United Slates
Environmental Prot« Jon
Agency
Office of
Emergency and
Remedial Response
EPA/ROD/R04-86/007
April 1986
&EPA
Superfund
Record of
Hollingsworth, FL
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TECHNICAL REPORT DATA
/Please read Initrucnons on the reverie before completing)
1. REPORT NO.
EPA/ROD/R04-86/007
2.
3. RECIPIENT'S ACCESSION NO.
. TITLE AND SUBTITLE
SUPERFUND RECORD OF DECISION
llingsworth, FL
5. REPORT DATE
ApriT If), IQflA
I. PERFORMING ORGANIZATION CODE
7. AUTMOR(S)
8. PERFORMING ORGANIZATION REPORT NO
9. PERFORMING ORGANIZATION NAME AND ADDRESS
10. PROGRAM ELEMENT NO.
1 I. CONTRACT/GRANT NO.
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
401 M Street, S.W.
Washington, D.C. 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final ROD
14. SPONSORING AGENCY CODE
800/00
13. SUPPLEMENTARY NOTES
tBSTnACT
The Hollingsworth Solderless Terminal Company (HSTC) site is located in Fort
Lauderdale, Broward County, Florida. The 3.5-acre site was in operation from 1968 until
the company closed the facility on October 1, 1982. HSTC manufactured solderless
electrical terminals. The manufacturing process included heat treatment in molten salts
baths, degreasing, and electroplating. For approximately eight years, HSTC disposed of
wash water and process wastewater contaminated with trichloroethylene (TCE), and/or
~vy metals into drainfields adjacent to the manufacturing plant. Disposal practices
[the site have been clearly documented; however, the amounts of TCE disposed of and
rne exact locations and duration of disposal remain undocumented. The waste TCE was
used both as a degreasing solvent and for cleaning floors, equipment, etc. Primary
contaminants at the site include TCE, vinyl chloride, trans-l,2-dichloroethene, and to a
lesser extent, nickel, tin, and copper.
The selected remedial action for this site includes: excavation, aeration and
replacement onsite of volatile organic contaminated soils and the recovery of
contaminated ground water from the sand zones of the aquifer, with treatment and
reinjection into the aquifer. Capital cost for the selected remedial action is
estimated to be $653,730 with O&M costs approximately $364,215 per year.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.lOENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Croup
Record of Decision
Hollingsworth, FL
Contaminated Media: gw, soil
Key contaminants: Trichloroethylene (TCE),
vinyl chloride, trans-l,2-Dichloroethene,
heavy metals, VOCs
18. DISTRIBUTION STATEMENT
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21. NO. OF PAGES
50
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None
22. PRICE
i 2220-1 (R«». 4-77) PREVIOUS coiTION is OMOLCTC
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Record of Decision
Remedial Alternative Selection
Site: Hollincsworth Solderless Terminal Company
Fort Lauderdale, Florida
DOCUMENTS REVIEWED
I an basing my decision primarily on the following documents describing
the analysis of cost-effectiveness of remedial alternatives for the
Hollingsworth Solderless Terminal Company site.
Feasibility Study for Hollingsworth Solderless Terminal Company.
Feasibility Study Work Plan for Hollingsworth Solderless Terminal
Company (summarizes all previous remedial investigation efforts)
Sumnary of Remedial Alternative Selection
Responsiveness Summary
State of Florida review cements
Staff recommendations
DESCRIPTION OF SELECTED REMEDY
The selected remedy includes:
- Excavation, aeration and replacement on-site of volatile organic
contaminated soils at the east drainfield of plant #1.
- Recovery of contaminated groundwater from the sand zones of the
aquifer, treatment and reinjection into the aquifer.
When this remedy is complete, there will be no continuing operation and
maintenance requirements.
DECLARATIONS
Consistent with the CcmprehelSsive Environmental Response, Compensation, and
Liability Act of 1980 (CERCLA), and the National Contingency Plan (40 CFR
Part 300), I have determined that the aeration of soils and recovery,
treatment and reinjection of groundwater at the Hollingsworth Solderless
Terminal Company site is a cost effective remedy and provides adequate
protection of public health, welfare, and the environment. Ihe State of
Florida has been consulted and agrees with the approved remedy.
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I have also determined that the action being taken is appropriate when
balanced against the availability of Trust Fund monies for use at. other sites,
Date Jack E. Ravan
Reaional Administrator
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RECORD OF DECISION
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
HOLLINGSWORTH SOLDERLESS TERMINAL COMPANY SITE
FORT LAUDERDALE, FLORIDA
Introduction
The Hollingsworth Solderless Terminal Company (HSTC) Site was proposed for
inclusion on the National Priorities List (NPL) in October 1981 and was
included on the first official NFL published in December 1982. The HSTC
Site has been the subject of a Focused Feasibility Study (FFS) conducted by
the REM II, Region IV Contractor, Camp Dresser & HcKee Inc.'(CDM). A
formal remedial investigation was not conducted at the si^e due to the
large amount of site investigation data previously collected. However,
additional site-specific soil and ground water quality studies and a ground
water modeling study were conducted by CDM prior to initiation of the
feasibility study in order to describe current site conditions.
A single decision document has been prepared to summarize remedial
alternative selection for remediation of the HSTC Site, and is presented
herein.
Site Location and Description
The HSTC Site is located at 700 NW 57th Place in Fort Lauderdale, Broward
County, Florida, as illustrated in Figure 1. The site encompasses
approximately 3.5 acres. HSTC operated at this location from 1968 until
the company closed the facility on October 1, 1982. The HSTC facility
consisted of two buildings separated by NW 57th Place. The entire facility
is bounded on the north and east by asphalt alleyways, to the south by NW
57th Court, and to the west by other properties which run west to Power line
Road. The HSTC facilities have been labeled Plant No. 1 (the southern
structure) and Plant No. 2 (the northern structure). Plant No. 1 was the
manufacturing plant where contaminants were generated and discharged into
the various drainfields. Plant No. 2 was strictly an assembly and storage
183/11
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- N -
BROWARO COUNTY, FLORIDA
FORT LAUOEROALE
NOT TO
SCALE
. ' HOLL1NGSWORTH
! SOLDERLESS
TERMINAL COMPANY
REM II
GENERAL LOCATION MAP
HOLLINQSWORTH SOLDERLESS TERMINAL COMPANY
FORT LAUOEROALE. FLORIDA
FIGUHC NO.
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1
•OtlTX
PIPI
ASPHALT ALLEYWAY
MPWtr ALLtTWT
!• HOMTN
SCAl
•UNPACI tUCNAJUl
fl.H. 57th PLACE
VASTI »IS»OtAk PIP! _
tAiT
OUAIHPItk
• ••r
li.M. 57th COURT
JB
-------
facility which did not utilize wet processes. Figure 2 shows the relative
between the two structures and the various waste disposal areas associated
with the operation. The building which once was designated as Plant No. 1
has been subdivided and is currently being rented tc a variety of small
industrial/commercial tenants. The building designated as Plant No. 2 is
currently vacant.
Land use in the vicinity of the HSTC Site is a mix between commercial,
industrial, and residential. The area immediately surrounding the site has
a high density of medium and light industry. The Fort Lauderdale Executive
Airport is located approximately one-quarter mile to the west. Seaboard
Coastline Railroad is located east of the site, and Interstate 95 (1-95) is
a few hundred feet beyond the railroad. There is a large residential
community on the east side of 1-95. In general, this area of Fort
Lauderdale is heavily developed and is experiencing increasing development
pressure. The area surrounding the commercial/industrial complex around
the Hollingsworth property and the Executive Airport and well field is
rapidly becoming a medium to high density residential area.
The nearest wells that are part of the City of Fort Lauderdale's primary
water supply, the Prospect Well Field, are located approximately two miles
to the west of the HSTC Site. The Prospect Well Field includes 38
functional wells (see Figure 3) located around the Fort Lauderdale
Executive Airport and Prospect Lake. The closest wells to the HSTC Site
are Wells 8 and 12. All of the easternmost wells are within 0.25 and 0.5
miles of the• HSTC Site. Wells 1, 4, 10, and 13 are no longer used or in
existence (wells 1 and 4 are not shown in Figure 3). These wells are
either contaminated or were destroyed by lawn maintenance equipment.
Although functional, most of the wells in the Executive Airport area are
used only during periods of extreme conditions. Host of these wells are
contaminated with volatile organic compounds from a variety of industrial
sources in the area. The locations of the well field wells are shown in
Figure 3.
183/11
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LEGEND
PROSPECT PRODUCTION WELLS
HOLUNO8WORTH SITF
CD
CO
CO
u
m
®
ABANDONED WELLS
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The Biscayne Aquifer, which is a highly permeable, wedge-shaped, unconfirmed
shallow aquifer composed of limestone and sandstone, underlies the site and
is the primary source of drinking water for 3 million residents of South
Florida. Both the Executive Airport and Prospect Lake wells tap the
Biscayne Aquifer for water supply. The top of the aquifer is near the
natural ground surface and its base is approximately 250 feet below ground
surface in the area of the site. The upper 60-70 feet of the aquifer are
primarily composed of fine to medium grained sands. This zone is underlain
by a transition zone of cemented shell and sandstone and finally by the
limestone which forms the major water producing zone of the Biscayne
Aquifer. The regional direction of ground water flow is southeast.
