United States Office of
Environmental Protection Emergency and
Agency Remedial Response
EPA/ROD/R04-93/135
October 1992
c/EPA Superfund
Record of Decision:
Sherwood Medical Industries,
FL
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50272-101
REPORT DOCUMENTATION
PAGE
1. REPORT NO.
EPA/ROD/R04-93/135
3. Recipient'* Accession No.
Title and Subtitle
SUPERFUND RECORD OF DECISION
Sherwood Medical Industries, FL
Second Remedial Action
& Report Date
10/08/92
7. Authors)
a Performing Organization Rapt. No.
9. Performing Organization Name and Address
10 Project Task/Work Unit No.
11. Contract(C) or Grant(G) No.
(Q
(G)
Sponsoring Organization Name and Address
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. Type of Report & Period Covered
800/800
14.
15. Supplementary Notes
PB94-964037
16. Abstract (Limit: 200 words)
The 42-acre Sherwood Medical Industries site is a medical supplies manufacturing plant
located three miles north of DeLand, Volusia County, Florida. Land use in the area is
predominantly residential, with some commercial properties. The site is bordered by
approximately 200 acres of woodlands and wooded marshes to the south, residential areas
to the east and north, and several developed large tracts of land to the northwest.
Lake Miller, a 12-acre swamp lake, is located partially on the western boundary of the
Sherwood site. Current site features include several manufacturing buildings, a
laboratory, and an industrial wastewater treatment facility. Since 1959, the company
primarily has manufactured hypodermic needles and other medical supplies, at the site.
Industrial operations include grinding, hub processing, and cleaning of stainless steel
and aluminum parts used for the manufacturing of the needles, and for the molds of
plastic syringes. The site overlies a confining surficial aquifer and a confined
Floridian aquifer, which is used in the manufacturing, cleaning, and industrial cooling
processes onsite, and as a water supply for most area residents. Between 1971 and
1980, the company disposed of approximately 2 tons of liquid and sludge waste into two
onsite, unlined percolation ponds. Types of manufacturing waste generated and disposed
of onsite included spent solvents; liquid wastes; and sludge containing metals,
(See Attached Page)
17. Document Analysis a. Descriptors
Record of Decision - Sherwood Medical Industries, FL
Second Remedial Action
Contaminated Media: soil, gw
Key Contaminants: VOCs (PCE, TCE), metals (chromium)
b. Identifiers/Open-Ended Terms
COSATt Field/Group
ia Availability Statement
(SeeANSI-Z39.1B)
19. Security Class (Thi» Report)
None
20. Security Ctiss (This Page)
None
21. No. of Pag**
80
See- instructions on Reverse
22. Price
OPTIONAL FORM 272 (4-77)
(Formerly NTIS-35)
Department of Commerce
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EPA/ROD/R04-93/135
Sherwood Medical Industries, FL
Second Remedial Action
Abstract (Continued)
dichromates, detergents, and TCE. From 1980 to 1982, Sherwood analyzed the contents of
the impoundments and disposed of the waste in an off site landfill, in 1982, the threat of
contamination from wastes in the holding ponds prompted a State removal action. In 1983,
an industrial wastewater treatment plant (IWTP) was constructed onsite to receive and
treat plant wastewater prior to discharge of the effluent into denitrification fields and
the perimeter percolation pond. In late 1985, an air stripper was installed to pretreat
production water used in onsite facility operations by removing chlorinated solvent
compounds. Subsequent onsite studies conducted at the request of EPA and the State, in
1986 and 1987, revealed contamination in the Floridian aquifer and onsite wells by VOC
compounds, used historically during onsite degreasing operations, including PCE and TCE.
From 1990 to 1991, several interim remedial actions were conducted onsite, which included
additional sampling; rehabilitation of aquifer supply wells; and adding wells. A 1991 ROD
addressed an interim action for the surficial aquifer and provided for installation of an
air stripper and additional extraction wells, as OU1. This ROD addresses remediation of
onsite soil and the contamination in the surficial and Floridian aquifers, as OU2. A
future ROD will address contamination of the Lake Miller sediment, as OU3. The primary
contaminants of concern affecting the soil and ground water are VOCs, including PCE and
TCE; and metals, including chromium.
The selected remedial action for this site includes extraction and continued operation of
the existing onsite air stripper to treat and remove VOCs from the surficial aquifer, with
discharge of the treated ground water onsite to Lake Miller; monitoring onsite and
downgradient residential wells, the surficial and Floridian aquifers, and Lake Miller; and
implementing institutional controls, including deed and land use restrictions, and site
access restrictions, such as fencing. The estimated present worth cost for this remedial
action is $1,017,000, which includes an estimated annual O&M cost of $104,000.
PERFORMANCE STANDARDS OR GOALS:
Ground water clean-up goals are based on the more stringent of Federal SDWA MCLs and State
standards. Chemical-specific ground water goals include acetone 0.7 mg/1; TCE 0.003 mg/1;
PCE 0.003 mg/1; 1,2-DCA 0.003 mg/1; vinyl chloride 0.0001 mg/1; and chromium 0.1 mg/1.
Air emissions from the air stripper will meet the more stringent of CAA or State
guidelines.
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RECORD OF DECISION
OPERABLE UNIT 2
SHERWOOD MEDICAL NPL SITE
DeLand, Volusia County, Florida
°*
\
Prepared By:
Environmental Protection Agency
Region IV
Atlanta, Georgia
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Record of Decision
Operable Unit 2
Declaration
SITE NAME AND LOCATION
She'rwood Medical Industries Site
DeLand, Volusia County, Florida
STATEMENT OF BASIS AND PURPOSE
This decision document presents the selected remedial action for
the Sherwood Medical Site in DeLand, Florida, which was chosen in
accordance with CERCLA, as amended by SARA, and, to the extent
practicable, the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). This decision is based on the
Administrative Record for this site.
The State of Florida, as represented by the Florida Department of
Environmental Regulation (FDER), has been the support agency
during the Remedial Investigation and Feasibility Study process
for the Sherwood Medical Site. In accordance with 40 CFR
300.430, FDER, as the support agency, has provided input during
this process. Based upon comments received from FDER, 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 action selected in
this Record of Decision (ROD), may present an imminent and
substantial endangerment to public health, welfare, or the
environment.
DESCRIPTION OF THE REMEDY
The remedy selected in this ROD addresses site soils and
groundwater that have been contaminated as a result of past waste
disposal activities at the Sherwood Medical Site. The selected
remedy continues operation of the pump and treat system installed
as part of the previous action and adds additional requirements.
An additional Operable Unit is planned to address contaminated
sediments in Lake Miller, a small Lake which is partially on-site
and historically received runoff from the Sherwood Site.
The primary components of the selected remedy will provide
protection of human health and the environment at the Sherwood
Site through. The components of this ROD include:
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o Groundwater pump and treat: system for remediation of
the surficiai aquifer;
o Discharge of treated effluent to Lake Miller, a 12 acre
lake located partially on the Sherwood Site;
o Groundwater monitoring program encompassing the
surficiai, Upper and Lower Floridan aquifers;
o Residential Well monitoring to ensure that no
contamination exists in wells immediately to the east
and west of the Site;
o Requirement for continued operation of the Floridan
Aquifer Water Supply well and the associated treatment
system to ensure capture and treatment of any migrated
contamination;
o Requirement that soil excavated following building or
parking lot removal meet TCLP criteria or contain less
than 520 mg/kg chromium. Soils exceeding these
standards would be required to be remediated or
disposed of in an appropriate waste facility.
o Land use restrictions allowing only industrial use of
the site in the future.
STATUTORY DETERMINATIONS
The selected remedy is protective of human health and the
environment, complies with Federal and State applicable or
relevant and appropriate requirements directly associated with
this action, and is cost-effective. This action utilizes
permanent solutions and alternative treatment technologies (or
resource recovery), to the maximum extent practicable, and
satisfies the statutory preference for remedies that employ
treatment that reduces toxicity, mobility, or volume as a
principal element. Because this final remedy will result in
hazardous substances remaining on-site above health-based levels,
a review will be conducted at least every five years after
commencement of the remedial action, to ensure that this remedy
continues to provide adequate protection of human health and the
environment.
reer C. Tidwell . Date
' Regional Administrator
U.S. Environmental Protection Agency
Region IV
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TABLE OF CONTENTS
1.0 Introduction 1
2.0 Site Name, Location and Description 1
3 . 0 Site History and Enforcement Activities 2
4 . 0 Summary .of Community Relations Activities 8
5.0 Scope and Role of This Action Within Site Strategy 9
6.0 Summary of Site Characteristics 10
6 .1 Waste Management Units 11
6 . 2 Potential Sources 11
6.2.1 Soils 14
6.2.2 Sediments 17
6.2.3 Surface Water 18
6.2.4 Groundwater 18
6.2.4.1 Surficial Aquifer 19
6.2.4.2 Floridan Aquifer 25
6.2.5 Air 27
7.0 Summary cf Sit- Risks 27
7 .1 Contaminants of Concern 27
7 . 2 Exposure Assessment 28
7.2.1 Current and Future Exposure Scenarios 37
7 .3 Toxicity Assessment 39
7 . 4 Risk Characterization 45
7 . 5 Ecological Effects 48
8 . 0 Description of Alternatives 53
8 .1 Alternative 1 54
8 . 2 Alternative 2 54
8.3 Alternative 3A 55
8 .4 Alternative 3B 57
9 . 0 Summary of Comparative Analysis 57
9.1 Overall Protection of Human Health and the
.Environment 58
9 . 2 Compliance with ARARs 59
9 .3 Short Term Effectiveness 59
9 .4 Long Term Effectiveness 59
9.5 Reduction of Toxicity, Mobility and Volume 59
9 . 6 Implementability 59
9 . 7 Cost 61
9 . 8 State Acceptance 61
9 . 9 Community Acceptance 61
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10.0 The Selected Remedy 61
10.1 Groundwater Extraction 62
10.2 Groundwater Treatment 64
10.3 Treated Water Discharge 65
10.4'Clean-up Levels 66
10 . 5 Monitoring Requirements 66
.10.6 Institutional Controls 67
"10.7 Cost Summary 68
11. 0 Statutory Determinations 68
11.1 Protection of Human Health and the Environment 68
11.2 Compliance with Applicable or Relevant
and Appropriate Requirements 71
11.2.1 Chemical Specific Requirements 71
11.2.2 Action Specific Requirements 72
11.2.3 Action Specific Requirements 73
11.3 Cost Effectiveness 73
11.4 Utilization of Permanent solutions and Alternative
Treatment Technology or Resource Recovery-
Technologies to the Maximum Extent Practicable 73
11.5 Preference for Treatment as a principal Element..'... 74
11.6 Documentation of Significant Changes 74
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RECORD OF DECISION
Operable Unit 2
The Decision Summary
Sherwood Medical Site
DeLand, Volusia County. Florida
1.0 INTRODUCTION
The Sherwood Medical Site (the Site) was proposed for inclusion
on the National Priorities List (NPL) in December 20, 1982 with a
Hazard Ranking System score of 39.83. The State of Florida was
designated the lead agency for the Site and remained in that
capacity until November of 1990, when both agencies agreed that
EPA should complete actions at the Site.
The Sherwood Medical Site was first the subject of an Interim
Remedial Measures Report performed by the responsible party,
Sherwood Medical, Inc., (Sherwood) under the direction of the
Florida Department of Environmental Regulation (FDER). In July
1988, Sherwood retained Roy F. Weston, Inc. (Weston) to perform
Interim Remedial Measures (IRM) activities recommended as a
result of the IRM study and, concurrently, initiate the Remedial
Investigation and Feasibility Study (RI/FS) according to an
Administrative Order on Consent entered into in October 1987 with
the U.S. EPA Region IV.
Based on the conclusions of the IRM report, EPA presented the
Proposed Plan for Interim Action to the public on January 31,
1991. A Record of Decision for Interim Action at the Sherwood
Medical Site was signed- by the EPA Regional Administrator in
March 1991. In July 1991 Sherwood Medical signed a Consent
Decree for performance of design and construction of the Interim
Action treatment system specified in the Record of Decision.
Final Inspection of the system was held on July 29, 1992, and
start up occurred on July 31, 1992.
The Final Remedial Investigation/Feasibility Study Report and the
Proposed Plan for additional Remedial Action was made available
to the public on July 23, 1992. A Proposed Plan public meeting
was held on July 30, 1992.
2.0 SITE NAME, LOCATION, AND DESCRIPTION
The Sherwood Medical Industries Site (Sherwood) is located
approximately three miles northeast of Deland, Florida. The Site
lies outside the city limits in an unincorporated area of Volusia
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County located in northeast Florida. Figure 1 shows the
geographic location of the Site within Volusia County. Figure 2
is a United States Geological Survey (USGS) 7.5 minute series
quadrangle map of De Land showing the location of the Sherwood
site.
The Site occupies approximately 42 acres, including a section of
Lake Miller along the Sites western boundary. U.S. Highway 92
runs along the northern boundary of the site while a wooded,
swampy area lies to the south. A commercial and residential area
along Kepler Road is located directly east of the Site. The
Sherwood property is currently occupied by several manufacturing
buildings, a biological laboratory, sizeable parking" areas, plus
additional structures, including an industrial wastewater
treatment facility. Figure 3 is a map of the Sherwood Medical
Site depicting site buildings, waste management areas, and Lake
Miller along the western boundary of the Site.
3.0 SITE HISTORY AND ENFORCEMENT ACTIVITIES
Sherwood Medical Industries has occupied the property since 1959
for the manufacturing of medical supplies, primarily hypodermic
needles. Industrial operations currently include grinding, hub
processing, and cleaning of stainless steel and aluminum parts
used to manufacture hypodermic needles. Sherwood also molds
plastic syringes and conducts in-house quality, assurance and
quality control.
The Sherwood facility pumps approximately 175,000 gallons of
water per day-from the underlying Floridan Aquifer.
Approximately 150,000 gallons of the water is used for industrial
processes and the remaining 25,000 gallons is used for domestic
purposes. Water drawn for industrial needs is used for cleaning,
manufacturing, and cooling processes. Several manufacturing
steps result in wastewater which must be treated. An industrial
wastewater treatment plant (IWTP) was constructed in July 1983 to
meet the Florida Drinking Water Standards. This facility is
permitted by FDER to receive and treat wastewater from the plant,
and to discharge the resulting effluent. The treated effluent is
currently disposed of by percolation and evaporation in the
denitrification fields and perimeter percolation pond. In late
1985, Sherwood installed an air stripper to pretreat production
water used on-site in the facility's operations. The air
stripper removes chlorinated solvent compounds existing in the
water pumped from the Floridan Aquifer production wells on-site.
Between 1971 and 1980, the company disposed of approximately two
tons of liquid and sludge waste into two unlined percolation
ponds. During this time, solids were removed from the ponds and
placed into on-site, unlined impoundments. From 1980 through
1982 Sherwood analyzed the contents of the impoundments and
disposed of the wastes in an off-site landfill.
