000
7 - Consolidation, Stabilization, and Cover
7a - Commercial Use
7b - Residential Use
32,991,000 71,250 34,223.000
34,457,000 35,689,000
'Based on a 30 Year Operation with a net interest rate of 4%. Includes both capital and O&M costs.
Page 55 of 61
-------
5 9 006.3
9.0 SUMMARY OF SELECTED REMEDY
Based upon the comparison of alternatives in the feasibility study (FS) and upon consideration of
the requirements of CERCLA, the NCP, the detailed analysis of alternatives and public and state
comments, EPA has selected Alternative 5b (Consolidating, Capping, and Zone Source Control -
Residential Use Scenario)for the Site. The selected alternative for the Site is consistent with the
requirements of Section 121 of CERCLA and the NCP. Based on the information available at the
time, the selected alternative represents the best balance among the criteria used to evaluate
remedies. The selected alternative will reduced the mobility and contain the toxicity of the
contaminants at the Site. In addition the selected alternative is protective of human health and the
environment, will attain federal and state ARARs, is cost effective, and utilizes permanent
solutions to the maximum extent practicable. The estimated present worth cost of the selected
remedy is $9,356,000 and will take approximately 3 years to complete.
Actual or threatened release, if not addressed by the implementation of the response action
selected in this ROD, may present an imminent and substantial endangerment to public health,
welfare, or the environment.
9.1 Major Components of the Selected Alternative
The selected remedy includes Institutional Controls, Excavation/Consolidation, Capping, and
Saturation Zone Source Control. Institutional Controls in the form of deed restrictions must be
placed on the consolidation area to prevent any construction or other activity that would threaten
the integrity of the selected remedy. A buffer zone (as determined in the Remedial Design) must
be established around this consolidation area to limit access to this area. Since the contamination
will be removed from the other areas of the Site and consolidated, these other areas which comply
with the Performance Standards will not require institutional control; however, the property
owner may voluntarily place deed restrictions or land use restrictions on the Site property. Site
fences and security must be maintained at an adequate level to ensure the security of the Site and
its remedy. The surface water must be monitored to ensure the source control remedy continues
to be effective. All waste material and soil that exceeds any of the Performance Standards for
the Site (Table 9-2) must be excavated and consolidated in the several consolidation areas. One
of the possible consolidation areas includes the areas where the clarifier is found, the water tower
area, the power house area, and the area where Ponds 44 through 51 are located..
This is the first of two operable units planned for the Site. This action addresses the source of the
soil contamination by treating and containing the source material.
The major components of the selected remedy include: •
• Excavation of radiologically and chemically contaminated material/soil which exceed
Residential Cleanup Standards.
• Consolidation of the radiologically and chemically contaminated material/soil in the main
Page 56 of 61
-------
5 9 0064
pond area. A Top Cover Cap which meets Florida's FAC 62-701.050 must be placed
over the Consolidation Area.
• Institutional Controls must be placed on the Site. Institutional controls must include deed
restrictions, land use ordinances, physical barriers, and water supply well permitting
prohibitions. These restrictions will limit access to the Site and prohibit the disturbance of
the remedy.
• Source Control will require the Insitu Solidification/ Stabilization of pond material and
contaminated soil below the water table.
The total present worth cost for the selected remedy as presented in the feasibility study is
$9,356,000.
9.2 Performance Standards
The performance standards for source remediation are based on the protection of the ground
water and/or protection of human health (Table 9-1 - Performance Standards: Remedial
Goals). The entire Site is considered an Area of Concern and a Corrective Action Management
Unit under the Resource, Conservation, and Recovery Act (RCRA).
9.2.1 Performance Standards - Cap
The selected remedy must adhere to the FDEP Land Disposal Requirements which are presented
in FAC 62-70] .050. FDEP requires that unlined landfills specify a final cover consisting of a final
18-inch thick layer of soil that will sustain vegetation to control erosion and placed on top of a
barrier layer which has a permeability of 1 x 10"' or less.
9.2.2 Performance Standards - Solidification
The Solidification Stabilization must utilize an binding mixture that meets the following criteria: a
compressive strength of 100 psi, a permeability equal to 1 x 10"*, pass the Toxicity Characteristic
Leaching Procedure (TCLP) Test for Arsenic, and pass the SPLP Test for Arsenic. All design
specifications will be will be developed through the remedial design process as to achieve
performance standards.