The Atlantic Ocean is located approximately five miles to the east of the
site and the Everglades lie about 10 miles to the west. Cypress Creek
Canal is located approximately 1.5 miles north of the site and Middle River
Canal is located about 2 miles to the south. The average rainfall for this
area is approximately 60 inches per year/ much of which comes in short,
intense thunderstorms during the summer months. The site is located within
the 100 year flood plain and is topographically flat.
Site History and Enforcement Activities
From 1966-1982, HSTC was in the business of manufacturing solderless
electrical terminals, consisting of a conductive metal portion and a
plastic sleeve. The terminals were designed to attach by means of crimping
rather than by soldering. The manufacturing process included heat
treatment in molten salts baths, degreasing, and electroplating. The
primary contaminants of concern at the site include trichloroethene
(trichloroethylene), vinyl chloride, trans-l,2-dichloroethene, and to a
lesser extent, nickel, -tin, and copper.
For approximately eight years, HSTC disposed of wash water and process
wastewater contaminated with trichloroethene (TCE), and/or heavy metals
into drainfields adjacent to the manufacturing plant (see Figure 2).
Disposal practices at the site have been clearly documented; however, the
183/11
-------
amounts- of TCE disposed of and the exact locations and duration of disposal
remain undocumented. The waste TCE was used both as a degreasing solvent
And for cleaning floors, equipment, etc.
As early as 1977, the Broward County Environmental Quality Control Board
(BCEQCB) was aware of the HSTC operation and began investigating HSTC
disposal practices. Between 1977 and 1980, HSTC supplied information to
BCEQCB concerning disposal practices, effluent quality, and proposed
modifications to their operation, designed to effect compliance with BCEQCB
standards. The full potential for ground water contamination at the HSTC
Site was not realized until 1980 when BCEQCB discovered the use of an
injection well for waste disposal during a routine site inspection. BCEQCB
was initially the lead regulatory agency. The Florida Department of
Environmental Regulation (FDER) became aware of the problems at HSTC when
the county requested assistance from EPA under the Comprehensive
Environmental Response, Compensation and Liability Act (CERCLA) program in
June 1981. At that time, HSTC also applied for RCPA interim status (Permit
No. FLD 004119681) for their electroplating operation. This permit was
never utilized and was allowed to expire. HSTC had no other regulatory
permits. In November 1981, HSTC filed for Chapter 11 status under the
Federal Backruptcy Code.
Pursuant to CERCLA procedures, a Remedial Action Master Plan (RAMP) was
commissioned by EPA in 1982 as the first step toward site cleanup. The
RAMP was prepared by the Region IV CERCLA contractor, Ecology and
Environment, Inc. (E&E), of Decatur, Georgia, based on data supplied by
HSTC consultants In addition to the RAMP, several investigations were
conducted by consultants to HSTC. These investigations were partially
controlled by the Federal court system, under provisions of Chapter 11 of
the Federal Bankruptcy Code. The HSTC consultants include Enviropact, Inc.
(Enviropact) of Miami Springs, Florida, and Geraghty & Miller, Inc. (G&M).
of West Palm Beach, Florida.
183/11
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To date, field investigations and other studies of this site-have included:
o Installation and sampling of 20 temporary, onsite (PVC) monitor
wells
i
o Installation and sampling cf nine permanent offsite
(stainless-steel) monitor wells
o Collection and analysis of 41 surface and subsurface soil samples
for metals
o Collection and analysis of 13 subsurface soil samples for volatile
organics
o Installation of 10 shallow, temporary observation wells for water
table measurements
o Contaminant transport modeling of pollutants discharged onsite, in
relation to nearby well fields
Enforcement Analysis
Hollingsworth Solderless Terminal Company owned and operated the facility
from 1968 until manufacturing operations were ceased in October 1982. The
company has been operating as a Debtor-in-Possession under the provisions
of Chapter 11 .-of the United States Bankruptcy Code since November 6, 1981.
The site was placed on the National Priority List in October 1981. Since
that time the company has attempted to be responsive to Agency requirements
for a Remedial Investigation/Feasibility Study, but has fallen short,
probably due to financial considerations. The Agency completed the work
begun by the company to investigate the site and has completed the
feasibility study. The company maintains that a no-action remedy would be
the appropriate site response, however they have indicated they may be
willing to conduct or fund a portion or all of the remedy if certain
conditions are met.
183VU
-------
Upon the finalization of the Record of Decision, the Agency intends to
formally notify the company of the selected remedy and initiate
negotiations with them for the conduct of the remedy. Negotiations with
the company will not exceed 60 days, thereafter if the company does not
formally commit to perform the remedy with assurances that adequate funding
is available to complete the remedy in a timely manner, EPA will proceed
with a Fund financed Remedial Design/Remedial Action.
Current Site Status
In 1981 and 1982, 18 monitor wells were installed on the HSTC property to
investigate ground water contamination problems at the site as shown on
Figure 4. These wells were generally 20, 50, 75, and/or 100 feet deep; no
offsite wells were installed. In 1983, a monitor well (MW-1) and test well
(TW-1), both of which are approximately 250 feet deep, were installed for
conducting pumping/aquifer tests. Ground water data from all of these
wells showed that TCE was present at concentrations ranging from <1.0
microgram per liter (ug/1) to 4,300 ug/1; dichloroethene was present at
concentrations ranging from <1.0 ug/1 to 2,160 ug/1, and trichloroethane
was not present. In general, the highest concentrations of contaminants
were found in samples collected from the 50 and 75-foot depths. Contam-
inants were not found in the test well. However, all three of the afore-
mentioned contaminants were present in samples collected from depths
between 106 and 230 feet during construction of the monitor well, which is
located next to the east well cluster. Multiple depth sampling was per-
formed during construction of both the test well and monitor well. Metals
(copper, tin, nickel, lead, and zinc) were analyzed for, but were not
present at measurable concentrations in ground water samples collected from
any of the shallow or deep wells. Since no offsite ground water samples
were analyzed, the extent of offsite contamination, at that time, was
unknown.
183/11
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*2- NORTH FIELD-;
u.
"'
# v
ASPHALT ALLEYWAY
"~" ~ I I
PLANT ^B| PLANT
:; h rj h r^
J*2A
*2B
"
* PN5 ; '
TEST WELL * e r-H
jVV-1 *7 D1 *<
*PS9 \;*8 i
*PS5 . \ i
M P**/**
•J" N
* MONITOR WELL
1 1
.*. 57tn PLACE
j. i
02 PLANT *1
* B ^--^ E f
>
?P^/
" NOT TO
SCALE
to*
5
|
» MONITOR WELL\
W ?7th COURT MW— 1 ^
.n. 3/tn V.UUH i MVY I
REFERENCE: ECOLOGY AND
ENVIRONMENT, WC. - DECEMBER 1962
REM II
ONSITE MONITOR WELL LOCATIONS
HOLLINGSWORTH SOLDERLESS TERMINAL COMPANY
FORT LAUOERDALE. FLORDA
^K.
:
FIGURE NO.
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Also during 1981 and 1982, soil samples were collected from the known
contaminated areas and analyzed for copper, tin, nickel, and lead. Most of
the samples contained various combinations of the metals at individual
concentrations in the 1-10 milligram per kilogram (mgAg) range. However,
a number of the samples contained metals at concentrations in the 100-1,000
mgAg range. A majority of these samples came from worst case locations
(i.e. near the discharge point in the electroplating wastewater drainfield
and the overflow discharge points). In the fall of 1984, Bnviropact
collected soil samples from the overflow area north of Plant 2 and analyzed
them for total and extractable copper, lead, nickel, and tin. In a major-
ity of the samples, metals levels were below detection (1 mgAg), for both
total and extractable metals. In the remaining samples, metals concentra-
tions were in the 1-10 mgAg range, which are concentrations that are
likely to be found in soil under normal or ambient conditions. In par-
ticular, the concentrations of lead and nickel, the two most toxic metals
that have been found onsite, were within the range of ambient conditions.
Due to the fact that the toxicity of tin, and copper, is low, and the fact
that these metals in addition to nickel should readily precipitate from
solution and become bound as hydroxides and/or carbonates in the limestone
formation, they do not present an environmental or public health threat via
the water supply. Even if these contaminants reached the water supply
wells, they would be readily removed by the water treatment process. Lead,
which was also found at the site, does not readily leach from soils and the
concentrations present in the soils are well below levels established as
cleanup criteria (1,000 mgAg) for other hazardous waste sites in south
Florida (e.g., Pepper's Steel and Alloys) where lead is a primary contami-
nant. The cleanup criterion is based on the leachability of lead and
predicted concentrations-in the ground water.
