EPA
United States
Environmental Protection
Agency
Office of
Emergency and
Remedial Response
EPA.ROD R04-85 004
September 1985
Superfund
Record of Decision
Biscayne, Aquifer Sites, FL
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,
TECHNICAL REPORT DATA
(Pletlse retld InSlNCflO'U on Ihe reveNe before completing)
1. AEPOAT NO, 12, 3. RECIPIENT'S ACCESSION NO.
EPA/ROD/R04-85/004
.. TITLE AND SU8TITLE 5. REPORT DATE
September 16, 1985
Biscayne Aquifer Sit~s. FL 6. PERFORMING ORGANIZATION COOE
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7. AUTHORCSI 8. PERFORMING ORGANIZATION REPORT r-..c
9. PERFORMING ORGANIZATION NAME AND ADDRESS 10. PROGRAM EL.EMENT NO.
11. CONTRACT/GRANT NO.
Same as Box 12
12. SPONSORING AGENCY NAME AND ADDRESS 13. TYPE OF REPORT AND PERIOD COVERED
Environmental Protection Final ROD Report
u.S. Agency 14. SPONSORING AGENCY CODE
401 M Street, S.N.
Washington, D.C. 20460 800/00
15. SUPPLEMENTARY NOTES
16. A8STRACTThe Biscayne Aquifer is the sole underground source of drinking water for 3
million residents of southeast Florida. It is a highly permeable, wedge-shaped, uncon-
fined shallow aquifer composed of lime stone and sandstone.
Three Biscayne Aquifer hazardous waste sites on the EPA National Priori ties List were
addressed as one management unit for the remedial investigation and feasibili ty study:
(1) Miami Drum Site, (2) Northwest 58th Street Landfill, and (3) Varsol Spi 11 Site. ThesE
sites are located near each other in north Dade County, Florida. The remedial actions
for t.he three hazardous waste sites are being addressed in four phases:
Phase I: Varsol Spill Site--immediate area soil and ground water. Record of DecisioI
(ROD) signed 3/29/85.
Phase II: Miami Drum--source control (soils and encountered ground water), completec
September 1982. ROD signed 9/13/82.
Phase III: 58th Street Landfill--immediate area soil, surface water, and ground wate]
Enforcement Decision Document (EDD) scheduled Fall 1985.
Phase IV: Study Area Ground Water--ROD signed 9/16/85.
The selected remedial action for Phase IV includes adding air stripping to the exist- :
~ng water treatment system in the study area and operating the Miami S9rings and Preston I
Imunicipal wells for the dual purpose of providing potable water and recovering, con'tami-
nated water from 'the aquifer. Total capital cost for the selected rem~dial alternative i~
!estimated to be $5,268,000 with O&M costs approximatelv 5334 400 per vear. ..
17. KEY WORDS AND DO~UMENT ANALYSIS I
Ia. DESCRIPTORS b.IDENTIFIERSOPEN ENDED TERMS C. COSATI hdJ,(,;r. ',:' I
I
Record of Decision I
Biscayne Aquifer Sites, FL !
Contaminated Media: gw ~
:
Key contaminants: Vinyl chloride, VOCs, I
trans-I, 2-dichloroethene
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-.
18. DISTRI8UTION STATEMENT 19, SECI..'RITY CLASS. nllS R"(1,lrf, 21. NO. OF PAGES
None &.&.
20 SECuR,T',. CL..:o.SS . Ti"s t"J~,': :!2. PRICE I
,
None
!PA Po,,,, 2220-1 (Rn. .-77)
PREVIOUS EOIT'C''''' ,5 OBSOL.ETE
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INSTRUCTIONS
,.
REPORT NUMBER
Insert Ihe EPA report number as it appears on the cover of Ihe publiciltion.
2.
3.
LEAVE BLANK
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RECIPIENTS ACCESSION NUMBE~
Reserved for use by e:lch report reclplenl.
..
TITLE AND SUBTITLE .
Title should indica Ie dC:l~IY and brien~ the subJe~'1 cover:l1=e uf the r~'port. ilnd be di'I'I;I)'~'d prul1lim'nlly. S~'I ,"1'1111.'. If """t. In '11I;11t~'r
type or otherwise subordlnale II to malnulle: When iI report's prepued In mur~' Iltan "n~' v"lul1le. r~'I",..1 Ih~' 1'11111;11)' 1111.'. ..,t" h.hlll1"
number and include subulle for the specific utle.
15.
REPORT DATE .
Each report shaU carry a dale indiealing at leasl month and year. Indicate II1\' 1>.1'1' un ,,'hid, II \\;" ,ded~'d (r./:.. ,Ill'" "1 ;nlll'. Jale' "1
IIPfJfOWlI. dIIle o[ prtfNZrtllion. elc.j.
PERFORMING ORGANIZATION CODE
Leave blank. .
e.
7.
AUTHORISI
Give name(s) in ..."nvenuonal order (Jolm R. Dex, J. Il.olx." Doc. ('(c/. list :luthur's :llrili:lllUfllf ir dilkr, 'r"", Ih.' ,,,'rfur,,,iflj: .
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SITE:
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Record of Decision
Remedial Alternative Selection
Biscayne Aquifer Sites - Study Area Ground Water, Dade County,
Florida.
DOCUMENTS REVIEWED:
I am basing my decision on the following documents describing
the analysis of cost-effectiveness of remedial alternatives for this
site: '
o
Evaluation of the Clean-up Activities Already Undertaken
at the Miami Drum Services Hazardous Waste Site, Dade
County, Florida, September 1, 1982
Phase I--Compilation and Evaluation of Data for the
Protection of the Biscayne Aquifer and Environment in
North Dade County, Florida, October 15, 1982
o
o
Remedial Investigation for Miami Drum Services Site,
Florida, Florida Department of Environmental Regulation,
Tallahassee, Florida 32301, November 1983
Phase II--Sampling, Analytical, and Investigative
Program for the Protection of the Biscayne Aquifer
and Environment in North Dade County, Florida,
February 1984
o
o
Phase III--Feasibility of Remedial Actions for the
Protection of the Biscayne Aquifer in Dade County,
.Florid.a" May 1985
Staff Summaries and Recommendations
o
o
Recommendations from Florida DER and Dade County DERM
DESCRIPTION OF SELECTED REMEDY:
The remedy selected is to add air stripping to the existing
water treatment system in the study area and to operate the Miami
Springs and Preston municipal wells for the dual purpose of '
providing potable water and recovering contaminated water from
the Aquifer. Operation and maintenance for air stripping includes
energy costs, labor to operate the system, materials and supplies
and equipment replacement (fans and pumps). Operation of the air
stripping system will continue until the cleanup goals are achieved
at the influent to the treatment plant.
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2
FUTURE ACTIONS:
Another decision document is planned to address proper closure
of the 58th Street Landfill. This should also include provisions
for' a potable water supply for the private well users in the
Landfill area. In addition, while the items in the Biscayne Aquife
Protection Plan are generally not within the Agency's scope of
authority', we are evaluating methods to encourage and, facilitate
these actions to prevent future contamination of the Aquifer and
the address, if necessary, the contaminants which will not be
removed by the chosen remedy.
DECLARATIONS:
-
Consistent with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), and the National
Contingency Plan (40 CFR Part 300), I have determined that
alternative 2 as described in the Summary of Remedial Alternatives
Selection - adding air stripping to the existing water treatment
system - 1s a cost-effective remedy and provides adequate protectio
of public health welfare and the environment. The State of
Florida has been consulted and agrees with the approved remedy.
The remedial action does not affect or impact any floodplain
or wetland areas. A key element of the Remedial Action includes
institutional controls over placement of wells in the study area.
I have determined that the action being taken is appropriate
when balanced against the availability of Trust Fund monies for
use at other sites.
q /;'liS
Date
Aan\lnlstrator
Emergency Respon~
Soli
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. RECORD OF DECISION
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
BISCAYNE AQUIFER SITES, DADE COUNTY, FLORIDA
BACKGROUND
INTRODUCTION
Three sites proposed for the National Priorities List in
October 1981 are located in northwest Dade County, Florida.
I
After consulting with the state and county, EPA.decided to
address these sites as a single managem.nt unit for the per-
. formance of the RI/FS. A major reason for this decision was
that all three sites affect the same general area of the
Biscayne Aquifer. Wells in this area supply water to
approximately 200,000 residents within the study area and
approximately 600,000 residents outside it. The agencies
recognized that the effects of these sites on the aquifer
could be interrelated and that some of the suspected prob-
lems would not be solely attributable to an individual site.
This management 8cheme worked well for the RI/FS and is also
appropriate for the remedy.
A package of four decision documents that address the three
sites is planned. This entire package is being completed in
phases, with the Phase III document due for completion in
the Fall of 1985. The four phases are:
Phase I:
Varsol'Spill Site--immediate area soil and
ground water. Record of Decision (ROD)
signed 3/29/85.
Phase II:
Miami Drum--source control
encountered ground water),
September 1982. Record of
8igned 9/13/82.
58th Street Landfill--tmmediate area soil,
8urface water, and ground water. Enforce~
ment Decision Document (EDD) scheduled Fall
1985. .
(soils and
completed
Decision (ROD)
Phase III:
Study Area Ground Water--Record of Deci-
8ion (ROD) included herein.
SITE LOCATION AND DESCRIPTION
Phase IV:
The Biscayne Aquifer is the sole underground source of
drinking water for three million residents of southeast
Florida. Three Biscayne Aquifer hazardous waste sites on
the EPA National Priorities List were addressed as one
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management unit for the remedial investigation and feasi-
bility study: (1) Miami Drum Site, (2) Northwest 58th Street
Landfill, and (3) Varsol Spill Site (Miami International
Airport). These sites are located near each other in north
Dade County, Florida. The study area including these sites
is defined in Fiqures l-A and 1~B. Locations of these sites
and public well fields, as well as private wells within the
study area, are shown in Fiqure 2. The topography in the
study area is flat,. approximately 5 feet above sea level.
The study area, which encompasses approximately 80 square
mi~es, includes several cities as well as unincorpora~ed
. areas (Figure 1-B). The Cities of Miami Springs and
Virginia Gardens are primarily residential, whereas the
Cities of Medley and Hialeah Gardens are heavily industrial.
The City of Hialeah is a mix of residential, commercial, and
industrial areas. .
° There are numerous and varied businesses, large and small,
located within the study area, including industrial manu-
facturing plants, reclamation plants, land disposal
facilities, and abandoned landfills. The western one-third
of the study area is essentially undeveloped.
. Miami Drum Services was an inactive drum recycling facility
located west of Miami Springs at 7049 N.W. 70th Street in
Miami. The dimensions of this site are 242 feet
(north-south axis) by 230 feet (east~west axis), and it is
located in a predominantly industrial area. The FEC Canal
is located about one quarter of a mile east of the Miami
Drum Site, and the Miami Canal is located less than one mile
northeast of the site. The Medley Well Field is located
approximately 750 feet west of this site, while the Miami
Springs and Preston Well Fields are located about 5,000 feet
southeast of the site.
The Northwest 58th Street Landfill occupies a one-square-mile
area near the western perimeters of the Town of Medley and
the City of Miami Springs. Present development adjacent to
this landfill site includes industrial uses to the south
(Northwest 58th Street) and east (Northwest 87th Avenue), a
rock pit operation to the north (Northwest 74th Street), and
~ndeveloped land to the west (Northwest 97th Avenue). A new
resource recovery plant is located directly west of, and
adjacent to, the landfill. The Medley and Miami Springs
Well Fields are approximately one and one-half miles and two
and one-half miles downgradient from the eastern edge of the
landfill, respectively.
The Varsol Spill Site is located in the northeast section of
Miami International Airport (MIA). The airport is located
less than one-half mile south of the lower Miami Springs
gnRI09B/02
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FIGURE 1A.
Project Location.
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FIGURE 2.
Location 01 Potential Contamination Sites, Public Well Relds, and Private Wells in the Study Area.
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Well Field. The Miami Canal runs adjacent to the northeast
corner of the airport, the Tamiami Canal runs immediately
south of the airport, and two other canals are located near
the western edge of the airport.
Almost all of the study area is within the 100-year flood
plain. Wetlands form the border of the western edge of the
area, but are not affected by it. The average annual rain-
fall over the study area is approximately 60 inches, of
which as much as 80 percent falls during the rainy season
(June'to September). Parts of the study area are inundated
intermittently during the rainy season. Surface water in
the area consists of man-made lakes and canals, and is not
used for drinking water. The water table beneath >the study
area 1s located approximately 2 to 3 feet below the natural
land surface. >
The major drainage systems of the area are the Miami and
Tamiami Canals draining into the Biscayne Bay. The
secondary drainage systems include the 58th Street, Dressel,
and 25th Street Canals. The Miami Canal originates at Lake
Okeechobee and flows south and southeast toward Biscayne Bay
at Miami. The portion of the Miami Canal in the study area
is regulated, and used principally for drainage and flood
control. It is used for navigation downstream of the study
area.
The Tamiami Canal runs west to east, between its mouth at
Miami Canal, immediately downstream of the study area, and
the Dade-Broward Levee, about i4 miles upstream. It oper-
ates as a typical Everglades canal and is used for drainage.
The Biscayne Aquifer, which is a highly permeable,
wedge-shaped, unconfined shallow aquifer composed of lime-
stone and sandstone, underlies the study area. The top of
the aquifer is near the natural ground surface, a~d its base
is approximately 60 feet below ground surface in the North-
west Well Field area and approximately 105 feet below ground
surface in the Miami International Airport (MIA) area.
Figure 3 shows the geologic section of the Biscayne Aquifer
in the Miami Springs/Preston Well Field area. In general,
this aquifer is divisible, from top to bottom, into three
distinct water-producing zones, of 15 to 20 foot thickness~
These zones are separated by dense, silty to sandy lime-
atones and well-cemented quartz sands that act as aquitards.