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PUTNAM
COUNTY
MARION
COUNTY
29'-
28*—
82'
M25I-1712
29'
I SEMINOLE
i COUNTY
ORANGE
COUNTY
VOLUSIA
_\ COUNTY
Scale in Miles
1:1,000,000
81'
Figure 1 GEOGRAPHIC LOCATION MAP
SHERWOOD MEDICAL COMPANY
DELAND, FLORIDA
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1—' x-"!^""' ~T,
"'* £**?"^ !J
OE LAND
SIDNEY H TAYLOR
cc$»i" \ ^. . A ;
N V"' ^ '
\orth
Lake TalmadQe I' ~.*?*=*
!• ' .-
*] '^~ . • O
Taimadge
i-'-'-^rV .->-
Scale In Feet
1/2
Source: USGS 7.5
Minut* Oeiand Qu«drangl«
Mmo Pho»xevis»d 1980
Scaie In Miles
Figure 2 SITE LOCATION MAP - SHERWOOD MEDICAL SITE
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SHERWOOD MEDICAL COMPANY
IM*«t Morfd.
t 1
t
III I
H«ur* S 3IIE LAVOUT
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In December 1982, the Sherwood site was proposed for inclusion on
the National Priorities List at the request of FDER because of
the threat of contamination from wastes in the holding ponds and
surface impoundments. FDER assumed the lead role for activities
at the Sherwood Site. FDER initially believed that the removal
of wastes from on-site storage areas was sufficient to eliminate
the threat of contamination. However, subsequent testing
conducted by Sherwood and FDER revealed groundwater contamination
in on-site wells.
In October 1985, Sherwood Medical notified EPA that"they would
perform a focused Remedial Investigation (RI) at the Site.
During 'EPA's negotiations with Sherwood to conduct the RI, FDER
and the Florida Department of Health and Rehabilitation Services
(HRS) received health related complaints about private wells from
nearby residents. Water samples were collected and analyzed in
September 1986 from off-site private wells and Sherwood's on-site
supply wells, but no violations of drinking water standards were
found in private well samples. However, additional samples
collected in October 1986 from on-site Floridan Aquifer wells
confirmed on-site contamination of trichloroethylene (TCE) and
tetrachloroethylene (PCE) in the Floridan Aquifer. These
compounds were historically used by Sherwood for degreasing
purposes. In light of this new information, it was agreed that a
full scale Remedial Investigation/Feasibility Study (RI/FS) would
be conducted at the Site. In October 1987 Sherwood Medical
entered into an. Administrative Order on Consent with the U.S. EPA
Region IV to perform the RI/FS.
In August 1987, at FDER's request, Sherwood sampled the on-site
Floridan water wells and a downgradient residential well to
assess the extent of contamination and evaluate the need to
implement interim remedial measures (IRM) to control and treat
the contamination of the Floridan Aquifer prior to completion of
the RI/FS. Based on the observed on-site Floridan Aquifer
contamination, FDER recommended an IRM action be undertaken. In
July of 1988 Sherwood retained Roy F. Weston, Inc. as primary
contractor for IRM and RI/FS activities. Sherwood developed an
investigation plan to evaluate the Floridan Aquifer and the
surficial aquifer through a thorough sampling program. Field
testing was completed in April of 1989.
As part of the IRM, Sherwood Medical tested all of the private
wells along Kepler Road semi-annually. The wells are located
immediately adjacent to the site and extend from the intersection
of U.S. 92 and Kepler Road through the intersection of Marsh and
Kepler Roads. Sherwood also monitored another private well, to
the west of the site, just across Lake Miller. The investigation
identified one private well with volatile organic compound (VOC)
concentrations above safe drinking water standards. This well is
located on Kepler Road, and the test results indicated PCE and
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TCE concentrations of 11 ppb and 4 ppb, respectively. The
applicable Florida Drinking Water Standard for both PCE and TCE
is 3 ppb.
In October 1989, Sherwood submitted a design workplan to FDER
outlining further interim measures to be conducted at the site
including the installc -'.on of a pump and treat system to extrac- ,
clean and discharge we..-er from the on-site affected surficial
aquifer. FDER approved the design workplan in September 1990
following the receipt of the Final IRM study report. In November
1990, FDER requested that EPA assume the lead role for all
actions at the Site. ~
In December 1989, EPA and FDER approved the Sherwood RI/FS
Workplan. The initial field work for the RI began in January
1990. The field work included; the installation and sampling of
additional Floridan aquifer monitoring wells; drilling and
sampling of soil borings; sampling and analysis of surface water,
sediment, surface soil, and a thorough resampling of all existing
wells. The first draft of the'RI was submitted to the Agency in
March 1991.
In January 1991, EPA issued a Proposed Plan for Interim Action at
the Sherwood Medical Site and initiated a Public Comment Period.
On January 31, 1991 a Public Meeting was held at Stetson
University to discuss the Proposed Interim Action and to allow
concerned citizens to ask EPA officials questions about the
Sherwood Site.
On March 27, 1991 the Regional Administrator for U.S. EPA Region
IV signed the Interim Action Record of Decision for the Surficial
Aquifer. Comments generated during the Public Comment Period and
at the Public Meeting were included, along with responses, as
Appendix A of the Record of Decision.
Between January 7 and April 17, 1991, additional IRM activities
were conducted at the site. These activities included the
rehabilitation of two Floridan aquifer water supply wells SMFW
and SMWS, conversion of an out of service Floridan aquifer well,
SMFA 1, to a stainless steel monitoring well, and installation of
nine extraction wells as part of the surficial groundwater
recovery system. In April 1991 Sherwood submitted the Remedial
Design Work Plan/Preliminary Design for the Surficial Aquifer
Groundwater Remedial Action (RD Work Plan). In June 1991,
Sherwood submitted a Final Design Package for the IRM Remedial
Design/Remedial Action. In a subsequent meeting between FDER,
EPA and Sherwood, on June 20, 1991, it was agreed that Sherwood
would undertake a study of Lake Miller's water quality to
determine if Lake Miller was in compliance with applicable FDER
Class III Ambient Water Quality Standards for metals and was
therefore suitable for treatment system discharge..
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Additional surface water and sediment samples were collected at
the Site from July 1991 through November 1991. The additional
samples were taken to further characterize the metals
concentrations in Lake Miller in order to verify the lake's
compliance with applicable FDER Class III Ambient Water Quality
Standards. In November of 1991 Weston submitted the Lake Miller
Water Quality Report detailing the surface water and sediment
sample results and verifying Lake Miller's compliance with FDER
Class III Water Quality Standards except for cadmium. At that
same time Weston submitted a National Pollutant Discharge
Elimination System (NPDES) application for the proposed discharge
to Lake Miller. This application was submitted in accordance
with CERCLA which requires that the "substantive requirements" of
the NPDES permit are met. The data gathered for the Lake Miller
study was incorporated in the RI.
In February 1992, Sherwood Medical resubmitted the Final Design
Package along with the Remedial Action Work Plan and the
Operation and Maintenance Plan for the Interim Action treatment
system. EPA approved these documents on March 24, 1992.
On May 5, 1992 a Pre-Construction Conference for the Interim
Action treatment system was held on-site at Sherwood Medical and
construction of the system began that same day. During the first
half of July 1992, the extraction well system was completed and
the air stripper was installed. Results from the initial round
of sampling from the treatment system were reviewed by EPA and
FDER on July 29, 1992 and system start-up followed on July 31,
1992.
4.0 SUMMARY OF COMMUNITY RELATIONS ACTIVITIES
In accordance with CERCLA 113 (k)(2)(B)(i-iv) and 117
requirements, a Community Relations Plan (CRP) for the Sherwood
Medical Site was developed. This Community Relations Plan
outlines citizen involvement and the community's concern.
In order to fulfill community relations requirements for the
Interim Action, the Interim Remedial Measures Report and the
Proposed Plan for the Sherwood Site were released to the public
on January 8, 1991. These two documents were made available in
both the Administrative Record and an information repository
maintained at the EPA Docket Room in Region IV and at the DeLand
Public Library. The notice of availability was published on
January 30, 1991. A public comment period was held from January
21, 1991 through February 21, 1991. In addition to the public
comment period and the information repository, a public meeting
was held on January 31, 1991. At this meeting, representatives
from FDER and EPA answered questions and addressed community
concerns. A response to comments received during the Interim
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Action comment period was included as Appendix A to the Interim
Action Record of Decision for the surficial aquifer.
.The Final Remedial Investigation/Feasibility Study Report was
placed in both the Administrative Record and the information
repository in the DeLand Public Library on July 23, 1992. On the
same date, the Proposed Plan for Final Action at the Sherwood
Site was sent to the information repository and to all members of
the public who have expressed interest in receiving information
related to Sherwood Medical. The notice of availability and the
announcement of the Public Comment period and Public Meeting were
published in the Daytona News Journal on July 16, 19-92, and again
on July 28, 1992. A Public Meeting was held on July 30, 1992..
At this meeting, representatives from EPA and FDER addressed
community concerns and answered questions. Responses to the
comments received during this period is included in the
responsiveness summary, which is included as appendix A of this
Record of Decision.
This decision document presents the selected remedial action for
the surficial aquifer at the Sherwood Medical Site in DeLand
Florida, chosen in accordance with CERCLA, as amended by SARA
and, to the extent practicable, the National Contingency Plan.
The decision for this site is based on the Administrative Record
for the Site.
5.0 SCOPE AND ROLE OF THIS ACTION WITHIN SITE STRATEGY
As with many Superfund Sites, the problems at the Sherwood
Medical Site are complex. It was determined early in the
Superfund process that the presence of on-site contamination in
the surficial aquifer posed an imminent and substantial
endangerment to human health and the environment if not addressed
through immediate action. As a result, EPA initiated an Interim
Action for the Site. That action represented Operable Unit (OU)
I in the site management strategy. EPA selected a remedy for OU
I in the Interim Action ROD signed on March 27, 1991. That
remedy addressed TCE and PCE contamination in the surficial
aquifer to reduce the potential for contaminant migration off-
site or downward to the Floridan aquifer, which is the primary
source of drinking water in the DeLand, Florida area. A series
of extraction wells and an air stripper were installed according
to the OU 1 Interim Action ROD. This remedy was implemented in
July of 1992.
The second OU, the subject of this ROD, addresses groundwater and
Site soils. This includes contamination in the surficial and
Floridan Aquifers, and elevated levels of chromium in Site soils.
Following the conclusion of the Remedial Investigation it was
determined that further study was necessary to determine effects
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of elevated levels of metals in Lake Miller sediments and a small
area of wetlands nearby. EPA and FDER have determined that an
additional environmental study is necessary to fully characterize
biological effects of chromium in Lake Miller sediments. EPA
will address Lake Miller sediments by conducting an additional
environmental study to determine if chromium levels in Lake
Miller are causing adverse effects for benthic and aquatic
organisms. This additional action will be addressed as OU 3 for
the Sherwood Medical Site.
6.0 SUMMARY OF SITE CHARACTERISTICS
The Sherwood Site is situated in a low topographic area 40 to 60
feet above Mean Sea Level (MSL). The lithologic units in the
region of the Sherwood site can be divided into three primary
categories -in terms of their stratigraphic characteristics and
geologic ages. They occur in the following order: the
unconsolidated surficial sandy deposits of Holocene to
Pleistocene age; the unconsolidated poorly sorted deposits of
Pliocene to Miocene age; the carbonated bedrock deposits of the
Eocene age Avon Park Formation.
The foliage typical of the Site is best described as floodplain
with fiatland soil and is a combination of deciduous and
coniferous trees with intermittent grazing lands and wetlands.
Due to the large number of freshwater lakes (e.g., Lake Miller,
Cypress Lake, North and South Lake Talmadge) and low topography,
much of the area is best described as wooded marsh.
The land surrounding the Sherwood Site is primarily residential,
with some commercial properties. Residential areas are divided
into 6-acre lots. According to real estate maps, 95% of the
individual parcels of land (419 out of 440) within a 0.5 mile
target area are north or east of the Site. Most of the
residential areas are sparsely populated and their growth is
restricted by zoning codes. There are 808 homes located within a
one mile radius of the .Sherwood Site and approximately 2,500
people.
Woodland and wooded marsh occupy approximately 200 acres of land
to the south of the site. Most of this land is owned in large
tracts. The area to the east of the site is almost entirely
residential. Next to the site on Kepler Road is an 80 acre
residential area with 15 homes. Approximately 1,000 feet to the
east of the Sherwood Site lies a residential area occupying one
to two square miles known as Daytona Park Estates. North of U.S.
92, the northern border for the Sherwood Site, lies a 150 acre,
moderately populated development, DeLand Highlands. This area
has shown the greatest recent growth, and the size of the housing
lots are the smallest in the area. Beyond the DeLand Highlands
the area is characterized as rural. Southwest of the Site is
10
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mostly wooded swamp. Northwest of the site are large tracts of
land owned by the DeLand Municipal Airport, the Municipal
Waterworks and the Florida Military School.
The Land near the Sherwood site is known to support recreational
activities including fishing, hunting, boating, and swimming.
Lakes generally used for fishing in the area include Cypress,
Daytona, and Talmadge. Because of the relatively large tracts of
undeveloped land, hunting occurs in the area.
The predominant natural feature of the Sherwood Site is Lake
Miller, a 12-acre swamp lake. Lake Miller, which is.partially on
the Sherwood Site, is located along the western boundary of the
Site and receives recharge from a lake north of the site via a
narrow canal, base flow from the surficial aquifer, and Site run-
off. Lake Miller is the primary area of concern for potential
ecological damage from the Site. Lake Miller is designated as a
Florida Class III water body. Class III water bodies are
designated for wildlife and recreational purposes.
6 .1 Waste Management Units
The primary waste management units at the Sherwood Site include:
a storm water holding pond; two unlined percolation ponds which
historically received chromium containing process effluent; a
retention basin which receives storm water runoff; an industrial
wastewater treatment plant including one pathway which receives
nitrate bearing wastes and another pathway which receives non-
nitrate bearing wastewater; a sewage treatment plant which
receives sanitary wastewater; denitrification pond which receives
wastewater from one side of the IWTP and; a barrier pond which
receives treated sanitary wastewater and effluent from the the
other side of the IWTP.
6.2 Potential Sources
Several wastes generated by Sherwood Medical were disposed or
stored on-site. Table 1 contains a list of the types of wastes
that were generated at the site as a result of manufacturing
operations and also contains the locations where these wastes
were discharged or stored. Figure 4 illustrates waste disposal
and storage locations.
The Remedial Investigation evaluated past disposal practices and
areas of known contamination and through a comprehensive sampling
program identified areas with elevated contaminant levels related
to the Site. Remedial Investigation activities included:
o Drilling and sampling of shallow and deep soil borings
11
-------
Table 1
Waste Storage arid Past Disposal Locations at the Sherwood Site
Manufacturing Operation
1. Treatment of cooling water
blowdown; hub processing and
grinding.
2. Grinding, cleaning, and hub proc-
essing of stainless sieel and
aluminum parts (Buildings B and F).
3. Grinding operations - cleaning of rc-
circulaling cooling tanks.
4. Plastic molding (Building A).
5. None
Type of Vfasie
Liquid and sludge containing sodium
dichromate.
Aqueous wastes containing spent solvents.
Discharge of aqueous wastes containing
detergents and lelrachloroelhene.
Floor washings containing
lelrachloroelhene.
Sludges (containing chromium and nickel)
from the percolation ponds.
Location
Percolation ponds east of Building A and discharge to tile drain
field located to the south of Building P.
Discharge to septic lank and graded sump (located south of
Building B).
Discharge to two septic tanks (located south of Building F) and
ultimately to a septic lank drain field located to the south of
Building F.
Retention basin (located near the existing IWTP) via graded
sumps and the slormwaler collection system.
Temporary storage in unlined impoundments located south of
the percolation ponds.
