United States Environmental Protection Agency
Region 4
345 Courtland Street
EPA	Atlanta, Georgia 30365
FINAL
ENVIRONMENTAL IMPACT STATEMENT
for
the Designation of an
Ocean Dredged Material Disposal Site
Located Offshore
1
Miami, Florida
August, 1995

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10 H-/R'^/00 5"
FINAL ENVIRONMENTAL IMPACT STATEMENT
FOR DESIGNATION OF AN
OCEAN DREDGED MATERIAL
DISPOSAL SITE LOCATED OFF
MIAMI, FLORIDA
Library Region iV
US Environmental Protection Agmcy
345 Courtlasid Street
kiknta, Georgia 30365
U.S. Environmental Protection Agency
Region 4
345 Courtlan'd Street N.E.
Atlanta, Georgia 30306
August 1995

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FINAL ENVIRONMENTAL IMPACT STATEMENT FOR
DESIGNATION OF AN OCEAN DREDGED
MATERIAL DISPOSAL SITE LOCATED OFF MIAMI, FLORIDA
TABLE OF CONTENTS
Section	Title	Page I
COVER SHEET	i
TABLE OF CONTENTS	ii
APPENDICES	v
LIST OF TABLES	vi
LIST OF FIGURES	vi
1.00 SUMMARY	1
1.01- Major conclusions and findings	1
1.02	Areas of controversy	1
1.03	Unresolved issues	1
2.00	PURPOSE AND NEED FOR ACTION	1
2.01	National Environmental Policy Act	1
2.03	Marine Protection, Research and
Scfrie.fcuaries Act	3
3.00	ALTERNATIVES	3
3.01	Non-ocean alternatives	3
3.06	Alternative sites on the continental
shelf	4
3.07	Designated interim site (candidate
site)	4
3.08	Alternative sites beyond the
continental shelf	7
3.09	No action	7
4.00	AFFECTED ENVIRONMENT	7
4.01	Introduction	7
4.02	Geological characteristics	7
4.04	Tides and currents	8
4.10	Water temperature	9
4.13 Salinity gradients	10
4.16 Physical and chemical
characteristics	10
4.29 Biological characteristics	12
4.3	9 Threatened and endangered species	13
4.41 Commercial fisheries	14
4.44	Recreational fishing	15
4.45	Other recreation	15
4.4	6 Shipping	15
4.47	Military usage	15
4.48	Mineral resources	15
4.4 9 Underwater video narrative	15
5.0	0 ENVIRONMENTAL EFFECTS	16
5.01	Introduction	16
5.02	Geographical position, depth of water,
bottom topography and distance
from coast [40 CFR228.6(a)1]	16
ii

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TABLE OF CONTENTS (continued)
Section	Title	Page £
5.04	Location in relation to breeding,
spawning, nursery, feeding or
passage areas of living
resources in adult or juvenile
phases [40 CFR 228.6(a)2]	20
5.06	Location in relation to beaches and
other amenity areas [40 CFR]
228.6(a)3]	20
5.09	Types and quantities of waste to be
disposed of and proposed methods
of release, including methods of
packing the waste, if any
[40 CFR 228.6(a)4]	20
5.10	Feasibility of surveillance and
monitoring [40 CFR 228.6(a)5]	20
5.11	Dispersal, horizontal transport and
vertical mixing characteristics of
the area, including prevailing
current direction and velocity,
if any [40 CFR 228.6(a)6]	21
5.16	Short-term modeling results	26
5.17	Long-term modeling results	2 6
5.18	Existence and effects of current and
previous discharges and dumping in
the area (including cumulative
effects) [40 CFR 228.6(a)7]	27
5.20	Interference with shipping^ fishing,
recreation, mineral extraction,
desalination, fish and shellfish
culture, areas of special scien-
tific importance, and other
legitimate uses of the ocean
[40 CFR 228.6(a)8]	27
5.23	Existing water quality and ecology
of the site as determined by
available data or by trend
assessment or baseline surveys
[40 CFR 228.6(a)9]	28
5.25	Potential for the development
or recruitment of nuisance
species in the proposed disposal site
[40 CFR 228.6(a)10]	28
5.26	Existence at or in close proximity
to the site of any significant
natural or cultural features of
historical importance [40 CFR
228.6(a)11]	28
iii

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TABLE OF CONTENTS (continued)
Section	Title	Page £
5.27	The dumping of materials into the
ocean will be permitted only at
sites or in areas selected to
minimize the interference of
disposal activities w/other
activities in the marine
environment, particularly
avoiding areas of existing
fisheries or shellfisheries,
and regions of heavy commercial
or recreational navigation
[40 CFR 228.5(b)]	28
5.29	Locations and boundaries of
disposal sites will be so chosen
that temporary perturbations in
water quality or other environmental
conditions during initial mixing
caused by disposal operations
anywhere within the site can be
expected to be reduced to normal
ambient seawater levels or to
undetectable contaminant concentra-
tions or effects before reaching
any beach, shoreline, marine
sanctuary, or known geographically
limited fishery or shellfishery
[40 CFR 228.5(b)].	29
5.30	If, at any time during or after
disposal site evaluation studies,
it is determined that existing
disposal sites presently approved
on an interim basis for ocean
dumping do not meet the criteria
for site selection set forth in
228.5 and 228.6, the use of such
sites will be terminated as soon
as alternative disposal sites can
be designated [40 CFR 228.5(c)].	29
5.31	The sizes of ocean disposal sites will
be limited in order to localize for
identification and control any
immediate adverse impacts and permit
the implementation of effective
monitoring and surveillance programs
to prevent adverse long-range
IV

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TABLE OF CONTENTS (continued)
Section
Title
Page #
impacts. The size, configuration, and
location of any disposal site will
be determined as part of the disposal
site evaluation or designation study
[40 CFR 228.5(d)].	29
5.32	EPA will, wherever feasible, designate
ocean dumping sites beyond the
edge of the continental shelf and
other such sites that have been
historically used
[40 CFR 228.5(e)].	30
5.33	Relationship between short-term uses
and long-term productivity	30
5.43	Irreversible or irretrievable
commitments of resources	31
6.00 LIST OF PREPARERS	31
7.00 PUBLIC INVOLVEMENT	33
7.03	Responses to Comments	3 5
8.00 REFERENCES	80
APPENDICES
APPENDIX A
Environmental Survey in the Vicinity
of an Ocean Dredged Material Disposal
Site, Miami Harbor, Florida
APPENDIX B
Evaluation of the Dispersion
Characteristics of the Miami and Fort
Pierce Dredged Material Disposal
Site
APPENDIX C
APPENDIX D
Site Management and Monitoring Plan
Miami ODMDS Designation Florida Coastal
Zone Management Program Consistency
Evaluation
APPENDIX E
Evaluation of the Miami Ocean Dredged
Material Disposal Site
APPENDIX F
Miami Harbor Dredged Material
Disposal Project
APPENDIX G
Miami Harbor Dredged Material Disposal
Project: Total Suspended Solids
Measurements
v

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LIST OF TABLES
Table No.	Title	Page No.
1	Relationship of Alternatives to
Environmental Requirements	2
2	Species of the Miami Harbor ODMDS
Area Classified as
Endangered or Threatened by-
Federal Agencies	14
3	Artificial Reef Sites in the Miami
Harbor ODMDS Vicinity	19
4	Summary of the Specific Criteria as
Applied to the Interim Designated
(Candidate) Site	22
LIST OF FIGURES
Figure No.	Title	Page No.
1	General Location Map	5
2	Bathymetric Map	6
3	Natural Reef Areas	16
4	Artificial Reef Sites	17
5	Park and Preserve Areas	25
vi

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1.00 SUMMARY
1.01	Maior conclusions and findings. Investigations were
conducted of the interim-designated ocean dredged material
disposal site (ODMDS) and of environmental amenities considered
to be within its zone of influence. Physical, chemical, and
biological characteristics and their interactive effects were
measured. The probable dispersion fate of dredged materials that
might be dumped at the site was modeled. All information was
compared with relevant provisions of Section 103 of the Marine
Protection, Research and Sanctuaries Act of 1972 (MPRSA),as
amended. The conclusion is that the interim-designated site is
suitable for designation for disposal of dredged material. The
site meets all evaluation criteria for use as an ocean dredged
material disposal site.
1.02	Areas of controversy. At this time, three areas of
controversy have been identified. The State of Florida believes
that all ODMDSs should, by rule, be restricted to prohibit the
disposal of beach quality sand. In addition, the State of
Florida believes that the Miami ODMDS should be restricted to
"prohibit the disposal of material with a grain size less than
.025 mm and material constituted by more than 10 percent fine
grained material." There is also concern regarding the disposal
of dredged material from the Miami River in the Miami ODMDS.
1.03	Issues to be resolved. No issues remain unresolved. The
issues of 1) prohibition of beach guality sand disposal and 2)
prohibition of fine-grained material have been resolved. Their
resolution is discussed within this EIS and in the response to
comments. Dredged material from the Miami River has not been
determined to be suitable for ocean disposal. Only dredged
material suitable for ocean disposal will be disposed in the
Miami ODMDS. The suitability of dredged material for ocean
disposal must be verified by the Corps of Engineers and agreed to
by EPA prior to disposal.
1.04	Relationship of alternatives to environmental protection
statutes, executive orders, and other requirements. Table 1
presents the status of the alternatives with environmental
requirements.
2.00	PURPOSE AND NEED FOR ACTION
2.01	National Environmental Policy Act. The National
Environmental Policy Act (NEPA) of 1969, as amended, requires
that an Environmental Impact Statement (EIS) be prepared for
major federal actions that may significantly affect the quality
of the human environment. A major purpose of this EIS is to
fulfill the NEPA requirements of two federal agencies. First,
1

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Table 1
Relationship of alternatives to environmental requirements
NO ACTION CANDIDATE
SITE
FEDERAL STATUTES
Archeological and Historic Preservation Act, as amended, 16 USC 469, et sea. PL 93-291	F/C*	F/C
Clean Air Act, as amended, 42 USC 1857h-7, et sea. PL 91-604	F/C	F/C
Clean Water Act, as amended, (Federal Water Pollution Control Act) 33 USC 1251, et seo.
PL 92-500	F/C	F/C
Coastal Barrier Resources Act, 16 USC 3501 et seo. PL 97-348	N/A**	N/A
Coastal Zone Management Act, as amended, 16 USC 1451, et sea. PL 92-583	F/C	F/C
Endangered Species Act, as amended, 16 USC 1531, et sea. PL 93-205	F/C	F/C
Estuary Protection Act, 16 USC 1221, et sea. PL 90-454	N/A	N/A
Federal Water Project Recreation Act, as amended, 16 USC 460-1(12), et sea. PL 89-72	F/C	F/C
Fish and Wildlife Coordination Act, as amended, 16 USC 661, et sea. PL 85-624	N/A	F/C
Land and Water Conservation Fund Act, as amended, 16 USC 4601-4601-11, et sea. PL 88-578	F/C	F/C
Marine Mammal Protection Act 16 USC 1361, et sea. PL 92-522	F/C	F/C
Marine Protection, Research and Sanctuaries Act, 33 USC 1401, et sea. PL 92-532	F/C	F/C
National Historic Preservation Act, as amended, 16 USC 470a, et sen. PL 89-655	F/C	F/C
National Environmental Policy Act, as amended, 42 USC 4321, et sea. PL 91-190	F/C	F/C
River and Harbor Act, 33 USC 4 01, et sea.	F/C	F/C
Watershed Protection and Flood Prevention Act, 16 USC 1001, et spn. PL 83-566	N/A	N/A
Wild and Scenic Rivers Act, as amended, 16 USC 1271, et sen. PL 90-542	N/A	N/A
EXECUTIVE ORDERS
Floodplain Management (EO 11988)	N/A	N/A
Protection of Wetlands (EO 11990)	N/A	N/A
Protection and Enhancement of Environmental Quality (EO 11514, as amended EO 11991)	F/C	F/C
Protection and Enhancement o£ the Cultural Environment (EO 11593)	N/A	N/A
Federal Compliance with Pollution Control Standards	F/C	F/C
STATE POLICIES
Florida Coastal Management Program	F/C	F/C
NOTES: For each item listed enter one of the following:
* F/C Full Compliance. Having met all requirement's of the statute, EO, or other environmental requirements in the current
stage of planning (either pre or post authorization).
** N/A. Not applicable
2

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Final E1S Miami ODMDS
August. 1995
this EIS carries out the U.S. Environmental Protection Agency's
(EPA) policy to prepare voluntary EIS's (30 FR 16186 [May 7,
1984]) as part of the designation process of an Ocean Dredged
Material Disposal Site (ODMDS) under Section 102 of the MPRSA.
Second, it will satisfy the U.S. Army Corps of Engineers (COE)
need for NEPA documentation relating to ocean disposal site
suitability for permitting under Section 103 of the MPRSA.
2.02	Marine Protection. Research, and Sanctuaries Act. The
dumping of all types of materials into ocean waters is regulated
by the MPRSA. Section 102 of the MPRSA authorizes the EPA to
designate sites for ocean disposal pursuant to criteria
established in this section. EPA's site designation does not by
itself authorize any dredging or on-site dumping of dredged
material. EPA Ocean Dumping Regulations (40 CFR 220-229)
establish procedures and criteria for selection and management of
ocean disposal sites and evaluation of permits. Section 103 of
the MPRSA authorizes the COE to issue permits for the
transportation of dredged material for the purpose of disposal
into ocean waters. The purpose of the action is to comply with
the provisions of the MPRSA and 40 CFR 220-229 by providing the
information required to evaluate the suitability of the proposed
site for designation as an ocean disposal site as well as
providing information about the site as a viable disposal option
required in the COE permitting process. Section 103 evaluation
of the dredged material proposed for disposal will still be
needed.
2.03	Other needs. The Miami Port Authority and other local
interests have requested the COE to provide increased depths in
the existing Federal Miami Harbor Project and locally constructed
channels to obtain transportation cost savings. Of immediate
need is an offshore site for offshore disposal of 5 .million cubic
yards of material currently being dredged for the Miami Harbor
deepening project. An ODMDS could also be used for disposal of
material from maintenance dredging of that portion cf the
Atlantic Intracoastal Waterway (AIWW) in the vicinity of Miami
Harbor. However, any proposed material would need a Section 103
evaluation and EPA concurrence prior to ocean disposal.
3.00	ALTERNATIVES
3.01	Non-ocean alternatives. Alternatives to ocean disposal may
include upland disposal within the port area, disposal in
Biscayne Bay, and beach disposal. Upland disposal in the
intensively developed Port of Miami - Biscayne Bay area has not
been found feasible. The Port of Miami itself is built partially
on fill in Biscayne Bay. Undeveloped areas within cost-effective
haul distances are environmentally valuable in their own right.
3
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Final EIS Miami ODMDS
August 1995
3.02	Almost all inshore waters of the Biscayne Bay area are part
of the Biscayne Bay Aquatic Preserve (see Figure 5). The waters
of the southern portion of Biscayne Bay, now included in the
Aquatic Preserve, are to be incorporated, along with some
offshore waters, into the Biscayne National Park in the near
future. The Florida Department of Environmental Regulation (DER)
has afforded the waters of these areas special protection as
Outstanding Florida Waters. This effectively removes virtually
all of the Biscayne Bay area from consideration for disposal of
dredged material.
3.03	The use of suitable dredged material for beach disposal is
usually the preferred disposal alternative for all dredging
projects. Consequently, the placement of beach quality material
in the Miami ODMDS is subject to agreement between the State of
Florida and the US Army Corps of Engineers as described in a
dredged material disposal plan. Suitable rock might be placed in
nearshore waters. These options are feasible only where a
substantial quantity of the desired type of material is separable
from silt or other undesirable material.
3.04	Maintenance dredging of Miami Hc.rbor has been performed
four recorded times: In 1957, 1960, 1968, and 1985. Each time,
dredged material was disposed in the ccean, about one nautical
mile (nmi) west of the candidate site.
3.05	The COE has been authorized to deepen Miami Harbor. For
that project, environmental and economic analyses w^re performed
and an EIS was prepared. The COE examined and documented the
feasibility of each of the above-described disposal options and
found none to be feasible. However, the COE agreed to make
further analyses during preconstruction engineering and design of
the project to determine whether rock dredged from t,
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25°30'
Miami Baach
	cs?
Govarnmant Cut
Virginia Kay
ODMDS
NORTH
258 40'
Capa Florida
ITATure MILCS
M4UTICAL UkLCS
0
O
00
O
O
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CD
FIGURE 1
GENERAL LOCATION MAP
Ocean Dredged Material Disposal Site Miami, Florida

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25°47'00"
23° 45" 30"
25°44'30'
25°43'OOm
I
03
o
o
O
CO
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o
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09
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NORTH
NAUTICAL MILC
FIGURE 2
BATHYMETRIC MAP
Ocean Dredged Material Disposal Site Miami, Florida
	-5	

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Final EIS Miami ODMDS
August 1995
25-44"30"N, 80-03'54"W. The site is centered at: 25°45'00"N and
80°03'22"W. This site is considered suitable in terms of
practicality and economic feasibility. Sections 228.5 and 228.6
of EPA's Ocean Dumping Regulations and Criteria 40 CFR establish
criteria for the evaluation of ocean disposal sites. The extent
to which the candidate site meets these criteria is addressed in
Section 5.00 (Environmental Effects) of this document.
3.08	Alternative sites bevond the continental shelf. The center
of the Gulf Stream lies about 15 nmiles offshore of Miami
(Section 4.00). Dumping in the center of the Gulf Stream was
considered, but the enormous task and expense of monitoring
disposal under such conditions caused sufficient concern to
eliminate that option.
3.09	No action. Under the "no action" alternative, the interim
site would not receive final designation and the Miami area would
have no EPA-designated ODMDS.
3.10	Proposed action. The proposed action is to designate the
interim ODMDS as a permanent dredged material disposal site. The
site will be managed and monitored according to the approved Site
Management and Monitoring Plan (SMMP).
4.00	AFFECTED ENVIRONMENT
4.01	Introduction. This chapter describes the environmental
characteristics of the area that may be affected by the disposal
of dredged materials at the proposed Miami ODMDS. A general
location map of the area is presented as Figure 1. The
information contained in this chapter was drawn from previous
surveys, interviews with local regulatory agency personnel,
individuals knowledgeable about the area, and from a survey of
the disposal site environment conducted in January 1986, by
Conservation Consultants, Inc., (CCI) and described in Appendix
A, and from a dispersion characteristic evaluation by the U.S.
Army Corps of Engineers Waterways Experiment Station (WES)
presented in Appendix B.
4.02	Geological characteristics. The proposed Miami ODMDS is
situated on the continental slope. Depths at the site range from
about 427 to 785 feet (130 to 239 m). The depth at the center of
the site is approximately 625 feet (191 m). The average
declivity of the slope at the ODMDS is approximately 325 feet
(100 m) per nautical mile (1.85 km). A bathymetric map of the
area is presented as Figure 2.
4.03	A January 1986 survey (Appendix A) found surficial
sediments in the proposed ODMDS vicinity to be comprised
7
U.S. EPA Region 4

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Final EIS Miami ODMDS
Augct 1995
primarily of very fine sands and coarse silt. Sediments are well
sorted and relatively uniform throughout the area. An underwater
video survey conducted at the same time visually confirmed this.
4.04	Tides and currents. Over most continental shelves,
circulation is primarily governed by tides and winds. Off the
southeast coast of Florida, circulation is also strongly
influenced by the nearby Florida Current. The Florida Current is
that portion of the Gulf Stream system that connects the Loop
Current in the Gulf of Mexico to the Gulf Stream as it proceeds
through the Straits of Florida and into the open Atlantic Ocean
(Lee, et al.-, 1977). The degree of coastal influence exerted by
this current is quite variable and reflects the dynamic nature of
the Gulf Stream system.
4.05	The Florida Current influences coastal circulation on the
southeast Florida Shelf in two ways, depending on the degree of
intrusion of this current over the continental shelf (EPA, 1973).
When the western edge of the Florida Current is over the shelf,
the current draws the coastal waters north, though velocities may
be considerably reduced due to bottom friction. When the western
edge of the Florida Current is seaward of the continental shelf,
cyclonic spin-off eddies are formed. These eddies with an
average diameter of 10 to 3 0 km, are carried north, but cyclonic
currents'inside the eddies may control local current patterns.
Meanders of the Florida Current and eddy formation may be
mutually related to atmospheric forces (Lee, et al., 1977).
4.06	Following their formation, spin-off eddies travel northward
along the continental margin at speeds ranging from 20 to 50
cm/sec. At these rates, it generally takes less than one day for
an eddy to pass a fixed point (Lee, et al., 1977) . Eddies occur
on the average of once per week and can be recognized as disrup-
tions of prevailing temperature and salinity fields and of local
current patterns (Lee and Mayer, 1977). These cyclonic eddies
play an important role in coastal exchange processes, removing
coastal water and replacing it with waters from the Florida
Current.
4.07	The proposed Miami ODMDS lies near the western edge of the
Florida Current. Horizontal meanders result in fluctuations of
about 2.6 nmi (4.8 km) in the location of the western edge of the
current that, on the average, lies 3.2 nmi (5.9 km) east of
Virginia Key (EPA, 1973). The center of the proposed ODMDS is
located 4.7 nmi (8.7 km) east of Virginia Key.
4.08	Ocean currents in the vicinity of the proposed site are
generally along the north-south axis. The predominant direction
of flow is to the north. Current speeds are highest in surface
8
U S. EPA Region 4

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Final EIS Miami ODMDS
August 1995
waters, decreasing to near zero at the bottom. Mean current
speeds in surface waters at the candidate site range from a low
of 62 cm/sec in the winter to about 95 cm/sec in the spring and
summer (Lee et al., 1977). Maximum surface currents are about
150 cm/sec to the north and 50 cm/sec to the south (Lee and
Mooers, 1977). Current speeds are lower and north-south
reversals are more common in near-bottom waters. Lee and Mooers
(1977) report a mean northerly flow in near-bottom waters in the
proposed ODMDS vicinity of 3.5 cm/sec, with maximum flows of 27
cm/sec to the north and 23 cm/sec to the south.
4.09	Tidal currents in the proposed disposal site vicinity are
also directed along the north-south axis. Measurements taken in
approximately 175 meters water depth show semi-diurnal tides with
amplitudes ranging from 10 to 2 0 cm/sec in near-bottom (10 meters
above the bottom) waters (Lee and Mooers, 1977) .
4.10	Water temperature. EPA (1973) reports surface water
temperatures for the coastal region off Miami ranging from a low
of 19-C in February to a high of 30-C in July. Over the
continental shelf the water column is generally well mixed from
mid-August to late April. Thermal stratification begins to
appear in April and continues through :nid-August. EPA (1973)
reports vertical temperature variation in the summer of up to
ll-C at the 90 ft. (27 m) depth contour.
4.11	Lee and Mooers (1977) report an-nual mean water tempera-
tures for the offshore area in the proposed disposal site
vicinity ranging from 26~C at the surface, to 21-C at 100 m (328
ft.), and approaching 10-C at a depth of 200 m (656 ft.). These
authors also cite Brooks (1975) who reports two years of
temperature data collected from a station located about 5.5 nmi
(10 km) south of the proposed ODMDS in waters of a similar depth
(689 ft.; 210 m). Mean seasonal surface water temperatures
varied from 24 to 29-C, while bottom waters ranged from 7.9 to
13.5-C. Seasonal surface-to-bottom thermal gradient.': ranged from
about 14- to 18-C. Lowest bottom water temperatures appear to
occur in the summer in the proposed disposal site vicinity (Lee
and Mooers, 1977). This phenomenon is thought to rellect both
the seasonal wind-induced upwelling of cooler waters.over the
slope and the increased volume transport of the Florida Current
in the summer.
4.12	A January 1986 survey of the proposed disposal site
vicinity (Appendix A) found waters to be generally isothermal to
a depth of 220 ft. (67 m). Temperatures recorded during this
survey ranged from 22.3 to 23.3-C., but the survey did not reach
the reported winter pycnocline depth of 325 feet.
9
U.S. EPA Region 4

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Final EIS Miami ODMDS
August 1995
4.13	Salinity gradients. Salinity in the proposed disposal area
ranges from approximately 33 to 37 parts per thousand (ppt) and
averages about 35.6 ppt (EPA, 1973). Subsurface core waters of
the Florida Current generally range from 36.2 to 36.6 ppt (CH2M
Hill, 1985). Surface waters of the Florida Current occasionally
exhibit reduced salinities as a result of the entrainment of
fresh water from the Mississippi River system by the Gulf Loop
Current during periods of increased river flow (U.S. Department
of the Interior {DOI}, 1977).
4.14	A January 1986 survey of the proposed ODMDS vicinity
(Appendix A), recorded salinities ranging from 35.5 to 36.8 ppt.
No vertical salinity stratification was apparent in the upper 220
ft. (67 m) of the water column. Only minor salinity gradients
are expected to occur in the area.
4.15	The density of seawater in the proposed disposal site
vicinity, based on average salinity and temperature values,
averages 1.024 grams per cubic centimeter (gms/cc) (EPA, 1973).
The average depth of the pycnocline varies seasonally from
approximately 60 ft. (18 m) in the summer to about 1!50 ft.
(46 m) in the winter (Marble and Mowell, 1971; in EPA, 1973). An
EPA (1973) winter reconnaissance survey found the pycnocline off
Miami at a depth of about 325 ft. (99 m) . Densities recorded
during this EPA survey ranged from 1.0236 gms/cc at the surface
to 1.0260 gms/cc to a depth of 380 ft. (116 m).
4.16	Physical and chemical characteristics. Chemical and
physico-chemical water quality parameters that are relevant to
this ODMDS evaluation include dissolved oxygen (DO), suspended
solids, turbidity, trace metals, pesticides, polychlorinated
biphenyls (PCBs), and high molecular weight (HMW) hydrocarbons.
4.17	Waters in the vicinity of the disposal site are believed to
be well oxygenated throughout the year. The DOI (IS 77) reports
average surface DO concentrations of between 6 and "> .2 ppm for
waters of the southeast Atlantic coast shelf and slope. Studies
conducted at inshore locations in, the general area lave found DO
levels to be near saturation throughout the year (Srith et al.,
1950; Voss and Voss, 1955).
4.18	EPA (1973) reports DO concentrations averaging about 6.8
ppm and ranging from 91 to 105 percent of saturation for a winter
survey conducted on the continental shelf off Dade County.
Little DO variation was observed in the upper portion of the
water column. A survey conducted at the proposed ODMDS in
January, 1986 (Appendix A) measured DO concentrations ranging
from 7.9 to 8.5 ppm. No vertical stratification was observed in
the upper 220 ft. (67 m) of the water column. Site waters during
10
U.S. EPA Region 4

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Final EIS Miami ODMDS
Augist 1995
this 1986 survey were supersaturated (115 to 121 percent) with
oxygen.
4.19 Suspended solids concentrations measured in surface and
bottom waters of the disposal area in January 1986 (Appendix A)
ranged from 11 mg/1 to less than 5 mg/1. No horizontal or
vertical patterns of distribution were noted.
4.2 0 Turbidity is defined as the optical property of a sample
which causes light to be scattered and absorbed rather than
transmitted in straight lines. Turbidity is commonly measured
with a nephelometer, which measures scattered light, and is
reported in NTUs (nephelometric turbidity units). Turbidity
samples were collected from surface and bottom waters at stations
in the ODMDS vicinity in January, 1986 (see Appendix A).
Turbidity values ranged from 4 to 9 NTU. Turbidity levels were
comparable throughout the area and no consistent differences
between surface and bottom waters were found.
4.21	In January 1986, water quality samples were collected from
surface and near-bottom waters in the proposed Miami ODMDS
vicinity to determine ambient concentrations of selected
contaminants. Specific groups of compounds analyzed included
trace metals, pesticides, pesticide derivatives, PCBs, and HMW
hydrocarbons. The results of these analyses are summarized below
and are detailed in Appendix A.
4.22	Mercury, cadmium, and lead were the trace metals selected
for analysis. Cadmium was not found at detectable levels in
surface waters, but was detected in near-bottom waters at two of
seven water quality sampling stations in the disposal site area.
Lead was only present at detectable levels in one of seven
surface water samples collected from the area. Mercury was not
detected in either surface or near-bottom water samples.
4.23	Levels of pesticides, pesticide derivatives, PCBs, and HMW
hydrocarbons were below analytical detection limits in all
surface and near-bottom water samples collected from the area.
4.24	Sediment quality samples from the proposed ODMDS vicinity
were collected in December 1985 and analyzed to determine
concentrations of selected trace metals, pesticides, pesticide
derivatives, PCBs, HMW hydrocarbons, total organic carbon (TOC),
and oil and grease. The results of these analyses are summarized
below and are detailed in Appendix A.
4.25	Ambient concentrations of the trace metals (mercury,
cadmium, and lead) are low in area sediments. No chlorinated
11
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Final EIS Miami ODMDS
August 1995
hydrocarbon pesticides, pesticide derivatives, or PCBs were
detected.
4.2 6 Concentrations of HMW hydrocarbons in the sediment samples
varied considerably. Lowest levels were found at stations
located north (downstream) of the ODMDS. Highest total HMW
hydrocarbon concentrations were measured in sediments collected
from stations located within and south (upstream) of the ODMDS.
In general, component HMW hydrocarbon fractions exhibited no
definitive spatial trends. Highest unresolved hydrocarbon con-
centrations were measured in sediment samples collected from
stations within the proposed disposal site.
4.27	Oil and grease concentrations in area sediments ranged from
12 to 41 ug/g. No apparent pattern of distribution was noted.
4.28	TOC concentrations in area sediments ranged from 11 to 18
mg/g. No trends in the distribution of TOC concentrations over
the area were observed.
4.2 9 Biological characteristics. The biological communities
addressed in this section are the benthic macroinfauna, benthic
meiofauna, epibenthic invertebrates, and fish. Species of
special concern which may utilize the proposed ODMDS vicinity are
also addressed. Biota restricted to the benthic environment are
of principal concern in disposal site investigations. Disposal
impacts on planktonic communities are generally considered to be
temporary, while larger, motile organisms (nekton) are able to
avoid disposal operations and localized areas of poor water
quality.
4.30	The benthic macroinfauna of the study area are dominated by
polychaete worms and amphipod crustaceans. Results from a
January 1986 survey (Appendix A) of the candidate site vicinity
found that polychaetes accounted for 37 percent, and amphipods 33
percent of total benthic community numbers. Molluscs and
nematodes were also common and comprised 14 percent and 9 percent
of the area's macroinfaunal assemblage, respectively.
4.31	The amphipod family Ampeliscidae was the most abundant
macroinvertebrate family represented in samples from the proposed
ODMDS vicinity (Appendix A). Polychaete families characteristic
of the area included Cirratulidae, Spionidae, Orbiniidae, and
Ampharetidae. Molluscs belonging to the families Thyasiridae and
Nuculidae were also common in the area.
4.32. The most abundant species at most sites in the disposal
area was found to be the tube-dwelling amphipod, Ampelisca
acrassizi . This species is abundant on and characteristic of the
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Final EIS Miami ODMDS
August 1995
upper continental slope off the southeastern U.S. (Boesch, 1977;
in EPA, 1983).
4.33	Faunal similarity indices indicate that the benthic
community throughout the proposed ODMDS vicinity is relatively
similar in composition. Cluster analyses did not reveal
differences between stations in the proposed ODMDS and those
located upstream and downstream. Faunal dissimilarities attri-
buted to depth were observed. These dissimilarities, however,
were not apparent over the range of depths encountered at the
disposal site.
4.34	The meiofauna of the proposed ODMDS vicinity are described
from a survey conducted in January 1986 and reported in Appendix
A. Nematode worms were found to dominate the meiofaunal
assemblage of the area. Nematodes accounted for 94 percent of
the meiofauna collected from the proposed ODMDS vicinity.
Harpacticoid copepods, larval polychaetes, and turbellarians,
while common, were never abundant.
4.35	Nematodes typically dominate the marine meiobenthos.
Pequegnat et al. (1981) observe that, in most marine sediments,
nematode worms account for 90 percent or more of the meiofaunal
community.
4.36	Epibenthic invertebrates were collected by trawl from the
disposal site vicinity in January 1986 (Appendix A). The most
abundant invertebrates collected from the area were pink shrimp
fPenaeus duorarum) and the lobster-like, galatheid crustacean
(Munida irrasa). Other invertebrates represented in trawl
samples were Jonah crabs (Cancer borealis), rock crabs (Cancer
irroratus), spider crabs (Nibilia antilocapra). portunid crabs
(Portunus soinicarpus and Qyfrlipes sp.), squid (Rossia tenera).
and hermit crabs (Paauridae sp.).
4.37	Demersal fish were collected in a January 1986 survey of
the ODMDS vicinity (Appendix A). The most abundant fish at all
trawl stations in the area was the largescale tonguefish
(Svmohurus minor). Other fish species frequently represented in
samples include the longspine scorpionfish (Pontinus
lonaispinus), freckled skate (Raia lentianosa). horned searobin
(Bellator militaris), and spotted hake (Uroohvcis reaius).
4.38	The distribution of fish over the area appears to be
variable and may be related to depth. Fish density was highest
at the shallowest of the sampling sites and decreased with
increasing station depth.
4.39	Threatened or endangered snecies. Marine species
classified by the U.S. Fish and Wildlife Service (FWS) and/or
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Final EIS Miami ODMDS	August 1995
National Marine Fisheries Service (NMFS) as endangered or
threatened and found in shore or coastal waters off Miami are
listed in Table 2.
4.40 This EIS will serve as a Biological Assessment for
purposes of Section 7 of the Endangered Species Act coordination.
Site designation of the Miami ODMDS will not, and use of this
site is not expected to adversely impact any threatened or
endangered species. In a letter dated October 14, 1994, the
National Marine Fisheries Service determined that populations of
endangered/threatened species under their purview would not be
adversely af-fected by the designation and use of the proposed
ODMDS. A copy of the letter is included Section 7.03 of this
document.
Table 2.	Species of the Miami ODMDS Area Classified as
Endangered or Threatened by Federal Agencies.
Common Name	Scientific Name	Status
REPTILES
Green turtle	Chelonia rnvdas	T
Hawksbill turtle	Eretmochelvs imbricata	E
Kemp1s ridley turtle	Lepidochelvs kempii	E
Leatherback turtle	Dermochelvs coriacea	E
Loggerhead turtle	Caretta caretta	T
MAMMALS
West Indian manatee	Trichechus manatus	E
Finback whale	Balaenoptera phvsalus	E
Humpback whale	Mecraptera novaeanaliae	E
Right whale	Eubalaena alacialis	E
Sei whale	Balaenoptera borealis	E
Sperm whale	Phvseter macrocephalus
(catodon)	E
Legend: E = Endangered
T = Threatened
4.41 Commercial fisheries. The proposed Miami ODMDS does not
support significant commercial fishery resources. While pelagic
species may utilize the area, heaviest commercial fishing
pressure is concentrated in inshore waters or at offshore natural
and artificial reefs.
14
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Final EIS Miami ODMDS
August 1995
4.42	Bait shrimp and mullet are the principal commercial species
taken from inshore waters (Heald, 1970). Major species taken in
offshore waters are red snapper, yellowtail snapper, groupers,
king mackerel, Spanish mackerel, and spiny lobster.
4.43	While commercial shrimping is not conducted in the proposed
ODMDS vicinity, the inshore waters of Biscayne Bay have been
identified as a nursery area for pink shrimp (Bielsa et al.,
1983). A January 1986 survey of the disposal area (Appendix A),
found pink shrimp to be relatively common at one trawl station
within the proposed ODMDS. Greatest concentrations of pink
shrimp occur inshore of the proposed disposal site at depths of
less than 144 ft. (44 m) (Kutkuhn, 1962, in Bielsa et al., 1983).
Shrimp are most common in deeper waters in the winter. Pink
shrimp utilization of the disposal area is not expected to be
high and is probably restricted to the winter. Depths at the
candidate site exceed the maximum depths of occurrence previously
reported for this species (Bureau of Commercial Fisheries, 1962;
in Bielsa et al. , 1983).
4.44	Recreational fishing. Like the commercial fishery,
recreational fishing in the waters off Dade County is
concentrated inshore or at offshore natural and artificial reefs.
The natural reef areas are shown in Figure 3. The artificial
reefs are shown on Figure 4 and described in Table 3. The
candidate disposal site is not located in or near areas used for
recreational fishing.
4.45	Other recreation. Dade County's waters support a wide
variety of recreational activities. Fishing has beer, addressed
previously in this document. Coastal waters are also used for
swimming, skiing, sailing, boating, surfing, skin diving, and
SCUBA diving. Few of these activities occur in, and none is
restricted to, the proposed ODMDS.
4.46	Shipping. The proposed Miami ODMDS is located;just to the
south and approximately 1.3 nmi (2.4 km) seaward of :he entrance
channel to the Port of Miami through Government Cut. While there
are no designated shipping lanes beyond the entrance channel, the
general area experiences heavy commercial shipping t::affic.
4.47	Military usage. While the Atlantic Ocean off Itiami may be
used by the United States armed forces for training, testing, and
research activities, the proposed ODMDS does not lie within any
designated fleet operating area as identified by the DOI (1977) .
4.48	Mineral resources. There are no known mineral resources in
the proposed Miami ODMDS vicinity.
4.4 9 Underwater video narrative. A video survey of the proposed
Miami Harbor Ocean Dredged Material Disposal Site (ODMDS) was
done on January 25 and 26, 1986. Depths at the site ranged from
about 400 feet on the western (shoreward) edge to nearly 800 feet
on the eastern (seaward) edge. Approximately 18 hours (9 2-hour
videos) of film were used to record the survey. Four transects
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U.S. EPA Region 4

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Final EIS Miami ODMDS
Aiigct 1995
were run, one on the shoreward edge of the site (V-l), one
approximately in the middle of the site (V-2), one on the eastern
edge (V-3) and one beginning in the southwest corner and ending
at the northeast corner (V-4). The video was continuous along
each transect.
4.50 The tapes show that the entire disposal area exhibits a
consistent pattern, regardless of depth. Much of the bottom
appears to be covered by a fine, silty material, easily put into
suspension by the actions of organisms startled into movement by
the video equipment. No evidence of hard bottom was seen in any
part of the proposed site. The area is sparsely populated by
burrowing organisms, sea urchins, crabs, shrimp, small demersal
fishes and other invertebrates. There is no visible plant life
growing on the bottom and the energy base of this community is
apparently sedimentary.
5.00	ENVIRONMENTAL EFFECTS
5.01	Introduction. Criteria promulgated in 40 CFR, Sections
228.5 and 228.6, deal with the evaluation of ocean disposal
locations and requirements for effective management to prevent
unreasonable degradation of the marine environment. These
criteria have been used as the basis of an environmental
assessment of impacts at the candidate site. Criteria in 40 CFR
228.5 are titled "General criteria for the selection of sites,0
and those in 228.6 are titled "Specific criteria for site
selection". Evaluation of the proposed Miami ODMDS utilized the
literature base, interviews, and baseline data collected at the
site (CCI, 1985) to assess compliance with both the general and
the specific criteria of 40 CFR. Table 4 summarizes the
application of the specific criteria to the site. Each of the
general and specific criteria is addressed in this section as it
relates to the site's suitability as a disposal site.
5.02	Geographical position, depth of water, bottom tonography
and distance from coast f40 CFR 228.6(a)11. The proposed Miami
interim ODMDS is approximately a one square nautica!. mile area
with the following corner coordinates:
(NW) 25-45130" N	(NE) 25~45'30" IJ
The center coordinates are: 25°45'00"N and 80°03,22"W. The
general location of the candidate site is shown on Figure 1. The
shoreward boundary of the disposal site is located approximately
3.6 nmi (6.7 km) from shore.
5.03 The proposed ODMDS is situated on the continental slope.
Depths at the site range from about 427 to 785 ft (130 to 239 m).
The average declivity of the slope at the ODMDS is approximately
325 ft (100 m) per nautical mile (1.85 km).
80-03154" W
80-02'50" W
(SW) 25-44'30" N
80-03'54" W
(SE) 25-44'30" N
80-02150" W
16
U.S. EPA Region 4

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2S°30'
Virginia Key
ODMDS
=mm
wvm
88p
NORTH
•XvX'X'I'X
¦
•TATUTC MILCl
25°40'
Cap* Florida
FIGURE 3
NATURAL REEF AREAS
Ocean Dredged Material OlSDosal Site Miami, Florida
17

-------
l2S°50'
Virginia Key
LJ
O2
0
o
03
o4
Os
a2
9* o15
Miami Baach
ODMDS
2cf
I
21 (J)
I.
19
O22
23a
o24
NORTH
260qQ_028
29
1TATUTC MIlCS
23o40*
NAUTICAL MILCS
Cap* Florida
30
r—i
0
o
®
FIGURE 4
ARTIFICIAL REEF SITES
Ocean Dredged Material Disposal Site Miami, Florida
~ PROPOSED SITES
O ~ ACTIVE SITES

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Artificial Reef Sites in the Proposed Miami ODMDS Vicinity.
Figv
No.
Year	Latitude IN)	l.onnirude IW)
Depth
I Ft.)
Cnmposltion
Rpferenrfi'
1	Proposed			25*54'00"
2	Crane Boom	1947	25*54*00"
3	Fireboat	1973	25"S0'31"
4	Mine Sweeper	1971	25*50'01"
5	Locus	1971	25"49'54"
6	Pflueger Site			25"49'30*
7	No Name			25*49'34"
7	Hopper Barge	1971	25*49'34"
7	San Rapael	1980	25*49'34"
7	Ostwind	1989	25"49'34"
8	Walka Q	1980	25*49'22*
9	PimelIons	1971	25*49'06"
10	West End	1973	25"49,05"
11	Billys Barge	1987	25*48'42*
11	Anchorage Reef	1987	25*48*42"
11	Cote Reef	1990	25*48'42*
11	Coquma	1987	25*48'42"
11	Hiss Karline	1989	25*48'42"
11	Shamrock	1985	25"48'42"
11	LandsEnd,Mary Ann	1984	25*48'42"
11	Pyramid Reef	1988	25*48'42"
11	Eg]oo	1987	25*48'42 *
11	Patricia	1990	25*48'42"
11	Leon's Barge	1988	25*48*42"
11	John Koppin Mem.	1986	2S"48'42"
12	LCI	1969	2 5*48 * 42 *
13	Pipes	1978	25*48*33"
14	Deep Freeze	1976	25*48*21"
15	Dry Dock	1978	25*48'19*
16	Hopper Barge	1970	25*47'18*
17	Bear Cut			25*43' 30"
18	No Name			25*43 '00"
19	Key Biscayne Site				25"42'30"
20	Proposed			25*42*30"
21	Biscayne Wreck	1976	25*42'
22	Shrimp Drift-Boats 1981	25*42'
23	No Name			25*42'04"
24	Dade County Reef	1977	25*42*00"
25	Arida	1982	25"41'43"
26	Orion	1981	25"41'26"
26	Belzona One	1990	25*42*04"
26	Mystic Isle	1986	25"42'04"
26	Rio Miami	1989	25*42'04"
26	Miracle Express	1987	25*42'04"
26	Key Biscayne Reef	1986	25*42'04"
26	Sarah Jane,	1981	25-42*04"
Drift Boats
26	South Seas	1983	25*42'04*
26	Grouper Site	1987	25*42*04"
26	Proteus	1985	25"42'04"
26	Sheri-Lynn	1987	25"42*04"
26	Dade County Reef	1977	25*42*04"
26	Belcher Barge »27	1985	25*42*04"
26	Big Lou	1989	25"42*04"
27	Lakeland	1982	25*41*29"
28	Star Trek	1982	25*41*28"
29	Cement Mixer	1982	25"41'05"
30	Proposed			25*37*00"
*08"
•09"
80*05
80"05
80-04
80*04
80*04
80*04
80-04
80"04
80*04 1
80*041
80-03
80*04
80-04 1
80*05 1
80*05'
80-05'
80*05'
80*05 '
80-05'
80-05'
80-05'
80-05'
80-05'
80-05 '
80*05'
80*04'
80*04'
80*04'
80*03'
80*03'
80*08'
80*06'
80-05'
80*05'
80*05'
80*05'
80-04'
80*04'
80*04 '
80*05*
80-05'
80*05'
80*05'
80*05'
80-05'
80-05'
80*05'
80*05'
80*05'
80*05'
80*05'
80*05'
80*05'
80*04 *
80*04'
80*04 *
80*05'
00"'
00"
02"
14"
00"
54-'
54"
54"
54"
54-
50"
11*
01"
40"
40"
40"
40"
40"
40*
40"
40"
40*
40"
40"
40"
03"
02"
23"
43"
54"
05"
30"
00"
20"*
17"
10'
24"
06"
24"
03"
21"
21"
21"
21"
21"
21"
21*
21"
21"
21"
21"
21"
21"
23"
01"
47"
00"*
50-450
70-85
222
180
216
75-225
125-250
234
330
275-
282
135
228
48
45
45
44
51
44
4 6
50
51
53
50
45
202
204
120
330
234
6-10
21
75-350*
50-75*
55
55-100
220
220
90
95-100
68
185
67
55
135
100
73
V
72
96
220
58
55
126-140
205-210
75-88
60-350*
Crane Boom
Steel Tug
Minesweeper
Coast Guard Tender
Unspecified
Metal, Concrete, Ships
175' Metal Barge
200' Steel Freighter
80' Steel Hull
Steel Freighter
Steel Ferry
Landing Craft
100' Barge
6	Concrete 90' Girders
4 1120 tons Concrete Pipe
Concrete/Tanks
S5' Steel Cargo Ship
85' Steel Ship
120' Steel LCT
2 vessels
19 Radio Antenna
70' Steel Cargo Ship
65* Steel Tug
100' Barge
7S1 Steel Barge, concrete
Landing Craft
Scrap Steel, Rubble
Transport Vessel
Pontoon Dock
Metal Barge
Barge
Autos
Unspeci f ied
Freighter
Vessels
Concrete Rubble
Concrete Rubble
Steel Vessel
Steel Tug
85' Steel Tug
103* Steel Ferry
105' Steel Tug
100' Steel Freighter
850 Tons of Bridge Girders
7	vessels (4 wood, 3 steel)
i75' Steel Yacht
50 Modules
220' Steel Freighter
235' Ship
Concrete Rubble
195' Steel Barge
36' Steel Hull
Steel Ship, Midwater Reefs
Steel Ship, Midwater Reefs
Twenty Cement Mixer Bowls
Approximate locations and depths (from charts).
1. Florida Sea Grant. 1979. Recreational U6e reefs in Florida, artificial and natural. Sea Grant Advisory Bulletin MAP-9. Florida Sea Grant.
2.	Aska, D.Y. and D.W. Pybas. 1983. Atlas of artificial reefs'in Florida. Sea Grant Advisory Bulletin MAP-30. Florida Sea Grant.
3.	Metropolitan Dade County Department of Environmental Resources Management. No date. Artificial
reef program Metropolitan Dade County.
4.	Florida Sea Grant. 1991. Atlas of Artificial Reefs in Florida - 4th Ed.

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Filial EIS Miami ODMDS
August 1995
5.04	Location in relation to breeding, spawning, nursery.
feeding or passage areas of living resources in adult or -juvenile
phases f40 CFR 228.6(a)21. The most active breeding and nursery
areas are located in inshore waters, along adjacent beaches, or
in nearshore reef areas. While breeding, spawning, and feeding
activities may take place near the proposed ODMDS, these activi-
ties are not believed to be confined to, or concentrated in, this
area.
5.05	While many marine species pass through the proposed ODMDS,
passage is not geographically restricted to this area. The
probability of significant impact from dredged material disposal
is directly related to the motility of these organisms.
5.06	Location in relation to beaches and other amenity areas [40
CFR 228.6(a)31. Beaches and inshore resources are outside the
area to be affected by disposal in the proposed ODMDS. These
amenities areas lie approximately 3.6 nmi (6.7 km) inshore of the
designated disposal site.
5.07	Several protected areas, shown in Figure 5, lie inshore of
the candidate disposal site. The Biscayne Bay Aquatic Preserve
encompasses almost all of the inshore waters in the area. The
waters of the southern portion of Biscayne Bay as well as some
offshore waters are expected to be incorporated into Biscayne
National Park in the near future. The Bill Baggs Cape Florida
State Recreational Area is located on the southern tip of Key
Biscayne. The Florida Department of Environmental Regulation
(FDER) has afforded the waters associated with each of these
areas special protection as Outstanding Florida Waters. ¦
5.08	Both natural and artificial reef sites' are found in the
proposed Miami ODMDS vicinity. Natural hardground reefs occur
primarily at depths ranging from 20 to 100 ft (6 to 30m). The
seaward extent of the natural reef zone in the area lies
approximately 1.3 nmi (2.4 km) inshore of the west side of the
interim disposal site. Two concentrations of artificial reef
sites are also located in the area. One group of artificial reef
sites is located about 3.3 nmi (6.1 km) north and slightly
inshore of the proposed ODMDS and another cluster of .sites is
located 1.7 nmi (3.2 km) south and inshore of the proposed
disposal site.
5.09	Types and quantities of waste to be disposed of. and
proposed methods of release, including methods of packing the
waste, if anv (40 CFR 228.6(a)4). The only material to be
disposed in the ODMDS will be dredged material that complies with
EPA Ocean Dumping Regulations (40 CFR 220-229). The site is
expected to be used for routine maintenance of the authorized
Federal channels and the Miami Harbor deepening project. It is
estimated that 5 million cubic yards of material will be disposed
from the deepening project.
5.10	Feasibility of surveillance and monitoring (40 CFR
228.6(a) (5)) . Bottom contours in the area can be monitored
20
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Final EIS Miami ODMDS
Aiigct 1995
through bathymetrie survey methods. Monitoring of the proposed
Miami ODMDS is discussed further in the Site Management and
Monitoring Plan (SMMP) provided in Appendix C. This SMMP is
intended to be flexible and may be modified by the responsible
agency for cause.
5.11	Dispersal, horizontal transport. and vertical mixing
characteristics of the area, including prevailing current
direction and velocity, if anv (40 CFR 228.6(a)6). Circulation
off the southeast coast of Florida is primarily influenced by the
Florida Current. The Florida Current is that portion of the Gulf
Stream system which connects the Loop Current of the Gulf of
Mexico to the Gulf Stream as it proceeds through the Straits of
Florida and into the open Atlantic Ocean (Lee et al. , 1977) . The
proposed Miami ODMDS lies near the western edge of the Florida
Current.
5.12	The Florida Current is a highly variable and dynamic
current system. Horizontal meanders result in fluctuations of
about 2.6 nmi (4.8 km) in the location of the western edge of the
current which, on the average, lies 3.2 nmi (5.9 km) east of
Virginia Key (EPA, 1973). In addition to horizontal meandering,
spin-off eddies are frequently formed along the western boundary
of the Florida Current. These cyclonic eddies occur on an
average of once per week, travel north at speeds ranging from 20
to 50 cm/sec, and result in internal currents that are directed
to the west, south, and east. Other factors contributing to the
variability of the Florida Current include tides, winds, and
seasonal variations in the volume of water transported in the
Gulf Stream system.
5.13	Currents in the proposed ODMDS vicinity are strongly
directed along the north-south axis. The predominant direction
of flow is to the north. Current speeds are highest in surface
waters, decreasing to near zero At the bottom. Mean current
speeds in surface waters at the site range from a low of 62
cm/sec in winter to about 95 cm/sec in the spring and summer (Lee
et al., 1977). Maximum surface water currents range from about
150 cm/sec to the north to 50 cm/sec to the south (Lee and
Mooers, 1977). Speeds are lower and north-south reversals more
common near the bottom. Lee and Mooers (1977) report a mean
northerly flow in near-bottom waters near the proposed ODMDS of
3.5 cm/sec, with maximum flows of 27 cm/sec to the north and 23
cm/sec to the south.
5.14	Tidal currents in the proposed disposal site vicinity are
also directed along the north-south axis. Measurements taken in
approximately 175 m water depth show semi-diurnal tides with
amplitudes ranging from 10 to 20 cm/sec in near-bottom (10 m
above the bottom) waters (Lee and Mooers, 1977).
5.15	In a response to a request by the Jacksonville District,
the Army Corps of Engineers Waterways Experiment Station (WES)
performed a technical study of the Gulf Stream meanders, frontal
21
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Final EIS Miami ODMDS	August 1995
Table 4
Summary of the Specific Criteria as Applied to
the Interim Designated (Candidate) Site
Criteria as Listed
in 40 CFR 228.6(a)
Interim Designated
(Candidate) Site
1. Geographical position,
depth of water, bottom
topography and distance from
coast.
See Figures 1 and 2. Depths at the
site range from about 427 to 785 ft
('130 to 239 m) . The site is located
on the steepest part of the conti-
nental slope, with a declivity of
about 325 ft (100 m) per nautical
mile (1.85 km). The site lies about
3.6 nmi (6.7 km) from shore.
2. Location in relation to
breeding, spawning, nursery,
feeding, or passage areas of
living resources in adult or
juvenile phases.
None concentrated in or restricted
to the interim disposal site. Most
breeding, spawning, nursery, and
feeding activities take place in
coastal waters or at reef areas
located shoreward of the site.
Passage through the proposed ODMDS
is not geographically restricted.
3. Location in relation to The interim site is located approxi-
beaches and other amenity	mately 3.6 nmi (7.4 km) from coastal
areas.	beaches and protected inshore
waters. The natural reef zone lies
about 1.3 nmi (2.4 km) inshore of
the site. Artificial reef sites are
located about 3.3 nmi (6.1 km) to
the north (downcurrent) and about
1.7 nmi (3.2 km) to the south
(upcurrent) of the disposal site.
4. Types and quantities of
waste proposed to be disposed
of, and proposed methods of
release, including methods of
packing the waste if any.
The only material to be disposed in
the ODMDS will be dredged material
that complies with the EPA Ocean
Dumping Regulations (40 CFR 220-
229) .
22
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Final EIS Miami ODMDS
Augst 1995
Table 4 (continued)
Summary of the Specific Criteria as Applied to
the Interim Designated (Candidate) Site
Criteria as Listed
in 40 CFR 228.6(a)
Interim Designated
(Candidate) Site
5. Feasibility of surveil-
lance and monitoring.
A Site Management and Monitoring Plan
has been developed for the Miami
ODMDS and is included in this EIS as
Appendix C.
6. Dispersal, horizontal
transport, and vertical
mixing characteristics of
the area, including
prevailing current direction
and velocity, if any.
Prevailing currents parallel the
coast and are generally oriented
along a north-south axis. Northerly
flow predominates. Mean surface
currents range from 62 to 95 cm/sec
with maximum velocities of about 150
cm/sec. Current speeds are lower
and current reversals more common in
near-bottom waters. Mean velocities
of 3.5 cm/sec and maximum velocities
of 27 cm/sec have been reported for
near-bottom waters in the area (see
text). A pycnocline occurs in site
waters throughout the year at
reported depths ranging from about
60 ft in the summer to 325 ft in the
winter. Dredged material
dispersion studies conducted by the
Corps for both short and long-term
fate of material disposed at the
proposed site indicate little
possibility of disposed material
affecting near-shore reefs.
7. Existence and effects
current and previous
discharges and dumping in
the area (including
cumulative effects)
The only use of this site was in
April 1990. Monitoring during dump-
ing activities verified the current
model results. No adverse impacts
were found.
23
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Final EIS Miami ODMDS
August 1995
Table 4 (continued)
Summary of the Specific Criteria as Applied to
the Interim Designated (Candidate) Site
Criteria as Listed	Interim Designated (Candidate) Site
in 40 CFR 228.6(a)
8. Interference with
shipping, fishing, recrea-
tion, mineral extraction,
fish and shellfish culture,
areas of special scientific
importance, and other
legitimate uses of the
ocean.
No significant interference is
anticipated. Closest fishing sites
are located 1.3 nmi (2.4 km)
inshore, 3.3 nmi (6.1 km) to the
north, and 1.7 nmi (3.2 km) to the
south of the designated interim
site.
9. The existing water
quality and ecology of the
site as determined by
available data, or by trend
assessment or baseline
surveys.
Water quality at the site is
influenced by inshore discharges,
oceanic intrusions, and periodic
upwelling. The location of the
Florida Current determines whether
site waters are predominantly
coastal or oceanic. The site
supports a benthic and epibenthic
fauna characteristic of the
continental slope habitat.
10. Potential for the
development of nuisance
species in the disposal
site.
No evidence of undesirable organisms
at the site noted. Disposal should
not recruit or promote the develop-
ment of nuisance species.
11. Existence at or in	No known features
close proximity to the site
of any significant natural
or cultural features of
historical importance.
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2 3° SO
23°40
Blscayne Bay
Aquatic Preserve
Miami Beach
Virginia Kay
ODMDS
Bill Baggs
Cape Florida
State Recreation
Area
PROJECTED
FUTURE BOUNDARY
Blscayne
National Park
NORTH
f

STATUTf UILES
NAUTICAL MILES
O
O
O
o
CD
FIGURE 5
PARK AND PRESERVE AREAS
Ocean Dredged Material Disposal Site Miami, Florida
25