Historically, the cone of depression resulting from the
withdrawal o~ approximately 150 million gallons per day
(mgd) of water from the Miami Springs and Preston Well
Fields encompassed the northern half of the Airport, all of
the Miam1 Drum Site, and extended as far west as one-half
mile east of the 58th Street Landfill. Dade County has
shifted pumping to the Northwest Well Field to minimize use
of the contaminated wells.
gnR109B/02 >
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Welt
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LEGEND
f.'::'::a-I Send. QU8I1Z and Umeet0n8 FfIIgIIWItI
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C£:) Sand. Quartz. Fln&1JI'8Ined
e;:a Umestone. Whtte-grIY, Sandy
sa! Umestone. Hard. Brown Shelly
~ Mart. Green, Shelly
e:a Umest~ Tan. Shelly,
.... . and Thin Beds of Sand
~ Sandstone, Whft81Jl1lY, Shelly, and Thfn
Beds.of Sand Near Bottom
(:::p:;:, Sandstone. Gray-green, Shelly, and
Sandy Concr8tfons
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The cone of depression corresponding to a drawdown of 0.25
foot that results from the withdrawal of water from the new
Northwest Well Field and a limited amount of water from the
Miami Springs/Preston Well Fields encompasses the western
edge of the 58th Street Landfill. .
SITE HISTORY
Miami Drum Site
The privately-owned Miami Drum Services (MDS) facility oper-
ated for approximately 15 years before Dade County, through
a local court order, forced it to cease operation in June
1981. As many as 5,000 drums of various chemical.waste
materials, including corrosives, solvents, phenols, and
toxic metals, were observed on the site while the. company
was operating. Drums were washed with a caustic cleaning
solution which, along with drum residues containing indus-
trial solvents, acids, and heavy metals, was disposed of
onsite in open, unlined pits. Eventually, the surface soils
on the site became saturated.
The abandoned Miami Drum Site was acquired by Dade County
for construction of the Palmetto Yard maintenance facility
of the Dade County Rapid Rail Transit Project. Extensive
80il borings were performed at the site during December 1981
and cores up to 10 feet deep were analyzed for contaminants.
Dade County contracted with O. B.Materials Company to
remove the 400 to 500 existing drums 'from the site, excavate
contaminated soils based. on the core analyses, and relocate
them to an existing, approved disposal facility. This
activity was jointly funded by theEPA and Dade County. In
addition to. this action, the contaminated water encountered
during excavation was removed, treated, and disposed of
onsite. At the present time, the maintenance facility of
the Dade County Rapid Rail Transit system is operating at
this site. .
Northwest 58th Street Landfill Site
Dade County owns this landfill, which began operation in
1952 as. an open dump. . Some waste was placed into shallow
trenche8 dug below the water table, resulting in deposition
of refuse in the saturated zone of the aquifer. Open
burning of waste was used as a volume reduction method until
it was banned in 1960. Since the ban, waste has accumulated
at approximately three times the 1960-61 rate. Since its.
startup in 1952, this facility has received from 100,000 to
1,000,000 tons per year of municipal solid waste. Garbage
from domestic and industrial sources comprises about 65
percent of the wastes disposed of at the site. The
remainder from other sources includes street debris, dis-
carded autos and appliances, furniture, tree trimmings,
gnR109B/02
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liquid wastes, and other rubbish. The estimated recent dis-
posal rate (applicable through July 1982) for garbage and
trash was about 90,000 tons per month, for liquid wastes,
consisting mainly of grease trap pump-outs, it was about.
200,~00to 400,000 gallons per month. Since January 1975,'
this landfill has been receiving daily cover consisting of
muck and crushed rock from quarry overburden and, more
recently, calcium carbonate sludge from the Miami Dade Water
and Sewer Authority water treatment plants. Since
September 1982, the landfill has been closed for all pur-
poses, except for the disposal of construction debris.
This site is not permitted as a sanitary landfill by the
Florida Department of Environmental Regulation (FDER).
According to preliminary close-out plans for the landfill,
it is classified as an open dump and has been operating in
violation of a consent order between the FDER and Metro Dade
County dated July 30, 1979. Final close-out plans for the
landfill are being prepared at this time and are planned to
include the private well users in the immediate area.
Varsol Spill Site
Industrial operations associated with a typical commercial
'airport have resulted in hydrocarbon contamination of sur-' '
face and ground waters in the vicinity of MIA. Since 1966,
approximately 15 hydrocarbon spills and leaks have been
recorded. The total discharge of hy~rocarbon materials is
estimated to be approximately 2 million gallons. This
includes the spillage of an estimated 1.5 million gallons of
, a light, petroleum-fraction solvent, discovered at the
Eastern Airlines maintenance base in the northeast section
of the airport around 1970. During 1970, a jet fuel spill
of approximately 66,000 gallons was discovered near the west
central area of Eastern Airlines properties. Also in that
year, National Airlines was responsible for an accidental
spill of an unknown amount of jet fuels into the'drainage
canals that ultimately discharge into the Tamiami. Canal.
They were ordered to stop discharging cleaning solvents and
degreasers to an airport drainage canal at this time. In
1981, Braniff Airlines was ordered to stop this same prac-
tice. Several other smaller spills and discharges of jet
oil, aviation gas, cleaning solvents, and degreasers have
also 'occurred at. the airport. Several areas within MIA have
heavy accumulations of oil lying on the ground. This is '
often the result of employees from various aircraft main-
tenance operations discharging oily wastes onto the ground
and into storm sewers. Another major underground jet fuel
spill was discover~d in 1983 in the vicinity of Concourse E
during ongoing construction and improvements in the area.
Removal of underground hydrocarbons at the airport was
attempted in the early 1970's, primarily at the Eastern
Airlines maintenance base. Hydrocarbon decontamination
gnR109B/02
-9-
-------
.
separator trenches were installed by Eastern Airlines in
1971 to remove the 1.5 million gallons of petroleum-fraction
solvent that had spilled underground. The recovery opera-
tions were terminated in August 1973 because of slime build-
up in the trenches and the extremely slow natural migration
of hydrocarbons into the trenches. Actual recovered volumes
were approximately 133,000 gallons of. hydrocarbons, or less
than 10 percent of the estimated spill volume. Other
recovery procedures at the airport have been implemented
only in conjunction wi~ dewatering operations at construc-
.tion sites within the airport and have been unsuccessful in
removing substantial quantities of hydrocarbons. During
April 1981, construction activities in the west-central area
of the Eastern Airlines maintenance base revealed .a thick
hydrocarbon layer floating on the water table in an
excavated trench, probably from previous fuel spills.
Eastern Airlines installed 54 shallow observation wells
during the early 1970's at their maintenance base in the
general area of the petroleum fraction solvent spill.
Measurements of fluid levels in these monitoring wells,
specifically the water-table depth and hydrocarbon thickness
in the upper layer of the water table, were taken twice per
year, during the dry 8easonand the wet season, from 1975 to
1981. The hydrocarbon layer thickness, according to these
data, shows a declining trend with time, and, in some wells,
the presence of the layer could not be detected in the
8econd year. In the Concourse E area, Dade County installed
43 monitoring wells to determine the extent and magnitude of
jet fuel spilled. Dade County also installed three recovery
wells in the Concourse E area and 8tarted the recovery oper-
ation in mid-1983. Through May 1984, over 102,000 gallons
of jet fuel had been recovered from this area. Recovery
operations are continuing.
CURRENT SITE STATUS
The initial study, conducted in 1982, compiled and evaluated
existing data relevant to the contamination problem. This
evaluation indicated the presence of dispersed, low-level.
concentrations of numerous toxic contaminants in the ground
water beneath the study area. . The conclusions were based on
limited data, relevant mainly to inorganics, with virtually
no ground water monitoring data available, especially for
organics.
The Remedial Investigation (RI), begun in late 1982, con-
sisted of a unified, planned, and intensive sampling effort
to fill in the data gaps found in the Phase I study and to
determine the magnitude and extent of ground-water
contamination. Criteria for data classification were
developed from existing literature, and were based on
gnR109B/02
-10-
-------
.
effects to ~uman health. Data evaluation based on the RI
indicated that widespread low to moderate levels of several
toxic contaminants, mostly in the volatile organics cate-
gory, are present in ground water throughout the study area.
Vinyl chloride was the most common contaminant detected and
its concentration often exceeded the cleanup goals. No
concentrated priority pollutant plume could be found.
Earlier investigations by ~astern Airlines, based on fluid
level measurements on top of the water table, showed
declining thickness of the petroleum-fraction solvent layer
with ~espect to time. By 1981, most Eastern Airlines data
showed no hydrocarbon thickness at the Varsol Spill Site.
The RI in 1982 and 1983 did not find a plume or pockets of
the 80lvent in ground water at and around the spill site and
in the neighboring low~r Miami Springs area.
In late 1981 (prior to cleanup of the contaminated soils),
FDER contracted with Technos, Inc., to determine the extent
.of ground-water pollution at the Miami Drum Site. Geophysi-
cal measurements using electromagnetics (EM) and ground
.penetrating radar (GPR) provided the data for this study.
The EM results showed a significant conductivity anomaly
coincident with the 8ite that provided evidence of a.strong
plume-like trend to the southeast in the direction of
ground-water flow and towards the Miami Springs/Preston Well
. Fields. Several less significant conductivity lobes were
also detected west and north of the .ite toward the Medley
Well Field. The Miami Drum Site signifi~antly contributed
to the areawide ground water problem. However, this RI, as
well as a separate remedial investigation conducted during
1983 by FDER at the Miami Drum Site, found no evidence of a
contaminant plume from the site.
During the late 1970'8, investigations by the U. S.
Geological Survey and Technos, Inc., had determined that,
based on the dissolved inorganic content 9f the ground
water, leachate from the 58th Street Landfill had
infiltrated the Biscayne Aquifer beneath and adjacent to the
landfill site in the form of a ground-~ater plume moving in
an easterly direction with the. natural dOWDgradient water
movement. However, examination of extensive priority
pollutant data from the 1982-1983 RI (heavy metals as well
as organics) that were non-existent during the earlier USGS
and Technos8tudies did not reveal a ground-water
contaminant plume in the vicinity of the landfill.
The results of these investigations indicate that, at this.
time, there is no concentrated contaminant plume emanating
from any of the three sites in the 8tudy area. However,
low, dispersed levels of volatile organic chemicals have
been.found throughout the study area and plumes have blended
together and become indistinguishable with the general poor
ground-water quality in the developed area. The main
gnR109B/02
-11-
-------
explanation for this is found in the geohydrologic condi-
tions within the study area: the high transmissivity of the
Biscayne Aquifer, the widespread interaction of ground water
with surface-water bodies throughout the study area: and the
high, continuous pumping of ground water at the several
municipal well fields. The overall ground-water quality in
the study area is addressed in Phase IV.
gnRI09B/02
-12-
-------
RECORD OF DECISION';'
SUMMARY OF REMEDIAL ALTERNATIVE SELECTION
BISCAYNE AQUIFER SITES, DADE COUNTY, .FLORIDA
PHASE IV:
STUDY AREA GROUND WATER
Phases I, II, and III of this Record of Decision (ROD) cover
on-site (source control) remedies. Phase IV summarizes off-
site contamination and corresponding remedies for contami-
nate~ ground water in the study area.
I
CURRENT SITE STATUS
Results of the remedial investigation (RI) showed that the
quality of the ground water in the developed study area is
virtually the same. No concentrated contaminant plume was
found emanating from' any of the three sites. However, low,
dispersed levels of volatile organic chemicals (VOC) have
been found throughout the developed study area, as shown
below and in Figure 4.
Total . Vinyl Tr&ne-l,
Geoqraphical Area VOCe . Chloride 2-dichloroethene
-
Airport Monitoring Wells 10 3.5 1.1
I.ower Miami Springs Welle 20 8.7 3.6
Upper Miami Springs Wells 33 17 7.3
Hialeah Area Wells 57 23 28
58th Street Landfill Wells 6.2 0.31 0.53
Unsewered Industrial ~ea Wells 1.0 0.25 0.25
Notes:
1. All values are mean values and are reported in \19/L.
2. There are fewer monitoring wells in the Un8ewered Industrial
Area than in other areas. Resul ts of analyses from these
wells mi9ht not be indicative of the water quality of the
whole area.
Because of geohydrologic conditions within the study area
(high transmissivity of the Biscayne Aquifer, widespread
interaction of ground water with surface-water bodies, and
the high, continuous pumping of ground water at the several
municipal well fields), plumes have blended together and
become indistinguishable from the general poor ground water
quality in the study area. However, we believe that a sub-
stantial portion of the contamination addressed in this
response action was released from the NPL sites mention~d
pr'ev iously.
u1.
-------
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o O8eecII!dIr'!"""'_--'bue..I_.II.................,c:rt18n8 .,~ y :: . [I. . \ill,' . ~.
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LEGEND
NI
. 8ft ''''.,2 .. tor ..... c .....,.,... Mtr. ...... ... .......... III ..
"If ....., ... (,.................. ........
W:.i:n:~! ~k;;~;;:';J.~!; r(";~lt,'i,~;~:' FlCBl'J1I2 l:;7 'JcJo\l]; IDVii:O:;;:,1,,~' : p~,
-
-------
.
.'
The effects of contaminated ground water on surface-water
quality were found to be similar to those identified in an
earlier county sampling program. In 1981, as part of
routine surface-water monitoring, Dade County conducted
analyses of water from the Miami Canal for a wide array of
physical and chemical parameters, including chlorinated
pesticides and herbicides. Runoff was determined to be the
primary source of high levels of dissolved solids and
bacteria. Some phenol from industrial pollution was
identified, as well as' minimal levels of metals, pesticides,
and herbicides. The only ground-water related problem
discovered was low levels of dissolved oxygen resulting from
ground water interaction with surface water. The current
sampling program results have not shown contaminants
traceable to the ground water.