In early 1985, nine additional offsite monitor wells were installed around
the HSTC Site. These wells and seven of the older monitor wells were
sampled and the samples were analyzed for the priority pollutant volatile
organic compounds, including those previously found onsite. The new wells
were installed in three clusters of three wells (25, 55, and 100 feet
deep). Two of the well clusters are located downgradient of the site, one
11
183/11
-------
about 500 feet to the southeast, and one approximately 200 feet to the
southwest. Contaminants were not present in any of the off site, down-
gradient wells. The third new well cluster, which was located slightly
upgradient of the site, showed contamination, in the 55-foot well. This is
most likely due to contaminants which were discharged between the Plant 2
buildings and to the field north of Plant 2. Of the seven older wells
sampled, the four wells (cluster of 25, 50, 75, and 100 foot wells) at the
southeast comer of Plant 1, next to the east drainfield, showed volatile
organic contaminations at concentrations similar to those reported in 1981
and 1982. The primary difference between the two data sets is the presence
of vinyl chloride at substantial concentrations (200-6,000 ug/1) in samples
collected from the 25, 50, and 75-foot wells of the east well cluster
during the 1985 sampling event. Apparently, vinyl chloride analyses were
not performed on samples collected in 1981 and 1982. Vinyl chloride is a
known carcinogen, and it is a cannon contaminant of the industrial-grade
TCE used as the degreasing agent for various plant operations by HSTC.
Vinyl chloride was not present in any of the samples taken from the offsite
monitor wells.
The recent ground water analyses indicate that the contaminants, which were
originally introduced on the ground, have migrated a short distance primar--
ily in a vertical direction, through the upper sand zone of the aquifer.
Migration of these contaminants is apparently being retarded at a depth of
50-70 feet below land surface (bis), in a zone where the formation changes
from sand to sandstone and cemented shell. Since the current concentra-
tions are very similar to previous concentrations, it appears that contami-
nants have not migrated substantially in the horizontal or vertical direc-
tions through the sand zone. This type and rate of movement is typical in
settings, such as this, where the ground surface and ground water gradient
are essentially flat and where a majority of the surrounding area in imper-
vious. In the limestone or production zone of the aquifer which occurs at
approximately 100 feet bis, water moves much more rapidly (300-600 feet per
year compared to 5-80 feet per year in the sand portion of the aquifer),
readily diluting and transporting contaminants offsite. Considering the
12
183/11
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concentrations of contaminants in relation to the vast water .bearing and
storage capacity of the Biscayne Aquifer, the absence of measurable levels
of contaminants in the production rone at the site is not unexpected.
In the past, attention has been focused on the fact that the HSTC Site lies
within close proximity to the City of Fort Lauderdale's Prospect Well
Field. A number of the easternmost Executive Airport wells have been
abandoned due to the presence of volatile organic contaminants, including
those found at the HSTC Site. However, recent investigations and site
inspections by the Broward County Environmental Quality Control Board have
identified at least 12 companies surrounding the Executive Airport that use
degreasing solvents and dispose of their wastes in a manner that may be
directly impacting water quality in the Executive Airport wells.
In late 1984, COM performed contaminant transport modeling of the HSTC Site
in relation to the nearby city wells. A number of pumping and discharge
scenarios were investigated. The model presumed the worst case, most con-
servative set of parameters and still showed that the HSTC Site could not
be a source of contamination of the well field. Some of the other indus-
trial sources identified by BCEQCB were factored into additional model runs
and these data showed that any of a number of the other sources could be
sources of contamination of the well field. Currently, the Executive Air-
port wells are used only under extreme conditions; the Prospect Lake wells
operate at approximately 30 million gallons per day, and supply drinking
water for 150,000 to 200,000 residents and industries of the City of Fort
Lauderdale, Florida.
The results of the public health evaluation indicate that currently there
are no complete pathways -for exposure of the public by direct contact,
ingestion, or inhalation^of contaminants from the Hollingsworth Site, but
that the potential for future exposure does exist. The primary route of
potential future exposure is via installation of private wells or indus-
trial supply wells downgradient of the site. The primary contaminants of
concern for exposure via this route are vinyl chloride, TCE, and trans
1,2-dichloroethene. Based on the potential for future use of contaminated
ground water and the fact that the Biscayne Aquifer is a sole source
13
183/11
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drinking water aquifer, the cleanup goals for ground water remediation at
this site were based on both the 10" cancer risk factors and the State of
Florida primary drinking water standards. These standards are summarized
as follows:
Contaminant
(ug/1)
Vinyl chloride
Trichloroethene
trans 1,2-Dichloroethene
10 u
Life-Time
Cancer Risk
Factor
2.0
3.2
None
State of
Florida
Drinking
Water
Criterion
1.0
3.0
None
Proposed
Maximum
Concen-
tration
Levels (MCLs)
1.0
5.0
70.0
.HSTC
Cleanup
Goal
*
1.0
3.2
70.0
* FR. Vol. 50, November61985.
Because there is no 10 cancer risk factor or state drinking water
criterion for trans 1,2-dichloroethene, the proposed MCL for this compound
has been adopted. It should be noted that the trans 1,2-dichloroethene
will be removed by the preferred treatment process to levels well below the
cleanup goal to within the 1-10 ug/1 range.
The public health evaluation assumed that exposure to contaminated soil
could be either by ingestion or by dermal contact. Both copper and tin
were present in a few soil borings at concentrations above backgound
levels. -Inorganic tin and copper, at the concentrations found in the west
drainfield, are unlikely to present health problems under a most probable
ingestion scenario of 50-100 mg/day soil by children, or under worst-case
scenarios of ingestion of up to 500 mg/day. Ingestion of an excessive
quantity (500-5,000 mg) of soil contaminated with copper at concentrations
present in the west drainfield (1,000-10,000 mgAg) might pose a slightly
increased health risk, namely irritation of the mucous membranes and pos-
sibly gastric upset. Because the west drainfield is surrounded by a fence
and the fact that the property is isolated from residential areas, the
likelihood that a child would ingest contaminated soils at the HSTC site
is negligible. Nonetheless, cleanup goals were developed for metals
14
183/11
-------
contaminated soils at the HSTC site. However remediation of metals con-
taminated soils is considered an element of site remediation that exceeds
applicable cleanup criteria due to the concentrations present and the
negligible risk.
the cleanup goals for soil contaminated with metals have been established
based on the concentration of the metals in leachate from the soils (as
determined by an EP toxicity test), as negotiated between FDER and EPA in
1983. The limit for each metal in the leachate has been set at 10 times
the concentration of the appropriate state water quality criterion. The
cleanup goal for soils contaminated by volatile organics, primarily the
soils in the east drainfield, is 1 ogAg in the coil. However, testing in
1984 showed that the current concentrations of VOCs in the soils in and
underlying the east drainfield do not exceed this level. The primary
concern and reason for remediation of this VDC contaminated drainfield is
the presence of volatilized contaminants in the void space of the drain-
field and the shallow zone underlying the pavement. Remediation focuses on
venting these trapped vapors by a passive system, in a manner that mini-
mizes exposure of workers and the public, and also minimizes the cost of
treatment. During the process additional soil testing will occur to verify
that soil concentrations are below 1.0 mg/kg. The standards and goals for
soils remediation can be summarized as follows:
Soils
Contaminant
Copper
Nickel
Lead
Total VDC
Maximum Contaminant
Concentration in
Leachate from
Cnsite Soils
21.7 mg/i*
0.3 mg/1
0.2 mg/1
Not Applicable
State of Florida
Water Quality
Criterion
1.0 ug/1
0.1 ug/1
0.05 ug/1
None
HSTC
Cleanup Goal
10.0 mg/1
1.0 mg/1
0.5 mg/1
1.0 mg/kg
* This value was reported for a sample collected from the Gaidry property
in 1982. The area was resampled in 1984 and the highest concentration of
copper in the leachate was 0.2 mg/1.
15
183/11
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All of these cleanup goals were used as a basis for developing and
evaluating the various remedial alternatives. Several of the alternatives
include removal and offsite disposal of the aetals contaminated soil
despite the fact that the levels of contaminants at the site do not
currently exceed the cleanup goals. Remediation of metals contaminated
soils at this site is considered an element that exceeds requirements for
site remediation.
Since ground water contamination at this site is the primary concern,
determining the extent of contamination and establishing a target zone for
ground water remediation were important elements of the feasibility study.
The existing database indicates that movement of VOCs in ground water
within the surficial sands is primarily in the downward direction. This
conclusion follows the reasoning that VOCs are relatively insoluble in
water and heavier than water such that, in the absence of significant hor-
izontal ground water flow or obstructions to vertical movement, the VOCs
will slowly 'sink until they reach a geological barrier or a zone of ground
water of the same density. Further, it is presumed that once the VOCs
penetrate the limestone aquifer where ground water flow is significantly
greater, the contaminants are rapidly dispersed in both the vertical and
horizontal direction. The more rapid horizontal movement of water in the
production zone of the aqifer also enhances the vertical gradient via a
"chimney effect."