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Final EIS Miami ODMDS
August 1995
eddies and prevailing tides and currents off the east coast of
Florida with respect to the potential for reef siltation by
disposed dredged material originating from the proposed Miami
ODMDS (Appendix B). A numerical modeling approach was used for
estimating both the short-term and long-term fate of dredged
material disposed at the proposed ODMDS. The modeling of the
short-term dumping operation was performed by the Disposal from
an Instantaneous Dump (DIFID) model. Long-term simulations,
using a newly developed coupled hydrodynamic/sediment transport
model, employed depth-averaged velocity fields to determine
whether non-storm related currents are capable of transporting
sediments outside of the proposed ODMDS over long periods of
time. The effects of storm erosion were separately modeled by
simulating the passage of a storm surge over the site. For the
short-term study, the dredged material was initially assumed to
be 90 percent sand (fine to medium) and 10 percent silt and clay.
A second modeling run was made using a 90 percent silt and clay
fraction and a 10 percent sand fraction. This proportion is
quite similar to that of dregded material from Miami Harbor
recently tested preparatory to maintenance dredging. A second
study (see Appendix E) was undertaken as a cooperative effort
between Rosenstiel School of Marine and Atmospheric Science
(RSMAS) of the University of Miami, Atlantic Oceanographic and
Meteorogical Laboratory of the National Oceanic and Atmospheric
Administration and WES. This study included the following: 1) a
verification of the .Short ^erm FATE (STFATE) model (a revised
version of the DIFID model) using field collected water samples;
2)a	model run using ambient conditions provided by RSMAS; and
3)an	analysis of the potential resuspension and transport of
bottom sediment at the site.
5.16	Short-term modeling results. Short-term modeling results
of both the 90 percent sand- 10 percent silt-clay and 90 percent
silt clay-10 percent sand show that most of the material from the
disposal load settles into a mound within several hours after
initial release from the dredge. The silt and clay portion of
the disposal load creates a suspension cloud or turbidity plume
that is transported by ambient currents. This cloud increases in
size and decreases in concentration with distance from the point
of disposal. The concentration of the suspended sediment cloud
was computed at specific depths for each simulation. The
modeling results for all three short-term modeling efforts
indicate concentrations of suspended materials, at the time they
reach the reefs, to be at or below 10 mg/1 above ambient levels.
5.17	Long-term modeling results. The long-term modeling efforts
were conducted to determine whether a disposal mound is stable
over long periods of time. In the first study, two types of
simulations were conducted. A long duration simulation of a
specified mound configuration was conducted. A 3-month
simulation showed no erosion of a mound in 600 feet of water.
Additional shorter duration simulations were made in order to
investigate storm-related transport of material from the mound
onto the reefs. A 24-hour sustained storm surge simulation
showed that essentially no material was transported as a result
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Final EIS Miami ODMDS
August 1995
of the surge. The second study investigated the potential for
moving material other than uniformly graded, non-cohesive
sediments by calculating shear stress values on the mound and in
the surrounding area. Under normal environmental conditions,
shear stress values at the ODMDS are low, and little movement is
anticipated for either cohesive or non-cohesive material. During
storm events, the shear stress values increase by an order of
magnitude. However, the shear stress on the dredged material
disposal mound increases by less than 2 dynes/cm2 above the shear
stress of the surrounding area. When subjected to storms,
material is anticipated to move from the mound for short periods
of time but large dispersion of the mound is not predicted. For
the proposed Miami ODMDS, simulations show that local velocity
fields are simply not adequate to move material in 600 feet or
more of water. Both the short-term disposal and long-term
erosion simulations of sediment transport as a function of local
velocity fields indicate little possibility of affecting reefs as
a direct result of use of the disposal site.
5.18	Existence and effects of current and previous discharges
and dumping in the area (including cumulative effects) f40 CFR
228.6(a)71. The existing EPA interim-designated ODMDS was first
used for dredged material disposal in April 1990. Required
maintenance dredging of Miami Harbor is relatively infrequent and
has occurred four times since 1957; 80,000 cy in 1957; 80,000 in
I960; 210,000 in 1968; and 15,000 in 1985. Materials generated
by these maintenance dredging operations were placed
approximately one nautical mile (nmi) shoreward of the proposed
site. No records of ocean disposal prior to 1955 are available
for this area. No incidents of adverse impacts from these
disposal actions are known.
5.19	Two additional disposal areas are indicated on navigational
charts for the area (National Oceanic and Atmospheric
Administration {NOAA}, 1985). These are located adjacent to and
to either side of the Miami Harbor entrance channel and inshore
of the site previously used. No record of the use of either site
has been found.
5.20	Interference with shipping, fishing, recreation, mineral
extraction, desalination, fish and shellfish culture, areas of
special scientific importance, and other legitimate uses of the
ocean [40 CFR 228.6 (a)81. The proposed ODMDS is located just
south of the entrance channel to the Port of Miami, an area of
heavy commercial shipping traffic. Most traffic passes to the
north of the proposed disposal area. The infrequent use of this
site should not significantly disrupt either commercial shipping
or recreational boating.
5.21	Commercial and recreational fishing activity is concen-
trated in inshore and nearshore waters or at offshore natural and
artificial reefs. The proposed ODMDS lies about 3.6 nmi (6.7 km)
from shore and 1.3 nmi (2.4 km) seaward of the natural reef line
(see Figure 3). Artificial reef sites are located approximately
3.3 nmi (6.1 km) north (downstream) and 1.7 nmi (3.2 km) south
27
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Final EIS Miami ODMDS
August 1995
(upstream) of the designated disposal area (see Figure 4). DIFID
model results and NOAA/WES plume monitoring show no likely-
effects to these resources from using the proposed ODMDS.
5.22	No mineral extraction, desalination, or mariculture
activities occur in the immediate area. Recreational and
scientific resources are present throughout the area but are not
geographically limited to the proposed Miami ODMDS or nearby
waters.
5.23	Existing water quality and ecology of the site as
determined bv available data or by trend assessment or baseline
surveys f40 CFR 228.6(a)91. Water quality at the proposed ODMDS
is variable and is influenced by discharges from inshore systems,
frequent oceanic intrusions, and periodic upwelling. The
proposed disposal site lies on the continental slope in an area
traversed by the western edge of the Florida Current. The
location of the western edge of the current determines to a large
extent whether waters at the site are predominantly coastal or
oceanic. Frequent intrusions or eddies of the Florida Current
transport oceanic waters over the continental shelf in the
proposed ODMDS vicinity. Periodic upwelling/ downwelling events
associated with wind stress also influence waters in the area
(Lee and Moores, 1977).
5.24	Surface and bottom water samples collected from the
proposed disposal site vicinity in January 1986 (Appendix A) did
not contain measurable concentrations of pesticides, pesticide
derivatives, mercury, PCBs, or HMW hydrocarbons. Cadmium was
detected in near bottom waters at two of the seven stations
sampled. Lead was found in surface water collected at one
station.
5.25	Potential for the development or recruitment of nuisance
species in the proposed disposal site f40 CFR 228.6(a)101. The
disposal of dredged materials should not attract or promote the
development of nuisance species. No pre-disposal nuisance
organisms were identified in a January 1986 (Appendix A) survey
of the proposed disposal site and none has been reported to occur
at previously utilized disposal sites in the vicinity-.
5.26	Existence at or in close proximity to the site of anv
significant natural or cultural features of historical importance
r40 CFR 228.6(a)111. No natural or cultural features of
historical importance are known to occur at or in close proximity
to the site. No such features were noted in a video survey of
the proposed disposal area conducted by Conservation Consultants,
Inc. in January 1986.
5.27	The dumping of materials into the ocean will be permitted
only at sites or in areas selected to minimize the interference
of disposal activities with other activities in the marine
environment, particularly avoiding areas of existing fisheries or
shell fisheri es. and regions of heavy commercial or recreational
navigation T4f) CFR 228.5(a) 1. The proposed Miami ODMDS does not
28
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Final EIS Miami ODMDS
Augid 1995
support an active commercial or recreational fishery. Fishery
and shellfishery resources are not concentrated in, restricted
to, or dependent upon the interim disposal site vicinity.
5.28 There are no specially designated shipping lanes in the
proposed disposal site vicinity. The candidate ODMDS is located
seaward and slightly south of Government Cut, the entrance
channel to the Port of Miami, and is in an area of heavy
commercial shipping traffic. However, it is not anticipated that
future, intermittent use of the site would result in a level of
activity that would significantly disrupt shipping.
5.2 9 Locations and boundaries of disposal sites will be so
chosen that temporary perturbations in water quality or other
environmental conditions during initial mixing caused bv disposal
operations anywhere within the site can be expected to be reduced
to normal ambient seawater levels or to undetectable contaminant
concentrations or effects before reaching anv beach, shoreline.
marine sanctuary, or known geographically limited fishery or
shellfishery r40 CFR 228.5(b)1. Any temporary perturbations in
water quality resulting from disposal operations would be reduced
to ambient or undetectable levels within a short distance of the
release point (see para. 5.15). Prevailing currents at this site
are to the north and parallel the coast. The proposed ODMDS lies
about 3.6 rani nautical miles (6.7 km) from the nearest landfall,
and 1.3 nmi from the nearest reef. At this location, the
likelihood of impacts to nearshore amenities and protected areas
is small. In addition, provisions in the Site Management and
Monitoring- Plan restrict disposal to prevent any residual
disposal plume from reaching the nearest reef. The proposed
disposal site does not lie in the vicinity of geographically
limited fishery or shellfishery resources.
5.30	If. at anv time during or after disposal site evaluation
studies, it is determined that existing disposal sites presently
approved on an interim basis for ocean dumping do not meet the
criteria for site selection set forth in 228.5 and 228.6. the use
of such sites will be terminated as soon as alternate disposal
sites can be designated f40 CFR 228.5(c)!. The proposed site
meets the cited criteria.
5.31	The sizes of ocean disposal sites will be limited in order
to localize for identification and control anv immediate adverse
impacts and permit the implementation of effective monitoring and
surveillance programs to prevent adverse long-range impacts. The
size, configuration, and location of anv disposal site will be
determined as part of the disposal site evaluation or designation
study r40 CFR 228.5(d)1. A limited area of about one square
nautical mile has been proposed as the ODMDS. Bottom contours in
the area can be monitored through bathymetric survey methods.
Monitoring of the proposed Miami ODMDS is discussed further in
the SMMP provided in Appendix C. This SMMP is intended to be
flexible and may be modified by the responsible agency for cause.
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Final EIS Miami ODMDS
August 1995
5.32	EPA will, wherever feasible, designate ocean dumping sites
bevond the edge of the continental shelf and other such sites
that have been historically used f40 CFR 22R.5(e)1. The
candidate site is located beyond the edge of the continental
shelf. Historically used sites are on the shelf, but their
proximity to environmental amenities makes their use
environmentally questionable.
5.33	Relationship between short-term uses and long-term
productivity. Use of the proposed ODMDS in the manner described
should have no effect on long-term productivity.
5.34	The disposal of dredged materials at the proposed Miami
ODMDS would not result in significant long-term water quality
degradation. Water quality impacts of concern with regard to
dredged material disposal include those associated with increased
turbidity, decreased dissolved oxygen levels, and the release of
sediment-bound contaminants such as heavy metals, nutrients, and
hydrocarbons, including pesticides and PCBs. Generally,
contaminants bound in sediments are not released under conditions
normally occurring at open water disposal sites (Burks and
Engler, 1978; Saucier, 1978). Most potential contaminants remain
sorbed on sediments or are readily scavenged from the water
column by particulate matter and metal oxides and precipitated.
In addition, only material meeting ocean disposal criteria will
be disposed at the site.
5.35	Increased turbidity resulting from dredged material
disposal is generally short-term and transient (Windom, 1976) .
Elevated turbidity levels occur during dredged material disposal,
but decrease rapidly as suspended sediments settle or disperse.
Some increases in turbidity could occur at the pycnocline.
5.3 6 Temporary decreases in dissolved oxygen would occur during
disposal. Given the depth of the well-mixed portion of the water
column at the proposed ODMDS, significant off-site impacts are
not expected and on-site impacts should be of short duration.
5.37 Nutrients bound in sediments would be released to the water
column during disposal. Soluble phosphorus would be-temporarily
released but would be rapidly scavenged from the water column
(Burks and Engler, 1978). Soluble nitrogen compounds,
particularly ammonia, would also be released during disposal.
Ammonia, which is toxic in high concentrations, should be rapidly
reduced below harmful concentrations by dilution (Burks and
Engler, 1978).
5.3 8 The potential for water quality impacts resulting from the
release of trace metals is minor. Most heavy metals are poorly
soluble and are readily sorbed by suspended matter and
precipitated (Windom, 1976; Burks and Engler, 1978). Hydro-
carbons, such as pesticides and PCBs, are generally poorly water
soluble. These substances generally remain sorbed on sediments
and are not released during disposal (Windom, 1976; Burkes and
Engler, 1978).
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Final EIS Miami ODMDS
Augct 1993
5.3 9 The disposal of uncontaminated sediments in compliance with
EPA's Ocean Dumping Regulations and Criteria (40 CFR 220-229)
would not be expected to result in sediment quality degradation.
Periodic bioassay testing (toxicity/bioaccumulation) of proposed
dredged material is required to ensure compliance.
5.40	Impacts of dredged material disposal upon organisms in the
water column are difficult to assess but are generally considered
to be minimal and temporary (Pequegnat et al., 1981). Most
motile organisms (nekton) can avoid disposal operations and
localized areas of poor water quality. Nonmotile (planktonic)
organisms such as phytoplankton, zooplankton, and ichthyoplankton
entrained within the disposal plume would be directly affected.
The impacts of disposal on these organisms is difficult to assess
in light of the high natural variability of planktonic
communities. Significant long-term impacts are not anticipated.
5.41	Sedentary and slow-moving benthic and epibenthic biota
could be impacted both directly and indirectly by dredged
material disposal. Direct impacts would result from the
smothering of bottom-dwelling organisms under varying depths of
dredge material. These impacts would result in the loss of some
of the disposal site biota and the resultant alteration of
benthic community structure. The high reproductive potential of
most benthic infauna should re-establish pre-disposal conditions
rapidly unless sediment characteristics are significantly
different.
5.42	Direct impacts would occur at the specific sites of
disposal. Recolonization from both the vertical migration of
resident infaunal species and the recruitment of species from
nearby areas would occur rapidly after completion of disposal
operations.
5.43	Irreversible or Irretrievable Commitments of resources.
Resources irreversibly or irretrievably committed through use of
the proposed site will include: (1) loss of fuel for the dredges
to transport any dredged material to the site; (2) loss of some
potentially recyclable material (i.e., sand for land fill); and
(3) loss of some benthic organisms that will be smothered during
disposal operations.
6.00 The following chart presents the list of preparers.
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The following people were primarily responsible for the preparation of this document.
Name
Pi sclpline/Eynertlse
Experience
Prelect Role
Mr. Rea Boothby
Mr. Elmar Kurzdach
Mr. William T. Marsh
Ecologist
Environmental Assessment
Aquatic Ecology, Coastal
Systems
Mr. William T. Hamilton Environmental Assessment
Mr. Lawrence J. Swanson Fisheries Resources,
Aquatic Biology
Ms. Dorothy S. Morse
Chemistry
Ms.	Sherne A Leman
Dr.	Norm Scheffner
Mr.	Gary W. Collins
Mr.	Robert B. Howard
Mr.	Chris McArthur
Mr.	Glenn Schuster
Analytical Chemistry
Environmental Scientist
Supervisory Engineer
Environmental Engineer
Environmental Engineer
21	years EIS studies
20 years NEPA Review
Staff Scientist, Environmental Science
and Engineering, Inc.; 2 years
Staff Scientist, Jones, Edmunds & Assoc.
Inc.; 5 years
Vice President, TAI Environmental Services
Inc.; 3 years
Senior Staff Scientist/ Division Manager,
Conservation Consultants, Inc.; 1 year
President, Conservation Consultants, Inc.;
17 years
Staff Scientist, Conservation Consultants,
Inc.; 13 years
Research Assistant, University of Miami;
1 year
Soil Chemist, University of Florida; 3 years
Laboratory Supervisory, Utility Service
Associates, Inc.; 4 years
Chemist, Manatee County Pollution Control;
1 year
Chief Chemist, Conservation Consultants, Inc.
8 years
Staff Chemist, Conservation Consultants
Inc.; 3 years
Laboratory Technician, Manatee County
Utilities; 2 years
Waterways Experiment Station
Oceanographic studies; 15 years
22	years in EPA programs
Transport Processes
16 years in Water Quality
EIS Facilitator
NEPA Supervisor
Project Manager,
Principal Investigator,
ODMDS Site Study
Project Advisor, ODMDS
Study
Field Team Coordination,
Fish and Epibenthlc
Invertebrate Taxonomy
Laboratory Supervisor,
Granulometry
Granulometry
Evaluation of Dispersion Characteristics
EPA Miami ODMDS Manager 1988-1992
Ocean Disposal Program Manager
EPA Miami ODMDS Manager
EIS Facilitor
2

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Final E1S Miami ODMDS
August 1993
7.00	PUBLIC INVOLVEMENT.
7.01	This EIS, in either draft of final form or both, has been
coordinated with the following agencies, groups and individuals:
Federal
Advisory Council on Historic Preservation
Council on Environmental Quality
Department of Agriculture
Forest Service
Soil Conservation Service
Department of Commerce
National Oceanic and Atmospheric Administration
National Marine Fisheries Service
National Ocean Survey
Office of Coastal Zone Management
Altantic Oceanographic and Meteorological Laboratory-
Department of Defense
Pentagon
Department of the Air Force
Department of the Army
Corps of Engineers
Department of the Navy
Department of Energy-
Department of Health and Human Services
Department of Housing and Urban Development
Department of Interior
Bureau of Mines
Fish and Wildlife Service
Geological Survey
Minerals Management Service
National Park Service
Department of Transportation
Coast Guard
Seventh District, Miami, FL
Federal Aviation Administration
Federal Highway Administration
Maritime Administration
Economic Development Administration
Environmental Government Affairs
Federal Emergency Management Administration
Federal Maritime Commission
Federal Power Commission
Food and Drug Administration
General Services Administration
National Science Foundation
U.S. Senate
Honorable Bob Graham
Honorable Connie Mack
U.S. House of Representatives
Honorable Dante Fascell
Honorable Ileana Ros-Lehtinen
33
U.S EPA Region 4

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Final EIS Miami ODMDS	Aiigid 1995
State
Florida Senate
Honorable Lincoln Diaz-Balart
Honorable Jack Gordon
Honorable Carrie Mack
Honorable Gwen Margolis
Florida House of Representatives
Honorable Elaine Bloom
Honorable Michael Friedman
Honorable Susan Guber
Honorable Alberto Gutman
Honorable Luis Morse
Honorable Jefferson Reaves
Florida Department of Environmental Regulation
Florida Department of Natural Resources
Office of the Governor
Governor of Florida
State of Florida A-95 Clearing House
Local
Dade County
Chairman of County Commissioners
Metropolitan Dade County Environmental Resources Management
Metropolitan Dade County Planning Department
Mayor of Miami
Miami Herald. The
Port of Miami
Miami River Coordinating Committee
Miami River Dredging Coalition
Organizations and Individuals
Alert Citizens Tri-City Alliance
Atlantic States Marine Fisheries Commission
Audubon Society of the Everglades
Center of Action - Endangered Species
Clean Ocean Action
Coalition to Cease Ocean Dumping
Conservation Consultants, Inc
Continental Shelf Associates
Florida Atlantic University
Ecology Action of Hollywood
Florida Audubon Society
Florida Coalition for Clean Water
Florida Conservation Foundation
Florida Institute of Technology
Florida Keys Audubon Society
Florida League of Anglers
Florida Sport Fishing Association
Florida Wildlife Federation
Friends of the Everglades
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Final EIS Miami ODMPS
August 1993
Organizations and Individuals Cont'd
Harbor Branch Oceanographic Institute
International Women's Fishing Association
Isaak Walton League of America
League of Women Voters
Miami-Dade Community College
Miami Women's Club
National Audubon Society
National Wildlife Federation
Natural Resources Defense Council
Nature Conservancy
Nova University
Oceanic Society
Organized -Fishermen of Florida
Rosenstiel School of Marine and Atmospheric Science - University of
Miami
Sierra Club
South Atlantic Fishery Management Council
Survive
Tropical Audubon Society
Thomas Nehrig
7.02	Coordination with the National Marine Fisheries Service as
required by Section 7 of the Endangered Species Act of 1973 has been
concluded. In a letter dated October 14, 1994, (see 7.03) the
National Marine Fisheries Service .determined that populations of
endangered/threatened species under their purview would not be
adversely affected by the designation and use of the proposed ODMDS.
Should additional information become available concerning possible
impacts or should the activity be modified, additional consultation
would be requested.
7.03	Responses to Comments. The Notice of Availability of the Draft
EIS was published in the Federal Register on September 7, 1990 and the
public comment period closed on December 7, 1990. A; total of 13
comment letters were received during the public review period. All
the comment letters are included on the following pages along with
responses to the comments. The comment numbers in left margin of
the comment letter correspond to the response numbers on the pages
immediately following the comment,letter.
35
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TWin Towers Office Bldg. • 2600 Blair Stone Road • Tallahassee, Florida 32399-2400
Florida Department of Environmental Regulatu
Bob Martinez, Governor
Dale Twachtmann, Secretary
John Shearer, Assistant Secretary
January 5, 1991
Mr. Wesley Crum, Chief
Wetlands and Coastal Programs Section
United States Environmental Protection Agency
Region IV
345 Courtland Street, Northwest
Atlanta, Georgia 30365
RE: Draft Environmental Impact Statement For Designation of an
Ocean Dredged Material Disposal Site Located Offshore Miami,
Florida
SAI: FL9009110358C
Dear Mr. Crum:
The State of Florida has completed its review of the referenced
document in accordance with the National Environmental Policy Act
and the Florida Coastal Management Program. The proposals in the
Draft Environmental Impact Statement (DEIS) could affect natural
and artificial reefs in state waters and the loss of beach
quality sand.
The Department of Environmental Regulation (DER), as the lead
coastal agency pursuant to section 306(c) of the federal Coastal
Zone Management Act, 16 U.S.C. section 1456(c), and section
380.22, Florida Statutes, hereby notifies the Region IV
Environmental Protection Agency, that the State of Florida cannot
support the findings described in the Draft Environmental Impact
Statement. The State's position is based on inconsistencies with
the following specific provisions of the Florida Coastal
Management Program: Sections' 403.021, .031, .061, .062, and
.918; 161.142; 370.025, .114', Florida Statutes.. State agency
concerns are explained in detail in the enclosed! correspondence.
In order for the State to reconsider its findings, EPA will need
to relocate the ODMDS site approximately three niutical miles to
the east of its present location. If this is not possible, the
State requests restrictions on the designation which prohibit the
deposition of material with a grain size less than .025 mm and
material constituted by more than 10 percent fine grained
material. These restrictions must be adopted by rule. In
addition, the model used to calculate the potential transport o.
fine grain material in a westerly direction must be correctly run
using the correct velocities for the water column and these
results published in the Final Environmental Impact Statement.

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Mr. Wesley Crum
Page Two
Under either of the two ODMDS proposed locations, the following
language must be added into the EIS and rule: "No beach quality
sand that can be placed on proximate beaches consistent with
existing federal, state and local requirements may be placed in
the Miami Harbor Ocean Dredged Material Disposal Site."
In accordance with 15 CFR 930.42(c), a copy of this letter has
been sent to the U.S. Department of Commerce, National Ocean and
Atmospheric Administration, Office of Ocean and Coastal Resource
Management. Mediation by the Secretary, U.S. Department of
Commerce, may be sought pursuant to 15 CFR 930, subpart G for
serious disagreements between the State and a federal agency
taking direct action governed by 15 CFR 930, subpart C. We
request a responce to this letter and to the specific comments in
the enclosed correspondence.
ncerely
Dale Twachtmann
Secretary
DT/dh
Enclosures
cc: A. J. Salem, Jacksonville District, Corps of Engineers
Tom Gardner, Department of Natural Resources
Russell Nelson, Marine Fisheries Commission
Tom Pelham, Department of Community Affairs
Estus Whitfield, Executive Office of the Governor
Timothy R. E. Keeney, Director, NOAA, Ocean and Coastal
Resource Management

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State of Florid/3
Department of Natural Resources
Marjory Sioneman Douglas Building • 3900 Commonwealth Boulevard • Tallahassee, Florida 32399
Tom Gardner, Executive Director
January 3, 1991
Ms. Karen MacFarland, Director
State Clearinghouse
Office of Planning and Budgeting
Executive Office of the Governor
The Capitol
Tallahassee, Florida 32399-0001
Dear Ms. MacFarland:
SAI No. FL9009110358C, Draft EIS for Designation of the
Miami Harbor Ocean Dredged Material Disposal Site (ODMDS)
The Department of Natural Resources has completed review of the
Draft Environmental Impadt Statement for the above referenced
project and the additional information provided at a joint meeting
of the applicant (U.S. Environmental Protection Agency), the U.S.
Army Corps of Engineers, and the state agencies involved in the
review process. The draft document proposes the unconditional
designation of a new site offshore of Miami Harbor for the placemen
of materials obtained from dredging projects anticipated in the
Miami area. The site, while located offshore of the territorial
waters of Florida, is sufficiently close to the natural resources of
the state to merit careful review under the Florida Coastal
Management Program.
The Department does not concur with the proposed designation of
the site pursuant to Chapters 161 and 370 of our approved program.
Specifically, the draft does not include a prohibition for the
placement of any material suitable for beach placement in the
ODMDS. The Department's position on the importance of beach quality
material was detailed in an objection to a similar proposed site
designation offshore of Canaveral Harbor. Our comments on this site
designation are the same and will not be reiterated here for the
sake of brevity. The EPA is well aware of the Department's
concerns. In addition, there remains considerable disagreement on
'the part of expert physical oceanographers with many years of
experience working in the Miami area in researching the Gulf Stream
current and the occurrence of frontal eddies as to the ultimate fate
of any material placed in the proposed ODMDS. The draft does not
adequately address these expert's concerns nor the Department's
concerns regarding the movement of silt and clay sized particles out
of the disposal area and onto the environmentally sensitive
hardbottoms and coral reefs which are as close as 1.3 nm to the west
Administration Beaches and Shores Law Enforcement Marine Resources Recreation and Parks Resource Management State Lands
Bob Martinez Jim Smith
Bob Buttcnvorth Gerald Lewis Tom Gallaeher
Doyle Conner
Betty Castor

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Letter to Ms. MacFarland
January 3, 1991
Page 2
of the proposed site. The turbidity generated from a typical
disposal event could be prolonged over a number of months and
materials placed in the water column could be transported for many
miles under the most severe cases. The Department is working
actively to protect coral reef tracts in this area and other areas
of the State and any activity which has the potential to negatively
impact reefs must be opposed until adequate assurance has been
^provided that no negative impact will occur.
In summary, the Department does not concur that the proposed
site designation is consistent with our authorities pursuant to
Sections 161.142, 370.025, and 370.114, Florida Statutes. The
applicant can make the proposed designation consistent by moving the
ODMDS further offshore to maximize the distance that material would
have to travel before encountering hardbottoms and to increase the
influence of the Gulf Stream in distributing the material over a
large area. We suggest a minimum of 3 additional nautical miles
offshore. In addition, the following language should be added to
the EIS and the rule designating the site: No beach quality sand
that can be placed on proximate beaches consistent with existing
federal, state, and local requirements may be placed in the Miami
Harbor Ocean Dredged Material Disposal Site.
Thank you for the opportunity to provide our position on this
proposal. If you have any questions, please contact David W. Arnold
at (904)488-2955.
Sincerely
Tom Gardner
Executive Director
cc: Bob Howard, EPA, Atlanta
Col. Bruce Malson, USACE-Jacksonville
Dale Twachtmann, DER
Pam McVety, Div. of Marine Resources

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Florida Department of Environmental Regulatior
X I w i! i I' i\\ i"i" i ^' i i. i ^• ji « 11' !'. :¦ si. n •; K i.k !
:i.r
JVlfcV
December 17, 1990
Ms. Karen MacFarland, Director
Florida State Clearinghouse
Office of -Planning and Budgeting
Executive Office of the Governor
The Capitol
Tallahassee/ Florida 32399-0001
Dear Ms. MacFarland:
Re: Draft Environmental Impact Statement,
Miami Ocean Dredged Material Disposal Site
Designation, SAI FL 90—0358C
We have reviewed the referenced document and met with the Corps
and EPA to discuss the proposed designation. Our specific
comments on the document are enclosed. We request that the-
document be revised to address these comments and to correct the
identified errors or omissions.
The central issue surrounding this designation is the suitability
of its location. The site is 1.5 - 2 nmi from natural reefs and
hard ground areas to the west and 2-5 nmi from several
artificial reefs to the north. Under ambient conditions, flow
through this site is influenced by the Florida current directed
to the north toward the artificial reefs. Under frequent
circumstances which occur during the passage of frontal eddies
spinning off of the Florida current, a strong westerly flow
toward the natural reefs results.
The DEIS includes modeling results for predominantly coarse and
predominantly fine material disposal events under conditions
estimated for westerly flow. The influence of the Florida
current axis was not considered in the dispersion analysis.
Under the westerly flow scenarios, the model concludes that no
significant quantities of sediment will be transported toward the
reef tract. However, certain of the current velocity assumptions
used in these runs were flamed and therefore produced incorrect
transport projections. Using correct velocity figures, transpor
of fine grained material to the reef tract by an onshore eddy

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Ms. MacFarland
Miami ODMDS
December 17, 1990
Page 2
would occur. Transport to the artificial reef sites by the
Florida current will occur also. We request that the model be
run again using correct velocities and include these results in
the final EIS.
We have previously concurred with the use of this site for coarse
grained material which settles rapidly. We believe there is
limited potential for this material to be transported to the reef
areas-.. Therefore, we can agree with the use of this site for
such material. However, it is likely that fine grained material
would be deposited on adjacent live bottom and natural and
artificial reef sites. Such deposition can severely impair
biological activity and 'ultimately cause mortality of the benthic
organisms in these areas. Subtropical marine habitat is
generally intolerant of excessive sedimentation and should not be
Subjected to such an impact.
We disagree with the proposed designt.tion based on the
availability of the site for the disposal of fine grained
material. The .probable damage "to adjacent marine resources is
inconsistent-with the following specific provisions of the DER's
authorities in the Florida Coastal Management Program: Sections
403.021, .031, .061, .062, and .918 Florida Statutes..
As an alternative, we recommend the EPA include language in the
FEIS which is formally adopted by rule to restrict the use of
this site to coarse grained material as defined by a grain size
of > .025 mm and < 10% fines.
We would be pleased to discuss these issues with EI'A and the
Corps as needed. If you have any questions, please contact Lynn
Griffin at 904-488-0130.
Sincerely
Mark Latch
Deputy Director
Division of Water Management
ML/clw
cc: Scott Benyon
Enclosure

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* '- vV .. *
";0^N •—
^ste of nonca	^^
DEPARTMENT Of ENVIRONMENTAL "EGL'L-TlCN 	
Interoffice Memorandum
TO:	Mark
FROM: Lynn Griffin a*
DATE:	December 20, 1990
SUBJECT: Comments on the Draft Environmental Impact Statement
for the Miami Ocean Dredged Material Disposal Site
Designation
I have reviewed the referenced document and offer the following
comments:
1.02 and 1.03: These sections should acknowledge the
considerable public concern as well as the state's reservations
for this designation. The controversy has primarily focused on
whether the Miami River sediments should be dumped in this site,
but there is some opposition to any designation o.': a site in such
close promimity to reefs and other hard bottom areas. It is
inaccurate to state that no controversy ezists or that there are
no unresolved issues.
2.03': Since the Corps has applied for permits to maintenance
dredge the Miami River and to dispose of the material in the
proposed Miami ODMDS, this project should be identified in this
discussion. If EPA has determined that Miami River material will
not be suitable for disposal in this site, this should be
explained.
3.04: The previous dumping history is new information. The DEIS
should include more details regarding volume and .ype of material
disposed, bathymetric changes and biological information of the
previously used site, particularly for the 1985 disposal.
Disposal 1 mile west of the ODMDS places the dump site in state
waters which means the dumping required state permits.
Permitting, information such as the permit number, conditions, and
fhonitordng requirements and results should have been included in
the DEIS..
3.08: Please explain what "additional variables" would preclude
a move further offshore.

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MEMO - Miami ODMDS
December 20, 1990
Page 2
4.50: As we have stated repeatedly in the past, the state should
have been consulted on the video survey design and then should
have been presented the survey for review. Survey transects
should have been run in an east - west direction and extended to
the west to document the proximity and type of hard bottom.
Transects should also have been run through the area used for
disposal in 1985.
5.lOt Why isn't sediment mapping a feasible monitoring option at
this site?
5.16: This discussion should be revised to reconcile the points
raised by Dr. Thomas Le^ regarding the inappropriate depth -
averaged velocity figures used in the model. Also, a model run
of a worst case scenario for the artificial reef sites to the
north should be completed using Gulf Stream currents.
5.17: According to oceanographic researchers, evidence of bottom
scour is quite pronounced in this area. Were there any
literature.suryeys or. consultations with local scientific experts
to ensure that the simulations .were based on solid assumptions of
bottom current velocities?
5.18: What is the basis for the statement that there were no
adverse impacts from the 1985 disposal to the west of the ODMDS.
Monitoring reports and field investigations of existing
conditions should be included in the DEIS.
5.25: Where is it reported that nuisance species are not present
in previously utilized disposal sites in the vicinity? As stated
above, pre v. post site surveys and monitoring of previously used
sites should have been performed and should have been included in
the DEIS. If they do not exist they should not be used as a
basis for conclusions that there will be no effects from use of
the ODMDS.
Appendix A, figure A-2: Had thfe state been consulted in
developing the survey design, a grid pattern of sampling stations
would have been recommended for the ODMDS. A transect of
stations to the west should have been included to document' the
proximity and biological characteristics of hard bottoms and to
evaluate the effects of previous disposal operations.
Appendix B,. p. 47: Neither the proposed designation nor the Site
Management and Monitoring Program includes a restriction on the
dumping location. Therefore, a central release point is not a
worst case factor. The release point can be at the western edge

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MEMO - Miami ODMDS
December 20, 1990
Page 3
of the site- as presently proposed. The model should be rerun
using a starting point for the plume 0.5 nmi closer to shore.
Figures 2.2 - 2.5: These sediment cloud plots are illegible and
^should be reproduced one to a page in the DEIS.
Figures 2.7, 2.9, 2.11, 2.13 and 3.6: These figures are also
illegible.
The copies: of the DEIS provided to the state did not include the
last part of Appendix B which addressed transport from the Miami
vsite. Everything after page 69 was omitted.
Appendix C
Part II C: Due to unresolved concern for transport of fine
material to adjacent-hard bottom communities and artificial reef
areas, the SMMP should include a restriction on the type of
material which can be eligible for disposal in the site.
Essentially, .a .grain size and percent fines limit should be
stipulated in the designation-rule. We propose limits of > .025
mm grain size and < 10% fines.
Part XI--E: Due to substantial opinion that even coarser grained
material may be transported, the dump station location should be
specified. The station should be located in the southeast
portion of the site to allow the greatest distance from areas of
biological concern.
Parts III A and B: Considering the concern for adjacent hard
bottom areas, a monitoring program consisting only of bathymetry
seems inadequate. Sediment mapping, discharge plume monitoring
and monitoring in amenity areas should be included.
Part III C: The NOAA plume tracking study took place because the
state made numerous requests to^monitor the Miami Harbor
maintenance dredging disposal wiuch took place earlier this
year. The reason we wanted the disposal monitored was to verify
the DIFID. model predictions so that this information could be
considered when we evaluated the proposal to designate the'site.
For this information not to be included in the DEIS is a
significant omission. The DEIS should be revised to include the
results and analysis of this information.

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Final EIS Miami ODMDS
August 1995
Responses
Florida Department of Environmental Regulation
Letter dated January 5, 1991:
The comments in this letter are a summary of comments explained in
detail in enclosed internal letters and memorandums. These comments
will therefore be addressed through addressing the detailed comments
of the enclosed correspondence.
Letter dated January 3, 1991:
1.	The disposition of any significant quantities of beach compatible
sand from future projects will be determined during permitting
activities for any such projects. It is expected that the State
of Florida will exercise its authority and responsibility,
regarding beach nourishment, to the full extent during any future
permitting activities. Utilization of any significant quantities
of beach compatible dredged material for beach nourishment is
strongly encouraged and supported by EPA. Disposal of coarser
material should be planned to allow the material to be placed so
that it will be within or accessible to the sand-sharing system,
to the maximum extent practical, and following the provisions of
the Clean Water Act. Additional language has been added to
Section 3.03 of the Final EIS addressing the use of suitable
dredged material for beach disposal.
2.	Since the completion of the Draft EIS, additional work has been
conducted in addressing the concerns regarding transport of fine
grained material towards environmentally sensitive areas. A joint
field data collection project was conducted in April 19$0 by the
Atlantic Oceanographic and Meteorological Laboratory (AOML) of the
National Oceanic and Atmospheric Administration, Jacksonville
District of the Corps of Engineers (SAJ), and the Coastal
Engineering Research Center (CERC) at the Army Corps of Engineers
Waterways Experiment Station. The project monitored the spatial
and temporal variations in suspended sediment load that occur
during disposal using acoustic technology. Data from this study
was used in verification and calibration of the CERC transport
model. Additional modelling was then conducted by CERC utilizing
environmental parameters provided by the Rosenstiel School of
Marine and Atmospheric Science (RSMAS) of the University of Miami.
The modelling concluded that the dispersion of the material will
reduce concentrations to within background levels before moving
sufficiently westerly to reach the coral reefs and that even in
the maximum westerly flow, the coral reefs are not anticipated to
be effected. Reports on both the field data collection effort and
the modelling are included in the Final EIS as Appendices.
As an added precaution, the current Site Management and Monitoring
Plan requires a real-time current monitoring program to be in
place during disposal until the effect of disposal during eddy
currents is better understood. The program will prohibit disposal
of dredged material during certain current conditions. The
45
U.S. EPARtgion 4

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Final EIS Miami ODMDS
Angst 1995
monitoring program is discussed in detain in the Site Management
and Monitoring Plan, Appendix C of the Final EIS.
Letter dated December 17, 1990:
1. Additional modelling was conducted by CERC utilizing environmental
parameters provided by the Rosenstiel School of Marine and
Atmospheric Science (RSMAS) of the University of Miami. The
modelling concluded that the dispersion of the material will
reduce concentrations to within background levels before moving
sufficiently westerly to reach the coral reefs and that even in
the maximum westerly flow, the coral reefs are not anticipated to
be effected. Reports on both the field data collection effort and
the modelling are included in the Final EIS as Appendices.
As an added precaution, the current Site Management and Monitoring
Plan requires a real-time current monitoring program to be in
place during disposal until the effect of disposal during eddy
currents is better understood. The program will prohibit disposal
of dredged material during certain current conditions. The
monitoring program is discussed in detain in the Site Management
and Monitoring Plan, Appendix C of the Final EIS.
Memorandum dated December 20, 1990:
1.	Section 1.02 and 1.03 have been changed.
2.	Placement of material from the Miami River in the ODMDS is not
planned at this time. Other options for disposal of this material
are being investigated. EPA has not been asked to make a
determination regarding the suitability of the Miami River
sediments for ocean disposal.
3.	There is no additional information available regarding the
previous dumping history.
4.	Additional variables includes the enormous task and expense of
monitoring disposal under conditions at the Gulf Stream (depth and
current velocity). Section 3.08 has been changed to reflect this.
5.	As a member of the Site Management and Monitoring Plan (SMMP)
team, the State of Florida will be a participating partner and
will be consulted on future monitoring plans. The survey
transects were selected to document resources that would receive
direct deposition due to disposal. The issue of indirect
deposition due to shore directed current events has since been
realized. The current direction/magnitude monitoring plan
discussed in the SMMP should ensure that any resources that were
not documented to the west of the site are protected. If the
proximity and type of hard bottom again become of concern in the
future due to a change in the monitoring plan, the SMMP team wil
again address this issue. A detailed survey of any resources ii
the 1985 site would have no bering on the current Miami ODMDS.
46
U.S. EPA Region 4

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Final EIS Miami ODMDS
August 1995
6.	The depth of the Miami ODMDS is beyond the current range of the
sediment mapping technology.
7.	This section has been revised and an additional study was
conducted using ambient currents provided by the Rosenstiel
School of Marine and Atmospheric Sciences at the University of
Miami.
8.	The Corps is now monitoring the site and will continue to do so
for the foreseeable future. Evidence of such scouring should be
disclosed by the monitoring.
9.	See comment 3 above.
10.	The focus of this EIS is the suitability of a site for disposal
of dredged material. A literature search was conducted and found
no reports of the development of nuisance species in the area.
The development of nuisance species has not been reported at
other ocean dredged material disposal sites in Florida where
post-disposal biological surveys have been conducted. It is not
feasible to conduct a search for nuisance species at all the old
disposal sites.
11.	See response to item 5.
12.	The Site Management and Monitoring Plan has been revised to
restrict the disposal location.
13.	14, & 15. These problems were addressed in the revised study and
report done by WES.
16.	A management and monitoring program described in the Site
Management and Monitoring Plan (Appendix C) has been initiated to
ensure that fine grained material is not transported towards the
reef and hardbottom areas.
17.	The current Site Management and Monitoring Plan specifies
disposal within a 500 foot radius of the center of the site to
additionally ensure protection of live bottom communities outside
of the site and to contain the disposal mound within the site
during periods of strong currents in all directions.
18.	Plume monitoring and methods for tracking sediment movement have
been added to the Site Management and Monitoring Plan. Options
for monitoring in amenity areas are also included.
19.	The EIS has been revised to include the results from the plume
tracking study. The related reports: "Miami Harbor Dredged
Material Disposal Project;" "Miami Harbor Dredged Material
Disposal Project: Total Suspended Solids Measurements;" and
"Evaluation of the Miami Ocean Dredged Material Disposal Site
(ODMDS)" are attached as Appendices F, G, and E, respectively.
47
U S EPA Region 4

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Ref: TNL/62:jg
October 30, 1990
Mr. Wesley Crum, Chief
Wetlands and Coastal Programs Section
U. S. Environmental Protection Agency
345 Courtland Street NE
Atlanta, GA 30365
Dear Mr. Crum:
I have reviewed the draft Environmental Impact Statement (EIS) for
designation of an ocean dredged material disposal site located offshore
Miami, FL, and I disagree with the conclusion that the interim-designated
site is suitable for disposal of dredged material from the dredging of
Government Cut. The designated site is located much too close to natural
and artificial reefs and should be relocated at least an. additional 3
nautical miles (nm) offshore. My reasons for this follow:
1)	The draft EIS contains a large number of errors, especially Part I
(pages 12-40). The most serious error is in determining the vertically
average velocity to use in the short-simulation of disposal operations.
On page 21, section 24, it is stated that "The site evaluation approach
is inherently conservative in that a constant, maximum-valued,
reef-directed velocity is selected as a boundary condition for sediment
transport calculations." However this is not the case, for the method
used consisted of selecting the minimum east-west velocity profile and
the minimum north-south velocity profile to calculate the maximum,
reef-directed, vertical averaged velocity. To properly compute a
"maximum, reef-directed velocity" would require the minimum east-west
velocity (maximum shoreward directed velocity) to be combined with the
maximum north-south velocity, not the minimum north-south' velocity.
This is especially important since the disposal site is located 3.3 nm
south and slightly offshore of a group of artificial reef sites. The
velocity profiles used to compute the maximum reef-directed velocity are
shown in Fig. 1.9 and Table 1.5. The effect of this error is
particularly glaring in Fig. 1.13 and Table 1.6, which show the
distribution of the computed maximum vertical average velocity vectors
and the velocity components. what strikes you in this figure is the
lack of a Gulf Stream. The currents shown at the 24 ft water depth site
are stronger than at the 258 ft or 834 ft sites or near 1000 ft, where
there should occur a strong Gulf' Stream axis. This is an obvious error
and the maximum reef-directed velocities should be recomputed using
minimum u and maximum v profiles, then used to rerun the short-term and
long-term simulations to estimate the impact on the nearby live and
artificial reefs.
2)	The disposal site chosen is located only 1.3 nm offshore of the live
reef line off Miami and 3.3 nm upstream of artificial reefs. Using the
EIS chosen value for the maximum reef-directed vertical average velocity
of 2.79 ft/sec (85 cm/sec) toward 320 degrees indicates that the
sediment plume resulting from the dredge disposal will reach the reef in
only 1.8 hours. Using the fall velocities for sand and silt/clay from
UNIVERSITY OF
Kosenstiel School of Marine and Atmospheric Science
Division of Meteorology and Physical Oceanographv
1600 Rickenbackcr Causeway
Miami. Honda 1 -49- 109H

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Letter to Mr. Wesley Crum dated 10/30/90, ref: TNL/62
page 2
Table 2.2 indicates that it takes 2.4 hours for sand to be deposited on
the bottom in a water depth of 400 ft and 43.4 hours for silt/clay
deposition. The depth of the reefs range from about 20 ft to 150 ft,
which will require about .3 to .8 hours for sand deposition and 5 to 15
hours for silt/clay. Therefore the silt/clay plume will extend over the
live reef line causing increased sedimentation and higher levels of
turbidity.
3)	The artificial reefs are almost directly downstream from the disposal
site. If we use a more reasonable downstream (northward) maximum current
of about 100 cny'sec (3.28 ft/sec) then the sediment plume will reach the
artificial reefs in only 1.6 hours and sand, as well as silt/clay size
particles, will still be in suspension for deposition on the reefs.
4)	Frontal eddies are a common feature of the local oceanography of this
region, having a frequency of about one per week. During the passage of
these eddies the total water column at the disposal site can undergo
westward currents for several hours' duration. Using a realistic
velocity of 50 cny'sec (1.64 ft/sec) would require only 1.3 hours for the
sediment plume to travel the 1.3 nm to the live coral reefs. I feel
this presents a serious hazard for the nearby live and artificial reefs.
It is just one more stress that the reefs are threatened by and an
unnecessary one at that, for there are suitable alternative disposal
sites nearby. A reasonable solution is to shift the discharge site
further offshore, increasing the distance from the reefs and decreasing
the possibility for harmful impact from short-term or long-term
consequences of the dredge disposal. A minimum offshore shift of 3 nm
would increase the travel time to the reef to about 4.3 hours from
onshore eddy-induced flow. Shifting the disposal site further offshore
would also increase the distance from the ship conjested entrance to
Government Cut and Miami Harbor, providing greater safety for ship
traffic.
5)	Any dredged materials that are suitable for beach nourishment should be
used for that purpose. The repeated dredging of Government Cut with
deep water disposal is removing sediment from the littoral environment,
i.e., a loss from the beach that will contribute to long-term beach
erosion and the need for expensive beach renourishment programs. There
may also be reuse alternatives available for the rock material.
Thank you for the opportunity to review this draft EIS.
Sincerely,
Dr. Thomas N. Lee
Research Professor
Rosenstiel School of Marine and Atmospheric Science
University of Miami
cc: Randall L. Armstrong
Dr. Ken Echternacht
Lynn F. Griffin
Walt Kolb
Sally Turner

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Final EIS Miami ODMDS
Augng 1993
Responses
University of Miami
Dr. Thomas N. Lee
1. The velocity data used in the original modeling did incorporate
the presence of the Gulf Stream. The input velocity data set was
developed through analysis and combination of data from
approximately 60 published and unpublished sources. The composite
data set was generalized in such a way as to maximize the effect
of the westward component, thereby maximizing the potential threat
to the shoreward reef. The objective was to simulate the possible
action of the frontal eddies of Gulf Stream "loop currents" that
appear with approximate 1- to 2-week period. The terminology
"loop current" was not used in this section of the draft EIS and
for that reason some misunderstanding of the calculation strategy
may occur.
Use of maximum westward-directed velocity component and minimum-
to-typical north component is considered appropriate because this
procedure maximized the potential residency time for dredged
material in the water column to reach or stay in the a^a of the
shoreward coral reefs. If a large northward component were to be
employed in the calculations, the material would be swept out of
the area. In fact, this situation of rapid northward sweeping of
material is the normal transport mode in the region and was
quantitatively observed in all eight dredged material plumes th
were tracked in a field monitoring project conducted at the Mi<.
ODMDS by the Jacksonville District during April 23-27, 1990, in
cooperation with WES and Dr. John Proni of the Atlantic
Oceanographic and Meteorological Laboratory, National Oceanic and
Atmospheric Administration, Miami, Florida.
An additional study has also been conducted using ambient currents
provided by the Rosenstiel School of Marine and Atmospheric
Sciences at the University of Miami. The results of this study
are included in this EIS in Appendix E.
2 . In a dredged material placement operation such as at the Miami
ODMDS, it is known that the vast majority of the material falls to
the bottom in a so-called "convective descent" phase. Basically,
the material falls collectively at the speed of a large object,
not as individual particles. This was verified conclusively for
relatively deep water at the Miami ODMDS during the aforementioned
monitoring operation. The only material remaining in the water
column, that comprises the visible surface plume that will move
with the current, consists of very fine particles that do have a
low settling velocity as described in the letter. The convective
descent of the vast majority of material and transport of the
remaining suspended material are accounted for in the numerical
model used in the simulations.
However, the results presented in the WES report for the short
term modelling are off by six orders of magnitude (too low) . rii.d
WES values were reported in units of mg/1, but were actually
unitless and representative of a solids volumetric ratio. The WES
50
U.S. EPA Region 4

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Final EIS Miami ODMDS
Augist 1995
values should therefore be multiplied by the density of the solids
to obtain concentration values -in units of mg/1. The values in
the report have not been corrected for this EIS because the
additional short-term transport modeling presented in Appendix E
supersedes the previous results.
3 . Material that remains suspended in the water column to disperse
laterally does not penetrate the picnocline (density surface)
normally located at about 80-m depth in the region of the ODMDS.
A rhodamine tracer dye study confirmed that this cloud of
extremely low concentration (See comments above) would be
dispersed to near background levels if it were directed towards
the deep water artificial fish haven located northwest of the dump
site.
4.	The response to this comment, in this regard, are discussed in
items 1 and 3 above. The calculations took account of the eddies
as a "worst-case" situation, and it was found that the material
did not arrive at the sensitive areas of concern. The Site
Management and Monitoring Plan further ensures that material will
not arrive at the sensitive areas of concern.
5.	The disposition of any significant quantities of beach compatible
sand from future projects will be determined during permitting
activities for any such projects. It is expected that the State
of Florida will exercise its authority and responsibility,
regarding beach nourishment, to the full extent during any future
permitting activities. Utilization of any significant quantities
of beach compatible dredged material for beach nourishment is
strongly encouraged and supported by EPA. Disposal of coarser
material should be planned to allow the material co be placed so
that it will be within or accessible to the sand-sharing system,
to the maximum extent practical, and following the provisions of
the Clean Water Act. Additional language has been added to
Section 3.03 of the Final EIS addressing the use of suitable
dredged material for beach disposal.
51
U.S. EPA Region 4

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-m jT UNIVERSITY OF
Miami
3 DECEMBER 1990
Mr. Wesley Cram, Chief
Wetlands and Coastal Programs Section
U.S. Environmental Protection Agency
345 Courtland Street NE
Atlanta, GA 30365
Dear Mr. Crum,
I am writing comments in response to a draft Environmental Impact Statement for
designation of an ocean dredged material disposal site located offshore Miami, Florida. It
is my understanding that the dredging will involve first removal of 'clean ocean dredged
material' and then later 'contaminated ocean dredged material' (the later from the Miami
River). I will address these two materials separately.
A. CLEAN OCEAN DREDGED MATERIAL
1. Any clean material that is dredged from Biscayne Bay should be redeposited within
Biscayne Bay so as to shallow the number of deep dredged holes and trenches in northern
kand north-central Biscayne Ba> that are not necessary for navigation.
Between 1900 and I960, extensive dredging took place in northern Biscayne
Bay both along its margins and on the Bay interior (see Harlem, 1976). The
purpose of much of this dredging was to obtain fill to create land for
development of for causeways. These dredged areas vary from 9 to 25 feet
in depth. There were also dredging activities for navigation, but these account
for only a small percentage of the artificially deepened bottom of northern
Biscayne Bay.
In the early 1980's, I undertook a study to ascertain the causes for high
sustained turbidity level in northern Biscayne Bay (Wanless et al., 1984). The
answer was that, areas greater than 8 to 10' in depth are not receiving
sufficient light to develop an effective benthic community of seagrass, algal
mat or hardbottom organisms. The turbidity remains high in the absence of
these bottom-stabilizing and water-filtering organisms. Areas of northen
Biscayne Bay that are slightly shallower (<7'), have moderate to dense
Roscnstiel School of Marine and Atmospheric Science
Division of Marine Geology and Geophysics
4600 Rickenbacktr C.ausewa\
Miami. Florida SJ1 <9-1098

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H.R. Wanless, page 2
benthic communities that are actively stabilizing the bottom and actively
filtering particulate materials form the water column.
The solution to improving the water clarity and quality and enhancing the
benthic communities of northern Biscayne Bay is to fill in those deeper
dredged areas that are not necessary for navigation to a depth where there is
sufficient light for beneficial benthic communities to re-establish. This would
mean shallowing all non-navigation channels to less than 6 feet and shallowing
intracoastal waterway and dock access channels to less than 7-10 feet depth.
Dade County has made efforts in this direction but have been hampered by
the lack of fill material. This harbor deepening project will provide the
unique opportunity to greatly enhance the environmental quality of northern
and north-central Biscavne Bay. As deepening and expansion of the Miami
Harbor channels are not an enhancement of the environmental quality of
Biscayne Bay, I should expect that all concerned will welcome the opportunity
to disposed of the clean fill in a manner that will enhance the quality of
Biscayne Bay.
B. CONTAMINATED OCEAN DREDGED MATERIAL
1. Bottom material dredged from the Miami River or other areas of the harbor
system that are contaminated should not be dumped offshore. The Florida Current
episodically generates extremely strong bottom currents that will rework any deposited
mound of sediment.
I have made several observation transects of the bottom of the Straits of
Florida by submersible from 450' to 150' depth. In the zone from 450' to 200',
there is usually a soft sediment bottom which has conical mounds of sediment
0.5' to 1.5' in height. These are produced by excavating burrowers. The age
of the mounds could be ascertained by the degree of algal stabilization. Only
the very fresh mounds were cones. All older mounds were deformed and
flattened and deformed by northward sediment movement. There are
episodic strong bottom currents to the north caused by flow of the Florida
Current. (Strong southward currents have also been observed by some
sedimentologists). These bottom currents will move the coarser sediment
along the bottom but will resuspend the finer sediment and transport it great
distances. Drs. John van Leer and Tom Lee (of Meteorology and Physical
Oceanography at RSMAS) can give you a good idea as to the transport
directions and durations.
During the serieh of submarine dives with which I was involved, other trips
encountered sufficient northward bottom currents to resuspend bottom
sediment and obscure vision.

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H.R. Wanless, page 3
Very simply the slope seaward of southeast Florida's shelf is a dynamic high
energy system and must not be used for dumping contaminated materials.
They will be recycled elsewhere by episodic erosion and transportation. As
contaminants are mainly associated with the very fine particulates, it is the
contaminants thai: will be most widely distributed.
2.	The bottom environments at 400' depth are valuable marine environments.
At 400' depth off Miami, the bottom has sufficient light for there to be
primary productivity. The bottom has a good algal mat cover and there are
a Variety of macro benthos. I do not think it is wise of necessary to smother
these bottoms with dredged material, and it is very unwise to place
contaminated fill on these environments. There is certainly a major ocean
community that interacts with this bottom environment.
3.	Contaminated ocean dredged material is a hazardous waste.
The contamination of the sediment at the bottom of the Miami River must
be treated in the same manner as any dump site. If it is a hazardous waste,
it should be removed, concentrated and transported to a suitable disposal site
as with any other hazardous waste site. Throwing hazardous waste in the
ocean is not a suitable solution. When one realizes how interactive the
proposed dump site is with important coastal and marine communities, this
ocean dumping solution is intolerable.
I look forward to working with the County, the Port Authority, the involved State of
Florida agencies, the Environmental Protection Agency, the Corps of Engineers, and those
contracted to the transfer of dredge material to assure that this is an environmental
opportunity and enhancement.
Sincerely yours,
Harold R. Wanless
Associate Professor
References:
Harlem, P.H., 1979. Aerial Photographic Interpretation of the Historical Changes in
Northern Biscayne Bay, Florida: 1925-1976. M.S. Thesis, University of Miami, 152p.
(also University of Miami Sea Grant Tech. Bull. No. 40, 15 lp.).

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H.R. Wanless, page 4
Wanless, H.R., D. Cottrell, R. Parkinson, and E. Burton, 1984. Sources and
Circulation of Turbidity, Biscayne Bay Florida. Final Report to Sea Grant and Dade
County, 499p.
cc: Commissioner Harvey Ruvin, Dade County
Dr. B. Rosendahl, Dean, RSMAS
Dr. Ken Echternacht, DERM
Mr. Huber Parsons, Miami River Coordinating Comm.

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Final EIS Miami ODMDS
August 1995
Responses
University of Miami
Harold R. Wanless
1.	The question of beneficial use of dredged material from Miami
Harbor and other areas and the bay were addressed in the Miami
Harbor Channel, Florida, Design Memorandum dated October 1991.
The conclusion of the study was that the cost of producing rock
material suitable for disposal in the bay was prohibitive;
therefore, this option was dropped from further consideration.
2.	Before any material can be placed within the ODMDS, it must be
evaluated and shown to be acceptable for ocean disposal in
accordance with ocean dumping regulations (40 CFR 227.13).
Certain portions of the sediments proposed to be dredged from the
Miami River have been found to be unsuitable for ocean disposal.
Transport of material disposed at the ODMDS has been addressed in
the Final EIS, Site Management and Monitoring Plan and in the
reports included as Appendices B and E.
56
U.S. EPA Region 4

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STATE OF FLORIDA
DEPARTMENT OF COMMUNITY AFFAIRS
2740 CENTERVIEW DRIVE • TALLAHASSEE, FLORIDA 32399-2100
LAWTON CHILES	LINDA LOOMIS SHELLEY
Governor	Secretary
September 6, 1994
Mr. Wesley Crum
Chief, Coastal Programs Section
WOWB-WMD
U.S. Environmental Protection Agency
34 5 Courtland Street, NE
Atlanta, Georgia 30365
RE: Miami Ocean Dredged Material Disposal Site Designation
SAI: FL9009110358C
Dear Mr. Crum:
Pursuant to Presidential Executive Order 12372, Gubernatorial
Executive Order 9 3-194, the Coastal Zone Management Act, 16 U.S.C. §§
1451-1464, as amended, and the National Environmental Policy Act, 42
U.S.C. §§ 4321, 4331-4335, 4341-4347, as amended, the State of
Florida hereby acknowledges the resolution of the concerns initially
identified by the state following its 1991 review of the proposed
Miami Ocean Dredged Material Disposal Site (Miami ODMS).
Based on the enclosed comments provided by the Department of
Environmental Regulation (DEP), the state hereby withdraws its 1991
objection to the designation of the proposed Miami ODMS. As a result
of the project modifications and agreements referenced by the DEP,
the state has determined that, as modified, the proposed Miami ODMS
is consistent with the Florida Coastal Management Program.
In closing, the state wishes to express its appreciation for the
efforts made to resolve this matter.
Very truly yours,
mis Shelley
LLS/jr
CC: Virginia Wetherell, Apartment ^of Environmental Protection
Lynn Griffin, Department of Environmental Protection
Estus Whitfield, Executive Office of the Governor
EMERGENCY MANAGEMENT • HOUSING AND COMMUNITY DEVELOPMENT • RESOURCE PLANNING AND MANAGEMENT

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Department of
Environmental Protection
Lawton Chiles
Governor
Marjory Stoneman Douglas Building
3900 Commonwealth Boulevard
Tallahassee, Florida 32399-3000
Virginia B. Wetherell
Secretary
August 1, 1994
Estus Whitfield
Executive Office of the Governor
Office of Planning and Budgeting
The Capitol
Tallahassee, Florida 32399-0001
Dear Mr. Whitfield:
Re: Miami Ocean Dredged Material Disposal Site
Designation
SAI FL90091103 58C
In 1991, the state reviewed a draft environmental impact
statement for the designation of an ocean dredged material disposal
site offshore of Miami. The Departments of Environmental
Regulation and Natural Resources disagreed with this designation
under the federal consistency provisions of the Florida Coastal
Management Program. The bases of these objections were l)that the
offshore site could be used for the disposal of beach quality
material and 2)the potential for fine sediments to be transported
to reef and hard ground habitat approximately 1 nmi downcurrent of
the disposal site. The first issue has been resolved since EPA has
agreed to place certain stipulations on site designations which
reguire beach quality material to be preferentially disposed'for
beneficial uses. The second issue, however, has been the subject
of continuing discussion since 1991.
Based on its modeling results, the Corps of Engineers did
not agree that dredged material would be transported far enough to
impact nearby amenity areas. However, physical oceanographers from
DER and the University of Miami, Rosenstiel School of Marine and
Atmospheric Sciences (RSMAS), concluded that such transport was
likely during the passage of frontal eddies which periodically spin
off of the Gulf Stream and move onshore. After consulting with
RSMAS, the Corps reevaluated the probable transport of material to
be disposed at the proposed site and issued a report of its
findings. This report was reviewed and discussed at a meeting last
September between the Corps, EPA, RSMAS, DEP and NOAA's Atlantic
Oceanographic and Meterological Laboratory. The result of this
meeting was that there still was not agreement among technical
experts on the assumptions or results of the Corps' model. Because
of this, the Corps suggested that a current monitoring program be
developed instead of continuing further predictive modeling
efforts. The development of that monitoring plan has been the
subject of a number of meetings over the last several months. Most
recently, all parties met with representatives of the Port of Miami
on July 27.
Pnn'ed on reqcfcd paper

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Mr. Whitfield
August 1, 1994
Page Two
The purpose of this letter is to inform you of the status
of this matter and the agreements which have been reached to
resolve the previous objections to the designation of the offshore
disposal site. The Corps has agreed to develop and implement a
program to detect real-time current data during dredging and
disposal operations. The objective of the program is to ensure
that disposal of fine sediments will not coincide with the presence
of onshore currents. This monitoring will be a part of the EPA's
site management and monitoring plan for this site.
The Corps is consulting with NOAA and RSMAS to develop the
technical protocols for implementing this monitoring program.
These protocols will specify the conditions and time periods for
restricting disposal. These details will be included as conditions
of a modification to the Port's wetland resource permit and water
quality certification for this project. The permit modification
can be issued as soon as these protocols are submitted and approved
by the Department. To meet the dredging contract schedule demands
of the Port of Miami, the Corps and the Department have committed
to issuing this permit modification by August 31, 1994.
Based on the agreements and implementation time schedule
described above, the Department can at this time remove its
previous objection to the designation of this site. Accordingly,
we agree that the proposed designation of the Miami ODMDS is
consistent with the Department's statutory authorities in the
Florida Coastal Management Program. The EPA should be notified as
soon as possible that the state's objections to this designation
have been removed.
If there are any questions concerning these comments,
please ^ontact Lynn Griffin at 487-2231.
Sincerely,
Wetherell
Secretary
VBW/1
cc: Kirby Green, DEP
Pam McVety, DEP
Jeremy Craft, DEP
Ray Keough, Port of Miami
Richard Bonner, USACE
John Proni, NOAA/AOML
Kevin Leaman, RSMAS
Wesley Crum, EPA

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r ypp rir»	'
* UNITED STATES Dt«»ARTMENT OF COMMERCE
p»SSt.	National Oceanic and Atmospheric Administration
1),	y Office of the Chief Scientist
Washington, D.C 20230
October 4, 1990
Mr. Wesley Crum
U.S. EPA
Region IV
345 Courtland Street, NE
Atlanta, Georgia 303 65
Dear Mr. Crum:
Enclosed are comments to the Draft Environmental Impact Statement
for Designation of an Ocen Dredged Material Disposal Site Located
Offshore Miami, Florida. We hope our comments will assist you.
Thank you for giving us an opportunity to review the document.
Sincerely
Director
Ecology and Environmental
Conservation Office
Enclosure

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UNITED STATES DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
NATIONAL OCEAN SERVICE
OFFICE OF CHARTING AND GEODETIC SERVICES
ROCKVILLE. MARYLAND 208S2
SEP 2 6 1990
MEMORANDUM FOR: David Cottingham
Ecology and Environmental Conservation Office
it
The subject statement has been reviewed within the areas of
Charting and Geodetic Services' (C&GS) responsibility and
expertise and in terms of the impact of the proposed actions on
C&GS activities and projects. Since safety of navigation is one
of C&GS' primary missions, this proposal was examined with that
in mind and any other impact this activity may have on C&GS
activities and projects. The feasibility report and
environmental impact statement referenced in this DEIS for the
Miami Harbor deepening project also were reviewed.
C&GS considers the maintenance and improvement.of navigation
channels tb be an extremely important and worthwhile effort and
encourages such activities. Although it is never desirable to
place materials in the ocean in the vicinity of ports and
harbors, C&GS concurs with the designation of the referenced
offshore site as the best alternative. This site is covered on
NOS nautical charts 11465 and 11466 and will continue to be shown
as appropriate. The effects upon navigation in the v:.cinity are
expected to be of minimal consequence.
Questions about this response should be directed to the Mapping
and Charting Branch, N/CG22x2, WSC1, Room 804, Nauticc.L Charting
Division, 6001 Executive Boulevard/ NOAA, Rockville, r
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U.S. Department
of Transportation
United States
Coast Guard
Commandant
United States Coast Guard
Washington D C. 20593-0001
Staff Symbol: G-MEP-1
Phone: (202) 267-0504
16004
12 OCT 1990
Mr. Wesley B. Crura
Chief
Wetlands and Coastal Programs Section
U.S. Environmental Protection Agency
Region IV
345 Courtland Street
Atlanta, Georgia 30365
Dear Mr. Crum:
We have reviewed the Draft Environmental Impact Statement
(DEIS) for designation of an Ocean Dredged Material
Disposal Site located offshore Miami, Florida. Based on
information presently available, we have no objections to
the DEIS. However, the Coast Guard is currently
conducting a study of Florida vessel traffic to determine
whether other vessel routing measures such as traffic
separation schemes are needed. The study is scheduled to
be completed by May 1991. This will determine if further
comments are in order regarding the DEIS.
Thank you for providing the opportunity to review the DEIS
for designation of an Ocean Dredged Material Disposal Site
located offshore Miami, Florida.
Sincerely,
T. G. BALUNIS
Commander, U.S. Coast iJuard
Chief, Prevention Enforcement
and Standards Branch
Marine Environmental P-otection Division
By direction of the Coiunandant

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General Services Administration
401 West Peachtree Street
Atlanta, GA 30365
i i
g" "> /

SEP 1 1 1990
Mr. Wesley Crum, Chief
Wetlands and Coastal Programs Section
U.S. Environmental Protection Agency
345 Courtland Street, NE
Atlanta, GA 30365
Re:' Draft Environmental Impact Statement (EIS) for
Designation of an Ocean Dredged Material Disposal Site
Located Offshore Miami, Florida
Dear Mr. Crum:
The Safety and Environmental Management Branch (4PMS) has
reviewed the submitted draft EIS. The proposed actions will not
affect General Services Administration (GSA) operations in the
area. GSA has no comment on the submitted draft.
If you have questions, please contact Gerald Hust, Chief, Safety
and Environmental Management Branch on 331-3125.
Thomas E. Davis
Assistant Regional Administrator
Public Buildings Service

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mENi-Q.
*Vlt)E*fcV
U.S. DEPARTMENT OF HOUSING AND URBAN DEVELOPMENT
ATLANTA REGIONAL OFFICE, REGION IV
Richard B. RuGsell Federal Building
75 Spring Street, S.W.
Atlanta, Georgia 303.03-3BB8
September 14, 1990
Mr. Heinz Mueller
EIS Project Officer
United States Environmental
Protection Agency, Region IV
345 Courtland Street, N.E.
Atlanta, Georgia 30365
Dear Mr. Mueller:
This refers to your transmittal of the Draft Environmental
Impact Statement (DEIS) for Designation of An Ocean Dredged
Material Disposal Site located offshore Miami, Florida.
Our review indicates there will be no significant adverse
impact on any HUD programs as a result of this action.
Thank you for the opportunity to review and comment on the
proposed project.
Very sincerely yours,
Regional Environmental Officer
Office of Community Planning
and Development

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DEPARTMENT Of THE AIR FORG.
REGIONAL CIVIL ENGINEER, EASTERN REGION (HQ AFESC)
77 FORSYTH STREET, SW, SUrTE 291
ATLANTA, GEORGIA 30335-6801
REPLY TO
ATTN OF:
ROV
5 September 1990
Air Force Review of the Draft Environmental Impact Statement for Designation
subject: ^ ocean Dredged Material Disposal Site (ODKDS) Located Offshore Miami, FL
TO: U.S.EPA Region IV
Attn: Mr Wesley Crum, Chief
Wetlands and Coastal Programs
Section
345 Courtland Street NE
Atlanta GA 30365
As the Air Force single point of contact for environmental matters in the
eastern United States, we have reviewed the Draft Environmental Impact
Statement (DEIS) for the ODMDS and find that implementation of the proposal
will not affect Air Force operations in the site area. Thank you for the
opportunity to review this DEIS. Our point of contact is Mr George Dodson at
^phone number 331-5313/6776
aNTOONY aTrWYSMm XIII, CaV&<
Deputy Chief
USAF
1 Atch
DEIS
Environmental Planning Division
cc: HQ USAF/LEEV wo Atch

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a

FLORIDA DEPARTMENT OF STATE
Jim Smith
Secretary of State
DIVISION OF HISTORICAL RESOURCES
R.A. Gray Building
500 South Bronough
Tallahassee, Florida 32399-0250
Director's Office	Telecopier Number (FAX)
(904) 488-1480
(904) 488-3353
September 13, 1990
Wesley Crum, Chief
Wetlands and Coastal Program
Section
U. S. Environmental Protection
Agency
Region IV
345 Courtland Street, N.E.
Atlanta, Georgia 30365
In Reply Refer To:
Susan M. Herring
Historic Sites Specialist
(904) 487-2333
Project File No. 902710
RE: Cultural Resource Assessment Request
Draft Environmental Impact Statement for Designation of an
Ocean Dredged Material Disposal Site Located Offshore
Mi ami, F1orida
Dade County, Florida
Dear Mr. Crum:
In accordance with the procedures contained in 36 C.F.R., Part
800 ("Protection of Historic Properties"), we have reviewed the
above referenced project(s) for possible impact to archaeological
and historical sites or properties listed, or eligible for
listing, in the National Register of Historic Places. The
authority for this procedure is tfye National Historic
Preservation Act of 1966 (Public Law 89-665), as amended.
We have reviewed the above referenced Environmental Impact
Statement and find it to be complete and sufficient. Thus, it is
the opinion of this agency that project activities will have
noeffect on any archaeological or historic sites or properties
listed, or eligible for listing, in the National Register of
Historic Places, or otherwise of national, state, regional, or
local significance. The project is consistent with the historic
preservation aspects of Florida's coastal zone program, and may
proceed without further involvement with this agency.