-------
SHERWOOD MEDICAL COMPANY
Odind. florid.
f (•» «
N
in i
Figure 4 WASIE SIOHAGE AND
DISPOSAL I OCA I IONS
-------
o Installation of additional surficial aquifer monitoring
wells
o Installation of five off-site Floridan monitoring wells
o Rehabilitation of selected on-site Upper Floridan and
Lower Floridan aquifer wells
o Sampling and analysis of all monitoring wells
o Sampling and analysis of sediment
•- o Sampling and analysis of surface water
o Sampling and analysis of surface soil
o Sampling and analysis of residential wells
o Geophysical logging of newly installed Floridan aquifer
monitoring wells ~
o Ecological Study
Table 2 summarizes the compounds that were detected in the
various media during the course of the RI.
6.2.1 Soils
The soil boring program conducted at the site consisted of
completing 46 soil borings in and around several on-site' waste
disposal areas (Figure 4). Samples collected from the soil
borings were analyzed for selected metals and VOCs.
Chromium was the predominant metal detected in the on-site soils.
Total chromium was detected in all of the on-site soil borings
except SB-17. The highest concentrations of total chromium were
found in the shallow soils (0-10 ft) and were restricted to the
area surrounding the percolation ponds and the area adjacent to
Building F. The maximum chromium concentration detected on-site
was 366 mg/kg in SB-39 near building F. This area is presently
covered by a continuous asphaltic parking lot.
Lead (total) was detected in all of the soil samples collected at
the site. The maximum concentration detected was 18.1 mg/kg at
SB-34 from the 0-5 ft interval. Concentrations of total lead
were found to be evenly distributed (vertically and horizontally)
in all areas of the site that were sampled. Lead (total)
concentrations (up to 1.8 mg/kg) were detected in two composite
background soil borings (SB-45 and SB-48).
Trace levels of arsenic were detected in 18 of the 46 soil
borings. The maximum concentration detected was 4.4 mg/kg in a
composite sample.
Low levels of VOCs were detected in several of the soil samples
collected. Acetone and methylene chloride were detected in
several soil samples and also in some of the associated
laboratory method blank samples. Concentrations of all other
VOC that were detected were less than 1 mg/kg, except for a grab
14
-------
Table 2
Summary of Chemicals Detected by Medium
Chemical
QTFV?"^
Acetone
Benzene
Benzoic Acid
Bis(2-ethylhexyi)phthalate
2-Butanone
Carbon Disulfide
alpha-Chlordane
Chloroform
Chloromethane
4,4'-DDE
4,4'-DDT
1,1-Dichloroe thane
1,1-Dichloroethene
1,2-Dichloroethene (total)
Ethylbenzene
Heptachlor
Methylene Chloride
4-Methyiphenol
Tetrachloroethene
Toluene
1,1,1-Trichloroethane
Trichloroethene
Vinvl Chloride
Xyicncs (total)
SoU
X
X
X
X
X
X
X
X
X
X
Surface
Water
X
X
X
X
X
X
X
X
X
X
Sediment
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Surfitial
Aquifer
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Upper
Floridan
Aquifer
X
X
X
X
X
X
X
X
X
X
Lower/
Upper
Floridan
Aquifers
X
X
X
15
-------
Table 2 (con't)
Summary of Chemicals Detected by Medium
Chemical
Aluminum
Arsenic
Barium
Cadmium
Calcium
Chromium (III)
Copper
Iron
Lead
Magnesium
Manganese
Mercury
Nickel
Potassium
Silver
Sodium
Vanadium
Zinc
Soil
X
X
Surface
Water
X
X
X
X
X
X
X
X
X
X
X
X
Sediment
X
X
X
X
X
X
X
X
X
X
X
X
X
X
SurficiaJ
Aquifer
X
X
X
X
X
X
X
X
X
Upper
Florida".
Aquifer
—
X
X
X
X
X
X
X
Lower/
Upper
Floridan
Aquifers
X
X
X
X
16
-------
soil sample collected from that indicated PCE at 1.9 mg/kg. The
primary site-related VOC compounds, PCE and TCE were detected at
very low levels in on-site areas where waste containing these
compounds were disposed in the past. This suggests that no major
VOC source areas remain in soils and that the bulk of VOC
contamination has been transferred to the surficial aquifer or
into the air.
6.2.2 Sediments
A total of 18 sediment samples were collected during-the 1990 RI
activities. Samples were collected in on-site drainage ditches
and basins, along the eastern bank of Lake Miller, and within,
upstream, and downstream of Lake Miller. These samples were
analyzed for all of the TCL compounds. Background samples were
also collected from the canal between Lake Miller and North Lake
Talmadge. Additional sediment samples were taken in Lake Miller
and in North Lake Talmadge, in 1991, to further define the extent
of metals concentrations in the sediments of these water bodies.
Six sediment samples were collected from on-site drainage ditches
and basins. These sediment samples indicated levels of VOCs up
to 0.11 ug/kg. Levels of benzene, toluene, and xylene detected
did not exceed .013 mg/kg.
Several metals were detected above their quantification limits.
Total chromium was detected in all of the samples, with a maximum
concentration of 922 mg/kg. Total lead was detected in all of
the samples, with a maximum concentration of 655 mg/kg. Arsenic
was detected in several samples with a maximum concentration of
5.3 mg/kg.
The highest levels of the site-related compounds TCE and PCE,
were found in the sediments located along the eastern bank of
Lake Miller. This area received aqueous wastes containing spent
solvents from floor drains in buildings B and F, which lead into
former' drain fields along the bank of Lake Miller. In addition,
these substances may have migrated from the surficial aquifer
since this aquifer discharges into Lake Miller. A total of
three sediment samples were collected along the bank of Lake
Miller adjacent to the Site. VOC analysis indicated the presence
of TCE, PCE, methylene chloride, acetone, 1,1-dichloroethene
(total), 2-butanone, vinyl chloride, toluene, and xylene.
Acetone was detected in several samples and was also detected in
an associated laboratory method blank. The VOC 1,2-
dichloroethene (total) was detected in three samples. The
concentrations of other VOCs were relatively low as compared to
TCE and PCE.
Concentrations of total chromium in the sediments were relatively
evenly distributed throughout Lake Miller with the exception of
the eastern shore, adjoining the Site, which showed
17
-------
significantly higher levels. Trace levels of chromium were also
detected in background sediments collected in North Lake
Talmadge. Total lead concentrations detected in Lake Miller were
also found to be evenly distributed within Lake Miller. However,
total lead was also detected at relatively lower levels in
sediments in North Lake Talmadge and in the sediments in the
canal connecting North Lake Talmadge and Lake Miller. These
water bodies are upstream of Lake Miller and the Sherwood Site.
Arsenic was detected only at trace levels in the sediments
collected in Lake Miller.
Of the metals of concern, only total chromium concentrations
detected in Lake Miller are known to be directly associated to
Site operations. Total chromium in Lake Miller is assumed to be
trivalent.
6.2.3 Surface Water
VOCs were detected on-site at levels less than 1 part per million
(ppm). PCE was not detected in any of the samples and TCE was
detected in one sample (SW_7), near the location where a
discharge line entered Lake Miller. TCE and PCE were not
detected in quantifiable concentrations in the surface water in
Lake Miller. Therefore, if transfer of these substances has
occurred from the surficial aquifer into Lake Miller, the
substances have been significantly diluted or have volatilized.
No base neutral compounds or pesticides were detected at levels
greater than the detection limit.
Lead, chromium, and arsenic, were detected in one sample, located
along the eastern shore of Lake Miller during the 1990 RI
sampling activities. Other metals, with the exception of
manganese and nickel, were also detected at SW-7 during 1990.
However, during resampling of this location during 1991 sampling
rounds in Lake Miller and in the vicinity, none of the metals of
concern were detected above the quantitation limit. None of the
metals, except for chromium, are known to be related to Site
manufacturing operations. Data obtained during the six rounds of
sampling conducted in 1991 have shown that the waters in Lake
Miller are in compliance with the applicable FDER Class III
Ambient Water Quality Standards with the exception of cadmium.
6.2.4 Groundwater
The hydrogeologic sequence at the Site includes the surficial
aquifer, a confining unit- composed of clay, sandy clay, and shell
layers, and the confined Floridan Aquifer. The Floridan Aquifer
is comprised of the Upper Floridan Aquifer, the primary drinking
water aquifer in the DeLand area and the Lower Floridan Aquifer.
Figure 5 represents a generalized hydrogeologic cross section at
18
-------
the vicinity of the Sherwood Site and Table 3 presents brief
descriptions of the lithological units.
The surficial aquifer extends from the uppermost saturated
sediments (typically less than 10 feet below ground surface) to
the top of the first aquitard. The first aguitard is 25 to 50
feet thick near Kepler Road bordering the eastern edge of the
site and 10 to 15 feet thick along the western property boundary
near Lake Miller.
The confining unit underlying the surficial aquifer is comprised
of a four to eight foot thick clay to sandy clay layer that
overlies a 35 to 40 foot thick poorly sorted deposit of shells,
sand, silt and clay. Collectively, these sediments serve to
restrict the vertical movement of water from the surficial
aquifer to the confined Floridan aquifer system below. Values
for the hydraulic conductivity of the confining unit ranged from
3.3X10'5 to 0.02 ft/day.
The Upper Floridan Aquifer is highly productive and is the source
of drinking water for most residents and municipalities in the
DeLand area. The Upper Floridan Aquifer is recharged from the
surficial aquifer.
6.2.4.1 Surficial Aquifer
Fourteen monitoring wells were installed in the surficial
aquifer. Twelve of these were installed as part of the IRM Study
and an additional two wells were installed during the RI
activities. The analytical results of the IRM study revealed
that the major contaminants were tetrachloroethene (PCE),
trichloroethene (TCE), and acetone. Concentrations of other
volatile organic compounds (VOCs) were also detected, but these
concentrations were low compared to the concentrations of PCE and
TCE. Analysis of the surficial aquifer concentrations of PCE
ranged from 130 to 11,000 ppb and concentrations of TCE ranged
from 16 to 420 ppb. The results indicated that generally the
highest concentrations of VOCs were present on the downgradient
side of the Site along Lake Miller. Figures 6 and 7 illustrate
PCE and TCE isoconcentration contours in the surficial aquifer.
From groundwater depth measurements taken for the surficial
aquifer, the RI determined that groundwater moves under the site
from the Northeast corner across the Site southwest toward Lake
Miller. Groundwater elevations fall approximately 12 feet from
the Northeast corner of the Site to the edge of Lake Miller.
Figure 8 illustrates the groundwater elevations in the surficial
aquifer.
19
-------
Avon
P.I.I.
I u IllOfl
MW vn?
MW;
iitrhnal At|inti>(
Confining
I Ms
I lOIMJ.W
A(jtnlt>i
luwet
Floi i(l.iii
At|\MIU1
Line of Cross Section A-A'
i.vv 1
aX-J
LeguiHl
Depth ol Bolloni ul Ouli.'r
„ GENERALIZED HVDROGEOl OGIC
r l|jure 5 CROSS SECTION AT THE SHERWOOD
MEDICAL SUE
-------
Table 3
Lilhologic Units in I he Vicinity or Sherwood
Medical Company, l)e Land, Florida
Age
Unit
Thickness
Description
Water-Bearing
Properties
llolocene to
Pleistocene
Pliocene to
Miocene
Surficial Aquifer 30-55 ft
Confining Unit
35-55 ft
Mid-Eocene Avon Park
Formation*
Upper and
Lower Floridan
Aquifer System
Early Eocene Oldsmar
Formation
800-1,000 ft
Beyond the
depth of this
investigation
Unconsoliduted fine to High primary porosity. Hydraulic
medium-grained sands and silty conductivities (K) range from 0.001
sands. to 3.5 ft/day.
Unconsolidated clays to sandy
clays overlying poorly sorted
deposits of shells, sands, silts,
and clays.
White to tan to gray limestone
and dolomite. Textures are
widely variable from chalky to
vuggy to densely crystalline.
Commonly fossiliferous.
Low water-bearing capability. Serves
to separate and confine the under-
lying Floridan aquifer system from
the overlying surficial aquifer
system. Hydraulic conductivities (K)
range from 3.3 x 105 to 0.02 ft/day.
High secondary porosity through
fractures, vugs, and solution
openings (some primary porosity
locally in Upper Floridan aquifer).
I lydraulic conductivities (K) range
from 15 ft/day.
•The interbcdded limestones and dolomites of Mid-Eocene age in peninsular Florida and southern Georgia are now referred
to as the Avon Park Formation. The term "l>ake City Limestone" has been abandoned, as these slratigraphic units cannot be
distinguished from one another on the basis of either lithology or fauna, except locally (6).
-------
SHERWOOD MEDICAL COMPANY
Defend, florid*
\
I I
W PCI f
0 V
N
Figure 8 PCE ISOCONCENIRAIION COMTOURS
SUNFICUl AOUIfER MONITOR WELLS
SHERWOOD MEDICAL SUE
APRIL I MO
-------
SHERWOOD MEDICAL COMPANY
Defend, Florida
> I «
f\ S-7
'* "!-n>i / x
_ . _ ',tv,~-,, «. ; , "VIM,
t*n*>r, '»
I I
Su/'/('o' oitultf ifttnfiat
fj'oM«At j/0e/(iyu"iA'/
InMalltd It iWWIt
tutconctnttitiott fniiltiui
IwlO JOi^I
DO'f: *" »€« Wll'/nni Of (
MIV Mmmw "»»
All «W rlrln In)
t
N
Ml I
FJfuro 7 ICE ISOCONCtNIHArtON CONIOUnS
SURFICIAl AQUIFER MONITOR WEllS
SHERWOOD MEDICAL SHE
APRIL 1990
-------
SHERWOOD MEDICAL COMPANY
Debnd, Florida
• ' ' I tf\ e
CD HutMln
Voufi
//Vf torUf'M.f'On
VlrtifKHrv/iti i'uiifiiiii tf
I /«(4bJtf Mr.ni Sf.i t t
\
N
Figure 8
GROUNDWATER ELEVATIONS
MAP BASED ON WATER LEVEL
MEASUREMENTS TAKEN IN
PVC PIEZOMETERS SCREENED
NEAR THE TOP OF THE
SURFICIAL AQUIFER 3<24/90
* A " »w
^•i V™
-------
6.2.4.2 Floridan Aquifer
Five off-site monitoring wells were drilled and installed into
the Floridan aquifer in the vicinity of the Sherwood Site. Two
of these were completed in the Upper Floridan Aquifer and three
were completed in the Lower Floridan Aquifer. The purpose of
these wells was to assess the extent of site contaminants present
in the groundwater ir. the Floridan aquifer beneath the site.
Previously existing wells also provided data for the RI. These
wells included six off-site residential wells. The off-site
wells have been sampled semi-annually to ensure that-off-site
migration is not occuring. VOCs were identified in one off-site
private well. That well was plugged and abandoned. A new
replacement well installed during the IRM activities has been
sampled and has not shown elevated levels of VOCs.
Three on-site, out of service, water supply wells (SMFA 1-3) were
also sampled to determine contaminant migration pathways in the
Upper Floridan Aquifer. Site related VOCs were identified in one
of these wells (SMFA 1) . This well was later converted to a
stainless stell monitoring well as part of the interim action.
Since the conversion, the levels of TCE and PCE have declined
indicating that breaches in the well casing were responsible for
migration of contaminants in the surficial aquifer. The other
two wells sampled did not show TCE and PCE contamination above
the quantification limit. However, samples drawn from these
wells did contain elevated levels of acetone in one round of
sampling.