9.2.3 Performance Standards - Design
The design and construction of the selected remedy must be conducted in accordance with all
ARARs, including the RCRA requirements set forth in 40 CFR. Part 264 (Subpart F), 40 CFR
Part 268, and 40 CFR Part 264. See table 8-1, 8-2, and 8-3 for a detailed description of the
Performance Standards which are listed as ARARs.
Page 57 of 61
-------
5 9 0065
Table 9-1
Performance Standards: Remedial Goals
Soil/Waste Contaminant
Arsenic
Antimony
Beryllium
Elemental Phosphorus
Thallium
Radium-226 (Lead-210)*
Total CPAHs **
Maximum Concentration
Detected (mg/kg)
127
32.3
1.6
0.854
13.4
73.8 pCi/g
-
Remedial Cleanup Goals
(mg/kg)
#
28.1
0.192
1.4
1.4
5pCi/g
0.089
* Note that this cleanup level is measured above the background (normal)
concentration. The background (normal) concentration will be established during
the Remedial Design.
** Total CPAHs include Benzo(a)anthracene, Benzo(a)pyrene, Benzo(b)fluoranthene,
Dibenzo(a,h)anthracene, and Indeno(l,2,3-cd)pyrene.
# EPA Region 4 regulates arsenic in soil as a systemic toxicant with a reference dose
of 0.0003 mg/kg/day. The safe soil level for residential use that would not exceed
this RfD for a child was determined in the Site's risk assessment to be 21.1 mg/kg.
EPA also considers arsenic to be a carcinogen in the form that may occur in
drinking water and has included an oral slope factor in its IRIS database. The
application of the slope factor here, though not considered appropriate, would
yield a calculated safe soil level for a child at the most protective 10"* risk level of
0.46 mg/kg. The latter soil cleanup level for arsenic is likely to be achieved since
soil containing arsenic above this level also contains other contaminants that will
require remediation.
The Remedial Goals have been derived from the Final Baseline Risk Assessment with the
exception of Radium-226 which has been establish in accordance with the relevant and
appropriate requirement (Federal Standards for the Cleanup of Land and Buildings Contaminated
with Residua] Radioactive Material 40 CFR 192).
Page 58 of 61
-------
5 9 0066
9.3 Compliance Testing
Surface water monitoring will be conducted at the Site. After the remedy has been completed the
Site will be evaluated and samples will be collected to verify that Site soil have been remediated.
Site soil outside of the consolidation area must meet the Performance Standards (Table 9-1). The
exact locations and sampling plan will be outlined in the Remedial Design/Remedial Action. If
monitoring indicates that the remedy is no longer effective or the Site contamination is being
released into the surface water additional remedial action measures may be required.
10.0 STATUTORY DETERMINATION
Under Section 121 of CERCLA, 42 USC 9621, EPA must select remedies that are protective of
human health and the environment, comply with applicable or relevant and appropriate
requirements (unless a statutory waiver is justified), are cost effective, and utilize permanent
solutions or permanent treatment technologies or resource recovery technologies to the maximum
extent practicable. In addition, CERCLA includes a preference for remedies that employ
treatment that permanently and significantly reduces the volume, toxicity or mobility of hazardous
waste as their principle element. The following sections discuss how the selected remedy meets
these statutory requirements.
10.1 Protection of Human Health and the Environment
The selected remedy provides protection of human health and the environment by eliminating
reducing, and controlling the risks through engineering controls and/or institutional controls and
soil treatment as delineated through the performance standards described in Section 9.0 -
SUMMARY OF THE SELECTED REMEDY. The residual risk due to individual
contaminants will be reduced to a probability of 1 x 10"* for carcinogens and a hazard Quotient of
1 for non-carcinogens. The residual carcinogenic risk at the Site, which is the sum of individual
carcinogenic risks, will be reduced to acceptable levels (i.e., cancer risks between 1 x 10"* and 1 x
lO^once performance standards are achieved. The implementation of this remedy will not pose
an unacceptable Short-Term risks or cross media impact.