The localized'areas of ground water contamination onsite are potential
sources of offsite ground water contamination. Remedial action to remove
these zones of known ground water contamination before mixing with the
ground water in the underlying limestone aquifer were examined. Removal of
ground waters from the principal water bearing zone of the Biscayne Aquifer
(100*250 foot zone) in the vicinity of the site was determined to be not
feasible or necessary for the following reasons.
o The relatively high transmissivity of the Biscayne Aquifer promotes
rapid dispersion and dilution of contaminants.
16
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o Attempts to adequately remove VDC contamination from the Biscayne
Aquifer would require a regional water treatment program. This site
is currently a minor contributor to that contamination problem.
o The concentrations cf ccntar.inan'-T in the 100-250 foot zone of the
aquifer onsite have been shown to r>e at or below the applicalle
cleanup goals.
The area targeted for ground water remediation can be defined as the areal
and vertical extent of contamination by VOCs at concentrations above back-
ground concentrations and the ground water cleanup goals. The maximum
depth to which volatile organic contamination was most recently detected in
the ground water is 75 feet. The depth of the target area for ground water
remediation has been defined as the top of the limestone aquifer at the
sand-limestone interface. The average depth to the top of limestone is
approximately 75 feet in the vicinity of the site.
The areal extent of contamination is poorly defined because of variations
in the degree of ground water contamination at different locations and
depths. Based on the most recent ground water quality data, the offsite
monitor well clusters 3 and 8 shown in Figure 5 show no contamination.
Therefore, it is reasonable to assume a minimum and maximum areal extent of
surficial ground water contamination based on the known clean zones and the
known contaminated areas, and application of engineering judgement con-
cerning aquifer characteristics and the behavior of the contaminants at
this site. Based on this analysis, two zones have been identified as
target areas for ground water remediation. These two target areas are
shown in Figure 5. The inner target area was constructed by drawing a
200-foot radius circle around the onsite monitor wells 7 and C, which are
the two 50-foot monitor wells that were found to be contaminated and are
the two locations proposed for ground water collection. The larger target
area was constructed by"assuming a 400-foot radius of contamination around
each well. The final configurations of the target zones were drawn to
encompass the circles at both well locations and define one area for each
radius. The target areas encompass the entire area of the plant site
without including areas shown to have no detectable contamination.
17
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LEGEND
LOCATION OF MONITOR
WELLS
SCALE: 1**400'
TARGET AREA BOUNDARY
FOR REMEDIAL ACTION ON
SURFICIAL
CONTAMINATED
GROUNDWATER
MINIMUM ESTIMATED EXTENT
OF CONTAMINATION
MAXIMUM ESTIMATED EXTEN
OF CONTAMINATION
REM II
TARGET AREAS FOR GROUND WATER REMEDIATION
HOLLINQSWORTH SOLDERLESS TERMINAL COMPANY
. FORT LAUDERDALE. FLORIDA
FIGURE
5
-------
It is probable that the 400-foot radius selected as the boundary between
contaminated and uncontaminated ground water is larger than the actual
areal extent of contamination. Based on the available monitoring data,
contaminant properties, and soil and aquifer characteristics, the movement
of VOCs in the surficial sands is more likely to be in a vertical rather
than a horizontal direction. Thus, a smaller area (200-foot radius) for
ground water remediation has been included as a reasonable estimate of the
probable extent of contamination.
Alternatives Evaluation
The primary objectives of the feasibility study are to:
o Prevent further migration of contaminated ground water in the
aquifer by cleaning up existing contamination in the aquifer
o Remove the sources of contamination from overlying soils and
drainfields
The following six remedial action alternatives were considered:
Alternative 1 - No action
Alternative 2 - Modified no action
Alternative 3 - Offsite disposal of VOC and metals contaminated soils
at approved facilities with discharge of VOC
contaminated ground water to city sewer system for
treatment at a local WWTF
Alternative 4 - Onsite treatment of VOC contaminated soils with
continued monitoring of the ground water
Alternative 5 - Onsite treatment of VOC contaminated soils and ground
water with continued monitoring and recharge of treated
ground water to aquifer
Alternative 6 - Onsite treatment of VOC contaminated soils and ground
water with continued monitoring, recharge of treated
ground water to aquifer, and excavation and offsite
disposal of metals contaminated soils
19
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Initial Screening of Alternative Technologies
An initial screening of applicable alternative technologies was performed
to select those which best met the criteria specified in Section 300.68 of
the National Contingency Plan (NCP). This initial screening is illustrated
in Table 1.
Detailed Evaluation of Alternatives
After the initial screening, remaining technologies were assembled into
six remedial action alternatives for further consideration. Table 2
provides a summary of actions involved and costs for each of the six
remedial action alternatives which are described in greater detail to
follow.
Alternatives 1 & 2; No Action and Modified No Action
The "no action" alternative was rejected because the harm that the
contaminants could cause require that, at an absolute minimum, contaminants
must be tracked and their location known to provide time to design and
initiate a response to the impending exposure.
The potential impacts of both alternatives are identical except that with
the modified no action alternative long-term monitoring would provide a
mechanism for .identifying future threats to existing receptors. Currently
the monitor wells located to the southeast of the site between HSTC and the
nearest residential area show that the ground water is free of VOCs. If at
some time in the future, monitoring shows that contaminants are migrating
toward the residential area, an effort can be made to notify the public and
possibly restrict use of shallow wells in the area.
Both alternatives involve no soil excavation and no ground water treatment.
With the modified no action alternative ground water from two of the
existing stainless steel monitor wells in the vicinity of the site and one
additional well to be installed further upgradient will be sampled and
analyzed on a quarterly basis for an indefinite period to monitor the
•
20
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TABLE 1
SCREENING ALTERWOTVE TECHNOLOGIES FOR
APPLICABILITY TO HCLLJNGSWCRTH SITE
HQLLEC3WORIH SOUGHLESS TERimftL COMPANY
FORT LAUDEROALE, FLCKEA
FEW II
Possible Technology
Retained (R)
or Eliminated (E)
Reason
Eliminated
Soil Treatment or Disposal
o Disposal/containment in cnsite facility
o Disposal offsite at a RCRA landfill
o Cnsite incineration
o Encapsulation/capping
o Cnsite treatment
- soil flushing
- steam stripping (in situ)
- till and evaporate
- venting
Ground Water Containment/Extraction
o Containment (slurry walls, etc.)
o Extraction
Ground Water Treatment
o Activated carbon adsorbtion
o Air stripping
o Steam stripping
R
E
E
R
R
R
E
R
R
E
Site lies in the 100-
year floodplain; no
suitable location;
high water table
Not effective for a
majority of the
contaminated soilsj- not
cost effective
Low effectiveness and
high cost
Infeasible due to dept
to confining layer
(But, produces
concentrated waste
residue).
Too expensive and
energy intensive
183
-------
(continued)
Possible Technology
o Reverse osmosis
o Ozonation
t
Retained (R)
or Eliminated (E)
E
E
Reason
Eliminated
Not effective for
volatile organics
Technical infeasi-
o Wet air oxidation
Ground Water Disposal
o Purap untreated water to nearest
water treatment plant
o Treat and discharge water to ocean
o Treat and discharge to nearest surface water
o Treat and reinject water
No action (modified)
E
R
R
R
bility, cost and safety
considerations
Not effective at low
concentrations; energy
intensive
Too expensive, loss of
fresh water
183.
-------
1ARLC ?
SUfWARY Or PfltlKMAI RIMCUIAL AC Ml* Al MRNAHVCS ANO ASSOCIAIUI COSfS
HOUINGSMORIH SOlOWtSS IIHMINAL COWAMV
TORT LMIOlRDAir. »LOR IDA
RIM ||
Alternative
Ho. Criterion Components of the Rowed Ml Alternative I
1 tin Action Non«?
? No Action Installation of ow addition*! Monitor Met)
(modified) long-term Monitoring (II) years)
Abandonment of onstto Bonltur wells
IOIAL
J Offslte Disposal Abandonment of onslto pmnitor wells
(ncavation anrt offslte disposal of netals
contaMlnated soils
(iiravttlon and disposal of V(K contaminated
soils at CPA-approvd landfill
Rotovery jnd discharge of VOC contaminated ground
water to city sewer system for treatment
TOIAL
4 l)o>*s not meet Abandonment of onsltc monitor wells
applicable Onslte treatment of VOC contaminated soils
criteria, but (source control)
reduces threat long Icmi ground water Monitoring ( JO years)
IOIAL
Minimum Tost
present worth)
0
1 S.OOO
/ 4. (Mill
10. 01(0
t at .000
t lO.fMKJ
2SJ.4J4
61,1)6
I.607.6S?
l\. 121.2*2
I 10.000
s/. IM;
79.000
t 146.047
Hanimim Cost
(present worth)
0
t S. (Hid
M. IWO
10.000
t fl'1,000
t 10.000
7SJ.4I4
61.116
?.787,67?
tl.ll?.l
-------
TABU 2
(continued)
Alternative Minimum Cost Maximum Cost
No. Criterion Components of the Remedial Alternative (present worth) (present worth)
5 Mo^ts applI- Abandonment of onslte monitor wells t lO.O(M) t 10.000
cable criteria Onslie treatment of VOC contaminated soils 5/.047 57.047
OnsIte-treatment of VOC contaminated ground 608.JM //7.SS3
water via air stripping
Recharge of treated ground water 142.527 415.359
TOTAL t 1.017.945 tl .259.959
6 txceeds appl I;- Abandonment of onslte monitor wells t 10.000 t 10,000
cable criteria Onslte treatment of VOC contaminated soils 57,047 S7.04I
Onslte treatment of VOC contaminated ground 608.371 m,SSI
water via air stripping
Recharge treated ground water 142.S?7 4IS,IS1)
Excavation and disposal of metals contaminated 251.434 251.434
soils
TOTAL 11.217.179 tl.511.19.1
-------
offsite migration of pollutants. The 4-inch diameter, 90 tcr 100-foot deep,
former injection well located onsite, will be abandoned by properly
plugging and sealing the well with grout and bentonite to eliminate any
future contamination from indiscriminant during of wastes, and to comply
with state regulations. In addition, all of the existing onsite PVC moni-
tor wells which are not suitable for long-term ground water monitoring will
be abandoned according to state regulations.