A comparison of the ground water in the developed portion of
the study area with that of the undeveloped western area
near the Northwest Well Field shows that the former is
poorer in quality than the Rtrue backgroundR ground water in
the latter. Fiqure 5 shows the monitoring well locations
. and corresponding geographical areas defined for data
evaluation. Wells G-3103, S-218A~ NW-l, NW-2, NW-3, and
NW-15, located in the undeveloped western area, were
monitored for all 129 EPA priority pollutants for background
conditions. Results, shown in Table 6 (see page 7), include
an absence of volatile organics in these wells. The RI
dete~ted extractable organics on only one occasion in
well G-3103, but we attributed this to the presence of trash
and debris in the vicinity.
Tables 1, 2, 7, 8, 9, and 10 (see pages 5, 6, 8, 9, 10, and
11) list the contaminants detected in each geographical area
within the study area. These results confirm the presence
of VOCs in low to moderate levels throughout the study area
and demonstrate that the ground water quality in the
developed areas is the result of contamination from multiple
sources.
The priority pollutants and reported carcinogens found in
the Biscayne Aquifer study area during the RI are given in
Table 11 (see pages 12 through 14). Table 11 also shows the
laboratory detection limits: the maximum concentrations
found in the study area,' the well fields, and the water
treatment plant finished water: and data classification cri-
teria/cleanup goals for each contaminant. These goals were.
developed from existing standards when available, such as
EPA primary drinking water standards, and from the most
recent toxicological information available. The Centers for
Disease Control (CDC) in Atlanta have reviewed the data
classification criteria and suggested changes and additions,
which have been incorporated into Table 11.. References used
in establishing the criteria are given in Table 12 (see page
15). The cleanup goal for vinyl chloride has been set
gnR109A/39
-3-
-------
I
..
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NW-3-e
NW-2-e
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r;-2t8A
~3t03
;?'&L.1..u:lI..-.~ ~ ~
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!llion, ~I.I J
LEGEND
,
A New MonoIorong WIll Nests ~ II-
. E.~ Wells .
o ' .. UonoIoring 1 .
. ; "" Plant Well".. 11
I-~
f
!I!" Sampling locations and Geographical Areas 'for Dal
-- -
_._~-
--.
--.
----
----
-------
.
WElL DESIGNATION
, PARAMETER .MW1 MW2 MW3 MW4 MW5 MW8
. MW7 MW8 MW9 MW11
S D S D S D S D S D S 0 S 0 S D D D
ARSENIC 0 0
CADMIUM 0 0 0
CHROMIUM 0 0 0 0 0 0 0 0 0
tJ LEAD 0 0 0 0 0 0 0 0
I MERCURY 0 0 0
; SELENIUM 0 0
ZINC . 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
i .
CHLOROBENZENE 0 0 0 0
2 CHLOROETHANE 6 6 6
~ 1,1-DICHLOROETHANE . . .
8 I TRAN$-1,2-DICHLOROETHENE 0 0 0 0
i 1.1,2,2- TETRACHLOROETHANE . .
TOLUENE 0 0 0
~ 1,1.1- TRICHLOROETHANE . . 0 .
~ TRICHLOROETHENE 0 0 0
VINYL CHLORIDE . . . . . . . . .
>
.
TOTAL RECOVERABLE PHENOLS 6 6 6 6 6 6 6 6
ACETONE 6
DIMETHYL SULFIDE 6
u METHYL BUTYL KETONE 6 A A
I! METHYL ETHYL KETONE A
.i~ METHYL ISOBUTYL KETONE 6
02 STYRENE 0 0
11:2
!8 UNIDENTIFIED COMPOUNDS (EXTRACTABLE) 6
0
LEGEND
6 Detected in at lust one sample.
no criteria given.
0 Detected in at leut one sample. but TABLE 1. ~
at levels .... than .t8blilhed criteria.
. Detected i.n at ".st ~ne sample Contaminants Detected in the ~irport ~
-------
. WELL DESIGNATION
. PARAMETER GII ! .. ~ :x C',' ., :h . .c u " III .c :? ~ . .c Ull
~ .
~ en en en ~ ~ ., ~ CO? 1'1 ~ ~ ~ ..
. 2 2 2 2 2 .c ' I I
en < < < < < <
ARSENIC 0
CADMIUM 0 0 0
CHROMIUM 0 0 0 0 0
B COPPER 0 0
1 LEAD 0 0 0
I MERCURY 0 0 0
SELENIUM 0 0 0 0 0
ZINC. ' 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
I BENZENE . .
CHLOAOBENZENE 0 0 0 0 0 0 0 0
CHLOROETHANE 6 6
~ CHLOROMETHANE 6
c B 1.1-DICHLOROETHANE . .
0 1 TRAN5-1,2-DICHLOROETHENE 0 0 0 0 0
i « 0 0
8 ETHYL BENZENE
11.1 METHYLENE CHLORIDE . . .
~ 1.1,2,2- TETRACHLOROETHANE .
i TETRACHLOROETHENE 0 0
TOLUENE 0 0 0 0 0
VINYL CHLORIDE . . . . . . . . . .
TOTAL RECOVERABLE PHENOLS 6
OIL & GREASE 0 0
ACETONE 6 6
C8 ALKYLPHENOL 6
DiMETHYLHEPTANE 6
METHYL BUTYL KETONE 6. -
U METHYL SULFIDE 6 I-
18
cz STYRENE 0
152 M-XYLENE 0
«2 O&P-XYLENE 0 0 0 0 ~
!I! 8
b UNIDENTIFIED COMPOUNDS (EXTRACTABLE) 6 6 6
LEGEND
6 Detected in at least one sample.
no criteria given.
0 Detected in at ....t 0'''' umple. but TABLE 2.10i2M1.
at levels less than ..tablished criteria;
. Detected in at least one umple Contaminants Detected.in the IIHILl
at Ie¥8I8 abOve criteria. lower Miami Springs Area.
-6-
-------
WELL DESCRIPTION
. PARAMETER
.. NW-1 ' NW-2 NW-3 NW-15 s.218a G-3103.
LEAD 0
MERCURY 0
I saENlUM 0
ZINC . 0 0 0 0
,
I -
-
I ~
I
!I
II .
i~ -
TOTAL RECOVERABLE PHENOLS
Ii HEXADECANE ~
PENTAOXAPENTADECANE ~
UNIDENTIFIED COMPOUNDS (EXTRACTABLE) .6
LEGEND eSampling results not Included ~ of
~ ~ In at I8IIIt one IImPIe. IUrf8ce tr8Sh at the wellhe8d 8t8L
no crit8rIa given.
0 Detec:tIId In at IeIIt one I8YIPIe. but TABLEs.lo-t2MI
. at levels less than established crtteria.
I - ..- -.. . . Contaminants Detected in the Undeveloped Area. IIHILL
. D8t8C18d In at I88It one enpIe
at .... 8boIII8 critIrta
-7-
-------
..
i PARAMETER . 1:1 U ~""-'. ~""-IU ~ = ... VI ~ ... ~
~ . :h - C1I - C1I C? ., It) ~
. ~ ~ ~ pepth in ft Depth in ft ",,n , . .
. '" '" '" '" :i ~ ~ ~ ,2 2
; . 15 30 60 10 30 60 2 2 2 2 2 2 2
,
" ARSENIC 0
CADMIUM 0 0
,
B CHROMIUM 0 0 0 0 0 0 0 0 0 l.-
I COPPER 0 1
C LEAD 0 0 0
It -0
' i MERCURY 0 0 0 0 0 0 0 0
; SELENIUM 0 0 0 0 0
ZINC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
~
:1 CHLOROBENZENE 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
CHLOROETHANE 6 6 6 6
:!; B 1,1-DICHLOROErHANE . . . . . . . . . . .
;i S 1,1-DICHLOROETHENE . . . . .
TRAN5-1,2-DICHLOROETHENE 0 0 0 0 0 0 0 0 0 0 -
. 8
& ETHYL BENZENE 0
2 Ilol METHYLENE CHLORIDE . . .
~
I ~ 1,1,2,2-TETRACHLOROETHANE . .
1,1,1,-TRICHLOROETHANE 0
>
TOLUENE 0 0 0 0 0 0 0 0 0
, VINYL CHLORIDE . . . . . . . . . . . .'
en PCB-125<' (AROCLOR 125<') .
!.- '
-CD
~~
~..
CYANIDE 0 -
TOTAL RECOVERABLE PHENOLS 6 6 6 6'
C8 ALKYLPHENOL 6
CHLOROMETHYLBENZENE 6 --
1-CHLORo-2-METHYLBENZENE ~
CHLOROTOLUENE 0
CJ 6 ~
I! ETHYL ETHER
CZ W~ADECANOIC ACID ~
It;:)
O~ HEXAHYDROAZEPINONE ~
It:! METHYL BUTYL KETONE 6 ~
!8 METHYLENEPENTANONE 6
o
STYRENE 0 0 0 0 0 "
O&P-XYLENE 0 0 0
UNIDENTIFIED COMPOUNDS (EXTRACTABLE) 6 6
.
...
LEGEND
6 Detected in at ....t one samp".
no criteria given.
0 Detected in at least one sample. but
at I8v8Is .... than fttablished criteria.
. Detected in at "..t one sample TABLE 7. ~.;Q
at 18v8I1 abOve criteria. Contaminants Detected in the Q-i~
Upper Miami Springs Area. ..,
-8-
-------
.
j WELL DESIGNATION
.
: . PARAMETER
I ~ ~ ~ ~ N
P1 P2 P3 P4 P5 P7 -
i - - (J)
o 0 ::E
CADMIUM .
\ CHROM.IUM 0 0 0 0 0 0 0
, B LEAD 0 0 0 .
.
. ~ SELENIUM 0
I 0 ZINC 0 0 0 0 0 0 0 0 0 0 0
a::
0
~
;i .
:S
-~ BENZENE .
B CHLOROBENZENE 0 0 .0
:i I TRAN5-1,2-DICHLOROETHENE 0 0 0 0 0 0 0 0 0 0 0
o METHYLENE CHLORIDE . . .
-I 8
TOLUENE 0
w
.,..J
r 5 VINYL CHLORIDE . . . . . . . . . .
t
t ~
,
~
!
,
TOTAL RECOVERABLE PHENOLS . I::t. I::t.
I ACETONE 6
HEXAHYDROAZEPINONE I::t.
0 STYRENE 0 0
~~
TETRAMETHYLPENTANONE 6
CJZ
a:::) 0 0
O~ O&P XYLENE
a::::E UNIDENTIFIED COMPOUNDS (EXTRACTABLE) I::t. -
wa
~
~ .
:
.
, LEGEND
I::t. Detected in at least one sample.
no criteria given.
0 Detected in at least one sample. but
I : at levels less than established criteria.
. Detected in at least one sample . . TABLE 8; I~I
: at levels above criteria.
. Contaminants Detected in Hialeah Area.
-9-
-------
WELL DESIGNATION
, LM-2 LM-4a LM-Sa LM-tia LM-8 LM-9
. PARAMETER Depth in Ft Depth in FI Deplh in FI Depth in Ft Depth in Ft Depth in Ft
, 10 30 60 20 40 64 10 30 60 10 30 60 10 30
60 10 "
ARSENIC 0 0 0
rJ CHROMIUM 0 0 0 0 Q 0 0 Q 0 0 0 0 0 0 0 "
I COPPER .
LEAD 0 0 0 0
I MERCURY 0 0 0 0 0
SELENIUM 0 0 0 0
ZINC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
BENZENE .
! CHLOROBENZENE . 0 0 0 0 0 0 0 0 0 0 0 0 0 0
i CHLOROETHANE 6
8 1.1-DICHLOROETHANE . .
i TAAN5-1.2-DICHLOROETHENE 0 0
III ETHYL BENZENE 0 0
~ ~ 1.1.2.2- TETRACHLOROETHANE . . . . .
TRICHLOROETHENE 0 0 0
2 > TOLUENE 0 0 0 0 0 0 f1:5
~ VINYL CHLORIDE .
II: C~ BENZYL BUTYL PHTHALATE 6
0 -z CHRYSENE .
I U<
<0 2."-DIMETHYLPHENOL 0
.~ 2."-DINITROPHENOL 0
~III 4-NITROPHENOL . t')
$a PENTACHLOROPHENOL .
&&1<
~U PHENOL 0
<
!~ . /
!.. "."'-DDT .'
-CD ENDOSULFAN SULFATE . 6
Uu .-/
~CL. PCB', Itotal) .
~.
TOTAL RECOVERABLE PHENOLS 6 6,6;6 6 6 6 6 6
ACETONE A ~
C2 ALKYL PHENOL 6
C3 ALKYLBENZOIC ACID 6
BENZOIC ACID 6
CARBON DISULFIDE 0
1.4-DIOXANE 0
. ETHYL ETHER 6 ..
HEXADECANE 6
CJ HEXADECANOIC ACID 6 6
!~ METHYL ACETATE 6 "~
oz
~f METHYL BENZOIC ACID . 6
METHYL BUTYL KETONE 6 ~
G:2
&&10 METHYL ETHYL KETONE 6 6
:Z:u
~ 2-METHYL PHENOL ~
4-METHYL PHENOL 6
PHOSPHORIC ACID. TRIBUTYL ESTER 6 ~ ~ 6
STYRENE 0 0 0 0 0
TETRAHYDROFURAN .
2,",5- TRICHLOROPHENOL 0
M-XYLENE 0 0
O&P-XYLENE 0 0 I
UNIDENTIFIED COMPOUNDS I EXTRACTABLE' 6 6 ~ ~ ~
6 DetlCted in 8I18aI1 one 18mp". TABLE 9. ~
. no criteria given. Contaminants Detected tn ttie ~
o DetICt8Cl in It leut one 18mple. but
at levels .... than ..taOIiIfI8cI cnteriL
. DetlCted in at I88It one 18mpJe 58th Street Landfill Area.
at levels above cr.terl8.
-10-
-------
.
WELL DESIGNATION
PARAMETER . Zj .., ~ Zj ~ . Zj .., ~ .p Zj ! . Zj 3
~ ~ ~ ('oj ;l ;l ;l : '? '?
cD cD cD cD iii iii CD " "
~ ARSENIC .
: CADMIUM 0
rJ CHROMI~M 0 0 0 0 0 0 0 0
i LEAD 0
!