10.2 Attainment of Applicable or Relevant and Appropriate Requirements f ARARs)
Remedial actions performed under Section 121 of CERCLA, 24 USC. 9621, must comply with
all applicable or relevant and appropriate requirements (ARARs). All alternatives considered
were evaluated on the basis of the degree to which they complied with these requirements. The
selected remedy was found to meet ARARs identified in Table 8-1 through 8-3. The following is
a short narrative explaining the attainment of relevant ARARs.
Page 59 of 61
-------
5 9 0067
Chemical-Specific ARARs
Performance Standards are consistent with the ARARs identified in Table 8-3.
Action-Specific ARARs
Performance Standards are consistent with the ARARs identified in Table 8-2.
Location-Specific ARARs
Performance Standards are consistent with the ARARs identified in Table 8-1.
The selected remedy is protective of species listed as endangered or threatened under the
Endangered Species Act. The requirements of the Interagency Section 7 Consultation Process
b50 CFR Part 402, will be met. The Department of Interior, Fish and Wildlife Services, will be
consulted during the Remedial Design to ensure that the endangered and threatened species are
not adversely impacted by the implementation of the remedy.
Waivers
Waivers are not anticipated at this Site at this time.
10.3 Cost Effectiveness
After evaluating all alternatives which satisfy the two threshold criteria, protection of human
health and the environment and attainment of ARARs, EPA has concluded that the selected
remedy, Alternative 5b affords the highest level of overall effectiveness proportional to its cost.
Section 300.430(1 )(ii)(D) of the NCP also requires EPA to evaluate three out of five balancing
criteria to determine the overall effectiveness: long-term effectiveness and permanence; reduction
of mobility, toxicity, or volume through treatment and short-term effectiveness. Overall
effectiveness is then compared to cost to ensure that the remedy is cost-effective. The selected
remedy provides for overall effectiveness proportional to its cost.
The selected remedy has a moderate present worth, capital, and operation and maintenance cost
compared to other remedies, and best satisfies the criteria for long-term effectiveness and
permanence and short-term effectiveness. This alternative will reduce toxicity, mobility, or
volume through treatment.
The estimated present worth costs for the soil/source selected remedy is $9,356,000.
10.4 Utilization of Permanent Solution to the Maximum extent Practicable
EPA has determined that the selected remedy represents the maximum extent to which permanent
solutions and treatment technologies can be utilized in a cost-effective manner for the final
remediation at the Site. Of those alternatives that are protective of human health and the
environment and comply with the ARARs, EPA has determined that Alternative 5b provides the
best balance of trade-offs in terms of long-term effectiveness and permanence, reduction of
toxicity, mobility, or volume achieved through treatment, short-term effectiveness,
implementability, and cost, while also considering the statutory preference for treatment.
Page 60 of 61
-------
OC68
10.5 Preference for Treatment as a Principal Element
The statutory preference for treatment is satisfied by the selected remedy.
11.0 DOCUMENTATION OF SIGNIFICANT CHANGES
Two significant differences have been added to the selected remedy, Alternative 5b, from the
preferred remedy described in the proposed plan. The addition of Asbestos to the list of Potential
Contaminants of Concern is the first significant difference from the proposed plan. This change
was necessitated by the detection of Asbestos on-Site. The second significant difference allows
for flexibility in the design and construction of consolidation areas. The ROD permits the creation
of one or more than one consolidation areas on-Site. The actual determination will be presented
and documented in the Final Remedial Design.
Page 61 of 61
-------
5 9 0069
Responsiveness Summary
Appendix A
-------
P, •"> o
5 9 0070
Responsiveness Summary
The U.S. Environmental Protection Agency (EPA) originally established a public comment period
from May 29, 1996, through August 29, 1996 in order to allow the public an opportunity to
comment on the Proposed Plan for Operable Unit One for the Stauffer Chemical Company,
Tarpon Springs, Superfund Site (Site). At the request of Pi-Pa-Tag (the Technical Assistance
Grant Group set up to aid the community), the public comment period was extended through
September 16, 1996. The comment period followed a public meeting held on May 29, 1996 at
the Gulfside Elementary School. At the public meeting, EPA presented the Proposed Plan for
Remedial Action for the Site for Operable Unit One. The meeting presented the results of the
studies undertaken and the preferred remedial alternative for Operable Unit One for the Site
This Responsiveness Summary provides a summary of the citizens comments and concerns as
raised during the comment period. Public comments are specifically addressed through EPA
responses. All comments summarized by this document have been factored into the final decision
for the cleanup of the Site.