With the no action and modified no action alternatives, contaminated soils
and ground water will be left onsite in their present state. The cleanup
objectives will not be met and the soils will continue to be a source of
further contamination and the contaminated ground water will continue to
migrate according to local gradients. The potential environmental impacts
associated with these alternatives are limited to degradation of the
shallow zone of the aquifer and possible exposure of listed endangered,
threatened, and special status species in Broward County. The Kite will
continue to violate the State of Florida ground water standards.
With regard to public health, two potential exposure routes of the public
to contaminants at or migrating from the HSTC site are direct contact with
contaminated soils and direct contact with contaminated ground water from
private water supply systems. The potential for human contact with con-
taminated ground water at toxic concentrations from shallow private veils
have been characterized as low, however, the possibility does exist. In
addition, the presence of ground water contamination at this site would
limit future- use of the ground water resource in this area, a highly
productive, sole source aquifer.
Implementing the "modified no action" alternative will not involve
obtaining permits, although certain EPA requirements have to be met.
Ground water monitoring of both upgradient and downgradient wells will be
required, and fences and warning signs at the site will have to be main-
tained. The presence of contaminants onsite will have to be recorded on
the property deed which could limit future use or redevelopment of the
property if either no action alternative is selected.
25
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The following is a summary of costs for this alternative:
1st Year Operation
and Maintenance
Capital Costs (O&M) Costs
New Monitor Well $ 5,000
Abandon Onsite Wells 10,000
Quarterly Sampling Analysis $ 7,800
Totals $15,000 $ 7,800
Total present worth cost
§ 10% discount rate for
30 years of monitoring - $73,500
Total present worth cost » $88,500
Alternative 3t Offsite Treatment or Disposal
A remedial action relying completely upon offsite treatment and disposal
requires soil excavation and disposal at an approved landfill. This alter-
native is based on excavation and hauling of approximately 50 cubic yards
of soils contaminated with VDC's to an EPA-approved landfill and 955 cubic
yards of soils contaminated with low concentrations of leachable metals to
a local landfill. This alternative also includes recovery and and dis-
charge of ground water to a local sewage treatment plant for offsite treat-
ment. In addition, all of the onsite monitor wells and the injection well
would be properly abandoned.
Excavation of contaminated soils, supplemented with qualified supervision
and laboratory analysis of soils, is an effective method for removal of all
contaminated soils onsite. Shallow excavation work should not require
dewatering which eliminates requirements for dewatering equipment and
handling of contaminated ground water.
The recovery of contaminated water within the estimated target area for
decontamination by pumping alone (at 1,000 gallons per minute (gpm)) will
require the disposal of a maximum of 1,600 million gallons over a 3.5 year
period or a minimum of 800 million gallons over a 1.5 year period. The
26
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ground water recovery system is estimated to consist of two, 10-inch
diameter wells with pumps and controls. Recovered ground water will be fed
to the sewer system by gravity flow.
Collection and treatment of contaminated ground water will continue until
the influent ground water meets the cleanup goals or until the system fails
to be effective. Contaminated soils will be excavated down to levels to
meet the cleanup criterion for each contaminant of concern. Excavated
soils will be replaced with clean fill material to restore the site to its
original condition.
The primary environmental impact associated with this alternative is the
loss of fresh water/ground water from an area where salt water intrusion on
the public water supply is a serious concern. Dewatering of the area will
not affect any environmentally sensitive areas, such as wetlands, although
it nay temporarily result in vegetative stress in the near vicinity of the
site. The impact on the native vegetation is expected to be minimal and
recoverable.
The potential for public health effects associated with Alternative 3
occurs primrily during offsite transportation and handling of the con-
taminated soils and to a lesser extent, transport of the ground water to
the treatment plant. Worker exposure during excavation of the VDC con-
taminated soils is also a consideration, however, actual exposure and risk
can be easily .controlled by following well established health and safety
procedures and closely monitoring for ambient VDCs during the operation.
Another factor that should be considered is the likelihood that the wastes
will become contaminants in the new environment (disposal area) in the
future, in the event that they are mismanaged.
The cost of ground water treatment and disposal offsite is primarily
dependent on the sewer service charge by the City of Fort Lauderdale. A
discharge of a minimum of 800 million gallons at a rate of $1.40 per gallon
represent a total fee of $1.1 million. Other costs include installation
and operation of the recovery system, installation of a force main to
connect to-the city sewer, and ground water monitoring on a monthly basis.
27
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The following is a summary of the total present worth costs of Alternative
#2:
1st Year
Capital Costs O&M Costs
Recovery Well System § 99,659 $ 43,426
Abandon Onsite Wells 10,000 —
Untreated Water to WWTP 34,375 $1,046,623
Excavate & Dispose of all
Contaminated soils 314,S70 —
Totals $ 458,604 $1,090,049
Total present worth cost
@ 10% discount rate to be
operated for 1.5 years to
treat the minimum target zone - $1,927,222
For the maximum target zone (3.5 yrs) • $3,112,192
Alternative 4; Action to Reduce Threat
Implementation of this alternative includes abandoning (grouting and
sealing) the existing 4-inch injection well and all onsite FVC monitor
wells, excavation and treatment of VDC contaminated soils onsite, and
continued ground water monitoring.
The preferred remedial alternative for treating VDC contaminated soils is
excavation, ventilation, and replacement. The expected length of time of
ventilation to completely remove VOCs from the soil is dependent upon
several factors. Under ideal conditions, i.e., a warm, sunny, and breezy
day, the process may require only a few hours of exposure. Under less than
ideal conditions, the pjocess may take a few days. Nonetheless, the time
of completion is relatively fast and the process can be expected to be
effective because of the volatile nature of the substances. The remedy
represents a method for eliminating a potential source of ground water
contamination. At the same time, any soil contaminated by substances not
amenable to this treatment could be easily segregated for disposal offsite.
28
183,
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The environmental impacts of implementation of this alternative include
vapor emissions and the potential for contamination of stormwater runoff.
Vapor emissions will not present a problem to local residents because of
dispersion and the travel distance to the nearest receptors. Adequate pro-
visions to prevent stormwater runon and runoff will be required and nay
include stand-by coverings for the soil spreading area and curbing to elim-
inate the runon of storm water from adjacent areas. Given proper precau-
tions there are no adverse health effects associated with this alternative.
This type of treatment process nay not be specifically regulated by local
agencies because of its relatively unique approach, although local regu-
latory approvals for utilization of city or county right-of-ways will be
necessary. No forseeable problems are anticipated, provided that adequate
controls and specifications are included as part of the contract documents
for this activity.
The following is a summary of the costs associated with this alternative:
Abandon Onsite wells $ 10,000
Excavate and Treat VOC Contaminated Soils 57,047
Continued Ground Water
Monitoring (present worth) 79,000
Total Present Worth Cost $146,047
Alternative 5; Meet the Minimum Required Criteria
Elements of Alternative 5, which conforms to the minimum cleanup goals,
are: properly abandoning the existing injection well and all other PVC
wells onsite, treatment of VOC contaminated soil onsite, treatment of VOC
contaminated ground water onsite, and recharge of treated ground water near
the site. Many of the components of Alternative 5, such as abandoning
wells, treatment of soils, and monitoring of effluents and emissions have
been discussed in the text of the first three alternatives. Therefore,
analysis of remedial actions involved in Alternative 5 will focus on
treatment and disposal of contaminated ground water.
29
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The preferred technology applicable to Alternative 5 for ground water
treatment is air stripping. An air stripping system will perform extremely
well given conditions at the HSTC Site. Removal of volatile organic con-
taminants from water at low influent concentrations is common practice
today. Removal of 99 percent of the contaminants is achievable. Due to
the fact that the primary sections of an air stripping operation contain no
moving parts and the reliability of the equipment is good, implementation
of the stripping procedure provides a means of relatively rapid and inex-
pensive cleanup of the contaminated ground water problem at the HSTC Site.