Sherwood's water supply well (SMWS) and fire well (SMFW) , which
are open in both the Upper and Lower Floridan Aquifer, were also
sampled for the RI. Site related VOCs were detected in isolated
groundwater samples collected from Lower Floridan aquifer during
a packer test and a pump test. Testing indicated that improper
well construction or deteriorated casings were the cause of the
VOC contamination in the Lower Floridan Aquifer. These wells
were also rehabilitated as part of IRM activities. Subsequent
sampling indicates that well casing rehabilitation was effective
in preventing further migration of VOCs from the surficial into
the Floridan Aquifer.No site related VOCs have been detected in
the off-site monitor wells completed in the Lower Floridan
aquifer.
Floridan Aquifer groundwater elevations in the vicinity of the
Site show a substantial area of convergent flow that has been
created as a result of on-site pumping from wells SMWS and SMSB
and from downward borehole flows SMWS and SMFW. Groundwater flow
direction in the Upper Floridan aquifer in the area of and around
the Sherwood Medical Site is toward the on-site Water Supply well
from all directions. Figure 9, illustrates groundwater
elevations in the Upper Floridan Aquifer.
25
-------
SHERWOOD MEDICAL COMPANY
Dtknd, Florida
tit. i f
nmt Itat
't "'«
f |
lttt *<•"
(o-f "cv/rfort V'r' We"
30 PflttntwnxtiK contow /HW "t '
ttrt M aom mil i *IAM rut or
?40H BUS
ftOtt: M wit! location) <*c a
Stf'Af Out of t*i*k
SW 4 ? Ifcrtto »»"
$«/ 4 J ttvrf'ar wr//
N
Figure 9
UPPER FIORIDAN AQUIFER
POTENTIOMETRIC CONTOURS
FROM WATER LEVEL
MEASUREMENTS TAKEN
ON30JULV 1990
-------
6.2.5 Air
The primary concern at the Sherwood Medical Site is the presence
of site related substances in various environmental media,
predominantly in the groundwater. There are no significant
levels of VOC in the soils at the Site there which would act as a
source of VOC emissions to the air.
7.0 SUMMARY OF SITE RISKS
CERCLA as amended by SARA establishes a national program for
responding to releases of hazardous substances into the
environment. The NCP, which is the regulation that implements
CERCLA, establishes the overall approach for determining
appropriate remedial actions at Superfund sites. The overall
mandate of the Superfund program is to protect human health and
the environment from current and future threats posed by
uncontrolled hazardous substance releases.
A Baseline Risk Assessment represents an evaluation of the "No
Action" alternative, in that it identifies the risk present if no
remedial action is taken. The assessment considers environmental
media and exposure pathways that could result in unacceptable
levels of exposure now or in the foreseeable future. Data
collected and analyzed during the RI provided the basis for the
four components: contaminant identification, exposure assessment,
toxicity assessment, and risk characterization.
7.1 Contaminant Identification
Sampling data from the various environmental media at the Site
(soils, sediments, surface water, and groundwater) were examined
and compiled to produce a list of all contaminants. This list
was reduced according to the Risk Assessment Guidance for
Superfund: Volume 1; Human Health Evaluation Manual (RAGS:
EPA/540/1-89/002) methodologies.
Data evaluated included the results of soil samples analyzed in
February and August 1990, and surface water and sediment samples
analyzed in April 1990, August 1990, and November 1991.
Groundwater samples from the surficial wells in March 1989
through the end of 1991, and from the Upper Floridan and mixed
Lower/Upper Floridan wells in April 1990 through the end of 1991,
were also included.
Data gathered during the RI for all environmental media was
analyzed to determine the nature and extent of contamination for
the Site. All organic contaminants identified in any media were
retained for further consideration. Because inorganic
constituents occur naturally in the environment, only those that
27
-------
exceeded background concentrations were retained for further
consideration. Background comparisons were conducted in
accordance with guidance from EPA Region IV. An inorganic
chemical was retained for further consideration if the mean (or
maximum) concentration in Site samples was more than two times
higher than the corresponding background mean (or maximum)
concentration.
The form of chromium (hexavalent verses trivalent) was
investigated through the collection of four surficial soil
samples in areas with elevated chromium levels. The results of
the analysis suggested that hexavalent chromium (chromium VI) was
not present at concentrations at or above the detection limit of
2.5 mg/Kg. Total chromium was reported in these samples at
concentrations ranging from 2.2 mg/Kg to 318 mg/Kg. Based on
these results it was assumed in the Risk Assessment that the
chromium present in soil, as well as in other site associated
media is present as trivalent chromium. Under most environmental
conditions, chromium VI is usually converted to chromium III.
Also, chromium III does not readily convert to chromium VI.
Based, on results of the Baseline Risk Assessment Chromium III,
does not contribute to risk above the EPAs level of concern for
carcinogenic or non-carcinogenic effects.
Tables 4 through 9 present the data summary for each of the
chemical constituents identified in a particular environmental
media. The Upper 95% Confidence Limit of the Mean represents the
assumed Exposure Point concentration or Reasonable Maximum
Exposure level for that specific contaminant in the given
environmental media.
7.2 Exposure Assessment
The objectives of the exposure assessment are to develop exposure
scenarios and to calculate exposure doses to the selected
potential receptors. The scenarios are based on both current and
potential or hypothetical future land and water uses. Doses are
calculated on the assumption that no additional remediation would
be performed at the facility.
The Sherwood Medical Site is zoned industrial. The land
surrounding the Sherwood Site is best described as semirural.
Although it is not a part of the incorporated City of DeLand, the
site is located close enough to this and other communities so
that residential housing tracts extend into the northern and
eastern areas abutting the Site. The presence of a wooded,
28
-------
Table 4
Surface Soil
Data Summary
Chemical
Frequency
of Detection
ftrganics
Acetone
2-Butanone
Carbon Disulfide
Ethylbenzene
Methylene Chloride
Tetrachloroethene
Toluene
1,1,1-TrichloToethane
Trichloroethene
Xylenes (total)
28/35
5/35
2/35
9/35
24/35
15/35
15/35
8/35
4/35
17/35
Range of
Sample
Quantitation
Limits
(mg/kg)
Range of
Concentrations
(mg/kg)
0.01-0.011
0.01-0.012
0.005-0.006
0.005-0.006
0.005-0.006
0.005-0.006
0.005-0.006
0.005-0.006
0.005-0.006
0.005-0.006
0.007J-12
0.009J-0.062
0.002J-0.006
0.002J-0.007
0.002J-0.052
O.OOU-038
0.002J-0.019
0.003J-0.013
0.003J-0.010
0.002J-0.022
Mean
Concentration
(mg/kgr
Upper 95%
Confidence
Limit of the
Mean
(mgAg)
024
0.0077
0.0021
0.0026
0.0078
0.027
0.0028
0.0038
.0.0025
0.0051
039
0.010
0.0023
0.0030
0.011
0.051
0.0039
0.0045
0.0030
0.0069
Inorganics
Arsenic
Chromium
11/43
39/42
0.17-0.44
2.0-2.1
0.17-1.7
1.6-366
022
18.1
030
32.5
Estimated value.
29
-------
Table 5
Surface Water - Lake Miller
Data Summary
Chemical
Frequency of
Detection
Range of
Sample
Quantitation
Limits
(mg/L)
Organic
Acetone
Bis (2-ethylhexyl)
phthalate
1,1-Dichloroethene
L2-Dichloroethene
(total)
Methylene Chloride
Tetrachloroethene
Toluene
Trichloroethene
Vinyl Chloride
Xylenes (total)
4/5
2/5
1/5
3/5
1/5
3/5
1/5
3/5
1/5
1/5
0.0050-0.042
0.0010
0.0025
0.0025
0.0025
0.0025
0.0025
0.0025
0.0050
0.0010-0.0025
Range of
Concentrations
(mg/L)
Mean
Concentration
4mg/L)
Upper 95%
Confidence
Limit of the
Mean
(«g/L)
0.007J-0.008J
0.004J-0.01LT
0.005
0.003J-0.19
0.003J
0.003J-0.004J
0.003J
0.003J-0.12
0.025
O.OOLJ
0.014'
0.0036
0.003
0.041
0.0026
0.0032
0.0026
0.026
0.009
0.0013'
0.027*
0.0073
0.004
0.11
0.0028
0.0039
0.0028
0.071
0.017
0.0019*
Inoreanics
AliitniniiTTi
Arsenic
Barium
Cadmium
Chromium
Copper
Iron
Lead
Mercury
Nickel
Vanadium
7inr
14/14
1/14
1/14
13/14
2/14
1/14
14/14
7/14
1/14
1/14
1/14
4/14
0.10
0.0010-0.0050
0.025-0.10
0.0003-0.0004
0.0050-0.010
0.0050-0.0125
0.050
0.0010-0.0050
0.0001
0.0050-0.020
0.0050-0.025
0.0050-0.015
0.14-13
0.0047
0.073
0.0004-0.0023
0.0063-0.19
0.12
0.16-2.9
0.0033-0.029
0.0003
0.016
0.025
0.014-028
026
0.0048*
0.073
0.0006
0.019
0.017
038
0.0051
0.0001
0.013
0.024
0.032
039
0.0049*
0.075*
0.0009
0.041
0.029
0.72
0.0082
0.0001
0.013 .
0.025
0.065
e maximum concentration.
J = Estimated value.
30
-------
Table 6
Sediment — Lake Miller
Data Summary
Chemical
Frequency
of
Detection
Range of
Sample
Quan citation
Limits
(mg/kg)
Range of
Concentrations
(mg/kg)
Mean
Concentration
(mg/kg)-
Upper 95<7c
Confidence
Limit of
the Mean
(mg/kg)
Qrganirt
Acetone
Benzole Acid
Bis(2-ethyihexyl)
phthalate
2-Buianone
Chloromethane
4,4'-DDT
1, 1-DichJoroe thane
1, i -Dichloroethene
12-Dichloroethenc
(total)
Ethylbenzene
Methyiene Chloride
4-Methylphenol
Tetrachloroethene
Toluene
Trichloroethene
Vinvi Chloride
Xylenes (total)
6/6
2/6
2/6
3/6
1/6
1/6
1/6
2/6
4/6
2/6
5/6
1/6
3/6
5/6
4/6
2/6
5/6
Tpflrganir*
Ajiirninijrn
Arsenic
Cadmium
Calcium
20/20
16/20
15/20
19/20
NAV
1.6
0.059-13
0.020-0.19
0.02-0.12
0.038-0.041
0.013-0.06
0.01-0.093
0.06-0.093
0.015-0.020
0.015
029-18.0
0.01-0.093
0.093
0.06-0.093
0.02-0.19
0.093
NAV
0.58-6.8
0.444.5
2390
0.13-9.5
1.6-1.9J
1.6J-11J
0.047-0.17
0.14J
0.038J
0.019J
O.OU-0.02
0.078-0.46
0.013J-0.04U
0.021-022
029J
83-30.0
0.007J-0.11
0.002J-8.8
0.036-0.051
0.007J-0.0074
1330-14,100
0.75-5.4
0.53-2.7
500-39,870
2.5
1.6
22
0.072
0.043
0.035
0.019
0.020
020
0.014
0.092
1.7*
8.6
0.049
2.7
0.045
0.037
5.2
1.7
SJ
0.12
0.081
0.041"
0.032°
0.032°
034
0.024
0.16
4.4"
17.4
0.082
53
0.068"
0.061"
9290
2.9
0.56
13,100
10,800
3J
1.6
16300
31
-------
Table 6 (con't)
Sediment — Lake Miller
Data Summary
(continued)
Chemical
Chromium
Copper
Iron
Lead
Maenesium
Nickel
Potassium
Sodium
Vanadium
Zinc
Frequency
of
Detection
20/20
16/20
-20/20
20/20
19/20
14/20
17/20
19/20
15/20
20/20
Range of
Sample
QuanOtation
Limits
(mg/kg)
NAV
1.7-22.5
NAV
NAV
2,390
1.7-343
60-2390
2.390
0.87-23.9
NAV
Range of
Concentrations
(mgAg)
4.9-922
102-132
222-9.870
2.7-228
85.8- 1.400
53-25.8
144-917
21.1-869
2.7-20.0
22-300
Mean_
Concentration
(mg/kg)
237
44.0
6.070
823
LOGO
13.1
. 516
505
US
143
Upper 95%
Confidence
Limit of
the Mean
(mg/kg)
332
57.1
7210
102
1.170
15.6
620
606
14.8
177
J = Estimated value.
NAV = Sample quantitation limits or method detection limits were not available.
32
-------
Table 7
Groundwater — Sorficial Aquifer
- Data Summary
Chemical
Organic
Acetone
Benzene
2-Biitanone
Carbon Bisulfide
Chloroform
1,1-Dichloroethane
1.1-Dichloroethene
1,2-Dicnloroethene
(Total)
Ethylbenzene
Methyiene Chloride
Tetrachloroethene
Toluene
1, 1, 1 -Trichloroethane
Trichloroethene
Vinvl Chloride
Xylenes (Total)
Inprganicj
Arsenic
Cadmium
Chromium
Magnesium
Manganese
Frequency of
Detection
Range of
Sample
Quantitation
Limits
(mg/L)
Range of
Concentrations
(mg/L)
Mean
Concentration
(mg/L)
13/13
2/13
:;i3
1/13
1/13
2/13
4/13
10/13
1/13
6/13
13/13
4/13
4/13
13/13
3/13
1/13
0.01'
0.005-0.012
0.01-0.023
0.005-0.012
0.005-0.012
0.004-0.0063
0.005
0.005
0.005-0.012
0.0037-0.082
0.005*
0.0047-0.012
0.0047-0.012
0.0051
0.01-0.017
0.005-0.012
9/13
4/13
11/13
13/13
13/13
0.0027-0.09
0.004-0.0069
0.017
02*
0.01*
0.0065-7.0
0.0025-0.016
0.0042-0.0098
0.0044J
0.0073
0.0022J-0.0053J
0.0020J-0.0055J
0.0064-0.064
0.0080
0.0023J-0.0073J
0.0025-10.1
0.0023J-0.052
0.0023J-0.0028
0.0025-031
0.0057J-0.014J
0.045
0.0033-0.072
0.0032-0.0050
0.01-028
1.1-5.6
0.011-0.097
1.0
0.0039
0.0058
0.0029
0.0033
0.0024
0.0026
0.019
0.0033
0.0031
1.7
0.0068
0.0028
0.092
0.0064
0.0062
0.017
0.0028
0.053
2J
0.031
Upper 95%
Confidence
Limit of
the Mean
(mg/L)
2.1
0.0056
0.0069
0.0034
0.0040
0.0029
0.0031
0.029
0.0041
0.0040
32
0.013
0.0032"
0.14
0.0077
0.012
0.028
0.0033
0.091
33
0.043
33
-------
Table 7 (con't)
Groundwater — Surficial Aquifer
Data Summary
(Continued)
Chemical
Nickel
Potassium
Silver
Sodium
Frequency of
Detection
8/13
13/13
2/13
13/13
Range of
Sample
Quaotitation
Limits
(mg/L)
0.02-0.054
0.2*
0.023-0.03
0.05-02*
Range of
Concentrations
(mg/L)
0.015-0.16
13-65.9
0.012-0.015
12.6-178
Mean
Concentration
(mg/L)
0.040
7.5
0.012
69.0
Upper 95%
Confidence
Limit of
the Mean
(mg/L)
0.061
15.9
0.013
93.8
'Method detection limit
"Exceeds the maximum concentration.