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Mr. Crum
September 13, 1990
Page 2
If you have any questions concerning our comments, please do not
hesitate to contact us. Your interest in protecting Florida's
archaeological and historic resources is appreciated.
Sincerely,

—-^JSeorge W. Percy, Director
pDivision of Historical Resources
and
State Historic Preservation Officer
GWP/smh

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UNITED SI. .S DEPARTMENT OF COMMERCE
National Oceanic and Atmospheric Administration
NATIONAL MARINE FISHERIES SERVICE
Southeast Regional Office
9721 Executive Center Drive N.
St. Petersburg, FL 3 3702
October 14, 1994
F/SE013:JEB
Mr. Wesley B. Crum
Chief, Coastal Programs Section
Region IV
Environmental Protection Agency
345 Courtland Street
Atlanta, GA 30365
Dear Mr. Crum:
This responds to your request for consultation on the proposed
designation of the Miami Ocean Dredged Material Disposal Site
(ODMDS) located approximately 4 nautical miles offshore east-
southeast of Government Cut at the entrance to Miami Harbor, Dade
County, Florida. A biological assessment (BA), in the form of a
draft environmental impact statement, was transmitted to us
pursuant to Section 7 of the Endangered Species Act of 1973
We have review the BA and have determined that populations of
endangered/threatened species under our purview would not be
adversely affected by the designation and use of the proposed
site, centered at 25*45,00,,N and 80°03122HW, as an ODMDS. Also,
we believe the Site Management and Monitoring Plan, summarized in
the draft State of Florida permit conditions for the Port of
Miami Water Quality Permit, is appropriiate for this project and
contributes to our determination.
This concludes consultation responsibilities under Section 7 of
the ESA. However, consultation should be reinitiated if new
information reveals impacts of the identified activity that may
affect listed species or their critical habitat, a new species is
listed, the identified activity is subsequently modified, or
critical habitat is determined that may be affected by the
proposed activity.
If you have any questions please'contact Jeffrey Brown, Fishery
Biologist, at (813) 570-5312.
(ESA)
Sincerely
Andrew J. Kemmerer
Regional Director
cc: F/PR2
F/SER2

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(r<
United States Department of the Interior
OFFICE OF THE SECRETARY
Office of Environmental Affairs
Richard B. Russell Federal Building
75 Spring Street, S.W.
Atlanta, Georgia 30303
OCT 1 8 1990
ER 90/822
Mr. Wesley Crum
Wetlands and Goastal Program Section
U.S. Environmental Protection Agency
345 Courtland Street, NE.
Atlanta, Georgia 30365
Dear Mr. Crum:
The Department of the Interior (Department) has reviewed your Draft
Environmental Impact Statement for Designation of an Ocean Dredged Material
Disposal Site located offshore of Miami, Florida, and have the following
comments.
The F1sh and Wildlife Service has recommended that the dredged material
disposal site not be located closer than 1/2 mile from the nearest known live
coral reef. Apparently, the proposed site is in very deep water and about
1 1/2 miles from any reef. The biological sampling 1n the deepwater site
(400 to 800 feet) Indicates the site will recover rapidly, since no hardbottom
was found in the disposal area.
Your study of the proposed site for preparation of this draft statement 1s
comprehensive and well done. The statement could be improved if it had
appended results of monitoring past dumping for Miami Harbor in the previously
used site. This would have helped indicate whether there would be any
problems expected for resources of concern to the Department. However, the
depth and distance away from priority resources are sufficient to remove any
concerns from the Department.
Thank you for the opportunity to comment on this statement.
Sincerely yours,
James H. Lee
Regional Environmental Officer

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Final EIS Miami ODMDS
August 1995
Responses
State of Florida
Department of Community Affairs
September 6, 1994
United States Department of Commerce
Office of the Chief Scientist
United States Department of Commerce
National Ocean Service
United States Coast Guard
General Services Administration
U.S. Department of Housing and Urban Development
Department of the Air Force
Florida Department of State
Division of Historical Resources
United States Department of Commerce
National Marine Fisheries Service
Comments -in these letters are appreciated, but do not warrant a
response.
69
U.S. EPA Region 4

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United States Department of the Interior
OFFICE OF THE SECRETARY
Office of Environmental Affairs
Richard B. Russell Federal Building
75 Spring Street, S.W.
Atlanta, Georgia 30303
November 27, 1990
ER-90/822
Mr. Wesley Crum
Wetlands and Coastal Program Section
U.S. Environmental Protection Agency
345 Court land St., NE
Atlanta, GA '30365
Dear Mr. Crum:
On October 18, 1990, we submitted comments concerning the Draft
Environmental Impact Statement (DEIS) for Designation of an Ocean
Dredged Material Disposal Site located offshore of Miami, FL.
Since that time we have received additional information and offer
the following supplemental comments.
We are concerned that the site may not be suitable for the disposal
of very fine sized, highly polluted sediment obtained from dredging
the Miami River and harbor. During events of strong onshore
breezes upwelling events occur that could possibly entrain the
deposited sediments and transport the sediments onto the reef
platform, potentially having an adverse impact to the coral reefs
of Biscayne National Park, and distribute them along the Florida
coastal platform.
The DEIS addresses the environmental impacts of the disposal site
for dredged material from the Miami River and harbor, but does not
discuss the types of material to be dredged or methods of transport
to the disposal site. Of concern is the design and method of
operation of the barges presently used in dredging operations.
Also of concern is the dewatering of the dredged material during
transit to the disposal site. Any dewatering should occur only in
the river behind the sediment screens or over the disposal site.
Thank you for the opportunity to make these additional comments.
Sincerely,
James H. Lee
Regional Environmental Officer

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Final EIS Miami ODMDS
AugBt 1995
Responses
United States Department of the Interior
Office of the Secretary
Letter dated October 18, 1990
1. No additional information regarding disposal at the previous
disposal site is available.
Letter dated November 27, 1990
1.	Before any material can be placed within the ODMDS, it must be
evaluated and shown to be acceptable for ocean disposal in
accordance with ocean dumping regulations (40 CFR 227.13).
Certain portions of the sediments proposed to be dredged from the
Miami River have been found to be unsuitable for ocean disposal.
Transport of material disposed at the ODMDS has been addressed in
the Final EIS, Site Management and Monitoring Plan and in the
reports included as Appendices B and E.
2.	Discussion on project specific types of materials to be dredged,
methods of transport and possible dewatering of dredged material
will be done on an individual project-by-project basis.
72
U.S. EPA Region 4

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Miami Group
Post Office Box 43-0741 • South Miami, Florida 33243-0741
Mr. Wesley Crum, Chief
Wetlands and Coastal Programs Sections
U.S. Environmental Protection Agency
Region IV
345 Courtland Street, NE
Atlanta Georgia 30365	October 17th, 1990
Dear Mr. Crum,
We are enclosing comments and an assessment done on the Environmental Im-
pact Statement of an Ocean Dredged Material Disposal Site Located Offshore Miami,
Florida, by Tcro Davenport, Ph.D.. The Sierra Club-Conservation Committee is for-
tunate to have Dr. Davenport as a member because of his expertise in this area.
His scientific background is in Biochemistry, Oceanography and Plant Physiology.
His training includes ecological surveys of benthic communities in the Gulf of
Mexico and he is an avid diver who is familiar with the local benthic communities,
sediments and currents as well.
The Conservation Committee feels, after a report on his review of the E.I.S.,
that this study is indeed misleading, erroneous and inadequate. Of particular im-
portance here is the proximity to valuable coral reef habitat, and the fact that
Miami River sediments, which have been considered to have many hazardous "hot
spots", have been proposed for disposal at this site. This assessment, however,
invalidates this site for any sediment disposal due to the following comments and
subsequent assessment by Dr. Davenport.
The model itself is inadequate, first of all, in that the edge of the Gulf-
stream fluctuates westward much more than stated. Also, the large macro-events
studied up and down the Florida coast and across to the Bahamas, have little or
nothing to do with this very specific coastal area. The stations are too far dis-
placed and not applicable to near-shore conditions of drag,;eddys, etc.. There
was also only one area tested shoreward of the proposed sits — in 300' of wa-
ter. This is not relevant to the areas of concern, namely th? coral reef commun-
ity, and none of those significant organisms were even tested. Furthermore, the
composition of the sediments were said at the beginning of tin? E.I.S. to be 90%
clay, which is closer to the actual composition for maintenance work, yet the
numbers were all based on 10% clay. Finally, current velocities were averaged
from the surface to the bottom which cuts the stronger, more significant surface
currents in half, thereby doubling the distance of sediment carrying to the reef.
In every example, the U.S. Army Corps gives the best case scenario, mixed with
statistically slanted figures to arrive at the conclusion that they want.
The living reef off South Florida, is currently showing heavy signs of stress
and siltation, especially north of the Government Cut area. W= are now on the
verge of losing this sensitive ecosystem. Therefore, we strongly urge you to con-
sider these comments and assessment of the E.I.S. and reject this site for dispos-
al. It is our belief that £f sediments are non-hazardous, that a land-based or an
ocean siting much further out be proposed. Either way, this study does little to-
wards a representative or conclusive plan.
&
Q.
S.	We are also forwarding copies of other studies which support these findings
T3
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SIERRA
CLUB


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SIERRA
CLUB
Miami Group
Post Office Box 43-0741 • South Miami, Florida 33243-0741
and hope that they can assist you in you responsible evaluation.
cc; John Renfrow, Director D.E.R.M
Fred Calder, Fl. Dept.fof Environmental Regulation
Scott Benyon, Fl. Deipt. of Environmental Regulation
Dick Townsend, Tropical Audubon Society-Coastal Committee
Lloyd Miller, Isaac Walton League
Susan Berryman, Wilderness Society
Bonnie Barnes, Friends of the Oleta River
Alex Atone, American Littoral Society
0)
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Sincerely.
Lee F. Bnerson, Sierra Club
Conservation Committee


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ASSESSMENT OF AN ENVIRONMENTAL IMPACT STATEMENT FOR
DESIGNATION OF AN OCEAN DREDGED MATERIAL DISPOSAL SITE
LOCATED OFFSHORE MIAMI, FLORIDA
A draft version o£ an "Environmental Impact statement
for Designation of an Ocean Dredged Material Dumping Site
Located Offshore Miami, Florida" has been submitted to the
U.S. Environmental Protection Agency by the U.S. Army Corps
of Engineers. In behalf of the Sierra Club of Miami, I had
the opportunity to read this document in Its entirety. It
consists of a 39-page summary; Appendix A, which is a
detailed report of the results of a January, 1986
envirohmental survey of the physical, chemical and
biological characteristics of the bottom and waters within
and adjacent to the disposal site; and Appendix B, which is
an April 1989 evaluation of a computer-simulated model of
dispersal characteristics of dumped dredge material.
The overall conclusion of this document is that the
environmental impact of periodic disposal of dredged
material, obtained from Miami Harbor maintenance and
Improvement projects, at the proposed, permanent, dump site
will be minimal. It is my opinion that this conclusion Is
based on Inadequate, non-existent, and misleading
information. Several important statements are inconsistent
with information presented in other sections of the
document. Moreover, a number of important considerations,
especially regarding the potential Impact on adjacent
Inshore coral reefs and potential environmentally-3ensltive
areas located on the continental shelf, have been ignored or
given cursory attention in the report. I am also concerned
about the lack of a proposal to monitor the impact of
suspended sediment drifting into these areas and the lack of
remedies which would be considered in the event that the
physiology of organisms residing on the shelf are adversely
affected. Some of these concerns are indicated below.
Biological Considerations
The Sierra Club's primary concern is the potentially
adverse environmental impact/ of man's activities on the
sensitive biology of ecologically important organisms.
Appendix A describes the diverse range of benthic organisms
residing within the dump site and in areas of similar bottom
characteristics north and south of the site. It is assumed
that extensive disruption of the biota in the dump site will
occur. I accept the conclusion that the dump site Itself is
not a particularly unique area requiring preservation.
Moreover, it is correctly assumed that, barring any
toxological problems associated with the spoils, new
communities will form in the disturbed areas.
Only one sampling was conducted shoreward of the site
at station M-5. This station is located only 0.5 miles west
of the proposed dump site in 300 ft of water. it is
characterized by a bottom structure and biota that are

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substantially different from those found at the site and at
stations north and south of the site. No further attempt
was made to document the locations, extent, or present
condition o£ reef complexes or other communities typical of
the shoreward continental shelf which would be adversely
affected by periodic drift of sllty clay material into these
areas. No information on the possible impact of chronic
sediment deposition on sediment and filter feeding organisms
residing in the shoreward areas are mentioned. Moreover,
there is no plan to monitor the detrimental or beneficial
Impact on these environmentally sensitive areas If dumping
.at the proposed site is approved
There Is a substantial body of literature describing
the detrimental effects of fine, suspended sediment on coral
and other sediment and filter feeders. Portions of only a
few of the available articles are attached. Considering
that sensitive reef complexes extend north and south of a
location 1.3 miles west of the dump site, the potential for
massive destruction of this environment is a real
possibility. Studies of the effects of dredge spoils when
constructing a harbor in Dubai have shown that reefs located
2 miles from a similar dump site with less ocean current
pressure than experienced In Miami were totally destroyed
(Dr. T. Bright, personal communication).
Sediment-carrying Current Considerations
Contrary to the statement in paragraph (p) 3.08, the
average western edge of the Florida Current is located one
mile shoreward of the proposed dump site and meanders 2.6
miles east or west depending upon a number of factors
discussed in the report. This places the dump site in a
highly dynamic area in which cylonic eddy currents occur.
These currents at the dump site and surrounding areas are
unpredictable in both vector and velocity as they are swept
northward by the Florida Current.
The model of sediment deposition (Appendix B) consists
of two parts: 1, the potential to displace fine suspended
particles to adjacent environmentally sensitive reefs
following each dumping event, 2, the potential to move the
settled mound during storm Conditions. I cannot argue with
the methodologies used to model mound movement on the
bottom. It is not likely to be substantially disturbed once
in place. The model presenting a hypothetical, worst-case
scenario of shoreward-moving currents which might carry clay
particles to reef areas concerns me greatly. Most of the
information presented has little bearing on the question of
local eddy currents which would impact the environmentally
sensitive areas along the continental shelf. Several
unrealistic assumptions are made in formulating the model.
1. Background data providing current direction and
velocities at one sampling station in the area were obtained
from only one 1977 study. Although the current direction
was toward the NW, it was erroneously assumed that the

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current is always In that direction and would thus displace
the location of sensitive reefs 3 mile from the dump site
rather than 1.3 when eddy currents sweep the plume
shoreward. More importantly, depth averaged velocities were
used. This not realistic since the highest velocities occur
in the upper half of the water column. Velocities at and
near the bottom approach zero, thus reducing the velocities
to be considered by up to one half.
2. A model using only 10% clay material was considered. I
found no results In the text regarding an evaluation of 90%
clay as Is Indicated in the summary. It Is my understanding
that most spoils would contain greater than 10% clay and
approach 90% in maintenance dredgings. The 10% model
clearly demonstrates that the turbid plume would travel 3
miles under the conditions specified. Considering the
potential for variable current vectors, the probable
loubllng of current velocities In the upper half of the
•rater column than those modeled, and the likelihood of
ilgher amounts of suspended particles contributing to a
3edlment plume, I would argue that the potential for serious
letrimental Impact Is far greater than is suggested by this
Inadequate study.
Conclusion
In the Interest of protecting the quality of our near
shore environment, I urge the EPA to.consider the lack of
meaningful information presented in this study. Designation
of a disposal site should be postponed until realistic
surveys of eddy currents, surveys of floral and fuanal
communities on the continental shelf adjacent to the site,
and a realistic assessment of the probable Impact of
recurring plumes of fine sediment on the local filter and
sediment feeders can be addressed. It should also include
means of monitoring sedimentation rates in these
environmentally sensitive areas prior to and after the start
of dumping.
Recommendat1ons
'	1. Consider a dumping*site several miles further into
the Florida Current, such as near Station C (see page 24 -26
of Appendix B) so that the possibility of encountering eddy
^currents is reduced to nil.
2. Consider deposition of spoils directly on the
bottom, beyond the influence of upper level currents. This
could be accomplished by either a closed-bucket system
lowered into place or a shunting flume system mounted on an
anchored barge as is currently practiced for dumping drill
muds from off-shore drilling platforms in the Gulf of
Mexico.

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Both possibilities would resolve numerous problems associated with dumping
of spoils along the coasts of Florida.
T.L Davenport, Ph.D
Sierra Club, Conservation Committee

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Final EIS Miami ODMDS
August 1995
Responses
Sierra Club Miami Group
The general concerns expressed by the Miami Group in their letter
dated October 17th, 1990 will be addressed by responding to the
specific comments of their attached assessment by Dr. Tom Davenport.
1.	Station M-5 was sampled as part of the benthic infaunal
characterization. It is well documented that this type of
community changes substantially as one moves shoreward and the
corresponding depths shallow and bottom sediments change. The one
station sampled (M-5) confirms that such a change occurs very near
the proposed site.
2.	The Site-Management and Monitoring Plan has addressed this issue.
See Appendix C.
3	. The Site Management and Monitoring Plan has addressed this
concern. See Appendix C.
4	& 5. Additional field studies and modeling have addressed these
concerns (Appendices E, F, and G). The model was applied for
a strong easterly current without a northern current component
and using ambient currents provided by the Rosenstiel School
of Marine and Atmospheric Sciences at the University of Miami.
The results of this study are included in this EIS in Appendix
E. In addition, management requirements have been implemented
as -described in the Site Management and Monitoring Plan
(Appendix C) to restrict disposal during specific current
events.
6.	Additional modelling was conducted with varying dredged material
characteristics. Results are presented in Appendices B and E.
7.	Use of a site several miles further offshore is not economically
feasible.
8.	Deposition of dredged material directly on the bottom is not
feasible at the depths at the site.
79
U S. EPA Region 4

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Final EIS Miami ODMDS	1995
8.00 REFERENCES
This section contains all references cited in the body of this
document and in appendices.
Aska, D.Y. and D.W. Pybas. 1983. Atlas of artificial reefs
in Florida. Sea Grant Advisory Bulletin MAP-30.
Florida Sea Grant.
Bielsa, L.M., W.H. Murdich, and R.F. Labisky. 1983. Species
profiles: life histories and environmental requirements
of coastal fishes and invertebrates (south Florida) -
pink shrimp. U.S. Fish and Wildlife Service. FWS/OBS -
82/11.17.
Boesch, D.F. 1977. A summary and analysis of environmental
information on the Continental Shelf and Blake Plateau
from Cape Hatteras to Cape Canaveral. Bureau of Land
Management.
Brooks, D.A.. 1975. Wind-forced Continental Shelf waves in
the Florida Current. Ph.D. dissertation, University of
Miami, Florida.
Bureau of Commercial Fisheries. 1962. Exploratory fishing
for shrimp, scallops, and small snappers in the south
Atlantic. M/V Silver Bay Cruise 34. U.S. Fish and
Wildlife Service, Commercial Fisheries Review 24: 29-
31.
Burks, S.A. and R.M. Engler. 1978. Water quality impacts of
aquatic dredged material disposal (laboratory inves-
tigations) . U.S. Army Waterways Experiment Station.
Technical report DS-78-4.
CH2M Hill, Inc. 1985. Application for discharge modification
for the Virginia Key sewage treatment outfall; General
information and basic data requirements. CH2M Hill
Southeast, Deerfield Beach, Florida.
Dunaway, V. and A. Pflueger. No date. Florida sportsman
fishing charts, No. 701; Greater Miami. Florida
Sportsman Magazine, Miami, Florida.
80
U S. EPA Region 4

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Final EIS Miami ODMDS
August 1993
REFERENCES (continued)
Florida Sea Grant. 1979. Recreational use reefs in Florida;
artificial and natural. Marine Advisory Program.
Map-9.
Heald, E.J. 1970. Fishery Resources Atlas I; New York to
Florida. University of Miami, Sea Grant Technical
Bulletin No. 3.
Hirsch, N.D., L.H. DiSalvo, and R. Peddicord. 1978. Effects
of dredging and disposal on aquatic organisms. U.S.
Array Waterways Experiment Station. Technical report
DS-78-5.
Kester, D.R., B.H. Ketchum, I.W. Duedall, and P.K. Park
(eds.). 1983. Wastes in the ocean; Volume 2, Dredged-
material disposal in the ocean. John Wiley & Sons, Inc.
Kutkuhn, J.H. 1962. Gulf of Mexico commercial shrimp
populations; trends and characteristics, 1956-59. U.S.
Fish and Wildlife Service, Fisheries Bulletin 62: 343-
402 .
Lee, T.N., I. Brooks, and W. Duing. 1977. The Florida
Current; its structure and variability. Technical
Report No. 77033. University of Miami, Rosenstiel
School of Marine and Atmospheric Sciences.
Lee, T.N. and D.A. Mayer. 1977. Low-frequency current
variability and spin-off eddies along the Continental Shelf
off southeast Florida. Jour. Marine Research, 35(1): 193-
220 .
Lee, T.N. and C.N.K. Mooers. 1977. Near-bottom temperature
and current variability over the Miami Slope and
Terrace. Bulletin of Marine Science, 27(4): 758-775.
Marble, R.W. and L.V. Mowell. 1971. Potential effects of an
offshore nuclear power plant. Volume II, Water
Pollution Control Research Series, No. 16130 FGI.
Metropolitan Dade County Department of Environmental Resources
Management. No date. Artificial reef program.
Metropolitan Dade County.
81
U S EPA Region A

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Final EIS Miami ODMDS
Augct 1995
REFERENCES (continued)
National Oceanic and Atmospheric Administration (NOAA). 1985.
Tide tables; high and low water predictions. East
coast of North and South America, including Greenland.
NOAA, National Ocean Service.
Pequegnat, W.E., L.H. Pequegnat, B.M. James, E.A. Kennedy,
R.R. Fay, and A.D. Fredericks. 1981. Procedural guide
for designation surveys of ocean dredged material
disposal sites. Final report by TerEco Corporation.
U.S. Army Waterways Experiment Station. Technical
report EL-81-1.
Saucier, R.T-., C.C. Calhoun, R.M. Engler, T.R. Patin, and H.K.
Smith. 1978. Executive overview and detailed summary;
dredged material research program. U.S. Army Waterways
Experiment Station. Technical report DS-78-22.
Smith, F.G.W., R.H. Williams, and C.C. Davis. 1950
Ecological survey of subtropical waters adjacent to
Miami. Ecology, 31(1): 119-146.
Scheffner, Norman W. and Abhimanyu Swain. 1990. Evaluation of the
Dispersion Characteristics of the Miami and Fort Pierce Dredged
Material Disposal Sites. Coastal Engineering Research Center.
U.S. Army.Coastal Engineering Research Center. 1977 Shore Protection
Manual.
U.S. Army Corps of Engineers. 1982 Beach erosion control and
hurricane protection study for Dade County, Florida, North of Haulover
Beach Park Survey Report and EIS Supplement.
U.S. Army Engineer Waterways Experiment Station. 197 6 Miscellaneous
Paper D-76-17 Ecological Evaluation of Proposed Discharge of
Dredged or Fill Material into Navigable Waters
U.S. Department of the Interior. 1977. Draft environmental
impact statement, Volume I. Proposed 1977 Outer
Continental Shelf oil and gas lease sale; South
Atlantic OCS Sale No. 43. Bureau of Land Management.
U.S. Environmental Protection Agency (EPA). 1973. Ocean
outfalls and other methods of treated wastewater
disposal in southeast Florida. Final Environmental
Impact Statement. USEPA; Region IV, Atlanta.
82
U.S EPA Region 4

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Final EIS Miami QDMDS
August 1995
REFERENCES (continued)
U.S. Environmental Protection Agency. 1983. Environmental
Impact Statement (EIS) for Savannah, Ga., Charleston, S.C.
and Wilmington, NC ocean dredged material disposal
sites. USEPA, Criteria and Standards Division,
Washington, D.C.
U.S. Fish and Wildlife Service. 1980. Atlantic Coast
Ecological Inventory. Miami, Florida.
Voss, G.L. and N.A. Voss. 1955. An ecological survey of
Soldier Key, Biscayne Bay, Florida. Bulletin of Marine
Science of the Gulf and Caribbean, 5(3): 203-229.
Warzeski, E.R. 1976. Storm sedimentation in the Biscayne Bay
region. Biscayne Bay Symposium 1: April 2-3,
197 6, University of Miami. Sea Grant Special Report
No. 5.
Windom, H.L. 197 6. Environmental aspects of dredging in the
coastal zone. CRC Critical Reviews in Environmental
Control. Vol. 6, No. 2. CRC Press, Cleveland, Ohio.
83
U.S EPA Region 4

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APPENDIX A
Environmental Survey in the Vicinity of
An Ocean Dredged
Material Disposal Site
Miami Harbor, Florida
December, 1985
CONSERVATION CONSULTANTS, INC.
Environmental Scientists and Engineers
Post Office Box 35
Palmetto, Florida 33561

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APPENDIX A
CONTENTS
Page
A. 1	Methods		A-l
A.1.1	Location of Study Area and Sampling
Location		A-l
A.1.2	Physical and Geological Characteristics		A-l
A. 1.2.1	Bathymetry		A-l
A. 1.2.2	Hydrography		A-6
A. 1.2.3	Granulometry		A-6
A. 1.3	Chemical Characteristics		A-8
A. 1.3.1	Water Quality		A-8
A. 1.3.2	Sediment Chemistry		A-8
A. 1.4	Biological Characteristics		A-9
A. 1.4.1	Benthic Macroinvertebrates		A-9
A. 1.4. 2	Meiofauna		A-10
A. 1.4. 3	Macroepifauna		A-11
A. 1.4.4	Tissue Analyses		A-11
A. 2	Results and Discussion		A-12
A.2.1	Physical and Geological Characteristics		A-12
A. 2.1.1	Bathymetry		A-12
A. 2,1.2	Hydrography		A-12
A. 2.1.3	Granulometry				A-19
A.2. 2	Chemical Characteristics			A-23
A.2. 2.1	Water Quality	'		A-2 3
A.2.2.2	Sediment Chemistry		A-2 4
A.2.3	Biological Characteristics		A-3 0
A.2.3.1	Benthic Macroinvertebrates		A-30
A. 2.3.2	Meiofauna				A-41
A. 2.3.3	Macroepifauna		A-4 3
A.2.3.4	Tissue Analyses			A-49
- i

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APPENDIX A
LIST OF FIGURES
Eaaa
Figure A-l
Figure A-2
Figure A-3
General Location Map
Ocean Dredged Material Disposal Site
Miami, Florida 	 a-2
Sampling Station Locations
Ocean Dredged Material Disposal Site
Miami, Florida 		 a-3
Bathymetric Map
Ocean Dredged Material Disposal Site
Miani, Florida 	 A-13
Figure A-4
Cluster Dendogram Shoving Station
Associations Based on Benthic Macro-
invertebrate Similarity as Determined
Using the Morisita Index
Ocean Dredged Material Disposal Site
Miami, Florida 	
A-38
Figure A-5
Cluster Dendogram Showing Station
Associations Based on Benthic Macro-
invertebrate Similarity as Determined
Using the Bray-Curtis Index
Ocean Dredged Material Disposal Site
Miami, Florida 	
A-39
Figure A-6
Cluster Dendogram Shoving Station
Associations Based on Benthic Macro-
invertebrate Similarity as Determined
By Simple Matching (Presence/Absence)
Ocean Dredged Material Disposal Site
Miami, Florida 	
A-40
- ii -

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APPENDIX A
LIST OF TABLES
Fag?
Table A-l Station Locations and Types of Samples
Collected from the Miami Harbor ODMDS
Study Area 	 a-4
Table A-2 Methods of Chemical Analysis of Water,
Sediment, and Tissue Samples 	 a-7
Table A-3 Water Depths at Stations in the Miami
Harbor ODMDS Study Area 	 A-14
Table A-4 Temperature, Salinity, and Dissolved
Oxygen Profiles Taken at Stations in the
Miami Harbor ODMDS Vicinity;
January 29, 1986 	 A-15
Table A-5 Total Suspended Solids Concentrations
and Turbidity Levels Measured at Stations
in the Miami Harbor ODMDS Vicinity 	 A-20
Table A-6 Grain Size Distribution of Sediments
Collected from the Miami Harbor ODMDS
Vicinity 	 A-21
Table A-7 Granulometric Characteristics of Sediments
Collected from the Miami Harbor ODMDS
vicinity 	 A-22
Table A-8 Results of Chemical Analyses of Near
Surface Waters Collected from the Miami
Harbor ODMDS Vicinity 	 A-2 5
Table A-9 Results of Chemical Analyses of Near
Bottom Waters Collected from the Miami
Harbor ODMDS Vicinity 	 A-2 6
Table A-10 Results of Chemical Analyses of Sediments
Collected from the Miami Harbor ODMDS
Vicinity 	 A-27
Table A-ll Mean Abundance and Diversity of Benthic
Macroinvertebrates Collected from
Stations in the Miami Harbor ODMDS
Vicinity	 A-31
Table A-12 Benthic Macroinvertebrate Composition;
By Major Group 	 A-33
- iii -

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APPENDIX A
LIST OF TABLES
(Continued)
Eass
Table A-13 Benthie Macroinvertebrate Taxa of the
Miami Harbor ODMDS Vicinity, Ranked in
Order of Abundance 	 A-34
Table A-14 Trophic Classification of Major Benthic
Macroinvertebrate Taxa Collected from
the Miami Harbor Interim ODMDS Vicinity .. A-3 6
Table A-15 Meiofauna Collected from Stations in
the Miami Harbor ODMDS Vicinity 	 A-4 2
Table A-16 Fish Collected by Trawl from the Miami
Harbor ODMDS Vicinity 	 A-44
Table A-17 Abundance and Diversity of Fish
Collected at Trawl Stations in the Miami
Harbor ODMDS Vicinity 	 A-46
Table A-18 Epibenthic Invertebrates Collected by
Travl from the Miami Harbor ODMDS
Vicinity 	 A-48
Table A-19 Total Wet Weight Biomass of Fish
and Epibenthic Invertebrates- Collected
by Trawl from Stations in the Miami
Harbor ODMDS Vicinity		 A-50
Table A-20 Results of Chemical Analyses of Fish
Tissues Collected from the Miami Harbor
ODMDS Vicinity 	 A-51
Table A-21 Results of Chemical Analyses of Epibenthic
Invertebrate Tissues Collected from the
Miami Harbor ODMDS Vicinity 	 A-54
- iv -

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APPENDIX A
This report details the methods and results of an environ-
mental survey of the Miami Harbor interim Ocean Dredged
Material Disposal Site (ODMDS) vicinity. This survey was
conducted by Conservation Consultants, Inc. (CCI) on
January 22 through 29, 1986.
A. 1 METHODS
A. 1.1 Location of Study Area and Sampling Locations
The Miami Harbor interim ODMDS is a one square nautical mile
area with the following corner coordinates:
(NW) 25 * 45'30" N	(HE) 25*45'30" N
The general location of the ODMDS is shown in Figure A-l.
Nine sampling stations were located in the Miami Harbor study
area. The relationship of these stations to the designated
interim ODMDS is shown in Figure A-2. The location and the
type of sampling conducted at each of these stations is given
in Table A-l.
A.1.2 Physical and Geological Characteristics
A.1.2.1 Bathymetry
A bathymetric survey was conducted along ten transects in the
Miami Harbor ODMDS study area. Each of these transects was
80* 03154" W
80* 02'50" W
(SW) 25*44130" N
80*03154" W
(SE) 25'44130" N
80*02150" W
A-l

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25*50'
Oov*rnm«iit Cut
Vlrflnla K«y
OOMDS
25*40'
FIQURC A-1
GENERAL LOCATION MAP
Oc—ii QrtdEafr 1—tfW Dtopy|l W# Miami, Florida

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SAMPLING STATION LOCATIONS
Ocean Dredged Material Dlepoaal Site Miami, Florida
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T*bl* *"1-	«m TypM of sapl. oollKUd tzm th.
Kit! Harbor OOC6 Study Ar«*.
Station No. Latitude (N) Longitude (W) Seniles Oollected
tt-1
25*47'00"
80*03*22"
Sediments
Benthlc Invertebrates
Water Quality
Trawl
M-2
25*46'30"
80*03'22"
Sediments
Benthic Invertebrates
M-3
25*46'00"
80*03'22"
Sediments
Benthic Invertebrates
Hater Quality
M-4
25*45«i5"
80*03'22"
Sediments
Benthic Invertebrates
Water Quality
Trawl
M-5
25*45,00,,
80*04'26"
Sedimenta
Benthic Invertebrates
Water Quality
M-6
25*45'00"
80*03*46"
Sediments
Benthic Invertebrates
Water Quality
Trawl
M-7
25*45'00"
•0*02'58"
Sediments
Benthic Invertebrates
Water Quality
M-8
25*44'00"
80*03'22"
Sediment!;
Benthic Invertebrates
ttatar Quality
M-9
25*43'00"
80*03'22"
Sediments
Benthic Invertebrates
Trawl
A-4

-------
approximately two nautical miles (3.7 km) in length and
oriented in an east-west direction. Transects were estab-
lished to run between 80*02'18" and 80'04'26" west longitude
at the following latitudes.
M-Tl, M-T2, and M-T3 were located approximately 1.5, 1.0 and
0.5 nautical miles north of the ODMDS, respectively. Transect
M-Tl crossed sampling Station M-l, while M-T2 crossed Station
M-2 and M-T3 traversed Station M-3. Transects M-T9 and M-T10
were established about 0.5 and 1.5 nautical miles south of the
disposal site, respectively. Transect M-T9 crossed sampling
Station M-8, and M-T10 crossed Station M-9. The remaining six
transects traversed the ODMDS. Transect M-T6 crossed Stations
M-5, M-6, and M-7 and M-T5 crossed Station M-4. Each of the
ten transects extended approximately 0.5 nautical mile (0.9
km) beyond both the east and west boundaries of the ODMDS.
Depths were measured using a Gifft 4000T receiver/recorder
linked to a 3.5 KHz transducer which was mounted in a towfish
and trailed from the survey vessel.
Transect No
Latitude fN)
M-Tl
M-T2
M-T3
M-T4
M-T5
M-T6
M-T7
M-T8
M-T9
M-T10
25*47'00"
25*46* 30"
25*46'00"
25* 4 5'30"
25*45'15"
25*45'00"
25* 44'45"
25*44•30"
25 * 4 4'00"
25*43'00"
A-5

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A.1.2.2 Hydrography
Hydrographic profiles were taken at each of the seven water
quality stations. At each station, measurements of tempera-
ture, salinity, and dissolved oxygen were taken at 20 ft
(6.1 m) intervals from the surface to a depth of 220 ft
(67 m). Temperature and dissolved oxygen measurements were
made with a Hydrolab TPD-2 temperature/dissolved oxygen meter.
Salinities were measured with a Hydrolab 4021 temperature/con-
ductivity meter. Meters were calibrated both before and after
measurements were taken.
Total suspended solids and turbidity levels were measured in
waters collected from 30 ft (91.5 m) below the surface and
from approximately 6.5 ft (2m) off the bottom at each of the
seven designated water quality stations. Analytical methods
are given in Table A-2.
A.1.2.3 Granulonetry
Sediment samples were collected from each of the nine sediment
sampling stations with a ponar grab sampler. Subsamples of
the relatively undisturbed grab samples were taken with 3 cm
(i.d.) Plexiglass coring tubes for granulometric analyses.
These tubes were pushed into the sediment, sealed top and
bottom with rubber stoppers, and then removed. The top ten
centimeters of each core was then extruded into a labeled
plastic bottle and transported to the laboratory for analysis.
A-6

-------

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Chll 1*4
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Chiliad
Chlllad
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Total Orpolo Carbon	tadlaant
Oil aad Ciaiti	(adlaant
Turbidity	Hatac
Chiliad
Chiliad
Chiliad
Cai Chraaata«raphf/f1aaa Ionlaatloa Patactor
Ca* Cbraaatoftaphjfflaaa lonliatlan Oatactor
loihlat latractlan (hanoa)
Kapha IoaaI>r
Analytical aa t hod* follawad thaaa out I t nad in Faquasnat (1•• 1 > U.S. Army Uatarvaya tapa.-laant
Station, Toehaleal Kapott SL-tl-1. rrgt««wr»l Culda fat Daif.n.lUn Surv.r, of Oca.n Oradaad K.nrUI
pimn> nm
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-------
Grain size determinations generally followed the procedures
outlined by Pequegnat et al. (1981) in U.S. Army Waterways
Experiment Station Technical Report EL-81-1; Procedural Guide
for Designation Surveys of Ocean Dredged Material Disposal
Sites. Samples were first wet aieved through a 62 urn sieve,
using a 5 g/1 sodium hexametaphosphate dispersant, to separate
the mand-shell fraction from the silt-clay fraction. The
sand-shell fraction then underwent grain si2e analysis by
sieving, while pipette analysis was used to quantify the silt-
clay fraction. A Tyler Sieve Shaker (Model R-X24) and nested
8-inch brass sieves with mesh sizes of 2.0, 1.0, 0.5, 0.25,
0.177, 0.12, and 0.06 mm were used to conduct the sieve
analysis.
A.1.3 Chemical Characteristics
A.1.3.1 Water Quality
Grab samples for chemical analysis were collected with a non-
contaminating Kemmerer-type sampler from 33 ft (10 m) below
the surface and fro® approximately 6.5 ft (2 m) off the bottom
at each of seven designated water quality sampling
stations. Methods of preservation and analysis are summarized
in Table A-2.
A.1.3.2 Sediment Chemistry
Sediment samples for chemical analysis were taken with a ponar
grab sampler. Well-mixed composite samples were collected
A-8

-------
from each station for analysis. Upon collection, sediment
samples were placed in labeled glass jars and kept on ice
until delivered to the laboratory.
Two methods were used for the extraction of sediment samples,
as recommended by Pequegnat et al. (1981). Seven of the nine
samples collected were treated by seavater elutriation and two
by 0.1 N HC1 partial extraction. Methods used for the
chemical analysis of the seawater and acid elutriates are
given in Table A-2.
A.1.4 Biological Characteristics
A.1.4.1 Benthic Macroinvertebrates
Benthic macroinvertebrates were sampled by ponar dredge at
nine stations in the Miami Harbor ODMDS study area. The ponar
dredge samples 0.054 square meters of sediment surface. Five
samples, representing 0.27 square meters of bottom surface,
were taken at each station.
Upon collection, samples were fixed in a ten percent solution
of buffered Formalin to which a stain, rose bengal (200 mg/1),
had been added. This stain concentrates in animal :issues and
facilitates the effective recovery of organisms for analysis.
In the laboratory, samples were sieved through a 500 u mesh
and re-preserved in a 70 percent solution of isopropyl
alcohol. Hie sieved samples were then sorted under a dissect'
ing microscope to recover all benthic organisms. All samples
A-9

-------
were cross-checked to ensure the efficiency of sample
processing.
Following sorting, identifications and counts were made under
a dissecting microscope. Representative specimens have been
preserved in a reference collection.
A.1.4.2 Meiofauna
Two meiofauna samples were collected at each of the nine
benthic sampling stations in the Miami Harbor ODMDS study
area. Meiofauna samples were taken by coring sediments
collected by ponar dredge with a 3 cm (1.2 in) i.d. Plexiglass
coring tube. The coring tube was ttien capped at both ends,
removed from the sediment, and the i:op 20 cm (7.87 in) of
material extruded into a labeled sample.container. Meiofauna
samples were preserved in a 5 percent solution of buffered
Formalin to which a stain, rose bengal (200 mg/1), had been
added.
In the laboratory, meiofaunal samples were first sieved
through a 500 u mesh screen to remove representatives of the
macrobenthos. The remaining material was passed through a
64 u sieve, and the portion retained sorted to remnve meio-
fauna. All counts and identifications were made under a
binocular dissecting microscope at a magnification of 25 X.
A-10

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A.1.4.3 Macroepifauna
Macroepifauna were collected by trawl at four sites in the
study area. Two 15 minute tows with a 10 ft. (3.1m) trawl
were made at each site. All trawls were made from north to
south, against the current, at an estimated bottom speed of
one to two knots. The wet weight biomass of each sample was
determined immediately after trawl retrieval with a Hanson
(Model 600) spring scale. Following biomass determination,
organisms were counted and identified to the extent possible
in the field. Those organisms which were selected for tissue
analyses were removed at this time, identified, weighed, and
placed on ice. All other organisms were preserved in a 10
percent Formalin solution. Upon return to the laboratory,
taxonomic verifications were made and all samples were placed
in storage.
A.1.4.4 Tissue Analyses
Tissues for chemical analysis were taken from macroepifaunal
organisms collected by trawl as described in Section A.1.4.3.
Following collection, fish and crabs selected for analysis
were frozen and transported in a chilled state to the labora-
tory for analysis.
Whole fish and crabs were analyzed for constituents listed in
Table A-2. Edible shrimp tissues were analyzed for trace
metals only using the methods of analysis given in Table A-2.
A-ll

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A.2	Results and Discussion
A.2.1 Physical and Geological Characteristics
A.2.1.1 Bathymetry
The Miami Harbor ODMDS is situated on the Continental Slope,
approximately 4 nmi (7.4 Km) east of the Port of Miami.
Depths at the designated interim disposal site range from
about 427 to 785 ft (130 to 239 m). The average declivity of
the Slope at the interim ODMDS is approximately 325 ft (100 m)
per nautical mile (1.85 km). A bathymetric map of the ODMDS
vicinity is presented as Figure A-3. Depths at each of the
nine sampling stations established in the Miami Harbor ODMDS
vicinity are given in Table A-3.
A.2.1.2 Hydrography
Hydrographic profiles were made at each of the seven water
quality stations established in the study area. Temperature,
salinity, and dissolved oxygen were measured at 20 ft (6.1 m)
intervals through the upper 220 ft (67 m) of the water column.
Results of these measurements are presented in Table A-4.
Temperature
Temperatures measured during this survey ranged from 22.3 to
23.3'C. These temperatures are comparable to winter tempera-
tures previously reported for the area. The Environmental
Protection Agency (EPA, 1973) reports temperatures in the
A-12

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M-T 2
2S°4«'00'
M-T3
M-T4
M-T 5
M-T6
25* 44'45
M-T7
M-T8
2S#43'00'
M.TIO
*
o
<1
N
o
CD
«
NORTH
0	!/»
NAUTICAL MlkC
FIGURE A-3
BATHYMETRIC MAP
Ocaan Pradgad Material Disposal Slta Miami, Florida

-------
Tabla A-3. Watar D«pth» at Stations	in tha Miami Harbor
ODMDS Study Araa.
Paoth
Station		a	
M-l 615	187
K-2 708	216
H-3 644	196
M-4 600	183
M-3 282	86
M-6 452	138
M-T 770	235
M—8 625	190
M-9 574	175
A-14

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Table A-4. TBBperature, Salinity, and Dissolved Gocygen Profiles Taken at
Stations in the Miami Harbor OCMDS Vicinity; January 29, 1986.
Dissolved Dissolved
Depth Tenperature Salinity Oxygen	Oxygen
Station Tire	CEtl	LLC)		(txan) % Saturation
M-l
0840
0
20
40
60
80
100
120
140
160
180
200
220
23.0
23.0
23.0
23.1
23.3
23.1
23.0
22.9
22.9
22.7
22.8
22.8
36.2
36.3
36.4
36.5
36.5
36.8
36.4
36.4
36.5
36.6
36.6
36.6
8.1
8.2
8.0
8.0
8.0
7.9
8.3
8.3
8.3
8.3
8.3
8.3
117
118
115
115
115
114
120
120
120
120
120
120
M-3
0915
0
20
40
60
80
100
120
140
160
180
200
220
22.6
22.4
22.6
22.6
22.7
22.7
22.6
22.6
22.6
22.6
22.6
22.5
35.9
35.9
35.9
35.8
35.8
35.8
35.9
35.9
36.0
35.9
35.9
36.1
8.3
8.5
8.3
8.2
8.3
8.3
8.3
8.2
8.1
8.1
8.1
8.2
118
121
118
117
118
118
118
117
116
116
116
117
M-4
1001
0
20
40
60
80
100
120
140
160
180
200
220
22.5
22.5
22.6
22.6
22.6
22.6
22.6
22.6
22.6
22.5
22.5
22.5
35.7
35.6
35.7
35.8
35.7
35.7
35.6
35.7
35.7
35.7
35.7
35.7
8.2
8.1
8.2
8.1
8.3
8.3
8.2
8.3
8.3
8.2
8.2
8.2
116
115
116
115
118
118
116
118
118
116
116
116
A-15

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Table A-4. (OantlxiMd)
D^Jth
Startler Tllffll tv*s
CO
Salinity
_ISBti	
Dlssolvad
Gkygan
	(HBB)
Dissolved
Qxygsn
JLSaSMntisn.
M-5
1045
0
20
40
60
80
100
120
140
160
180
200
220
22.5
22.6
22.6
22.7
22.6
22.5
22.5
22.3
22.3
22.3
22.3
22.4
35.7
35.7
35.6
35.6
35.7
35.7
35.7
35.7
35.7
35.7
35.7
35.7
8.3
8.3
8.2
8.1
8.2
8.2
8.2
8.2
8.2
8.2
8.2
8.2
118
118
116
115
116
116
116
116
116
116
116
116
M-6
1111
0
20
40
60
80
100
120
140
160
180
200
220
22.6
22.7
22.7
22.7
22.7
22.6
22.6
22.6
22.6
22.6
22.5
22.5
35.5
35.7
36.0
36.1
35.9
35.7
35.7
35.7
35.7
35.7
35.7
35.7
8.3
8.3
8.3
8.3
8.3
8.2
8.2
8.2
8.2
8.2
8.2
8.2
118
118
118
118
118
116
116
116
116
116
116
116
M-7
1145
0
20
40
60
80
100
120
140
160
ISO
200
220
22.8
22.7
22.7
22.6
22.6
22.6
22.5
22.5
22.5
22.6
22.7
22.4
35.7
35.7
35.7
35.7
35.7
35.7
35.7
35.7
35.7
35.7
35.7
35.7
8.4
8.3
8.3
8.2
8.2
8.2
8.1
8.1
8.1
8.2
8.2
8.2
119
118
118
116
116
116
115
115
115
116
116
116
A-16

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Table A-4. (Continued)
Dissolved Dissolved
Depth Tnperatuzw Salinity Oxygen	Oxygen
Statigo—line	LEfc)	LSI	QSEt)	(pan) % Saturation
0
22.9
35.5
8.2
117
20
22.8
35.7
8.2
117
40
22.8
35.9
8.1
115
60
22.8
35.9
8.1
116
80
22.8
35.9
8.1
116
100
22.8
36.2
8.1
116
120
22.7
36.2
8.1
116
140
22.7
36.4
8.0
115
160
22.7
36.5
8.1
117
180
22.7
36.5
8.0
115
200
22.7
36.6
8.1
117
220
22.7
36.5
8.1
117
A-17

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ODMDS vicinity ranging from a low of around 23 *C in February
to over 29*C in July.
No evidence of thermal stratification vaa noted. Temperatures
measured from the surface to a depth of 220 ft (67 m) did not
vary by more than 0.5'C.
Salinity
Salinities measured in the upper water column during this
January 1986 survey ranged from 35.5 to 36.8 parts per
thousand (ppt). Similar salinities have previously been
reported for the area (EPA, 1973).
Little variation in salinity with depth was observed.
Salinity in the upper 220 ft (67 m) of the water column
generally varied less than 1 ppt. Salinities of near-bottom
waters (Table A-9) were also in the 35 to 36 ppt range.
Dissolved Oxygen
Dissolved oxygen (DO) concentrations measured in study area
waters on January 29, 1986 ranged from 7.9 to 8.5 ppm and
were consistently above saturation. Little variation in DO
concentrations between stations or with depth was noted.
Total Suspended Solids
Total suspended solids (TSS) samples were collected from near-
surface and near-bottom waters at each of the seven water
quality stations. Results of TSS analyses are presented in
A-18

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Table A-5. TSS concentrations were generally low, ranging
from below detection (5 mg/1) to 11 mg/1. Values were below
detection in ten of the fourteen samples taken.
Turbidity
Turbidity is defined as the optical property of a sample which
causes light to be scattered and absorbed rather than trans-
mitted in straight lines. Turbidity is commonly measured with
a nephelometer, which measures scattered light, and is
reported in NTUs (nephelometric turbidity units). Turbidity
samples were collected from near-surface and near-bottom
waters at each of the seven designated water quality stations.
Results of these analyses are given in Table A-5.
Turbidity levels ranged between 4 and 9 NTU. No consistent
differences or trends were noted between levels in near-
surface and near-bottom waters or in the distribution of
values between stations.
A.2.1.3 Granulometry
The grain size distributions of surficial sediments collected
in the study area are presented in Table A-6. Mean grain
sizes, modes, and inclusive standard deviations, calculated
for the sediments collected from each station are given in
Table A-7.
Surficial sediments in the Miami Harbor interim ODMDS vicinity
are primarily comprised of very fine sands and coarse silt.
A-19

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Table A-5. Total Suspended Solids Concentrations and Turbidity
Levels Measured at stations in the Hiami Harbor
OQMDS Vicinity.