MERCURY 0 0 0
.' i SELENIUM 0
ZINC 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
. .
~
ACRYLONITRILE .
:i IIIrJ 1.1.2.2- TETRACHLOROETHANE . . '
~~ TRICHLOROETHENE 0
i ~! TOLUENE 0 0 0 0 0
,;.;
:~ (I) PCEs-1260 .
a: ~,
0
:i ~~
I tn..,
;
; f
: C~ BIS 12-ETHYLHEXYLt PHTHALATE 0
-Z
"C
, Co
. ~~
:
.
, ~i
.. !t>
I i~
.
~
TOT AL RECOVERABLE PHENOLS A A A A A
ACETONE A A
-
BUTANEDIOL A
1,4-DIOXANE 0
HEXADECANOIC ACID A
" METHYL BUTYL KETONE A A A ~
i; METHYL ETHYL KETONE A
~~ METHYL ISOBUTYL KETONE A
STYRENE 0
C:.I
.~8 TETRAHYDAODIOXIDETHIOPHENE A,
0 TETRAHYDAOFURAN 0 i
TETRAHYDROTHIOPHENE A A A
: TETRAHYDROTHIOPHENE DIOXIDE A
OIP-XYLENE 0
UNIDENTIFIED COMPOUNDS ,EXTRACTABLE, A A A A A
LEGEND
A Deteeted In at 18..t one umple.
no criteria giYen.
.0 Detected in at "ast one sample. but TABLE 10. ~
at 18vell lesS than atabliShed criteria.
. Detected in at ""t one 18mple Contaminants Detected in the ~
at levels above criteria. Unsewered Industrial Area.
-------
'l'able 11
PRIORm fOWJ'fAlft'S/CARCINOGI!NS romm 1M
'!'HE BISCAYNE AQUIFER 8!ODY AREA
IPA Contrect Lab
AnaI,Ucal Method Ma.188 Ccmc:8atraUoa Detected ~
Detect!oa L1JIlt Entire Finis er Fro8
Coaualnant (ua/L) . Study Are8 .11 Pielda treat.8ent Plants
:eavy Met!!!' (PrJ.ll8nZ
rinklnG Water sta rds)
Arsenic 10 50 a 320 II) 20
Cattli- 1 10 a 12 2 NO
Chroai- 10 50 a 40 20 NO
Lead 5 50 a 260 25 10
Mercu=y 0.2 2 a 1.8 1.4 NO
Seleni- 2 10 a 4 2 2
Priority Pollutant Volatile
Organic COIIPOunds (VOCS)
Vin,l Chloride 5 1 I 190 79 9.4
1,1,2,2-Tetracbloroetbane 5 0.2 b 5.7 3* NO
I Benzene 5 0.7 b 8 II) NO
.... Methylene Chloride 5 0.2 b 20 6.. NO
N l,l-Dichloroethane 5 0.9 b 55 55 3*
I l,l-Dicbloroethene 5 D.04 b 22 22 NO
Acrylonitrile 100 0.34 d 70* HI> HI>
Cblorobenzene 5 488 e 30 20 3*
1,2-Dichloroetheae
(cis and trans) 5 270 d 140 55 17
'I'oulene 5 340 c! 38 3* NO
a - xylene 5 620 (total) d 20 II) NO
0 , P - xylene 5 23 .* NO "t.
trichloroethene 5 28 c 3* NO NO
Ethyl benzene 5 1,400 f 5 NO NO
'l'etracbloroethene 5 9 c 3* NO NO
Chlorofora 5 100 a NO II> 18
BrolllocUcblol'Cl8ethane 5 100 d NO NO 6.1
I,l,l-trichloroethane 5 22 b 58 .* NO
Cbloroaetbane 5 4* HI> 94
Chloroethane 5 23 23 NO
MOte: NO -Not Detected
* .. EsUaated Value
pll
-------
'able 11
(ConUnued)
EPA Contact tab Data Cl...ifieaUon
Anal,Ucal Method Crlterla/Clean-up Goal. lint.. CoDCl8lltraUon Detected (UQIL)
Detection L1ait CoDcentraUon Refereace Entire Finished titer Fro8
ContUllnant (UO/L) hICJ/L) (See Table 12) Study Area 11811 "ftel41 Treat8eot Plant.
Prlorltl Pollutant Base/Jleutral
and Ad Extractable OrQanic
Compounds
Chr,sene 20 0.2 9 20 II) NO
Anthracene 20 0.2 9 20 NO NO
Benzo (A) Antbraoene 40 0.2 9 40 NO NO
Benzo (B and It) Fluorant.bene 40 0.2 9 40 NO NO
Benzo (A) Pyrene 40 0.2 9 90 ND NO
Benzo (GifU P8r,lene 40 0.2 9 40 NO NO
Phenantbrene 20 0.2 9 20 NO NO
Pyrene 20 0.2 9 20 NO NO
Fluorantbene 20 0.2 Q 20 NO' NO
Indeno U,2,3-cD) Pyrene 40 0.2 Q 40 NO NO
2,4-Di8ethylpbenol 20 400 f 110 NO NO
2,4-Dlnltropbenol 100 70 f 14 NO NO
I 4-Nitrophenol 200 70 f 200 NO NO
....
w Pentachlorophenol 40 30 b 40 NO NO
I Phenol 20 3,500 i 38 NO NO
Bls (2-Etb,lbexyl) Pbtbalate 20 6,000 b 86 NO NO
Benz,l But,1 Pbtbalate 20 20 NO NO
Pesticides and PCBs
PCB-Us4 0.11 (CCIIIbined 0.00008 b 0.83 ND NO
PCB-1260 0.1 total) 3.1 NO NO
PCB (tot81) 0.1 0.00008 b 7.7 NO NO
4,4'-DDr 0.1 0.00002 b 0.10 NO NO
2,4-D 1.0 100 8 26 NO NO
Silvex (2,4~s-!'P) 0.2 10 a 17 NO NO
Endosulfan Sulfate 0.1 0.18 ,NO NO
Note. NO. Not Detected
. . £aU_ted Value
gnRI09a/4C1»
-------
Contulnant
~her U::a~: ~
. PO~anrn or ,
stJrene
Cblorotoluene
Carbon Disulfide
'l'etrabJdrofuJ::an
rber Ex~r~1 OrL.8D1C
~n ory
u ants)
I
~
~
I
1,C-Dioxane
2,C,5~icbloropbeaol
Note: NO. Not Detected
* . Esti..tect Value
gnRI09I
EPA Contnct LIb
Anal,tical llethod
Dltectioa L1ait
(1Ia/L)
5
10
200
Table 11
(ContiDUed)
1,330
3,C5O
830
57
570
2,600
b
f
f
j
It
f
lie.... CoDC8DuaUon De~
Dture F n 8 er FroII
Study Area ..11 Pleld8 Treat.8ent Plants
6.3
80
3*
tOO
C.
80
NO
NO
NO
NO
NO
NO
10
lC.
tID
NO
lID
NO
-------
. b..
Table 12
DATA CLASSIFICATION CRITERIA REFERENCES
a.
EPA primary drinking water standards. National Interim .
Primary Drinking Water Regulations. EPA-570/9-76-003.
u.s. EPA, Office of Water Supply, Washington, D.C.
'Criteria for statistical cancer risk of 10-6. u.S.
Environmental Protection Agency. 1980. Ambient Water
Quality Criteria. EPA 440/5-80-027, -038, -019, -053,
-052, -026, -033, -029, -042, -069, -073, -077, and
-078.
EPA, Cancer Assessment Group. Recommendations.
Written communication between EPA Region IV and
CB2M BILL.
Value established by EPA, Office of Drink~nq Water,
Criteria and Standards Division.
Based on available toxicity data for protection of
public health, note that taste and odor problems are
experienced with concentrations in excess of 20 ~g/L.
U.S. Environmental Protection Agency. 1980. Ambient
Water Quality Criteria. EPA 440/5-80-028.
EPA suggested permissible ambient goal based on health
effects. Sittiq, M. 1981. Handbook of Toxic and
Hazardous Chemicals. Noyes Publications, Park Ridge,
N.J.
c.
d.
e.
f.
9.
The World Health Organization has established a value
of 0.2 ~g/L as a recommended total concentration for
the sum of six Polynuclear Aromatic Hydrocarbons
(PAB's) that are considered animal carcinogens in
drinking water. This value has been assigned to each
PAH in this table, even though they have not all been
identified as carcinoqens. Written communication
between CDC (Atlanta) and CH2M HILL.
National Academy of Science Guidance to EPA, Office of
Drinking Water. Written communication between EPA
Region IV and CB2M BILL.
Based on available toxicity data for protection of
pUblic health; note that taste and odor problems are
experienced with concentrations in excess of 300 ~g/L.
u.s. Environmental Protection Agency. 1980. Ambient
Water Quality Criteria. EPA 440/5-80-067.
Value is one tenth of the ten day value established by
EPA, Office of Drinking Water, Criteria and Standards
Division.
Centers for Disease Control (CDC) recommended
criterion. Written communication between CDC (Atlanta)
and CH2M BILL.
Florige VOC standard based on statistical cancer risk
of 10 . State of Florida rule 17-22.
h.
i.
j.
k.
1.
gnR109a/40c
-15-.
-------
at 1.26Pg/L'which is the State of Florida'!6standard based
on 10 cancer risk level. The federal 10 cancer risk
level, based on a different study, is 2.0 pg/L (corre-
,spondence from State of Florida). A list of organic
contaminants found in in the study area that are not
priority pollutants or carcinogens and for which no criteria
are available is given in,Tab1e 13 (see page 17)~
The priority pollutant VOCswere the most prevalent contami-
nants found throughout'the study area, in the well fields
(Upper Miami Springs, Lower Miami Springs, Preston and
Medley Well Fields), and in finished water from the water
treatment plants (Hialeah and Preston WTPs)., Heavy metals
were found sporadically in the study area, with maximum con-
centrations in the well fields and the water treatment
plants at levels lower than primary drinking water standard
maximum contaminant levels (MCLs). The priority pollutant
base/neutral and acid extractable organic compounds were
found sporadically in the study area, 'but were not detected
in the well fields or the water treatment plants. Priority
, pollutant pesticides and PCBs were found in a few instances
in the study area, but were not detected in the well ,fields
or the water treatment plants. Other volatile and extract-
able organic compounds with criteria available, also listed
in Table 11, are not priority pollutants. They were found
sporadically in the study area and in a few instances in the
well fields, but were not detected in the water treatment
plants. Other volatile and extractable organic compounds
with no criteria available, listed in Tab'le 13, are not pri-
ority pollutants or known or suspected carcinogens. They
were found sporadically in the study area and in a few
instances in the well fields, but were generally not
detected in the water treatment plants.
The ground water quality in the study area is of special
concern because of VOC contamination detected in the Miami
Springs, Preston, and Medley Municipal Well Fields as well
as in treated water from the Hialeah and Preston Water
Treatment Plants. In general, the water from the municipal
production wells (except the Northwest Well Field) was more
contaminated than'that from the other monitoring wells.
This is probably due to the continuous pumping of the pro-
duction wells, which tends to draw contaminants from within
and around the cone of influence of the well field area.
VOC contamination of the Biscayne Aquifer in the study area
was detected in all three vertical levels (water-producing,
zones).' The middle and bottom zones had two to three times'
as high a degree of contamination as was encountered in the
upper zone (Table 14, page 18). This dispari~y probably
occurs because the production wells in the two lower zones
draw contaminants from the upper zone while pumping.
gnR109A/39 .
-16-
-------
Table 13
~R CONTAMINANTS FOUND IN THE BISCAYNE AQUIFER STUDY AREA
FOR WHICH CLASSIFICATION CRITERIA ARE NOT AVAILABLE
(NOT PRIORITY POLWTANTS OR maffl CARCINOGENS)
Contaminant
Volatile Orqanic Compounds
Acetone
1-chloro-2-Methylbenzene
Methyl Butyl Ketone
Methyl Ethyl ICetone
Dimethylheptane'
Olloromethylbenzene
Ethyl Ether
Methyl Acetate
Tetrahydrothiophene
Tetramethy lpentanone
Dimethyl Sulfide
Methyl Isobutyl JCetone
Methyl Sulfide
Extractable Organic
Compounds
Dimethylheptane
C8 Alkylphenol
Hexadecanoic Acid
Benzoic Acid
C2 Alkylphenol
C3 Alkylphenol
Rexadecane
Methyl Benzoic Acid
2-Methyl Phenol
4-Methyl Phenol
Pho8phoric Acid,
Tributyl. Eater
ButaDecUol
Tetrahydrothiophene
Dioxide
Pentaoxapentadecane
Hexahydroazopinone
MethylenepentaDone
Unidentified
Extractable organics
Note: ND - Not Detected
gnJU09a/40d
Maximum Concentration Detected (~q/L)
Entire Study Finished Water From
Area Well Fields Wate% Treatment Plant
200
97
150
13,000
8
70
20
30
100
20
20
90
10
ND
97
110
ND
ND
70
20
ND
ND
ND
"ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
8 ND ND
50 6 ND
100 100 ND
200 ND ND
120 ND ND
21 ND ND
700 .700 ND
50 ND ND
390 'ND ND
150 ND ND
30 ND ND
200 ND ND
50 ND t-~
10 10 ND
700 700 ND
60 60' ND
800 800 33
-17-
-------
At present, the Medley Well Field has been permanently shut
, off and the Miami Springs and Preston Well Fields are in
minimal use. Use of the new, uncontaminated Northwest Well
Field is being maximized, and water from this well field is
being pumped to the Hialeah and Preston Water Treatment
Plants.' The peak day water demand in the area is increasing
yearly and is projected to be 255 million gallons per day
(mgd) in the year 2005 (see Figure 6). Since the capacity
I
.
Table 14
MEAN VALUES FOR SELECT ANALYTICAL PARAMETERS FOR
WELLS IN THE SHALLOW, MEDIUM, AND DEEP ZONES
Cleanup
Upper Middle Deep Goal
Vinyl Chloride 0.35 12 10 1
..