This responsiveness summary for the Stauffer Chemical/Tarpon Springs Site is divided into the .
following sections:
I. Overview This section discusses the recommended alternative for remedial
action and the public response to this alternative.
II. Background on Community Involvement and Concerns. This section
provides a brief history of community interest and concerns regarding the
Site.
III. Summary of the Major Questions and Comments Received During the
Public Comment Period This section presents written comments submitted
during the public comment period, and provides responses to these
comments.
IV. Remaining Concerns This section discusses community concerns that EPA
should be aware of in design and implementation of the remedial action
alternative for the Site.
I. Overview
The preferred remedial alternative was presented to the public in a fact sheet released April 29,
1996, and presented to the public at the proposed plan public meeting on May 29, 1996. The
Page 1 of 8
-------
59 0071
recommended alternative addresses the source of the contamination by excavating the
contaminated material, consolidating it, solidifying the material that is below the water table, and
capping the contaminated material.
In general, the community favors the selection of the recommended alternative. However, the
community is concerned about the height of the mound containing the consolidated material.
Some community members recommended that the waste be sent off-site to a disposal facility.
II. Background on Community Involvement
The Tarpon Springs community has been aware of the contamination at the Site for several years.
The Site operated in this community from 1947 through its shutdown in 1987. The first fact sheet
was distributed to the community by EPA in March 1993. A total of four public meeting have
been held by EPA to solicit public input in the decision-making process. Interviews have been
conducted with members of the Tarpon Springs community.
At the fourth public meeting, on May 29, 1996, the recommended alternative was presented to the
community. Sampling results, the Remedial Investigation, the Feasibility Study, and alternatives
for the cleanup were discussed at this meeting. EPA answered specific questions and informed
the public that their comments will be addressed in the responsiveness summary.
At the meeting the key issues and concerns were as follows:
• Off-site Disposal of Contaminated Material. Many of the residents of the surrounding
community recommended that EPA excavate and transport all contaminated material to a
an off-Site landfill. Many of these citizens voiced their opinion that the hazardous waste
should be dug up and transported out of their community.
• Cap the Contaminated Material. Meyer's Cove residents recommended that EPA not
move the contaminated material, but only cover it in place. These residents are very
concerned that the contamination will become airborne. Some residents expressed
concern about the proposed location of the consolidated zone and the height of the
resulting mound of consolidated material.
ffl. Summary of the Major Questions and Comments Received During the
Public Comment Period
Thirty-six letters were received during the extended comment period, including two letters that
requested an extension to the comment period. Many of the comments and suggestions were the
same although they were sent by different individuals or groups. These duplicated comments will
be addressed only once in this summary. Topics relevant to the selected remedy are addressed in
this summary. Comments related to the Remedial Design phase of the Superfund process will be
addressed when the Remedial Design documents are written, finalized, and approved.
Page 2 of 8
-------
_ ^% »^» *~y ,-\
5 9 Ou/2
Comment #1: Several comments stressed that the material should not be moved. They stated
that it should be left in place and "not disturbed".
EPA Response #1: One of the nine balancing criteria used to evaluate the selected remedy is
the Reduction in Toxicity, Mobility, or Volume through Treatment.
The consolidation and solidification/stabilization is needed to fulfill this
requirement. To address the communities concern, EPA has modified the
remedy proposed in the Proposed Plan by creating more than one
consolidation area. By making this change, the movement of hazardous
substances is kept to a minimum. Some movement of hazardous
substances will be necessary to bring the Site from an uncontrolled state to
a controlled state.
Comment #2: Several letters expressed concerns about the health and welfare of the children,
faculty, and staff at Gulfside Elementary School.
EPA Response #2: Every practical precaution will be taken to ensure the safety of the children,
faculty and staff at the elementary school. Also, precautions will be taken
to protect the surrounding residents.
Comment #3: Many of the comments received during the public comment period were related to
the Remedial Design (top cover design, engineering controls, real-time air
monitoring, siren/alarm, dust suppression, etc.).
EPA Response #3: EPA will address all issues that pertain to the Remedial Design during the
next phase of the Superfund process. Design details and specifications will
be presented in the Final Remedial Design.
Comment #4: A number of letters commented that EPA should remove the hazardous material
from the Site either by sea, by rail, or by truck.