Depth
Total Suspended
Turbidity
Station
Position
(Ft.)
Solida (mg/1)
(NTU)
M-l
Surface
33
<5
5

Bottom
608
<5
4
M-3
Surface
33
<5
5

Bottom
637
<5
6
M-4
Surface
33
5.7
4

Bottom
593
<5
4
M-5
Surface
33
<5
4

Botton
275
5.8
6
M-6
Surface
33
<5
5

Bottom
445
<5
4
M-7
Surface
33
11
9

Bottom
763
<5
5
M-8
Surface
33
<5
5

Bottom
618
6.2
6
A-20

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.able A-6. Grain Size Distribution of Sediments Collected from the Miami
Harbor ODMDS Vicinity.
	Percent Composition				
Shell Coarse sands Medium sands Pine sands	Silt	Clay
Station (< -1 0) (-1 to 1 0)	(1 to 2 0)	(2 to 4 0) (4 to 8 0) (> 8 0)
M-l
<1
<1
<1
61
38
0
M-2
<1
<1
<1
74
25
0
M-3
<1
1
2
75
22
0
M-4
0
1
1
73
25
0
M-5
1
5
7
64
9
14
M-6
0
1
1
70
28
0
M-7
<1
1
2
73
24
0
CO
l
X
0
1
2
73
24
0
M-9
<1
3
1
69
27
0

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Tabl« A-7. GranolaaBtrio Characteristic* of Sedlamta Collected trm the
Miami Harbor OCHD& Vicinity.
than	Hodt	Inclusive standard
Station	(phi/ 0)	(fbi, 0}	DBwiaticn (phi, 0)
M-l
4.0
4.0
O.fr
H-2
a.s
4.0
0,4
M-3
3.8
4.0
».4,
M-4
3.8
4.0
0»4
JH5
4.2
4.9
2.3
M-6
3.8
4.0
0.4
M-7
3.8
4.0
0.4
WW
3.9
4.0
0.4
M-9
3.*
4.0
0.4
A-22

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Sediment composition was generally uniform at most stations in
the ODMDS area. The greatest differences in sediment composi-
tion were found at M-5, the sampling station located farthest
inshore. Sediments at M-5 contained more clay, coarser sands,
and less silt than sediments collected from the other station
in the study area.
Inclusive graphic standard deviations were calculated as a
measure of the uniformity or sorting of sediments. Values for
this statistic generally range from 0.35 phi for well-sorted
sediments to 4.00 phi for poorly sorted, non-uniform sediments
(Pequegnat et al., 1981). Surficial sediments at most
stations in the study area were well sorted, with inclusive
standard deviation values of 0.4 and 0.6. Sediments at
Station M-5 were less well sorted and had a inclusive standard
deviation value of 2.3.
A.2.2 Chemical Characteristics
A.2.2.1 Water Quality
Water samples for chemical analysis were collected from
approximately 33 ft (10 m) below the surface and 6.5 ft (2 m)
above the bottom at Stations M-l, M-3, M-4, M-5, M-6, M-7, and
M-8. Samples were analyzed for a number of potential contami-
nants, including selected trace metals, pesticides and
pesticide derivatives, polychlorinated biphenyls (PCBs), and
high molecular weight (HMW) hydrocarbons. Salinity was also
measured as an indicator of stratification (discussed
A-23

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previously in Section A.2.1.2). Specific parameters measured
and results of analyses of near-surface and near-bottom waters
are presented in Tables A-8, and A-9, respectively.
Trace metals analyzed in water samples were mercury, cadmium,
and lead. Mercury was not detected. Cadmium was present in
near-botton waters collected from Stations M-4 and M-5. Lead
was only detected in one near-surface water sample collected
from Station M-6.
Levels of pesticides, pesticide derivatives, PCBs, and HMW
hydrocarbons were below analytical detection limits in all
near-surface and near-bottom waters sampled.
A.2.2.2 Sediment Chemistry
Sediments were collected from each station for chemical
analysis. Constituents analyzed were selected trace metals,
pesticides, polychlorinated biphenyls (PCBs), high molecular
weight (HMW) hydrocarbons, total organic carbon, and oil and
grease. Metals were extracted from sediments collected from
Stations M-l, M-2, M-3, M-5, M-6, M-7 and M-9 by seawater
elutriation. Weak acid (0.1 N HC1) leaching was used to
extract metals from sediments collected from M-4 and M-8.
Results of sediment chemistry analyses are presented in Table
A-10.
Concentrations of metals in sediments were below analytical
detection limits in all seawater elutriates. Mercury,
A-24

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Table A-8. Results of Chemical Analyses of Near Surfaoe Waters Collected frcm the
Miami Harbor OCMDS Vicinity.
Station
PARAMETER
M-l
M-3
M-4
M-5
M-6
M-7
M-8
Trace Metals







Mercury, ppb
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
<0.2
Cadmium, ppb
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
Lead, ppb
<0.5
<0.5
<0.5
<0.5
0.6
<0.5
<0.5
Pesticides







Alpha-BHC, ppb
<0.005
<0.005
<0.005
<0.005
<0.005
<0.005
<0.005
Gaimta-EHC, ppb
<0.006
<0.006
<0.006
<0.006
<0.006
<0.006
<0.006
Heptachlor, ppb
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
Beta-BHC, ppb
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
Aldrin, ppb
<0.009
<0.009
<0.009
<0.009
<0.009
<0.009
<0.009
Heptachlor Epoxide, ppb
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
4,4'-DDE, ppb
<0.02
<0.02
<0.02
<0.02
<0.02
<0.0 2
<0.04
4,4*-COD, ppb
<0.05
<0,05
<0.05
<0.05
<0.05
<0.05
<0.05
4,4'-DOT, ppb
<0.06
<0.06
<0.06
<0.06
<0.06
<0.06
<0.06
o.p'-DOD, pj±>
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
o.p'-DOT, ppb
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
Chlordane, ppb
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
Dieldrin, ppb
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
Endrin, ppb
<0.06
<0.06
<0.06
<0.06
<0.06
<0.06
<0.06
Total PCBs as Archlor 1254. ppb
<0.4
<0.4
<0.4
<0.4
<0.4
<0.4
<0.4
Hicth Molecular Weiaht Hydrocarbons







Volume of sanple extracted, ml
1500
1500
1500
1500
1500
1500
1500
Weight of extractables, ppn
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
Aliphatics and arcnatics, ppb
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
Resolved hydrocarbons, ppb
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
Unresolved hydrocarbons, ppb
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
Sum of n-alkanes, ppb
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
Sum of even n-alkanes, ppb
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
Sum of odd n-alkanes, ppb
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
Salinitv. ppt
36
36
36
35
36
36
35

-------
Table A-9. Results of Chemical Analyses of Near Bottom Waters Collected
Miami Harbor 0CMD6 vicinity.
frcm the
rararisnas	
Trace Metalg
Mercury, ppb
C&dmiun, ppb
Lead, PPb
Fwrticlflg
Alpha-EHC, ppb
Ganra-EHC, ppb
Heptachlor, ppb
Beta-BHC, ppb
Aldrin, ppb
Heptachlor Efccod.de, ppb
4,4'-ECE, ppb
4,4 '-DCD, ppb
4,4•-00T, ppb
o,p'-DCO, ppb
OjP'-DOT, ppb
Chlondane, ppb
Dieldrin, ppb
Endrin, ppb
Tntfll FTPb 99 ArflUor 1254. ppb
Hich Molecular Weight Hydrocarbons
Volune of sample extracted, ml
Weight of extractables, ppra
Aliphatics and aranatics, ppb
Resolved hydrocarbons, ppb
Unresolved hydrocarbons, ppb
Sim of n-alkanes, PPb
Sura of even n-alkanes, ppb
Sura of odd n-alkanes, pjpb
salinity, ppt
Jfcl-
<0.2
<0.05
<0.5
Jfc2_
<0.2
<0.05
<0.5
Jfci.
<0.2
0.07
<0.5
Station
H-5
<0.2
0.06
<0.5

<0.2
<0.05
<0.5
JfcZ.
<0.2
<0.05
<0.5
Jfcft.
<0.2
<0.05
<0.5
<0.005
<0.005
<0.005
<0.005
<0.005
<0.005
<0.005
<0.006
<0.006
<0.006
<0.006
<0.006
<0.006
<0.006
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.009
<0.009
<0.009
<0.009
<0.009
<0.009
<0.009
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.02
<0.04
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.05
<0.06
<0.06
<0.06
<0.06
<0.06
<0.06
<0.06
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.1
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.03
<0.06
<0.06
<0.06
<0.06
<0.06
<0.06
<0.06
<0.4
<0.4
<0.4
<0.4
<0.4
<0.4
<0.4
1500
1500
1500
1500
1500
1500
1500
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<5.0
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
<0.5
35
36
35
36
35
35
35

-------
Table A- 10
R• • u1t • of Chamlcal Analysts of S»dlm«nti Collected from the
NLaat Harbor 0 DM 0 S Vicinity.
PARAMETER
M - 1
H- 2
H - 3
H - 4
M- 5
H - 6
M - 7
H- •
«- •
If Iff fit t # I 1









Htrtutjr (In iatv>t«f • lutllttt) , • uf/1
<0.05
<0.05
<0 0 5
	
<0.05
<0.05
<0.03
—
<0.05
C•da Iua (In •lutrltti) . u»/1
<0.5
<0.3
<0.5
	
<0.5
<0 3
<0.5
—
<0.5
L*ld (In tlivitir «lutclat«), u|/I
<0.1
<0.2
<0.2
	
<0.2
<0 2
<0.2
—
<0.2
Mercury (In acid 1aichit«),¦' U|It, dry
	
...
- » -
<0.03
	
...
...
0.0]
		
Cadalua (in acid lochlt*) , u||| , dry
	
	
	
0.1*
	
	
	
0.1*
	
Lead (In acid l*achata), u»/$, dry
	
	
	
1 . /
	
	
—
2 2
	
Pf ft If !<».*»









Alpha-IHC, u|/k|
<0.04
<0.04
<0.04
<0.04
<0.04
<0.04
<0.04
<0.0*
< 0 . 0 »
C «¦««-1BC, u|/kt
<0.6
<0.6
<0.6
<0.6
<0.6
<0.6
<0.6
<0.4
< 0 . •
B«pC»chlot( u|/k|
<0.08
<0.08
<0 oa
< 0 . Oft
< 0 . Oft
<0.08
< 0 . OS

-------
Table A - 1 0 . (Continued)
Stat Ion
M - 1	H - 2	HO	M-4	H - 5	M - 6	H-7	M-ft	W - 9
N)
00
Hl«h Haliculu KHiht ltdtctirb.nl
Wet «•Ighc of	eatracted. |
Or y «• l|ht of laopla aitnotod, |
Allphat lei and iroaitUi, PP«< dr y
R«iolv«d hydroearkon•f pp*, dry
Unroiolvad hydrocarbons, 9P*, dr7
Sua of n-alkanea, ppa, dry
Sua of ovin n-ilkinoi, ppo, dry
Sua of odd n-alkanee, pp*« dry
(Inriiolvtd hf dro0«rk*iii/r«<»lvad
kydrocarboDi
Odd n-ilkinia/ivoo a*ilkan«i
01 1 and trim . u|/|
Total ocnnlc carbon. ¦
15 0
2)0
2)0
2)0
2)0
2)0
2)0
2)0
2)0
1 3 ft
1 1 ft
10 0
1
3 3
1 ))
12ft
1)0
1 1 )
1 3 3
5 2
4 7
4 3

5 )
3 4
5 1
4 0
4 6
) 3
4 9
) 7
) 9
HO
) 2
«ft
4 ft
16 0
ft!
0 . Of
0.12
0.09
0
. 1 2
0 Oft
0.13
0.07
0.14
0.10
0.27
0.4)
0.20
0
. 3 2
0.31
0.29
0.21
0.21
0.2)
0.1)
0.1)
0.1)
0
. 1 0
0.21
0.32
0.38
0.14
0.23
0.06
0.02
0.04
0
. 0 3
0.07
0.06
0.03
0.0)
0.03
0.03
0.0 1
0.03
0
. 0 2
0.0)
0.0)
0.02
0.04
0.02
0.0)
0.01
0.01
0
. 01
0.02
0.01
0.01
0.01
0.01
0.40
0 . s 0
0.54
0
. 3 1
0 . Aft
1 . 1
1 . ft
0.67
1 . 0
1 . 0
1 . 0
0 . ) 3
0
. 50
0.40
0.20
0.30
0.2)
0 . 30
1 2
24
2 1

1 4
3 2
4 1
2 7
2 7
30
1 )
1 8
1 7

1 7
1 1
1 4
1 6
1 6
1ft
alutrlatlon conducted	In accordanca with Cnvlronaantal Protection Agancy/Corpi of Engineers
Technical Report EFA/CC-ftl-1:	Sadlaant:watar ratio of 1:4 (vol/vol).
extraction with 0.1 R HC1	In accordanca with Peque|nat et al. ( 1 9 ft 1 ) 1 Cory* of Engineer*
Technlcel Report EL-ftl-1.

-------
cadmium, and lead concentrations were comparable in acid
leachates of sediments from M-4 and M-8.
No chlorinated hydrocarbon pesticides, pesticide derivatives,
or PCBs were detected in sediments collected from the study
area.
Sediment concentrations of total high molecular weight (HMW)
hydrocarbons exhibited a considerable range. Lowest levels
were found at stations located north (downstream) of the
ODMDS. Highest concentrations were measured in sediments
collected from Station M-4, located within the ODMDS, and from
Station M-8, located south (upstream) of the ODMDS. In
general, component HMW hydrocarbon tractions exhibited no
definitive spatial trends. Highest unresolved hydrocarbon
concentrations were measured in sediments collected from
Stations M-6 and M-7, within the designated interim disposal
site.
Oil and grease concentrations in study area sediments ranged
from 12 to 41 ug/g. The highest oil and grease concentration
was measured in sediments from M-6, within the designated
disposal area. Low concentrations were found at Station M-l,
downstream of the ODMDS, and Station M-4, near the center of
the ODMDS. No distinct pattern of distribution was apparent.
Total organic carbon (TOC) concentrations ranged from 11 to
18 mg/g. Ho trends in the distribution of TOC concentrations
over the study area were observed.
A-29

-------
A.2.3 Biological Characteristics
A.2.3.1 Benthic Macroinvertebrates
About 9,000 organisms representing approximately 200 indi-
vidual taxa were inventoried from collections made in the
Miami Harbor interim ODMDS study area. A listing of the
benthic macroinvertebrate taxa identified is given in
Appendix B, Table B-l. The composition, abundance, and
diversity of macroinvertebrates collected in each sample taken
from the nine stations in the study area are presented in
Appendix B, Table B-2 through Table B-10.
The mean abundance, total number of taxa, and Shannon-Heaver
diversity of benthic macroinvertebrates collected from each
station are presented in Table A-ll. Mean densities ranged
from a low of 1,852 organisms/m2 at Station M-2 to 6,041
organisms/m2 at Station M-3. The mean density of benthic
macroinfauna, averaged over all stations in the study area,
was 3,753 organisms/m2.
The interim ODMDS and the surrounding area support a diverse
assemblage of benthic macroinvertebrates. The nuiiser of
individual taxa represented at stations in the study area
ranged from 61 at Station M-2 to 88 at Station M-3 and
primarily reflects the relative numbers of organisms
encountered in samples. Shannon-Weaver diversities were high,
ranging from a value of 3.38 at Station M-l to 4.66 at
A-30

-------
Table A-ll. Mean Abundance and Diversity of Benthic Macro-
invertebrates Collected from Stations in the
Miami Harbor ODMDS Vicinity.
Abundance	Number of Shannon-Weaver
Station	(Organisms/a2)*	Taxa**	Diversity**
M-l
4054
t
2169
70
3.38
M-2
1852
±
1031
61
4.24
M-3
6041
±
2701
88
4.11
M-4
2779
t
1201
72
4.13
M-5
3324
i
1089
73
4.66
M-6
3278
±
1656
69
3.85
M-7
5867
t
1065
79
3.42
M-8
4044
±
2865
74
3.80
M-9
2536
±
1554
66
4.08
~Value given is the mean ± one standard deviation of the five
samples taken at each station.
"Calculated based on data composited from the five samples
taken at each station.
A-31

-------
Station M-5. Values in this range are generally considered
characteristic of stable environments.
No patterns were apparent in the distribution of macroinfaunal
densities or diversities over the study area. While the
depths of the stations sampled ranged approximately 488 ft.
(149 m), no trends in quantitative community descriptors with
depth were observed.
The composition of the benthic macroinfauna, by major taxo-
nomic group, is given in Table A-12. Polychaete worms and
amphipod crustaceans were co-dominants in the 6tudy area.
Polychaetes were the dominant group at four stations, while
amphipods were dominant at five stations. Polychaetes
accounted for 37 percent of the area's macroinfaunal
assemblage and were most abundant at Station M-3 and least
abundant at Station M-4. Amphipods comprised 33 percent of
the macroinfaunal community. Amphipod densities were lowest
at the shallowest station (M-5) and highest at the deepest
station (M-7).
Molluscs and nematodes were also well represented at all
stations. Molluscs accounted for 14 percent of the benthic
macroinvertebrate community and were evenly distributed over
the study area. Nematodes comprised 9 percent of the
macrobenthos.
Table A-13 presents rankings of the most abundant benthic
macroinvertebrates present at each station, and in the overall
A-32

-------
Table A -12. Banthlc Macroinvertebrata Oaqpositior; Dy Major Group
Station
PolychMtes
Aqphipods
Molluscs
Nematodes
Others
M-l
24
51
11
8
6
M-2
36
31
13
12
8
M-3
39
29
10
15
7
M-4
30
38
17
(
9
M-5
62
4
19
5
10
M-€
36
42
10
6
6
M-7
25
53
8
7
7
M-8
27
43
15
8
7
M-9
51
6
20
17
6
Average
37
33
14
9
7
A-33

-------
Ifeble A-13. Benthic Macro invertebrate Taxa of the Miami Harbor 0006 Vicinity, Ranted in
Order of Abundance.
¦Emm* Ran*
Station
1
2
3
4
5
M-l
Anpeliacidae
Nenatoda
Paraonidae
Mjculidae
Cirratulidae
M-2
Anjpeliacidae
Nenatoda
Spicriidae
Iu&rineridae
Cirratulidae
M-3
Aapeliacldae
Nanatoda
Cirratulidae
Orbiniidae
Spicriidae
M-4
Angel lacldae
Thyasiridae
Nenatoda
CoBsuridae
Anpharetidae
M-5
Spianidae
Orbiniidae
Cirratulidae
Paraonidae
Capitellidae
M-6
Anpeliacidae
Cirratulidae
Orbiniidae
Nenatoda
Spicriidae
M-7
Anpeliscidae
Nenatoda
Spicriidae
Cirratulidae
Nuculidae
H-6
Aapellacidae
Nanatoda
Orbiniidae
Itaculidae
Aqpharetidae
M-9
Cirratulidae
Nenatoda
An|pharetidae
Ihyasiridae
Paraonidae
Overall Anpeliacidae	Nanatoda	Cirratulidae Spicriidae	Orbiniidae
*Ranked by taxonanic family or by next lowest practical taxmanic level.

-------
study area. Rankings were made at the family level or at the
next lowest level to which the organisms were identified. The
most abundant family overall, and at seven of the nine
stations sampled, was Ampeliscidae. This amphipod family
accounted for almost one-third of the macroinvertebrates
collected from the disposal site vicinity. The nematodes,
representing several families, were ranked second in overall
abundance followed by the polychaete families Cirratulidae,
Spionidae, and Orbiniidae. Other locally abundant taxa
included the pelecypod mollusc families, Nuculidae and
Thyasiridae, and the polychaete families, Paraonidae,
Lumbrineridae, Cossuridae, Capitellidae, and Ampharetidae.
The most abundant macroinfaunal species in the disposal site
vicinity was Aropelisca aaassizi. a tube-dwelling amphipod.
This species has previously been reported as an abundant
species characteristic of the upper Continental Slope off the
southeastern U.S. (Boesch, 1977; in EPA, 1983). aoassizi
accounted for almost all of the amphipods encountered in
samples from the Miami Harbor interim ODMDS vicinity. This
species was the dominant infaunal species at all stations
except M-5 and M-9.
A trophic classification of the most abundant ben :hic macroin-
vertebrate taxa of the study area is presented in Table A-14.
Deposit feeding taxa were dominant at all station!;.
Three similarity indices were used to aid in the classifica-
tion and evaluation of the benthic macroinfauna collected at
A-35

-------
Table A-14. Trophic Classification of Major Benthic Macroinvertebrate Taxa
Collected from- the Miami Harbor Interim ODMDS Vicinity.



Trophic
Trophic
Phvlum
Class/Order
Familv
Guild
TvDe
Annelida
Polychaeta
Ampharetidae
SDT
SDF
Annelida
Polychaeta
Capitellidae
SMX
NSDF
Annelida
Polychaeta
Cirratulidae
SDT
SDF
Annelida
Polychaeta
Cossuridae
BDT
SDF
Annelida
Polychaeta
Lumbrineridae
CMJ
C
Annelida
Polychaeta
Nephtyidae
CMJ
C
Annelida
Polychaeta
Orbiniidae
SDT
SDF,SF
Annelida
Polychaeta
Paraonidae
SDT
SDF
Annelida
Polychaeta
Spionidae
SDT
SDF
Arthropoda
Amphipoda
Ampeliscidae
SDX
SDF,SF
Arthropoda
Cumacea
Leuconidae
SMX
SF
Aschelminthes
Nematoda
	
SMX
NSDF
Mollusca
Pelecypoda
Nuculidae
FSX
SF
Mollusca
Pelecypoda
Thyasiridae
FSX
SF
Trophic Guild Codes:
Feeding Preference:
Mobility:
Feeding Structures:
Trophic Type Codes:
S - Surface deposit; B - Subsurface deposit; C - Carnivore;
F - Filter feeder
M - Motile; D Discreetly motile; S - Sessile;
J - Jaws; T - Tsntacles; X - Miscellaneous.
c - Carnivore; o - Omnivore; SF - Suspension feeder;
SDF - Selective deposit feeder;
NSDF - Non-selective deposit feeder.

-------
stations in the Miami Harbor interim ODMDS vicinity. Indices
used were the Morisita Index, Bray-Curtis Index, and a simple
matching index. The Morisita and Bray-Curtis indices are
quantitative and take into account both the occurrence and the
abundance of organisms. The simple matching index is qualita-
tive and is based solely on the presence of common species in
samples compared.
Cluster analyses were based on the above determinations of
faunal similarity. Results of cluster analyses based on the
Morisita Index, Bray-Curtis Index, and simple matching are
presented in Figures A-4, A-5, and A-6, respectively.
Cluster analyses based on the quantitative similarity indices
yielded similar results. Both the Morisita Index and the
Bray-Curtis Index clustered Stations M-3, M-4, M-6, M- 7, M-8,
and M-9 as a major group. These indices also paired the
northernmost Stations, M-l and M-2. The Morisita Index also
associated this pair with the largest station cluster at a
relatively high similarity level. Both indices identified the
shallow water station, M-5, as a distinct outlier.
Results of clustering based on 'presence/absence agreed well
with results of the quantitative similarity analyses. Simple
matching also identified Station M-5 as an outlier and paired
Stations M-l and M-2. The largest cluster, including the
remaining six stations, exhibited a higher degree of internal
differentiation than was indicated by the quantitative
indices.
A-37

-------
STATION
M-9
M-S
M-6
M-3
IfcA
M-4
M-2
M-1
M-5
too
L
75
JL

_L
_L
50
_L
LEVEL OF SIMILARITY (PERCENT)
FIGURE A-4
CLUSTER DENDOGRAM SHOWING STATION ASSOCIATIONS BASED ON BENTHIC
MACROINVERTEBRATE SIMILARITY AS DETERMINED USING THE MORISITA INDEX
Ocean Dredged Material Disposal Site Miami, Florida

-------
STATION
M-9
M-8
M=3_
M=S.
M=Z
Jti
MrZ
M-1
M-S
"00	73	50	25
1	J	1	1	1	1	1	I	I	I	I	I	I	I	I	I
LEVEL OF SIMILARITY { PERCENT)
FIGURE A-5
CLUSTER DENDOGRAM SHOWING STATION ASSOCIATIONS BASED ON BENTHIC
MACROINVERTEBRATE SIMILARITY AS DETERMINED USING THE BRAY-CURTIS INDEX
Ocean Dredged Material Disposal Site Miami, Florida

-------
STATION
M-9
M-e
II-4
Jbfl-
M-3
M=l.
Jfc*.
M-1
M-5
>00
75	50
J	I	I	I	I	L
LEVEL OF SIMILARITY (PERCENT)
25
J
FIGURE A-6
CLUSTER DENDOGRAM SHOWING STATION ASSOCIATIONS BASED ON BENTHIC
MACROINVERTEBRATE SIMILARITY AS DETERMINED BY SIMPLE MATCHING (presence/absence)
Ocean Dredgid ftftatarlal Disposal Slta Miami, Florida

-------
Based on the results of this survey of benthic macroinverte-
brates of the Miami Harbor interim ODMDS vicinity, the
folloving observations can be made.
1.	Polychaete worms and amphipod crustaceans co-dominate
the benthic macroinfauna of the area numerically.
2.	The interim disposal site vicinity supports a diverse
macroinvertebrate community.
3.	A relatively high degree of similarity was found
between most of the stations in the study area.
Greatest faunal differences are attributed to depth.
A.2.3.2 Meiofauna
The composition, abundance, and diversity of meiofauna
collected.from the study area is presented in Table*A-15.
Analysis of the meiofauna samples revealed several anomalies
apparently introduced through sampling. It is felt that
during the extended period required to retrieve the sampling
dredge from the depths worked, substantial sediment disruption
occurred in some samples. As a result, surficial sediments
were not always obtained in meiofaunal subsamples. Th.s was
apparently the case at Stations M-6, M-7, and M-9 where very
few meiofauna were found in samples. Data from these stations
have not been reported.
Nematodes comprised the overwhelming majority of the meiofauna
collected. Pequegnat et al (1981) note that in most marine
A-41

-------
Ifcble A-15. Meiofauna Collected fran Stations in the Miami Harbor OCMDS Vicinity.
Riylum
Class
Subclass
Station/Reolicate/Abundanoe*
M-l
A	B.
Jfc2_
_a	a.
M-3
a	a.
JtA.
_&	B_
_u=£.
.h	a.
jfcft.
A	B_
Platyhelminthes
•Rubellar ia
Nenetoda
Gastrotriciia
Kinortiyncha
Priapulida
Annelida
Folychaeta
Arthropoda
Crustacea (lazvae)
Oopepoda
Harpaticoida
Cyclopoida
Arachnida
Acarina
11	4	235	69
188 363 278 115 85 118 238 533
12
290
2
200
1
12
13 11
1
1
1
1
33 10
1 1
129 181
1
3
Total Sanple Abundance
(No./Sanpie) 1S3 368
293 122
96 135
248 558
350 225
130 189
Mean Station Abundance 279
208
116
403
288
160
Shannon-Weaver Diversity 0.11
0.39
0.72
0.33
0.86
0.24

-------
sediments, nematode worms account for 90 percent or more of
the meiofauna community. In samples from stations in the
Miami Harbor ODMDS vicinity, nematodes accounted for 94 per-
cent of the meiofaunal assemblage. Harpacticoid copepods,
larval polychaete worms, and turbellarians were common but
never abundant in samples.
Meiofauna diversity was quite low, reflecting the degree of
nematode dominance. Shannon-Weaver diversities, calculated
for each station, ranged from 0.11 to 0.86.
A.2.3.3 Macroepifauna
Fish
Table A-16 lists the fish collected in replicate 15-minute
tows at Stations M-l, M-4, M-6f and M-9. A total of 459
individuals representing 20 species were collected.
The abundance of demersal fishes, the number of taxa represen-
ted, and the diversity of fish species calculated for each
station is presented in Table A-17. The fish fauna was most
abundant and diverse at Station M-6, within the ODMDS. The
lowest number of fish and the fewest taxa were captured in
trawls at Station M-4, also within the ODMDS. Fish diversity,
as determined by the Shannon-Weaver Index, was lowest at
Station M-l, located to the north of the designated disposal
area.
A-43

-------
Table A-16. Fish Oollectad by Trawl frees the Mia&i Harbor OCMDS Vicinity.
Station
Trawl
(No.)*
Scientific Name
Gannon Name
Number
M-l	(1) Bellator mil i tar is
Baia lentignosa
Svnchurus minor
(2) Brtlftor militaris
Qilorophthaljms
Rartinus lomigpinis
SYircftmre oiosr
vraftreig rwiug
Horned searobin
Freckled skate
Largescale tcnguefish
Horned searobin
Shortnose greeneye
Lcrgspine soorpianfish
largescale tcnguefish
Spotted hake
5
1
M-4	(1) Bellator militaris
Qilorcchthalflus aoassizi
Pontinus loxrispinus
Svnchurus minor
(2) Svnchurus minor
Horned searobin
Shortnose greeneye
Lcngspine soorpianfish
largescale tcnguefish
Largescale tcnguefish
10
M-6	(1) Ancvlcosetta aadres^Llata
Antennarius sp.
Antiaonia sp.
militaris
ftlUgnymg sp-
«P*
Oaoooephalus sp.
Paraaanxr
ftntinus IgmigplfMS
Prt<*gtug
Eala lentianosa
Soorraena cnl
-------
Table A-16. (Ccntirued)
Trawl
Station (No.) Scientific Name	Cootncn Name	Number
Anticrcnia «prw
Deepbody bonrfish
1
MacrrehanEtosus sp.
Snipefish
1
Paraoonoer caudilimbatus
Maxgintail ocnger
3
Partiiws Ismispiiws
Lnngspina soorpionfish
5
Ftetftiw vicixus
Moray eel
1
Rala lenttqnow
Freckled skate
S
Symftums miner
Largescale tcnguefish
55
Vrwfrrcis raius
Spotted hake
7
Iepqphidium so.
Cusk-eel
1
pcpopephalus sp.
Batfish
1
ftraUtfftiws alfciqvftta
Gulf flounder
1
Porrtijius loroisDinus
Langspine soorpionfish
1
Fa1a lenttqmea
Freckled skate
10
Syirotois miner
Laxgescale tcnguefish
40
Vrspftwis rwivs
Spotted hake
4
*IUo 15 minute replicate tows were taken at each trawl station.
A-45

-------
Table A-17. Abundance and Diversity of Fish Collected at Trawl
Stations in the Miami Harbor ODMDS Vicinity.
Station
Abundance
Number of
Taxa
Shannon-Weaver
Diversity
M-l
49
6
1.19
M-4
16
4
1.32
M-6
255
15
2.04
M-9
139
11
1.67
A-46

-------
Station M-6 is the shallowest of the sites sampled by trawl,
at an approximate depth of 450 ft (137 m) . Depths at the
other trawl sites are similar, ranging from about 574 ft
(175 m) at Station M-9, to 600 ft (183 m) at Station M-4, to
615 ft (187 m) at Station M-l. Results of this survey, though
cursory, suggest that fish density and diversity may be
greatest at shallowest sites within the study area. This may
reflect differences in food availability with depth. Food
materials and organic substrate transported from coastal
waters would be most available to biota inhabiting inshore
portions of the study area.
The most abundant fish present in all collections, throughout
the study area, was the largescale tonguefish fSvmphurus
minor). The species accounted for 68 percent of all fish
collected. Other fish which were frequently present in
samples include the longspine scorpionfish (Pontinus
lonaispinus), freckled skate f Raia lentianosa), horned
searobin (Bellator militarist, and spotted hake (Urophvcis
regjus).
Epibenthic Invertebrates
Epibenthic invertebrates collected from the Miami Harbor ODMDS
are listed in Table A-18. Replicate tows at the four
designated trawl stations resulted in the collection of 845
individuals representing 9 species. Species collected
included pink shrimp (Penaeus duorarum). the lobster-like,
galatheid crustacean, Munida irrasa. rock crabs (Cancer
A-47

-------
Table A-18. Epibenthic Invertebrates Collected by Trawl fran the Miami Harbor
OCMDS Vicinity.
Station
Trawl
(No.)
Scientific Name
Qjiuxji Name
Number
M-i (i) amiSs Ana§§
Nihilia antiiccapre
Portunus gpjiucaiWS
(2) Career torealls
Sneer insratus
MffUte irrasa
Portunus ppjjiigaiT^g
Galatheid crustacean
Spider crab
Portunid crab
Jcrah crab
Rock crab
Galatheid crustacean
Portunid crab
48
1
6
1
3
4
1
m-4 (i) canoer irrvratus
Nlbilia antilw^pu
Portunus spinicartMS
Rossia tenera
(2) Fmreug fluoracw
Rock crab
Spider crab
Portunid crab
Squid
Pink shriap
2
1
1
2
M-6	(1) Nibilia antlioogpra
Penaeus flixpratw
Rossia tenera
(2) Cancer fesrsaJULs
HJiida irrasa
Hibiiia Mrtil
Rgtunus a?inigarwp
Hermit crab
Squid
Jonah crab
Spider crab
Pink shrinp
Portunid crab
2
1
2
1
2
2
A-48

-------
irroratus), Jonah crabs I Cancer borealis), spider crabs
(Nibilia antilocapra), portunid crabs (Portunus spinicarpu^
and Ovalipes sp.), hermit crabs fPacruridae sp.), and squid
fRossia	•
Considerable variation in the distribution of invertebrate
species over the study area was observed. Pink shrimp were
locally dominant at Station M-6. The crustacean, Munida
irrasa, was relatively common at Stations M-l and M-6 but not
present in collections from M-4 or M-9.
Epibenthic Biomass
Table A-19 gives the total wet weight biomass of all fish and
invertebrates collected in each trawl sample.
A.2.3.4 Tissue Analyses
I±sh
Results of the chemical analysis of fish tissues collected
from the Miami Harbor ODMDS are presented in Table A-20.
Species selected for analysis are those which are thought to
be "residential" and/or common to the area. Residential
organisms are those which spend much or all of their time in a
specific environment. Species selected for analysis were the
freckled skate (Paia lenticmosa) . longspine scorpionfish
(Pontinus loncrispinis), largescale tonguefish fSvmphurus
minor), and spotted hake fUroohvcis reqiusl. Because disposal
activities have not occurred at the Miami site, data obtained
A-49

-------
Table A-19. Total Wet Weight Biomass of Fish
and Epibenthic Invertebrates
Collected by Trawl from Stations in
the Miami Harbor ODMDS Vicinity.

Trawl
Wet Weight
Station
Number*
Biomass (kg)
M-l
1
2.27

2
2.04
M-4
1
2.72

2
0.09
M-6
1
2.04

2
1.63
M-9
1
0.73

2
1.54
*Two 15 minute replicate tows were taken at
each trawl station.
A-50

-------
Tabl« A-20
Ratult* of CK«olcal Analy*** of Flih Tlnuti Collected f coo lh« Hltal Harbor OOMDS Vicinity
=r
LH
Stat Ion
Sc Ltnc1f ic Has*

M - 9
fit
PARAMETER~
Tr»<=f H*\f1t
Common Naaa
l>ntItnot a Pont lm lonitiplnli	Symphuru> minor	S ymphurut minor
F r«ck 11 d lkat« Loniiplnr icnrnlonfl»h Larte»c>[» tontutfl»h L»rn«icil« tontuef lih
Toi«l PCB»«« «. Archlof 12M. o«/k,	«6
Hl«h fpl»cul»r "tlihl Hrdrocubqn*
Walght of *aapla •atractad, g	100
Weight of tat(actable*, ppm	2400
Aliphatic* and aroaitlei, PP»	0 01
Paiolvad hydrocarbon*, PP*	0 11
Untaiolvad hydrocarbon*, ppa	0 11
100
2200
0 09
0 1 2
0 0 5
100
1 1 00
0 1 0
0 2 I
0 2 4
29
100
1 600
0 04
0 \\
0 09
Urophrc 1» rttlui
Spot Hd hak*	
Ma r curj a|/g
0
0)
0
10
<0
.03
0.06
0
. 20
Cadalua ug/g
0
. 100
0
007
0
1 70
0 043
0
001
Laad ug / g
0
0 9
< 0
0 7
0
1 2
0 09
<0
06
Pf It Uld*«









Alpha-BRC, ug/kg
<0
02
<0
03
<0
0)
<0 02
<0
02
Ga««a-BBCf ug/kg
<0
.03
<0
04
<0
04
<0.03
<0
03
Raptachlor, ug/kg
<0
. 0 4
<0
03
<0
05
<0.04
<0
04
Bata-BRC, ug/kg
<0 .
1
<0
2
<0
2
<0 . 2
<0
2
Aldrln, ug/kg
<0
05
<0
08
<0
08
<0 06
<0 .
06
Haptachlor Cpoalda, ug/kg
<0 .
06
<0
08
<0
08
<0.07
<0.
07
4,4'-00t. ug/kg
<0
1
<0
3
<0
2
<0.1
<0.
1
*,4'* ODD, ug/kg
<0
2
<0
3
<0 .
3
<0 2
<0
2
4.4'-DOT, ug/kg
<0
2
<0
3
<0
1
<0 2
<0
2
o,p'-DDO, ug/kg
<0
2
<0
3
<0
3
<0.2
<0
2
o,p'-DOT, ug/kg
<0
2
< 0
3
<0
3
<0 3
<0
3
Chlordana, ug/kg
<0
3
<0
5
<0
4
<0 4
< 0
»
DlaLdrln, ug/kg
<0
1
<0
1
< 0
1
<0.1
<0
1
End rIn, ug/kg
<0
1
<0
2
< 0
2
<0 1
<0
1
22
100
1800
0 08
0 21
0 00

-------
Tabl« A20 (Continued)
StKCIon
Scientific R«i«
HI.

W i-
ft«l« ItntHmil ftntHl lgn»t««tnH
>II*fhuSVI tlMI

trwnhwrui slasX
H?
UtPPhrcLi UliU
CMMIIi!
CfflCtt l>tL
fr«ckl«d »k«f	Laniiclin icomlonfnh	tpr>«u«M»h	Ip.tl'Ufll <«Uhl flrdiffttibttni (Cont>
Sum 0i «
-------
serve primarily to aid in the establishment of baseline
conditions.
Each of the fish tissue samples was analyzed for mercury,
cadmium, and lead. Mercury concentrations ranged from below
detection (0.03 ug/g) to 0.2 0 ug/g and were highest in spotted
hake and lowest in tonguefish. Cadmium concentrations ranged
from 0.007 ug/g in scorpionfish to 0.170 ug/g in tonguefish.
Lead levels were below detection (0.07 ug/g) in scorpionfish
and hake tissues and measured up to 0.12 ug/g in tonguefish.
Chlorinated hydrocarbon pesticides and pesticide derivatives
were not detected in the tissues of any of the fish selected
for analysis.
Polychlorinated biphenyls (PCBs) ranged in concentration from
2 2 ug/kg in hake to a level of 46 ug/kg in skate and scorpion-
fish tissues.
Total high molecular weight fHMW) hydrocarbon levels were
highest in skate tissues. While total extractable HMW
hydrocarbon levels were lowest in a tonguefish sample from
Station M-6, this sample yielded highest concentrations of
those component fractions potentially indicative of
anthropogenic contamination.
Results of the chemical analysis of invertebrate tissues
collected from the study area are presented in Table A-21.
A-53

-------
T a b I e A - 2 1
Results of Chin 1 c • 1 Analyses of EpLbinthlc Invirtibrm Tlssuss Collected f r o • the
Hiial Hubor ODHDS Vicinity
Parameter*
s t¦t Ion
Scientific Mas*
Coaaon !>¦¦¦	
M - 1
H - «
1-6
JLJL
Ont't C»nc»t limiiui MMIh 'ItU'cipf
	Rock Crib	Rgtk Cl't1	spU'I	fi I * b	
rtnuvt
	Pink ShH»i	
T r »ci h« t . 1 »
H e r c u r y	u| / |
Ckdttlus	u|||
Lead u| / |
0 . 4 0
0 1 7 •
<6 0 4
3 0
0 3 1
<0.03
0.30
0.092
<0 0 4
0.13
0.070
0 12
r»n u n«»
=r
ui
A I p h
C
Sept
Bete
A 1 d r
Hept
4,4'
* , * '
« > P '
o . P '
Chlo
0 1 e 1
End t
e- IH C , u|/k|
t*IHC , u|/k|
»ehlOt, U»>k.
- IBC , u| / tt|
In, u|/k|
u» I k»
•DDK,
-DDD ,
-	00T ,
-	DDD ,
-DOT,
t d & n •
d[ln,
u ¦ / k «
«» f k |
«»/k|
u« I kg
u« / k i
»* I k«
u I / k i
In, u t/k g
T9tt» PCB»»« .. Archlor 123«. u,/kg
H i lh—KgUgultr	BTdroc»rbon»
Weight e f ««sp 1 e extracted, g
Weight of estrectables, p pn
Altphetlee end 11seat i c a , pp«
Resolved hydrocarbons, ppe
Unresolved hydrocarbons, ppie
<02
<0.01
<004
<	0 1
<0.03

-------
Tabl* A - 2 1
(Cont lnuid )
Slat Ion	M - I		H - *	_	H - 6 		 	*1 " 6
Scientific Nasa	C>nc« r 1 r r o r a t u s	Cancer lrroratus	H 1 b 1 1 1 t inUloc»pti_	P e n a e u > juoritvf
rARAHETER*	CoMan ».¦«	Bock Cr.b	R o c >. Cr.b	S p 1 d « r cr»b	E-ULk	ShttHg	
PHh H 0 L « c u I » t W| 1 « h t HrdrocTbom	(Cont)
• ua of n-iUina>, PPa	0 0 1	0 0 2	o 02			
Sua of tvin n-iUinil, pp«	003	001	002			
lu« »( odd n-ilkinii, ppi	<0.01	0.01	<0.01	....
Uniaiolvtd hrdrocirboni / rnoifid
hydrocarbon*	027	023	068	- - - -
Odd n-ilkmia/ivin n-ilkinti	W / A • • •	10	H/A	- - - -
•All viluii iiprinid on a vat weight basis
* * PCI i - Polfchlorlnattd bLphinfll
•'•Ratio cannot b a calculated (one para a*e ter not datected)
LH
LT»			Analyses not performed

-------
Benthic Macroinfauna Collected from
the Miami Harbor ODMDS Vicinity,
December, 198 5

-------
Table B-l. Benthic Macroinvertebrates Collected from Stations
in the Miami Harbor Interim ODMDS Vicinity.
Phylum
Class
Subclass
Order
Family
	Genus species	
Protista
Foraminifera
Porifera
Unidentified sp. A
Unidentified sp. B
Cnidaria
Anthozoa
Actiniaria
Hydrozoa
Rhynchocoela
Aschelminthes
Nematoda
Mollusca
Aplacophora
Gastropoda
Atlantidae
Columbellidae
Glycymeridae
Haminoeidae
Marginellidae
Granulina ovulifonnis
Retusidae
Rissoidae
Trochidae
Turridae
Pelecypoda
Cuspidariidae
Limacinidae
Limacina inflata
Lucinidae
An9d
-------
Table B-l. (Continued)
Phylum
Class
Subclass
Order
Family
	Genus species	
Veneridae
Vitrinellidae
Cephalopoda
Sepiolidae
Annelida
Oligochaeta
Polychaeta
Ampharetidae
Isolda pulchella
Isolda sp.
Amphinomidae
Capitellidae
Notomastus sp.
Cirratulidae
Cossuridae
Dorvilleidae
Flabelligeridae
Pherusa sp.
Glyceridae
Goniadidae
Soniatifl masvlata
Goniada sp.
Hesionidae
Lumbrineridae
Lumbrineris brgvjP
-------
Table B-l. (Continued)
Phylum
Class
Subclass
Order
Family
	Genus species	
Oweniidae
Mvriochele sp
Paraonidae
Ariciflea sp.
Pectinariidae
Phyllodocidae
PhYllQtigce sp.
Sabellidae
Spionidae
Paraprionospio sp.
Prionospio gt?enst;rupi
Prionospio sp.
Syllidae
Terebellidae
Sipuncula
Golfingiidae
sp.
Nymphonidae
HYFPh9n sp.
Arthropoda
Crustacea
Cephalocarida
Hutchinsoniellidae
Hutchinsoniella macraca
mantla sp.
Malacostraca
Amphipoda
Aeginellidae
Mgyerglia sp.
Ampeliscidae
Ameplisca aaassizi
Aropelisca c.f. verrilli
AnpgHsca sp. b
Haploops sp. A
Haplpppg sp. b
Haplp
-------
Table B-l. (Continued)
Phylum
Class
Subclass
Order
Family
	Genus species	
Aoridae
Unicola ggrrflU
Vnienqfll
-------
Table B-l. (Continued)
Phylum
Class
Subclass
Order
Family
	Genus species	
Synopiidae
SYrrh
-------
Table B-l. (Continued)
Phylum
Class
Subclass
Order
Family
	genus specie?	
Isopoda
Anthuridae
Ptilanthura tricarinata
Xenanthura brevitelson
Unidentified genus A
Cirolanidae
Cpnilera 
-------
Table B-l. (Continued)
Phylum
Class
Subclass
Order
Family
	Genus species
Sariellidae
Sarsiella sp.
Pycnogonida
Ammotheidae
Heterofraailia sp.
Nymphonidae
Nvmphon sp.
Echinodermata
Ophiuroidea
Amphiuridae
ftmphiura sp.
ftmphigplus sp.
Ophiuridae
Chordata
Cephalochordata
Branchlostona sp.
Urochordata
Ascidiacea

-------
Table B-2. Macro infauna Collected at Station H-l, Miami Harbor Interim
OCMDS Study Area.
Riylum
Class
Subclass
Order
Family	Replicate/ fOroanisms/m2 i	 Mean Afcundance
	Genus Spec;	1 2 3 4 5 fOttranisms/m2)
Protista
Foraminifera	19	4
Cnidaria
Anthozoa
Actiniaria

210



42
Rhynchocoela
19

19
19

11
Aschelminthes






Neatnatoda
115
421
134
229
650
310
Mollusca






Aplacophora

19


19
8
Gastropoda

57



15
Columbellidae

19


Hamiroeidae

19

19

8
Rissoidae

19



4
Turridae

33



8
Pelecypoda






Cuspidariidae


19
38
38
19
Nuculanidae

19


19
8
Nuculidae

76
593
287
76
206
Thyasiridae
96
268

115
229
142
Scaptvopoda






Dentaliidae
19
38
19
19
38
27
Sipharxxtenfcal iidae

18
37

37
18
Annelida






Oligochaeta
57




11
Polychaeta






Anjpharetidae




19
4
isoWa ralctella

191
57
57
76
76
Capitellidae
19


38

11
sp-
19




4
Cirratullda
96
478
38
57
249
184
Dorvilleidna

19


19
8
f 1 aHol 1 IrprldM






fftirnwf «p-


38
38

15
Gorviadidw






r-/Tl1frt* aaculata
38
19


19
15
LuDbrinexiite
96


19

23
ijjntoriwis brevities



19

4
ItiiferiJHns SP-
38
57

19
76
38

-------
Table B~2. (Ccntirued)
Ftiylum
Class
Subclass
Order
Family	Replicate/ (Otttanisws/nt2)	 Mean Abundance
	Genus Species 	1 2 3 4 5 fOraanisns/m2)
Magelonidae


38



8
Maldanidae

38

57

19
Nephtyidae






Nephtvs Dicta
57
38



19
Nechtvs squappsa


38
19

11
NebhtVS sp.
38


19
19
15
Onuphidae



38

8
Ophkliidae



38

8
Ochelira
19
19


38
15
Ochelina so.


57


11
Orbiniidae


38
268

61
Oweniidae






KVTiKtwle sp-



19

4
Paraonidae






toricitea sp-
96
631
115
134
249
245
Spicridae
57



57
23
Prionosoio steenstruoi




19
4
Prionosoio so.
96
210
191
153
96
149
Sipuncula


19


4
Golfingiidae






sp.




19
4
Arthropoda






Crustacea






Malaooetraca






Airphipcda






Anpeliscidae






Ancelisca aaassizi
38
3442
3021
2887
516
1981
Ancelisca cf. verrilli
19




4
HaDloccs sc. B


19


4
Aoridae






uinciola serrata




19
4
Oedioerotidne

19



4
Unidentified sp. A



19

4
Unidentified sp. B


38



FhaxDOpyfta3 iAe




19
4
Haroinia wp. A



19

4
ep- B


19


4
Synopiidae






Svrrhoe bo.
38

38
57

27

-------
Table B-2. (Continued)
Fhylum
Class
Subclass
Order
Family	—Replicate/ (Ornanigns/m2)	 Mean Abundanoe
Cumaaea






Diastylidae






Diastvlis so. A
19
19



8
Leuocnidae






Eudorella sd. A


115
57

34
Leuoon so. A


19
19

8
Nannastacidae
19


19

8
Gaircfvlasois so. A
19




4
CanuvlasDis so. B



19

4
ProcancvlasDis so.A

19



4
Decapoda






Parapaguridae






sp.


19


4
Pasiphaeidae






Lectochela sd.

19



4
Isopoda






Cirolanidae






Oonilei* cvclindracea



19

4
Gnathiidae






grathia bp-

153

19

34
Mysidacea






Mysidae






Pseudcra« sd.
38




8
Tanaldaoea






Leptognathi idn«






Typhiotarwi« sp.


19


4
Sphyrapidhw






Snhvram s>.

19

19

8
Ectiirtodernata






Ophiurida*
19
96
19
57

38
Totals
1184
6746
4758
4928
2616
4054
Number of Specie*
25
32
26
35
24
70
Shannon-Weaver Diwii lity	4.34 2.92 2.27 2.79 3.53	3.38

-------
Table B-3. Macro infauna Collected at Station M-2, Miami Harbor Interim
0CHD6 Study Area.
Fhylum
Class
Subclass
Order
Family	Pgp]) rate/ fOrganisans/m2)	 Mean Abundance
	Genus Species	 1 2 3 4 5 fOraanisms/m2)	
Cnidaria
Hydrozoa
19
19



8
Forifera






Unidentified sp. B
76
115

38
19
50
Aschelminthes






Nematoda
57
38
402
497
96
218
Mollusca






Aplacophora


19


4
Gastropoda






Ooluntoellidae


19
19

8
Karginellidae



19

4
Rissoidae
19


38

11
Trochidae

38



8
Unidentified spp.



19

4
Turridae

19



4
Pelecypoda






CUspidariidae



57

11
hfuculidae
19
38
96
153

61
Nuculanidae




19
4
Ihyasiridae
134
38
115
76
134
99
Scaphcpoda


19.


4
Dentaliidae




57
11
S iphcrodentaliidae


19


4
Annelida






Polychaeta






Airpharetidae






I so Ida culchella
19
38
38
172

53
Capitellidae

19

19
57
19
Crrratulidae
191
115

210
38
111
Flabelligeridae


38


8
Glyoeridae




19
4
Goniadidae






Gcniada sp.

38
38


15
LLcnbrineridae






Lurfcrineris brevioes



76

15
Lunfcrineris so.
96
191
19
57
134
99
Magelcnicfap






Maaelcro so.

19



4
Maldanidae


19
19
19
11

-------
Table &-3. (Osntinuod)
Riylum
Class
Subclass
Order
Family
	Genus Species
Replicate/fOrganisms/m2^	 Mean Abundance
-1	1	3	4 5 (Oruanisrcs/m2)
Nephtyidae
Neohtvs sp.
Onuphidae
Opheliidae
ochelira sp.
Orbiniidae
Paracnidae
sp-
Spioridae
ParaprionosDio sp.
Prioncspio sp.
Arthropoda
Crustaoea
Malacastraca
Anjphipoda
Anpeliscidae
19
19
38
76
38
76
19
57
76
19
19
38
76 134 172
57 172
249
38
115
19
76
19
15
46
8
23
4
107
8
115
Aapelisca aaas3i2i
153
19
1358
994

505
Ajqphilocftidae


19


4
Lysianassidae

19



4
Hifparafcn sp-
19




4
FtiaxDoephalidae


19
19

8
Haroinia sd. A


38


8
HajpiJU? sp. B

19

57

15
Oedioerotidae

38


19
11
Unidentified sp. A

19


19
8
Unidentified sp. C

38



8
Synopiidae




19
4
5yrctw? sp-
19




4
Caridean shriap



19

4
nimrwi






Bodotriidae

19



4
Diastylidae


19


4
ep.


19
19

8
T«iirwj
-------
Table B-3. (Ccntinued)
Ftiylum
Class
Subclass
Order
Family	Replicate/ fOrnanisms/m2^	 Mean Abundance
		Qenus Species	1	2	2	4	5 (Organisms/m2)	
Euphausiaoea
Euphausiidae
Euphausia sp.	19	4
Mysidaoea
Mysidae
PseudcriTB sp.	19	4
Echinodermata
Anjphiuridae
Anchiura sp.	19	4
ophiuridae	38	8
Totals	1163 1238 2733 3188 935	1852
Number of Species	21 23 23 29 19	62
Shannon-Weaver Diversity
3.91 4.39 2.82 3.63 3.82
4.24

-------
Table B-4. Macroinfauna Collected at Station M-3, Miami Harbor Interim
OCMDS Study Area.
Fhylum
Class
Subclass
Order
Family	Reel icate/ (Organists An2)	 Mean Abundance
	Genus Species	1 2 3 4 5 fOrrranisms/m2)	
Crudaria






Hydrozoa


19
19

8
Porifera






Unidentified sp. A

19



4
Unidentified sp. B

19


19
8
AschelmiiTthes






Nematoda
631
841
1033
994
1109
922
tollusca






Gastropoda






Oolunbellidae
76
38
19
76

42
Glycymeridae
38




8
Haminoeidae



19

4
Marginellidae






Granulina ovuliformis

19



4
Rissoidae




38
8
Trochidae



38

8
Turridae

19



4
Pelecypoda






cuspidariidae
38




8
Nuculidae
210
134
344
76
76
168
hfuoilanidae
19



3J
11
Tellinidae






Hiyasiridae






Volrulella Dersimilis
191
306
172
268
287
245
Scaphopoda






Dentaliidae
76
19
38
38
9(
53
Siphonodentaliidae

57


IS
15
Annelida






Oligochaeta
38
57

19

23
Polychaeta





95
Aa^haretidae
38
134
229
57
19
Iaolda sp.

402
229

172
161
Iaolda rxilchella
153


325

96
Capif Ilidae
96
38
38
38

42
Cirrartulidae
325
956
363
899
440
597
Darvilleidae
19


134

31
Flabelligeridae

19

19

4
Gcniadidae
57

19

19
Glyoeridae



38
19
11
Hesicnidae


19


4

-------
Table B-4. (Continued)
Riylum
Class
Subclass
Order
Family	Replicate/fOrqamsms/m2)	 Mean Abundance
	Genus Specie?	1 2 3 4 5 roroanisms/m2}
Lunbrineridae

96
115

57
54
Ltf^riJTWiS sp.
76


57

27
Magelcnidae




19
4
Maaelona sp.
19
19



8
Maldariidae
38
38
38


23
Nephtyidae

76
57

76
42
l*epfitY5 sp-
57


76

27
Onuphidae
19



38
11
Opheliidae .




19
4
Oohelina sp.



38

8
Orbiniidae
210
535
937
344
440
493
Paracrvidae






Aricifoe sp-
210
191
535
287
134
271
Fhyllodocidae






Rrvllodoce ed.
19




4
Polynoidae


19


4
Spicnidae

38



8
Pri«T«??s>iUi^Mwy


19
19
19
11
Lysianassidae




19
4
Hinjuitsiii sp.
19

38
38
19
23
Oedioerotidne
19


19
19
11
Pcrrtocrates sp.

19



4
Unidentified sp. A


19
19

8

-------
Table B-4. (Ocntinuad)
Riylum
Class
Subclass
Order
Family
	Genus Species
Paraded iscidae
EtoGKooephalidae
Harpinia sp. A
Harpinia sp. B
Harpinia sp. C
Harpinia sp.
Stagooephal idae
SEsgssasbaleids sp.
Synqpiidae
syrrtws sp.
Cumaoea
Diastylidae
niastvlis sp.
Leuocnidae
P^TTSlla sp.
Nannastacidae
CanTYlrepig sp. b
Decapoda
Paguridae
Pasiphaaidae
Sexrjestidae
Isopoda
Cirolanidae
ftmlara
PesnrYvn sp.
Gnathiidae
Sa££ti« sp-
Tanaidaoea
Apseudidae
sp-
tafhi 1 rtv»
LBPtanrthla sp-
E^ratanaidH
Pseudctanaidae
P^rtThwnls sp.
SphyrapidM
Schvracac sp.
Replicate/ fOroanisjns/m2^
A	2	3	4 5
Mean Abundance
fOmanisms/m2)
19
38
19
57
19
76
19
19
38
19
19
19
19
19 19
19
76
19
19
38
19
38
19
57
19
38
19
19
19
19
19 19
19
38
96
57 19 115 57 57
19 76 19
19
19
38 38 38 19
19
8
23
42
8
11
4
15
11
61
27
4
4
4
8
4
27
11
4
34
4
19

-------
Table B-4. (Oontirued)
Riylum
Class
Subclass
Order
Family	Reel icate/ (Ornanisns/m2)	 Mean Abundance
		c;,enus Species	1 2 3 4 5 (Omanisms/m2)	
Ostraaoda
Myodoccpida
Asteropidae	19	4
Halocyprididae
Euconchoecia sp.


38

8
Riilcniedidae





ffcltMnSMS p?ucichel.atus
38
38
19

19
Unidentified genus A
19



4
Podocopida





Cvtherellidae



19
4
Unidentified family A
19



4
Echinodennata





Ophiuroidea

96
38

27
Ophiuridae
76 38
38


30
Airphiuridae
19



4
Totals
3395 9248
8599
4831
4069
6041
Number of Species
41 48
38
41
35
88
Shannon-Weaver Diversity
4.51 3.20 3.44 4.10 3.86
4.11

-------
Table B-5. Macro iruCauna Collected at Station M-4, Miami Harbor Interim
OCMDS Study Area..
Ftiylum
class
Subclass
Order
Family
	Genus Species
Porifera
Unidentified sp. B
Rhynchoooela
Aschelminthes
Nematoda
Mollusca
Aplacophora
Gastropoda
Oolurnbel 1 idae
Epitmiidae
Haminoeidae
Rissoidae
Trochidae
Turridae
Pelecypoda
CUspidariidae
Nuculidae
Nucalanidae
Solenyacidae
Thyasiridae
Scaphopoda
Dentaliidae
S iphcnodental i idae
Annelida
Oligochaeta
Polychaeta
Aapharetidae
Isolda BJldieUa
iselsto sp.
Capitellidae
drratulidae
OoGsuridae
Gcniadldae
Lurixineridae
HitrlTyriff sp.
Maldanidae
Nephtyidae
ftephtY? sp-
Ox^phidae
Qrbiriiidae
Rgpl icate/ (Organisms /m2 1	 Mean Abundance
•/«£&
172




34

38

38

15
191
363
76
115
153
180
19







96
19



19



4

19

38

11


19


4
38




8
19




4
19


19

8

115
19
249
191
115

19



4

76



15
115
631
134
268
134
256

19
76


19

19

19

8

38

38

15



38
38
15

363
57
76
134
126
96




19

115
38
19

34
96

115
76
325
122

784



157
19
19



8

57



11
115

38
38

38

19

38

11

38
19


11
57


38
19
23

19



4
38
96
57
191
76
92

-------
Table B-5. (Continued)
aiylum
Class
Subclass
Order
Family
	Genus Species
Repl icate/ f Organisms /nt21
1 2 3	4	L
Mean Abundance
(Onranisms/m2)
Paracnidae
Aricidea sp.
Spicrudae
Prionospio sp.
Syllidae
Arthropoda
Crustacea
Cephalocarida
Hutchinsoruel 1 idae
Hutchinsoniella pacraca
Natantia sp.
Malaacstraca
Anphipoda
Aaginellidae
Maverella sp.
Anpeliscidae
ftirelisqi yassisi
Haplocps sp. B
Aoridae
Vnigpls «?rrata
Vnioola sp-
Garanaridae
Lysianassidae
HiiAjaiitaXn sp.
Oedicerotidae
Monocolodes sp.
Unidentified sp. A
Pardalisciffap
Riotidae
Fhcxooephal iifae
Harpiiua sp. A
Harpinia sp. B
Haroinia qpp.
Methanrira
Stenottaoidae
PmmrtwUa sp-
Synopiidtae
Smfoe SP-
19
57
76
19
19
19
19
19
19
19
19
57
153
19
19
593
19
19
19
134
19
153
38
76
96
19
19
210 1644 2199
19
19
38
19
19
19
19
19
19
19
19 19
11
23
31
88
11
19
4
4
4
4
944
4
8
.4
8
4
4
8
4
4
4
4
4
8
4
4
8
11

-------
Table B-5. (Continued)
Riylum
Class
Subclass
Order
Family
Replicate/ f Organisms Art2)	 Mean Abundance
Cumacea
	A...
, * .
. ..


iuiwuxLSTB/nr- j
Bodotriidae






Cvclasois sd.



19

4
Diastylidae






Diastvlis so. A
19
19
76


23
L«epty5tYliS sp.




19
4
Leucxnidae






Mtorella sp.
76
38
76
57
38
57
Nannastac idae






carovlasois sp. B
36

19
38

19
Isopoda






Cirolanidae






Conilera cvlindraoea

19

19

8
Giathiidae






enattua sp.

19

38
19
15
Tanaidaoea






Paratanaidae

19



4
Ostracoda






Myodooopida






Halocyprididae






Unidentified genus A
19




4
Unidentified genus B
38




8
Sipuncula




19
4
Echinoderaata






Ophiuroidea






Aiqphiuridae



19

4
C^hiuridae
19


19

8
Totals
1507
3859
1430
3418
3650
2779
Number of Species
30
32
25
30
21
72
Shanncn-Vfeaver Diversity
4.41 3.73 4.20 3.19 2.42
4.13

-------
Table B—6. Macro infauna Collected at Station M—5, Miami Harbor Interim
0CMD6 Study Area.
Phylum
Class
Subclass
Order
Family
	Genus Species
Ftepl icate/ fOrganisms/in2)	 Mean Abundance
_1	2	3	4	5 f Praam sns/m2)	
Cnidaria






Hydrozoa
19
19

19
19
15
Parifera






Unidentified sp. B

76
57


27
Rhynochocoela

19
19


8
Aschelminthes






Nematode
134
306
153
96
172
172
Mollusca






Aplacophora

19



I
Gastropoda






Epitcniidae






Haminoeidae
19



19
1
Retusidae


19


i
Pelecypoda






Cuspidariidae






Lucinidae
57

153


42
Nuculidae
115
57

96
344
122
Semelidae



57

11
Abra aeaualis




19
4
Abra geoua

19



4
Limacina inflata

19



4
Solenyacidae
210
191
96

402
180
Tellinidae
19
57
76
76
57
57
Thyasiridae
19
115

19
210
73
Scaphopoda






Dentaliidae
57
57
134

76
65
S iphcrodental i idae
153

57

38
50
Annelida






Oligochaeta
76
57
96
76
57
72
Polychaeta






An^haretidae
38
268
38
57
210
122
Aqphironidae
19

57


15
Capitallidae
612
38
210
38
19
183
Cirratulidae
115
459
229
172
631
321
Darvilleidae
57
38

19

23
Glyceridae
19

19

57
19
Gcrtiadidae
38
96

38
96
54
Hesicnidae
19




4
Iisbrineridae



19

4
Iurbrineris so.
19
38
19

96
34

-------
Table B-6. (Continued)
ttiylum
Class
Subclass
Order
Family	Replicate/(Orcranisms/m2!	 Mean Abundance
Genus Species	1 2	3 4 5 fOramisms/m2)
Magelcrudae
Maaelcra sp.
Maldanidae
Nephtyidae
talaqrcftus sp.
Nereidae
Opheliidae
Cfrhelina SP-
Onuphidae
sp.
Orbiniidae
Paraanidae
ftricifea sp-
Pactinariidae
Ffiyllodocidae
Polynoidae
Sabellidae
Spicrvidae
Pricncspio sp.
Syllid&e
Teretoellidae
Sipuncula
Arthropoda
Malacostzaca
Anphipoda
Airpeliscidae
Ampelisca ftgassizi
A»elisca sp. A
Aoridae
sp-
Hyperiidae
icjLms temalensis
pnliiUM iAw
nil trhi* Bp.
Syncpiidaa
Qjnaoww
NanraBtaddae
CfWiylMgiS sp. A
sp. B
SP- A

19



4




38
8



19
57
15
19
19
38


15


19


4




19
4


19


4
19
76

57
57
42


19


4
191
746
325
363
535
432
76
516
115
191
268
233

19



4

19

19

8
57
76
115

57
61
19




4
249
899
516
229
306
440
19




4


19


4
38




8
19
134
115
96
134
100

38
19
19

15

19
57


15




19
4



19

4




19
4
19




4


19


4

19



4

-------
Table B-6. (Continued)
Hiylura
Class
Subclass
Order
Family	Replicate/ fOroanisms/m2)	 Mean Abundance
	Genus gRayteg	1 2 3 4 5 f Organ
Decapoda
Alpheidae
AlPheus fl
-------
Table B-7. Macroinfauna collected at Station M-6, Miami Harbor Interim
CCHD6 Study Area.
Fhylura
Class
Subclass
Order
Family	Replicate/ fOraanisns/Tn2!	 Mean Abundance
		Genus Species	1 2 3 4 5 f Organisms/m2)	
Cnidaria
Anthozoa






Artiiuaria sp-


19


4
Hydrozoa
19
19

19

11
Rhynchocoela


38


8
Aschelminthes






Nematoda
38
229
287
249
210
203
Mollusca






Aplacophora


19


4
Cephalopoda






Sepiolidae


19


4
Gastropoda






Coluntoellidae

38


19
11
Haminoeidae


19


4
Retxisidae






Rissoidae



19
19
8
Pelecypoda





19
Cuspidariidae



19
76
Lucinidae

38



8
Nuculidae

134

287
57
96
Nuculanidae

76



15
Semelidae
19




4
Tellinidae






Thyasiridae
19
57
229
38
306
130
Scaphopoda






Dentaliidae


38
19

11
S iphcnodental iidae



19
38
11
Annelida






Oligochaeta
19

19


8
Polychaeta





19
Aqpharetidae



38
57
Tsolda oulchella
19
440



92
Isolda sp.



134
134
54
Capitalliffaw
38
38
76
57

42
Chaedtqpteridae
19




4
Cirratulidae
191
803
153
268
153
314
Darvillf iftw



19
19
8
Glyoeridae
76



19
15
GcniadLidae

19
19
38
19

-------
Table B-7. (OortiruBd)
Fhylura
Class
Subclass
Order
Family	Reel icate/ (Organisms/m2)	 Mean Abundance
	Genus Species	1 2 3 4 5 fOroanisrns/ro2)	
Lumbrineridae

57
76


27
Lumbrineris sd.
210


96
57
73
Magelcnidae






Maaelona sp.