Trans-1,2-dichloroethene 0.36 6.7 4.3 270
Total VOCs 7.8 22 19
Note:
All values repo~ted in pg!L.
of the Northwest Well Field is only 150 mgd, conditions in
the near future will demand additional water withdrawal,
ei ther from the existing well fields or from new well
fields.
ENFORCEMENT ANALYSIS
The Miami Drum Services site, the Northwest 58th Street
Landfill site and the Varsol Spill site were collectively
designated as 'the Biscayne Aquifer Site to address the,'
threat to the regional ground water supply.
Miami Drum Services
EPA is currently proceeding with cost recovery actions to
recover EPA's removal expenditures at this site. According
'to information gathered during a responsible party search'
and financial assessment study, the owners and operators .of
the site are not financially capable of remedial activities
or reimbursement to EPA for its remedial expenditures. EPA
and DOT are currently investigating generators and trans-
porters as financially viable potential responsible parties.
Notice letters for the Remedial Design/Remedial Action phase
are being drafted and wil! be mailed in the near future.
gnRI09A/39
-18-
"
-------
?(
c
ffi
a..
U)
z
o
j
I ~
~ CJ
D Z
I 0
3
~
- 100
1980
-. .-.-.,..-.--- --.
280
260
240
244
220
Plant Rated Capacity
214
200
180
160
140
120
120
LEGEND
. 1 Preston Riter MedIa Change
2 HIaleah Riter MedIa Change
. 3 Demand Shifted to err Plant
Source: Miami Water and Sewer Authority.
2000
2005
. FIGURE 6. ~
Implementation Schedule Based on' Water Demand, ~.tl
. Plant Rated Capacity, and Aquifer Clean Up. .
-------
Northwest 58th Street Landfill
The State of Florida is planning the closure of the
Northwest 58th Street Dump pursuant to the requirements of
Chapter. 17-7.07 of the Florida Adminstrative Code. An
Enforce~ent Decision Document is currently being prepared by
EPA. A consent decree with Dade County detailing the
elements of the closure will be prepared concurrently with
the EDD. Notice letters for the Remedial Design/Remedial
Action phase are being drafted and will be mailed in the
near future. .
Varsol Spill Site
A no~action record of decision was signed for the .Varsol
Spill site on March 29, 1985.
ALTERNATIVES EVALUATION
The primary objective of the remedial action resulting from
the remedial investigation/feasibility study is to provide
uncontaminated drinking water to the public. A secondary
benefit of the remedial action is significant cleanup of the
contaminated portion of the aquifer.
Ground water treatment at the source was considered before
off-site remedial alternatives were developed. Ground-water
quality at the source, i.e., in the. immediate vicinity of
. the Miami Drum site, the Northwest 58th Street Landfill, and
the Varsol Spill site was found by the RI to be very similar
to the ground-water quality throughout the study area.
Source control action taken at the Miami Drum site (soil
excavation and removal as well as treatment of ground water
encountered. during excavation) has already reduced
ground water contamination at this site to levels as low as
those offsite. Prior to any source control action taken,
data indicate that the Miami Drum site significantly
contributed to the areawide. ground water problem. Source
control at the 58th Street Landfill in the form of proper
landfill closure and leachate control has been recommended
in the feasibility study (FS)~ The landfill closure plan is
presently being prepared by Dade County and its consultants.
Also, Dade County commissioners have approved, in concept, a
bond issue for implementation of the closure plan1 details
of the bond issue are being worked out before it is
presented to the public. The County is also taking.
appropriate actions ~o address the private well users in the
immediate area of the landfill. The spill site at the Miami
International Airport no longer has detectable levels of
petroleum-fraction solvent.. Therefore, the no-action
alternative was selected. No concentrated contaminant plume
was found emanating from any of the three sites.
gnR109A/39
-20-
-------
Besides these sources, there are numerous other unidentified
smaller sources (small businesses and individuals) scattered
throughout the study area that are known to be contributing
. to ground-water contamination. However, no distinguishable
plume could be identified from any of these sources. In
addition, the RI found that continuous pumping of the Miami
Springs and Preston production wells tends to draw contami-
nants from within and around the cone of influence of the
well field area, covering most of the developed study area.
In view of these data,' it was deemed impractical to treat
the ground water at each source. Since the mechanism exists
for withdrawing water at centralized locations at the well
fields, it was more reliable and practical to consider with-
drawal and treatment of ground water at these locations
offsite. Therefore, the alternative of ground-water treat-
ment at each source was rejected in favor of the off-site
. treatment alternative.
Alternatives Considered
. The following ten off-site remedial action alternatives were
considered:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
No action.
Use well fields for contaminant recovery and provide
treatment systems using air stripping, granular
activated carbon, or both.
Abandon contaminated well fields, find clean well
fields, and pump to existing WTPs.
Abandon contaminated well fields and WTPs and relocate.
Provide bottled water for consumption and continue
operating WTPs for non-consumptive purposes. .
Provide home treatment ~ystems.
Establish countywide spill prevention, containment, and
cleanup plans.
Develop land~use restrictions to protect the aquifer
from the effects of urbanization.
Use the Medley Well Field for ground-water recoverY1 .'
treat using air stripping, granular activated carbon,
or both1 and discharge treated ground water into the
aquifer.
Abandon septic tanks and provide centralized collection
and treatment.
gnR109A/39
-21-
-------
Initial Screening of Alternatives
An initial. screening of, the above alternatives was based on
conceptual costs, effects of the alternative, and acceptable
engineering practices as recommended in Section 300.68(h) of
the National Contingency Plan (NCP). Remedial actions that
far exceeded the cost of other alternatives, yet did not
offer significantly greater protection to public health or
the environment were rejected. Remedial action alternatives
were - also rejected if they failed to mitigate and prevent
harm to public health or welfare, or to the environment. If
the remedial action alternatives were infeasible for the
location and conditions of the release, inapplicable to the
problem, or represented an unreliable means of addressing
the problem, they were rejected on the basis of unacceptable
-engineering practices.
Table 15 (see page 23) presents a qualitative summary of the
ini tia1. screening process for all the off-site remedial;
action al terna ti ves. Al terna ti ves 4, 5, and 6 were
rejected. Alternatives 7, 8, and 10 were accepted only as
supplemental remedies to a primary remedy, since they were
only partially applicable to the problem. The remedial
action alternatives accepted for detailed evaluation as
primary remedies included Alternatives 1, 2, 3, and 9.
Detailed Evaluation of Alternatives
Details of the remedial action alternatives accep~ed for
further evaluation are provided below.
Alternative 1: The no-action alternative was considered
before proceeding to other off-site alternatives. The
Superfund Implementation Group of the Centers for Disease
Control (CDC) made the following comments following an
~ndependent review of the RI data:
-All study areas show serious concentrations of the
Biscayne Aquifer ground water with priority pollutants
and carcinogens. For many pollutants the chemical con-
centration is far above the EPA ambient water quality
criteria, the concentration associated with the EPA
estimate of a lifetime excess cancer risk of 1:100,000,
or the national drinking water standard... With this
in mind we consider the. Biscayne Aquifer a serious
potential threat to the public health.-
Implementing the no-action alternative would result in
adverse public health and environmental effects since the.
ground water would remain contaminated and human consumption
would continue. This alternative is infeasible, inappli-
cable, and unreliable since, without remedial actions, safe
drinking water will not be provided to the public.
gnRI09A/39 .
-22-
-------
lte8edial Off.i" CoIItnl Alt8naU..
1. No ecUOII
2. 0....11 fiel48 for coataiD8nt
recovery end prodd8 treat88Dt
syst- U8iD9 air 8trlpplD9,
granular ecU.ated carboD, or
both.
J. Abandon COIIuaiD8t.ec1 ..11 fielda,
find clea ..11 fielda, aDd PI8IP
to ex18tlng wrPs.
t. Aba1Ic!oD contaainated ..11 fiel48
and wrP8 and relocate.
I
~
w
I
5. ProdcJe bottled .ater for con-
8U8PUCID end continue aperat1D9
WTP1 s for DOII-con8U8IpU.e
purposes. .
6. ProdcJe bc8e trut8ent .,.t-
7. Eatabl18h count,..icJe 8P111
prevention, contalr-.t, end
cleanup plana.
8. Develop land UN re8trlctiou
to protect the aquifer froll
tbe . effect. of urbaD1aaUon.
9. 0.. 1Iedl., 8811 'ield for
ground-wat.r recover" treat
using air .tripping, GAe, or
a CIOIIb1nation of both, 8Dd
dlscbarge treated grouDd.
vater into the aquifer.
10. ~ septic bnts aDd
prowlcJe centraliaed collection
and treet8e1'lt.
pRl09A1Uc:/2
Mt. 15
OOTlAL' 8CREI!IIIIIG or orrslU RDUDIAL IC!ICII AL'I'IIINA!'IVrS
P\artb8r Coa8id8nUOII
,..
o-..t.
"
,..
,..
No
Aval18bl1it, of adequate vater aappl, queatioaeble.
11111 not clean up the aquifer. £XU-I, expeasiYe
. (approx18atel, $110 8ill1011).
'I'eIIporarr 8888UI'8.
Difficult to control 8CC8U.
No
No
'I'eIIporarr 888sure.
Difficult to aonitor, requires nplar _iat--.
£XpensiY. OUt.
Sappleaedtal to pr18ar, alternative.
'es, partial
",
'e., partial
. aappl.-n."l to pr18r, alteraative.
'e8
. .
,.., partial
SUpple8Dtal to pr18r, aUemative. .
'. 1 ..
-------
Alternative 2: This alternative recommends that the
existing contaminated Miami Springs and Preston Well Fields
be used as recovery wells. Water will be treated for
removal of contaminants that existing treatment cannot
remove. .
The types of contamination found in the study area during
the RI included volatile organic compounds (VOCs),
base/neutral and acid extractable organic compounds, and
metals. . The VOCs were. the predominant type of contamination
found in the well fields. Base/neutral and acid extractable
organic compounds were found at very low concentrations, if
at all. At the well fields, metal concentrations were below
primary drinking water standards and will be further reduced
in. the softening process at each WTP. In a few cases, some
heavy metals (primarily lead) were found in monitoring wells
at levels above the primary drinking water standards. How~.
ever, even if the maximum lead concentrations found in the-
study area entered the well fields, the existing treatment
process would reduce the level below the primary drinking
water standard.
It was determined that the types of organic compoun!1s
present. in the ground water of the well fields can be
effectively removed by aeration alone, including the maximum
VOC concentrations. Granular activated carbon (GAC) treat-
ment was not necessary since it was determined. that there
was no need to treat the low or non-existent concentrations
of base/neutral and acid extractable organic compounds.
Should the need arise, GAC treatment can be added to the
WTPs. . The extractable organic compounds are highly
immobile, and have not exhibited significant migration to
date and are not expected to do so. If they do, and are
found in the Miami Springs/Preston Well Fields at levels
above cleanup goals, additional actions would be evaluated.
Low levels that remain in the aquifer at this time are
presently being addressed through institutional .controls.
Final actions on the low levels remaining will be addressed
at a later date. .
Onder this alternative, raw water from the Miami Springs
Well Field will be treated at a new air stripping unit
located on land owned by the Miami-Dade Water and Sewer
Authority (WASA) near Wells No. MS-10 and MS-14. An ai~
stripping system to treat raw water from the Preston Well
Field will be constructed at the Preston Water Treatment.
Plant. The location and schematic of these proposed systems
are shown in Figure 7.
The combined design capacity of the Hialeah and Preston WTPs
will be approximately 244 mgd in the year 2000. The
Northwest Well Field will be used to provide 150 mgd of
uncontaminated water to the above WTPs. The remaining WTP
gnR109A/39 .
-24-
-------
.
t. ~Ii----~.\i~. &;tth I~~Pro=;::~onl~.<.;IJ'~~'iYi-.:-::~
I',:.. ti= ,,~;f~j:otM~:i..,~-,!.~'O=_.:,,:t a~ ".'~
! ~5:! ,~~c::"..,~~W8II won Flold ;.~ .', ,P-2' ... ,!,"f,ro.i~ WTP
1 . ! i :::....,~.,.:..':-.:.! M5-1 ). .;:;:" :'::;::'."';..".. .. -- ' ~. r tl~f(:~!-l2f(S/ . ..
II i 1', ,"'", RAJ£N \\:J£',.,~<;tf;i~~~~ i'i/'{i1i~1~~~~: ..~:'H~~~;j~,~:rIC
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, ); ',l'~ '.."'. . :','~.""""". .. ",'.;...,..c"'.' :to MS-S'~ M8-' ~. ... b.r....'~ ~
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. ~ . ': I .., "'... r.~.. .. ..... .... .'. ... ... '.... .. ..- - .,.--... . ..... f,., ~
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. ... \ ..: e': ~!i .~iTc ~~Hall..:":.. ':,.': ':="'.:',.,.,:,~.:;:f:.}':(~;:. ',' +L-~u .~' ,,'::':\'!:.::::. . e. fl,
:~ 1i34', ~ .. ,.'., .. " ..., .,.'';ivi~,:~:?:''j7TH .:;t' '\I.ST . !~\-.!.!..!-."- -
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,~"~.~", ~\ ~-~~,.-~..~~~ .:.: .....:. ':.'~A;'='~6 LANE,'.:' ,
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, ..,. I Ie r: ..... . ,.. ' I ,..., ',~' -.
IN] -~. - \ ,/-U-' 1\1 ! ill. U.. ) ,:! ...
- . I' - I I . . I I .. ..' LEGEND
- i ~!! I ~~ '-1 j:"i . 1\1 2 ~,...I_......I\ n \-r-" j
88; r!. V .!E [I . ,~!. ~'::.: .. - Existing Force Main
Seal. In Feet : ""1 - '" , ,.o . :: .'. '.
o 1.000 2,000 =. .- ~; [ : i.'. ;..~ - ~i!; . :\- :.~ :'1 -. --- New Force Main
. -; ,\ i ....--1 '. \ I .8 "' =
FIGURE 7.1Q-I:zM1
Location of the Proposed Treatment Systems. UH1Ll
-25-
-------
.
demand of 94 mgd will be provided by treating contaminated
raw water from the Preston Well Field and the Upper Miami
Springs Well Field. The air stripping pretreatment system
for the Hialeah WTP will be designed to treat 43.2 mgd of
raw water from the Upper Miami Springs Well Field, and the
.air stripping pretreatment system for the Preston WTP will
. be designed for treating 60 mgd . of raw water from the
Preston Well Field.