J = Estimated value
34
-------
Table 8
Groundwater - Upper Floridan Aquifer
Data Summary
Chemical
Frequency of
Detection
Range of
Sample
Quantitation
Limits
(mg/L)
Range of
Concentrations
(mg/L)
Mean
Concentration
-(mg/L)
Upper 95%
Confidence
Limit of
the Mean
(mg/L)
Organic
Acetone
Bis (2-ethyihexyl)
phtbalate
Carbon Disulfide
alpha-Chlordane
4,4'-DDE
IJ-Dichloroethene
(Total)
Heptachlor
Tetrachloroethene
1,1,1-Trichloroethane
Trichloroethene
3/4
2/3
2/4
2/4
1/4
2/4
2/4
1/4
1/4
1/4
0.01
0.006
0.005
0.00045-0.0011
0.00009-0.00022
0.005
0.000045-0.00011
0.005
0.005
0.005
0.014-31.0
0.006J-0.007J
0.031-0.035
0.00024-0.00061
0.00008
0.0048J-0.0053
0.000027J-0.000053
020
0.0058
0.069
12.0
0.0053*
0.018
0.00040
0.00007
0.0038
0.000039
0.052
0.0033
0.019
273
0.0082*
0.036'
0.00061
0.00010*
0.0053
0.000056*
0.15
0.0050
0.0:.
iQQIEanis
Cadmium
Chromium
Iron
Lead
Nickel
Potassium
Zinc
2/4
2/4
4/4
3/4
1/4
4/4
3/4
0.004-0.0045
0.02
0.03"
0.002-0.056
0.02
020"
0.01
0.0031-0.0041
0.050-0.055
0.16-0.87
0.0025-0.15
0.033
0.91-36.9
0.069-0.15
0.0029
0.031
0.45
0.053
0.016
10.1
0.091
0.0039
0.056*
0.76
0.12
0.028
283
0.16*
'Exceeds the maximum concentration.
"Method detection limit.
35
-------
Table 9
Groundwater - Mixed Lower/Upper Floridan Aquifers
Data Summary
Chemical
Organic*
1,2-Dichloroethene
(total)
Tetrachloroethene
Trichloroetheae
Frequency of
Detection
Range of
Sample
Quantitation
Limits
(mg/L)
Range of
Concentrations
(mg/L)
Mean
Concentration
(mg/L)
Upper 95%
Confidence
Limit of
the Mean
(mg/L)
1/2
1/2
1/2
0.005
0.005
0.005
0.014
0.041
0.054
0.008
0.022
0.028
0.033*
0.11*
0.141
Inorganics
dadmiiitn
Potassium
Sodium
Zinc
1/2
1/2
2/2
1/2
0.005
2.0
0.05-0.2*
0.01
0.11
49.4
8.6-27.8
0.13
0.056
252
182
0.068
030*
D31
61.1'
035*
'Exceeds the maximum concentration.
"Method detection limit.
36
-------
swampy area to the south of the Site limits residential
development, and a single resident owns a large tract of land to
the west of the site. The topography of the area is essentially
flat as the site is within the coastal plain of the Atlantic
Ocean.
The current potentially exposed populations include the workers
(700-900 employees) at the operating facility and residents
living in housing tracts located to the east of the site. There
are no residents living to the south of the site, although there
is a maintenance facility operated by the Florida Department of
Transportation on the southeast corner. "U.S. Highway 92 borders
the northern portion of the site, and a residential area is
located on the north side of the highway. Groundwater from the
Upper Floridan and Lower Floridan Aquifers is utilized for
drinking and domestic purposes in the area. Several residents
surrounding the Sherwood Site have private wells which are
screened in the Upper Floridan Aquifer. In addition, Sherwood
Medical draws 175,000 gallons per day from their on-site water
supply well screened in the Upper Floridan Aquifer. This water
is treated prior to use in the plant with an on-site air
stripper. Sherwood Medical expects to remain on-site and
continue current operations for the foreseeable future. However,
a future land use scenario for an on-site resident was evaluated.
7.2.1 Current and Future Exposure Scenarios
Table 10 summarizes the evaluated exposure scenarios for the
Site. The receptor, exposure frequency, medium, and exposure
routes are listed for all of the current use and future use
scenarios.
The current use scenarios were based on limited access to the
site due to the presence of an 8 foot security fence and a 24
hour guard. The future use scenarios were based on the
assumption that the site would be developed for residential use.
In both the current and future resident scenarios, it is assumed
that the resident is exposed to contaminants for 30 years, 6
years as a child and 24 years as an. adult. An individual who
works at the Sherwood facility 250 days/year for 25 years is
evaluated in the worker scenario.
Both the trespasser and swimmer are assumed to be an adolescent,
aged 10 to 18 years. It is assumed that a trespasser, or a
swimmer in a relatively inaccessible surface water body such as
Lake Miller, most likely would be in this age range. The
trespasser is assumed to be on the site 1 day/month, 12
months/year or 12 events per year. The swimmer is assumed to use
Lake Miller for 78 swimming events per year. Swimming in Lake
Miller is considered as a future use scenario because swimming is
not known to currently occur in Lake Miller. Exposure to
37
-------
Tuble 10
Exposure Scenarios Evaluated for the Sherwood Medical Site
1
Scenario/Receptor
Exposure
Frequency* and
Duration
Medium
Exposure Route
Current Use
Offsite Resident
Onsite Worker
350 days/year;
30 years
250 days/year;
25 years
Air
Surface Water
Air
Soil
Inhalation of fugitive dust.
Ingest ion of recreutionally caught fish.
Inhalation of fugitive dust.
Incidental soil ingc&tion; dermal contact with soil.
Future Use
Onsitc Resident
Trespasser
Swimmer (Lake Miller)
350 days/year;
30 years
12 days/year;
9 years
78 days/year;
9 years
Air
Soil
(iroundwaler
Surface Water
Air
Soil
Surface Water
Sediment
Inhalation of fugitive dust.
Incidental soil ingest ion; dermal contact with soil; ingestion of
homegrown fruits/vegetables.
Drinking water ingeslion; noningeslion household uses; ingeslion of
homegrown fruits/vegetables irrigated with groundwatcr; incidental
water ingeslion from swimming pool; dermal contact with water in
swimming pool.
Ingeslion of recrealionally caught fish.
Inhalation of fugitive dust.
Incidental soil ingeslion; dermal contact with soil.
Incidental water ingeslion; dermal contact with water.
Incidental sediment ingeslion; dermal contact with sediment
oo
ft
'Exposure frequency may differ for some exposure routes.
-------
chemicals through the incidental ingestion of water, dermal
contact with water, incidental ingestion of sediment, and dermal
contact with sediment while swimming are exposure pathways
evaluated for an individual aged 10 to 18 years assumed to swim.
Future use scenarios have assumed residential use for the land
which is now occupied by Sherwood Medical. However, Sherwood
Medical has no plans to abandon manufacturing activities in the
foreseeable future.
7.3 Toxicity Assessment ~
Slope factors (SFs) have been developed by EPA's Carcinogenic
Assessment Group for estimating excess lifetime cancer risks
associated with exposure to potentially carcinogenic
contaminant(s) of concern. SFs, which are expressed in units of
(mg/kg-day) ~l, are multiplied by the estimated intake of a
potential carcinogen, in mg/kg-day, to provide an upper-bound
estimate of the excess lifetime cancer risk associated with
exposure at that intake level. The term "upper bound" reflects
the conservative estimate of the risks calculated from the SF.
Use of this approach makes underestimation of the actual cancer
risk highly unlikely. Slope factors are derived from the results
of human epidemiological studies or chronic animal bioassays to
which animal-to-human extrapolation and uncertainty factors have
been applied (e.g., to account for the use of animal data, to
predict effects on humans).
Reference doses (RFD's) have been developed by EPA for indicating
the potential for adverse health effects from exposure to
contaminant(s) of concern exhibiting noncarcinogenic effects.
RfDs, which are expressed in units of mg/kg-day, are estimates of
lifetime daily exposure levels for humans, including sensitive
individuals. Estimated intakes of contaminant(s) of concern
ingested from contaminated drinking water can be compared to the
RfD. RfDs are derived from human epidemiological studies or
animal studies to which uncertainty factors have been applied
(e.g., to account for the use of animal data to predict effects
on humans).
Cancer Slope Factors and Chronic Reference Doses are included in
Tables 11 and 12 respectively. It should be noted that dermal
Cancer Slope Factors as well as dermal Chronic RfDs have not been
developed. Therefore, a dermal slope factor was derived for each
applicable chemical, in accordance with EPA guidance. Likewise,
chronic dermal RfDs were derived for the chemicals of concern, in
accordance with EPA established guidelines.
39
-------
Table 11
Cancer Slope Factors (CSFs)
(mg/kg-day)'
1
Chemical
EPA Categorization*
Inhalation
Route
Reference or
Basis
Oral Route
Organics
Benzene
Bis(2-elhylhexyl)phlhalale
alpha-Chlurdanc
Chloroform
Chloromclhane
4,4'- DDE
4,4'-DDT
1,1-Dichloroclhanc
1,1-Dichloroelhene
lleplachlor
Melhylcne Chloride
4-Mclhylphenol
Telrachloroelhene
Trichloroelhene
Vinyt Chloride
A
B2
B2
B2
C
B2
B2
C
C
B2
C
C
B2
B2
A
2.90-02*
NC
NC
a.iE-or
NC
NC
NC
NTV
1.8E-OI"
4.6E + txr
I.6E-03*
NC
I.8E-03*
1.7E-02
2.9E-01'
IRIS, 1992
...
...
IRIS, 1992
...
...
...
...
IRIS. 1992
IRIS, 1992
IRIS, 1992
...
EPA, 199 la
EPA, I99la
EPA. 1991 a
2.9E02
1.4E02
1.3E + 00
6. IE 03
1.3E-02
3.4E-01
3.4E01
NTV
6.0E-OI
4.5E + 00
7.5E03
NTV
5. IE 02
I.IE-02
l.9Ef(X)
Reference or
Basis
Dermal
Route*
IRIS, 1992
IRIS, 1992
IRIS, 1992
IRIS, 1992
EPA, 1991 a
IRIS, 1992
IRIS, 1992
...
IRIS, 1992
IRIS, 1992
IRIS, 1992
—
EPA, 1991a
EPA, 199la
EPA, I99la
3.2E-02 (V)
2.8E-02 (SV)
2.6E+00(SV)
6.8E-03 (V)
1.4E-02 (V)
6.8E-OI (SV)
6.8E-01 (SV)
NTV
6.7E-OI (V)
9.0E + 00(SV)
8.3E 03 (V)
NTV
5.7E 02 (V)
1.2E 02 (V)
2.IE+00(V)
Inorganics
Arsenic
A
1.511 + 01*
IRIS. 1992
I.HIiMN)
IRIS, 1992
3.6E + 01 (1)
-------
Table 11 (con't)
Cancer Slope Factors (CSFs)
(mg/kg-day)'
(Continued)
Chemical
1
Cadmium
Lead
Nickel
EPA Calegori/alion*
Bi"
B2
A"
Inhalation
Roulc
NC
NC
NC
Reference or
Basis
...
...
...
Oral Route
NA
NTV
NA
Reference or
Basis
...
...
...
Dermal
Route1*
NA
NTV
NA
"Reference: EPA,
Group A - Human carcinogen
HI - Probable human carcinogen
B2 - Probable human carcinogen
C - Possible human carcinogen
"Dermal CSFs were derived for volatile organics (V), scmivolatile organics (SV), and inorganics (I) from the oral CSFs as described in Subsection 6.2.3.2.
'Converted from a unit risk by assuming the inhalation of 20 in' of air/day and a body weight of 70 kg.
""Catcgori/ed as a carcinogen through the inhalation route only.
NA = Not applicable. Chemical is not categorized as a carcinogen through this exposure roule.
NC = Chemical is not of concern through this exposure route.
NTV = No loxicity vjihi- is available.
-------
Table 12
Chronic Reference Doses (RfDs)
(mg/kg-day)
Chemical ,
Inhalation
Route
Reference or
Basis
Oral Route
Reference or
Basis
Dermal Route*
Organics
Acetone
benzene
Denzoic Acid
His(2-elhylhexyl)phthalate
2-Butanone
Carbon Disulfide
alpha-Chlordane
Chloroform
Chloromethane
4,4'-DDE
4,4'-DDT
1,1-Dichloroethane
1,1-Dichloroethene
1,2-Dichloroethene (total)
Ethylhenzene
1 leptuchlor
Methylcne Chloride
4-Mclhylphenol
5.1E + 00
9.1B-02
NC
NC
9.0E-02
2.9E-03"
NC
1.4E-01
NC
NC
NC
2.3E-KH)
5.7E-02
2.3E + 00
2.9E-01"
1.4E03
8.6E-01"
NC
ACGIH-TWA
ACGIH-TWA
—
—
EPA, 199 la
EPA, 1991a
—
ACGIII-TWA
—
--
—
ACGIH-TWA
ACGIH-TWA
ACGIH-TWA
IRIS, 1992
ACGIH-TWA
EPA, 199 la
-
l.OE-01
l.OE-03
4.0E+00
2.0E-02
5.0E-02
l.OE-01
6.0E-05
l.OE-02
2.3E-01
5.0E-04C
5.0E-04
l.OE-01
9.0E-03
l.OE-0211
10E-OI
5.0E-04
6.0E-02
5.0IZ-02
IRIS, 1992
Derived
IRIS, 1992
IRIS, 1992
EPA, 199 la
IRIS, 1992
IRIS, 1992
IRIS, 1992
Derived
IRIS, 1992
IRIS, 1992
IRIS, 1992
IRIS, 1992
EPA, 1991a
IRIS, 1992
IRIS, 1992
IRIS, 1992
EPA, 199 la
9.0E-02 (V)
9.0E-04 (V)
2.0E+00(SV)
l.OE-02 (SV)
4.5E-02 (V)
9.0E-02 (V)
3.0E-05 (SV)
9.0E-03 (V)
2.1E-01 (V)
2.5E-04 (SV)
2.5E-04 (SV)
9.0E-02 (V)
8.1E-03 (V)
9.0E-03 (V)
9.0E-02 (V)
2.5E-04 (SV)
5.4E-02 (V)
2.5E-02 (SV)
-------
Table 12 (con't)
Chronic Reference Doses (KfUs)
(nig/kg-day)
(Continued)
1
Chemical
Telrachloroethene
Toluene
1 , 1 , 1 -Tr ichloroethane
TrichloroeChene
Vinyl Chloride
Xylenes (to(al)
Inhalation
Route
9.7E-01
5.7E-01
3.0E-01
7.7E-01
3.7E-02
8.6E-02"
Reference or
Basis
ACGIH-TWA
EPA, 1991a
EPA, 1991a
ACGIH-TWA
ACGIH-TWA
EPA, 199 la
Oral Route
l.OE-02
2.0E-01
9.0E-02
7.4E-03
1.3E-03
2.0E+00
Reference or
Basis
IRIS, 1992
IRIS, 1992
EPA, 1991a
EPA, 1991a
Derived
IRIS, 1992
Dermal Route"
9.0E-03 (V)
1.8E-01 (V)
8.1E-02 (V)
6.7E-03 (V)
1.2E-03 (V)
1.8E+00 (V)
Inorganics
Aluminum
Arsenic
Barium
Cadmium
Calcium
Chromium (111)
Copper
Iron
Lead
NC
5.7E-04
NC
NC
NC
5.7E-07b
NC
NC
NC
—
ACGIII-TWA
—
--
--
EPA, 199 la
—
—
—
1.9E-02
3.0E-04
7.0E-02
5.0E-04
(water)6
l.OE-03 (food)
1.1E+01
l.OE+00
3.7E-02*
2.6E-01
9.4E-04
Derived
IRIS, 1992
IRIS, 1992
IRIS, 1992
Derived
EPA, 1991a
EPA, 199 la
Derived
Derived
9.5E-04 (1)
1.5E-05 (1)
NC
5.0E-05' (1)
5.5E-01 (I)
5.0E-02 (1)
1.9E-03 (I)
1.3E-02 (I)
7.0E-06 (I)
ro
-a-
-------
Table 12 (con't)
Chronic Reference Doses (KIDs)
(mg/kg-day)
(Continued)
1
Chemical
Magnesium
Manganese
Mercury
Nickel
Potassium
Silver
Sodium
Vanadium
Zinc
Inhalation
Route
NC
NC
NC
NC
NC
NC
NC
NC
NC
Reference or
Basis
~
—
—
—
--
-
—
-
--
Oral Route
5.7E + 00 '
l.OE-01
3.0E-04
2.0E-02
8.0E + 00
5.0E-03
4.7E + 01
7.0E-03
2.0E-OI
Reference or
Basis
Derived
IRIS, 1992
EPA, 199 la
IRIS, 1992
Derived
IRIS, 1992
Derived
EPA, 1991a
EPA. 1991a
Dermal Route*
2.9E-01 (I)
NC
NC
l.OE-03 (I)
4.0E-01 (I)
NC
2.4E+00 (I)
3.5E-04 (1)
l.OE-02 (I)
"Dermal RfDs were derived for volatile organics (V), semivolatile organics (SV), and inorganics (I) from the oral RfDs as
described in Subsection 6.2.3.3.