As proposed, the ground water treatment system will include two extraction
wells located near the two wells which show the highest concentrations of
contaminants. Each well will be pumping at a rate of approximately 500
gallons per minute. The ground water will be passed through the air
stripping column and then recharged via a network of 10 shallow recharge
wells located at the circumference of the target zone shown in Figure 5.
Effluent from the treatment system will be monitored on a weekly basis.
Recharge of the treated ground water offers several benefits unique to tfirs"
technology, including: reduction of the duration of treatment, minimal
effects from drawdown during ground water recovery, and creation of a
ground water boundary to deter inflow of contaminants from outside the
target zone. Recharge of the treated water also preserves a significant
volume of fresh water in an area that is subject to severe droughts and
salt water intrusion. Recharge via shallow wells eliminates losses via
evaporation. .Recharge will raise the level of ground water in localized
areas around the recharge wells, however this is not expected to have
adverse impacts on surface drainage characteristics or vegetation. Wells
will be carefully located to ensure that building foundations, roadways, or
other facilities are not impacted by activities associated with ground
water recharge. Since the ground water will be treated to comply with the
cleanup goals before recharge, there will be no adverse environmental or
public health impacts. The pumping and piping equipment associated with
the recharge system is all conventional, relatively inexpensive, and will
require minimum maintenance.
30
183.J
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Operation of an air stripper poses no threat to individuals working on or
near the treatment equipment, however, the issue of vapor emissions must be
addressed. Considering that typical air to water ratios in air stripping
columns are generally in excess of 10:1, the volume of air diluting the
effluent stream will reduce organic emissions sufficiently until external
air currents have the opportunity to dilute and disperse emissions to
levels well below the exposure limits. Periodic monitoring will be con-
ducted to ensure that emissions pose no risk to the public or environment.
Once initiated the ground water treatment system will operate until the
concentration of contaminants measured in the influent to the system meets
the cleanup goals or until an analysis of the system performance confirms
that it is reaching the limit of its ability to withdraw contaminated
ground water, e.g., the recovery is no longer effective. If the system
reaches its limit of recovery of contaminants before the cleanup goals are
met, an analysis of the need for further action will be conducted at that
time.
The duration of remediation is expected to be between 1 and 2 years. The
capital and p&M costs for implementing the ground water recovery, treat-
ment, and recharge systems as described above, and the other elements of
Alternative 5 are presented below, along with the total estimated present
worth for treating the minimum (1 year) and maximum (2 years) target zones.
Abandon Cnsite Wells
Recovery Well System
Ground Water Treatment
(Air Stripping)
Recharge System
Excavate and Treat VOC Soils
Totals
Capital Costs
$ 10,000
99,659
$ 254,649
$ 232,375
$ 57,047
$ 653,730
1st Year
O&M Costs
$ 43,426
$210,637
$110,152
$364,215
31
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Total present worth cost @
10% discount rate for 1 year
to treat the minimum target
zone (1 year)
For the maximum target zone
(2 years)
- 51,017,945
- $1,259,959
Alternative 6: Exceed the Minimum Required Criteria
Remedial actions included in Alternative 6 are abandonment of the existing
injection well and onsite monitor wells, onsite treatment of soils contam-
inated with VOCs, onsite treatment of ground water contaminated with VDCs
and subsequent recharge of ground water via shallow wells, and excavation
and removal of metals contaminated soils for offsite disposal.
All aspects of this alternative were discussed in texts of the first four
alternatives. The addition of remediation of metals contaminated soils
exceeds the cleanup goals for the project and therefore Alternative 6
exceeds the minimum criteria.
The following is a sunmary of capital and O&M costs for this alternative:
Abandon Onsite Wells
Recovery Well System
Ground Water Treatment
(Air Stripping)
Recharge System
Excavate and Treat VOC Soils
Offsite Disposal of
Metals Soils
Totals
Total present worth cost
§ 10% discount rate to
treat the minimum target
zone (1 year)
For the maximum target
zone (2 years)
Capital Costs
$ 10,000
99,659
$ 254,649
$ 232,375
$ 57,047
$ 253,434
$ 907,164
$1,271,379
$1,513,393
1st Year
O&M Costs
$ 43,426
$210,637
$110,152
$364,215
32
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Recommended Remedial Action
A critical part of the feasibility study is to evaluate the remedial
alternatives and identify the most appropriate and cost effective alterna-
tive which meets the remedial response objectives. In addition to the
response objectives, several other important factors are used to evaluate
each alternative. These factors include: level of cleanup, reliability,
special engineering considerations, implementability, environmental effects
(air, surface water, ground water, and soils), capital costs, operation and
maintenance costs, institutional considerations, and the time required for
implementation. A detailed evaluation was conducted by Camp Dresser 4
McKee Inc. and is presented in the feasibility study report. This
evaluation is summarized in Table 3.
The "no action" and "modified no action" alternatives are unacceptable
solutions to the problems at the Hollingsworth Site, since they do not meet
the remedial response objectives nor state law and may result in public
exposure to contaminants. The shallow ground water at the site is contain--^.
inated with a carcinogenic, organic compound that poses a potential future
threat to public health and the environment.
Alternative 3, which involves offsite disposal, would meet the objectives
of the response, however, the cost is considerably higher than other alter-
natives that also meet the objectives and would result in a significant
loss of fresh water and temporary dewatering of the area.
Alternative 4 does not meet the objectives and provides minimal remediation
via source control. The existing ground water contamination would not be
addressed except by continued monitoring.
Alternative 5 is the preferred alternative because it meets the cleanup
goals and the objectives of the remedial response for the lowest cost using
proven technology.
33
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TABU 1
SOLOCRLCSS TERMINM. COMPANY
FORT LAIMRDAU, FLORID
RIM II
Alternative
Capital
W.UOO)
1st yr. Present*
(MM Morth
Ul.OOO) ($1.000)
Public Health Consideration
Environmental Effects
technical Consideration
15 74 89 Does not meet any of the remedial
response objectives. Possible future
contamination of residential water
supply and public water supply.
Present public health threat low.
however, future worst-case situation
Indicates unacceptable level of risk.
458 1.090 1.927 Meets remedial response objectives.
3.112 Reduces public health threat at the
site, but creates potential for
exposure during transportation to an
offslte disposal area.
146 -- 146 Does not «eet the remedial response
objectives. Possible future contami-
nation of private irrigation wells and
public water supply from existing
ground water contamination. Elimi-
nates source of *OC contamination.
low to moderate risk of worker expo-
sure during soil treatment.
653 364 1.01H Meets all remedial response objec-
l.?60 lives. Reduces public health threat
to acceptable levels. Moderate risk
associated with worker exposure during
soil treatment. Low to Moderate
potential risk to workers during soil
treatment results in low level air
emissions ofVOCs.
Potential migration of contami-
nated ground water offslte nay
result in contamination of
private Irrigation wells.
Presence of contaminants might
Impact future use of the ground
water.
Permanent loss of substantial
quantity of fresh water. Re-
location of contaminants with
the long-term potential for
environmental release. Poten-
tial adverse effects from
dewaterlng the area via offslte
disposal of ground water.
Potential migration of contami-
nated ground water offslte may
result In contamination of
private irrigation wells.
Presence of contaminants might
impact future use of the ground
water.
Does not comply with
state law
Removes source of ground water
contamination. Alleviates
current and future potential
for offslte migration of
contaminants and contamination
of private or public water
supply welts. Conserves fresh
water by recharge.
V(1Cs will be removed during
transit to the treatment plant
and ituring pre-treatment. OM1
for qround water recovery
systra.
Must make provision for runoff
contalnwnt/diversion. Passive
tr«Mbwnt with minimum energy
requirements. Rapid effective
tre.itim.-nt.
Proven technology which oper-
ates at high removal efficien-
cy. Short treatment perliHl;
one time cleanup, no waste
residue for treatment or
disposal.
-------
TABU J
(conttnuH)
Alternative
1st Yr. Present*
Capital (MM Worth
(JI.UOO) ($1.000) (It .(Ml)
Public Health Consideration
environmental Effects
T"chnlr.al Consideration
907 364 1.771. rxcerds remedial response objectives
I.SIJ • l>y rnmvtng metals contaminated soils.
lllmiiMl"s every potential public
health effect, low to Moderate
potential for worker exposure (tiring
soil treatment. Results in low lev*)
air emissions of VOCs. Additional low
risk exposure of workers during excav-
ation etc. of metals contaminated
soils.
Removes all source of content-
nation. Allevlatrs all nirrent
and potential future offsite
migration of contMinants via
ground water and eliminates
potential combination of
private and pub)Ic water supply
wells. Conserves fresh water by
recharge. Restores all areas
of the site to clean condition.
Offsite disposal of «etils
contaminated soils could result
In environmental release In the
future.
Proven technology which oper-
ates at high trivtbnent
efficiency. Short treatment
period; one tinr cleanup. No
waste residue for treabiwnl or
disposal.
Iwo costs are based on treatment of ground water within the mlnlnum and eaxlnum target zones.
For Alternative ?. the times are I.S and 3.5 years. For
Alternatives 4 and S. the tines are I and ? years.