Air stri2iing the contaminated water will reduce the VOCs to
below 10 . excess lifetime cancer risk concentrations (see
Table 16, page 27). Although, as noted on ~tge 3, there is
a discrepancy between State and Federal 10 cancer risk
levels for vinyl chloride, the air stripping system would.
reduce the vinyl chloride to 0.03 pg/L, well below either at
the same cost. This alternative will have minimum adverse
environmental impact and no air pollution problem will be
created (see later section on consistency. with other.
environmental laws). Implementation will be relatively
simple and take only one year or less to complete. Use of
this alternative will provide uncontaminated drinking water
to the public, and aid in cleaning up the contaminated
portion of the aquifer.
Total present worth cost for this alternative is estimated
at $8,420,400. This includes a capital cost of $5,268,000
and operation and maintenance cost of $334,400 per year.
Alternative 3: The uncontaminated new Northwest Well Field,
located at the western edge of the Biscayne Aquifer study
area, has a capacity of 150 mgd, with fifteen 10-mgd wells.
.Well field water is pumped to the Hialeah and Preston WTPs
through a 96-inch diameter force main approximately 9 miles
long. Alternative No.3, by adding ten new 10-mgd wells,
will increase the capacity of the Northwest Well Field from
150 mgd to 250 mgdand enable it to meet the needs of both
the Hiale~h and Preston WTPs in the year 2000. Once the
expansion of the Northwest Well Field is complete, the Upper.
and Lower Miami Springs Well Fields, the Preston Well Field,
and the Hialeah plantsite wells will be abandoned.
Adequate capacity for additional ground-water withdrawal
will have to be determined and a consumptive-use permit
obtained from the South Florida Water Management District.
This will require an extended period for implementation of
l~ to 2 years. Implementation will create a potential for
contamination of the Northwest Well Field by (1) migration
of contaminants from other areas of the aquifer into the
well field's cone of influence which extends into the
Northwest 58th Street Landfill and the unsewered industrial
area of Medley, and (2) industrial development of land, if
permitted, within the well field's cone of influence,
gnRI09A/39
-26-
-------
fill.. II
-.. II" ISIIICIIftII II. 'l1li111"'" .. fIIImII ftP ""I~A_. ftIIIIII IlL-tift ID. 21
......
~- LI'"'' ............. ..... a_Iller
....- 111 ~ II. C.I "IU, Mo'-n Caalu ~I ... 1...18 nor." ts. .:.ltft.8I
-.- II Yel- Iltn 10" ~ ........ .t- "1"'1:1_. CI- -I.
~ ...- C_I fIet...t_t --I ...13.. ~ a.r.ac It.. IwlLI leI Ite. IW La I" IW/LI
"1",1 01'_'. n.n 0.01 1.0 . ~ 1.0 '.0
1.I-oIdllor-"'" S.II 0.01 o.OM It.M I.oao CD JO 0.08
I,I-Dldllor_"'" lI.n 0.1 0." ... 0..
"_-I, J-Dldllora8t..... n.. 0." 1.700 no ,;c..n 1'10
01100_- .., O.DOt 00 CD ..
tIIl- I.. 0.01S 21.5011 2.200 140 "0
...t..,1 ...,1"'" 20.0 1.1
1t..,1 It... ... 0.1.
011_"'" 0.10 0.001
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I.I,I-bldll_t..... 0.10 0.01 '.000 .. 200 II
"1",1 OIlerl" ".8 0.08 2.. . rI' 1.0 '.0
b_-I.J-oIdll.......... ... 0.1' 2.,. 2'10 1'10
...t..,l- Olio.'. I.r O.OJ 0." I,' .,.oao ..5011 =C..,. 0.1
011_- ..n O.GOt ..
.., 1,1- 0." ..GOt 120
St,... ... ..01 I,';C...' I.J.
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C., ... ..... -. o-lIt, Crltftia 1IaI:88t8. ItIII. .................,....... a-b ,. .... ..,. . .
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."oct- II t.. - _1- lor tile \1- ..... 18acot...
leI II.'.'" 'ot.to ......1.. -- .......... ....... ........ ~ S. ... ...... U. I".
101 ra_l. ",,1..1- 1'_'" -. nor.. ......81...... «:8. CII88tor 17-121
I 1., ... tr"""" 1- . 1_.- -..... ....1. ......1 ....-. .... II. ....
~ In ....ua 118M tt.tnl.. OIIoct., ....-.. .8 . III!I..
I I" ....ua 118M ttlt.s.. ,.... ....." b .. 181"-
..
....Oto/tOt
-------
.:
. .
, . '
resulting in aquifer contamination. Uncontaminated drinking
water will be provided to the public, but the aquifer will
not be restored through use of this alternative. .
Totai present worth cost for this alternative is estimated
at $22,e15,000. This includes a capital cost of $10,651,600
and an operation and maintenance cost of $1,290,300 per
year. .
Alternative 9: Medley Well Field's location in the study
area provides a suitable site for an off-site recovery well
system. Ground-water quality is similar to the rest'of the
study area, except that there are higher concentrations of
base/neutral and acid extractable organic compounds which
are highly immobile. Under this alternative, raw water from
the Medley Well Field'will be pumped to an on-site treatment
system and reinjected into the aquifer after treatment.
Three of the six wells will be used to pump water from the
aquifer to a treatment system consisting of air stripping
followed by carbon adsorption. Treated water will be re-
injected into the aquifer through the well casings of the
remaining three Medley wells. The well field will act as, a
recovery well system for the study area. However, it would
recover ground water from only a small part of the study
area because of its smaller cone of influence, compared to
that of the Miami Springs and Preston Well Fields.'
I~plementation,of this alternative will be fairly easy and
require a, relatively short period of time (one year or
less). It will cause mi~imum adverse environmental impact.
Although it will clean up a portion. of the extractable
organic compounds, it will not recover a large volume of
drinkable ground water. The goal of providing
uncontaminated drinking water would not be met in the
immediate future.
Total present worth for this alternative is estimated at
$105,047,000 (this does not include refurbishing pumps and
other equipment recently removed from the 'wellhead). This
includes a capital cost'of $14,625,100 and an operation and
maintenance cost of $9,591,900 per year. .
Table 17 (see page 29) presents a summary of the detailed
analysis of these four alternatives for cost, public health,
environmental, technical, and other considerations.
Table 18 (see page 30) presents a summary of the cost
evaluation of these alternatives, including total present,
worth.
RECOMMENDED ALTERNATIVE
Alternative No.1, no act.ion, was the least ,desirable -
alternative considered in the detailed evaluation, and was
gnR109A/39
-28-'
-------
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I
w
o
I
Alternative No.
2
3
9
. Table 18
SUMMARY OP COft EVALUATION OF PRIMARY ALTERNATIVES
Description
Use veil fields for contaminant
recovery and provide treatment systems
using air stripping.
Abandon contaminated well fields, find
clean veil fields, and pump to
existing W'rPs.
Use the Medley Well Pield for ground-
water recovery, treat using air
stripping and GAC, and discharge treated
ground water back to the aquifer.
Cost (January 1984 dollars)
Total
a
Present Worth
Capital
0'"
8,420,400
22,815,000
105,047,000b
~otal present worth costs were developed based on 30-year life and 10 percent interest rate.
Does not include costs for refurbishing pumps and other equipment recently removed from the wellhead.
gnRI09A/41a
5,268,000
334,400/yr
10,651,600
1,290,300iyr
14,625,100b
9,591,900/yr
-------
rejected on both public health and environmental grounds
(see Table 17). Alternative No.2 (air stripping 'at Miami
Springs and Preston Well Fields) was selected over Alterna-
tive No.3 (expansion of the Northwest Well Field). The
operation' of the Northwest Well Field has created a cone of
influence that extends almost to the western boundary of the
Northwest 58th Street Landfill. Therefore, the ground-water
movement .while the well field west of the landfill is
operating is westward toward the well field. However, the
RI found that water in the western part of the study area
was uncontaminated. tf the Miami Springs and Preston Well
Fields are not used in the future, and if the present
withdrawal capacity of the Northwest Well Field is increased
due to heightened water demand, great potential exists for
the contaminants from the study area to move into the
uncontaminated Northwest Well Field because of the expansion
of its cone of influence under those conditions. .
Alternative No.2 was selected over Alternative No.9
(ground water recovery, treatment, and discharge to aquifer,
from Medley Well Field) since Alternative No.9 would not
provide acceptable drinking water to the affected community.
In addition, the alternative is more costly than Alternative
No.2.
The remedy provided for in Alternative No.2 (air stripping
at Miami Springs and Preston Well Fields) was found to be
superior to the other alternatives ,investigated in the
detailed evaluation. Only Alternative No.2 will fulfill
both goals of the study by providing uncontaminated drinking
water. to the public as well as providing significant cleanup
of the aquifer. Also, Alternative No.2. has the lowest
present worth cost of the feasible remedies ($8,420,400)
(excluding the no-action alternative). .
On the basis of the above comparisons, Alternative No.2 is
recommended as the appropriate remedial action for the study
area ground water. . Use of existing Miami Springs and
Preston Well Fields for' contaminant recovery and provision
of treatment systems using air stripping (see Figure 7) will
provide clean drinking water to the public. A secondary
benefit of this remedial action is significant cleanup of ~
the contaminated portion of the aquifer.
Figure 8 shows the water tabl~ contour in .the study area
when Miami Springs and Preston Well Fields were fully oper-
ational. The cone of influence from these well fields and
the direction of ground-water flow are indicated in this
figure. The cone of influence covers a large portion of the
study area and the ground water within this cone would move
toward the well fields, if .Alternative No.2 were imple-
mented. Furthermore, since the natural ground-water flow is
toward the east/southeast, ground water upgradient of the
-------
I
,.,"-~
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WIll Filld
11SW8III1
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Sc:81e In Miles
1':0/1..."
1.0
2.0
M
-~. t
o
Weter Table Contour-8h0w8 ARItuda of Water T8bIe.
Contour Interval Is 1 end 2 feet. Datum Is
National Geodetic Vertical Datum 0' 1929 (NOVO).
,
, ' .--
FIGURE 8. ~
rater Row in the Study Area, May 1980. ;am
. Direction of G"
U - rFlow.
Altitude of Water Table and Grol
-
-------
.
cone of influence would eventually move into either the cone
of influence or the Miami Canal. The Miami Springs and
Preston Well Fields will thus recover most of the
contaminated ground water from the study area.
Most of" the remaining contaminated ground water from the
study area will flow into the Miami Canal, with ultimate
discharge to the Biscayne Bay and the Atlantic Ocean. The
ground water from the upper (least contaminated) layer of
the aquifer flowing from the study area to the Miami Canal
for a short time period each year will not adversely affect
. water quality in the canal, which is used only for flood
control, navigation, and industrial purposes. In addition,
through gradual expansion of potable water lines and
regulatory controls, Dade County has virtually eliminated
the potable use of private wells in the study area. The
emall number of private wells in the immediate area of the
58th Street Landfill will be addressed in the EDD.
The remedy provided by
choice, in theory, of
removal either before
treatment at the WTPs.
the recommended alternative offers a
treating the ground water for VOC
or after existing conventional
WASA is currently conducting studies to design and build a
treatment system that will handle the combined capacity of
the Preston and Hialeah WTPs. This system will be designed
to treat .approximately 170 mgd of finished water, and will
include the blended water from Northwest, Miami Springs, and
Preston Well Fields. While this alternative is technically
feasible, it was not selected for detailed evaluation in the
FS because of the added expense of treating an additional
. 67 mgd of water above the proposed design capacity of 103
mgd (Alternative No.2). As a large portion of the blended
water would come from the uncontaminated Northwest Well
Field, it was decided in the FS not to treat the Northwest
Well Field water by the air stripping system. .
WASA's motive for treating the finished water (as opposed to
the raw water) from the WTPs is to reduce the level of tri-
halomethanes (resulting mainly from chlorination of the
water at the WTPs) and color in the water. The additional
treatment for this purpose is unrelated to the hazardous
waste contamination of the ground water in the study area,
and thus the added costs are not eligible for federal par-
ticipation. The recommended remedial action of Alternative
No.2 compares favorably with WASA's plans because it .
essentially reduces the VOC contaminants to similar levels
while incurring lower costs.
gnRl09A/39 .
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i.
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 study area contains elevated
levels of VOCs in the' ground water. These levels pose a
thre~t to public health and the environment, especially
since the ground water is being used for drinking water pur-
poses. The recommended treatment would bring the quality of
the water withdrawn from the contaminated well fields to
levels below those set by the cleanup goals to protect
public health. The regional administrator concurs with the
cleanup goals. Thus, the recommended' remedial action will
be environmentally sound with respect to drinking water,
quality.
Wi th respect to air quality standards, the recommended
alternative would generate VOC emissions from air stripping
towers. However,: these emissions would be far below the
levels allowed by the State of Florida (see Table 19,
page 35). An air quality analysis using EPA-approved
modeling techniques was performed to predict the impact of
VOCs from the installation of air stripping towers at the
proposed Miami Springs and Preston Well Field locations.
'EPA air quality models ISC, PTDIS, and PTPLU were used to
determine the impact from the stripper tower complexes at
various distances downwind. The air stripping towers would
be located in residential neighborhoods, with the nearest
residences being approximately 40 meters from each stripper
complex. .