""Converted from a reference concentration (RfC) by assuming the inhalation of 20 m3 of air/day and a body weight of 70 kg.
'Value for 4,4'-DDT was used.
dValue is for the cis isomcr.
'The value for water was used to evaluate the surface water and groundwater ingcstion pathways; the value for food was used
to evaluate the sediment and fish ingestion pathways.
'Based on the RfD for food.
'Calculated from the current drinking water standard, assuming the ingestion of 2 liters of water/day and a body weight of 70
kg-
ACGIII-TWA = Derived from the time-weighted average developed by the American Conference of Governmental
Industrial Hygienists.
NC = Chemical is not of concern through this exposure route.
-------
7.4 Risk Characterization
For carcinogens, risks are estimated as the incremental
probability of an individual developing cancer over a life-time
as a result of exposure to the carcinogen. Excess life-time
cancer risk is calculated from the following equation:
" Risk = GDI x SF
where:
risk = a unit less probability (e.g., 2xlO~5) of an
individual developing cancer;
GDI = chronic daily intake averaged over 70 years (mg/kg-
day)
SF = slope-factor, expressed as (mg/kg-day)
-i
These risks are probabilities that are generally expressed in
scientific notation (e.g., IxlO"6) . An excess lifetime cancer
risk of IxlO"6 indicates that, as a reasonable maximum estimate,
an individual has a 1 in 1,000,000 chance of developing cancer as
a result of site-related exposure to a carcinogen over a 70-year
lifetime under the specific exposure conditions at a site.
The potential for noncarcinogenic effects is evaluated by.
comparing an exposure level over a specified time period
(e.g.,liver) within a medium or across all media to which a given
population may reasonably be exposed, the Hazard Index (HI) can
be generated.
The HI is calculated as follows:
Noncancer HI = CDI/RfD
where:
GDI = Chronic Daily Intake
RfD = reference dose; and
GDI and RfD are expressed in the same units and represent the
same exposure period (i.e., chronic, subchronic, or short-term).
Table 13 summarizes the total hazard indices and lifetime cancer
risks for all receptors. The values presented have been rounded
to 1 significant figure.
The total hazard index for both the child (6.88x10*°) and the
adult 3.78 exceeded the criterion of concern which is 1.0. The
elevated total hazard indices resulted from the contribution of
45
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Table 13
Summary or Total Hazard Indices and Lifetime Cancer Risks - All Receptors"
Receptor
Total Hazard Index6
Total Lifetime Cancer Risk0
Current Use (
Offsitc Resident
Onsite Worker
7E + 00 (child)
4E + 00 (adult)
4E-01
2E-04
2E-07
Future Use
Onsite Resident*1
Trespasser
Swimmer (Lake Miller)
2E+OI (child - surficial aquifer)
2E+01 (child - Upper Floridan aquifer)
2E+01 (child - Lower/Upper Floridan aquifers)
2E+01 (adult - surficial aquifer)
2E+01 (adult - Upper Floridan aquifer)
1C+01 (adult - Lower/Upper Floridan aquifers)
5E-03
7E-01
5E-03
5E-04
3E-04
(surficial aquifer)
(Upper Floridan aquifer)
(Lower/Upper Floridan aquifers)
1E-08
1E-05
'Values are rounded to one significant figure.
bA hazard index exceeding one (1E+00) is usually considered the benchmark of potential concern.
rMaximum cancer risk at hazardous waste sites is usually regulated in the range of IE-06 to 1E-04 (10"6 to 10"*). Risks of less
than IE-06 are generally not considered to be of concern.
dDifferent values for the same receptor reflect use of different aquifers, as indicated.
-------
the fish ingestion exposure route. Mercury had a hazard quotient
of greater than one through fish ingestion in both the child and
adult residential scenarios.
The total lifetime cancer risk to the off-site resident was
calculated to be approximately 2 in 13,000 (2.1xlO'4). This
value exceeds EPA's targe- risk rang- of 10"6 to 10"4 or 1 in 1
million to 1 in 10,000, t.-.e range wizh which EPA usually
regulates maximum risk at hazardous waste sites. The fish
ingestion exposure route contributed more than 99% of the risk.
Chemicals that were estimated to pose a greater than 10"6 risk
(but less than 10"4) through fish ingestion included "bis (2-
ethylhexyDphthalate, 1,1-dichloroethene, tetrachloroethene,
trichloroethene, vinyl chloride, and arsenic. Only arsenic posed
a risk of greater than 10~4, contributing 71% of the total risk.
There is no apparent risk of noncarcinogenic health effects posed
to the worker. The total hazard index was calculated to be
approximately 0.4, which is below the criterion of concern of
one. The lifetime cancer risk to the worker was calculated to be
approximately 2 in 10 million (2.17xlO~7). Cancer risks below
10'6 are considered to be below the EPA's level of concern.
The total hazard quotient for both the child and the adult
exceeded the criterion of one. The total quotient for the child
ranged from approximately 15 to 25. The total indic'es for the
adult ranged from approximately 11 to 21.
The estimated lifetime cancer risk calculated for the future on-
site resident ranged from approximately 1 in 10,000 to 4 in 1000,
depending on the aquifer that is assumed for domestic use.
Assuming use of the surficial aquifer, each of the exposure
routes associated with groundwater use exceeded a 10"4 risk,
except for the Ingestion of Groundwater while swimming route.
The groundwater ingestion route exceeded a 10"3 risk.
Tetrachloroethene, arsenic and vinyl chloride posed the greatest
risk. The surficial aquifer is not currently used for drinking
water purposes in the DeLand area because of poor background
water quality. It is highly unlikely that this aquifer would be
utilized for domestic purposes.
Assuming use of the Upper Floridan aquifer, each of the exposure
routes exceeded a 10"6 risk. Groundwater ingestion poses the
greatest risk at approximately 10"4. Assuming use of the mixed
Lower/Upper Floridan aquifers each exposure route posed greater
than a 10"6, but less than 10"4 risk, except for ingestion while
swimming which was below 10"6. Groundwater ingestion posed the
highest risk (3.96xlO"5).
The chemicals that were calculated to have hazard quotients that
exceeded the criterion of one or posed a cancer risk of greater
than 10"6 in the future on-site resident scenario are summarized
47
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in Table 14 by medium and exposure route. Chemicals with hazard
indices greater than 10 or that posed risks that exceeded 10^ are
also indicated.
Elevations in chromium levels were not shown to warrant
remediation in exposed areas according to the Baseline Risk
Assessment. Chromium contamination existing under current
surface coverings (paved areas or buildings) has no current route
of exposure and is not of immediate concern. However, if
structures or pavement are removed or excavation occurs on-site,
exposed soils must meet TCLP criteria or contain chromium at less
than 520 mg/kg to remain on-site without treatment. This level
was developed by EPA and FDER based on the assumption that 10% of
total chromium is hexavalent. This level has been determined to
be protective of human health and the environment.
Actual or threatened releases of hazardous substances from this
site, if not addressed by implementing the response action
selected in this ROD, may present an imminent and substantial
endangerment to public health, welfare, or the environment.
7.5 Ecological Effects
The area in which the Sherwood site is located is part of the
Outer Coastal Plain Forest ecoregion. This ecoregion is
dominated primarily by beech, sweetgum, magnolia, pine, and oak
forests. The predominant natural feature at the site is Lake
Miller, a 12-acre swamp lake that receives recharge from North
Lake Talmadge via a narrow canal, base flow from the surficial
aquifer, and Site runoff.
The Ecological Risk Assessment for the Sherwood Site served to
identify and estimate the actual and potential ecological impacts
associated with the release of chemicals from the Sherwood
Medical facility into the environment. This assessment focused
primarily on Lake Miller the primary environmental receptor for
the Sherwood Site.
Following the conclusion of the Remedial Investigation, EPA and
FDER determined that further study would be necessary to fully
characterize sediment quality in Lake Miller, as well as sediment
of a small area of wetlands located nearby. In order to further
characterize the nature and extent of the effects of elevated
chromium levels in Lake Miller sediments, EPA will conduct an
additional ecological study. Following the completion of the
additional study the Ecological Risk Assessment for Lake Miller
will be presented. This additional action will be addressed as
Operable Unit 3 for the Sherwood Medical Site. The Sherwood Site,
with the exception of Lake Miller and its immediate surroundings,
is largely unsuitable for wildlife habitat.
48
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Table 14
Chemicals Posing the Greatest Risk Potential
Future Onsite Resident Scenario
Medium/ i
. Exposure Route
Hazard Quotient
>1
>10
Lifetime Cancer Risk
>10^
>IQ4
Soil
Dust Inhal; :; >n
Soil digestion
Dermal Contact
Vegetable Ingestion
None
None
None
None
None
None
None
None
None
None
None
Tetrachloroethene
Arsenic
None
None
None
None
3urficial Aquifer
Ground water
Ingcslion
Noningestion Use
Ingestion While
Swimming
Telrachloroethene (C, A)
Trichloroethcne (C)
Arsenic (C,A)
None
None
None
None
None
None
None
Benzene
1,1-Dicliloroethene
Trichloroethene
Benzene
Chloroform
1,1-Dichloroethene
Tetrachloroethene
Trichloroethcne
Vinyl Chloride
Tetrachloroethene
Vinyl Chloride Arsenic
Tetrachloroethene
Vinyl Chloride
Arsenic
None
None
-------
Table 14 (con't)
Chemicals Posing the Greatest Risk Potential
Future Onsite Resident Scenario
(continued)
Medium/
Exposure Route
Dermal Contact While
Swimming
Vegetable/Fruit
Ingestion
Upper Floridan
Aquifer
Groundwater
Ingestion
Noningestion Use
Ingestion While
Swimming
Hazard Quotient
>1
Tetrachloroethene (A)
None
>10
None
None
Lifetime Cancer Risk
1 >\0*
1 , 1 -Dichloroethene
Trichloroelhene
Vinyl Chloride
Arsenic
>10^
Tetrachloroethene
None
Acetone (C,A)
Lead (C.A)
None
None
None
None
None
Bis(2-ethylhexyl)phthalate
alpha-Chlordane
Heptachlor
Trichloroethene
Heptachlor
Tetrachloroethene
Trichloroethene
Tetrachloroethene
Tetrachloroethene
None
None
-------
Table 14 (coii't)
Chemicals I'osing (he Greatest Risk Potential
Future Onsite Resident Scenario
(continued)
1
Medium/
Hxposure Route
Dermal Contact While
Swimming
Vegetable/Fruit
Ingestion
Mixed Lower/Upper
Floridan Aquifers
Groundwater
Ingestion
Noningestion Use
Ingestion While
Swimming
Dermal Contact While
Swimming
Hazard Quotient
>1
None
alpha-Chlordane (C, A)
>10
None
None
Lifetime Cancer Risk
MO"6
Bis(2-ethylhcxyl)phthalate
alpha-Chlordane
Heptachlor
Tetrachloroethene
Trichloroethene
Bis(2-ethylhexyl)phthalate
alpha-Chlordane
4,4'-DDE
>l
-------
Table 14 (con't)
Chemicals Posing the Greatest Risk Potential —
Future Onsite Resident Scenario
(continued)
Medium/ '
Exposure Route
Vegetable/Fruit
Ingestion
Hazard Quotient
>1
None
>10
None
Lifetime Cancer Risk
>1(T*
None
>10*
None
Surface Water
Fish Ingestion
Mercury (C,A)
None
Bis(2-ethylhexyl)phthalate
1,1-Dichloroethene
Tetrachloroethene
Trichloroethene
Vinyl Chloride
Arsenic
CM
in
(A) = Adult scenario.
(C) = Child scenario.
-------
No surface water bodies exist on site except as part of the IWTP.
The rest of the site consists of pavement or short mown grass.
The remedial action following this ROD in conjunction with
Operable Unit III will effectively protect Lake Miller.
8.0 DESCRIPTION OF ALTERNATIVES
A Feasibility Study (FS; was conducted to develop and evaluate
remedial alternatives to address the groundwater and_ soils at the
Sherwood Medical Site. The primary objective of the FS was to
determine and evaluate alternatives for appropriate remedial
action to prevent or mitigate the migration or the release or
threatened release of hazardous substances from the Site. The
following section of this ROD provides a summary of the four
alternatives that were developed as part of the FS.
The FS was conducted in several stages and used data gathered
during the Remedial Investigation as well as data gathered during
the Interim Remedial Measures study, for the identification of
ARARs and development of management strategies and remedial
alternatives to address contamination at the Site. The
groundwater beneath the Site is the primary medium of concern.
The surficial aquifer is the primary source of VOCs at the Site.
Significant amounts of VOCs are not present in the site soils;
therefore, there are no contaminated solid wastes or residues on-
site that are contributing to site contamination that require
remediation and handling. However, in accordance with the
requirements of 40 CFR 264 (the applicable regulations under the
Federal Resource Conservation and Recovery Act (RCRA)) , the
residues resulting from treatment must be considered. In
addition, there is no significant migration of site-related
substances, via surface water and sediments, beyond the eastern
shore of Lake Miller, which is on the Sherwood property,
Therefore, the focus of this FS was on the VOC contamination
contained in the surficial aquifer and all possible points of
migration. The primary VOCs detected in the surficial aquifer
are PCE and TCE. Their products of degradation, such as 1,2-
dichloroethylene and vinyl chloride, were also found in surficial
groundwater and are addressed by this ROD. Site related metals
such as trivalent chromium were detected at low levels in the
surficial aquifer. Non Site related metals such as arsenic and
cadmium were also detected in various media at the Site as well
as in background samples.
Remedial Action alternatives were initially identified and were
subject to screening to identify the best possible alternatives
for further consideration. The fncus of the screening process
was to eliminate technologies, based on information obtained from
the studies conducted at the Site, that would not be
53
-------
implamentable due to Site specific conditions or technical
impractibility.