JflV?7
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Alternative 6 meets and exceeds the objectives and is exactly the same as
Alternative 5, except that it includes excavation and offsite disposal of
all metals contaminated soils. Based on the types and levels of metals
present, removal of these soils is not warranted since the public health
risks are minimal.
Community Relations
Two public meetings were held to inform the public of activities at the
HSTC Site. Fact sheets were prepared for both meetings. The second
meeting was held to present the Draft Feasibility Study Report and to allow
for public comment. The public comment period was extended-by two weeks to
allow additional time for review and comment. A responsiveness summary
outlining the results of public conment is enclosed. An information repos-
itory was established at the main branch of the Broward County Public
Library in Fort Lauderdale, Florida. When approved, this Record of
Decision will be sent to the repository,
Consistency with Other Environmental Laws
The recommended remedial action protects public health and welfare, and the
environment. It is consistent with other related environmental laws and
requirements such as RCRA, Air Quality Standards, and Executive Orders
related to floodplains and wetlands.
As explained-earlier, the HSTC Site contains elevated levels of VDCs in the
ground water. These levels may pose a threat to public health and the
environment, especially since ground water is used for drinking water pur-
poses. The reconmended_'treatment would bring the quality of the water
withdrawn from the study area to levels at or below those set by the clean-
up goals to protect public health. Thus, the recommended remedial action
will be environmentally sound with respect to ground water protection and
drinking water quality.
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With respect to air quality standards, the recommended alternative will
generate VOC emissions from air stripping towers. However, these emissions
will be far below the levels allowed by the State of Florida (60 Ib/hr or
15 tons/yr). A simple air quality dispersion model was used to calculate
the dispersion of VOC emissions from the air stripping column. The results
showed that even under worst case atmospheric conditions, the concentration
of VOCs is substantially less than the threshold limit values for the vola-
tile organic compounds found onsite. The air stripping facility will be
located in a commercial industrial area, at least a quarter of a mile from
the nearest residence. A 40-foot stack will be used for discharge from the
air stripping unit to enhance dilution and dispersion and minimize the
potential for exposure of the public.
The HSTC Site lies within the range of several threatened, endangered, and/
or special status species; however, none are known to frequent the area.
The site is, like almost all of Breward County, located in the 100-year
floodplain. However, several flood control structures in the area minimize
and control flooding, including the area proposed for air stripping facil-w
ities. Also, building permits are issued by Broward County only if the
ground at the proposed structures is raised above the 100-year flood eleva-
tion before the structure is built on it. In this case, the elevation of
the existing surface at the construction sites will need to be raised by
only 1 to 2 feet to ensure that the air stripping treatment facilities are
not built on the 100-year flood plain.
To the extent that contaminated ground water flows to or is in contact with
area surface water, it causes no known violation of any water quality
standards.
Operation and Maintenance
In addition to the $653,730 estimated capital costs required for the
recommended alternative, operation and maintenance (O&M) costs will be
incurred for the 1 to 2 year life of the project. O&M costs pertain to the
operation of the air stripping treatment facilities, the ground water
recovery system, and the ground water recharge system. These include costs
•
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.•«.) energy
for labor (operator ti«). «"«»
.nd ^i^Bt puc—t (fans
S364,215 per year, the
«»">• «>«"als "^ suppU"'
estimate. * ^ ^ wiu
«^P ^
of
schedule
initiate Remedial Design
Begin Remediation
Operate Remedy
Upon reauthorization
Of CERCIA
10 months after
notice to proceed
1-2 years
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RESPONSIVENESS SUMMARY
DRAFT FEASIBILITY STUDY REPORT
HOLLINGSWORTH SOLDERLESS TERMINAL COMPANY SITE
FORT LAUDERDALE, FLORIDA
INTRODUCTION
The Draft Feasibility Study Report on the Hollingsworth Solderless Terminal
Company (HSTC) Site, Fort Lauderdale, Florida was submitted for public
review and the subject of a public meeting held on August 23, 1985 in the
main branch of the Breward County public library in Fort Lauderdale,
Florida. Following the public meeting, the public cement period began.
Typically, the public content period for a draft feasibility study report
is three weeks; however, at the request of the responsible party, the
comment period was extended an additional two weeks until September 27,
1985. The following is a susnary of the questions and issues raised both
at the public meeting and in written comnents received from the responsible
party and others. The questions or issues and answers presented herein
have been organized into general topics and are being addressed on that
basis.
1. Cleanup Goals or Criteria
The cleanup goals for ground water established in the draft
feasibility study report were based on both the state drinking water
criteria 'and the 10 life time cancer risk factor. These criteria
are applied to the site because the aquifer at the site is classified
as a drinking water aquifer. The cleanup goals for soils were based
on state water quaiLty criteria and the results of EP toxicity
testing. Standards were set at levels in the leachate at 10 times the
appropriate water quality criterion.
2. Introduction of Pollutants into the Air from the Air Stripping Tower
Preliminary air modeling of the situation at the HSTC Site and
extensive modeling studies done at other air stripping sites in south
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Florida have shown that the level of contaminants emitted into the air
from air stripping columns is typically well below the current Clean
Air Act standards and does not present a public health threat.
i
3. Locating Monitor and/or Recharge Wells on Private Property
In the past, EPA has had good success in obtaining permission from
property owners to conduct activities or construct wells which have
been shown to be in the public interest. A number of the recharge
wells may be located on city, county, or state right-of-ways, in which
case negotiations will be undertaken with the appropriate agency.
4. The Area-Wide Ground Water Contamination Problem
An area-wide ground water contamination problem in the Executive
Airport area does not relieve the responsible party of responsibility
for cleaning up the contaminants at its site. The EPA, in
coordination with the State and Breward County, has a substantial
program underway at this time to identify other contributors to ground
water contamination in this area. The comment that EPA has listed
area-vide ground water contamination on the NPL in Dade County is
incorrect.
5. The Contractor for Site Remediation
EPA would like to use one of the firms that is already under contract
so that remediation can proceed as quickly as possible.
6. What Area will be Cleaned Up
The purpose of remediation is to mitigate ground water contamination
at the site. For planning purposes, two areas were identified in the
feasibility studyr These two areas describe minimum and maximum
target zones for ground water remediation based on the data which show
that certain wells on site are contaminated. The ground water
collection and treatment system will be operated in a manner such that
once the concentration of contaminants in the influent meets the
criteria, treatment will be discontinued. Therefore, only that area
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where ground water contamination exists will be cleaned up, even
though hypothetical areas that may be much larger than the actual zone
of contamination have been identified for planning purposes.
i
7. Depth of Recharge Wells
The recharge wells to be used to reintroduce treated water back into
the ground water system will be approximately 20 feet deep. Shallow
recharge wells such as these are conmonly used in south Florida for
storm water, and heating and air conditioning system water disposal.
8. Length of Project
Based on the hypothetical target zones of contamination identified in
the draft feasibility study and a withdrawal and treatment rate of
1,000 gallons per minute, it will take approximately 1 year to collect
and treat the ground water within the minimum target zone, and
approximately 2 years to collect and treat the ground water within the
maximum target zone, which is considered to be the maximum possible
extent of contamination. These time frames are based on use of the
reinjection system design presented in the report. Reinjection of
ground water outside the zone of contamination creates a mound of
ground water which forces ground water toward the collection wells and
shortens the total time to collect and treat the ground water within
the target zone. The actual length of the project will depend upon
the actual zone of contamination as described under Item 6. As soon
as the influent ground water quality meets the criteria, remediation
will cease.
9. The Hazard Ranking System (HRS) Score
At the time the HSTC Site was placed on the NPL, it was appropriately
scored and the score was adequate for its inclusion on the NPL. There
was an official public comment period provided for cooment on the
listing. Response actions taken after NPL listing do not result in a
rescoring of the site.
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10. Ingestion versus Dermal and Inhalation Exposure of Residents with
Shallow Irrigation Wells Downgradient of the Site
It is true that the analysis under the public health evaluation did
include consideration of the ingestion criterion versus the dermal and
inhalation criterion. The ingestion criterion oust be used in a case
like this where there is a possibility that children or anyone else
might come into contact with or actually drink water from the
irrigation system. There is no way to absolutely preclude this from
happening; therefore, the more conservative criterion was applied in
the analysis.
11. Consideration of Other Sources of Contamination to the Ground Water in
the Hollingsworth Area
The objective of this study was to evaluate the HSTC Site as a source
of contamination and to determine a method to adequately clean up that
contamination. It is clear which areas have been contaminated by
Hollingsworth and only those areas have been included in the
feasibility study for remediation.
12. Fouling of the Air Stripping System
The use of air stripping columns for removal of volatile organics from;
ground water is a proven technology that is widely being applied in
this field. The fact that over time, air stripping columns decrease
in efficiency of removal of contaminants is a maintenance problem.
Maintenance costs were included in the feasibility study to cover
proper monitoring and scheduled maintenance of the system to prevent
production of effluent which does not meet the cleanup criteria.