EPA Response #4: As presented previously in the feasibility study, off-site disposal was
eliminated through the screening process. First, the excavation and
removal of all contaminated hazardous substances would not be protective
of human health and the environment. In fact due to the presence of
elemental phosphorus and radium-226 which is air reactive, the excavation
of all hazardous substances and contaminated soil would create an even
greater hazard than the one that currently exists at the Site. Contaminated
substances would have a greater opportunity to be released to the
atmosphere. Second, the cost as documented in the feasibility study make
the option impractical (the low cost estimate = S200 Million and the high
cost estimate - $1.6 Million). Third, the truck traffic would be extremely
high (15,000 trucks per year). Fourth, transportation by rail and by truck
Page 3 of 8
-------
5 9
would unnecessarily expose or potentially expose residences in Tarpon
Springs and other communities to hazardous substances. Finally, after
considering all of these factor, EPA views the off-site alternative as
inappropriate and unsafe. EPA rejects this alternative.
Comment #5: A few comments mentioned the fact that EPA's decision was based on old
demographic data. Also, many commented that they felt that residential cleanup /
standards should be used.
EPA Response #5: EPA has made the decision to use residential cleanup standards which are
the most conservative available. The fact that EPA is using the most
stringent standards possible makes the question of demographics irrelevant.
Comment #6: A few groups asked EPA to extend the public comment period.
EPA Response #6: EPA granted an extension from August 29, 1996. until September 16,
1996.
Comment #7: Several people commented that the height and the aesthetics of the consolidation
area were unacceptable.
EPA Response #7: In an effort to provide flexibility in the design and to minimize the release
of hazardous substances to the environment, EPA has added flexibility to
the ROD to allow more than one consolidation area to be created. A final
decision concerning the number of consolidation areas will be decided
during the Remedial Design phase.
Comment #8: A few comments were made concerning the groundwater (the surficial and the
Floridan aquifers).
EPA Response #8: Since groundwater will not be addressed by this operable unit, comments
concerning the groundwater will be addressed in a subsequent (second)
Record of Decision.
Comment #9: One person commented that the consolidation area may collapse into the Floridan
Aquifer.
EPA Response #9: The hydro-geologic studies that have been performed do not indicate that
this is a likely outcome. On the contrary, the semi-confining layer should
support the consolidation areas proposed for the Site. There is no evidence
that the consolidation areas will created an unnecessary burden on the
confining layer.
Page 4 of 8
-------
5 9
.-> ft ,.
u / 4
Comment #10:
EPA Response #10:
Comment
EPA Response #11
A few residents of Myers Cove wrote and expressed concern about how
the remediation would affect their property and their health.
EPA will make every effort to ensure the safety of the Meyers Cove
residents. Engineering controls will be specified in the Remedial Design.
One person commented that she was concerned that the Site may have
been used for military exercises.
The fact that the Site may have been used for military exercises is not
relevant to the cleanup of the Site. The investigation conducted for this
Site was comprehensive and was independent of any biases. The
contamination that exists has been documented by collecting samples using
the full scan of constituents.
One letter received during the comment period commented that a building
moratorium should be placed on the property and permits in the area
should be restricted.
Deed restrictions will be placed on the property once the Remedial Action
has been completed.?- Permits and zoning are under the jurisdiction of the
county and other local government agencies.
One person stated that he was concerned that the Potentially Responsible
Party (PRP) was monitoring the Site as opposed to EPA monitoring the
Site. He suggested that EPA take a more active role in monitoring the
Site.
EPA has collected samples in all media at the Site, and EPA collected split
samples during the Remedial Investigation. The nature and extent of
contamination at the Site is well known and well documented. EPA will
continue to monitor the situation and if conditions change appropriate
actions will be taken.
One letter commented that the 1x10"* risk level should not be used at the
Site. The letter also included several attachments supporting this statement.
The letter asked EPA to consider utilizing a commercial/industrial scenario
and cleaning to the 1 x 10*4 risk level.
EPA Response #14: EPA views the risk level of 1 x 10* as appropriate. The proximity of the
elementary school and other sensitive populations must be protected.