19


4
Maldanidae

19



4
Nephtyidae


19
38
38
19
sp.
57
96



31
Opheliidae



19

4
Ctohelina sd.
76




15
Orbiniidae
96
115
306
229
287
207
Paraemdae






Aricid*# sp.
57
19
76
38
19
42
Pisicsiidae


19


4
Folytnoidae




19
4
Sabellidae

19



4
Spicnidae

19



4
Pricoosoio so.
134
19
287
306
96
168
Sipuncula
19




4
Arthropoda






Crustaoea






C£phalocarida






Hutrfiinscniel 1 idae






Hutrhinsoniella maeraca




19
4
Malacostraca






OmaoRa






Nannastacidae
19




4
Caircvlasois so. B

19


19
8
Diastylidae






DiasWliS sp.

19
19

38
15







Euderella sp-

57
19
19
57
30
Isopoda






QTatbi idae






Gnathla sp.
19

19
19
19
15
Cirolanidae






Ccnilera cylirifrawa


19
38
19
15
Anphipoda






Aaginellidae






Maverella sd.

19



4

-------
Table B-7. (Qcntiruad)
Fhylun
Class
Subclass
Order
Famil>r	Replicate/fOrganisms/m2^	 Mean Abundance
Anjpeliscidae






Airoelisca aaassizi
2027


3920
402
1270
Airoelisca sd.


19


4
Aoridae






Urciola so.

19



4
Eusiridae






Eusirus sp.
38




8
Lysianassidae

19



4
Hinocnedon sc.
19


19

8
Oediaercrtidae

19
38

38
19
Unidentified sp. A
19
19
19
19

15
Paramphithoidae






Epiperi? sp.

19



4
Paradaliscidae



19

4
RvDxooephalidae






Paff9PhWJS sp.
19




4
Synopiidae

19



4
SYUtYX sp.
19
76


38
27
Decapoda






Pasiphaeidae






Leotochela Dacwlata
19



38
11
Process idae






Processa sd.




19
4
Tanaidacea






Paratarwidae


19
38

11
Ostraooda






Podoocpida






Paracyprididae


19


4
Echinodernata






C^hiuroidea






Ophiuridae

76
19
57
38
38
Totals
3285
2672
1927
6097
2367
3278
Nfumber of Species
25
33
28
29
30
69
Shcvnnon-Weaver Diversity
2.50 3.81 3.90 2.37,'4.13
3.85

-------
Table B-8. Macro irifauna Collected at Station M-7, Miami Harbor Interim
OCMDS Study Area.
Riylura
Class
Subclass
Order
Family	Replicate/fOrganians/m2)	 Mean Abundance
	Germs Species	1 2 3 4 5 fOroanisms/m2)	
Cnidaria
Hydrozoa
19


19

8
Rhynchocoela

19
19
19

11
Asc±ielmirtthes






Nematoda
497
363
746
134
363
421
Mollusca






Gastropoda






Oolumbellidae
19


19
38
15
E^itoniidae






Haminoeidae
19
19
19


11
Marginellidae






Granulina ovuliformis






Retusidae






Turridae
19



19
8
Pelecypoda






Cuspidariidae
19
19
76
38
76
46
Lucinidae




38
8
Nuculidae
172
249
268
287
249
245
Nuculanidae
19



19
8
Solemyacidae






Thyasiridae






Volrulella Dersimilis
96
76
210
172

111
Scaphqpoda






Dentaliidae


19

38
11
S iphonodental iidae


19


4
Annelida






Oligochaeta

38
3S
57
57
38
Polychaeta






Aqpharetidae
191
19
76
19
57
72
Tsolda pilchella

115
38


31
Isolda sp.
19



325
69
Capital 1 JiiM
19
76

115
172
76
drzatulidae
96
325
191
134
803
310
_DccrvillftidBe



38

8
Flabelligeridae



19

4
Ganiadidae




19
4
Glyoeridae


38


8
Hesicriiftftp

19



4
Luntorineridae
38



19
11
sp.

19
19
57
38
27

-------
Table &-8. (Oantinued)
Fhylun
Class
Subclass
Order
Family	Reel icate/ (Organisms/m2)	 Mean Abundance
	Genus Species	1 2 3 4 5 (Oraanisns/nt2)	
Magelonidae
19




4
Maldanidae
76
38
19
19

30
Nephtyidae






Nechtvs sp.



19
96
23
Nereidae



19

4
Orruphidae

38
19
57
19
27
Opheliidae
38

19


11
Orbiniidae
134
134
382
96
115
172
Paraonidae






Aricide? sp-
115
115
153
191
19
119
Polynoidae



19

4
Sabellidae



19

4
Spicrddae



19

4
Pri
-------
Table B-8. (Continued)
Fhylum
Class
Subclass
Order
Family
	Genus Species
Replicate/ (OrganisnE/m2)	 Mean Abundance
1 2 3 4 5 (Oroanisms/m2^	
Rvoooooephalidae (dam.)
Haroinia sp. A
Haminia spp.
Paraphoxus sp.
Stegooehalidae
steoooeohaloides sp.
Syncpiidae
Svrrhoe sp.
CXmaoea
Bodotriidae
Cvclaspis sp. A
Diastylidae
PiflgtYliS sp.
Unidentified genus A
Leuccnidae
Eudorella sp.
Leuoon sp.
Nannastacidae
Canpvlaspis sp. B
Isopoda
Anthuridae
Cirolanidae
Ctnilera cvlindraoea
DesnoGcnidae
Desnoscroa sp.
Giiathiidae
Cftattlia sp-
Mysidiaaaa
Taraidaoea
Apseudidae
toseudes sp.
Paratanaidae
Spbyrapiilae
atiynpg sp-
Ostracoda
Pycnogcnida
Nyi^iicriidae
EYlTtaO sp.
38
19
19
19
19
38
57
19
19
38
38
38
38
19
38
57
76
57
38
19
57
38
19
19
19
38
19
19
19
19
38
96
19
19
76 134
19 19
38
19
96
19
38
19
19
4
8
11
4
8
15
4
4
69
8
38
4
15
15
54
4
11
30
15
4
19

-------
Table B-8. (Continued)
Hiylum
Class
Subclass
Order
Family	Replicate/fOrganisms/m2)	 Mean Abundance
		SSIUS-SES^K—		1 2	2	4 5 fOroanisns/m2)	
EcJunodernata
Ophiuroidea	57	11
Air^hiuridae	19	57 19 19	23
Ophiuridae	76	57	57	38
Totals	4698 5234 7050 5388 6936	5867
Number of Species	39 34 32 41 41	79
Shannon-Weaver Diversity
3.41 3.22 2.69 3.45 3.07
3.42

-------
Table B-9. Macro infauna Oollectod at Station M-8, Miami Harbor Interim
0CMD6 Study Area.
Fftylura
Class
Subclass
Order
Family	Replicate/ (Ortaanisms/rc2)	 Mean Abundance
Cnidaria




? .
(un-ieuu-sj;
Hydrozoa




19
4
Porifera






Unidentified sp. A

96

38
115
50
Rhynchoooela


19


4
Aschelminthes






Nematoda
76
172
344
134
860
317
Mollusca






Cephalopoda






Sepiolidae






Gastropoda






Columbellidae

19
19
38
115
38
Glycymeridae



19

4
Haminoeidae



19
19
8
Marginellidae






Granulina cvuliformis






Retusidae



19

4
Rissoidae


19

38
11
Pelecypoda






Cuspidariidae


19 .


4
Muculidae
38
96
344
.631
134
249
Nuculanidae
38
38



15
T.imaninidae






Limacina inflata
19
19



8
Lucinidae




210
42
Scsnelidae






Tftyasiridae
38
172
191

96
99
Volrulella rarsimilis



172

34
Veneridae

57



11
Scaphopoda






Dental iidae


19

153
34
Siphfncxlental i idafi

38
38
38
57
34
Annelida






Polychaeta



57

11
Arpharetidae


76
57

27
Isolds pulchella

19

172
497
138
IsQld^ sp.


153


31
Capital 1idrte


57
134
38
46
Cirratulidae
287
96
96
172
325
195
Glyceridae
38



19
11

-------
Table &-9- (Continued)
Fftylum
Class
Subclass
Order
Family
	Genus Species
¦Reelicate/(Oroanisms/m2 ^
-1	2	3 4 5
Mean Abundance
forganisms/m2)	
Goniadidae
19




4
Lumbrineridae






Luntorineris sd.
19
134
19

38
42
Magelcnidae






Maaelona so.


19


4
Maldanidae



19

4
Nephtyidae


19

76
19
NephtY5 sp.
38
76

19

27
Cnuphidae


19


4
Opheliidae


19


4
Ppheiina sp.

57

19

15
Orbiniidae
76
57
631
631
76
294
Paracnidae






Aricidea sd.
19
38
57
38
134
57
Spionidae




19
4
Prianosoio so.
38
134
287
229
38
145
Syllidae



38

8
Sipuncula






Golfinqiidae

19



4
Arthropoda
Crustaoea
Malaoostraca
Acphipoda
Aeginellidae
sp-
Anpeliscidae
Airoelisca
Haplocro sp. B
Aoridae
Unciol* SSX2
GamoaridBB
HyperiidM
Tpata-imn
Lysianassidae
Hi|i»iwtn sp.
Oedicerrtidhe
Unidentified sp. A
Paradaliacditae
Harpinia sp. B
H^iirinitf **>•
38
306 3499 4379
38
19
19
38
19
19
19
19
19
38
19
19
19
38
19
38
19
57
1652
8
4
4
15
8
4
4
30
4

-------
Table B-9. (Qontlmed)
Hiylum
Class
Subclass
Order
Family	Replicate/ (Orqanisns/nt2^	 Mean Aburriance
	GfflU? Spegjes	1 2 3 4 5 fOmanisns/m2^	
Synopiidae
Svrrtioe sp.	57 19	15
Cumaaea
Leucxnidae
Euriorella sp.	76 76	19	34
Nannastacidae
CgFPYlaSPiS sp. A	19	4
Cairovlasois sp. B	19	19	8
amella 6p. B	19	4
Presarrylflspjg sp.	19 19 38	15
Isopcda
Cirolanidae
Conllera cvlindraoea	38	8
Gnathiidae
Gnathla sp.	57 57 IS	27
Tanaidaoea
Leptognathiidae
Laptoanathia sp.	19	4
Paratariaidae	19 38	11
Sphyrapidae
Sahvracus sp.	19	4
Ostracoda
Myodooopida
Asteropidae	38	8
HiUcraedidae
Hart>arwp rerreictelfltu?	115	23
Padooopida
Cytherellidae	19 19	8
Paracyprididae	19 19	8
Ophiuroidea
Ariphiuri*e	19	4
OphiuridBB	57	38 38 38	34
Pycnoqcnida
Anootheiik*
tiStfiEBCOQilifl sp.	19	4

-------
Table B-9. (Oontimad)
Fhylum
Class
Subclass
Order
Family
Repl icate/ (Ornanisms/m2)	 Mean Abundance
Chordata
Ascidiacea
Unidentified juvenile


19

4
Totals
914 1852
6439
7528
3456
4044
Number of Species
19 26
34
37
35
74
Shanncn-Weaver Diversity
3.64 4.19 2.83 2.69 4.05
3.80

-------
Table &-10. Macroinfauna Collected at Staticn M-9, Hiami Hartoor Interim
0CMD6 Study Area.
Fhylum
Class
Subclass
Order
Family
	Genus Species
Replicate/(Organisms/m2!
1 2 3	4 5
Mean Abundance
fOrctaiusng/TTi^	
Cnidaria
Arrthozoa
Actiriiaria
Pliynchocoela
Aschelmirrthes
19
19
Nematoda
841
401
19
96
860
443
Mollusca






Aplacophora
19
19

19

11
Cephalopoda






Sepiolidae






Gastropoda






Atlarttidae

19



4
Colunbellidae
76
57

38

34
Glycymeridae
19




4
Haminoeidae

38


19
11
Retusidae






Rissoidae



38
19
11
Pelecypoda






Cuspidariidae

134
38
38

42
Nuculidae



38
96
27
Limacinickke






Limacina inflate




19
4
Lucinidae



38

8
Anodantia alist




19
4
Thyasiridne
363
765
38
19
268
291
Verier idae

38



8
Vitr inellidae
38

19

19
15
Scaphopoda






Dental iidae
19
38

19
57
27
Siphcnodentaliidaft

38

19

11
Annelida






Oligochaeta

57



11
Polychaeta






Aqpharetidae




19
4
capitellidtoc

37



11
drratajl idae
1128
669
38
57
937
566
Glyaeridae




19
4
Gcniadidae


19
19

8
IxmbrxnexiAse

38



8
Iirifcrinaris so.
57

96
19

34

-------
Table B-10. (Continued)
Riylum
Class
Subclass
Order
Family	Replicate/(Organisms/m2)	 Mean Abundance
	 Genus Species	1 2 3 4 5 (Oroanisms/m2)	
Maldanidae	19	19	8
Opheliidae
Oohelina sp.	19	38	11
Orbiniidae	115 57 19 96 19	61
Paraonidae
Aricidea sp.	96 19	19 325	92
Fhyllodocidae
Rwllodooe sp.	19	4
Pilargiidae	19	4
Spicriidae	19	4
PrionoGPio sp.	134 96	76 115	84
Sipuncula	38	8
Golfingiidae
Arthropoda
Crustaoea
Malaoo6traca
Anphipoda
Anpeliscidae
Ancelisca aoassizi	76 38	57	34
Hyperiidae
19	4
TffjtnqpT"" scftizwenra	is	4
Lysianassidae
Hinxjnedcn sp.	19 4
Oedicerotidae	38 76 23
Unidentified sp.	A 38 38 15
Unidentified sp.	B 19 19 19 11
unidentified sp.	C 19 4
Partial isddae	57 38 19
RKBtDoepbalidae
ap. B	19 38 19 19 19
Rirosinicte
Primp icfcmcnl	19 4
ScinidM
f^Hnia rnp.	19 4
19	4
Syncpiida®
Svrrftoe 9p.
Cunaaea
DiastyliAw
sp.	19 38	11

-------
Table B-10. (Continued)
Fhylura





Class





Subclass





Order





Family
Reolicate/ fOmanisms/m2'

Mean Abundance
Genus Species
1
2
3 4
5
(Oroanisne/m2)
Leuconidae





Eudorella so.
38
19
57

23
Nannastacidae





CaircvlasDis so. B
19

19

8
Decapoda





Dorippidae





Clvthocerus so.

19


4
Isopoda





Gnathiidae





Gnathia so.
19



4
Tanaidacea





Paratanaidae

19
19
19
11
Ostracoda





Myodocopida





Halocyprididae





Unidentified genus A

19


4
Unidentified genus C
19



4
Fhilaredidae



19
4
Harbartsus paucichelatus

19


4
Sarsiellidae





Sarsiella so.


19

4
Rriooopida





Paracyprididae



19
4
Echinoderrnata





Ophiuroidea
57

19
19
19
Ophiuridae

19


4
Totals
3820
3570
553 1144 3573
2536
Number of Species
29
33
14 23
34
66
Shannon-Weaver Diversity
3.38
3.78
3.44 3.97 3
.51
4.08

-------
APPENDIX B
EVALUATION OF THE DISPERSION CHARACTERISTICS OF THE MIAMI
AND FORT PIERCE DREDGED MATERIAL SITES
PREFACE
This Appendix contains the report by Scheffner and Swain of the Coastal Engineering Research Center
and a supplementary letter by Scheffiier presenting results for a sediment distribution representative of
sediment from Miami Harbor The report contains results for a sediment distribution representative of
the Miami Channel.
Since the completion of the both the report and supplementary letter, it was discovered that incorrect
units for the suspended sediment concentrations were presented. Concentrations were given in mg/1
whereas the concentrations were actually volummetric void ratios. To convert the volummetric void
ratios to concentrations, the values must be multiplied by the particle density (2 65g/cc) The values in
Figures 2 6 and 2 10 and Tables 2 4 and 2.5 of the report and the table in the supplementary letter need
to be multiplied by 2 65x10s to represent concentrations in mg/1 Table 2.4 and the table in the
supplementary letter are reproduced with modified values below
Table 2.4 (modified)
Summary of Computed Suspended Sill, and Clav Concentration
^Concentration in mg/1 above ambient)
Elapsed Time (sec) I Approximate Distance from Dredge (Miles)
Depth
1500
3000
4500
6000
(ft)
0.8
1 6
2.3
3.2
200
0.000000318
1 7755
4 505
2.65
250
0 018815
11.395
6.625
2.438
300
14.575
23.055
5 83
1.749
350
151.05
15 37
2.915
1.007
400
39 75
6 36
1.8285
0.689
Summary of Computed Maximum Suspended Silt and Clav Conce Oration
(Concentration in mg/1 above ambient)
Elapsed Time (sec) / Approximate Distance from C'redge (Miles)
Depth
1500
3000
4500
6000
(ft)
0 8
1 6
2 3
3 2
200
0 0000053
9 01
20 405
10 865
250
0 17755
53
29 15
10 335
300
87 45
103 35
24 91
7,42
350
715 5
68 9
13 515
4 24
400
193 45
26 5
7 95
2915

-------
EVALUATION OF THE DISPERSION CHARACTERISTICS
OF THE MIAMI AND FORT PIERCE
DREDGED MATERIAL DISPOSAL SITES
by
Norman U. Scheffner
and
Abhiaanyu Swain
Coastal Engineering Research Center
April 1989
Final Report.
Prepared for
US Army Engineer District, Jacksonville
Jacksonville, Florida 32232-0019

-------
PREFACE
This report describes a comprehensive approach for evaluating the
environmental suitability of proposed open water disposal sites for dredged
material. Two proposed Florida disposal sites are evaluated in this investi-
gation, one off the coast of Miami and one off the coast of Fort Pierce. The
purpose of the evaluation is to determine whether either site poses a contami-
nation threat to sensitive nearshore coral reefs. Two criteria are necessary
of a site if it is to be approved as environmentally acceptable. The first is
concerned with the immediate effects of the disposal operation, material from
the descending plume of sediments can not contaminate areas outside the
designated disposal site. This short-term phase analysis represents several
minutes to several hours following the initial release of material from the
dredge. The second phase of investigation determines whether material
deposited within the disposal site can be eroded and subsequently transported
out of the site by either local current fields or by storm conditions. This
long-term phase examines mound stability for periods of time up to one year
following the disposal operation.
A two-phase numerical modeling methodology was selected for this
investigation. The approach utilizes the Disposal From an Instantaneous Dump
(DIFID) model for calculating the short-term fate and a coupled hydrodynamic/
sediment transport model for computing the long-term fate of the disposed
material. The project was authorized and funded by the US Army Engineer
District, Jacksonville (SAJ), under the project management of Mr. Ronald Tapp
and Ms. Elizabeth Rhodes and under the general direction of Mr. A. J. Salem.
Much of the prototype data required for numerical model input were
provided by or extracted from research publications of Dr. T. N. Lee, School
of Marine and Atmospheric Science, Division of Meteorology and Physical
Oceanography, University of Miami, Florida. Supplementary velocity
measurement data were also obtained from other sources. The study was
conducted at the US Army Engineer Waterways Experiment Station's (WES) Coastal
Engineering Research Center (CERC). The numerical investigation was
completed, and this report prepared by Drs. Norman U. Scheffner and A. Swain.
Providing general supervision were Dr. James R. Houston and Mr. Charles C.
Calhoun, Jr., Chief and Assistant Chief, respectively, CERC; direct supervisior
1

-------
the proiect was provided bv Mr u i a
y "r » L. Butler, chief of the Research Division
and Mr Bruce A. Eb.r.oU, Chief of the Coastal Processes Branch of th.
Research Division. Commander and Director of WES during the course of this
study and che preparation and Dublleatinn nf »-u«
UQ puoiicacion ot this report was COL Dwayne G.
Lee, CE. Technical Director was I)jr. Robert. V. Whalin
2

-------
CONTENTS
Page
PREFACE 		]
INTRODUCTION 		6
Background and Objective 	 		6
Scope of Report		1C
PART I: LITERATURE REVIEW		12
The Gulf Stream		12
Gulf Stream Meanders		1£
Spin-off Eddies 		2C
Prototype Velocity Data 		2]
Depth Averaged Velocity 		22
Velocity Field Input Data 		36
Upwelling and Dovmwelling		37
PART II: THE SHORT-TERM SIMULATION OF DISPOSAL OPERATIONS 		3S
Input Data Requirement	 		4C
Method and Procedure for Short-Term Model Simulations 		4^
Miami Disposal Site		4S
Fort Pierce Disposal Site		52
PART III: THE SIMULATION OF LONG-TERM DISPOSAL FATE 		56
Sediment Transport 		57
Velocity Field Distribution 		6£
Sediment Transport Due to Non-Storm Velocity Fields 		62
Fort Pierce		63
Miami		69
PART IV: CONCLUSION		74
REFERENCES		75
3

-------
LIST OF TABLES
No .	Pap.e
1.1	Disposal Sice Characteristics for Miami and Fort Pierce		11
1.2	Basic Dimensions of the Gulf Stream Meanders		20
1.5	Current Meter Locations and Depth Averaged Velocities 		28
1.6	Velocity Distribution Offshore of Miami 		34
1.7	Velocity Distribution Offshore of Fort Pierce 		34
1.8	Summary of Upwelling Related Velocity Calculations
(Osgpod et al. 1987) 		38
2.1	Instantaneous Dredge Capacities and Dimensions 		42
2.2	Characterization of Dredged Material for Miami and Fort Pierce . .	43
2.3	Input Data Related to Disposal Operation for the Miami and Fort
Pierce ODMDS 		44
2.4	Summary of Computed Maximum Suspended Silt and Clay Concentration
(Concentration in rag/1 above ambient) 		51
2.5	Summary of Computed Maximum Suspended Sediment Concentration
(Concentration in rag/1 above ambient) 		53
LIST OF FIGURES
NcL_	Pa&e
1.1	Location of ODMDS, bathymetry map, and coral reefs for the Miami.
site . :		7
1.2	Location of ODMDS, bathymetry map, and coral reefsfor the Fort
Pierce site		8
1.3.	A schematic diagram of the origin of the Gulf Stream Gurrent
(after Sverdrup, JOhnson, Flemming, and Stommel 1965) 		13
1.4.	Satellite-derived path of the Gulf Stream (NOAA 1983)		15
1.5.	Mean position and meander deviation of the Gulf Stream surface
(Bane and Brooks 1979)			18
1.6.	Example of the propagation of Gulf Stream meanders at
quarter - period snapshots (Bane 1983)		19
1.7.	Current meter locations for Miami (Lee, Brooks, and Duing 1977) . .	24
1.8.	Current meter locations for Fort Pierce (Lee, Brooks, and Duing
1977) 	'		25
1.9.	Measured velocity profiles offshore of Miami 		26
1.10 Measured velocity profiles offshore of Fort Pierce 		27
1.11.	Depth-averaged current vectors from Miami to Fort Pierce 		32
1.12.	Depth-averaged current vectors north of Fort Pierce 		33
1.13.	Velocity vector distribution offshore of Miami 		35
1.14 Velocity vector distribution offshore of Fort Pierce 		35
2.1. Computational phases of the DIFID model (from Brandsma and Divorky,
1976) 		41
2.2	Suspended sediment cloud at 200 ft deep at 1500 sec after dump . .	47
2.3	Suspended sediment cloud at 200 ft deep at 3000 sec after dump	47
2.4	Suspended sediment cloud at 200 ft deep at 4500 sec after dump . .	48
2.5	Suspended sediment cloud at 200 ft deep at 6000 sec after dump ...	48
4

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No	Pa g
2 6 Time - concentration for Miami at 200, 250, 300, 350, and 400 ft. , .	5
2 7 Deposition pattern for the Miami site		5
2.8	Three-dimensional view of the Miami site disposal mound 		5
2.9	Contour plot of the deposition pattern for the Miami site 		5
2.10	Time-concentration for Fort Pierce at 10, 20, 30, 40, and 50 ft . .	5
2.11	Deposition pattern for the Fort Pierce site		5
2.12	Three-dimensional view of the Fort Pierce site disposal mound ...	5
2.12 Contour plot of the deposition pattern for the Fort Pierce site . .	5
3.1	Sediment transport vs velocity - Miami disposaL site 		5
3.2	Sediment transport vs velocity - Fort Pierce disposal site ....	5
3.3	WIS station 163 wave characteristic summary for the Miami site . .	5
3.4	WIS station 153 wave characteristic summary for the Fort Pierce
site		.
3.5	Velocity vectors around an idealized disposal mound 		6
3.6	Gradation curve of Fort Pierce sediment 		6
3.7	Initial mound configuration for Fort Pierce 		£
3.8	Fort Pierce mound configuration at 6 months 		6
3.9	Final Fort Pierce mound configuration at 12 months 		6
3.10	Time history of long-term erosion of the Fort Pierce mound		6
3.11	Final (24 hr) Fort Pierce storm mound configuration 		6
3.12	Time history of storm erosion of Fort Pierce mound		6
3.13	Initial mound configuration for Miami 		"6
3.14	Final Miami mound configuration at 3 months 		7
3.15	Time history of long-term erosion of the Miami mound 		7
3.16	Final (24 hr) Fort Pierce storm mound configuration 		7
3.17	Time history of storm erosion of Miami raound 	 7
5

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evaluation OF THE DISPFRSTQN characteristics
OF THE MIAMI AND FORT PIERCE
DREDGED MATERIAL DISPOSAL SITES
INTRODUCTION
Background and Objective
1.	Dredging of estuaries, bays, harbors, and coastal inlets in the
United States is often required in order to maintain minimum navigation
depths. The selection of an environmentally acceptable disposal site for this
dredged material requires some means of predicting the effects of the disposal
operation on the coastal and inland water environment. One means of predic-
tion is the utilization of numerical models capable of simulating the short-
and long-term diffusion and transport of dredged material from the disposal
site.
2.	The Corps of Engineers have become increasingly active in the area
of maintenance dredging of harbor channels and coastal inlets. The
designation of acceptable disposal sites for this material-is, however,
becoming increasingly difficult. Open water disposal sites are often selected
as a means of minimizing any adverse effects resulting from the disposal of
material in the vicinity of the dredging operation. This approach is accept-
able if the designated site is far enough removed from any environmentally
sensitive area that material at the site will remain at the site and not
represent a possible source of contamination.
3.	The Planning Division, US Army Engineer District, Jacksonville
(SAJ), is preparing an Environmental Impact Statement (EIS) for submission to
the US Environmental Protection Agency (EPA). The purpose of the EIS is to
evaluate the environmental impact of dredged material disposed at the proposed
Ocean Dredged Material Disposal Sites (ODMDS) offshore of Miami and Fort Pierce,
Florida. The location and bathymetries of these .sites are shown in Figures 1.1
and 1.2.
6

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Wjom» Beoch
Government Cut
OOMOS
Coral R*«f«
STATUTE MILES
NAUTICAL WILES 8|
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GENERAL LOCATION WAP
Oceon Dredged Uolenol Oisposol Site Miomi,florido.
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25 44 30"
25'«'OflT
23'43'OOT
T10
NAUTICAL Mll£S
BATHYMETRIC MAP
Oceon Dredged Moteriol Disposal Site Miorni,Florida.

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¦ The EPA has expressed a concern regarding the fate of the disposed
materials at both proposed ODMDS. It is feared that discharged sediments frc
either disposal site may be carried by the Gulf Stream and its spin-off eddie
onto sensitive shore-parallel coral reefs located approximately 1 mile off-
shore of the barrier islands. In addition to sediment transported by eddies
and ambient currents, the possibility of resuspension and subsequent transpor
of material from the disposal site during storm events is also an expressed
concern.
5.	The SAJ requested the US Army Engineer Waterways Experiment
Station's (WES) Coastal Engineering Research Center (CERC) to perform a
technical study of the Gulf Stream, the spin-off eddies, and other relevant
environmental forces, with respect to the potentials for reef contamination b
dredged material originating from either proposed ODMDS. The CERC was first
requested to study the acceptability of the proposed sites offshore of Miami
and Fort Pierce. If these sites are not found to be environmentally
acceptable, the first acceptable offshore location which does not pose a
contamination threat to the reefs should be identified.
6.	A preliminary technical review was performtid by the CERC (MFR,
9 February 1988) of the available literature provided by SAJ (Memorandum,
4 December 1987). The review concluded that a detailed disposal site evalua-
tion should be performed in order to determine whether velocities in the Gulf
Stream and its spin-off eddies are sufficient in magnitude to transport
disposed material from the proposed ODMDS onto the coral reefs.
7.	The study reported here uses a numerical modeling approach for
estimating both short-term and long-term fate of dredged material disposed at
a proposed ODMDS. The modeling of the short-term diuaving operation is
performed by the Disposal From an Instantaneous Dump [DIFID) model (Johnson
et al. 1988). Long-term simulations, using a newly teveloped coupled
hydrodynamic/sediment transport model (Scheffner 1981) , use depth averaged
velocity fields to determine whether non-storm related currents are capable o]
transporting sediments outside of the designated 0DMD3 over long periods of
time following the initial deposition. The effects o! storm erosion are
separately examined with the model by simulating the passage of a storm surge
over the site.
9

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Scope of Report
8.	The purpose of this study is to evaluate the dispersion character-
istics of the proposed disposal sites offshore of Miami arid Fort Pierce.
These two sites were selected as representative of the two primary
environments found off the east coast of Florida. The first is typified by
the proposed Miami site at which the bathymetry is complex, the water is deep
(greater than 500 ft), and the site is directly influenced by the Gulf Stream
and its spin-off eddies. Due to the close prqximity of the Gulf Stream to the
disposal site, it is feared that disposed sediments may be carried onto the
coral reefs by spin-off eddies shed by the Gulf Stream.
9.	In contrast to the Miami site, the Fort Pierce disposal site is
removed from the direct effects of the Gulf Stream, is situated on a broad,
gently sloping shelf, and is located in shallow water (less than 75 ft). This
ODMDS has a small cross-sectional area of flow compared to that of the Miami
site. A comparison of the site characteristics of both the Miami and
Fort Pierce ODMDS is given in Table 1.1.
10.	This investigation will classify each of the proposed disposal sites
as either dispersive of non-dispersive according to whether the local current
fields are capable of transporting material fron the disposal site onto the
reef area. This approach requires documenting the local velocities, at each
site in order to identify a reef-directed component which may be attributed to
the Gulf Stream. This component will be used to compute a sediment transport
rate and direction for use in evaluating the possibility of disposal site
related reef contamination. The following section represents the result of an
extensive literature review which begins with a description of the Gulf Stream
and its major characteristics. This portion of the review is included to
verify that shoreward directed spinoff eddies do exist and should be inves-
tigated as a possible source of sediment transport. This background d>cumen-
tation will be followed by a quantification of velocity magnitudes and
directions which are shown to be representative of each site. These
velocities will then be used as model input for the short- and long-teirm
stability analyses of Parts II and III.
10

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Table 1.1
Disposal Site Characteriseics for Miami and Fort Pierce
Characteristics
Miami
Fort Pierce
Vater depth
Greater than 500 ft
Less than 75 ft
Bottom slope
Steep (0.02-0.05)
Mild (0.001-0.002)
Topography
Complex (nonlinear)
Simple (linear)
Terrace
Miami Terrace confined
to a 2 mile offshore zone
No terrace zone
Flow cross-
section of
ODHDS
About 3,168,000 sq ft
About 294,000 sq ft
Continental
Margin
Wide
Narrow
Continental
Contains inner, mid, and
and outer shelf with sharp
shelf break.
Contains inner shelf
only
Direction of
Velocity
Westerly and northerly
Northerly
Magnitude of
velocities:


westerly
northerly
0.15-1.5 ft/sec
0.7-3.5ft/sec
0.05-0.5ft/sec
0.20-1.5ft/sec
Average axis of
Gulf Stream
15 miles offshore
80 miles offshore
Coastal currents
are primarily
driven by
Gulf Stream
Wind and tidal forcing
Gulf Stream
Effects
Present
Free
Dredged
materials
90% sand (fine
to medium)
90% sand (fine
to medium)

10% clay
10% clay
11

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part i: literature review
The Gulf Stream
11.	The objective of the literature review is to identify the primary
characteristics of the Gulf Stream and quantify Its basic structure,
magnitude, and limits of influence along the south and southeast coast of the
United States. A brief summary of the origin and dynamics of the Gulf Stream
is presented in this section as a preliminary background for the present ODMDS
selection study as well as for future site selection studies. The terms Gulf
Stream or stream are used throughout this section of the report to refer to
the entire current system off the south and east coast of the United States,
including the Florida Current.
12.	Figure 1.3 presents a schematic diagram of the dominant currents
and current induced secondary circulation patterns off the east coast of the
United States. The origin of the Gulf Stream begins as the Atlantic and North
Equatorial Current systems combine with the South Equatorial and Guyana
Current systems. This combined flow discharges through the Caribbean Sea
and Yucatan Channel into the southeastern portion of the Gulf of Mexico.
Because the waters are colder than the surrounding Gulf of Mexico, a density
differential is created which results in a deflection of the current from the
Gulf of Mexico toward the Straights of Florida. This density driven flow is
most pronounced during winter months. During this time, the current is often
sharply deflected from the Yucatan Channel through the Straights of Florida
as shown in Figure 1.3. However, the loop current can extend well into the
Gulf of Mexico during the summer months (Leipper 1967). Regardless of the
specific path, the current enters the Straights of Florida in nearly the' same
temperature, salinity, and density as when it entered the Caribbean Sea
(Lee, et al. 1977).
13.	The dynamics of the Gulf Stream are driven by the large tides of
the Caribbean Sea which dominate the smaller tides of the Gulf of Mexico.
These large tides force water through the long channel between the Florida
Peninsula and the islands of Cuba and the Bahamas, developing a water level
differential of about 2/3 ft (Stommel 1965) between the Gulf of Mexico and
12

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the Atlantic Ocean. As the current flows through the Straights of Florida
toward Miami, the axis of flow makes an abrupt 90 degree turn to the north and
enters the continental shelf channel. The approximate point of deflection is
indicated as position A in Figure 1.3. The cross-sectional area occupied by
the stream undergoes a change from approximately 90 miles wide and 1 mile deep
at Key West to approximately 50 miles wide and 0.5 miles deep in the vicinity
of Miami. This reduction in flow area causes an increase in stream velocity
with an accompanying decrease in free surface water level between Key West and
Miami.
14.	The Gulf Stream continues along the south and southeast coast of
the United States as shown in Figure 1.3. It is seen that the stream hugs the
continental shelf from the deep water region offshore of Miami, north to
shallow water depths of less than 100 m at Cape Canaveral. Beyond Cape
Canaveral, the stream is diverted into deeper water in the vicinity of the
Charleston bump (Brooks and Bane, 1978; Legeckis 1979), a topography anomaly
in the continental shelf slope between the 200 and 600 m isobaths. North of
the bump, the stream moves back onshore into waters of about 300 a. This
onshore shift o£ the current is primarily due to a steady Increase in bottom
slope north of Charleston. This increasing slopq, coupled with ridge and
trough bottom features, prevalent strong northwest winds, and barocllnic
instabilities cause the stream to subsequently deflect off the continental
shelf and become confined to a path between the 300 m and 400 m isobaths.
Position B in Figure 1.3 Indicates the approximate location of the offshore
point of deflection.
15.	The lateral extent of the width of the stream about its average
axis is shown in Figure 1.4. This figure, obtained from the National Oceanic
and Atmospheric Administration's (NOAA) field station at Miami and reproduced
in the Journal of Geophysical Research (1983) represents satellite imagery of
the Sea Surface Temperature (SST) structure of the Gulf Stream. The figure
demonstrates the variability in width of influence of the Gulf Stream about
its mean axis. The following section will investigate the spatial and
temporal characteristics of the Gulf Stream.
14

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jr 
Figure 1 U Satellite-derived path of tho Gulf Stream (NOAA 1983)
15

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Culf Stream Meanders
16.	The Gulf Stream is a high velocity thermal current which flows
along the outer continental shelf. The time-dependent structure of the stream
is a function of a combination of forces including the current distribution,
bottfom topography, wind stress, entrainment of fluid from below the free
surface, and rotational forces developed due to the rotation of the earth.
The constantly changing spatial and temporal structure of the streaa has been
widely studied and documented in the literature. Although an attempt to
quantify these dynamics are beyond the scope o£ this report, many of the
references used in this literature review to document the characteristics of
the Gulf Stream have been included in the list of references. Since this
report is intended to determine whether the Gulf Stream can adversely affect
either of the two proposed disposal sites, this section begins with a
description of commonly observed features which may directly impact either
ODMDS.
17.	The high velocity main body of the Gulf Streaa propagates in wave
like patterns referred to as meanders. The dynaaic features are'a result of
forces such as shearing Instabilities of the stream, geostrophic imbalances,
the transfer of kinetic energy to the mean flow, the passage of cold fronts,
the random passage of wind events, etc. Although the mean axis of the stream
propagates to the north, these forcings can produce localized undulations
about the mean axis which can locally flow either upstream (southerly),
downstream (northerly), onshore or offshore.
18.	Many documenting measurements quantifying the spatial variation of
meanders have been reported. Duing (1975) obtained 2 weeks of current profile
measurements off the coast of Miami and identified a current meander with a
^*-6 day period which was propagating to the north at approximately 45 cm/sec
with a wave length of nearly 200 km. Duing's data showed that when the lxis
of the Gulf Stream was displaced offshore, southerly flows occurred over
portions of the Miami terrace. Conversely, when the axis of the stream vas
displaced onshore, flows over the terrace were directed to the north. Thermal
gradients can be used to measure the primary features of meanders as they grow
in size or become skewed. Lee and Moore (1977), for example, have correlated
the distribution of meanders with the propagation of SST derived isotherms.
16

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19.	Meanders of the scream are commonly observed between Jupiter Inlet
and Cape Hatteras where the stream enters the wide continental shelf region
after passing through the topographic constriction formed by the Florida coast
and the Little Bahama bank. This discharge of water from a confined to an
unconfined area results in meanders in the stream axis which are no longer
primarily controlled by the continental shelf bathymetry (Lee et al 1981) but
are strongly influenced by weather patterns, long waves from the deep sea,
tidal forcing, and local wind fields Northeast of Cape Hatteras, the Gulf
Stream moves beyond our area ,of interest into deep water where they are no
longer controlled by continental shelf bathymetry.
20.	The meandering process is well illustrated in an example presented
by Bane and Brooks (1979) and Bane (1983), shown in Figures 1.5 and 1 6. In
Figure 1.5, a 64-week period of SST data are used to show the shoreward and
seaward envelope of occupation of the Gulf Stream in relation to the location
of the time - averaged mean axis shown by the dashed line. Figures 1.6 uses
quarter-period (16-week) incremental plots of the axis to illustrates how two
typical meanders (labeled A and B) occupy the shaded limits of the stream as
they propagate northward. Table 1.2 lists the basic dimensions of meanders
typical of those documented along the south and southeast coasts of Florida.
17

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200
200 km
Figure 1.5. Mean position and meander deviation of the Gulf Stream surface
(Bane and Brooks 1979)
18

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700
V
200
TOO rn
WOO
700
200 m
700
Figure 1.6. Example of the propagation of Gulf Stream meanders at
quarter-period snapshots (Bane 1983)
19

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Table 1.2
Basic Dimensions of the Gulf Stream Meanders
Wave length (longitudinal)
Lateral displacement (east-west)
Average velocity of propagation
Maximum downstream current speed recorded
Features
Dimensions
90 - 260 km
1 - 100 km
47 cm/sec
134 cm/sec
Results of this investigation have shown that much of the Continental Shelf
area south of Cape Hatteras is subject to the direct influence of the Gulf
Stream. Nearshore areas can also be affected by the Gulf Stream even though
the area in question may not be directly impacted by the envelope of meanders.
The following section will address Gulf Stream eddies in order quantify their
potential impact on the proposed Miami and Fort Pierce disposal sites.
21.	The movement of the Gulf Stream through the continental shelf often
creates rotational patterns which propagate away from the main body of the
Stream, These patterns generally represent unstable meanders which have
become detached from the main body of the stream. This can occur if the
meander becomes too pronounced or deviates too far from the main axis of flow,
in which case , detachment into the low velocity ambient current can be caused
by topography anomalies, wind fields, or barotropic Instabilities. These
detached secondary currents are referred to as spin-off eddies and are
commonly observed in the shallow slope and terrace waters (40-80 a) off the
coast of Florida. The following sections describe some of their basic
characteristics.
22.	Richardson (1985) identifies three distinct zones of the Gulf
Stream. These are the clockwise rotating onshore eddy, the axis or main body
of the Stream, and the counterclockwise rotating offshore eddy. The high
velocity axis of the Gulf Stream acts as a barrier separating the onshore and
offshore regions. Depending on the environmental conditions, detached onshore
eddies can propagate to the north, shoreward, or to the south with short-lived
Spin-off Eddies
20

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periods ranging from 2 days Co 2 weeks. Eddy diameters range from 10 to 30 k
and can extend from the surface to a depth of approximately 200 m (Lee and
Mayer 1977). Detached eddies have been observed to propagate with surface
velocities ranging from 20 to 100 co/sec
23. The above sections of this report have documented the dynamic
properties of the Gulf Stream and its spin-off eddies. The data presented
indicate that, at times, the Gulf Stream does generate, or contribute to,
shoreward directed velocity fields which may affect either or both of the
proposed disposal sites. Thfe effects can be compounded when coupled with
shoreward-directed flood tide conditions. The magnitude of this total
shoreward directed velocity field will be determined from the available data
such that a boundary condition velocity field for each ODMDS can be defined a«
input to the short- and long-term sediment transport calculations. The
following sections describe the selection of a maximum shoreward-directed
velocity for each of the designated sites based on available prototype data.
Prototype Velocity Data
2U. The site designation approach utilizes sediment transport theory
and numerical modeling techniques to determine possible magnitudes of erosion
and/or transport of sediment from a specified disposal site. The computation:
are based on a specific depth and background velocity field for each site
which will be documented to be representative of the location. The site
evaluation approach is inherently conservative in that a constant, maximum-
valued, reef-directed velocity is selected as a boundary condition for
sediment transport calculations. In reality, the velocity field is continu-
ously fluctuating as a function of tides, wind fields, waves, the Gulf Stream,
etc.; therefore, no single representative value is truly descriptive of any
-location. Also, two measuring periods would yield two different values;
however, when the length of data is sufficiently long, the two computations
should not vary significantly in magnitude. Data which cover sufficiently
long periods of time to satisfy these criteria will be used in determining
appropriate boundary conditions.
25. Since maximum values are to be selected, the degree of accuracy
achieved by this approach is considered adequate as a basis for reliable
21

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predictions of the dispersion characteristics of a disposal site. If it can
be shown, for example, that the prototype velocity in 500 ft of water never
exceeds 30 cm/sec (or 40, or 50) and that a velocity magnitude of 100 cm/sec
is necessary for initiating and transporting sediment transport at that depth,
then the data are adequate to show that the site under investigation is non-
dispersive and will not represent a source of contamination. Severe storm
conditions are not included in this analysis since it is assumed that disposal
operations would be discontinued during storm events.
26.	A large data base of published current meter data was identified
i
which was acceptable for quantifying the velocity patterns off the eastern
coast of Florida. Data included measurements at multiple depths in the water
column for various mooring string sites extending from south of Miami to north
of Fort Pierce and from less than 1 km to more than 100 km offshore. Although
the spatial distribution of data is sparse in its coverage of the disposal
site locations, the data base is adequate for determining a velocity field
which is representative of each survey area and can be used to evaluate the
transport potential of each disposal site. In the present context, adequacy
refers to data which covers a sufficient length of time and number of vertical
locations within the water column, that a reliable depth-averaged velocity can
be computed.
27.	Multiple sources of acceptable velocity data were located*for
application in the present Miami and Fort Pierce disposal site study. The
following sections will use this data, in addition to other available data, to
develop a spatially consistent data base of depth averaged velocity vectors.
The intent of this multiple station analysis and inter-comparlson is to
develop velocity vectors which are consistent with surrounding data and are,
therefore, truly representative of the area.
Depth Averaged Velocity
28.	The site designation approach computes short-term and long-term
potentials for sediment transport as a function of a site-specific, depth-
averaged velocity field. The depth averaged condition was selected for two
reasons. First, due to the limited time available for this study, a represen-
tative velocity field had to be defined from existing data. Available data
22

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was sufficient for determining a maximum shore-directed, depth-averaged
current but was not adequate in either duration or distribution to define any
meaningful vertical velocity distribution trend. Secondly, an "average"
vertical distribution probably does not exist, since the vertical velocity
structure shows a continuously changing current gradient due to variations in
the wave fields, salinity gradients, thermoclines, and Gulf Stream meanders.
Also, attempting to compute site-specific sediment movement as a function of a
three-dimensional velocity distribution is not feasible. For these reasons, a
depth-averaged current was selected for input to both the DIFID and long-terra
sediment models. The computation of the selected velocity field is described
in the following sections.
29.	Two examples data sources are used here to demonstrate the
computation of a shoreward-directed depth-averaged velocity field. Both
sources of data are reported by Lee, Brooks, and Duing (1977). The Miami data
was collected as a portion of the SYNOPS 71 (Synoptic Observations of Profiles
in the Straights) project. The research vessels Calanus (C), Humble (H),
Pillsbury (P), and Gerda (G) simultaneously collected 16 days of vertical
profiles of horizontal velocities. These measurements were taken every*3
hours at the four locations between Miami and Bimini shown in Figure 1.7.
Ship - deployed measurement stations for the Fort Pierce area are shown in
Figure 1.8. These reported data are based on the analysis of multiple data
sets, collected at each of the data collection stations over a period-of
approximately 5.5 years.
30.	Velocity measurements for the Miami transects are based on
Profiling Current Meter data (PCM). The data were reduced to u (+• to the
east) and v (+ to the north) velocity components and then averaged over 5 m
depth intervals. Details of the deployment can be found in Lee, Brooks, and
Dulng 1977, Duing and Johnson 1972 and Duing 1973. Figure 1.9 displays three
types of velocity profiles which were constructed from the velocity time
series data records for mooring sites C, H, P, arid G. These represent the
measured maximum, minimum, and mean velocity. The depth averaged value is
also indicated in the figure. The minimum u velocity (negative referring to
westward) and corresponding v component were used to compute the shore-
directed depth-averaged velocity vector indicated by the dotted line.
23

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CMAMJS
KJMBUC
wasauffr
GtHOA
ttscdrmf
Current meter locations for Miami (Lee, Brooks, and Duing 1977)

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Current Meter
Locotionj
FORT PIERCE
80'	79'W
Figure 1 8. Current neter locations for Fort Pierce
(Lee, Brooks, and Duing 1977)
25

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STATION C
U-COuPONENT CM/SEC	V-COMPONEfn CM/SEC
- too
too 200
200
400
MINIMUM
600
800
100 200
-100
200
U MAXIMUM
J 400
600
800
STATION- H
200
£ 400
c.
U-COUPONENT CM/SEC
-too 0 100 200
MAXIMUM
U,
600
MINIMUM
800 L
V-COMPONEMT cm/scc
-100 0 100
MAXIMUM
LEGEND
800 l-
CURRENT PROHlfS
uean
vuiu:i
DEPTH AVERACED
	VUIMIMUM / V MAXIMUM
Figure 1 9
Measured velocity profiles offshore of Miami
26

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STATION. P
U-COWPONENT cm/sec
¦100 0 100 200
200 -
J 400
Q.
600
BOO
U MAXIMUM
MINIMUM
V-COUPONENT CM/SEC
-100 0 100 200
t 400
MAXIMUM
MINIMUM
U-COUPONENT CU/SEC
-100 0 100 200
200
£ 400
Q.
O
600
S00

V 1 1
\
V
i
(
i
(
- K
i
^ MAXIMUM

\_U MINIMUM
STATION. C
200
£ <00
a
600
V-COUPONEXT CU/SEC
-100 0 100 200
rrv-
800 L-
f / (
/ / A* MAXIMUM
MINIMUM
LEGEND
Current profiles
	 MEAN
	VUIMIMUU / v MAXIMUM
depth Avtraced
Figure 1 9
27
(Continued)

-------
31. The Dropsonde data collection method was used to measure the
velocity distribution for the Fort Pierce transects shown in Figure 1,8. This
technique Involves the deployment of multiple Dropsonde Instruments which
record the vertical distribution of the horizontal velocity field as the
instrument descends through the water column. A cubic spline function Is then
used to compute a vertically averaged velocity vector at 50-o Increments
throughout the water column. The data set for Fort Pierce is based on 18 days
of Dropsonde deployment (Lee, Brooks, and Dulng 1977). Details of the
measurement technique are reported in Richardson and Schmitz 1965. The
minimum (westerly) u , corresponding v , ancl computed depth averaged values
for each of the Fort Pierce stations are shown in Figure 1.10.
STATION 40
u-ccuponcwt cu/src
-200 -100 0 100 200
200
~00
too
000
T
T
I
1
STATION 60
l'-CCvD0Nf>T cu/stc
-700 -100 0 '00 JOO
200
X ,00
600
800 L-
T~
T
T
~1
STATION 70
U-COKPONtMT CW/StC
-100 0 1 00 200
:oo
£. «CO
600
BOO
I
I
T
n
V-C0UP0NC*T CM/SCC
-200 -100 0 100 200
~i	r
200
400
600
#00 >-
I
~T7	1
r
v-C0UP0«.C-l Cu/StC
200 -100 0 100 200
"1	1	1	1—r-|
y
JOO
J
I «00
a
w
o
600
/
BOO L-
v-COmpONCmT cw/SCC
-200 -100 0 100 200
"i	1	r	1—7—•
/
JOO
}
* 400
&
w
o
600
600
/
ircc.o
VUbN UUU
OCPTH AVtHACCO
Figures 1 .10. Measured velocity profiles offshore of Fort Pierce
28

-------
STATION 100
U-COmPOnEnT cm/sec
-100 o 100 200
T—TT
200
£ *00
a
600
800 L-
T
n
\
/
(
\
\
200
£ 400
Si
o
600
eoo L
STaTiON no
U-COUPONENT CM/SEC
-100 0 100 200
	1	fl	1	1
)
(
)
\
\
station 120
U-COMPONCNT CM/SEC
-100 0 100 200
200
£ *00
a.
600
800 L
1
/
\
200
£ *oo
a
600
800 L-
V-COUPONENT CM/SEC
100 0 100 200
H	1—JT	1
I
\

200
£ *oo
a.
600
'800 —
V —COMPONENT CM/SEC
-100 0 100 200
	T	1	I
/
/
V-COUPONENT CM/SEC
-100 0 100 200
200
£ +00
a.
600
800
T
\
LEGEND
VUINIUUM
depth avcracc:
Figure 1.10 (Continued)
29

-------
32. Available current meter data for all additional locations between
Miami and Fort Pierce were similarly analyzed. The purpose was to demonstrate
a spatial consistency in depth averaged velocities in order to show that the
velocities assigned to each proposed site are representative of their
respective locations. Table 1.5 identifies the current meter stations,
coordinates, and depth-averaged u and v velocity components for all gage
locations identified in the literature review.
Table 1.5
I
Current Meter locations and Depth Averaged Velocities
Current Eastward Northward Direction
Meter Latitude Longitude Velocity Velocity Vector (from north)
Stations (North) (West) cm/sec cm/sec cm/sec degs	
Lee,
Brooks, and
Duing 1977
Miami(Spring)


10
25
32.0
80
3.0
17.5
55.5
58.2
342
20
25
31.0
80
0.0
12.2
45.3
46.9
345
30
25
32.0
79
57.1
7.1
66.8
67.;:
354
40
25
32.0
79
54.1
8.2
59.7
60.*
352
50
25
32.0
79
51.1
22.6
26.9
35.2
320
60
25
32.0
79
48.1
21.2
50.8
55.C
337
70
25
32.0
79
42.1
12.5
54.9
56.3
347
80
25
32.0
79
36.2
21.3
43.5
48.4
334
90
25
32.0
79
30. 2
19.1
34.2
39.2
330
100
25
32.2
79
24.2
20.4
23.4
31.1
319
110
25
32.2
79
21.2
22.7
26.3
34.8
319
120
25
32.2
79
19.5
24.5
20.9
32.2
310
130
25
32.2
79
17.1
35.3
20.4
40.8
300
Lee,
Brooks, and
Duing 1977
Miami



C
25
45.0
79
59.0
25.6
20.4
49.3
343
H
25
45.0
79
52.5
29.3
44.7
53.4
327
P
25
45.0
79
47.0
21.2
50.8
55.0
337
G
25
45.0
79
36.0
24.0
58.8
63.5
328
10
25
44. 5
80
3.0
14.5
47.0
49. 3
343
20
25
44.5
80
0.0
25.6
20.4
32.8
309
30
25
44.5
79
57.0
29.0
5.3
29.4
280
40
25
44.5
79
54.0
31.4
14.0
34.4
294
50
35
44. 5
79
51.1
29.3
44.7
53.4
327
60
25
44.5
79
48.1
25.2
12.4
28.1
296
70
25
44.5
79
42.1
26.3
57.1
63.0
335
80
25
44. 5
79
36.1
24.0
58.8
63.5
338
90
25
44. 5
79
30.1
23.4
35.8
CD
CM
327
100
25
44. 5
79
19.4
13.5
26.8
30.0
333
100
25
44. 5
79
27.1
15.2
38.9
41.8
339
30

-------
110	25	44.5	79 24.1	12.1	43.3	45.0	344
120	25	44.5	79 21.2	16.2	43.5	46.4	340
130	25	44.5	79 19.4	13.5	26.8	30.0	333
Lee,	Brooks, and	Duing 1977	Miami Bal Harbor
10	25	51.0	80 5.7	21.0	46.0	50.6	335
20	25	51.0	80 4.5	18.0	46.0	76.2	346
30	25	51.0	80 1.6	21.5	28.8	35.9	323
40	25	51.0	79 58.6	32.6	3.8	32.8	276
50	25	51.0	79 56.1	30.5	1.8	30.6	275
60	25	51.0	79 53.6	37.8	43.0	57.3	319
70	25	51.0	79 51.1	36.2	64.0	73.5	330
80	25	51.0	79 47.4	29.4	24.1	38.0	309
90	25	51.0	79 41.0	21.1	44.8	49.5	335
100	25	34.6	79 34.6	19.6	UU.Q	48.2	336
110	25	51.0	79 28.3	10.1	33.0	34.5	343
120	25	51.0	79 21.2	12.1	14.0	14.8	305
130	25	51.0	79 17.8	12.3	6.0	13.7	296
Lee,	Brooks, and	Duing 1977	Near Miami
R	25	50.7	80 05.0	31.0	72.4	78.9	337
R2	25	50.9	80 4.3	34.8	79.0	86.3	334
R3	25	51.0	80 3.3	29.1	10.5	30.9	290
R5	25	51.1	79 57.3	41.2	20.4	45.0	296
R6	25	51.1	79 51.1	52.4	17.5	55.3	289
N1	25	51.2	79 47.4	25.1	55.0	60.5	336
N2	25	50.9	79 22.0	5.0	5.0	7.1	315
R7	25	34.5	80 04.0	26.2	57.4	63.1	336
R9	26	8.9	80 3.7	18.2	55.5	58.4	342
R10	26	23.0	80 1.8	28.7	55.4	62.4	333
Lee,	Brooks and Duing 1977	Fort Pierce
40	27	26.0	79 53.7	21.3	78.0	80.8	345
50	27	26.0	79 50.7	12.6	31.0	33.5	338
60	27	26.0	79 47.6	32.5	69.8	77.0	335
70	27	26.0	79 44.6	17.6	86.4	88.2	349
80	27	26.0	79 38.5	7.7	100.0	100.2	356
90	27	26.0	79 32.5	10.4	74.5	75.2	352
100	27	26.0	79 26.4	28.5	48.8	56.5	330
110	27	26.0	79 20.3	29.0	49.5	57.4	330
Leaman and Vertes 1982 Near	Jupiter Inler
1	27	01	79 52	11.8	91.2	92.0	353
2	27	01	79 48	7.9	103.6	103.9	355
3	27	01	79 42	2.9	106.8	106.9	359
4	27	01	79 38	27.9	96.2	100.4	344
5	27	01	79 31	2.3	79.8	78.9	358
6	27	01	79 25	11.8	65.0	66.0	350
7	27	01	79 18	11.1	70.0	70.9	351
8	27	01	79 12	10.5	45 4	46.7	347
31

-------
Richardson, Schmitz,
and Niiler 1969 Cape Kennedy


Sec 5
28
20

80
06
16.2
33.5
37.2
334

28
20

79
58.5
19.0
51.8
55.2
339

28
20

79
52.5
16.3
75.0
77.0
348

28
20

79
33
18.0
80.7
82.0
347

28
20

79
07
31.7
33.5
46.1
317
Lee et
al
1986
Ponce
De Leon
Inlet



1
26
58.0

79
56.8
17.2
58.2
60.6
344
2
27
29.9

79
59.1
19.9
75.1
77.7
345
3
28
00.2

79
59.8
19.2
22.1
29.0
345
4
28
58.2

80
39.2
5.7
44.8
45.0
353
5
29
00. 7

80
21.7
15.1
44.6
47.0
341
6
29
00.0

80
08.2
25.5
52.9'
58.7
334
7
29
00.2

80
02.2
23.5
35.4
42.5
327
8
29
03 . 9

79
50. 9
11.7
39.3
41.0
344
9
29
00.2

79
00. 2
27.1
11.1
29.3
293
10
29
00. 1

79
07. 5
16.8
20.4
26.1
320
11
30
00. 6

80
16. 3
20. 7
53.4
57.3
339
Lee and Atkinson
1983 Near St
. Augustine
Inlet


4
29
10.0

80
10.0
20.0
6.0
20.9
287
5
29
30.0

80
30.0
14.0
14.0
19.8
315
6
29
30.0

80
20.0
12.0
75.0
76.0
351
9
30
00.0

80
30.0
30.0
28.1
41.1
313
10
30
00.0

80
20.0
35.0
75.0
82.8
345
12
30
40.0

80
15.0
18.0
10.0
20.6
300
15
30
50.0

80
10.0
10.0
8.0
12.8
307
25
32
30.0

78
30.0
30.0
15.1
33.5
297
Lee and Waddel
1983





A
30
00.0

80
15.0
20.2
31.4
37.3
327
B
30
00.0

79
40.0
32.2
1.2
32.3
270
C
30
00.0

79
20.0
19.6
5.4
20.4
286
D
30
00.0

78
10.0
20.4
26.6
33.5
323
E
30
00.0

77
00.0
26.0
34.4
43.6
323
Williams and Lee
1987




Al
28
35.8

80
31.2
5.2
60.3
60.5
355
A2
28
37.9

80
21.2
14.3
46.3
48.5
343
B1
29
53.6

81
14.9
2.8
12.0
12.3
347
B2
29
57.8

81
1.2
4.2
34.0
34.3
353
CI
31
1.1

81
16.6
5.6
15.0
20.0
340
C 2
30
57.2

80
56.1
4.9
31.5
31.9
351
32

-------
33.	The velocity data presented in Table 1.5 are shown in vector form
in Figure 1.11 for the lower east coast (Miami to Fort Pierce) and Figure 1.1
for the upper east coast. At Miami the mainstream vectors are directed towar'
the shore due to the combined effects of a complex bathymetry and the approxi
mate 90 degree northerly deflection of the Gulf Stream at Miami. Flow is
generally directed to the north at Jupiter Inlet and Fort Pierce, as demon-
strated by the vectors at these two locations. This uniform orientation is
partially due to the fact that the offshore topography at Jupiter Inlet and
Fort Pierce is smooth and mild in gradient across the entire continental shelf
(Lee and Atkinson 1983). In addition to the mild bathymetry and shallow water
depth, the area is relatively free from the direct influence of the Gulf
Stream.
34.	The velocity data presented in Table 1.5 and shown in Figures 1.11
and 1.12 were analyzed to produce summary velocity vectors at 2 mile intervals
across transects offshore of Miami and Fort Pierce. The proposed disposal
site locations are each located approximately U miles offshore. Tables 1.6
and 1.7 present these vector data along with the corresponding distance
offshore, water depth, and bottom slope. The results presented in Tables 6
and 7 are shown in vector form in Figures 1.13 and 1.14.
33

-------
FT. \
PIERCE
JUPITER 'NLET
ATLANTIC
OCEAN
WEST
PALM BEACH
SCALE
100 CM/SEC
FORT •
LAUDERDALE
\ \ \ VV
\ \
MIAMI •;
79rW
Figure 1.11. Depth-averaged current vectors from Miami to Fort Pierce
34

-------
CHARLESTON
HARBOR
Savannah
32'
ATLANTIC
SCALE
ponce; de
llon inlett
29'
CAPE
CANAVERAL
2
8Cr
79'W
Figure 1.12. Depth•averaged
current
35
vectors north of Fort Pierce

-------
Table 1.6
Velocity Distribution Offshore of Miami
Dlatano* D«pth
allea	ft
0	V	Hafiiiuid* Dlr«otlon
c«/»*C c"/»ec _cm />ee D««r»» '!!! P*—r|t
2
21
0.0222
34 .4
71.9
79.7
335.
U
258
0.0222
11.1
17.0
19-3
313.
6
B31
0.0515
25.6
20.1
32.B
309.
B
960
0.0119
27.3
12.9
30.2
295.
10
1092
0.0125
30.2
9.7
31.7
288.
12
1152
0.0057
31.«
1<4 0
31.1
291.