Following this screening process, four alternatives were retained
for further consideration in the FS.
A detailed evaluation of the remedial alternatives based on the
following nine criteria was conducted. ' These criteria include:
1) Overall Protection of Human Health and the-Environment,
2) Compliance with Applicable or Relevant and Appropriate
Requirements (ARARs),
3) Long-Term Effectiveness and Permanence,
4) Reduction of Toxicity, Mobility, and Volume,
5) Short-Term Effectiveness,
6) Implementability,
7) Cost,
8) State/Support Agency Acceptance, and
9) Community Acceptance.
In addition a comparative analysis of the alternatives was
included for the remaining alternatives, which compared the
alternatives with each other.
8.1 Alternative 1 - No Action
In accordance with the National Contingency Plan (NCP), EPA has
evaluated a "No Action" alternative as part of the FS. The No
Action alternative serves as a basis against which other
alternatives can be compared. Under the No Action Alternative,
no remedial response would be performed on any of the media of
concern at the Site. There is no implementation cost associated
with this alternative. Monitoring would be conducted in all
groundwater aquifers on a semi-annual basis. Under this
alternative the treatment system installed as part of the Interim
Action would be turned off.
8.2 Alternative 2 - Limited Action
Alternative 2 would utilize institutional controls and long-term
monitoring. Reduction in the VOC levels in the surficial aquifer
54
-------
would be due to: 1) Slow volatilization over a long period of
time; 2) migration to Lake Miller; 3) migration to the Upper
Floridan aquifer, and 4) natural attenuation. Institutional
controls to be implemented would include; posting of signboards
around Lake Miller indicating "NO FISHING OR SWIMMING IN LAKE
MILLER", notification of the adjacent proper-'7 owner on Lake
Miller that hazardous substances are present ...n like Miller,
maintenance of current security fence around che 3ite property,
maintenance of current Sherwood policy restricting access to Site
by the public and prohibiting use of Lake Miller by Sherwood
employees.
This alternative would provide for continued monitoring of
surficial and Floridan Aquifers and Lake Miller. In addition,
any soils excavated on-site would be sampled and any soils
containing chromium greater than 520 mg/kg would be remediated or
disposed of off-site. Use of the Site would be restricted to
industrial operations.
In this alternative the treatment system installed as part of the
Interim Action would be turned off.
8.3 Alternative 3A - Groundwater Interception and Treatment
The objective of the groundwater extraction system is to
effectively reduce VOC concentrations present in the surficial
groundwater by effectively recovering and treating VOC
contaminated groundwater. This alternative woi__d completely
utilize the nine well extraction system installed as part of the
Interim Action for the Site. Using a groundwater model
(MODFLOW), it was determined that locating six surficial aquifer
extraction wells along the eastern side of Lake Miller and three
extraction wells in the southeast corner of the site would create
an effective capture zone. A margin of safety would be provided
by the three wells located along the southeastern corner of the
Site.
The air stripper installed as part of the Interim Action is the
treatment technology selected for this alternative. PCE and TCE
would easily be removed from the groundwater by the air stripper
to levels in compliance with FDER surface water quality and
groundwater standards. Other VOCs would also be easily removed
by the air stripper and will also meet all Federal and State
ARARS.
Since the concentrations of the background metals in the
surficial aquifer are generally low, no metal treatment would be
required.
55
-------
All of the institutional controls listed in Alternative 2 would
also be implemented for alternative 3A. Monitoring requirements
set forth as part of this alternative would include:
1. Floridan Aquifer monitor wells MW-201 through MW-205
will be monitored semi-annually for VOC;
2. Floridan Aquifer wells SMWS and SMFW will be monitored
quarterly for the first year and semi-annually
thereafter to determine the reduction of VOC
concentrations due to the continued pumping- from the
on-site water supply well SMWS. Water pumped from
water supply well is currently routed through an air
stripper.
3. Floridan Aquifer wells SMFA-1, SMFA-2, and SMFA-3 will
be monitored quarterly for the first year and semi-
annually thereafter to determine the reduction of VOC
due to continued pumping of on-site production wells
SMWS and SMSB.
4. Eight residential wells located east of the site on
Kepler Road and one residential well located west of
the site will be sampled and analyzed for VOCs semi-
annually.
5. Water levels will be recorded and samples taken from
the surficial aquifer monitor wells (MW-101 through MW-
114) quarterly for the first year and semi-annually
thereafter to determine the drawdown and VOC reduction
in the surficial aquifer. In addition these samples
will be analyzed for metals.
Monitoring of the surficial aquifer will continue until the EPA
and FDER determine that contamination in the surficial aquifer
has been remediated and the treatment system can be shutdown. In
order for shutdown to occur, two successive semi-annual rounds of
sampling must indicate that the remediation goals have been
reached. The Floridan Aquifer will be monitored until two
successive semi-annual sampling rounds indicate that the
contaminant levels have declined to acceptable levels.
Monitoring of the treatment effluent will continue as long as the
treatment system is in operation. Monitoring of residential
wells will continue until two successive rounds of sampling,
following start up of the treatment system, show no contamination
above drinking water standards. A round of confirmation sampling
will be conducted following system shutdown to ensure that
contaminant levels remain stable.
56
-------
8.4 Alternative 3B - Concentrated Area Interception and Treatment
In this alternative, groundwater will be extracted from two
localized areas near Lake Miller, identified with the highest
levels of VOC contamination in the surficial aquifer. The
objective of this extraction well system is to encompass areas
with VOC contamination above 1,000 parts per billion in the
capture zone. Groundwater would be recovered from three
extraction wells located in the primary concentrated contaminant
area and one well in the secondary concentrated contaminant area.
Although the capture zone includes most of the western side of
the site, it does not encompass the entire site, especially the
eastern half of the property where PCE and TCE contamination has
been detected in the surficial groundwater.
The treatment system would utilize the same air stripper
indicated in alternative 3A. The stripper would be operated at a
lower flow rate to account for fewer extraction wells.
The treated groundwater would be discharged to Lake Miller as in
Alternative 3A. All of the monitoring requirements and
institutional controls would be implemented in the same manner as
Alternative 3A.
9.0 SUMMARY OF THE COMPARATIVE ANALYSIS OF ALTERNATIVES
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 and in
Section 300.430 of the NCP. The major objective of -he FS was to
develop, screen, and evaluate alternatives for groun...water
remediation at the Sherwood site. The remedial alternatives
selected from the screening process were evaluated using the
following nine evaluation criteria:
o Overall protection of human health and the environment.
o Compliance with applicable and/or relevant Federal or
State public health or environmental standards.
o Long-term effectiveness and permanence.
o Reduction of toxicity, mobility, or volume of hazardous
substances or contaminants.
o Short-term effectiveness, or the impacts a remedy might
have on the community, workers, or the environment
during the course of implementing it.
o Implementability, that is, the administrative or
technical capacity to carry out the alternative.
57
-------
o Cost-effectiveness considering costs for construction,
operation, and maintenance of the alternative over the
life of the project, including additional costs should
it fail.
o Acceptance by the State.
o Acceptance by the Community.
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 primary balancing factors used to weigh major
trade-offs among alternative hazardous waste management
strategies; and
(3) Modifying Criteria - state and community acceptance are
modifying criteria that are formally taken into account
after public comment is received on the proposed plan
and incorporated in the ROD.
The selected alternative must be protective of human health and
the environment and comply with all ARARs or be granted a waiver
for compliance with a specific ARAR. Any alternative that does
not satisfy both of these requirements is not eligible for
selection and are not evaluated further in the comparative
analysis. The Primary Balancing Criteria are the technical
criteria upon which the detailed analysis is primarily based.
The final two criteria, known as Modifying Criteria, assess the
public's and the state agency's acceptance of the alternative.
Based on these final two criteria, EPA may modify aspects of a
specific alternative.
The following is a summary of the comparative analysis of
alternatives.
9.1 Overall Protection of Human Health and the Environment
Alternative 1 does not provide protection to human health and the
environment. The VOC migration pathways to Lake Miller and
potentially to the Upper Floridan aquifer would remain unchanged.
The current risks to human health due to swimming and fishing in
Lake Miller would continue. This alternative does not comply
58
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with federal or state ARARs. Therefore it will not be considered
further.
Alterative number 2 provides moderate protection to human health.
Restricted access to the Site and Lake Miller, along with the
land use restrictions would limit the potential for exposure.
However, continued migration of contaminants in the surficial
aquifer could threaten residential wells with ruptured casings.
VOC migration pathways to Lake Miller and potential for migration
to the Upper Floridan Aquifer would remain. Institutional
controls, if properly implemented and maintained would provide
moderate protection to human health but would not further reduce
the potential for harm to the environment.
Potential risks to human health and the environment are
sufficiently addressed in Alternative 3A. The reduction of VOCs
in the surficial aquifer will effectively mitigate the risk of
VOC migration to Lake Miller or the Upper Floridan Aquifer. The
use of institutional controls and an extensive groundwater
monitoring ensure protection of human health.
Potential risks to human health and the environment are not
sufficiently addressed in Alternative 3B. Since the groundwater
extraction capture zone does not include the total VOC
contaminated area of the Site, residual VOC contamination can
still potentially migrate to Lake Miller or to the Floridan
aquifer. Threats to human health and the environment are not
sufficiently addressed in this alternative.
9.2 Compliance with ARARs
Alternatives 1 and 2 do not comply with all State and Federal
ARARs. Surficial aquifer groundwater standards would not be met
since groundwater would remain untreated in the surficial
aquifer.
Alternative 3A complies with all Federal and State ARARs.
Currently, the VOC levels in the surficial aquifer do not meet
surface water or drinking water standards. The groundwater will
be treated to meet the Clean Water Act or Florida Surface Water
Quality Criteria as outlined in FAC 17-302, whichever is more
stringent, prior to discharge to Lake Miller. The surficial
aquifer will be treated until the remediation criteria have been
met.
Air emissions will easily meet the established guidelines of the
Clean Air Act or Florida Administrative Code 17-2 whichever is
more stringent.
Alternative 3B does not comply with all Federal and State ARARs.
Due to the fact that only the source areas of the groundwater
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would be treated, PCE and TCE may not be completely removed and
may remain on Site at levels above applicable water quality
standards. VOCs remaining would pose the risk of migration to
Lake Miller or the Upper Floridan aquifer and would not meet
ARARs in a reasonable time.
9.3 Short Term Effectiveness
Alternatives 1, 2, and 3B did not meet the threshold criteria
and, therefore, are not evaluated further. _
A short-term risk of exposure is encountered by workers in
Alternative 3A during the excavation activities for air stripper
installation. Dust-control measures have been implemented to
minimize this risk. Workers will be required to use appropriate
safety equipment and take precautionary measures during remedial
activities.
9.4 Long Term Effectiveness
Alternative 3A addresses potential risks to human health and the
environment. Since the surficial groundwater VOCs are totally
removed upon completion of the remedial actions, there will be no
migration of VOC to Lake Miller or to the .Floridan aquifer.
9.5 Reduction of Toxicity, Mobility and Volume of Contaminants
In alternative 3A, the toxicity and volume of contaminants will
be eliminated upon completion of the remedial actions, as the
surficial aquifer groundwater will be treated until there is no
threat posed to human health or the environment. The mobility of
the VOC in the surficial groundwater has been virtually
eliminated with the commencement of the remediation activities.
9.6 Implementability
Alternative 3A can easily be implemented. The construction
materials and technical expertise for implementing this
alternative are readily available.
For Alternative 3A, an air stripper design has been completed for
surficial aquifer groundwater remediation as part of the Interim
Action treatment system. No specialized construction techniques
will be necessary for installation of the air stripper. The
groundwater extraction wells have already been installed, and
pump tests have been conducted to verify its performance. A
groundwater monitoring program can be easily implemented due to
the existence of a current program to which additional wells can
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be added. Groundwater sampling and analysis is easily
implemented using conventional methods.
9.7 Cost
Present worth costs were calculated for each alternative to
provide a baselire for comparison. All of the costs represent
construction and 3&M costs of each alternative. The present
worth cost of Alternative 3A is $1,017,000.
9.8 State Acceptance
The State of Florida Department of Environmental Regulation
(FDER) has had input at virtually every step of the Superfund
process for Sherwood Medical. FDER provided valuable input
during the RI/FS process. FDER has reviewed this Record of
Decision and concurs with EPAs alternative selection.
9.9 Community Acceptance
EPA solicited input from the community on the Proposed Plan for
clean-up of the Sherwood Medical Site. Public comments were
addressed at a Public Meeting held in DeLand Florida on July 31,
1992. Comments received during the meeting and in written form
indicated community support for alternative 3A.
10.0 THE SELECTED REMEDY
Based upon consideration of the requirements of CERCLA, the NCP,
the detailed analysis of alternatives, and public and state
comments, EPA has selected Alternative 3A. Alternative 3A
consists of a groundwater remedy and institutional controls. The
selected remedy consists of the following components:
1. Extraction of the affected groundwater from the
surficial aquifer via the nine extraction well network;
2. Treatment of the recovered surficial aquifer
groundwater by an on-site air stripper for VOC removal;
3. Discharge cf treated water to Lake Miller;
4. Groundwater monitoring;
5. Access restrictions for the Site and Lake Miller;
6. Other institutional controls including; a requirement
for excavated soils to meet TCLP criteria or contain
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chromium at levels less than 520 mg/kg, and deed
restrictions requiring that the Sherwood Medical site
remain industrially zoned.
7. Continued operation of the Floridan Aquifer groundwater
recovery and treatment system associated with the
Sherwood's water supply well.
The surficial•aquifer groundwater treatment system has already
been installed as part of the Interim Action. The system
includes nine extraction wells and an air stripper. Following an
initial round of effluent sampling, that indicated successful VOC
removal, the system was started on July 31, 1992.
The components of the selected remedy are discussed in detail
below.
10.1 Groundwater Extraction
The objective of the groundwater extraction system is to
efficiently and effectively recover VOCs exeeding site cleanup
criteria present in the surficial aquifer groundwater by creating
a groundwater capture zone. Using the groundwater model MODFLOW,
it was determined that six wells located along the eastern side
of Lake Miller and three wells located in the southeast corner of
the site would create an effective capture zone in the surficial
aquifer. The six extraction wells located along the east side of
Lake Miller will capture groundwater moving toward the Lake. The
three extraction wells in the southeast corner of the site will
reduce the potential for off-site migration of the substances of
concern. This potential exists due to the mounding in the
surficial aquifer caused by the discharge of treated wastewater
from the IWTP.
Figure 10 depicts the predicted potentiomentric surface in the
surficial aquifer under pumping conditions.
The predicted draw down created when pumping groundwater from the
nine wells is depicted in Figure 11.
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SI ILRWOOD MEDICAL COMPANY
Pumping Rale (gpm)
EW I 15 EW4 50 EW 7 20
EW 2 20 EW 5 50 EW 8 20
EW3 t5 EW6 40 tW 9 20
Contour Interval = 1 It
59 — Equipolenlial Contour Line
CO
vD
Figure 10 PREDICTED POTENTIOMETRIC SURFACE IN THE
SURFICIAL AQUIFER - NINE PUMPING WELLS - ALTERNATIVE 3A
-------
SI II RWOOD MIOICAL COMPANY
Pumping Rale (gpm)
IW I 15 FW 4 50 LW / ;>()
FW2 20 FW5 bO rWH ;•()
l:.W;j (5 F.W6 40 IW'J 'A]
Contour Interval = 05 ft.