Comment #12:
EPA Response #12:
Comment #13:
EPA Response #13:
Comment #14:
Page 5 of 8
-------
5 9
0;^ «T
u/
Comment #15:
EPA Response #15.•
Comment #16:
EPA Response #16:
Comment #17:
EPA Response #17:
Comment #18:
One letter suggested several action levels for different chemicals of
concern.
EPA considered all suggestions; however, no changes were recommended
by the EPA which are less stringent than the 1 x 10* risk level.
One group asked where the slag material generated at the Site was
transported?
Some slag material remains on-Site and will be consolidated with other
contaminated materials. EPA is currently investigating the off-Site
locations where the Stauffer material may have been deposited.
One group stated that there has never been a health survey to determine
how many people were affected by this Site.
The Agency for Toxic Substance and Disease Registry (ATSDR) is the
agency that addresses health related issues. ATSDR has begun the
notification process. The notification process included contacting the
former employees of the Site and informing them that the Site is on the
National Priorities List.
Another group asked - Can it be guaranteed without a shadow of a doubt
that no contamination exists on the areas not included in the remediation
plans including the groundwater beneath them?
EPA Response #18: Although EPA does not provide guarantees, EPA has conducted extensive
sampling of soil and groundwater. EPA will outline specific plans to
cleanup the soil within the RD. Remediation of the groundwater will be
handled through a separate ROD (Operable Unit 2).
Comment #19:
Another group asked - What has been the experience of dealing with
similar phosphate site? Where are these sites and how have they been
cleaned up?
EPA Response #19: EPA Region 4 has consulted with other Region's that have handled similar
phosphate sites and has considered the information received in formulating
cleanup options for this Site. However, it is EPA's policy not to directly
compare one site to another, but instead to judge each site on a site-
specific basis using the Nine Criteria evaluation method as specified by the
National Contingency Plan, 40 CFR 300.430.
Comment #20:
Another question asked - What will be the effect of the proposed
Page 6 of 8
-------
5 9 CG76
EPA Response #21:
Comment #21:
EPA Response #21;
Comment #22:
desalination plant on this Site?
The construction and operation of a desalination plant should have no
effect on the remediation of the Site, and the remediation of the Site should
have no effect on the plant.
One comment stated that there was a large pit that was used for disposal.
The group wanted to know - what will be done to this area?
This comment is ambiguous and unclear as to where the "pit" is located. If
the intent of the comment was to ask about a pit on-Site, then it will be
cleaned up and addressed during the Remedial Action at the Site. If the
comment was directed towards an area off-Site, further investigation would
be necessary. All disposal areas on-Site will be addressed as part of the
Remedial Action.
Another person asked - How will the horizontal movement of the
contaminated water be dealt with when solidification is carried out?
EPA Response #22: By eliminating the source of contamination by solidifying it in a matrix that
has a low permeability, the volume of contaminated groundwater will
decrease. Groundwater will be specifically addressed in the next operable
unit ROD.
Comment #23:
EPA Response #23:
Comment #24:
Another group wanted to know - How many sites did Stauffer pollute?
To ascertain information about other sites that Stauffer Management
Company (SMC) owns, SMC has been contacted. The answer to this
question will be made available to the public.
A group asked - Have you contacted the union in order to contact former
employees of Stauffer?
EPA Response #24: Health related issues are addressed by ATSDR.
Comment #25: Another asked - Who will carry out the Five Year Review?
EPA Response #25:
Five year reviews will be necessary for this Site because contamination will
be left on Site above levels that allow for unlimited use and unrestricted
exposure. EPA will compile the documentation for the Five Year reviews.
It is too early in the process to predict who will collect samples.
Page 7 of 8
-------
Comment #26:
EPA Response #26:
Comment #27:
EPA Response #27:
5 9 O
Another question asked - Who will decide who will perform the
remediation work?
This question will be determined once the Consent Decree negotiations for
the Remedial Design/Remedial Action are completed. If a Potentially
Responsible Party (PRP) signs the Consent Decree, then the PRP will
conduct the RD/RA with EPA oversight.
Finally, one group asked - Since it appears that many questions cannot be
answered before the RD, how can the best option be chosen?
Many of the questions posed to EPA can only be answered when the final
RD is written and approved. As stated earlier, the nine criteria
comparative analysis was used to evaluate cleanup alternatives.
IV. Remaining Concerns
EPA believes that all relevant issues that have been raised are addressed in this responsiveness
summary.
Page 8 of 8
------- |