1800
0.0670
29.3
Ml.7
53.1
327.
16
2H00
0.0568
25.2
12.1
28.1
296.
18
2562
0.0)53
26.3
31.8
13.6
323.
20
2568
0.0006
26.2
57.1
63.0
335.
Too ahillou to dump
Table 1.7
Velocity Distribution Offshore of Fort	l'lerce
Distance Depth	U	V	Magnitude	Direction
ml les	ft Slope cm/sec cnusec ca/sec	Degrees	frenr.ark
2
32
0.0021
5.6
15.0
16.0
340.

«3
0.0010
10.0
8.0
12.8
308.
b
50
0.0009
20.0
6.0
20.9
287.
8
60
0 0009
25.5
52.9
58.7
331.
10
63
0.0003
23.5
35.1
12.5
326.
12
77
0.0013
28.7
55.1
62.1
333.
14
102
0.0021
25.0
66.7
71.2
339-
16
155
0.0050
21.3
78.0
80.85
315.
18
255
0.0095
12.6
31.0
33.5
338.
20
376
0.0115
32.5
69.8
77.0
335.
Too shallow to dump
36

-------
MIAMI

100
U. • DtriH AVERAG! D f AST £ Rl Y VELOCITY
--C
Vg • Of PTH AVERAGE NOPTHf fllY VClOClTV
70
I
U
it
>•
4
0
14
0TTAJ»C4 f ACM ImOU MilU
Figures 1.13. Velocity vector distribution offshore of Miami
fOATPKUCt
<~
too
TOO
U •DirtM AVERAGED tAJURlY VELOCITY
v# • 0{ rrn av( ftAcco no at hi h y vf ioc»t y
xo
0
1

I
I
14
>1
Olf T	' HQm ImO" I Willi

Figures 1.1^ Velocity vector distribution offshore of Fort Pierce
37

-------
Velocity Field Input nam
35.	The short-term D1FID model and the long-term sediment transport
model require a velocity field boundary condition for each site in order to
calculate sediment transport. The velocity fields for driving the long-term
simulations were based on an approximate average of the 2, 4, 6, and 8 mile
offshore values for the Miami and Fort Pierce data shown In Tables 1.6
and 1.7. Values of 50 cm/sec (1.64 ft/sec) for Miami and 30 cm/sec (0.98
ft/sec) for Fort Pierce were used. In order to account for short-term
velocity fluctuations about the selected long-term values, the approximate
maximum of the inner 8-mile values shown in Tables 1.6 and 1.7 were selected
for the short-term simulations. Values of 85 cm/sec (2.79 ft/sec) and 60
cm/sec (1.97 ft/sec) were adopted for the Miami and Fort Pierce sites. The
corresponding angles of orientation (measured clockwise from true north) for
the velocity vectors are approximately 320 and 317 degrees for Miami and Fort
Pierce.
36.	The depth averaged non-storm related velocity field approach for
analyzing the stability of each proposed ODMDS was used to analyze sediment
dispersion during dumping and to investigate long-term erosion resulting from
normal meteorological conditions. However, storm-induced erosion of an
existing mound may initiate sediment transport which may adversely impact the
reefs when normal long-term conditions would not. For this reason, a storm-
related velocity field was selected for simulation with the long-term model.
37.	Peak velocities for a storm event were based on prototype obser-
vations during hurricane David. Smith (1982) Investigated the influence of
this hurricane on the continental shelf waters off south Florida north of Fort
Pierce Inlet. On 3 September 1979 hurricane David passed over an inner and
middle shelf prototype data collection area near Fort Pierce, producing a
record water level at the Fort Pierce inlet. Bottom pressure fluctuations
recorded on the inner shelf indicated a storm surge of approximately 3 ft
above the normal high water mark with a corresponding current of over
2.7 ft/sec. Based on these prototype velocity data, a numerical model input
velocity of 6 ft/sec for Miami and 4 ft/sec for Fort Pierce were used in the
Mng-term sediment transport model to simulate storm effects at the respective
l rps
38

-------
Upvelllnp and Downwelling
38.	All prototype velocity data obtained in the literature review
represent horizontal velocities and all numerical modeling efforts are depth
averaged; therefore, vertical transport of sediments are not addressed in the
present approach. This section of the report briefly investigates the
occurrences of upwelling and downwelling in the vicinity of the Gulf Stream as
a possible source of transport of dredged material from the disposal site onto
the reefs. During upwelling, the deep waters are brought into the euphotic
zone (water depth less than 50 m) along the outer continental shelf (Lee et al
1981). The intent of this section is to determine whether these vertical
currents are adequate to erode and transport sediment.
39.	The precise origin of upwelling and downwelling appears unclear;
however, it is suspected that they are a response to the movement of the Gulf
Stream (Smith 1983). Upwelling and downwelling events have been observed in
the vicinity of meander crests (Brooks and Bane, 1983) and have been corre-
lated with wind stress forcings which contribute to the formation of meanders.
Green (1944) documented an upwelling event off Daytona Beach which was
associated with southerly winds during July and August. Brooks and Mooers
(1977) investigated the relationship between wind fields and upwelling and
downwelling offshore of Miami. They concluded that southerly winds cause
upwelling while northerly winds produce downwelling on both side of the Stream
axis. The purpose of this section is to review the available literature and
document the magnitude of the vertical velocity w associated with an
upwelling event in order to assess its potential for transporting sediment.
40.	Lee and Atkinson (1983) documented upwelling velocities associated
with a frontal eddy to be on the order of 0.01 cm/sec based on the measured
movement of an isotherm associated with an upwelling event. They also
estimated w by using vortlcity conservation principles and calculated a
value of 0.014 cm/sec. Osgood et al. (1987) used surface floats and current
meter data to compute a value of 0.048 cm/sec for a time series of data from a
documented event. A summary of reported upwelling velocity magnitudes
reported by Osgood et al. (1987), is shown in Table 1.8.
39

-------
Table 1.8
Summary of Upwelling Related Velocity Calculations
	(Osgood et al. 1987^	
Researchers	
Lee and Atkinson
(1983)
Lee and Atkinson
(1983)
Chew et al
(1985)
Chew et al
(1985)
Rossby et al.
(1985)
Levine et al.
(1986)
Osgood et al.
(1987)
Method of
Calculation
tracking an Isotherm
vorticity conservation
tracking an isotherm
thermal wind balance
Rafos floats
Swallow float
Heat equation
Depth of	w
Calculation (m) cm/sec
50
50
28-45
200
500
400
219
0.010
0.014
0.010
0.100
0.100
0.080
0.048
41. The results of this brief examination indicate that vertical
velocities during an upwelling event are on the order of 0.1 co/sec. As a
sediment transporting mechanism, velocities of this magnitude are not
considered significant with respect to horizontal velocities on the order of
30 to 40 cm/sec. Any possible transport by these vertical velocities would be
insignificant in comparison to sediment transported by the horizontal velocity
field. The following sections will, therefore, address sediment transp6rt as
a function of only the horizontal velocity fields previously described.
40

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PART II: THE SHORT-TERM SIMULATION OF DISPOSAL OPERATIONS
42. Section II of this report Investigates the short-term fate (less
than a day) of dredged material at the proposed Miami and Fort Pierce disposal
sites. The analysis approach will determine whether the combined effects of
the local topography at the site and the depth-averaged velocity field
developed in Section I, impact the effectiveness of the dredged material
disposal operation. Can the dredged material be physically placed within the
designated ODMDS limits as the material descends through the water column to
the ocean floor or are the local currents of sufficient magnitude to transport
material from the disposal vessel onto sensitive coral reefs? If the dredged
material can not be confined within the designated ODMDS limits, then an
alternate site further offshore should be evaluated for site designation.
A3. The short-term site evaluation phase is made by numerically
modeling the disposal operation using the DIFID numerical model. Theory and
background of the model are reported in Johnson and Holliday (1978), Johnson
(1987), and Johnson, Trawle, and Adamec (1988). The model computes the time
history of a single disposal operation from the time the dredged material Is
released from the barge until it reaches equilibrium on the ocean floor. The
DIFID model separates the dumping operation into three distinct phases. In
the first phase, material released from the bin Is assumed Co form a
hemispherically shaped cloud which descends through the water column under the
influence of gravity. This phase is called the convective descent phase. In
shallow water, such as the Fort Pierce site, this can be completed within a
few seconds of the initial dump. In deep water, such as the Miami site, this
time can be greater than 3 minutes. The increased descent time is due to both
the greater depth and to a corresponding loss of momentum of the released
material as it travels through the water column.
44. The cloud of material continues to descend through the water column
until it either impacts the bottom or has reached a stable point of neutral
buoyancy. In either case, the horizontal spreading of material marks the end
of the descent phase and beginning of the dynamic collapse phase. If the
disposal load is primarily composed of non-cohesive material, this phase nay
simply represent a settling and consolidation of the sediment into a mound;
however, if the load contains cohesive sediment, a comb ination of buoyancy ar.
41

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suspension may occur in which the cloud of suspended sediment may be
transported a considerable distance from the point of disposal.
45.	When the rate of horizontal spreading in the dynamic collapse phase
becomes lfess than the spreading rate due to turbulent diffusion, the material
begins the final transport-diffusion phase. The termination of this phase
marks the end of the short-term investigation. The resulting post-disposal
sediment mound represents the initial boundary condition for the long-term
transport computations to be described in Section III. An idealization of
all three phases of the short-term disposal are shown in Figure 2.1
Input Data Requirement
46.	The DIFID model requires site-specific input data in order to
quantitatively predict the short-term fate of sediment released during a
disposal operation. Input data include the characteristics of the dredge, a
description of the local environment to include the local depth and velocity
field, and a knowledge of the characteristics of the dredged material. In
addition, certain modeling parameters and coefficients must be specified. A
brief description of these input parameters is presented here.
47.	The primary goal of the short-term modeling effort Is to determine
whether disposed material could be transported from the disposal site onto the
reefs. Since the potential for reef contamination increases with increasing
volumes of material in the water column, a conservative approach was adopted
in which a large capacity dredge was specified for model simulation. The
selected dimensions shown in Table 2.1 are representative of the largest
instantaneous dumping type dredge anticipated by SAJ (Tapp, 1988) to be
involved with the Miami and Fort Pierce dredging operation. A dredge of these
dimensions was, therefore, used for both the Miami and Fort Pierce
s emulations.
a2

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BARGE

'//////
CONVECTIVE
DESCENT
DYNAMIC COLLAPSE ON
BOTTOM
LONG-TERM PASSIVE
DIFFUSION
BOTTOM
ENCOUNTER
DIFFUSIVE SPREADING
¦ ¦GREATER THAN
DYNAMIC SPREADING
NOTE. Typical durations of descent and collapse
phases in 400-ft-deep water.
Convective descent - 1 /2 mm.
Dynomic collapse - 10 min.
Figure 2.1. Computational phases of the DIFID model
(from Brandsma and DIvorky, 1976)

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Table 2.1
Instantaneous Dredge Capacities and Dimensions
Overall length	236 ft
Beam length	53 ft
Depth of container	21 ft
Opening width of bin	12 ft
Unloaded draft of vessel	3.9 ft
Loaded draft of vessel	19.7 ft
Volume 4000 cu yds
Capacity	5400 tons
The location maps shown in Figures 1.1 and 1.2 show the disposal site
environment for Miami and Fort Pierce.
48.	The Miami site is located in deep water with bathymetry contours
between approximately 400 and 750 ft. A depth of 400 feet, corresponding to
the shoreward limit of the designated site, with a bottom slope of 0.0658 was
specified for the simulations. An examination of bathymetry at the Fort
Pierce site indicates that the water depth varies between approximately 40 and
54	ft.
49.	The DIFID model computes the convectlve descent of a cloud of
sediment from the bottom of the loaded dredge through the water column. In
order to properly model the descent phase, the total water depth must be
greater than the loaded draft of the dredge plus the computed radius of the
released sediment cloud. The specified dredge dimensions used for both site
simulations required a minimum of 60 ft of depth. The shallower depth at Fort
Pierce produced unstable results because the sediment cloud corresponding to
the 4000 cu yd load did not have a chance to complete the convective descent
stage. The choice of utilizing the 60 ft depth for the Fort Pierce simula-
tions was selected over the option of specifying a smaller capacity dredge.
This is not a severe assumption considering that depths of almost
55	fr. are representative of that site. A bottom slope of 0.0 was specified.
30 Depth-averaged velocities of 2 79 ft/sec (85 cm/sec) for the Miami site
and 1 97 it/sec (60 cm/sec) for the Fort Pierce site were selected as input to
44

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the DIFID modal- The angles of orientation of the velocity vectors for the
Miami and Fort Pierce sites is 320 and 317 degrees, measured clockwise from
magnetic north. The simulations performed in this section are relative to
this axis.
51. Additional input required for the D1F1D model include specifying
the composition of the material in the dredge. Normally, the dredged materi
is composed of a solid fraction (rock, sand, clay, etc.) and a fluid
component. Each component must be defined according to its respective
density, concentration by volume (component percentage of total load volume)
fall velocity, and voids ratio (volume of water to volume of solids ratio).
In addition, the in-barge percent distribution of solids must be specified.
The selection of material densities, fall velocities, and void ratios for bo
the Miami and Fort Pierce sices was based on information obtained from SAJ
(Tapp 1988), from a recent DIFID application in Mobile Bay (Reese 1988), and
from numerous DIFID applications reported by Johnson and Holliday (1978). T1
selected composition of the disposal load used for both sites is shown in
Table 2.2
Table 2.2
Characterization of Dredged Material for Miami and Fort Pierce

Density
Volumetric
Fall Velocity

Cohesive
DescriDtion
e/cc
ratio
ft/sec
Voids Ratio
(1 or 0)
SAND
2.650
0.6300
0.04660
0.00
0
SIL-CLAY
2.650
0.0700
0.00256
1.00
1
WATER
1.023
0.3000
0.00


52. The concentration percentages of the total load are based on an
assumed solids content of 70 percent by volume of the material in the barge.
Sieve analyses received from SAJ (Tapp 1988) showed medium well graded sand
(non-cohesive) was representative of at least 90 percent of the solids in the
load (90* of 70% - 63*). Cohesive silts and clays were specified for the
remaining 10 percent of solids A bulk density of 2.16 gm/cc and an aggregat
^5

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void ratio of 1.4 was specified for both sites to compute the final thickness
of the composite mound.
53. There are numerous model parameters in addition to the internal
model coefficients required as input to the DIFID model. Grid resolution and
time step parameters were selected to best represent each disposal site. The
internal model coefficients recommended by Johnson and Holliday (1978) and
used by Reese (1988) were used for both site simulations. The parameters and
coefficients used are shown in Table 2.3.
Table 2.3
Input Data Related to Disposal Operation for
the Miami and Fort Pierce ODMDS
Variables		Miami	Fort Pierce
Grid sire (ft)	200	200
Number of cells:
cross-shore direction	105	105
Alongshore direction	28	28
Time step (sec)	100	100
Duration of simulation (sec)	6000*	10800
Ambient velocity (ft/sec)	2.79	1.97
Ambient density (gm/cc)	1.023	1.023
DINCR1	1.0	1.0
DINCR2	1.0	1.0
Entrainment coefficient A1APH0	0.200*	0.235
BETA	0.0	0.0
CM	1.0	1.0
Drag coefficient for sphere, CD	0.5	0.5
GAMA	0.25	0.25
Drag coefficient for elliptic
cylinder, CDRAG	10	10
US

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CFRIC	0.01
CD3	0.10
CDA	1.00
Entrainment due to cloud collapse,
ALPHAC	0.0010
Bottom friction, FRICTN	0.0100
A1AMDA.	0.005
Vertical diffusion coefficient,
AXYO	0.0100
0.01
0.10
1.00
0.0010
0.0100
0.005
0.0100
* Adjustments in value from those of Fort Pierce were required for the deepei
depths of the Miami site.
Method and Procedure for Short-Term Model Simulations
54. The objective of the short-term simulations was to determine
whether dredged material could be effectively placed within the limits of the
designated disposal sites under the action of a realistic localized velocity
field. Of particular interest was whether the settling material (primarily
sand) or the suspended sediment cloud (silts and clays) could be transported
from the dredge onto the reef area. Data received from SAJ (Tapp, 1988) and
shown in Figures 1.1 and 1.2 indicated that the reef areas are located a
minimum of approximately 1.5 miles due west of the shoreward edge or 2.0 miles
from the center of either ODMDS. If the average release point is considered
to be at the center of the designated site, an effective distance between the
disposal site and the nearest reef of approximately 3.0 miles is computed from
Che angle of orientation of the velocity vector. In order to investigate
these far field effects, the model grid dimensions were specified to be 105
cells in the flow direction by 28 cells in the transverse direction. The grid
spacing of 200 ft produces an effective modeling area of 1 mile by U miles
The disposal release point was selected at approximately 0 U miles (grid cell
10) from the upstream boundary
U]

-------
55.	The approach taken Co investigate the possibility of reef contamina-
tion was to determine both the depth and extent of deposition and the sediment
plume concentration impact produced by a single disposal load under the
maximum, reef-directed, non-storm condition likely to be encountered during a
dumping operation. Two parameters were of interest. First, the total
deposition pattern was computed to indicate the maximum distance from the
dredge at which measurable (above 0.01 ft) deposition could be expected. This
maximum excursion distance provides an indication of the spatial extent of
direct deposition of material on the bottom.
56.	The second measure of impact, and the primary parameter of interest
to this study, quantifies the movement and concentration of the moving cloud
of suspended sediments. As the cloud is transported from the dredge by the
ambient currents, it grows larger (diffuses) and, correspondingly, less
concentrated. The second phase of Investigation looks at the change in time
of the location and concentration of this cloud of sediment as it is diffused
and transported toward the reef area. An example of transport and diffusion
of the cloud is shown in Figures 2.2, 2.3, 2.4, and 2.5 in which the horizon-
tal distribution of the suspended sediment concentration of the silt-clay
cloud is shown at the 200 ft level (below the surface) for the Miami simula-
tion. With the release point assumemed to be at the center of the disposal
site (specified as cell 10, the nearest reef is located at approximately grid
cell number 89. The 1500, 3000, 4500, and 6000 sec snapshots shows the
increase in size and corresponding decrease in concentration of the settling
cloud as it is transported toward the reef area.
57.	Results of the concentration computation are used to produce a
concentration (in ppt or mg/1 above ambient conditions) versus distance
relationship along the axis of the grid at five discrete depths for four
specified time periods (i.e., along the axis of symmetry at grid N - 14 of
Figures 2.2-2.5). Quarter-point times were selected to show results at the
1/4, 1/2, 3/4 and final point of any specified time period following the
initial release of material from the barge. The following sections present
the results of these simulations for the Miami' and Fort Pierce sites.
8

-------
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U 9

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Figure 2 5 Suspended sediment cloud at 200 ft deep at 6000 sec after dump
50

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Miami Disposal Site
58. Results of the sediment concentration computation for Miami are
shown in Figure 2.6. The disposal release point is located at approximately
mile 0.4 and the reef at approximately mile 3.5. Note that these figures
represent distance-concentration plots at the quarter-point times along the
reef-directed cloud axis. The uppermost graph of Figure 2.6, for example,
summarizes the data presented in Figures 2.2 through 2.5. The depths of 200,
250, 300, 350, and 400 ft were used in order to present an overall representa-
tion of the numerical results. For example, at 1500 sec after the initial
dump, simulations of the disposal operation shows concentrations of suspended
silt and clay at the 200 ft depth to be 10 ppm. Results demonstrate that
the descent phase of the hemispherically shaped cloud passes through the water
rapidly leaving little sediment in the upper water column. The examples
presented in Figure 2.6 indicate that a point of maximum concentration is
reached at a depth of approximately 350 ft and that a concentration decrease
Is seen both above and below this point. This relationship of maximum
concentration is maintained for each quarter point as the cloud disperses.
All results indicate a decreasing concentration in both time after disposal
and distance from the release point as shown In the summary Table 2.A.
51

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3000
see
x~
4300
see
1
3000
1
see
200 FEET
0 0 0 3 to 15 2 0 2.3 3 0 3.3 4 0
250 FEET
00 05 10 15 2 0 23 '3 0 3 3 40
O
3
§ o
f= °
























300 FEET
0 0 0 5 1.0 1.3 2 0 2.5 2 0 3.9 4.0
U
Z
o
o
6000
350 hEl
3D 05 '0 15 ?0 25 JO 3 5 <0










A






)
\





400 FEET
CO 05 10 15 10 2 5 30 3 5 <0
D'Stance: in uiles
Figure 2 6 i ime - concent r,it l on for Miami at 200, 250. 300, 330, and 400 ft
5 2

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Table 2.4
Summary of Computed Maximum Suspended Silt and Clay Concentration
(Concentration In mg/1 above ambient)
Elapsed Time (sec)/Approxlmate Distance from
Dredge (Miles)
6000
3.2
Depth
1500
0.8
3000
1.6
4500
i_
liti
200
250
300
1. 2x10"13
7.1x10"9
5.5x10"6
5.7x10"^
1.5xlO"5
6.7x10"7
4.3xl0"6
8.7xl0"6
5.8x10"^
2.4x10"6
1.7xlO"6
2.5xl0"6
2.2xl0"6
l.lxlO"6
6.9x10"7
l.OxlO"6
9.2x10"7
6.6x10"7
3.8x10"7
2.6x10"7
350
400
59. A plot of the total sediment deposition versus distance along the
axis of the disposal grid is shown in Figure 2.7. A three-dimensional view of
the resulting disposal pattern is shown in Figure 2.8 with the corresponding
contour plot shown in Figure 2.9. The stable material mound is composed
primarily of the sand portion of the disposal load and will be the subject of
the long-term disposal simulations described in Section III.
53

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10IPL DCPOSITION
r
in
m
i
I:
£
om%a i" «iici
Figure 2.7. Deposition pattern for the Miami site
Figure 2 8 Three-dimensional view of the Miami site disposal mound
^ ~
fe§i=
I:
2.79rr/S£C
¦200 FT
0 0
XGKD *	18.0
200 rr
"Lg'jre 2 9 Contour plot of the deposition pattern for the Miami site
56

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Fort Pierce Disposal Site
60.	Results of the sediment concentration computation for the Fort
Pierce site are shown In Figure 2.10. Depths of 10, 20, 30, 40, and 50 ft
were specified In the simulation. Note that because of the shallow depth,
sediment remains in suspension throughout the water column. Also, the figures
show the depth of maximum concentration to be located at approximately the
30 ft depth. A trend, similar to that shown in the Miami simulations, of
decreasing concentration with increasing distance and time is seen. This
trend can be seen in the concentration summary Table 2.5.
61.	A plot of the total deposition in ft versus distance along the axis
of the disposal grid is shown in Figure 2.11. Three-dimensional results of
the disposal mound are shown in Figure 2.12 with the corresponding contour
plot shown in Figure 2.13. Due to the shallow water depths and relatively low
velocities, the stable mound can be seen to be conical in shape.
Table 2.5
Summary of Computed Maximum Suspended Sediment Concentration
(Concentration In rim/l above amblentl
Time (sec)/Approximate Distance from Dredge (Miles)
Depth
2700
5400
8100
10800
(ft)
1.0
2.0
3.0
4.0
10
1.2x10-5
2.4x10-6
7.8x10-7
*
20
2.3x10-5
4.4x10-6
1.4x10-6
*
30
2.8x10-5
5.5x10-6
1.7x10-6
*
40
2.3x10-5
4.4x10-6
1.4x10-6
*
50
1.2x10-5
2.4x10-6
7.8x10-7
*
+ Results at the 10800 sec were below the computationa . threshold of the
model, hence, no values are reported.
53

-------
o
n
2700
S£C
o
r4
200 FEET
5400
StC
6100
STC
o
o
o
2 0
0 1
0 0
2 5
3.0
3 5
o
250 FEET
o
o
o
0 0
2.0
0
2 5
3 0
0 5
5
4.0
o
SEC
2700
o
see
8100
StC
300 FEET
o
o
o
0.0 0.5
2 0
3.3 JO
J.5 4.0
5
o
o
ru
350 FEET
o
o
o
00
0 5
2.3
2 0
3 5
3.0










A







A





400 FEET
00 05 10 15 20 2.5 30 35 40
distance; in wiles
Figure 2 10 Time-concentration for Fore Pierce ac 10. 20, 30, AO, and 50 ft
56

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IOTP*, dcpositjon
M li II It )• II » • 1 *
DISTWCt JN MU5
Figure 2.11. Deposition pattern for the Fort Pierce site
Figure 2.12 Three-dimensional view of the Fort" Pierce site disposal mound
i o


-

-
-

--
-

-
! __


¦



_j
_j





j
-



1 A..
1 1_
—
"1

n

-
-

—
- i

-
-
-
-
-
- -
---
n ,





A
_ _
, ^


i
tj


li!.:
1 ! 1 1 i
	


-
i
t
S
y r
~ n
T
.j

i ; i i i . i
—

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r

-
-
-
-





. .

- ¦


	
J
_1	


0.0	* CRD	180
Figure 2.13. Contour plot of the deposition pattern for the Fort Pierce site
57

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PART III: THE SIMULATION OF LONG-TERM DISPOSAL FATE
62.	The final task of the evaluation study investigates the long-term
fate of disposed material in open water. This analysis will concentrate on
classifying the disposal sites as either dispersive or non-dispersive based on
whether the local velocity field is adequate to erode and transport material
from the mound onto the coral reefs. Transport simulations will be made for
periods of time ranging from a day to a year. This phase of the project
differs from Phase II in that the short-term investigation determined whether
the material could be effectively placed within a designated site during the
dumping process when material descends through the water column and collapses
on the ocean bottom. The long-term analysis assumes that the material has
been successfully deposited on the bottom and has assumed a stable mound
configuration. Whether the mound is dispersive or non-dispersive now depends
on whether the local current field is capable of resuspending and transporting
material such that the mound deformes and is moved from its initial position.
Changes in the computed sediment transport patterns are used to compute these
changes in location and configuration. For example, as material is eroded
from the higher velocity regions near the top of the mound and deposited in
areas of lower velocity in the lee of the mound, the shape, orientation, and
center of mass of the mound change.
63.	The long-term analysis will consist of two approaches. The first
will utilize the long-term velocity field developed in Section I of this
report to determine whether these velocities are sufficient in magnitude to
suspend and transport bottom sediments from an existing disposal mound of a
specified initial configuration. The second phase will simulate the passage
of a storm surge over the mound. Both approaches will use a sediment
transport model to compute non-cohesive sediment transport and the associated
bathymetric change as a result of a time varying velocity field around the
mound. A brief description of the modeling approach follows.
58

-------
Sedlmpnc Transport
64.	Empirical relationships for computing sediment transport as a
primary function of ambient water velocity, depth, and sediment grain size
were reported by Ackers and White (1973). These relationships were subse-
quently modified by Swart (1976) to reflect an increase in sediment transport
when a wave field is superimposed on the ambient current field. This addi-
tional transport reflects the fact that additional sediments are suspended by
wave induced bottom orbital velocities. These additional sediments in the
water column are available for transport by the localized velocity field.
Details of an application of the combined Ackers-White and Swart modification
methodology were reported by Vemulakonda et al. (1987) in which computed
erosion and deposition volumes were shown to adequately reproduce measured
bathymetric changes computed from periodic maintenance dredging surveys in the
entrance channel of St Marys Inlet, Florida.
65.	Prior to computing long-term simulations, a sensitivity test of the
transport predictions was performed for the local conditions at the proposed
Miami and Fort Pierce disposal locations. The goal of this testing was to
determine threshold velocities needed to initiate sediment movement at each
site under the localized environmental conditions of depth and wave field.
Sediment transport curves were prepared for each site for a velocity range of
0.0 to 4.0 ft/sec and for a sediment diameter size of 0.1 mm to 0.2 mln in
increments of .02 mm. These curves are shown in Figures 3.1 and 3.2.
66.	Approximations for wave height and period used in the generation of
Figures 3.1 and 3.2 were determined from the Wave Information Study (WIS)
20-yr hindcast data base (Jensen, 1983). Figures 3.3 and 3.4 represent a
reproduction of the wave summary statistics for WIS Stations 163 (for the
Miami site) and 153 (for the Fort Pierce site). Note that the wave heights
and periods selected are representative of larger than average wave
conditions; hence the transport rates used in this analysis will be
conservative. Average depths of 600 ft for Miami and 50 ft for Fort Pierce
were selected from Figures 1.2 and 1.3 to represent depths at the center of
Che designated sites.
59

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H - 6.53 FT, T - 6 SEC, D - 600 FT








.20
.12






r
WOmm
50






























125.0 JSI-0 ro.O SCO.O OS.O rSD.O 875.0
smirorr transport ¦ ioooo icu ft/sec/fti
Figure 3.1. Sediment transport v« velocity • Miaai disposal alt*
H - 8.17 FT, T - 0 SEC, D - 50 FT
Q
.14
.12
OflOmm
vt.o sae.o oro ro.o
SaiPtWT TRUSTOR! » 10000 (CU FT/SEC/fT)
Figure 3.2. Sediment transport vs velocity - Fort Pierce disposal site
60

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SHOBfLIHe
^IfiEtHroCCURRtNdEfxioin OF HEIG
FOP ALL DIRECTIONS
AZIMUTH
height! nrraes)
HEIGHT AND PERIOO FOR ALL DIRECTIONS
PERIOD!SECONDS)

<:i
*•!
5.i
i]
n
5 S:»	* ?:. 'WiWfc.
"" 1?il iJf|' |R '« !U "t " "! n
: 'It ijj | ,j j
- 4.J9
ota^" ™ laAi 26l9 tjiv l^iz sSs 4J9 1A4 49 lii
AVE MSiri) ¦ O.SJ LARGEST HS!M) « *.91 TOTAL CASES « 5M40
4e
TOTAL
??S
Figure 3.3. WIS station 163 wave characteristic summary for the Miami site

FOP ALL DIRECTIONS
AZIrtUTH
HEIGHT!METRES)
>0 •
0 -
H
! |i|
& - GftEAUR
TOTAL
HEIGHT AND PERIOD FOR ALL DIRECTIONS
PERIOD!SECONDS)
0.0- 30- 4.0- 5.0- 6.0- 7.0- 8.0- 9.0- 10.0- 11.0-
2.9 5.9 <..9 S.9 {.9 7.9 6.9 ?.9 io.9 LONGER
644
™ 'is f|| \\i n $ si !i
s? m
AVE HS!MI * 0.78 LARGEST HSIMI e 3.61 TOTAL CAGES *
*8
25*
6^4 I4j9 16lS 10>7 7i 7 1JJ4 942 737 469 9^4
5M<>0
TOTAL
Figure 3 U UI5 station 1S3 wave cha r nc t c r i s t i c summary for che
Fore Pierce ^ i t c
61

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67. Depth-averaged non-storm velocity fields were shown in Section I of
this report to be approximately 1.64 ft/sec (50 cm/sec) for the Miami site and
0.98 ft/sec (30 cm/sec) for the Fort Pierce site. Results shown in Figures
3.1 and 3.2 indicate that these velocities are marginally adequate to trans-
port sediment; however, locally elevated velocity vectors in the vicinity of
the mound crest may be adequate to transport sediment from the mound. The
following section will address the velocity field distribution as the ambient
current field flows over the mound.
Velocity Field Distribution
68.	The sediment transport modeling approach is based on an accurate
velocity distribution around the mound. A steady state numerical model was
developed specifically for this purpose. The model, based on the simplified
equations of motion and the continuity equation, computes a velocity
distribution around a mound of specified dimensions as a result of a constant
imposed "upstream" velocity field boundary condition. A sample computation is
shown in Figure 3.5 in which the depth averaged velocity vectors can be seen
to increase in magnitude and change orientation as the velocity field is
influenced by the presence of the disposal mound.
69.	A sediment transport rate corresponding to each vector is computed
for the entire numerical grid in order to yield a spatial transport
distribution. This distribution is input to a non-cohesive sediment con-
tinuity model which computes bathymetric changes as a result of transport
gradients. When more sediment enters a computational cell than exits the
cell, deposition will occur. Conversely, when more leave than enter, erosion
will be shown. No net change occurs for a uniform flow field in which equal
amounts of sediment enter and leave a cell. When the velocity field is below
the local transport threshold value (such as those shown in Figures 3.1 and
3.2), no transport occurs and no net erosion or deposition results.
62

-------
i r t M
mil
Mill
I t II I
Mill
ihii
11 ii i
ii m i
11111
11 i i
m 11
MOUN
Figure 3.5. Velocity vectors around an idealized disposal mound
70.	Velocity field simulation computations are updated at a 3-hr time
step to reflect the changing shape of the mound. As the transport patterns
adjust in response to the time-varying velocity field, material is transported
from regions of high velocity and deposited in regions of low velocity. This
process will continue until either the velocities fall below the threshold
value required to transport sediment or the mound reaches an equilibrium
condition in which equal amounts of sediment enter and leave a computational
cell. In the latter scenario, the mound has dispersed to the point that the
Identity of the mound has been lost and it no longer effects the current
regime.
71.	Erosion and deposition patterns associated with the changing shape
of the disposal mound are also computed at every 3-hr time step. These
computations indicate the time variation in depth of sediment deposition
versus distance from the mound. The distance at which zero depth changes
occur will indicate the first location from the mound at which no mound
material has been deposited; hence, the maximum radius of mound influence on
the environment If material from the mound is deposited beyond a designated
63

-------
point, i.e., on the reefs, then the disposal site can be considered
dispersive. For the present study, the critical distance of excursion is the
distance from the disposal mound to the reefs.
72.	Two simulations will be used to determine whether the presence of
the mound poses a potential threat to the coral reef area. The first is a
long-term simulation in which the mean non-storm velocity field and wave
condition for each site is continually subjected to the mound. Simulations
are performed to determine either an excursion rate of the mound in feet per
day or to demonstrate that a point of equilibrium has been reached and the
mound ceases to move. The second is to simulate a storm related event and
compute the total excursion associated with that storm. This simulation will
utilize a sustained storm driven velocity surge for a duration of 24 hours, a
time scale typical of a hurricane event. If either the long-term average
velocities or the high intensity storm induced velocities can be shown to be
of sufficient magnitude to transport material from the mound onto the reef
areas, it can be concluded that the site is potentially dispersive with
respect to long-term events, and that alternate disposal areas further
offshore should be investigated.
Sediment Transport Due to Non-Storm Velocity Fields
73.	The results shown in Figures 3.1 and 3.2 indicate that sediment
transport is initiated at velocity threshold values of approximately 1.0
ft/sec and 2.0 ft/sec for the Fort Pierce and Miami sites respectively.
Although the observed ambient velocities at both sites are below these
critical values (0.98 and 1.64 ft/sec), the effect of the mound on the
velocity distribution may result in elevated velocities on the mound which are
sufficient in magnitude to erode and transport material. In addition to the
velocity magnitude, model input includes the specification of a single
sediment size.
74.	Although Figures 3.1 and 3.2 show that the mean sediment diameter
is not a critical parameter when the velocity magnitude is near the sediment
transport threshold, a sediment size of 0.2 mm was selected for all
simulations. The specification of a fine-grained non-cohesive sediment for
both sites provides a threshold evaluation of the onset of mound erosion since
64

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fine grained materials are eroded before coarse grained materials are.
Results obtained from SAJ (Tapp, 1988) indicate average specific gravLties of
materials which will be disposed of at the Miami and Fort Pierce sites to be
2.78 and 2.70 respectively, indicative of quartz sand. A typical grain size
analysis of a sample obtained from the Fort Pierce harbor is shown in Figure
3.6. The report classifies the material as "poorly graded sand (SP)." In
view of this classification, a fine sand specification will provide an
estimate of maximum erosion potential. The analysis further indicates a D50
diameter of approximately 3 mm; therefore, the use of a 0.2 mm material in the
I
transport computations serves two functions. It provides a threshold
indication of fine material transport, and it provides an indication of fine
grain mound transport; as such, it yields a "worst case" prediction of
sediment erosion from the mound.
75.	A test mound measuring 250 ft square and 10 ft high was used as the
design mound configuration for both simulations. A mound of this dimension
would contain a volume of approximately 20,000 cubic yards. Although
idealized, this configuration will provide an indication of mound stability.
The following sections will address the long-term and storm event analysis.
Fort Pierce
76.	The proposed disposal site offshore of Fort.Pierce (Figure 1.1) is
located in shallow water, with ^n average depth of only approximately 50 ft.
A wave with a height of 8.17 ft (2.49 m) and period of 8 seconds was used to
indicate a rough, but non-storm, sea state. Results of Section I indicate
this area to be outside of the direct influence of the (lulf Stream; therefore,
depth averaged velocities are relatively low, on the or
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-------
77.	A 1-year simulation of the idealized mound at the Fort Pierce site
was made. Results indicate that material from the mound migrated a total
distance of 600 ft in 6 months of sustained maximum current. At this point,
the outer edge of the mound reached the computational boundary. The
approximate center of mass of the mound migrated approximately 700 ft during
the 1 year simulation. During this tine, the shape of the mound became
elongated, and a scour hole developed in front of the mound. Figures 3.7,
3.8, and 3.9 show the initial configuration, the mid-simulation shape, and the
configuration at the end of the simulation. Figure 3.10 presents the monthly
change of shape through a central cross-section of the mound. The rate of
excursion of the leading edge of the mound is approximately 3 ft per day.
Center of mass migration is less than 2.0 ft per day. At either rate, a
migration onto the reef area would require in excess of 10 years. During this
time, the mound would realistically erode and disperse in many directions,
resulting in a lower, less dispersive profile.
78.	In order to Investigate the erosion producing capability of a storm
event, a hypothetical hurricane was constructed with a sustained 24-hour
depth-averaged surge velocity of 4 ft/sec. The initial mound configuration is
identical to that shown in Figure '3.7. The final mound shape at the end of
the storm event is shown in Figure 3.11. Cross - sectional profiles at 6-hr
intervals are shown in Figure 3.12. Results indicate that the maximum radius
of transport resulting in deposition of more than 0.1 ft to be approximately
500 ft The corresponding mound crest migration is 350 ft.
6 7

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TOTAL ELAPSED TIME - 0.00 HOURS
Figure 3.7. Initial mound configuration for Fort Pierce
TOTAL ELAPSED TIME - 4320.00 HOURS
Q
Figure 3
Fort Pierce mound configuration at h months
68

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TOTAL ELAPSED TIME - 8640.00 HOURS
i
7 /
o
*0
Figure 3.9. Final Fort Pierce mound configuration at 12 months
O
O
UJ o
O d
O o
107 5	0	0 93> S
DISTRNCC in rcCT
F:rure 3 10 Tirr.e history of long-term erosion of the Fort Pierce mound
69

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n
I
v-
Ql
id
Q
TOTAL ELAPSEO TIME
24.00 HOURS
Figure 3.11. Final (24 hr) Fort Pierce storm mound configuration

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OlblHNCC IN nci
1)1? S IS'^ 0
Figure 3 12
Time hiscorv of scorn erosion of Fort: Pierce mound
70

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Miami
79.	The proposed disposal site for Miami Is located at a depth of
approximately 600 ft with a corresponding maximum velocity field of approxi-
mately 1,64 ft/sec (50 cm/sec). A 3-month simulation of the idealized mound,
using a wave height of 6.53 ft (1.99 m) and period of 6 sees, was performed.
The initial and final mound configuration and the evolution of the mound with
time, shown on Figures 3.13, 3.14, and 3.15, indicate no transport or erosion.
The result that the velocity field is not adequate to either suspend or
I
transport material at a depth of 600 ft is not surprising in view of the
threshold values shown in Figure 3.1.
80.	A storm event for the Miami site was assumed to have a sustained
velocity of 6.0 ft.sec for 24 hours. The post-storm mound configuration is
shown in Figure 3.16. The corresponding time changes of the cross - section at
6-hr intervals is shown in Figure 3.17. As can be seen in the figures, a
mound located in 600 ft of water is little effected by velocities of a
magnitude realistically representative of the disposal site offshore of Miami.
TOTAL ELAPSED TIME - 0.00 HOURS

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TOTAL ELAPSED TIME - 2160.00 HOURS
FLgure 3 14. Final Miami mound configuration at 3 months
52
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o
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-3
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M
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H •
0 0 167.S W0 56*. S 7VJ.0 9P.5 )i«.0 131? 5 lUO.O
DISTANCE IN ret7
.J
Figure 3 IS Time hisrory of long-terra erosion of the Miami mound

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TOTAL ELAPSED Time - 24 00 HOURS
Figure 3.16. Final (24 hr) Fort Pierce storm mound configuration
R"
O
o
5*
Z
o
CO
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^ 6
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distance in rcrr
Figure 3 1/
Tirr.c hi.-:cory ot iiorra erosion <> f Mi..mi rno'ind
n

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PART IV: CONCLUSION
81.	The purpose of this investigation is to determine whether sediment
from the proposed Miami and Fort Pierce disposal sites could be transported
onto the sensitive near-shore coral reefs. Numerical modeling techniques were
utilized to answer these questions. The approach taken was first to review
the available literature and document the magnitude of velocities which are
representative of each site. The question of reef contamination was then
addressed in a two-phase modeling approach. In the short-term analysis, the
actual disposal operation was modeled to determine whether material from the
descending sediment plume could be carried In suspension by the ambient
velocity field onto the reefs before settling into the disposal site. The
long-term investigation computes sediment transport and the associated erosion
and deposition of the disposal mound as a function of the local velocity
field. Results of the study indicate that neither the Miami nor the Fort
Pierce site pose an environmental threat to the reef areas. These results are
briefly summarized below.
82.	The first level of investigation requires the defining of a non-
storra velocity field for both proposed disposal sites. Existing velocity
records were extensively examined to quantify a depth-averaged velocity field
which would represent the most severe reef-directed currents. The approach is
based on the assumption that shore parallel or offshore directed velocities
present no environmental threat to the reefs but that a worst case condition
of maximum shoreward directed velocities could possibly effect the reef areas.
The review of data showed that a maximum depth-averaged, velocity of 0.97
ft/sec (30 cm/sec) and 1.64 ft/sec (50 cm/sec) was representative of the
Fore Pierce and Miami sites. In order to simulate a more extreme condition,
larger values of 2.79 ft/sec (85 cm/sec) for Miaibi and 1.97 ft/sec (60 cm/sec)
for Fort Pierce were selected for the short-term simulation phase.
83.	The short-term modeling of the disposal operation shows that most
of the material from the disposal load settles into a mound within several
hours after the initial release of sediment from the dredge. Model results
indicate the maximum distance from the barge showing deposition in excess of
0 01 ft was 1600 ft for Miami and ^00 ft for Fort Pierce The silt and clay
portion of the disposal load creates a suspension cloud or turbidity plume
1U

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which is transported toward the reefs by the specified ambient currents. This
cloud increases in size and decreases in concentration with distance from the
point of disposal. The concentration of the suspended sediment cloud was
computed at five specified depths for each site simulation. Results at the
conclusion of the simulation indicate maximum concentrations above background
levels at the reef (taken to be approximately 3 miles from the disposal area)
to be 0.00000089 mg/1 at a depth of 200 feet for the Miami site. This value
corresponds to an elapsed time of 1.66 hours after the initial sediment
release. At 2.25 hours after disposal, a maximum concentration of 0.0000017
I
mg/1 at a depth of 30 ft was computed for the Fort Pierce site. As shown,
both values are less than one part per million. The short-term modeling
efforts, therefore, indicate that the local ambient velocity fields are not
adequate in magnitude to transport any significant amount of material from the
dumping operation onto the reef area.
84. The long-term modeling effort was conducted to determine whether a
disposal mound is stable over long periods of time. Two types of simulations
were conducted. A long duration simulation of a specified mound configuration
was conducted for each site using a reef directed non-storm depth-averaged
velocity field of 0.97 ft/sec (30 cm/sec) and 1.64 ft/sec (50 cm/sec) for the
Fort Pierce and Miami sites. Results of these simulations show that the local
velocity field at Miami is below the threshold value required for eroding and
transporting material, i.e., a 3-month simulation showed no erosion of a mound
located in 600 ft of water. The mound at Fort Pierce was shown to erode,
deform, and migrate at a rate of approximately 2-3 ft/day. These results were
based on a 1-year simulation in which the centroid of the mound moved approx-
imately 700 ft. Additional shorter duration simulations were made for each
site in order to investigate storm related transport of material from the
mound onto the reefs. A 24-hour sustained storm surge velocity of 4.0 ft/sec
for Fort Pierce and 6.0 ft/sec for Miami was input to the long-term sediment
transport model. . Results for the Fort Pierce simulation show that material
was moved a maximum distance of approximately 550 ft in 24 hours. The Miami
simulation showed that essentially no material was transported as a result of
the surge Conclusions of the long-term simulation indicate that sediment
will be transported from the Fort Pierce site during both ambient and storm
conditions, but that the race of movement should not effect the reef system.
75

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For the proposed Miami site, simulations show that local velocity fields are
simply not adequate to move material in 600 ft of water.
85. The simulation approach taken in this study involves the specifica-
tion of a local velocity field directed to maximize the transport of material
from the disposal site onto the sensitive reef area. Numerical simulations
are used to evaluate whether this velocity field is adequate to contaminate
the coral reef with dredged material. The disposal operation and the disposal
mound are modeled as a potential source of contamination. Both the short-term
disposal and long-term erosion simulations of sediment transport as a function
of local velocity fields indicate little pqssibility of reef contamination as
a direct result of either proposed Miami or Fort Pierce disposal sites.
76

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REFERENCES
Ackers, P., and White, R. W. 1973. "Sediment Transport: New Approach and
Analysis," Journal of the Hydraulics Division. American Society of Civil
Engineers, Vol 99, No. HY11, pp 2041-2060.
Bane, J. M., and Brooks, D. A. 1979. "Gulf Stream Meanders Along the
Continental Margin from the Florida Straight to Cape Hatteras," Geophysics
Research Letters, No. 6, pp. 280-282.
Bane, J. M. , and Dewar, W. K. 1988. "Gulf Stream Bimodality and Variability
Downstream of the Charleston Bump," Journal of Geophysical Research. Vol 93,
No. C6, pp 6695-6710.
Brandsma, M. G., and Divoky, D. J. 1986. "Development of Model for
Prediction of Short-Term Fate of Dredged Material Discharged in the Estuarine
Environment," Contract Report D-76-5, US Army Engineer Waterways Experiment
Station, Vicksburg MS.
Brooks, L. H. 1979. "Fluctuations in Transport of the Florida Current at
Periods Between Tidal and Two Weeks," Journal of Physical Oceanography.
Vol 9, pp 1048-1053.
Brooks, D. A., and Bane, J. M. 1983. "Gulf Stream Meanders off North
Carolina During Winter and Summer 1979," Journal of geophysical Research.
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Brooks, D. A., and Bane, J. M. 1978. "Gulf Stream Deflection by a Bottom
Feature off Charleston, South Carolina," Science, No. 201.
Brooks, D. A._, and Mooers, N. K.. 1977. "Wind-Forced Continental Waves in
Florida Current," Journal of Geophysical Research. Vol 18, pp 2569-2576.
Chew, F., Bane, J. M., and Brooks, D: A. 1985. "On Vertical Motion, Diver-
gence, and the Thermal Wind Balance in Cold-Dome Meanders: A Diagnostic
Study," Journal of Geophysical Research. Vol 90, No. C2, pp 3173-3183.
Duing, W. 1975. "Synoptic Studies of Transients In the Florida Current,"
Journal of Marine Research. Vol 33, No. 1, pp 53-73.
Duing, W., Moores, N. K., and Lee, T. N. 1977. "Low-Frequency Variability
in the Florida Current and Relation to Atmospheric Forcing from 1972 to 1974,"
Journal of Marine Research. Vol 35, pp 129-161.
Hall, H. M. 1986. "Horizontal and Vertical Structure of the Gulf Stream
Velocity Field at 68 W," Journal of Physical Oceanography. Vol 16, pp 1814-
1828.
Hood, P. L. 1985. "Surface Energetics of the Gulf Stream Cyclonic Frontal
Zone off Onslow Bay, North Carolina," Journal of Geophysical Research. Vol 88,
No. C8, pp 4651-4662.
Jensen, R. E. 1983 (Jan). "Atlantic Coast Hindcast, Shallow-Water
Significant Wave Information," WIS Report 9, US Army Engineer Waterways
Experiment Station, Vicksburg MS.
77

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Johnson, B. H. 1987 (Jul). "Users Guide for Models of Dredged Material
Disposal in Open Water," Draft Technical Report, US Army Engineer Waterways
Experiment Station, Vicksburg, MS.
Johnson, B. H. , and Holliday, B. W. 1978. "Evaluation and Calibration of the
TETRA TECH Dredged Material Disposal Model Based on Field Data," Technical
Report, D-78-47, US Array Engineer Waterways Experiment Station, Vicksburg, MS.
Johnson, B. J., Trawle, M. J., andAdamec, S. A. 1988. " Dredged Material
Disposal Modeling in Puget Sound," Journal of the Waterway. Port. Coastal and
Ocean Division. American Society of Civil Engineers, Vol 114, No. 6,
pp 700-713.
Learaan, K. D. , and Vertes, P. S. 1982. "The Subtropical Atlantic Climate
Study (STACS), Summary of RSMAS Pegasus Observations in the Florida Straits,"
Technical Report, UM RSMAS No. 83012, University of Miami, Rosenstiel School
of Marine and Atmospheric Science, Miami, Florida.
Lee, T. N. 1975. "Florida Current Spin-Off Eddies," Deep Sea Research,
Vol 22, pp 753-765.
Lee, T. N. 1972. "Florida Current Spin-Off Eddies," Ph.D Dissertation,
Florida State University, Tallahassee, Florida.
Lee, T. N., and Atkinson, L. P. 1983. "Low Frequency Current and
Temperature, Variability from Gulf Stream Frontal Eddies and Atmospheric
Forcing along the Southeast U.S Outer Continental Shelf," Journal of Geophysi-
cal Research. Vol 88, No. C8, pp 4541-4567.
Lee, T. N., Atkinson, L. P., and Legeckis, R. 1981. "Observation of a Gulf
Stream Frontal Eddy on the Georgia Continental Shelf, April 1977," Deep sea
Research, Vol 29, pp 347-378.
Lee, T. N., Brooks, I., and Duing, W. 1977. "The Florida Current: Its
Structure and Variability," Technical Report UM-RSMAS, No. 77003,
The University of Miami, Rosenstiel School of Marine and Atmospheric Science,
Miami, FL.
Lee, T. N., Ho, J. W. , Kourafalou, V., and Wang, J. D. 1984. "Circulation on
the Continental Shelf of the Southeastern United States. Part I: Subtidal
Response to Wind and Gulf Stream Forcing During Winter," Journal of Physical
Oceanography. Vol 14, No. 6, pp 1001-1012.
Lee, T. N., and Mayer, D. A. 1977. "Low Frequency Current Variability and
Spin-Off Eddies along the Shelf off Southeast Florida," Journal of Marine
Research. Vol 35, No. 1, pp 193-220.
Lee, T. N. , and Mooers, N. K. 1977. "Near Bottom Temperature and Current
Variability over the Miami Slope and Terrace," Bulletin of Marine Science,
Vol 27, No. 4, pp 758-775.
Lee, T. N., and Waddel, E. 1983. "On Gulf Stream Variability and Meanders
Over Black Plateau at 30 N," Journal of Geophysical Research. Vol 88, No. C8,
pp 4617-4631.
Legeckis, R. 1979. "Satellite Observations of the Influence of Bottom
Topography on the Seaward Deflection of the Gulf Stream off Charleston, South
Carolina," Journal of Physical Oceanography. Vol 9, pp 483-^97.
78

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Legeckis, R., and Bane, J. M. 1983. "Comparison of the TRISO-N Satellite and
Air Craft Measurements of Gulf Stream Surface Temperatures , " Journal of
Geophysical Research. Vol 88, No. C8, pp 4611-4616.
Leipper, D. F. 1967. "A Sequence of Current Patterns in the Gulf of Mexico,B
Report 67-9T, Texas A&M University, College Station, Texas.
Levine, E. R. , Connors, P. C. , Cornillon, P. C., and Rossby, H. T. 1986.
Gulf Stream Kinematics along an Isopycnal Float Trajectory," Journal of
Physical Oceanography. Vol 16, pp 1317-1328.
Osgood, E. K. , Bane, J. M. , and Devar, K. U. 1987. "Vertical Velocities and
Dynamical Balances in Gulf Stream Meanders," Journal of Geophysical Research.
Vol 92, No. C12, pp 13029-13040.
Reese, S. I. 1988. "Personal dommunication on Short-Term Simulation of
Disposal Operations in Mobile Harbor," Al.
Richardson, P. L. 1985. "Average Velocity and Transport of the Gulf Stream
Near 55 W," Journal of Marine Research. Vol 43, pp 83-111.
Richardson, U. S., Schmitz, W. J. , and Niller, P. P. 1978. "The Velocity
Structure of the Florida Current from the Straights of Florida to Cape Fear,"
Deep Sea Research, Vol 16, pp 225-234.
Richardson, W. S., and Schmitz, U. J. 1965. "A Technique for the Direct
Measurement of Transport with Application to the Straits of Florida," Journal
of Marine Research. Vol 23, No. 2, pp 172-185.
Rinkel, M., Vargo, S., Lee, T. N. , Schott, F., Zantopp, R. , Leaman, K., Smith,
K., Maul, G., and Proni, J. 1986. "Physical Oceanography Study of Florida's
Atlantic Coast Transport Study," Florida Institute of Technology,
St. Petersburg, FL.
Rossby, T. A., Bower, S., and Shaw, P. T. 1985. "Particle Pathways in the
Culf Stream," Bulletin, American Meteorological'Society, Vol 66, No. 9,
pp 1106-1110.
Scheffner, N. U. (in preparation). "Dredged Material Disposal Numerical
Modeling for Site Selection in New York Bight," Technical Report, Coastal
Engineering Research Center, US Army Engineer Waterways Experiment Station,
Vicksburg, MS.
Schott, F. A., Lee, T. N., and Zantopp, R. 1988. "Variability of Structure
and Transport of the Florida Current in the Period Range of Days to Season,"
Journal of Physical Oceanography. Vol 18, pp 1209-1230.
Schwing, F. W., Kjerfve, B., and Sneed, J. E. 1983. "Nearshore Coastal
Currents on the South Carolina Continental Shelf," Journal of Geophysical
Research. Vol 88, No. C8, pp 4719-4729.
Smith, N. P 1983. "Temporal and Spatial Characteristics of Summer Upwelling
along Florida's Atlantic Shelf," Journal of Physical Oceanography. Vol 13, pp
1709-1715.
Smith, N. P. 1982 "Response of Florida Atlantic Shelf U'acers to Hurricane
David," Journal of Geophysical Research. Vol 87, No. C3, pp 2007-2016
Stommel, H 1965 "The Culf Stream' A Physical and Dynamic Description,"
79

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University Press, Berkeley, California, and Cambridge University Press,
London.
Swain, A. 1988. "Open Water Dredged Material Disposal Site for Port
Everglades, Florida," Memorandum for Records, Coastal Engineering Research
Center, US Army Engineer Uatervays Experiment Station, Vlcksburg, MS.
Swart, D. H. 1976. "Predictive Equations Regarding Coastal Transports,"
Proceedings of the 15th Coastal Engineering Conference. Honolulu, Hawaii.
Tapp, R. L. 1988. "Personnel Communication on Dredges and Dredged Material
Characteristics associated with the Proposed Miami and Fort Pierce Disposal
Sites".
Vemulakonda, S. R., Scheffner, N. W., Earickson, J. A., and Chou, L. V.
1988. "Kings Bay Coastal Processes Numerical Model," Technical Report
CERC-88-3, US Army Engineer waterways Experiment Station, Vicksburg, MS.
Webster, F. A.. 1961. " A Description of Gulf Stream Meanders off Onslow
Bay," Deep Sea Research, Vol 8, pp 130-143.
Zantopp, R. J , Leman, K. D , and Lee, T. M. 1987. "Florida Current
Meanders: A Closed Look in June-July 1984," Journal of Physical Oceanography.
Vol 17, No 5.
SO

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Norain U. Sch«££n«r, PhD
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APPENDIX C
MIAMI ODMDS
SITE MANAGEMENT AND MONITORING PLAN

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MIAMI ODMDS
Site Management and Mnnirorina Plan
Introduction. It is the responsibility of EPA under the Marine
Protection, Research, and Sanctuaries Act (MPRSA) of 1972 to
manage and monitor each of the Ocean Dredged Material Disposal
Sites (ODMDSs) designated by the EPA pursuant to Section 102 of
MPRSA. As part of this responsibility, a management and
monitoring plan has been developed to specifically address the
deposition of dredged material into the Miami ODMDS.
Site Management and Monitoring Team. An interagency Site
Management and Monitoring team, consisting of representatives of
EPA, COE, State of Florida, NOAA-AOML, University of Miami, and
the Port of Miami has been established to review and comment on
all Miami ODMDS management and monitoring activities. Other
agencies will be asked to participate where appropriate. This
SMMP team will evaluate existing monitoring data, the type of
proposed disposal (i.e., O&M vs. construction), the type of
material (i.e., sand vs. mud), location of placement within the
ODMDS and quantity of proposed material. This team will make
recommendations to the responsible agency on appropriate
monitoring techniques, level of monitoring, significance of
results and potential management options.
SITE MANAGEMENT
Section 228.3 of the Ocean Dumping Regulations (40 CFR 228.3)
defines ODMDS site management as "..regulating times, rates, and
methods of disposal and quantities and types of materials
disposed of; developing and maintaining effective ambient
monitoring programs for the site; conducting disposal site
evaluation studies; and recommending modifications in site use
and/or designation." The plan may be modified if it is
determined that such changes are warranted as a result of
information obtained during the monitoring process.
Management Objectives. There are three primary objectives m the
management of each ODMDS. These are:
o Protection of the marine environment;
o Beneficial use of dredged material whenever practical; and
o Documentation of disposal activities at the ODMDS.
The following sections provide the framework for meeting these
objectives to the extent possible.