Figure 11 DRAWDOWN PREDICTED IN THE SURFICIAL
AQUIFER - NINE PUMPING WELLS - ALTERNATIVE 3A
-------
Results of groundwater modeling indicate that the majority of
groundwater moves southwest towards one of the six wells located
along the eastern side of Lake Mil. r.r, while a smaller portion is
directed to the three wells located in the southeast corner of
the site. The maximum expected yield from all of the wells
combined is approximately 325 gpm.
7 .a'groundwater velocity rross the site under pumping conditions
has been calculated to decermine the amount of time required for
groundwater to be intercepted by the extraction well field.
Under ideal conditions, groundwater located across the Site from
Lake Miller would require approximately 3 years to reach the
extraction well field and be intercepted (1,400' ft.). This model
includes a high degree of uncertainty and groundwater sampling
will be used to determine treatment completion.
10.2 Groundwater Treatment
Air stripping of the contaminated surficial aquifer groundwater
is the treatment technology to be utilized in this alternative.
Data analysis indicates that the upper 95% confidence level of
the mean concentration of PCE and TCE in the groundwater is 3,200
ug/L and 140 ug/L, respectively. These chemicals are easily
stripped from the water to meet the applicable surface water
quality standards for the treated groundwater. Vinyl chloride
and other VOCs determined to be present at lower levels are also
easily stripped to meet surface water standards.
Air emissions from the stripper will meet the guidelines
established by the Clean Air Act or, Florida Administrative Code
17-2 whichever is more stringent.
10.3 Treated Water Discharge
The treated water from the air stripper will be discharged to
Lake Miller. A single port diffuser will be installed at the end
of the cischarge pipe at a distance of 60 feet from the shore.
The treated effluent will meet the discharge criteria of the
Clean Water Act (40 C.F.R. § § 122-125) including the substantive
requirements of the NPDES program or, FAC 17-3 surface water
standards, whichever is more stringent.
According to the schedule set by EPA and FDER the effluent will
be sampled weekly for the first month, monthly for the first
quarter, quarterly for the first year and semi-annually
thereafter.
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10.4 Cleanup Levels
The purpose of this response action is to control risks posed by
ingestion of surficial aquifer groundwater. The carcinogenic
risk posed by a hypothetical future on-site resident ingesting
surficial aquifer groundwater is 3.42X10'3. The hazard index
associated with the same scenario is 1.32. Both of these values
are above EPAs level of concern.
This remedy will also address migration of surficial aquifer
contaminants to the Floridan Aquifer by requiring Sherwood to
continue operating their Floridan Aquifer water supply well and
associated treatment system.
Groundwater will have to meet clean-up criteria, in monitoring
well samples, for two successive semi-annual sampling rounds in
order for Site remediation to be considered complete. The
following table lists the remediation goals for specific
compounds which correspond to the MCLs set by the Safe Drinking
Water Act and, where more stringent, Florida groundwater
regulations. The remediation goal for acetone represents Florida
Groundwater Guidance Concentrations.
Chemical
Acetone
Trichloroethene
Tetrachlorethene
1,2- dichloroethane
Vinyl Chloride
Chromium
Cleanup Goal (ARAR)
0.700 mg/1
0.003 mg/1
0.003 mg/1
0.003 mg/1
0.001 mg/1
0.10 mg/1
Regulation
FGWGC
FAC 17-550
FAC 17-550
FAC 17-550
FAC 17-550
SDWA
FGWGC - Florida Groundwater Guidance Concentration
FAC - Florida Administrative Code
SDWA - Safe Drinking Water Act
10.5 Groundwater Monitoring
The groundwater monitoring program for this alternative will
include all monitoring activities proposed under the limited
action alternative and other activities as listed below:
1. Floridan Aquifer monitor wells MW-201 through MW-205
will be monitored semi-annually for VOC;
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2. Floridan Aquifer wells SMWS and SMFW will be monitored
quarterly for the first year and semi-annually
thereafter to determine the reduction of VOC
concentrations due to the continued pumping from the
on-site water supply well SMWS. Water pumped from the
water supply well is currently routed through an air
stripper.
3. Floridan Aquifer wells SMFA-1, SMFA-2, and SMFA-3 will
be monitored quarterly for the first year and semi-
annually thereafter to determine the reduction of VOCs
due to continued pumping of on-site production wells
SMWS and SMSB.
4. Eight residential wells that draw water from the Upper
Floridan aquifer located upgradient (east of Kepler
Road) and one residential well located downgradient
(Mills) will be sampled and analyzed for VOCs semi-
annually.
5. Water levels will be recorded and samples taken from
the surficial aquifer monitor wells (MW-101 through MW-
114) quarterly for the first year and semi-annually
thereafter to determine the drawdown and VOC reduction
in the surficial aquifer. In addition these samples
will be analyzed for metals.
10.6 Institutional Controls
Institutional controls will include:
l. Installation of 10 signboards around Lake Miller
indicating "NO FISHING OR SWIMMING IN LAKE MILLER".
Placement of these signs will be reviewed by EPA
personnel.
2. Installation of signs on all sides of the groundwater
treatment facility warning that it is a hazardous waste
treatment facility.
3. Notifying Mr. Mills, a property owner across Lake
Miller from Sherwood, that Lake Miller should not be
used for fishing or swimming purposes.
4. Maintenance of security fence to discourage trespassing
on the Site property and maintenance of current
Sherwood regulations restricting employee access to
Lake Miller.
5. Requirement that Sherwood notify FDER and EPA of plans
to excavate soils, demolish buildings, or remove
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pavement. Soils exposed as a result of these
activities will be required to meet TCLP criteria or
contain less than 520 mg/kg of chromium to remain on-
site untreated.
6. Requirement that Sherwood Medical Site remain
industrially zoned area or address elevated contaminant
levels in all environmental media at the site such that
the site does not pose a threat to human health and the
environment as defined by EPA and FDER.
10.7 Cost Summary
Table 15 summarizes the capital costs associated with the
implementation of the selected remedy 3A. Table 16 summarizes
the operation and maintenance costs associated with Alternative
3A.
11.0 STATUTORY DETERMINATIONS
EPA's primary responsibility at Superfund sites is to select
remedial actions that are protective of human health and the
environment. In addition, Section 121 of CERCLA establishes
several other statutory requirements and preferences. These
specify that when complete, the selected remedy for this site
must comply with applicable or relevant and appropriate
environmental standards established under Federal and State
environmental laws unless a statutory waiver is justified. The
selected remedy also must be cost-effective and utilize permanent
solutions and alternative treatment technologies or resource
recovery technologies to the maximum extent practicable.
Finally, the statute includes a preference for remedies that
employ treatment that permanently and significantly reduce the
volume,'toxicity, or mobility of hazardous wastes as their
principal element. The following sections discuss how the
selected remedy for the Sherwood Medical Site meets these
statutory determinations.
11.1 Protection of Human Health and the Environment
The selected remedy for the Sherwood medical Site protects human
health and the environment through extraction and treatment of
the affected surficial aquifer. Treatment of the surficial
aquifer will effectively reduce risk from exposure to the
surficial aquifer as well as prevent further migration of the
groundwater contaminant plume to the Floridan aquifers and Lake
Miller. The combined institutional controls along with the
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Table 15
Estimated Capital Costs for Alternative 3A:
Groundwater Interception and Treatment
Item
Total
(S)
1. Air stripper and associated equipment, including foundation
2. Piping and valves for groundwater collection and discharge
system
3. Electrical work
4. Instrumentation, including flow metering equipment
5. Health and safety equipment (for construction workers)
6. Access-restriction signs*
7. Subtotal
8. Mobilization/demobilization, construction management (22%)
9. Technology implementation, designs, plan specifications,
regulatory approval, insurance, bonds, and permits (22%)
10. Contingency (25%)
11. Total
55,100
87,200
127,900
24,100
10,000
1.000
305,300
67,200
67,200
76,300
5516,000
'Does not include administrative costs for deed restrictions.
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Table 16
Estimate of Annual O&M Costs for
Alternative 3A: Groundwater Interception and Treatment
Item
1.
2.
3.
4.
5.
6.
8.
9.
10.
11.
Description
Labor (2 hrs/day) — inspections
Maintenance — (5% of total equipment
cost)
Health and safety equipment
Utilities (electricity and chemicals)
Air stripper monitoring
• Water sample at inlet and outlet of
air stripper (VOC)
• Labor: 2 hrs/month
• Labor: report (quarterly)
Groundwater monitoring
• Samples (66 VOC/4 blanks/
4 duplicates)
• Labor: sampling
• Labor: report
• Other expenses
Subtotal (rounded)
Administrative (15%)
Contingency (25%)
Total (rounded)
- Quantity
520 hrs/year
24
24
so
74
60 hrs/year
50 hrs/year
Unit Cost
($)
21/hr
lump sum
lump sum
250/sampie
21 /hi
35/hr
250/sample
50/hr
60/hr
lump sum
Total Cost/Year
($)
10,900
14,700
5,000
7,200
6.000
500
2,800
18,500
3,000
3,000
2.000
74,000
11,100
18.500
$104,000
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monitoring requirements will serve to ensure protection of human
health and the environment.
The current risks associated with the site are a carcinogenic
risk of 2xlO~4 for the current off-site resident and 2x10"' for
the current worker. The Hazard Indices are 4 and 0.4 for the
off-site resident and the on-site worker respectively. Through
implementation of the selected remedy risk levels should be
effectively reduced to acceptable levels.
Potential short term risks will be controlled through the
utilization of standard engineering practices. —
11.2 Compliance with Applicable or Relevant and Appropriate
Requirements
Section 121 (d)(2)(A) of CERCLA incorporates into the law the
CERCLA Compliance Policy, which specifies that Superfund remedial
actions must meet any federal and state standards, requirements ,
criteria, or limitations that are determined to be legally
applicable or relevant and appropriate requirements (ARARs).
Also included is the provision that state ARARs must be met if
they are more stringent than federal requirements.
Applicable requirements are defined as cleanup standards,
standards of control, and other substantive environmental.
protection requirements, criteria, or limitations promulgated
under Federal or State law that specifically address a hazardous
substance, pollutant, contaminant, remedial action, location, or
other circumstance at a CERCLA site.
All potential ARARs for treating contaminated groundwater at the
Sherwood Medical Site are presented below. Where VOCs and
inorganic compounds affect groundwater, the Safe Drinking Water
Act (SDWA) provides potential ARARs for establishing cleanup
goals, i.e., Maximum Contaminant Levels (MCLs). In addition, the
State of Florida has established MCLs under Florida
Administrative Code (FAC) for specific Volatile Organic
Compounds, which, when more stringent than the federal MCL, have
been selected as the cleanup goals for this project.
The recommended alternative was .found to meet or exceed the
following ARARs.
11.2.1 Chemical Specific Requirements
Clean Water Act (CWA) / Safe Drinking Water Act (SDWA)
Safe Drinking Water Act (40 C.F.R. § § 141, 142 and 143), which
specifies the MCLs for the contaminants of concern that will be
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applicable as the remediation levels for contaminated
groundwater. However, should the State drinking water standard
under Florida Administrative Code (FAC) 17-550, for a particular
contaminant be more stringent, the State standard will be used as
the remediation level.
Clean Water Act (40 C.F.R. § § 122-125) which specifies the
substantive requirements of the National Pollutant Discharge
Elimination System (NPDES). The treatment system will meet the
substantive requirements of the NPDES program but will not be
permitted since it is an on-site action. However, sJiould the
State effluent limitations for surface water, under 17-302, be
more stringent, the State standard will be applicable.
Florida Administrative Code (FAC) 17-550
FAC 17-550 establishes contaminant concentrations acceptable in
potable water. These standards will be applicable when more
stringent than the federal MCL.
Resource Conservation and Recovery Act (RCRA)
RCRA (40 C.F.R. § 261.31) applies to chemical concentrations in
groundwater. RCRA is relevant and appropriate.
Florida Administrative Code Chapter 17-302
FAC 17-302 establishes effluent limitations and operating
requirements for surface water discharge. This requirement will
be applicable in those instances where it is more stringent than
an applicable Federal requirement.
Florida Administrative Code Chapter 17-736
FAC 17-736 requires that warning signs be placed on all sides of
the groundwater treatment facility with the warning that there is
a hazardous waste treatment system present. FAC 17-736 is
applicable.
Florida Groundwater Guidance Concentrations
Health based guidance concentrations developed using EPAs
Integrated Risk Information systems.
11.2.2 Action Specific Requirements
Clean Air Act (CAA) (40 C.F.R. § 61, CAA § 112)
CAA applies to air emissions from treatment technologies, such as
air stripping. Also, 40 C.F.R. § 51, 61, and 112. Since
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treatment will occur on-site, only the substantive requirements
of the PSD permit must be met. The CAA is applicable.
Florida Administrative Code 17-550
FAC 17-550 establishes drinking water MCLs for groundwater and
effluent from treatment systems. These standards will be
applicable when more stringent than the Federal reg-__ations under
the SDWA.
Florida Administrative Code 17-2 ~~
FAC 17-2 applies to air emissions from treatment technologies,
such as air stripping. Standards included in this regulation
will be applicable when more stringent than Federal regulations
under the Clean Air Act.
11.2.3 Location Specific Requirements
Endangered Species Act (ESA) (50 C.F.R. § 402)
The selected remedy is protective of species listed as endangered
or threatened under the ESA. Requirements of the Interagency
Section 7 consultation process, 50 CFR part 402 will be met. The
U.S. Department of Interior (DOI) and the U.S. Fish and Wildlife
will be cc suited during the RD to ensure that endangered or
threatened species are not adversely impacted by implementation
of this remedy. The ESA is a relevant and appropriate
requirement.
11.3 Cost Effectiveness
This remedy employs a proven technology which can be easily
implemented at the Sherwood Medical Site. This technology
provides the most cost effective treatment when compared to the
other alternatives due to its ability to most effectively treat
and limit further spread of contamination.
11.4 Utilization of Permanent Solutions and Alternative Treatment
Technology or Resource Recovery Technologies to the Maximum
Extent Practicable
EPA and the Florida Department of Environmental Regulation have
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 contaminant treatment at
the Sherwood Medical Site. The selected alternative complies
with the ARARs, EPA and the State have determined that the-
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selected remedy provides the best overall balance of tradeoffs in
the terms of the five balancing criteria: long term effectiveness
and permanence; reduction of toxicity, mobility, or volume;
short-term effectiveness; implementability; and cost.
Additionally, the selected remedy fulfills the two modifying
criteria: state acceptance: and community acceptance.
The selected remedy meets the statutory preference to utilize
permanent solutions and treatment technologies, to the maximum
extent practicable. Remediation of the surficial aquifer with
continual pumping and treating of the Floridan aquifer will
effectively permanently remove the contaminant plume from the
surficial aquifer and prevent further migration to the Floridan
aquifer or Lake Miller the primary environmental receptor at the
Sherwood Site.
11.5 Preference for Treatment as a Principal Element
The principal threats posed to human health and the environment
are addressed through the use of air stripping, a proven
treatment technology. Therefore, the statutory preference for
remedies that employ treatment as a principal element is
satisfied.
11.6 Documentation of Significant changes
The Proposed Plan for the Sherwood Site was released for public
comment on July 23, 1992. The Proposed Plan identified the Pump
and Treat System with institutional controls and groundwater
monitoring as the preferred alternative for this action. EPA
reviewed all written and verbal comments submitted during the
public comment period. Upon review of these comments, it was
decermined that no significant changes to the remedy, as it was
originally identified in the Proposed Plan, were necessary.
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