For the air quality analysis, impact receptors were placed
downwind from each source at 25, 50 I 75, 100, 150', 300, 600,
1,000, and 1,600 meters. Using worst conditions, it was
determined that ~aximum predicted I-hour concentrations,
which would be expected to be greater than longer-term
averages, are at 100 meters downwind of each treatment
facility. Table 20 (see page 36) presents the maximum
predicted I-hour impacts (concentrations) from each facility
for each contaminant emitted into the air. Table 20 also
compares these concentrations to threshold limit values
(TLVs) set by the American Conference of Governmental,
Hygienists, which are daily 8-hour averages that would not
be expected to produce adverse effects on workers. This
comparison shows that the maximum concentrations are several
orders of magnitude below the corresponding TLVs.
The smallest ratio of TLV to estimated maximum concentra-
tions is for vinyl chloride, over 800 and 650 for Miami
gnRI09A/39 ,
-34-
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I
W
U1
I
WTP
Hialeah
Preston
GNR157
gn~109A/41b
Table 19 "
SUMMARY OF VOC EMISSIONS FROM THE PROPOSED TREATMENT SYSTEMS (ALTERNATIVE NO.2)
Description
Treat water frOli the upper and lower
Miami Springs wells and the Hialeah.
plantsite wells
Treat water from Preston Well Field,
abandon Medley Well Field, and blend
with Northwest Well Field
Total VOCs from Pretreatment
Mean Values Maximum Values
(!b/d) (tpy) (lb/d) (tpy)
14.6
2.7
30.8
5.6
15.0
2.74
25.0
4.53
State of Plorida
Allowable
Emission
CUtoff Levels
(lb/hr) (tpy)
60
15
60
15
-------
Springs and Preston facilities, respectively. Moreover~ EPA
Prevention of Significant Deterioration (PSDL regulations
(available only for vinyl chloride in the list in Table 20)
define significant emission rates and monitoring concentra-
tions for vinyl chloride of 1 ton per year and 0.015 mg/ms
(24-hour average), respectively. For comparison, the
equivalent l-hour impact significant monitoringconcentra-
tion (derived from the PSD regulations) would be
approximately 0.038 mg/mJ. Maximum I-hour impacts for vinyl
chloride at either facility are well below 0.038 mg/mJ
(approximately one-third of this value). Thus, comparison
of maximum air emission impacts with the TLVs and PSD values
suggests that the health impact from inhalation of released
VOCs is not likely to be significant.
. table 20
JW[IMtJM PREDICTED I-HOUR AVERAGE CONCENTRATI~ FROM DfISSICIlS ~
AIR STRIPPING FACILITIES (JUX:CHU:NDID ALTERNATIVE) AND CClG'ARISON WITH TINs
LocaUon of
'acilUy
1Uu1 SpriDgs
8811 '1814
ColllPOund
ViDfl Cblorld8
1,I-D1CbloroelbeDe
1,1-D1CbloroetbaDe
1,2-D1CbloroetbeDe
CblorobeD&8De
'I'olueoe
lletbfl IUIfl IetO{1e
Ethfl Ether
CbloroetbaDe
1,1,2,2-TelraCbloroetbaDe
1,1,I-TrlCbloroetbaDe
1lax1ln.ul I-Hour
Concentration (mql.J)
0.012
0.003
0.006
0.013
0.002
. 0.0008
0.008
0.002
0.0005
0.0002
0.0005
PrutoD
Well '1814
.ViDfl CblorlcJe
1,2-D1Cbloroetbee
lletbflene Cblorlde
Q1orobeD&ene
Ifl8D8
Stfnae
0.015
0.024
0.001
0.001
0.0003
0.0009
TLV
Cmq/mJ)
10
20
810
790
350
375
20
1,200
Not Available
7
1,900
10
790
250
350
U5
215
The area of the proposed air stripping facilities contains
neither known threatened or endangered species nor wetlands.
It is, like almost all of Dade County, located in the.
lOO-yearfloodplain. However, the Miami Canal with its
several flood control structures minimizes and controls the.
flood in the study area, including that proposed for air
gnRI09A/39 '.
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stripping facilities. Also, building permits are issued by
.Dade County only if the ground at the proposed structures is
raised above the lOO-year flood elevation before the struc-
ture is built on it. In this case, both at the Miami
Springs and Preston Well Field locations, the elevation of
the existing surface at the construction sites will need to
be raised by only one to two 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 violation
of any water quality standards.
COMMUNITY RELATIONS
An extensive community relations program was implemented
during the course of the RI and FS. Local and state
agencies, such as Florida DER and Dade County DERM, were
active participants during the entire project.
A public me.ting was held in Miami in September 1982
present the results of the initial study (evaluation
existing data) and to outline the plans for the RI.
issues of Remedies, a newsletter summarizing project
activities and reports, were mailed to over 400 individuals
and organizations, primarily in the Dade County area, in
October 1983, March 1984, and July 1984.
A public meeting to present the RI findings, outline the FS
activities" and solicit comments on possible cleanup
alternatives was held in the study area in October 1983.
Preliminary results of the detailed evaluation of the
remedial action alternatives were explained in a public
meeting in March 1984 and public comments and suggestions
were sought. EPA sponsored another public meeting in July
1984 to present and r~eive public comment on the
recommended remedial action. Two workshops on study
findings, risk assessments, and proposed cleanup and pre-
vention activities were held for the press, elected and
appointed officials, and .the general public during
July 1984. A final public meeting was held in February 1985
in the Miami Springs City Ball to discuss the draft FS
report and to accept public comments (up to three weeks
after this meeting). A community relations. responsiveness
summary is attached. .:
to
of
Three
The above activities provided excellent opportunities in
both formal and informal settings for communication between
interested citizens and the agencies: EPA, Florida Depart-
ment of Environmental Regulation, Dade County Department of
Environmental Resources Management, and the Centers for
Disease Control. Except for a few minor concerns, the
gnR109A/39
-37-
. .
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public was generally supportive of the remedial action
recommended for the study area. Some questions were raised
on the potential for air pollution problems resulting from
implementation of the recommended remedial action (air
stripping). Others were concerned about the availability of
EPA funds for implementation of the recommended remedial
action, as they wished to avoid the use of water user
charges to fund cleanup actions. These and other public
comments are addressed in the attached responsiveness
swmnary.
At this time, two other community relations activities are
planned for the near future. . An Executive Summary of the
entire project will be published and distributed to citi-
zens, educational institutions, the press, and concerned
officials. The Summary will highlight ~he findings of the
RI, detail the present and potential risks to 'the environ-
ment and public health, present recommendations for remedial
actions, and list measures that can be taken by individuals
and local governing bodies to prevent future hazardous waste
contamination.'- In addition, a final issue of the news-
letter, Remedies, will be published and distributed, to
provide an update on the agency decisions for implementation
and funding of the recommended remedial actions.
OPERATION AND MAINTENANCE
In addition to the $5,268,000 capital costs required for the
recommended alternative, shown in Table 18 (see page 30),
operation and maintenance (O&M) costs will be incurred for
the life of the project. All O&M costs pertain to the
operation of the air stripping treatment facilities. These
include costs for labor (operator time), energy (power
' costs), materials and supplies, and equipment replacement
(fans and pumps). Detailed O&M costs for each facility are
presented in Table 21 (see page 39). Total estimated O&M
costs are $334,400 per year (January 1984 dollars).
In addition to these O&M activities, monitoring of water at
both the Hialeah and Preston Water Treatment Plants will be
required. At present, water at these WTPs is monitored for
all VOC'priority pollutants twice a year--once by Miami-Dade
WASA and once by Dade County DERM. This monitoring is
sufficient and should be continued. The recommended air
stripping treatment systems will be operated until monitor~
ing of raw water quality confirms that all cleanup goals
have be~n met. It will be the responsibility of the Florida
DER to ensure that these goals are met.
gnR109A/39
-38-
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Table 21
SUMMARY OF O&M COSTS
Item
Miami Springs
Facility
Preston
Facility
Labor
Time Requirements (hr/wk) 20 28
Cost - Hourly ($/h) 20.00 20.00
- Yearly ($) 21,000 29,100
Energy
Total Power Requirements (BHP) 207 287
Power Cost - Hourly ($/kW-hr) 0.07 0.07
Yearly ($) 94,500 131,200
Materials and Supplies ($) 3,600 5,000
Equipment Replacement
Fans
Operating Life (yr)
Annual Cost ($/yr)
Pumps
Operating Life (yr)
Annual Cost ($/yr)
Combine Equipment Replacement
Cost ($/yr)
Total Annual O&M Costs ($/yr)
5
7,400
10
13,600
5
10,300
10
18,900
21,000
140,100
29,000
194,300
As will be set out ~n. the cooperative agreement, EPA and the
state/county will share capital costs for the proposed air
stripping systems. In addition, EPA will reimburse a
portion of the O&M costs during the first twelve months of
the operation of the treatment facility. All water quality
monitoring costs will be the responsibility of Dade County.
SCHEDULE
Based on the project goals of cleaning up the aquifer and
providing uncontaminated drinking water to the public, the
recommended implementation schedule is to design, construct,
and start up the two air stripping treatment facilities
concurrently. This method of implementation also provides' a
backup water source in case one of the well fields is not
operational.
Key milestones and dates for project implementation are
presented in Table 22 (see page 40).
gnR109A/39
-39-
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Table 22
PROJECT IMPLEMENTATION SCHEDULE
Key Milestones
Approve Remedial Action (sign ROD)
I
Award Cooperative Agreement for Design
Date
August 1985
September 1985
Start Design
Complete Design
September 1985
January 1986
Start Construction
Mid 1986
Complete Construction
Late 1986
FUTURE ACTIONS
Remedial Action
Once the air stripping treatment systems are constructed and
operating, remedial response at the site will be completed
through continued treatment of the well field water, until
it meets or exceeds the cleanup goals. When it does, the
goal of providing safe drinking water to the public will
have been met.. A secondary benefit provided by the remedial
action will be significant cleanup of the contaminated
portion. of the aquifer. Miami-Dade Water and Sewer
Authority will be responsible for operating thes~ facilities
in a proper manner. The monitoring well system installed
for this RIfFS and selected county monitoring wells can be
used to measure the effectiveness of the remedy for aquifer
cleanup. Certain contaminants will remain in the aquifer "in
the study area. Should these. contaminants create a problem,
they can be addressed in a future action.
An enforcement decision document (EDD) is planned for the
Northwest 58th Street Landfill, and would include proper.
closure plans for the landfill which would also address the
private wells in the immediate vicinity of the landfill.
This EDD is scheduled for fall 1985.
Existinq In.titutional Controls
There are existing regulations in Dade County to control
potable water quality and regulate wells in the study area
gnRI09Af39 .
-40-
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. .
(applicable to all of Dade County). Dade County Code 24-11
prohibits discharges affecting water quality to surface
water and ground water, as well as sewers. This regulation
is aimed at prohibiting water pollution in the area, and it
establishes water quality standards for Dade County. Dade
County Code 24-45 regulates construction and operation of
wells in the study area (applicable to all of Dade County).
Construction and/or operation of a new or existing well
requires a permit from Dade County Department of
Environmental Resource$ Management (DERM). Thus, through
. existing institutional controls, Dade County can con~rol the
installation of wells through the County.
Supplementary Institutional Controls
The RI/FS acknowledged that ground-water contamination in
the study area is being caused not only by the three
Superfund sites discussed in this ROD package, but also by
small generators such as individuals and homeowners, through
indiscriminate disposal of such items as automobile oils,
paint cans, and pesticide bottles. Small industries and
businesses also contribute, with operating practices leading
to the runoff and eventual disposal of chemicals, solvents,
cleaning fluids, and oils into the aquifer.
The feasibility study recommended a preventive action
program for the entire Biscayne Aquifer area of Dade,
Broward, and Palm Beach Counties. County-level responsi-
bility for the program, which is called the Biscayne Aquifer
Protection Plan, was suggested, to ensure adequate consid-
eration of hazardous waste issues not fully addressed by the
federal and state agencies. Proper implementation of these
kinds of supplementary preventive actions through local
agencies can eliminate most existing and potential sources
of ground-water contamination in the Biscayne Aquifer area.
The 20 .recommended actions of the plan are listed in
Table 23 (see pages 42-44), along with the current status of-
Dade County's implementation program for the
recommendations.
gnR109A/3J
-41-
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Table 23
'1'IIE BISCAYHB AQUIPBR PROJ.'ECTION PLAN
Priority No.
Recommendat.ion
Status of Implementation
in Dade Count.y
1
Local government.s should consider providing a local
hazardou8 wast.e 8torage and transfer facilit.y for
individuals and 8111811 generators.
Not. Implemented,
Count.y has designated 5
acres for the locat.ions
of potent.ial hazardous
waste storage t.ransfer
sit.es, as required by
Florida statutes
2
A vell field protection program should be developed
to regulate land use within the cones of influence
of producing wells.
Implemented
3 Existing local inspect.ion and enforcement. programs Beil1CJ Implement.ed
should be examined for ways t.o strengthen their
ability to provide surveillance over the multitude
I of small quantit.y producers of industrial and
... commercial wastes.
N
I
4 The effectiveness of existing, local programs t.o Not. Implemented, Planned
regulate the act.ivities of 8111811 quant.ity industrial' ,
and COIIIIIercial waste generators, including their
waste disposal practices, should be increased or new
programs developed.
5 Public awareness and education ,programs on hazardous Partially Implemented
I. waste issues .should be developed.
I
6 A program regulat.ing the installation, maintenance, Being Implement.ed
and replacement of storage tanks should be developed.
7 A prOgram for the handling and disposal of liquid, Implemented
and other hazardous vaste mat.erials by commercial
haulers s~ould be developed.
8 Leak-proof severs should be -.~vided in all areas Not Implemented
within well field protect~ ~es and ultimately
in aIr commercial and indu L areas.
-------
Table 23
THE BISCAYRE AQUIFER .PRO'I'EC'l'ION PLAN
(continued)
Priority No.
ReCOlllD8ndation
Status of Implementation
in Dade County
9
A spill prevention, control, and countermeaSUre
program should be developed.
Partially Implemented
10
Pretreatment of wastes from commercial and indus-
trial users should be required before discharging
wastewater to a sewer system.
Implemented
11
12
t
..
w
I
13
14
A program should be implemented to control exfil-
tration from existing sewers.