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Miami ODMDS Site Management and Monitoring Plan				Angust 1995
Material volumes. The Miami ODMDS was first used in April, 1990
for disposal of maintenance material. Because routine
maintenance dredging is sporadic, the next expected disposal at
the proposed ODMDS should be the newly authorized deepening of
the Federal Miami Harbor Project. Approximately five million
cubic yards is expected to be disposed within the ODMDS from this
project. Subsequent maintenance dredging should not occur until
2000.
TABLE: Volumes Disposed and Estimated Volumes of Material to be
Disposed at Miami Site
Completion Type of	Volume	Composition
Date	Action	(cubic yards)
1990
1995
1995
1996
Maintenance	225,000
U.S. Coast Guard	3,000
Basin
NOAA Restoration	300
Deepening Proj.	5,000,000
silt/clay
sand/gravel
limerock rubble
sand/silt/
clay/rabble
2000
Maintenance
250,000
silt/clay
Because the site is located in deep water (427 to 785 ft.), no .
restrictions are presently placed on disposal volumes. Disposal
of unrestricted volumes is dependent upon results from future
monitoring surveys.
Material suitability. Two basic sources of	material are expected
to be placed at the site, i.e. construction or new wDrk dredged
material and maintenance dredged material.	These sediments will
consist of mixtures of silt, clay and sand,	in varyi ig
percentages.
The disposition of any significant quantities of bea':h compatible
sand from future projects will be determined during permitting
activities for any such projects. It is expected that the State
of Florida will exercise its authority and responsibility,
regarding beach nourishment, to the full extent during any future
permitting activities. Utilization of any significant quantities
of beach compatible dredged material for beach nourishment is
strongly encouraged and supported by EPA where environmentally
acceptable. Disposal of coarser material should be planned to
allow the material to be placed so that it will be within or
accessible to the sand-sharing system, to the maximum extent
practical, and following the provisions of tine Clean Water Act.
In addition, the suitability of dredged material for ocean
2
EI* \ Return 4

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Miami QDMOS Site Management and Monitoring Plan
August 1995
disposal must be verified by the COE and agreed to by EPA prior to
disposal. Verification will be valid for three years from the
time last verified with the option of a two year extension.
Verification will involve: 1) a case-specific evaluation against
the exclusion criteria (40 CFR 227.13(b)), 2) a determination of
the necessity for bioassay (toxicity and bioaccumulation) testing
for non-excluded material based on the potential for contamination
of the sediment since last tested, and 3) carrying out the testing
and determining that the non-excluded, tested material is suitable
for ocean disposal.
Documentation of verification will be completed prior to use of
the site. Documentation for material suitability for dredging
events proposed for ocean disposal more than 5 years since last
verified wili be a new 103 evaluation and public notice.
Documentation for material suitability for dredging events
proposed for ocean disposal less than 5 years but more than 3
years since last verified will be an exchange of letters between
the COE and EPA.
Should EPA conclude that reasonable potential exists for
contamination to have occurred, acceptable testing will be
completed prior to use of the site. Testing procedures to be used
will be those delineated in the 1991 EPA/COE Dredged Material
Testing Manual and 1992 Regional Implementation Manual. This
includes how dredging operations will be subdivided into project
segments for sampling and analysis. Only material determined to
be suitable through the verification process by the COE and EPA
will be placed at the designated ocean disposal site.
Time of disposal. At present no restrictions have been determined
to be necessary for disposal related to seasonal variations in
ocean current or biotic activity. If new information indicates
that endangered or threatened species are being adversely
impacted, seasonal restrictions may be incurred.
The disposal of dredged material with a median grain size of less
than 0.125 mm and material with a composition consisting of
greater than 10% fine grained material (grain size of less than
0.074mm) by weight will be halted at the Miami ODMDS during
periods of onshore current eventst An approved real-time current
monitoring program must be implemented by the user prior to
disposal to ensure that fine grained sediments disposed at the
Miami ODMDS are not transported to area reefs and hardbottoms.
Disposal Technique. No specific disposal technique Ls required
for this site. Dredged material will be placed within a 500 foot
radius of the center of site to additionally ensure protection of
live bottom communities outside of the site and to contain the
majority of the disposal mound and plume within the ODMDS
boundaries during periods of strong currents.
3
EI* \ Region 4

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Miami ODMDS Site Management and Monitoring Plnn
August 1995
SITE MONITORING
The MPRSA establishes the need for including a monitoring program
as part of the Site Management Plan. Site monitoring is conducted
to ensure the environmental integrity of a disposal site and the
areas surrounding the site and to verify compliance with the site
designation criteria, any special management conditions, and with
permit requirements. Monitoring programs should be flexible, cost
effective, and based on scientifically sound procedures and
methods to meet site-specific monitoring needs. A monitoring
program should have the ability to detect environmental change and
assist in determining regulatory and permit compliance. The
intent of the program is to provide the following:
(1)	Information indicating whether the disposal activities
are occurring in compliance with the permit and site
restrictions; and/or
(2)	Information concerning the short-term and long-term
environmental impacts of the disposal; and/or
(3)	Information indicating the short-term and long-term fate
of materials disposed of in the marine environment.
The main purpose of a disposal site monitoring program is to
determine whether dredged material site management practices,
including disposal operations, at the site need to be changed to
avoid significant adverse impacts.
Baseline Monitoring. The results of investigations presented in
the designation EIS will serve as a general pre-disposal
characterization of the ODMDS and nearby vicinity (see EIS
Appendix A). Site specific investigations included: 1985
Environmental Survey in the Vicinity of An Ocean Dredged Material
Disposal Site, Miami Harbor, Florida; and 1986 Miami Harbor
Interim Ocean Dredged Material Disposal Site Video Survey.
A bathymetric survey will be conducted by the COE or site user not
more than 60 days prior to the dredging cycle or project disposal.
The surveys will be taken along lines spaced at 500 foot intervals
or less and be of sufficient length to adequately cover the
disposal area. Accuracy of the surveys will be +. 0.5 feet. These
surveys will be referenced to the appropriate datum and corrected
for tide conditions at the time of survey.
Disposal Monitoring. For all disposal activities, the dredging
contractor will be required to prepare and operate under an
approved electronic verification plan for all disposal operations.
As part of this plan, the contractor will provide an automated
system that will track (1 to 5 minute intervals) the horizontal
location and draft condition (vertical) of the disposal vessel
from the point of dredging to the disposal area, and return to the
point of dredging. Required digital data for each load are as
fol1ows:
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Miami ODMDS Site Management and Monitoring Finn	August 1995
(a)	Date;
(b)	Time;
(c)	Vessel Name;
(d)	Dump Number;
(e)	Map Number on which dump is plotted (if appropriate);
(f)	Beginning and ending coordinates of the dredging area
for each load;
(g)	Actual location at points of initiation and completion
of.disposal event and the compass heading at the
beginning of each dump;
(h)	Description of material disposed, e.g., rock, sand,
silt, or clay;
(i)	Volume of material disposed; and
(j) Disposal technique used.
As a precaution to protect marine mammals as well as sea turtles
during disposal operations, a bow observer will be stationed on
vessels participating in disposal activities.
As a follow-up to the baseline bathymetric survey, the COE or
other site user will conduct a bathymetric survey within 30 days
after disposal. The number of transects required will be the same
as in the baseline survey. The user will be required to prepare
daily reports of operations and submit to the COE a monthly report
of operations for each month or partial month's work. The user is
also required to notify the COE and EPA within 24 hours of
becoming aware of a violation of the permit and/or contract
conditions during disposal operations.
Material Tracking. Based on the type and volume of material
disposed, various monitoring surveys may be used to determine if
and where the disposed material is moving.
The primary concern regarding use of the Miami ODMDS is the
potential for adverse impact on nearshore reefs due to short and
long-term transport of dredged material from the ODMDS and
subsequent sedimentation and/or light attenuation. The management
requirements discussed previously have been adopted to minimize
this potential. To further quantify the potential of impact, the
Site Management and Monitoring Team has decided to focus
monitoring efforts on analysis of the transport mechanisms at the
ODMDS.
The Site Management and Monitoring Team has identified two major
monitoring objectives: 1) Assess intensity and frequency of
S
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Miami ODMDS Site Managemtnl and Monitoring Plan
August 1995
disposal plumes reaching nearshore reefs, 2) Assess the potential
for long-term transport of dredged material towards critical
habitats. Additional objectives may be added as new information
is obtained from the current monitoring system and from the
studies described below.
Objective 1
Field studies will be conducted during the current Miami-Harbor
Deepening Project to quantify disposal plume concentrations during
onshore current events due to Florida Current Spinoff Eddies.
Data collected from these field studies will be used to calibrate
computer models for at least two separate current regimes (eddy
present and eddy absent) for assessing the intensity and frequency
of disposal plumes reaching nearshore reefs. Results from the
computer modelling will be examined with respect to potential
impact on the reef communities. Based on the expected impact, the
real-time current monitoring management requirement can be
modified or discontinued. The monitoring plan for this objective
is currently under development.
Objective 2
Field studies will be conducted to quantify bottom currents and
dredged material resuspension at the Miami ODMDS. Data collected
from these field studies will be used m calibrating computer
models for assessing the potential for long-term transport of
dredged material towards critical habitats. Should the modelling
indicate that significant quantities of dredged material will
reach critical habitats, management techniques will be examined or
the ODMDS will be relocated. The monitoring plan for this
objective is currently under development.
Reporting and Data Formatting. Disposal summary reports should be
provided by the COE to EPA within 45 days after project
completion. These should consist of dates of disposal, volume of
disposal, approximate location of disposal and pre- and post-
disposal bathymetric survey results in both hard copy and
electronic formats. Other disposal data should be available upon
request. In addition, EPA should be notified of ODMDS use 15 days
prior to dredging cycle or project disposal.
A brief report on the real-time monitoring results should be
provided to SMMP team members by the permittee within 45 days
after project completion. This report should include: number of
times disposal was delayed due to restricted current conditions;
the date, time and duration of each delay; any operational or
logistical inconsistencies or complications in conducting this
program; and any conclusions or recommendations.
Material tracking, disposal effects monitoring and any other data
collected should be provided to SMMP team members and federal and
state agencies as appropriate. Data will be provided to other
interested parties requesting such data to the extent possible.
Data will be provided for all surveys in a report generated by the
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Miami ODMDS Site Management and Monitoring Plan
August 1995
action agency. The report should indicate how the survey relates
to the SMMP and previous surveys at the Miami ODMDS and should
provide data interpretations, conclusions, and recommendations,
and should project the next phase of the SMMP.
Modification of ODMDS SMMP. The SMMP will be modified on an as
needed basis. Should the results of the monitoring surveys
indicate that continuing use of the ODMDS would lead to
unacceptable impacts, then either the ODMDS Management Plan will
be modified to alleviate the impacts, or the location of the ODMDS
would be modified. In addition, should the results of the
monitoring surveys indicate that specific management practices are
not needed, then the SMMP would be modified. The SMMP will be
reviewed and revised if appropriate at a minimum of every ten
years.
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APPENDIX D
MIAMI OCEAN DREDGED MATERIAL DISPOSAL SITE DESIGNATION
FLORIDA COASTAL ZONE MANAGEMENT PROGRAM
CONSISTENCY EVALUATION
Submitted by:
U.S. Environmental Protection Agency
Region IV
August 1995

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Florida Coastal /.one Management Program Consistency Evaluation
August 1995
I.	INTRODUCTION
The U.S. Environmental Protection Agency (EPA), in cooperation with the
U.S. Army Corps of Engineers (COE), has prepared an Environmental Impact
statement (EIS) titled "Environmental Impact Statement For Designation of a
Miami, Florida Ocean Dredged Material Disposal Site." This EIS evaluates the
environmental conditions relevant to the designation of an ocean disposal site
offshore Miami, Florida. Additionally, the EIS evaluates the proposed Miami
site according to the eleven environmental criteria required for site
designations under 40 CFR 228.6 (Ocean Dumping Regulations).
The site proposed for final designation is the Miami site that received
an EPA interim designation (40 CFR 228.12) and was used for dredged material
disposal for the first time in April 1990. The total area of the proposed
site is 1 square nautical mile (nmi). The western boundary of this site is
located 3.6 ami east of Virginia Key, Florida in the Atlantic Ocean. Since
April 1990, approximately 300,000 cubic yards of dredged material have been
disposed at the interim site.
The site designation is needed in this area to provide an ocean disposal
option for dredging projects in the area. Potential sources of the dredged
material are Government Cut, the Port of Miami channels and turning basins,
and the Miami Harbor Deepening Project. It should be emphasized that final
designation of the interim Miami site does not by itself authorize any
dredging or on-site disposal of dredged material. EPA and the COE must
conduct an environmental review of each proposed ocean disposal project. That
review ensures that there is a demonstrated need for ocean disposal and that
the material proposed for disposal meets the requirements for dredged material
given in the Ocean Dumping Regulations.
II.	THE FLORIDA COASTAL ZONE MANAGF.MF.NT PROGRAM (CZMP)
There are eight Florida statutes relating to ocean disposal site
designations. This assessment discusses how the referenced EIS for thg Miami
site designation will meet the CZMP objectives to protect coastal resources
while allowing multiple use of coastal areas. Consult the EIS for further
data and information.
Although the EIS serves a dual role of NEPA documentation for site
designation and COE permitting under Section 103 of the Marine Protection,
Research, and Sanctuaries Act (MPRSA) of 1972, as amended (see Section 2.01 of
EIS), this CZMP consistency evaluation is only relevant for si :e designation.
Therefore, COE permitting actions will need a separate CZMP co i:ustency
evaluation.
A. Chapter 161: Beach and Shore Preservation
The intent of Chapter 161 is the protection of thousands of miles of
Florida's coastline by regulating construction activities near and within
these areas. The Miami site designation will, by itself, require no new
construction and therefore no related support activities will t e; subject to
the construction regulations in this chapter
The western boundary of the Miami ODMDS is located 3.6 nxr l from Virginia
Key, the nearest beach and shore-related amenity. Sediment transport an the
vicinity of the site is driven mainly by the Florida Current. However, eddy
currents associated with the Florida Current have been shown to occur within
this area. Modelling, which has been compared to field studies, has indicated
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Florida Coastal Zone Management Prot^ram Consistency Evaluation
August 1995
that these frontal eddies should not result in significant transport of
dredged material toward the shore. In addition, provisions have been
established in the Site Management and Monitoring Plan to ensure that
transport does not occur toward the shore. In the event that significant
accumulation of the dredged material towards any amenity is evident, use of
the site can be modified or terminated by EPA.
B. Chanter 253:	State Land?
This chapter addresses the responsibilities of the State Board of
Trustees in managing the State sovereign lands by issuing leases, easements,
rights of way, or other forms of consent for those wishing to use State lands,
including State submerged lands.
Since the Miami site is not within State waters, Chapter 253 is not
re 1evant.
C. Chapter 258: State Parks and Preserves
Figure 5 in the EIS locates the Parks and Preserves in the vicinity of
the proposed Miami site. As similarly discussed in Section A above, the
distance from these areas to the proposed site should prevent any impacts to
these areas from use of the site.
D.	Chapter 267: Historic Preservation
There are no known features of historical importance in the vicinity of
the proposed site, and therefore it is unlikely that the proposed site
designation will result in any impact to these areas. The bottom video survey
of the ODMDS did not reveal any new such areas.
E.	Chapter 288: Commercial Development and Capital Improvements:
Industrial Siting Act
The final designation of the Miami site provides an environmentally
acceptable ocean location for the disposal of dredged material that meets the
Ocean Dumping Criteria. If ocean disposal is selected as the most feasible
option for a dredged material disposal project, this site designation ensures
that an ocean disposal option is available in the area. Therefore, the
designation removes one barrier to free and advantageous flow of commerce in
the area in that dredging projects and their associated navigational benefits
cannot be halted due to the lack of an acceptable ocean disposal site.
The Industrial Siting Act is not applicable to this proposed site
designation.
F.	Chapter 370: Saltwater Fisheries
Chapter 370 ensures the preservation, management and protection of
saltwater fisheries and other marine life. Most commercial and recreational
fishing activity in the Miami vicinity is concentrated in inshore and
nearshore waters. No natural hardbottom areas are known to occur in proximity
to the proposed site. The nearest fisheries area is located about 1.3 nmi
from the site. In short, the Miami site does not represent a unique habitat
for any of the important commercial or recreational fisheries. Use of the
site will smother the non-motile or slow moving benthic organisms at the site.
However, the ability of these organisms to recolonize in similar sediments
render 3 this impact short-term and insignificant. Should the disposed
material differ m grain-size, other benthic organisms would likely colonize
the area. The EIS served as the Biological Assessment from which the National
Marine Fisheries Service (IIMFS) determined that populations of
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Honda Coastal Zone Management Program Consistency Evaluation
August 1993
endangered/threatened species under their purview would not be adversely
affected by the designation and use of the ODMDS (See FEIS section 7.03).
G.	Chapter 37 6: Pollutant Discharge Prevention and Removal
Possible effects associated with the use of this site are local
mounding, temporary increases in turbidity and the smothering of benthic
organisms. The effect on the benthos should be minor as discussed in Section
F above. The great depths at the site will ensure that any mounding does not
become a hazard to navigation. Turbidities resulting from use of the site
will be temporary. Any suspended sediments remaining in the water column will
be diluted and dispersed so that the long term effect would not be greater
than ambient suspended solids concentrations. This is supported by the results
of dispersion modelling, which has been compared to field studies and has
indicated that these frontal eddies should not result in significant transport
of dredged material toward the shore. In addition, provisions have been
established in the Site Management and Monitoring Plan to ensure that
transport does not occur toward the shore.
Any material proposed for ocean disposal must meet the criteria given in
40 CFR Part 227 (Ocean Dumping Criteria) . EPA and the COE will continue to
monitor the site as long as it is used to detect movement of the material and
any associated impacts. The Site Management and Monitoring Plan (SMMP) for
the Miami ODMDS is included in the EIS (see Appendix C).
H.	Chapter 403: Environmental Control
The principle concerns raised in this chapter are similar to those
addressed in many of the chapters discussed above: pollution control, waste
disposal and dredging.
The COE and EPA will evaluate all federal dredged material disposal
projects in accordance with the EPA criteria given m the Ocean Dumping
Regulations (40 CFR Sections 220-229), the COE regulations (33 CFR 209.120 and
209.145), and any state requirements. The COE will also issue permits to
private dredged material disposal projects after review under the same
regulations. EPA has the right to disapprove any ocean' disposal project if,
in its judgement, all provisions of the MPRSA and associated implementing
regulations have not been met.
III. CONCLUSIONS
Based on the information presented in the EIS and the above summary, EPA
concludes that the proposed designation of the Miami ODMDS is consistent with
the Florida CZMP to the extent feasible.
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APPENDIX E
EVALUATION OF THE
MIAMI OCEAN DREDGED MATERIAL DISPOSAL SITE (ODMDS)

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CEWF.S-CR-P
21 March 1995
Evaluation of the Miami Ocean Dredged Material Disposal Site (ODMDS)
Introduction
1.	Limited capacity in existing disposal sites for dredged material in the Miami, Florida area
combined with the planned deepening of the Miami Harbor creates a need to designate an
environmentally acceptable, adequately sized, and economically feasible offshore Qcean Dredged
Material Disposal Site (ODMDS). In December 1987, the US Army Engineer District,
Jacksonville (SAJ) requested assistance from the US Army Engineer Waterways Experiment
Station's Coastal Engineering Research Center (CERC) to perform a site designation investigation
of the proposed ODMDS offshore of Miami, see Figure la. Figure lb shows the bathymetry at
the proposed ODMDS. The purpose of the study was to determine the acceptability of the site
with respect to the potential effects of the dredging operation on live coral reef areas located
shoreward of the ODMDS. Specifically, the question was whether material from the ODMDS
could be transported from the disposal site and deposited onto coral reefs located along the
adjacent coast.
2.	Conclusions of the study were reported by Scheffner and Swain (1989) and indicated that the
proposed disposal site did not pose a threat to the live reef areas. These conclusions were based
on numerical model simulations of: 1) the short-term (Johnson et al. 1988) fate and transport of
material in the water column from the disposal site to the reef and 2) a long-term (Scheffner
1989) simulation of the erosion and transport from a non-cohesive disposal mound located in the
ODMDS. Because data were not available for validation of the short-term modeling results, no
quantitative verification of the results were presented in the initial report. Additionally, the long-
term transport was limited to non-cohesive material of a single, uniform grain size.
3.	Although the numerical approach adopted for the study represented the state-of-the-art in
disposal site analysis, the lack of model verification to prototype measurements has resulted in a
reluctance to accept the conclusion that the disposal site will not adversely impact the coral reefs.
As a result of these concerns, the proposed ODMDS designation request may not be approved by
the Florida State Department of Environmental Resources (DER). Although these concerns are
valid, the amount of data necessary for such a verification has never been available and such data
collection effort was not planned as a component 6f the original study. However, an acceptable
and cost effective ODMDS must be located and approved in the near future; otherwise, SAJ
dredging activities in the Miami area will have to be terminated.
4.	At the time that the numerical model tests were run, the technology was not available to
monitor the spatial and temporal variations that occur during the disposal of dredged material.
However, during a field data collection activity in Mobile, Alabama (Kraus 1991), it was shown
that such measurements could be accurately taken acoustically. This acoustic technology along
with conventional sampling techniques were used to monitor the proposed Miami ODMDS (Proni
et al. 1991 and Tsai et al. 1992) in a joint field data collection project performed by the Atlantic
Oceanographic and Meteorological Laboratory (AOML) of the National Oceanic and Atmospheric
Administration, SAJ, and CERC.

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5.	In response to a recent request by SAJ, a cooperative effort between Rosenstiel School of
Marine and Atmospheric Science (RSMAS) of the University of Miami, AOML, and CERC has
been undertaken. RSMAS provided data describing the environmental conditions at the study
site. AOML analyzed field data, and CERC utilized predictive numerical models to characterize
movement of suspended material and bottom sediments at the ODMDS. This memorandum
describes the use of theory and field measurements to address all reservations concerning the
conclusions reached by the original numerical modeling investigation and provides predictions
based on the most recent model versions. The following three sections summarize findings with
respect to: 1) analyzing water samples and developing a theoretically based and field calibrated
acoustic backscatter versus sediment concentration curve, 2) running of the Short Term FATE
(STFATE) model with hydrodynamic data specified according to the field conditions which
occurred during monitoring and are representative of the site, and 3) performing an analysis of
the potential resuspension and transport of bottom sediment at the site.
Field Measurements
6.	The primary concern of the DER is founded on the lack of verification of the numerical
model predictions of suspended sediment concentrations at the reef area. The 1990-91 field data
collection project at Miami produced the data capable of providing quantitative verification of the
numerical model predictions. The field monitoring was comprised of three phases. During the
first field monitoring project, which was conducted from 24 to 26 April 1990, conductivity,
temperature, current, and total suspended solids (TSS) concentration measurements were
obtained. Water samples were gathered with a water sampling arrangement utilizing a towed
body in which the entrance port of a pumping system was mounted at a depth between 3 and 8
meters below the ocean surface. This is the only portion of the water column from which water
samples were obtained. On 28 August 1990, a second field collection exercise was conducted, in
which Rhodamine dye was introduced into the hopper of the dredge while enroute to the disposal
site. After disposal, the residual plume was monitored using NOAA's Acoustic Concentration
Profiler. Water samples were drawn from the residual plume and analyzed for the presence of
dye with a Turner Fluorometer. No dredged material discharges occurred during the third
monitoring period, 26-28 June 1991, due to dredging contractors scheduling. This effort was
undertaken to gather background water samples only.
7.	It is desirable to compare acoustical measures of TSS with conventional water samples in
order to obtain an empirical calibration of the relationship between acoustic backscatter intensity
and suspended material for each particular dredged material and disposal site. However, the
20kHz system, used in phase one of the field exerfcise, has a certain zone (several meters adjacent
to the transducer face), over which the data becomes saturated from immediate return. Because
of the method of the pumped sampling and limitations of the acoustical data at locations where
water samples were collected, a calibration of the acoustical data to field measurements is
difficult.
Sample Analysis
8.	Despite the inability to perform an acoustic calibration to field data, it was determined that
analyzing the existing samples would provide valuable information regarding the residual plume
9

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left after dredged material discharge. Tsai et al. (1992) determined that, although the bulk of
the discharged material descends as a viscous mass, a small portion, perhaps in the form of
individual fines, remains within the water column.
9.	TSS concentrations were determined by AOML from pumped samples (Proni et al. 1993)
taken from residual plumes as they moved along a nearly straight path to the North-Northeast.
Values for all samples of dredged material discharges plotted against time are shown in Figure 2.
Data from three of the discharges have been selected and included in Figure 3 to obtain a
smoother estimate of dilution with time (or distance) from the discharge. A curve can be fit to
the data to give an estimate of the normalized dilution with time or distance for discharges
occurring within the designated site. From Figure 3, a dilution factor of 0.1 occurs 20 minutes
after discharge. For example, an initial concentration of 80 mgIt (no bottle samples exceeded a
concentration of 80 mg It) would diminish to 8 mg/f after 20 minutes or at a distance of 600 m
from the point of discharge (current speed assumed to be 50 cm/s). The dilution factor decreases
to approximately 0.05 at 45 minutes. The concentration in the example becomes 4 mg/f at a
distance of 1350 m. The maximum background concentration measured in June 1991 was 3.1
mg/f. Therefore, the TSS concentration of dredged material will not impact the coral reefs a
distance of about 3 miles ( = 5000 m) from the ODMDS with concentrations in excess of
background levels.
Acoustic Calibration
10.	Because it was not possible to perform an acoustic calibration to TSS samples taken in the
field, an alternate method had to be devised to produce concentration data which would be used
to determine if the Short Term FATE (STFATE) model was producing concentration values
within an order of magnitude of those obtained in the field. It was determined that.the
environmental conditions (i.e. grain size, cohesiveness, salinity) at the disposal site could be
adequately represented in the conversion from acoustic backscatter to concentration by acoustical
theory calibrated to field data. The acoustical theory used in the conversion has been elucidated
by Thevenot and Kraus (1993). The concentration ratio between a scattering volume and a
volume of known concentration is given by
C = 10{K ' °5']	W
where a = 0.1 according to theory, and K is a site specific constant.
11.	The coefficients a and K are typically determihed empirically through fitting to field data.
Because field data corresponding to acoustic backscatter measurements are not available, the
theoretical value 0.1 is used for a. Bottom grab samples taken at the Miami dredging operations
were found to be similar to the material disposed during the Mobile, Alabama field data
collection project. Therefore, it was determine that the same value for K (6.78) would be used in
this study. Figure 4 (from Ogushwitz 1992) shows a comparison of data taken from two acoustic
instruments at Mobile, Alabama, the best fit to the data greater than 10 mg/f, and the theoretical
backscatter versus concentration relationship. This figure shows that the best fit line deviates
only slightly from the theoretical line for concentration values greater than 10 mg/f. Converting
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die Miami acoustical measurements using the above theory will provide estimated concentration
within an order of magnitude for concentrations ranging from 10 to 1000 mgIt (Ogushwitz
1992).
Short Term Fate Analysis
12.	In order to run STFATE, four types of input data are required. The first two types of input
data pertain to the ambient conditions at the disposal site. Specifically, a density profile of the
water column is required as well as an indication of the current velocities at the site. Because
Scheffner and Swain (1989) were criticized for using depth averaged velocities, the velocity
profile option of STFATE was selected. Input is also required regarding the material to be
disposed and the dimensions and velocity of the disposal vessel.
Verification to Prototype Data
13.	The primary concern expressed by the DER regarding the Scheffner and Swain (1989) study
was that the STFATE model was not verified to prototype data. Therefore, an initial set of
STFATE runs were made with the input parameters which coincided with a dredged material
discharge operation monitored on 26 April 1990 (Proni et al 1991). Although several disposal
operations were monitored, the disposal associated with the highest quality acoustic data was
selected for verification of the STFATE model due to limited time to complete the study.
Density stratification information that occurred at the time of the disposal was derived from
measurements of conductivity, temperature, and depth taken during the monitoring project. An
Acoustic Doppler Current Profiler obtained current profiles, and these data were used as input to
STFATE. Grain size information was obtained from a bottom grab sample taken from the
channel being dredged. The final input required are the dimensions of the vessel and its speed
during disposal. Estimates of the dimensions of a typical disposal vessel were the same, as used
in Scheffner and Swain (1989). The speed of the vessel at disposal was estimated based on
observations of the disposal operations.
14.	After all of the required input information was obtained, vertical contours of TSS
concentration were developed for the STFATE simulations and compared to concentration
measured with acoustic techniques. The acoustic backscatter was converted to concentration
using the relationship discussed above. The residual plume was followed during the acoustic
monitoring by visual observation of the surface plume, thus the vertical concentration profiles
from the STFATE model were taken at the highest concentration for the least depth of calculation
and were consistent throughout the water column.' Six passes were made through the discharge
plume, covering the period between disposal and 25 minutes after disposal. Because each pass
through the plume took over 150 sec, the spatial distribution shown in the acoustic transects may
vary from the snapshot of the water column developed to represent the STFATE model output.
However, this difference was considered to be well less than an order of magnitude. Because
data was previously unavailable to verify the spatial and temporal distribution of concentration
results of such models, this data represents the first comprehensive data set which is spatially
adequate for verifying the STFATE model.
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15.	Figure 5 shows acoustical measurements of the water column taken over a period of 0 to 150
sec after the disposal of dredged material. Contour intervals representing one half order of
magnitude illustrate the TSS in the water column, ranging from .1 to 1000 mg/£. The period
shown in Figure 5 includes the convective descent phase, 0 to 42 sec after discharge according to
model results, and dynamic collapse phase, 42 to 177 sec after discharge, of the material's
descent in the water column. During these two phases of the discharge, the model results
illustrate a single cloud of material falling through the water column with decreasing density,
similar to the field data (Figure 5).
16.	Figure 6 shows acoustic measurements of TSS concentration taken 150 to 300 sec after the
discharge of dredged material. Two distinct clouds of material can be seen, one in the upper
water column and one in the lower water column, both with maximum concentrations exceeding
1000 mg/£. During this phase of material descent model results were converted to vertical
profiles of TSS concentration to facilitate comparison to prototype data. Scales on figures
showing model results are arbitrary (i.e., 0 does not represent the point of discharge). The
figure is centered around the maximum concentration of the plume, and the scale is based on the
plume extent. Figure 7 illustrates model results at 240 sec after discharge at which time the
center of the plume is approximately 90 m north (to the right on Fig 7) of the discharge location.
Contour lines represent the TSS concentration of dredged material in the water column and are
given in orders of magnitude, i.e., .1, 1, 10, 100, 1000 mgIt. Similar to the prototype data
shown in Figure 6, Figure 7 shows two clouds of material with maximum concentration
exceeding 1000 mgII, one at approximately 30 meter depth and another near the ocean floor.
17.	Figures 8 and 9 show the TSS concentration measurements taken in the field and the TSS
concentration from model simulation, respectively. The field data was collected during the
period from 570 to 720 sec after disposal of dredged material. The simulated data shown in
Figure 9 represents a snapshot of the water column 600 sec after discharge. Disposal occurred
360 m east (to the right in Fig 9) and 450 m south (out of the page) of the center of the plume,
about 575 m total distance from the location of discharge to the center of the plume. In both
plots, a cloud of material with concentrations exceeding 100 mg/I can be seen suspended in the
water column. Except for minor differences, e.g. the numerical simulation predicts that the
cloud of material to be deeper in the water column than observed in the field data, the simulated
concentrations seem to be an accurate account of the fate of the disposed dredged material.
18.	Figure 10, the TSS concentration measured in the field from 930 to 1080 sec after disposal,
shows a cloud of material comparable to that seen in Figure 8, with maximum concentrations in
Figure 10 lower (100 mg/£) than those found in Rgure 8 (1000 mg/O- Similarly, Figure 11, the
TSS concentration in the water column from model simulations at 1000 sec after disposal (about
985 m from the discharge point), shows a cloud of material comparable to Figure 9, with lower
maximum concentrations (10 mgU as compared to 100 mg/f). When the field data (Figure 10)
are compared to simulated data (Figure 11) 1000 sec after disposal, each illustrate a cloud of
suspended material with concentrations greater than 10 mgH. A significant portion of the cloud
exceeds 100 mg/£ in the field data; however, concentrations do not exceed 35 mg It in the
simulated data.
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19.	In Figures 9 and 11, the simulated plume descends deeper in the water column than shown in
the field data, Figures 8 and 10. The simulated plume is effected by the density gradient which
occurs at an approximate 105 m depth causing the plume to remain in suspension above this
depth. Another density gradient was measured at 43 m, and the field data indicate that material
is trapped at this depth. The difference in the plume depth in the model results and field data
during 570 to 1080 sec after disposal are due to the lack of sensitivity of the STFATE model to a
change in density occurring at a depth of 43 m. The material shown in the field data to be
trapped at the surface has been effected by a similar density stratification occurring at a depth of
23 m. The density profile described has been documented by Proni et al (1991). Stripping of
the material from the barge, which has been added to subsequent versions of STFATE, may also
attribute to this difference in field data and simulated results.
20.	Figure 12 illustrates the TSS concentration in the water column from the field measurements
taken 1350 to 150O sec after dredged material discharge. Figure 13 shows the TSS concentration
calculated 1400 sec after disposal for the simulation. These data were taken between two plumes
of higher concentration about 550 m from the location of discharge. This appears to coincide
with monitoring procedures. Both figures show similar distributions of TSS concentration below
60 m with maximum concentrations exceeding 1 mgII. The simulation computed concentrations
in the center of the plume are in excess of 10 mg/f but the field data indicate lower
concentrations.
21.	Figures 5 through 13 illustrate that the STFATE model provides reasonably accurate
predictions of the fate of dredged material from the time of disposal to 25 minutes after the
discharge in that the simulated spatial distributions of material are similar to the actual spatial
distribution with concentrations within an order of magnitude. The spatial distributions of
material from field and simulated data cannot be compared at precisely equivalent times because
the acoustic technology used to obtain the field measurements required 150 sec to pass through
the dredged material residual plume. The simulated data are reported as a snapshot of the water
column at a single time providing a more intuitive insight into the material dispersion. Other
differences regarding the comparison of field and simulated data include assumptions made
regarding the disposal vessel and discharged material. Samples of dredged material were taken
and are being analyzed but the bulk density could not be included as input in the short time frame
allowed for this study. The results show that the simulation is predicting the convection and
advection of material up to 25 minutes after disposal to the degree required for the present study
(within an order of magnitude for concentration measurements taken in mg/£).
Prediction of Plume Movement
22.	For the purpose of predicting the long term diffusion of dredged material and to determine if
material will reach the coral reefs, environmental conditions pertaining to velocity and density
stratification of the water column at the study site were provided by RSMAS. Information which
was not provided by RSMAS included parameters related to dredged material and vessel
dimensions, therefore, this input remained the same as that used for the verification of the
STFATE model. The depth, which must remain constant if a velocity profile is used, was
selected to be 750 ft. If the slope were included, it is reasoned that material would settle to the
bottom more quickly than simulated, decreasing the amount of material remaining in suspension.
6

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This represents the maximum depth of the disposal site, and it was reasoned that the deeper the
dredged material had to fail the more likely it was to be trapped in suspension. The velocity
distribution used as input into STFATE for the purpose of predicting dredged material movement
originated from Lee et al (1977). The mean velocities, which included northerly velocities of
175 cm/sec at the surface and 43 cm/sec mid-depth in the water column and westerly currents of
5.4 cm/sec at the surface and 1.9 cm/sec near the bottom, were used. These data were obtained
in June 1971 and are representative of the summer conditions when most material is discharged.
23. Measurements of temperature and salinity were taken from Roemmich and Wunsch (1985)
and were converted to density with the equation
= p
P a +0.698F
where
p = density (g/cc)
P = 5890 + 38T- 0.3757*2 +35
a - 1779.5 + 11.257-0.0745r2 - (3.8 + 0.017)5
T — temperature (°C)
S — salinity (ppt).
These data were collected in September, 1981 and do not represent the density during the
summer months. Summer temperatures presented by RSMAS were not adequate (not sufficiently
deep) to describe the density profile. The data described were input into STFATE and represent
average conditions encountered at the site.
24.	Results of the sediment concentration computation for Miami are shown in Figure 14. The
disposal release point is located at the origin, and the distance is the absolute distance from the
disposal site to the residual plume. The depths of 27.4 m (90 ft), 54.9 m (180 ft), 82.3 m (270
ft), 109.7 m (360 ft), and 135.6 m (445 ft) were used in order to present an overall
representation of the numerical results. For example, at 3000 sec after the initial dump,
simulations of the disposal operation shows concentrations of suspended silt and clay at the 27.4
m (90 ft) depth to be 5.5 mg/l. Results illustrate a decreasing amount of material suspended in
the water with time. The simulated TSS concentration simulated falls below the maximum
background concentration measured in June 1991 p.l mg/f) after 9000 sec at all depths.
25.	It may seem unacceptable to incur concentrations twice the background level for periods of
almost 2 hours in an area of coral reefs (i.e., 6.5 mg/f, at time 6000 sec, at depth 54.9 m).
However, the plume can be shown to move almost due north for over 2.5 hours, not reaching the
reefs with concentration levels below background levels. The path of the simulated TSS
concentrations is illustrated in Figure 15, with squares representing points along its path. The
"X" is the location of the disposal, assumed to be in the center of the disposal site.
26.	In the August 1990 field study, acoustical methods were combined with adding a tracer to the
material to follow the residual plume. The plume was monitored for 1.5 hours using this method
7

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and was found to move due north. After the tracer could no longer be detected, the reef areas
were monitored, and no tracer was detected. The circles, shown in Figure 15, represent the
results of the dye study conducted by SAJ and AOML in August 1990. Filled circles indicate
dye was detected and open circles indicate no dye detected. The simulated path of the dredged
material is almost identical to the actual path of dredged material in August, 1990.
27.	The question can then be asked if the coral reefs are effected at times of maximum westerly
currents. The same conditions as above were run with the maximum westerly currents reported
by Lee et al (1977) (57 cm/sec at the surface and 16 cm/sec near the bottom), and the residual
plume reached the coral reefs at approximately 1.7 hr (see asterisk in Figure 15). The maximum
concentration predicted near the coral reefs at this time was computed to be 0.02 mg/t. During
the verification runs, a maximum westerly current speed of 66.8 cm/sec was input at the mid
depth of the profile, which exceeds the velocity reported by Lee et al (1977) (57 cm/sec). The
resulting location of the residual plume after approximately 17 minutes is shown as a triangle in
Figure 15. The maximum TSS concentration was found to be greater than 10 mg/t by both
simulation and prototype data. However, the maximum concentration decreases to below 1 mg/£
in about 23 minutes. The material is not anticipated to reach the coral reefs before 40 minutes.
Long Term Fate Analysis
28.	The final task of the study investigates the long-term fate of disposed material. Scheffner and
Swain (1989) determined the Miami ODMDS to be non-dispersive, i.e. the velocities at the site
were not sufficient to move significant amounts of the dredged material on the bottom. Empirical
relationships for computing sediment transport as a primary function of ambient water velocity,
depth, and sediment grain size were reported by Ackers and White (1973). These relationships
were subsequently modified (Swart 1976) to reflect an increase in sediment transport when a
wave field is superimposed on the ambient current field. The Long Term FATE (LTFATE)
model uses the Swart (1976) modification to compute sediment transport at the dredged material
disposal site. The model has been verified to prototype data by Scheffner (1991) and was shown
to be a viable approach to providing quantitative predictions of disposal site stability. The
program was modified to output the shear stress based on the equation taken from Ackers and
White (1973).
29.	The present investigation involves determining the potential for moving material other than
uniformly graded, non-cohesive sediments. This question is addressed by calculating shear stress
values on the mound and in the surrounding area that can be used to determine the effect on any
dredged material. The difference between shear stress values on the mound and the surrounding
area provides an indication of the normal movement and the increase caused by the disposal
mound.
Non-Storm Conditions
30.	In order to run LTFATE to determine long term mound evolution, two types of input data
are required, wave data characteristics at the site and time series of tidal elevations and
velocities. The wave height, period and direction data were taken from the 20-year Wave
Information Study (WIS) Revised Atlantic Coast Hindcast (Hubertz, et al 1993) database This
8

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database was processed through a wave simulation procedure, developed by Borgman and
Scheffner (1991), that generates waves statistically similar to those known to occur at the site,
i.e., preserving seasonality, directionality, distribution, sequencing, etc. The advantage of the
procedure is that the simulated data reflect the trends of the entire 20-year database, not merely
one specific event. The tidal database is composed of tidal harmonic constituents which can be
used to simulate a tidal time series at the disposal site. The constituents are based on a 6-month
simulated tidal time series computed by a long-wave hydrodynamic finite element model (Luettich
et al. 1992). A residual current velocity of 50 cm/sec to the west was used because this was
determined to be an approximate threshold value for the initiation of sediment movement by
Scheffner and Swain (1989).
31. As in the Scheffner and Swain (1989) study, the Miami ODMDS was found to be non-
dispersive. The shear stress values were determined as an indication of the potential of material
resuspension. For non-storm conditions, the shear stress ranged from 2.54 to 3.64 dynes/cm2,
throughout the simulated domain. As shown in Figure 16, the critical shear stress for cohesive
dredged material for field data illustrated by Teeter and Pankow (1989) was found to be 2.5
dynes/cm2. This value is conservative because the typical critical shear stress value is given to
be 5.0 dynes/cm2 (Teeter and Pankow 1989). A difference of 0.14 dynes/cm2 (3.64-3.50) is
shown to be the difference between the shear stress on the disposal mound and that of the
surrounding area. This variability in shear stress represents the maximum difference between the
values on the dredged material mound and the surrounding area. The minimum difference was
shown to be 0.10 dynes/cm2 when the surrounding shear stress was 2.54 dynes/cm2. If the
critical value for shear stress is taken from Figure 16, the entire simulated domain is in the
significant erosion range. If the typical value of 0.5 dynes/cm2 is used, the entire simulated
domain is below the significant erosion range. In either case, the mound has little consequence
to the amount of sediment moved.
Storm Conditions
32.	A storm event for the Miami site was assumed to have a sustained velocity of 6.0 ft/sec for
24 hours. The findings of this study agree with those of Scheffner and Swain (1989), in which
the mound located in 600 ft of water is little effected by the velocities of a magnitude realistically
representative of the disposal site offshore of Miami. The shear stress increased by an order of
magnitude over non-storm conditions, ranging from 38.9 to 45.9 dynes/cm2. The maximum
difference in shear stress between the dredged material mound and the surrounding area is
1.8 dynes/cm2. The increase in shear stress to due the presence of the dredged material mound is
only 5% of the shear stress of the surrounding area. This increased in shear stress is anticipated
to have little impact on the sediment movement in the area.
Summary and Conclusions
33.	Background conditions and dredged material plumes were monitored offshore of Miami,
Florida as a cooperative effort between SAJ, AOML, and CERC on three occasions, and the data
were subsequently analyzed to determine the validity of numerical simulation methods used in
9

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predicting the fate of dredged material. The objective was to determine if dredged material
would reach coral reefs located shoreward of the Miami ODMDS.
34.	Field samples taken in April 1990 and June 1991 were analyzed for TSS concentration by
AOML. The dredged material plume was found to decrease in concentration to the level of
background measurements in approximately 45 minutes. During that time, the plume may move
about 1500 m but not nearly the 5000 m necessary for the material to reach the sensitive coral
reefs.
35.	Acoustic backscatter measurements were used to verify the residual plume concentrations
predicted by the STFATE model. Acoustic theory was used to convert backscatter intensity to
TSS concentrations. The simulated concentrations accurately predicted the acoustic field
measurements to within an order of magnitude. After being verified, the STFATE model was
run with input provided by RSMAS. The results indicate that the disposal site is dominated by
northerly flows produced by the Gulf Stream Current. Thus, the material generally moves in a
northerly direction as verified by field data collect in August 1990. The dispersion of the
material will reduce concentrations to within background levels before moving sufficiently
westerly to reach the coral reefs. Even in the maximum westerly flow, the coral reefs are not
anticipated to be effected.
36.	Under normal environmental conditions, shear stress values at the ODMDS are low, and little
movement is anticipated for either cohesive or non-cohesive material. During storm events, the
shear stress values increase by an order of magnitude. However, the shear stress on the dredged
material disposal mound increases by less than 2 dynes/cm2 above the shear stress of the
surrounding area. When subjected to storms, material is anticipated to move from the mound for
short periods of time but large dispersion of the mound is not predicted, therefore the material is
not expected to effect the coral reefs.
37.	Amongst the data collected during three field monitoring studies and two numerical model
prediction studies, no evidence has been found to indicate that dredged material will migrate on
to coral reefs. The predominant current velocities are toward the north-northeast, away from the
sensitive areas. Even in the maximum anticipated westerly currents, the dredged material is
shown in field data to disperse to well within the limits of background concentrations
in approximately half the time it would take to reach the reefs. The model predictions have not
been fully verified to prototype data in the upper few meters of the water column (results are
illustrated beginning at 30 meters), however, field data collected and analyzed by AOML indicate
that concentrations in the upper 3 to 8 m of the water column decrease to just above background
levels in the minimum time required to reach the reefs. Therefore, the discharge of dredged
material at the placement site is not predicted to cause an increase in naturally occurring
concentration of TSS on the coral reefs located shoreward of the Miami ODMDS.
REFERENCES
Ackers, P. and White, R.W. 1973. "Sediment Transport: New Approach and Analysis,
Journal of the Hydraulics Division, Vol 99, No HY11, pp 2041-2060.
10

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Bergman, L.E. and Scheffner, N.W. 1991. "The Simulation of Time Sequences of Wave
Height, Period, and Direction," Technical Report DRP-91-2, Coastal Engineering Research
Center, US Army Engineer Waterways Experiment Station, Vicksburg, MS.
Johnson, B.J., Trawle, M.J., and Adamec, S.A. 1988. "Dredged Material Disposal Modeling in
Puget Sound," Journal of the Waterway, Port, Coastal, and Ocean Division, Vol 114, No. 6, pp
700-713.
Hubertz, J.M., Brooks, R.M., Brandon, W.A., and Tracy, B.A. 1993. "Hindcast Wave
Information for the US Atlantic Coast," WIS Report 30, Coastal Engineering Research Center,
US Army Engineer Waterways Experiment Station, Vicksburg, MS.
Kraus, N.C. (ed.) 1991. "Mobile, Alabama, Field Data Collection Project, 18 August - 2
September, 1989, Report 1: Dredged Material Plume Survey Data Report," Technical Report
DRP-91-3, Coastal Engineering Research Center, US Army Engineer Waterways Experiment
Station, Vicksburg, MS.
Lee, T.N., Brooks, I., and Diiing, W. 1977. "The Florida Current; its Structure iand
Variability," Technical Report UM_RSMAS 77003, Rosenstiel School of Marine and
Atmospheric Sciences, University of Miami, Miami, FL.
Luettich, R.A., Westerink, J.J., and Scheffner, N.W. 1992. "ADCIRC: An Advanced Three-
Dimensional Circulation Model for Shelves, Coasts, and Estuaries - Report 1: Theory and
Methodology of ADCIRC-2DDI and ADCIRC-3DL," Technical Report DRP-92-6, Coastal
Engineering Research Center, US Army Engineer Waterways Experiment Station, Vicksburg,
MS.
Ogushwitz, P.R. 1992. "Analysis of Measure Sound Scattering from Suspended Sediment
Plumes," Coastal Engineering Research Center, US Army Engineer Waterways Experiment
Station, Vicksburg, MS.
Proni, J.R., Tsai, J.J., and Dammann, W.P. 1991. "Miami Harbor Dredged Material Disposal
Project," Coastal Engineering Research Center, US Army Engineer Waterways Experiment
Station, Vicksburg, MS.
Proni, J.R., Craynock, J.F., and Tsai, J.J. 1993. "Miami Harbor Dredged Material Disposal
Project: Total Suspended Solids Measurements," 'Coastal Engineering Research Center, US
Army Engineer Waterways Experiment Station, Vicksburg, MS.
Roemmich, D. and Wunsch C. 1985. "Two Transatlantic Sections: Meridional Circulation and
Heat Flux in the Subtropical North Atlantic Ocean," Deep Sea Research, Vol 32, No 6, pp 619-
664.
Scheffner, N.W. and Swain, A. 1989. "Evaluation of the Dispersion Characteristics of the
Miami and Fort Pierce Dredged Material Disposal Sites," Coastal Engineering Research Center,
US Army Engineer Waterways Experiment Station, Vicksburg, MS.
11

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Scheffner, N.W. 1989. "Disposal Site Evaluation for the New York Bight," Coastal Engineering
Research Center, US Army Engineer Waterways Experiment Station, Vicksburg, MS.
Scheffner, N.W. 1991. "A Systematic Analysis of Disposal Site Stability," Proceedings of
Coastal Sediments '91, ASCE, pp 2012-2026.
Swart, D.H. 1976. "Predictive Equations Regarding Coastal Transports," Proceedings of the 15A
Coastal Engineering Conference, ASCE, pp 1113-1132.
Teeter, A.M. and Pankow, W. 1989. "Schematic Numerical Modeling of Harbor Deepening
Affects on Sedimentation, Charleston, SC," Miscellaneous Paper HL-89-7, Hydraulics
Laboratory, US Army Engineer Waterways Experiment Station, Vicksburg, MS.
Thevenot, M.M. and Kraus, N.C. 1993. "Comparison of Acoustical and Optical Measurements
of Suspended Material in the Chesapeake Estuary," Journal of Marine Environmental
Engineering, Vol 1, pp 65-79.
Tsai, J.J., Proni, J.R., Dammann, W.P., and Kraus, N.C. 1992. "Dredged Material Disposal at
the Edge of the Florida Current," Chemistry and Ecology, Vol 6, pp 169-187.
Michelle M. Thevenot, PE
Research Division
Coastal Engineering Research Center
12

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Covornmeni Cut
ODMDS
STATUTE MILES
NAUTICAL MILES
GENERAL LOCATION MAP
Ocean Dredged Molenal Disposal Site Miami, Florida
25* 4 7' OD
25* 46' JO'
25* <6 00
25* *5 30
25' 15 '
25* 45 00
25* 4* 45
?b' 44 JO
25' 4 4 CO'
25' 43" 00
ODMDS
	I	
NAUTICAL miles
0A7HYME TRlC MAP
Oceon Oreaged Material Disposal S"le Miomi, Florida

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103
Miami Harbor Project
All Discharges
o°
1 0
-2
I | I I I I [ 1 I I I | I I I I | F I I I (
I f I I 1 I I I I I I I I I I I I I 1 I I 1 I F I I I I I I I I I
0
5 10 15 20 25 30 35 40 45 50 55
Time (min)
• ¦ i •11 ¦ i
60 65

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Normalized Concentration
Discharges Nos. 1, 3 & 4
10° —
o.i
nm-J
20 25 30 35 40
Time (min)

-------
-20
-30J
-40-
best fit to data
-50-
o«
- 60 H
theory
-80-
00
-90-
O - 100-
LlJ
-110
10	100
Concentra on (m
1000

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SCATTERING STRENGTH ABOVE BACKGROUND
MHDP 04-26-90 14:16:00—14:18:30 Background time = 14:16:00
Vertical avg. = 3.0 meters. Repeated 5 times.
Horizontal avg. = 2.50 seconds. Threshold = 15.0 millivolts.
D.C. Offset = 0.0 millivolts. Absorption coefficient = -.00500 dB/m.
0 20 40 60 80 100 120 140 160 180 200 220
Distance (M)
0
Time (sec)
150

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SCATTERING STRENGTH ABOVE BACKGROUND
MHDP 04-26-90 14:18:30-14:21:00 Background time = 14:16:00
Vertical avg. = 3.0 meters. Repeated 5 times.
Horizontal avg. = 2.50 seconds. Threshold = 15.0 millivolts.
D.C. Offset = 0.0 millivolts. Absorption coefficient = .00500 dB/m.

o 80
1 20 -
m
0 20
150
80 100 120 140
Distance (M)
Time (sec)
160 180 200 220


Concentration
(mg/l)
>1000
500
100
50
10
5
1
.5
.1
<. I
300

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T-240
30
2 60
90
120
137
450
900
600
300
750
150
Distonce (M)

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SCATTERING STRENGTH ABOVE BACKGROUND
MHDP 04-26-90 14:25:30-14:28:00 Background time = 14:16:00
Vertical avg. = .3.0 meters. Repeated 5 times.
Horizontal avg. = 2.50 seconds. Threshold = 15.0 millivolts.
D.C. Offset = 0.0 millivolts. Absorption coefficient = .'00500 dB/m.

0)
a 80-
1 00 -
1 20 -
0 20
570
80 100 120 140
Distance (M)
Time (sec)
160 180 200 220
720
eeo
EZ]
Concentration
(mg/l)
>1000
500
100
50
10
5
1
5
.1
<.1

-------
T-600
30
60
90
120
137
150
300
450
Distance (M)

-------
SCATTERING STRENGTH ABOVE BACKGROUND
MHDP 04-26-90 14:31:30-14:34:00 Background time = 14:16:00
Vertical avg. = 3.0 meters. Repeated 5 times.
Horizontal avg. = 2.50 seconds. Threshold = 15.0 millivolts.
D.C. Offset = 0.0 millivolts. Absorption coefficient = .00500 dB/m.
Concentration
(mg/l)
J	,	,	,	,	¦	.	1 I I '¦* a
0 20 40 50 80 100 120 140 160 180 200 220
Distance (M)
Time (sec)
930
v	
1080

-------
Distance (W)

-------
SCATTERING STRENGTH ABOVE BACKGROUND
MHDP 04-26-90 14:38:30-14:41:00 Background time = 14:16:00
Vertical avg. = 3.0 meters. Repeated 5 times.
Horizontal avg. = 2.50 seconds. Threshold = 15.0 millivolts.
D.C. Offset = 0.0 millivolts. Absorption coefficient = .00500 dB/m.



0 20 40
I ' I i ¦ I i	1	1	r
80 100 120 140 160 180 200 220
Distance (M)
Time (sec)

Concentration
(mg/l)
>1000
500
100
50
10
5
1
.5
.1
<.1
1350
1500

-------
T-1400
30
_c
a
a>
O
90
100
137
0
900
600
300
Distance (M)

-------
12 0
10 0
8 0
6 0
4- 0
2 0
0
CP
E
c
o
c

270 FT
0ACKCROUND
^	 3 1 mg/l
4500 SEC
6000 SEC
disposal site
(109 7m)
360 FT
BACKCROUND
3 1 mg/l
9000 SEC
bOOu SIC
DISPOSAL SITE
_L
1135 6M)
445 FT
BACKCROUND
3 1 mg/l
9000 SEC
	I I
3	<	5	6
Distance (Miles)
1 , /''/

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Coral R< efs
1 7hr •
2 5hr
50mm
Government Cut
min
17 min
ODMDS
STATUTE MILE
nautical miles
path or residual plumc
Ocean Dredged Material Disposal Site Miami, Florida
FT, f£T
^ ¦

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significant
erosion „
particle erosion
b dynes/cm

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APPENDIX F
MIAMI HARBOR DREDGED MATERIAL DISPOSAL PROJECT

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MIAMI HARBOR DREDGED MATERIAL DISPOSAL PROJECT
John R. Proni, Ph.D.
Director, NQAA/ERL/AOML Ocean Acoustics Division
John J. Tsai, Ph.D.
Research Physicist, NQAA/ERL/AOML Ocean Acoustics Division
Paul Dammann, P.E.
Research Oceanographer, NQAA/ERL/AOML Ocean Acoustics Division
National Oceanic and Atmospheric Administration
Atlantic Oceanographic and Meteorological Laboratory
4301 Rickenbacker Causeway
Miami, Florida 33149
June 1991

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TABLE OF CONTENTS
Page
I. INTRODUCTION		1
II. FIELD OPERATION		5
III. DATA ANALYSIS		9
Water Depths		9
Temperature Profiles		15
Density Stratification		19
Salinity Measurements		20
Current Velocity		21
Dredged Materials		23
Acoustic Profiles		26
IV. DISCUSSION		28
V. RESULTS		41
VI. CONCLUSIONS AND COMMENTARY		43
VII. ACKNOWLEDGMENTS		45
VIII. REFERENCES	 45
IX. APPENDICES		47
Appendix A	 A-l
Appendix Bl	 Bl-1
Appendix B2	 B2-1
Appendix Cl		Cl-1
Appendix C2		C2-1
Appendix C3		C3-1
Appendix C4		C4-1
Appendix D		D-l
Appendix El	 El-1
Appendix E2		E2-1
Appendix E3		E3-1
Appendix E4	 E4-1

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FIGURE CAPTIONS
Figure	Page
1.	Location map of Miami ODMDS. Insert at the upper right
corner indicates the location of the map in Florida.
Circles and squares represent active artificial reefs,
except dotted squares are proposed artificial reefs	 2
2.	Signal flow chart of acoustic concentration profiler
system	 7
3.	Bathymetric map in the vicinity of the Miami ODMDS;
water depth in feet	 14
4.	Temperature profiles from six CTD stations of Phase 1	 16
5.	Density profiles from six CTD stations of Phase 1	 17
6.	Salinity profiles from six CTD stations of Phase 1	 18
7.	Location map of the Miami Harbor. The turning basin
is indicated as a * at the end of the Miami Ship
Channel. The insert at the lower left corner shows
the three sediment stations	 24
8.	Gradation curves of particle-size distribution for
the three sediment stations in the Miami Harbor
Turning Basin	 25
9.	Acoustic iso-concentration contours of one dump on
April 26, 1990, corresponding to four transects at
different times. The gap in concentration indicated
in (a) at 90 to 100 m distance is attributed to
acoustic absorption at the frequency of 20 kHz by a
cloud of bubbles in the water near the surface	 30
10. Acoustic iso-concentration contours of the first
transect of Fig. 9, showing the method to calculate
the entrainment coefficients. The backscattering
strength levels shown in Figs. 9 and 10 are in
decibels and represent particulate concentrations
of suspended materials in the water column	 32
11.	Temperature, salinity and density profiles at
15:59:00 on April 25, 1990 during Phase 1	 35
12.	Comparison between acoustic scattering strength
from ACP and echo amplitude from ADCP at 30 m and
50 m. Top: from ACP; bottom: from ADCP	 36
13.	Comparison between acoustic scattering strength
from ACP and echo amplitude from ADCP at 70 m and
90 m. Top: from ACP; bottom: from ADCP	 37

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FIGURE CAPTIONS (continued)
Figure	Pag
14.	Peak concentration as function of time at six fixed
depths for April 26, 1990 during Phase 1	 38
15.	Time series of echo amplitudes at seven fixed depths
from 10 ra (top) to 130 m (bottom) for April 26, 1990
during Phase 1	 40
16.	Current profiles for the five transects of second
dump on April 26, 1990 during Phase 1	 42

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I. INTRODUCTION
There are only limited upland disposal sites of dredged material in
the Miami, Florida area and the recently planned deepening of the Miami
Harbor creates a need to designate by the U.S. Environmental Protection
Agency (EPA) an environmentally acceptable, adequately sized and
economically feasible offshore Ocean Dredged Material Disposal Site
(ODMDS) for the greater Miami, Florida area (EPA, 1990). Two independent
studies were carried out to comply with the Marine Protection, Research,
and Sanctuaries Act (MPRSA) of 1972. Physical, chemical and biological
characteristics and their interactive effects were measured (Conservation
Consultants, Inc., 1985) and the probable dispersion fate of dredged
materials that might be dumped at the site was modeled (Scheffner and
Swain, 1989). The Draft Environmental Impact Statement of EPA (EPA, 1990)
concluded that the interim-designated site, about five nautical miles
offshore from Government Cut at Port of Miami and shown in Fig. 1, is
suitable for designation for disposal of dredged material.
Both natural and artificial reefs are found in the proposed Miami
ODMDS vicinity. The seaward extent of the natural reef zone in the area
lies approximately 2.4 km inshore of the west side of the interim
disposal site (Fig. 1). Two concentrations of artificial reef sites are
also located in the area, one group about 6 km north and slightly inshore
and the other about 3 km south and inshore of the proposed disposal site
(Fig. 1). There are concerns about the potential contamination of these
reef areas due to the proposed disposal of up to 6 million cubic yards of
material from the Miami Harbor deepening project. One of the major
reasons is that the proposed ODMDS is situated on the continental slope
where the ocean circulation is strongly influenced by the nearby Florida
Current. The Florida Current is that portion of the Gulf Stream system
that connects the Loop Current in the Gulf of Mexico to the Gulf Stream
1

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Miami Ocean Dredged Material Disposal Site
23° 30*
Os
ARTIFICIAL REEF I
Port of Miami G
Virginia Key
ODMDS
STATUTE MILES
NAUTICAL MILES
Cape Florida
JO
Fig. 1. Location map of Miami OOKDS. Insert at the upper right
corner indicates the location of the map in Florida.
Circles and squares represent active artificial reefs,
except dotted squares are proposed artificial reefs.