In this system, the-"water will be withdrawn from a depth of
approximately 60 to 70 feet. This is the lower sand zone, a zone
above the production zone or the limestone aquifer. The total
dissolved solids level in this zone is somewhat less than the
production zone of the aquifer, therefore the tendency for fouling is
diminished. Further, there are a number of techniques that can be
used to reduce the fouling problem in both the air stripping system
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and recharge system. One of these methods includes the introduction
of low concentrations of hydrogen peroxide into the influent. The
hydrogen peroxide keeps iron in solution through the air stripping
column and reduces fouling; it also helps to keep iron in solution
throughout reintroduction via the recharge system. The peroxide
itself readily decomposes to water and oxygen and it does not
represent a contaminant. The use of hydrogen peroxide has the added
benefit of actually cleaning the air stripping system due to creation
of bubbles on the surface of the columns which effectively scrub the
air stripping columns. Hydrogen peroxide also prevents or reduces the
growth of biological organisms. There are. other techniques to reduce
fouling that can be applied depending upon the specific water quality
characteristics of the water in the zone to be treated. These
determinations will be made during final design.
13. Intrusion of Contaminants from Offsite
The ground water collection, treatment and recharge system designed
for the HSTC Site will minimize the possibility that contaminants from.
offsite will be collected by the system. The configuration of the
recharge wells is designed to create a ground water barrier in the
shallow zone. Reinjection of the water will create a mound of ground
water or a ground water divide, which will prevent water from moving
outside of the target zone into the recovery system. Water may still
pass under the site in the production zone; however, the
concentrations of contaminants in the production zone have been
documented to be very low due to the high volume of water and dilution
and further, this zone has not been slated for treatment. The
recharge system is not expected to result in the spread of
contaminants offsite. At the time the recharge wells are installed at
each of the 10 locations, water samples will be collected and
analyzed. If contamination is present at these wells, the wells will
be relocated and the information will be passed along to the
appropriate local agency for investigation into the source of
contamination.
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14. Accidental Spills within the Zone of Cleanup
To date there is no evidence that spills have occurred in the vicinity
of the HSTC Site that may be influencing the presence of contaminants
at that site. Therefore, there is no reasonable cause for concern
that spills will occur in the future which may impact remediation of
the site. Obviously, there is no way to police this entire area
against accidential or intentional spills; however, the fact that this
has not been a problem in the past indicates that in all likelihood it
will not be a problem in the future.
15. Leaking in the Ground Water Recharge System
The water that will be transported from the treatment system to the
recharge wells will be of drinking water quality. Therefore, if a
leak should occur in the distribution system itself, no contamination
or violation should occur. Damage due to the presence of water alone
may be a consideration; however, over the short time period of this
project, properly laid piping should not present a major problem of
leaking, and further, maintenance costs have been included to cover
periodic checking of the distribution system.
16. The Size of the Ground Water Treatment System
The air stripping system designed for this project has been optimized
rather than over built, to minimize the length of time to recover and
treat contaminated ground water at the site, thereby minimizing the
operatipn and maintenance cost and the overall project costs.
17. The Ability of the Ground Water Recovery System to Recover
Contaminants
Recovery of ground* water contaminated with volatile organics, such as
the trichloroethene found on the HSTC Site, has been successfully
demonstrated at several sites across the country and is considered to
be an effective technology for collection of these contaminants. The
fact that trichloroethene is relatively insoluble and heavier than
water does not prevent it from being recovered in the ground water.
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The extraction wells have been located in the areas and at depths
where the highest concentrations of contaminants have been found to
optimize contaminant recovery.
t
18. Financial Conditon of the Hollinqsworth Solderless Terminal Company
While the National Contingency Plan requires that EPA choose a cost
effective site remedy, the financial condition of a potentially
responsible party is not an element of this determination. CERCLA was
adopted with recognition that responsible parties might not be able to
afford the appropriate site remedy.
19. Sampling and Test Data
While all available data was used in evaluating this site, the most
recent data depicting current site conditions was used to evaluate
site remedies, rather than data that depicted conditions at some time
in the past. An analysis of the results of the most recent episode of
ground water sampling where samples were split between EPA and
Enviropact showed that the results from both labs were consistent with
the exception of the values for vinyl chloride. Enviropact failed to
detect vinyl chloride in the samples, whereas the contract lab
detected vinyl chloride at estimated concentrations ranging from 200
to 5,000 parts per billion. Otherwise, the data for each of the wells
were very similar and within reasonable variation between two
laboratories. Both laboratories found trichloroethene and
dichloroethene in the intermediate depth well at the upgradient
location. The probability that this is from offsite contamination is
extremely low since contaminants deposited onsite have not migrated
very far downgradient of the site. There are no known nearby sources
of contaminants other than the discharge to the Gaidry property and
the area between the two former Hollingsworth buildings (north plant).
Because the ground water gradient at this site is extremely flat,
dispersion may partially account for the fact that well 17 is
contaminated. The ground water gradient varies by only 1/10 of an
inch in this area.
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Since Enviropact did not measure toluene and xylene, it is impossible
to compare the two data sets with regard to these contaminants. There
is no known source for these contaminants at the HSTC Site and
therefore, it it likely that they are contaminants of the regional
aquifer, probably from gasoline spills. These contaminants would be
removed by air stripping, along with the volatile organic contaminants
from the site. Therefore, they would not be a source of offsite
contamination. The presence of other contaminants that may or may not
be attributable to this site does not preclude the need to address
contaminants that can be unequivocally linked to the HSTC Site.
20. Absence of Contaminants in the Production Zone of the Aquifer
The test well and monitor well onsite are completed into the
production zone of the aquifer. This zone is extremely permeable and
large volumes of water move through the site in this zone.
Contaminants moving vertically into this zone would be greatly
diluted. Thus, it is no surprise that contaminant concentrations are
below detection limits. A similar explanation could be expected to
apply to wells at the 100-foot depth. However, these results could
not be directly compared to the shallower test results where
contaminants are known to be moving through the sand zone. The fact
that contaminants are below detection limits in the deeper zones does
not eliminate the responsibility to clean up the contamination of the
shallow zone, nor is it conclusive unless it is to indicate that once
contaminants migrate into the production zone they are diluted and
transported offsite.
21. Monitoring the Ground Water Treatment System
Once the air stripping unit has been properly set up and set into
operation, monitoring of the treated ground water will occur on a
weekly basis. This type of treatment unit is considered very reliable
and hence, there is no justification for continuous monitoring. The
only way the system can fail (given proper setup and maintenance) is
if the pump goes out. In this case, an alarm will go off and the
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system will automatically shut down. Therefore, untreated ground
water will not be recharged. Time for proper maintenance has been
included in the cost estimate.
/
22. Application of In Situ Aeration
In situ aeration was not considered in the feasibility study.because
it does not meet the criterion of being a proven engineering
technology. The effects and effectiveness would be difficult to
control and monitor. Further, this technique could potentially
enhance offsite migration of contaminants.
23. Disruption of Hollingsworth's Tenants During Site Remediation
Although this may be a legitmate concern, it ffcauld be noted that
during December 1984, 11 soil borings were performed on and in the
immediate vicinity of the Hollingsworth property without any
disruption of the tenants. In February 1985, monitor wells were
installed around the site, also with no disruption of the tenants or
their normal activities. The remediation work can be scheduled and
conducted in a manner to minimize any inconveniences.
24. Delisting the Site Following Remediation
Some comments have raised the issue of when EPA will delete a site
from the NFL. In general, a site will be removed from the NPL when
the site remedy has been implemented and information confirms that it
is performing as anticipated.
25. NCP Requirements and CERCLA Program Goals
Several comments were received relative to the National Contingency
Plan (NCP) and whether the remedy proposed was consistent with it.
One issue was that"there are no drinking water wells in the path of
contaminants, thus no action was appropriate. Several factors combine
to demand rejection of the no-action scenario, the aquifer is the
sole source of drinking water for the area. State standards are
violated because of the contamination from the site. As a natural
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resource, the aquifer is harmed. Water users are at risk, not only
those users who are in the computer simulated path of contamination,
but others as well. The computer simulation does not guarantee that
contamination has not nor will not enter the Prospect Lake Well Field
and thus be supplied to the public. Private wells for irrigation, or
for drinking water, cannot be completely precluded from the area.
Even forceful regulation is not 100 percent effective. There exist no
effective natural or man-made barriers to contaminant migration.
There exists no alternative source of potable water at this time or in
the reasonable future except this aquifer. The contaminants detected
include known carcinogens. A remedy is available which is safe,
effective, technically feasible and reliable, and will provide reduced
risks to public health and the environment.
The recommended technology has been applied at similar sites. Dade
County plans a much larger air-stripping system for their water supply
with confidence in its anticipated benefits. The environmental
effects are far less than the benefits and are controllable. The cost
is well within the range of other alternatives that provide less
benefits to public health, welfare and the environment. The NCP
(Section 300.68(j)) describes "The appropriate extent of remedy shall
be determined by the lead Agency's selection of the remedial
alternative which the Agency determines is cost effective (i.e., the
lowest cost alternative that is technologically feasible and reliable
and which effectively mitigates and minimizes damage to and provides
adequate•protection of public health, welfare, or the environment).
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