Not Implemented
Responsible parties should be held liable for con-
tamination at the site and responsible for paying
the cost of ground-water cleanup. .
Partially Implemented
An emergency spill cleanup program should be
developed.
Partially Implemented
The PUblic should be encouraged to report improper
disposal of hazardous wastes through continuation
of existing programs or the development of new
programs.
Partially Implemented
15
A program to control ground-water pollution from
agricultural chemicals should be developed.
Rot Implemented, Planned
16
A program to collect and recycle automobile drain
oils should be developed.
Implemented
17
A tri-county coordinating committee on hazardous
waste and related issues should be established.
Not Implemented
18
Regulatory review of tenants in industrial parks
should ~ obtained to ensure that stormwater and
wastewater systems are adequate for each tenant.
Partially Implemented
gnRI098/15
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I
~
~
I
Tabl. 23
THE BISCAYNE AQUIPER PRO't~ION PLAR
(continued)
Priority No.
ReCOlllllendation
19
A .saf.. contamination level of pollutants in
local soils should be detemined.
20
Rev qround-water IIOni torinq systema should be
established or existinq systems expanded to study
areas close to producinq wells for early siqns of
qround-water contamination. .
IB/15
Status of IInplementation
in Dade County
Rot. Impl8118n~
Partially Implemented
-------
COMMUNITY RELATIONS
RESPONSIVENESS SUMMARY
BISCAYNE AQUIFER SITES
FEASIBILITY STUDY
INTRODUCTION
EPA held a public meeting on February 7, 1985, at the Miami
Springs City Hall to discuss the Feasibility Study (FS) .
report for the Biscayne Aquifer site and to accept public
comment. The meeting, held from 7:30 to 11:00 p.m., was
attended by 34 people.
James Orban, EPA's site manager for the project, chaired the
meeting. . Be was assisted by Udai Singh and Ken Cable of
CH2M HILL, EPA's technical consultant. .They provided a
brief description of the site history, the nature of the
problem, and .the findings of the Remedial Investigation
. CRI). This was followed by a more detailed presentation of
the cleanup alternatives considered and the recommended
actions.
Mr. Orban then requested questions and comments from the
audience and stated that EPA would also accept written
comments until February 28, 1985. He indicated that all
comments would be considered in the decision-making process
and that a written response to the comments would be
included in the Record of Decision.
SUMMARY OF PUBLIC COMMENT AND AGENCY RESPONSE
Questions and comments offered at the meeting are summarized
below. They are divided into three categories: general
comments relating to the project as a whole, those
pertaining to specific sites, and those concerning
recommended cleanup activities for the area's ground water.
No written comments were received during the public comment
period.
GENERAL COMMENTS/QUESTIONS
1.
Public Involvement: Speakers thought that public
notice for the meeting was inadequate, that there had
not been sufficient involvement of citizens during the
study process, and that the plans had been prepared.
-behind closed doors-.
Res~onse: Public notice for the meeting was provided
by isplay advertisements in the Ft. Lauderdale News
and the Miami Herald". A press release announcing the
meeting was distributed to all local newspapers. The
RI a~d FS reports were available for public review at
the Paln Beach, Dade, and Broward County offices. EPA
R109b/16
-1-
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had previously implemented an extensive community
relations program for the site.
A public meeting was held in September 1982 to present
the results of the initial study and to outline the
plans for Remedial Investigations. Three issues of
Remedies, a newsletter summarizing- project activities
and reports, were mailed to over 400 individuals and
organizations in ~ctober 1983, March 1984, and
,July 1984.
,
. .
A public meeting to present the Remedial Investigation
findings, outline the Feasibility Study activities, and
.solicit comments on possible cleanup alternatives to be
evaluated was held in October 1983. Preliminary
results of the detailed evaluation of the remedial
action alternatives were explained in a public meeting
in March 1984. Also presented for comments and
suggestions at this meeting was the preliminary outline
of the program for the protection of the Biscayne
Aquifer.
2.
EPA sponsored. another public meeting in July 1984 to
present and receive public comment on the recommended
alternatives and the Biscayne Aquifer Protection Plan.
Two workshops on study findings, risk assessments, and
proposed cleanup and prevention activities were held
for the press, elected and appointed officials, and the
general public during July 1984. EPA believes these
activities provided excellent opportunities in both
fo~al and informal settings for two-way communication
between interested citizens and the agencies: EPA,
Florida Department of Environmental Regulation, Dade
County Department of Environmental Resources
Management, and the Centers for Disease Control.
:~:~t:6ii~~yc~~a~:i:f~:si~~n~m~~~:~~:~i~:eOf cleanup'
activities, private sector responsibility for cleanup,
and incentives to encourage private sector site
cleanup. Commenters indicated that water user charges
should not be used to fund cleanup actions.
3.
Response: EPA has identified the responsible parties,
and will influence these parties to do what is .
necessary to clean up the site. EPA will also use
available Superfund funds to implement the cleanup.
Local Aqencies: Speakers expressed a lack o~
confidence in the ability of county agencies to deal
with hazardous waste issues. They were critical of the
County's hydrocarbon removal oper.tion at the airport,
the lack of technical training of Dade County
RI09b/16
-2-
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Oepartment of Community Affairs staff, inaccuracies in
the County's report on Munisport landfill, operation of
the 58th Street landfill, and the lack of information
about contamination on the west side of the airport.
Response: EPA pursued the Remedial Investigation and
Feasibility Study for the Biscayne Aquifer and made
recommendations for cleanup activities under the
authority of the Superfund program. Expenditure of
program funds is 'limited to cleanup of existing
,'uncontrolled hazardous waste sites and cannot be
extended to cover costs of developing and implementing
plans designed to prevent the occurrence of future
hazardous waste disposal problems. These are
responsibilities" of local agencies.
4.
Federal Agencies: Respondents indicated that the,
process for study and cleanup of sites takes too long,
and that EPA should have proposed an Environmental
Impact Statement (EIS) on the use of wetlands near the
Northwest Well Field for industrial development.
Response: EPA recognizes that the length of the
Remedial Investigation and Feasibility Study process
causes frustration among local residents who are
, concerned about the effects o~ the sites on their
health and property values. Yet, if the problems are
, to be effectively" solved it is essential that they be
thoroughly understoQd before long term cleanup actions
are recommended. At Biscayne Aquifer, this required
extensive testing at a numherof different sites and
evaluation of 12 source control and 10 off-site
remedial action alternatives. These activities were
accomplished as expediently as possible.
Responsibility for implementation of an EISrests
within a different division of EPA. Officials will
refer the request to the appropriate section within EPA"
for further consideration. 'Wetlands were given
proper consideration during the remedial investigation
and feasibility study. The result showed that no
wetland areas would be impacted by the remedial action.
This RI/FS process and the public involvement is
equivalent to an EIS.
SITE SPECIFIC COMMENTS/QUESTIONS
1.
~;~~~~a:C~~~ :~t:~~ ~~~~~e~~t:h~~g~~dt~:V:r:::~c: of
target for Superfund action. '
Response: As the speaker indicated, hydrocarbons are
not included in the list of hazardous substances
RI09B/16
-3-
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2. .
RI09B/16
-
regulated by the Superfund program. The project
studies did assist the State and local officials in
identifying and addressing the problem. However,
formal Superfund action is not appropriate.
Over 1.5 million gallons of Varsol were believed to
have been spilled at the site in 1968. EPA conducted
an extensive sampling program at the site, but was
unable to confirm the presence of a plume of toxic
substances. It is possible that the solvent was
biodegraded or dispersed through the aquifer. .
Miami Drum Site and 58th Street Landfill:
a.
Speakers suggested that EPA in its RI did not
identify a contaminant plume at the 58th Street
landfill because it did not have much concern
about contaminant migration since the adjacent
. Miami Springs Well Field is only used as a back-up
water supply source.
Response: The presence of a contaminant plume in
ground water doWftgradient of the 58th Street
landfill was documented in the late 1970s by the
U.S~ Geological Survey and various studies by
consultants: however, that was a non-toxic,
non-organic substance survey. Between November
1982 and March 1983, EPA conducted a more
. comprehensive survey: a series of six sampling
programs which tested for all 129 priority
pollutants, including organic as well as inorganic
toxic substances.
b.
Speakers thought EPA's focus on municipal drinking
water and ground water was too narrow and did not
permit sufficient consideration of problems that
require attention at these sites. They were
concerned about cleanup and closure of the 58th
Street landfill and felt these activities should
be included as recommended remedial actions.
. Response: EPA considered a wide range of
alternatives for remedial action at the sites,
related both to specific sources of contamination
as well as to the off-site, area-wide nature of
the problem. EPA did include in the FS an
analysis of remedial alternatives for the 58th
Street 1andfil1~ including proper closure. The
closure plan will also address the private wells
in the immediate area of the landfill.
-4-
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2.
3.
RECOMMENDED ACTION COMMENTS/QUESTIONS
1.
Recommendation Development: One speaker questioned the
process of developing recommendations for cleanup
actions and indicated he did not feel the
recommendations covered all problems identified by
project studies. He suggested consideration of a
variation of Alternative 3 that would keep Preston and
Miami Springs Well Fields open for emergency backup and
would implement plans to minimize future contamination
in the Miami Springs area. ..
Response: EPA performed a detailed evaluation of
Alternative 3 and found that i~ was not cost-effective
(the total present worth cost for Alternative 3 was
over $23 million as compared to the cost of the
recommended alternative ($8.5 million). Alternative.3
also would not provide the additional benefit provided
by Alternative 2: significant cleanup of the
contaminated portion of the aquifer, which will be
accomplished by pumping from the Miami Springs and
Preston Well Fields. .
Biscayne Aquifer Protection Plan: Speakers identified
the need for federai protection of wetlands in the
Northwest well field area. Th,ey suggested preparation
of an EIS or use of EPA's veto power over Corps of
Engineers' 404C permits to control land development
near the ~ew Northwest Well Field.
Response: The suggested actions are not within the
domain of the Superfund branch at EPA. Officials will
refer this recommendation for consideration to the
proper division within EPA.
~irls~ri~ini: Commenters were concerned about the
ea t e ects of airborne pollution on people living
near the proposed tower sites. They asked about the
benefits of air stripping and the end result of the
remedial action on water quality.
Re~lon~e: EPA completed a detailed estimate of air
po ut on resulting from air stripping towers and found
that air stripping meets all state air emission
requirements and is far below allowable air emission
limits. It will not have adverse impacts upon the
environment or human health. The benefit of air
stripping is that it will be removing 97 percent to
over 99 percent of the volatile organic compounds from
the water withdrawn from the Miami Springs and Preston.
Well Fields, thus considerably improving the quality of
potable water in the study area.
R109B/16
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I
i
4.
Effect on Land Values: One speaker (from the flooded
area) was concerned about the effect of the cleanup
activities on land values in her Miami Springs
neighborhood. She wanted to know the effect of the
recommended alternative on her property value.
Response: The Miami Springs and Preston Well Fields
had been pumping for 20 to 30 years, artificially
lowering the water table in the area. When pumping
began at the new Northwest Well Field and the Miami
Springs and Preston Well Fields were shut down, the
water table in t~e area rose, causing flooding of
residential properties.
EPA's recommendation is to begin pumping the Miami
Springs and Preston Well Fields, and to treat the water
by air stripping so as to provide clean water to the
public. Although this study was not meant to address
the flooding problem at ~he sites, the effect of the
recommended actions is to return the water table to its
former position, thus resolving the flooding problem.
RI09B/16
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. -
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, .. .
....,,'D '4"
~.... 1',
i. ... \
,~i
X; "
4I~
UNITED STATES ENVIRONMENTAL PROTECTION AGENCY
REGION IV
S.5 COURTLAND STREET
ATLANTA. GEORGIA '0385 .
Mr. Udai P. Singh
Water Resource Engineer
CH2M Hi 11
7201 N.W. 11th Place.
P.O. Box 1647
, Gainesville, Florida 32602
Dear Uda1.
I have recently received the review and comments on the Biscayne Aquifer
Project, Phase2 Groundwater Monitoring Data from the CDC Superfund Implemen:"
tation Group. As you and I have previously discussed, low to moderate
'concentratiOns of additional compounds not identified in Phase 1 sampling
have been identified. It was for these compounds that you requested
guidance on minimally acceptable drinking water standards to protect public
health. We have also taken the liberty to comment on a number of other
compounds for which your criteria appears either too low or high or had
no criteria established. °1 '.: ;'.l' l' :..'2 '".
Please feel free to contact me if there are any questions regarding the
attachment to this letter.
Sincerely Yours,
oL~
Chuck Pietrosewicz
Public Health Advisor
cc: Jim Orban, EPA
Georgi Jones, CDC/SIG
Attachment-l
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ATTACHMENT
Compound
Recommended Minimum Standard (ppb)
Reference
Boron I None Available
Aluminum 10 1
Zinc 5,000 2
Iron 300 2
Vanadium 70 1
1-1 dichloroethene 0.31-0.34 2
Trihalomethanes - 100 2
.-
Acenapthene .28 , .2 3,4
Methyl xylene 620 .,.
Toluene I
340 ~
Trichloroethane 1,000 2
Di~N-Butylphthalate 1,100 5
Bis(2-ethylhexyl)phthalate 6,000 5
Pentachlorophenol 30 5
Heptachlor .24 5
Lindane 1.1 5
Chlordane .23 3
Endrin aldehyde .2 2
Carbon disulfide None Available
l,4-dioxane 570/10 days; c 570/>10 days 2
2,4,5-T 1,000 5
Polynuclear Aromatic Hydocarbons Equal criteria can be given to all
1,2-dichloropropane 100/ 10days ~
I Acr; lonitri le 3/short term; .34!lifetime 3
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ATTACHMENT
REFERENCES
cont'd
p.2
1-
2-
3-
4-
5-
CDC/SIG literature Review
EPA Primary & Secondary Drinking Water Standards
EPA Cancer Assessment Group Recommendations
World Health Organizatio~
National Academy of Science
(current)
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