-------
as the flow proceeds through the Straits of Florida and into the open
Atlantic Ocean (Lee et al., 1977). When the western edge of the Florida
Current is over the continental shelf, the current draws the coastal
waters north with it. When the western edge is seaward of the shelf,
cyclonic spin-off eddies are formed. Following their formation, spin-off
eddies travel northward along the continental margin at speeds ranging
from 20 to 50 aVsec. Eddies occur on the average of once per week and
can be recognized as disruptions of prevailing temperature and salinity
fields and of local current patterns (Lee and Mayer, 1977). These
cyclonic eddies play an important role in coastal exchange processes,
removing coastal water and replacing it with water from the Florida
Current.
Because the designated Miami ODMDS lies near the western edge of the
Florida Current and the mean current can be greater than 100 ao/sec in
the spring and summer, transport, dispersion and mixing of dredged
material dumped in this area could be affected greatly by physical
processes associated with the Florida Current. Therefore, a monitoring
study of dredged materials from the turning basin area, Port of Miami,
that were dumped in the designated Miami ODMDS was undertaken during the
period of April 24 to April 26, 1990. A second phase of study took place
between June 26 and June 28, 1990. One major objective of the study is
to identify and monitor environmentally significant physical processes at
the ODMDS site, which would change the fate of dredged materials dumped
at: the site. One of those significant quantities is the maximum
reef-directed shoreward current that would transport dumped material to
the coral reef area. Another objective is to. compare the in-situ
measurements and observations with results of a numerical modeling study
(Scheffner and Swain, 1990).
3

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The Ocean Acoustic Division (QAD) of the Atlantic Oceanographic and
Meteorological Laboratory (AOML), a component of NQAA (National Oceanic
and Atmospheric Administration), has been at the forefront of the
analysis and technology required for understanding coastal ocean
processes and their influence on the dispersion of material discharged
into the open ocean. During the last 15 years, OAD has applied this
acoustic remote sensing technique to study ocean disposal of different
materials at various environments and locations. Among these studies were
sewage sludge in New York Bight (Proni et al., 1976), river bottom
dredged material in Lake Ontario (Proni et al., 1977), pharmaceutical
wastes off Puerto Rico, drilling muds from an oil rig in the Gulf of
Mexico (Trefey arid Proni, 1983), dredged material in New York Bight
(Tsai, 1984; Tsai and Proni, 1985), and more recently dredged material in
Mobile Bay. Results from these studies have provided good evidence that
acoustic remote sensing can be very useful for studying waste disposal in
the ocean.
• The Miami Harbor Dredging Material Dumping Study is a joint project
of the U.S. Army Engineer District, Jacksonville and the Coastal
Engineering Research Center (CERC) of the U.S. Army Engineer Waterways
Experiment Station (WES), Vicksburg, Mississippi, and was conducted by
QAD/AQML of NQAA, Miami. Hie plume concentration of discharged material
and current velocity were monitored continuously to depths as great as
160 m and are believed to provide the first reliable measurements of
sediment plume dynamics over such depths in the open ocean. The data and
observations for all dredged material placement operations during this
project indicate that the waste plume moved toward the north to north-
east, that is northward and away from sensitive coral reef areas of
concern. The results also support predictions from previous numerical
modeling and certain conclusions reached in the EPA Draft EIS. The
4

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procedures followed and results obtained are expected to provide
information on other ODMDS's managed by the Jacksonville District.
II. FIELD OPERATION
The entire operation took place in two phases, Phase I from April 24
to 26, 1990 and Phase II from June 26 to 28, 1990. During Phase I, eight
dumps of dredged material from the Miami Harbor turning basin area were
carried out, and the waste plumes were monitored continuously with an
Acoustic .Concentration Profiler (ACP) of QAD/AOML and an Acoustic Doppler
Current Profiler (ADCP) of RDI (RD Instruments, Inc.). Hie ADCP was not
used during the Phase II because it was not available during that time.
There were no dumps monitored during Phase II because the contracted
dredging operation was unexpectedly finished early. During both phases,
CTD (Conductivity-Temperature-Depth) stations were taken using a Seabird
CTD profiler, and water/sediment samples were collected continuously from
a towed pump sampler when the ship was underway. Sediment samples were
collected from the dredging vessel with a sediment grab sampler during
Phase I.
The ADCP was mounted at the port side of the monitoring vessel (Sea
Explorer), opposite to the towed transducer of the ACP. The ADCP
transmits short acoustic pulses along narrow beams at a known, fixed
frequency (150 MHz). It listens to and processes the echoes from
successive volumes (depth cells or'bins) along the beams to determine how
much the frequency has changed. The difference in frequency between
transmitted and reflected sound is proportional to the relative velocity
between the ADCP and the particles in the water that do the reflecting
(backscattering). This frequency shift results from the Doppler effect.
The ADCP uses an autocovariance method to compute the mean value or first
moment of the Doppler frequency, and from this computed first moment of
5

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frequency, velocity of the scatterers is determined. However, the current
at each depth cell is assumed to be the same for all beams (the
homogeneous velocity assumption). The ADCP also provides echo amplitude
as a byproduct of the AGC (Automatic Gain Control) circuits. This echo
amplitude estimates backscatter intensity and is comparable with the
acoustic intensity measurement from ACP. Backscattering cross sections
derived from both the ADCP echo amplitude and the ACP acoustic intensity
can be used to estimate the particulate concentrations of suspended
wastes in the water column and to compare with particle concentrations
derived from bottle samples.
The ACP has five major components as a system (Fig. 2). (1) It has
transducers mounted in a streamlined towbody, aiming vertically downward
and towed on the starboard side of the ship at a nearly constant depth of
about 1 m below the water surface. The two transducers have acoustic
frequencies of 20 kHz and 200 kHz. (2) The ACP uses a Datasonic model
DFT-210 dual channel acoustic transceiver with several features not found
in standard acoustic transceivers. It provides digital control of
transmitter output pulse and receiver gain characteristics to allow
accurate measurement of target echo levels. A precision low noise
preamplifier is incorporated within the receiver to extend the system
dynamic range and to allow measurement of very low backscattering levels.
The DFT-210 also offers multiple receiver outputs and interfaces for
simultaneous recording and display. (3) Two Raytheon TDU-850 digital
chart recorders were used to record echographs from the DFT-210, one for
20 kHz signals and the other for 200 kHz. The TDU-850 is a thermal
display unit which generates hard copy of true gray shades at high speed
and with high resolution, producing near photographic quality. It
features a universal interface that transfers data rapidly and relies on
synchronization of clock and data signals to transfer the image in a
6

-------
•ZBM ComDuter
"with A/D Converter
Raytheon TDU-850
Thermal Paper Recorder
°t t 3
Sharp SX-DJ 00
DAT Recorder
3bH 83 .59 54
* ©_® e
Systron Dormer Model 8720
Time Code Generator
= 1 1

G
• g.~,n.- i.i • i - I-1 i i.i.i i +
i ni
Sharp SX-DJ 00
DAT Recorder
aoaa
o a
Sony PCM-F1
Audio Digital Processor
r
5E39G
5c=-==-*3


5S~S£[q
I
Datasanic DFT-210
Transceiver
20 KHz and 200 KHz
Transducers
Video Cassette Recorder
Video Cassette Recorder
Fig. 2. Signal flow chart of acoustic concentration profiler system.
7

-------
raster scan format. (4) Both receiver outputs from the 20 kHz and
200 kHz transducers were also recorded respectively onto two Sharp
SX-D100 digital audio tape (DAT) recorders with IRIG-B tine code gene-
rated from a Systron Donner Model 8720 time code generator. The recorded
outputs were processed later to obtain the acoustic back-scattering
strength from which the waste concentration is derived. (5) The receiver
outputs were recorded separately on two standard VHS video cassette
tapes using a Sony PCM-Fl Audio Digital Processor. These VHS tapes serve
as backup and have the same data as those on the DAT.
There were eight dumps in total for the entire operation. Before
each dump and between successive dumps, the Sea Explorer monitored the
water column to obtain background concentrations of suspended materials
and ambient currents in the area using the ACP and ADCP on board the
vessel. Ambient density and salinity were measured by taking CTD
stations at the previous dumping spots that were determined from the ship
track records. There were six CTD stations in Phase I and 50 stations in
Phase II. CTD stations taken during Phase II were not based on the
actual dumping location because no dumping took place in Phase n.
Sediment samples were collected directly from the dredging vessel
Atchafalaya for each dump. The dumping would occur for most of the dumps
when Atchafalaya had just made the turn to head shoreward. Both the ADCP
and ACP were set r^ady to operate upon the approach of Atchafalaya and
the Sea Explorer proceeded to make the transects immediately after the
dumping commenced. The Sea Explorer would track the waste plume for
several transects until the ACP could not detect the plume any more. It
usually took about 40 minutes since the release. During each transect,
water samples were taken by a towed V-fin with a pump that pumps water
continuously through a hose to the deck of the moving ship. The water
sampling took place at approximately constant depth by maintaining
8

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constant ship speed, and collecting samples only during the time when
transects were in the plume. During the first two-day operation, ship
positions were automatically logged with a computer and displayed in real
time to assist monitoring. A drift buoy was to be deployed to mark the
spot of each dump but was never used. However, the surface features of
the waste plume were visible up to 30 minutes and were helpful in
tracking the plume. All ship tracks are presented in Appendix A for
reference.
III. DATA ANALYSIS
The primary data obtained from the Phase I were the ACP data
recorded on the DAT and VHS tapes and the ADCP data stored on computer
diskettes. In addition, water samples and sediment samples were
collected during Phase I. However, no detailed analysis has been done
with the water samples and the sediment samples. Grain size distribu-
tions are available from analysis of samples taken in 1988. CTD data
were obtained in Phases I and II and made up the major portion of data
collected in Phase II. CTD stations are summarized in Table 1 for Phase
I and in Tables 2-1, 2-2 and 2-3 for Phase II. Station locations are
presented on page Bl-2 of Appendix Bl and page B2-2 of Appendix B2. For
Phase II, station locations are separated into three sections for the
three days and listed on pages B2-4, 19, and 38. All temperature,
salinity, and density profiles fdr both phases were plotted for each
station as shown in Appendices Bl and B2. All observational data and
results of analysis are described below.
Water Depths
The Miami ODMDS is situated on the continental slope with depths
ranging from 425 to 785 feet, or 130 to 240 m (Fig. 3). The depth at the
9

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Table 1
CTD stations and temperature, density and salinity gradients
for Phase I
CTD
No.
Date
Time
Temperature
Gradients
(deg C/ta)
Density
Gradients
(gn^cc/m)
Salinity
Gradient
(ppt/m)



Overall
Middle
Overall
Middle
Overall
1
04/24/90
10:49:30
-0.107
-0.055
-0.275
0.023
0.014
0.064
0.011
2

13:16:30
-0.108
-0.107
0.025
0.019
0.017
3

18:17:00
-0.109
-0.068
0.023
0.019
0.018
4
04/25/90
11:12:00
-0.127
-0.081
0.030
0.019
0.029
5

15:59:00
-0.124
-0.130
0.030
0.027
0.018
6
04/26/90
09:29:00
-0.138
-0.100
0.028
0.027
0.017
10

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Table 2-1
CTD stations and temperature, density and salinity gradients
for June 26, 1990 of Phase II
CTD Date
No.
Time
Temperature
Gradients
(deg C/hi)
Density
Gradients
(gta/cc/m)
Salinity
Gradient
(ppt/ta)


Overall
Middle
Overall
Middle
Overall
1 06/26/90
10:12:00
-0.135
-0.195
0.038
0.058
0.002
3
12:34:20
-0.106
-0.155
0.027
0.036
0.006
4
13:25:13
-0.112
-0.155
0.032
0.044
0.008
5
14:21:50
-0.103
-0.147
0.025
0.043
0.008
6
15:18:30
-0.103
-0.162
0.026
0.039
0.005
7
16:04:44
-0.104
-0.201
0.024
0.056
0.009
8
16:59:23
-0.098
-0.227
0.022
0.071
0.012
9
18:18:00
-0.105
-0.332
0.026
0.126
0.014
11

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Table 2-2
CID stations and temperature, density and salinity gradients
for June 27, 1990 of Phase II
CTD
Date
Time
Temperature
Density
Salinity
NO.


Gradients
Gradients
Gradient



(deg C/to)
(gtVcc/ln)
(ppt/m)



Overall
Middle
Overall
Middle
Overall
17
06/27/90
00:47:14
-0.113
-0.320
0.028
0.096
0.012
18

01:50:43
-0.109
-0.285
0.024
0.085
0.010
19

03:39:23
-0.088
-0.098
0.018
0.026
0.010
20

10:50:57
-0.137
-0.365
0.035
0.115
0.010
21

11:25:13
-0.124
-0.133
0.030
0.039
0.008
22

12:39:16
-0.101
-0.140
0.023
0.033
0.010
23

14:10:02
-0.105
-0.222
0.025
0.066
0.007
24

14:50:13
-0.132
-0.660
0.038
0.210
0.002
28

16:36:39
-0.113
-0.214
0.026
0.062
0.008
29

17:46:03
-0.118
-0.199
0.028
0.059
0.007
30

19:31:08
-0.119
-0.216
0.027
0.062
0.008
31

20:25:12

-0.332

0.098

32

22:14:20
-0.111
-0.288
0.025
0.092
0.015
12

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Table 2-3
CTD stations and temperature, density and salinity gradients
for June 28, 1990 of Phase II
CID Date
No.
Time
Temperature
Gradients
(deg C/m)
Density
Gradients
(gm/cc/m)
Salinity
Gradient
(ppt/in)


Overall
Middle
Overall
Middle
Overall
33 06/28/90
00:04:15
-0.119
-0.314
0.029
0.088
0.006
34
01:03:26
-0.112
-0.157
0.026
0.042
0.006
35
02:49:02
-0.132
-0.185
0.031
0.055
0.006
37
05:02:39
-0.093
-0.143
0.018
0.033
0.010
38
06:52:58
-0.119
-0.268
0.027
0.070
0.006
39
07:43:14

-0.413

0.133

42
15:05:34

-0.354

0.099

13

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Miami Ocean Dredged Material Disposal Site
23*47'oo"
25° 45 30
2SC44'30"
25* 4 j'OO"
ODMDS
I
NORTH
NAuTlCA. UlLl
Fig. 3. Bathymetric map in the vicinity of the Miami ODMDS;
water depth in feet.
14

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center of the site is approximately 625 feet (191 m). The average
declivity of the slope at the ODMDS is approximately 325 feet (100 m) per
nautical mile (1.85 km). The eight dumps during Phase I took place at
locations with depths varying from 120 m to 170 m.
Temperature Profiles
The temperature profiles indicate a well mixed surface layer of 25°C
temperature for the three-day period of Phase I (Fig. 4). There are
strong gradients below 50 m depth and extend possibly all the way to the
ocean bottom. The surface temperature varies only about 0.5 degree a
day. Temperature gradients differ significantly from time to time and
day to day, however. This temperature difference creates important
variations in density stratification (Fig. 5) because the salinities do
not change significantly (Fig. 6). One temperature profile at the time
10:49:30 on April 24, 1990 shows a distinguishable second gradient at the
intermediate water of small depth region between 35 and 65 m. There also
exists a slight gradient instead of constant temperature in the surface
layer for April 25, 1990 at 11:12:00. On April 24 at 10:49:30, the
temperature profile indicates a four layer structure with different
gradients.
Temperatures in June show stronger gradients, but in general there
is a shallower mixed layer near the surface. In fact, six profiles on
June 26, three on June 27 and one oh June 28 show no mixed layer near the
surface. In contrast, two mixed layers were observed at 06:52:58 on June
28. Daily differences seem to be small when temperature profiles were
grouped together and plotted in the same graphs for similar depths. All
individual temperatures for each station with their salinity and density
profiles are included in Appendix Bl for Phase I and Appendix B-2 for
Phase II.
15

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0.0
	 04/24/90 10:49:30
	 04/24/90 13:16:30
.... 04/24/90 18:17:00
	 04/25/90 1 1:12:00
	 04/25/90 15:59:00
	 04/26/90 09:29:00
22.0-
44.0-
66.0-
88.0-
22.0
20.0
24.0
1 6.0
18.0
26.
Temperature (deg C)
Fig. 4. Temperature profiles from six CID stations of Phase I.

-------
0.0
_ 04/24/90 10:49:30
.. 04/24/90 13:16:30
.. 04/24/90 18:17:00
. 04/25/90 1 1:12:00
.. 04/25/90 15:59:00
.. 04/26/90 09:29:00
22.0-
£ 44.0-
x:
66.0-
88.0-
1 10.0
23.8
24.6
23.0
25.4
26.2
27.0
Sigma —t
Fig. 5. Density profiles from six CID stations of Phase I.

-------
0.0
_ 04/24/90 10:49:30
.... 04/24/90 13:16:30
... 04/24/90 18:17:00
... 04/25/90 1 1:12:00
... 04/25/90 15:59:00
... 04/26/90 09:29:00
22.0-
£ 44.0-
si
£ 66.0-
88.0-
34.0
34.8
36.4
35.6
37.2
38.0
Salinity (ppt)
Fig. 6. Salinity profiles from six CTD stations of Phase I.

-------
The observed temperature gradients are listed in Table 1 for Phase I
and in Tables 2-1, 2-2, and 2-3 for Phase II. The maximum overall
gradient is about -0.138°C per meter depth for Phase I (April 26 at
09:29:00, page Bl-7) and -0.137°C for Phase II (June 27 at 10:50:57, page
B2-24). However, the temperature profile observed on April 24 shows
double gradients at 10:49:30 (page Bl-3). In fact, there exist more than
two gradients at different depths for this station. The middle water
temperature gradient is always greater than that of deeper water. Most
of the June profiles also show these double gradients. Three profiles on
June 27 (12:39:16, 14:10:02 and 14:50:13 on pages B2-26, 27, and 28
respectively) and four on June 28 (05:02:39, 06:52:58, 07:43:14 and
15:05:34 on pages B2-43, 44, 45 and 46 respectively) have more than two
gradients.
Maximum temperatures always occur at the surface and range from 25°C
in April to about 29°C in June. These observations are in the ranges of
annual mean reported by Lee and Mooers (1977) and EPA (1990).
Density Stratification
Density profiles also show gradients at all times and days and are
strongly associated with the temperature variation. Whenever there is a
constant temperature layer near the surface, there is a constant density
layer in the same depth range. Whenever there are temperature gradients,
there are density gradients withifi the same depth range. The multiple
layer structure at 10:49:30 on April 24 also appears in the density
profile. The double mixed layer in temperature at 06:52:58 on June 28
also appears in density. Clearly the density variations largely follow
the temperature variations.
Observed density ranges from 1.024 gm/cc to 1.027 gm/cc in April.
In June, the surface density was about 1.023 gm/cc or smaller, and
19

-------
densities near the bottom can be larger than 1.027 gm/cc because of the
deeper water at some of the stations. These values agrees fairly with
the report by EPA (1990). Density gradients are shown in Tables 1 and
2-1, 2-2, 2-3 for overall depths and the middle water column. Itie middle
water column gradients in general are greater than those in deeper water
near the bottom just as in the case of temperature. The maximum overall
density gradient is 0.038 gnv/cc/m at 10:12:00 on June 26 (page B2-5).
Salinity Measurements
Salinity at the dump site was fairly constant through all depths
except at the deep water below 100 m for Phase I (Fig. 6). Salinity
fluctuates vigorously in deep water with apparent local variations at
different times and locations. The salinity profile generally increases
slightly with depth from the surface and begins to decrease at about the
thermocline depth. The surface salinity is about 36.3 ppt, and maximum
salinity can be as much as 36.6. The lower salinity near-bottom water
can reach as low as 35.6 in April (Phase I). One profile on April 24 at
10:49:30 (page Bl-3) shows a rapid increase and decrease within 10 m
depth, and indicates a salt finger.
In June, the salinity generally remains constant to some depth,
increases very slightly to a certain maximum, and then decreases rapidly
to the bottom with strong gradient. It reached 35.0 ppt at 240 m depth
(June 27, at 03:39:23, page B2-23'). In some cases, salinity near the
surface and the bottom appear to be constant at differert times, but it
varies significantly in the middle water column (June 27 j'rom 01:50:43 to
22:14:20 and June 28 from 02:49:02 to 15:05:34). One profile from June
28 at 06:52:58 (page B2-44) shows distinguishing features from the
others. It indicates a rapid increase in salinity and then decreases
20

-------
with a strong gradient. The maximum salinity gradient occurred at
11:12:00 on April 25 with value of 0.029 ppt/m (page Bl-6).
Current Velocity
The current profiles from the ADCP provide very good information on
the current structure at the Miami ODMDS. However, ADCP data were
available only for Phase I, and there are no current measurements during
Phase II.
An i-nitial sample interval of two minutes was selected for the first
day of Phase I. The primary objective of the current measurements was to
determine the. water column ambient current profile and, in particular,
the vertical shear, i.e., the change of horizontal current with depth at
the time of discharge and during the subsequent tracking period. Since
the tracking ship crosses a plume in about 15-30 sec, it was not antici-
pated that the ADCP should provide data on plume-related currents.
Furthermore, since the key assumption of spatial homogeneity of currents
in different beam "look" directions for the JANUS geometry is clearly
violated for dredged material discharge plumes, it is unrealistic to
expect reliable horizontal current data for plume traverses. However,
once the initial transient currents generated by the falling plume
material have been reduced or eliminated and the "quasi-equilibrium"
plume condition has been reached, then reliable current data may be
gathered during (residual) plume traverses.
Nevertheless, it was decided to reduce the ADCP sample intervals to
30 seconds to evaluate ADCP plume-related current data. The sample
intervals were reduced to 30 seconds for the second and third days. The
processed current profiles are presented in Appendices CI, C2 and C3.
Appendix Cl presents horizontal (north and east) and vertical
current components with AGC (Automatic Gain Control) amplitude at fixed
21

-------
depths for all transects of each dump. When the ship was inside the
plume judging from the acoustic profiles, the current components are
represented by different symbols. Those current measurements outside the
tracked plume are represented by a star (*) symbol. Whenever a question
mark (?) appears, it indicates the current data at that depth were
invalid and are placed there for continuity of the time series. For each
transect at a fixed depth, two plots were presented to indicate the
current direction and its speed.
Appendix C2 presents current measurements as a function of depth at
different times either from the center position of each transect or from
all positions within one transect for each dump. The time indicated in
the plots is the guide to tell whether it is a collection of all center
positions of the transects or a collection of all measurements within the
plume. In most of the cases, the north component keeps constant to the
thermocline depth and then decreases with depth, and sometimes reverses
direction in deep water. The maximum north component can be as high as
150 cm/sec. The east component mostly fluctuates between +20 cnv^sec to
-20 cnv/sec, with the maximum value sometimes reaching 60 cnv/sec. The
vertical component fluctuates as the east component does, but with a
smaller maximum value.
Appendix C3 presents five current measurements at fixed depths for
each transect of all dumps. Based on the ship track, the plots were
rearranged such that the directions of transects are the same from west
to east when several transects were plotted together. No consistent
pattern was observed. Four consecutive current measurements for each
transect of all dumps are also plotted and shown to indicate the change
of current within the plume.
Hie ADCP also provides an echo amplitude signal that represents the
concentration of suspended material in the water column. Appendix C4
22

-------
shows time series of echo amplitudes that were observed at fixed depths
and corrected for spherical spreading during Phase I. The depth
intervals are between 10 m and 130 m with a 20 m increment for the eight
depths in each plot. Generally, the top curve is for a 10 m depth and
the bottom curve is for 130 m depth.
The ADCP current profiles were processed with programs developed in
NQAA/AOML that are similar to programs provided by R&D Instruments. The
transmit pulse and bin length is 4 m for 150 kHz frequency. The data
were averaged over 30 seconds which consists of 9 individual pings. The
standard deviations of north and east current are 19.7 cm/sec and
18.5 cn\/sec respectively (Atle Lohrmann, personal communication). They
include the variance introduced by ship motion (pitch and roll) and the
variation in the current field over the survey area as well as the
instrument noise. The standard deviation of the vertical current
measurements is 9.5 aVsec which includes the instrument noise and the
variation introduced by the ship motion. Variances of both east current
component and vertical component are almost as large as the magnitudes
themselves.
Dredged Materials
The disposed material was dredged from the turning basin of Miami
Harbor shown as a star in Fig. 7. Sediment samples and field data were
collected from this basin area on' December 12, 1988 and again on April
19, 1989. The 1988 sample stations were labeled MHTB-1 to MHTB-3 and
shown as * in the lower left corner insert of Fig. 7. The gradation
curves for 1988 data are shown in Fig. 8 for all' three stations. An
individual curve of each station is presented in Appendix D along with
corresponding suspended sediment-time curves for test specimens of
23

-------
CORPS OF £NG'N£gR5
MIAMI
t CUOC COVMT?
M^er rtiiMrpiAu
^^•(A«AH0O«|(Q
«crto
t
W fl«6Uft fT
MHTB-1 *
MHTB-2 *
MHTB-3
Sediment Stations
Miami Harbor Turning Basin
MIAMI HARBOR. FLA.
ICALC W 'CCT
DCPARTMEKT of TMt AMfT
VACKSOffYllLC OlSTlllCT, C0*P9 Of (WUtltM
jACJCiOffvriLC, njJ/GSA
Fig. 7. Location map of the Miami Harbor. The turning basin is
indicated as a * at the end of the Miami Ship Channel.
Ttie insert at the lower left corner shows the three
sediment stations.
?Cl

-------
Gradation Curves
M
Class
IT
ifioation
Sand
Co4r^
Medium
Fine
Silt
Cojric
F.r*
CJay
Co*rw
Medium
Fine
j-.

• MHTB-J
X MHTB-2
a MHTB-3

10
1.0
01	0.01
Grain Size (mm)
0.001
ooooi
Fig. 8. Gradation curves of particle-size distribution for
the three sediment stations in the Miami Harbor
Turning Basin.
?c;

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50 gras/liter and 100 gms/liter. The most common materials are coarse
silt and fine to medium sand.
Acoustic Profiles
There were two types of acoustic data recording. CXie type was
recorded on Raytheon thermal paper recorder, which was also displayed in
real time during the field study. Portions of these acoustic echograms
are shown in Appendix El, which correspond to transects of the eight
dumps during a three-day period. The vertical coordinates are depth in
meters and have different depth scales for different dumps. The
horizontal coordinates show hour and minute. Except the first dump on
April 24, 1991 (page El—2), all time scales shown represent a 21 minute
time period, and have a horizontal distance of 1890 m when the ship speed
was taken to be constant at 3 knots for all transects.
The other type of acoustic data was recorded on DAT tapes. These
data represent the same data as the first type, but can provide more
detailed plume structure when processed numerically to extract the
acoustic backscattering intensity from the data. The acoustic intensity
is considered to be proportional to the particulate concentration (Tsai,
1984), and contour plots of equal intensity levels will provide the
detected sediment plume field for each transect. These contour plots are
shown in Appendix E2. The concentration levels are shown in db and
equivalent to backscattering strength which is proportional to the
logarithm of acoustic intensity. The actual processing is summarized in
the following.
The recorded acoustic signal on DAT represents the root mean square
voltage V in integer format at the output of the receiver. This 10-kHz
double side band signal was filtered to remove 60-cycle noise and to
provide anti-aliasing protection for analog demodulation. Output from
26

-------
the demodulator was further filtered and amplified for input to a 12-bit
analog to digital (A/D) converter interfaced to an IBM compatible
personal computer (PC). The voltage at the input of the A/D converter is
proportional to the root mean square plane wave sound pressure P at a
reference location 1 m from the face of the acoustic transducer, that is,
20Log(V) = RR + RL + G
where FR is the receiving response of the transducer given in decibels
referenced to 1 volt per micropascal (db/lV/luPa), G is the overall
system gain in db, and RL is the reverberation level given by
RL = 20Log(P).
For a cloud of particulate scatterers such as a sediment plume, the
reverberation level is given by
RL = SL - 20Log(r) - 2ar + S + 10Log(ctb/2),
where SL is the source level (db/uPa/V), r is range in meters, a is
absorption coefficient in db/to, S is the volume scattering strength in
db, c is speed of sound in the water and is taken to be 1500 iVsec, t is
transmitted pulse duration in sec, and b is equivalent solid angle of a
uniform beam containing the same integrated power as the actual trans-
mitted beam and is given in steradians. Therefore, the volume scattering
strength is
S - 20Log(V) - RR - G - SL +20Log(r) + 2ar - 10Log( ctb/2).
These scattering strengths represent the waste concentrations observed in
the water column, and are plotted in constant levels as contours shown in
Appendix E2.
27

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The horizontal axis of those contour plots is distance in meters
which is calculated from time of transect by the ship velocity of 3
knots. One of the important observations is the waste materials near the
ocean bottom at the first few transects. It is proved that the material
does reach the bottom and acoustic imaging is useful to provide
information for tracking wastes even in strong current and deep water.
During the first or two transects of each dump, it appears to indicate
that acoustic signals were blocked by the bubbles generated during the
dumping process. It occurred in the Mobile Bay Project too.
Appendix E3 shows time series of acoustic backscattering strength at
fixed depth for Phase I. Each plot represents waste concentration at one
fixed depth for one particular dump. Each peak of the time series is the
observed plume and its peak value provides the maximum waste
concentration during that particular transect. Hie distance obtained by
multiplying time by tracking ship speed gives the plume width at that
time.
Appendix E4 is an illusion of detailed plume structure at fi'xed
depth for a particular transect. The plume width increases with depth to
some point and stays unchanged or even decreases thereafter in most
cases. The plume width also increases with time as indicated by
transects at later times. However, the peak value or maximum
concentration decreases both with depth and time in general.
IV. DISCUSSION
A central question in the present study is whether the discharged
material remained within the designed site boundaries. The present study
encompassed a grand total of six days, April 24 through 26, 1990, and
June 26 through 28, 1990. Discharge events occurred in the period of
April 24 through April 26, 1990, so that observations on discharged
28

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material remaining within the site are restricted to this 72-hour period.
Generally speaking, there are two time frames regarding escape of
material from the designed site: a short term time frame, e.g., a few
hours or so and a larger term time frame extending over days and beyond.
Model results have indicated that the vast bulk of the discharged
material should fall directly to the bottom and that a gradually
diminishing quantity of material should remain within the water column.
The material that remains within the water column for some period of time
is expected to be "fine" material, i.e., of small size, and of low
concentration. In the early stage of a dredging operation, the material
dredged may contain much "fines" whereas as the operation continues a
lesser quantity of fines may result.
Consider the sequence of plume transects presented in Fig. 9. The
first transect, shown in Fig. 9(a), was taken less than one minute after
initiation of discharge. Acoustic returns are obtained from throughout
the water column to the bottom. Thus a portion, most likely the largest
portion, of discharge material falls rapidly to the bottom. A portion of
the material remains within the water column as a wispy cloud. This
portion was tracked not only for the discharge shown in Fig. 9(b) to (d),
but for each discharge in the entire study.
It may be readily discerned from these data that the width of the
discharged plume increases with depth. This increase in width with depth
is due to the entrainment process. ' An entrainment coefficient, a, may be
estimated directly from the acoustical data. To see this, Brandsma and
Divoky (1976) that the entrainment, E, may be expressed as
E » Aa (v - v )
X	*
29

-------
04-26-90 14:16.00-14:18:30	04-26-90 14:18:30-14:21:00
0 20 40 60 BO 100 120 MO 160 160 200 220	0 20 40 60 80 100 120 140 160 180 200 220
i^->
o
04-26-90 14:25:30-14:28:00
a. 80 -
0 20 40 60 80 100 120 140 160 180 200 220
Distance (M)
04-26-90 14:31:30-14:34:00
100 -
20 -
100 120 140 160 160 200 220
Distance (M)
rig. 9. Acoustic iso-concentration contours of one dump on April 26, 1990,
corresponding to four transect at different times. TTie qap in
concentration indicated in (a) at 90 to 100 m distance is attributed
to acoustic absorption at the frequency of 20 kHz by a cloud of
bubbles in the water near the surface.

-------
where A	«= area of hemispherical dump volume,
a	» entrainment coefficient,
v	« vector velocity of discharged material,
v^	- vector velocity of ambient water.
For v >> va
clV/dt = aA(dz/dt)
where V * volume of hemispheric discharge. Then,
a - (1/A) (dV/dz),
and for a hemispheric radius, r,
V = (2/3) Jir3 ,
A - 2jir2
so that
a - dr/dz.
Thus, by measuring the coordinates, i.e., depth and distance, of an
iso-backscatter contour at two different depths, the value of a may be
estimated. For example, from Fig. 10, for the iso-concentration line
marking the outer boundary of the • plume, i.e., scattering strength above
background equals -70 decibels, at 20 m depth, a horizontal coordinate of
118 m is indicated while at 50 m depth, a horizontal coordinate of 138 m
is indicated. Thus,
a - dr/dz « (138-118)/(50-20) = 0.67.
31

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SCATTERING STRENGTH ABOVE BACKGROUND
MHDP 04-26-90 14:16:00—14:18:30 Background time = 14:16:00
Vertical avg. = 3.0 meters. Repeated 5 times.
Horizontal avg. = 2.50 seconds. Threshold = 15.0 millivolts.
D.C. Offset = 0.0 millivolts. Absorption coefficient = .00500 dB/m.
Q_ 80
80 100 120 140 160 180 200 220
Distance (M)
m
ein
L~3
ABOVE
-40
-45
-50
-55
-60
-65
-70
-75
BELOW
-35
-35
-40
-45
-50
-55
-60
-65
-70
-75
Fig. 10. Acoustic iso-concentration contours of the first transect
of Fig. 9, showing thfe method to calculate the entrainment
coefficients. The backscattering strength levels shown in
Figs. 9 and 10 are in decibels and represent particulate
concentrations of suspended mat lis in the water column.

-------
for a given discharge plume, two estimates for a may be made: a plume
ingress estimate and a plume egress estimate. Depending on the circum-
stances of the discharge and time of transect, both or neither estimates
may be made. For Fig. 10, the egress estimate appears superior to the
ingress estimate. Nevertheless, in the 25 m to 50 m depth interval, an
ingress estimate for a of 0.57 was obtained.
Estimates of a have been made for various discharges in the present
rtudy; these estimates are summarized in Table 3. In selecting the depth
interval for estimation of a, some care with regard to the water column
vertical density structures and current structure must be given. From
the density profile shown in Fig. 11, it may be seen that the upper 50 m
c r so of the water column are well mixed with little structure in the
censity profile. At about 55 m depth, a density step occurs and struc-
ture appears within the water column. A change in the slope of the
iso-backscattering contour line occurs there, thus leading to a different
estimate for a in that depth region.
The wispy clouds of material which remain within the water column
cradually diminish in density or concentration as time goes by; within
the first 20 minutes the concentration of material within the water
column and below the 50 m depth horizon diminishes by about four orders
cf magnitude. Note that this concentration reduction is measured rela-
tive to the concentration which existed within the water column about two
minutes after discharge. The reduction of water column concentration
with time is illustrated in Figs. 12 and 13 for a discharge on April 26,
1990 and in Fig. 14.
Various processes affect the cloud of discharged material remaining
within the water column. One of these processes is the advection of the
material by ambient water currents. Our concern is principally with the
horizontal advection of the material; ambient vertical currents were in
33""

-------
Table 3
Entrainment Coefficients calculated frcm acoustic profiles.
lhe ingress and egress depths are water depths used to
calculate the the Entrainment Coefficients.
Dump Date	Time Interval	Ingress	Egress
Estimate Depth Estimate Depth
2
04/24/90
16:13:30-16:15:30
0.74
50
m
0.80
80
m
5
04/25/90
14:37:00-14:39:30
0.78
50
ra
0.50
30
m
7
04/26/90
11:29:30-11:31:30
0.53
60
m
0.83
40
m
8
04/26/90
14:16:30-14:18:00
0.57
50
m
0.67
60
m
Average
Standard Deviation
0.66
0.11
0.70
0.13

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Temperature (deg C)
16.0	18.0	20.0	22.0	24.0	26.0
i	i	i	i	i	i
Salinity (ppt)
35.0	35.4	35.8	36.2	36.6	37.0
0.C
MHDP-I 04/25/90 15:59:00
24.0-
i—D
E 48.0-
—S
jC
J" 72.0-
96.0-
120.0
24.6
25.2
24.0
25.8
26.4
27.0
Sigma-t
Fig. 11. Temperature, salinity and density profiles at 15:59:00
on April 25, 1990 during Phase I.

-------
MH0PU60 14 16.00- 14 36 00 20KHj Background lima* M: 16:00
Depth - JO 0 meters
-20-i
-120
220-
| 190-
Q.
^ 160-
130
8 10 12 14 16 18 20
Time (minutes)
MHDPI 160 14 16 00- 1 4 J 6:00 20KH2 Dock ground time k | 4 16 00
Depth - 50 0 meters
-70-,
-40 -
cn
C
-60
-»0
- 100
•120
190 -1
160-
° 130
o
100
1 ' 1	I 1
8 10 12 14
Time (minutes)
16
> 1 ¦
18
• 1
20
Fig. 12. Comparison between acoustic scattering strength from ACP
and echo amplitude from ADCP at 30 m and 50 m. Top: from
ACP; bottom: from ADCP.

-------
LO
WH0P116D 14:16:00-106 00 20KH* Oockground lima* 1 4:1 6.00
Ocplh - 70 0 meters
-20-1
-40-
(/)
cr
c
190 -i
T3

D
160-
Q.
£

O
r
1 JO-
u
LJ

100
¦ i ¦' t ' * i
2 4
• I ' ¦ ' I ¦ ¦ ' I '
8 10 12
Time (minutes)
• i '
14
16
¦—i—1—«—¦—i
18 20
MHDP116B 14-16 00- 14 3600 20KHi Background lime* 1 4.1 6 00
Deplh ¦» 90 0 meters
-20-,
-100
190-
° 160-
6 8 10 12 M 16 18 20
Timo (minutes)
Fig. 13. Comparison between acoustic scattering strength from ACP
and echo amplitude from ADCP at 70 m and 90 m. Top: from
ACP; bottom: from ADCP.

-------
MHDP 04/26/90
for 40 m, 50 m, 60 m, 70 m, 80 m, 90 m, 100 m
Fig. 14. Peak concentration as function of time at six fixed depths
for April'26, 1990 during Phase I.

-------
general quite small during the exercise. A key question is the existence
of vertical shear within the water column and its effect in displacing
the upper portion of water column material vs. the deeper portion of
water column material. There are two different components of data which
bear on this issue; the first is the acoustic Doppler measurements of the
north and east directed components of the ambient current as a function
of depth, and the second is the relative displacement of the centroid of
cloud concentration as a function of depth as determined from acoustic
backscattered measurements.
An estimate of the difference in the horizontal current vL at two
h
different depths in the water column zx and z2 can be made directly from
the backscatter amplitude information. The AGC amplitude will be used to
compare with Doppler estimates. For depths zx and z2, one can write
[vh (z2)-vh (zx ) ]t - c(z2 )-r(z1 ,
where t equals the time from initial discharge to the time of plume
observation, and r(z) is the range from coordinate origin (cyclindr'ical
coordinates) at the time of plume observation.
From Fig. 15, we see that the maximum time difference between peak
concentrations encounters at amy two depths in the water column is
approximately 30 seconds. Thus, for a ship speed of 1.5 in/sec,
r(z,)-r(z,) < 45 m = 4500 cm.
2	1	i
Then
vh(z2 )-vh(z1 ) < 4500/t
Now t « 18 minutes = 1080 seconds, so
v. (z, ) -v. (z, ) < 4.3 cm/sec.
n 2 11
39

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MHDP-I ADCP 04/26/90
Begin at 14:15:51
2501
200-
UJ
100-
50
14
Time (minutes)
Fig. 15. Time series of echo amplitudes at seven fixed depth; from 10 m
(top) to 130 m (bottom) for'April 26, 1990 during Hiase I.

-------
How does the Doppler estimate compare with the proceeding result?
From Fig. 16, we note that there is much variability in the estimate of
horizontal (north) velocity from the ADCP. If the first two plume
transects are disregarded, the remaining transects indicate very little
vertical shear to be present with an uncertainty greater than the
AGC-derived limit.
In each of the discharge events, a portion of the discharged
material was observed to remain in the upper portion of the water column.
iMs material remaining in the upper part of the water column exists as a
wispy cloud having undergone a reduction in concentration in excess of
three orders of magnitude from the original concentration which existed
immediately after discharge. The material below 50 m depth in the water
column has undergone em even greater reduction in concentration.
A series of plume crossings was carried out for approximately
one-half hour after discharge. The locations and time of these plume
crossings for each of the discharges is shown on pages A2 to A6 of
Appendix A. We see that for each discharge the motion of the material
remaining in the upper portion of the water column is generally in'a
north-northeast direction. The discharges occurred over a three-day
period and available ship tracks resulting from an approximately 48 hour
period consistently indicated a generally north-northest movement of the
residual plume material. The discharge site is sufficiently far at sea
that tidal current influences are expected to be minimal.
V. RESULTS
(1) Acoustical detection and mapping of dredged material discharge plume
within the entire water column and impacting the ocean bottom, have
been made for the interim Miami ODMDS located at the western edge of
the Florida Current (Gulf Stream). These detections and complete
41

-------
ADCP 04/26/90
ADCP 04/26/90
-fc»
(\5
E
u
u
>
E
V
o
z
1 00.0 T
60 OH
20.0-
-20.0H
-60.0 H
I 4.1 7:51
I 4:20:2 J
14-26:21
14:32:21
14-39:52
-ioo.o-
00
20 0
40.0
60.0
80.0
o
u
>
'€
£
150.0-1
90.0-
30.0 H
-30.0-
-90.0-
100.0
14:17:51
I 4:20:23
14:28:21
14:32:21
I 4:39:52
-150.0-
0 0	20 0 40 0 60.0
O^plh- (m)
80.0
100.0
E
U
8
2
E
CJ
ft
o
UJ
150 O-i
90.0
30.0
-30.0
-90.0
-150.0
0.0
250.0-)
j
210.0-
a 170.0
20.0
40.0
60.0
80.0
^ 130.0
90.0
50.0
T
0.0	20.0 40 0 60.0
Depth (m)
80 0
4 17 51
4-20 23
4 28 21
4 32 2 1
4 39 5)2
100 0
4-17-51
4:20-23
4 26 21
4-32 21
4 39 52
100 0
Fig. 16. Current profiles for the five transects of the second
dump on April 26, 1990 during Phase I.

-------
mappings have been achieved at the deepest dredged material site
(typically 140 m depth) studied to date.
(2)	A high concentration central portion of the discharge descended
quickly and directly to the bottom. This central portion descended
with a speed of 2 m per second or greater.
(3)	The deep water discharge plumes observed in this study displayed the
major generic features observed in shallow water discharge plumes,
namely lateral growth through entrainraent, rapid descend of a
central core, impact with the bottom and formation of an expanding
bottom surge and rapid decrease of water column concentration
residual with time.
(4)	Of the residual material left in the water column, that material
below about 50 m depth underwent approximately a four order of
magnitude reduction in concentration in one-half hour while that
remaining in the upper portion of water column underwent approxi-
mately a three order of magnitude reduction in concentration.
(5)	Over the time period during which the residual material remaining
within the water column from various discharges was detected and
tracked, about 48 hours, the general movement was towards the
north-northeast. Vertical current shear did not separate the top
and bottom portions of the plume in most cases of the observations.
VI. CONCLUSIONS AND COMMENTARY
The key conclusion is that the material discharged , except for a
low concentration residual remaining within the water column, reached
bottom within the designated site boundaries. A total of eight discharge
plumes were detected and tracked for a period of about one-half hour on
average; for the three day time period during which the discharge
43

-------
occurred, the resulting plumes were observed to be transported in a north
to northeast direction.
A very interesting point regarding the knowledge gained on
discharged plume behavior during the course of the present three day
study is this: while it is a valid criticism that only a very limited
sample of ambient current conditions were obtained during the course of
the study, and that the ambient current field may undergo significant
changes in both magnitude and direction over the course of a year thereby
significantly affecting the transport of any residual plume material left
within the water column, the same may not be said of the ambient density
profile. That is to say, so long as the physical structure and constitu-
tion of the dredged material being discharged remains essentially the
same, it may be expected that the changes which occur over the course of
a year in the ambient water column density structure will not signifi-
cantly alter the main discharge features, as listed in section V, item 3,
observed in the present study.
The principal basis for this conjpcture is that a very rapid
convective descent of a central core plume discharge portion is oberved
to occur. The discharge material descends at a much higher rate than
would be expected on the basis of individual particulate settling
velocities, thereby indicating a cohesive body structure in the central
plume. This descent is so rapid that any variations which may be
expected to occur in the water column density profile over the course of
a year will not significantly affect the descent.
The effects of water column density structure are, however, of
significance in affecting both the formation and longer-term fate of the
water column residual plume. It is this residual plume which is most
strongly affected by both ambient current and density water column
profiles.
44

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Not addressed in the present study is the issue of resuspension of
material deposited on the ocean's bottom. To address this question,
near-bottom current data is required and observation of resuspension
events, if any.
VII.	ACKNCWLEDGMENTS
The help and assistance in planning and execution of the present
study of Mr. Mark Skarbek of the Jacksonville District and of Dr. Nick
Krause of the Waterways Experiment Station are hereby gratefully
acknowledged. The expert electronic assistance of Charles A. Lauter is
appreciated.
VIII.	REFERENCES
Brandsma, M. G., and D. J. Divoky, 1.976. Development of models for
prediction of short-term fate of dredged material discharged in the
estuarine environment. Report D-76-5, U.S. Army Engineering
Waterways Experiment Station, Vicksburg, Miss.
Conservation Consultants, Inc., 1985. Environmental survey in the
vicinity of an ocean dredged material disposal site, Miami Harbor,
Florida. Final Report to EPA.
EPA, 1990. Draft environmental impact statement for iesignation of a
dredged material disposal site located offshore Miami, Florida.
Wetlands and Coastal Programs Section, U.S. Environmental Protection
Agency, Region V, Atlanta, Georgia.
Lee, T. N., I. Brooks, and W. Duing, 1977. The Florida Current: Its
structure and variability. Technical Report No. 77033, University
of Miami, Rosenstiel School of Marine and Atmospheric Sciences.
45

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Lee, T. N., and D. A. Mayer, 1977. Low-frequency current variability and
spin-off eddies along the continental shelf off southeast Florida.
J. Mar. Res., 35 (1), 193-220.
Lee, T. N., and C. N. K. Mooers, 1977. Near-bottom temperature and
current variability over the Miami slope and terrace. Bull. Mar.
Sci., 27 (4), 758-775.
Proni, J. R., F. C. Newman, E. R. Meyer, H. B. Stewart, D. J. Walter, R.
L. Sellers, and C. A. Lauter, 1977. On the use of acoustics in
applied, oceanographic and coastal engineering problems with emphasis
on the oceanic transport of particulate material. Thalassia
Juqoslavica, 13, 389-393.
Proni, J. R., F. C. Newman, R. L. Sellers, and C. Parker, 1976. Acoustic
tracking of of ocean-dumped sewage sludge. Science, 193, 1005-1007.
Scheffner, N. W., and A. Swain, 1989. Evaluation of thu dispersion
characteristics of the Miami and Fort Pierce dredged material
disposal sites. Coastal Engineering Research Center, Final Report
to U.S. Army Engineer District, Jacksonville.
Trefry, J. H., and J. R. Proni, 1983. Drilling fluid discharge near the
Texas Flower'Gardens, northwest Gulf of Mexico. In: Energy Wastes
in the Ocean, I. W. Duedall (ed.), Wiley-Interscience, New York.
Tsai, J. J., 1984. Acoustic remote sensing of waste disposal. NQAA
Tech. Memo. ERL AOML-59, 100 pp.
Tsai, J. J., and J. R. Proni, 1985. 'Acoustic study of dredged-material
dumping in the New York Bight. _In: Wastes in the C:ean, Vol. 6,
Near-Shore Waste Disposal, B. Ketchum et al. (eds.),
Wiley-Interscience, New York.
46

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APPENDIX G
MIAMI HARBOR DREDGED MATERIAL DISPOSAL PROJECT.
TOTAL SUSPENDED SOLIDS MEASUREMENTS

-------
MIAMI HARBOR DREDGE MATERIAL
DISPOSAL PROJECT:
Total Suspended,Solids Measurements
John R. Proni, Jules F. Craynock, John J. Tsai
A Report to the
U.S. Army Corps of Engineers
National Oceanic & Atmospheric Administration
Atlantic Oceanographic and Meteorological Laboratory
4301 Rickenbacker Causeway
Miami, Florida 33145
April 16, 1993

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Mention of a caimercial establishment, company or product does not
constitute any endorsement by the fO^/Environmental Research
laboratories or the U.S. Government. Use, for publicity or
advertisement, of information fran this publication concerning
proprietary products or their testing is not authorized. This report
has been prepared by personnel of the Ocean Acoustics Division and
represents their best scientific judgement. This report does not
represent any official position by the National Oceanic and Atmospheric
AAninistration.

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TABLE OF CONTENTS
I.	Introduction	pg 1
i
II.	Procedure	1
III.	Data Presentation & Analysis	2
A.	Presentation	2
Discharge One	2
Discharge Two	3
Discharge Three	3
Discharge Four	4
Discharge Five	4
Discharge Six	4
Discharge Seven	4
Background Samples	5
B.	Analysis	5
Summary	9
Acknowledgements	9
References	10
List of Figures	11
Appendix

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I.	INTRODUCTION
In April 1990, a field data collection project was undertaken to investigate the short-
term fate of dredged material discharged in the designated Miami Ocean Dredged
Material Disposal Site (ODMDS) before dredging of the Miami River and the Miami
Harbor Turning Basin begins. A discussion of this project is presented in reference one
and two. As part of the study, series of water column samples of total suspended
material was obtained. Later, in June 1991, a second project was carried out in order to
obtain an expanded series of background water column suspended material values.
II.	PROCEDURE
Sediment plumes resulting from eight placement operations, occurring in the period
April 24 to April 26, 1990, of dredged material were sampled and monitored acoustically.
A test discharge, for logistics evaluation, was conducted in the morning of April 24th.
Water column sediment sampling was guided by acoustical systems employed, in
particular by the Acoustic Concentration Profiler or ACP, and by visual surface detections
of subsequent-to-discharge plumes. Before each discharge, and between successive
discharges, the surveying vessel Seaward Explorer monitored the water column to obtain
background concentrations of suspended material and ambient currents :n the area using
the ACP and ADCP on board the surveying vessel. Ambient density ;ind salinity
were measured by taking CTD casts at locations of previous discharge that were
determined from ship track records. Sediment samples were collected directly from the
dredging vessel Atchafalaya for each discharge. Discharge occurred when the
1

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Atchafalaya began to turn to return shoreward. The ACP was set ready to operate upon
the approach of Atchafalaya, and the Seaward Explorer proceeded to make the transects
immediately after the dumping commenced. The Seaward Explorer tracked the sediment
plume for several transects until the concentration of suspended material could no longer
be detected by the ACP. This reduction in concentration usually took about 60 minutes
after the release. During each transect, water samples were collected by a towed V-Fin
with a pump that discharged water continuously via a hose to the deck of the Seaward
Explorer. The water sampling took place at approximately constant depth by maintaining
constant ship speed, and only during the periods when transects crossed the plume.
Ship position was determined using LORAN and GPS and was automatically logged with
a computer and displayed in real time to assist monitoring. Surface features of the
sediment plume were visible up to 60 minutes after discharge and were helpful in tracking
the plume.
III. DATA PRESENTATION AND ANALYSIS
(A) Presentation
Three data sets for each discharge are presented: (i) acoustical data including the
first several transects for each discharge (ii) track data for each discharge and (iii) water
bottle sample data for each discharge.
Discharge One
The first discharge of the study occurred at about 16:14 on April 24, 1990. In
Figure 1 the acoustical data are shown from the first five passes over the discharge
2

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plume. The Seaward Explorer first encountered the discharge plume between 16:14 and
16:15. Other encounters shown in Figure 1 occurred at about 16:17, 16:19,16:21 and
16:26. In Figure 2 the ship track for this discharge event is shown. Plume encounters
were made at various times subsequent to the first few minutes following the discharge
event shown in Figure 1. These encounters are marked by various symbols on the ship's
track. For example, the encounter at 16:40 is marked by a hexagon, the encounter at
16:45 with a triangle and so on. The small stars are time marks. In Table I, the
concentrations of particulate matter, measured in mg/liter, for the sample stations shown
in Figure 2 are given. The sample concentration values are plotted against time after
discharge in Figure 3.
Discharge Two
The second discharge occurred at about 09:37 on April 25, 1990. In Figure 4 the
acoustical data from the first five passes over the discharge are shown. The track data
for discharge two are shown in Figure 5. The suspended particulate values measured
are given in Table II and plotted in Figure 6.
Discharge Three
Discharge three occurred at 12:04 on April 25, 1990. The acoustical data for the
first six passes over this discharge are shown in Figures 7 and 8. Extensive absorption
by bubbles is seen in the first pass over this discharge. Some residual bubble absorption
is seen in the second pass over the discharge and no discernable absorption is seen in
^ny of the subsequent plume encounters The track data for discharge three are shown
3

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in Figure 9. The suspended particulate values measured during discharge three are
shown in Figure 10.
Discharge Four
Discharge four occurred at about 14:37:30 on April 25, 1990. The acoustical data
for the various transects over this discharge are presented in Figure 11. The
corresponding ships track is presented in Figure 12. The corresponding total suspended
material data is presented in Figure 13.
Discharge Five
Discharge five occurred at about 17:49 on April 25, 1990. The acoustical data for
the various transects over the discharge are presented in Figure 14. The corresponding
ship track and total suspended solids (TSS) data are presented in Figures 15 and 16,.
respectively.
Discharge Six
Discharge six occurred at about 11:30 on April 26, 1990. No track data was
available for this discharge. The acoustical data for the various transects over the
discharge are presented in Figure 17. The corresponding TSS data is presented in
Figure 18.
Discharge Seven
Discharge seven occurred at about 14:16 on April 26, 1990. No track data was
available for this discharge. The acoustical data for the various transects over the
discharge are presented in Figure 19 The corresponding TSS data is presented in
Figure 20.
4

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June 1991 Background Samples
Additional Background TSS Measurements were obtained by NOAA/OAD and US
Army Corps of Engineers personnel aboard the S/V Sable on June 27 and 28, 1991.
These data are presented in the appendix. Sampling transects were conducted through
Government Cut and north and south atong the predominant offshore reef line. Water
samples for TSS analysis were collected using a small V-Fin pump sampler deployed
from the side of the S/V Sable. Simultaneous CTD casts were conducted utilizing a
Seabird CTD system. Pumped samples were analyzed for turbidity with a HACH portable
turbidimeter. Offshore fixes were determined via LORAN-C, samples sites A, B, C within
Government Cut were determined by shore sightings. Table A-1 and Table A-2
summarize the TSS/turbidity measurements. Charts 1, 2, and 3 indicate sampling
positions as well as a detailed depiction of the Government Cut positions. CTD cast data
are included for each of the stations completed within the two days. On both days of
operations sample stations were conducted during an outgoing tide. Ship traffic during
the sampling period through Government Cut was relatively light and seas we're calm.
(B) Analysis
As discussed in reference one, during the disposal operation a quantity of the
dredged material discharged remains suspended for some period of time within the water
column. Although the bulk of the discharged material is thought to descend as a
cohesive mass, a small portion ot the, perhaps in the form of individual fines, are thought
5

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to remain within the water column. Entrapment processes, which are known to occur
within such discharges, could play a key role in the formation of the residual cloud of
material within the water column. Once the residual cloud is formed, the cloud then drifts
with the ambient current with continued settling and dispersion of the cloud material.
In the present study, samples of the residual cloud material were gathered using
a pumping system to fill water bottles aboard ship. The nozzle of the hose used in the
pumping system is attached to a V-Fin device which was towed about 1 meter below the
ocean's surface. It took about 30 seconds to fill a bottle, so with a ship's speed typically
being one to two knots, or 0.5 m/sec to 1.0 m/sec, water is included in the sample
gathered over a 15 to 30 meter distance. This has the effect of smoothing peak
concentration values in cloud volumes of size less than about 30 meters. This smoothing
effect is more pronounced in the earlier portion of residual water column material tracking
than in later portions, say three or so minutes after discharge, as the material has
dispersed or spread out in space and has become more homogeneous through mixing.
Consider the TSS data displayed in Figure 10 for discharge number three. This
data displays a series of peaks of diminishing order in time, i.e. 61 mg/l, 10.2 mg/l, 5.8
mg/l, 1.9 mg/l and 2.0 mg/l, separated by a set of relatively low concentration sample
values. This data is interpreted in the following way: the sampling device more accurately
passed through higher concentration regions of the cloud (at the towing depth of the V-
fin) to obtain the afore-listed concentration peaks and in between those peaks did not so
accurately target or pass through high concentration regions of the cloud. Inasmuch as
it is always a question in sampling of material discharged in the ocean as to whether the
6

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sampling device was indeed within the volume of material to be sampled, it is noted that
the basic confirmation for proper space-time sampling was achieved using acoustical
devices. In addition to acoustical detection of residual water column material a visible
ocean surface signature (a milk-like coloring) was available. The acoustical systems
show the subsurface distribution of material corresponding to a particular surface
detection
TSS values for all discharges plotted against time are shown in Figure 21. A
background concentration estimate may be obtained from the lowest of the TSS values
shown in Table I, as such values presumably are obtained from complete or partial
"misses' in sampling of the residual plume. A second background concentration estimate
may be made from the data gathered on June 27 and 28, 1991 and displayed in Table
II assuming, of course, that data gathered on those dates are also applicable for April
1990. Using the data from Table II gathered at those points proximate to the designated
discharge area (stations 1,2,3,5,6 and 7 for Jun 27, 1991 and station 6 for June 28, 1991
a background value of about 0.5 mg/l is obtained. Using in-between-peak low values
from discharge 2 for example, a background value of about 0.2 mg/l is obtained. As
discussed earlier, many of the values are judged to be gathered at locations somewhat
separated from cloud regions of highest concentration. Data from three of the discharges
have been selected and included in Figure 22 to obtain a smoother estimate of dilution
with time (or distance) from the discharge. Figure 22 has been constructed by
normalizing the data for three discharges, i.e discharges one, three and four, by the
largest (i.e. initial) value recorded for each discharge respectively. From among these
7

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three discharges local maximum values, i.e. values higher than at least one preceding
value were selected and plotted. An estimated fit curve has been drawn to give a crude
estimate of the normalized dilution with time or distance for discharges occurring within
the designated site. Thus, for example, an initial concentration of 80 mg/l would diminish
to 8 mg/l after one-half hour or at a distance of 900 meters from the point of discharge
(current speed assumed is 100 cm/sec).
In reference one, a very crude estimate was made of the quantity of material
residing within the residual water column cloud about 20 minutes after discharge. The
main drawbacks of that were the delineation of the geometric dimensions of the plume
of material within the water column and the lack of TSS measurements for a calibration
of the acoustical system. The geometric delineation issue is still not resolved so that the
assumption made in reference one, namely that the geometric delineation is provided by
the plume delineation beginning one to two meters below the ocean's surface, is still
required. The TSS measurements discussed in this document were obtained in the upper
few meters of the water column. The assumption made in reference one is that an
average TSS of about 10 mg/l is present in the residual cloud. If it is assumed that the
near-surface TSS data values are typical of the subsurface cloud as a whole, the 10 mg/l
assumed in reference one appears to be reasonable perhaps even conservative.
Retaining the 10 mg/l estimate a very crude estimate that about 0.6% of the total solid
material discharged remains within the water column about 20 minutes after discharge.
8

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SUMMARY
Total suspended material (TSS) samples were obtained for a number of dredged
material discharges at the Miami Ocean Dredged Material discharge site. Initial TSS
values gathered in the upper few meters of the water column, approximately one minute
after discharged, ranged from about 34 mg/l to 77 mg/l. A residual plume of dredged
material remained within the water column. The plume was tracked for about forty-five
minutes to one-hour and TSS samples obtained. About one-half hour after discharge
plume concentration was observed to have a value of about a few mg/l. The general
direction of movement of the residual plume cloud was North-Northeast.
ACKNOWLEDGEMENTS
The assistance and support of Dr. Nick Kraus and Michelle Thevenot, of the U.S.
Army Corps of Engineers Waterways Experiment Station, is greatly appreciated. The
support and field participation of Mr. Mark Skarbek of the Jacksonville District U.S. Army
Corps of Engineers is also greatly appreciated.
9

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REFERENCE
1.	Tsai, J.J., Proni, J.R., Dammann, W.P., and Kraus, N.C., (1992), Dredged Material
Disposal at the Edge of the Florida Current, Chemistry and Ecology 6, pp. 169-187.
2.	Proni, J.R., Tsai, J.J., and Dammann,. W.P., (1991), Miami Harbor Dredged Material
Disposal Project, A report to the U.S. Army Corps of Engineers.
10

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LIST OF FIGURES
Table 1 Total Water Column Suspended Material
Figure 1 Acoustic Record 04/24/90,16:11-16:31
Figure 2 Navigational Track 04/24/90,16:17-17:19
Figure 3 TSS Plot Discharge One
Figure 4 Acoustic Record 04/25/90, 09:35-09:55
Figure 5 Navigational Track 04/25/90,09:30-10:39
Figure 6 TSS Plot Discharge Two
Figure 7 Acoustic Record 04/25/90,12:03-12:23
Figure 8 Acoustic Record 04/25/90,12:17-12:37
Figure 9 Navigational Track 04/25/90, 12:05-12:59
Figure 10 TSS Plot Discharge Three
Figure 11 Acoustic Record 04/25/90,
Figure 12 Navigational Track 04/25/90,
Figure 13 TSS Plot Discharge Four
Figure 14 Acoustic Record 04/25/90,
Figure 15 Navigational Track 04/25/90,
Figure 16 TSS Plot Discharge Five
Figure 17 Acoustic Record . 04/26/90,
Figure 18 TSS Plot Discharge Six
Figure 19 Acoustic Record 04/26/90,
Figure 20 TSS Plot Discharge Seven
Figure 21 TSS Plot All Discharges
Figure 22 Normalized Concentration
Discharge One, Three and Four
Figure 23 Acoustic Record 04/24/90,
Test Discharge
14:36-14:56
14:30-15:09
17:40-18:00
16:30-17:59
11:29-11:49
14:15-14:35
11

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TABLE I
Total Water Column Suspended Material
Discharge TSS Time
# (mg/l) Since
Discharge

Discharge TSS Time
# (mg/l) Since
Discharge

Discharge TSS Time
# (mg/l) Since
Discharge
TEST
| 13:57
77.4
01:00
No. 2
09:37
0.0
00:00
No. 3
12:04
61.0
02:00


0.6
03:00

0.6
04:00
I No. 1
33.6
01:00

2.7
12:00

0.2
06:00
;
7.0
03:00

0.2
13:00

2.0
07:00

0.1
06:00

1.6
17:00

1.7
10:00

0.5
08:00

0.3
20:00

10.2
12:00

3.1
11:00

0.5
23:00

1.0
16:00




0.1
30:00

1.4
19:00




*0.4
34:00

5.8
20:00
I



0.0
38:00

1.1
24:00




0.2
42:00

0.2
29:00




0.5
46:00

1.9
35:00




0.2
55:00

0.8
39:00




0.2
56:00

2.0
49:00

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TABLE I continued
Total Water Column Suspended Material
Discharge TSS Time
# (mg/l) Since
Discharge

Discharge TSS Time
# (mg/l) Since
Discharge

Discharge TSS Time
# (mg/l) Since
Discharge
No. 4
29.5
00:30
No. 5
3.0
02:00
No. 6
0.1
00:00

0.6
08:30

2.0
04:00

0.1
02:00

3.4
11:30

3.3
05:00

0.5
05:00
|
1.1
16:30

5.1
06:00

4.5
08:00

0.3
19:30

0.6
07:00

1.2
14:00

1.7
22:30




0.1
17:00
1
'






0.8
20:00







0.9
26:00







0.6
31:00







1.2
38:00







0.4
45:00
TSS is measured in milligrams per liter
Time is measured in minutes and seconds

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TABLE I continued
Total Water Column Suspended Material
Discharge TSS Time
# (mg/l) Since
Discharge
No. 7
6.1
04:00

2.8
10:00

1.4
15:00

0.8
17:00

1.5
21:00

3.4
23:00

0.1
25:00

0.6
35:00

0.1
44:00

0.1
54:00

1.0
58:00

0.4
64:00
TSS is measured in milligrams
Time is measured in minutes and seconds

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30-
60-
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Normalized Concentration
Discharges Nos. 1 , 3 & 4
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Time (min)

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